Pressure Drop Reduction of Slush Nitrogen in Turbulent Pipe Flows

Ohira, K.; Nozawa, Masakazu; Ishimoto, Jun; Koizumi, Noriko; Kamiya, Tamotsu

doi:10.1063/1.2908657

Cited by 7 publications

(2 citation statements)

References 8 publications

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“…The precise study of two-phase pipe flow of slush nitrogen (SN 2 ) is now being performed by our research group [10]. In that study, the pressure drop reduction phenomenon of two-phase slush nitrogen is mainly focused on to investigate the optimized working fluid velocity of SN 2 cooling in application to an actual HTS cable.…”

Section: Experimental Systemmentioning

confidence: 99%

Development of production system of cryogenic micro-slush particles using a two-fluid nozzle

Ishimoto

2008

International Communications in Heat and Mass Transfer

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Section: Experimental Systemmentioning

confidence: 99%

Development of production system of cryogenic micro-slush particles using a two-fluid nozzle

Ishimoto

2008

International Communications in Heat and Mass Transfer

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“…に示す23,24) 。入口流速を U in = 1.5、2.0、3.0、4.0、 5.0 m/s、初期体積固相率をα s = 0.05、0.13、0.20、0.25 として、流速、固相率が変化する場合の流動・伝熱構造を解析した。著者がフリーズ・ソー法にて製造したスラッシュ窒素の固体粒子径(絶対最大値)の平均値は 1.36 mm4,6) …”

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Numerical Study of Flow and Heat-transfer Characteristics of Cryogenic Slush Fluid in a Horizontal Circular Pipe (SLUSH-3D)

勝秀¹,

敦人²,

康晃³

et al. 2011

TEION KOGAKU

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Cryogenic slush fluids, such as slush hydrogen and slush nitrogen, are two-phase, single-component fluids containing solid particles in a liquid. Since their density and refrigerant capacity are greater than those of liquid-state fluids alone, there are high expectations for use of slush fluids as functional thermal fluids in various applications, such as fuels for spacecraft engines, clean energy fuels to improve the efficiency of transportation and storage, and as refrigerants for high-temperature superconducting equipment. In this research, a three-dimensional numerical simulation code (SLUSH-3D), including the gravity effect based on the thermal non-equilibrium, two-fluid model, was constructed to clarify the flow and heat-transfer characteristics of cryogenic slush fluids in a horizontal circular pipe. The calculated results of slush nitrogen flow performed using the numerical code were compared with the authors' experimental results obtained using the PIV method. As a result of these comparisons, the numerical code was verified, making it possible to analyze the flow and heat-transfer characteristics of slush nitrogen with sufficient accuracy. The numerical results obtained for the flow and heat-transfer characteristics of slush nitrogen and slush hydrogen clarified the effects of the pipe inlet velocity, solid fraction, solid particle size, and heat flux on the flow pattern, solidfraction distribution, turbulence energy, pressure drop, and heat-transfer coefficient. Furthermore, it became clear that the difference of the flow and heat-transfer characteristics between slush nitrogen and slush hydrogen were caused to a large extent by their thermo-physical properties, such as the solid-liquid density ratio, liquid viscosity, and latent heat of fusion. Keywords: slush nitrogen, slush hydrogen, solid-liquid two-phase flow, turbulent pipe flow, hydrogen energy 1. はじめに極低温固液二相スラッシュ流体は、高密度流体、冷媒として優れた特性を持っている。スラッシュ流体の実用上代表的なものとして、温度 14 K のスラッシュ水素と温度 63 K のスラッシュ窒素がある。重量固相率 50 wt.%(体積固相率 47 vol.%)のスラッシュ水素の場合、温度 20 K の液体水素と比較して密度が 16%、寒冷保有量(エンタルピ)が 18%増加する。重量固相率 50 wt.%(46 vol.%)のスラッシュ窒素もスラッシュ水素と同様、密度が 16%、寒冷保有量が 22%増加する。スラッシュ水素を利用すると、水素の効率的な輸送、貯蔵が可能になると共に、機器の高性能化、小型・軽量化が期待できる。燃料電池の飛躍的な普及、情報技術による電力需要増加に鑑み、著者は Fig. 1 に示す水素エネルギーシステムを提案して 1) 、図中の左上に示す研究・開発を実施してきた。水素をスラッシュ水素の形態で長距離(パイプライン)輸送する際、MgB 2 を利用した超伝導送電および超伝導電力貯蔵と組み合わせると、燃料と電力の輸送および貯蔵が同時に可能となる。即ち、シナジー効果が期待できる。また、極低温スラッシュ流体が配管中を流動する際、侵入熱や超伝導線のクエンチによる発熱がある場合、熱の一部は固体

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Numerical study of cryogenic micro-slush particle production using a two-fluid nozzle

Ishimoto

2009

Cryogenics

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Pressure Drop Reduction of Slush Nitrogen in Turbulent Pipe Flows

Cited by 7 publications

References 8 publications

Development of production system of cryogenic micro-slush particles using a two-fluid nozzle

Development of production system of cryogenic micro-slush particles using a two-fluid nozzle

Numerical Study of Flow and Heat-transfer Characteristics of Cryogenic Slush Fluid in a Horizontal Circular Pipe (SLUSH-3D)

Numerical study of cryogenic micro-slush particle production using a two-fluid nozzle

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