Abstract: Water ring heat pump air conditioning system in our application of several issues 0 Overview Geothermal as a clean energy, both "hot" value, but also "water" value, the advantages of heating and domestic hot water is obvious , Which has been rapidly developed in the north of our country. Domestic geothermal heating applications mainly in Tianjin, Beijing, Hebei, Xi'an and other places. Tianjin geothermal heating applications are more common. At present, the geothermal heating area in Tianjin has reached 5 million m2. According to the calculation of alternative coal-fired boiler heating, more than 110,000 tons of coal are replaced in each heating season, and good environmental protection benefits have been achieved. Geothermal heating in a prominent issue is that after the heat of geothermal discharge water temperature is relatively high, usually above 45 ℃, and some even up to 60 ℃, resulting in waste of resources and environmental pollution. In addition, a few geothermal fields have low temperatures (below 55 ° C). Such low-temperature heat source to be used for heating, to be further heated, such as the use of traditional boiler heating, heating the water after the discharge temperature will remain above 40 ℃. Such as the use of heat pump technology, not only to reclaim the geothermal discharge of water heat, heating temperature heating water temperature, while increasing the geothermal heating capacity, can make a well equivalent to one and a half to two wells to use, in addition to reduce the geothermal discharge water temperature reaches Environmental requirements. 1 geothermal heat pump heating program previous analysis [1,2]: geothermal heat pump heating system, geothermal heat pump peak heating mode of heating costs and investment is lower than the heat pump alone as a heat source of heating. This paper selects the geothermal heat pump peak heating as the basic system for three kinds of geothermal heat pump heating program of technical and economic analysis. Option 1: Geothermal heat pump peak heating system design Geothermal heat pump peak heating system schematic scheme shown in Figure 1. Geothermal heating for the basic heat source to meet the basic heating load requirements of the heating system, to the heating period, geothermal calories can not meet the heating load requirements, enable heat pump peak shaving to increase heating cycle water temperature, peak heating to achieve the requirements. In this system, the tailrace water after geothermal heating acts as the heat source of the heat pump evaporator, so the geothermal drainage temperature will be further reduced. Option 2: Geothermal heat pump peak heating and living hot water supply to meet the program 1 heating requirements, but also take into account the supply of domestic hot water, that is, the use of geothermal heating of the tail water as domestic hot water supply. Compared with a single geothermal heating, geothermal heating and domestic hot water supply not only use the geothermal "heat", but also the use of geothermal "water." Since the temperature of the tail water after geothermal heating is lower than 45 ° C, a system of heating the tail water is needed. Here, a certain amount of geothermal water is designed to be mixed with a certain amount of geothermal tail water to reach 45 ℃ for domestic hot water. As shown in Figure 1, this solution involves reducing the supply of geothermal heat, ie reducing the supply of geothermal heat Therefore, correspondingly, it is necessary to increase the amount of heat regulation of the heat pump. Option 3: Geothermal heat pump peak heating supply of domestic hot water and taking into account the summer air conditioning to meet the above program 2 geothermal heat pump based on the heat pump to consider the use of summer air conditioning. The working principle of a heat pump is the same as that of a refrigerator, and both have the same main components except for the operating temperature and pressure range. Heat pump unit with dual-use, improve the utilization of equipment, a corresponding reduction in heating, air-conditioning system, the initial investment of equipment, while the initial installation fee only one-time charge, the investment economy can be improved. Heat pump air conditioner dual-use, and the unit running time in summer air conditioning heating peak winter than the long running hours, so the initial investment of the heat pump can be 50% or even more than 60% of the air-conditioning system. Technical and Economic Analysis of Geothermal Heat Pump Heating System According to the above mentioned three kinds of geothermal heat pump heating programs and two types of geothermal resources: geothermal utilization of tail water or new drilling geothermal wells for heating the basic heat source heat pump peak heating for heating . Calculation and analysis of technical and economic parameters of the program are based on the actual parameters of a project in Beijing: geothermal water supply temperature is 55 ℃, flow rate is 80t / h; heating and return water temperature is calculated at 35 ℃; heating area is 50,000 m2, The thermal index can be 50w / m2. The local energy price is 0.36 Yuan / kWh, the geothermal water fee is 0.3 yuan / ton, the tap water water fee is 0.7 yuan / ton, the coal price is 220 yuan / ton and the natural gas price is 1.8 yuan / m3. As the heating supply and return water temperature is low, the choice of the terminal radiator will be considered. Calculation