Multivariate analysis of heat transfer and pressure drop in finned tube bundles
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The exhaust gas from gas turbines contains a large amount of heat that can be utilized for process purposes or for further power generation. The heat recovery units on offshore platforms are required to be as compact and light as possible. During the design of waste heat recovery units correlations are used to estimate the heat transfer and pressure drop. The correlations in the literature have limited validity ranges. The aim of this project was to develop correlations with a wider range of validity than the correlations in the literature. Data from different experimenters, collected in databases, were used in order to establish the new correlations. The report can be divided into the following two parts:1) Literature survey of multivariate analysis:A literature survey of the method of multivariate analysis was done. Here the aim was to find a method that could be used in order to develop the new correlations. The multivariate method called multiple linear regression was chosen. In order to select which variables to include in the multiple linear regression, the variable selection procedure called best subsets regression was carried out. The regression analysis was performed with the statistical software Minitab 16.2) Regression analysis:The data from the two available databases for serrated and solid fins were used in the regression analysis. Correlations for heat transfer and pressure drop were developed for both serrated and solid fins. It was decided to develop two different versions for each correlation: The first version was using different dimensionless groups for fin geometry, while the second version was using Ar (defined by PFR (1976)) as fin geometry effect. For both versions the effect of the Reynolds number and the tube bundle layout was included. In addition, the effect of the segment height on the heat transfer and the pressure drop was investigated.