• 제목/요약/키워드: Volume Efficiency

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소형 열병합 연료전지 연계형 연료처리시스템 개발 (The development of fuel processor for compact fuel cell cogeneration system)

  • 차정은;전희권;박정주;고윤택;황정태;장원철;김진영;김태원;김인기;정영식;갈한주;윤왕래;정운호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.323-327
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    • 2009
  • To extract hydrogen for stack, fuels such as LPG and LNG were reformed in the fuel processor, which is comprised of desulfurizer, reformer, shift converter, CO remover and steam generator. All elements of fuel processor are integrated in a single package. Highly active catalysts (desulfurizing adsorbent, reforming catalyst, CO shift catalyst, CO removal catalyst) and the various burners were developed and evaluated in this study. The performance of the developed catalysts and the commercial ones was similar. 1 kW, 5 kW class fuel processor systems using the developed catalyst and burner showed efficiency of 75 %(LHV, for LNG). The start-up time of the 1 kW class fuel processor was less than 50 minutes and its volume including insulation was about 30 l. The start-up time of 3 kW and 5 kW class fuel processors with the volume of 90 l and 150 l, respectively, was about 60 minutes. In the case of LPG fuel, efficiency, volume and start-up time of 1kW class fuel processor showed 73 %(LHV), < 60 l and < 60 min, respectively. Advanced fuel processor showed more highly efficiency and shorter start-up time due to the improvement of heat exchanger and operating method. 1 kW and 3 kW class fuel processors have been evaluated for reliability and durability including with on/off test of developed catalysts and burner.

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과실 채소중 잔류농약(유기인제)에 관한 연구 (Organophosphorus Insecticide Residues in Fruits and Vegetables)

  • 윤숙자
    • 환경위생공학
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    • 제5권1호
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    • pp.83-92
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    • 1990
  • Adapting two step aeration system to a waste water treatment of W-paper manufactory as Full-Scale Plants, we drew a following conclusion from its practical working. 1. Because BOD removal efficiency was 20% in A-Stage, 90% in B-Stage and total removal efficiency was 97%. It worked treatment plant well and was suitable for effluent water standard as well. Because COD removal efficiency was 42% in A-stage, 71% in B-stage and the total removal efficiency was 94% COD control was possible in effluent water quality. 2. Treatment efficiency according to a load capacity was average 20% in 1.401 BOD kg/m3/d load of A-Stage and average 90% in 0.273 BOD kg/$\textrm {m}^3$ / d load of B-Stage. 3. Treatment efficiency according to a ratio of F/M was 2.657--5.024 kg BOD/kg MLSS/d in A-Stage and BOD removal efficiency was 16-261 in the same stage. The ratio of F/M was 0.068-0.094 kg BOD /kg MLSS/d and BOD removal efficiency ratio was 85-94%. Therefore treatment efficiency could be kept stably and volume of aeration tank could be reduced wholly. 4. Treatment efficiency according to MLSS appeared BOD 20%. COD 42%, in A-Stage and removal efficiency appeared BOD 90%, COD 71% in B-Stage. They were suitable for plan condition. 5. Because of working of complemented treatment plant by AB-Process. 20,000,000 Won a month was saved than the ordinary working cost. Therefore, it was assumed that invested cost could be recollected in 19 months or so consequently.

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국내 중소건설업체의 효율성 평가에 관한 연구 (A Study on the Evaluation of Efficiency in the Korean Small and Medium sized Construction Firms)

