60 MW超临界CO_2分流再压缩闭式循环热力性能优化分析

Analysis and Optimization on Thermal Performance of a 60 MW Supercritical CO_2 Recompression Closed Brayton Cycle

针对60 MW超临界CO_2分流再压缩闭式循环建立数学模型,采用Matlab语言编制程序,研究各循环参数对循环效率和循环功率的影响,并对循环参数进行了优化,根据优化结果给出60 MW超临界CO_2间接加热闭式循环参数方案。结果表明:随着透平进气温度的升高,循环效率与循环功率线性升高,但由于CO_2在临界点附近的物性呈非线性变化以及低温回热器冷端端差的约束限制,分流比、透平进气压力、主压缩机进气温度与压力等参数对循环效率的影响呈现非单调变化关系。

A mathematical model was established for the 60 MW supercritical CO2 recompression closed Brayton cycle to study the effects of various cycle parameters on the cycle efficiency and cycle power using Matlab language.The cycle parameters were then optimized,after which,optimal parameters were finally presented for the 60 MW supercritical CO2 recompression closed Brayton cycle.Results show that the cycle efficiency and cycle power increase linearly with the rise of turbine inlet temperature;however,the cycle efficiency varies non-monotonically with the split ratio,turbine inlet pressure,and main compressor outlet temperature and pressure,due to the highly non-linear change of carbon dioxide properties near critical point and the constraints of pinch point.