Test method for thermal conductivity of refractory materials

　　The thermal conductivity of refractories is one of the important indicators to evaluate their thermal conductivity. The following are two commonly used test methods to measure the thermal conductivity of refractory materials:

　　1. Flat plate heat flow method:

       The flat plate method is a commonly used experimental method, which is suitable for testing the thermal conductivity of block or plate refractory materials.

　　1.1. Experimental principle: The sample is prepared in the form of a flat plate and tested under a constant temperature difference. The thermal conductivity is calculated by measuring the temperature difference across the sample and the applied heat flux.

　　1.2. Experimental steps:

　　a. Prepare flat samples: Cut the refractory material into flat samples of specified size.

　　b. Set up the experimental setup: Place the sample in the setup between the heat source and the cool source, ensuring good thermal contact.

　　c. Apply heat flow: apply a certain heat flow to the sample through the heating source.

　　d. Measure the temperature difference: Use a temperature sensor to measure the temperature difference on both sides of the sample.

　　e. Calculate the thermal conductivity: Calculate the thermal conductivity based on the experimental data and the heat conduction equation.

　　2. Guarded Hot Plate Method:

      The hot plate method is a more accurate method that can be used to measure the thermal conductivity of refractory materials of various shapes, including thin plates, powders and coatings.

　　2.1. Experimental principle: The sample is clamped between two hot plates, one of which applies a constant heat flux, and the other keeps a constant temperature. The thermal conductivity is calculated by measuring the temperature difference between the two hot plates and the applied heat flux.

　　2.2. Experimental steps:

　　a. Prepare samples: prepare samples according to the experimental requirements.

　　b. Set up the experimental setup: Sandwich the sample between two hot plates to ensure good thermal contact.

　　c. Apply heat flow: apply a certain heat flow to the sample through the heating plate.

　　d. Measure the temperature difference: Use a temperature sensor to measure the temperature difference between the two hot plates.

　　e. Calculate the thermal conductivity: Calculate the thermal conductivity based on the experimental data and the heat conduction equation.

　　Key points to note in these test methods include ensuring good thermal contact, accurate measurement of temperature differences and corresponding heat fluxes, and application of appropriate heat transfer equations for calculations. In order to obtain accurate thermal conductivity data, it is recommended to carry out under standardized experimental conditions and follow relevant international or industry norms and standards, such as ASTM, ISO, etc.