What is the reason for overheating of the exhaust gas of oil-free screw air compressor?

In operation, oil-free screw air compressors often encounter heating problems, so what is the main reason? Our company has made the following summary of this issue.

1. High return air temperature

The return air temperature unevenness is related to the evaporation temperature. In order to prevent liquid return, general return air pipelines require return air superheat of 20℃. Assuming that the insulation of the return air pipeline is not good, the superheat will far exceed 20℃. The higher the return air temperature, the higher the cylinder intake temperature and exhaust temperature. For every 1℃ increase in the return air temperature, the exhaust temperature will increase by 1~1.3℃.

2. Electrical heating

Regarding the return-cooled screw air compressor, the refrigerant vapor is heated by the motor as it flows through the motor cavity, and the suction temperature of the cylinder is once again increased. The heat output of the motor is affected by power and power, while the power consumption is closely related to displacement, volumetric power, working conditions, frictional resistance, etc.

For the return-cooled semi-enclosed screw air compressor, the temperature rise of refrigerant in the motor cavity is planned to be approximately between 15 and 45℃. The cooling in the air-cooled (air-cooled) screw air compressor does not pass through the windings, so there is no problem with motor heating.

3. The tightening ratio is too high

The exhaust temperature is greatly affected by the contraction ratio. The larger the contraction ratio, the higher the exhaust temperature. Reducing the contraction ratio can significantly reduce the exhaust temperature. Specific methods include treading suction pressure and reducing exhaust pressure. The suction pressure is selected by the evaporation pressure and the suction line resistance. Trekking the evaporation temperature can effectively trekking the inhalation pressure, actively reduce the contraction ratio, and then reduce the exhaust temperature.

To sum up, I will share the reasons for overheating of exhaust gases here. I hope this article can help you.