Is Your Boiler Delivering Efficiently ?
Having an efficient boiler does not always ensure that it will run efficiently. Many factors affect the efficiency of boiler operation, and while plant personnel are aware of the losses, it is important to understand the cause in order to take appropriate corrective action.
Some of the factors affecting boiler efficiency :
Draft pressure : Excess negative draft leads to unburnt fuel, which is then carried by the induced draft. Maintaining an optimum draft band ensures that optimum air is available for combustion to get most beneficial air to fuel ratio.
TDS level : Boiler efficiency monitoring systems, such as the Forbes Marshall Effimax system provide a boiler blowdown control system to maintain TDS at optimum level. If not maintained, it can lead to steam loss or lower boiler life.
Combustion parameters : The air to fuel ratio settings should be such that maximum efficiency is obtained without hampering load or starving the plant of steam. It is necessary to understand that the plant load should always be fulfilled at all times with peak efficiency.
Feedwater temperature : It is important that feedwater is at the highest possible temperature at all operating loads. Drop in feed water temperature will lead to excess energy consumption.
Bed temperature: The furnace bed temperature should be kept healthy at all times. Fluidization will ensure optimum heterogeneous (primary) and secondary combustion in chamber.
Fuel temperature and pressure : It is important to atomise the fuel at the optimum temperature and pressure to get the best calorific value from the fuel.
Excess air : Ensuring that the boiler is combusting at the most effective air levels, oxygen trimming and balancing is necessary. This will ensure minimum dry flue gas loss. Combustion air levels should not drop below theoretical value. This will ensure minimum unburnts.
Fuel quality : Excess moisture in fuel can result in loss of fixed carbon and volatile burning in the furnace. Air to fuel ratio needs to be adjusted to cope with this. This is bigger problem in case of solid fuel boiler where one can observe ash particles, GCV and %mH20 variation.
The SCADA system acts as a diagnostic tool to monitor efficiency and serves as a prescription provided by boiler experts to improve the performance and health of the boiler.
Forbes Marshall provides total solutions that not only monitor the above parameters, but also provide diagnostics, as well as complete control and automation to ensure that your boiler runs efficiently at all times.