• Title, Summary, Keyword: Deicing system

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A Study on Deicing Current Estimation Technique and Configuration Process for Deicing System in the Conventional Line (기존선 해빙시스템을 위한 해빙전류 예측기법 및 구성 절차에 관한 연구)

  • Kwon, Sam-Young;Park, Young;Jung, Ho-Sung
    • Journal of the Korean Society for Railway
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    • v.9 no.2
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    • pp.237-243
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    • 2006
  • Deicing system is to melt frost or ice freezed in catenary line when the temperature is lower than $0^{\circ}C$ in winter. The principle of deicing system is to melt frost or ice by Joule heat of catenary impedance. The performance of deicing is dependant of deicing current determined by the length of deicing section, deicing impedance and current division ratio of catenary line and messenger line. So, we present technique for estimating deicing current and process for determination of deicing section in the conventional line. Deicing impedance is estimated using Carson-Pollaczek equation, and current division ratio of catenary line and messenger line is estimated using voltage drop, and deicing current is estimated using power system data of deicing system. For the determination of the final deicing section, we verified estimated value comparing with experiment value of deicing impedance and current division ratio of catenary line and messenger line using low voltage experiment. Finally, we verified the validity of estimation technique and process using a simulated test data of real deicing system operation in the Chungju Substation, Chungbuk line.

Estimation Technique of deicing current for configuration of deicing system in conventional line (기존선 해빙시스템 구성을 위한 해빙전류 예측기법)

  • Jung, Ho-Sung;Kwon, Sam-Young;Park, Young;Ahn, Byeong-Lib;Lee, Ju
    • Proceedings of the KIEE Conference
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    • pp.288-290
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    • 2005
  • Deicing system operated in high speed line is to melt frost or ice freezed in catenary line when the temperature is lower than 0 in winter. The principle of deicing system is to m디t frost or ice by Joule heat of catenary impedance. The performance of deicing is dependant of deicing current determined by the length of deicing section, deicing impedance and current division ratio of catenary line and messenger line. So, We present technique for estimating deicing current in convention line. Deicing impedance is estimated using Carson - Pollaczek, current division ratio of catenary line and messenger line is estimated using voltage drop, and deicing current is estimated using power system data of operation secion for deicing system in this technique. To verify the validity of technique, we compare the estimated current using technique of this paper with deicng current of high speed line.

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Fuzzy Rulebase Application for Estimation of Snow Accretion on Power Lines and Deicing Countermeasure Plan (퍼지 룰베이스에 의한 전선착설 예측 및 대책 지원 기법)

  • 최규형
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.10
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    • pp.782-788
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    • 2003
  • Making deicing countermeasure plan against snow accretion on power line is a very complicated problem, which should take into account both the possibility of accidents due to snow accretion on power line and the stable operation of power system. As knowledge engineering can be a good solution to this field of problems, a prototype expert system to assist power system operators in forecasting snow accretion on power lines and making a list of all the feasible and effective deicing countermeasures has been developed. The system has been remodelled into a fuzzy expert system by adopting fuzzy rulebase and fuzzy inference method to systematically process the fuzziness included in the heuristic knowledges. Simulation results based on the past snow accretion accident data show that the proposed system is very promising.

The Study of FAA's certification policy for approving the ground use of deicing/anti-icing fluids on airplane (항공기용 결빙방지액의 지상 사용승인을 위한 FAA의 최근 인증정책 연구)

  • Kim, You gwang
    • Journal of Aerospace System Engineering
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    • v.7 no.3
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    • pp.51-57
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    • 2013
  • This study describes the Federal Aviation Administration(FAA) certification policy for approving the use of Type II, III, and IV deicing/anti-icing fluids on small category airplanes. These fluids can be characterized as non-Newtonian, pseudo-plastic fluids, also known as "thickened" fluids. Deicing fluids are used before takeoff to remove frost or ice contamination, while anti-icing fluids are used before takeoff to prevent frost or ice contamination from occurring for a period of time(referred to as "holdover time") after application. Thickened deicing/anti-icing fluids can affect airplane performance and handling characteristics and their residue may cause stiff or frozen flight controls. This study also describes an approval process that may be used by type certificate holders and applicants for a type certificate under parts 23 to support operational use of these fluids on their airplanes.

Knowledge Engineering Method Ie Estimation of Snow Accretion on Power lines and Decision of Deicing Countermeasures (지식공학에 의한 전선 착설 예측 및 대책 결정 기법)

  • 최규형
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.3
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    • pp.95-102
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    • 2003
  • To Prevent the damage of power system facilities by snow accretion on transmission lines, a prototype expert system has been developed. The system has the basic functions of forecasting snow accretion on transmission lines and making a list of all feasible and effective deicing countermeasures to assist power system operators. As estimating of snow accretion on power lines and making countermeasure plans are very difficult to solve analytically, knowledge engineering can be an effective method for this problem. The heuristics about the effect of weather conditions on the snow accretion process on power lines and power system operation for the deicing constitutes main nile base. Simulation results based on past snow accretion accident data show that the proposed system is very premising.

