• 한국화재소방학회논문지
• /
• 제16권2호
• /
• pp.75-80
• /
• 2002

지하공동구에 사용되는 케이블의 연소특성 중 열방출량과 연기 유독성 실험을 수행하였다. 열 방출량 실험은 22.9 kv 전력용 케이블을 대상으로 ISO 9705 규격의 공간에서 수행하였으며 유독성가스의 정량적 위험성 평가를 위하여 NES 713(British-Naval Engineering Standard)을 적용하였다. 실험 결과 측정높이 1.2 m를 기준으로 계산한 케이블의 열 방출 율은 60 kW로 예측되었다. 한편, 케이블의 연기유독성을 위한 NES 실험 결과, 인체에 치명적인 CO의 경우 30분 노출시 사망에 이를 수 있고 의식불명상태가 될 수 있는 수준으로 판정되었다

• 한국안전학회지
• /
• 제34권1호
• /
• pp.1-7
• /
• 2019

Electromagnetic measurements of the power cable tunnel were conducted from August 10 to 20, 2018, in the ${\bigcirc}{\bigcirc}$ city underground utility tunnel. During this period, the average temperature was $31.89^{\circ}C$ and the humidity was 67.56% in power cable tunnel. As a result of the electromagnetic measurement, the highest electric field was 25.3 V/m and the magnetic flux density was $42.6{\mu}T$. The average electric field was 18.56 V/m and the magnetic flux density was $29.32{\mu}T$ in the power cable tunnel. As a result of comparison with the electric equipment technical standard, the electric field in the power cable tunnel was 0.5% of the electric equipment standard and 35.2% of the magnetic flux density. It's similar value that electric field is about robotic vacuum(15.53 V/m), and magnetic flux density is similar value about capsule- type coffee machine ($23.07{\mu}T$). The number of cable lines and the size of the electromagnetic waves were not proportional to each other through comparison of cable lines in the power cable tunnel. It was confirmed that 154 kV, rather than 22.9 kV, could have a greater influence on occupational.

• 한국안전학회지
• /
• 제20권2호
• /
• pp.44-49
• /
• 2005

Real-scale experimental study was performed to characterize the surface flame propagating velocity along the OF cable in the underground utility fire. Temperatures of oil filled OF cable and dried OF cable with the diameter of 90mn were measured using thermocouple and data log system. The hexane and alkyl-benzene oil were used as a fire source using the ignition device. As a result while the surface flame propagating velocity of the three cables was $0.06\~0.09cm/s$, the surface flame propagating velocity of the one cable was $0.028\~0.032cm/s$. Therefore, it was found that the surface propagating flame velocity of the three OF cables is $2.1\~2.8times$ faster than that of one OF cable case. The results show that the surface propagating flame velocity became larger as increase of the number of cable, the volume of alkyl-benzene oil in the cable. The characteristics of surface propagating flame velocity in the OF cable can be helpful to fire suppression system in utility.

• 한국정보통신학회논문지
• /
• 제21권8호
• /
• pp.1597-1603
• /
• 2017

지하공동구의 화재 발생 빈도는 다른 화재에 비하여 낮은 편이나 화재로 인한 피해는 경제적 손실 뿐만 아니라 사회운영 마비로 사회적 손실을 초래할 수 있다. 이에 본 논문은 지하공동구 내 설치된 누설 동축케이블을 이용하여 지하공동구의 상태감시시스템 구축에 대한 실증 시험 결과를 제시한다. 이를 위해 지하공동구에 설치된 누설 동축케이블에 삽입손실 특성이 $-6{\pm}2dB$인 유도성 커플러와 200 Mbps급 전력선 통신 모뎀을 연결하여 실증 시험한 결과, 500 m까지 IP 카메라의 송/수신을 확인하였다. 따라서 데이터 전송을 위한 통신선로의 추가 설치 없이도 지하공동구 내 설치된 누설 동축케이블을 이용하여 지하공동구에 상태감시시스템 구축이 가능할 것으로 판단된다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 A
• /
• pp.175-177
• /
• 2002

The use of underground transmission cables has increased continuously in densely inhabited urban and suburban for power transmission. Two or more transmission lines are outgoing from one substation in many cases, and one line comprises twin circuits. In order to meet the increasing do and for electric power, underground tables of two or fore circuits are installed in ducts in parallel for several kilometer in the same route. It, however, has not been known generally that the sheath circulating current is generated in a system where a large number of cables are laid on the same route. Therefore, this paper describes an improved analysis method for sheath circulating current on underground transmission cables using EMTP. Author propose several methods to reduce sheath circulating current. The analysing method and reduction methods for two or more underground cables will be really improved for cable system utility.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
• /
• pp.148-150
• /
• 2002

