High interstage temperature of oil-free screw air compressor

The following reasons may cause the interstage temperature to be abnormally high in the unloaded state:: 1. Return air system problems: There is a blockage or failure in the return air system, which prevents smooth circulation of air and causes an increase in interstage temperature. 2. Cooling system problems: The cooler is faulty or the cooling water supply is insufficient, resulting in the inability to effectively reduce the interstage temperature. 3. Oil lubrication system problems: The screw air compressor has an oil-free design, but it still requires an oil lubrication system for cooling. If the oil lubrication system fails or the oil lubrication is insufficient, it may cause the interstage temperature to rise. It is recommended that you check the above aspects, especially the return air system and cooling system. You can also contact the after-sales service personnel of the air compressor manufacturer for consultation and problem solving. .

The current explanation from the manufacturer is that the coating inside the second stage has fallen off, causing the rotor gap to increase and the efficiency to decrease. As a result, the gas at the outlet of the first stage cannot be effectively compressed by the second stage. The pressure and temperature of the gas increase between stages. However, it is not clear why the temperature returns to normal when the air compressor is not under load and when it is under load.

According to the manufacturer's explanation, if the coating inside the second stage peels off and the rotor gap increases, it will indeed affect the compression efficiency of the air and may cause the interstage temperature to rise. As for why this situation occurs when the air compressor is not under load, but the temperature returns to normal when it is under load, there may be several reasons:: 1. The load can provide additional pressure and flow, so that the gas at the outlet of the first stage can be effectively compressed by the second stage, thereby reducing the interstage temperature. 2. When under load, the operating state of the screw air compressor is more stable, and the lubricating oil has better lubrication effect, which can effectively reduce the heat generated by friction between stages. 3. When under load, the cooling system of the air compressor can operate normally and provide enough cooling water to reduce the interstage temperature. It is recommended that you continue to communicate with the after-sales service personnel of the air compressor manufacturer to learn more about their explanation and seek solutions. At the same time, you can also consider inspection and maintenance, repair or replacement of the second-level internal coating to restore the normal operation of the screw air compressor. .

Thanks for the technical support, the second-stage rotor has been replaced and the high temperature condition has returned to normal. It seems to be caused by the decrease in the second-stage efficiency.

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Brief description of the problem: Detailed description of high temperature instantaneously or irregularly after GA132-10 is turned on.: The machine occasionally displays a high temperature alarm or even shuts down when it is turned on or from time to time. ； Judging from the fault phenomenon, it is judged that the oil cut-off valve is stuck, resulting in a blocked oil path and a lack of lubrication for the rotor. As a result, the high temperature at the rotor outlet rises instantly. During B-level maintenance, special inspection is carried out to check that the oil shut-off valve is indeed stuck. However, after handling the valve seat and valve body on site, the manual test of the valve parts is flexible, and the valve parts are flexible in the air pressure test. ； In addition, no abnormalities were found in the oil supply pipeline and oil filter seat. ； Recently, customers have reported the same fault phenomenon. This fault has also been encountered at other customer sites (inclined machine heads), and the running time is about 20,000 hours. ； Please provide an analysis of the cause of the failure.: 1. The oil cut-off valve is stuck, causing the rotor to not be lubricated and cooled when the air compressor is started, and the outlet temperature rises to the point of tripping instantly. ； 2. When the unloading state is transferred to loading, the regulating valve failure causes the oil circuit to be unable to circulate through the oil circuit, the rotor cannot be lubricated and cooled, and the rotor outlet temperature becomes so high that the machine trips. ； Under normal circumstances, the failure of the rotor outlet temperature to instantly rise to the point of tripping is mostly due to the blockage of the oil circuit and the rotor cannot be effectively lubricated. ； If the rotor outlet temperature rises in the unloading state, it may be due to the oil filter being clogged. In the unloading state, the oil loop pressure drops, causing the oil to be unable to effectively pass through the oil filter. As a result, the temperature rises in unloading state. ------------------------------------------(Dividing line) This is a high-temperature analysis of an oil-based engine that I saw in an article. The fault we encountered was an oil-free engine, but this can also be used as a reference.

Thanks for the information and references. Although your situation is for an oil-free machine, you can refer to it from some aspects. In the case of an oil-free machine, the reasons for high temperature alarm or shutdown may be as follows:: 1. Lubrication system failure: Although oil-free machines do not require the use of oil for lubrication, a lubrication system is still required to provide cooling and protection. If there is a fault in the lubrication system, such as poor oil circulation or insufficient cooling, it may cause the rotor temperature to rise. 2. Cooling system problems: Oil-free machines are usually equipped with a cooling system to ensure normal operating temperatures. If the cooling system is faulty or the cooling water supply is insufficient, it may also cause the rotor temperature to rise. 3. Failure of other mechanical components: In addition to the lubrication and cooling systems, failures of other mechanical components, such as fans, sensors, control valves, etc., may also cause rotor high temperature. In order to solve this problem, it is recommended that you take the following measures: 1. Check the lubrication system to ensure its normal operation, including smooth oil circulation and good cooling effect. 2. Check the cooling system to ensure sufficient cooling water supply, and check whether the cooler, pump and other components are working properly. 3. Check other mechanical components, such as fans, sensors, control valves, etc., to ensure their normal operation and secure connections. If the above measures cannot solve the problem, it is recommended that you contact the after-sales service personnel or professional maintenance personnel of the air compressor manufacturer for detailed investigation and solution. They can give accurate fault causes and solutions based on specific situations and models. .

When unloading Ingersoll Rand's oil-free machine, the air inlet valve will leave 10% of the opening to prevent the machine from holding pressure. Although the opening is small, there is air. If the unloading time is long, the air will be in the cooler cavity and cannot be discharged, so the interstage temperature will be high.

This post was last edited by we11we11 on 2023-7-19 19:28. Does this situation often happen? That's a problem with the original design of the machine. There was no problem for a few years after our unit started operating, but it happened the year before last.