Study On Thermal Conductivity Of N-Decane And N-Dodecane

Since the 21 st century,with the rapid development of the national economy and the increasing population,China is facing increasingly serious problems such as energy shortage,rising oil prices,environmental pollution,etc.The search for clean alternative fuels has attracted great attention of the industry.At present,petroleum is widely used in national production and life,and its main component is alkanes.Therefore,it has certain engineering significance and practical value for the thermophysical study of alkanes in petroleum.Thermal conductivity is one of the most important thermophysical properties of materials.It is not only the basis of thermal calculation,but also the premise of reasonable engineering design.Transient hot wire method is widely used in measuring thermal conductivity because of its advantages of simple operation and accurate measurement results.Therefore,the thermal conductivity of alkanes is experimentally studied by using the transient hot-wire method.The main contents are as follows:1.Calibration and validation of the thermal conductivity meter by toluene show that the repeatability and maximum deviation of the experimental values of toluene are less than 1% under the conditions of 0.1 MPa and 253-373 k,which proves that the accuracy and reliability of the thermal conductivity meter are good.2.Under 253-373 k and 0.1-30 MPa working conditions,the thermal conductivity of n-decane was experimentally studied by using the developed thermal conductivity instrument.The repeatability of the experimental results was less than 1%,and the maximum deviation was-1.48%.The experimental results show that the thermal conductivity of n-decane is inversely proportional to temperature at the same pressure,and is proportional to pressure at the same temperature.3.Under 273-393 k and 0.1-30 MPa working conditions,the thermal conductivity of n-dodecane was experimentally studied by using the developed thermal conductivity instrument.The experimental results were within 1% repeatability and the maximum deviation was-0.64%.According to the experimental results,it can be concluded that the thermal conductivity of n-decane is inversely proportional to temperature at the same pressure,and is proportional to pressure at the same temperature.4.The experimental results of the two substances show that the thermal conductivity increases with the increase of the number of carbon atoms under the same working condition.In this paper,data processing software is used to fit the experimental data of thermal conductivity under different temperatures and pressures into the correlations of temperature and pressure.The thermal conductivity can be easily calculated under any working condition within the applicable range of the equation,which provides reliable physical data for future scientific research and engineering applications.The instrument for measuring the thermal conductivity of transient double hot wires developed and designed in this paper has high accuracy and good reproducibility,and can be popularized and applied.