排ガス流量測定方法 - Research Institute for Road Safety and Environment

Title:

排ガス流量測定方法

Document Type and Number:

Japanese Patent JP4032115

Kind Code:

B2

Abstract:

To provide, in place of a CVS method, a novel exhaust gas flow rate measuring method which can accurately and swiftly measure an exhaust gas flow rate of an automobile without affecting an exhaust system.

In an exhaust gas flow having catalyst system of honeycomb structure, pressures of exhaust gas before passing through the catalyst system and after passing through the catalyst system are measured, and based on a difference of the measured pressures, a volume flow rate of the exhaust gas is found thereby measuring the exhaust gas flow rate. The volume flow rate Q is calculated based on the pressure difference ▵p of the exhaust gas before and after passing through the catalyst system from a following equation. Q=πd4n/128L(1/μ)▵p, where d: a diameter (mm) of each of capillary tubes constituting the honeycomb structure, L: length (mm) of each of the capillary tubes, n: the number of capillary tubes, and μ: a coefficient of viscosity of the exhaust gas.