The exhaust temperature of the air screw compressor is the temperature of the exhaust gas after the compressor compresses the gaseous refrigerant. It is usually fixed within a range. By observing the temperature change, the working condition of the compressor can be predicted to prevent safety hazards.
一： Five major hazards of compressor exhaust temperature
1. Overheating of refrigeration compressor
High exhaust temperature indicates that the compressor is working abnormally, which usually causes overheating and overload. In severe cases, it will cause damage to the compressor cylinder, causing hidden dangers to safety.
2. Failure of lubricating oil in the refrigeration system
High exhaust temperature will cause the air transmission coefficient of the refrigeration system to decrease and the shaft power to increase. Long-term high temperature will cause the viscosity of the lubricating oil to decrease, leading to subsequent cylinder wear, burning and other serious accidents, resulting in huge losses.
3. Cause compressor motor failure
Overheated temperature environment will cause abnormal expansion of compressor components, which will seriously cause them to get stuck in the cylinder, causing failure of the built-in motor of the closed compressor.
4. Cause refrigerant and lubricant to deteriorate
Under high temperature conditions, refrigerant and lubricant will undergo catalytic thermal decomposition, forming harmful acidic substances, carbon compounds and moisture in the compressor, which will accumulate on the exhaust valve, causing poor sealing and increased flow resistance. [Source: kapa] Foreign matter such as metal will block pipes, valves, capillaries or dryers and other components, seriously threatening the safety of the refrigeration system.
5. Cause premature damage to the compressor
Long-term high exhaust temperature will affect the working life of the compressor. Data show that if the temperature of the electrical insulation material rises by 10 degrees, [Source: kapa] its life will be halved. For a fully enclosed compressor, only by controlling the compressor exhaust temperature can the chiller be in a suitable operating condition.
In view of the above compressor exhaust temperature overheating phenomenon, once the system prompts the compressor overheating, the refrigeration equipment operator should take measures as soon as possible to avoid equipment safety accidents.
二：7 common reasons for high exhaust temperature
1. Unqualified cooling water pressure or temperature
When the cooling water temperature is too high, the oil cooler will have a poor effect; when the cooling water pressure is too low or the Y-type filter at the cooling water inlet is blocked, it will cause insufficient water. If it is found that it is not handled in time, it will cause the lubricating oil temperature to be high, causing the unit exhaust temperature to be high.
2. Lack of oil in the refrigeration system
Poor oil return of the compressor will lead to a decrease in the flow rate of the lubricating oil, too low oil pressure, and less oil return, which greatly reduces the amount of oil entering the head, causing the exhaust temperature to rise rapidly, and even the compressor will burn due to oil loss. In addition, frequent compressor startup is not conducive to oil return.Since the continuous operation time is very short, the compressor has no time to form a stable air pressure difference, and the lubricating oil can only remain in the pipeline, and the compressor will be short of oil.
3. Failure of the temperature control valve
The function of the temperature control valve is to automatically control the opening and closing of the valve according to the oil temperature. If a fault occurs, the lubricating oil will be directly sprayed into the head without passing through the condenser, which will cause the exhaust temperature to rise. We can check, repair and replace the temperature control valve.
4. Deterioration of lubricating oil quality
Deteriorated lubricating oil will cause the lubricating oil film of the screw compressor to become thinner and unable to form a sufficient lubricating oil film, thus causing abnormal operation of the compressor and abnormal noise. The solution is to replace the new lubricating oil.
5. Cooling system blockage and poor heat dissipation
Blockage or poor heat dissipation of the cooling system will cause internal scaling, poor heat dissipation, and failure to dissipate exhaust heat, causing high temperature; [Source: kapa] Similarly, damage to the cooling fan will also cause the cooling system to fail to dissipate heat in time. The solution is to check the cooling system, remove dirt or overhaul the exhaust fan.
6. Detection of control pipeline failure
This reason is caused by filter blockage, temperature detection system failure, abnormal operation of the unloading valve, etc. The solution is to clean or replace the air filter; check whether the unit load increases and causes overtemperature; check the working condition of the unloading valve and adjust it; inspect, repair and replace the system temperature detection system circuit, etc.
7. Oil filter is clogged
The screw oil filter can remove impurities such as metal particles and oil degradation in the oil to protect the normal operation of the bearings and rotors. When the oil filter is clogged and not replaced in time, it will directly lead to insufficient oil flow and excessively high exhaust temperature of the head. At the same time, insufficient lubricating oil will also affect the life of the bearings.
