• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.620-621
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• 2005

• JOURNAL OF ELECTRICAL WORLD
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• s.355
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• pp.55-58
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• 2006

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.849-850
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• 2005

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2613-2615
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• 2005

증기터빈 발전소에서 터빈제어밸브는 운전중 적절히 개도를 조절하여 보일러에서 공급되는 유량을 조절하여 터빈속도 및 발전기의 전기적 출력을 제어할 수 있도록 해준다. 이러한 터빈제어밸브는 4개로 구성되어 있으며, 운전중 최적의 발전효율을 얻기 위해 저부하에서는 4개의 제어밸브가 동일하게 조절되다가 밸브 전환 운전을 완료한 후 4개의 밸브가 주어진 특성에 따라 각기 조절되어야 할 필요성이 있다. 이때 수행되는 과도기적인 운전절차인 밸브 전환운전시 발전기 출력 등의 변화가 없어야 한다. 본 논문에서는 밸브전환 운전시 발전기 출력을 일정하게 유지하기 위하여 고압터빈 1단 압력을 궤환받아 발전기 출력을 보상하는 제어알고리듬을 제시하고 실제 발전소에 적용한 결과를 소개하고자 한다.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1873-1874
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• 2006

증기터빈 발전소에서 터빈제어밸브는 운전중 적절히 개도를 조절하여 보일러에서 공급되는 유량을 조절하여 터빈속도 및 발전기의 전기적 출력을 제어할 수 있도록 해준다. 이러한 터빈제어밸브는 4개로 구성되어 있으며, 운전중 최적의 발전효율을 얻기 위해 저부하에서는 4개의 제어밸브가 동일하게 조절되다가 밸브 전환운전을 완료한 후 4개의 밸브가 주어진 특성에 따라 각기 조절되어야 할 필요성이 있다. 대상 발전소에서 시행하고 있는 운전절차중 하나인 밸브전환 운전은 발전기 출력의 변화가 수반되며 이를 최소화하기 위해 고압터빈측의 1단 압력을 궤환하여 보상하는 알고리듬을 사용하고 있다. 사용중에 발전기 출력변화가 발생되어 이를 개선하기 위해 적용되는 알고리듬을 보완하여 실제 발전소 현장에 적용한 결과를 소개하고자 한다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.177-182
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• 2007

We simulated an electric upsetting process by the rigid-thermoviscoplastic finite element method. Several engineering assumptions were made to calculate the heat generation due to the electric resistance. The skin effect of the bar was taken into account for the heat generation. The approach was applied to simulate an artificial electric upsetting process for the exhaust valve of the ship engine.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.152-158
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• 2011

An electric upsetting process by the rigid-thermoviscoplastic finite element method was simulated in this study. Several engineering assumptions were made to calculate the heat generation due to the electric resistance. The skin effect of the bar was taken into account for the heat generation. The approach was applied to simulate an artifical electric upsetting process for the exhaust valve of the ship engine.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.967-973
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• 2004

Electro-pneumatic servo valve is an electro-mechanical device which converts electric signals into a proper pneumatic flow rate or pressure. In order to improve the overall performance of pneumatic servo systems, electro-pneumatic servo valves are required, which have fast dynamic characteristics, no air leakage at a null point, and can be fabricated at a low-cost. The first objective of this research is to design and to fabricate a new electro-pneumatic servo valve which satisfies the above-mentioned requirements. In order to design the mechanism of the servo valve optimally, the flow inside the valve depending upon the position of spool was analyzed variously, and on the basis of such analysis results, the valve mechanism, which was formed by combination of the spool and the sleeve, was designed and manufactured. And a tester for conducting an overall performance test was designed and manufactured, and as a result of conducting the flow rate test, the pressure test and the frequency test on the developed pneumatic servo valve.

• 연구논문집
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• s.34
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• pp.69-77
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• 2004

Electro-pneumatic servo valve is an electro-mechanical device which converts electric signals into a proper pneumatic flow rate or pressure. In order to improve the overall performance of pneumatic servo systems, electro-pneumatic servo valves are required, which have fast dynamic characteristics, no air leakage at a null point, and can be fabricated at a low-cost. The objective of this research is to design and to fabricate a new electro-pneumatic servo valve which satisfies the above-mentioned requirements. In order to design the mechanism of the servo valve optimally, the flow inside the valve depending upon the position of spool was analyzed variously, and on the basis of such analysis results, the valve mechanism, which was formed by combination of the spool and the sleeve, was designed and manufactured. Further, the performance of pneumatic servo valve has been verified through an overall performance test on the developed product.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2593-2595
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• 2000

We analyzed an existing turbine speed control logic in steam turbine power plant. If it is too late to respond a valve position demand signal, it is difficult to control turbine speed. In this paper we proposed a modified control logic and showed a good result by computer simulation.