Comparações entre diferentes métodos para dimensionamento de trocadores de calor tipo placa

Abstract

Heat exchangers are equipment responsible for providing a favorable environment for the transfer of thermal energy. They act in cooling or heating processes in the most diverse branches of industry, such as food, chemical, agricultural supplements, among others. The choice of the applied model and its characteristics is the duty of mechanical engineers in order to meet the demand of a particular application. Thus, this work aims to compare results obtained from the design of a plate heat exchanger without mixing via analytical methods with empirical correlations and numerical solutions obtained from ANSYS software. In order to achieve the objective, a common problem was proposed that will be worked using the different methodologies, thus establishing a common basis for comparison. Two analytical methods will be evaluated, namely: the logarithmic mean temperature difference method and the Ɛ-NTU. These will be evaluated when subjected to different processes for calculating the overall heat transfer coefficient. TCALOR program, developed in Matlab, will also be used, which allows the analytical solution in a more practical and efficient way of several types and configurations of heat exchangers. These methods will then be compared with the numerical solution simulated in ANSYS, with a downscaling being necessary to respect the limitations of the student version of the software. The results obtained allowed us to understand the influence of the stagnation zone thickness on heat exchanger performance, the importance of having a diagonally arranged fluid inlet and outlet orifice, and the gauging of analytical simplifications of unmixed flow lines and constant fluid properties.