Process Simulation Technology Research Articles

Design and simulation of fuselage product digital assembly based on DELMIA

As the core process of aircraft manufacturing, fuselage assembly directly affects the performance and quality of the aircraft. However, unreasonable assembly processes, collisions and interferences usually occur in the case of actual assembly. This paper develops the fuselage assembly process design and simulation in a virtual environment established by DELMIA platform. The digital environment consists of products, equipment, workers and other assembly elements. Finally, interference detection and ergonomic analysis are completed through the assembly process simulation. The case indicates that digital assembly process design and simulation technology could reduce the error rate and improve assembly quality.

Present Situation and Prospect of Welding Simulation Technology

In this paper, we mainly introduce the research status and development trend of welding numerical simulation technology. It is mainly reviewed that the simulation of molten pool flow field, welding temperature field and mechanical field, welding deformation and residual stress, hydrogen diffusion analysis, carbon migration of dissimilar steel welded joints, special welding process, microstructure of welded joints and grain growth process of welding heat affected zone. Then we discuss the special welding process simulation technology and special software for welding simulation. Finally, the development of welding numerical simulation technology in China are concerned.

Investigating the inherent safety designs of typical exothermic reaction processes

In this study, “attenuation” and “substitution” strategies were applied to improve the inherent safety designs of exothermic reaction processes. The two strategies were implemented in the exothermic process of the esterification of methanol with acetic anhydride. Process simulation technology was used to compare the two strategies, and the process with moderate increases in temperature–pressure curves was identified. Large quantities of thermally inert and high-boiling-point reactants can be added to a reaction system to dilute the system. Thus, “attenuation” can reduce the values of process parameters such as temperature and pressure. The flammability, explosiveness, toxicity, and thermal inertness of the reaction system were examined for investigating the inherent safety characteristics of the solvent. Selecting a high-safety solvent considerably improves the inherent safety of processes. Transforming the strongly exothermic batch reaction process into a semibatch production process or a continuous production process reduces the severity of thermal runaway and improves process controllability. Thus, “substitution” of a process that has low inherent safety with a process that has high safety was realized.

Simulation analysis of shot peening on the surface of high-load connecting rod

This paper is aimed at the high load connecting rod of the engine, which bears huge combustion pressure and inertia during the working process. Using process simulation technology to establish limited shot blast Meta-model, the law of influence of shot peening time, shot speed, shot angle, shot diameter and other parameters on the surface integrity of the connecting rod was obtained. The shot peening test of the connecting rod verified the correctness of the simulation and reached the project technical requirements.

Life cycle assessment for bioethanol production from whole plant cassava by integrated process

A new integrated process is proposed to convert whole plant cassava to bioethanol. It could improve the utilization of straw and contribute to the industrial production of cellulose ethanol. The key technologies were the by-products organic acids enhanced pretreatment of straw, and the mixed liquefaction and fermentation of cassava root starch and cassava straw sugar. Process simulation technology and life cycle assessment were employed to simulate and analyze the bioethanol processes from the cassava root, cassava straw and whole plant cassava, respectively. The results showed that cassava root ethanol had the lowest process energy consumption as 4186 MJ/1000L ethanol. Cassava straw bioethanol had a negative net energy value as −1329 MJ/1000L ethanol. The whole plant cassava bioethanol showed a competitive net energy ratio = 1.45, the highest reproducibility = 2.35–2.55, and the lowest environmental emissions. The effects of fermentation efficiency and straw utilization rate on the integrated process were further investigated, which would help the practical application of the integrated process. When the fermentation efficiency was maintained at more than 80%, the straw utilization rate was more conducive to improving the renewability and environmental friendliness of bioethanol. Moreover, the influence of the process simulation deviation on life cycle assessment was determined by Monte Carlo Analysis. The net energy analysis and environmental impact assessment proved that the proposed integrated process was beneficial for energy utilization and cleaner production.

Reliability evaluation and management of PetroChina's large-scale system of natural gas pipeline networks

To adapt to the current situation of large-scale and network development of China's natural gas pipeline industry, we must pay attention to the gas transmission support capability of the entire pipeline network system during its operation period and evaluate its reliability with respect to the fulfillment of transmission tasks. This study focuses on the safe and efficient operation and management of large-scale natural gas pipeline network systems, with the objectives of analyzing the reliability indicators, system reliability, unit reliability, reliability data, and reliability management framework of the pipeline network system. The above incentives have lain a foundation for future sustainable reliability management of large-scale systems of natural gas pipeline networks in China. Herein, the purpose, significance, and content of reliability studies on natural gas pipeline networks are discussed in detail at the system level. We establish a distributed step calculation model of physical pipeline network system reliability based on pipeline process simulation technology, which can simplify and rapidly calculate the reliability of the pipeline network/pipelines/station system. The reliability calculation model of the system was tested in a compressor station. According to the sequence of station yard-typical structure-basic circuit-equipment unit, the network topology structure was divided into reliability block diagrams of different levels from top to bottom, which we used to calculate the reliability of individual equipment from bottom to top. Finally, the reliability of the compressor station under different start-up and shutdown schemes was obtained. Overall, the discussed methods are promising and will provide technical and decision-making support for the safe operation of natural gas pipeline networks.

