【摘要】 为了研究液化天然气冷能和核工业余热相结合的高效利用方式，构建双级串联联合循环（TTC）和双级并联联合循环（TPC）系统。分析了工质冷凝温度和液化天然气（LNG）汽化压力对系统性能的影响。将6种工质作为备选，以净输出功最大为目标函数，采用遗传算法对系统的参数进行优化。结果表明，系统均存在最优冷凝温度，使系统净输出功达到峰值。TTC和TPC系统的最优工质组合分别为C₂H₆+C₂H₄F₂和C₂H₄F₂+i-C₄H₁₀。在最优工况下，TTC系统展现出了更高的净输出功、热效率和火用效率。与此同时，TPC系统所需换热面积显著增加，这可能对其经济性产生一定负面影响。更多还原

【Abstract】 In order to investigate the cold energy of liquefied natural gas（ LNG） and nuclear industrial waste heat efficient utilization,two-stage tandem cycle system（ TTC） and two-stage parallel cycle system（ TPC） were established. Effects of condensation temperature and LNG vaporization pressure on system performance were analyzed. Six working fluids were selected as candidates,with the objective function of maximizing net power output,genetic algorithm was utilized to optimize the system parameters. The results show that there exists a first-stage and second-stage condensation temperature making the performance of the TTC and TPC system optimal. The optimal working fluids for TTC and TPC systems are C₂H₆+C₂H₄F₂and C₂H₄F₂+i-C₄H₁₀,respectively. In optimal conditions,the TTC system demonstrates higher net output power,thermal efficiency and exergy efficiency,while the TPC system required heat exchange area has significantly increased,which may have an impact on system economy.更多还原