고 유량 혈액 투석 시스템에서 박동류 펌프에 대한 대류 향상에 관한 연구

최대석,임기무,이정찬,이사람,문초혜,최혁,민병구,김희찬,Choi, D.S.,Um, K.M.,Lee, J.C.,Lee, S.R.,Mun, C.H.,Choi, H.,Min, B.G.,Kim, H.C. 대한의용생체공학회 2008 의공학회지 Vol.29 No.5

High-flux dialysis treatment removes various toxins via diffusion as well as convection, which is induced by ultrafiltration and backfiltration. In this study, in vitro (Using the distilled water and the bovine's blood) comparison test was performed to determine whether utilization of a high flux dialyzer paired with different pumps would increase the efficiency of convection. At the same blood flow rates, a pulsatile pump and a roller pump were employed to propel the distilled water and bovine whole blood to a high flux dialyzer. Pressures at the dialyzer inlet and outlet in the blood circuit and in the dialysate circuit were measured, respectively. From these data, we calculated the transmembrane pressure and predicted the ultrafiltration and backfiltration rates developed by both pumps. Using the bovine's blood experiment, ultrafiltration and backfiltration rates were 1.6 times higher with the pulsatile pump than with the roller pump. We conclude that utilization of a pulsatile pump in high flux hemodialysis treatments increases ultrafiltration volume, compared with a roller pump under conditions of the same blood flow rate.

Magnetic-field analysis of an MHD channel in a liquid-metal circulation system of a prototype GenIV sodium fast reactor

Lee, Geun Hyeong,Kim, Hee Reyoung Elsevier 2018 Annals of nuclear energy Vol.115 No.-

<P><B>Abstract</B></P> <P>A helical-type direct current (DC) electromagnetic pump with a developed pressure of 10 kPa and flow rate of 0.005 m<SUP>3</SUP>/s was analyzed at a temperature of 226 °C for an active decay heat-removal system (ADHRS) of a prototype GenIV sodium fast reactor. The rectangular-type DC electromagnetic pump, which was selected for the ADHRS, required a very large current (>1000 A). A helical-type DC electromagnetic pump was considered to provide multiple current to a pump duct to reduce the input current requirement. The magnetic flux density of a permanent magnet is one of the important factors that determine the performance of the electromagnetic pump. The magnetic field for the flow channel of the helical-type DC electromagnetic pump was analyzed in which a Sm<SUB>2</SUB>Co<SUB>17</SUB> permanent magnet was used to generate the Lorentz force for the circulation of liquid metal. The Lorentz force, which directly affected the developed pressure of the electromagnetic pump, was increased proportional to the magnetic flux density, which led to the increase in the velocity of the liquid metal in the flow channel. The permanent magnet in the +z and −z directions and the ferromagnetic material added in the r direction increased the magnitude of the magnetic flux density, which led the magnetic flux line to the flow channel. The arrangement of the permanent magnet system showed the optimized geometry of the inner ferromagnetic material with a radius of 110 mm and outer ferromagnetic material with a thickness of 30 mm and height of 70 mm. The average value of the magnetic flux density in the liquid-metal flow channel was 0.848 T under maximum condition by considering the mechanical and spatial restrictions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The magnetic field of helical-type DC electromagnetic pump is analyzed. </LI> <LI> The additional permanent magnets along z direction increase magnetic flux density. </LI> <LI> The ferromagnetic material is analyzed to minimize the size and weight. </LI> </UL> </P>

Design analysis of DC electromagnetic pump for liquid sodium–CO₂ reaction experimental characterization

Lee, Geun Hyeong,Kim, Hee Reyoung Pergamon Press 2017 Annals of nuclear energy Vol. No.

<P><B>Abstract</B></P> <P>A DC electromagnetic pump with a rectangular channel was optimally designed and fabricated for studying the reaction between liquid sodium and carbon dioxide (CO<SUB>2</SUB>) gas in a sodium fast reactor. Heat exchange using CO<SUB>2</SUB> gas has recently been proposed for the secondary sodium loop of the sodium fast reactor being developed in Korea because of the strong chemical reaction between liquid sodium and water. A DC conduction-type electromagnetic pump with a rectangular channel was selected to circulate liquid sodium in the experimental test loop for the sodium–CO<SUB>2</SUB> reaction. Electromagnetic force, which was generated by the Lorentz force of an electrical equivalent circuit, was used to drive the liquid sodium. The developed pressure of the pump was investigated using optimization of the geometrical and electromagnetic variables of the pump considering Lorentz force, electromotive force, and hydraulic loss in the narrow channel of the pump. The characteristics of the developed pressure were studied with respect to the flow rate, and the pump was fabricated using the optimized design specifications. The distributions of current and magnetic flux density in the narrow channel were calculated for the fabricated DC electromagnetic pump with a flow rate of 3L/min and developed pressure of 0.05bar, operated at a temperature of 300°C. A comparative analysis of the performance of the designed pump was investigated by considering the fringe effects and Lorentz force using both the equivalent circuit method and numerical analysis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Rectangular DC electromagnetic pump is analyzed using equivalent circuit method. </LI> <LI> Design variables of DC electromagnetic pump are optimized. </LI> <LI> Lorentz force is calculated using distribution of current and magnetic flux density. </LI> </UL> </P>

