A Laboratory Apparatus to Determine Fluid-Solid Heat Transfer Coefficient and Effective Thermal Conductivity of Solid Porous Media
A single-blow apparatus was designed and built to specifically eliminate most systematic errors in characterizing thermal properties of solid porous media. By matching temperature profiles calculated from the solid-fluid transient energy balance in a porous bed to experimental profiles, the heat transfer coefficient between solid and fluid and the effective longitudinal thermal conductivity can be determined. The specifications of such an apparatus require strict accounting of sources of heat leak and other systematic errors. Here, we present a detailed study in identifying and minimizing these systematic errors. Details on the design, construction and testing of this apparatus are shown, including utilization of low thermal conductivity materials for components, and meticulous design and construction of temperature probes. We also present for the first time a methodology to correct for parasitic heat leaks inherently present in the system. This correction procedure to correct the temperature profiles eliminates the effect of the major systematic errors. This apparatus is being used as a screening-design tool to characterize overall effectiveness of high performance regenerators for regenerative cycle refrigerators and liquefiers.
KeywordsHeat Transfer Coefficient Thermal Resistance Effective Thermal Conductivity Temperature Probe Thermal Mass
Unable to display preview. Download preview PDF.
- 2.K. Kratschmar. “The Development of a Cryogenic Regenerator Test Apparatus”, M.Sc. Thesis, University of Victoria, Victoria, BC (1995).Google Scholar
- 3.J.H. Stang. “The Periodic Technique for Testing Compact Heat Exchanger Surfaces”, M.Sc. Thesis, Marquette University, Milwaukee, WI (1968).Google Scholar
- 4.K.J. Caudle. “Characterization of Regenerator Geometries Through Modeling and Experimentation”, M.Sc. Thesis, University of Victoria, Victoria, BC (1997).Google Scholar
- 5.A. Frydman, and J.A. Barclay, Proceedings of the Cryogenic Eng. Conference, Montreal (1999). To be published.Google Scholar
- 6.W.H. McAdams. “Heat Transmission”, 3rd ed., McGraw-Hill Book Co., N.Y. (1954).Google Scholar
- 8.DSM Engineering Plastics Product, Inc. (company’s catalog), printed in USA (1997).Google Scholar
- 9.E. Oberg, F.D. Jones, H.L. Horton, and H.H. Ryffel. “Machinery’s Handbook”, 25th ed., Industrial Press Inc., N.Y., 24 (1996).Google Scholar