Effects of flow orientations on the coking characteristic of jet fuel RP-3

In order to investigate the effects of flow orientations on surface coke deposition of oxygen-saturation RP-3 fuel flowing through a single-channel heated stainless-steel tubes. The system pressure was 5 MPa and the mass flow rate was 780 kg/(m²·s). Experiments were conducted for different tube orientations, namely: horizontal, vertical with flow from bottom to top and vice versa. High outlet temperature and high pressure were utilized to simulate actual working conditions. The amount of surface coke deposition was obtained by weighting method. The results show that, the deposition initially increases and then decreases with fuel temperature under different flow orientations, and the location of coking peak value moves by gravity along the experimental segment, but the shapes of surface coke deposition distribution curve are similar, and total deposition is the same.