|
|
Experimental study on liquid jet pump based on cyclic symmetrical aeration |
LI Mengqiu, CHEN Yunliang*, HUA Youming, XU Yong |
State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China |
|
|
Abstract In order to improve the performance of liquid jet pump, a method of cyclic symmetrical aeration in the throat was proposed. Through the hydraulic experiments of jet pump, the basic perfor-mance and cavitation characteristics of different flow ratios under different aeration conditions were studied. The results show that when the throat is aerated properly, the pressure ratio increases slightly when the limit flow ratio is not reached, and the increment of efficiency change rate is 0.3%-4.9% and more obvious when the flow ratio is close to the critical flow ratio. Under extreme working condition, aeration can improve cavitation performance and the measured pressure pulsation of throat and diffuser is obviously weakened.Moreover, the increase of critical flow ratio indicates that the normal working range is enlarged after aeration. The optimum aeration rate(volume flow ratio of air to mixture)is about 2%-3%. The research shows that compared with water, the viscosity coefficient of air is much smaller than water and a small amount of air is carried by the liguid and flows against the inner wall, which can reduce the flow resistance near the wall, and also reduce the frictional head loss. Therefore, the efficiency of jet pump will be improved. Under extreme working conditions, natural gas inhalation can increase the pressure in the throat, reduce cavitation and improve the operation perfor-mance of the jet pump. The research results of cyclic symmetrical aeration can provide a reference basis for the performance optimization of liquid jet pump.
|
Received: 21 January 2021
|
|
|
|
|
|
|