0

Full Content is available to subscribers

Subscribe/Learn More  >

Improving Biporous Heat Transfer by Addition of Monoporous Interface Layer

[+] Author Affiliations
Sean W. Reilly, Ivan Catton

University of California, Los Angeles, Los Angeles, CA

Paper No. HT2009-88257, pp. 327-333; 7 pages
doi:10.1115/HT2009-88257
From:
  • ASME 2009 Heat Transfer Summer Conference collocated with the InterPACK09 and 3rd Energy Sustainability Conferences
  • Volume 3: Combustion, Fire and Reacting Flow; Heat Transfer in Multiphase Systems; Heat Transfer in Transport Phenomena in Manufacturing and Materials Processing; Heat and Mass Transfer in Biotechnology; Low Temperature Heat Transfer; Environmental Heat Transfer; Heat Transfer Education; Visualization of Heat Transfer
  • San Francisco, California, USA, July 19–23, 2009
  • Conference Sponsors: Heat Transfer Division
  • ISBN: 978-0-7918-4358-1 | eISBN: 978-0-7918-3851-8
  • Copyright © 2009 by ASME

abstract

Biporous evaporator wicks, generated by sintering copper particles into semi-uniform clusters, were demonstrated to achieve high flux, heat transfer performance for use in heat pipes by Semenic (2007). The effective thermal conductivity of thick biporous wicks at high heat fluxes was found to be reduced because the region next to the wall dried out prematurely allowing the wall interface temperature to rise well above the saturation temperature. The region above the dried out portion of the wick continued to work with the large pores between the clusters being primarily occupied with vapor and the small pores between the particles being occupied with the liquid. In this work, we report our efforts to reduce the size of the wall-wick interface dry-out region by sintering a thin layer of uniform size particles on the wall as originally suggested in a thesis by Seminic (2007). The boiling curve for this “double layer” wick diverges from a standard “single layer” biporous wick at the point of nucleation by reducing the wall temperature, and concurrently the overall temperature drop across the wick needed to drive a given heat flux. The temperature drop across the wick is reduced because the thin layer of particles between the biporous wick and the wall reduces the wall-wick interface resistance and also provides additional capillary channels underneath the biporous wick. Experimental data supports this hypothesis by showing a clear divergence between measured wall temperatures for the double layer wick from its single layer counterpart. The presumed point of nucleation in both wicks is similar, with the heat flux increasing much more rapidly than the liquid superheat and it is clear that this slope is much steeper for the double layer wick. This finding has great potential to expand the performance capabilities of heat pipes and vapor chambers because the new double layered wick can transfer more heat with less superheat thereby increasing the effective thermal conductivity of the wick and decreasing the wall-wick interface temperature for a given heat flux.

Copyright © 2009 by ASME
Topics: Heat transfer

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

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 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