Abstract: Ground source heat pump is a kind of underground shallow geothermal resources (also known as geothermal energy, including groundwater, soil or surface water, etc.). As the geothermal temperature is relatively stable throughout the year, generally 10 ~ 25 ℃, its cooling or heating performance coefficient can reach 3.5 to 4.4, compared with the air source heat pump (air - air or air - water heat pump) to 40 %about. Therefore, in recent five years, the ground source heat pump air conditioning system in North America, such as the United States, Canada and Central and Northern Europe, such as Switzerland, Sweden and other countries have made rapid development, China's ground source heat pump market is also becoming increasingly active. Keywords: water source heat pump water source heat pump, water as a heat source. As a "refrigerator" application, the water is hot, as "heat pump" application, the water is low temperature heat source. Water source heat pump and ground source heat pump, its common is water (or other liquid medium) as a medium. Water source heat pump is the more widely used form; ground source heat pump is currently being actively developed models. Water source heat pump, summer as a "refrigerator" application, through the cooling tower and air heat (wet) exchange, the final high temperature heat sink, and the air heat pump, still the atmosphere. However, its efficiency is higher than that of air-air or air-water heat pump due to the characteristics of the utilization of air-the wet bulb temperature is lower than the dry bulb temperature. However, in the case of "heat pump" applications in winter, , Without using solar energy, you need to set up a separate source of heat, its efficiency is lower than the air - air or air - water heat pump. Ground source heat pump is a use of underground shallow geothermal resources (also known as geothermal energy, including groundwater, soil or surface water, etc.). As the geothermal temperature is relatively stable throughout the year, generally 10 ~ 25 ℃, its cooling or heating performance coefficient can reach 3.5 to 4.4, compared with the air source heat pump (air - air or air - water heat pump) to 40 %about. Therefore, in recent five years, the ground source heat pump air conditioning system in North America, such as the United States, Canada and Central and Northern Europe, such as Switzerland, Sweden and other countries have made rapid development, China's ground source heat pump market is also becoming increasingly active. Water source heat pumps, usually monolithic water source heat pumps, that is, in the form of a single unit that radiates or absorbs heat to the environment (water and heat source), indirectly (or indirectly) with water (or other liquid medium) or air ) Water source heat pump, but also developed as a separate water source heat pump, that is, a combination of multiple units through the water loop to the environment (water heat source) exothermic or endothermic, the same water (or other liquid substances) or air, Indirectly or directly cooling (or heating) the controlled object. This type of water source heat pump also said: water loop heat pump. When the water source heat pump is in the cooling condition, the final high temperature heat sink can still be the atmosphere; in the heating condition, the final low temperature heat source can be the atmosphere, the sun, the waste heat, or the auxiliary heat source. Therefore, the application of water source heat pump is a certain geographical and occasional restrictions. Ground-source heat pump, the final high-temperature heat sink or low-temperature heat are geothermal. Only in the cooling conditions, the geothermal high-temperature heat sink, heat to the geothermal; in the heating conditions, the geothermal heat source for low heat to the geothermal heat. Different forms of ground source heat sources make this type of heat pump different in composition. For example, surface water can directly (or indirectly - through heat exchangers) discharge (or absorb) heat. If groundwater is used as a heat source, It is necessary to set the discharge (or absorption) heat of the water intake and recharge wells; if the soil is a heat source, horizontal (or vertical) buried pipes are required to discharge (or absorb) the heat. Therefore, the former two forms have some advantages over the latter in terms of initial investment and construction and the rate of heat exchange in the application process, which is also the form currently being experimented in many areas in China. However, if groundwater is improperly applied, ground subsidence and groundwater pollution will result. In addition to the initial investment in soil and construction problems, urban land shortage, inadequate underground pipe, soil heat transfer performance and poor, likely to cause summer soil heat is difficult to dissipate, damage and long-lasting operation; winter soil heat is not easy to absorb and supplement soil Will form a freeze, destroy the underground structure, damage to the building foundation. Therefore, the application of ground source heat pump is also a certain geographical and occasional restrictions. From the history of the product development in the refrigeration industry, refrigerators using water as a high-temperature hot exchange take precedence over refrigerators with air as high-temperature hot exchange; heat pumps using air as a low-temperature heat source and a heat pump using water as a low-temperature heat source; Since then, heat geothermal heat source for low-temperature heat pump. China's refrigeration and air conditioning manufacturing industry basically follow the process of development. China first in the 50s of last century, had in Shanghai, Tianjin and other places to try summer and winter irrigation pumping groundwater cooling, Tianjin University Institute of Thermal Energy Professor Lucan Ren launched the earliest study of China's heat pump, successfully developed in 1965 the first domestic Water-cooled heat pump air conditioners. At present, many domestic universities and research institutes such as Tsinghua University, Tianjin University, Chongqing University of Architecture, Tianjin Business School and Guangzhou Institute of Energy, Chinese Academy of Sciences are studying water source heat pumps. Among them, Tsinghua University has made achievements in industrialization after many years of research on water pumps with multiple working conditions and has built a number of demonstration projects. To water (ground source) heat