A liquid recirculating refrigeration system

with ejector as a throttling device

was proposed in this paper. Furthermore

a gas–liquid separator was set after the evaporator in the system. By using the pressure difference between high-pressure refrigerant and liquid refrigerant in the vapor–liquid separator to inject the liquid

the evaporator can form a super-feeding without consuming additional energy

which can improve the cooling capacity of the system. An experimental bench of the system was set up to conduct experimental studies on the changing conditions of the system's ejection ratio and system performance

and they were compared with that obtained via the two phase flow injection method. The experimental results indicated that under the condition of evaporation temperature in the range of -13 to -6 ℃ or condensation temperature in the range of 36–42 ℃

the cooling capacity of the ejector liquid recirculation method is 24.6%–45.9% higher than that of the two phase flow injection method

and the maximum COP of the system increases by 14%

while the COP of the system slightly decreases when the evaporation temperature is lower than -13 ℃ or the condensation temperature exceeds 42 ℃. At the same time

it was determined that the pressure difference between the ejector inlet and outlet was the main factor that affected the ejection ratio of the liquid recirculating refrigeration system.