  • 김혁;유한주;송광석
    • 품질경영학회지
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    • 제38권3호
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    • pp.463-474
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    • 2010
  • In this study, we evaluate the efficiency of Construction Industry using Data Envelopment Analysis(DEA). Since the Construction Industry has been traditionally operated through competition, it is important to measure the efficiency. In this paper, we empirically analyze the Efficiency of the 50 Korean Construction Industry. In detail, we used the scale of efficiency in order that efficiency cannot be affected by the total technical efficiency of each company and the scale of DMU by applying CCR or BBC model. Also, we analyzed the changes of measurement DEA model score. we adopted the basic DEA, RTS Region and MPSS(Most Productive Scale Size) method which are combined with efficiency measurement model in order to analyze the operational status. Furthermore, by complementing the shortfalls of the scale efficiency value of the DEA Model, RTS Region Model can be recommended to be appropriate in the evaluation of ideal input/output Quantity. In particular, input variables are total assets, construction capacity, the technical staff and output variables are sales volume, operating income. The result of RTS Region and MPSS shows that 9 DMUs of the efficiency frontier in the Construction Industry are analyzed to be relatively efficient DMUs, and 41 DMUs are analyzed to be inefficient DMUs, and finally inefficient DMUs are separated with Region 1 and Region 6.

중질유 오염토양의 세정효과를 증진시키기 위한 전기저항가열의 최적 운전조건 도출 (Derivation of Optimum Operating Conditions for Electrical Resistance Heating to Enhance the Flushing Effect of Heavy Oil Contaminated Soil)

  • 이환;정재윤;강두레;이철효
    • 환경영향평가
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    • 제29권3호
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    • pp.219-229
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    • 2020
  • 본 연구에서는 해안매립지역내 벙커C유로 오염된 토양을 대상으로 토양세정 효과를 증진시키기 위한 전기저항가열의 운전인자 별 최적 조건을 도출하여 융복합 적용가능성을 평가하였다. 회분식 실험결과 Tween-80 세정제 보다 VG-2020 세정제에서 약 1.5배 이상의 높은 세정효율 보였으며, 상온 시 대비 60℃에서 약 1.4배의 세정효율 증가를 가져왔다. 전기저항가열 박스 실험결과, 함수율 20~40%의 토양에서 약 40~80분 내에 100℃까지 상승하였으며, 포화 토양층 내 STS 316재질의 파이프형 전극봉을 3각 배열 시 열전달효율이 우수한 것으로 나타났다. 또한 상기 최적조건으로 토양온도를 60℃ 이상을 유지하기 위한 전극봉의 간격은 1.5 m인 것으로 확인되었고, 전기저항가열과 동반된 토양세정 박스실험에서는 5 PV(Pore Volume)에서 약 55%의 급격한 TPH 저감효율을 보였으며 10 PV(Pore Volume)에서 토양오염 우려기준(TPH 2,000 mg/kg 미만)을 만족하였다.

A Study on Efficiency for the Department of Trade in Universities

  • Park, Hyun-Chae;Kang, In-Kyu
    • 무역상무연구
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    • 제52권
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    • pp.97-118
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    • 2011
  • 85% of South Korea's gross domestic product(GDP) depends on trade. Exports amount in 2011 exceeds $ 5,000Billion. Korea is expected to achieve $ 1 trillion in total trade volume and will become finally the ninth in the world. We do not have a lot of natural resources and are bound to export the finished products to pursue economic development. In other words, trade sector is very essential for Korea to continue economic growth. The department of trade in universities have brought up the concerned students serving for trade sectors. Currently, "half-price tuition" in universities has become very controversial issue in Korea so this paper studies the efficiency of "the Department" because the universities may reconsider the adjustment of tuition fee, if they can enhance the efficiency level. DEA model is used for the analysis. As a result, 8 DMUs like KAN1, KEI5, BAE10 etc. show relatively higher efficiency levels.

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단조해머의 타격효율 결정 (Determination of Blow Efficiency of the Forging Hammer)

  • 이성호;조남춘;이종수
    • 대한기계학회논문집
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    • 제19권6호
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    • pp.1539-1544
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    • 1995
  • Copper blow test to measure the forging capability of 35 ton counterblow hammer and upset of plasticine on the model hammer to investigate the change of the blow efficiency during the forging process have been performed together with finite element analyses of these experiments. The blow efficiency of the hammer has been found to be dependent on the friction and on the contact area between the die and the workpiece. The effects of the volume and the aspect ratio of the billet have not been found. Inferring from the experimental results and Schey's empirical formula on the forging load, we expect that the efficiency also varies with the flow stress of the workpiece material and with the shape complexity of the forging product.

