Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
NUMERICAL COMPARATIVE STUDY OF HEAT EXCHANGER COILS
Submission Author:
Jonatha Wallace da Silva Araújo , RN
Co-Authors:
Jonatha Wallace da Silva Araújo, Felipe Pinheiro Maia, Ramon Carneiro, Sandi Souza
Presenter: Ramon Carneiro
doi://10.26678/ABCM.COBEM2021.COB2021-0648
Abstract
One of the most common applications in any industry is the heat exchangers, i.e., devices that use the temperature difference between fluids in flow as a mechanism to promote the thermal energy flux between separated systems. Examples of heat exchanger applications are the evaporation and condensation processes of refrigeration systems, the heating or cooling process of food products, heat regenerative systems and the processing of industrial products. The development of studies aimed at increasing the efficiency of thermal exchange processes has great importance in this economic scenario. According to this, the objective of this paper was to analyze, using Computational Fluid Dynamics (CFD) methods, four different coil geometries for a shell and tube heat exchanger. To this study, the coils selected are a helical geometry, geometry with vertical ducts and horizontal ducts, and a straight duct used as the reference, all with the size delimited by a determined maximum shell volume. The simulations were performed following the RANS method and using the k-ω-SST model to calculate the turbulent flows. Unstructured meshes formed by tetrahedral elements were adopted to the domain’s discretization and the necessary wall treatment required by the model was applied. The fluid used to flow into the coils is the water. As a boundary condition for the three geometries was imposed the prescribed coil surface temperature of 25°C and the inlet flow with uniform velocity profile equivalent to Reynolds numbers 3000, 6000, 9000, 12000 and 15000, average temperature of 100°C, and turbulent intensity of 5 %. As a result of these simulations, the general aspects of the flow into the coils, the Nusselt number curves for each case, as a function of the Reynolds number, and the respective pressure drop for the four configurations were obtained. With such data, the best geometry for heat exchange in the determined volume can be identified in terms of thermal efficiency.
Keywords
CFD, RANS, Heat exchanger, Coil, Thermal Analysis
