Energy-flow methodology for thermodynamic analysis of manufacturing processes: a case study of welding processes

摘要

Manufacturing processes involve the input of high quality energy and/or dissipation of low quality energy to manipulate a material; similarly the input of high quality material usually leads to the generation of low quality materials. A useful output involves the operation of conventional processes including a wide variety of functions such as lubrication, air compression, cooling, heating, pumping, etc., which have, on the one hand, high energy and material consumption and, on the other hand, losses due to an inherent departure from reversible processes. This paper presents an energy-flow methodology to determine the ratio between the additional energy required per useful energy unit for the manufacturing processes. As an application of the method proposed in this work, an assembly and welding production line is shown as a case study. This process is a common technique used in the manufacturing industry and its energy consumption depends on several parameters e.g. heat and electrical input. As a result of this study, the energy consumption of the production line has been reduced by approximately 30% from the 645.04 Wh total energy consumption, where the consumption of real useful energy is 4% of this total.