等温加热修正Diesel循环及其内可逆特性

Endoreversible performance of a modified Diesel cycle via isothermal heat addition

提出一种新的Diesel循环,即等温加热修正的Diesel循环,并运用有限时间热力学理论建立内可逆修正Diesel循环模型,导出循环功率与效率、功率与压缩比和效率与压缩比的特性关系,研究循环温比、预胀比和传热损失对循环性能的影响,将修正后的循环性能与传统的Diesel循环性能进行比较。结果显示:循环功率与效率的关系曲线呈扭叶型,而功率与压缩比和效率与压缩比的关系曲线均呈类抛物线型;随着预胀比和循环温比的变大,循环性能明显提升;与传统的Diesel循环相比,修正后的循环性能更优。

A new Diesel cycle,the modified Diesel cycle via isothermal heat addition,is proposed.An endoreversible modified Diesel cycle model is established by using finite time thermodynamics.The characteristic relationships of power vs.efficiency,power vs.compression ratio as well as efficiency vs.compression ratio are derived.The effects of cycle temperature ratio,pre-expansion ratio and heat transfer loss on cycle performance are studied,and the performance of the modified Diesel cycle is compared with that of the traditional Diesel cycle.The results show that the relationship curve of power vs.efficiency is loop-shaped one,the relationship curves of power vs.compression ratio and efficiency vs.compression ratio are parabolic-like ones;with the increase of pre-expansion ratio and temperature ratio,the cycle performance will be obviously improved.Compared with the traditional Diesel cycle,the modified Diesel cycle has better performance.