KEYWORDS
TOPICS
ABSTRACT
In the present study, an innovative design of the urea-selective catalytic reduction (SCR) system without conventional mixing elements was developed. The aim was to obtain a high degree of urea decomposition, and uniform ammonia distribution at the inlet to the catalyst, while minimising the liquid film deposition and keeping the compact design. The concept of the design was based on creating high turbulences and elongating the flow paths of the droplets. The design was verified through a series of numerical simulations based on the Reynolds-averaged Navier–Stokes (RANS) approach and a discrete droplet model (DDM) spray representation. The analysis included various operating conditions as well as subcooled and superheated sprays. A uniform ammonia distribution was achieved regardless of the operating points and spray properties. Additionally, in the case of the flash-boiling injection, a further reduction of the wall film was observed.
FUNDING
The project leading to this application has received funding from the National Centre for Research and Development (NCBiR), grant no. MAZOWSZE/0101/19-00, programme Ścieżka dla Mazowsza, project budget: 9 880 490.25 PLN.
 
REFERENCES (30)
1.
AVL LIST GmbH FIRE TM 2019.2 Wall Film Module User Guide. Wall Film module. 2019.
 
2.
BIRKHOLD, F. Selektive katalytische Reduktion von Stickoxiden in Kraftfahrzeugen: Untersuchung der Einspritzung von Harnstoffwasserlösung. 2007, 15(6), 893–900.
 
3.
BRIZI, G., POSTRIOTI, L. Experimental analysis of SCR spray evolution and sizing in high-temperature and flash boiling conditions. SAE International Journal of Fuels and Lubricants. 2019, 12(2), 87-107. https://doi.org/10.4271/04-12-....
 
4.
BROCKLEY GROUP LTD. Safety data sheet BlueCat AdBlue. 2014.
 
5.
CHO, Y.S., LEE, S.W., CHOI, W.C. et al. Urea-SCR system optimization with various combinations of mixer types and decomposition pipe lengths. International Journal of Automotive Technology. 2014, 15(5), 723-731. https://doi.org/10.1007/s12239....
 
6.
DUKOWICZ, J.K. A particle-fluid numerical model for liquid sprays. Journal of Computational Physics. 1980, 35(2), 229-253. https://doi.org/10.1016/0021-9....
 
7.
EDELBAUER, W. Coupling of 3D Eulerian and Lagrangian spray approaches in industrial combustion engine simulations. Journal of Energy and Power Engineering. 2014, 8(1). https://doi.org/10.17265/1934-....
 
8.
FORCHHEIMER, P. Wasserbewegung durch boden. Zeitschrift des Vereins deutscher Ingenieure, 45th edition. 1901.
 
9.
GROUT, S., BLAISOT, J.-B., PAJOT, K. et al. Experimental investigation on the injection of an urea-water solution in hot air stream for the SCR application: evaporation and spray/wall interaction. Fuel. 2013, 106, 166-177. https://doi.org/10.1016/j.fuel....
 
10.
HUANG, H., CHEN, Y., LI, Z. et al. Analysis of deposit formation mechanism and structure optimization in urea-SCR system of diesel engine. Fuel. 2020, 265, 116941. https://doi.org/10.1016/j.fuel....
 
11.
KAPUSTA, Ł.J., ROGOZ, R., BACHANEK, J. Experimental and numerical study to evaluate the effect of flash boiling on urea-water solution sprays and SCR system performance. Atomization and Sprays. 2021, 31(5), 89-117. https://doi.org/10.1615/Atomiz....
 
12.
KAPUSTA, Ł.J., ROGOZ, R., BACHANEK, J. et al. Low-pressure injection of water and urea-water solution in flash-boiling conditions. SAE International Journal of Advances and Current Practices in Mobility. 2020, 3(1), 365-377. https://doi.org/10.4271/2020-0....
 
13.
KAŠPAR, J., FORNASIERO, P., HICKEY, N. Automotive catalytic converters: current status and some perspectives. Catalysis Today. 2003, 77(4), 419-449. https://doi.org/10.1016/S0920-....
 
14.
KATAOKA, I., ISHII, M., MISHIMA, K. Generation and size distribution of droplet in annular two-phase flow. Journal of Fluids Engineering. 1983, 105(2), 230-238. https://doi.org/10.1115/1.3240....
 
