Summary: In winter, we not only need to protect ourselves from the cold, but as a refrigerating person, we have to "care and maintain" our refrigeration equipment, especially in the cold north. We must pay attention to central air conditioning and take ......
In winter, we not only need to protect ourselves from the cold, but as a refrigerating person, we have to "care and maintain" our refrigeration equipment, especially in the cold north. We must pay attention to central air conditioning and take measures to prevent cold, especially shopping malls, manufacturing companies, and hotels. Commercial central air conditioners in large-scale fields need anti-freezing, so how to prevent freezing and what measures are there to prevent freezing?
1. Antifreeze of the host
Close the inlet and outlet valves of the condenser or evaporator of the main engine, open the drain valve and the vent valve, and then use compressed air to blow off the remaining water.
Second, the antifreeze of the water pump
Close the inlet and outlet valves of the refrigerant water pump, open the water pump drain valve and vent valve, and drain the water. Open the lowest point valve of the cooling water system, drain the cooling water, and open the water pump drain valve. After the system water is drained, in order to prevent rainwater from entering through the cooling tower, close the cooling tower water main valve and open the cooling tower water tray drain valve , So that rainwater can be drained from the drain valve in time.
Three, antifreeze of cooling tower water supply pipe
In general, cooling tower water supply pipes are exposed outdoors, and most designers use heat preservation methods to prevent freezing, but in actual use, even if heat preservation, frost damage often occurs.
In order to solve this problem, add a valve when the cooling tower water supply pipe is connected from the room, and add a drain valve at the lowest point of the water supply pipe. (This article comes from the public account of Refrigeration Encyclopedia) When winter comes, close the indoor valve and open the lowest drain valve to drain the water in the outdoor pipe, so that the pipe does not need to be insulated and will not be frozen.
Fourth, the antifreeze of the expansion tank
Expansion water tanks are generally located in the equipment room on the roof or the top floor. Although the outer surface of the expansion water tank is insulated and is equipped with a circulating pipe, in actual use, the circulating pipe can really circulate very few, that is, there are expansion water tanks in winter The water stays in a low temperature environment for a long time, although it keeps heat, it will still be frozen. If the expansion tank is frozen, it will not expand. When the temperature in the system rises, the pressure increases.
In order to solve this problem, a dn20 interface can be installed in the air-conditioning water supply main pipe during construction, and a valve can be installed to open properly to ensure that the water in the water tank is circulated. (This article comes from the WeChat public account of Refrigeration Encyclopedia) If you do not use the air conditioner at night, you can open this valve before stopping the pump to increase the water temperature in the expansion tank, which can keep the expansion tank from freezing for a long time after stopping the pump ice.
5. Antifreeze of fresh air system
The function of the fresh air unit is to process the outdoor fresh air and send it to each room. In winter, the fresh air unit heats the outdoor cold air, that is, the surface cooler of the fresh air unit directly contacts the outside cold air, in order to prevent the surface cooler from being frozen when the heating is stopped. , An electric multi-leaf control valve should be added at the fresh air inlet and linked with the fresh air unit. When the fresh air unit is running, the air valve is opened, and when the fresh air fan is closed, the air valve is closed. This prevents the outdoor cold air from cooling the water in the surface cooler directly after the fresh air unit and the refrigerant water pump stop running, causing the water to freeze and freeze. Table cooler.
Six, add antifreeze
In winter, when the unit is inconvenient to drain water and there is a possibility of water and power outages, supplementary antifreeze must be added to the heating of the equipment, and the minimum temperature of the local area must be used as an important parameter for selecting antifreeze.
The main component of the antifreeze is ethylene glycol. The antifreeze is poured into the water supply tank. After the chilled water of the water system is discharged, the antifreeze stock solution is injected first, and then the chilled water is injected if it is insufficient, and then the water pump is turned on to make the antifreeze and water sufficient Fusion, by the way, all the air in the water system is discharged. The water system cannot have air. The presence of air will cause the air conditioning equipment to report water flow switch protection, and it is easy to form cavitation.
Seven, all refrigeration pipelines are insulated
The main purpose of chilled water pipe insulation is to prevent condensation on the outside of the pipe. Another function is to prevent the water in the pipe from freezing. The thickness of the insulation layer is generally above 20mm.
In addition, it is necessary to wind the electric heating cable on the outside of the water pipe. As long as the heating cable is supplied with electricity, it can continue to heat the pipe. The water temperature in the pipe is above 10°C, plus the insulation outside the heating cable, it will not appear because Freezing causes water shortage protection for the hot water machine. The heating cable should be equipped with a temperature limiter, and it is enough to maintain a certain temperature. 333333333