Research And Development Of Thermophysical Properties Testing Device For Loose Coal And Uncertainty Study

Thermophysical properties have always been the focus of research at home and abroad,widely spread in various disciplines and closely related to the development of our industry and agriculture.It is a basic parameter to study the heat storage,heat transfer and thermal conductivity of an object.In this paper,scientific calculation method and experimental test method are mainly used to study the thermophysical parameters of materials.Therefore,only uncertainty analysis can make the accuracy of the whole measurement result and the use value of the test device have a complete meaning.In this paper,a method based on the unsteady heat conduction product heat transfer model to measure the thermal physical properties of loose coal under constant temperature boundary heat source is presented.The mathematical model was established,the parameter inversion numerical solution method was used to write the solution program combined with MATLAB software,and finally the other thermal physical property values were inverted.According to the theory and physical model,a set of equipment for measuring the thermal properties of loose coal under the action of a constant temperature water bath heat source is developed Respectively using statistical analysis and uncertainty evaluation method,to analyze the uncertainty of the test system evaluation,statistical analysis of the possible existence of uncertainty factors,choose the anthracite as standard sample to be tested for thermal physical properties,the thermal physical parameters of matches the basic experimental data and references,verified the effectiveness of the results from this test system.Based on the thermal properties data of anthracite,Pan-Yi mine coal,Kong-Li coal and Gas-Fat coal,the uncertainty analysis and evaluation of the whole test platform test system are carried out.It is found that the anthracite and Pan-Yi mine coal with low thermal diffusivity have an average synthetic uncertainty of less than 2.6%and extended uncertainty of less than 4.75%,while the coal Kong-Li and Gas-Fat coal with high thermal diffusivity have an average synthetic uncertainty of less than 6%and extended uncertainty of less than 10.3%.The feasibility of the thermal physical property test system for the loose coal,the scientific nature of the mathematical model derivation and the accuracy of the experimental calculation results are explained,and the main factors affecting the uncertainty of the experimental test accuracy are obtained.Finally,thermal property based on the analysis of test results found that the thermal diffusivity of loose coal measure value and literature reference value relative deviation are less than 5%,and the thermal diffusion rate of about 1.5(10-7 m2/s)Kong-Li coal the stability of the test results is better than other materials for many times,and the thermal diffusion rate of about 1.75(10-7 m2/s)Gas-Fat coal test results of the stability of the high.Again,therefore,this device is more suitable for testing small thermal diffusivity of loose coal(general thermal diffusion rate is less than 2(10-7 m2/s)),and the uncertainty of tested samples is low.Figure[64]Table[18]Reference[90]...