• Title/Summary/Keyword: Fusion Temperature

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A Study of Chemical Properties and Fusibility of Korean Anthracite Coal Ash (국내 무연탄회의 화학조성 및 용융특성에 관한 연구)

  • Park, Cheol-Woo;Lee, See-Hoon;Shon, Eung-Kwon
    • Analytical Science and Technology
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    • v.5 no.4
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    • pp.433-441
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    • 1992
  • Chemical composition and fusibility of coal ash were measured for 23 Korean anthracite coals. The relationship between chemical properties and fusion temperature of coal ash was investigated. The slagging and fouling in firing the pulverized coal for boiler was assessed for the coal samples. It was found that most ashes contained more than 80% of $SiO_2$ and $Al_2O_3$ whereas less than 1% of $Na_2O$. And also fusion temperature of ashes occured relatively higher for Korean coals. Therefore it can be predictable that the slagging and fouling formation has a little problem in a pulverized coal firing system. A base/acid ratio did show a good correlation with fusion temperature for these coal ashes.

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Research on Powder Metallurgy Technology in Fusion Materials in China

  • Ge, Chang-Chun;Zhou, Zhang-Jian;Du, Juan;Song, Shu-Xiang
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.896-897
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    • 2006
  • In the viewpoint of engineering, materials problem is a key problem, which determines whether the exploitation of fusion energy will be success. The most important class of fusion materials is plasma-facing materials (PFM). W, as high Z high melting-point metal is one of the most important candidate materials due to its high plasma erosion resistance. Improving the ductility of W and W based alloy, lowering its ductile-brittleness transition temperature for meeting the requirements of fusion application is an important task. In this paper, severalpowder meatllurgy methods of fabricating W and W based materials are being investigated.

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Accuracy Improvement for Measurement of Heat of Fusion by T-history Method (T-history법에 의한 잠열량 측정 정확도의 향상)

  • 박창현;백종현;강채동;홍희기
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.8
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    • pp.652-660
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    • 2003
  • T-history method, measuring heat-of-fusion of phase change material (PCM) in sealed tubes, has the advantages of a simple experimental device and no requirements in sampling process. However, a degree of supercooling used in selecting the range of latent heat release and neglecting sensible heat during the phase change process can cause significant errors in determining the heat of fusion in the original method, which has been improved in order to predict better results by us. In the present study, the modified method was applied to a variety of PCM such as paraffin and lauric acid having very small or no supercooling with a satisfactory precision. Also the selection of inflection point and temperature measurement position was fumed out not to affect the accuracy of heat-of-fusion significantly. As a result, the method can provide an appropriate means to assess a new developed PCM by cycle test even if a very accurate value cannot be obtained.

Synthesis and Structural Properties of YBa2Cu3O7-x Films/ZnO Nanorods on SrTiO3 Substrates

  • Jin, Zhenlan;Park, C.I.;Song, K.J.;Han, S.W.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.169-169
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    • 2012
  • The high-temperature superconductor YBa2Cu3O7-x (YBCO) have attached attentions because of a high superconducting transition temperature, low surface resistance, high superconducting critical current density (Jc), and superior superconducting capability under magnetic field. Moreover, the Jc of YBCO superconductors can be enhanced by adding impurities to the YBCO films for vortex-pinning. Understanding and controlling pinning centers are key factors to realize high Jc superconductors. We synthesized vertically-aligned ZnO nanorods on SrTiO3 (STO) substrates by catalyst-free metal-organic chemical vapor deposition (MOCVD), and subsequently, deposited YBCO films on the ZnO nanorods/STO templates using pulsed laser deposition (PLD). The various techniques were used to analyze the structural and interfacial properties of the YBCO/ZnO nanorods/STO hybrid structures. SEM, TEM, and XRD measurements demonstrated that YBCO films on ZnO nanorods/STO were well crystallized with the (001) orientation. EXAFS measurements from YBCO/ZnO nanorods/STO at Cu K edge demonstrated that the local structural properties around Cu atoms in YBCO were quite similar to those of YBCO/STO.

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Electrodelss Plasma Torch Powered by Microwave and Its Applications (무전극 마이크로웨이브 플라즈마 토치와 응용)

  • Hong, Yong-Cheol;Jun, Hyung-Won;Lho, Tai-Hyeop;Lee, Bong-Ju;Uhm, Han-Sup
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.889-892
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    • 2009
  • A microwave plasma torch at the atmospheric pressure by making use of magnetrons operated at the 2.45 GHz and used in a home microwave oven has been developed. This electrodeless torch can be used to various areas, including industrial, environmental and military applications. Although the microwave plasma torch has many applications, we in the present work focused on the microwave plasma torch operated in pure steam and several applications, which may be used in future and right now. For example, a high-temperature steam microwave plasma torch may have a potential application of the hydrocarbon fuel reforming at one atmospheric pressure. Moreover, the radicals including hydrogen, oxygen and hydroxide molecules are abundantly available in the steam torch, dramatically enhancing the reaction speed. Also, the microwave plasma torch can be used as a high-temperature, large-volume plasma burner by injecting hydrocarbon fuels in gas, liquid, and solid into the plasma flame. Lastly, we briefly report an underway research, which is remediation of soils contaminated with oils, volatile organic compounds, heavy metals, etc.

