Theoretical Analysis of Miniature Ejector Refrigeration Powered by Thermoelectric Cooler
This paper presents a theoretical analysis of a hybrid cooling system consisting of a thermoelectric cooler and a miniature ejector. The thermal energy from the hot junction of the thermoelectric cooler is used to power the ejector cooling unit which can produce additional cooling. In this way, the coefficient of performance (COP) of the hybrid cooling system can be significantly increased. In this investigation, the thermodynamic analysis of this system is first conducted. Results show that the COP of this hybrid system can be significantly increased. If the thermoelectric cooler has a COP of 0.5 and the ejector has a COP of 0.5, the total COP can achieve 1.25.
Based on the thermal energy from the thermoelectric cooler, the miniature ejector was designed, and fluid flows for both the primary and secondary fluids occurring in the ejector are analyzed. Results show that the wick structures embedded in the system is sufficient to pump both fluids from the condenser section to the high temperature evaporator and low temperature evaporator. In addition, the effects of operating temperature in the range of 50−70°C and input power on the total COP is investigated. The investigation shows that the total COP of the thermoelectric cooler and the ejector increases by an average of 16.1% when integrated. At constant power input, COP increases exponentially to a maximum 1.35.