1. The impact of high ambient temperature on the screw air compressor in two aspects
A: The higher the temperature, the thinner the air (like the low efficiency of the air compressor in plateau areas), resulting in a decrease in the working efficiency of the air compressor, which makes the air compressor spend more time in the loaded state and carries more loads, resulting in empty air. The more heat generated by the compressor, the higher the temperature of the air compressor must be.
B: Generally, when the air compressor is designed, there is a design operating environment temperature (30-40 degrees), and the highest temperature of the air compressor operating at the design operating environment temperature is generally close to the protection temperature of the air compressor. If the air compressor environment If the temperature is higher than the design operating environment temperature, the temperature of the air compressor will be increased so that the air compressor will even exceed the shutdown temperature of the air compressor, resulting in high temperature of the air compressor.
2. The air compressor system lacks oil
The oil level of the oil and gas barrel can be checked. After the shutdown and pressure relief, when the lubricating oil is static, the oil level should be slightly higher than the high oil level mark H (or MAX). During the operation of the equipment, the oil level cannot be lower than the low oil level mark L (or MIX). If it is found that the oil quantity is insufficient or the oil level cannot be observed, stop the machine immediately and refuel.
3. The oil stop valve (oil cut-off valve) is not working properly
The oil stop valve is generally a two-position two-position normally-closed solenoid valve, which is opened when starting and closed when stopping, so as to prevent the oil in the oil and gas barrel from continuing to spray into the machine head and spray out from the air inlet when the machine is stopped. If the component is not turned on during loading, the main engine will heat up rapidly due to lack of oil, and in severe cases, the screw assembly will be burned.
4. Oil filter problem
A: If the oil filter is clogged and the bypass valve is not opened, the air compressor oil cannot reach the machine head, and the main engine will heat up rapidly due to lack of oil.
B: The oil filter is clogged and the flow rate becomes smaller. One case is that the air compressor is not completely taken away by the heat. The temperature of the air compressor rises slowly to form a high temperature. The other case is that the air compressor becomes high temperature after the air compressor is unloaded. , because the internal oil pressure of the air compressor is high when the air compressor is loaded, the air compressor oil can pass through, but after the air compressor is unloaded, the air compressor oil pressure is low, and it is difficult for the air compressor oil to pass through the air compressor oil filter, and the flow rate is too small, resulting in air Press high temperature.
5. The thermal control valve (temperature control valve) fails to work
The thermal control valve is installed in front of the oil cooler, and its function is to maintain the exhaust temperature of the machine head above the pressure dew point. Its working principle is that when the oil temperature is low, the thermal control valve branch is opened, the main circuit is closed, and the lubricating oil is directly sprayed into the machine head without the cooler; when the temperature rises above 40°C, the thermal control valve is gradually closed. The oil flows through the cooler and the branch at the same time; when the temperature rises above 80°C, the valve is completely closed, and all the lubricating oil passes through the cooler and then enters the machine head to cool the lubricating oil to the greatest extent.
If the thermal control valve fails, the lubricating oil may directly enter the machine head without going through the cooler, so that the oil temperature cannot be lowered, resulting in overheating. The main reason for its failure is that the elastic coefficient of the two heat-sensitive springs on the spool changes after fatigue, and cannot operate normally with temperature changes; the second is that the valve body is worn, the spool is stuck or the action is not in place and cannot be closed normally. . Can be repaired or replaced as appropriate.
6. Check whether the fuel volume regulator is normal, and increase the fuel injection volume if necessary
The fuel injection volume has been adjusted when the equipment leaves the factory, and it should not be changed under normal circumstances.
7. The engine oil has exceeded the service time and the oil has deteriorated
The fluidity of the engine oil becomes poor, and the heat exchange performance decreases. As a result, the heat from the head of the air compressor cannot be completely taken away, resulting in high temperature of the air compressor.
8. Check whether the oil cooler works normally
For water-cooled models, you can check the temperature difference between the inlet and outlet pipes. Under normal circumstances, it should be 5-8°C. If it is lower than 5°C, scaling or blockage may occur, which will affect the heat exchange efficiency of the cooler and cause heat dissipation. Defective, at this time, the heat exchanger can be removed and cleaned.
9. Check whether the cooling water inlet temperature is too high, whether the water pressure and flow are normal, and check whether the ambient temperature is too high for air-cooled models
The inlet temperature of the cooling water should generally not exceed 35°C, the water pressure should be between 0.3 and 0.5MPA, and the flow rate should not be less than 90% of the specified flow rate. The ambient temperature should not be higher than 40°C. If the above requirements cannot be met, it can be solved by installing cooling towers, improving indoor ventilation, and increasing the space of the machine room. Also check that the cooling fans are working properly. If there is a fault, it should be repaired or replaced.
10. Inspection of air-cooled unit
The air-cooled unit mainly checks whether the difference between the inlet and outlet oil temperatures is about 10 degrees. If it is less than this value, check whether the fins on the radiator surface are dirty and clogged. If they are dirty, clean the dust on the radiator surface with clean air and check the radiator fins. Whether it is corroded. If the corrosion is severe, it is necessary to consider replacing the radiator assembly. Whether the internal pipes are dirty or blocked. If there is such a phenomenon, you can use the circulating pump to circulate a certain amount of acidic liquid to clean it. Be sure to pay attention to the concentration of the liquid and the cycle time to avoid The radiator is pierced through the cavity due to the corrosion of the liquid medicine.
11. Air cooler fan problem
The problem of the fan of the air-cooled machine is that the fan does not turn, the fan is reversed, and only one of the two fans is turned on.
12. Problems with the exhaust duct installed by the customer of the air-cooled model
There are exhaust ducts with too small wind surface, too long exhaust ducts, too many bends in the middle of the exhaust ducts, too long and many bends in the middle. Is there an exhaust fan installed, and the flow rate of the exhaust fan is smaller than that of the original cooling fan of the air compressor? .
13. Temperature sensor reading is not accurate
14. Computer readings are inaccurate
15. Head problems
Generally, the bearings of the head of the air compressor are required to be replaced every 20,000-24,000 hours, because the gap and balance of the air compressor are guaranteed by the bearings. If the wear of the bearings increases, the heat generated by the head of the air compressor will increase. Cause high temperature of the air compressor.
16. Incorrect specification or poor quality of lubricating oil
The lubricating oil of the screw machine has strict requirements and cannot be substituted at will. The requirements in the equipment instruction manual should prevail.
17. Check the air filter for clogging
The clogging of the air filter will cause the load of the air compressor to be too large, and it will be in a loaded state for a long time, which will cause high temperature. It can be checked or replaced according to the alarm signal of the differential pressure switch. Generally, the first problem caused by the blockage of the air filter is the reduction of gas production, and the high temperature of the air compressor is the secondary performance.
18. Check if the pressure is too high
The system pressure is generally set at the factory. If it is really necessary to adjust, it should be based on the rated gas production pressure marked on the equipment nameplate. If the adjustment is too high, it will cause overheating due to the increased load on the machine. This is also the same reason as the previous one. The high temperature of the air compressor is a secondary manifestation, mainly manifested in the increase of the motor current of the air compressor and the protection shutdown of the air compressor.