pump products cut home and medium-sized central air-conditioning market, not only proved a few years ago the practice is very effective measures, but also the future plan of many manufacturing plants. Domestic water source heat pump manufacturers in Tsinghua Tongfang artificial environment equipment company, Shandong Haiyang Fulda is a relatively early water source heat pump manufacturers, but there are quite a number of refrigeration and air conditioning manufacturers to transform their ordinary water-cooled units into water source heat pump. Through the use of groundwater coupling of the earth, the use of pumped back to save energy. Shandong high to evaporative condensation, the introduction of Swedish patented technology, the production of small water-cooled chillers, sales in the northern market is good. Guangzhou Zhongyu development of water loop separation of water (ground) heat pump air conditioning system, widely used in Guangdong and Guangxi and Zhejiang. The U.S. Department of Energy and Ministry of Science and Technology of China signed the Protocol on Cooperation on Energy Efficiency and Renewable Energy between China and the United States in November 1997. One of the major contents is the "Ground Source Heat Pump", which is planned to be implemented in Beijing, Hangzhou and Guangzhou in China The city built a ground-source heat pump heating and air conditioning commercial buildings to promote the use of this "green technology" to ease China's reliance on coal and oil, so as to achieve the purpose of diversifying energy resources. Allegedly "Huating Jiayuan" is the application of this project. June 2000 June 19 to 23 in Beijing by the National Science and Technology High-tech Development and Industrialization Division held a Sino-US geothermal pump technology conference, the theme of the meeting is "to provide the use of geothermal pump technology for residential quarters or public buildings, heating and cooling , Energy-saving solutions that significantly reduce operating costs ". In the coming years, China faces enormous energy pressure. On the one hand, China's economy needs to maintain its rapid growth. On the other hand, it must also consider environmental protection and sustainable development. Therefore, it is required to improve the efficiency of energy utilization and require the adjustment of energy structure. The improvement of energy efficiency will encourage the popularization of various energy-saving equipment and technologies. The direction of energy structure adjustment will shift from coal-based gas to gas-based electricity. In China's energy consumption, the proportion of building energy consumption is quite high. In order to meet market requirements and participate in international competition, we must accelerate the industrialization of water-heat pump research and development in China. At present, the popularization and application of water source heat pump in China has the following problems: water source heat pump as a new type of refrigeration and heating mode, from a technical point of view, especially heat pump unit point of view should be quite mature, no problem. However, taking into account China's national conditions, as well as water source heat pump refrigeration and heating as a whole system to promote the application, there are still some problems: 1) the use of water policy At present, in order to protect the limited water resources, China has formulated the "Water Law of the People's Republic of China," and all cities have formulated their own "urban water management regulations." These policies emphasize water approval and water charges. The approval criteria for similar water source heat pump technology does not require, so water source heat pump can easily be limited by the water index. Even though water approval has been adopted, as the water extraction and emission are doubled in some places and the standards of the charges are not harmonized in the whole country, the result may be that the water fee is too high, resulting in insufficient water conservation cost for the operation of the water source heat pump , Water source heat pump economic change investigation. Therefore, the promotion of water source heat pump requires that the government, from the perspective of sustainable development, take into account all aspects of energy, environment and resources and adjust the policies on the use of water sources and heat pumps to redefine the management and charging of water sources in order to promote its large-scale development. 2) Water exploration and mining technology and costs In China, exploration and mining technologies for water sources, especially urban water sources, should be improved. One of the preconditions for the application of water source heat pumps is that local water sources must be known. In the early stage of using water source heat pumps, the status of water sources must be carried out on the ground Investigate whether there is enough water in the groundwater, whether the amount of water will be sufficient and whether the site is suitable for well drilling and recharge. The exploration and mining technology to improve and reduce costs, will promote the better application of water source heat pump units. 3) Groundwater recharge technology Water source heat pump if the use of groundwater, we must consider the water recharge, for irrigation technology, must be combined with the local geological conditions to consider, to consider the technology of recharge. We do not know much about the geological structure in different regions, which restricts the popularization and application of water source heat pump units. 4) The overall system design Water source heat pump system, energy-saving as a system, must consider from all aspects, if the water source heat pump units can do to use more water to provide more energy, but the system design of pumps and other energy-saving equipment improper selection or control, Will also reduce the energy-saving effect of the system. Similarly, if the unit provides high water temperatures, the end of the air-conditioning system being designed has not been properly accounted for and may either degrade the overall system or increase the initial investment in the overall system. Therefore, the popularization and application of water source heat pump needs more professionals in all fields to work together to work together, from government policies, host design and manufacture, system design and operation and management to participate in all aspects.