Avaliação térmica do sistema de vapor visando oportunidades de melhorias em indústria de alimentos

Abstract

Water vapor is utilized as a thermal energy source (heat) by most food industries, typically obtained at the expense of burning fossil fuels to supply a substantial amount of heat to properly treated water. Therefore, the competitiveness and sustainability of these industries depend on the energy efficiency of these processes, meaning the maximum utilization of heat in the steam system must be ensured, along with the imperative minimization of points of high-cost heat loss. In this context, this study evaluated typical critical points indicative of energy efficiency in the steam system of a corn oil industry, where steam consumption exceeded the estimated theoretical values. Initially, data and thermodynamic variables were collected through direct measurements from process lines and supervisory systems, resulting in a descriptive report and the recovery of the process flow diagram. Based on the practical data obtained, the optimal thermal insulation thickness of the steam distribution lines was calculated as 10mm, identified as a critical point for steam loss. The cost of steam was 50% higher than the calculated theoretical value, with a monthly average cost of R$48,000.00, mainly attributed to the non-recovery of condensate, also representing a critical point. Furthermore, the existing Flash steam recovery system, despite an expected return on investment in 13.3 months, had not been successful in operation and was inactive, necessitating reevaluation and constituting the third identified critical point for the efficiency of the studied system. Therefore, prior to the company’s Downsizing adoption, the results indicate that energy losses can be reduced by insulating pipelines and recovering condensate with recycling to the boiler, significantly impacting energy efficiency by decreasing the costs of the evaluated system. This work contributes to the theory and applications of methods for generating, transporting, and reusing residual steam energy, while also updating the plant with specifications of parameter behavior and points for energy efficiency.