FIELD OF THE INVENTION The present invention generally relates to a system and method for improving the efficiency of a combustion process, for example in a combustion machine and/ or engine, in particular, the invention relates to a system and method for the recovery and regeneration of waste engine heat and exhaust gas to improve the efficiency of combustion engines.

BACKGROUND OF THE INVENTION

Conventional gasoline or other fossil fuel engines operate on what is known as the Otto cycle wherein a carbu retted mixture of fuel and air is ignited following compression in the well-known manner, and thereafter, expelled to the surroundings through an exhaust manifold and muffler system. Such engines, however, exhibit substantia! losses of heat and other energy which, in turn, results in poor fuel to mechanical work energy conversion. It is also well-known that worldwide, people rely on fossil fuels to operate these combustion engines. Fossil fuels are non-renewable resources because they take millions of years to form, and reserves are being depleted much faster than new ones are being made. The production and use of fossil fuels raise environmental concerns.

It is known that proper stoichiometric mixtures for complete fuel burning do not always ignite readily and, therefore, excessive fuel (i.e. rich mixture) is generally provided. This, in turn, results in partial or unbumed carbon exhaust products and other harmful emissions contributing to environmental pollution and further losses in efficiency. As an alternative, conventional fuel injection systems may be employed to directly inject fuel droplets into the airstream. Although more efficient than conventional carburettors, the injection of relatively large droplets still results in incomplete combustion. Furthermore, this unburnt fuel can form soot, also known as Volatile Organic Compounds (VOC). Soot can be seen and smelt on exhaust vents and in the air, Essentially soot forms when fuel is not completely burnt inside the combustion chamber.

For internal combustion engine soot build-up is a very common (and basically inevitable) plague of engines since soot's primary ingredients are components of fossil fuels. As soot builds, engine problems begin. Soot thickens oil and l negatively affects viscosity (the engine has to work harder to start and run during cold temperatures) . Soot circulation also contributes to the formation of varnish and carbon deposits throughout the engine, which reduces combustion efficiency. When excessive soot collects, it forms a congealed mass known as sludge, which is a leading cause of premature failure in engines, Onee the damag is done, there's no way to alleviate its symptoms by simply using motor oil additives. This soot collection is one reason why engine oil should be replaced regularly, as oil deteriorates from the build-up of sludge deposits. The only effective way to reduce soot is to increase the thermal combustion efficiency.

Therefore the overall efficiency of an internal combustion engine, or simply "engine" for present purposes, depends in part on the amount of fuel that can be burned in an given cycle. In recent years, environmental concerns have had an increasing effect on such engines, For example, the air/fuel mixture fed into the engine typically is adjusted to prevent complete combustion so that the catalytic converter will be able to reduce emitted nitrogen oxides to the level required by governmental standards. However, since such an adj ustment prevents complete combustion, increased amounts of unburn ed hydrocarbons and carbon monoxide result.

In addition to the above described unburned fuel losses, the exhaust gases are quite hot, often in excess of 815 degrees Celsius, thereby adding further to the heat energy loss. Systems which add or inject water and/or steam into a combustion engine are known however they require precise timing to affectively improve the combustion process and or reduce emissions. These systems can be complex and expensiv to install and are not reliable. Typically these systems are used in conjunction with reclaiming exhaust gas. However these systems have proven to be problematic. For example, the extra weight of a device to reclai m exhaust gas installed on a moving engine would detract from any measurable gains. Where the engine is a stationary system and weight is not a concern, the cost of the device compared to the cos of available water would be questionably. This redirection can cause a negative effect on combustion efficiency. Recirculating exhaust gases into an engine can increase toxic emissions, if for example the recirculation is not precisely implemented with the requirements of engine demands, due to the known problem known of carbon fouling . EGR redirected exhaust gas contains carbon, the flow of gas through the EGR passages and the controiling valves are interrupted due to carbon fouling . The introduction of exhaust gas can decrease the thermal combustion due to the carbon in the exhaust gas. The carbon can also coat the associated components with a film of carbon that may cause a misfire and rough idling and detonation due to combustion temperature spike, therefore decreasing thermal efficiency, increasing fuel consumption and toxic emissions To successfully recirculate exha ust gas, the gas needs to be cooled and filtered and the system needs to prevent carbon fouling It is an object of the present invention to provide a system and/or method for improving engine efficiency by at ieast ameiiorating some of the shortcomings described above, or to at least provide the public with a useful choice.

SUMMARY OF THE INVENTION

In a first aspect the invention may broadly be said to consist of a method for improving efficiency of an engine having a combustion chamber and an exhaust gas outlet, the method comprising the steps of:

redirecting at least a portion of a volume of exhaust gases fluid flowing from the exhaust gas outlet into one or more condensers for condensing one or more condensable gases or constituents in the exhaust gases fluid into liquid,

directing the exhaust gases fluid through a body of liquid to saturate non- condensable gases of the exhaust gases fluid and generate a treated exhaust gases fluid comprising saturated gases,

vaporising a liquid component of the saturated gases in the treated exhaust gases fluid to generate steam, and

introducing the steam into the combustion cha mber.

Preferably the body of liquid comprises the liquid generated by the step of redirecting the exhaust gases fluid into the one or more condensers,

Preferably the one or more condensable gases or constituents comprise water vapour. Preferably the step of redirecting at least a portion of a volume of exhaust gas into the one or more condensers reduces the temperature of the redirected exhaust gas to approximately a dew point temperature of the condensable gases or constituents in the exhaust gases fluid or below. Preferably the step of redirecting at least a portion of a volume of exhaust gas into the one or more condensers reduces the pressure of the redirected exhaust gas to approximately zero or negative atmospheric pressure before vaporising the liquid component of the saturated gases and introducing the steam into the combustion chamber.

Preferably the step of redirecting at least a portion of a volume of exhaust gas into the one or more condensers reduces the pressure of the redirected exhaust gas to approximately zero or negative atmospheric pressure at the output of the one or more condensers.

Preferabl method comprises directing the treated exhaust gases fluid towards a fluid pathway fluidly coupled to a gases/air inlet of the combustion chamber.

Preferably the fluid pathway comprises a lo pressure fluid relative to a pressure of the fluid traversing through the gases inlet of the combustion chamber;

Preferably the step of vaporising the liquid component of the saturated gases to generate steam occurs prior to introducing the treated exhaust gases fluid into the low pressure fluid pathway,

Preferably the method comprises substantially non-restrictively allowing a flow of exhaust gases fluid from the exhaust gas outlet of the combustion chamber back to the gases inlet of the combustion chamber.

Preferably the flow of the exhaust gases fluid from the exhaust gas outlet back to the gases inlet of the combustion chamber is predominantly or primarily controlled by gas pressure cycles generated by the combustion chamber.

Preferably the flow exhaust gases fluid is wholly or entirely controlled by gas pressure cycles generated by the combustion chamber.

Preferably the flow of exhaust gases fluid is not controlled by a valve.

Preferably the flow of exhaust gases fluid is dependent on the load and/or speed of the engine. Preferably the step of redirecting at least a portion of an exhaust gas comprises redirecting none or a relatively small portion of the volume of exhaust gas flowing through the exhaust gas outlet during idle and/or light speed and/or light load states of the engine, and redirecting a relatively larger portion of the volume of exhaust gas flowing through the exhaust gas outlet during high load and/or high speed states of the engine.

Preferably the one or more condensers comprises a conduit of a volume sufficient to reduce the temperature of a substantial portion of a volume of the redirected exhaust gas to below a dew point temperature of the gas.

Preferabl the conduit is of a volume sufficient to reduce the pressure of a substantial portion of a volume the redirected exhaust gas to zero or negative atmospheric pressure.

Preferably the method further comprises the step of mixing a portion of the volume of saturated gases with a volume of substantially dry gases and directing the mixture into the relatively iow pressure fluid pathway.

Preferably the step of vaporising comprises heating the saturated gases to a boiling temperature of the liquid component to generate steam.

Preferably the ste of vaporising comprises directing a portion of the treated exhaust gases fluid into a fluid pathway adjacent a heat source and/or into one or more heat exchangers to heat the fluid. Alternatively or in addition the step of vaporising comprises heating the treated exhaust gases fluid via the flow of gases in the treated exhaust gases fluid causing the saturated gases of the fluid to become energised.

Preferably the relatively low pressure fluid pathway is an inlet of an outlet of an air filter and/or inlet of a nozzie assembly connected to the gases inlet of the combustion chamber, In one embodiment the method further comprises the step of utilising the liquid generated by the condenser(s) to scrub the exhaust gas and dissolve and/or separate unwanted solid material in the gas. Preferably the method further comprises the step of discarding separated unwanted solid material in the gas.

In one embodiment the method further comprises directing a portion of the saturated gases and/or liquid to an atomiser to generate an aerosol fluid from the saturated gases of an increased flow rate.

Preferably the method further comprises directing a portion of the engine's air intake towards the atomiser to generate a flow of the engine's air for drawing in the portion of the saturated gases and/or liquid into the atomiser nozzle assembly.

Preferably the method further comprises heating the aerosol fluid to generate steam and introducing the steam into the combustion chamber. In one embodiment the method further comprises storing a volume of liquid generated from the saturated gases upon cooling of engine.

Preferably the method further comprises directing a portion of the volume of liquid towards stored to a heat exchanger to generate steam from the directed liquid, and directing the steam to the combustion chamber.

