In Power-generating production

the optimal vacuum in condenser is commonly maintained by using different combination mode of the circulating water pump. Taking two 300 MW units no.3 and no.4 in one company as example

three methods for determining the optimal operation mode of circulating water pumps

i.e. calculation method

test method

and statistic method

have been presented. After comparison of advantages and disadvantages of three said methods

the statistic method to be the most suitable one for practical use has been pointed out.