HEAT PUMP AND AIR CONDITIONING SYSTEM ANALYSIS BASED ON VARIABLE SPEED COMPRESSOR

Abstract

Experiments were carried out to investigate the effect of ambient air temperatures on the heat pump performance using a variable speed compressor. Ambient air temperatures were varied from 40 to 60 °F to simulate different seasons. The compressor frequencies of 45 Hz, 50 Hz, 55 Hz, and 60 Hz were studied to determine the optimal frequency under various heating loads. The investigation was carried out by showing the compressor power input, heating output, and coefficient of performance for each case. Thermal cycle analysis along with the heat exchanger theory was used to analyze the system energy balance, heat transfer rates, p-h diagrams, and coefficient of performance. The overall heat transfer coefficients were also determined for both the evaporator and the condenser. Only the capillary tube was used to regulate the refrigerant flow rate. The variable speed compressor system used in this study will help save energy when compared with the traditional steady speed system. The variable speed compressor system will hopefully provide a more comfortable and steady indoor temperature than the traditional system, which is controlled by only an on-off switch. The speed controlled compressor system proposed we believe will help saving more energy than traditional steady speed system. The variable speed compressor system will hopefully provide a more comfort and steady indoor temperature than the traditional system which is controlled by one switch. It is believed that the variable speed compressor system may allow the indoor temperature air to be steady-going and prevent the switch working frequently.