太阳能-动力复合驱动制冷循环的能量互补分析

Energy Interdependent Mechanism of Hybrid Refrigeration Cycle Driven by Solar Heat and Mechanical Work

低温太阳能集热器的效率高、成本低,但获取的热源温度偏低(<100℃),难以制取0℃以下的冷量。因此,本文提出采用太阳能-动力复合驱动的氨水制冷循环。为了剔除热和功的品位不同对复合制冷循环评价的困扰,本文采用热驱动性能系数(w)和热驱动制冷率(a)进行循环性能评价。采用Aspen Plus过程模拟软件,对复合制冷循环进行了模拟计算,考察了压缩机出口压力变化对低品位热在复合制冷循环中利用率的影响,分析了复合制冷循环中两种品位不同的能量在复合制冷过程中的互补机理。结果表明,在压缩机出口压力变化的过程中,存在最佳出口压力范围,使得复合制冷循环的性能最优。

This paper focused on how to establish an effective refrigeration system using low-temperature solar heat owing to the low-temperature solar collector held the advantages of high solar collection efficiency and low cost. However, the temperature was too low to power the single effect absorption refrigeration cycle for making the refrigeration below 0℃. Therefore, the hybrid ammonia- water refrigeration cycle, which consisted of an absorption-compression combined refrigeration cycle powered by low-temperature solar heat and mechanical work, was adopted. Two new criteria, i.e. the heat powered coefficient of performance (w) and the heat powered refrigeration ratio (a), were used to evaluated the cycle. They could not only be used to assess the situation of low-temperature heat used in the hybrid cycle, but also could be used to decide whether it has positive effect on combining absorption cycle and compression cycle to the hybrid cycle. By means of Aspen plus, the hybrid cycle was simulated and the energy interdependent mechanism of compressor pressure increasing on the solar heat utilization performance was studied. It was found that, in a certain range, there was an optimum compressor outlet pressure region, where the hybrid cycle had the maximum performance.