闭式氦气轮机循环建模及循环特性优化分析

Modeling and optimization analysis of helium turbine cycle

氦气闭式布雷顿循环可用作高温气冷堆热电转换装置,能够有效降低传统核电机组复杂程度,提升热电转换效率。为详细研究氦气闭式布雷顿循环特性,指导工程样机设计,基于Refprop提供的真实气体模型建立了简单、间冷、回热以及间冷-回热四种闭式布雷顿循环数学模型;然后通过对比分析方法,揭示了关键参数变化对循环特性的影响,重点阐述了间冷、回热对循环性能的作用机制。结果表明:1)回热器能够有效回收涡轮出口氦气热量,大幅提升循环热效率,并且能够降低系统达到最佳循环效率所需压比;2)间冷器虽然能够降低压缩系统功耗,但受间冷器流道内压损影响,需综合考虑系统复杂度、研制成本及循环性能等因素确定系统是否需要间冷器。

The Closed Baryton Cycle with helium gas can be used as the high temperature gas-cooled reactor power conversion unit, which can effectively reduce the complexity of traditional nuclear power plants and improve the power conversion efficiency. In order to study the characteristics of helium Closed Brayton Cycle in detail and guide the design of engineering prototypes, based on the real gas mode proved by Refprop, four Closed Brayton Cycle mathematical models were established, including simple, intercooling, regenerative and intercooling recuperator cycle. By comparative analysis the effects of key parameters on cycle performance were revealed, and the mechanism of inter cooler and regenerator on cycle performance were clarified. It is found that 1) The regenerator can effectively recover the helium heat from the turbine outlet, greatly improve the cycle thermal efficiency, and reduce the pressure ratio required by the system to achieve the best cycle efficiency;2) Although the use of an inter cooler can reduce the power consumption of the compression system, it is affected by the pressure loss in the indirect cooler flow pipeline. Whether the system needs an inter cooler, the factors such as the system complexity, development cost and cycle performance need to be considered comprehensively.