Hot Water Heat Pump, Vapor Compression, Alternative Refrigerant
In typical commercial dishwasher application, high temperature water (>82.2°C) is needed for rinse process and electrical booster heater is used to provide such hot water. In the same time, exhausted high humidity hot vapor must be vented out with specially installed hood. This paper presents the development of a high temperature water heat pump to reclaim the heat in the exhaust vapor and deliver high temperature hot water to save electrical energy used in booster heater. While in the same time, the dehumidified exhaust air can be vented directly indoor without a specially installed hood. Both R-134a and R-513A refrigerant are tested successfully in a prototype system on a typical conveyor commercial dishwasher. More than 80% dehumidification target achieved and more than 20 kW energy saving potential demonstrated with the prototype system.