Heat exchanging apparatus and a method of preventing corrosion

摘要

A heat exchanging apparatus includes a composite structure of a ferrosoferric oxide and a molybdenum oxide at the internal surface of a heat exchange cycle tube located in a generator. A process of suppressing corrosion of this heat exchanging apparatus includes the step of preparing an ammonia solution including dissolved oxygen of a concentration of approximately 3-8 ppm. Approximately 1 wt %-5 wt % molybdate is added into the ammonia solution. This ammonia solution is sealed within the heat exchange cycle tube to be heated to at least a predetermined temperature in the generator of the heat exchanging apparatus. Thus, a composite structure of a ferrosoferric oxide and molybdenum oxide is formed on the internal surface of the generator. This composite structure allows the suppression of corrosion in the internal surface of the generator.