为优化燃气-串级超临界二氧化碳（GT-CSCO2）联合循环的变工况运行特性，建立以5.67 MW燃气轮机为原动机的GT-CSCO2联合循环模型。分别确定各设备的变工况运行方法，提出联合循环变工况运行策略，进而分析GT-CSCO2联合循环的变工况特性。研究表明：进口导叶达到最小全速角前后燃气轮机排气温度和流量随负荷变化的特性有较大改变，燃气轮机排气温度对底循环的影响大于排气压力；变工况中为维持压缩机入口温度与最终排气温度，底循环流量的减少幅度大于排气流量；负荷在100%~30%之间，GT-CSCO2联合循环热效率由54.80%降低到43.91%,净输出功率与效率约为燃气轮机单机的2倍；与简单回热结构相比，CSCO2循环具有更高的效率，是一种具有良好变工况性能的发电技术。

In order to optimize the offdesign characteristics of gas turbinecascaded supercritical carbon dioxide(GTCSCO2) combined cycle,a GTCSCO2 combined cycle model with 5.67 MW gas turbine as prime mover was established in this paper. The offdesign operation methods of each equipment were determined respectively,and the offdesign operation strategy of the combined cycle was put forward,and then the offdesign condition characteristics of the GTCSCO2 combined cycle were analyzed. The results show that the characteristic of gas turbine exhaust temperature and flow rate changes with load greatly before and after IGV reaches the minimum fullspeed angle,and the influence of gas turbine exhaust temperature on bottom cycle is greater than exhaust pressure. The decrease of bottom cycle flow rate is greater than exhaust flow rate in order to maintain compressor inlet temperature and final exhaust temperature under offdesign conditions. During the 100% to 30% load,the thermal efficiency of GTCSCO2 combined cycle reduces from 54.80% to 43.91%,and the total output power and efficiency is about twice that of a single gas turbine.Compared with simple recuperative structure,CSCO2 cycle has higher efficiency which means it is a kind of power generation technology with good offdesign performance.

江苏省基础研究计划（自然科学基金）青年基金项目（BK20210240）