基于碳排放的机加工工艺方案评估与参数优化

发布时间：2018-10-21 17:02

【摘要】：制造业的高速发展在给人类生产生活带来便利的同时,也造成了严重的环境影响问题,低碳制造模式成为当代制造业发展的迫切需要。机械产品机加工工艺方案是影响机加工过程碳排放的重要因素,但由于工艺方案制定阶段,碳排放源的多样性以及零件加工信息存在一定不确定性,如何在该阶段进行工艺方案碳排放评估、低碳决策优化将有力提升制造企业节能减排能力,也是该领域研究中待解决的难点问题。本文将全生命周期评价思想与工艺方案制定过程结合,建立了面向机加工工艺方案的评估、决策和优化流程,并基于此分别对工艺碳排放评估方法和参数优化方法进行了重点研究,具体如下:(1)针对工艺方案碳排放的量化问题,结合全生命中周期评价方法建立了机加工工艺方案碳排放评估流程。已有相关研究绝大多数面向的是已经投入生产的制造过程,且对于加工设备的功率数据的获取往往采用取额定功率值或现场测量获取的方法,由于设备能耗特性曲线是根据机床运行状态呈动态变化的,因此采用额定功率值的量化方法在准确性上有待提升。本文结合生命周期评价方法建立了工艺方案碳排放评估流程,对机加工系统碳排放的系统边界进行了界定并确定了机加工系统碳排放的主要来源及主要表现形式,并针对目前已有的工艺碳排放量化模型实用性不强的特点进行了优化改进,建立了基于碳排放因子的工艺方案碳排放量化模型以支持机加工工艺过程碳排放的量化。最后以CA6140法兰盘为例对机加工工艺方案的碳排放评估、决策、参数优化过程进行了说明,并对其结果进行了分析。(2)针对工艺方案切削参数的低碳优化问题,结合比能耗法和工艺单元能耗法,建立了机床系统碳排放参数化量化模型。已有相关研究,功率建模方法主要有单元过程建模法、切削力功率模型建模法和比能耗法,但在实施条件和精确性上难以平衡。本文结合比能耗法和工艺单元能耗法,考虑了铣削过程中主轴转速对材料去除功率的影响,建立了以铣削四要素为变量的铣削过程碳排放量化函数模型,并介绍了获取模型参数的实验条件的简易性和模型的准确性;最后,采用遗传算法以碳排放和机加工时间为目标进行多目标优化求解得出最优的加工参数组合。(3)针对当前针对机加工工艺的碳排放评估与优化软件工具系统的相对缺乏的问题,开发了机加工工艺方案碳足迹评估系统。基于上述理论评估模型,分析了软件系统的设计需求,构建了系统架构,规划了各模块内容与功能。采用Visual studio2010软件基于ASP.Net对软件进行了开发,实现对机械产品机加工工艺方案的碳排放评估,并以变速箱体为例介绍了软件使用流程。
[Abstract]:The rapid development of manufacturing industry not only brings convenience to human production and life, but also causes serious environmental problems. Low-carbon manufacturing model has become an urgent need for the development of contemporary manufacturing industry. The machining process scheme of mechanical products is an important factor affecting carbon emission in machining process. However, the diversity of carbon emission sources and parts processing information are uncertain due to the process planning stage. How to evaluate the carbon emission of the process plan in this stage and how to optimize the low carbon decision will be able to enhance the energy saving and emission reduction ability of manufacturing enterprises. It is also a difficult problem to be solved in this field. In this paper, we combine the whole life cycle evaluation idea with the process of making process plan, and set up the process of evaluation, decision making and optimization for machining process scheme. Based on this, the evaluation method and parameter optimization method of process carbon emission are studied in detail as follows: (1) aiming at the quantification of process carbon emission, Combined with the whole life cycle evaluation method, the process of carbon emission assessment of machining process scheme was established. Most of the related studies have been focused on the manufacturing process that has been put into production, and the power data of the processing equipment are often obtained by taking the rated power value or the method of obtaining the field measurement. Because the energy consumption characteristic curve of the equipment changes dynamically according to the running state of the machine tool, the accuracy of the quantization method of rated power value needs to be improved. In this paper, the process scheme carbon emission assessment process is established, and the system boundary of machining system carbon emission is defined, and the main sources and main forms of carbon emission of machining system are determined. Aiming at the lack of practicability of the existing process carbon emission model, the carbon emission model based on carbon emission factor is established to support the quantification of carbon emission in machining process. Finally, taking the CA6140 flange as an example, the carbon emission assessment, decision making and parameter optimization process of the machining process are explained, and the results are analyzed. (2) aiming at the low carbon optimization problem of the cutting parameters of the process scheme, Combined with specific energy consumption method and process unit energy consumption method, a parameterized quantization model of carbon emission of machine tool system is established. The power modeling methods mainly include the element process modeling method, the cutting force power model modeling method and the specific energy consumption method, but it is difficult to balance the implementation conditions and accuracy. In this paper, combined with specific energy consumption method and process unit energy consumption method, considering the effect of spindle speed on material removal power during milling, a carbon emission function model of milling process with four factors as variables is established. It also introduces the simplicity of the experimental conditions and the accuracy of the model. The genetic algorithm is used to solve the problem of multi-objective optimization with carbon emission and machining time as the goal. (3) aiming at the relative shortage of the current software tool system for carbon emission assessment and optimization for machining processes, the genetic algorithm is used to solve the problem of multi-objective optimization. A carbon footprint evaluation system for machining process scheme is developed. Based on the above theoretical evaluation model, the design requirements of the software system are analyzed, the system architecture is constructed, and the contents and functions of each module are planned. The software is developed by using Visual studio2010 software based on ASP.Net to evaluate the carbon emission of machining process of mechanical products, and the software flow is introduced by taking the gearbox as an example.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH16

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