|
Heat pump technology is a new energy-saving cooling heating technology, has long been mainly used in building Heating Air conditioning. Heat pump system for energy saving and environmental protection in the good performance of the sanitary hot water supply systems are also more and more as the heat source heat pump equipment. Which the outdoor air as heat source Air Source Heat Pump Simple structure, no special rooms, convenient installation, hot water supply in the health irreplaceable advantages, in addition to the larger air-source heat pump hot water system, now has a small number of brands of household air source heat pump water heater is also on the market. However, one of the main air source heat pump heating capacity and heating drawback is that the coefficient of performance decrease as the outdoor temperature decreases, so its use is restricted by environmental temperature, generally applies to the lowest temperature of -10 above areas. The heat pump technology combined with solar domestic hot water supply, domestic and foreign for a lot of research in this area are mainly two methods for a direct air-source heat pump as an auxiliary heating equipment, solar systems, the other is use of solar water heating for the low-temperature heat source or solar collectors as a heat pump Evaporator Solar heat pump system. The former mainly solar heat directly to secondary air source heat pump, solar heating to solve the continuity problem, but still can not get rid of environmental temperature on the thermal performance of heat pump system; the latter entirely to solar energy as heat source heat pump, solar energy has greatly enhanced use efficiency, but is insufficient solar energy resources still need to add other auxiliary heat source and heat pump heating capacity constraints by the solar heat collector, generally small scale. In large solar central hot water system, air-source heat pump is undoubtedly an ideal auxiliary heating equipment, in order to improve the air source heat pump in heating operation under low temperature performance, and expand its use area, with domestic Solar heat pump outside the advanced experience of the study, we developed a low-temperature environments for solar? heat pump central hot water system. The system uses a novel low-temperature solar-assisted air-source heat pump and solar heating system combines solar and heat pump each other auxiliary heat source, to maximize the use of solar energy to solve rainy weather and low winter temperature is insufficient solar energy resources hot water supply guarantee rate, this year's total, all-weather hot water supply. 1, solar energy? Heat pump central hot water system components Solar? Heat pump central hot water system as the main component of solar collectors and solar assisted air-source heat pump units, and other auxiliary equipment and the same conventional central heating system, including solar loop pump, hot water heating loop pump , Heat exchanger , Hot water tank and controller. Order to air source heat pump efficiency at low temperature environment, stable and reliable operation, foreign and domestic research institutes and production enterprises in the development and improvement, summarized in three ways. One is to rely on outside heat pump auxiliary heat source to enhance the thermal performance of low temperature, for example, by electric heating hot water temperature to improve heat pump system, using Burner Auxiliary heating outdoor heat exchanger, the compressor installed around the PCM to increase the low temperature heating run output, etc.; Second, by improving Refrigerants Circulatory system to improve low-temperature heat pump heating performance, such as dual-stage compression of air source heat pump, set the middle of qi and other air source heat pump loop; third frequency converter system work under low temperature conditions to increase high-speed refrigerant compressors circulation rate, while the working chamber to the compressor spray to prevent overheating, so that heat pump unit to normal operation. Solar assisted air-source heat pump is based on the first approach generated, shown in Figure 2. Evaporator in the unit adds a secondary heat exchanger. Heat pump heating in low temperature run-time, higher than the ambient temperature of the solar hot water flowing through the auxiliary heat exchanger, and will enter the evaporator to the outdoor air heat exchange to improve its temperature, so that the refrigerant at a relatively high environmental in evaporation, evaporation temperature increases, improved working conditions of the compressor. 2, solar assisted air-source heat pump schematic And ordinary compared to air source heat pumps, solar assisted air-source heat pump units operating in low temperature conditions has several distinctive features as follows: (1) COP significantly increased In the same ambient temperature, solar assisted heating system, the refrigerant evaporation temperature is increased, the unit heating coefficient of performance than ordinary air-source heat pump units have significantly improved thermal performance of heat pump system with the evaporation temperature coefficient the situation shown in Figure 2. (2) to prevent the evaporator frost, reducing defrost time Auxiliary heat source because the heating effect, increase the air entering the evaporator temperature to reduce the possibility of frost, so that you can prevent the evaporation of frosting, so as to maintain high heat transfer efficiency, while unit The frequency and duration of frost has also greatly reduced, you can save a lot of power, and to ensure uninterrupted operation of heat pump units. (3) to improve the working environment air compressor to extend unit life In the ambient temperature is low, the air conditioning compressor compression ratio increased sharply, the compressor discharge temperature often exceeds the scope of work permitted by the compressor, resulting in frequent start and stop the compressor, does not work, if things continue will damage the overall performance of the compressor to reduce the service life of air conditioning. Through the solar system as an auxiliary heat source to improve the evaporation temperature, indirectly improve the compressor's working environment, not only to solve the compressor in the outside world does not work under low temperature environment issues, and the heat pump can effectively prolong the service life. Auxiliary heat exchanger is located outside the evaporator heat pump, heat pump unit as a part of sync with the heat pump design and production, and the evaporator using the same shape size and material of the fin tube heat exchanger. Auxiliary heat exchanger heat transfer area, heat pump air through the evaporator temperature and with the spacing should be based on solar collectors to provide auxiliary heat, solar water temperature, ambient temperature and the heat pump evaporating temperature, the design parameters such as exhaust calculation. Current solar hot water project solar collector commonly used mainly flat solar collector, all glass vacuum tube collectors, U-tube vacuum tube collectors, heat pipe vacuum tube collector and DC vacuum tube collector of five [8]. For the full year comparison of large-scale use of solar energy central hot water system to require solar collectors should have a certain commitment We are high quality suppliers, our products such as Profile Projector Manufacturer , Ultrasonic Thickness Gauge Manufacturer for oversee buyer. To know more, please visits X-ray Pipeline Crawlers.
Related Articles -
Profile Projector Manufacturer, Ultrasonic Thickness Gauge Manufacturer,
|
