重型卡车朗肯-朗肯制冷系统热力学研究

Theoretical Study on the Rankine-Rankine Refrigeration Cycle System Driven by Heavy Truck Waste Heat

本文针对重型卡车发动机冷却液余热工况,采用R245fa作为循环工质建立了朗肯-朗肯制冷系统,剖析了此系统的基本原理和结构特点,根据系统分析建立了数学模型,模拟分析了发生温度、冷凝温度、蒸发温度对系统性能的影响。结果表明:在发生温度85℃、冷凝温度50℃、蒸发温度5℃时,系统COP达到0.254,虽然此系统的效率要低于相同工况下的吸收制冷循环,但是朗肯-朗肯制冷系统相对于吸收制冷系统具有尺寸小、易于控制和快速响应等优点,利用朗肯-朗肯循环回收重型卡车发动机冷却液余热迚行制冷是可行的。

The paper established a Rankine-Rankine refrigeration cycle system driven by heavy truck engine coolant waste heat, which uses R245fa as working medium. The basic principle and structural characteristics of the system are analyzed. According to the system analysis, the mathematical model is established. The effects of generating temperature, condensation temperature and evaporation temperature on the system performance are investigated. The COP reaches 0.254, when the generating temperature is 85oC, the condensation temperature is 50oC and the evaporation temperature is 5oC. The Rankine-Rankine refrigeration cycle system has the advantages of small size, easy to control and fast response, although the COP is lower than that of the absorption refrigeration under the same condition. We can believe that Rankine-Rankine refrigeration cycle system is feasible to recovery engine coolant waste heat.