Effect of flow rate on the gas-liquid two-phase pressure drop in the evaporative cooling generator stator bar

Abstract

In the design of generator evaporative cooling circulation system, usually by using M-N equation, the magnification of the single-phase pressure drop of two-phase frictional pressure drop is determined by the exit steam quality, that the two-phase pressure drop is composed solely of frictional pressure drop, without considering the acceleration pressure and gravity drop, also does not pertain to the effect of flow rate on pressure drop, will bring greater error. This paper aims to improve the accuracy of pressure drop, determination of magnification of two-phase frictional pressure drop of the flow rate and the outlet of the steam quality in common, and combined with the L-M equation and M-N equation, calculated and corrected two-phase frictional pressure drop. Based on the operating conditions of the 400MW evaporative cooling hydro generator, a test platform is established, the two-phase pressure drop impact test by the flow and outlet steam quality. Through the test data and theoretical calculation results show that: the acceleration pressure drop is an important part of two-phase pressure drop, should be independent accounting, and with the increase of flow rate of two-phase pressure drop in the proportion increase; In the range of experimental flow (m=1.33g/s∼4.69g/s), the magnification of two-phase frictional pressure drop calculated values and experimental values of the error is within 10%, can better meet the needs of industrial applications.