DOI QR코드

DOI QR Code

A Study on Velocity Profiles between Two Baffles in a Horizontal Circular Tube

  • 투고 : 2014.05.27
  • 심사 : 2014.10.14
  • 발행 : 2015.02.28

초록

The shell and tube heat exchanger is an essential part of a power plant for recovering transfer heat between the feed water of a boiler and the wasted heat. The baffles are also an important element inside the heat exchanger. Internal materials influence the flow pattern in the bed. The influence of baffles in the velocity profiles was observed using a three-dimensional PIV (Particle Image Velocimetry) around baffles in a horizontal circular tube. The velocity of the particles was measured before the baffle and between them in the test tube. Results show that the velocity vectors near the front baffle flow along the vertical wall, and then concentrate on the upper opening of the front baffle. The velocity profiles circulate in the front and rear baffle. These profiles are related to the Reynolds number (Re) or the flow intensity. Velocity profiles at lower Re number showed complicated mixing to obtain the velocities and concentrate on the lower opening of the rear baffle as front wall. Numerical simulations were performed to investigate the effects of the baffle and obtain the velocity profiles between the two baffles. In this study, a commercial CFD package, Fluent 6.3.21 with the turbulent flow modeling, k-${\epsilon}$ are adopted. The path line and local axial velocities are calculated between two baffles using this program.

키워드

참고문헌

  1. B. B. Gupta, J. A. Howell. D. Wu, and R. W. Field, "A helical baffle for cross-flow microfiltration", Journal of Membrane, vol. 99, pp. 31-42, 1995.
  2. J. J. Dijk, A. C. Hoffmann, D. Cheesman, and J. G. Yates, "The influence of horizontal internal baffles on the flow pattern in dense fluidized beds by X-ray investigation", Power Technology, vol. 98, pp. 273-278, 1998. https://doi.org/10.1016/S0032-5910(98)00069-2
  3. C. Tomasz and B. Andrzej, "Method of calculation of new cyclone-type separator with swirling baffle and bottom take off of clean gas-part I : Theoretical approach", Chemical Engineering and Processing, vol. 441, pp. 441-448, 2000.
  4. D. Leith and W. Leith, "The collection efficiency of cyclone-type particle collectors-a new theoretical approach", American Institute of Chemical Engineers Symposium Series, vol. 68, no. 126, pp. 196-206, 1972.
  5. L. Du, J. Zh, Yao, and W.G. Lin, "Experimental study of particle flow in a gas-solid separator with baffles using PDPA", Journal of the Chemical Engineering, vol. 108, pp. 59-67, 2005. https://doi.org/10.1016/j.cej.2004.12.043
  6. D. Rensheng, Y. A. Davis, Y. Mak, and C. H. Wang, "Taylor vortex flow in presence of internal baffles", Chemical Engineering Science, vol. 65, pp. 4598-4605, 2010. https://doi.org/10.1016/j.ces.2010.05.001
  7. H. Asgharzdeh, B. Firoozabadi, and H. Afshin, "Experimental in investigation of effects of baffle configurations on the performance of a secondary sedimentation tank", Scientia Iranica B, pp. 938-949, 2011.
  8. J. Mahboubeh, K. M. Mostafa, D. Reza, M. Z. Fathollah, and M. Masoud, "Three-dimentional simulation of turbulent flow in a membrane tube filled with semi-circular baffles", Desalination, vol. 294, pp. 8-19, 2012. https://doi.org/10.1016/j.desal.2012.02.031
  9. L. P. Nguyen and I. Kazuide, "Experimental and numerical study of airflow pattern and particle dispersion in a vertical ventilation duct", Building and Environment, vol. 59, pp. 466-481, 2013. https://doi.org/10.1016/j.buildenv.2012.09.014
  10. N. Xesus, B. J. Taylor, G. Hector, C. Ignasi, and M. R. Mackley, "Experimental and computational modeling of oscillatory flow within a baffled tube containing periodic-tri-orifice baffle geometries", Computers and Chemical Engineering, vol. 49, pp. 1-17, 2013. https://doi.org/10.1016/j.compchemeng.2012.09.015
  11. S. Mahdi, R. Fatemeh, M. Azlin M. Said, and Syafalni, "Numerical modeling of baffle location effects on the flow pattern of primary sedimentation tanks", Applied Mathematical Modeling, vol. 37, pp. 4486-4496, 2013. https://doi.org/10.1016/j.apm.2012.09.060
  12. J. F. Yang, M. Zeng, and Q. W. Wang, "Effects of sealing strips on shell-side flow and heat transfer performance of a heat exchanger with helical baffles", Applied Thermal Engineering, vol. 64, pp. 117-128, 2014. https://doi.org/10.1016/j.applthermaleng.2013.11.064
  13. D. H. Doh, T. G. Hwang, and T. Saga, "3D-PTV measurements of the wake of a sphere", Measurements Science Technology, vol. 15, pp. 1059-1066, 2004. https://doi.org/10.1088/0957-0233/15/6/004
  14. G. R. Cho, M. Kawahashi, H. Hirahara, and M. Kitadume, "Application of stereoscopic particle image velocimetry to experimental analysis of flow through multiblade fan", Journal of the Japan Society of Mechanical Engineers International Series B, vol. 48, no. 1, pp. 25-33, 2005.