Thermodynamic Effect and Cavitation Performance of a Cavitating Centrifugal Pump

Abstract

The thermodynamic effect which affects the cavitation performance of a cavitating centrifugal pump was investigated experimentally by using liquid nitrogen. To measure the pump cavitation performance, the test setup which can be carried out experiments using both liquid nitrogen and cold water was constructed. The cavitation performance using liquid nitrogen or cold water could be obtained from the measurement of the pump suction and delivery pressure, the pump suction and delivery temperature and the discharge flow rate. And an improvement of the pump cavitation performance due to the thermodynamic effect of the cavitation could be shown from the comparison of the experimental results between using liquid nitrogen and using cold water. From experimental results, it was indicated that the cavitation performance using liquid nitrogen was better than that using cold water. This improvement of the cavitation performance was thought to be due to the thermodynamic effect of the cavitation. And the estimated temperature depression due to the thermodynamic effect decreased with decreasing flow coefficient. Moreover, it was shown that the estimated temperature depression due to the thermodynamic effect on low cavitation performance impeller was larger than that on high cavitation performance impeller at same flow coefficient.