In a second aspect the invention may broadly be said to consist of an engine efficiency system configured to recirculate an exhaust gas produced by an engine back into a combustion chamber of the engine, the system comprising:

an input fluid pathway configured to fluidly connect to an outlet of an exhaust gas pathway associated with the engine for receiving an exhaust gases fluid,

at least one condenser configured to fluidly couple the input fluid pathway for condensing one or more condensable gases or constituents of the exhaust gases fluid flowing therethrough into liquid,

an output fluid pathway fluidly connected to an output of the at least one condenser for receiving a treated exhaust gases fluid comprising saturated gases, wherein the output fluid pathway is configured to allow heating and vaporising the saturated gases of the exhaust gases fluid into steam and the output fluid pathway is configured to direct the generated steam towards or into an air inlet pathway associated with the combustion chamber. Preferably the one or more condensable gases or constituents comprise water vapour.

Preferably the output fluid pathway is associated with at least one heat source or heat exchanger for heating and vaporising the saturated gases- Alternatively or in addition the output fluid pathway is configured to allow the flow of gases in the treated exhaust gases fluid to energise and heat th saturated gases in the treated exhaust gases fluid, Preferably the at least one condenser is configured to reduce the temperature of the exhaust gases fluid to below a dew point temperature of one or more condensable gases or constituents of the fluid.

Preferably the at least one condenser is configured to reduce the pressure of the exhaust gases fluid to approximately zero or negative atmospheric pressure at the output of the condensers).

Preferably a fluid pathway from the input fluid pathway to the output fluid pathway is substantially non-obstructed to aliow non- restrictive fiow of the exhaust gases fluid from the exhaust gas outlet of the combustion chamber.

Preferably the flow of exhaust gas fluid through the engine efficiency system is predominantly or primarily controlled by gas pressure cycles generated by the combustion chamber,

Preferably the flow of exhaust gases fluid is wholly or entirely controlled by gas pressure cycles generated by the combustion chamber,

Preferably the at least one condenser comprises a conduit of a volume sufficient to reduce the temperature of exhaust gases fluid to below a dew point temperature of at least one condensable component of the gas.

Preferabl the conduit is of a volume sufficient to reduce the pressure of the exhaust gases fluid to approximately zero or negative atmospheric pressure.

Preferably the output fluid pathway is fluidiy connected to a relatively low pressure fluid pathway fluidiy connected to a relatively high pressure gases/air inlet pathway of the combustion chamber. Preferably the relatively low pressure fluid pathway is an output fluid pathway of an air filter and/or inlet of a nozzle assembly connected to the gases/air inlet of the combustion chamber. Preferably the system further comprises a second output fluid pathway fluidly connected to the outlet of the at least one condenser for receiving a mixture of saturated gases and substantially dry gases and directing the mixture into the relatively low pressure fluid pathway fluidly connected to the gases/air inlet of the combustion chamber.

In a preferred embodiment the flow of exhaust gases fluid is not controlled by a valve.

In an alternative embodiment the system further comprises an input control valve coupled between the input fluid pathway and the exhaust gas pathway outlet for controlling a volume of exhaust gas flowing through the input fluid pathway. Preferably the input control valve is configured to control the volume of exhaust gas flowing through the input fluid pathway based on the load and/or speed of the engine.

Preferably the system is configured to permit no or a relatively lower volume flow of exhaust gas at idle and/or relatively low engine speeds/ioads and a relatively larger volume flow of exhaust gas at relatively hig h engine speeds/loads. Preferably the system further comprises a receptacle configured to retain a body of liquid, the receptacle being fluidly coupled between the output of the at least one condenser and an input of the outlet fluid pathway and configured to receive a flow of the exhaust gas fluid from the at least one condenser and saturate the non- condensable gases with the fluid to provide a flow of saturated gases to the outlet fluid pathway.

Preferably the receptacle further comprises a d ivider or baffie between the output of the condenser and the output fluid pathway for separating the body of liquid within the scrubber from the output fluid pathway, and wherein the receptacle comprises an opening at an upper end of the divider for permitting the flow of treated exhaust gases fluid to the output fluid pathway. Preferably the receptacle is of a volume sufficient to act as an expansion chamber to help prevent or at least reduce pressure build-up of the exhaust gases fluid flowing therethrough. Preferably the system comprises a scrubber comprising the receptacle and configured to isolate non-condensable and non-dissolvable solid components of the exhaust gas and/or other sediments.

Preferably the scrubber further comprises a release valve for discarding non- dissolvable components and/or other sediments of the exhaust gas.

Preferably the body of liquid within the receptacle is composed of liquid generated by the at least one condenser. Preferably the at least one heat source is configured to heat the saturated gases flowing through the output fluid pathway to a boiling point temperature of a liquid component of the saturated gases in the treated exhaust gases fluid to generate steam. Alternatively or in addition the flow of gases of the treated exhaust gases fluid causes the saturated gases to become energised and heat up to a boiling point temperature of the liquid component of the saturated gases in the treated exhaust gases fluid.

Preferably the at least one heat source is waste heat from the engine. In one embodiment the system further comprises at least one draw tube and an atomiser, the draw tube being submerged within the body of liquid in the scrubber at one end and coupled to the atomiser at an opposing end,

Preferably the draw tube extends within the intermediate fluid pathway and proximate the at least one heat exchanger.

Preferably the system further comprises an atomiser output fluid pathway fluidly coupled to the air inlet pathway associated with the combustion chamber. Preferably the system further comprises a balance fluid pathway fluidly coupled to the air intake of the engine at one end and to the atomiser output fluid pathway at an opposing end. In one embodiment the system further comprises a storage vessel configured to receive and retain a body of iiquid generated by cooling of fluid within the system when the engine is substantially cooi. Preferably the storage vessef is positioned to gravitationally receive the flow of iiquid .

Preferably the storage vessel is provided within one of the at least one heat exchanger.

Preferably the system further comprises at least one other heat exchanger fluidly coupled to the storage vessel for receiving a portion of the liquid stored therein and heating the Iiquid to generate steam. Preferably an output of the at least one other heat exchanger is fluidly coupled to the air inlet pathway associated with the combustion chamber.

Preferably the system comprises a nozzle assembly coupled at an input to an air intake pathway of the engine and to one or more of the output fluid pathway, the atomiser output fluid pathway and the output of the at least one other heat exchanger, and coupled at an output of the nozzle assembly to the air inlet pathway of the combustion chamber.

In one embodiment the system comprises an exhaust gas recirculation (EGR) system having an EGR input fluid pathway connected to the outlet of the exhaust pathway, an EGR valve connected to the EGR input fluid pathway and an EG output fluid pathway connected to an output of the EG valve and to the air inlet fluid pathway associated with the combustion chamber.

Preferably the input fluid pathway is coupled to the EGR output fluid pathway. Alternatively the input fluid pathway is directly fluidly coup!ed to the outlet of the exhaust gas pathway.

In a third aspect the invention may broadly be said to consist of a machine comprising :

a combustion chamber having an air/fuel inlet and an exhaust gas outlet, an air inlet fluid pathway fluidly coupled to the air/fuel inlet,

an exhaust gas pathway fluidly coupled to the exhaust gas outlet, and a recirculation system fluidiy coupled between the exhaust gas pathway and the air inlet pathway of the combustion chamber for recirculating at least a portion of the exhaust gas in the exhaust gas pathway back into the combustion chamber, the recirculation system comprising:

an input fluid pathway configured to fluidiy connect to an outlet of an exhaust gas pathway associated with the engine for receiving an exhaust gases fluid,

at least one condenser configured to fluidiy couple the input fluid pathway for condensing one or more condensable gases or constituents of an exhaust gases fluid flowing therethrough into liquid,

an output fluid pathway fluidiy connected to an output of the at least one condenser for receiving a treated exhaust gases fluid comprising saturated gases, wherein the output fluid pathway is configured to allo heating and vaporising the saturated gases of the exhaust gases fluid into steam and the output fluid pathway is configured to direct the generated steam towards or into an air inlet pathway associated with the combustion chamber.

In a fourth aspect the invention may broadl be said to consist of a kit of parts for retrofitting a gas recirculation system to an existing engine system having a combustion chamber associated with an air let pathway and exhaust gas pathway, the kit of parts comprising;

at least one conduit configured to form an inlet fluid pathway and fluidiy connect to an outlet of the exhaust gas pathway associated with the engine for receiving exhaust gases fluid,

at least one condenser configured to fluidiy couple the input fluid pathway for condensing one or more condensable gases or constituents of an exhaust gases fluid flowing therethrough into liquid,

at least one conduit configured to form an output fluid pathway and fluidiy connect to an output of the at least one condenser for receiving a treated exhaust gases fluid comprising saturated gases, wherein the output fluid pathway is configured to allow heating and vaporising the saturated gases of the exhaust gases fluid into steam and the output fluid pathway is configured to direct the generated steam towards or into an air inlet pathway associated with the combustion chamber.

Preferably the output fluid pathway is associated with at least one heat source or heat exchanger for heating and vaporising the saturated gases. Alternatively or in additio the output fluid pathway is configured to allow the flow of gases in the treated exhaust gases fluid to energise and heat the saturated gases in the treated exhaust gases fluid.

Preferably the at least one condenser is configured to reduce the temperature of the exhaust gases fluid to below a dew point temperature of one or more condensable components of the fluid.

Preferably the at least one condenser is configured to reduce the pressure of the exhaust gases fluid to approximately zero or negative atmospheric pressure at the output of the condensers) .

Preferably a fluid pathway from the input fluid pathway to the output fluid pathway is substantially non-obstructed to allo non-restrictive flow of the exhaust gases fluid from the exhaust gas outlet of the combustion chamber.

Preferably the flow of exhaust gas fluid through the engine efficiency system is predominantly or primarily controlled by gas pressure cycles generated b th combustion chamber. Preferably the flow of exhaust gases fluid is wholly or entirely controlled by gas pressure cycles generated by the combustion chamber.

Preferably the at least one condenser comprises a conduit of a volume sufficient to reduce the temperature of exhaust gases fluid to below a dew point temperature of at least one condensable component of the gas.

