STEAM GENERATOR

A steam generation apparatus includes: a heat medium flow passage through which a heat medium flows; a primary economizer disposed in the heat medium flow passage; a secondary economizer disposed in the heat medium flow passage at an upstream side of the primary economizer with respect to a flow direction of the heat medium; a primary evaporator disposed in the heat medium flow passage at an upstream side of the secondary economizer with respect to the flow direction of the heat medium; a first flash tank for generating flash steam; a first feed water line configured to supply water heated by the primary economizer to the secondary economizer; and a second feed water line disposed so as to branch from the first feed water line and configured to supply the water heated by the primary economizer to the first flash tank.