内可逆工质恒比热Meletis-Georgiou循环有限时间热力学建模与性能优化

Finite-Time Thermodynamic Modeling and Optimization of Endoreversible Meletis-Georgiou Cycle with Constant Specific Heat of Working Fluid

应用有限时间热力学理论建立内可逆工质恒比热Meletis-Georgiou(MG)循环模型,导出循环各点温度、循环功、效率等性能参数表达式,并对MG循环性能进行分析和优化。应用数值计算方法,得到循环功与效率特性关系;分别以循环功和效率为目标,对压缩比、转换比、过膨胀比进行优化并得到一系列优化结果;分析了传热损失及循环各参数对循环性能与优化结果的影响。所得结果对实际MG发动机的设计优化有一定指导作用。

An endoreversible Meletis-Georgiou （MG） cycle model with constant specific heat of working fluid has been established and the analytical formulae of performance parameters including each point temperatures, work output and efficiency are derived by using the finite time thermodynamic theory. The performance of the MG cycle is analyzed and optimized. The relation between work output and efficiency is obtained by detailed numerical examples. Taking the work output and efficiency as objectives, a series of optimal results are obtained by optimizing the compression ratio, changeover ratio and over-expansion ratio. The effects of the heat transfer loss and design parameters on the cycle performance and optimization are analyzed. The results may provide guidelines for the optimal design of practical MG engine.