• 제어로봇시스템학회지
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• 제5권4호
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• pp.14-20
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• 1999

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2007년도 추계학술 발표회
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• pp.242-245
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• 2007

• 에너지공학
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• 제26권4호
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• pp.100-106
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• 2017

재가열로에서 분위기 온도에 따른 소재온도 변화를 예측하기 위해 SUS304, SS400 소재가 적용되었으며, 소재내부에 깊이 방향으로 열전대를 5개씩 설치한 후 분위기 온도를 1200도까지 상승시켰다. 그 결과 소재온도는 평균적으로 1150도 이상 도달했으며, 국부적으로 소재 표면과 내부는 10도 이상의 온도차를 나타내었다. 실험결과의 타당성 검증을 위해 열모델을 적용하여 수치해석 되었으며, 실험결과 대비 해석결과는 출구 평균온도 기준 15도 이내의 범위에서 오차를 나타내었다. 또한 오차는 SUS304 소재에 비해 비열 변화가 큰 SS400 소재에서 상대적으로 높게 나타났다. 결론적으로 재가열로에서 소재 온도는 분위기 온도 제어를 통해 달성할 수 있으며, 분위기 온도에 따른 소재 온도 변화는 출구에서 3% 오차범위 내에서 열모델을 사용하여 유추할 수 있음이 실험적으로 증명되었다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.229-234
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• 2006

The oxy-fuel combustion heating characteristics is investigated experimentally by measuring furnace and steel temperature variations for batch type furnace simulator with a specially designed low NOx oxy-fuel burner. Economics of using oxy-fuel combustion is confirmed and, the furnace and steel temperature variations for different heating conditions are compared to deduce optimal heating control pattern for energy savings and rapid uniform heating. High $CO_2$ concentration (> 80-90%), low NOx (< 40ppm) and CO (< 10ppm) are measured in the flue gas. Temperature differences (< $30^{circ}C$) inside the furnace and steel are reduced relatively by increasing the burner jet momentum.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.590-591
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• 1988

In this paper computer control system is introduced for the reheating furnace in steel making process, and in order to support computer system and process operation, the configuration of expert system application is demonstrated breefly, which is under development.

• 제어로봇시스템학회논문지
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• 제16권10호
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• pp.1006-1012
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• 2010

The hot rolling process ranks the highest position for production in steel making process. The hot strip manufacturing processes consist of the reheating furnace, roughing and finishing mill and coiler. The reheating furnace heats the slab. The roughing and finishing mill produce the hot strip from slab. The hot strip quality mainly depends on finishing mill, which consists of 4-high 7 stands. The looper is installed between stands and is used for controlling the strip tension by the looper angle for better material flow. It is difficult to control the strip tension with the coupled looper system from interaction between the looper angle and strip tension. Too much deviation of strip tension severely affects the poor width quality of the hot strip. It is important to control simultaneously both the looper angle and strip tension with each of their target values. This paper proposes the fuzzy tension control, which is developed to minimize the width deviation of the hot strip by maintaining the proper strip tension between stands and to achieve the stable operation of the coupled looper system. The fuzzy tension control performance is compared with the conventional PID control by experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2513-2515
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• 2000

The Hot Strip Mill(HSM) process consists of reheating furnace, roughing mill, finishing mill and coiler. Reheating furnace heats slab and roughing mill, finishing mill produces strip from this slab. The quality of this production mainly depends on finishing mill, which consists of 6 or 7 stands. Between stands a looper is installed for the better material flow. Automatic gage control(AGC), speed control system and looper system, which are connected with each other, are the main control systems for HSM. The low strip tension can make a loop between stands, which can be caused cobble. On the other hand, high strip tension causes thickness and width reduction, which affects the product quality, and can lead to tear the strip, if it is too high. Because of it, a proper strip tension is needed for better material flow: e.g. A good looper control system is substantial for the better production quality. What is handled in this paper is, the looper controller, which is developed to minimize the fluctuation of width of strip by maintaining an appropriate strip tension between stands and to achieve the stability of the looper control system. And its performance compared with a conventional PID controller is also discussed. The difficulties associated with the maintenance of the constant tension are described.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.69-74
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• 2006

An Experimental study was conducted on $CO_2$ recycle combustion heating system using pure oxygen instead of conventional air as an oxidant, which is thereby producing a flue gas of mostly $CO_2$ and water vapor($H_2O$) and resulting in higher $CO_2$ concentration. The advantages of the system are not only the ability to control high temperatures characteristic of oxygen combustion with recycling $CO_2$. but also the possibility to reduce NOx emission in the flue gas. A small scale industrial reheating furnace simulator and specially designed variable flame burner were used to characterize the $CO_2$ recycle oxy-fuel combustion, such as the variations of furnace pressure, temperature and composition in the flue gas during recycle. It was found that $CO_2$ concentration in the flue gas was about 80% without $CO_2$ recycle, but increased to $90{\sim}95%$ with $CO_2$ recycle. The furnace temperature and pressure was decreased due to recycle and the NOx emission was also reduced to maintain under 100ppm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.98-100
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• 1989

In this paper, computer control system is introduce for the reheating furnace in the hot rolling process, and in order to support computer control system and process operation, the configuration of expert system application is demonstrated breefly, which is under fine tuning.

• 대한금속재료학회지
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• 제46권11호
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• pp.737-746
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• 2008

Mechanisms of sticking phenomena occurring during hot rolling of a modified STS 430J1L ferritic stainless steel have been investigated in this study by using a pilot-plant-scale rolling machine. As the rolling pass proceeds, the Fe-Cr oxide layer formed in a reheating furnace is destroyed, and the destroyed oxides penetrate into the rolled steel to form a thin oxide layer on the surface region. The sticking does not occur on the surface region containing oxides, whereas it occurs on the surface region without oxides by the separation of the rolled steel at high temperatures. This indicates that the resistance to sticking increases by the increase in the surface hardness when a considerable amount of oxides are formed on the surface region, and that the sticking can be evaluated by the volume fraction and distribution of oxides formed on the surface region. The lubrication and the increase of the rolling speed and rolling temperature beneficially affect to the resistance to sticking because they accelerate the formation of oxides on the steel surface region. In order to prevent or minimize the sticking, thus, it is suggested to increase the thickness of the oxide layer formed in the reheating furnace and to homogeneously distribute oxides along the surface region by controlling the hot-rolling process.