• Title/Summary/Keyword: 설계적정성

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A Study on Cogeneration System Using 5ton/day Scale Downdraft Waste Wood Gasifier (5톤/일 하향류식 가스화기를 이용한 폐목재 가스화 열병합 발전기술 연구)

  • Yoon, SangJun;Kim, YongKu;Lee, JaeGoo;Kim, KiSe;Kang, ByungChan
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.174.2-174.2
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    • 2011
  • 최근 유가상승과 석유, 천연가스의 가채 매장량의 한계등과 함께 온실가스에 의한 지구온난화 방지를 위하여 미국, 유럽국가 및 캐나다 등에서는 바이오매스를 이용한 에너지 회수 기술개발에 많은 관심과 연구를 수행하고 있다. 바이오 매스는 에너지 밀도 대비 존재하는 지역이 광범위하여 발생, 수집, 수송에 따른 비용이 많이 소요되는 특성이 있어 산지에서 직접처리하거나 수집하여 대규모처리등과 같이 여러 가지 현장상황에 따라 적정한 플랜트 운용의 유연성을 갖추고 있어야 한다. 일반적으로 바이오매스로부터 중소형으로 분산형 발전이나 수소제조를 위해서는 직접 연소법 보다는 가스화 방식을 이용하고 있는데, 연소에 의해 열을 생산하여 전기를 생산하는 방식은 스팀터빈을 이용하는 것이며, 스팀터빈은 소형 운용이 어렵기 때문이다. 본 연구에서는 폐목재로부터 합성가스제조를 위하여 5톤/일 규모 가스화기를 제작하였으며, 타르 및 수트와 같은 미반응 물질을 제거할 수 있는 집진, 세정장치를 설계 및 제작하였다. 또한 합성가스에 함유된 현열로부터 열회수를 위하여 열교환기를 설치하였으며, 정제된 합성가스를 이용하는 가스엔진을 통하여 열병합 발전시스템 연계운전을 수행하였다. 운전 실험을 폐목재 가스화 3톤/일 규모로 수행하였으며, 평균 1,500kcal/$Nm^3$의 발열량을 갖는 합성가스를 생성시킬 수 있었다. 사이클론, 스크러버 및 기수분리 장치를 이용하여 정제된 합성가스는 합성가스 엔진을 통하여 72kW 이상의 전력생산이 가능하였다. 열교환기를 통하여 평균 15,000kcal/h의 배열 회수가 가능하였으며, 바이오매스 가스화 합성가스를 이용한 열병합 발전이 가능함을 입증하였다.

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Reduction Effect of Moment of Steel Composite Bridge according to Camber Control in Middle Support (중간지점부의 캠버 조정에 따른 강합성교의 모멘트저감 효과)

  • Kim, Kyoung-Nam;Lee, Seong-Haeng;Hahm, Hyung-Gil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.2
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    • pp.634-643
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    • 2010
  • In this study, both an experimental test and a time history analysis with 3D modeling were performed to verify the structural analysis model in a 2-span two girder bridge of high speed railway, which was under constructed according to the ballast load of track structure. In the basis of the structural analysis model, the analysis of construction step was carried out to investigate the reduction effect of moment in middle support of the bridge which has initial prestressing force according to camber control. The initial prestressing force of proper level was calculated, and then the reduction of moment for economical bridge section was studied. Finally, a bridge analysis method was presented for an economical and efficient design in steel composite bridge.

Design and Implementation of Science Experiment Models for Artificial Chemistry Laboratory (과학실험에서의 모델 설계 및 구현)

  • 변영태
    • Korean Journal of Cognitive Science
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    • v.10 no.1
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    • pp.57-66
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    • 1999
  • We believe that science experiments in a laboratory are essential for science education. Scientific experiments begin with situations set by selecting and locating tools and reagents. and by proper experimental behavior, and thereafter situations are changed by natural laws and intermediate experimental behavior. While scientists and students do experiments, they build a cognitive model internally, do causal reasoning on the model to derive system behavior, and then learn scientific truth. We suggest not only a representation method for a 2-dimentional model and for ontological entities necessary in causal reasoning, but also an inferencing method to derive behavior. Chemistry experiments are chosen for the implementation. For the ontological entities, we consider experimental tools, reagents and their heirarchical structures, physics and chemistry natural laws, and functional abstraction knowledge. In order to show the usefulness of our methods, we have developed a program, called ACUArtificial Chemistry Laboratory), which provides an experiment environment where students can do non-predetermined experiments, and shows experiment려 system behavior similar to what happens in the same situation in a real world and descriptions about why it happens.

