内可逆Ericsson循环有效功率特性研究

Study of Efficient Power Characteristic of Endoreversible Ericsson Cycle

基于有限时间热力学理论,在已有文献建立的理想回热式内可逆Ericsson循环模型基础上,导出了循环的有效功率表达式。通过数值计算,比较了循环最大功率P_(max)和最大有效功率(E_(P))_(max)对应的效率,分别分析了参数K/lnr_(p)和传热系数α对有效功率与功率、效率和工质温比x特性关系的影响。结果表明:(E_(P))_(max)对应的效率ηE_(P)大于P_(max)对应的效率η_(P),以(E_(P))_(max)为优化目标时用部分功率的损失换来了效率的提高;随着K/lnr_(p)的增大,循环(E_(P))_(max)、(E_(P))_(max)对应的工质温比x_(opt)、(E_(P))_(max)对应的功率P_(E_(P))和(E_(P))_(max)对应的效率ηE_(P)均减小;随着α的增大,循环(E_(P))_(max)、x_(opt)、P_(E_(P))和ηE_(P)均增大。研究结果可为Ericsson热机的优化设计提供新的思路。

Based on the finite-time thermodynamic theory and the ideal regenerative endoreversible Ericsson cycle model established in the previous literature,the efficient power expression of the cycle is derived.Through numerical calculations,the efficiencies on the conditions of the maximum power P_(max) and the maximum efficient power(E_(P))_(max) are compared,and the effects of parameter K/lnr_(p) and heat transfer coefficientαon the characteristic relations of efficient power and power,efficiency and working fluid temperature ratio x are analyzed respectively.The results show that the corresponding efficiencyηE_(P) in(E_(P))_(max) condition is larger than the corresponding efficiency η_(P) in P_(max) condition,and the efficiency is improved with the part loss of power when(E_(P))_(max) is taken as the optimization objective.With the increase of K/lnr_(p),the cycle(E_(P))_(max),the corresponding working medium temperature ratio x_(opt) in(E_(P))_(max) condition,the corresponding power P_(E_(P)) in(E_(P))_(max) condition and the corresponding efficiencyηE_(P) in(E_(P))_(max) condition will all decrease;with the increase ofα,the cycle(E_(P))_(max),x_(opt),P_(E_(P)) andηE_(P) will all increase.The research results can provide a new idea for the design optimization of Ericsson heat engine.