Cold and hot shock testing machine refrigeration system blocking explanation

The thermal shock test machine is generally composed of compressor, air conditioner evaporator, cooler and piping system software. Refrigeration system blockage generally has two types: dirty blockage and ice blockage. Oil blockage is relatively rare.

1. Dirty blockage

When the compressor of the thermal shock test machine is damaged, and there is waste in the refrigeration system, this waste is very easy to cause blockage in the capillary tube or filter device, which is called dirty blockage. Dirty clogging is caused by residues (oxidized skin, copper scraps, weld penetration) in the refrigeration system. When it circulates with the refrigerant in the system, it will block the capillary or filter device.

Dirty block removal method: use gas cutting to remove the capillary tube, filter device, cooler, air-conditioning evaporator, dismantle and replace the carbon molecular sieve in the capillary tube and filter device, clean the cooler and air-conditioning evaporator, carry out drying, vacuum packaging, and then welding, Charge with refrigerant.

2. Ice block

Ice blockage is caused by moisture entering the refrigeration system of the thermal shock test machine. f-12 itself has a certain amount of moisture. In the process of overhauling or adding refrigerant, moisture and gas enter the system software. Under the ultra-high pressure effect of the compressor, the refrigerant changes from liquid to vapor, so that the moisture is free. Enter the narrow and long capillary tube with the refrigerant circulation system. When the moisture content per kilogram of refrigerant exceeds 20mg, the moisture content of the filter device is saturated, and the moisture cannot be filtered out. When the temperature of the inlet and outlet of the capillary reaches 0℃, the moisture is converted from the refrigerant and becomes ice, resulting in ice Blocking.

3. Oil blocking

The compressor cylinder is seriously worn or the clearance between the piston and the cylinder is too large.