System Development Of A Household Heat Pump Water Heater Using Solidification Heat Of Domestic Sewage And Its Operational Characteristics Experimental Research

With the rapid development of China’s economy and the continuous improvement of the urbanization level and people’s living standards, the demand for living hot water in families, hotels, schools, hospitals and public baths is also rising. At present, the living hot water energy consumption accounts for about 20%of the building energy consumption. As a result, people begin to attach increasingly importance on the living hot water energy saving, leading to the development of the heat pump water heater in the market. However, the common air-source heat pump water heater has a low running efficiency in winter in cold regions, or even unable to run normally. And in real life, the temperature at discharging the sanitary sewage is relatively high, reaching 30 °C. Therefore, rich heat energy is contained in the sanitary sewage. In order to recycle the low-order heat energy in the sanitary sewage, reduce the running cost of the living hot water, and solve the problem of system running instability of common water-source heat pump water heater in condition of such wastewater temperature, this paper develops a kind of heat pump water heater with the solidification heat of sanitary sewage as the low-order heat source and tests the running characteristics of this system.First of all, it takes heating water volume 1201 as the design objective and carries out thermos technical and structural calculation of evaporimeter, the key component of the heat pump water heater. It designs a paralleling spiral coil evaporimeter and carries out model selection calculation of other parts of the heat pump water heater (condensator, compressor, automatic expansion valve).Secondly, based on the parts of the heat pump designed, it establishes the household sanitary sewage solidification heat pump water heater experimental platform and analyzes the errors of the test system.Thirdly, based on the test system established, it tests and studies the dynamic change characteristics of the parameters of heating coefficient and power of the compressor in the process of ice storage, ice melting and ice re storage after ice melting in conditions of different water temperatures. It analyzes the comprehensive energy consumption of the system and makes a contrast research on the influence of compressor types on the dynamic performance of the heat pump water heater on this basis.