Journal of Nuclear Science, Engineering and Technology (JONSAT)
In cooperation with the Iranian Nuclear Society

Modeling and Optimization of Operating Conditions of Condensers in UF6 Separation Unit

Document Type : Research Paper

Authors

S. M. Ghoreishi
H share Mohammadi
F Mohammadi
Abstract
In this study, modeling and optimization of two in-series UF6 shell and tubes separator condensers were performed to improve the prediction of the amount of the mist output, physical properties of condensing gases and condensed mass of UF6 by computing the mist formation conditions. The main objective of this research was to predict the optimal operating conditions in order to reduce the uranium in the outlet mist from the condenser system. These two shell and tube condensers were modeled via control volumes with finite length in axial direction of input gases. The equations of mass, energy and momentum balance were written for each condenser and then surface temperature of UF6 condensed layer on the condenser tube was determined by the trial and error method. The mass and heat transfer parameters were calculated at each time step during the process. Comparison of the modeling predictions with the Isfahan UCF industrial data in regard to important variables indicated a very good compatibility. The average error between the modeling and industrial data for the first and second condensers were calculated to be 1.39 and 2.24%, respectively. Finally, the analysis of the effective variables via the developed modeling computer software revealed that the optimal temperature of cooling brine water and the input gas velocity are 10 ˚C and 0.09 m/s, respectively.

Highlights

[1] H. Grin, V. Lein, Aerosols-dusts, smokes and fogs, Leningrad, Moscow: Khimia (1969).

 [2] P.A. Smolkin, A.S. Buynovskiy, V.V. Lazarchuk, A.A. Matveev, V.L. Sofronov, Mathematical model of desublimation process of volatile metal fluorides, Bulletin of the Tomsk Polytechnic University, 310 (2006) 69-71.

 [3] V.L. Sofronov, A.S. Buinovskiy, K.F. Vasiliev, on sublimation purification of titanium tetra-fluoride, Moscow: Nauka (1984).

 [4] A.A.S. Abed, Mathematical Model for Definition of Thermal Conditions in Desublimation Process of Volatile Metal Fluorides, Int. Journal of Current Engineering and Technology, 3 (2006) 1396-1401.

 [5] J. Bilik, R. Krupiczka, Heat transfer in the desublimation of Phethalic Anhydride, Chemical Engineering Journal, 26 (1982) 169-180.

 [6] D. Seker, H. Karatas, N. Egrican, Frost formation on fin-and-tube heat exchangers, Int. J. of Refrigeration, 27 (2003) 375-377.

 [7] K. Lenic, A. Trp, B. Frankovic, Unsteady heat and mass transfer during frost formation in a fin-and-tube heat exchanger, Int. J. of Refrigeration, 27 (2011) 367-374.

 [8] J. Cui, W.Z. Li, Y. Liu, Y.S. Zhao, A new model for predicting performance of fin-and-tube heat exchanger under frost condition, Int. J. Heat and Fluid Flow, 32 (2010) 249-260.

 [9] P.J. Mago, S.A. Sherif, Heat and mass transfer on a cylinder surface in cross flow under supersaturated frosting conditions, Int. J. refrigeration, 26 (2003) 889-899.

 [10] F.P. Incropera, D.P. De Witt, Introduction to heat transfer, fourth edition, Mcgraw-Hill (2000(.

 [11] D.H. Lee, D.K. Yang, K.S. Lee, Frost formation on a cold cylinder surface in cross flow Int. J. of Refrigeration, 27 (2004) 367-374.

[12] J.M. Coulson, J.F. Richardson, Chemical Engineering, Mcgraw- Hill (1999).

 [13] D.K. Yang, K.S. Lee, S. Song, Modeling for predicting frosting behavior of a fin-tube heat exchanger, Int. J. of Heat and Mass Transfer, 49 (2006) 1472-1479.

 [14] T. Gao, J. Gong, Modeling the airside dynamic behavior of a heat exchanger under frosting conditions, J. of Mechanical Science and Technology, 25 (2011) 2719-2728.

