BOILER, COMBINED CYCLE PLANT, AND STEAM COOLING METHOD FOR BOILER

摘要

The purpose of the present invention is to minimize the loss of energy from exhaust gas when cooling superheated steam and thereby minimize decreases in efficiency. A boiler is provided with: economizers (a medium-pressure economizer (13) and a high-pressure secondary economizer (18)) for heating water supplied by water supply pumps (a medium-pressure water supply pump (27) and a high-pressure water supply pump (28)); evaporators (a medium-pressure evaporator (16) and a high-pressure evaporator (21)) for evaporating the water that is heated by the economizers; and cooling devices (a medium-pressure system and a high-pressure system) for mixing water that has passed through the economizers via the water supply pumps into steam as a coolant.