Optimization Design On Cascade Air Source Heat Pump Water Heater With Thermal Storage

Air source heat pump water heaters are widely used in various hotels, public baths, hospitals, nursing homes, schools, fitness centers, production process, using hot water units. The traditional air source heat pump water heater applications face many problems to be solved: heat pump heating system startup time longer than, the initial hot water temperature is low, can not always meet user needs; When the outdoor temperature decreases, heat pump hot water temperature is not prepared to demand occasions, urged the need to use supplemental heating, electric heating current general way, in order to satisfy the moment may require a larger amount of hot water, heating power configuration required large, the corresponding distribution are large, high distribution costs, or a large hot water demand may not meet the requirements; traditional electric heat pump to add water according to time of heating time, heating time, regardless of high and low price, running costs are high; when outdoor air temperatures lower, air source heat pump to defrost, etc., the actual efficiency of the lower, or even better than using only electric heating; to meet user needs higher temperature water needs, to improve the heat pump condensing temperature, while increasing the condensing pressure, equipment shorten life, reducing efficiency. Based on these issues, using cascade regenerative air source heat pump hot water system can be solved.this paper seeks to cascade regenerative air source heat pump hot water system study, mainly from the following aspects of the system matching and optimization of a more comprehensive solution.1, the cascade refrigeration cycle applied to the heat pump water heater, using cascade hot water circulating system to take to solve the air source heat pump water heater at low ambient temperatures get hot water without the rule of law, and the low temperature and low efficiency problem;2, exploration and research on air source heat pump water heater for the phase change material (PCM), of a suitable phase transition temperature, high latent heat value, high long-term cycle stability of the phase change material, to meet the air source heat pump water heaters, energy storage requirements;3, the cascade refrigeration cycle with the combination of phase change thermal storage technology, through the cascade heat pump system with phase change thermal storage system of coupled research and development of new energy efficient heat exchanger; use of cascade heat pump Preparation of high temperature hot water, use of the energy storage phase-change heat storage, heat pump water heater system to improve the economy of operation;...