Preferabl the conduit is of a volume sufficient to reduce the pressure of the exhaust gases fluid to approximately zero or negative atmospheric pressure. Preferably the output fluid pathway is fluidly connected to a relatively low pressure fluid pathway fluidly connected to a reiativefy high pressure gases inlet pathway of the combustion chamber.

Preferably the relatively low pressure fluid pathway is an output fluid pathway of an air filter and/or inlet of a nozzle assembly connected to the gases inlet of the combustion chamber. Preferably the kit of parts further comprises a second output fluid pathway fluidly connected to the outlet of the at least one condenser for receiving a mixture of saturated gases and substantially dry gases and directing the mixture into the relatively low pressure fluid pathway fluidly connected to the gases/air inlet of the combustion chamber.

In a preferred embodiment the flow of exhaust gases fluid is not controlled by a valve,

Preferably the kit of parts further comprises a receptacle configured to retain a body of liquid, the receptacle being fluidly coupled between the output of the at least one condenser a nd an input of the outlet fluid pathway and configured to receive a flow of the exhaust gas fiuid from the at least one condenser and saturate the non-condensable gases with the fluid to provide a flow of saturated gases to the outlet fluid pathway.

Preferably the receptacle further comprises a d ivider or baffle between the output of the condenser and the output fluid pathway for separating the bod of liquid within the scrubber from the output fluid pathway, and wherein the receptacle comprises an opening at an upper end of the divider for permitting the flow of treated exhaust gases fluid to the output fluid pathway.

Preferably the at least one heat source is waste heat from the engine.

In one embodiment the kit of parts further comprises at feast one draw tube and an atomiser, the d raw tube configured to be submerged within the body of liquid in the scrubber at one end and to couple the atomiser at an opposing end.

Preferably the draw tube is configured to extend within the intermediate fluid pathway and proximate the at least one heat exchanger,

Preferably the kit of parts further comprises at least one conduit configured to form an atomiser output fluid pathway and fluidly couple the output of the atomiser and the air inlet pathway associated with the combustion chamber. Preferabl the kit of parts further comprises at least one conduit configured to form a balance fluid pathway and fluidly couple the air intake of the engine at one end and to the atomiser output fluid pathway at an opposing end. In one embodiment the system further comprises a storage vessel configured to receive and retain a body of liquid generated by cooling of fluid within the system when the engine is substantially cooi. Preferably the storage vessel is positioned to gravitationally receive the flow of liquid.

Preferably the storage vessel is provided within one of the at least one heat exchangers.

Preferably the kit of parts further comprises at least one other heat exchanger configured to fiuidiy couple an outlet of the storage vessel for receiving a portion of the liquid stored therein and heating the liquid to generate steam. Preferably an output of the at least one other heat exchanger is configured to fiuidiy couple the air inlet pathway associated with the combustion chamber.

In a fifth aspect the invention may broadly be said to consist of a method for improving efficiency of a combustion process involving combustion of a fuel/oxidiser mixture and the production of exhaust gas from the combustion, the method comprising the steps of:

redirecting at least a portion of a volume of exhaust gases fluid flowing from the exhaust gas outlet into one or more condensers for condensing one or more condensable gases or constituents in the exhaust gases fluid into liquid,

directing the exhaust gases fluid through the liquid to saturate non- condensable gases of the exhaust gases fluid and generate a treated exhaust gases fluid comprising saturated gases,

vaporising a liquid component of the saturated gases in the treated exhaust gases fluid to generate steam, and

introducing the steam into the combustion chamber.

In a sixth aspect the invention may broadly be said to consist of a system configured to improve the efficiency of combustion in a combustion chamber, the system comprising:

an input fluid pathway configured to fiuidiy connect to an outlet of an exhaust gas pathway associated with the engine for receiving an exhaust gases fluid, at least one condenser configured to fluidly couple the input fluid pathway for condensing one or more condensable gases or constituents of the exhaust gases fluid flowing therethrough into liquid,

an output fluid pathway fluidly connected to an output of the at least one condenser for receiving a treated exhaust gases fluid comprising saturated gases, wherein the output fluid pathway allows the saturated gases of the exhaust gases fluid to heat and vaporise into steam and the output fluid pathway is configured to direct the generated steam towards or into an air inlet pathway associated with the combustion chamber.

In a seventh aspect the invention may broadly be said to consist of a method for installing a system configured to improve the efficiency of combustion in a combustion chamber, the method comprising the steps of:

tapping into an exhaust gases output pathway association with the combustion chamber to provide a redirected exhaust gases pathway,

fluidly coupling one or more condensers to the redirected exhaust gases pathway, the condensers being configured to condense one or more condensable gases or constituents in the exhaust gas into liquid,

fluidly coupling an input of an output fluid pathway to an output of the at least one condenser for receiving a treated exhaust gases fluid comprising saturated gases, and an output of the output fluid pathway to an air inlet pathway associated with the combustion chamber, and wherein the output fluid pathway is configured to allow heating and vaporising the saturated gases of the exhaust gases fluid into steam and the output fluid pathway is configured to direct the generated steam towards or into an air inlet pathway associated with the combustion chamber.

Preferably the method further comprises fluidly coupling a receptacle intermediate the one or more condensers and the output fluid pathway, the receptacle being configured to retain a body of liquid.

Preferably the method comprises connecting the output of the fluid pathway to a relatively low pressure fluid pathway fluidly connected to a relatively high pressure gases inlet pathway of the combustion chamber.

Any one or more of the above embodiments or preferred features can be combined with any one or more of the above aspects. The term "condenser" as used in this specification and claims mean a device or devices configured to reduce a temperature and/or pressure of a fluid within the device to temperature and/or pressure sufficient to cause the fluid or any components of the fluid to condense and change phase. For example a "condenser" may refer to a conduit or an externally powered cooling device. Related terms and phrases such as "condensing device" are to be interpreted in the same manner.

The term "comprising" as used in this specifteation and claims means "consisting at least in part of". When interpreting each statement in this specification and claims that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner.

As used herein the term ^w and/or" means "and" or "or", or both, As used herein "(s)" following a noun means the plural and/or singular forms of the noun.

The invention consists in the foregoing and also envisages constructions of which the following gives examples only. BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will be described by way of example only and with reference to the drawings, in which : Figure 1 shows a flow chart of an engine efficienc process in accordance with a preferred embodiment of the invention

Figure 2 illustrates a schematic diagram of an engine efficiency system for an internal combustion engine in accordance with a first preferred embodiment of the present invention ;

Figure 3 illustrates a schematic diagram of an engine efficienc system for an external combustion engine in accordance with a second embodiment of the present invention;

Figure 4 illustrates a schematic diagram of an engine efficiency system for an external combustion engine in accordance with a third embodiment of the present invention;

Figure 5 shows a flow chart of a process of operation a first circuit of the third embodiment; Figure 6 shows a flow chart of a process of operation a second circuit of the third embodiment; and Figure 7 shows a flow chart of a process of operation a third circuit of the third embodiment,

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a method and/or system for improving the efficiency of combustion of a fuei/oxidiser mixture, for example in a combustion chamber of a heat engine. While the invention is particularly suited and will be described in detail with reference to a heat engine, it will be appreciated that the invention may be incorporated in other machine, systems and/or applications utilising a combustion process to generate usefui forms of energy, such as electrical or heat energy for example. The present invention provides an improved closed loop engine efficiency system. The apparatus uses water (and other gases) which is(are) recovered, filtered and condensed from exhaust gases and used in the engine as superheated steam to act as an expansion fluid and increase the thermal combustion efficiency of the engine. A system and method will now be described that not only improves spark fired internal combustion engines but is aiso suited for compression ignition and external combustion engines. Generally applications being an internal or an external combustion engine will have an exhaust vent. Some vents are fitted with noise reduction and exhaust gas filter technology. The vents can also vary in length and dimensions, depending on the capacity of the engine. These technologies and dimensions can reduce the exit heat of the exhaust gases and volume of volatile organic compounds (VDC) exiting the exhaust vent.

The present invention provides improved efficiency by recovering and regenerating waste engine heat and exhaust gas expelled by engines. An internal combustion engine works by burning fuel, and producing high levels of heat and exhaust gas to run the system. On average, 30% of this heat is lost in the exhaust gas, while 35% is lost as heat through the cylinder walls, where ifs expelled throug the cooling system. The remaining 35% is used in the engine doing the work to produce motion. In the process, on average for every litre of fuel burnt to run the engine, 2,3 kilograms of carbon dioxide (for fuei 2.6 of diesei) is expelled out the exhaust system to the atmosphere. The present invention has been designed to recover a proportion of this expelled exhaust gas and wasted engine heat to increase the thermal combustion efficiency of the engine.

Exhaust gas is typically composed of Carbon Dioxide (C0 ₂ ), Nitrogen Oxides (NO _x ), Nitrogen (N), Carbon Monoxide (CO), water vapour and other compounds. Referring to figure 1, the system and method of the invention operates to implement an exhaust gas recirculation process 100 for improving engine efficiency and/or reducing toxic emissions. The process 100 involves the redirection of exhaust gas towards a condensing device (hereinafter: condenser) at step HQ, where condensable compounds of the exhaust gas, including water vapour, are separated from the other non-condensable compounds, including C0 ₂ and NO*, by changing phase (step 120). The condenser is thus configured to reduce the temperature of the exhaust gases fluid flowing therethrough to below a dew point temperature of at least the condensable gases or constituents of that fluid, preferably at atmospheric pressure. The condensable compounds change phase into a liquid, namely water. This liquid is used as the working medium of the system to saturate the non-condensable gases (step 130) to create a saturated gases fluid flowing through the system. The condenser is configured to reduce the pressure of the gases flowing therethrough to zero or negative atmospheric pressure. The low pressure working medium is also used to clean and purify the exhaust gas in the preferred embodiment. The saturated gases fluid is revaporised (step 140) by heating the fluid to generate steam from the liquid component of the fluid and ensure liquid does not enter the engine/combustion chamber. Revaporising also increases the velocity of the fluid prior to direction into the combustion chamber as steam is lighter than air. The generated steam is then directed back into the air inlet of the combustio chamber of the engine (step 150).

