Removal pattern of particulate matter from condensing heat exchanger after wet desulfurization of coal-fired unit

Abstract

The flue gas after wet desulfurization of coal-fired units still contains a large amount of particulate matter. Flue gas condensing heat exchangers are often used to further remove particulate matter. However, current research focuses on the overall removal effect of the heat exchangers, but ignores the difference of pollutant removal ability of the inner tube bundle along the flue gas flow direction. This paper studied the correlation between pollutant removal and operating parameters of condensation heat exchanger, so as to make the removed amount of pollutants as large as possible. A field experimental platform was built on a 3?350 MW supercritical circulating fluidized bed coal-fired unit. The total amount of pollutants removed between the 3rd and 6th rows of tube bundles from the inlet of the heat exchanger was the largest. The removal of particulate matter near the outlet of the heat exchanger was the smallest. The highest removal rate of filterable particulate matter (FPM) reached 76 %. The proportion of condensable particulate matter (CPM) in the total removal of particulate matter reached around 90 %. The mass ratio of both H2SO4 and SO3 to the removed CPM were more than 95 %.