Estimation of local heat transfer coefficient in coiled tubes under inverse heat conduction problem approach

Abstract Wall curvature is a widely used technique to passively enhance convective heat transfer and it is particularly effective in the thermal processing of highly viscous fluids. These geometries produce a highly uneven convective heat flux distribution along the circumferential coordinate, impacting on the performance of the fluid thermal treatment. Although many authors have investigated the forced convective heat transfer in coiled tubes, most of them have presented the results only in terms of the Nusselt number averaged along the wall circumference. Moreover, regarding the laminar flow regime, few data about the local heat transfer coefficient are available. In this paper a procedure to estimate the local convective heat flux in coiled tubes is presented and tested: the temperature distribution maps on the external coil wall are employed as input data for the inverse heat conduction problem in the wall under a solution approach based on Tikhonov regularization method. The investigation was particularly focused on the laminar flow regime.

[1]  Frank P. Incropera,et al.  Fundamentals of Heat and Mass Transfer , 1981 .

[2]  Fabio Bozzoli,et al.  Characterization of an uncooled infrared thermographic system suitable for the solution of the 2-D inverse heat conduction problem , 2008 .

[3]  Fabio Bozzoli,et al.  Compound convective heat transfer enhancement in helically coiled wall corrugated tubes , 2013 .

[4]  Liejin Guo,et al.  Turbulent heat transfer in a horizontal helically coiled tube , 1999 .

[5]  M. A. Ebadian,et al.  Laminar forced convection in a helicoidal pipe with finite pitch , 1995 .

[6]  Per Christian Hansen,et al.  Rank-Deficient and Discrete Ill-Posed Problems , 1996 .

[7]  Michele Ciofalo,et al.  Numerical prediction of turbulent flow and heat transfer in helically coiled pipes , 2010 .

[8]  Somchai Wongwises,et al.  A review of flow and heat transfer characteristics in curved tubes , 2006 .

[9]  Cha'o-Kuang Chen,et al.  Estimation of unknown outer-wall heat flux in turbulent circular pipe flow with conduction in the pipe wall , 2005 .

[10]  Teresa Reginska,et al.  A Regularization Parameter in Discrete Ill-Posed Problems , 1996, SIAM J. Sci. Comput..

[11]  C. J. Hoogendoorn,et al.  Laminar convective heat transfer in helical coiled tubes , 1978 .

[12]  Win-Jin Chang,et al.  Inverse problem of estimating transient heat transfer rate on external wall of forced convection pipe , 2008 .

[13]  Fabio Bozzoli,et al.  Experimental investigation on the convective heat transfer in straight and coiled corrugated tubes for highly viscous fluids: Preliminary results , 2012 .

[14]  B. Blackwell,et al.  A technique for uncertainty analysis for inverse heat conduction problems , 2010 .

[15]  Fabio Bozzoli,et al.  Numerical analysis of convective heat transfer enhancement in swirl tubes , 2011 .

[16]  B. Blackwell,et al.  Inverse Heat Conduction: Ill-Posed Problems , 1985 .

[17]  Dianne P. O'Leary,et al.  The Use of the L-Curve in the Regularization of Discrete Ill-Posed Problems , 1993, SIAM J. Sci. Comput..

[18]  Kannan N. Iyer,et al.  CFD analysis of single-phase flows inside helically coiled tubes , 2010, Comput. Chem. Eng..

[19]  L. Talbot,et al.  Flow in Curved Pipes , 1983 .

[20]  A. Zachár,et al.  Analysis of coiled-tube heat exchangers to improve heat transfer rate with spirally corrugated wall , 2010 .

[21]  John A. Nelder,et al.  A Simplex Method for Function Minimization , 1965, Comput. J..

[22]  Fermín S. V. Bazán,et al.  Fixed-point iterations in determining the Tikhonov regularization parameter , 2008 .

[23]  Aoyama Yoshiyuki,et al.  Laminar heat transfer in a helically coiled tube , 1988 .