Process for controling catalytic denitrification and system for combustion of burnt off gases.

摘要

Process for controling catalytic denitrification and system for combustion of burnt off gases. Control process and system for the catalytic denitrification of burnt off gases that contain nitrous oxides derived from a fuel burning unit such as a gas turbine, by addition of ammonia to the burnt off gas upstream of a catalytic denitrification unit. The rate of addition of ammonia is controlled by means of a basic signal which is generated on the basis of functional parameters that include the fuel which is being burnt, its combustion temperature, the flow rate of the burnt off gas, the flow rate of the ammonia and the catalytic activity, with the aim of initially injecting a smaller amount of ammonia than is theoretically needed into the stream of burnt off gas. Afterwards the concentration of nitrous oxides in the exhaust gas downstream of the catalytic unit is compared with the appropriate standard, the amount of ammonia added initially is further adjusted until the concentration of nitrous oxides in the gas discharged to the atmosphere is reduced sufficiently to comply with the local clean air standards, while at the same time avoiding the unsatisfactory injection of excessive ammonia and fluctuation of the system. IMAGE