Summary of High Temperature Faults of Air Compressors in Summer

The high temperature phenomenon in the air compressor is caused by various reasons. Below, we will briefly summarize it as follows:

1. The air compressor system is out of oil.

 The oil level in the oil and gas tank should be slightly higher than the high oil level mark H (or MAX) when the lubricating oil is in a static state after shutdown and pressure relief. During equipment operation, the oil level should not be lower than the low oil level mark L (or MIX). If insufficient oil is found or the oil level cannot be observed, the machine should be stopped and refueled immediately.

2. The oil cut-off valve (oil stop valve) is not working properly.

 The oil cut-off valve is usually a two position two normally closed solenoid valve, which is opened during startup and closed during shutdown to prevent the oil in the oil and gas barrel from continuing to spray into the machine head and exiting from the air inlet during shutdown. If the component is not turned on during loading, the host will rapidly heat up due to oil shortage, and in severe cases, it may cause the screw assembly to burn out.

3. Oil filter (machine filter, oil filter) issue.

 A: If the oil filter is blocked and the bypass valve is not opened, it will cause the air compressor oil to not reach the machine head (main engine), and the machine head will quickly heat up due to oil shortage.

 B: The oil filter is blocked, the flow rate decreases, and the heat cannot be effectively taken away. The temperature of the air compressor gradually increases, forming high temperatures. Another situation is that the air compressor is at high temperature after unloading, because the internal oil pressure of the air compressor is high during loading, and the air compressor oil can pass through. However, after unloading, the pressure of the air compressor oil is low, making it difficult for the air compressor oil to pass through the air compressor oil filter. The flow rate is too small, resulting in high temperature in the air compressor.

4. The temperature control valve (thermal control valve) is malfunctioning.

 The temperature 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 machine is first started, due to the low oil temperature, the temperature control valve branch is opened, the main circuit is closed, and lubricating oil is directly sprayed into the machine head without passing through the cooler; When the temperature rises to above 40 ℃, the thermal control valve gradually closes, and oil flows through both the cooler and the branch at the same time; When the temperature rises above 80 ℃, the valve closes, and the lubricating oil enters the machine head through the cooler to cool the lubricating oil to a large extent.

 If the temperature control valve malfunctions, lubricating oil may enter the machine head directly without passing through the cooler, preventing the oil temperature from dropping and causing overheating.

The main reasons for its failure are:

 One is that the elastic coefficient of the two thermal sensitive springs on the valve core changes after fatigue, and they cannot operate normally with temperature changes;

 The second reason is that the valve body is worn, the valve core is stuck or the action is not in place and cannot be closed normally. It can be repaired or replaced according to the situation.

5. The fuel quantity regulator is abnormal, and if necessary, the fuel injection quantity can be increased appropriately.

 The fuel injection quantity has been adjusted when the equipment leaves the factory and should not be changed in general. This situation should be attributed to design issues.

6. The lubricating oil has exceeded its usage time and the engine oil has deteriorated.

 The fluidity of engine oil deteriorates and the heat exchange performance decreases. The heat from the air compressor head cannot be carried away, resulting in high temperature in the air compressor.

7. Check if the oil cooler is working properly.

 For water-cooled models, the temperature difference between the inlet and outlet water pipes can be checked. Normally, it should be 5-8 ℃. If it is lower than 5 ℃, there may be scaling or blockage, which will affect the heat exchange efficiency of the cooler and cause poor heat dissipation. At this time, the heat exchanger can be removed and cleaned.

8. Check if the inlet temperature of the cooling water is too high, and if the water pressure and flow rate are normal. For air-cooled models, check if the ambient temperature is too high.

 The inlet temperature of cooling water should generally not exceed 35 ℃, and the flow rate should not be less than 90% of the specified flow rate when the water pressure is between 0.3 and 0.5 MPA.

 The ambient temperature should not exceed 40 ℃. If the above requirements cannot be met, they can be solved by installing cooling towers, improving indoor ventilation, and increasing the space of the computer room. It is also possible to check whether the cooling fan is working properly, and if there is a malfunction, it should be repaired or replaced.

