有机朗肯循环系统的传递分析

Exergy Transfer Analysis for ORC System

为了分析有机朗肯循环系统能质传递和利用的动态特性,以热力学第二定律为基础建立了有机朗肯循环系统的传递分析模型。参照工程传递评价准则,应用阻流密度、流密度降低率等,完成对ORC系统的传递分析。通过与常规的分析结果,得出了一些信息:流密度降低率最高的部位为冷凝器,最低的部位为膨胀机,阻最高的部位在回热器和冷凝器;蒸发器中的阻较小,损率、流密度降低率都较高,因此有机朗肯循环节能改造的关键在于蒸发器的改造;在回热器中由于温度差小,即强度量差(温差)较小,因此推动传递的动力就较小,从而阻较大。

In order to analyze the mass of energy transfer and utilization in the ORC system, this paper based on the second law of thermodynamics, establishes the organic Rankine cycle system exergy transfer model. Referen- cing works exergy transfer evaluation criteria, completes the ORC system exergy transfer analysis. New information is obtaines by comparison with exergy analysis. The condenser is the highest parts for the rate of exergy flow density reduce and the exergy resistive highest parts is in the regenerator and condenser. Exergy resistarice in the evapora- tor is lower and the exergy loss rate, exergy current density reduction rate are higher. The transformation of the or- ganic Rankine cycle system lies in the evaporator. Because the temperature defference is lower, the power to pro- mote exergy transfer is fewer and the resistance is more.