Combustion monitoring and control system

Abstract

A real time monitoring and control system for single or multi-fired combustion systems which permits adjustment of the air fuel ratio in the system for optimized efficiency and minimized pollution content in the exhaust gas, while providing safety control of the combustion process. The system includes a high sensitivity light sensor which is utilized to monitor the combustion flame and provide an electrical output proportional to flame temperature, that is utilized to control the air fuel ratio of the system. The wavelength sensitivity of the sensor is capable of selection, for example by selection of sensor type and/or use of appropriate filters, to monitor a predetermined range or region of the flame emission spectrum in order to enable correlation of the intensity of the emission spectrum of the type of fuel being utilized, i.e., oil or natural gas, with temperature and combustion efficiency. A sensor having a defined field of view is utilized and means are provided to sample signals from selected portions of the field of view of the sensor to enable temperature monitoring of a multi-flame system. The output of the sensor is provided to a computer which in turn is electrically connected to control a valve that individually adjusts the air fuel ratio of each flame of the system to permit real time adjustment of the combustion process. The system enables control of combustion at or near optimum burning efficiency, i.e., in the range of 1/2 to 1 percent excess oxygen.