Reconstructing Heat Exchange Matching for Zeotropic Mixtures Based on Active Vapor-liquid Adjustment
Zeotropic mixtures has temperature glide characteristics during phase transition,leading to a matching with the temperature variation of heat or cold sources.However,the nonlinear of temperature-enthalpy relationship disables the perfect matching,resulting in large irreversibility in heat exchange.Base on the thermodynamic properties of zeotropic mixtures and the principle of active vapor-liquid adjustment,this paper proposes to reconstruct heat exchange matching for zeotropic mixture.According to entransy analysis,the irreversibility during the heat exchange process is correlated with mass flow rate and equivalent specific heat capacity.Liquid-separation leads to an increased slope of refrigerant heat exchange curve,while liquid refilling causes a reduction in temperature.The heat exchange model featured with active vapor-liquid adjustment is built.Both single-objective and multi-objective optimizations are conducted.The results show that active vapor-liquid adjustment can reduce the total entransy dissipation rate by 8.7％and heat exchange area by 9.7％when working with R170/R290.This confirms the reduction in irreversibility and enhancement of heat transfer performance simultaneously.
active vapor-liquid adjustmentzeotropic mixturesnonlinearthermal matchheat transfer enhancement
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