Simple workflow of cold room refrigeration equipment

Compressor (compression), condenser (heat dissipation), throttle valve (throttling), evaporator (refrigeration), returns to the compressor to complete the refrigeration cycle

Compressor: suction, compression, and delivery of refrigerant vapor.

Throttle valve: throttle and depressurize, and regulate the refrigerant flow into the evaporator.

Evaporator: absorb heat (output cooling capacity) and refrigerate.

Condenser: to cool and condense the refrigerant superheated steam discharged from the booster of the compressor into liquid. Our company now uses air-cooled condenser

High-pressure area: from compressor outlet to throttle valve inlet.

Low-pressure area: throttle valve outlet to the compressor suction.

Fault diagnosis method

1 look, 2 touch, 3 listen, 4 tests

1. Look

Carefully observe whether the shape is in good condition, whether the components are damaged, whether the pipelines are broken, and whether the welding joints are oil-stained (oil-stained indicates leakage).

Check whether the installation position of electrical components is loose.

Use the pressure gauge to check whether the operating pressure is normal. When the ambient temperature is 30C, the pressure of low-pressure gauge and high-pressure gauge of the R22 air conditioner should be 0.49 ~ 0.51mpa and 1.8 ~ 2.0MPa respectively.

2. Touch

Remove the shell of the outdoor unit of the tested air conditioner and start the compressor for 15 minutes.

Put it on the air outlet by hand, if there is hot air, it is normal.

Check whether the compressor shell is overheated (it should be hot in summer).

Touch the high-pressure exhaust pipe of the compressor. It should be hot in summer and very hot in winter. If it is not hot or hot, it may be refrigerant leakage.

Feel cool when touching the low-pressure suction pipe.

3. Listening

Listen to the sounds of the air conditioner running:

The running sound of the fan shall be stable and even. If there is metal collision sound, it means that the fan leaf is deformed or the axis is not right

The running sound of the compressor shall be stable and even. If there is a "buzzing" sound in the compressor after power on, it means that the compressor has a mechanical fault and cannot be started.

4. Tests

Use a multimeter to measure the power supply voltage and insulation resistance.

Use an ammeter to measure whether electrical parameters such as running current meet the requirements.

Use an electronic leak detector to check the refrigerant for leakage and the degree of leakage.