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Evaluation of Shoulder Rumble Strip Effectiveness based on Driver's Physiological Signal (운전자 생리신호로 본 노면요철포장의 설치효과분석)

  • Kim, Ju-Yeong;Jang, Myeong-Sun
    • Journal of Korean Society of Transportation
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    • v.24 no.7 s.93
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    • pp.7-14
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    • 2006
  • Most researches about rumble strips have Presented only the before-and-after analysis of the accidents. So, Researchers have not dealt with the estimation of rumble strip's effectiveness on the driver's alertness. In this study. the effectiveness of the rumble strips on the driver's alertness was estimated by measuring the bio-signal transmitted from the driver. The bio-signal acquired for this experiments were theta wave in central lobe. The experimental results revealed that the theta waves as measured form the drivers's head while in the rumble strip section differed from those while in non-rumbled section; 74 percent decrease in theta wave value, respectively. This fact finding could mean that the driver's alertness increased from 74 percent while in the rumble strip section of the road. In all five trials of driving experiments on the rumble strip section, all the drivers showed the best alertness as measured by the theta waves in the first driving trial.

A Qualitative Analytic Study on Job Skill Elements and its Training Demand of the Display Industry (디스플레이 산업의 직무기술요소에 대한 정성적 훈련수요 분석 연구)

  • Lee, Jae-Won;Yoon, Seock-Chun
    • The Journal of Korean Institute for Practical Engineering Education
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    • v.3 no.1
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    • pp.127-135
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    • 2011
  • The past quantitative analysis of the demand for job skill training had mainly focused on personnel shortage and oversupply, so it has the problems of the qualitative discrepancies called skill mismatch. As a supplementary study relating to specific industries and occupations, a discussion to improve the job skills training programs through a qualitative analysis is needed. This study provide the analysis of urgency evaluation using the relative importance and gap of the job skill elements in the display industry. And renewal possibilities of the training program based on this qualitative bottom-up approach will be discussed. We carried out a job skill demand survey in the display industry as research methods. Industry related jobs and each job task, the qualitative demand for each job skills, and procurement methods for each job skills were analyzed. Adequate supply of vocational training programs have tried to find ways by illustrating some related training courses.

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Comparative Analysis of Column Connection Characteristics of Green Frame (그린 프레임의 기둥접합부 특성 분석)

  • Kim, Keun-Ho;Lee, Taick-Oun;Lee, Sung-Ho;Kim, Sun-Kuk
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.4
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    • pp.415-425
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    • 2012
  • Green Frame was developed to embody a Green structural system that can provide long life, resource reduction, and availability of remodeling in apartment buildings. Composite precast concrete column and beam, the major structural material of Green Frame, can be installed precisely and promptly through connection of steels and concrete. The connection of Green Frame can be divided into four types, based on the method and characteristics of connection. To select an appropriate type for the site, a comparative analysis of the four types is necessary. The objective of this study is to compare the duration, cost, quality, and safety of four types. The findings of this study can be applied during the selection that appropriate composite precast concrete column reflected project characteristics in design phase.