By isolating the water vapour component from the non-condensable gases in the exhaust gas mixture, the condensate can be provided to the system to thereby moisten the non-condensabl gas components of the exhaust gas and preferably clean and purify the exhaust gas (by removing dissolvable or separable components or sediments), producing a flow of working medium through the system composed of non-condensable gases saturated in water. Referring to figure 2, a schematic of engine system 200 operative in associated with the process 100 described above is shown, The engine 200 comprises an internal combustion engine 210 (partially shown) having a combustion chamber 211, an air/fuel inlet 212 and associated inlet valve 213 and an exhaust outlet 214 and associated exhaust valve 215. The inlet valve 213 and exhaust valve 215 fluidiy couple the combustion chamber 211 with air inlet and exhaust pathways 216 and 217 respectively. The operation of the engine or combustion machines will not be discussed in detail as this is well known in the art and so not to obscure the details of the invention. The engine 210 may be a two or four stroke engine for example. The engine is shown as an internal combustion engine, however in alternative embodiments the invention may be incorporated into an external combustion engine system for example, A retrofitted recirculation system 230 of the invention is coupled to the engine 210 for recirculating exhaust gas in accordance with the process 100 described above, In particular, the recirculation system 230 comprises at least an inlet pathway 231 fluidiy coupled to the exhaust pathway 217, at least one condenser 232 fluidiy coupled to the inlet pathway 231, a scrubber or container 234 coupled to the output of the condenser 232 and having a body of liquid 300 retained therein and a divider 238 for sepa rating the liquid from one or more outlets 237A-C of the scrubber, and one or more output fluid pathways 236, 243 connected to the outlets 237A-C for directing fluid back towards or into a iow pressure side of an inlet pathway 216 of the engine 210. In one preferred embodiment the system 230 extracts water vapour/exhaust gas from the tail pipe of an engine system, i.e., well downstream of the catalytic converter, after which the mixture is then processed and injected, or d rawn, into the intake air system just upstream from the throttle body. In the preferred embodiment, one or more condensers 232 are provided for condensing the condensable gases of the received exhaust gases fluid by reducing the temperature of the condensable gases to a dew point or below a dew point temperature of the gases. The condenser(s) 232 is (are) also configured to reduce the pressure of the exhaust gas flowing into the device 232 to approximately zero or negative atmospheric pressure. At the output 232a of the condensers the exhaust gases fluid flow is at approximately zero or negative atmospheric pressure. In the preferred embodiment, the condenser 232 comprises a conduit of increased diameter fluidiy connected to the exhaust gas inlet 231. The increase in volume in the pathway of the exhaust gases fluid reduces the pressure and temperature of the gas to the desired levels. The volume or size, or diameter or length or any combination thereof of the conduit is designed to cause a significant reduction in pressure and temperature of the gases so the gases a re cooled to at least the dew point temperature or below of one or more condensable components of the gases, namely water vapour. In the preferred embodiment, the condenser 232 is configured to reduce the temperature of the exhaust gas to approximately 100°C and below 100°C to condense water vapour in the gas. It will be appreciated that other forms of passive and/or active cooling devices may be utilised to reduce the temperature of the gas flowing through the circuit to the dew point temperature of one or more condensable components. For example, in some embodiments relatively cold air may be redirected from a vehicle's air conditioning or other cooling system to cool and condense the exhaust gas. In some embodiments, the engine's fuel gas (prior to heating of the gas) such as in a Liquid Petroleum Gas (LPG) or a Liquid Nitrogen engine can be used to cool and condense the exhaust gas. The output of the condenser 232 is fluidly coupled to the intermediate fluid pathway 237. In the preferred embodiment the output of the one or more condensers 232 is fluidiy coupled to a scrubber 234 in the form of a container, conduit or any other receptacle configured to retain and store a body of liquid 300 therein. The liquid may be initially provided from an externa! source, however during operation of the system 230 the liquid is predominantly provided by the condensation of condensable gases flowing through the condenser(s) 232.

A divider 238 is located within the scrubber 238 for substantially separating the liquid 300 from the gases outlets 237A-C. The dtvider 238 may be any form of baffle located between the inlet of the scrubber and the outlets 237 A-C. The divider 238 is preferably substantially vertically oriented within the container to prevent Iiquid 300 from flowing into the outlets 237A-C. An opening 238a is provided at an upper end of the divider 238 for gases to flow therethrough. At an outlet of the condenser(s) 232 a plurality of apertures 232a are preferably provided for non- condensed gases to exit out of and bubble through the body of iiquid 300, thereby generated treated exhaust gases fluid. The treated exhaust gases fluid comprises saturated gases. The treated fluid continues to flow above the body of Iiquid and into the opening 238a towards the outlets 237A-C. Heavier saturated gases B, C flow down towards the lower outlets 237b, 237C, whilst lighter dry gases A flow directly into upper outlet 237A. The term "treated" as used in this specification in reiation to the exhaust gases fluid means an exhaust gases fluid altered in its constituents relative to an exhaust gases fluid exiting a combustion chamber. An output fluid pathway 243 connects to the outlet 237C for enabling the Row of treated exhaust gases fluid comprising saturated gases past at least one associated heat source. Saturated gases are heated, preferably past a boiling point of the liquid components of the gases, produce vapour and/or steam. The output fluid pathway 244 is fluidly coupled to the inlet gases pathway 216 of the combustion chamber for delivering the vapour/steam to the chamber. The outlet fluid pathway 243 is in the preferred embodiment fluidly coupied to a relatively lo pressure fluid pathway that is fluidly connected to the high pressure gases infet pathway 216 of the combustion chamber. In particular, the outlet fluid pathway 243 is fluidly coupled to a low pressure output pathway 271 of an air filter assembly 270 via a nozzle assembly 260.

In a preferred embodiment a second output fluid pathway 236 is fluidly connected between the outlets 237A, 237B of the scrubber and the low pressure side of the inlet fluid pathway 216. The second output 236 is configured to direct a mixture of substantially dry and saturated gases towards the low pressure side of the inlet pathway 216. The second output 236 is preferably also fluidl coupled to the nozzle assembly 260. Fluid flowing through the second output pathway 236 may also be heated and vaporised by an associated heat source.

The nozzle 260 collects fluid in the form of steam, saturated gases and dry gases supplied by the outputs 243 and 236 and supplies it to the engine's combustion chamber 211 through inlet path 216. The low pressure gases flow of the air fitter outlet 271 draws the gases supplied by the outputs 243 and 236 to the inlet 216.

In the preferred embodiment the nozzle 260 is located above the scrubber 234 to gravitationally prevent or discourage flow of liquid 300 and sediments/other unwanted particles into the nozzle assembly 260. During operation, as exhaust gas is expelled through the exhaust outlet 214 and into the pathway 216, a portion or all of the gas is redirected into the inlet pathway 231 of the recirculation system 230 by action of the pressure cycles produces by the combustion chamber. The induced exhaust gases fluid is directed towards the condenser(s) 232 configured to reduce the temperature of the gas to dew point or below the dew point temperature of the condensable components of the gas. The dew point temperature may be for example approximately 100°C, In this manner, water vapour and other condensable components within the exhaust gas are condensed to form a liquid. The liquid 300 accumulates at the condenser 232 output for non-condensed gases to traverse through. The body of liquid 300 and/or the condenser(s} 232 also reduce the pressure of the gases flowing through the system 230 to approximately zero or negative pressure. As exhaust gases flow through the liquid 300 some of the particles become saturated. Substantially saturated and substantially dry gases then flow through the opening 238a at the upper end of the divider and into the outlets 237A-237C. Treated exhaust gases fluid comprising saturated gases C flows through outlet 237C and into output pathway 243 traversing adjacent one or more heat sources or heat exchangers coupled to heat sources for absorbing heat and vaporising the liquid components of the saturated gases. Alternatively or in addition, the flow of gases in the treated exhaust gases fluid can energis and heat up the saturated gases within the output pathway 243. This vapour is then supplied to the relatively low pressure region at the nozzle assembly 260 to be drawn into the relatively high pressure region of the gases inlet pathway 216, Similarly, a mixture of dry and saturated gases A, B flows from the outlets 237A, 237B into the output pathway 236 and is supplied to the relatively low pressure region at the nozzle assembly 260 for drawing the gases mixture into the relatively high pressure region of the gases inlet pathway 216. As steam enters the combustion chamber via inlet 212, it will further heat and change phase into superheated steam. Superheated steam acts as an expansion fluid and increase the engine's thermal combustion efficiency. The process of condensing the exhaust gas separates the useful condensate component of the exhaust gas mixture from the non-condensable exhaust gas components (at substantially atmospheric pressure); such as C0 _2/ NO*, CO, N and other particulate matter that otherwise reduce engine efficiency.

