Transient heat transfer from a wire to a forced flow of subcooled liquid hydrogen passing through a vertically-mounted pipe

Tatsumoto, Hideki; Shirai, Yasuyuki*; Shiotsu, Masahiro*; Naruo, Yoshihiro*; Kobayashi, Hiroaki*; Nonaka, Satoshi*; Inatani, Yoshifumi*

IOP Conference Series; Materials Science and Engineering, 101, p.012177_1 - 012177_8, 2015/12

https://doi.org/10.1088/1757-899X/101/1/012177

Transient heat transfers from PtCo wire heaters inserted into vertically-mounted pipes, through which forced flow subcooled liquid hydrogen was passed, were measured by increasing the exponential heat input with various time periods at a pressure of 0.7 MPa and inlet temperature of 21 K. The flow velocities ranged from 0.3 to 7 m/s. The PtCo wire heaters had a diameter of 1.2 mm and lengths of 60 mm, 120 mm and 200 mm and were inserted into the pipes with diameters of 5.7mm, 8.0 mm, and 5.0 mm, respectively. With increase in the heat flux to the onset of nucleate boiling, surface temperature increased along the curve predicted by the Dittus-Boelter correlation for longer period, where it can be almost regarded as steady-state. For shorter period, the heat transfer became higher than the Dittus-Boelter correlation. In nucleate boiling regime, the heat flux steeply increased to the transient critical heat flux (CHF), which became higher for shorter period. Effect of flow velocity, period, and heated geometry on the transient CHF was clarified.

Pressure and temperature fluctuation simulation of J-PARC cryogenic hydrogen system

Tatsumoto, Hideki; Otsu, Kiichi; Aso, Tomokazu; Kawakami, Yoshihiko

IOP Conference Series; Materials Science and Engineering, 101, p.012109_1 - 012109_8, 2015/12

https://doi.org/10.1088/1757-899X/101/1/012109

The J-PARC cryogenic hydrogen system provides supercritical cryogenic hydrogen to the moderators at a pressure of 1.5 MPa and temperature of 18 K and removes 3.8 kW of nuclear heat from the 1 MW proton beam operation. We prepared a heater for thermal compensation and an accumulator, with a bellows structure for volume control, to mitigate the pressure fluctuation caused by switching the proton beam on and off. In this study, a 1-D simulation code named DiSC-SH2 was developed to understand the propagation of pressure and temperature propagations through the hydrogen loop due to on and off switching of the proton beam. We confirmed that the simulated dynamic behaviors in the hydrogen loop for 300-kW and 500-kW proton beam operations agree well with the experimental data under the same conditions.

Effect of change of aging heat treatment pattern on the JK2LB jacket for the ITER central solenoid

Ozeki, Hidemasa; Saito, Toru; Kawano, Katsumi; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Yamazaki, Toru; Isono, Takaaki

Physics Procedia, 67, p.1010 - 1015, 2015/07

https://doi.org/10.1016/j.phpro.2015.06.190

Accuracy of prediction method of cryogenic tensile strength for austenitic stainless steels in ITER toroidal field coil structure

Sakurai, Takeru; Iguchi, Masahide; Nakahira, Masataka; Saito, Toru*; Morimoto, Masaaki*; Inagaki, Takashi*; Hong, Y.-S.*; Matsui, Kunihiro; Hemmi, Tsutomu; Kajitani, Hideki; et al.

