Application of a Vortex Shedding Flowmeter to the Wide Range Measurement of High Temperature Gas Flow

摘要

A single flowmeter was required for helium gas measurement in a Gas Cooled Fast Breeder Reactor loss of coolant simulator. Volumetric flow accuracy of +-1.0% of reading was required over the Reynolds Number range 6 x 10 exp 3 to 1 x 10 exp 6 at flowing pressures from 0.2 to 9 MPa (29 to 1305 psia) at 350 exp 0 C (660 exp 0 F) flowing temperature. Because of its inherent accuracy and rangeability, a vortex shedding flowmeter was selected and specially modified to provide for a remoted thermal sensor. Experiments were conducted to determine the relationship between signal attenuation and sensor remoting geometry, as well as the relationship between gas flow parameters and remoted thermal sensor signal for both compressed air and helium gas. Based upon the results of these experiments, the sensor remoting geometry was optimized for this application. The resultant volumetric flow rangeability was 155:1. The associated temperature increase at the sensor position was 9 exp 0 C above ambient (25 exp 0 F) at a flowing temperature of 350 exp 0 C. The volumetric flow accuracy was measured over the entire 155:1 flow range at parametric values of flowing density. A volumetric flow accuracy of +- % of reading was demonstrated. (ERA citation 06:016865)