In the preferred embodiment, the flow of fluid through the system 230 is substantially un -obstructed/ unrestricted by valves or any other such components. In this manner, the flow of fluid is predominantly or primarily controlled by the pressure cycles generated b the operation of the combustion chamber. For example, during an idle state the combustion chamber produces minima! to no exhaust gases so gases do not flo through the system. As load is increased, exhaust gas flow and pressure is increased and causes more fluid to flow through the system 230, The condenser(s) 232 in response to increased gas flow condense a larger volume of gases and generate more liquid 300 to be stored in scrubber 234. To condense the condensable gams the condenser needs to also reduce the pressure of gases to approximately zero or negative. The reduction in pressure is achieved by the increased volume of the condenser 232, the body of liquid 300 at the output of the condenser and the connection of the output pathways 236, 243 to the low pressure region directly adjacent the intake 216. The scrubber/receptacle is also of a volume to act as an expansion chamber for reducing the pressure of exhaust gases fluid flowing through the system 200. As the level of the liquid 300 rises due to increased generation of condensate, liquid may spill over through the opening 238a at the top of the divider 238 and block the outlets 237B, C. This provides a restriction to the flow of gases through the system 230, Such a restriction reduces the flow of gases and reduces generation of condensate, in turn causing the level of the liquid 300 to reduce. The upper outlet 237ft ensures a flow of gas through the system 230 at all times, however, a flow through outlets 237B and 237C is also required to achieve sufficient flow for replenishing the liquid 300 and ensuring sufficient saturation of gases flowing therethrough. In this manner the system 230 becomes self-sufficient without the need for any external valves and/or external control. Also liquid/water 300 does not need to be replenished by an external source expect for during initial priming and servicing for example.

During installation of the recirculation system 230, the exhaust gases outlet pathway 217 is tapped into and a relatively smaller diameter conduit is fluidly coupled thereto. The relatively larger diameter condenser 232 is then fluidly coupled to the smaller diameter conduit extending from the exhaust outlet, The receptacle 234 is then fluidly coupled to the outlet of the condenser(s) 232. The outlet output fluid path ways/ conduits 243 and 236 are then coupled between the nozzle 260/low pressure fluid pathway and the respective receptacle outlets 237A- C.

Referring to figure 3, a schematic of a second embodiment engine system 200 operative in associated with the process 100 described above is shown. The engine 200 comprises an internal combustion engine 210 (partially shown) having a combustion chamber 211, an air/fuel inlet 212 and associated inlet valve 213 and an exhaust outlet 214 and associated exhaust valve 215. The inlet valve 213 and exhaust valve 215 fluidly couple the combustion chamber 211 with air inlet and exhaust pathways 216 and 217 respectively, The operation of the engine or combustion machines will not be discussed in detail as this is well known in the art and so not to obscure the details of the invention. The engine 210 may be a two or four stroke engin for example. The engine is shown as an internal combustion engine, however in alternative embodiments the invention may be incorporated into an external combustion engine system for example. A retrofitted recirculation system 230 of the invention is coupled to the engine 210 for recirculating exhaust gas in accordance with the process 100 described above. In particular, the recirculation system 230 comprises at feast an inlet pathway 231 fluidiy coupled to the exhaust pathway 217, at least on condenser 232 fluidl coupled to the inlet pathway 231, an intermediate fluid pathway 237 fluidly coupled to the output of the condenser 232, at least one heat exchanger 235 associated with the intermediate fluid pathway 237 and an outlet fluid pathway directing fluid back towards or into the inlet pathway 216 of the engine 210.

The engine system 200 may also comprise an existing conventional exhaust gas recirculation (EGR) system 220 installed therein. The existing EGR system 220 may comprise an inlet fluid path 221 fluidiy coupled to the exhaust pathway 217 that redirects some or all of the exhaust gas back towards the inlet pathway 216. An EGR valve 222 may be incorporated for controlling the timing and volume of induction of exhaust gas through the existing EG system 220. The EGR valve 222 may be controlled by a separate EGR control unit or preferably by the existing power control module of the engine 210. The output end of the valve taps into the inlet pathway 216 through an outlet pathway 223 of the existing EGR system 220. In the conventional EGR system 220, exhaust gas is typically cooled as it is recirculated back into the engine but the temperature of the gas remains sufficiently above the dew point of any condensable components of the gas and thus does not cause a change in phase of any of the gas components at the EGR system operating conditions. For example, exhaust gas exiting the engine may be at approximately 35Q°C. At the EGR outlet 223, the gas may have cooled to approximately 140°C.

In embodiments where the engine 210 is equipped with a pre-existing EG system 220, the recirculation system 230 of the invention may be installed in parallel with the entire existing EGR system 220 (from the exhaust pathway 217 to the inlet pathway 216 - as shown in dotted lines in figure 2). In this case the modified EG system 230 may comprise a valve 239 for controlling the timing and volume of induction of exhaust gas. Alternatively, as show in figure 4, the recirculation system may be installed in series with the existing EGR system 220 tapping into the fluid path at the output of the EGR valve 222. In some embodiments, the engine 210 is not equipped with a pre-existing EGR system 220, and in which case the recirculation system 230 of the invention is coupled directl to the exhaust pathway 217 and preferably comprises a valve 239 as described above. The vaive 239 and/or the valve 222 control(s) the flow of redirected or recirculated gases. The valve 239 and/or 222 controls) the flow and/or pressure of exhaust gas through the recirculation system 230. Alternatively or in addition a control unit associated with the valve, such as the engine power control module, senses the properties of the engine's exhaust gas such as flow and pressure and controls the operation of the valve accordingly. Controi of the valve achieves a desired flow rate and/or pressure through the modified and (if fitted} existing EGR systems, A reed/poppet valve may be used to redirect the flow of exhaust gas through the system. Typically a poppet valve is a va!ve used to control the timing and volume of gas flow into the recirculation system 230, It will be appreciated that any other type of valve suitable for use with engine conditions may be used. The valve(s) also provide(s) a means of regulating the systems internal temperature, preventing water, condensed from the exhaust gases and contained in the system storage (as later described) from freezing in cold climates. The regulated temperature also assists in emulsification, atomization and flow of the mixture of gas and water. Furthermore the invention's condenser operation is enhanced by this flow control.

In the preferred embodiment, one or more condensers 232 are provided for condensing the condensable gases of the exhaust gas mixture. The condensers 232 may be configured to reduce the pressure of the exhaust gas flowing into the device 232 to reduce the temperature of the gas as described above for the first preferred embodiment. In some alternative embodiments, the controi valve 222 or 239 by controlling the flow of gas may increase the efficiency of the condenser 232. The reduction of exhaust gas fiow though the vafve at higher speed may provide the system with the time for the exhaust gas to be condensed. This action could increase the efficiency of the condensers 232 and allows for an inexpensive condenser design.

The one or more heat exchangers 235 are configured to transfer waste heat from the engine 210 to the fluid flowing through the intermediate fluid pathway 237. The heat exchanger(s) 235 heat the fluid within the intermediate pathway 237 above the dew point temperature of one or more liquid components of the fluid, namely water to generate vapour or steam. It will be appreciated that any type of heat exchanger known in the art of mechanical and/or thermodynamic engineering may be used. The heat exchanger(s) are preferably installed proximate any one or more waste heat sources including a cooling device (radiator) associated th engine and/or combustion chamber walls for example.

During operation, as exhaust gas is expelled through the exhaust outlet 214 and into the pathway 216, a portion or al! of the gas is redirected into the inle pathway 231 of the recirculation system 230 by action of the EGR valve 239 or 222 (depending on installation). The induced exhaust gas is directed towards the condenser(s) 232 configured to reduce the temperature of the gas to dew point or below the dew point temperature of the condensable components of the gas. The dew point temperature ma be for example approximately 100°C. In this manner, water vapour and other condensabl components within the exhaust gas are condensed to form a liquid. This liquid is used as a component of a fluid traversing through the intermediate fluid pathway 237. The liquid is reheated by the heat exchanger(s) 235 to above the boiling temperature of the liquid to create vapour/steam. Steam is then redirected back towards the inlet pathwa 216 of the engine 210 via output fluid pathway 236. As steam enters the combustion chamber via inlet 212, it will further heat and change phase into superheated steam, Superheated steam acts as an expansion fluid and increase the engine's thermal combustion efficiency. The process of condensing the exhaust gas separates the useful condensate component of the exhaust gas mixture from the non- condensable exhaust gas components (at substantiall atmospheric pressure); such as CQ ₂ , NO _;< , CO, N and other particulate matter that otherwise reduce engine efficiency. In the preferred embodiment, the recirculation system 230 further comprises a wet scrubber 234 fluidly coupled between intermediate fluid pathway 237 and the condenser 232. The scrubber contains a body of liquid 234a configured to dissolve and/or separate solid components/sediments of the exhaust gas to clean the fluid flowing through the system 230. The body of liquid contained within the scrubber 234 is preferably the liquid generated by the condenser 232. As the non- condensable components of exhaust gas flow out of the condenser 232 and through the scrubber 234 they become saturated to produce a saturated gases fluid. The saturated gases fluid flows through the intermediate fluid pathway 237 where it becomes heated by the heat exchanger 235. Water surrounding the gas mo!ecules is vaporised into steam by action of the heat exchanger 235 and this steam is then directed through the outlet pathway 236 to the air inlet pathway 216 of the combustion chamber. The flow of gas and liquid through the recircuiation system 230 is controlled by the pressure cycles of the engine 210. In particular, during the idle state, the engine 210 does not generate sufficient pressure for circulating the exhaust gas through the main circuit of the recirculation system 230. As the engine is loaded (during and in between low, medium and high throttle stages for instance) positive and negative pressures exhibited at the exhaust outlet 214 and air/fuel inlet 212 are created on either side of the main circuit of the recircuiation system 230 moves the fluid within the circuit through the system 230. In this manner, the modified recirculation system 230 does not require the use of additional pumps or injection units for example to actively facilitate the circulation of gas and liquid through the circuit of the system 230,

Referring to figure 4, a third embodiment eng ine system 200 of the invention is shown . The engine system 200 of the third embodiment comprises an engine 210, an existing EGR system 220 and a recirculation system comprising three circuits; a primary circuit 230, and two supplementary circuits 240 and 250. The components of the engine 210 and existing EG system 220 are as described above. The components and operation of the circuits 230-250 will now be described in further detail .