The distributed jointing method is used in the underground tunnel due to narrow space of jointing. This method causes non-uniform length between cable joints. It has an effect on the sheath circulating current and the induced voltage. Furthermore the distributed jointing method may cause transient overvoltage resulting from lightning in underground cable which is connected with overhead line. The author diversely studied the sheath circulating current and induced voltage on underground cable depending on the distributed jointing length under the normal and the transient circumstances. The various simulation results really improve the cable system utility.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
• /
• pp.213-215
• /
• 2001

This paper describes an improved analysis method for sheath circulating current on three-underground transmission cables using EMTP(Electromagnetic Transient Program). Author studied diversely the sheath circulating current on three-underground cables depending on the various length rate, the phase arrangement, and the grounding resistance of the sheath in the cross-bonded section. It was clear that very large circulating current is generated in cable systems due to unbalanced length rate and phase arrangement in the cross-bonded section. The analysing method for two or more underground cables will be really Improved for cable system utility.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.1845-1850
• /
• 2003

The underground utility tunnels are important facility as a mainstay of country because of communication developments. The communication and electrical duct banks as well as various utility lines for urban life are installed in the underground utility tunnel systems. If a fire breaks out in this life-line tunnel, the function of the city will be discontinued and the huge damages are occurred. In order to improve the safety of life-line tunnel systems and the fire detection, the behaviors of the fire-induced smoke flow and temperature distribution are investigated. In this study we assumed that the fire is occurred at the contact or connection points of cable. Numerical calculations are carried out using different velocity of ventilation in utility tunnel. The fire source is modeled as a volumetric heat source. Three-dimensional flow and thermal characteristics in the underground tunnel are solved by means of FVM (Finite Volume Method) using SIMPLE algorithm and standard ${\kappa}-{\varepsilon}$ model for Reynolds stress terms. The numerical results of the fire-induced flow characteristics in an underground utility tunnel with different velocity of ventilation are graphically prepared and discussed.

• 한국화재소방학회논문지
• /
• 제16권1호
• /
• pp.66-76
• /
• 2002

본 연구는 지하구 미분무수 소화설비 적용에 관한 것으로, 화재 초기에 신속한 소화를 통한 케이블 열적손상의 최소화와 신속한 본래 기능의 회복을 위한 소화 시스템의 최적화에 그 목적이 있으며, 이를 위해 미분무수 노즐개발을 위한 화재실험을 수행하였다. 실험은 2.5m(H)$\times$2.5m(W)$\times$25m(D)의 콘크리트 지하구에서 소화설비가 작동되지 않는 경우와 2가지 종류의 미분무수노즐이 적용되는 경우를 수행하였다. 실험 결과 소화설비의 개입이 없는 경우, 2분 이내에 열적 변형에 의한 치명적인 손상을 입었으며, 2～3분 경과 후 케이블의 내부까지 손상되었다. 노즐적용실험의 결과, 타입 1(입자분포 약 470$\mu{m}$)노즐과 타입 2(입자분포 약 650$\mu{m}$) 노즐은 모두 케이블의 피해 온도제어($4000^{\circ}c$ 이하)를 만족하였다. 실험을 통하여 지하구 공간특성에 적합한 미분무수 헤드의 특성을 설정할 수 있었으며, 그 성능을 입증할 수 있었다.

• 한국초전도ㆍ저온공학회논문지
• /
• 제5권2호
• /
• pp.20-29
• /
• 2003

As power systems grow more complex and power demands increase, the need of underground transmission system is increasing gradually. But it is very difficult and high in cost to construct new ducts and/or tunnels for power cables in metropolitan areas. HTS (High Temperature Superconducting) cable can carry very high current densities with strongly reduced conductor loss and allow high power transmission at reduced voltage. Therefore HTS cable can transfer more power to be moved in existing ducts, which means very large economical and environmental benefits. A development project for a 22kV class HTS cable is ongoing at a research centers, and the cable manufacturer in Korea. In this paper, we carried out investigation for application of 22kV class HTS cable in Korean utility networks. The results show that the HTS cable is applicable to replace IPB in pumping-up power plant, withdrawal line in distributed generation, withdrawal line in complex power plant, and conventional under ground cable. Finally, as the cost of HTS wire and refrigeration drops, the technical and economical potential of HTS cable is evaluated positively.