Two Stage Vapor Compression Heat Pump with Solution Circuits: Catering to Simultaneous Chilling and Water Heating Needs

Abstract

The benefits of using a two stage vapor compression heat pump with ammonia water solution circuits (VCHSC) to simultaneously provide chilled water for air conditioning and hot water for various uses are reviewed. The performance results for a two stage VCHSC are summarized. Experimental results indicate that the two stage VCHSC can achieve cooling coefficient of performances as high as 1.04 while pumping heat through a lift of 194°F (108°C). Comparison is made with a system consisting of a vapor compressor chiller and a gas fired furnace. The basis for comparison being primary energy usage, energy cost and initial cost of the systems. Energy saving at various operating conditions is estimated. In some cases, energy saving could be as high as 31%. Based on the national average energy prices in 1991 and the projected prices for 1995, suitable applications for the two stage VCHSC have been identified.