Water source heat pump: the best solution for indoor air thermal environment
Product innovation is the eternal topic of the real estate industry, but whether the innovation is successful or not is entirely determined by the innovative motivation. HVAC experts, China Academy of Building Research consultant, deputy chief engineer Lang Siwei reminded us that commercial residential HVAC, air conditioning a lot of new ways, but if only from the convenience of collecting heating costs starting application of new technologies, obviously not considered. Safety, health, hygiene, energy saving and environmental protection are recognized as the direction of residential construction. Energy-saving heat pump The usual dual-use machine, to summer cooling, winter heating equipment is the "heat pump." Heat pump function is to transfer heat, the summer heat to move out of the house, the heat moved to the interior in winter. Therefore, Lang Siwei his profession known as "moving heat." Compared with the traditional way of HVAC, heat pump itself is energy-saving products, is the energy crisis gave birth to a heat pump. According to the different transfer of heat medium, heat pump can be divided into air-cooled heat pump and water source heat pump. Lang Siwei first proposed the shortcomings of air-cooled heat pump: in a very cold or hot environment, it can play the opposite role and the actual needs. Because of the heat transfer between indoor and outdoor air environment, the cooler the outdoor, the less heat can be supplied to the room; the more outdoor the heat, the less indoor heat may be transferred out. In other words, it is very difficult to heat air-to-air heat pumps in very cold climates in and beyond Beijing. In contrast, the use of water as a medium water heat pump, the impact of climate and environment is not so obvious. And because the intensity of heat exchange with water is greater than that of air, water-source heat pumps are more efficient, which means less energy consumption. Water source water heat pump According to the different water conditions, water source heat pump has four forms, what form of water source heat pump needs to be determined according to the specific circumstances. First, surface water source heat pump. If you live near rivers, lakes, water source heat pump can be used rivers and lakes, sea water and other surface water. Surface water Summer water temperature is about 27-28 degrees Celsius; in winter, the surface temperature of non-freezing surface water in the South at least 4-5 degrees Celsius, even in the northern frozen winter, if the deep water without ice, at least 4 degrees Celsius Water temperature, which creates the conditions for transferring heat between surface water and the indoor environment. Second, groundwater source heat pump. In the underground 10 meters to 70 meters, the groundwater temperature and soil temperature, the soil temperature is equal to the annual average temperature of the atmosphere in Beijing, the average annual temperature of the atmosphere is about 14-15 degrees Celsius, this form of water source heat pump Is the use of cool water in winter and summer and indoor air heat exchange. Third, geothermal water source heat pump. The technique is to lay plastic pipes in the soil and get water from the soil as it flows through the pipe or release heat into the soil, transferring heat between the indoor air and the soil through heat pump equipment. This approach is more in northern Europe. Fourth, closed-loop water source heat pump. Water-based heat pump equipment is combined with a closed water system in which a cooling tower is added in the summer to reduce the water temperature with indoor heat; in winter, a heat source is added to provide heat to the room. Due to some square (with inner and outer area) buildings, there is no outer window in the inner area, air-conditioners are often required for perennials, while the outer area needs heating in autumn and winter. At this time, the heat in the inner zone can be "moved" to the outer zone for heating by the closed loop water system, neither the cooling tower nor the auxiliary heating equipment is required. Lang Siwei that its advantages lie in not undermining the groundwater, compared with the traditional heating methods to reduce energy consumption, reduce the impact on the environment a lot of cooling towers, heating efficiency in winter is better. Compared with the air-cooled heat pump, the water source heat pump is more efficient in transferring heat with the same energy (the energy consumed in driving the heat pump device, the same below), and will not cause the heat island effect ratio to have a small impact on the environment. At the same time, he pointed out that there are some problems with groundwater heat pumps. First, after groundwater is drained, groundwater level will decrease and must be recharged. And because of the complex geological structure, it is difficult to recharge the water to the same water layer. Second, there are some unknowns. For example, with the extraction of water, some fine particles such as fine sand may be transferred along with water extraction for a long time, which may affect the geological structure. However, if the water is contaminated during the transfer, the consequences are even more unpredictable. The use of surface water can avoid these problems, but the amount of water in the water is insufficient for the General Assembly to become a constraint. Geothermal heat pump will not affect the groundwater and geological structure, but may increase costs, you need to play 60-70 meters deep hole, buried 120-140 meters deep U-shaped pipe, each pipe can be roughly 3.5 kilowatts of cold. If in a multi-storey or even high-rise district, there is still a problem of whether the area of ​​buried pipe is enough. Product standards will be introduced It is reported that the relevant departments will organize the recent review of China's national standards for water source heat pump products. Lang four-dimensional that, compared with air-cooled heat pump, water-source heat pump less energy consumption, higher efficiency, and the use of geothermal resources belonging to the soil of renewable energy, the overall environmental impact is very small, the limiting factor is how to properly water . The amount of groundwater, the length of the pipe or the size of the body of surface water and the related factors of the water system form constraints on what type of water source heat pump to take. Heat pump equipment itself has mature products at home and abroad. Therefore, he suggested, the first to prevent random wells. If there is no prospecting wells dig wells, well drilling recharge, often lead to failure, which requires professional support of the environmental protection and geological departments. The second is deep-seated issues such as the transfer of fine solid particles from groundwater sources that need to be done in accordance with the policies of the environmental protection authorities. The third to consider whether the free area is enough, villas or low-rise apartments more appropriate way to use buried pipe, which can also be used as a source of domestic hot water. At the same time, Lang Siwei is willing to remind the development of enterprises, although this technology is already a mature technology in the world, but in our country only two or three years of development history, but also the lack of empirical data, such as how much depth should be buried, how long? Tube and so on. Although data are available abroad, soil conditions are not the same at home and abroad. It is understood that at present a number of domestic research institutes have carried out research in this area, but also has some application examples. China Academy of Building Research assumed a research project of Beijing Science and Technology Commission and Beijing Construction Commission and made a technical and economic analysis of geothermal source water source heat pump. Water source heat pump unit itself costs, in general, with the boiler, chiller close to the input. Although the water source heat pump to increase buried pipe or drilling, recharge and other costs, but these inputs can be saved in the later use back. ECU Environmental Control Unit Taizhou Tentcool Electrical Appliance Co., Ltd. , https://www.tentcool.com
Recently, the hot topic - water source heat pump technology is mature, what are the advantages and disadvantages, and whether it is possible in the housing industry in China is widely used? Lang Siwei put forward his own point of view.