Development and control of a meso-scale vapor compression refrigeration system

Abstract

This paper presents a development and control of a meso-scale vapor compression refrigeration system. The system consists of four main parts the evaporator, the compressor, the condenser, and the expansion device. The optimal design of the micro-channel evaporator robust to the change of the flow rate and the cooling load was conducted via the Taguchi method. The meso-scale rotary sliding vane type compressor was designed to realize the pressure ratio of 2.87 and the flow rate of 5.376 lpm. The performance of the developed compressor was the pressure ratio of 3.15 and the flow rate of 8. The expansion nozzle which is a passive type expansion device was designed to be most robust to the change of the flow rate. The condenser was designed considering the convective heat transfer coefficient between the heatpipe and the refrigerant. The theoretical value of C.O.P. is 8.11. By integrating the developed main parts the meso-scale vapor compression refrigeration was developed. The system was designed to have the cooling capacity of 80 watt, the temperature of the heat source of 50℃, and the COP of 2 within the system size of 100x100x100 mm3. From the performance test the cooling capacity of 80 watt, the minimum temperature of the heat source of 46℃, and the COP of 2.15 were achieved. For the developed system, the system identification using a black-box model approach was conducted to design a controller. The PI controller and the robust controller were designed for the identified models and verified experimentally.