Improving the Fuel Combustion Quality Control System in Medium Power Boilers

Abstract

The constant development of electronic devices and components allows for older systems (which have been well received) with electronic control of combustion processes in municipal thermal energy to be improved to new levels, with significant economic and ecological effects. This article presents details of the development of an improved natural gas combustion quality control system in the modernized DKVR 6.5-13 steam boiler. This paper presents the results of comparative tests of this boiler obtained for various variants of the system operation. It has been proven that maximum boiler efficiency indicators and minimum toxicity of exhaust gases discharged into the atmosphere can be achieved by using a proposed control system. The system uses the regulated residual chemical underburning method, based on simultaneous control of the oxygen and carbon dioxide content in the exhaust gases. As a result of the use of the proposed method, an increase in boiler efficiency was achieved by 1.5–2.1% compared with standard automatic regulation and an increase by 0.3–0.8% compared with regulation based only on the oxygen content in the exhaust gases. These results were achieved by reducing the excess air coefficient. In addition, nitrogen oxide emissions were reduced by 25–30%, which, with a justified safe carbon monoxide content in exhaust gases of up to 250 ppm, reduced the exhaust gas toxicity index to 20%.

Keywords

• steam boiler
• natural gas
• automatic control
• combustion quality
• efficiency
• exhaust gas toxicity