在Hagen-Poiseuille定律的基础上，利用双毛细管法，设计了一套适用于液态碳氢燃料高压低温粘度测量实验系统，测量压力：0.1~10 MPa，温度测量范围：233.35~313.75K，扩展相对不确定度为：2.10%~5.08%（置信因子k=2）。实验在利用纯物质正己烷和质量比1:1正庚烷-正辛烷二元混合物对测量系统可靠性进行验证的基础上，测试了两种碳氢燃料A、B压力0.7、1.5、3和6 MPa，温度：233.55~313.65 K下的粘度值，结果表明：在相同压力下，两种燃料的粘度值随温度的增加而减小；在233.55~273.25 K附近，两种燃料粘度值随温度的变化率要大于273.25~313.65 K，表明低温区碳氢燃料A、B粘度受温度的影响比高温区大，且温度越低温度的影响程度越大；在233.55~273.25 K低温区范围内，燃料A粘度值受温度的影响程度要小于燃料B。实验中还发现，当温度接近231.25 K时，燃料B在毛细管中瞬间凝固，系统压力急剧升高，而燃料A在此温度下依然处于液态。在相同温度下，两种燃料的粘度值随着压力的增加稍有增大。此套高压低温粘度测量系统简单可靠，测量精度高，能够实现液态碳氢燃料高压低温粘度的在线测量。

Based on Hagen-Poiseuille’s law and using double capillary method,a viscosity measurement system of liquid hydrocarbon fuels was designed for low temperature and high pressure conditions,with test pressure of 0.1~10 MPa and temperature range of 233.35~313.75 K.The expanded relative uncertainty of the system was 2.10%~5.08%(the coverage factor k=2).Firstly,the pure substance n-hexane and the binary mixture of n-heptane and n-octane with the mass ratio 1:1 were used to calibrate the viscosity measurement system,then two kinds of hydrocarbon fuels named A and B were measured at pressure of 0.7 MPa,1.5 MPa,3.0 MPa and 6.0 MPa and temperature from 233.55 K to 313.65 K.The results showed that under the same pressure,the viscosities of the two fuels decrease with temperature in the vicinity of temperature 233.55~273.25 K,and the changing rate of the viscosity is greater than that in the 273.25~313.65 K,indicating that the viscosity of hydrocarbon fuel A and B is more influenced by temperature in the low temperature zone than that in high temperature zone,and the lower the temperature is,the more evident the viscosity is affected. In the other hand,the viscosity of hydrocarbon fuel A is less influenced by the temperature than that of hydrocarbon fuel B in the low temperature region 233.55~273.25 K.The experiment also showed that when the temperature is close to 231.25 K,hydrocarbon fuel B is solidified suddenly,and the system pressure increased sharply,while the fuel A was still under the liquid state at this temperature.At the same temperature,the viscosities of the two fuels increase slightly with pressure. The presented viscosity measurement system is simple and reliable,and enables online viscosity measurement for liquid hydrocarbon fuel at high pressure and low temperature conditions with high measurement accuracy.

TK311

青年科学基金项目（21306147）；国家博士后科学基金项目（2013M532044）