植物油 脫臭溜出物의 利用에 關한 硏究

김점식,Kim, Jeom Sik 대한화학회 1974 대한화학회지 Vol.18 No.4

植物油 脫臭溜出物에 함유되어 있는 sterine과 tocopherol의 效率的인 分離精製方法을 검토하였다. 시료를 가열하여 水層과 油層으로 分離하고 油層을 取하여 메틸에스테르화한 후 脂肪酸을 溜去하였다. 殘油分을 비누화하여 불비누화분만을 抽出, 濃縮한 후 메틸알코올에 녹여, 냉각함으로서 sterine을 분리하였다. 위의 母液을 메틸알코올에 녹인 후 $-20^{\circ}C$ 냉각하여 遊離脂肪酸을 제거하고 이온交換樹脂로 처리하여 高濃度의 tocopherol을 얻는 조건을 확립하였다. An investigation has been performed to find an effective separation method of steriols and tocopherols from the deodorized condensates of vegetable oils. Simple heating of the starting mixture isolated the oil layer from water, and the former was collected. It was then methyl esterified followed by a distillation for the removal of fatty acid. The ensuing step was to saponify the residue. The unsaponifiable matter was extracted by both methanol and concentrated. The sterol was crystallized by cooling such concentrated solution. To obtain tocopherol, the mother liquor was first dissolved in methanol. Cooling this solution to $-20^{\circ}C$ trapped fatty acid which was filtered out. The filtrate was then treated with ion exchange resin.

22.9kV 배전선로 중성선 설치 구조에 따른 유도뢰 차폐효과 분석

김점식,김도영,박용범,Kim, Jeom-Sik,Kim, Do-Young,Park, Yong-Beom 대한전기학회 2010 전기학회논문지 P Vol.59 No.2

The electricity distribution system in Korea is adopting a multi-grounding system. Protection of this distribution system against lightning is performed by installing overhead ground wires over the high voltage wires, and connecting the overhead ground wires to the ground every 200 m. The ground resistance in this system is limited not to exceed $50\Omega$ and overhead ground wire and neutral wire are multiple parallel lines. Although overhead ground wire and neutral wire are installed in different locations on the same pole, this circuit configuration has duplicated functions of providing a return path for unbalanced currents and protecting the distribution system against induced lightning. Therefore, the purpose of this study is to analyze the induced lightning shielding effect according to the neutral wire installation structure of a 22.9kV distribution line in order to present a new 22.9kV distribution line structure model and characteristics. This study calculated induced lightning voltage by performing numerical analysis when an overhead ground wire is present in the multi-grounding type 22.9kV distribution line structure, and calculated the induced lightning shielding effect based on this calculated induced lightning voltage. In addition, this study proposed and analyzed an improved distribution line model allowing the use of both overhead wire and neutral wire to be installed in the current distribution lines. The result of MATLAB simulation using the conditions applied by Yokoyama showed almost no difference between the induced lightning voltage developed in the current line and that developed in the proposed line. This signifies that shielding the induced lightning voltage through overhead wire makes no difference between current and proposed distribution line structures. That is, this study found that the ground resistance of the overhead wire had an effect on the induced lightning voltage, and that the induced lightning shielding effect of overhead wire is small.

22.9㎾ 배전선로 가공지선 설치 구조에 따른 유도뢰 차폐효과 분석

김점식(Kim Jeom-Sik),박용범(Park Yong-Bum),권세원(Kwon Se-Won),권신원(Kwon Sin-Won),김도영(Kim Do-Young),임성정(Rim Seong-Jeong) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.10

본 논문은 가공지선의 유도뢰 차폐효과에 대한 실증적 데이터가 없는 상황에서 22.9㎾ 배전선로의 구조에 따른 유도뢰 차폐효과를 알아보고자 한다. 이를 위해 현행 22.9㎾ 중성점 다중 접지방식의 배전선로 구조에서 수치해석을 통해 유도뢰전압올 계산하고 이를 기반으로 유도뢰 차폐효과를 계산하였다. 또한 현행 배전선로 구조를 대체하는 가공지선과 중성선을 겸용하는 선로를 제안하여 동일한 해석을 수행하였으며 제안한 구조의 타당성을 입증하기 위해 유도뢰 차폐효과를 비교하였다.

