Measurement and Calibration of Thermal Cross-Correlation-Based Flowmeter Operating in Harsh Environment

In the harsh environment present in nuclear reactors, due to degradation caused by corrosion and/or erosion, the available nonintrusive flow rate measurement devices are capable of working only for a short period of time. The transit-time-based flowmeter using thermocouples (TC) with grounded stainless steel shielding is by far the most robust and reliable solution to this problem. This method suffers from a few signal processing problems, such as flat peak plateau or multiple peaks that result in wrong transit-time estimation. We have previously introduced a signal processing technique to correct the transit time estimation. However, as we conducted experiments, the calculated flowrates using the estimated transit-time are not in good agreement with readings from a standard flowmeter. To adjust the calculated flow, in this paper, we apply a regression method through the calibration process with measurements obtained from a standard flowmeter using an in-house developed apparatus. We observe a nearly linear relationship between the readings from the standard flowmeter and those from our flowmeter for flowrates ranging from 0.5-3 gpm (gallon per minute). The calibration results are quite consistent across different experiment scenarios.