Glycol chiller refrigeration principle

Glycol chiller, as the name suggests, is a chiller that uses glycol as the carrier refrigerant of the chiller.
Sometimes the cold-carrying liquid needs to go below 0°C. If the cold-carrying liquid with water will freeze, adding some antifreeze liquid can avoid freezing, and ethylene glycol can be antifreeze.
In the all-air system, when the outdoor temperature is too low in winter, it is not easy to realize the air conditioning method of using cooling tower to supply cold directly to the inner area. At this time, the cold outdoor air can be used as a cold source, and glycol solution can be used as a refrigerant to introduce the natural outdoor cold source into the room to supply cold to the inner zone. When it is necessary to supply heat to the outer zone and cold to the inner zone, turn off the chiller and still use the boiler or city hot water as the heat source to supply heat to the outer zone.
Glycol solution cooling works:
Plate heat exchanger is installed in the outdoor area, and the cold outdoor air is introduced into the plate heat exchanger by the fan, and the glycol solution and the cold outdoor air exchange heat in the plate heat exchanger. The cooled glycol solution enters the air-conditioning unit in the inner zone, where it exchanges heat with the mixed air (the air after mixing the new and return air), and the mixed air is cooled and enters the room in the inner zone at a lower temperature, supplying cooling to the room in the inner zone. Glycol solution temperature rises, and again back to the outdoor plate heat exchanger, and outdoor cold air for heat exchange, the temperature is reduced to continue the cycle. This type of heat exchange is often used in heat recovery systems. Glycol and high-temperature exhaust air for heat exchange, the temperature rises, into the fresh air cabinet, to the new air for preheating. Thus, the heat in the exhaust air is recovered to heat the fresh air, saving electricity and operating costs.
This way of using the glycol solution as a refrigerant and introducing the cold air from the outdoor cold air to supply cold to the inner zone is a very energy-saving air conditioning method. It is only necessary to install a plate heat exchanger outdoors, and when in operation, the chiller is turned off and only the fan and air-conditioning unit are turned on to bring in a natural cooling source to supply cooling to the inner zone, saving electricity and reducing operating costs. However, in the process of utilizing outdoor cooling capacity to supply cooling to the inner zone, the cold air has to be exchanged with glycol, and the glycol is then exchanged with the mixed air, and after the two heat exchanges, the loss of cooling capacity is larger, and the efficiency of the heat exchange is not high, generally lower than 60%.