Burner Controls

The functions of a burner control system are to maintain the quality of combustion over the complete firing range, to optimise efficiency and to minimise emissions. Precise and repeatable control of the air/fuel ratio is essential to minimise the level of excess combustion air and to reduce heat losses in the exhaust gases. Modulating burner output improves the boiler temperature or pressure control, and thus increases fuel efficiency.

The traditional mechanical method of controlling the air and fuel ratio of modulating burners, using adjustable cams and linkages to position fuel valves and air dampers, is susceptible to mechanical wear and hysteresis and is no longer considered the optimum solution for efficient burner operation.

Electronic and microprocessor control systems offer more precise and repeatable control (which improves fuel efficiency), and other benefits including improved reliability and reduced maintenance requirements.

Only forced draught burners with a control system that accurately modulates thermal output and offers close control of the air/fuel ratio are eligible for Enhanced Capital Allowances. The minimum requirements for this control system depend on whether burner has a thermal rating above or below 1,200kW.