热重法分析不同纳米CeO_2粒径和添加量对燃油热动力学的影响  

Thermodynamics of fuels with different CeO_2 sizes and addition amount based on thermogravimetric analysis

作　　者：梅德清[1] 孙潮 王子胥 陈志宇 陈晨 陶俊 Mei Deqing;Sun Chao;Wang Zixu;Chen Zhiyu;Chen Chen;Tao Jun(School of Automobile and Traffic Engineering,Jiangsu University,Zhenjiang 212013,China;Jiangsu Su Yang Package Company Limited by Shares,Yangzhou,211400,China)

机构地区：[1]江苏大学汽车与交通工程学院,镇江212013 [2]江苏苏扬包装股份有限公司,扬州211400

出　　处：《农业工程学报》2018年第16期65-70,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(51506101);江苏高校品牌专业建设工程资助项目(苏政发办[2014]82号);江苏省科技厅重点研发计划项目(BE2016139)

摘　　要：采用恒温热重法研究纳米燃油的蒸发特性,并求解纳米燃油蒸发过程的活化能、蒸气压和蒸发焓等热动力学参数。以正十四烷(C14)作为基液燃油、十六烷基三甲基溴化铵为分散剂,配制粒径分别为20和50 nm、质量分数分别为50和100 mg/L的CeO_2纳米燃油。结果表明:在燃油蒸发过程中,由于纳米粒子具有较低的比热容,从外界吸收的热量被加快向液体内部传递,延滞了气液自由界面处液体分子的挥发,因此纳米燃油蒸发需要更大的活化能,且随着纳米粒子尺度减小或质量分数增加而增大,20 nm Ce50、20 nm Ce100、50 nm Ce50和50 nm Ce100纳米燃油较基液分别增大了5.6%,9.3%,3.2%和6.8%。纳米粒子的加入增大了燃油的表面张力,阻滞液相分子向气相扩散,因而其蒸气压降低,其中20nm Ce100纳米燃油较C14降低了18.1%。此外,由于燃油分子与纳米粒子之间的范德华力及氢键作用,纳米燃油蒸发所需的蒸发焓升高,20 nm Ce100纳米燃油较基液增大了16.7%。纳米燃油热力学基础物性参数研究可为其应用提供重要的基础数据。By the combination of physical dispersion and chemical dispersion methods,various types of nano-fuel blend containing 20 and 50 nm CeO2 with the dosing levels of 50 and 100 mg/L(20nmCe50,20nmCe100,50nmCe50 and 50nmCe100)were prepared,in which the pure tetradecane(C14)served as the base fuel to surrogate diesel and the CTAB worked as the surface active agent to prevent agglomeration by altering the surface properties of suspended nanoparticles.The evaporation characteristics of various nano-fuel blend and C14 were investigated using isothermogravimetrical analysis.According to the boiling point of C14,the evaporation experiments were performed at different constant temperatures ranging from 100 to 140℃with an interval of 5℃,and each isothermal section was held for 10 min.The principles to determine the activation energy,vapor pressure and vaporization enthalpy of nano-fuel were also briefly described.Based on isothermal thermogravimetry experimental data,the activation energy needed for fuel evaporation was figured out by the Arrhenius equation,the vapor pressure at various temperatures was calculated according to the Antoine and Langmuir equations,and the vaporization enthalpy was solved by correlating the Clausius-Clapeyron equation with the vapor pressure.It is revealed that owing to the lower specific heat capacity of nanoparticles,during the fuel evaporation the heat transfer from the outside to the inside was accelerated,which delayed the volatilization of fuel molecules located at gas-liquid surface.As a result,for nano-fuels,the activation energy needed for vaporization increases with the decrease in nanoparticle size or the increase in nanoparticle mass fraction.The 20nmCe50,20nmCe100,50nmCe50 and 50nmCe100 nano-fuel are increased by 5.6%,9.3%,3.2%and 6.8%respectively compared with that of the base C14.Moreover,the presence of nanoparticles in fuel leads to an increase of the surface tension,and the postponing of the diffusion of fuel molecules into gas.Therefore,the nano-fuel has a lower vapor pressu

关 键 词：纳米 燃油 热动力学 二氧化铈 恒温热重法 活化能 蒸气压 蒸发焓 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]