Excessively high outlet temperature of the three-stage aftercooling system in the centrifugal air compressor
Thread Content
Process: Air compressed by a 260 Nm3/min air compressor, cooled through a three-stage after-cooler —— then passed through a combined dryer —— and stored in the air purification tank. Temperature measurements taken on May 29, 2019, at 8:50: Inlet temperature of the compressor’s three-stage cooler: 119.3°C; outlet temperature of the same cooler: 80.3°C; outlet temperature of the circulating water: 22.6°C; temperature of the air entering the combined dryer: 75.9°C. The specifications on the label of the combined dryer require that the inlet air temperature be ≤45°C. Currently, there is a serious problem of water content in the purified air. Apart from scaling in the after-cooler causing a high outlet temperature, what other possible causes could there be?
The outlet temperature of the circulating water is 22.6 degrees; the temperature difference for heat exchange is quite large, yet the heat exchange efficiency is very poor. This is usually caused by scaling. Also, check whether there are any issues with the water flow rate
The outlet temperature of the circulating water is only 22.6 degrees, while the outlet temperature of the cooler is as high as 80.3°C. If this problem did not occur during previous operations, then dirt buildup should be considered as a possible cause. You can also compare the pressure drop values of the gas and circulating water with past operation records; it is logical for the pressure drop to increase over time. As for the possibility mentioned above regarding water flow volume, it’s very unlikely; given such a low outlet temperature, it indicates that the water flow volume must be high. Even then, cooling isn’t possible. Either you have increased the flow rate beyond the original design capacity, in which case the existing equipment cannot meet the requirements, or there may be issues with the design of the original equipment, resulting in the cooler being unable to provide sufficient cooling even when the water flow volume is increased while the air compressor is operating at full load. It’s also possible to check whether the thermometer is distorted.
Although the water temperature seems good, it is still necessary to check whether the valves in the water circuit of the third-stage cooler are fully open, as well as the inlet and outlet water temperatures of the third-stage cooler. Instead of only looking at the circulating water outlet temperature. The after-cooling outlet temperature is essentially consistent with the dryer temperature, indicating that the measurements are accurate. As mentioned on floors 2 and 3, with such a large difference between the water temperature and the outlet temperature of the cooler, the problem must lie with the third-stage cooler
An outlet water temperature of 22.6 is such a waste! Check the cooler