The primary and two supplementary circuits 230-250 share common initial stages, including a condenser 232, a scrubber 234 and a heat exchanger 235 as described above for the second embodiment. The circuits comprise an exhaust gas inlet 231 (connected to either the existing EGR system outlet or directly to the exhaust gas outlet pathway 217 of the engine 210) and a condenser 232 flu idly coupled to this inlet 231 preferably via a control valve 222/239 as described above. The condenser 232 is preferably a conduit of increased diameter configured to reduce the temperature of the exhaust gas flowing through the circuit 230 to a dew point temperature of a least the one condensable component of the gas. This condensable component is preferably water vapour. The conduit is designed to reduce the temperature of the exhaust gas to the dew point temperature of water- vapour which is approximatel 100°C for instance. The circuit may comprise any number of condensers of the same and/or different sizes and/or structures and coupled in series or parallel to condense the condensable components of the fluid flowing therethrough and supply the resulting fluid to the scrubber 234.

The condenser 232 is fluid!y coupled to a wet scrubber 234 comprising a container 234 having a body of liquid retained therein . The body of liquid is the condensed liquid (e.g. water) produced by the condenser 232. In some embodiments the container is initially filled with a body of liquid which is eventually used up and replaced by the condensed liquid during operation. The scrubber 234 dissolves and/or otherwise removes some of the unwanted substances in the exhaust gas and prevents it from traversing further through the system. The scrubber 234 also allows the non-condensable gases of the exhaust gas to flow/bubble through the liquid contained therein to output a saturated gases fluid composed of non- condensable gases saturated with liquid (e.g. water). An internal fluid pathway 251 provided by a conduit or set of conduits such as tube(s) 251 is(are) provided through the container 234 to allow some of th saturated gases fluid to flow therethrough and into the pathway of the circuit 250 as will be described in further detail below. The scrubber 234 forms part of all three circuits 230-250 and the conduit 251 is (are) provided for the third circuit 250. The scrubber filters and traps any solid particles and dissolves these particles. In the preferred embodiment a release valve is associated with the container for discarding and trapped solid matter tha is not dissolved. The release valve may also be used for priming the scrubber/system with water and as a testing port. This forms a supply of new liquid (water) that is used in the system and eventually is vaporised to form steam for use in the combustion chamber 211. In the preferred embodiment, this new water is the only water source employed in the system and there is no requirement to add more water to form the source of steam. The system is a self-supporting closed loop system.

In th third embodiment, a one way check valve 233 is provided between the condenser 232 and the scrubber 234 for limiting the direction of travel of fluid through the circuits 230-250 from condenser to scrubber and substantially preventing fluid from flowing back through the condenser from the scrubber.

The output of the scrubber 234 is fluidly coupled to the intermediate fluid pathway 237 that traverses proximate (preferably via) the heat exchanger 235, The heat exchanger 235 is configured to heat the saturated gases fluid exiting the scrubber 234 to above a boiling point temperature of the liquid in the fluid to produce vapour/steam, One or more heat exchangers 235 may be provided in series to aid in the production of va our/ steam from the saturated gases fluid. Typically the heat exchanger is an indirect single pass heat exchanger 235. However, it should be appreciated that any type and any number of heat exchanger(s) 235 may be utilised. The heat exchanger 235 is coupled to one or more heat sources for transferring heat to the fluid flowing through the exchanger. In the preferred embodiment, the one or more heat sources are any of one or more other components of the engine system 200 that generate, recover and/or transfer waste heat from the engine system 200. For example, in some embodiments the heat exchanger may be coupled to any combination of one or more of: the engine's cooling system/radiator, the engine oil and/or transmission cooling system, the engine lubrication oils, hydraulic pump units driven by the engine, and/or the engine's exhaust system.

In the third embodiment a receptacle or storage vessel 241 is provided after the scrubber 234, forming part of the second circuit 240. The receptacle 241 is closely associated with the heat exchanger 235 and configured to retain a volume of liquid therein. The receptacle is configured to receive, accumulate and store a volume of liquid produced through condensation of the condensable components of the saturated gases fluid after sufficient cooling of the system (when the engine is not operating or cool for example). The receptacle 241 may also store and accumulate condensate of other gases or other liquid within the recirculation system. The receptacle is also configured to allow the expansion of gases as described for the first embodiment. The receptacle 241 is, in the third embodiment, located below the scrubber 234 and the majority of the components of the recirculation circuit to gravitationally receive and accumulate liquid formed within the system. The receptacle 241 is closely associated with the heat exchanger 235 to heat the liquid contained therein . The receptacle 241 is provided as pa rt of the heat exchanger 235 but in alternative embodiments may be a separate device fiuidly coupled to the scrubber and closely associated with the heat exchanger 235 for receiving heat therefrom. In yet another alternative the receptacle 241 is separate and not associated with the heat exchanger 235. The second circuit 240 of the system 200 produces a continuous supply of water from exhaust gas by redirecting and condensing a proportion of exhaust gas. This provides a method to maintain a predetermined volume of generated wate in a chambe to change phase into steam as required by the engine.

In the third embodiment, the conduit or tube 251 of the third circuit 250 extends through the scrubber 234 at one end, through the fluid pathway 237 and heat exchanger 235 and is fiuidly coupled to an atomizer 252 at the other end . In some embodiments a set of two or more conduits 251 may be provided in parallel from the scrubber to the atomiser. The conduit or conduits 251 is/are preferably formed from a non-metal material, for example a plastics material . The heat exchanger 235 heats up the fluid flowing through the conduit 251. The conduit 251 may alternatively run parallel or foe otherwise be closely associated with the heat exchanger 235 for heating up the fluid flowing there through.

An output fluid pathway 236 is fluidiy coupled with and extends from an output of intermediate fluid pathway 237 after the heat exchanger 235 and towards a collective nozzle assembly 260 common to all circuits 230-250. A mixture of steam, produced by the heat exchanger 235, and other non-condensable gases flows through the conduit 236 towards the nozzle assembly 260, In this manner, the components of the first circuit comprise: a fluid path 231 connecting the output of the exhaust pathway 217 to a condenser 232, a condenser 232, a scrubber 234 at the output of the condenser 232 with an optional one way valve 233 there between, an intermediate pathway 237 coupled to one or more heat exchangers 235 and the output of the scrubber 234, and an output pathway 236 coupled between the heat exchanger output and an inlet of th nozzle assembly 260,

A second circuit fluid pathway 242 extends from an output of the receptacle 241 of or closely associated with the heat exchanger 235 to deliver fluid through a heat exchanger 243 of the second circuit 240. The heat exchanger 243 is coupled to one or more heat sources to generate heat sufficient to increase the temperature of the fluid flowing there through to at least the boiling temperature of the liquid, thereby creating steam. In one embodiment, the heat exchanger 243 is closely associated with the cylinder walls of the combustion chamber 211 and/or to the exhaust manifold of the engine 210. An outlet of the heat exchange 243 is fluidiy connected with an output fluid pathway 244 coupled to the input of the nozzle assembly 260. The pathway 244 delivers the steam generated by the heat exchanger 243 to the nozzle assembly 260.

The conduit or tube 251 of the third circuit 250 extending through the scrubber and heat exchanger 235 is fluidiy coupled to an atomizer nozzle assembly 252 configured to generate an aerosol fluid (preferably of an increased flow rate) from the heated saturated gas and/or steam. The atomiser nozzle 252 consists of a draw tube with dra vents which extends through the heat exchanger 235 and connecting conduit 251. The draw tube is perforated throughout its length to encourage the flow and consistency of the water/gas mixture and a consistent temperature of the water/gas mixture.

An output fluid pathway 253 of the third circuit 250 fluidiy couples the output of the atomizer nozzle assembly 252 to deliver the aerosol fluid and/ or steam to the nozzle assembly 260. The fluid pathway 253 is preferably routed in a manner which allows the recovery/tra nsfer of external engine heat. In the third embodiment, one or more heat sources, for example engine waste heat sources, are closely associated with the output conduit 253 for heating the aerosol fluid and assisting in generating steam as the fluid flows through the pathway 253. In the third embodiment, the atomizer nozzle 252 only permits fiuid through the nozzle 252 in the direction of connecting conduit 251 towards the output path 253.

A balance fluid pathway 254 extends between the atomizer nozzle assembly 252 and the air intake path 271 of the engine system 200 to form a closed loop circuit. The balance pathway 254 is fluidly coupled to the output pathway 253 to provid filtered air from the engine's air intake to the pathway 253. The balance pathway 254 is also fluidly coupled to the atomiser nozzle 252. Air flow through the balance pathway creates a vacuum or suction pressure at the atomiser nozzle assembly 252. This action forces the saturated gases fluid i n through tube(s) 251, through the atomiser to generate an aerosol fluid from the heated saturated gases mixture and/or steam, and into the outlet pathway 253,

Fluid pathway 253 is fluidly coupled at the nozzle 260 closer to the engine to allow air to pass through 252. Air is sourced through fluid pathway 254 upstrea m from fluid pathway 253 but from the same air intake duct 271 of the engine. This arrangement provides clean air post the engine's ai r filter 270 and generates a flow of air through the atomiser 252 to draw moist gas therethrough. As the engine speed/ load increases either at a fast rate or steady rate, fluid pathway 254 balances the flow rate through the closed loop, as pressure differential between the connection passages of fluid pathway 254 and fluid pathway 253 to the air intake 271 are reduced . At idle there is slightly lower pressure (vacuum) closer to the engine than the air filter 270, The design of the atomiser nozzle 252 only allows liquid to be drawn in one direction . As the engine increases its speed, fluid pathway 254 prevents the possibility of water being drawn u into th engine by pulling back on 253,

The nozzle 260 assembly is coupled to the output fluid pathways 236, 244 and 253 of the three circuits 230-250. The nozzle 260 is also coupled to the air intake path 271 of the engin system 200. The air intake path 271 may be the output of an air filter 270 for example. An output of the nozzle assembly couples the air inlet path 216 of the engin 210. The nozzle 260 collects steam produced by the three circuits 230-250 and supplies it to the engine's combustion chamber 211 through inlet path 216,

In the third embodiment the nozzle 260 is located above at least the scrubber 234 and preferably also the heat exchangers 235 and 243 and the receptacle 241 to gravitationally prevent or discourage flow of sediments and other unwanted particles into the nozzle assembly. The scrubber 234 is preferably located below the heat exchangers 235 and 243 to gravitationally encourage the flow of working medium fluid towards the scrubber.

