Diseño de un intercambiador de calor de tubos concéntricos mediante un estudio teórico para el proceso de calentamiento de amoníaco

Abstract

The objective of this work is the design of a concentric tube heat exchanger through a theoretical study for heating ammonia. It was determined that the basic principle for designing this type of equipment consists in establishing the initial parameters: temperature of the fluids and the internal diameter of the pipes. On the other hand, the design criteria were selected, which consisted of two phases: technical design and thermal design. The technical design consisted mainly in the selection of the most suitable material to achieve optimal operating performance, in this case it was stainless steel; while for the thermal design the following parameters were established: Reynolds number (Re), Nusselt number (Nu), volumetric flows (v), heat capacities (C), convection coefficients (h), global heat transfer coefficient (U), among others. Finally, after using a simplified calculation model such as the one proposed in this written work, the main thermal parameters for the design of the concentric tube heat exchanger were obtained, which are: internal diameter (D1) of 100 mm, external diameter of the inner tube (D2), inner diameter of the outer tube (D3), thickness (e) and length (L); with which it was possible to raise the temperature of liquid ammonia (NH3) from 20℃ to 62.54℃ using water at 80℃ as heating medium and, obtaining an efficiency of 70.9% for its use in the synthesis of granulated urea in the fertilizer industry.