HomeServicesRefrigerationGlycol’C02 Systems

Glycol’C02 Systems

Glycol/CO2 systems are hybrid refrigeration systems that use a combination of glycol and carbon dioxide (CO2) as refrigerants. These systems are commonly used in commercial and industrial refrigeration applications, particularly in supermarkets, food processing plants, and cold storage facilities. The primary objective of using such systems is to enhance energy efficiency, reduce environmental impact, and improve overall refrigeration performance.

Key Components and Operation of Glycol/CO2 Systems

  1. Primary Refrigerant Loop (CO2):
    • CO2 Compressors: Compressors that circulate CO2 through the primary refrigeration loop.
    • CO2 Condensers: Heat exchangers where CO2 gas is condensed into liquid form after releasing its heat.
    • CO2 Expansion Valves: Devices that reduce the pressure of liquid CO2, causing it to evaporate and absorb heat in the process.
  2. Secondary Refrigerant Loop (Glycol):
    • Glycol Chillers: Heat exchangers where glycol is cooled by the CO2 refrigeration loop.
    • Glycol Circulation Pumps: Pumps that circulate the cooled glycol through the secondary loop to various refrigeration units.
    • Glycol Heat Exchangers: Devices where glycol absorbs heat from the refrigerated space or products, thereby cooling them down.

How Glycol/CO2 Systems Work

  1. Primary Loop (CO2):
    • The CO2 refrigerant is compressed and circulated through the primary loop.
    • The CO2 passes through condensers where it releases heat and condenses into a liquid.
    • The liquid CO2 then flows through expansion valves, where it evaporates and absorbs heat in evaporators, cooling the glycol in the secondary loop.
  2. Secondary Loop (Glycol):
    • The cooled glycol is circulated by pumps through the secondary loop.
    • The glycol flows through heat exchangers located in various refrigeration units (e.g., display cases, storage rooms).
    • As the glycol absorbs heat from the refrigerated spaces, it warms up and returns to the chiller to be cooled again by the CO2 system.

Advantages of Glycol/CO2 Systems

  1. Energy Efficiency:
    • CO2 has excellent thermodynamic properties, leading to higher energy efficiency and lower operating costs.
  2. Environmental Impact:
    • CO2 is a natural refrigerant with a low global warming potential (GWP) and no ozone depletion potential (ODP), making it environmentally friendly.
    • Glycol is typically non-toxic and biodegradable, adding to the system’s overall environmental benefits.
  3. Safety:
    • CO2 operates at high pressures but is non-flammable and non-toxic at typical concentrations used in refrigeration.
    • Glycol provides a safe secondary loop that can be used in areas where direct contact with CO2 might be hazardous.
  4. Operational Flexibility:
    • The secondary glycol loop allows for flexible and modular installation, making it easier to expand or modify the refrigeration system.
    • Glycol can be used to cool various types of equipment and spaces, providing versatility in system design.
  5. Improved Temperature Control:
    • The use of a secondary glycol loop allows for precise temperature control, which is critical in applications requiring consistent and specific temperatures.

Applications of Glycol/CO2 Systems

  1. Supermarkets:
    • Used in large refrigeration systems for display cases, walk-in coolers, and freezers.
  2. Food Processing Plants:
    • Applied in processes requiring precise temperature control for food safety and quality.
  3. Cold Storage Facilities:
    • Used to maintain low temperatures in large storage areas for perishable goods.
  4. Breweries and Beverage Production:
    • Employed to maintain consistent temperatures during fermentation and storage processes.