Author : M. Velliangiri 1
Date of Publication :20th June 2019
Abstract: This research study aims to predict LMTD Correction factor F and the number of shells needed to design a shell and tube, heat exchanger. There are various available approaches for heat exchanger analysis like LMTD, and effectiveness ε are two of these. Traditional analysis methods use heat exchanger charts to evaluate the expressions for Log Mean Temperature Difference (LMTD) Correction Factor' F' because it is difficult to calculate. In addition, these charts are limited to only one type of heat exchanger and are greatly nonlinear. The LMTD correction factor 'F' is challenging to read in regions of a steep slope. An analytic approach to determining LMTD correction factor 'F' is presented in this study, utilizing two non-dimensional parameters (P, W, G and R). By considering multi-pass shell and tube heat exchangers with any number of shell passes and even the number of tube passes per shell, a single algebraic equation is derived that specifies the LMTD correction factor for all of these heat exchangers. To calculate the correction factor, we must first find the number of shells, N, and the heat exchanger terminal temperatures, T. The new equation gives the value of 'F' calculated by the graph to agree with the value calculated from the equation. A set of equations have been derived to predict suitable the number of shells for a suitable correction factor 'F' and terminal temperatures of the shell tube heat exchanger.
Reference :
-
- L. Hu, T. Ma, P. Zhang, and Q. Wang, "Thermal design of a shell and tube heat exchanger with internal fins," Chem. Eng. Trans., vol. 76, no. 1, pp. 259–264, 2019.
- F. Neves Teixeira, L. G. Monteiro Guimarães, M. dos Santos Guzella, L. Cabezas-Gómez, and J. Antônio da Silva, ―Numerical Procedure for LMTD Correction Factor Calculation for One Tube and One Shell Pass Shell-and-Tube Heat Exchangers,‖ Appl. Mech. Mater., vol. 789–790, no. September, pp. 426–429, 2015.
- A. A. H. Mostafa, E. E. Khalil, G. El-Hariry, W. A. Abdelmaksoud, and E. M. Saad, "Shell and tube heat exchanger performance," 15th Int. Energy Convers. Eng. Conf. 2017, vol. 3, no. 9, pp. 1872–1881, 2017.
- S. K. Bhatti, C. M. Krishna, C. Vundru, M. L. Neelapu, and I. N. N. Kumar, "Estimating number of shells and determining the log mean temperature difference correction factor of shell and tube heat exchangers," WIT Trans. Eng. Sci., vol. 53, pp. 323–335, 2006.
- S. M. S. Jeter, "Effectiveness and LMTD Correction Factor of the Cross Flow Exchanger: a Simplified and Unified Treatment," Icee.Usm.Edu, pp. 1–10, 2006. [6] J. R. Thome, "3 . Heat Exchanger Design," pp. 1– 41, 2008.
- I. P. Smith, C. Ave, S. P. Shea, and P. Marzocca, "Imece2014-38581 Numerical and Experimental Investigation of Membrane Wing for Micro," pp. 1–6, 2014.