带回热两级喷射制冷循环的特性分析

Performance Analysis on Two-stage Ejection Refrigeration System with Internal Heat Exchanger

为了提高喷射制冷系统的性能系数,建立了双热源驱动的带回热两级喷射制冷循环的理论计算模型。以纯工质R236fa为研究对象,讨论回热对单工质两级喷射制冷系统性能的影响,并与传统单级喷射系统性能进行比较。最后利用?分析比较传统单级系统和新型两级喷射系统的?损情况。研究结果表明,在相同工况下,当系统采用单工质时,加回热的系统性能更优,系统的性能系数可以提高约15%~20%,相对于传统的单级系统可以提高50%以上,其?效率相对传统单级喷射系统更具明显优势。

In order to improve the COP of ejector refrigeration system, a theoretical calculation model of two-stage ejectorrefrigeration system with internal heat exchanger driven by two heat sources is built. R236fa is chosen as working substance tostudy the influence of internal heat transfer on system performance, which is compared with that of traditional single-stage ejectionrefrigeration system. Finally, exergy analysis is performed to compare the exergy loss of pure refrigeration single-stage system andpure refrigerant two-stage ejector system. Research results indicate that under the same working condition, by adding internal heatexchanger, the performance of pure substance eject refrigeration system can be enhance by 15% ～20%, which is more than 50%higher than that of traditional single-stage system, which exergy efficiency compared to conventional single-stage ejector systemmore obvious advantage.