CONSIDERATIONS IN DETERMINING O//2 AND CO CONTROL FOR COMBUSTION EFFICIENCY AND QUALITY.

Abstract

During the past 20 years much has been published on the pros and cons of excess air trim as applied to combustion boiler control systems. The products of combustion used to directly measure the fuel/air ratio and in excess air trim control systems are carbon dioxide (CO//2), oxygen (O//2), and carbon monoxide (CO). The application of O//2 or or O//2 plus CO excess air trim to the combustion process is a very attractive proposition for any combustion control system. Oxygen measurements are a true indication of excess air, but have no relationship to combustion quality and completeness of combustion. Carbon monoxide measurements have no relationship to excess air but do provide an index of combustion quality and completness of combustion. By combining the two measurements in one O//2 plus CO trim system, the best combustion control system is attained.