Two kinds of important equipment i.e. selective catalytic reduction system (SCR) and flue gas cooler are applied in coal-fired power plant to achieve energy conservation and to reduce emission. However

few studies have been published on the influence of ammonia escaped from SCR system on flue gas cooler. In this study

the condensates deposited on the wall of the cooler at the downstream of SCR were analyzed by XRD

XRF

SEM and EDS. The results indicated that the white crystalline material in the condensates is mainly ammonium fluoroborate and some intermediates such as ammonium fluoride

boric acid and ammonium fluorosilicate. The formation of crystalline layer took place by coupling reaction between the ammonia escaped from SCR system and both fluorine element and boron element volatilized in combustion of coal. Although the deposition layer has only a limited thickness

it could be hamper directly for operation of flue gas cooler.