Introduction of additive manufacturing process simulation technology

Introduction of additive manufacturing process simulation technology

A Study on the Application of Computer Process Simulation Technology in Ammonia Synthesis

A chemical process simulation software, AspenPlus, is applied to simulate the ammonia synthesis in the ammonia production process. A reasonable unit operating model is selected, and the RKS-BM thermodynamic method is adopted for calculations. The simulation results are in favorable agreement with the actual operation results, and the simulation data has a guiding significance on the actual production. Meanwhile, this paper analyzes the influence of the changes in the synthesis pressure, the outlet gas temperature of the synthesis tower, the hydrogen/nitrogen ratio of fresh air and other operating parameters on the ammonia synthesis section. The net profit of the synthetic section is taken as the objective function to optimize the operating parameters. The optimal process operating parameters are obtained: the synthesis pressure is 20MPa, the convertor outlet temperature is 313°C, and the H2/N2 ratio of fresh air is 3.0.

Application of Computer Process Simulation in Chemical Synthesis of Urea

The computer process simulation technology can simulate the chemical process of urea, effectively reflect the technological parameters of the chemical production process, and provide practical guidance for chemical production of urea. This paper conducts computer process simulation of the high-pressure urea synthesis tower, the center piece of the chemical synthesis of urea. The chemical parameters in the production process of the synthesis tower are simulated and analyzed with the aid of the equilibrium stage model and computer technology. The calculation results are consistent with the design values of the synthesis tower, indicating that the equilibrium stage model satisfies the technological design requirements. Suffice it to say that the research provides meaningful guidance for the chemical production of urea.

Single and multiple objective optimization of a natural gas liquefaction process

Benefit from the development of process simulation technology, the optimal operating conditions of the natural gas liquefaction process can be obtained by simulation modeling and analysis. Based on the concept of the evolution theory, the genetic algorithm is an effective tool for the optimization of the liquefaction process. A single nitrogen expansion process with carbon dioxide pre-cooling is modeled in Aspen HYSYS, which is connected to MATLAB by ActiveX technology to establish a hybrid simulation platform. Taking the unit energy consumption and the liquefaction rate as the objective functions, the multi-objective optimization problem of the liquefaction process is constructed. The penalty function is employed to realize the conversion of the constraints. The simple and the fast elitist non-dominated sorting genetic algorithm are adopted to solve the single and multi-objective optimization problem of the liquefaction process, respectively. Results indicate that the simple genetic algorithm achieves low unit energy consumption and high heat transfer efficiency with the main objective method, while the results of the fast elitist non-dominated sorting genetic algorithm better realizes the synthetical performance of the process. The economic analysis shows that the initial investment is the key factor which restricts the economic performance of the project.

Research on Simulation of Complex Distillation System for Biomass Fuel Ethanol Based on Virtual Assembly

Virtual assembly was introduced in the chemical process simulation, and the method of virtual assembly for common chemical process was studied. The process of biomass fuel ethanol was analyzed which is combined by the first-grade distillation system in industrial ethanol production and the salt-added extractive distillation system in fuel ethanol production, and the scene graph structure was established. According to the assembly characteristics of the chemical process, the assembly equipment model was designed and constructed. The assembly points were added, and the assembly, simulation and transitive properties of the assembly points were defined. The 1+1and 1+n universality assembly method was proposed. By choosing unit equipment freely to assembly, the complex distillation system was realized. Results have shown that the assembly effect was good and accuracy, the method was proved correct and feasible. It is of great significance in the visual design of chemical process, digital construction of chemical plant and development of three-dimensional (3D) chemical process simulation technology.

Study on a Craft Simulation Technology for the MEMS Thermal Element

On the basis of the craft manufacturing and designing about micro fluidic gyroscope, according to analyze the craft information and studying on the process simulation technology about the MEMS thermal components. Established a basic model of t the craft structure about the MEMS thermal components, based on this model, the L-Edit editor to edit creating a complete mask layout structure; studying a simulation method of craft process, the use of the technological editor which development based on the TCL/TK language to draw out the craft process document, then reconstructed the layout structure based the craft process in a 3D platform. It could be used to detect the rationality of the process program technology.

Simulation and Experimental Study on Size Effect in Steel Micro Milling Machining Process

Size effect is a critical factor that needs to be considered when conducting micro mechanical machining processes. In this paper, a cutting process simulation technology is used to simulate a single tooth’s engagement with workpiece from the entry point to the exit point in a slot milling operation. The obtained specific cutting forces from simulation are employed to analyze the size effect and the minimum chip thickness with variable radii of tool edges. Micro machining experiments with different machining conditions are implemented by use of a high speed and high precision machining spindle to investigate the size effect on machined surface integrity and burr width. The optimal cutting parameters have been analyzed based on the simulation and cutting test results.

