0
Research Papers

Spray-Formed, Metal-Foam Heat Exchangers for High Temperature Applications

[+] Author and Article Information
H. R. Salimi Jazi

Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran; Centre for Advanced Coating Technologies, University of Toronto, Toronto, M5S 3G8, Canada

J. Mostaghimi, S. Chandra, L. Pershin, T. Coyle

Centre for Advanced Coating Technologies, University of Toronto, Toronto, M5S 3G8, Canada

J. Thermal Sci. Eng. Appl 1(3), 031008 (Apr 06, 2010) (7 pages) doi:10.1115/1.4001049 History: Received July 01, 2009; Revised January 07, 2010; Published April 06, 2010; Online April 06, 2010

Open pore metal foams make efficient heat exchanger because of their high thermal conductivity and low permeability. This study describes a novel method of using wire-arc spraying to deposit Inconel 625 skins on the surface of sheets of 10 and 20 pores per linear inch nickel foam. The skins adhere strongly to the foam struts, giving high heat-transfer rates. Tests were done to determine the hydraulic and thermal characteristics of the heat exchangers and correlations developed to calculate Fanning friction factor and Nusselt number as a function of Reynolds number for airflow through the foam. Measured heat-transfer coefficients for the foam heat exchangers are greater than those of straight flow channels at the same flow rate. A ceramic thermal barrier coating was deposited on one face of the heat exchanger using plasma spraying. The coating and heat exchanger survived prolonged exposure to the flame of a methane-air burner.

FIGURES IN THIS ARTICLE
<>
Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

(a) 20 PPI nickel foam and (b) nickel foam with ceramic (lower sample) or metallic coating (upper sample)

Grahic Jump Location
Figure 2

SEM micrographs of the metallic skin deposited by wire-arc spraying and YSZ deposited by APS

Grahic Jump Location
Figure 3

10 mm thick, 10 PPI nickel foam with end caps attached in the shape of (a) a flat plate and (b) a section of a cylinder

Grahic Jump Location
Figure 4

Schematic of the experimental apparatus used to measure the characteristics of the skin coated nickel foam heat exchangers

Grahic Jump Location
Figure 5

Burner rig experiment set up

Grahic Jump Location
Figure 6

Variation in pressure drop with air velocity for the 10 and 20 PPI nickel foam heat exchangers

Grahic Jump Location
Figure 7

Variation in Fanning friction factor f with Re number for 10 and 20 PPI foam heat exchangers

Grahic Jump Location
Figure 8

Increase in air temperature flowing through the 20 PPI foam heat exchanger at various coolant flow velocities. Inlet temperature was approximately 25°C.

Grahic Jump Location
Figure 9

Temperature differences between the hot side and cold side of the 20 PPI foam heat exchanger at various hot side temperatures

Grahic Jump Location
Figure 10

Outlet air temperature and heat exchanger cold side temperature for the 10 and 20 PPI foam heat exchangers at various air flow velocities. The hot surface temperature was kept constant at 500°C.

Grahic Jump Location
Figure 11

Variation in Nusselt number with coolant flow velocities at various hot side temperatures in (a) 10 PPI foam heat exchanger and (b) 20 PPI foam heat exchanger

Grahic Jump Location
Figure 12

Cold side temperature of the 10 PPI foam heat exchanger, with and without TBC, as a function of air velocity

Grahic Jump Location
Figure 13

Temperature variations versus time in the burner rig experiment. T1: temperature of back (cold) surface close to the entrance, T2: temperature of back surface opposite the flame impingement point, T3: temperature of back surface close to the exit, and Tair,out: temperature of the coolant air at exit.

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