The present study aimed to perform the parametric analysis on thermo-hydraulic performance of a compact heat exchanger using computational fluid dynamics (CFD). The analysis has been carried out at different frontal air velocities by varying the geometrical parameters such as fin pitch, transverse tube pitch, longitudinal tube pitch, louver pitch and louver angle. The air side performance of the heat exchanger has been evaluated by calculating Colburn factor (j) and Fanning friction factor (f). The comparison of CFD results with the experimental data exhibited a good agreement and the influence of various geometrical parameters for the selected range of values on the pressure drop, heat transfer coefficient and goodness factor was analyzed. The results obtained from the analysis will be very useful to optimize the louvered fin and flat tube compact heat exchanger for better thermo-hydraulic performance analysis without the need of time consuming and expensive experimentation. Ó 2015 Faculty of Engineering, Alexandria University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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Abstract:For the reliable design of crude oil and residua fractionators and fired heaters, accurate calculation method for ASTM Distillation curves and ASTM distillation temperature at the required volume percentage distilled is necessary. The present work deals with fitting literature data of ASTM Distillation curves and obtain a new correlation suitable to use in modeling when optimizing the refining processes, such as distillation, FCC, catalytic reforming, hydrotreating, etc. The results showed that the values predicted by the new correlation are in very close agreement with literature data and the range of mean overall deviation (%MOD) is (0.305-0.585). Also a shortcut correlation is presented to calculate the ASTM distillation temperature at the required volume percentage distilled. Based on temperatures obtained we can have an estimate of the heating costs involved to perform distillation and temperature at which different cuts are obtained.

The present work numerically investigates for a latent heat thermal storage (LHTS) unit, the effect of key design parameters such as the inlet temperature of the heat transfer fluid (HTF), initial and melting temperatures of the PCM, thermophysical parameters such as specific heat, thermal conductivity etc., on its performance. A numerical model has been developed considering the discharging mode of operation and solved employing finite difference technique. The parametric study reveals that the effect of HTF inlet temperature on the unit's thermal response is more compared to initial temperature of the PCM and the influence of thermal conductivity of the PCM is very strong compared to specific heat capacity of the solid PCM