Investigation of amplification process of heavy oil viscosity reduction device based on jet cavitation using lab experimental and numerical simulation method

With the increasing requirement of global energy resources, researchers seek for new ways to deal with unconventional crude oil resources. Using the Computational Fluid Dynamics numerical simulation method, the standard k-e turbulence model and the cavitation dynamics model are used to simulate the internal flow field of the 10(5)t/a heavy oil viscosity reduction spray nozzle device which is designed by the jet cavitation theory. The jet cavitation intensity is evaluated by cavitation number and gas content. The influence of spray nozzle structural parameters such as inlet diameter, contraction length, expansion cone angle and expansion length on the cavitation effect of the spray nozzle are studied. The results show that the cavitation effect is the best when the inlet diameter, contraction section length, expansion section cone angle, and expansion section length of the large capacity device are 120 mm, 110 mm, 10 degrees, and 150 mm, respectively. A laboratory test device with a processing capacity of 2000 t/a is built to conduct jet cavitation test on a batch of Saudi crude oil to obtain the change rate of crude oil viscosity, density and molecular weight. The numerical results are consistent with the outcome of laboratory experiments, and it is concluded that this spray nozzle can meet the needs of large processing capacity while ensuring a high cavitation rate.