中文摘要：

建立了考虑工质变温热容、热漏、有限时间传热、摩擦损失、非等熵绝热压缩和非等熵绝热膨胀过程的空气标准的不可逆Miller热机循环模型。应用有限时间热力学理论导出了该模型下的输出功率和效率的解析表达式。通过数值计算，得出了输出功率与效率之间的关系，并作图来反映它们的变化情况。讨论了热漏损失、摩擦损失、内不可逆性和工质变温热容对该热机各种性能参数的影响，同时给出了一些重要参数的优化范围。所得结果对实际Miller热机的优化设计提供了理论依据。

英文摘要：

An irreversible gas Miller heat engine cycle model, in which the primary irreversibilities are taken into account, such as the temperature-variable heat capacities, the non-isentropic adiabatic compression and expansion processes, finite-time heat transfer processes, and heat leak loss and the friction loss, is set up in this paper. Based on finite time thermodynamics the analytical expressions of the power output and efficiency are derived. The optimal relations between the power output and the efficiency of the Miller cycle are shown by numerical example. Moreover, the influence of heat leak loss, friction loss, internal irreversibility and temperature-variable heat capacities on the performance parameters of the Miller heat engine is discussed. The results obtained here may provide some significant guidelines for the optimal design and operation of the practical Miller heat engines.