A Simplified Model for Effective Thermal Conductivity of Highly Porous Ceramic Fiber Insulation

Keywords

Porous ceramic fiber insulation, Thermophysical model, Effective thermal conductivity, Natural convection, High temperature applications

Abstract

Highly porous ceramic fiber insulations are beginning to be considered as a replacement for firebrick insulations in high temperature, high pressure applications by the chemical process industry. However, the implementation of such materials has been impeded by a lack of experimental data and predictive models, especially at high gas pressure. The goal of this work was to develop a general, applied thermophysical model to predict effective thermal conductivity, keff, of porous ceramic fiber insulation materials and to determine the temperature, pressure, and gas conditions under which natural convection is a possible mode of heat transfer. A model was developed which calculates keff as the sum of conduction, convection, and radiation partial conductivities. The model was validated using available experimental data, including laboratory measurements made by this research effort. Overall, it was concluded that natural convection is indeed possible for the most porous insulations at pressures exceeding 10 atm. Furthermore, keff for some example insulations was determined as a function of temperature, pressure, and gas environment.

Original Publication Citation

Nicholas P. G. Lumley, Emory Ford, Eric Minford, Jason M. Porter, A Simplified Model for Effective Thermal Conductivity of Highly Porous Ceramic Fiber Insulation, J. Thermal Sci. Eng. Appl, (2015) vol. 7, no. 4, pp. 041022-041022.

Document Type

Peer-Reviewed Article

Publication Date

2015-10

Publisher

Journal of Thermal Science and Engineering Applications

Language

English

College

Ira A. Fulton College of Engineering and Technology

Department

Mechanical Engineering

University Standing at Time of Publication

Associate Professor

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