A PERFORMANCE TEST RESULT OF CHORDAL TYPE FLOWMETER USING HIGH REYNOLDS NUMBER FACILITY IN NMIJ

In this paper, test result of two performance tests of the "Chordal Type" ultrasonic flowmeter made by Cameron inc. using NMIJ's high Reynolds number calibration facility will be presented. This type flowmeter have been introduced to nuclear power plant in USA to MUR uprating. First test is the investigation of the effect of the inner roughness of the upstream pipe. In this test, the difference of the K-factor, which is one of correction factors of a flowmeter, between Ra=1.7 (mm) and 14.2 (mm) is about 0.1%. To obtain the high efficiency of MUR uprating, actual flow calibration is recommended. Second test is the investigation of the relationship between "Profile Factor" and "Velocity Ratio". As a result, the correlation obtained by calibration for many upstream conditions at Re=3.0 x 10(6) can estimate "Profile Factor" at Re=1.4 x 10(7) within +/-0.25% However, the correlation with Reynolds number does not behave as expected by theorem. To obtain the correction factor of flowmeter with high accuracy and reliability, the actual flow calibration under the same Reynolds number at the actual plant condition is the only effective method.