Numerical Investigation for the Design of a Central Recuperator with Hybrid Air Preheating

Abstract Industrial furnaces, especially in steel industry but also in non-ferrous, ceramic or chemical industry, are often fired with fossil fuels like natural gas, oil or coke. Considering the transition to green energy, it is necessary to enable the use of renewable energies like wind and solar energy in fossil-fueled furnaces. Resulting from this motivation, a hybrid recuperator for combustion air preheating with off-gas heat and electric energy is being developed in a public research and development project. The hybrid recuperator consists of a conventional tube bundle module and an electric heating module. The design of the prototype is based on numerical investigations to determine pressure loss, increase in temperature and heat transfer. This article introduces the concept of the new hybrid recuperator and initial results of numerical investigations for a small-scale hybrid recuperator geometry.