Abstract The present paper evaluates numerically the feasibility of a solar jet-ejector refrigeration system from an efficiency maximization perspective with three low environmental impact refrigerants, namely, R1234yf, R1234ze and R600a. Special emphasis is given to the jet-ejector internal geometry optimization as a mechanism to improve the overall cycle performance. The jet-ejector entrainment ratio in different operating conditions and geometric configurations is determined by using a Computational Fluid Dynamics (CFD) approach experimentally validated which includes real gas models of R1234yf, R1234ze and R600a. R1234yf exhibited the best performance in terms of overall system efficiency closely followed by R600a and R1234ze. This suggests that the influence of the working fluid can be considerably mitigated if a thorough design of the jet-ejector is carried out. Afterwards, the refrigerant R1234yf is selected to carry out sensitivity studies with different collector typologies and solar irradiation scenarios. The Evacuated Tube Collector (ETC) model provided the highest overall system efficiency ( η ov = 0.213 ) for the peak solar irradiation (1000 W / m 2 ). Nevertheless, one of the Parabolic Trough Collectors (PTC) models under investigation offered the most robust performance if a wider range of solar irradiation scenarios is considered.

中文翻译：

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太阳能辅助射流喷射制冷系统的数值评价：环保制冷剂的筛选

摘要 本文从效率最大化的角度用三种对环境影响低的制冷剂，即 R1234yf、R1234ze 和 R600a，对太阳能射流喷射器制冷系统的可行性进行了数值评估。特别强调射流喷射器内部几何优化作为提高整体循环性能的机制。不同操作条件和几何配置下的射流喷射器夹带比是通过使用经过实验验证的计算流体动力学 (CFD) 方法确定的，其中包括 R1234yf、R1234ze 和 R600a 的真实气体模型。R1234yf 在整体系统效率方面表现出最佳性能，紧随其后的是 R600a 和 R1234ze。这表明，如果对射流喷射器进行彻底的设计，则可以大大减轻工作流体的影响。之后，选择制冷剂 R1234yf 对不同的集热器类型和太阳辐射场景进行敏感性研究。真空管集热器 (ETC) 模型为峰值太阳辐射 (1000 W / m 2 ) 提供了最高的整体系统效率 (η ov = 0.213 )。尽管如此，如果考虑更广泛的太阳辐射场景，正在研究的抛物线槽收集器 (PTC) 模型之一提供了最强大的性能。真空管集热器 (ETC) 模型为峰值太阳辐射 (1000 W / m 2 ) 提供了最高的整体系统效率 (η ov = 0.213 )。尽管如此，如果考虑更广泛的太阳辐射场景，正在研究的抛物线槽收集器 (PTC) 模型之一提供了最强大的性能。真空管集热器 (ETC) 模型为峰值太阳辐射 (1000 W / m 2 ) 提供了最高的整体系统效率 (η ov = 0.213 )。尽管如此，如果考虑更广泛的太阳辐射场景，正在研究的抛物线槽收集器 (PTC) 模型之一提供了最强大的性能。