시스템 엔지니어링 기반의 냉간압연기 개념설계 프로세스 개발

이은진 포항공과대학교 엔지니어링대학원 2015 국내석사

시스템엔지니어링 기반의 환경플랜트 FEED 프로세스 개발

변희철 포항공과대학교 엔지니어링대학원 2015 국내석사

To protect earth from the various sources of impacts, worldwide regulations have been implemented for the last decades. Due to the regulations, so called the Global Environmental Market is anticipated to grow from $923.6 billion dollars in 2013 to $1,870 billion dollars in 2020. Even if the market share of Korea has been increased significantly, the global market is mostly taken by a few advanced countries, such as US and Western Europe. The key barrier to move into the market is due to lack of technology, called FEED (Front End Engineering Design; composed of Conceptual Design (CD) and Basic Design (BD)) for environmental plants. Up to present, FEED level of Korean industry is very primitive without track record as most of the Korean industry has focused on detailed engineering and construction (EPC). Due to the various reasons and complexity of environmental pollution, FEED technology for environmental plants is related with multidisciplinary domain knowledge; science (physics, chemistry, biology, etc.) and engineering (mechanical, chemical, civil, electric, etc.). Thus, to level up the FEED capability, the core technology as well as development process technology are required. In this thesis, we approach FEED problem by systems engineering (SE), a powerful approach to deal with complex and multidisciplinary domain problem, typically applied for defense and aircraft industry in US. In this thesis, we first analyze FEED process taken by the advanced countries and compare with the generic international SE process formalized as ISO 15288. Then, a tailored process for FEED process for environmental plant has been derived. The developed FEED process was verified by the domain experts in the industry by questionnaires. The results indicated that the developed SE-based FEED process is very powerful process to enhance the FEED capability for Korean Industry. The developed in this thesis can be applied to other plant engineering domain as a means for enhancing FEED capability. Keywords: Environmental Plants. FEED Process, Systems Engineering, Plant Systems Engineering

스마트 워터 그리드 시스템 아키텍처 프레임워크

김선영 포항공과대학교 엔지니어링대학원 2015 국내석사

Due to unprecedented change of global climate, the structure of the global water resource has been changed in an unpredictable way. How to cope with the change of the water structure has become a crucial agenda for the water resource management area. The smart water grid (SWG), considered as an infrastructure for the future water resource management, is recently being actively researched and developed in the world wide. Looking over the state-of-the-art, they are not clearly established, viewed from their own perspectives; e.g., IT-based SWG, Pipeline Technology-based SWG, Filtering Technology-based, without showing: 1) The whole system view, 2) System lifecycle, and 3) User and stakeholder perspectives. In view of the above, we approach the problem of SWG from a systematic perspective, by clearly defining development items in the conceptual stage based on the systems engineering international standard. Specifically, in this thesis, we develop system architecture for SWG based on Zachman framework, a powerful method that can give a compact and clear architecture in the conceptual stage. It contains all the viewpoints required for the system development from the goal-oriented to technological as well as implementation, analysis, and utilization of the SWG. Based on the architecture developed in this thesis, an architecture for Korean Smart Water Grid System has been proposed, followed by verification through interviews and questionnaire. The smart water grid system architecture development framework presented in this study can give a reference model for the smart water grid system, which can be applied to the various environments where water resource and amount can be varied significantly.

열연 형상제어 압연기의 스트립 사행에 관한 엔지니어링 연구

전병호 포항공과대학교 엔지니어링대학원 2014 국내석사

In hot rolling process, pair cross mill is widely used to control flatness of strip by crossing top and bottom rolls. If there is a difference of crossing angle between top and bottom rolls, thrust force in the axial direction of rolls is developed. Thrust force can be the main reason of lateral motion of strip. Lateral motion has been commonly encountered in pair cross mill and it affects productivity and quality. To carry out its quantitative assessment of lateral motion and thrust force is significantly recognized. In this paper, lateral behavior of strip and thrust force is analyzed by using ABAQUS 3D FEM simulation tool considering difference of crossing angle and strip off-centering and width. This results are also an important design factor in engineering stage because it can be used in design and operation. Based on results of analysis, the improvement of side guide system is presented in stage of design, and also guidance of setting critical angle difference of pair cross mill is proposed as an operational standard.

