Optimalisasi Geometri Tungku Peleburan Aluminium Untuk Meminimalisir Kehilangan Panas (Heat Loss) Berbasis CFD

Abstract

Small and medium-scale crucible-type aluminum melting furnaces commonly suffer from significant heat loss through conduction across furnace walls, reducing thermal efficiency and increasing fuel consumption. This study aims to optimize the geometry of a 5 kg gas-fired aluminum melting furnace to minimize heat loss using a Computational Fluid Dynamics (CFD) approach. Three-dimensional steady-state numerical simulations were conducted using ANSYS Fluent, incorporating three combustion chamber geometry variations (cylindrical, hexagonal, and square) and two crucible-to-bottom-wall distance variations (60 mm and 120 mm), yielding six design configurations. Simulations simultaneously considered conduction, convection, and radiation heat transfer mechanisms using SK-34 refractory brick and Salamander A10 crucible materials. Results show that design B2P2, a cylindrical geometry with a 60 mm crucible distance, consistently outperformed all other configurations, achieving a monitor temperature of 1,015.51 K, a crucible heat flux intensity of 552.16 W/m², the highest turbulence kinetic energy (TKE) of 0.217521 J/kg, and the lowest refractory wall heat loss of 2,432.11 W. Further numerical calculations yielded a thermal efficiency of 26.5% with a heat input rate of 5,539.93 W. The cylindrical geometry proved superior by eliminating dead zones, enabling hot gas flow to form a cyclonic circulation pattern that uniformly surrounds the crucible. Design B2P2 is recommended as a technical reference for developing more efficient aluminum melting furnaces in small and medium-scale foundry industries.