Ecological Efficient Power Performance for an Endoreversible Closed Braysson Cycle with Constant-temperature Heat Reservoirs
Based on the finite-time thermodynamic theory and endoreversible closed Braysson cycle model with constant temperature heat reservoirs established in previous literature,this paper studies the cycle performance characteristics with ecological efficient power(Eη)as the objective function.The expression ofEηis derived.Through numerical analysis method,the effects of heat capacity(Cwf)of working fluid,logarithmic temperature ratio(x)of working fluid and thermal conductivity distribution(u)onEηare analyzed.The performance differences are compared when cycle works under the maximum dimensionless ecological efficient power Eη,the maximum dimensionless powerPmax,the maximum dimension-less ecological function Emax and the maximum efficient power EP,max conditions.The results show that there are the optimal logarithmic temperature ratio(xopt)of working fluid and optimal thermal conductivity distribution(uopt)to maximize the cycle Eη with the given Cwf.With the given x and u,Eη decreases with the increase of Cwf.When the design objective is changed from other objectives to Eη,the efficiency can be improved with the sacrifice of part power.
万方数据
维普
