Power plants are integral units of a manufacturing unit as they supply the power required for the operations. In the power plants, heat energy is converted into the electrical energy. The heat energy is produced in a thermal power plant by combustion of renewable and non renewable sources. The steam produced in the boiler is utilized in the turbines to produce electricity. The heat from combustion off gases or flue gases from the boiler is recovered in pre-heating the combustion air. The ash or unburnt fuel particles are removed from the flue gases by bag filters and finer particles are removed by Electrostatic precipitator. Finally the clean flue gases are released to the atmosphere from Chimney. The flue gas circuit in the power plant includes :
- Steam boiler
- Ductings
- Electrostatic Precipitator
- Pre heaters
- Fans
- Chimney
- Cyclones
- Bag house
Typical Operating Challenges in a power plant
- Inefficient Combustion detected by higher Oxygen percentage at the boiler outlet: Inefficient combustion can happen due to improper fuel-air mixing, residence time of fuel.
- Ash Deposition on tube banks: This happens due to higher carryover of the fly ash. The air blanket created by the staged air injections might not be as per the design. This in turn can happen due to incorrect location or number of air injection jets, non uniform flow distribution in the air injection nozzles. The interaction of primary combustion air, secondary and tertiary air might lead of local re- circulations or short circuiting leading to deposition.
- Higher Pressure Drop in the Duct layout: The duct layout from preheaters to Chimney consists of several sharp bends, expansion, contraction, splitting of ducts resulting in higher pressure drops.
- Duct Erosion: The high velocity in the duct and higher dust loading can lead to Duct erosion.
- Fan Efficiency: Fan experience intermittent power surge, noise. This could be due to several reasons like inlet and outlet duct design, operation fluctuations, impeller wear etc.
Application of CFD in Power Plants
Computational Fluid Dynamics is extremely useful tool to understand the flow pattern, mixing profile of primary, secondary and tertiary air stream. It also gives important insights in combustion process and predicts temperature profile, computes fuel and oxygen consumption, production of combustion products, extent of fuel burning, understanding fuel trajectories. It also helps in predicting and understanding the causes of pollutants formation. One of the important output of CFD simulations is pressure drop prediction.
Once the root cause of the issue is identified from the CFD analysis, alternative solution methodologies can be identified and simulated. Thus CFD helps in identifying and selecting optimized solution for the problem. The solution might involve design change or operating condition change leading to improved combustion efficiency, reduced pressure drop, enhanced collection efficiency.
How can FluiDimensions help
FluiDimensions has expertise in modeling combustion of solid, liquid, and gaseous fuel. We have modeled and optimised the performance of boilers, furnaces, ESP through simple design changes that are easy to implement. We have helped our valued customers to improve the cyclone collection efficiency and reduce pressure drop. We have successfully reduced pressure drop in the ducting in Power plants. Please visit our Case studies section to get more details.
if you are facing any performance challenge in your power plants, please contact us. We will be happy to help.