Performance optimization of CO2 heat pump water heater

Experimental Study on the Performance of Water Source Trans-Critical CO2 Heat Pump Water Heater

The effect of the discharge pressure on the performance of the trans-critical CO2 heat pump with a low gas-cooler outlet temperature is experimentally investigated on a test rig of water source heat-pump water heater. The optimal discharge pressure of the trans-critical CO2 heat pump is investigated under different external operation conditions. When the tap-water temperature is low, the charac...

Performance study on solar assisted heat pump water heater using CO2 in a transcritical cycle

This study reports the numerical analyses of a CO2 transcritical cycle on solar assisted heat pump water heating system in which evacuated tube U-pipe solar collector is utilized as an evaporator. This simulation model can predict operating characteristics for moderate meteorological conditions of North Dakota. The main purpose of this work is to simulate the overall performance of the heat pum...

Comparison of Two Gas Coolers in CO2 Heat Pump Water Heater

Experiences with Application of a CO2 Reciprocating Piston Compressor for a Heat Pump Water Heater

This paper describes some of the challenges experienced in the application of a carbon dioxide reciprocating piston compressor to a water heating heat pump. Due to the characteristics of CO2 in a trans-critical cycle, including high pressures, high discharge temperatures, and high solubility in oil, particular difficulties may be experienced such as reduced bearing reliability caused by bearing...

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 ...