A high-temperature and high-pressure dual-capillary viscometer
was developed to measure the dynamic viscosity of liquid and supercritical
coal-based kerosene in the temperature range of 299.6–678.8
K and pressure range of 0.3–40.4 MPa. The extended relative
uncertainty of the measurement results ranged from 0.8–5% (confidence
factor k = 2). Using the differential of the pressure
drop across the capillary with flow rate in the viscosity derivation,
rather than the pressure drop directly, gave better experimental precision.
The measurement accuracy was validated using cyclohexane and toluene
as standard fluids; the absolute average deviations (AADs) were 1.7%
for cyclohexane at 0.3–20.0 MPa and 321.8–576.6 K and
2.0% for toluene at 0.3–40.6 MPa and 285.3–315.8 K.
The effects of temperature and pressure on the viscosity of coal-based
kerosene were investigated using four parameters: isobaric viscosity
change rate, viscosity-temperature coefficient, isothermal viscosity
change rate, and viscosity-pressure coefficient. It was found that
the viscosity-temperature coefficient curves of coal-based kerosene
intersect each other at different pressures, which are of great significance
for the establishment of viscosity predictive models. Based on the
characteristics of the kerosene η–T curve,
we proposed a new modified Arrhenius–Andrade model and introduce
the pressure term into the model. Compared with the modified VFT model
and 10-parameter nonlinear surface model, the modified Arrhenius–Andrade
model best fitted the experimental data with AAD of 1.6%.