Carbon Footprint Evaluation And Decision Of Mechanical And Electrical Products Design Scheme

In recent decades,global warming,as one of the most serious challenges to sustainable development,has attracted widespread public attention.The main cause of global climate change is the emission of greenhouse gases,which will cause potential damage to the ecological environment.According to statistics,40%of global CO2 emissions can be attributed to industrial production activities.As the end product of industrial production,products emit large amounts of CO2 throughout their life cycle.Therefore,taking some measures to reduce the carbon emissions of the life cycle of mechanical and electrical products is essential to mitigate global warming.The design phase plays a very important role throughout the life cycle of a product.It is worth noting that about 90%of product costs and environmental impacts are determined at the design stage,and green design integrates environmental factors into the design process and is considered to be an effective way to reduce the environmental impact of products.However,because the product design information in the design stage is limited,vague and incomplete,which restricts the development of low-carbon design,the product carbon footprint assessment and decision-making from the design stage is still in the exploratory stage.In view of the above mentioned problems,this paper systematically studies a set of lowcarbon design systems of mechanical and electrical products in the design stage taking the modeling of the design information method,the construction of the carbon footprint evaluation model,the uncertainty analysis,and the design scheme decision making as the main line.Moreover,the corresponding low-carbon design software support system is developed.This paper is studied based on the National Natural Science Foundation(face items)"Modeling of macro-micro Characteristics and carbon Emission Correlation and carbon Benefit Assessment of Products Oriented to Scheme Design"(NO.51175312)and the Green Manufacturing System Integration Project of the Ministry of Industry and Information Technology of the People’s Republic of China "Construction and Integration Demonstration of Metal Cutting Machine Tool Green Design Platform"(No.201656261-1-3).The main research contents of this paper are as follows:(1)The carbon footprint assessment method of product design schemes based on the carbon feature.In order to solve the problem that the existing carbon footprint evaluation methods are not suitable for the design stage,this paper proposes a carbon feature-based carbon footprint evaluation method for product design schemes.Firstly,the concept of carbon feature is proposed and defined(from macro and micro levels).The macro-feature represents different operating states of products and the constraint relationship between parts,while the micro-feature represents the specific attributes of parts.Moreover,based on the functionbehavior-structure(FBS)model,a function-structure-feature(FSF)multi-level model is constructed by mapping the carbon features to the functional layer and the structural layer,which visually represents the design information related to the product lifecycle carbon footprint.Then,a carbon footprint calculation method based on feature operation activities is developed by analyzing the correlation mechanism between product design features and life cycle carbon footprint.Finally,the feasibility of the proposed method is verified by an example of a gear hobbing machine.This method can effectively guide designers to address the life cycle carbon emission information implied in product design schemes,so as to support the subsequent low-carbon design decisions.(2)An uncertainty optimization method for carbon footprint assessment of product design schemes is proposed.Due to the high uncertainty of product information,the evaluation results of carbon footprint evaluation studies without uncertainty analysis are often questioned and lack credibility.To solve the above problems,this paper proposes an uncertain optimization method for the carbon footprint assessment to analyze and optimize the uncertainty of the design schemes.Firstly,the sources of uncertainty in the carbon footprint evaluation of product design schemes are analyzed,and the probability distribution of uncertainty parameters is obtained by mathematical statistics and data quality evaluation methods.Secondly,the Monte Carlo simulation method is used to analyze the influence of uncertainty parameters on the carbon footprint assessment results,and the coefficient of variation was used as the evaluation index to judge the robustness and reliability of the evaluation results.Then,the Sobol sensitivity analysis method is used to effectively identify and quantify the degree of influence of parameters on the uncertainty of evaluation results and the interaction between variables.Moreover,an optimization strategy is proposed for the high-sensitivity parameters to improve the robustness and reliability of the evaluation results.Finally,the carbon footprint assessment in the use stage of the hobbing machine is taken as an example to verify the feasibility and effectiveness of this method.(3)A decision-making method of product design scheme based on double-layer game theory is developed.The carbon tax policy of government departments is regarded as an effective mechanism to regulate the carbon emission of enterprises.It has been extensively carried out and studied worldwide.The introduction of carbon tax policy in the process of the product design stage and its chain reaction on the design process is significantly important for enterprises.This paper analyzes the impact and conflict of the government’s carbon tax policy on the transformation of the enterprise’s design decision demand and constructs the internal demand model of the enterprise considering carbon emission,cost,and performance,and the external demand model considering the satisfaction of the enterprise,the government,and the user.To sum up,a decision method based on double-layer game theory is proposed to satisfy the internal and external design requirements at the same time.Facing the internal demands of the enterprise,the sub-function is divided into game strategy sets through the fuzzy clustering method with carbon emissions,costs,and performance indicators as the main players in the game,and the multi-objective solving problem is transformed into a non-cooperative game model to balance the interests of each goal and obtain multiple balanced dominant solutions.Based on this,the main players of the game are transformed into enterprises,governments,and users facing the external demands of the enterprise.Through the Nash negotiation model of cooperative games,a comprehensive satisfaction optimal solution is negotiated among the above balanced dominant solutions.Finally,the feasibility of the proposed method is verified by a case study of the machine tool.(4)The Carbon footprint assessment and decision support system for electromechanical products design scheme is constructed.Combined with the above research,the hardware footprint carbon footprint evaluation support tool based on Java language is developed by using IntelliJ IDEA software.It can realize the carbon footprint assessment,uncertainty analysis,and optimization of product design schemes,as well as the decision of design schemes based on double-layer game theory.This software effectively guides and assists designers to carry out low-carbon design.Moreover,the effectiveness of the system is verified by taking the refrigerator as an example.