Air source heat pump defrosting method - defrosting method
Reverse cycle defrosting
The exhaust pressure of the reverse cycle defrosting system is small during defrosting. Changing direction through the four-way valve can easily bring many impacts to the system and cause "oil leakage" problems. When running the hot gas bypass defrost mode, the pressure changes are relatively gentle, and the average exhaust pressure is 1.30mpa, which can basically meet the normal operation needs of the unit, and there will be no "oil rush" phenomenon, which improves the reliability of the system. Compared with the hot gas bypass defrost mode, the energy storage defrost mode increases the exhaust pressure during defrost and is 50% higher than the reverse cycle defrost mode, which increases the condensation temperature and heat transfer temperature difference, which is more conducive to defrosting. frost.
Traditional defrosting method - reverse cycle defrost. During defrost, it stops supplying heat to the room. The water supply temperature drops sharply from 45℃ to about 7℃, and the indoor heat must be absorbed for defrosting. , causing the indoor temperature to drop sharply, seriously affecting human comfort. The hot gas bypass defrost method does not need to absorb indoor heat, but can also provide a small amount of heat at the same time, avoiding the phenomenon of cold wind blowing during defrost. The water supply temperature drops slowly, but the defrost time is too long and the indoor temperature is still 10 ℃ drop. For energy storage defrost, the defrost heat comes from the heat storage of energy storage materials. There is no need to take heat from the room. The water supply temperature is relatively stable and the indoor temperature does not fluctuate greatly, which can meet the comfort requirements.
Storage defrost
The storage defrost time is greatly shortened because the four-way valve does not need to be reversed and the defrost heat comes directly from the storage heat exchanger. The time to restore normal heating is shortened by about 160 seconds compared with traditional reverse cycle defrost. At the end of defrost, the surface temperature of the outdoor heat exchanger fins reaches 30°C, which is about 6°C higher than both reverse cycle defrost and hot gas bypass defrost. This leaves the outdoor heat exchanger of the traditional defrost system with residual Defrost water problem solved. In the hot gas bypass mode defrost system, since the power consumption of the system during defrost comes entirely from the input power of the compressor, the defrost time is longer than the other two defrost times.
In terms of defrosting energy consumption, although the defrosting time of the hot gas bypass defrost system is longer than that of the reverse cycle defrost system, after the defrost is completed, the heating mode is restored to reach the set indoor temperature. The temperature reverse cycle defrost system requires a long time, so the energy consumed by the two modes is not much different, 4600kj and 4374kj respectively. The defrosting energy consumption of the hot gas bypass defrost system is reduced by about 5. Compared with the first two defrost modes, the energy-storage defrost system has a better energy-saving effect. Because during energy-storage defrost, the defrost energy comes directly from the energy-storage heat exchanger, and the indoor temperature does not fluctuate greatly during the defrost time, so the defrost system The frost time and short recovery time of indoor temperature are greatly shortened, the energy consumed is reduced, and the energy saving effect reaches 31.3.
Bada Microwave answers!