Refrigerant charge optimisation for propane heat pump water heaters

Experimental Investigation on the Influence of Refrigerant Charge on the Performance of Trans-critical CO2 Water-Water Heat Pump

For the environmentally aware, natural refrigerant such as CO2 is recommended and pursued by researchers for refrigerators. In this paper, a transcritical CO2 heat pump system was set up to investigate the influence of refrigerant charge on the performance of a small-sized heat pump water heater. The transcritical CO2 heat pump system was composed of a rotary compressor, a tube-in-tube evaporat...

Model Predictive Control of Heat Pump Water Heaters for Energy Efficiency

Water heating accounts for 17.7% of total residential energy use in the United States and is the second largest end use after space heating and cooling. There is great potential to improve the energy efficiency of residential water heaters and reduce their energy use in new and existing homes. Previous efforts primarily focused on improving the insulation and combustion efficiency of water heat...

Influence of Refrigerant Charge Amount and EEV Opening on the Performance of a Transcritical CO2 Heat Pump Water Heater

Besides compressor rotary speed and parameters of water flowing through gas cooler and evaporator, refrigerant charge amount and electronic expansion valve (EEV) opening are two important parameters that have significant effects on the performance of a transcritical CO2 heat pump system. In this study, the effects of refrigerant charge amount on the performance of a transcritical CO2 heat pump ...

Control Method Of Circulating Refrigerant Amount For Heat Pump System

A heat pump system requires proper refrigerant charge amount. Once refrigerant is charged into a heat pump system, its charge amount is fixed. For this reason, prediction of optimal refrigerant charge amount is very important in order to yield best performance. Too low charge amount degrades capacity of heat pump. On the other hand, excessive charge amount decreases coefficient of performance (...

Performance Evaluation of a Two-Stage Compression Heat Pump System With Refrigerant Charge and EEV Opening