The winter temperature in the northern region is usually below zero, and the operation of the closed cooling tower is becoming increasingly prominent. If it is not solved well, it may freeze the heat exchange tube or other parts of the cooling tower. According to the process characteristics of different users, some closed cooling towers run all day in winter, some run for part of the time, and some completely stop running. However, it is necessary to consider the winterization of equipment.
Equipment winter antifreeze related instructions and operating specifications:
1, winter basic use of anti-freeze measures
If the closed cooling tower does not need to run in winter, the spray water and the internal circulating water of the heat exchange tube must be emptied when it is shut down.
Specific operation sequence:
① Turn off the axial fan and spray pump power supply successively;
② Close the equipment inlet valve, open the tube bundle to vent gas, drain seal cover, connect the DN32 water pipe to the tube bundle drain pipe into the water tank, then close the water tank refill valve, open the drain valve to empty the water tank, open the spray pump drain port to empty the pump body water;
③ Open the bottom wire plug of each pipe, and exhaust the residual water in the pipe with high pressure air;
④ Install the wire plug on the equipment, and cover the tube bundle with air discharge and sewage discharge outlet.
(For the closed cooling tower with flexible coil structure, the inlet and outlet valve of the equipment can be opened when disabled to empty the medium in the tube)
2. Anti-freezing measures for some time periods of operation
Because the equipment load becomes smaller in winter, for the system with multiple devices running in parallel, the fan pump of some devices is disabled, and the internal flow of the heat exchange tube (not less than 80% of the design flow) should be kept running; For small circulating water system antifreeze can be considered to add glycol solution; Adding antifreeze can solve the problem once and for all.
Glycol solution is the main component of most antifreeze, antifreeze formula refer to the following table:
Ethylene glycol (wt%)
For the equipment with electric heater, it is generally turned on when the spray water is below 5 ° C and stopped above 8 ° C. The temperature probe transmits the signal to the control cabinet to automatically control the start and stop of the electric heater.
Frost protection of spray water system:
If the spray pump is switched on and on, seal the upper water pipe flange on the deactivated pump side with the flange cover or remove the standby water pump to ensure that there is no water in the upper water pipe on the deactivated side.
Specific operation sequence:
① First turn off the spray pump power supply;
(2) Put the butterfly valve of the upper water pipe in the fully open position, and then remove the PVC upper water connection pipe on the deactivated pump side;
③ Choose the appropriate flange cover (the upper water pipe flange is usually DN125) to close the deactivated side;
④ Turn on the spray pump to be used, check whether the water flange on the disabled side is leaking, if it is leaking, tighten the flange bolt, or replace the sealing gasket.
3. Anti-freezing measures for year-round operation
If the equipment is working without interruption, there is no need for antifreeze, when the ambient temperature is between 0 ° C and -5 ° C, the shutdown must have antifreeze measures for more than 10 hours, when the ambient temperature is between -5 ° C and -10 ° C, the shutdown must have antifreeze measures for more than 5 hours, when the ambient temperature is below -10 ° C, the shutdown must have antifreeze measures for more than 1 hour. The specific anti-freezing measures can refer to the anti-freezing measures for operating occasions in some time periods.
