【摘要】 对提出的利用LNG冷能与低温太阳能的新型联合动力循环系统进行参数优化分析和分析,选取R143a为循环工质,研究了循环蒸发温度、透平进口温度、冷凝温度和LNG汽化压力对循环系统效率、效率和单位做功的换热面积的影响.结果表明:循环系统效率和效率随蒸发温度的升高均先升高后降低,随透平进口温度和LNG汽化压力的升高而升高;冷凝温度越高,循环系统效率和效率越低;单位做功的换热面积随各变量的变化趋势与循环系统效率和效率随各变量的变化趋势相反;当蒸发温度为298.15K、透平进口温度为353.15K、冷凝温度为213.15K和LNG汽化压力为3 MPa时,循环性能最优,在该工况下进行分析发现,换热器损占总损的80%,而泵的损最小.更多还原

【Abstract】 Parameter optimization analysis and exergy analysis were conducted for a novel combined cycle system using LNG cold energy and low-temperature solar energy.Taking R143 aas the working fluid,the effects of four independent variables,such as the evaporative temperature,turbine inlet and condensing temperature,and LNG vaporizing pressure,were studied on the cycle system efficiency,exergy efficiency and heat transfer area per unit work,etc.Results show that both the system efficiency and exergy efficiency increase first and decrease later on with the rise of evaporative temperature,which also increase with the rise of turbine inlet temperature and LNG vaporizing pressure;the higher the condensing temperature,the lower the cycle system efficiency and exergy efficiency;the change of the area of heat exchanger per unit net work with these variables is opposite with that of system efficiency and exergy efficiency.Optimum cycle performance can be obtained at the evaporative temperature of 298.15 K,turbine inlet temperature of353.15 K,condensing temperature of 213.15 Kand the LNG vaporizing pressure of 3MPa,in which case,the heat exchanger exergy loss accounts for 80%of the total cycle exergy loss,and the pump exergy loss is the minimum among all the components.更多还原