Tham khảo tài liệu 'air pollution control systems for boiler and control problems_8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Sim poiPDF Mergeíand Split Unregistered Version - http air operation and flue-gas recirculation must be implemented simultaneously from a design point of view. LEA operation may require installation or retrofitting of air registers to maintain proper combustion air speed and mixing at reduced levels or air flow. Flue gas recirculation will require larger air registers to accommodate the increased volume of flow. Therefore simultaneous application of LEA operation and flue-gas recirculation may minimize the need for redesign of burner air registers. Knowledge of furnace thermal design must accompany any application of flue-gas recirculation which effectively lowers furnace temperature and thus radiative heat transfer. Convective heat transfer is also increased by increased gas flow due to the dilution of combustion air. It is advisable to consult boiler manufacturers as to the applicability of flue-gas recirculation to their furnaces. e. Summary. The potential and applicability of each NOx reduction technique is summarized in table 11-4. 11-6 Simpo PDF Merge and Split Unregistered Version - http 5-815-1 AFR 19-6 COMPARISON OF NOy REDUCTION TECHNIQUES Disadvantages Reduction in generating capacity possible reduction in boiler thermal efficiency. A combustion control system which closely monitors and controls fuel alr rations is required. Boiler windboxes must be designed for this application. Furnace corrosion and particulate emissions may increase. Control of alternate fuel rich and fuel lean burners may be a problem during transient load conditions. Not applicable to coal or oil fired units reduction in boiler thermal efficiency Increase in exit gas volume and temperature reduction in boiler load. Boiler windbox must be modified to handle the additional gas volume ductwork fans and controls required. Advantages Easily implemented no additional equipment required reduced particulate and sox emissions. Increased boiler thermal .
