Eventos Anais de eventos
CONEM 2022
XI Congresso Nacional de Engenharia Mecânica - CONEM 2022
SHELL AND TUBE HEAT EXCHANGER WITH HELICAL BAFFLES: A PARAMETRIC THERMAL-HYDRAULIC ANALYSIS
Submission Author:
Rafael Alberto de Araujo Silva , PE
Co-Authors:
Rafael Alberto de Araujo Silva, JORGE RECARTE HENRIQUEZ GUERRERO, JOSÉ ÂNGELO PEIXOTO DA COSTA
Presenter: Daniel Rodríguez López
doi://10.26678/ABCM.CONEM2022.CON22-0318
Abstract
Heat exchangers are a widely used equipment in both industry and non-industrial applications. The classic example of an industrial application for heat transfer is the shell and tube heat exchanger. This model of heat exchanger varies in size, in tubes profile, quantities, fluid direction and baffle geometries, which can increase thermal efficiency and to reduce pumping costs. The field of study of heat exchangers is not new to science, but when the baffle geometry is changed for a determined application, the performance can vary widely. The present study aims to investigate and compare different heat exchanger’s baffle geometry and its effect for overall heat transfer and equipment. The study was conducted through Ansys CFX software with nine different inputs for each geometry, the analysis was conducted by solving the mass, momentum and energy conservation equations through Conjugate Heat Transfer (CHT) analysis. To understand turbulence, the standard k-epsilon model was utilized to simulate turbulent flow. The geometries studied were continuous helical (CH) with the setups of 360º and 1080º; segmented helical (SH) baffles, both for the same sized heat exchanger with a counterflow configuration. The cold fluid inputs were (0.051 kg/s, 0.1kg/s and 0.2kg/s) at 25ºC. The hot fluid inputs were (60ºC, 50ºC and 40ºC) for 0.05kg/s, both analysed fluids were water. The results have shown that for overall equipment performance, the SH configuration has shown the best results for any given hot inlet temperature and cold fluid flow. An interesting finding happens for lower temperature inlet, which the design performs significantly better than CH configurations. For an economic point of view, the higher ratio h/∆p seen for the SH design must be considered as an indicator for the industry. The decreased energy consumption by lower pumping power can represent a more competitive operational cost. On the other hand, when the best thermal performance is to be achieved, the 1080CH baffle configuration has performed better than any other geometry, showing a very relevant finding about continuous baffles for the inputs presented in this work, being an alternative when the highest temperature exchange application is necessary. For most of the inputs, the 360CH shown the worst overall equipment and thermal performance.
Keywords
Shell-and-Tube Heat Exchanger, Continuous Helical Baffles, Segmented Helical Baffles, Circumferential Overlap
