0
Research Papers

Experiments on Thermosyphon Loops for Low-Temperature Waste-Heat Recovery

[+] Author and Article Information
Koji Matsubara

Department of Mechanical and
Production Engineering,
Niigata University,
Ikarashi 2-nocho 8050,
Niigata 950-2181, Japan
e-mail: matsu@eng.niigata-u.ac.jp

Suguru Tachikawa, Yusaku Matsudaira

Department of Mechanical and
Production Engineering,
Niigata University,
Ikarashi 2-nocho 8050,
Niigata 950-2181, Japan

Itaru Kourakata

Institute for Research
Collaboration and Promotion,
Niigata University,
Ikarashi 2-nocho 8050,
Niigata 950-2181, Japan

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS. Manuscript received October 1, 2013; final manuscript received April 2, 2014; published online May 9, 2014. Assoc. Editor: Hongbin Ma.

J. Thermal Sci. Eng. Appl 6(4), 041006 (May 09, 2014) (8 pages) Paper No: TSEA-13-1165; doi: 10.1115/1.4027417 History: Received October 01, 2013; Revised April 02, 2014

We tested a thermosyphon loop with water as the working fluid using heating rates between 100 W and 400 W. Four kinds of core blocks were installed in the evaporator and tested: a hollow block, and blocks with narrow holes: Φ 2.2 mm × 90; Φ 2.5 mm × 55; and Φ 4.0 mm × 30. The temperature distribution indicated stable flow circulation inside the thermosyphon at low volume ratios but was unstable when the volume ratio was increased higher than 30%. The characteristics of the flow pattern are summarized as a flow map showing the heating rate versus the volume ratio. The recovered heat and the thermal resistance of the thermosyphon loop were clearly improved by using the core blocks with narrow holes instead of hollow blocks for the treated volume ratios from 20% to 80%. The thermal resistance increased when the volume ratio reached high values, suggesting that the effects from the abnormality of the flow circulation affected thermal resistance. The velocity of the gas stream in the thermosyphon was estimated by assuming an isothermal state, and it is diagrammed showing the heating rate at different temperatures. The current experiment of the thermosyphon loop is plotted in this diagram, which indicates the need for a wide margin due to the limitations of the sonic velocity and the pressure head at the full height of the heat pipe.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Experimental setup: (a) schematic and (b) photograph

Grahic Jump Location
Fig. 2

Evaporator: (a) cross-section and (b) core block

Grahic Jump Location
Fig. 3

Temperature distribution in case 1

Grahic Jump Location
Fig. 4

Temperature distribution in case 2

Grahic Jump Location
Fig. 5

Temperature distribution in case 3

Grahic Jump Location
Fig. 6

Temperature distribution in case 4

Grahic Jump Location
Fig. 7

Flow map: (a) case 1, (b) case 2, (c) case 3, and (d) case 4

Grahic Jump Location
Fig. 12

Heat flow maps of experimental values (α = 30%): (a) heat flow map of mass flow rate and (b) heat flow map of gas phase velocity

Grahic Jump Location
Fig. 11

Specific volume, quality, and real volume ratio: (a) specific volume, (b) quality, and (c) real volume ratio

Grahic Jump Location
Fig. 10

Thermal resistance in relation with volume ratio of water: (a) Qh = 120 W, (b) Qh = 235 W, and (c) Qh = 390 W

Grahic Jump Location
Fig. 9

Amount of recovered heat against volume ratio of water: (a) Qh = 120 W, (b) Qh = 235 W, and (c) Qh = 390 W

Grahic Jump Location
Fig. 8

Amount of recovered heat at the condenser compared with heating rate: (a) case 1, (b) case 2, (c) case 3, and (d) case 4

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In