9. The air-cooled unit mainly checks the inlet and outlet oil temperature

 Is the difference around 10 degrees. If it is less than this value, the fins on the surface of the radiator should be checked for dirt and blockage. If it is, clean air can be used to remove dust from the surface of the radiator and check if the fins are corroded. If the corrosion is severe, it is necessary to consider replacing the radiator assembly and checking if there is dirt and blockage in the internal pipelines. If there is this phenomenon, a circulating pump can be used to cycle with a certain amount of acidic solution for cleaning. It is important to pay attention to the concentration of the solution and the circulation time, Avoid the radiator from penetrating the cavity due to corrosion caused by liquid medicine.

10. There are issues with the exhaust duct installed by the air-cooled model customer.

 There are exhaust ducts with too small ventilation surfaces, too long exhaust ducts, and too many intermediate bends in the exhaust ducts. Most of the intermediate bends in the exhaust ducts are too long, and there is no exhaust fan installed. The flow rate of the exhaust fan is smaller than the original cooling fan of the air compressor.

11. The temperature sensor reading is inaccurate (sensor malfunction).

 If the temperature sensor is disconnected, the device will alarm and shut down, and display sensor abnormalities. If it is a poor job, sometimes good and sometimes bad, it is much more hidden and difficult to troubleshoot. It can be ruled out using alternative methods as good.

12. Head issue.

 This general air compressor head bearing requires replacement within 20000 to 24000 hours, as the clearance and balance of the air compressor are determined by the bearings. If the wear of the bearings increases, it will cause direct friction and increased heat in the air compressor head, resulting in high temperature of the air compressor. In severe cases, it is more likely that the main engine will lock up and be scrapped.

13. Incorrect specification or poor quality of lubricating oil.

 The lubricating oil for screw machines generally has strict requirements and cannot be arbitrarily substituted. The requirements in the equipment manual should prevail.

14. The air filter (air filter) is blocked.

 Blocking the air filter can cause excessive load on the air compressor, which can cause high temperatures if it is in a long-term loading state. It can be checked or replaced based on the alarm signal of the pressure difference switch. The common problem caused by clogging of air filters is a decrease in gas production, with high temperature in the air compressor being a secondary manifestation.

15. The system pressure is too high.

 The system pressure is generally set at the factory. If adjustment is necessary, the upper limit should be the rated gas production pressure marked on the equipment nameplate. If the adjustment is too high, the increase in machine load will inevitably lead to excessive temperature and current overload. This is also the same as the previous reason. High temperature of the air compressor is a secondary manifestation, and the main manifestation of this reason is the increase in motor current of the air compressor and the shutdown of the air compressor protection.

16. The oil gas separator (oil separation core) is blocked.

 Blocking the oil gas separator can cause excessive internal pressure, which can cause many problems, with high temperature being one of them. This is also the same as the first two reasons, the main manifestation of blockage in the oil gas separator is high internal pressure.

 The above is a summary of some possible reasons for high temperatures in screw air compressors, for reference only.

JOY MACHINERY always adheres to the corporate vision of "building a leading brand of oil-free air compressors in the world", and hopes to provide high-quality, clean and safe air for food, beverage and other production enterprises on the road of oil-free air compressor research and development, production and sales. Source protection, and also contribute a little bit to people's health and safety.

JOY MACHINERY oil-free air compressor series is widely used in the food and beverage processing industry due to its clean air source and continuous and stable gas transmission. If you have any needs, please contact us! JOY Machinery (Shanghai) Co., Ltd. has a professional design team with rich experience and welcomes customization. Diversified products can meet most applications and meet your one-stop shopping needs. The air compressor series includes power frequency screw air compressors, variable frequency screw air compressors, permanent magnet variable frequency screw air compressors, two-stage compression screw air compressors, integrated screw air compressors, laser cutting air compressors, medium and high pressure air compressors. Air compressors, oil-free water-lubricated screw air compressors (special oil-free screw air compressors for the medical industry), diesel-moving screw air compressors, electric-moving screw air compressors and other products.

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