The hottest pump is used for the preparation of do

2022-10-16
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In order to protect the natural environment and improve people's living standards, the development and utilization of green energy (non polluting natural energy, such as solar energy, geothermal, etc.) should be a new technology actively promoted by the discipline of building hot water. This paper discusses the technology of using the heat energy of air or air conditioning water as the heat source of domestic hot water through heat pump

2 working principle of heat pump

the work of heat pump is to use the principle of "air conditioning" to transfer the heat energy of air or water, but unlike air conditioners, it is not to discharge the heat outdoors, but to transfer it to water, so as to achieve the purpose of heating water, and at the same time, produce cold air (or cold water) to remove excess water in the air. During the operation of the heat pump, it is proposed to simplify processing and provide better performance. The heat supplied is larger than the heat it obtains from air or water. This is because the air compressor of the heat pump also converts electric energy into heat energy output, and there is no pollution problem of fuel oil or gas heating equipment. The development and application of heat pumps in the United States has a history of more than 20 years, and has been applied in more than 50000 systems. It has been applied in Hong Kong for more than ten years and has been used in many systems. In Shenzhen, which reduces the amount of alloy added, Shenzhen has also been applied in recent years. According to different energy sources, heat pumps can be divided into water water series, gas water series and other types. Figure 1 shows the heat pump with air as the energy source. 4. The accuracy of experimental force: the structure and working process better than ± 1% of the indicated value. In the figure, the refrigerant is vaporized, pressurized by the compressor, and then transmitted to the pool water heat exchanger through the three-way valve (this type of heat pump is generally used for the heating of pool water and the dehumidification of air). The high-temperature gaseous refrigerant is cooled by the pool water, liquefied, and then flows to the collector. The liquid refrigerant evaporates in the low-pressure evaporation coil through the expansion valve. When the refrigerant evaporates, it absorbs a large amount of heat energy to cool the air flowing through the outside. After gasification, the refrigerant is pressurized by the compressor and then transmitted to the pool water heat exchanger through the three-way valve. This action cycle keeps cooling or heating. Figure 2 shows the structure and working process of the heat pump with the chilled water of the air conditioner as the energy source. The chilled water of the air conditioner enters the evaporation heat exchanger, and the liquid refrigerant evaporates in the low-pressure evaporation coil to absorb the heat energy of the chilled water and reduce the chilled water temperature. The vaporized refrigerant returns to the condensation heat exchanger after being pressurized by the compressor, and is liquefied in the condensation coil to release heat and heat domestic water

3 engineering application example

Figure 3 is the system diagram of water water series heat pump. Table 1 shows the parameters of water water series heat pumps. Figure 4 shows the appearance of water water series heat pumps. On the side where the evaporation heat exchanger may cause equipment failure, the return water of chilled water enters the heat pump after passing through the circulating water pump, and each circulation can reduce the water temperature by 4 ℃. At the evaporation heat exchanger side, hot water also enters the heat pump after passing through the circulating water pump, and each circulation can increase the water temperature by 5 ℃. When the water temperature of the hot water tank reaches 65 ℃, the compressor stops working. In order to improve the efficiency of the heat pump, the first hot water tank is used as the preheating tank, and the heat pump only provides the basic heat load. The second hot water tank with heating element is used as the final heating means of water. The volume of the second hot water tank shall be calculated according to the heat required by the whole building for the maintenance of heat pump or air conditioning system. Figure 5 shows the hot water system diagram of the Gold Coast Hotel in Hong Kong. This hotel is a five-star hotel, which was originally designed with oil fired hot water boilers, and then combined heat pump and positive displacement electric heater according to the requirements of Hong Kong environmental protection department and power department. A total of four heat pumps are selected for domestic hot water in the hotel, of which each two are installed in series, and the original heat exchangers (3 for guest rooms and 2 for kitchens) are used as the second level hot water storage tanks. Five volumetric electric water heaters are selected according to the total heat demand of the hotel. Due to the space limitation of underground equipment room, the total heating capacity of the four heat pumps cannot meet the total demand, and 2-3 electric water heaters need to be put into operation during the peak water supply period. The hotel has begun to carry out the transformation of phase II work, and then install four air-water series heat pumps for the heating of swimming pool water and the dehumidification of air, and supplement the insufficient part of domestic hot water heat pumps

4 conclusion

as a new pollution-free environmental protection equipment, heat pump has been widely used in developed countries and regions. China has joined the WTO and successfully bid for the 2008 Olympic Games. Green Olympics and high-tech Olympics as our basic policies have been recognized by the International Olympic Committee. In the next seven years of construction, heat pumps will be widely used in hot water systems and air conditioning systems

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