Pumping-up Current Characteristics of Linear Type Magnetic Flux Pump

Chung, Yoondo,Muta, Itsuya,Hoshino, Tsutomu,Nakamura, Taketsune,Ko, Taekuk The Korea Institute of Applied Superconductivity a 2004 한국초전도저온공학회논문지 Vol.6 No.2

The linear type flux pump aims to compensate a little bit decremental persistent current of the HTS magnet in NMR and MRI spectrometers. The flux pump mainly consists of DC bias coil, 3-phase AC coil and Nb foil. The persistent current in closed superconductive circuit can be easily adjusted by the 3-phase AC current, its frequency and the DC bias current. In the experiment, it has been investigated that the flux pump can effectively charge the current in the load coil of 543 mH for various frequencies in 18 minutes under the DC bias of 10 A and the AC of 5 $A_{rms}$. The maximum magnitudes of pumping current and load magnet voltage are 0.72 A/min and 20 ㎷, respectively. Based on simulation results by the FEM are proved to nearly agree with experimental ones.

Review Of Groundwater Contaminant Mass Flux Measurement

Mark N. Goltz,Seh Jong Kim,Hyouk Yoon,Jun Boum Park 대한환경공학회 2007 Environmental Engineering Research Vol.12 No.4

The ability to measure groundwater contaminant flux is increasingly being recognized as crucial in order to prioritize contaminated site cleanups, estimate the efficiency of remediation technologies, measure rates of natural attenuation, and apply proper source terms to model groundwater contaminant transport. Recently, a number of methods have been developed and subsequently applied to measure contaminant mass flux in groundwater in the field. Flux measurement methods can be categorized as either point methods or integral methods. As the name suggests, point methods measure flux at a specific point or points in the subsurface. To increase confidence in the accuracy of the measurement, it is necessary to increase the number of points (and therefore, the cost) of the sampling network. Integral methods avoid this disadvantage by using pumping wells to interrogate large volumes of the subsurface. Unfortunately, integral methods are expensive because they require that large volumes of contaminated water be extracted and managed. Recent work has investigated the development of an integral method that does not require extraction of contaminated water from the subsurface. We begin with a review of the significance and importance of measuring groundwater contaminant mass flux. We then review groundwater contaminant flux measurement methods that are either currently in use or under development. Finally, we conclude with a qualitative comparison of the various flux measurement methods.

연료 송출용 제트펌프 3차원 전산해석 모델

박다인,윤진원,유상석 한국수소및신에너지학회 2017 한국수소 및 신에너지학회논문집 Vol.28 No.3

Jet pump in automotive fuel tank module is used to deliver fuel to fuel pump so that the pump is operated without aeration in suction side. In this study, three dimensional simulation model of jet pump is developed to understand performance variation over design parameters. Performance of jet pump is also investigated experimentally in terms of operating pressures. The experimental data is used to verify the three dimensional simulation model of jet pump. Verification results show that the three dimensional simulation model of jet pump is about 1% error with experiment. The simulations are conducted in terms of throat ratio and primary flow induction angle. As the throat ratio is increased, the flux ratio is trade-off at 3 times of throat diameter. On the other hand, as primary flow induction angle is increased, vapor pressure inside the nozzle is decreased. In summary, the results show that liquid jet pump has to be optimized over design parameters. Additionally, high velocity of induced flow is able to evolve cavitation phenomena inside the jet pump.

