Research On The Heat Pump Hot Water System Uesdin In Bathroom With The Bath Wastewater As Heat Source

With the rapid development of our social economy, the energy crisis and environmental problems have been increasingly prominent. Many people begin to seek ways to solve these problems from increasing income and reducing expenditure. Reducing expenditure refers to saving the existing energy, including developing the new energy-saving products and recycling the energy could be used secondary. As one of the functional constructions with large energy consumption,56%-77%of total energy consumption of the bathroom is caused by the heat in bath wastewater discharged into sewer directly, which has a very large heat recovery using space.Traditional bathroom hot water system includes coal-fired boiler, gas boiler, solar water heaters and electric water heaters which have some limitations. A novel regenerative heat pump hot water system which was combined with heat storage technology and preheating device was proposed in this paper. The system used bath wastewater as a low temperature heat source, which was mainly made up by the heat pump, hot water storage tank, preheater, several pipelines and valves. There was a copper coil heat exchanger in the hot water storage tank, whose outlet could take2-6bathroom shower nozzles. Firstly the heat pump was running for making high temperature hot water reserved in the hot water storage tank, and then let the tap water flow through the coil heat exchanger continuously. After heat exchange with hot water, the tap water could achieve the bath temperature requirements eventually. Not only does the system have the advantages of simple structure, no need to configure hot water tank separately and saving a large number of the initial investment, but also has less pipes and valves so that reducing the difficulty of regulation and controlling.The mathematical model and the characteristic equation of regenerative heat pump hot water system were established, and the operation characteristics of the unit under different conditions were discussed in this paper. In addition, the influence of preheating device on the system parameters and performance was discussed. Through experimental research and analysis, the actual coefficient of performance in the system could reach4.0. The experimental results showed that, hot water and running water outlet temperature decreasing rate is different under different water flow rate, heat transfer coefficient and heat transfer areas, which played a very important role in controlling the bath water temperature effectively.