Pump-less Ejection Refrigeration System Investigation

Nowadays, the increasing energy consumption has become a serious problem. In order to reduce the consumption of fuel, ejection refrigeration system using environmental friendly refrigerant is absolutely the best choice. As one of systems that can be driven by low grade, ejection refrigeration has the extra advantages of low investment, steady working situation and simple structure. With the objective of completely being heat-driven, along with developing stability and reducing mechanical vibration, a pump free ejection refrigeration system with switching valves is presented in this study. The objectives and conclusions have been presented as followings:1) This paper gives a brief review on the operation principle of ejector refrigeration, the parameters of ejector and recent studies on pump-less systems. After that, this research proposes a pump free ejection refrigeration, based on switching valves.2) The simulation about this system has been carried out by visual basic language, with the foundation of1-D model and focusing on the backwater effect to the system. The calculation results show that, by low switching frequency the system can get better performance, but may cause a bad effect on the ejector. Besides, it is also significant to find a better way of controlling the heating to generator.3) Under the consideration of switching valves, pipe inner diameter, the volume and installation height of liquid storage, the pump free ejector refrigeration is set up. The experimental results under different switching frequency show that long accumulation time contributes to heat energy reducing and better working performance. However, longer accumulation time means more water backing to generator. Besides, liquid storage and the amount of refrigerant are limited. So there is the best accumulation time at the working condition. Reducing the backwater time can be helpful for the whole system. The optimum backwater time is based on installation height of the equipment, pipe inner diameters and working condition.4) Both the simulation and experiment results show the regularity of the pump free ejection refrigeration system under switching valves, and matches well, which establish the foundation of further research.