Water Heat Pump Application With Double Stage Back Injection

Experimental Investigation on the Two-stage Compression Heat Pump Water Heater System with Refrigerant Injection

Nowadays heat pump water heater becomes a very hot topic in hot water industry. However it still has many problems such as higher condensing temperature, large-scale operation conditions and lower COP in cold regions. Based on these problems, the paper presents a prototype assembled with a two-stage rotary compressor which can be used in cold regions. The working principle and the basic feature...

An Experimental Study on the Heat Pump Water Heater System with Refrigerant Injection

Nowadays Heat pump water heater becomes a very hot topic in hot water industry. However it has many problems because of higher condensing temperature and large-scale operation conditions. Based on the problems, this paper presents a prototype which was assembled using a rotary compressor with refrigerant injection port. By making use of the liquid injection function of the compressor, the syste...

Investigation of Vapor Injection Heat Pump System with a Flash

Title of Dissertation: INVESTIGATION OF VAPOR INJECTION HEAT PUMP SYSTEM WITH A FLASH TANK UTILIZING R410A AND LOW-GWP REFRIGERANT R32 Xing Xu, Doctor of Philosophy, 2012 Dissertation Directed by: Professor Reinhard Radermacher Department of Mechanical Engineering Vapor injection technique has proven to be effective in improving heat pump system performance, especially for cooling application a...

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...

Screw Compressors for Heat Pump Application