Physics Procedia, 67, p.536 - 542, 2015/07

https://doi.org/10.1016/j.phpro.2015.06.072

Japan Atomic Energy Agency (JAEA) has developed the tensile strength prediction method at liquid helium temperature (4K) using the quadratic curve as a function of the content of carbon and nitrogen in order to establish the rationalized quality control of the austenitic stainless steel used in the ITER superconducting coil operating at 4K. ITER is under construction aiming to verify technical demonstration of a nuclear fusion generation. Toroidal Field Coil (TFC), one of superconducting system in ITER, have been started procurement of materials in 2012. JAEA is producing materials for actual product which are the forged materials with shape of rectangle, round bar, asymmetry and etc. JAEA has responsibility to procure all ITER TFC Structures. In this process, JAEA obtained many tensile strength of both room temperature and 4K about these structural materials, for example, JJ1: High manganese stainless steel for structure (0.03C-12Cr-12Ni-10Mn-5Mo- 0.24N) and 316LN: High nitrogen containing stainless steel (0.2Nitrogen). Based on these data, accuracy of 4K strength prediction method for actual TFC Structure materials was evaluated and reported in this study.

Forced convection heat transfer of saturated liquid hydrogen in vertically-mounted heated pipes

Tatsumoto, Hideki; Shirai, Yasuyuki*; Shiotsu, Masahiro*; Hata, Koichi*; Naruo, Yoshihiro*; Kobayashi, Hiroaki*; Inatani, Yoshifumi*

AIP Conference Proceedings 1573, p.44 - 51, 2014/01

https://doi.org/10.1063/1.4860681

Heat transfers from the inner side of vertically-mounted heated pipes to forced flow of saturated liquid hydrogen were measured with a quasi-steady increase of a heat generation rate for wide ranges of flow rate and saturated pressure. The tube heaters have lengths L of 100 mm and 167 mm with the diameter D of 4 mm and lengths of 150 mm and 250 mm with the diameter of 6 mm. The heat fluxes at departure from nucleate boiling (DNB) were higher for higher flow velocity, lower pressures and shorter L/D. The effect of L/D on the DNB heat flux was clarified. It is confirmed that our DNB correlation can describe the experimental data.

Evaluation of inter-laminar shear strength of GFRP composed of bonded glass/polyimide tapes and cyanate-ester/epoxy blended resin for ITER TF coils

Hemmi, Tsutomu; Nishimura, Arata*; Matsui, Kunihiro; Koizumi, Norikiyo; Nishijima, Shigehiro*; Shikama, Tatsuo*

AIP Conference Proceedings 1574, p.154 - 161, 2014/01

https://doi.org/10.1063/1.4860618

Japan Atomic Energy Agency (JAEA), as Japan Domestic Agency, has responsibility to procure 9 ITER Toroidal Field (TF) coils. The insulation system of the ITER TF coils consists of 3 layers of insulations, which are a conductor insulation, a double-pancake (DP) insulation and a ground insulation, composed of multi-layer glass/polyimide tapes impregnated a resin. The ITER TF coils are required to withstand an irradiation of 10 MGy from -ray and neutrons since the ITER TF coils is exposed by first neutron ( 0.1 MeV) of 10 n/m during the operation of 20 years in the ITER. Cyanate-ester/epoxy blended resins and bonded glass/polyimide tapes are developed as insulation materials to realize the required radiation-hardness for the insulation of the ITER TF coils. To evaluate the radiation-hardness of the developed insulation materials, the inter-laminar shear strength of glass-fiber reinforced plastics (GFRP) fabricated using developed insulation materials is measured as one of most important mechanical properties before/after the irradiation in a fission reactor of JRR-3. As a result, it is demonstrated that the GFRPs using the developed insulation materials have a sufficient performance to apply the ITER TF coil insulation.

Estimation of tensile strengths at 4K of 316LN forging and hot rolled plate for the ITER toroidal field coils

Iguchi, Masahide; Saito, Toru; Kawano, Katsumi; Takano, Katsutoshi; Tsutsumi, Fumiaki; Chida, Yutaka; Nakajima, Hideo

AIP Conference Proceedings 1435, p.70 - 77, 2012/06

https://doi.org/10.1063/1.4712082

A prediction method for tensile strengths at liquid helium temperature (4K) has been developed in order to rationalize qualification tests of cryogenic structural materials used in large superconducting magnet for a fusion device. This method is to use quadratic curves which are expressed as a function of carbon and nitrogen contents and strengths at room temperature. This study shows results of tensile tests at 4K and confirmation of accuracy of prediction method for tensile strengths at 4K for large forgings and thick hot rolled plates of austenitic stainless steels, which can be used in the actual coil case and radial plates of the ITER toroidal field coils. These products are 316LN having high nitrogen from 0.09 to 0.24% and maximum thickness is 600mm. As the results, it was confirmed that the tensile strengths of these products at 4K can be predicted by using appropriate quadratic curves. And distribution of strengths for each product was estimated.