A Study on the Variation of Temperature and the Deformation Characteristics in Asphaltic Concrete Pavement by Air Temperature (대기온도(大氣溫度)에 따른 아스팔트포장(鋪裝) 내부(內部) 온도변화(溫度變化)와 변형특성(變形特性)에 관(關)한 연구(硏究))

  • Kang, Min Soo;Kim, Soo Sam;Lee, Suk Keun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.5
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    • pp.1115-1128
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    • 1994
  • The condition of temperature gradients in asphaltic concrete (Ascon) pavement have been analyzed based on the data collected from 5 major sites in Korea. From this. considering heat transfer by insolation flux and air temperature within pavement slab. temperature variation on the surface of pavement was computed and numerical model using the theory of thermal conductivity was applied to estimate the temperature gradients in depth. To investigate the present condition of asphalt generally used in Korea. the asphalt property tests were applicated on 5 different AP-3 (AC 85~100), and AP-5 (AC 60~70) asphalts classified by penetration index. Uniaxial compression test and indirect tensile test were also carried out for varying temperature conditions to analyze the effect of temperature on the deformation characteristics of Ascon pavement by calculating the variation of static elastic modulus and layer coefficients.

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Irrigation Criteria based on Estimated Transpiration and Seasonal Light Environmental Condition for Greenhouse Cultivation of Paprika (파프리카 재배에서 계절별 광환경 조건과 증산량 예측에 근거한 관수공급 기준 제시)

  • Shin, Jong Hwa;Son, Jung Eek
    • Journal of Bio-Environment Control
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    • v.24 no.1
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    • pp.1-7
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    • 2015
  • Irrigation control plays an important role in improving productivity of paprika which is very sensitive to moisture condition. Among environmental factors, light intensity and distribution are not easily controlled and showed a big difference depending on season and region. For adequate irrigation control, therefore, transpiration and irrigation amounts considering light environmental data should be estimated. In current study, modified transpiration model was used for more precise estimation of transpiration. Seasonal transpiration and irrigation amounts at different regions were compared by using light environmental data provided from Korea Meteorological Administration. The transpiration amount in summer was rather smaller than those in spring and autumn seasons in Korea due to large deviations in light intensity as well as rainy period in summer. Irrigation system capacities at various regions could be recommended by using the transpiration amount in the spring having the longest photoperiod in the year. These results will be useful to the design of irrigation system and optimization of input energy in greenhouse.

The optimum damping retrofit for cabinet structures of NPP by μ-GA (μ-GA를 이용한 원전 캐비닛구조물의 최적감쇠보강)

  • Lee, Gye-Hee;Ha, Dong-Ho
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.1 s.41
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    • pp.1-7
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    • 2005
  • The optimal seismic retrofitting of NPP(Nuclear Power Plant) cabinet structures that contain seismic category 1 relays was studied in this paper. During earthquake event, the failure modes of relays are not appeared in form of structural failure, but are appeared in form of contact chatter of relay. Therefore, the retrofitting of cabinet has to be aimed at the reducing of the structural response, such as acceleration. In this study, the optimal characteristic values of dampers were searched by ${\mu}$-GA (micro-Genetic Algorithm) scheme for several installation patterns. To keep accuracy and efficiency of analysis, the structural models of cabinet were considered as a frame structure. The responses of structure were obtained inform of acceleration response spectra derived from the results of nonlinear time history analysis including damping nonlinearity. The objective function of the optimum procedure was constructed based on the maximum ratio of maximum spectral value and target GERS (General Equipment Ruggedness Spectra). The results show the good improvements of fitness for adequate retrofitting pattern. Especially, the improvements of fitness were remarkable when the values of damping exponents are low.

An Experimental Study on Structural Behavior of Segmental Joint in Prestressed Composite Girder (프리스트레스트 강합성거더의 분절 접합부 구조거동에 관한 실험적 연구)

  • Lee, Juwon;Ha, Taeyul;Yang, Inwook;Han, Jongwook
    • Journal of the Society of Disaster Information
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    • v.12 no.4
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    • pp.422-431
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    • 2016
  • This study was evaluated in the performance of the connection according to the details of the concrete casing segment in the prestressed composite girder by fabricating and testing specimens with different segments. A total of four comparative specimens were fabricated by using the variables of general composite girders, reinforcement or non-reinforcement, and details of reinforcing bars in the segments so as to evaluate the structural behavior of steel girders. In addition, the possibility of non-cracking grade design of segmented composite girders as well as the effects of stiffness and strength according to the loop connection types after cracking were analyzed, and the appropriateness of the crack width control both the embedded steel plate and the concrete surface were evaluated.