Carbon Emissions Model Of Mechanicial Manufacturing System Based On Modified Value Stream Mapping And Its Application Research

Mechanical manufacturing industry in China faces the pressure of high-energy consumption,high-resource consumption and inefficiency.Under the strategtic development goal of energy-saving and emission reduction,accelerating transformation of engineering industry from resource consumption and environmental pollution to low carbon manufacturing is the only way to sustainable development.Therefore,the binding challenge of resource,environment and energy forced the pattern of “Low Carbon Manufacturing” to be paied more attention from academia and industry.As a typical discrete manufacturing system,mechanical manufacturing system is affected by production time,output and production value.That makes carbon emission of mechanical manufacturing system be of multisources and variety.To achieve lowcarbon mechanical manufacturing process,combine carbon emission characteristics of manufacturing system with the value added and the non-value added characteristics of production process,and realize low carbon manufacturing from value flow of lean production,which has important guide for enterprises.Under the support of National Science Foundation of China project(NO.51075415),the paper carries out the research for carbon emissions model of mechanicial manufacturing system based on modified value stream mapping and its application.Firstly,the carbon emission source of mechanical manufacturing system is identified and quantified.From the perspective of material flow,energy flow,information flow,value flow and time flow of manufacturing process,the characteristics of mechanical manufacturing system is analysed.Accroding to classify the machining equipment,the auxiliary equipment and the peripheral equipment and identify carbon emission source of mechanical manufacturing system,the carbon emission boundary of mechanical manufacturing system is established.Based on this boundary,the quantitative method of carbon emission of energy flow,material flow,moving process and time flow storing process are presented.Secondly,based on Modified Value Stream Mapping,a carbon emission model of mechanical manufacturing system is established.Focusing on value flow of lean production,the Modified Value Stream Mapping that can represents the non-value added and the value added time flow,material flow,energy flow,moving flow and carbon emission flow is proposed and the quantative method of value added and non-value added carbon emission is built.According to the eco-efficiency,the comprehensive evaluation index of carbon efficiency is provided to evaluate the low carbon performance of manufacturing system considering the production rate,production return and value added.Thidly,an optimization analysis approach of carbon emission of mechanical manufacturing system based on seven wastes is made.From the perspective of non-value added characteritics,the environmental and carbon emission impacts caused by seven wastes of mechanical manufacturing system is analysed.Combining the quantative approach of non-value added carbon emission,the quantative method of carbon emission caused by seven wastes is proposed.Meanwhile,an optimization solution aiming at eliminating wastes form production level.Finally,the production line of decelerator secondary gear is chosen as an example.Through establishing Modified Value Stream Mapping and analyzing its non-value added characteristics,existing wastes of this system is identified.Taking corresponding production improvements,the non-value added carbon emission is reduced,and then the comprehensive evaluation index of carbon efficiency is improved,in order to verify the feasibility of the proposed method.