 [15] K. Lenic, A. Trp, B. Frankovic, Unsteady heat and mass transfer during frost formation in a fin-and-tube heat exchanger, Int. J. of Refrigeration, 27 (2011) 367-374.

 [16] A. Claire, S. Howard, Purification by Sublimation, New Jersey (2006).

 [17] A.G. Amelin, Theoretical basis of fog formation at vapor condensation, Moscow: Khimia (1972).

 [18] P.A. Smolkin, A.S. Buynovsky, V.L. Sofronov, Determining the optimal process conditions for volatile metal fluoride desublimation, Chemistry  for Sustainable Development, 19 (2011) 417-421.

 

Keywords

Uranium-hexafluoride
Condensation
Condenser
Modeling
Optimization
[1] H. Grin, V. Lein, Aerosols-dusts, smokes and fogs, Leningrad, Moscow: Khimia (1969).
 [2] P.A. Smolkin, A.S. Buynovskiy, V.V. Lazarchuk, A.A. Matveev, V.L. Sofronov, Mathematical model of desublimation process of volatile metal fluorides, Bulletin of the Tomsk Polytechnic University, 310 (2006) 69-71.
 [3] V.L. Sofronov, A.S. Buinovskiy, K.F. Vasiliev, on sublimation purification of titanium tetra-fluoride, Moscow: Nauka (1984).
 [4] A.A.S. Abed, Mathematical Model for Definition of Thermal Conditions in Desublimation Process of Volatile Metal Fluorides, Int. Journal of Current Engineering and Technology, 3 (2006) 1396-1401.
 [5] J. Bilik, R. Krupiczka, Heat transfer in the desublimation of Phethalic Anhydride, Chemical Engineering Journal, 26 (1982) 169-180.
 [6] D. Seker, H. Karatas, N. Egrican, Frost formation on fin-and-tube heat exchangers, Int. J. of Refrigeration, 27 (2003) 375-377.
 [7] K. Lenic, A. Trp, B. Frankovic, Unsteady heat and mass transfer during frost formation in a fin-and-tube heat exchanger, Int. J. of Refrigeration, 27 (2011) 367-374.
 [8] J. Cui, W.Z. Li, Y. Liu, Y.S. Zhao, A new model for predicting performance of fin-and-tube heat exchanger under frost condition, Int. J. Heat and Fluid Flow, 32 (2010) 249-260.
 [9] P.J. Mago, S.A. Sherif, Heat and mass transfer on a cylinder surface in cross flow under supersaturated frosting conditions, Int. J. refrigeration, 26 (2003) 889-899.
 [10] F.P. Incropera, D.P. De Witt, Introduction to heat transfer, fourth edition, Mcgraw-Hill (2000(.
 [11] D.H. Lee, D.K. Yang, K.S. Lee, Frost formation on a cold cylinder surface in cross flow Int. J. of Refrigeration, 27 (2004) 367-374.
[12] J.M. Coulson, J.F. Richardson, Chemical Engineering, Mcgraw- Hill (1999).
 [13] D.K. Yang, K.S. Lee, S. Song, Modeling for predicting frosting behavior of a fin-tube heat exchanger, Int. J. of Heat and Mass Transfer, 49 (2006) 1472-1479.
 [14] T. Gao, J. Gong, Modeling the airside dynamic behavior of a heat exchanger under frosting conditions, J. of Mechanical Science and Technology, 25 (2011) 2719-2728.
 [15] K. Lenic, A. Trp, B. Frankovic, Unsteady heat and mass transfer during frost formation in a fin-and-tube heat exchanger, Int. J. of Refrigeration, 27 (2011) 367-374.
 [16] A. Claire, S. Howard, Purification by Sublimation, New Jersey (2006).
 [17] A.G. Amelin, Theoretical basis of fog formation at vapor condensation, Moscow: Khimia (1972).
 [18] P.A. Smolkin, A.S. Buynovsky, V.L. Sofronov, Determining the optimal process conditions for volatile metal fluoride desublimation, Chemistry  for Sustainable Development, 19 (2011) 417-421.
 

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