What are the considerations when choosing a refrigerant? It should meet the temperature range requirements for the process; it should have high refrigerating efficiency, high specific heat, high thermal coefficient, and low viscosity; it should be corrosion-resistant and non-corrosive to metals; it should be non-toxic, safe, and environmentally friendly, and not explosive. Refrigerants are widely used in the refrigeration industry, and their applications are very common in various industries, enterprises, and even in daily life. So, what are the commonly used refrigerants and what are their advantages and disadvantages?
Coolants primarily consist of water, inorganic salt, and organic compound aqueous solutions, yet they all have significant drawbacks. For instance, water has a high freezing point, making it suitable only for temperatures above 0 °C, which poses practical challenges. Saltwater solutions, such as calcium chloride solutions, are highly corrosive. Organic compound aqueous solutions, like ethylene glycol solutions, are stable and have good thermal properties, but they are also highly corrosive to equipment. Research has shown that their refrigerating capacity is significantly affected by temperature, flow rate, and humidity. The viscosity of ethylene glycol solutions is greatly influenced by temperature, with a sharp increase in viscosity as the temperature drops, leading to increased pump work and deteriorating system performance.
When it comes to food-grade refrigerants, refrigerated warehouses cannot be overlooked. Currently, a portion of the refrigerated warehouses on the market are food-grade warehouses, which are subject to stricter regulatory requirements than standard warehouses. They must ensure food safety while also preventing leaks of refrigerants and refrigerating agents. Since the market primarily features two cooling solutions—direct and indirect cooling—direct cooling involves the refrigerant being sent into the warehouse after the refrigeration unit cools it, posing a risk of refrigerant leaks. The refrigerants commonly used in refrigerated warehouses are ammonia, carbon dioxide, and Freon. Ammonia, well-known for its toxic effects, can contaminate food upon leakage, causing harm to humans and even posing life-threatening risks. Freon, on the other hand, is unfriendly to the environment, and in recent years, international environmental organizations have taken measures against the use of Freon in refrigerated warehouses. The carbon dioxide system, however, has high operating pressures and potential hazards; an accident could have dire consequences. Therefore, the indirect cooling system has emerged and gradually gained attention.
The application of secondary refrigeration systems in cold storage has garnered more attention and recognition, particularly regarding the safety issues of ammonia refrigeration systems and the environmental concerns of fluorinated refrigerants. With continuous development and improvement, indirect cooling refrigeration technology is poised for future prospects and opportunities. In this context, indirect cooling refrigeration systems using ammonia as the refrigerant hold potential for application. The professional refrigerant, Ice River Refrigerant, plays a crucial role in indirect refrigeration systems, and its development will significantly impact the application and promotion of these systems.
