Optimizing Thermal Behavior of Compact Heat Exchanger

Heat transfer is one of the key aspects of machines, devices and industrial processes to maintain their functionality and obtain better product quality. Therefore, heat exchangers of various types and sizes are used in these applications to dissipate additional heat from the process/device and to maintain the desired operating temperatures. However, the size of a heat exchanger is an important consideration for any type of process/device, since it determines the space (i.e. the size) of the machine/device or treatment plants. The purpose of this study is, first of all, to theoretically examine the design process of a heat exchanger, then to analyze and optimize its performance using computer-assisted fluid dynamics. A counter-current heat exchanger was considered for design purposes and its length was theoretically calculated using the LMTD method, while the pressure drop and energy consumption were also calculated with the Kern method. In the CFD analysis, the three-case model was used in this study to analyze the behavior of heat transfer, mass flow rates, pressure drops, flow velocities and vortices of the bundle flows in the heat exchanger. Theoretical and CFD results showed only a 1.15% difference in the cooling performance of hot fluids. The axial pressure drops showed positive correlations with the total heat transfer coefficient and the required pumping power. Overall, the results of this study confirm that CFD modeling can be promising for the design and optimization of heat exchangers and that it can test many design options without producing physical prototypes.