Keywords
heat conductivity coefficient
pipe apparatus
thermal measurements
experimental research
How to Cite
Abstract
The aim of the work was to design and build a laboratory measuring stand for determining the thermal conductivity coefficient of insulation laggings with an annular cross-sectional area and a specific length. This is a particularly important issue in the case of district heating pipelines, where thermal insulation plays a significant role in the correct operation of the installation. Measurement of the thermal conductivity coefficient of insulating covers on the constructed test stand is based on the tubular method, which consists in solving the differential equation of steady heat conduction in a cylindrical partition of infinite length. The stand is equipped with two measuring sections, where it is possible to simultaneously measure two different samples of the tested insulation. Initial thermal measurements of various insulation materials were carried out on each section separately and on both sections launched simultaneously. On the basis of the performed measurements, it was possible to verify the correctness of the construction and operation of the measuring station, as well as to validate the measurement method used. Temperature measurements were also made with the use of a thermal imaging camera, which made it possible to determine the temperature distribution in the measuring sections. The obtained values of the thermal conductivity coefficient of the tested insulation materials were compared with the catalog values of these materials and the possible discrepancy of the results was analyzed.
References
Furmański P., Wiśniewski T.S., Banaszek J., Izolacje cieplne. Mechanizmy wymiany ciepła, właściwości cieplne i ich pomiary, Instytut Techniki Cieplnej, Politechnika Warszawska, Warszawa 2006.
Górzyński J., Przemysłowe izolacje cieplne, wyd. Sorus, Poznań 1996.
Tychanicz-Kwiecień M., Wilk J., Gil P., Review of High Temperature Thermal Insulation Materials, Journal of Thermophysics and Heat Transfer 33(11):1-13 August 2018.
Kulesza J. i in., Pomiary cieplne – część I: podstawowe pomiary cieplne, Wydawnictwa Naukowo-Techniczne, Warszawa 2001.
Wulf R., Barth G., Gross U., Intercomparison of Insulation Thermal Conductivities Measured by Various Methods, International Journal of Thermophysics (2007) 28:1679-1692.
Yüksel N., The Review of Some Commonly Used Methods and Techniques to Measure the Thermal Conductivity of Insulation Materials, Insulation Materials in Context of Sustainability (2016).
Zehendner H., Thermal Conductivity of Thermal Insulation Materials on Pipes, Journal of Thermal Insulation, Vol. 7, July 1983.
Cremaschi L., Shanshan C., Worthington K., Ghajar A.J., 2012. Measurements of Pipe Insulation Thermal Conductivity at Below Ambient Temperatures Part I: Experimental Methodology and Dry Tests. ASHRAE Transactions. 118(1):1061-1076.
Carlson J.D., Bhardwaj R., Phelan P.E., Kaloush K.E., Golden J.S., Determining Thermal Conductivity of Paving Materials Using Cylindrical Sample Geometry, Journal of Materials in Civil Engineering 2010.22:186-195.
Iyengar A.S., Abramson A.R., Comparative Radial Heat Flow Method foe Thermal conductivity Measurement of Liquids, Journal of Heat Transfer June 2009, Vol. 131/064502-1.
Flynn D.R., A Radial-Flow Apparatus for Determining the Thermal conductivity of Loose-Fill Insulations to High Temperatures, Journal of Research of the National Bureau of Standards-C. Engineering and Instrumentation, Vol. 67C, No. 2, April-June 1963.
Williams R.K., Radial Heat Flow Thermal Conductivity Apparatus for Measurements on Sulfide and Telluride Melts, The Review of Scientific Instruments, Vol. 39, No. 8 August 1968.
Fesmire J.E. et all, Apparatus and method for thermal performance testing of pipelines and piping systems, United States Patent US 6,715,914 B1, April 2004.
Wesołowski A., Urządzenia chłodnicze i kriogeniczne oraz ich pomiary cieplne, Wydawnictwa Naukowo-Techniczne, Warszawa 1980.