SIMULATION ON ABSORPTION HEAT PUMP WATER HEATER

The energy consumption of the civilian sector has increased rapidly with the increase in the standard of living, and in which, hot water supply accounts for approximately 30% of all in Japan. From the viewpoint of promoting energy conservation, it is necessary to improve the efficiency of water heaters. Conventional water heaters boil tap water by direct combustion of natural gas. Therefore, their coefficient of performance (COP) is less than 1. In this study a novel absorption heat pump water heater is proposed. By adopting absorption heat pump for water heating, we expect that the COP of the proposed water heater will be considerably higher than that of the conventional gas water heaters. In order to avoid crystallization and obtain a high temperature rising, H(2)O and NH(3) are used as the absorbent and refrigerant, respectively. In this study, the efficiencies of a single-effect standard absorption cycle system, an absorber heat exchanger (AHE) cycle system, and a dual cycle system are compared by cycle simulation. The AHE cycle system differs from the standard cycle system in that it is equipped with an extra heat exchanger to recover absorption heat. The dual cycle system consists of a H(2)O/NH(3) cycle and a LiBr/H(2)O cycle at the low-and-high-temperature sides, respectively. From the cycle simulation, it was observed that the COP increases to 1.35 for the standard cycle system, and 1.59 for thedual cycle system.