Experimental Research On Thermal Conductivity Of Alternative Fuel

With the excessive dependence on fossil energy,the global energy crisis is becoming increasingly severe.In addition,in the process of fossil energy utilization,excessive emissions of combustion products such as inhalable particulate matter and greenhouse gases have caused serious environmental pollution and global warming.In the face of the increasingly serious energy crisis and environmental and climate problems,the development of alternative fuels has become a research hotspot.Biodiesel is a novel environmentally friendly alternative energy source,and its main component is long-chain fatty acid esters with carbon numbers range from C6 to C24.It is considered as a high-quality alternative fuel.Scholars from various countries have carried out extensive research on it,which is an important direction of energy development and utilization.Thermal conductivity is an important thermophysical property of fuel,which is essential for thermal design and internal combustion engine optimization.However,the research on thermal conductivity of alternative fuel biodiesel is still rare.The main purpose of this paper is to provide urgently needed thermal conductivity data and calculation equations for the large-scale application of biodiesel as a green energy alternative fuel and in-depth research in other thermal design fields.The thermal conductivity of alternative fuels was studied by using the transient single hot-wire thermal conductivity experimental system.The main achievements are as follows:1.An experimental system for measuring the thermal conductivity of liquid is established based on the transient single hot-wire method.The experimental system was tested with pure water at the pressure range of 0.1Mpa to 15 Mpa and the temperature range of 300 K to 340 K.The maximum relative deviation between the experimental value and the reference value is-0.72%,and the average absolute deviation is 0.33%.The results show that the measurement results of the experimental system are accurate and reliable,and the system can be used to measure the thermal conductivity of other liquids.The expanded uncertainty of the experimental system is less than 2%(confidence level 0.95),and the repeatability is better than ±0.5%.2.The liquid phase thermal conductivity of methyl nonanoate,methyl enanthate and methyl caproate was studied experimentally at the pressure range of 0.1Mpa to 15 mpa and the temperature range of 272 K to 352 K.The thermal conductivity was fitted to an equation about temperature and pressure.The maximum relative deviations between the experimental values and the calculated values of the fitting equation were-0.18%,0.12% and-0.07%,respectively,and the average absolute deviations were 0.06%,0.05% and 0.02%,respectively.3.The liquid phase thermal conductivity of binary mixtures of methyl caprate,ethyl caprate and n-dodecane was studied experimentally at the pressure of 0.1MPa and the temperature range of 292 K to 362 K.Based on the experimental data of thermal conductivity,three classical equations for calculating the liquid phase thermal conductivity of binary mixtures were optimized to calculate the thermal conductivity of binary mixtures at any concentration ratio.The maximum relative deviations between the experimental values and the calculated values of the improved three classical equations were 0.48% and-0.53%,respectively.4.The liquid phase thermal conductivity of binary mixtures of ethyl laurate with n-propanol,n-butanol and n-pentanol was studied experimentally at the pressure of 0.1MPa and temperature range of 292 K to 362 K.Based on the experimental data of thermal conductivity,three classical equations for calculating the liquid phase thermal conductivity of binary mixtures.The maximum relative deviations of the thermal conductivity of the binary mixture of ethyl laurate and n-propanol,n-butanol,and n-pentanol from the calculated values of the improved three classical equations were-0.64%,-0.52% and 0.35%,respectively.