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Design and simulation of a blanket module with high efficiency cooling system of tokamak focused on DEMO reactor

  • Sadeghi, H.;Amrollahi, R.;Zare, M.;Fazelpour, S.
    • Nuclear Engineering and Technology
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    • v.52 no.2
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    • pp.323-327
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    • 2020
  • In this study, the neutronic calculation to obtain tritium breeding ratio (TBR) in a deuterium-tritium (D-T) fusion power reactor using Monte Carlo MCNPX is done. In addition, by using COMSOL software, an efficient cooling system is designed. In the proposed design, it is adequate to enrich up to 40% 6Li. Total tritium breeding ratio of 1.12 is achieved. The temperature of helium as coolant gas never exceed 687℃. As regards the tolerable temperature of beryllium (650℃), the design of blanket module is done in the way that beryllium temperature never exceed 600℃. The main feature of this design indicates the temperature of helium coolant is higher than other proposed models for blanket module, therefore power of electricity generation will increase.

Commissioning result of the KSTAR in-vessel cryo-pump

  • Chang, Y.B.;Lee, H.J.;Park, Y.M.;Lee, Y.J.;Kwag, S.W.;Song, N.H.;Park, D.S.;Joo, J.J.;Moon, K.M.;Kim, N.W.;Yang, H.L.;Oh, Y.K.
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.4
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    • pp.53-58
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    • 2013
  • KSTAR in-vessel cryo-pump has been installed in the vacuum vessel top and bottom side with up-down symmetry for the better plasma density control in the D-shape H-mode. The cryogenic helium lines of the in-vessel cryo-pump are located at the vertical positions from the vacuum vessel torus center 2,000 mm. The inductive electrical potential has been optimized to reduce risk of electrical breakdown during plasma disruption. In-vessel cryo-pump consists of three parts of coaxial circular shape components; cryo-panel, thermal shield and particle shield. The cryo-panel is cooled down to below 4.5 K. The cryo-panel and thermal shields were made by Inconel 625 tube for higher mechanical strength. The thermal shields and their cooling tubes were annealed in air environment to improve the thermal radiation emissivity on the surface. Surface of cryo-panel was electro-polished to minimize the thermal radiation heat load. The in-vessel cryo-pump was pre-assembled on a test bed in 180 degree segment base. The leak test was carried out after the thermal shock between room temperature to $LN_2$ one before installing them into vacuum vessel. Two segments were welded together in the vacuum vessel and final leak test was performed after the thermal shock. Commissioning of the in-vessel cryo-pump was carried out using a temporary liquid helium supply system.

Evaluation on Creep properties of Reduced Activation Ferritic Steel(RAFs) for Nuclear Fusion Reactor (핵융합로용 저방사화 철강재료(RAFs)의 크리프 특성평가)

  • Kong, Yu-Sik;Yoon, Han-Ki;Kim, Dong-Hyen;Park, Yi-Hyen;Nahm, Seung-Hoon
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.10a
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    • pp.146-151
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    • 2003
  • Reduced Activation Ferritic/Martenstic (RAFs) are leading candidates for structural materials of D-T fusion reactor. One of The RAFs, JLF-1 (9Cr-2W-V, Ta) has been developed and proved to have good resistance against high-fluency neutrino irradiation and good phase stability. Recently, in order to clarify the strengthening mechanical at high temperature, a new scheme to improve high temperature mechanical properties is desired. Therefore, the creep properties and creep life prediction by Larson-Miller Parameter method for JLF-1 to be used for fusion reactor materials or other high temperature components were presented at the elevated temperatures of $500^{\circ}C$, $550^{\circ}C$, $600^{\circ}C$, $650^{\circ}C$ and $704^{\circ}C$. It was confirmed experimentally and quantitatively that a creep life predictive e벼ation at such various high temperatures was well derived by LMP.

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A Study on Tribological Characteristics of Powder Sintered Fe-base Alloy (SMF9060) (Fe계 합금 분말 소결품(SMF9060)의 마모 특성 연구)

  • Kim, Sang Youn;Kim, Dae Wook;Park, Yeong Min;Shin, Dong Chul;Kim, Tae Gyu
    • Journal of the Korean Society for Heat Treatment
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    • v.27 no.2
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    • pp.65-71
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    • 2014
  • SMF9060 material is a Fe-based powder sintered alloy that is used for several automobile components such as Synchronize Hub, oil pump and transmission. These components are required excellent wear resistance and durability. In this study, we have performed a dry wear test at the ambient air and Ar gas conditions in the room temperature, and a lubricant wear test at the room temperature and engine oil temperature of $100^{\circ}C$. The amount of wear volume and coefficient friction are measured by a Profilometer and a Ball on disk type wear tester. The wear volume in Ar gas condition was a little higher than that in the ambient air condition. However the wear volume in the lubricant wear condition was much lower than in the dry wear condition. XRD analysis of the debris in Ar gas condition showed that the oxide film was not formed.