Experimental investigation on a parallel pressure compensation technology for the performance improvement of the steam ejector in ejector refrigeration system

The steam ejector, as a typical energy-saving device, plays a crucial role in the ejector refrigeration system (ERS). This study proposes a parallel pressure compensation technology to mitigate the high-pressure effect of the mixing chamber inside the steam ejector, thereby achieving the purpose of the performance improvement of the steam ejector and the ERS. A visualization ERS experiment platform, featuring a newly designed two-phase steam ejector, is designed and constructed to verify the feasibility of the pressure-compensation scheme and determine the optimal pressure-compensation method for various working conditions simultaneously. The experimental results demonstrate that the region near the mixing chamber upstream has a greater impact on the entrainment performance and is more sensitive to the low-pressure potential compensation. Furthermore, the PMM connection type can provide a better entrainment performance than other types. Under existing experimental conditions, there exists an optimal combination among the pressure-compensation schemes to adapt to various working conditions except the subcritical condition. Specifically, the TU pressure compensation method of the single-bypass type can be selected in the near-critical condition. For the critical point condition, the TU-TD pressure-compensation method of the double-bypass type is an optimal choice. Under the supercritical condition, the TU-TD-DU pressure-compensation method of the multi-bypass type should be adopted. More importantly, the insights gained from this work contribute to improving the performance of the steam ejector and the ERS, as well as expanding the engineering application of the steam ejector.