• 제목/요약/키워드: BOR

검색결과 150건 처리시간 0.048초

반응표면법을 이용한 DTF의 석탄 연소 안전성 평가 (Assessment of Coal Combustion Safety of DTF using Response Surface Method)

  • 이의주
    • 한국안전학회지
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    • 제30권1호
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    • pp.8-13
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    • 2015

  • The experimental design methodology was applied in the drop tube furnace (DTF) to predict the various combustion properties according to the operating conditions and to assess the coal plant safety. Response surface method (RSM) was introduced as a design of experiment, and the database for RSM was set with the numerical simulation of DTF. The dependent variables such as burnout ratios (BOR) of coal and $CO/CO_2$ ratios were mathematically described as a function of three independent variables (coal particle size, carrier gas flow rate, wall temperature) being modeled by the use of the central composite design (CCD), and evaluated using a second-order polynomial multiple regression model. The prediction of BOR showed a high coefficient of determination (R2) value, thus ensuring a satisfactory adjustment of the second-order polynomial multiple regression model with the simulation data. However, $CO/CO_2$ ratio had a big difference between calculated values and predicted values using conventional RSM, which might be mainly due to the dependent variable increses or decrease very steeply, and hence the second order polynomial cannot follow the rates. To relax the increasing rate of dependent variable, $CO/CO_2$ ratio was taken as common logarithms and worked again with RSM. The application of logarithms in the transformation of dependent variables showed that the accuracy was highly enhanced and predicted the simulation data well.

  • https://doi.org/10.14346/JKOSOS.2015.30.1.008 인용 PDF KSCI

KC-1 Membrane LNG 탱크 단열시스템의 열해석에 관한 연구 (Thermal Analysis of Insulation System for KC-1 Membrane LNG Tank)

  • 정현원;김태현;김석순;심재우
    • 한국해양공학회지
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    • 제31권2호
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    • pp.91-102
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    • 2017

  • Recently, a new type of LNG membrane Tank called the "KC-1 membrane LNG Tank" was developed by KOGAS (Korean Gas Corporation). It is necessary to estimate the temperature distribution of the hull structure and insulation system for this new LNG tank, as well as the BOR (Boil-Off Rate) when exposed to outside temperature conditions to ensure the integrity of the tank structure and limit LNG evaporation, from a safety evaluation point of view. In this study, temperature distribution calculations for the hull structure and insulation system of the KC1 membrane tank were compared by employing four numerical approaches under the IGC condition. Approaches 1-3 studied 2D simulations and approach 4 used a 3D numerical simulation. Approach 1 was calculated by in-house Excel VBA codes and the three other approaches utilized ANSYS Fluent. The BOR of approach 4, the 3D simulation case, for the IGC condition was 0.0986%/day.

  • https://doi.org/10.5574/KSOE.2017.31.2.091 인용 PDF KSCI

참돌꽃의 캘러스로부터 salidroside 생산에 미치는 배지성분의 영향 (Effect of Macro-nutrients for the Salidroside Production from Callus Cultures of Rhodiola sachalinesis A. Bor)

  • 이재승;최혜진;황백;박형재;안준철;황성진
    • 한국약용작물학회지
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    • 제15권4호
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    • pp.246-250
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    • 2007

  • 대량 원소의 종류 및 적정 농도의 규명은 식물의 생장뿐 아니라 유용한 2차 대사산물의 생합성량 증가를 위해 필수적이다. 참돌꽃 배양조직에서 salidroside의 생산성을 높이기 위해 기본 배지의 대량 원소의 농도를 달리하였을 때 $KNO_3$는 98.92 mM, $(NH_4)_2SO_4$는 1.01 mM, $NaH_2PO_4{\cdot}2H_2O$는 2.18 mM, $CaCl_2{\cdot}2H_2O$는 2.04 mM, 그리고 $MgSO_4{\cdot}7H_2O$는 1.01 mM 일 때, salidroside의 생산량이 가장 높았다. 또한 이와 같은 무기이온의 농도를 조합한 $S4B_5$배지에서 기본배지인 $2XB_5$배지에 비해 2.5배 salidroside 함량 증가를 확인할 수 있었다.

  • PDF KSCI