• Title/Summary/Keyword: relief energy

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A Study on the Improvement of Disaster Relief Aid (재해구호물자 개선에 관한 연구)

  • Park, Sang Hyun;Kim, Chan-O
    • Journal of the Korean Society of Safety
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    • v.33 no.2
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    • pp.138-144
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    • 2018
  • Disaster relief goods are those that help disaster victims to carry on ordinary life in a disaster. Along with the improvement of national economic level and raise of people's standard of living and diversified lifestyles, demands for relief goods in a disaster are also being diversified. In step with frequent and rather large-scale occurrence of disasters, diversity of related goods for disaster relief is likely to be needed ever more in the future, while more assistance to disaster victims is required from the aspect of securing their normal daily lives. To this end, the study conducted comparative analysis of how Korea, the US and Japan managed disaster relief goods and also examined, analyzed the opinions regarding the betterment of relief goods among disaster victims and ordinary people and civil servants in charge. Based on this, the study suggested the improvement draft for disaster relief goods, the point of which was to minimize disaster relief goods commonly prepared by the central government with goods that may assist victims' lives in shelters, while local governments may prepare relief goods appropriately according to actual situation.

A Study on the Recovery of Delay Time According to the Relief of Precedent Trains for Energy Savings (에너지 절약을 위한 선두열차군의 구원에 의한 지연회복)

  • Kim, Yang mo
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.6
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    • pp.629-636
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    • 1988
  • The reduction of recovery time for delay, in the train movements, is generally realized through train operations in the shortest running time and it leads to maximum energy consumption. At the region of this shortest running time, the amount of energy consumption is sharply reduced according to the running time. So the effect for the energy savings can be largely obtained by furnishing a little spare time on train operations. In this paper, it has been modelized the delay and it's enlargement phenomena and formualted the relief patterns in order to restore the delay by restraint and relief of precedent traints. Also it has been proved the number of relief trains for minimum energy consumption exists and then represented one example of relief patterns.

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A Study on Safety Engineering & System Optimization in the Closed Piping System (밀폐배관계에 있어서의 열팽창에 대한 안전설계 및 시스템 최적 설정에 관한 고찰)

  • Char, Soon-Chul;Hwang, Soon-Yong;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.9 no.1
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    • pp.1-8
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    • 2007
  • To improve the practical application of the thermal expansion of closed long pipeline exposing to external heating sources such as solar energy, safety engineering and system optimization for relief valve in the closed piping system are suggested through theoretical approach, correlation in view of temperature and pressure increase caused by external solar energy in the closed piping system. The profile for thermal relief valve including relieving capacity, influx heat energy, sizing criteria, set pressure, selection against back pressure is also presented. It is noted that following topic on solar relief valve should be applied to engineering, installation and commissioning.

Liquid Relief Valves/Degasser Condenser Relief Valves Incidents and Countermeasures for CANDU 6 Nuclear Plants

  • Kim, S.C.;K.S. Oh;Lee, J.S.;Kim, D.H.;J.P. Oh
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.643-648
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    • 1996
  • Recent failures of Heat Transport (HT) system Liquid Relief Valves (LRVs) at several CANDU 6 plants resulted in heavy water spills. A multi-discipline KAERI task team along with AECL representatives was set up to assess the specific implications on the Wolsong 2/3/4 station. The study applied the knowledge gained from the generic study by conducting a fundamental review of the specific design of Welsong 2/3/4. The purpose of the study was to demonstrate compliance with the relevant codes and licensing regulations and to identify the improvements to the design and operating procedures applicable to Wolsong 2/3/4. This paper presents the key recommendations of this study.

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Characteristics of polymer arrester with pressure relief structure (폴리머 피뢰기의 방압구조 및 특성)

  • Han, Dong-Hee;Cho, Han-Goo;Han, Se-Won
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1109-1112
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    • 2004
  • This study reports on the pressure relief design and braided composite of surge arrester. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. As a solution, this study describes pressure relief design performance of arresters with braided composite module. In general, braided composite has Potential for improved impact and delamination resistance. Manufacturing processes of the braided composite could also be automated and could potentially lead to lower costs. Therefore, in consideration of characteristics of pressure relief for polymer arrester, the fabric pattern of braided composite was decided. And Polymer arrester module was manufactured with braid. The mechanisms of pressure occurrence and relief were investigated basically by analyzing arc energy and the correlation between thermal shock and indoor pressure in pressure relief test.

