Patent ID: 7504260
Filing Date: 2009-03-17
Classification: G05D,Y10T

Abstract:
1. An apparatus used in a fossil-fired system to control the temperature of combustion gases entering pollution reduction equipment, said fossil-fired system heating a working fluid with combustion gases in at least one heat exchanger, the working fluid having a working fluid pathway through the system, the apparatus comprising: a pollution reduction equipment having a temperature window required for proper operation; a heat exchanger upstream from the pollution reduction equipment disposed in the working fluid pathway; a temperature probe measuring the temperature of the combustion gases entering the pollution reduction equipment, and having a temperature probe output; a control valve having an inlet connection and an outlet connection; a pipe carrying a re-routed working fluid from a location within the system to the inlet connection of the control valve; an attemperation device disposed in the working fluid pathway and upstream from the heat exchanger, having an inlet connection for attemperating fluid; a pipe carrying the re-routed working fluid from the outlet connection of the control valve to the inlet connection for attemperating fluid; and a control device which controls the temperature of the combustion gases entering the pollution reduction equipment to a value which lies within the temperature window required for proper operation of the pollution reduction equipment, having as an input the temperature probe output, and having an output signal which actuates the control valve to achieve changes in the flow rate of the re-routed working fluid resulting in controlling the temperature of the combustion gases.