Estimates on appropriate storage for deicing materials for the 2018 Pyeongchang Winter Olympic Games (평창 동계올림픽을 대비한 적정 제설제 비축량 추정)

  • Kim, Jin Guk;Yang, Choong Heon
    • International Journal of Highway Engineering
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    • v.18 no.6
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    • pp.51-59
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    • 2016
  • OBJECTIVES : The objective of this study is to estimate the appropriate storage required for deicing materials in Gangwon-do for successful snow removal operations during the 2018 Pyeongchang Winter Olympic Games. The final estimates of the deicing chemicals can be used by public agencies to aid decision making. METHODS : First, the database that exists in the road snow-removal management system (RSMS) of the Ministry of Land, Infrastructure, and Transport, South Korea was used to determine historical characteristics of snow removal experiences in Gangwon-do. The database includes historical information, including regional and road weather data and number of snow-removal works. Second, both the maximum and the actual amount of storages used for deicing materials in the past three years were analyzed. Lastly, the final estimates of the deicing materials were evaluated using an additional equation. It considers frequency of salt spray application, total administrative road length estimated by road agencies, and number of days required for snow removal works in Gangwon-do. Consequently, the results show that significant differences were not observed between the final estimates and the maximum amount used during the past three years. RESULTS : The final estimates of the deicing materials are almost similar to the maximum amount used during the past three years in Gangwon-do. CONCLUSIONS : The study shows that the estimates of deicing chemicals can be useful when decision making is required for the snow-removal policy.

Fundamental Study of Deicing Pavement System Using Conductive Materials (전도성 재료를 사용한 도로결빙방지 포장시스템 개발을 위한 기초연구)

  • Lee, Kanghwi;Lee, Jaejun
    • International Journal of Highway Engineering
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    • v.17 no.5
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    • pp.11-18
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    • 2015
  • PURPOSES : The purpose of this study is to develop a deicing pavement system using carbon fiber or graphite with high electrical conductivity and thermal conductivity. METHODS: Based on literature reviews, in general, conventional concrete does not exhibit electrical and thermal conductivity. In order to achieve a new physical property, experiments were conducted by adding graphite and carbon fiber to a mortar specimen. RESULTS: The result of the laboratory experiment indicates that the addition of graphite can significantly reduce the compressive strength and improve the thermal conductivity of concrete. In the case of carbon fiber, however, the compressive strength of the concrete is slightly increased, whereas, the thermal conductivity is slightly decreased against the plain mortar irrespective of the length of the carbon fiber. In addition, a mixture of the graphite and carbon fiber can greatly improve the degree of heating test. CONCLUSIONS : Various properties of cement mortar change with the use of carbon fiber or graphite. To enhance the conductivity of concrete for deicing during winter, both carbon fiber and graphite are required to be used simultaneously.

A Study on the Highway Snow Melting and Deicing System Using Geothermal Energy (도로의 결빙방지를 위한 지열이용 시스템 연구)

  • 신현준;서정윤
    • Journal of the Korean Society of Safety
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    • v.8 no.4
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    • pp.139-148
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    • 1993
  • Thermosyphons are simple devices that can passively transport thermal energy over relatively long distance with little temperature degradation. These attributes permit the use of low grade thermal energy for thermal control of structures including the snow melting and deicing to the pavement surface. The thermosyphon system requires no costly energy input and Is completely maintenance free. This paper presents the experimental results of the snow melting system in which thermosyphon was utilized to transfer the geothermal energy to the pavement to obviate slipping traffic accidents due to freezing of pavement in winter.

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An Implementation of Wireless Based Sensing System for Catenary Deicing (무선기반 전차선로의 해빙 감지시스템 구현)

  • Kim, Joo-Uk;Na, Kyung-Min;Park, Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.6
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    • pp.512-515
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    • 2019
  • Overhead contact systems (OCS) consist of contact and messenger wires, in which the contact wire supplies electric energy to the railway vehicle by contacting a pantograph. However, this mechanical contact is interrupted during frosts or temperatures below $0^{\circ}C$ in the winter. In these conditions, railway vehicle accidents can occur during operation because of the low energy efficiency that results from the increase in the arcing between the contact wire and pantograph. Therefore, the detection of frost or freezing temperatures is necessary to maintain the stable operation of these trains. In this study, we proposed the development of a frost or freezing condition monitoring system on the OCSs that utilizes wireless communication.

Numerical technique for chloride ingress with cover concrete property and time effect

  • Lee, Bang Yeon;Ismail, Mohamed A.;Kim, Hyeok-Jung;Yoo, Sung-Won;Kwon, Seung-Jun
    • Computers and Concrete
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    • v.20 no.2
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    • pp.185-196
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    • 2017
  • Durability problems initiated from steel corrosion are unseen but critical issues, so that many researches are focused on chloride penetration evaluation. Even if RC (Reinforced Concrete) structures are exposed to normal environment, chloride ingress varies with concrete surface conditions and exposed period. This paper presents an analysis technique for chloride behavior evaluation considering time effect on diffusion and surface conditions assumed as double-layered system. For evaluation of deteriorated surface condition, field investigation was performed for concrete pavement exposed to deicing agent for 18 years. In order to consider enhanced surface concrete, chloride profiles in surface-impregnated concretes exposed to chloride attack for 2 years from previous research were investigated. Through reverse analysis, effectively deteriorated/enhanced depth of surface and the related reduced/enlarged diffusion coefficient in the depth are simulated. The proposed analysis technique was evaluated to handle the chloride behavior more accurately considering changes of chloride ingress within surface layer and decreased diffusion coefficient with time. For the concrete surface exposed to deicing agent, the deteriorated depth and enlarged diffusion coefficient are evaluated to be 12.5~15.0 mm and 200% increasing diffusion coefficient, respectively. The results in concrete containing enhanced cover show 10.0~12.5 mm of impregnated depth and 85% reduction of chloride diffusion in tidal and submerged conditions.