Diseño y simulación de un intercambiador de calor para una cámara de secado de (2 x 4 x 3) m, con una capacidad de 100 kg de granos de cacao, en un período de tres a cuatro horas

Abstract

The aim of this technical project is to design and simulate an applicable heat exchanger for a drying chamber of 2x4x3 meters to raise the temperature of the air used for dehydrating cocoa beans and optimizing the process time through the artificial use of the drying. This research was developed starting from the design of the heat exchanger, through a thermal analysis of transference which is accomplished by conduction and convection. The working fluids are saturated steam at 111.35 °C and air at 25 °C. A compact heat exchanger is ideal to develop this activity, according to the design. Its power is 54.64 kW. The geometry used to make the model contributes to obtaining a favorable thermal evolution, since, with the arrangement of the tubes and the use of extended surfaces in them, the effectiveness of the equipment reaches a value of 0.90. In order to corroborate the work, it was developed through simulation in SolidWorks software with the FlowSimulation complement, analyzing the air temperature in the exit to verify if the demanded energy was transferred, reaching 64 °C. In addition, the time needed to obtain the required moisture of 7% was evaluated analytically and computationally (EES software), reaching a time of 3.53 h. Finally, the calculation of the design allowed to select the components for the system, having an ELECON boiler of 80 BPH and a centrifugal ventilation equipment of the series: CDXRT-355-0.75.