Xinfeng Mini-Classroom--- Primary Causes of Abnormal Bearing Temperature Rise in Double-Suction Centrifugal Fans

Two double-suction centrifugal fans are installed simultaneously. However, during actual operation, one bearing repeatedly exhibited abnormal temperature rise issues.

We understand that abnormal bearing temperatures require prompt attention to prevent compromising the safe and stable operation of the centrifugal fan.

Let's analyze the causes. This issue stems from inherent quality defects in the centrifugal fan itself.

However, on-site inspections revealed normal bearing oil levels, no deterioration in lubricant quality test results, and adequate bearing cooling water flow.

After comparing and analyzing the abnormal conditions, the equipment quality was confirmed to be normal. With this cause ruled out, load fluctuations are the likely culprit.

Typically, when the centrifugal fan's rotational speed is constant, fluctuations in its current value reflect variations in the load applied to the fan.

Furthermore, as the load acts on the bearings, the friction between the moving and stationary parts of the bearings changes. Increased friction naturally generates significant heat, leading to elevated temperatures. Analysis of the on-site production conditions revealed that during the operation of the desulfurization system, there was an issue of sudden increases in flue gas density.

However, increased flue gas density directly increases the load on the centrifugal fan bearings. Consequently, friction forces on the bearings significantly rise, causing temperature changes to exceed permissible limits and exacerbating bearing temperature increases.

Additionally, elevated flue gas temperatures at the worksite contribute to the issue.

In other words, during centrifugal fan operation, increased flue gas temperature and density at the worksite lead to higher loads on the bearings. Simultaneously, as flue gas temperature rises, bearing clearance decreases, static and dynamic friction increases, and bearing temperature further escalates.