无水坝抽水蓄能系统高压溶气问题研究

无水坝抽水蓄能系统利用封闭容器内的高压气体构建虚拟水坝,是兼具压缩空气储能和抽水蓄能优点的新型储能系统。但该系统的封闭容器内水和气在高压状态共存有可能造成水中溶气,从而对水轮机造成汽蚀等破坏。本文采用实际气体状态方程及分子动力学模拟方法,研究了宽广的压力、温度范围下气体在水中的溶解及扩散规律,揭示了水中气体溶解量随时间和水深的变化规律。研究结果表明释能结束后保证水-气共容舱内剩余水的高度大于0.5 m时,高压溶气不会对水轮机产生危害,该结论对系统的工程应用及推广具有指导意义。

Analysis of the High Pressure Air Solution in Constant-pressure Pumped HydroCombined With Compressed Air Energy Storage System

The Constant-pressure Pumped Hydro Combined with Compressed Air Energy Storage(CPHC-CAES) System is a novel energy storage system, which has combined the advantages of compressed air energy storage and pumped hydro energy storage system. The CPHC-CAES constructs a virtual dam in a closed vessel with the help of high pressure air. However, the high pressure air may solute in the water and resulting in the cavitation damage in turbine. In this paper, the dissolution and diffusion of air in water were studied under a wide range of pressure and temperature. With the help of real gas equation of state and molecular dynamics simulation, the variation of the amount of dissolved gas in water with the change of time and depth were proposed. The results show that the cavitation damage would not appear in turbine when the depth of water is higher than 0.5 m after discharging process.