Landfill gas waste heat power generation is an effective way to promote the efficiency and economics of power plants. However, the operating performance of the power generation system needs to be improved further. In this paper, a systematic optimization research on the off-design characteristics of the partial heating supercritical carbon dioxide power system for exhaust heat utilization from gas turbine cycle are conducted. Optimal operating conditions in thermodynamics and economics obtained by genetic algorithm are determined as design conditions. Gradient descent method is used to obtain the best operating point under a certain off-design working condition. With the goal of maximizing net power output, separation control and inventory control are applied to the system. The results exhibit that the best thermoeconomic performance can be gained when the pressure ratio is 2.28 with separation ratio of 0.35 at design stage. In the off-design stage, the maximum net power shows an approximately linear growth trend from 1581 kW to 2924 kW with increasing heat source temperature and mass flow rate under the inventory control, while growth rate of net power output gradually decreases under the separation control. Finally, the best control scheme mixed with inventory control and separation control is proposed and determined quantitatively.

垃圾填埋气余热发电是提高电厂效率和经济性的有效途径。但发电系统的运行性能有待进一步提高。本文对用于燃气轮机循环余热利用的部分加热超临界二氧化碳动力系统的非设计特性进行了系统优化研究。通过遗传算法获得的热力学和经济学中的最佳操作条件被确定为设计条件。梯度下降法用于在一定的非设计工况下获得最佳工作点。以最大化净功率输出为目标，对系统应用分离控制和库存控制。结果表明，在设计阶段，当压力比为2.28，分离比为0.35时，可以获得最佳的热经济性能。在非设计阶段，存量控制下，随着热源温度和质量流量的增加，最大净功率从1581 kW到2924 kW呈近似线性增长趋势，而分离控制下净功率输出的增长率逐渐减小. 最后，提出并定量确定了混合库存控制和分离控制的最佳控制方案。而在分离控制下，净发电量增速逐渐下降。最后，提出并定量确定了混合库存控制和分离控制的最佳控制方案。而在分离控制下，净发电量增速逐渐下降。最后，提出并定量确定了混合库存控制和分离控制的最佳控制方案。