Correlation and Engineering Study of Wide Spread Factors on Material of Wire Rod Rolling : 선재압연 중 소재에 발생하는 인자들에 따른 폭퍼짐 상관관계와 엔지니어링 연구

정화영 포항공과대학교 엔지니어링대학원 2016 국내석사

Roll force and filling rate are essential for wire rod rolling. Width Spread is very important on wire rod rolling because roll force and filling rate are determined by width spread. And, because cross-section area of material is circle shape, wire rod rolling has groove, unlike plate rolling. Width spread is affected by groove. We should know the factors that affect width spread in groove. Also, we need to know correlation of width spread and factors. This study confirmed factors to affect width spread and measured width spread through FEM. Through measured result, I reviewed the correlation with width spread and factors. This study compared and analyzed between theoretical width spread value and measured width spread value. Also, as the width spread change, I confirmed effectiveness of rolling force and filling rate. Existing theoretical formula of width spread was only reflected geometrical part of material and groove. There is difference between theoretical width spread value and actual width spread value that included property of material and rolling conditions. Threrfore, rolling force and filling rate are difference between theoretical value and actual value because there are influenced from width spread. To reflect accurate width spread, this paper suggested correction factor to existing theoretical formula of width spread. This correction factor is calculated through difference of theoretical value and FEM analysis value. This corrected formula could be help for accurate prediction of width spread at design work.

SEM 기반의 PJT 특성별 Engineering Management Framework개발

조래혁 포항공과대학교 엔지니어링대학원 2016 국내석사

Systems Engineering(SE) is an advanced engineering philosophy ensuring the completeness of the technology development. However, SE has not been easily implemented to the field of plant engineering in Korea. It is thought that the nature of the Korean plant engineering industry demanding efficient technical managements rather than the perfection of technology development is the main cause. Is SE unnecessary in Korean plant engineering industry? The application of SE is essential for Korean plant engineering companies to perform FEED phase for themselves. To do so, it requires the implement of SEM(System Engineering Management) as a management framework of plant engineering management. And SEM needs to be customized to be utilized in the Korean plant engineering industry. In this study, I proposed a SEM system as a plant engineering management framework. The proposed SEM framework was optimized to meet technical and business aspects of plant engineering projects. Based on the integrity of the SE, the SEM framework was developed to maximize the efficiency of engineering management. The proposed SEM framework classified plant engineering projects into four types through the analysis of each project’s characteristics. Then tailored frameworks for each project type were suggested for practical applications of the SEM framework.

인터-모듈러팩토리 시스템 아키텍처 개발(고객주문관리시스템 중심으로)

김준영 포항공과대학교 엔지니어링대학원 2016 국내석사

A manufacturing supply chain is a set of multi-vendors directly connected by one or more upstream and downstream processes producing goods from source materials for customers. From this point of view, management is an activity optimizing its value-added processes, materials, final goods, and related information among suppliers, manufacturers and customers. Most previous researches about manufacturing supply chain optimization had concentrated on statistically analyzing and configuring fixed supply chains such as vertical or horizontal integrations as there was little possibility of flexible and adaptable production systems. However, some state-of-the-art researches, especially oriented from Germany, have recently recognized potentials of a highly flexible and adaptable production system called Modular factory based on the realization of Internet of Things, Industry 4.0. This research is an extension of the concept of Modular factory. This research proposed the Inter-Modular factory architecture for general manufacturing supply chains of higher flexibility and adaptability which can meet customers’ specific needs. Then the designed architecture was realized as the order management system prototype. The primary functions of Inter-Modular factory realized by the system prototype are followings, (1) searching multi-vendors, (2) confirming their facility specifications, (3) verifying their enabling manufacturing schedules before order acknowledgement. Effectivenesses of the primary functions were verified by survey of field experts.

