At what temperature range should cooling water be added to turbine bearings that are generating heat?

The correct answer of the temperature range for adding cooling water to turbine bearings that are generating heat is grounded in the operational needs of turbine systems. When turbine bearings operate, they generate heat due to friction and load. Maintaining an optimal temperature range is crucial to prevent overheating, which can lead to premature wear or failure of the bearings.

The 100-120°F range is ideal because it is warm enough to effectively prevent thermal shock to the bearings while still ensuring that the cooling water can absorb excess heat. Water in this range is capable of removing heat efficiently without risking dramatic temperature shifts, which could occur if significantly colder water were introduced.

In contrast, the other temperature ranges may be insufficient or excessive. The lower ranges, such as 80-90°F, might not provide adequate cooling, failing to keep the bearings at a safe operational temperature. The upper ranges, like 120-140°F, approach the thermal limits for lubricated components and could exacerbate existing heat generation, leading to potential damage. Thus, the 100-120°F range aligns with those needs effectively and ensures the longevity and reliability of the turbine bearings.