Study On Process And Performance Of Direct Sewage Source Heat Pump System

Use of sewage-source heat pump technology, extracted from sewage heat energy used for heating and air conditioning, has broad application prospects for its energy saving and environmental protection. In recent years, research and application of sewage source heat pump technology has made great progress, but mainly concentrated in the area of indirect systems, direct system blockage and dirt problems cannot be effectively resolved and cannot be applied to engineering. Therefore, the the direct process and its performance was studied in this paper.First, summized and analysed the advantages and disadvantages of filtering devices, developed a static row filters and restore the device. Thickening of the filtering surface, we solved the traditional filter winding problem. By changing the direction of water flow in the filter, realized the different filter alternately filters and restore. By changing the sewage heat exchanger for heat pump unit in the direction of water flow, solved the suspension on heat retention issues. And, with Fluent simulation filters of flow, when water from the in and out on the same side, and filter pore water velocity distribution between 0.7m/s ～ 1.5m/s, when the water from the opposite when you access, filters flow more evenly in the holes, some 1m/s, two types of flow close to the filter surface is not returned, verify the feasibility of Backwashing.Then, establish a direct system relative to the total indirect cost savings model, and the direct economy was discussed. Thermal coefficient x is defined, it is equal to the evaporator outlet water temperature and temperature difference. Through the direct model and analysis of systems cost savings, arrived at a different price and wastewater economic value range type x. Original health sewage in electric price for 0.5 Yuan/kWh, and 0.75 Yuan/kWh and 1.0 Yuan/kWh Shi, x economic take value interval respectively for 2 ℃～5.6 ℃, and 2 ℃～5.8 ℃, and 2 ℃～ 5.9 ℃; has processing sewage x economic zone between in different electric price Shi are for 2 ℃, 6.2 ℃; When industrial effluent less than 0.75 Yuan per kWh in electricity price, direct system economy rather than the indirect system, when the price of 0.75 Yuan per kWh, x economic zone 2.2℃～4.3 ℃, when the price of 1.0 Yuan per kWh, x economic zone 2℃～5 ℃.Secondly, the establishment of a mathematical model and simulate the performance of different values of x units, combined with the economic value range analysis units design for different types of electricity and sewage programme. Price at the time of 0.5 to 1.0 Yuan per kWh, untreated sewage unit, processed sewage and industrial wastewater 2℃～4.5℃,2℃～ 4℃,4℃～5℃, when the price is low, x takes large values; when the price is high, x takes smaller values.Last, according to unit optimization design programme, design out 3 Taiwan unit, and for has variable workers condition Xia of simulation, obtained following conclusion: dirt hot resistance each increased 0.1m2?K/kW, unit evaporation temperature reduced about 0.7 ℃, unit business heat attenuation about 1.5% ～ 2.2%, power reduced about 0.3% ～ 1%, unit COP reduced about 1% ～ 1.6%; sewage water temperature each increased 1 ℃, unit business heat improve 2%, power increased 0.7% ～ 1.2%,COP improve 1% ～ 1.6%; unit heating capacity with the increase of water temperature at the end decay faster, end return water temperature increased from 35 to 50 ℃, the return water temperature at the end of each 1 ℃, heat attenuation increasing from 0.4% to 0.8%.