• 제목/요약/키워드: Cryo-cooler

검색결과 13건 처리시간 0.019초

Investigation on Effective Operational Temperature of HTS Cable System considering Critical Current and AC loss

  • Kim, Tae-Min;Yim, Seong-Woo;Sohn, Song-Ho;Lim, Ji-Hyun;Han, Sang-Chul;Ryu, Kyung-Woo;Yang, Hyung-Suk
    • KEPCO Journal on Electric Power and Energy
    • /
    • 제2권2호
    • /
    • pp.307-310
    • /
    • 2016
  • The operational cost for maintaining the superconductivity of high-temperature superconducting (HTS) cables needs to be reduced for feasible operation. It depends on factors such as AC loss and heat transfer from the outside. Effective operation requires design optimization and suitable operational conditions. Generally, it is known that critical currents increase and AC losses decrease as the operational temperature of liquid nitrogen ($LN_2$) is lowered. However, the cryo-cooler consumes more power to lower the temperature. To determine the effective operational temperature of the HTS cable while considering the critical current and AC loss, critical currents of the HTS cable conductor were measured under various temperature conditions using sub-cooled $LN_2$ by Stirling cryo-cooler. Next, AC losses were measured under the same conditions and their variations were analyzed. We used the results to select suitable operating conditions while considering the cryo-cooler's power consumption. We then recommended the effective operating temperature for the HTS cable system installed in an actual power grid in KEPCO's 154/22.9 kV transformer substation.

6.6 ㎸-200A급 HTS 한류기 DC Reactor용 과냉질소 냉각시스템의 개발 (Development of cooling system with sub-cooled nitrogen for DC Reactor of 6.6 ㎸-200A class HTS fault current limiter)

  • 김형진;권기범;강형구;배덕권;안민철;정은수;장호명;고태국
    • 한국초전도저온공학회:학술대회논문집
    • /
    • 한국초전도저온공학회 2003년도 추계학술대회 논문집
    • /
    • pp.171-175
    • /
    • 2003
  • The sub-cooled nitrogen cooling system at 65 K with GM cryo-cooler is developed for cooling down the DC reactor of 6.6 ㎸-200 A class HTS Fault Current Limiter(SFCL). The sub-cooled nitrogen cooling is more economic than saturated nitrogen cooling, because the length of HTS wire is reduced in the same capacity, as well as, more stable. The cooling system with the GM cryo-cooler installed on the cryostat is not only compact but also efficient for energy saving. In the nitrogen vessel, after evacuating with vacuum pump to saturated nitrogen at 65 K, sub-cooled nitrogen at 65 K is made by putting in gas helium to 1 atm. During the short circuit test occurring the fault current of 1000 A, the sub-cooled nitrogen cooled DC reactor for SFCL is kept the state of sub-cooled nitrogen at 65 K.

  • PDF

스터링 극저온 냉동기의 운전주파수 의존성에 관한 연구 (Study of the Dependency on Operating Frequency of the Stirling Cryocooler)

  • 홍용주;박성제;고득용;김효봉;김양훈;김종학
    • 한국초전도저온공학회:학술대회논문집
    • /
    • 한국초전도저온공학회 2002년도 학술대회 논문집
    • /
    • pp.63-66
    • /
    • 2002
  • A free piston and free displacer (FPFD) Stilting cryocooler for the cooling infrared and cryo-sensor is currently under development at Korea Institute of Machinery & Materials. In this study, the dynamic characteristics of the displacer in the expansion space of the Stirling cooler was investigated by experiment. The experimental results show that the Stirling cryocooler has maximum cooling capacity at the certain relation between operating frequency and natural frequency of the displacer and the operating frequency of the Stirling crycooler should be determined by natural frequency of the linear compressor and displacer.

  • PDF

77K Inertance tube 맥동관 극저온 냉동기에 관한 연구 (An Experimental Study for the 77K Inertance Tube Pulse Tube Cryocooler)

  • 박성제;고득용;김효봉
    • 연구논문집
    • /
    • 통권29호
    • /
    • pp.17-27
    • /
    • 1999
  • The experimental results of the 17K inertance tube pulse tube cryocooler for cooling cryosensors are presented in this paper. In prototype experiments, linear compressor is driven by linear motor, and inertance tubes are inserted between one liter reservoir and pulse tube. Design of the inertance tube pulse tube cryo-cooler is conducted by ARCOPTR program of NASA Ames Research Center. To find optimal conditions of inertance tube pulse tube cryocooler, no load temperature and refrigeration capacity according to the variations of inertance tube volume, reservoir volume and charging pressure are measured. and the cool down and load characteristics at the particular conditions are presented. As the representative results, no load temperature of the cold end is 52.7K and refrigeration capacity is 5W at 72K..

  • PDF

스터링 극저온 냉동기 성능의 운전주파수 의존성에 관한 연구 (Study of the Dependency of the Stirling Cryocooler′s Thermodynamic Performance on the Operating Frequency)

  • 홍용주;박성제;김효봉;유병건;최영돈
    • 한국초전도ㆍ저온공학회논문지
    • /
    • 제4권1호
    • /
    • pp.140-144
    • /
    • 2002
  • A free piston and free displacer (FPFD) Stirling cryocooler has been widely used for the cooling infrared and cryo-sensor. The thermodynamic performance of the free piston and free displacer type (FPFD) Stirling cryocooler is highly dependent on the operating frequency of the linear compressor and the natural frequency of the displacer. In this study, to find optimal relation between operating and natural frequency of the displacer the dynamic characteristics of the displacer in the expansion space of the Stirling cooler was investigated by experiment. The experimental results show that the Stifling cryocooler has maximum cooling capacity at the operating frequency of about 0.8 times of the natural frequency of displacer. Therefore the operating frequency of the Stirring cryocooler should be determined by natural frequency of the linear compressor and displacer.