고효율 침전조 설계를 위한 실험 및 수치해석 (Numerical and Experimental Studies for the Design of High Efficiency Sedimentation Bed)

  • 김홍민;최상철;김광용;김병희;임영택
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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    • pp.425-432
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    • 2002
  • Both numerical and experimental studies on sedimentation efficiency of a sedimentation bed were carried out. Three different structures of sedimentation bed and five different combinations of blockage ratio of center feed wall and angle of distributor are implemented to find the optimal values of geometric parameters. The effect of rotation of the distributor on sedimentation efficiency is also investigated. It reveals that the effect of blockage ratio and angle of distributor on sedimentation efficiency is considerable, while rotation effect can be neglected, and that calculated efficiencies show good agreements with those of experiment, qualitatively.

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고효율 침전조 설계를 위한 실험 및 수치해석 (Numerical and Experimental Studies for the Design of High Efficiency Sedimentation Bed)

  • 김홍민;최상철;김광용;김병희;임영택
    • 한국유체기계학회 논문집
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    • 제6권2호
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    • pp.54-61
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    • 2003
  • Both numerical and experimental studies on the sedimentation efficiency of a sedimentation bed were carried out. Three different structures of sedimentation bed and five different combinations of blockage ratio of center feed wall and angle of distributor are implemented to find the optimal values of geometric parameters. The effect of rotation of the distributor on sedimentation efficiency is also investigated. It reveals that the effects of blockage ratio and angle of distributor on sedimentation efficiency are considerable, while rotation effect can be neglected, and that calculated efficiencies show good agreements with those of experiment, qualitatively.

마이크로 적층기술을 이용한 열교환기 생산모델 개발과 경제성 평가 (Development of Heat Exchanger Production Model Based on the Microlamination Technology and Estimation of its Economic Efficiency)

  • 유범상;김재희;박상민
    • 한국공작기계학회논문집
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    • 제15권3호
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    • pp.97-103
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    • 2006
  • The development of a heat exchanger production model based on the microlamination technology and it's economic efficiency is addressed. A microchannel production model is proposed for the high-volume production. The microlamination system is made up of lamina patterning, laminae sorting and laminae bonding. A cost estimation model is developed based on the hewn cycle time and capital equipment costs. An economic efficiency analysis is performed to determine the cost drivers under the different market and product scenarios. The result of the economic efficiency analysis indicated that the device size and the production rate have a great effect on the overall manufacturing cost of microlamination devices. And it can be concluded that the microlamination should focus on bonding larger laminae and reducing both cycle time and warpage.

공명기를 이용한 4기통 SI기관의 체적효율 향상에 관한 연구 (A Study on the Improvement of Volumetric Efficiency by the Resonators for the 4-Cylinder SI Engines.)

  • 이재순;이성두;윤건식
    • 한국자동차공학회논문집
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    • 제4권3호
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    • pp.232-242
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    • 1996
  • In this study, the simulation program for the prediction of volumetric efficiency of the internal combustion engine by the resonator has been developed, when the resonator is mounted on the intake system of 4-cycle SI engines for the improvement of volumetric efficiency. The experimental work has also been carried out for the verification of the program, and it is found that the result of calculation by the simulation program fits qualitatively well with that of experiment. To get the optimal mounting position of resonator on the intake system, the influence of the variation of dimensions of resonator such as neck length, volume and neck diameter were examined by the numerical calculation of the program in advance and the results were compared with the experiments. It is found that the position which is departed 150cm from plenum chamber is better than any other positions, and the average amount of the increase of volumetric efficiency is about 2∼3%

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