How should I protect my air conditioning unit from freezing in the winter?

Winter is not only our own need to prevent cold and warm, as refrigeration people, we also have to "care and maintenance" of our refrigeration equipment, especially in the cold north, pay attention to the central air conditioning also need to do a good job of cold measures, especially shopping malls, manufacturing enterprises, hotels and other large-scale field of commercial central air conditioning need to prevent freezing, then how to prevent freezing, freezing there! What measures?
First, the host of the anti-freeze
The host condenser or evaporator import and export valves closed, the water discharge valve and air release valve open, and then use compressed air to blow the remaining water.
Second, the water pump anti-freeze
Close the refrigerant pump inlet and outlet valves, and open the pump drain valve and air release valve to drain the water. The lowest point of the cooling water system valve open, put the cooling water, and open the water pump drain valve, to be the system after the water put clean, in order to prevent rainwater through the cooling tower into the cooling tower, close the cooling tower out of the water valve, open the cooling tower catchment disk drain valve, so that the rainwater in a timely manner from the drain valve drain off.
Third, the cooling tower water pipe anti-freezing
General cooling tower water supply pipe exposed to the outdoors, most of the designers are using insulation method of anti-freeze, but the actual use of the process, even if the insulation is often frozen phenomenon.
In order to solve this problem, in the cooling tower water supply pipe from the indoor connection, additional valves, in the water supply pipe at the lowest point to increase a water discharge valve. When winter comes, the valve will be closed indoors, and will be the lowest point of the discharge valve open, the outdoor pipe water discharge, so that the pipe does not need insulation and will not be frozen.
Fourth, the expansion tank of anti-freezing
Expansion tanks are generally located in the roof or the top floor of the equipment room, expansion tanks, although the appearance of insulation, and has a circulating pipe, but the actual use of the circulating pipe can really play a circulating role in very few, that is, in the winter there is an expansion tank of water in the long term in a low-temperature environment, although the insulation will still be frozen, the expansion tank is frozen can not play the role of expansion, the temperature within the system rises, then the pressure increases.
In order to solve this problem, in the construction of air conditioning water supply pipe can be set up a DN20 interface, install a valve to open properly to ensure that the water in the tank to get the cycle of water. (This article comes from the refrigeration encyclopedia weibo public number) If the night does not use air conditioning, water pumps stop before the valve can be opened all the way, so that the expansion tank of water temperature, can ensure that the pump stops for a long time after the expansion of the water tank does not freeze.
Fifth, the new air system to prevent freezing
The role of the fresh air unit is to send the outdoor fresh air into the rooms after treatment, in winter, the fresh air unit heats the outdoor cold air, that is, the fresh air unit table cooler directly in contact with the outside world cold air, in order to prevent the table cooler is frozen when the heating is stopped, the fresh air inlet should be added to the motorized multi-leaf regulating valves, and the fresh air unit linkage. When the new air unit is running, the air valve is open, and when the new air unit is closed, the air valve is closed, so as to prevent the new air unit and the refrigerant water pump from stopping the operation, the cold outdoor air will directly cool the water in the water-cooled table cooler, so that the water freezes and freezes, freezing the table cooler.
Sixth, add antifreeze
In winter, the unit is not convenient to drain the water to empty and the possibility of water and electricity cuts, equipment heating must be added to make up the antifreeze, and must be based on the lowest local temperature as an important parameter in the choice of antifreeze.
The main component of antifreeze is ethylene glycol, antifreeze from the water tank into the water system after the discharge of frozen water, first injected antifreeze liquid, not enough and then injected into the frozen water, and then turn on the pump so that the antifreeze and the water is fully integrated, by the way, the water system of all the air out of the water system, the water system can not be air, the presence of air will make air-conditioning equipment to report the flow of water to switch the protection, but also prone to the formation of vapor corrosion.
Seventh, all the frozen pipe insulation
The main purpose of frozen water pipe insulation is to prevent condensation on the outside of the pipe, there is also a role in preventing the water inside the pipe from freezing, the thickness of the insulation layer is generally more than 20mm.
In addition, but also in the water pipe outside around the electric accompanied by tropical, as long as to accompany the tropical power supply, it can continue to give the pipeline heating, is the water temperature in the pipeline in more than 10 ℃, plus accompanied by the tropical outside of the heat preservation, there will not be because of icing caused by the hot water machine lack of water protection. The accompanying heat tape should choose with limit thermostat, keep a certain temperature on it.
Eight, case study
Case 1: There is a villa user, the family does not often live in people, last winter to go abroad for vacation, the electricity all cut off, and no drainage, as a result of the return of the machine after all frozen. Winter temperature in the north is low, because of the long time not used without drainage, resulting in the machine all frozen.
Case 2: In a rural area, the machine froze in winter and called the contractor to repair it. The temperature is very low in winter, if the anti-freezing is not done well, it is easy to be frozen. Water will freeze when the temperature is lower than 0℃, the volume of water expands when it freezes, and the expansion coefficient of pipe and water is different, so when the water temperature in the pipe is lower than 0℃, the pipe has the possibility of freezing, when the ambient temperature is lower than 0℃, and the unit is not powered on or the unit is in standby state when the internal antifreeze protection is out of order.
Xinxiang Yukun Refrigeration Technology Co. is a production and sales of refrigeration two apparatus parts and sheet metal products, mainly engaged in condenser, evaporator, heat exchanger, reservoir, filter drier, Fin Evaporator (condenser), Stamping Parts, sheet metal parts, aluminum tubes for refrigeration, etc.

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Our company mainly produces products for:Fin Evaporator.Fin Type Condenser.Capillary Tube.Aluminum Coolant Reservoir.Plate Reinforcement Parts.Stamped Parts.Aluminum Tube.Instrument Testing Equipment.
Supermarket Refrigeration Show Case Copper Condenser Coil
1. OEM or ODM can be accepted
2. Fin type: Louver or corrugated
3. Be customerized according to samples and drawings.
4. High quility and low price and energy saving 60% (CE, RoHS, EMC and ISO9001 certification) The CD series products can be used in Various specificantion Condensing Units .