적외선 센서 냉각용 스터링 냉동기의 수명/신뢰성 시험 (Reliability Test of the Stirling Cryocooler for cooling infrared detector)

  • 박성제;홍용주;김효봉;유병건;이기백
    • 한국초전도저온공학회:학술대회논문집
    • /
    • 한국초전도저온공학회 2003년도 학술대회 논문집
    • /
    • pp.156-159
    • /
    • 2003
  • A free piston and free displacer(FPFD) Stirling cryocooler for cooling infrared and cryo-sensors is currently under development at KIMM(Korea Institute of Machinery & Materials). Our coolers are specifically designed to work in the thermal imaging device and to meet requirements such as cooling capacity, COP and high reliability. In this work, Stirling cryocooler is designed, manufactured and fabricated, and performance characteristics are investigated. This cooler delivers approximately 0.5W cooling at 77K for 30W ∼ 40W of input power from AC power supply. And, after the climate performance and reliability for the cryocooler is discussed, operating test without cooling load at the cold end is performed.

  • PDF

열상장비용 스터링 극저온 냉동기 특성평가 (I) : 성능시험 (The performance evaluation of Stirling cryocooler for thermal imaging system (II) : Performance test)

  • 박성제;홍용주;김효봉;김양훈;이성래;이기백;나종문
    • 한국초전도저온공학회:학술대회논문집
    • /
    • 한국초전도저온공학회 2003년도 추계학술대회 논문집
    • /
    • pp.320-323
    • /
    • 2003
  • This paper presents the results of a series of performance tests for the Stilting cryocooler. A free piston and free displacer(FPFD) Stilting cryocooler for cooling infrared and cryo-sensors is currently under development at KIMM. Our coolers are specifically designed to work in the thermal imaging device and to meet requirements such as cooling capacity, COP and high reliability. In this work, Stilting cryocooler is designed, manufactured and fabricated, and performance characteristics for the cooling capacity / applied input power and cool down time are investigated. This cooler delivers approximately 0.9W cooling at 80K for 30W ~ 40W of input power. And, It takes approximately 2 minutes to cool down to 80K at the ambient temperature of 23$^{\circ}C$.

  • PDF

풍력 터빈용 750 kW 급 고온초전도 발전기 모듈의 코일 구조 설계 및 열 해석 (Structural Design and Thermal Analysis of a Module Coil for a 750 kW-Class High Temperature Superconducting Generator for Wind Turbine)

  • 투덴수런 오운자르갈;고병수;성해진;박민원
    • 한국산업정보학회논문지
    • /
    • 제24권2호
    • /
    • pp.33-40
    • /
    • 2019
  • 많은 풍력회사들은 큰 용량, 작은 크기 및 가벼운 무게의 풍력 발전기를 개발하기 위해 노력해 왔다. 고온초전도 풍력발전기는 기존의 풍력 발전기에 비해 부피와 중량을 줄일 수 있기 때문에 풍력 발전시스템에 더 적합하다. 그러나 고온초전도 발전기는 큰 진공 용기 및 계자 코일의 유지 보수가 어려운 문제를 가지고 있다. 이러한 문제는 고온초전도 계자 코일의 모듈화를 통해 해소될 수 있다. 그런데 고온초전도 모듈 코일에는 직류 전류를 전달하기 위한 전류 리드가 필요하며, 이는 큰 열전달 부하를 발생시킨다. 따라서 전류 리드는 전도 및 Joule 열 부하를 줄이기 위해 최적으로 설계되어야 한다. 본 논문에서는 750 kW급 고온초전도 발전기에 대한 모듈 코일의 구조 설계 및 열 해석을 다루었다. 모듈 코일의 전도 및 복사열 해석은 3D 유한요소법 프로그램을 사용하여 분석하였으며, 그 결과 총 열부하는 극저온 냉각장치의 냉각 용량보다 작았다. 본 논문에서 제시한 설계 및 해석결과는 풍력 발전시스템의 초전도 발전기 개발에 효과적으로 활용할 수 있을 것이다.

배전급 초전도한류기 및 전력 IT 응용을 위한 실시간 모니터링 시스템 개발 (Development of Distribution Superconducting Fault Current Limiter and its Monitoring System for Power IT Application)

  • 박동근;석복열;고태국;강형구
    • 전기학회논문지
    • /
    • 제57권3호
    • /
    • pp.398-402
    • /
    • 2008
  • Recently, the development of superconducting fault current limiters (SFCLs) has been required as power demands increase in the power system. A distribution-level prototype resistive SFCL using coated conductor (CC) has been developed by Hyundai Heavy Industries Co., Ltd. and Yonsei University for the first time in the world. The ratings of the SFCL are 13.2kV/630A at normal operating condition. A novel non-inductive winding method is used in fabricating coils so there is almost zero impedance during normal operation. The distribution SFCL is cooled by sub-cooled liquid nitrogen $(LN_2)$ of 65K and 3 bar to enhance cryo-dielectric performance, critical current density, and thermal conductivity. In order to make reliable operation of an SFCL in real power systems, we monitored and controled its operation conditions by using supervisory control and data acquisition (SCADA) method. Thus, a monitoring system for the SFCL employing information technology (IT) is proposed and developed to be on the lookout for the operation conditions such as inside temperature, inside pressure, $LN_2$ level, voltage and current. Since operation temperature should be kept constant, bang-bang control for temperature feedback with a heater attached to the cold head of cryo-cooler is applied to the system. Short-circuit tests with prospective fault current of 10kA and AC dielectric withstand voltage tests up to 143kV for 1 minute were successfully performed at Korea Electrotechnology Research Institute. This paper deals with the development of a distribution level SFCL and its monitoring system for reliable operation.