Dynamic simulation and weather-responsive operation strategy of a solar ejector-compression hybrid refrigeration system with cold storage

Abstract

Solar ejector refrigeration can reduce building cooling electricity demand by utilizing low- and medium-temperature solar heat, but its performance is sensitive to solar radiation and ambient temperature. To improve off-design performance, this study developed a TRNSYS-EES dynamic model of a solar ejector-compression hybrid refrigeration system for a residential building in Zhengzhou and proposed a weather-responsive, rule-based control strategy. The strategy integrates time- and temperature-difference-based control of the solar collection and storage subsystem with variable generation-temperature regulation according to ambient temperature and solar radiation. Model predictions agreed with experimental ejector cooling capacities within 2.9-5.2%. Under typical-day conditions, the proposed strategy increased the ejector cooling capacity from approximately 3.0 to 3.5 kW (16.7%), while maintaining a COP of 0.23-0.26. In hybrid mode, cooling output became more stable and reached 11.53 kW, generally meeting the building cooling demand. The results demonstrate that weather-responsive generation-temperature regulation improves cooling stability and adaptability under short-term weather fluctuations.