Basic Characteristics Required for Refrigerant

Basic Characteristics Required for Refrigerant


Refrigerant is an indispensable working medium to realize refrigeration, and we can judge its pros and cons by whether the refrigerant has basic characteristics. This article will specifically introduce the basic characteristics of refrigerants.

Basic Characteristics Required for Refrigerant
the basic characteristics required for refrigerants

The basic characteristics of the refrigerant are directly related to the refrigeration effect of the refrigeration device. Some inferior refrigerants may lack the properties required by some refrigerants, resulting in poor refrigeration effects and even safety accidents. The following are the basic characteristics required for refrigerants.

1. Higher latent heat of vaporization

In the refrigerant, high latent heat of vaporization is required. This results in a high cooling effect and a low refrigerant circulation rate. In each refrigeration cycle, more heat can be absorbed and discharged.

2. High suction density and low compression ratio

The high suction density at the suction port of the compressor means a small size compressor and a less powerful compressor motor. After the refrigerant passes through the evaporator, the refrigerant gas expansion is not very high, ie. The expansion of the fluid to the gas is low. This property of the refrigerant provides a low compression ratio for the compressor, and the higher mass flow rate of the refrigerant results in a low circulation rate in the system.

3. Non-corrosive, non-toxic, non-flammable

(1) The refrigerant must not be toxic or fatal to air conditioners, human health, and food. When in contact with metal parts such as pipes and compressors, it shall not cause any form of electrochemical corrosion.

(2) It must be compatible with non-metallic parts, such as nitrile rubber tube, O-ring (for sealing).

(3) When the refrigerant is compressed under high pressure and high temperature inside the compressor, it must not cause an explosion or fire in the system and keep its non-flammability.

4. High critical temperature

At this temperature, the vapor refrigerant remains in a vapor state and cannot be liquefied into a liquid even after passing through the condenser or any cooling medium at any given pressure. This happens only when the refrigerant temperature exceeds its critical temperature (ie, critical temperature). When the critical temperature of the refrigerant is low.

Therefore, it is best to choose a refrigerant with a higher critical temperature, otherwise, the vapor refrigerant after being compressed into hot vapor inside the compressor will not condense into liquid after passing through the condenser coil.

In order to allow hot external air to pass through the condenser coil through a fan in summer, so that the high-temperature vapor refrigerant is condensed into a liquid refrigerant, the refrigerant must have a high latent heat of vaporization.

5. Compatibility with lubricating oil

The refrigerant used must be compatible and miscible with the compressor oil (meaning that the refrigerant is easily separated), because the compressor has a greater chance of mixing inside.

6. High latent heat

Latent heat refers to the amount of heat required by the refrigerant to change its state from liquid to vapor. With high latent heat, the refrigerant absorbs more heat from the load. This improves the cooling efficiency of the system. Moreover, it reduces the required mass flow and amount of refrigerant.

7. Low boiling point

The low boiling point allows the refrigerant to evaporate into vapor at a lower temperature. The refrigerant enters the evaporator coil as a liquid and leaves as a vapor. When the refrigerant leaves the evaporator, the refrigerant must be in the form of 100% vapor to prevent liquid refrigerant from entering the compressor because the liquid is not compressible.

In addition, low-temperature refrigerants can easily absorb indoor heat and convert them into vapor form due to their low boiling point refrigerant characteristics.

Therefore, in the case of a low boiling point, we can keep the temperature lower, just like in a household air conditioner, we can set the temperature to +16°C, and for a household refrigerator, we can keep the temperature at -5°C For commercial systems, we can keep it at a lower temperature. Keep it as low as -25°C.

The cooling process is performed by circulating the same cold air in the refrigerator space because of the temperature of the recirculating airdrops. The expansion valve throttles the flow of refrigerant.

Now, the key here is the cold air that is recirculated as it passes through the evaporator. Due to its low boiling point, the refrigerant can extract latent heat from the cold air and convert it into 100% vapor.

8. Low condensing pressure

The lower condenser pressure reduces the power drawn by the compressor during the compression process, thereby making the compressor smaller. The condenser tube does not have to handle high-pressure refrigerant. Thereby reducing the overall design cost.

9. High dielectric strength (used for compressors with integrated motors)

When the refrigerant directly contacts the motor windings in the hermetic compressor, the refrigerant with high insulation strength can avoid short circuits. The dielectric strength of any material is a measure of its insulating properties.

10. Should be cheap and easily available

In case of repairs, maintenance, or accidental leakage; the refrigerant must be readily available at a reasonable price.

11. Easy to detect leaks

You can use the soap solution on the connector to keep the pipe under pressure for 20 to 30 minutes through a pressure test method to check the pressure drop, thereby detecting leaks by odor.

In the UV leak detection method, we inject a small amount of fluorescent dye into the running refrigeration system and then use the leak detection lamp to scan the system. The dye escapes from the leak and appears as a green or yellow solution.

Perform halide leak testing on halogenated hydrocarbons (freon compounds) refrigerants. It involves keeping the torch or flame near the leak area. If the refrigerant leaks, the flame turns green. In each case, perform the halide torch test in a well-ventilated room.

After we purchase a refrigerant, we can test whether it has the above characteristics through some tests, so as to avoid the adverse effects caused by the continued use of inferior refrigerants. If you want to learn more about refrigerants after reviewing the above content, you can contact us for more detailed solutions.

As a professional supplier of refrigerants and fluoropolymers, we have won praise and trust from many customers with our excellent technology and high-quality and safe products. We have a strict production department and established a complete quality inspection system, which can strictly control the quality of products. We can also provide thoughtful one-stop service according to the diverse needs of customers. If you want to buy our refrigerants, please contact us immediately!