TFE-E181高温型第二类吸收式热泵热力过程分析

Analyses of thermodynamic cycle of Type II high temperature absorption heat pump using TFE-E181 as working fluids

TFE-E181是一种新型工质对,尽管TFE和E181的沸点差较大,工质与吸收剂分离不需采用精馏器,但仍有微量的E181进入蒸发器中.为了避免E181在蒸发器中累积而影响系统的稳定操作,采用蒸发器回流方式将累积在蒸发器中的E181回流到发生器中,并对具有这种回流方式的第二类吸收式热泵的热力循环过程进行了模拟计算.研究了高压区压力对蒸发器回流比、进入吸收器工质量、回流液浓度、系统性能系数、灯用效率的影响规律.发现吸收温度、换热器效率、发生温度、冷凝温度对系统性能系数、蒸发器回流比、放气范围、灯用效率有一定影响.分析所得的规律可为TFE-E181高温型吸收热泵性能的提高及优化设计提供必要的理论依据.

TFE-E181 is a new working pairs. Although having large difference in the boiling point between TFE and E181, there is still rare E181 being out of the generator and accumulating in the evaporator. In order to ensure the system's operation being steady, the E181 accumulated in the evaporator should be refluxed back to the generator, so the reflux from the evaporator to the generator was adopted. The thermodynamic cycle of the Type II high temperature absorption heat pump with this reflux and using TFE-E181 as working fluid was researched. The effects of pressure at high pressure zone on the system's COP, the reflux ratio of evaporator, the mass flow rate into absorber, concentration of refluxed liquid and exergetic efficiency were analyzed. Absorption temperature, exchanger efficiency, generation temperature, condensation temperature can affect system's COP, the reflux ratio of evaporator, gas-emission scope and exergetic efficiency. The results can be helpful to improve the system's performance and optimize the design of the system.