Heat transfer performance of cryogenic oscillating heat pipes for effective cooling of superconducting magnets

Natsume, Kyohei; Mito, T.; Yanagi, N.; Tamura, H.; Tamada, T.; Sueoka, Koji; Hirano, Naoki; Nagàya, Shigeo

doi:10.1016/j.cryogenics.2010.07.001

Cited by 65 publications

(16 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ever-changing pressure field and fluid phase induces the chaotic displacement and circulation of the internal working fluid. The performance (running limits [2], temperature oscillation [3], heat transfer resistance ) of an OHP is known to depend on working fluid [4][5], filling ratio [6], channel geometry, number of serpentine-arranged turns, operating orientation, heating/cooling methods [7][8][9] and application [10][11][12][13]. Furthermore, the investigation was also carried on by simulation or theory.…”

Section: Introductionmentioning

confidence: 99%

Influence of filling ratio and working fluid thermal properties on starting up and heat transferring performance of closed loop plate oscillating heat pipe with parallel channels

Shi

Pan

2017

J. Therm. Sci.

View full text Add to dashboard Cite

Using ethanol or acetone as the working fluid, the performance of starting up and heat transfer of closed-loop plate oscillating heat pipe with parallel channels (POHP-PC) were experimentally investigated by varying filling ratio, inclination, working fluids and heating power. The performance of the tested pulsating heat pipe was mainly evaluated by thermal resistance and wall temperature. Heating copper block and cold water bath were adopted in the experimental investigations. It was found that oscillating heat pipe with filling ratio of 50% started up earlier than that with 70% when heating input was 159.4 W, however, it has similar starting up performance with filling ratio of 50% as compared to 70% on the condition of heat input of 205.4 W. And heat pipe with filling ratio of 10% could not start up but directly transit to dry burning. A reasonable filling ratio range of 35%-70% was needed in order to achieve better performance, and there are different optimal filling ratios with different heating inputs -the more heating input, the higher optimal filling ratio, and vice versa. However, the dry burning appeared easily with low filling ratio, especially at very low filling ratio, such as 10%. And higher filling ratio, such as 70%, resulted in higher heat transfer ( dry burning ) limit. With filling ratio of 70% and inclination of 75°, oscillating heat pipe with acetone started up with heating input of just 24W, but for ethanol, it needed to be achieved 68 W, Furthermore, the start time with acetone was similar as compared to that with ethanol. For steady operating state, the heating input with acetone was about 80 W, but it transited to dry burning state when heating input was greater than 160 W. However, for ethanol, the heating input was in vicinity of 160 W. Furthermore, thermal resistance with acetone was lower than that with ethanol at the same heating input of 120 W.

show abstract

Section: Introductionmentioning

confidence: 99%

Influence of filling ratio and working fluid thermal properties on starting up and heat transferring performance of closed loop plate oscillating heat pipe with parallel channels

Shi

Pan

2017

J. Therm. Sci.

View full text Add to dashboard Cite

show abstract

“…Stable operations of the cryogenic OHP within the wide operational ranges has been confirmed [4], [5]. In addition, it has been shown to have high heat transport characteristics which surpass those of high-purity metals.…”

Section: A Proof-of-principle Experimentsmentioning

confidence: 95%

“…In this respect, the operating characteristics of the proto-type OHPs were examined by changing the installation orientation [6] using the experimental setup shown in Fig. 8.…”

Section: B Effects Of the Installation Orientationmentioning

confidence: 99%

Achievement of High Heat Removal Characteristics of Superconducting Magnets With Imbedded Oscillating Heat Pipes

Mito

Natsume

Yanagi

et al. 2011

IEEE Trans. Appl. Supercond.

Self Cite

View full text Add to dashboard Cite

Oscillating heat pipes (OHP) for cryogenic use are being developed to improve the heat removal characteristics of high-temperature superconducting (HTS) magnets. It is generally difficult to remove the heat generated in HTS windings, because the thermal diffusivities of component materials decrease with an increase of the operating temperature. Therefore, a local hot-spot can be rather easily generated in HTS magnets, and there are possibilities of observing degradation of superconducting properties and/or mechanical damages by thermal stresses. As a new cooling technology to enhance the heat removal characteristics in HTS magnets, the cryogenic OHP is proposed to be imbedded in magnet windings. The feasibility of cryogenic OHP has been confirmed by fabricating proto-types and by observing stable operations using hydrogen, neon and nitrogen as the working fluid. A high thermal conductivity was achieved that surpasses those of high-purity metals. We also propose a modified-type OHP to mitigate the orientation dependence.The OHP has a long capillary which is bent into many turns and a working fluid with two-phase mixture is filled inside the capillary as shown in Fig. 1. The OHP is a highly efficient two-phase heat transporting device which can transport the amount of heat several orders of magnitude greater than that by thermal conduction in solid metals. In order to effectively cool HTS magnets, it is required that cryogenic OHPs can operate in a variety of installation orientations. The operating characteristics of the proto-type OHPs were examined by changing the installation orientation using the experimental setup shown in Fig. 2. The measured effective thermal conductivities are summarized in Table 1.

show abstract

“…In practical use, it can be often seen that an HTS is referred to as a material with a critical temperature above 77 K as it allows employment of liquid nitrogen (LN2) as the cryogenic liquid in practical applications. Given that LN2 is readily available and relatively cheap in comparison with competing cryogenic solutions, most notably helium used for high field applications such as powerful magnets, as they allow for wider adoption of HTS [3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Nanosized Pinning Centers in the Rare Earth-Barium-Copper-Oxide Thin-Film Superconductors

et al. 2020

View full text Add to dashboard Cite

Since the discovery of high-temperature superconductivity, significant progress in the fabrication of REBCO-based (Rare Earth Barium Copper mixed Oxides) thin-films superconductors has been achieved. In our review, we described the approaches and possibilities of the improvement of superconducting properties by the introduction of nanosized pinning centers. We focused on the synthesis and viability of the material for artificial pinning centers and methods used for the introduction of the pinning centers into superconducting REBCO-based thin-films. This article summarizes available materials and procedures regardless of the financial cost of the individual method. According to available literature, the most significant superconducting REBCO tapes can be obtained when a combination of 1D and 0D nanoparticles are used for nanoscale pinning.

show abstract

Heat transfer performance of cryogenic oscillating heat pipes for effective cooling of superconducting magnets

Cited by 65 publications

References 8 publications

Influence of filling ratio and working fluid thermal properties on starting up and heat transferring performance of closed loop plate oscillating heat pipe with parallel channels

Influence of filling ratio and working fluid thermal properties on starting up and heat transferring performance of closed loop plate oscillating heat pipe with parallel channels

Achievement of High Heat Removal Characteristics of Superconducting Magnets With Imbedded Oscillating Heat Pipes

Nanosized Pinning Centers in the Rare Earth-Barium-Copper-Oxide Thin-Film Superconductors

Contact Info

Product

Resources

About