http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
최연석,김동락,이병섭,양형석,정원묵,Choi, Y.S.,Kim, D.L.,Lee, B.S.,Yang, H.S.,Jung, W.M. 한국초전도학회 2008 Progress in superconductivity Vol.10 No.1
A conduction-cooled superconducting magnet system is developed for material separation. The superconducting magnet for material separation has to be designed to have a strong magnetic field in a control volume. Since the magnetic field gradient is larger at the end rather than at the center of the magnet, we developed a design method to optimize the superconducting magnet for material separation. The safety of the superconducting magnet is evaluated, taking into account the electro-magnetic field, heat and structure. The superconducting coil is successfully wound by the wet-winding method. The superconducting coil is installed in a cryostat maintaining high vacuum, and cooled down to approximately 4 K by a two-stage GM cryocooler. The performance of the conduction-cooled superconducting magnet system is discussed with respect to the supplied current, cooling medium and cooling power of a cryocooler.
최연석,정은수,Choi, Y.S.,Jeong, E.S. 대한설비공학회 1996 설비공학 논문집 Vol.8 No.2
Performance of a VM heat pump is considerably affected by various losses, such as enthalpy dump, reheat loss, pumping loss, conduction loss and shuttle loss. A second-order analysis model of VM heat pumps, which allows consideration of the major losses, was presented. Actual heat transfer rates for heat exchangers were calculated from the heat transfer rates obtained by the adiabatic analysis and various losses. New effective temperatures of heat exchangers were calculated from the actual heat transfer rates and the mean heat transfer coefficients until there was no appreciable change in the effective temperatures. Effects of design parameters, such as phase angle, swept volume ratio, regenerator length and speed on heating capacity, cooling capacity and COP were shown.
최연석(Y.S.Choi),Hongming Tang,김동락(D.L.Kim),양형석(H.S.Yang),이병섭(B.S.Lee) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
The design of thermal radiation shield cooled by a cryocooler is presented. This study is motivated mainly by our recent development of prototype superconducting magnet system for the Cyclotron K120. The superconducting magnet system is composed of the magnet cryostat, transfer line and supply cryostat. In order to minimize thermal radiation load, the superconducting coil form in the magnet cryostat is enclosed by the thermal radiation shield which is thermally connected to the first-stage cold head of a two-stage cryocooler in the supply cryostat. Since the supply cryostat is located far from the magnet cryostat large temperature gradient along the thermal shield is unavoidable. In this paper, the thermal radiation shield is optimized to minimize temperature gradient with taking into account the cryogenic load, system structure and electrical load. The effect of heat source from thermal conduction through mechanical supports on the temperature distribution of thermal radiation shield is also discussed.
최연석(Y.S. Choi),김명수(M.S. Kim),김동락(D.L. Kim),복민갑(M.G. Bok),전종수(J.S. Jeon),이종현(J.H. Lee) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11
The natural circulation loop is designed for cryogenic insert in the Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. Sensitivity is the key parameter of a FT-ICR mass spectrometer and the cryo-cooling of preamplifier can reduce the thermal noise level and thereby improve the signal-to-noise ratio. The preamplifier consisted of non-magnetic materials is thermally connected to the cooling loop which is passing through the flange maintaining ultra-high vacuum in the ion trap. The cryogenic liquid passes through inside of the loop in order to cool the preamplifier indirectly. At the other end, a two-stage cryocooler is located to recondense cryogenic vapor generated due to the heat from the preamplifier. The vapor is condensed and flows back to the preamplifier through the loop. The circulating cryo-fluid removes heat from the preamplifier or heat source and transports it to the cryocooler or heat sink. In this paper, the natural circulation loop for cryogenic preamplifier is introduced and the detail of design is presented for improving the sensitivity of detector.
최연석(Y.S. Choi),김동락(D.L. Kim),문성주(S.J. Moon),양형석(H.S. Yang),김재휘(J.W. Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5
The natural circulation loop by a cryocooler is designed and fabricated. This study is motivated mainly by our recent development of cryogenic cooling system for superconducting cyclotron K120 magnets without any replenishment of the cryogen. In the natural circulation system, a cooling channel is attached on the outer surface of the aluminum block and the cryogenic liquid passes through inside. of the channel in order to cool the block indirectly. A cryocooler is located at the top to recondense cryogenic liquid coming from the aluminum block. The experimental apparatus has a similar configuration to the recently designed superconducting magnet system for cyclotron K120, except that the electrical heater is used to simulate the heat generation in the superconducting windings. The heat transfer in the natural circulation loop is discussed and the detail of design as well as fabrication is also described.
Thermal Characteristic of Natural Circulation Loop for Cryogenic Cooling Application
최연석(Y.S. Choi),김동락(D.L. Kim),양형석(H.S. Yang),문성주(S.J. Moon),김재휘(J.W. Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11
The natural circulation loop by a cryocooler for cryogenic cooling application is designed, fabricated and tested. In the natural circulation loop system, a cooling channel is attached on the outer surface of the aluminum block and the cryogenic liquid passes through inside of the channel in order to cool the block indirectly. A cryocooler as a heat sink is located at the top to recondense cryogenic liquid coming from the aluminum block in which electrical heater as a heat source is installed. The main dimensions are determined using the existing empirical correlation and the natural circulation loop is successfully fabricated. The initial cooling using liquid nitrogen and temperature distribution of an aluminum block is discussed.