| 摘要 |
PURPOSE:To measure the flowing speed of fluid at high temperature under high pressure highly accurately by measuring the average propagating speed of an ultrasonic waves at the wedge parts of ultrasonic-wave transceivers which are provided at the upstream and the downstream at small directing angles and a pipe wall, substituting the speed into a specified function, and determining the speed of the fluid in the pipe. CONSTITUTION:Similar ultrasonic-wave transceivers 1 and 2 having the small directing angles, the long wedge parts and the high temperature limits of ultrasonic-wave piezoelectric transducers 1A and 2A are arranged on the upstream side and the downstream side of a pipe 3 at a specified distance Lx. Transmitting and receiving circuit parts 11 and 12 are switched through a transmission/reception switching part 10. The propagating time of the ultrasonic wave which is reciprocating between the wedge parts of the transceiver 1 and the like is counted with a clocking means 13. Thus, the average propagating speed C at the wedge part and the ultrasonic-wave propagating speed C' of the ultrasonic wave which is propagating in the pipe wall are measured and stored in a first memory 14. When hot metal is used at this time, the linearly changing speeds C1 and C'1 are stored in the memory 14 together with the temperature. The function of the expression I is used based on the propagating times td and tn of the ultrasonic wave which is propagating through the fluid from the upstream side and the downstream side based on the stored values. Then, the fluid flowing speed at high temperature under high pressure is measured accurately. |
