Absolute Steady-State Thermal Conductivity Measurement of insulation Materials Using Square Guarded Hot Plate Apparatus

摘要

An absolute steady-state thermal conductivity measurement of fibrous and non-fibrous insulation materials is carried out using Square Guarded Hot Plate (SGHP) apparatus. The light weight fibrous insulating blankets (25 kg/m{sup}3 to 190 kg/m{sup}3) as well as the heavy insulating slabs (1800 kg/m{sup}3 to 2000 kg/m{sup}3) of 300 mm × 300 mm size specimens are considered for the thermal conductivity measurement. The thermal conductivities of fibrous insulation blanket and heavy insulating plates are found in the range of 0.0357 to 0.112 ± 0 0028 W/m.K and 0.050 to 0.239 ± 0.0048 W/m.K respectively. The thermal conductivity data obtained from measurements are compared with analytical model for various heavy insulating plates. The results are in good agreement with the analytical model with maximum deviation of ± 21 % for heavy insulating plates. An uncertainty analysis yields a combined measurement uncertainty of ± 5.75 % at no flow condition. The steady-state square guarded hot plate apparatus can be used effectively to estimate the effective thermal conductivity for all types of insulation materials.