found that for low temperature heating below 55 ℃, such as the use of conventional radiator, the required radiator area increased by at least 50%, the corresponding investment will increase by 50%. At present, a new PP-C pipe floor radiant radiator is emerging and put into use, because it is buried under the floor of the room, the cooling mode is radiated from the bottom up, suitable for human body and life needs. This feature, even if it is to reduce the temperature of its supply and return, such as the use of 50 ℃ / 35 ℃, its cooling effect is not much effect. This makes radiant floor radiator radiator in the low temperature heating in a very competitive. Therefore, the combination of building the actual situation, the terminal can be used radiator, radiator or radiant floor. According to the conditions and parameters mentioned above, the specific calculation of the three kinds of geothermal heat pump heating programs is carried out. The results are shown in Table 1 and Table 2 below. Analysis and comparison of calculation results: 1, Table 1 calculates the investment and unit operating costs of different heating terminals and new drilling geothermal wells system. From the three geothermal heating programs, the low investment in program 1, heating costs are low, but there is no domestic hot water supply. Comprehensive comparison, Option 3 has both heating, domestic hot water supply, but also take into account the summer air-conditioning, from the investment and operating costs, the program 3 in between programs 1 and 2 can be used as the preferred solution. 2, Table 2 calculates the economic parameters when calculating and excluding geothermal wells. Excluding geothermal wells, the system has only heat pumps, pipelines and heating terminals. There is no geothermal well investment and running costs, and its heating costs are only accounted for about 55% of geothermal well systems. Table 1 Calculation of Economic Parameters of Geothermal Heat Pump under Different Schemes Terminal Geothermal Heating Scheme Geothermal Well Network Terminal Investment (10,000 Yuan) Initial Investment of Heat Pump (10,000 Yuan) Electricity of Heat Pump Unit (Yuan / m2) Heating Unit Cost (Yuan / m2 ) Domestic Hot Water Investment (10,000 Yuan) Water Supply Unit Cost (Yuan / m2) Initial Investment Total (10,000 Yuan) Heating Radiator Solution 1 600 124 0.70 18.02 / / 724.0 Option 2 600 169 1.22 19.55 46 1.35 815.0 Option 3 600 67 17.60 46 1.35 713.0 Floor radiator program 1 890 124 0.70 19.24 1014.0 Program 2 890 169 1.22 20.78 46 1.35 1105.0 Program 3 890 67 18.82 46 1.35 1003.0 Heating increase Investment program 1 460 124 0.70 15.83 / 584.0 Program 2 460 169 1.22 17.37 46 1.35 675.0 Proposal 3 460 67 15.41 46 1.35 573.0 Table 2 Comparison of geothermal heat pump heating and boiler heating (calculated according to heating investment) Heating scheme Investment in heating system (10,000 yuan) Heating unit cost (yuan / m2) Water System Investment (10,000 Yuan) Water Supply Unit Cost (Yuan / m2) Initial Investment Total (10,000 Yuan) Cost of Geothermal Well Geothermal Heat Pump Heating Scheme 1 584 15.83 / / 584 Geothermal Heat Pump Heating Scheme 2 629 17.37 46 1.35 675 Geothermal heat pump heating scheme 3 527 15.41 46 1.35 573 Excluding geothermal well costs Geothermal heat pump heating scheme 1 334 8.28 / / 334 Geothermal heat pump heating scheme 2 379 9.66 46 1.35 425 Geothermal heat pump heating scheme 3 277 7.70 46 1.35 323 boiler coal-fired boiler heating 215 13.65 70 4.50 285 gas boiler heating 240 26.76 105 11.32 3453 Comparison between geothermal heat pump heating and boiler heating Users are more concerned about is the geothermal heat pump heating with the traditional boiler heating For this purpose, the initial investment and unit cost of heating and domestic hot water supply for coal-fired boilers and gas boilers are calculated as shown in Table 2, and the geothermal heat pump heating solution (with or without geothermal well costs) Those who invest and cost comparison. From Table 2, the heating unit cost of a coal-fired boiler is 13.65 yuan / m2. The heating unit cost of the heat pump peaking heating scheme 3 is 15.41 yuan / m2, 13% higher than that of the boiler. The heating cost excluding the geothermal well is 7.70 yuan / m2, about 56% of the boiler. However, the heating costs of gas-fired boilers have exceeded the heating standard of 20 yuan / m2. Compared to the cost of living hot water supply, the cost of supplying hot water for geothermal life is only 1.35 yuan / ton, lower than the cost of coal-fired boilers 4.50 yuan / ton, much lower than the cost of gas-fired boilers of 11.32 yuan / ton. Based on the above calculated geothermal heating system investment and cost, as well as the investment and cost of boiler heating, the annual gross profit (heating revenue and domestic hot water revenue) of geothermal heating and boiler heating can be calculated separately and the investment recovery period can be calculated separately. See Table 3. Geothermal heat pump heating scheme 3, the highest annual heating and domestic hot water revenue, you can consider maximizing the geothermal heat for the domestic market, make full use of geothermal "hot" and "water." Investment recovery period, the coal-fired boiler about 7 years, geothermal heat pump system, when included in geothermal wells, the investment recovery period of about 9 years, excluding geothermal wells about 4 years, lower than the boiler system. It should be said