Protection properties of HTS coil charging by rotary HTS flux pump in charging and compensation modes

Seunghak Han,Ji Hyung Kim,Yoon Seok Chae,Huu Luong Quach,Yong Soo Yoon,Ho Min Kim 한국초전도저온공학회 2021 초전도와 저온공학 Vol.23 No.4

The low normal zone propagation velocity (NZPV) of high-temperature superconducting (HTS) tape leads to a quench protection problem in HTS magnet applications. To overcome this limitation, various studies were conducted on HTS coils without turn-toturn insulation (NI coils) that can achieve self-protection. On the other hand, NI coils have some disadvantages such as slow charging and discharging time. Previously, the HTS coils with turn-to-turn insulation (INS coils) were operated in power supply (PS) driven mode, which requires physical contact with the external PS at room-temperature, not in persistent current mode. When a quench occurs in INS coils, the low NZPV delays quench detection and protection, thereby damaging the coils. However, the rotary HTS flux pump supplies the DC voltage to the superconducting circuit with INS coils in a non-contact manner, which causes the INS coils to operate in a persistent current mode, while enabling quench protection. In this paper, a new protection characteristic of HTS coils is investigated with INS coils charging through the rotary HTS flux pump. To experimentally verify the quench protection characteristic of the INS coil, we investigated the current magnitude of the superconducting circuit through a quench, which was intentionally generated by thermal disturbances in the INS coil under charging or steady state. Our results confirmed the protection characteristic of INS coils using a rotary HTS flux pump.

Numerical analysis of the electromagnetic force for design optimization of a rectangular direct current electromagnetic pump

이근형,김희령 한국원자력학회 2018 Nuclear Engineering and Technology Vol.50 No.6

The force of a direct current (DC) electromagnetic pump used to transport liquid lithium was analyzed tooptimize its geometrical and electrical parameters by numerical simulation. In a heavy-ion accelerator,which is being developed in Korea, a liquid lithium film is utilized for its high charge-stripping efficiencyfor heavy ions of uranium. A DC electromagnetic pump with a flow rate of 6 cm3/s and a developedpressure of 1.5 MPa at a temperature of 200 C was required to circulate the liquid lithium to form liquidlithium films. The current and magnetic flux densities in the flow gap, where a Sm2Co17 permanentmagnet was used to generate a magnetic field, were analyzed for the electromagnetic force distributiongenerated in the pump. The pressure developed by the Lorentz force on the electromagnetic force wascalculated by considering the electromotive force and hydraulic pressure drop in the narrow flowchannel. The opposite force at the end part due to the magnetic flux density in the opposite directiondepended on the pump geometrical parameters such as the pump duct length and width that defines therectangular channels in the nonhomogeneous distributions of the current and magnetic fields.

Protection properties of HTS coil charging by rotary HTS flux pump in charging and compensation modes

Seunghak Han,Ji Hyung Kim,Yoon Seok Chae,Huu Luong Quach,Yong Soo Yoon,Ho Min Kim 한국초전도저온학회 2021 한국초전도저온공학회논문지 Vol.23 No.4

The low normal zone propagation velocity (NZPV) of high-temperature superconducting (HTS) tape leads to a quench protectionproblem in HTS magnet applications. To overcome this limitation, various studies were conducted on HTS coils without turn-toturn insulation (NI coils) that can achieve self-protection. On the other hand, NI coils have some disadvantages such as slowcharging and discharging time. Previously, the HTS coils with turn-to-turn insulation (INS coils) were operated in power supply(PS) driven mode, which requires physical contact with the external PS at room-temperature, not in persistent current mode. Whena quench occurs in INS coils, the low NZPV delays quench detection and protection, thereby damaging the coils. However, therotary HTS flux pump supplies the DC voltage to the superconducting circuit with INS coils in a non-contact manner, which causesthe INS coils to operate in a persistent current mode, while enabling quench protection. In this paper, a new protection characteristicof HTS coils is investigated with INS coils charging through the rotary HTS flux pump. To experimentally verify the quenchprotection characteristic of the INS coil, we investigated the current magnitude of the superconducting circuit through a quench,which was intentionally generated by thermal disturbances in the INS coil under charging or steady state. Our results confirmedthe protection characteristic of INS coils using a rotary HTS flux pump.

Persistent Current Mode Operation of A 2G HTS Coil With A Flux Pump

Seyeon Lee,Woo-Seok Kim,Yungil Kim,Ji-Yung Lee,Sang-Ho Park,Ji-Kwang Lee,Gye-Won Hong,Sungsoo Kim,Jinho Han,Young Jin Hwang,Kyeongdal Choi Institute of Electrical and Electronics Engineers 2016 IEEE transactions on applied superconductivity Vol.26 No.4

<P>A flux pump is a kind of power source that energizes superconducting magnets usually embedded in the cryogenic system. Therefore, heat loss through current leads is eliminated, allowing for more efficient cooling design. A winding technique, the so-called 'wind-and-flip,' had been proposed by the authors to realize a jointless HTS coil for a perfect resistanceless closed loop, which may enable to induce a persistent current in an HTS coil wound with second-generation HTS tape. In this paper, we investigated charging/discharging characteristics and a possibility of persistent current operation of a jointless HTS coil with a flux pump. Results are discussed with regard to current capacity and temporal stability with a prototype jointless HTS coil.</P>