高压肉豆蔻酸甲酯比定压热容的实验测量

Experimental study on isobaric specific heat capacities of methyl myristate at elevated pressures

采用流动型量热法实验系统测量了肉豆蔻酸甲酯的比定压热容,温度测量范围为323.20~393.26K,压力测量范围为0.11~25.12MPa。实验系统的温度和压力扩展不确定度分别为0.02K和5kPa,比定压热容的相对扩展不确定度为1.45%。基于实验数据,建立了一个可用于高压肉豆蔻酸甲酯比定压热容的计算关联式,其计算值与实验值的相对偏差绝对平均值为0.13%,最大偏差为0.38%。

The biodiesel, comprised of fatty acid methyl ester and ethyl ester, is considered as an environment-friendly and promising alternative of fuel. The thermophysical properties of biodiesels as well as their components are essential information for the better knowledge of their industrial applications. For instance, in the spray and combustion processes of engine, isobaric specific heat capacity (cp) of fuel has a significant influence on its heat-transfer characteristic. In this work, the cp of methyl myristate are investigated using a flow calorimeter at the temperature range of 323.20-393.26 K and pressures up to 25.12 MPa. The expanded uncertainties of temperature and pressure are decided to be 0.02 K and 5 kPa respectively, while the relative expanded uncertainty of cp is 1.45%. Then based on the experimental data, a correlation is proposed for calculating the cp of methyl myristate, and a satisfactory agreement between calculated results and experimental values can be observed, with the average absolute relative deviation and maximum deviation of 0.13% and 0.38% respectively.