유압식 확장기가 내장된 오거 크레인의 특성 및 신뢰성 평가

김점식(Jeom-Sik Kim),권신원(Sin-Won Kwon) 대한전기학회 2010 전기학회논문지 P Vol.59 No.1

This study evaluated the characteristics and reliability of an auger crane with a built-in hydraulic extender. The field test of the hydraulic extender was performed with the hydraulic lines filled with hydraulic fluid and free of air. The pressure generated during the test was measured with a digital pressure gauge. The crane was considered to have undergone one cycle of the excavation process after it had performed excavation under three conditions at the same location. This process was performed three times in total. From the results of the excavation using the hydraulic extender, it was found that the maximum pressure and torque measured were 19.9 [㎫] and 895.4 [㎏fㆍm], respectively. The rotation force of the auger crane generated at this time signifies a horizontal force. If the excavation diameter of the auger crane is increased, the rotation speed is reduced causing the circumferential speed to also be reduced. The torsional shear stress of the extendable auger crane was calculated to be approximately 23.5 [㎫]. However, the rotation shaft material used for this system was carbon steel for machine structural use (SM45C). Since the minimum torsional yield stress is greater than 150 [㎫] according to KS D 3752, it means the equipment has secured a safety factor greater than 6. Therefore, it was found that when performing work using the extendable auger crane, it exhibited no problems with the safety and reliability of its shaft.

22.9㎸ 배전선로 중성선 설치 구조에 따른 유도뢰 차폐효과 분석

김점식(Jeom-Sik Kim),김도영(Do-Young Kim),박용범(Yong-Beom Park) 대한전기학회 2010 전기학회논문지 P Vol.59 No.2

The electricity distribution system in Korea is adopting a multi-grounding system. Protection of this distribution system against lightning is performed by installing overhead ground wires over the high voltage wires, and connecting the overhead ground wires to the ground every 200 m. The ground resistance in this system is limited not to exceed 50Ω and overhead ground wire and neutral wire are multiple parallel lines. Although overhead ground wire and neutral wire are installed in different locations on the same pole, this circuit configuration has duplicated functions of providing a return path for unbalanced currents and protecting the distribution system against induced lightning. Therefore, the purpose of this study is to analyze the induced lightning shielding effect according to the neutral wire installation structure of a 22.9㎸ distribution line in order to present a new 22.9㎸ distribution line structure model and characteristics. This study calculated induced lightning voltage by performing numerical analysis when an overhead ground wire is present in the multi-grounding type 22.9㎸ distribution line structure, and calculated the induced lightning shielding effect based on this calculated induced lightning voltage. In addition, this study proposed and analyzed an improved distribution line model allowing the use of both overhead wire and neutral wire to be installed in the current distribution lines. The result of MATLAB simulation using the conditions applied by Yokoyama showed almost no difference between the induced lightning voltage developed in the current line and that developed in the proposed line. This signifies that shielding the induced lightning voltage through overhead wire makes no difference between current and proposed distribution line structures. That is, this study found that the ground resistance of the overhead wire had an effect on the induced lightning voltage, and that the induced lightning shielding effect of overhead wire is small.

아치형 기초근가 수치모형 시험에 의한 안정성 비교 분석

김점식(Jeom-Sik Kim),문성원(Sung-Won Mun),박용범(Yong-Beom Park),권신원(Sin-Won Kwon) 대한전기학회 2011 대한전기학회 학술대회 논문집 Vol.2011 No.4-1

축소모델을 이용한 22.9㎸-Y 배전선로의 유도뢰 분석

김점식(Jeom-Sik Kim),김도영(Do-Young Kim),박용범(Yong-Beom Park),권신원(Sin-Won Kwon),길경석(Kyung-Suk Gil) 대한전기학회 2010 전기학회논문지 P Vol.59 No.4

