The through-plane thermal conductivity of many components of a fuel cell, dry Nafion®, various diffusion medias and catalyst layers are studied. The thermal contact resistance between the diffusion media and a metal plate with respect to temperature and pressure was also determined. The measurements were made with a guarded heat flow meter device. The least accurate measurement was of the Toray carbon ...
This paper introduces a compensation algorithm and a different-layers calibration method that will improve the temperature measurement speed and thermal resistance elimination of a guarded heat flow meter instrument. Without these additions to the method, heat will travel through a thin slice of material too fast for thermal couples to measure accurately. Thermal contact resistance would cause inaccuracy with a thin slice ...
A new analysis method based on the guarded heat flow meter apparatus is proposed to measure the thermal properties of cement-based pastes in a hydrated form. In a steady state, a specimen with 0.4 water-to-cement ratio was found to have a thermal conductivity and a thermal contact resistance of 1.28Wm−1 K−1 and 0.038 m−2 KW−1. A computerized system of heat flow meters provided non-steady ...
The variability within the results presented from the guarded hot-plate (GHP) and guarded heat-flow meter (GHF) methods was determined. Multiple thermal properties of polymethyl methacrylate (PMMA) were analyzed to compare methods. These measurements are taken in the range of −70◦C and +80◦C. Providing reference data for PMMA is the main objective of this paper as well as quantifying the effects of thermal contact of the measuring instruments....
In this paper, a new method is proposed for measuring the through plane thermal conductivity of two catalyst layers of different thicknesses by the guarded heat flow meter (GHF) method, and the transient plane source method (TPS). These catalyst layers were made from two catalyst-coated substrates. The effects of pressing, and hot pressing the layers were also studied and shown to have ...
