How to Antifreeze for Industrial Chillers in Winter? Antifreeze can protect equipment from low ambient and freezing process conditions. If your chiller is exposed to freezing ambient conditions, you must protect your water chiller system. Here inform you how to antifreeze for your industrial water chiller.
Why do industrial chillers need to be anti-freeze?
When winter comes, the ambient temperature is too low, which may lead to ice formation in the circulating cooling water pipe of industrial chiller, and the density of ice is smaller than water, so the volume will expand when ice formation occurs, and in the closed volume, due to the action of ice, the copper pipe and heat exchanger shell will be frozen and cracked or deformed. In order for the chiller unit to have a smooth winter and avoid irreversible damage to the equipment caused by the low-temperature environment, we remind all users to do the relevant anti-freeze work.
How do industrial chillers do freeze protection?
In order for the chiller unit to survive the winter and avoid irreparable damage to the equipment caused by the low-temperature environment, it is necessary to drain the equipment in time. Such as chillers, pipes, pumps, cooling towers, and ends, when the ambient temperature is below zero degrees, the water must be drained in advance.
- the following provides some chiller winter drainage measures.
- Condenser: open the end cover of the other end of the water pipe. After opening, pay attention to put the end cover and screws away. (Remember: Evaporator drain do not do this!)
- Evaporator: Open the blowdown valve below the evaporator connection to drain all the water. It is best to keep the blowdown valve in the normally open state in winter and close the water supply before starting the machine in the second year.
- Pipes and pumps: Drain the water from the pipes and pumps at the lowest place.
- Cooling tower: open the blowdown valve at the lowest part of the cooling tower water tray to drain the chassis.
- End: There is a blowdown valve at the bottom of the coil, and the blowdown valve is also opened. The blowdown valve is in the normally open state during winter.
During the day or night, the pump must be kept in running condition, and the water must be drained if not used for a long time. In case of bad weather (temperature below -10℃), it is better to stop and drain the water or add antifreeze to the water.
- Properly adding antifreeze is the key to preventing freezing.
The full name of antifreeze coolant is antifreeze coolant, that is, a coolant with antifreeze function, can prevent the cold winter coolant freeze, expand the laser and chiller internal pipeline and damage the pipeline seal.
Now there are a variety of different kinds of different formulations of antifreeze on the market, so many customers do not know how to choose, deployment, or have chosen some of the antifreeze is not suitable for our chillers to use.
In fact, our chillers have certain requirements for antifreeze, wrong choice or inappropriate use will damage the internal piping of the equipment, chillers for antifreeze performance requirements are as follows 5 points.
- Chemical stability
- Good anti-freeze performance
- Low-temperature viscosity
- Anti-corrosion and anti-rust
- No swelling and erosion of rubber sealing conduit.
Most of the antifreeze is ethylene glycol and propylene glycol, and this type of antifreeze can be used directly in the appropriate proportion according to the ambient temperature requirements.
But the mother liquor, i.e. concentrated type, can not be used directly but should be modulated to a certain concentration with softened water according to the requirements of the operating temperature. Let’s introduce the commonly used antifreeze in the market.
The freezing point of ethylene glycol antifreeze solution changes with the change of ethylene glycol in the aqueous solution, when the volume concentration is below 56%, the concentration of ethylene glycol in the aqueous solution increases and the freezing point decreases.
It rises until its freezing point rises to -13°C at 100% concentration. This is an important reason why concentrated antifreeze cannot be added directly to the chiller for freeze protection.
- In the area where the minimum temperature is -3.5℃, you can use the volume concentration of 9.1% ethylene glycol antifreeze, the ratio is approximately adjustable to 1:9 [10% ethylene glycol, 9% pure water].
- in the lowest temperature of -15 ℃ area, you can use a volume concentration of 28% ethylene glycol antifreeze, the ratio is about adjustable to 3:7 [3 into ethylene glycol, 7 into pure water].
- Finally, our recommendations for storing your water chiller when it’s not working during the cold winter months.
- If the equipment is shut down within a short time, it is recommended to start the chiller separately and keep it running continuously to maintain the normal working water temperature. And always pay attention to the running state of the chiller in case of a power cut.
- If the equipment does not work at night, and to make sure that there will be no power outage, please start the chiller alone, and set the water temperature of the low-temperature system and the high-temperature system to 5~10℃ for the sake of energy saving. Ensure that the coolant is in circulation and the water temperature is not below the freezing point.
- If the chiller is shut down for an extended period of time, be sure to drain the coolant from inside the chiller and empty the coolant from inside the water tank, heat rod housing, pump, filter, and heat exchanger with nitrogen gas. (If you are unable to drain the coolant due to environmental limitations, refer to step 2 to ensure that the coolant is circulating and the water temperature is not below freezing.
PS: If the water draining chiller is started for the first time after adding water, the flow rate may be low due to the air in the pipes and then the water flow alarm may occur, if this happens, please exhaust the water cycle through the exhaust hole of the pump, or restart the pump several times at 10-20 seconds intervals.
If you have any questions ,kindly to contact our expert to supply you free technical support.