This study fabricated a simulation facility which reduced the structure of a current distribution line to 50:1 in order to analyze the induced lightning shielding effect of a 22.9㎸-Y distribution line according to ground resistance capacity, grounding locations, etc. When installing an overhead ground wire, the standard for grounding a distribution line with a current of 22.9㎸-Y requires that ground resistance in common use with the neutral line be maintained less than 50Ωevery 200m span. The reduced line for simulation had 7 electric poles and induced lightning was applied to the ground plane 2m apart from the line in a direction perpendicular to it using an impulse generator. If induced voltage occurred in the line and induced current flowed through the line due to the applied current, the induced voltage and current of the ‘A’ phase were measured respectively using an oscilloscope. When all 7 electric poles were grounded with a ground resistance of less than 50Ω respectively, the combined resistance of the line was 7.4Ω. When an average current of 230A was applied, the average induced voltage and current measured were 1,052V and 13.8A, respectively. Under the same conditions, when the number of grounding locations was reduced, the combined resistance as well as induced voltage and current showed a tendency to increase. When all 7 electric poles were grounded with a ground resistance of less than 100Ω, the combined resistance of the line was 14.9Ω. When an average current of 236A was applied, the average induced voltage and current of the ‘A’phase calculated were 1,068V and 15.6A, respectively. That is, in this case, only the combined resistance was greater than when all 7 electrical poles were grounded, and the induced voltage and current were reduced. Therefore, it is thought that even though ground resistance is slightly higher under a construction environment with the same conditions, it is advantageous to ground all electric poles to ensure system safety.

가공지선과 중성선을 겸용하는 실증 배전선로 구축 사례

김점식(Jeom-sik Kim),김도영(Do-young Kim),박용범(Yong-Beom Park),권신원(Sin-won Kwon),권세원(Se-won Kwon),길경석(Gyung-suk Gil) 대한전기학회 2011 대한전기학회 학술대회 논문집 Vol.2011 No.4-1

축소모의선로 모델을 이용한 가공지선 겸용 중성선 선로의 유도뢰 분석

김점식(Jeom-Sik Kim),김도영(Do-Young Kim),박용범(Yong-Beom Park),권신원(Sin-Won Kwon),길경석(Kyung-Suk Kil) 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.11

본 논문에서는 다중접지에 적합한 접지장소별 접지저항의 영향이나 연결에 따른 영향을 보기 위해 접지저항값과 접지개소를 다양하게 바꾸어 유도뢰 차폐에 가장 효율적인 방법을 제시하고자 하며 22.9㎸ 배전선로의 구조에서 가공지선과 중성선을 겸용하는 선로를 제안하여 겸용선로의 유도뢰 차폐효과를 알아보고자 하였다. 이를 위해 현행 22.9㎸ 중성점 다중 접지방식의 배전선로 구조를 50:1로 축소한 축소모의선로를 제작하여 실험을 진행하였다. 실험결과 모든 전주 50Ω 접지시 유도전압은 현행 5W 시스템에서 1,052V, 4W 시스템에서 1,127V로 나타났으며, 현행 시공기준인 200m마다 50Ω을 접지하였을 경우 5W 시스템에서 1,393V로 측정되었다. 따라서 현행 5W 시스템에 비해 제안 4W 시스템에서 유도전압은 약간 상승하였으나 유도전류는 감소하여 현행선로를 겸용선로로 대체해도 시스템 안정성이 확보될 것으로 판단되며, 낮은 접지저항값을 일부 접지하는 것보다 접지저항값이 다소 높더라도 보다 많은 전주를 접지하는 것이 보다 효율적임을 알 수 있었다.

배전설비 접지극 종류 및 설치방법에 따른 대지전위 분석

김점식(Jeom-Sik Kim),문성원(Sung-Won Moon),김도영(Do-Young Kim),박용범(Yong-Beom Park),권신원(Sin-Won Kwon) 대한전기학회 2013 대한전기학회 학술대회 논문집 Vol.2013 No.7