• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.373-378
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• 2003

It is important that overheat protection of super heated tube in boiler operation and maintenance. The overheat of super heat tube can make damage and rupture of tube material, which causes accidental shutdown of boiler. The super heated tube overheat is almost due to the lack of uniformity of gas temperature distribution. There are two ways to protect overheat of super heated tube. The one is to control hot gas operation pattern which is temperature or flow distribution. the other is to control super heated steam flow distribution. The former is difficult than the later, because of control device design. In this paper steam flow control method which uses orifices is proposed to protect overheat of super heat tube.

• Tribology and Lubricants
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• 제35권2호
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• pp.99-105
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• 2019

This study presents an experimental investigation of the wear and oxidation of the bristles of a brush seal in a super-heated steam environment. We construct a model reflecting normal force and radial interference to predict the amount of wear. To monitor the volume loss of the bristle induced by the swirl phenomenon of the rotor, we measure the clearance between the rotor and the brush seal by using a non-contact 3-D device. We calculate the area by using the area-wise measurement method. Considering the obvious brush seal wear variables, we use two disks with different roughness($Ra=0.1{\mu}m$ and $100{\mu}m$) to determine the effect of roughness on wear. Considering an actual steam turbine, we utilize a steam generator and super-heater to generate a working fluid (0.95MPa, 523.15K) that has high kinetic energy. We observe the abrasion of the bristles in the hot steam environment through a scanning electron microscope image. This study also conducted energy dispersive X-ray (EDX) analysis for a qualitative evaluation of local chemistry. The results indicate that the wear and elimination of bristles occur on the disk with high roughness, and the weight increases due to oxidation. Furthermore these results, reveal that the bristle oxidation is accelerated more under super-heated steam conditions than under conditions without steam.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.310-315
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• 1997

System-Integrated Modular Advanced Reactor (SMART), where major primary components such as modular helical steam generator and self regulating pressurizer are integrated into reactor vessel, is currently under development. The pressurizer is designed to control the primary pressure mainly with partial pressure of nitrogen gas and to maintain the fluid temperature as low as possible for the purpose of minimizing steam contribution. The steam generator (SG) is designed to produce super-heated steam inside tube at power operation. Because the in-vessel pressurizer and in-vessel SG are classified as the characteristic components of SMART, it is important to perform a steady state calculation of these components in order to evaluate the adoption of these components. A steady state analysis of the in-vessel pressurizer and in-vessel SG has been performed under normal power operation and the results show an acceptable performance of the components.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.210-211
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• 2005

Desuperheater is a passive device to control the temperature of steam in various plants. However, in spite of its simple structure, the accurate prediction of a desuperheater is very difficult because there are many designed factors for the design of a desuperheater. In this study, the theory of heat transfer phenomena in a desuperheater was developed and the various design factors are evaluated. As a results, we confirmed that the droplet size of 30 - 200 is best effective for the performance of a desuperheater.

• 자원리싸이클링
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• 제18권6호
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• pp.10-17
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• 2009

과열 증기를 이용하여 생활 폐기물내 유기성 성분의 분해를 수행하고 폐기물의 특성 및 반응 시간이 폐기물의 분해율에 미치는 영향을 살펴보았다. 과열 증기를 이용한 분해 후 음식 및 폐지와 같은 생분해성 유기 성분은 쉽게 분해되었고 생분해성 유기 성분중 나무와 석유계 유기성 성분인 플라스틱, 금속과 같은 무기성 성분이 분해되지 않은 상태로 남아 쉽게 분리가 가능한 상태를 형성하였다. 입자의 크기 변화를 살펴본 결과 폐기물 내 생분해성 유기 성분이 적을수록 짧은 반응 시간에도 높은 입자 크기 감소를 보였으며 반응 시간이 60분 이상에서 최대 90% 이상의 입도 감소를 나타내었다.