전자기장을 이용한 AZ31 마그네슘 합금 빌렛 주조에 대한 엔지니어링 연구

배준호 포항공과대학교 엔지니어링 대학원 2018 국내석사

With the adoption of the Paris Climate Treaty, the importance of environmental and energy issues has once again highlighted globally. Major industrial fields such as automobiles, aerospace, steelmaking, and electrical appliances have been intensively conducted research to replace steel with environmental-friendly materials that are lightweight, energy efficient and highly recyclable. Magnesium alloy is a typical alternative material for steel because it has abundant reserves, excellent specific strength and high recycling rate. However, Magnesium alloy is low in heat capacity and contain many solute elements, so it is weak to micro segregation and crack defects during casting process. In this thesis, electromagnetic stirrer (EMS) is proposed to resolve these casting problems. EMS generates a rotating flow in a mold to reduce air bubble, micro segregation and crack defects. The shear force due to the rotational flow increases the number of nucleus growth by cutting the dendrite and minimizes the temperature deviation, thereby ensuring excellent casting quality. In order to optimize EMS, the solidification characteristics of magnesium alloy billets were analyzed by numerical analysis method. First, the optimal mold cooling condition without break-out was confirmed. Secondly, the change of solidification profile and pool depth according to continuous casting speed were analyzed. Third, the change of the rotating flow in the mold according to the conditions of the electromagnetic field was observed and the optimum current and frequency were suggested. As the casting speed increased, the temperature deviation on the meniscus decreased and the pool depth deepened. The smaller the current in the electromagnetic field, the less the temperature deviation, because the rotating flow below submerged entry nozzle (SEN) interfere the flow to rise. Conversely, the higher the frequency of the electromagnetic field, the less the temperature deviation and the lower the pool depth.

Development of Reconfigurable Manufacturing System for Dynamic Manufacturing Environment: Architecture and Prototype

김형민 포항공과대학교 엔지니어링대학원 2017 국내석사

Recently a dramatic change or paradigm shift in the consumer market and ICT has affected manufacturing industry significantly. Under the circumstance, reconfiguration capability dealing with the change has become a key issue for the manufacturing industry in the form of Reconfigurable Manufacturing System (RMS). RMS has been studied since a long time from a variety of point of view based on the technologies available at the time of study. In this thesis, RMS has been investigated from the concept of Industry 4.0 and Smart Factory emerged a few years ago by Germany. In particular, we identified reconfigurable items in terms of: 1) hardware reconfiguration or purchase, 2) software reconfiguration, 3) layout reconfiguration, 4) rerouting, etc. Based on that, we developed architecture of RMS systematically based on ISO 15288, largely composed of stakeholder requirements, system requirements, and architecture. The developed architecture was in part implemented in the test bed for smart factory under development.

빌렛 주형 설계에 대한 엔지니어링 연구

오지운 포항공과대학교 엔지니어링대학원 2015 국내석사

Billet mold is a casting device which turns liquid steel to solid one. In the past, production is only an important factor in the steelmaking industry. However, quality also becomes very crucial due to diversification of demand. Since high production needs high casting speed and it cause various surface cracks, High production with high quality of billet product was a contradiction. To overcome the problem, surface crack should be prevented by minimizing air gaps, which are the main cause of uneven solidifying shell, between shell and mold by controlling mold distortion in the side of mold device itself. Also, cooling water of mold should be under conditions of reducing boiling, which makes water scale deposit interrupting heat transfer. This paper mentions how to minimize mold distortion and control boiling conditions of cooling water. To do the former, heat transfer analysis by ANSYS was firstly performed to achieve a right taper size, and after that, Thermal mechanical analysis was done to get optimal conditions of minimizing mold distortion with various cases such as tapers, support positions, wall thicknesses, and cooling water velocities. It becomes clear that wall thicknesses and cooling water velocities were the most important factors to be related with mold distortion. And this study suggested proper conditions of mold design concepts. In addition, operating conditions of cooling water were calculated to prevent boiling of cooling water. Boiling curve was used to set boiling phases, and heat flux of each phase is calculated. Surface temperature of mold and partial boiling temperature of cooling water were calculated and compared to figure out boiling status, and suggested non-boiling conditions.