To utilize solar energy efficiently, a thermodynamic model of Rankine-EVI (with efficiency by secondary suction) Vapor Compression refrigeration system was established. Under the proposed working conditions, working fluid R236fa, R245fa, RC318 and R141b were selected and compared by investigating the effects of generating temperature, condensation temperature, condensing temperature, evaporation temperature, expander isentropic expansion efficiency and compressor isentropic compression efficiency on the system performance to identify suitable working fluid which may yield high system efficiencies. The calculated results showed that R141b was the most appropriate working fluid for the system. Condensation temperature and condensing temperature had important influences on system performance. The COPs reached 0.2528 when the generating temperature was 85oC, the condensation temperature was 40oC, the condensing temperature was 40oC and the evaporation temperature was-15oC. The application of EVI technology has a great advantage in north areas with rich solar energy and low ambient temperature.%为有效利用太阳能，以有机朗肯-喷气增焓（带二次吸气的增效）蒸汽压缩式制冷系统为研究对象，建立了系统的热力学模型，分别选取R236fa、R245fa、RC318和R141b作为系统工质，研究了发生温度、凝结温度、冷凝温度、蒸发温度、膨胀机等熵膨胀效率及压缩机等熵压缩效率对系统性能的影响，并以系统性能最佳为目标对工质进行了优选。计算结果表明：对整个系统而言，R141b是最合适的工质，凝结温度和冷凝温度对系统性能有重要影响。以 R141b 为例，当发生温度在85℃、凝结温度为40℃、冷凝温度为40℃、蒸发温度为-15℃时，系统COPs达到0.2528，采用喷气增焓技术对于环境温度很低、太阳能资源丰富的北方地区具有很大的优势。
展开▼
