液体活塞近等温压缩空气储能过程热力性能评估

Thermodynamic Performance Evaluation of the Near-Isothermal Compressed Air Energy Storage System with Liquid Piston

为进一步实现液体活塞在压缩空气储能过程全局热力性能的准确与快速评估,建立了基于容器尺寸(a)和喷淋参数(b)的储能过程热力性能无量纲评价模型,探究了压缩空气在近等温储能过程的热力性能变化特性,进而明确了液体活塞设备在近等温压缩空气储能系统中的重要地位。研究结果表明:无喷淋条件下,空气侧相对温度在无量纲a达到120时变化平缓,此时液体活塞可实现接近等温压缩,而较小的a会导致空气相对温度剧烈变化;喷淋条件下,近等温压缩过程主要出现在压缩过程中期,且增加无量纲b导致a对空气侧相对温度的影响逐渐弱化;液体活塞近等温压缩空气的理想运行效率可达到95%以上,而采用D155-30型号水泵驱动的液体活塞近等温压缩储能过程仅能实现66%的运行效率。

In this paper,a dimensionless evaluation model is established based on the container size(a)and spray parameter(b)to realize the accurate and rapid evaluation of the global thermodynamic performance in the near-isothermal compressed air energy storage process with a liquid piston.Research is conducted on the variation of thermodynamic parameters during the near-isothermal compressed air energy storage process.Finally,the significant effect of liquid piston on the compressed air energy storage system is clarified.The results show that,without spraying,the air-side relative temperature changes gently when the dimensionless number of a reaches 120,which indicates that the liquid piston can realize near-isothermal compression.However,a smaller value of a can result in dramatic change of the air-side relative temperature.Under the spraying condition,the near-isothermal compression mainly occurs in the middle stage of the compression process,and the increase of the dimensionless number of b can weaken the effect of a on the air-side relative temperature.The efficiency of near-isothermal compression with a liquid piston can be higher than 95%under ideal conditions,but with a D155-30 water pump under experimental conditions,it can only be 66%.