基于动态特性的S-CO_(2)布雷顿循环构型对比

Comparison of Dynamic Performance of Different S-CO_(2) Brayton Cycle Configurations

S-CO_(2)布雷顿循环因其结构紧凑和热效率高等优点而被认为是最具有发展前景的动力系统之一。不同构型的动态特性对构型优选至关重要。本文基于Matlab/Simulink搭建了简单回热、再压缩和再热三种S-CO_(2)布雷顿循环构型的动态模型,并探究了不同构型在热源温度阶跃下的开环特性和控制冷端温度下的负荷追踪特性。结果表明,三种构型均可以在控制冷端温度的前提下实现负荷的及时追踪。在设计工况下再热构型的热效率高于再压缩构型,但随着负荷的下降,结果则相反。

The S-CO_(2)Brayton cycle is considered as one of the most promising power systems due to its compactness and high thermal efficiency. The dynamic performance of different configurations is crucial to the selection of optimum configurations. In this paper, dynamic models of three S-CO_(2)Brayton cycle configurations of simple reheat cycle, recompression cycle and reheat cycle is built based on Matlab/Simulink. The open-loop performance of different configurations under step change of the heat source temperature and load tracking with controlled cold-end temperature are investigated. The results show that all configurations can track the load timely with well controlled cold-end temperature. Notably, the thermal efficiency of the reheat cycle is higher than that of the recompression cycle under design conditions, but as the load decreases, the result is opposite.