Research And Evaluation On Reclaimed Water Source Heat Pump Used In Heat Supply System

Nowadays, the energy we used for heating includes coal, oil, natural gas, electricity, solar, geothermal, etc. Although more kinds of energy are used for heating, boilers and cogeneration burning coal are used most with the total amount of over 80%, leaving the others very small proportion. As China's energy shortage becomes more and more serious, cogeneration plant and district boiler houses using fossil fuels face large challenge.At the same time, the urban sewage (including original sewage, reclaimed water, intermediate water) contains rich energy whose temperature is low. Despites the energy is not suitable for application in industrial production considering its low grade, it is good heat source for water source heat pump. Heat pump system uses part of high grade energy such as electricity to improve the energy contained in sewage and outputs all the two parts energy which we can use for district heating. We can see that while supplying the same quantity of heat, heat pump needs less fossil fuels. Therefore, it releases less air pollutants and is more environmental friendly. In this paper some jobs are done for reclaimed water using in district heating. In this paper, what we called reclaimed water means water that after treated in the water treating plant.First, this paper introduces how to design a reclaimed water heat pump system, using the heat source design of a planning district in Fu Jin city for example. The take and drainage system, heat exchanger, application mode of reclaimed water and heat pump unit are involved.Then the heat economy models of reclaimed water heat pump system and coal boiler, gas boiler, oil boiler are established and the composition of heating costs is analyzed. The four schemes are compared using economic analysis method, analyze how the electricity price and loan interest influence the heating cost of reclaimed water source heat pump.What's more, using life cycle assessment as a tool, this paper discuss the environmental impact of reclaimed water source heat pump and three traditional heating source. In this chapter, simplified system boundary of the four schemes are established firstly. Then the total emission of air pollutants is calculated before they are standardized. The next step is weighted assessment, and conclude the environmental impact load of the systems. The evaluation results show that the environmental impact of reclaimed water source heat pump system is less than the coal boiler room.At the end, from the angle of PER (short for Primary Energy Ratio),evaluates the energy efficiency of the reclaimed water heat pump while using electricity, steam turbine and gas turbine as drive energy, in order to provide reference for practice.