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The Spray Characteristics of Twin Fluid Nozzle on Urea-SCR Applied to Marine Diesel Engines

ICFMCE 2017, November 24-26, 2017, Dubai. The Spray Characteristics of Twin Fluid Nozzle on Urea-SCR Applied to Marine Diesel Engines. Hyung Sun Park, Sang Ji Lee and Jung Goo Hong. School of Mechanical Engineering, Kyungpook National University. Opportunity for the Environment.

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The Spray Characteristics of Twin Fluid Nozzle on Urea-SCR Applied to Marine Diesel Engines

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  1. ICFMCE 2017, November 24-26, 2017, Dubai The Spray Characteristics of Twin Fluid Nozzle on Urea-SCR Applied to Marine Diesel Engines Hyung Sun Park, Sang Ji Lee and Jung Goo Hong School of Mechanical Engineering, Kyungpook National University

  2. Opportunity for the Environment By Natural Resources Defense Council (NRDC)

  3. Opportunity for the Regulation MARPOL (Marine pollution treaty) Annex VI NOx Emission Limits , 2000 , 2011 ( ≥ 80 %) , 2016 - International Maritime Organization (IMO) has decided to enforce NOx reduction regulations

  4. Opportunity for De-NOx tech. HAM (Humid Air Motors) IEM (Internal Engine Modification) LNG (Liquefied Natural Gas) FEW (Fuel & Water Emulsion) or DWI (Direct Water Injection) EGR (Exhaust Gas Recirculation) De-NOX SCR (Selective Catalytic Reduction) Shipping NOx reduction potential by Azzara, A. et al. 3

  5. Outline for Urea-SCR system BLUENOX SCR System. Temp. sensor NOx sensor Catalyst Soot blowing nozzles Soot blowing system Injector Dosing Pulsation damper SCR control unit Nozzles Engine control unit Valves Temp. sensor Digital dosing pump Urea tank NOx sensor Pressure sensor Marine diesel engine Urea pipe

  6. Outline for Urea-SCR system Temp. sensor NOx sensor Catalyst Soot blowing nozzles Soot blowing system Injector Pulsation damper SCR control unit Nozzles Engine control unit Valves Temp. sensor Digital dosing pump Urea tank NOx sensor Pressure sensor Marine diesel engine Urea pipe

  7. Problem of the present SCR tech. Catalyst Exhaust pipe An example of deposit formationon the face of an SCR catalyst monolith. (By John M.E. Storey et al.) Since the exhaust gas temperature and the residence time in the exhaust pipe is insufficient for complete thermal urea decomposition, a major fraction of the injected urea and byproducts by side reaction remain intact before it enters the SCR catalyst. Stoichiometric imbalance of the urea consumption Degradation of the structural and thermal properties of the catalyst surface

  8. Basic Mechanism of Urea-SCR (NH2)2CO + xH2O Urea Solution evaporation (NH2)2CO → NH3 + HNCO HNCO + H2O → NH3 + CO2 ----------------------------- 4NO + 4NH3 + O2 → 4N2 +6H2O 6NO2 + 8NH3 → 7N2 + 12H2O Urea thermal decomposition HNCO hydrolysis SCR reaction Urea Solution Injector Evaporation and thermal decomposition by exhaust gas temperature NOx CO O2 HC SCR Catalyst N2 CO2 H2O

  9. Caldyn’s Nozzle Sovani et al. (Progress in energy and combustion science, 2001) Caldyn’s nozzle Liquid Inlet Typical effervescent atomizer Perforated Aerorator - Two-phase flow through a nozzle chokes at a significantly lower velocity than that at which a single phaseflow would choke - Atomization quality is greatly enhanced by the sudden pressure drop at the nozzle exit Exit Orifice Hole

  10. Previous Work : Flow rate Jewe Schroder et al. 2011 Caldyn’s nozzle Relative high ALR - Generally, effervescent nozzle is operated with 0.1 ~ 0.3 of ALR

  11. Effervescent Nozzles Liquid Air Air Liquid Liquid Air Liquid & Air Mixture Liquid & Air Mixture (A) Outside-in air injection (B) Inside-out air injection

  12. Configuration of Test Nozzle Aerorator Exit orifice D2 D1

  13. Experimental Setup On-off valve Compressor Regulator Needle valve On-off valve Regulator Flow meter N2 Flow meter Needle valve Pressure transducer Image grabber & DAQ board CCD camera Stroboscope Air Signal Detector Laser for SMD Water *The drop size at 200mm from nozzle tip

  14. Configuration of Test Nozzle *Area ratio = Nozzle Configuration Spray Condition [실험조건 (540 cases)] - Exit orificeDia. (3) - AeroratorDia. (6) - Injection Pressure(3) - Liquid flow rate(10)

  15. Comparison of Mass Flow rate *Area ratio = • - At the same liquid mass flow rate, air mass flow rate increases with increasing of exit orifice diameter.

  16. Comparison of Mass Flow rate

  17. Comparison of Mass Flow rate

  18. Comparison of Mass Flow rate

  19. Droplet Size Measurement - Compared with Caldyn’s data, it has same tendency. - SMD is not a large difference in the value of ALR ratio in 0.3 or more.

  20. Droplet Size Measurement  SMD is not affected by area ratio of an efferverscent nozzle.

  21. Droplet Size Measurement  SMD is not affected by area ratio of an efferverscent nozzle.

  22. Summary • [Conclusion] • The liquid flow rate of the effervescent nozzle used in this study is affected by the diameter of the exit orifice. • It was found that the change of the liquid and air flow rate according to the aerorator diameter was not large at the same exit orifice diameter. • In the case of ALR above 0.3, there is almost no change in SMD even if the air flow rate increases. • In the efferverscent nozzle, the droplet size is not affected by the area ratio. • [Application] • From the results of this study, the droplet size can be predicted according to various ALR and area ratios. • It can be applied to Urea-SCR nozzle design technology according to various engine power.

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