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http://dx.doi.org/10.3795/KSME-B.2016.40.1.001

Numerical Investigation on the Urea Melting Characteristics with Coolant and Electric Heaters  

Lee, Seung Yeop (Department of Aerospace Engineering, Chonbuk Nat'l Univ.)
Kim, Man Young (Department of Aerospace Engineering, Chonbuk Nat'l Univ.)
Publication Information
Transactions of the Korean Society of Mechanical Engineers B / v.40, no.1, 2016 , pp. 1-7 More about this Journal
Abstract
A Urea-SCR(Selective Catalytic Reactor) system, which converts nitrogen oxides into nitrogen and water in the presence of a reducing agent, creates a major exhaust gas aftertreatment system for NOx reduction among other compounds. With regard to vehicle applications, a urea solution was chosen based on its eutectic composition of a 32.5wt% urea-water solution. An important advantage of this eutectic composition is that its melting point of $-11.7^{\circ}C$ is sufficiently low to avoid solidification in cold environments. However, the storage tanks must be heated separately in case of low ambient temperature levels to ensure a sufficient amount of liquid is available during scheduled start ups. In this study, therefore, a numerical investigation of three-dimensional unsteady heating problems analyzed to understand the melting processes and heat transfer characteristics including liquid volume fraction, temperature distributions, and temperature profiles. The investigations were performed using Fluent 6.3 commercial software that modeled coolant and electric heater models based on a urea solution. It is shown that the melting performance with the electric heater is higher than a coolant heater and is more efficient.
Keywords
Urea Solution; Melting; Phase Change; Coolant Heater; Electric Heater;
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Times Cited By KSCI : 1  (Citation Analysis)
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1 Swaminathan, C. R. and Voller, V. R., 1992, "A General Enthalpy Method for Modeling Solidification Processes," Transaction of Metallurgical, Vol.23(B), pp. 651-664.
2 Hong, Y. D. and Park, C. K., 2002, "Numerical Analysis on Phase-change of Pure Water by Using Moving Grid," Fall Conference Proceedings, KSME, pp. 1906-1911.
3 Kang, K. G., Ryou, H. S. and Hur, N. K., 2003, "Numerical Analysis of Solidification and Melting Phase Change Using Modified PISO Algorithm," Transactions of KSCFE, Vol. 3, No. 8, pp. 12-20.
4 Kim, H. K., Jeong, S., Hur, N., Lim, T. and Park, Y. S., 2007, "Numerical Analysis of Melting Process in a Water Tank for Fuel-cell Vehicle," Transactions of SAREK, Vol. 19, No. 8, pp. 585- 592.
5 Hwang, J., Heo, H. and Lee, C., 2010, "The Thawing Characteristics of Frozen Urea Solution for Heating System Design of Urea-SCR System on Commercial Heavy Duty Vehicle," Annual Conference Proceedings, KSAE, pp. 1065-1069.
6 Choi, B. C., Seo, C. K. and Myong, K. J., 2009, "Freezing and Melting Phenomena of Ureawater Solution for Diesel Vehicle SCR System," Transactions of KSPSE, Vol. 4, No. 13, pp. 5-10.
7 Stefan, W., 2007, "Numerical Heat Transfer and Thermal Engineering of AdBlue(SCR) Tanks for Combustion Engine Emission Reduction," Applied Thermal Engineering, Vol. 27, pp. 1790-1798.   DOI
8 Gau, C. and Viskanta, R., 1986, "Melting and Solidification of a Pure Metal on a Vertical Wall," Journal of Heat Transfer, Vol. 108, pp. 174-181.   DOI
9 Ansys Inc., Release 12.0 User's Guide, Fluent, 2009.
10 Egal, M., Budtova, T. and Navard, P., 2008, "The Dissolution of Microcrystalline Cellulose in Sodium Hydroxide-Urea Aqueous Solution," Cellulose, Vol. 15, pp. 361-370.   DOI