15.
KOEBEL, M., ELSENER, M., KLEEMANN, M. Urea-SCR: a promising technique to reduce NOx emissions from automotive diesel engines. Catalysis Today. 2000, 59(3), 335-345. https://doi.org/10.1016/S0920-....
 
16.
KUHNKE, D. Spray/wall-interaction modelling by dimensionless data analysis. 2004.
 
17.
LECOMPTE, M., OBIOLS, J., CHEREL, J. et al. The benefits of diesel exhaust fluid (DEF) additivation on urea-derived deposits formation in a close-coupled diesel SCR on filter exhaust line. SAE International Journal of Fuels and Lubricants. 2017, 10(3), 864-877. https://doi.org/10.4271/2017-0....
 
18.
LEE, C. Numerical and experimental investigation of evaporation and mixture uniformity of urea-water solution in selective catalytic reduction system. Transportation Research Part D: Transport and Environment. 2018, 60, 210-224. https://doi.org/10.1016/j.trd.....
 
19.
LI, M., ZHANG, Y., LIU, X. et al. Numerical investigation on the urea deposit formation process in a selective catalytic reduction system of a diesel engine based on a fluid–solid coupling method. ACS Omega. 2021, 6(8), 5921-5932. https://doi.org/10.1021/acsome....
 
20.
LIAO, Y., DIMOPOULOS EGGENSCHWILER, P., RENTSCH, D. et al. Characterization of the urea-water spray impingement in diesel selective catalytic reduction systems. Applied Energy. 2017, 205, 964-975. https://doi.org/10.1016/j.apen....
 
21.
MAIZAK, D., WILBERFORCE, T., OLABI, A.G. DeNOx removal techniques for automotive applications – a review. Environmental Advances. 2020, 2, 100021. https://doi.org/10.1016/j.enva....
 
22.
MICHELIN, J., GUILBAUD, F., GUIL, A. et al. Advanced compact SCR mixer: BlueBox. SAE Technical Paper 2014-01-1531. 2014. https://doi.org/10.4271/2014-0....
 
23.
NISHAD, K., STEIN, M., RIES, F. et al. Thermal decomposition of a single AdBlue® droplet including wall–film formation in turbulent cross-flow in an SCR system. Energies. 2019, 12(13). https://doi.org/10.3390/en1213....
 
24.
PARK, T., SUNG, Y., KIM, T. et al. Effect of static mixer geometry on flow mixing and pressure drop in marine SCR applications. International Journal of Naval Architecture and Ocean Engineering. 2014, 6(1), 27-38. https://doi.org/10.2478/IJNAOE....
 
25.
PRABHU, S.S., NATESAN, K., SHIVAPPA NAYAK, N. Effect of UWS spray angle and positioning of injector on ammonia concentration in urea-SCR system. Materials Today: Proceedings. 2021, https://doi.org/10.1016/j.matp....
 
26.
SHAHARIAR, G.M.H., LIM, O.T. A study on urea-water solution spray-wall impingement process and solid deposit formation in urea-SCR de-NOx system. Energies. 2019, 12(1), 1-18. https://doi.org/10.3390/en1201....
 
27.
SMITH, H., LAUER, T., SCHIMIK, V. et al. Evaluation and prediction of deposit severity in SCR systems. SAE International Journal of Engines. 2016, 9(3), 1735-1750. https://doi.org/10.4271/2016-0....
 
28.
TAN, L., FENG, P., YANG, S. et al. CFD studies on effects of SCR mixers on the performance of urea conversion and mixing of the reducing agent. Chemical Engineering and Processing: Process Intensification. 2018, 123, 82-88. https://doi.org/10.1016/j.cep.....
 
29.
ZHANG, C., SUN, C., WU, M. et al. Optimisation design of SCR mixer for improving deposit performance at low temperatures. Fuel. 2019, 237, 465-474. https://doi.org/10.1016/j.fuel....
 
30.
ZUO, B., GOMES, A.M., RUTLAND, C.J. Modelling superheated fuel sprays and vaproization. International Journal of Engine Research. 2000, 1(4), 321-336. https://doi.org/10.1243/146808....
 
eISSN:2658-1442
ISSN:2300-9896