燃煤发电系统热力学特性研究

Thermodynamic Characteristics of Coal-fired Power Generation System

为了解决化石燃料的使用带来的环境问题,探究了循环燃煤发电系统的热力学特性,进行了燃烧过程的热力学分析、热力学循环效率的计算。通过对循环燃煤发电系统的热力学特性进行深入分析,得出当预压缩机进气压力接近临界点时,工质的比热容会急剧增大,导致工质在低温回热器中的冷却效果变差。为了提高系统的循环效率,需要根据实际工况合理选择预压缩机进气压力。对关键设计参数进行全局优化后,部分冷却循环的性能越来越接近再压缩循环的性能,再压缩循环的主/再热气温、高压透平入口压力及各部件压降与部分冷却循环保持一致。

In order to solve the environmental problems caused by the use of fossil fuels,this paper explored the thermodynamic characteristics of the cycle coal-fired power generation system,carried out the thermodynamic analysis of the combustion process,and the calculation of the thermodynamic cycle efficiency.Through in-depth analysis of the thermodynamic characteristics of the cycle coal-fired power generation system,the results show that when the inlet pressure of the pre-compressor is close to the critical point,the specific heat capacity of the working fluid will increase sharply,resulting in a decrease in the cooling effect of the working fluid in the low-temperature regenerator.In order to improve the cycle efficiency of the system,the inlet pressure of the pre-compressor needs to be reasonably selected according to the actual working conditions.After global optimization of key design parameters,the performance of the partial cooling cycle is also getting closer to that of the recompression cycle.The main/reheat air temperature,high pressure turbine inlet pressure,and pressure drop across components for the recompression cycle are the same as those for the partial cooling cycle.