二甲醚介电常数随温度变化特性及应用研究

Characteristics and application of dimethyl ether dielectric constant with temperature change

为了精确获得某温度下二甲醚液体的质量,研究二甲醚静态介电常数随温度的变化行为,对273K至323K温度区间二甲醚饱和液体和饱和蒸汽进行了测量。实验结果表明,二甲醚静态介电常数大小随温度存在反相关的变化规律,利用获得的实验数据拟合得到在不同温度下二甲醚液体的介电常数变化曲线。二甲醚饱和蒸汽在温度区间277.5K^318K下,介电常数较大且几乎无变化。在圆柱形电容式传感器模型中进行二甲醚液体液位测量的实验验证,实验计算值与实际观测值之间的误差分布在3.7%~6.5%。应用实验结果,借鉴二甲醚饱和蒸汽与饱和液体密度与温度之间的关系数据,便可精确求出在某温度下二甲醚液体的质量。文中的研究成果对二甲醚工业燃料的应用与控制起到基础性作用。

Saturated liquid and saturated steam of dimethyl ether （DME） were measured with the change of temperature from 273 K to 323 K to accurately obtain the quality of DME liquid under certain temperature and the change of DME static dielectric constant with temperature. The experimental results showed that DME stat- ic dielectric constant was negatively correlated with the temperature change and DME liquid dielectric constant change curve in different temperatures was obtained by fitting of experimental data. In the temperature range of 277.5 K to 318 K, DME liquid saturated steam dielectric constant was large and almost did not change. DME liquid level was measured in cylindrical capacitance sensor model and the results showed the error between the experiment calculated values and the observed value distributed in 3.7% - 6.5%. Applicationl experiment showed that the quality of DME liquid under a certain temperature can be accurately calculated with the refer- ence of the relational data between density and temperature of DME saturated steam and saturated liquid. The research achievements play a fundamental role in the application and control of industrial fuel DME.