INSTALLATION FOR STUDYING THERMAL CONDUCTIVITY OF POWDER-VACUUM AND SCREEN-VACUUM HEAT INSULATION

摘要

FIELD: testing equipment. ;SUBSTANCE: invention relates to the field of testing equipment, namely to the creation of installations for the experimental determination of the thermal characteristics of powder-vacuum and screen-vacuum thermal insulation used for thermal protection of construction objects, objects of military, space and cryogenic technology, as well as in other sectors of the national economy. An installation for determining the effective thermal conductivity of powder-vacuum and screen-vacuum thermal insulation contains a heat source, means for measuring the temperature on the hot and cold sides of the sample from the material under study, and pumps of various types to achieve the required vacuum. Effective thermal conductivity is determined on samples of powder-vacuum and screen-vacuum thermal insulation, which are placed in a vacuum chamber consisting of 2 or 3-piece concentric spheres or hemispheres of different diameters with an electric heater acting inside a smaller sphere or hemisphere located in a heat-conducting electric insulator and associated with the device for recording the power it produces, while the two outer hemispheres form an additional evacuated cavity and have a selective coating on the outer and inner surfaces with a reflection coefficient ρ of 0.75-0.95. ;EFFECT: increasing reliability of the results of measurements of the effective thermal conductivity of powder-vacuum and screen-vacuum thermal insulation.;5 cl, 12 dwg