Complex cleaning system for heat exchanger

Abstract

The purpose of the present disclosure is to solve the problems of a difficult operation or occurrence of corrosion damage to equipment caused by the attachment of ammonium sulfate salt, which is generated when unreacted ammonia (NH3 slip) and sulfur trioxide (SO3) in exhaust gas are bonded with each other when a selective catalytic reduction (SCR) is used to eliminate nitrogen oxides that are contained in the exhaust gas generated during the combustion of a boiler or the like, to a heat exchanger of an air preheater (APH) or the like installed at the rear of an SCR device and blocks a passage of the exhaust gas such that the pressure inside the boiler is increased. To this end, a dry ice cleaning device is installed at the front of an exhaust gas inlet in an air preheater such that the blocking of a heat exchanger caused by ammonium sulfate salt or the like is removed by spraying dry ice pellets, and at the same time, high-temperature steam spraying device is installed at a cold end of the air preheater so as to spray the steam in the same direction as that of air supplied to a boiler, thereby removing contaminants more effectively. Furthermore, in order to effectively prevent blocking which occurs in a cold end of the air preheater, dry ice is sprayed to the front of an exhaust gas inlet of the air preheater and also, to the front of a supply air inlet of the air preheater which is an opposite direction thereof, such that a cleaning effect is increased.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method of cleaning a heat exchanger, and more particularly, to a complex cleaning system for the heat exchanger, which is to solve the problems of a difficult operation or shutdown caused by the attachment of ammonium bisulfate, which is generated when unreacted ammonia and sulfur trioxide in exhaust gas are bonded with each other when a selective catalytic reduction (SCR) method is used to eliminate nitrogen oxide that are contained in the exhaust gas generated during combustion of a boiler or the like, to a heat exchanger of an air preheater or the like installed at the rear of the SCR device and blocks a passage of the exhaust gas.BACKGROUND ART

[0002] Nitrogen oxide, as a pollutant causing environmental harm, which is contained in the exhaust gas generated when coal, oil, gas, or combustible materials, etc. burn in a combustion engine, should be eliminated before being exhausted in air.

[0003] To eliminate nitrogen oxide conta...

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