Cold Storage, Cold Room, or a walk-in room designed to maintain an artificially created temperature. This room is insulated and built with compressors, evaporators, condensers, etc as an integral part of that cooling process. Insulation is the major component while setting up a cold storage facility because without it the energy efficiency will be affected and the purpose and impact of the cold storage preservation will be reduced.
Types of Cold Storage-
- Refrigerated Containers: Most basic and effective option for cold storage. They are also mobile and thus have an advantage over themselves.
- Cold Rooms: They are just dark cold rooms with certain humidity.
- Blast Freezers and Chillers: Mostly used by companies, restaurants, etc who have to quickly store and cool food before it reaches its end consumer.
Chemicals Used In Cold Storage
Ammonia (NH3) is used as a refrigerant in cold storage facilities since the 1930s, it is so far acknowledged as the most efficient refrigerant chemical and environment-friendly refrigerant. The GWP (Global Warming Potential) and ODP (Ozone Depletion Potential) of Ammonia are equal to zero, which makes it the first and major choice as a refrigerant in cold storage facilities.
NH3 has a low boiling point, is highly energy-efficient, and has minimal impact on the environment. It offers a wide array of benefits for the refrigeration industry. The cost of ammonia/kg is much lower than the cost of HFCs (Hydrofluorocarbon), one more type of refrigerant used in cold storage.
Ammonia has better heat transfer properties and has smaller pipe sizes for both vapor and liquid ammonia. With all the benefits of using ammonia as a refrigerant, there is also a con that must not be neglected. NH3 is highly flammable at certain concentrations and a toxic refrigerant, it has a strong pungent smell that can be recognized early and any leakage can be checked.
HFC (Hydrofluorocarbon) is another type of refrigerant that is used in cold storage facilities, it is considered the 3rd generation of fluorinated refrigerant gases. HFCs are a good alternative to CFCs and they are environment-friendly with an OPD of zero.
Other industrial refrigerants are CO2, Water Refrigerant, HCs (Hydrocarbons), and HCFC (Hydro-chlorofluorocarbons).
Machinery used in Cold Storage Facility-
- Compressor: It is the only device among all in a cold storage facility, that needs the energy to run. Compressors are the main component that runs the facility and are used to raise the temperature and pressure of the refrigerant vapor coming out of the evaporator.
- Condenser: It removes the heat and circulates the water. Its heat exchange efficiency determines the efficiency of the storage facility.
- Receiver: After phase change from the condenser, the high-pressure liquid condensate is stored here.
- Expansive Valve: Reduce the temperature and pressure of the refrigerant using a device.
- Evaporator: It takes heat from the storage compartment that is supposed to be cold. That heat is then used to vaporize the liquid refrigerant.
- Blowers: The cool air is spread across with a convection process.