内可逆等温加热修正Miller循环功率效率特性

Power and Efficiency Characteristics of an Endoreversible Isothermal Heating Modified Miller Cycle

提出了一种对传统Miller循环改进后得到的新循环——等温加热修正Miller循环,应用有限时间热力学理论建立了内可逆等温加热修正Miller循环模型,得到了循环功率与压缩比、效率与压缩比和功率与效率的关系曲线,分析了循环最大温比、预胀比、修正Miller循环比和传热损失对循环性能的影响,并将修正前后的Miller循环性能进行了对比。结果表明:循环的功率与压缩比和效率与压缩比的关系曲线为类抛物线型,功率与效率的关系曲线为扭叶型;随着循环最大温比、预胀比和修正Miller循环比的增大,循环性能显著提升;修正Miller循环性能明显优于传统Miller循环性能。

A new cycle,i.e.,isothermal heating modified Miller cycle,is proposed by improving the traditional Miller cycle.The endoreversible isothermal heating modified Miller cycle model is established by using the finite time thermodynamic theory.The relationship curves between cycle power and compression ratio,efficiency and compression ratio,as well as power and efficiency are derived.The effects of the cycle maximum temperature ratio,pre-expansion ratio,modified Miller cycle ratio and heat transfer loss on cycle performance are analyzed,and the Miller cycle performances before and after modified are compared.The results show that the relationship curves between power and compression ratio and between efficiency and compression ratio are parabolic-like ones,while the relationship curve between power and efficiency is loop-shaped one.With the increases of pre-expansion ratio,maximum temperature ratio of cycle and modified Miller cycle ratio,the cycle performance can be improved significantly.The performance of modified Miller cycle is obviously better than that of traditional Miller cycle.