The cold and thermal shock Test Chamber has a freezing failure, what should I do?

The cold and heat shock Test Chamber is a relatively complicated environmental experimental equipment. During the operation process, due to incorrect operation, freezing failures sometimes occur, which affects the test cycle. Today, I will share how the freezing impact testing machine can solve the problem of freezing failure.

First, the refrigeration compressor does not start normally

1. First check whether the power supply voltage is too low or the motor circuit is not well connected.

If it is true that the grid voltage is too low, please restart after the grid voltage returns to normal; otherwise, please restart. If the wiring is poor, the connection between the wiring and the motor should be tested and repaired.

2. Check whether the exhaust valve is leaking

If the exhaust valve is damaged or leaking air is not tight, it will cause excessive pressure in the crankcase, which will prevent proper starting. Vent valve and seal line need to be replaced.

3. Check whether the energy regulation mechanism fails

Mainly check whether the oil supply pipeline is blocked, whether the pressure is too low, whether the oil piston is stuck, etc., and repair it according to the cause of the failure.

4. Check if the temperature controller is damaged or out of adjustment

5. Check whether the pressure relay is faulty

Check pressure relay and reset pressure parameter.

Second, the oil temperature is too high

The shaft and pad are not installed correctly, the clearance is too small. The size of the gap between the shaft and the pad assembly should be adjusted so that the gap meets the standard requirements.

Lubricating oil contains impurities that can cause bushings to fluff. In this regard, the brushed bearing bushes should be scraped off and replaced with new oil. If the tiles are heavily brushed, they should be replaced with new ones.

The shaft seal friction ring is installed too tightly or the friction ring is rough. The friction ring of the shaft seal should be readjusted; if the friction ring is severely brushed, it should be replaced with a new one.

If the suction and discharge temperature of the compressor is too high, the liquid supply valve of the system should be adjusted appropriately to restore the suction and discharge temperature to normal.

Third, the failure of the energy regulation mechanism

Check whether the oil pressure is too low or the oil pipe is blocked. If the oil pressure is too low. Just adjust and increase the oil pressure; if the oil pipe is blocked, the oil pipe should be cleaned and dredged. Is it because the oil piston is stuck. The oil piston should be removed and cleaned, and the dirty oil should be replaced, and then reassembled correctly.

Fourth, the pressure in the crankcase rises

Piston rings are not sealing tightly, resulting in high pressure to low pressure. The piston seals should be replaced with new ones. The exhaust valve is not closed tightly, causing the pressure in the crankcase to rise. The tightness of the exhaust valve seat should be checked. If the seal is not firm, replace it with a new valve in time. The tightness between the cylinder liner and the base has deteriorated. The cylinder liner should be removed, the joints cleaned and sealed, and then reassembled. Too much refrigerant enters the crankcase, causing pressure to rise after evaporation. Just drain the excess refrigerant in the crankcase.

Fifth, no oil pressure

Check for oil leaks or blockages at the oil pump piping system connections. If the connection is loose, the joint should be tightened; if it is blocked, the oil pipeline should be dredged.

Is it because the oil pressure regulating valve is opened too large or the spool falls off. If the oil pressure regulating valve is not adjusted properly, adjust the oil pressure regulating valve and adjust the oil pressure to the required value; if the spool falls off, reinstall the spool and tighten it firmly.

If there is too little oil in the crankcase or there is refrigerant, the oil pump will not enter the oil. If there is too little oil, refuel in time; if the latter, stop the machine in time to remove the refrigerant.

The oil pump is severely worn and the gap is too large, causing the oil pressure to fail. In this case, the oil pump should be repaired, and it should be replaced directly when the fault is serious.

Check whether the connecting rod bearing bush, main bearing bush, connecting rod small end bushing and piston pin have been severely worn. At this time, the relevant parts should be replaced in time.

The gasket of the rear end cover of the crankcase is misplaced, blocking the oil inlet passage of the oil pump. It should be disassembled and inspected, and the position of the gasket should be fixed again.

Sixth, a large amount of foam is generated in the crankcase

There are two reasons for the liquid foaming of lubricating oil in the crankcase:

A large amount of refrigerant is mixed into the lubricating oil. When the pressure is reduced, the refrigerant will evaporate severely and produce a lot of foam. To do this, the refrigerant in the crankcase should be evacuated.

Too much oil was added to the crankcase, and the big end of the connecting rod was agitating the oil, causing a lot of foam. To do this, excess lubricating oil in the crankcase should be released so that the oil level reaches the specified oil level line.

There is a freezing failure in the thermal shock Test Chamber, which can be analyzed and solved from the above points, and I hope to help you.