不可逆卡诺热机的性能界限

用有限时间热力学方法分析不可逆卡诺热机循环性能，考虑工质与高、低温热源问换热器的热阻损失和循环工质内部的不可逆损失，以循环周期为优化函数，导出不可逆卡诺热机最短循环周期与冷热源熵变化量的关系并得到了热力学第二定律的类比表达式，获得了最佳效率，热源熵变化量和循环周期的优化关系，由此对不可逆卡诺热机的效率、输出功率、冷热源熵变化率和工质在两个等温过程中的温度等参数作了较详细的讨论，所得结论可为不可逆卡诺热机的优化设计和最佳工况选择提供新的理论途径。

Performance limits of irreversible Carnot engine

Performance analysis has been performed for irreversible Carnot engine cycles using the finite time thermodynamics. The irreversibilities involve heat resistance losses in high and low temperature side heat exchangers and internal dissipation of working fluid. The cyclic time is taken as an objective function for optimization. The minimum cyclic time is described in terms of entropy changes in reservoirs, and then an analogue of the second law of thermodynamics is derived. The optimal relation between efficiency, entropy changes in reservoirs and cyclic time is achieved. They are used to discuss the efficiency, power output, rate of entropy change in reservoirs, and temperatures of working fluid in the isothermal processes of engine.