Discharge Superheated Control, DSH, Heat Pump, COP improvement
This research presents how to improve the heat pump efficiency by using Discharge Superheat Control (DSH). Normal heat pump uses Suction Superheat Control (SSH) about 5 K. At this condition, it is an optimum condition for cooling COP but it is not the highest cooling capacity. To improve Heat Pump efficiency, it needs to get maximum heat from Evaporator and internal heat of Compressor to discharge at Condensing. This condition needs to be controlled at SSH ~ 0 K. Unfortunately normal heat pump can not be controlled at this condition because of limitation of expansion valve controlling and operating limit of some compressor. New control method under this condition, is called Discharge Superheat Control (DSH). It uses discharge temperature for controlling refrigerant flow to get the maximum heat at Evaporator and Compressor. From the experiment with Brine to Water(BTW) and Air to Water Heat Pump (ATW), DSH control will lead to highest HCOP up to 25 % improved, comparing to the original control method.