• 한국가구학회지
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• 제11권2호
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• pp.1-6
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• 2000

This study was carried out to investigate the effect of steaming on mechanical properties of heat-compressed wood specimens. The specimens for this mechanical strength tests were prepared to super-heated steam treatment after compression to the radial direction of sonamu (Pinus densiflora). The specimen's size is $50(L)mm{\times}20(R)mm{\times}17(T)mm$. Steaming temperature and treatment time is $120^{\circ}C$ and 20, 40, 60, 80, 100 minutes, respectively. Modulus of elasticity(MOE) in compressive test is directly proportional to steaming time. On the other hand, modulus of elasticity in bending test between steaming and not steaming after heat-compressed wood is similar irrespective of steaming time. The reason for this phenomenon is not clear yet.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.415-418
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• 2008

This paper presents an innovative prototype of a new conceptual electromagnetic induction-based fluid beating appliance using voltage-fed type scries capacitor-compensated load resonant high-frequency IGBT inverter with a phase-shifted PWM and a power factor correction schemes. Its operating characteristics in steady-state are illustrated including unique features and evaluated on the basis of its computer simulation and experimental results of 10kw breadboard appliance for hot water producer and superheated steamer. The promising cost effective inverter-fed boiler appliances for electromagnetic induction-heated type fluid-heating in the pipeline systems are proposed for induction-heated boiler, super heat steamer, high temperature water producer, hot gas producer and metal catalyst heating for exhaust gas cleaning in engine, which are more suitable and acceptable for industrial, chemical, and consumer energy utilization for household and business from a practical point of view.

• 대한기계학회논문집
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• 제16권5호
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• pp.965-973
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• 1992

본 연구에서는 산업용 가스전소자연순환보일러를 모델로 선정하여 이 모델에 영향을 주는 인자에 대하여 동적 해석을 하였다. 수위와 압력을 연결한 자연순환 보일러의 제어를 위한 총괄적인 블록 선도를 제시하였고, 이 선도를 토대로 전산프로 그램을 개발하고 계산치와 실제 측정치를 비교, 검토하여 이론 해석상의 모순이 없음 을 확증하였다. 연구결과를 산업용 자연순환 gas 보일러의 설계에 응용하도록 하여 보일러의 동특성을 제시하고 이것에 의한 전제어시스템의 신속하고 정확한 설계치를 제시하여 응용사용토록 하여 무엇보다도 전보일러시스템의 안전운전과 경제성(제작비 및 가동비)을 제고하는데 있다. 본 논문을 제1부, 제2부로 나누어 발표해야 하므로 제1부는 결론을 포함시키지 못하며 제2부에서 결론을 제시하겠으니 참조하여 주시기 바랍니다.

• Journal of the Korean Wood Science and Technology
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• 제32권2호
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• pp.9-18
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• 2004

본 과제는 Spruce재가 사우나와 같은 고온 공간용 부재(部材)로 사용되어질 때 나타나는 수지삼출의 문제점을 해결하여 그 방안을 제시코저 수행하였다. 건식(乾式)공간용 부재(部材)의 경우 적절한 열기건조가 이루어진다면 별도의 처리를 실시하지 않더라도 110℃의 수지삼출 안정선을 얻을 수 있는 것으로 확인되었으며, 고주파진공건조에 의해 수지삼출 안정선이 열기건조보다 약 20℃ 정도 더 상승하였다. 습식(濕式)폭로시험에서는 저압증기폭쇄처리재의 경우 열기건조재나 고주파진공건조재 모두 수지가 전혀 삼출되지 않은 반면에, 무처리재의 경우 건조방법에 관계없이 130℃ 이상의 폭로조건에서는 수지삼출의 정도가 건식(乾式)폭로시험의 경우보다 심한 것으로 나타나, 수지삼출을 예방하기 위하여 인공건조중 저(低)함수율 상태의 건조말기에 고온(高溫)을 적용하여 건조하는 것보다는 건조전 고(高)함수율 상태에서 과열(過熱)증기로 분무(噴霧)처리하는 것이 더 바람직한 것으로 확인되었다.