Use of Glycol in Chiller system

Author: Shubham Karnani

Glycol releases and absorbs huge amount of heat without changing system’s temperature and hence finds its association with chiller system, for process cooling and heating applications. Water, as a coolant, in chillers, possess several kinds of issues such as scaling, corrosion and algal growth. As per this, if glycol is added in water, and pumped through the pipes of a glycol chiller, it manages to slow the freezing rate, even inhibiting bacterial growth within. Glycol is an organic water-miscible antifreeze liquid that is used as a heat transfer fluid which draws away heat, and allows the engine to operate efficiently, with lesser malfunctions and damages to its parts.

A process cooling and heating system provides consistent pressure and temperature to industrial process, ensuring highest grade performance. Owing to glycol’s antifreeze property, it helps in cooling of fluid below boiling temperature in order to complete water condensation. Water is used as coolant in most of the cases but it takes part in rust formation, algal growth, scale deposition, which adversely affects internal metallic chamber. So, adding glycol along with water ensures more heat transfer capability and low freezing point as well as ensures protection. The glycol solution prevents bursting and freezing in cooling system. For most chiller applications, mixture of glycol and water is used for enhanced heat exchange. Two most common areas where glycols are used are chiller cooling system and evaporators.

Glycol chillers are mainly categorized into Ethylene and Propylene chillers, used in chiller machines through HVAC system, as per different end use perspectives. These are closed looped systems where the glycol mixture circulates constantly without coming in contact with outside environment. Since, the system is a closed one, there is a negligible chance for glycol contamination and water loss from evaporation. In Evaporators, the heat exchanger transfers heat between glycol solution and the refrigerant. It works around the flowing glycol that absorbs heat from the refrigerant and passes it away.

Ethylene Glycol has more desirable physical proper ties, specially at lower temperatures. It also possesses superior heat transfer properties due to high boiling point and viscosity. On the other hand, Propylene glycol posses less temperature, contain corrosion inhibitors to enhance heat exchange. Its pH and toxicity are low, so basically Propylene Glycol used in food industry, beer manufacturing, cold shortages and other manufacturing units. Ethylene Glycol has been used in industrial water-cooling system (pharmaceutical industry, cold rolling mills, vegetable oil manufacture and other F&B industry) for its indirect cooling application. Besides this, glycol is anti-oxidising element which needs inhibitors to prevent for long time. Ethylene Glycol is more toxic than Propylene, so it needs to be handled safely. Glycol water coolant mixture from a refrigeration unit in a Glycol chiller funnel linked with thermal heat exchanger piping. It absorbs heat from industrial process, and then warmed the coolant. Theses warmed coolant hence return to refrigeration unit in order to repeat cooling process.

Chemtex Speciality Limited is an eminent supplier of both Ethylene and Propylene Glycol all over India. Also available are its inhibited variants, with coolants, rust inhibitors, and antifoulants, to be used in any automotives, pharmaceuticals, bio-tech, food & beverage, hydraulics, paints, polyester manufacturing, cosmetics, and geo-thermal applications. For more details, please visit https://www.chemtexltd.com/products-and-solutions/heat-transfer-fluid/glycol-antifreeze/. For other information, contact us at info@chemtexltd.com.