Helium gas (He-gas) / Lithium Lead (LiPb) Dual-cooled LiPb (DLL) blanket is one of the promising candidates for the DEMO fusion reactor for power generation. Brayton cycle based on He-gas has been used as the power generation system for the fusion and fission power reactors. In this work, a modified and efficient design of the power generation system with concept of two stage expansions and one intercooler named as Schematic-I has been proposed for the DLL blanket of Fusion Power Reactor (FDS-II) to increase the thermal performance (e.g. power density and efficiency) of the system and optimized the parameters of the system. The engineering equation solver tool was used to calculate the performance of the system. It is found that the use of more than one expansion stage with proper selection of intercooler is very effective as compared with either splitting the flow equally for the expansion in two turbines or a single stage expansion. The concept of two-stage expansions in the Schematic-I increased the thermal efficiency of the system up to 51%, which was 4% higher than previous design of DLL blanket power generation system. The main parameters of the system such as isentropic efficiency of turbine and compressor, pressure ratio, recuperator performance, the terminal temperature difference of the recuperator, the inlet temperature of DLL blanket and effect of different pressures on the system have all been analyzed and optimized to achieve high performance.

氦气（He-gas）/锂铅（LiPb）双冷却LiPb（DLL）毯是用于DEMO聚变反应堆发电的有前途的候选人之一。基于氦气的布雷顿循环已被用作聚变和裂变动力反应堆的发电系统。在这项工作中，针对聚变动力反应堆（FDS-II）的DLL覆盖层提出了一种改进的高效发电系统设计，该设计具有两级扩展和一个名为Schematic-I的中冷器的概念，以提高热性能（系统的功率密度和效率），并优化了系统参数。工程方程求解器工具用于计算系统性能。据发现，用中间冷却器的适当选择使用一个以上的膨胀阶段的是与任一分裂同样的流动在两个涡轮膨胀或单级膨胀相比，是非常有效的。Schematic-I中的两阶段扩展概念使系统的热效率提高了51％，比DLL毯式发电系统的先前设计高出4％。分析并优化了系统的主要参数，例如涡轮和压缩机的等熵效率，压力比，换热器性能，换热器的终端温差，DLL覆盖层的入口温度以及不同压力对系统的影响，实现高性能。Schematic-I中的两阶段扩展概念使系统的热效率提高了51％，比DLL毯式发电系统的先前设计高出4％。分析并优化了系统的主要参数，例如涡轮和压缩机的等熵效率，压力比，换热器性能，换热器的终端温差，DLL覆盖层的入口温度以及不同压力对系统的影响，实现高性能。示意图I中的两阶段扩展概念使系统的热效率提高了51％，比DLL毯式发电系统的先前设计高出4％。分析并优化了系统的主要参数，例如涡轮和压缩机的等熵效率，压力比，换热器性能，换热器的终端温差，DLL覆盖层的入口温度以及不同压力对系统的影响，实现高性能。