Research on Horizontal Well Development Effect Assessment in Super-Low-Abundance Thin Reservoir

Based on the actual production data, this paper selected some evaluation parameters and established reasonable evaluation criterion for the horizontal well development effect in the ultra low-abundance and thin zone reservoir by using statistical analysis method，reservoir engineering analysis process and reservoir numerical simulation technology .In addition, a development effect evaluation system specially for the horizontal well development effect in the ultra low-abundance and thin layer reservoir was build up with the fuzzy comprehensive evaluation approach. Finally, the evaluation system were applied in several low-abundance and thin reservoir blocks. It was shown that the evaluation system can scientifically estimate the development effect of this kind of reservoir and has a practical application value.

Design on Support Training System of High-Speed Wheel Engineering Equipment Based on Virtual Reality

Based on the analysis of the structure characteristics of high-speed wheel engineering equipment, a design method for virtual support training systems was presented, founded on virtual reality (VR), software engineering, process simulation technology. According to the function requirements, the system software and hardware platform were established. Combined with practical teaching needs, virtual support system of high-speed wheel engineering equipment was developed. The practice demonstrates that the system has high practical value and guiding significance on the aspects of talents cultivation, the teaching application, science research, etc.

Environmental Impact Assessment of Chemical Process Using the Green Degree Method

Achieving sustainable development while limiting environmental pollution is one of the main enormous challenges for chemical engineering at present. To develop and design a greener alternative to replace or retrofit a current polluted process, it is essential to establish a method for quantitatively evaluating the environmental impact of a chemical process so that its environmental performance can be improved by identifying and discovering the bottlenecks that cause the pollution. In this work, a green degree (GD) method is proposed to quantitatively evaluate the environmental impact of a chemical process and related energy-generation system. Definitions and calculation formulas of green degrees for a substance, a mixture, a stream, and a unit (process) are illustrated. The green degree is an integrated index that includes nine environmental impact categories (including global, air, water, and toxicological effects). Therefore, it is comprehensive for assessing and understanding the environmental performance of a complex multicomponent chemical system. Three illustrative case studies are presented to further describe and verify the applicability of the method: (1) solvent screening by comparing the green degree values of solvents, (2) process route screening for producing methyl methacrylate (MMA), and (3) green degree analysis of the methyl methacrylate process (i-C4 route) by integration with process simulation technology.

MODELING AND SIMULATION TECHNOLOGY IN DIGITAL MANUFACTURING

Three types of modeling and simulation technology in digital manufacturing are analyzed, i.e. product modeling and simulation technology, process modeling and simulation technology, manufacturing system modeling and simulation technology. Based on some research projects, digital product modeling technology oriented to manufacturing, numerical control pipe bend process modeling and simulation technology, virtual assembly and assembly process simulation technology, production line modeling and simulation technology are discussed emphatically. A conclusion is pointed out that process modeling and simulation technology, including product's machining process, assembly process, production system planning, reorganization and simulation technology is very important to improve manufacturing system's efficiency and reliability, realize the optimization of production resource and machining process, transfer mode from traditional manufacturing to foreseeable manufacturing. At last, some key techniques which enhance digital modeling and simulation technology's practicability are listed.

Achieving Agile Enterprise Through Integrated Process Management

Project management tools are used to manage projects from time as well as from resource leveling perspectives. Workflow management systems guide users through processes by driving the processes based on formal process definitions also called workflow types. This paper describes an integrated process management system that will integrate project management, business process modeling, simulation, and workflow technologies in order to support scheduled workflow execution. The target will be achieved by utilizing a tool for modeling work processes that can semi-automatically generate workflow processes based on a scheduling tool and then export it to a workflow engine via Web services using XML process definition language (XPDL). Addition of simulation capability allows testing workflows before deployment.

Toward a Dynamic Simulation Model for Strategic Decision-Making in Life-Cycle Project Management

This paper argues that process simulation technology is an added facility in the quest for optimizing project decisions based on market and external uncertainties associated with the project's environment. The authors put forward a dynamic simulation modeling system (DSMS) as a tool for proactive and optimal decision-making in the project life cycle. DSMS is geared toward representing generic processes with a hierarchical and modular model structure. DSMS facilitates the optimization of technical and operational functionality during development and operation phases of projects. Project life-cycle objective functions are the basis for decision-making throughout the project's life. The paper reviews the limitations of the current systems’ ranges and capabilities. A review of the existing simulation techniques leads to a discussion on the need for setting up an integrated model to encompass the entire project life cycle. Details of the system are described, and a case study is used to demonstrate its capabilities.

Bulldozers or Ships—What’s the Difference?

This paper explains Caterpillar's approach to maintaining leadership position in designing and manufacturing fabricated structures, and highlights some of the technologies that are used to make welded steel components. Caterpillar's customers continue to look for maximum value from our machines and, to meet their increasing expectations, investment in new technology is a necessity. To build lightweight, high quality, long life structural components, Caterpillar uses state-of-the-art design tools, process simulation technologies and the latest manufacturing processes. It is the authors' perception that there are many synergisms between ship construction and the manufacture of earthmoving equipment. This paper debates networking between the two industries for cross-industry technology development and knowledge transfer. This can potentially improve the competitiveness of the United States in the ever-increasing global marketplace.