不同超临界CO_2布雷顿循环性能的对比研究

Comparative Analysis About the Cycle Performance Between Different S-CO_2 Brayton Cycles

以超临界CO_2布雷顿循环为研究对象,分析了5种不同S-CO_2布雷顿循环的性能差异,分析了循环最低压力、最低温度、最高压力、最高温度等参数对循环效率的影响及不同循环的效率对比,研究了不同循环在主要参数相同情况下透平及压缩机的做功情况;分析了再热压力、预压缩压力及循环压比对循环效率的影响。结果显示,S-CO_2循环中增加再热环节及预压缩环节都可以提高系统循环效率,不过增加再热环节后循环效率提升更明显;对再压缩循环中包含再热及预压缩环节的循环,分别存在一个最佳的循环压比、再热压力、预压缩压力使得循环效率最高。

Because of the better output stability,the concentrated solar power has a wide application prospect, but its cost is high. The cost may be reduced greatly when it used the supercritical CO2 power cycle in the future. In order to analyze the characteristic of some different S-CO2 Brayton cycles, a comparison on the cycle performance was made between 5 different S-CO2 Brayton cycles, the effect of the key parameters such as the max cycle pressure, the max cycle temperature, the min cycle pressure and the min cycle temperature on cycle efficiency was analyzed, the effect of the reheat pressure, the pre- compression pressure and the cycle compression ratio on cycle efficiency was analyzed. The results show that an added reheat or pre-compression structure can increase the cycle efficiency, and the reheat structure has a better effect. There is an optimal pre-compression pressure, reheat pressure and cycle compression ratio that made the cycle efficiency optimal.