April 2020

32 | Plant & Works Engineering www.pwemag.co.uk April 2020 Energy, the Environment & Water Focus on: Boilers, Burners & Controls T he output of a boiler is reliant on the performance of its burner. A poorly designed boiler with an efficient burner may at times outperform a well-designed boiler reliant on a poor burner. Burners are designed to maximize combustion efficiency while minimizing the release of emissions. Specialist combustion controls are the most commonly used method of controlling emissions in all types and varieties of boilers. Combustion controls can manage the following; low excess air (LEA), burners-out-of- service (BOOS), biased-burner firing (BF), flue gas recirculation (FGR), overfire air (OFA), and low-NOx burners (LNB). The facts Typically, combustion of 1m3 of Natural gas in an industrial boiler produces 2.03kg of C02, and 1 kWh of electricity generated in a gas fired power station produces 0.420kg of C02. It is not unusual for an industrial burner/boiler to use in excess of 130,000 pounds of fuel per annum, directly emitting up to 15,700 tonnes of C02. If we add to that figure, the electricity used to power the burner fan, then the total C02 emissions caused by a single burner of this size can exceed 15,750 tonnes per annum. From an environmental perspective it obviously makes sense to aim for a reduction in CO2 emissions, there is however also a business case for this as reduced CO2 is usually a result of improved efficiency and better fuel consumption. The solution Electronic controllers By using electronic combustion controllers that are specifically customised to meet the needs of Martin Thirsk, managing director of Energy Technology and Control, explains to Plant and Works Engineering how effective combustion control can reduce emissions by up to 10% each year, saving industrial burner operators thousands in energy costs. Can effective combustion control reduce emissions by 10% each year?