Effects of RP-3's wall coke deposition on flow resistance under supercritical pressure

The effect of the jet fuel RP-3 coking deposition in stainless micro-tube on flow resistance and heat transfer characteristics under long heating condition is analyzed based on experimental results. In the experiment, fuel flowing through miniature tube was heated from 130℃ to 450℃ under the pressure 5 MPa when dissolved oxygen in fuel saturated. The whole experiment lasted 36 h with the mass flow rate maintained at 3 g/s. The experimental results show that with the growth of time, coking amount in the tube increases along time. The results also show that the effect of coke deposition on flow resistance and heat transfer is significant. As more and more coke particles adhere, the heat transfer resistance increases rapidly in the early stage of the test and gradually stabilizes, while the flow resistance along the miniature tube increases as the experiment continues. As time grows, the flow resistance in the tube presents a “rapid growth to steady growth, then to exponential growth” process. Besides, based on the test results, an influence coefficient used as an engineering model to value the impact of the coke deposition on single tube of the heat exchanger is proposed.