AMMONIA INJECTION DEVICE AND METHOD FOR EXHAUST HEAT RECOVERY BOILER

摘要

PROBLEM TO BE SOLVED: To provide an ammonia injection device and a method for an exhaust heat recovery boiler by which the denitrification operation of plant exhaust gas can be performed without time delay after start-up of a plant by shortening the start-up time of a denitrification apparatus while saving electric power utility without needing any special additional equipment.;SOLUTION: This ammonia injection device introduces exhaust gas 2 of a relatively high temperature drawn out of an inlet part of the boiler 1 to an evaporator 15 for heating it, at the start-up time of the exhaust heat recovery boiler 1 having a heat transfer tube group such as a superheater 3, the denitrification apparatus 6, and ammonia injection nozzles 5 provided in the upstream region of the denitrification apparatus 6. When the temperature of the exhaust gas at the inlet part of the boiler 1 or the temperature of gas at an outlet of the evaporator 15 reaches a given temperature, gas introduced into the evaporator 15 is switched with the gas at the inlet of the denitrification apparatus 6, ammonia water is introduced into the evaporator 15 at a given temperature or higher, and ammonia obtained by evaporation by gradually increased gas, is supplied to the inlet of the denitrification apparatus 6 of the boiler 1.;COPYRIGHT: (C)2008,JPO&INPIT