Unless otherwise specified, the fluid pathways 231, 236, 237, 242, 244, 253 and 254 of the recirculation system and/or any other pathways are each formed from any combination of one or more conduits including tubing, piping, ducting manifolds and/or any other components well known in the art. The conduits are preferably formed from a non-ferrous metal material . It should be appreciated that a non-ferrous metal conduit could be any metal conduit, including alloys, that does not contain iron in appreciable amounts.

The routing and location of the pathways 236, 242 and 253 configured to deliver gas and steam to the engine 210 are designed to allow condensed steam to reenter the liquid receptacle 241 under the action of gravity when pressure forces within these pathways are substantially low. The pathways 236, 253 and 254 are also designed to trap any liquid (water) within the pathway and prevent the liquid from entering the engine 210 when steam is not being drawn by the engine. This action of returning and trapping iiquid eliminates the possibility of creating an engine operating deficiency. The system components are operating continuously regardless of the engine speed/ load. The system is designed to contain the recovered and reclaimed heat and exhaust gas within the closed loop system. An internal combustion engine has been described above and in relation to figures 2 and 3. An engine in the context of this invention shall be understood to include a machine designed to convert heat energy into another useful form of energy such as mechanical motion or electrical energy for example. This includes but it is not only limited to heat engines, including internal combustion engines and external combustion engines that burn a fuel to create heat, which then creates motion.

In some embodiments in order to ensure the system operates at safe levels a mixture monitoring control vaive (not shown) is installed. The mixture monitoring control valve controls maximum safe working level, flow rate and also acts as a test port for any maintenance or fault finding. The mixture monitoring control valve also ensures no water can enter the engine directly by flooding the system or by an excess build-up of water in the system.

The operation of the three circuits 230-250 to achieve the above described system functionality will now be described.

Referring to figure 5, the primary circuit 230 is operable when the engine is under load, for example during throttle and/or during cruise of a vehicle engine for exampie. During load, air intake pressure changes, thereby creating a venturi at the nozzle assembly 260 wherein the output conduit 236 of the primary circuit 230 couples. This pressure draws in exhaust gas from the output of the exhaust pathway 217 or existing EGR system 220 (depending on where input 231 of primary circuit is located) and into the primary circuit 230 (step 110) . The exhaust gas flowing through the primary circuit may be regulated by a control valve of the primary circuit 239 or of the existing EGR system 222, or by the orifice sizing into the exhaust gases passage. Exhaust gas exiting the valve flows into the condenser 232 where condensable components of the exhaust gas including water vapour a re condensed into a liquid state (step 120) .

Liquid generated from condensation is transferred (via flow of gas pressure through the circuit 230) into the scrubber 234 where it is retained and used for dissolving/separating unwanted sediments and/or saturating non-condensable gases (step 125). A minimum level of liquid within the scrubber is maintained during operation of the primary circuit 230. As non-condensable gases, such as Nitrogen (N), C0 ₂ and NO _x , flow through the liquid in the scrubber 234, they pick up droplets of the liquid and become saturated. These gases also move the liquid constituents of the fluid to heat up the fluid and encourage vaporisation of the liquid constituents. The liquid produced from the condensed gases (including water vapour) of the exha ust gas mixture aiso dissolves a nd separates solid components sediments of the exhaust gas, including volatile organi compounds that may otherwise be harmful to the engine and/or detrimental to the engine's combustion efficiency. A sediment drain and/or associated relief valve may be associated with the scrubber 234 for removing trapped matter that did not dissolved in th liquid in use. As non-condensabl gases of the exhaust gas mixture traverse past the condenser and into the scrubber 234 they become saturated (step 130). A wet satu rated gases fluid exits the scrubber 234 and enters the fluid pathway 237 leading to the heat exchanger 235. Saturated gas molecules collide with one another as they traverse through the fluid pathway 237 thereby increasing the temperature of the wet gases fluid flowing through the pathway. The heated gases mixture then flows past the heat exchanger 235 wher it is further heated to the boiling point temperature or above of the liquid (water) carried by the gas molecules (step 140) , As fluid flows through the pathway 237 and heat exchanger 235 it is thus heated to a temperature sufficient to generate steam/water vapour.

A mixture of steam and non-condensable gases, including C0 ₂ and N for example, is drawn through the output of the heat exchanger 235 through output pathway 236 and into the nozzle assembly 260. Air flowing through the intake 271 and into the nozzle assembly 260 picks up the drawn steam and delivers it to the air inlet 212 of the internal combustion engine 210 (step 150). The steam as it enters the combustion chamber is further heated to change phase into superheated steam, which acts as an expansion fluid improving the engi ne's thermal combustion efficiency (step 160).

The primary circuit 230 is operative only when the engine is under load and a sufficient pressure of air flows through the intake pathway 271. This creates the necessary suction at the nozzle assembly for drawing the exhaust gas through the various components of the primary circuit.

Referring to figure 6, the second circuit 240 operates during all stages of engine operation including idle provided there is liquid in the receptacle 241 , As the engine cools after operation, any condensable gas such as water vapour steam contained in any of the circuits 230-250 and not delivered to the engine condenses into a liquid. This liquid is directed towards and accumulates in the receptacle 241 of the second circuit 240. Other liquid present within the system and not driven by gas pressures through the system also flows towards and is accumulated within the receptacle 241 , The receptacle is positioned such that all liquid and condensate within the recirculation system g ravitationaily flows into the receptacle when not otherwise influenced by gas pressures (step 170) . When the engine is restarted, the liquid in the receptacle 241 is redirected through the conduit 242 to the heat exchanger 243 where it is heated to its boiling temperature to create steam (step 175). Steam is drawn into the nozzle assembly under load (ste 180) and is then fed into the combustion chamber to generate superheated steam (step 185) as described for the primary circuit 230 above. The steam entering the engine at idle and under load, continuously removes and prevents carbon deposits from forming and stabilizes the air to fuel mixture, this in turn reduces fuel consumption and emissions at idie.

Referring to figure 7, the third circuit 250 similar to the first, only operates during engine loading under the influence of redirected air flowing from the intake pathway 271 and into the balance pathway 254. This creates a vacuum at the atomizer nozzle assembly 252 drawing exhaust gas through the condenser 232 and scrubber 234 and then through tube(s) 251 (step 190). Non-condensable exhaust gases flowing through the conduit 251 become saturated as they traverse through scrubber 234 (step 191). As described for the primary circuit, as these saturated gas molecules traverse through the conduit 251, they collide with one another increasing their energy and thus their temperature. As the gases are led through or adjacent the heat exchanger 235 the are further heated and a portion of which may have their liquid components revaporise into steam (step 192). The wet gases mixture and steam are fed through the atomiser nozzle (step 193) and the aerosol fluid output by the atomiser nozzle assembly 252 is directed into fluid pathway 253 for delivery to the nozzle assembly 260 (step 194). The aerosol fluid is further heated by one or more heat sources cioseiy associated with the pathway 253 to generate steam. The steam is deiivered to the internal combustion engine and superheated to generate an expansion fluid (step 195) as described for the primary circuit 230 above.

The air flow through the third circuit is controlled by the engine. As engine speed increases it draws more air through the air intake 271 and into the balance pathway 254. This pushes more air through the outlet pathway 253 and increases the flow of atomised fluid through this outlet path. The flow of air through the balance pathway 254 also creates a venturi at the junction with the tube(s) 251 to draw in fluid through the atomiser 252. Atomised fluid remaining in the outlet pathway 253 after the engine has stopped drains back towards the atomiser nozzle 252 preventing water entering the engine on start up. The balance conduit 254 performs in a way which is similar to the outlet pathway 253 in that as engine speed increases the flow of filtered air increases. This subsequently slows the air flow in the pathway 253. Overall the volume of atomised water slows when engine speed increases. The pathways 253 and 254 are located in specified positions to draw air quickly and to prevent excess air draw when the engine speed/load increases or decreases rapidly. The routing and location of the connection of the pathways 253 and 254 provide a closed loop system, thus not releasing or adding any air to the engine 210. The closed loop system afso provides a confined chamber for the atomised water to absorb engine heat quickly and be maintained in a gaseous phase, regardless of the air temperature and engine speed. The absorption of heat by steam entering the combustion chamber causes a rapid expansion of the steam in the chamber 211. This expansion increases the engine compression pressure, therefore increasing engine efficiency. In superheated steam the temperature of the steam is higher than the boiling point temperature corresponding to the pressure of the steam. The superheated steam cannot exist in contact with the fluid, nor contain fluid particles. An increase in pressure or decrease in temperature will not - within limits - condensate out liquid particles in the steam, As a follow on effect steam moving through the engine 210 provides a method to remove and prevent carbon deposits from forming in the engine 210. The steam moves towards the engine's combustion chamber(s) 210 and carbon is removed and prevented from forming, due to the effects of the steam cleaning.

Steam also prevents engine denotation, regardless of the fuel quality. Typically detonation or knocking in spark-ignition or compression fired interna! combustion engines occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front. The fuel-air charge is meant to be ignited by the spark plug only, and at a precise time in the piston's stroke cycle. Detonation or knock occurs when the peak of the combustion process no longer occurs at the optimum moment for the four-stroke cycle. The shock wave creates the characteristic metallic "pinging" sound, and cylinder pressure increases dramatically. Effects of engine knocking range from inconsequential to completely destructive. The injection of steam into the combustion chamber 211 ensures that all of atr/fuef mixture is combusted in the combustion chamber 211 and therefore prevents any detonation or knocking.

