Title:
METHOD FOR MONITORING ACCURACY OF VORTEX FLOWMETER IN FLOW CONTROL SYSTEM
Document Type and Number:
Japanese Patent JPH05264306
Kind Code:
A
Abstract:
PURPOSE:To use a vortex flowmeter by fixing the aperture of a flow regulating valve and generating an alarm when both a first and second variation values exceed a set value. CONSTITUTION:The flow rate of a fluid is measured at prescribed time intervals by means of a vortex flowmeter 18 and detected values are inputted to a controller 25. The controller 25 finds a first variation value from the difference between the latest measured value FD and a value FD' measured immediately before the value FD. In addition, the manipulated variable MV of a flow regulating valve 20, butane gas temperature T, primary pressure P1, secondary pressure P2, etc., are inputted to the controller 25. The controller 25 finds the theoretical flow rate of the fluid based on the opening of the valve 20 and calculates a second variation value from the difference between the theoretical flow rate and actually measured value FD of the flowmeter 18. Then the first and second variation values thus found are respectively compared with a set value and, in case both values exceed the set value, the controller 23 discriminates that the value FD is a sudden change in flow rate and does not control the valve 20 based on the actually measured value, but maintains the valve 20 in the same fixing state. At the same time, the controller 25 generates an alarm so as to indicate that the measurement of the flowmeter 18 is abnormal.
Inventors:
Kenji Fujita
Application Number:
JP6924691A
Publication Date:
October 12, 1993
Filing Date:
March 08, 1991
Export Citation:
Assignee:
Ishikawajima Harima Heavy Industries Co., Ltd.
International Classes:
G01F1/00; G01F1/32; G01F15/00; G05D7/06; (IPC1-7): G01F1/32; G01F1/00; G01F15/00; G05D7/06
Attorney, Agent or Firm:
Toru Sakamoto (1 person outside)