I. Why should refrigerator compressor refrigeration test?

The compressor is the heart of the refrigeration system. Refrigerant leakage is a hidden danger and fault of the compressor, which will lead to prolonged operation time of the refrigeration shrinkage machine, incomplete or non-frosting of the evaporator, resulting in product defects and failure of the system to achieve refrigeration effect. Infrared thermal camera can accurately locate the leakage position of refrigerant and prevent product quality accidents. The compressor is generally composed of housing, motor, cylinder block, piston, control equipment (starter and thermal protector) and cooling system.

1. Low refrigerant temperature: the refrigerant leakage leads to energy loss and refrigeration failure;

2. Abnormal temperature of the compressor housing affects the service life of the compressor;

3. Abnormal temperature of the motor housing and its bearing may cause the motor and the whole refrigeration system to stop running;

4. The temperature of the cylinder block or the outlet of the cooling fluid is abnormal, and the refrigeration effect cannot be achieved;

5. control equipment temperature anomaly, affect the system's working stability and service life of components.

In China, refrigerators are divided into four grades: A, B, C and D. Grade A for classy article (the international advanced level), grade B as well (the international average level), grade C for general product (domestic advanced level), D for supplies (domestic average level), as the basis of quality evaluation of the refrigerator, according to the grade standard of refrigerator regulation, refrigerant leakage is divided into four levels: A level 0.16 grams/year or less; Grade B ≤ 40.32g/year; Grade C ≤ 0.40g/year; D≤0.50 g/year, so refrigerant leakage detection is an important process for refrigerator production.

Infrared thermal camera refrigerant leakage can be found in time, avoid continued leak accident and reduce energy losses, at the same time can also be the shell of compressor system, motor, cylinder, cooling liquid export, control equipment and inspection, timely find out whether the compressor is in good working condition, found the problem, improve the working efficiency of the compressor, to avoid accidents.

II. Which parts of the compressor are prone to refrigerant leakage?

In the refrigeration system, the refrigerant leakage is mainly involved in the welding part of the compressor part connecting the pipe fitting (process pipe, high-pressure pipe, low-pressure pipe), filter (there are two welding spots), capillary tube and other welding spots connecting the copper pipe.

Among them, the functions of process pipe, high pressure pipe and low pressure pipe on the compressor are as follows:

1. Process tube: Mainly conveying refrigerant to the compressor.

2. High-pressure tube: the refrigerant output tube of the compressor. The gaseous refrigerant becomes a high-pressure liquid under the action of the compressor and the throttle valve.

3. Low-pressure tube: after the completion of refrigeration, the refrigerant recovers the low-pressure state and enters the compressor through the low-pressure tube to start a new round of refrigeration cycle.

Generally, brazing and silver welding are mainly used in the welding of refrigeration system. This welding method (especially brazing) is easy to produce surface lap joint, but there is no internal fusion, resulting in non-compact joints and leakage.

Generally, refrigerant leakage detector is used to detect refrigerant leakage on the production line. However, it is very difficult to adjust the sensitivity of refrigerant leakage detector, and the sensitivity adjustment will lead to false alarm or wrong indication. If the sensitivity is lowered, the products with the problem will be missed. Therefore, the infrared thermal camera can be used to solve the above problems.

III. How to use infrared thermal camera to detect refrigerant leakage?

Since the leakage point is generally small, and sometimes the temperature difference on the pipe wall is also small, attention should be paid to the detection of refrigerant leakage by using infrared thermal camera:

1. The infrared thermal camera with high thermal sensitivity (NETD) should be used for detection under possible conditions.

2. Coolant leakage is mainly in the compressor part of the joint pipe welding part (process pipe, high-pressure pipe, low-pressure pipe), filter (there are two welding spots), capillary tube connection copper pipe welding spot, these are the key detection parts, the whole copper pipe leakage possibility is very small.

3. To prevent other heat sources on the site from transmitting and causing interference at the detection site, it is suggested to install shielding on the site.