Performance evaluation of the solar-driven multi-ejector refrigeration cycle without an auxiliary heat source

Solar-driven ejector refrigeration (SER) systems have been granted special attention as a green and sustainable replacement for conventional vapor compression cooling systems. However, despite their significant advantages, SER systems suffer from a relatively low coefficient of performance and failure at high ambient temperatures and low solar radiations. Therefore, the need for an auxiliary heat source and cooling system has hindered their adoption in practice. In an attempt to eliminate the need for an auxiliary heat source and cooling system, this contribution puts forward a novel Solar-driven Multi-Ejector Refrigeration (SMER) system with an internal heat exchanger, a regenerator, and a storage tank. A numerical model of the proposed SMER system and a compu-tational fluid dynamics model of the ejector have been developed. The developed model is then used to evaluate the dynamic annual performance of the proposed SMER system through a case study. Shape optimization is also carried out to optimize each ejector based on its specific working conditions. The sensitivity of the system performance to design parameters is also analyzed, and the optimum design parameters are determined. Ac-cording to the results, the proposed SMER system can provide up to 94% of the required cooling load of the sample building with a 250 m2 solar collector area. However, the conventional SER system can provide only 71% of the building load. It is also demonstrated that the proposed SMER system requires a 75% lower solar collector area than the conventional SER system to provide 100% of the required cooling load.

Automated summary

This paper proposes a novel solar-driven multi-ejector refrigeration system with internal heat exchanger, regenerator, and storage tank, aiming to eliminate the need for an auxiliary heat source and cooling system. Numerical and computational fluid dynamics models are developed to evaluate the performance, optimize design parameters, and analyze sensitivity. Results show that the proposed system can provide the required cooling load more efficiently than conventional systems.