At Energy Technology & Control we’re confident that effective combustion control can reduce emissions by up to 10% each year, saving industrial burner operators thousands in energy costs. Our combustion control specialists explain how…
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 fuel consumption.
The solution
Electronic controllers
ETC’s electronic combustion controllers are usually customised for each burner manufacturer. This ensures that the unique design features of each burner are fully realised. Integration of burner and boiler control into a small electronic controller removes the need for large cabinets or housing; this lowers capital cost and in turn improves space utilisation.
When using an electronic controller, the low fire point can be set lower than the ignition point meaning that the turn-down ratio can be increased and burner on/off cycles and their associated cold air purges reduced. Savings of 5% have been reported on a burner that prior to conversion had an on/off frequency of approximately once every 10 minutes.
If a plant does not run continuously then a second modulation control setpoint can be used to switch the boiler to a lower steam pressure or hot water temperature during periods of reduced activity.
Oxygen trim
When oxygen trim is employed oxygen levels can be trimmed to their optimum level. This process automatically and continuously compensates for the variables that affect efficient combustion. An adaptive trim system will contribute energy savings of approximately 3% per annum.
Air dampers
Unfortunately air dampers can leak and even when fully closed the air flow can be significant. However combustion efficiency can be improved at low fire if the fan speed is reduced. By simply adding fan speed control, burner turn-down can be increased further without compromising low fire efficiency, and additional fuel savings can quickly be achieved.
Inverter
When an inverter is used to slow the speed of an ac electric motor, electrical energy savings result. For example, when a fan motor is slowed to half speed an 80% electrical energy saving is achieved and emissions at the power generation plant reduced.
Electronic control facilitates direct driving of the fuel valves and air dampers resulting in no wear/backlash and on frequently modulating burners additional energy savings of up to 1% are common.
Benefits
More efficient combustion in industrial burners conserves fuel, lowers emissions, reduces plant operating costs and prolongs the life of the boiler plant.
The benefits for the burner manufacturer include, full integration, better control, improved flexibility, increased performance, improved reliability, lower cost, simplified wiring and a reduction in storage space required.
By reviewing your burner control strategy it is possible to achieve significant energy savings and substantially reduce outgoings. If you would like to discuss how the above could help your business please do get in touch.