AA-CAES系统释能过程运行特性分析

为了研究释能过程中膨胀机运行特性对先进绝热压缩空气储能(AA-CAES)系统性能的影响,提出3种膨胀机运行方式:定压运行、定滑运行和滑压运行,并建立AA-CAES系统热力学模型。使用数值计算的方法,对比3种方式的系统性能差异,并分析关键参数对采用不同方式的系统性能的影响。计算结果表明:基本运行参数相同时,膨胀机采用滑压运行时储能效率和储能密度最大;适当调整储气压比差值,可改善3种方式的系统性能;存在最佳换热器效能使得3种运行方式的储能效率最大;膨胀机效率下降系数对定滑方式的影响最大;3种方式的稳定间隔时间较接近,对流换热系数增加到一定值时,不存在稳定间隔时间。

ANALYSIS OF OPERATION CHARACTERISTICS ON DISCHARGE PROCESS OF AA-CAES SYSTEM

To investigate the influence of operation characteristics of expander on the performance of advanced adiabatic compressed air energy storage(AA-CAES)system in the discharge process,this paper puts up with three operation modes of expander,which include constant-pressure mode,constant-sliding-pressure mode and sliding-pressure mode,and establishes the thermodynamic model of AA-CAES system.Systems’performance difference of three modes and the influence of critical parameters on the performance of systems which adopt different modes are analyzed by employing the method of numerical calculation.The result of calculation shows that energy storage efficiency and energy storage density of the last mode are all the biggest,when basic operation parameters are identical.Systems’performance of three modes can be improved by adjusting the difference of storage pressure ratio properly.There is the optimal heat exchanger efficiency which makes three modes’energy storage efficiency biggest.Efficiency-dropping coefficient of expander has an biggest effect on constant-sliding-pressure mode.The steady interval time of three modes is very close and there is no the time when heat transfer coefficient reaches certain number.