8 Factors to Consider when Choosing a Refrigerant

The nature of the refrigerant will directly affect the cooling effect of the refrigeration equipment, as well as the form and performance of the refrigeration cycle. Therefore, a reasonable choice of refrigerant is a very important issue. The following are eight factors to consider when choosing a refrigerant.

The first thing to consider when choosing a refrigerant is safety, non-toxic, non-irritating odor, non-combustible, non-explosive.

We need to consider environmental protection, including the destruction of the ozone layer, expressed in ODP, and an impact on the greenhouse effect (GWP). There is not much consideration about the greenhouse effect, and science is still inconclusive because water vapor and carbon dioxide have an effect on the greenhouse effect. We need to focus on the destruction of the ozone layer, which is the ODP indicator. Ordinary freons have great damage to the ozone layer. Hydrocarbons and those that do not contain chloride ions are relatively better.

If the fluidity and transmission of the refrigerant are relatively good, the flow transmission resistance in the system will be smaller, the loss will be less, and the entire equipment will be smaller when selecting the model.

The thermodynamic properties are better, such as the condensation compression is not too high, the evaporation pressure is not too low, the pressure ratio is not too large, too large is not good for selecting the compressor, but the high pressure is too high, and the pipeline requirements are too high, which is not good. In addition, the latent heat of vaporization is larger, and the heat absorbed when changing from liquid to gas is a bit larger, which is equivalent to a larger cooling capacity. The boiling point is lower, the temperature range of the preparation can also be lower. The density of the substance should be slightly larger, the relative cooling capacity should be smaller, and the equipment may be larger. But too much density is not good, too much will cause the viscosity to be too high, which is not conducive to flow.

In addition, the stability is better, and it is not prone to chemical reactions with other substances, such as water and oil. Also, it is not easy to decompose at high temperatures. After decomposition, some non-condensable gas will affect the refrigeration performance.

There is also a better solubility with oil, but this is also contradictory. It has good oil solubility and is miscible with oil. When the system is set up, it is not necessary to consider oil return. Freon and oil are always mixed, and the lubricating performance is also relatively good. Better but participate

There is more oil circulating in the system. When the refrigerant boils in the evaporator, the oil will also become foam, which will also affect the heat transfer. Another problem with good oil solubility is that after the oil and the working fluid are mutually dissolved, it is equivalent to the refrigerant in the oil, and the refrigerant in the oil involved in the lubrication may affect the lubrication effect. However, if the oil solubility is not good, it is almost incompatible with the oil, the oil will form an oil film on the surface of the heat exchanger, which will also affect the heat transfer.

Note: Good oil solubility is actually a prerequisite, but in the high-temperature section, especially the liquid part, the two can be completely miscible, but in the low temperature and low-pressure section, the refrigerant evaporates, but the oil does not evaporate. It can only be affected by the airflow of the refrigerant. Take away part, some will always settle inside the evaporator, more and more over time, especially for large systems and flooded evaporators. In addition, the mixture of Freon and lubricating oil can dissolve copper. When the dissolved copper ions circulate with the refrigerant and return to the compressor and come into contact with steel or cast iron parts, they will precipitate and deposit on the surface of these steel components to form a Layer of copper film-the so-called copper plating phenomenon.

This is especially important for semi-sealed and fully sealed compressors because the motor is in direct contact with the refrigerant. At this time, the refrigerant is required to not corrode the winding coils and electrical components, and has good insulation, and cannot easily conduct electricity or leak electricity.

Because the refrigerant Freon is all organic, it is almost insoluble in water. The disadvantage of insoluble is that it is easy to block, especially the position of the throttle valve is easy to be blocked by ice, and it has disadvantages when it is dissolved in water. It is corrosive after reacting with water, so it is better not to dissolve in water. Note: Both Freon and hydrocarbon refrigerants are difficult to dissolve in water. For refrigerants that are difficult to dissolve in water, if the water content in the system exceeds the solubility of water in the refrigerant, free water will appear in the system. When the evaporation temperature is lower than 0°C, the free water will freeze, blocking the expansion valve or other narrow flow channels-the so-called ice block. Freon, which has strong water solubility, does not have the problem of ice blocking, but if it contains water, it will hydrolyze to form acidic substances and corrode metals.

For example, small-scale hermetic compressor household appliances often use fluorine refrigerants. Ammonia is mostly used in large-scale industrial refrigeration, and hydrocarbons are mostly used in petrochemicals.

Only by considering the above factors can we ensure that we choose safe and high-quality refrigerants so that the refrigeration equipment can exert the best refrigeration effect. If you want to know more about refrigerant problems after reading the above content, you can contact us for more detailed solutions. At the same time, our production is safe and high-quality, with stable performance.

As a professional manufacturer of refrigerants and fluoropolymers, we have accumulated more than 20 years of experience in the production of this field. We have leading technology and a professional manufacturing team and produce products in full compliance with standards. We can also provide thoughtful one-stop service and develop effective solutions for you according to your needs. If you want to buy our refrigerant, please contact us immediately!