As described above the flow of redirected exhaust gas to the system is created by the engine's exhaust flowing through the exhaust control valve 222/239. In the third embodiment the control valve 222/239 is configured to regulate the flo of exhaust gas through the recirculation system 230-250 depending on the state of the engine, such as the speed or load experienced by the engine.

In one embodiment, the control valve 222 is configured to permit a relatively higher/large volume of exhaust gas through the system 230 during low exhaust gas pressure or flow and/or during idie and/or during light load states of the engine, and to permit no exhaust gas or a relatively lower/small volume of exhaust gas flow through the system 230 at medium-high ioads and/or increased speed and/or high exhaust gas pressure or fiow states of the engine. This creates a bubble flow of exhaust gas and flow of water through the system. The bubble action excites the body of water i the system helping the atomisation of water drawn through the atomising nozzle assembly (ANA) 252. When the engine increases its speed/load the fiow through the exhaust control valve 222 reduces allowing substantially full fiow of the engines exhaust to the atmosphere. This action also enhances the condensing of exhaust gas in the system and the connecting conduit.

In an alternative embodiment, and typically in an embodiment where the system is fitted to an existing EGR system 220, the control valve 239 is configured to permit no exhaust gas or a relatively lower/smaii volume of exhaust gas through the system 230 during low exhaust gas pressure or flow and/or during idle and/or during light load states of the engine, and to permit a relatively higher/large volume of exhaust gas flow through the system 230 at medium-high Ioads and/or increased speed and/or high exhaust gas pressure or flow states of the engine,

In yet another alternative embodiment, the control valve 222/239 permits a constant volume of gas and/ or does not operate depending on engine load or speed. In summary, the second and third embodiment systems 200 uses exhaust gas extracted from an existing Exhaust Gas Recirculation system (EGR). The exhaust gas flow to the system is controlled by the EG system and or the engine control unit (ECU) which can also be known as the Powertrain control module (PCM). The system can be controlled fully by the EGR system, therefore integrating the system with the engine control and safety systems. The volume and flow rates of the exhaust gas through the system and the resulting gas mixture introduced to the engine are controlled by the engine. The system can be tuned to suit specified engine types, speeds and loads. The system ha rvests exhaust gas from the EG system from the point of lowest temperature, but prior to the exhaust gas / air mixing stage. It reduces the temperature and pressure of this harvested exhaust gas further and below the temperature of the EGR mixing stage above. The harvested gas is then separated into its condensable and non-condensable components (at low pressure), The condensate component is used as a scrubbing medium (trapping solid matter) as well as absorbing some of th non-condensable gas component. These components are allowed to move freely through the system.

Overall the decrease in pressure, cleaning and cooling of the exhaust gas forms the system's working medium, which consists of gas, liquid and steam. The entire working medium is both drawn and pushed through the system by the engine's pulsation pressures caused by the engine expelling exhaust gas and consumption of air. The system employs a heat exchanger (using engine waste heat) to heat the components producing a working mixture of gas and steam. The reformed working medium is then drawn into the engine's air intake via convection at the connection of the system nozzle and the engine's air intake duct.

The engine's pulses, creates a method to maintain a flow of working medium throughout the system.

The working medium/ system fluid moves in a non-uniform motion. Gas can bubble through the condensate within the scrubbing vessel or move through the device above the condensate.

The working mixture flows into at least one heat exchanger of the system before entering the engine's combustion chamber.

The system diverts some of the working medium into another heat exchanger to raise the temperature above that harvested from the EGR.

When the engine's speed and load increases, the system diverts some condensate into an atomiser nozzle, where it changes phase to steam as it is drawn through the system's heat exchanger,

The steam component of the working medium flows at a faster rate due to its lower density when compared to the engine's air intake. The steam moves through the system and into the engine's combustion chamber at a higher velocity than the air intake cha ge,

As the steam moves towards the engine's combustion chamber it is superheated due to the higher temperature. This the superheated steam acts as an expansion fluid which increases the engine's compression pressure, while reducing combustion temperature. The steam component prevents carbon formation and removes preexisting carbon deposits. It aiso discourages formation of NOx due to combustion temperature control. ADVANTAGES

The following list provides the main actions carried out by the improved engine efficiency system :

Recovering and regenerating engine heat and exhaust;

Filtering and Condensing exhaust gas

Emulsifying and Atomising Gas and Water mixture;

Redirecting and recirculating a proportion of the engine's air intake flow;

Creating steam in the redirected air flow;

Introducing steam into the engine's air intake manifold;

Creating superheated steam inside the engine's combustion chambers; and /or

Capturing and recirculating gas vapour.

The components described above play critical roles in the device's operation, The device of the present invention allows the driver of a vehicle for example to ease off the gas pedal (accelerator) and reduce fuel consumptions and emissions. The device has fail safe systems, preventing excess steam and untreated exhaust gas entering the engine. The water level in the device wili remain constant. The flow of exhaust gas through the device is controlled by the engine. The exhaust gas flow to the engine is also controlled by the engine, In a typical engine, flow increases when the engine is under load or when speed increases; this provides more power to the engine when required.

A key feature to this device Ss it is progressive, providing small amounts of steam and exhaust gas over a longer period, right across the engine's operation demands. This action increases the engine efficiency by prevention carbon deposits and stabilizing the air/fuel mixture. The device does not compromise the engine's computer management system or affect automotive design regulations.

The present invention provides a design which is a less complicated system requiring no ongoing servicing. The invention design is a progressive approach to introducing steam into an engine. Where some systems require large amounts of water, this method requires relativity small amounts of water to make measurable improvements in combustion efficiency. This approach combined with the exhaust flow control at the exit point of an exhaust system increases the overall performance.

Redirecting exhaust gas at the exit point of the exhaust system/vent provides a cost effective way of installing the device, it is non-intrusive, reduces the potential of solid contaminations from re-entering the engine. When installed in a motor vehicle, the system eliminates the need for a bulky cooling device and complex condensers to recirculate exhaust gases into an engine.

Introducing steam into an engine can be done by a simple vacuum system or by a pumping system. Ultimately, the volume and timing of steam introduction is critical, too much steam can destroy an engine. Introducing steam in most applications requires replenishing the water reservoir and requires maintenance, and when used in a vehicle will add extra load. Fo any type of system to work correctly it needs to communicate with the engine. The present invention provides an apparatus and method that is an inexpensive solution to reducing emissions and fuel consumption in engines. This technology can be scaled up or down to suit any type of engine that has an exhaust gas vent.

The properties of steam have added benefits. When introduced into spark ignited engine and compression ignited engines; steam acts as a cleaner, removing carbon deposits, this also improves the engine efficiency and extends the life of the lubrication properties of oil due to a cleaner burn. Steam by absorbing heat from inside the engine's combustion chamber prevents a destructive issue known as "detonation" which is an uncontrolled explosion inside the engine caused by fuel igniting at the wrong time. One way modern engines control this issue is by adjusting the air to fuel ratio; adding more fuel reduces detonation. The fuel quality also plays a part in preventing detonation; higher quality and higher octane rating fuel equals less detonation issues. When steam is injected a lower quality/octane fuel can be used, as steam absorbs heat, thus preventing fuel from igniting to early.

Introduction of steam at idle/light load and all other operating speeds improves fuel consumption and reduces exhaust emissions. Modern engines are required to operate within strict emission output levels. They are programmed to maintain the correct air to fuel ratio in order for the catalytic exhaust converter to function effectively. Generally in colder operating temperatures, especially when the engine is at idle speed fuel consumption increases. An average engine consumes 0.6 litres of fuel for every litre of displacement. The idle fuel consumption generally increases as the ambient temperature decreases. As the engines air intake temperature decreases, oxygen levels increase. This prompts the engines control unit to add more fuel to maintain the correct air/fuei ratio. Fuel is also affected by the cooler temperatures. Fuel needs to be atomised and dose to vaporization point to burn correctly. By Introducing steam at idle the air/fuel atomization and vaporization is enhanced- Engines fitted with a throttle piate/butterfly generally do not operate efficiently at idle due to the choking of air supply. At idle the air ftow is restricted - this reduces compression pressures when the air/fuel mixture is ignited. Introducing superheated steam at idle and at ail other engine speeds and loads acts as expansion fluid which increases the engines compression pressures regardless of the choking affect at idle.

Overall steam injection into an engine reduces fuel consumption and emissions. It also provides a method to remove and prevent carbon deposits building u inside the engine. The continuous removal of carbon deposits enhances the engine's combustion efficiency and promotes a cleaner burn, as carbon traps and prevents complete burning of fuel. This cleaner burn decreases the amount of contaminates by-passing the piston and entering into the engines lubrication system. Steam injection stabilizes the air/fuei ratio, increases the thermal combustion efficiency, resulting higher engine performance and reduced exhaust volatile organic compounds. This also extends the life of an engine.

The system connections betwee the engine's exhaust vent and air intake duct and the system provide the method and means for both an engine and the system to communicate with each other, ensuring reclaimed exhaust gas and steam are delivered in time with the engine's requirements. The invention does not rely on mechanical pumps or electronic systems. Furthermore the system is a dosed loop system which utilises waste heat from the engine and condenses exhaust gas to form a working medium or water for the conversion to steam. This basically means that no added water is required to fuel the system. The steam is generated by condensing the exhaust gas to produc a working medium which when converted to steam is injected into the combustion chamber of an engine to act as an expansion fluid to increase the thermal combustion efficiency of the engine. The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scop of the invention as defined by the accompanying ciaims.