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Surface Relief Holograms on azo-polymer film

  • Yatagai, Toyohiko;Harada, Kenji
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.293-296
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    • 2002
  • Surface relief holograms are fabricated by means of irradiation of laser interference patterns. The diffraction efficiency and the surface relief depth depend on the writing energy and the polarization of the writing laser beam. This structure is very stable at temperatures under glass transition temperature $T_g$ and can be erased by heating above $T_g$. We proposed a new technique to control the surface relief structure. The electric charge was deposited on the surface relief grating in a corona-depositing poling setup in an oven. The first-order diffraction efficiency measured before and after corona discharge increased from about 0.24 % to about 28 %. This diffraction efficiency increase is mainly caused by the increase of the relief depth caused by the electric charge. The relief depth is increased from 20 nm to 350 nm by corona charging. .

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Numerical simulation of pressure relief in hard coal seam by water jet cutting

  • Song, Dazhao;Wang, Enyuan;Xu, Jiankun;Liu, Xiaofei;Shen, Rongxi;Xu, Wenquan
    • Geomechanics and Engineering
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    • v.8 no.4
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    • pp.495-510
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    • 2015
  • The applications of water jet cutting (WJC) in coal mine have progressed slowly. In this paper, we analyzed the possibility and reasonableness of WJC application to pressure relief in hard coal seam, simulated the distributive characteristics of stress and energy fields suffered by hard coal roadway wallrock and the internal relationships of the fields to the instability due to WJC (including horizontal radial slot and vertical annular slot) on roadway wallrock. The results showed that: (1) WJC can unload hard coal seam effectively by inducing stress release and energy dissipation in coal mass near its slots; its annular slots also can block or weaken stress and energy transfer in coal mass; (2) the two slots may cause "the beam structure" and "the small pillar skeleton", and "the layered energy reservoir structure", respectively, which lead to the increase in stress concentration and energy accumulation in coal element mass near the slots; (3) the reasonable design and optimization of slots' positions and their combination not only can significantly reduce the scope of stress concentration and energy accumulation, but also destroy coal mass structure on a larger scale to force stress to transfer deeper coal mass.

A Study on the Relief Valve Modeling and Performance Analysis of Hydrogen Compressor (수소 압축기용 릴리프 밸브 모델링 및 성능해석에 관한 연구)

  • Park, Sang-Beop;Kim, Gyu-Bo;Jeon, Chung-Hwan;Yun, So-Nam;Kewon, Byung-Soo
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.3
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    • pp.179-187
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    • 2009
  • This paper presents a static and dynamic characteristics of the relief valve which is a kind of direct operated pressure control valve for hydrogen compressor. The valve is consisted of a main poppet, a spring, an adjuster and a valve body. The purpose of this study is development of the simulation model for relief valve by using commercial AMESlM$^{(R)}$ tool. Poppet with sharp edge seat type and ball poppet with sharp edge seat type compare for P-Q characteristic. The dynamic simulation results are presented the operating pressure characteristics of relief valve. High pressure power unit of which maximum pressure control range is 100MPa was manufactured, and the pressure control valve was experimented using the above-mentioned power unit. The new model of pressure control valve from this results was suggested. It was confirmed that the suggested valve has a good control performance from experimental setup.

Safety Evaluation of Non-refillable Butane Can Equipped with Relief Valve for Prevention of Explosion (안전밸브가 장착된 휴대용 부탄캔에 대한 안전성 평가 연구)

  • Kang, Seung-Kyu;Choi, Kyung-Suhk
    • Journal of Energy Engineering
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    • v.17 no.4
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    • pp.212-217
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    • 2008
  • This study carried out the safety evaluation of non-refillable butane can for portable gas range equipped with relief valve for prevention of explosion. The can is heated by electric heater at the real using condition and the extreme condition after installing at a portable gas range for checking the operating pressure and the evaluating suitability of releasing flux. And the possibility of fire or explosion was tested when the gas was released from the relief valve at the real condition. As a result of this safety evaluation test, a non-refillable butane can with relief valve prevents the can from exploding by control of internal pressure.

Relief Performance of Fault Current and Design/Manufacturing of Polymer Arresters for Power Distribution (배전선로용 폴리머 피뢰기의 모듈 설계/제조 및 성능)

  • Cho, Han-Goo;Yun, Han-Su;Jang, Tae-Bong;Chie, In-Hyuk
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05b
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    • pp.175-179
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    • 2005
  • The main objective of this paper is to module design and pressure relief test a new type of polymer gapless surge arrester for power distribution line. Metal oxide surge arrester for most electric power system applications, power distribution line and electric train are now being used extensively to protect overvoltage due to lightning. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of gapless elements in a surge arrester occurs due to flashover, fault short current flows through the arrester and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock, pressure rise, etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion.

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