| Автор | Graves, R., S. |
| Автор | Yarbrough, D., W. |
| Автор | McElroy, D., L. |
| Дата выпуска | 1985 |
| dc.description | An unguarded longitudinal heat flow apparatus for measuring the apparent thermal conductivity (Λ<sub>α</sub>) of insulations was tested with mean specimen temperatures from 300 to 330°K on samples up to 0.91 m wide, 1.52 m long, and 0.15 m thick. Heat flow is provided by a horizontal electrically heated Nichrome screen that is sandwiched between test samples that are bounded by temperature controlled copper plates and 9 cm of mineral fiber insulation. A determinate error analysis shows Λ<sub>α</sub> measurement uncertainty to be less than ± 1.7% for insulating materials as thin as 3 cm. Three-dimensional thermal modeling indicates negligible error in Λ<sub>α</sub> due to edge loss for insulations up to 7.62 cm thick when the temperature difference across the sample is measured at the screen center. System repeatability and reproducibility were determined to be ± 0.2%.Differences of Λ<sub>α</sub> results from the screen tester and results from the National Bureau of Standards were 0.1% for a 10-kg/m<sup>3</sup> Calibration Transfer Standard and 0.9% for 127-kg/m<sup>3</sup> fibrous glass board (SRM 1450b). Measurements on fiberglass and rock wool batt insulations showed the dependence of Λ<sub>α</sub> on density, temperature, temperature difference, plate emittance, and heat flow direction. Results obtained for Λ<sub>α</sub> as a function of density at 24°C differed by less than 2% from values obtained with a guarded hot plate.These results demonstrate that this simple technique has the accuracy and sensitivity needed for useful Λ<sub>α</sub> measurements on thermal insulating materials. |
| Издатель | SAGE Publications |
| Название | Apparent Thermal Conductivity Measurements by an Unguarded Technique |
| Тип | Journal Article |
| DOI | 10.1177/174425918500900206 |
| Electronic ISSN | 1744-2583 |
| Print ISSN | 1744-2591 |
| Журнал | Journal of Building Physics |
| Том | 9 |
| Первая страница | 123 |
| Последняя страница | 139 |
| Аффилиация | Graves, R., S., Martin Marietta Energy Systems, Inc. Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge, Tennessee 37831 |
| Аффилиация | Yarbrough, D., W., Martin Marietta Energy Systems, Inc. Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge, Tennessee 37831 |
| Аффилиация | McElroy, D., L., Martin Marietta Energy Systems, Inc. Metals and Ceramics Division Oak Ridge National Laboratory Oak Ridge, Tennessee 37831 |
| Выпуск | 2 |
| Библиографическая ссылка | 1. Jury, S. H., McElroy, D. L., and Moore, J. P., “Pipe Insulation Testers,” Thermal Transmission Measurements of Insulation, ASTM STP 660, R. P. Tye (ed.), American Society for Testing and Materials, pp. 310–326 (1978). |
| Библиографическая ссылка | 2. Moore, J. P., McElroy, D. L., and Jury, S. H., A Technique for Measuring the Apparent Thermal Conductivity of Flat Insulations, ORNL/TM-6494, Oak Ridge National Laboratory, Oak Ridge, TN (October 1974). |
| Библиографическая ссылка | 3. Moore, J. P., McElroy, D. L., and Jury, S. H., “A Technique for Measuring the Apparent Thermal Conductivity of Flat Insulations,” Thermal Conductivity, 17, J. G. Hust (ed.), Plenum Publishing Corporation, pp. 727–735 (1983). |
| Библиографическая ссылка | 4. Niven, C. and Geddes, A. E. M., “On a Method for Finding the Conductivity for Heat,” Proc. Roy. Soc., London, A87, 535–539 (1912). |
| Библиографическая ссылка | 5. Gilbo, C. F., “Experiments with a Guarded Hot Plate Thermal Conductivity Set,” ASTM Special Technical Publication No. 119, 45 (1951). |
| Библиографическая ссылка | 6. Hager, N. E., Jr., “Thin Heater Thermal Conductivity Apparatus,” Rev. Sci. Instrum., 37(2), 177–185 (Feb. 1960). |
| Библиографическая ссылка | 7. Hager, N. E., Jr., U.S. Patent No. 3,045,473 (July 24, 1962). |
| Библиографическая ссылка | 8. Hager, N. E., Jr., “Minature Thin-Heater Thermal Conductivity Apparatus,” ISA Transactions, 8(2), 104–109 (1969). |
| Библиографическая ссылка | 9. Turner, W. D., Elrod, D. C., and Siman-Tov, I. I., HEATING5—An IBM 360 Heat Conduction Program, ORNL/CSD/TM-15, Oak Ridge National Laboratory, Oak Ridge, TN (March 1977). |
| Библиографическая ссылка | 10. Report of Test on Thermal Resistance of Glass-Fiber Insulation, U.S. Department of Commerce, National Bureau of Standards, F. J. Powell to D. L. McElroy, Purchase Order 21X-48695 (May 10, 1983). |
| Библиографическая ссылка | 11. Excerpt from Reference 10, “The uncertainty in the thermal resistance values is estimated to be not more than +0.5 percent and includes apparatus systematic error and apparatus repeatability.” |
| Библиографическая ссылка | 12. Phoenix Wire Cloth, Inc., 40 × 40 Per Inch Nichrome V Wire, 0.010 Inch, P.O. Box 610, Troy, Michigan 48084. |
| Библиографическая ссылка | 13. Leeds and Northrup, Philadelphia, PA, 0.01 Standard Resistor Model No. 4361, 100 amps dc current rating. |
| Библиографическая ссылка | 14. Hewlett Packard DC Power Supply Model 6260B (10V, 100A). |
| Библиографическая ссылка | 15. Leeds and Northrup K-5 Potentiometer with 1.6 Volt Accuracy of +(0.001% + 2μV). |
| Библиографическая ссылка | 16. Astrodyne, Inc., Thermal Bond 312, Burlington, MA. |
| Библиографическая ссылка | 17. B. Braun Instruments, Thermomix 1480 and Frigomix 1495, San Mateo, CA. |
| Библиографическая ссылка | 18. Fisher and Porter Company, Warminister, PA 18974, Flowrator Meter Model 10A1755XZ. |
| Библиографическая ссылка | 19. McElroy, D. L., Graves, R. S., Yarbrough, D. W., and Moore, J. P., “A Flat Insulation Tester that Uses an Unguarded Nichrome Screen Wire Heater,” Forum on the Guarded Hot Box Plate and Heat Flow Meter State-of-the-Art, Quebec City, Quebec, Canada (October 7–8, 1982). |
| Библиографическая ссылка | 20. Moore, J. P., Williams, R. K., and Graves, R. S., “Precision Measurements of the Thermal Conductivity, Electrical Resistivity, and Seebeck Coefficient from 80 to 400 K and Their Application to Pure Molybdenum,” Rev. Sci. Instrum., 45(1), 87–95 (1974). |
| Библиографическая ссылка | 21. Tye, R. P., Desjarlais, A. O., Yarbrough, D. W., and McElroy, D. L., An Experimental Study of Thermal Resistance Values (R-Values) of Low-Density Mineral-Fiber Building Insulation Batts Commercially Available in 1977, ORNL/TM-7266 (April 1980). |
| Библиографическая ссылка | 22. Touloukian, Y. S., Liley, P. E., and Saxena, S. C., Thermophysical Properties of Matter, 3, Plenum Publishing Corp., New York, p. 512 (1970). |
