DC/AC SYSTEM COOLING COLUMN WITH WHITE SMOKE PREVENTION FUNCTION

PROBLEM TO BE SOLVED: To adjust the amount of the generation of dried air, and to prevent white smoke from being generated by dividing an upper water tank into at least three sprinkling parts in the width direction of an outdoor air intake, and by dividing a sealed-type heat exchanger into at least three heat exchange parts corresponding to each sprinkling part. SOLUTION: When white smoke is easily generated, the indirect heat exchange between sprinkling water and circulation cooling water is made only by heat exchange parts B1 and B3 at both sides, the sprinkling water is indirectly cooled by air flow for discharging to an exhaust side as wet air, a center heat exchanger part B2 does not sprinkle water, the air flow is set to high temperature and high humidity for discharging from the exhaust port in a non-supersaturated state, and the generation of the white smoke is prevented. Then, when the amount of heated air is increased, water is sprinkled only by a center sprinkling part 10b, sprinkling from sprinkling parts l0a and 10c of both sides is stopped, and a large quantity of heated air is generated for preventing the white smoke from being prevented.