Forced convection heat transfer of subcooled liquid hydrogen in a small tube

Tatsumoto, Hideki; Shirai, Yasuyuki*; Shiotsu, Masahiro*; Hata, Koichi*; Kobayashi, Hiroaki*; Naruo, Yoshihiro*; Inatani, Yoshifumi*; Kato, Takashi; Futakawa, Masatoshi; Kinoshita, Katsuhiro*

Proceedings of International Cryogenic Engineering Conference 23 (ICEC-23) and International Cryogenic Materials Conference 2010 (ICMC 2010), p.491 - 496, 2010/07

Forced flow heat transfers of liquid hydrogen through a vertical tube with the diameter, d, of 3.0 mm were measured at the pressure of 0.7 MPa for various inlet temperatures and flow velocities. The non-boiling heat transfer coefficients agreed with those by the Dittus-Boelter correlation. The heat fluxes at the inception of boiling and the departure from nucleate boiling (DNB) heat fluxes were higher for higher flow velocity and subcooling. The DNB heat fluxes were higher for larger diameter, compared with those for = 6.0 mm. The effect of tube diameter and subcooling on the DNB heat flux was clarified.

Performance test of a centrifugal supercritical hydrogen pump

Tatsumoto, Hideki; Aso, Tomokazu; Otsu, Kiichi; Uehara, Toshiaki; Sakurayama, Hisashi; Kawakami, Yoshihiko; Kato, Takashi; Futakawa, Masatoshi; Yoshinaga, Seiichiro*

Proceedings of International Cryogenic Engineering Conference 23 (ICEC-23) and International Cryogenic Materials Conference 2010 (ICMC 2010), p.377 - 382, 2010/07

A dynamic gas bearing centrifugal pump that circulated supercritical hydrogen with a large flow rate of more than 0.16 kg/s was developed to minimize the hydrogen density change at the moderator. The two pumps were simultaneously operated in parallel for redundancy. The performance test results indicated that the dimensionless characteristics for the single and the parallel operations existed on an identical curve. An outstanding peak adiabatic efficiency exited at the flow coefficient of 0.046, independently of the revolution. It was verified that the developed hydrogen pump satisfied the design requirement.

Development of the cryogenic hydrogen system for a spallation neutron source in J-PARC

Tatsumoto, Hideki; Aso, Tomokazu; Otsu, Kiichi; Uehara, Toshiaki; Sakurayama, Hisashi; Kawakami, Yoshihiko; Kato, Takashi; Futakawa, Masatoshi

AIP Conference Proceedings 1218, p.297 - 304, 2010/04

https://doi.org/10.1063/1.3422367

In JSNS, supercritical hydrogen at around 20 K and 1.5 MPa was selected as a moderator material. Three kinds of hydrogen moderators are installed to provide pulsed neutron beam with higher neutronic performance. A cryogenic hydrogen system, in which a hydrogen circulation system is cooled by a helium refrigerator system with the refrigerator capacity of 6.45 kW at 15.6 K, provides the supercritical hydrogen to the moderators and absorbs nuclear heating in the moderators. Through the off-beam commissioning, we have confirmed that the cryogenic hydrogen system can be cooled down to 18 K within 19 hours. The supercritical hydrogen with the mass flow rate of 190 g/s can be circulated at the rated condition. It is verified that the cryogenic hydrogen system is satisfied with the performance requirements. In May 2008, we have succeeded in providing the first cold neutron beam cooled by the cryogenic hydrogen system.