Generator air cooler design for a powerplant refurbishment

The selection of air coolers may appear to be a rather routine item to consider when designing the uprating of a generator. But designing air coolers for an uprated generator presents more challenges to the cooler designer than for the design of a new machine, because the new coolers must dissipate more heat, but are limited to the original opening size and air flow. This paper discusses issues that would help the generator designer in evaluating cooler design options, and preparing air cooler specifications which will provide cost-effective designs and optimum performance from the air coolers.