Data Collection Of Environmental Burdens In Welding And Environmental Impact Assessment

Welding is one of manufacturing techniques,which plays an indispensible role in modern manufacturing and widely used in aviation,railway transportation,automotive industry and so on.A lot of power and materials are consumed for melting and connecting metal in welding.It will generate pollution and that may pose potential burdens for environment and human beings.To realize sustainable manufacturing of welding,the primary task is measuring the consumption of resources and emission of environmental burdens in welding,which can evaluate the environmental impact of welding.By analyzing the literature review on the challenges,some obstacles that are still not being overcome are found and listed as follows:1)In previous experiments,the concentrations of gas pollutants（i.e.CO₂,O₃,and NO_x）were measured at finite measurement points.However,the uneven distribution of gas pollutants caused by its fluidity and diffusivity,which results in the inaccurate result of the emission of the gas pollutants.2)The data is not enough to support the inventory analysis and evaluate the environmental impact of welding.3)Since the seams may have different geometry,which results in different consumption of material and energy,emission of pollutants.Focusing on the aforementioned problems,the following research activities have been performed in the dissertation.An arc profile based approach to evaluate the emissions of gas pollutants in welding was proposed for quantitatively analyzing the emission of gas pollutants.The emission of gas pollutants in welding can be calculated according to the chemical reaction and the reaction condition,i.e.,the intensity of discharge that determines the coverage volume of the welding arc.Then,the emission of the gas pollutants in welding can be quantitatively analyzed,which provides the concentration range for measuring the emission of gas pollutants.From the perspective of obtaining the consumption of resources and the emission of environmental burdens,a device is developed for measuring energy consumption and emissions of CO₂,NO_x,O₃,PM_2.5,and PM₁₀ in welding.Furthermore,BP neural network model,RBF neural network model,and RBF-BP neural network model are used for predicting the generation of environmental burdens under different parameters,which can provide a range reference for distinguishing the emission of environmental burdens.Moreover,the method is proposed for estimating the consumption of resource and energy,and the emission of welding fume.The Gaussian plume model,the arc profile based model,and RBF-BP neural network model are used for estimating the emission of environmental burden in welding.Besides,the material consumption in welding is estimated according to the bevel type and geometry of the weld.Moreover,the energy consumption in welding is calculated according to the melting of the metal material in welding.Then,the inventory data in welding can be obtained for supporting the environmental impact assessment.The environmental impact assessment method base on the consumption of filler material was proposed for evaluating the environmental impact of welding process.Its environmental impact was calculated by evaluating the environmental impact of the filler material with specific quality.Then,the carbon emission of a white-in-body was evaluated by calculating the environmental impacts of four welding processes（GMAW,SAW,PAW and LW）.Meanwhile,the key factors can be identified,which is considered as the optimization objective.Then,the parameters are optimized to minimize the environmental impact and reduce the emission of environmental burdens in welding.Finally,combined with welding technology,the methods are applied in the manufacturing of an aluminum white-body,including data acquisition methods,data processing method,and environment impact assessment method.The results shown the reliability and accuracy of these methods were verified.