The flow and heat transfer process of supercritical water in a half cycle heated internally threaded tube was studied through numerical simulation. The SST kωturbulence model was used to solve the fluidstructure interaction heat transfer. The effects of the screw thread height, pitch and shape on the heat transfer of supercritical water were studied under the conditions of pressure 25 MPa, mass flow rate 600 kg/(m2〖DK〗•s), and heat flux density 280 kW/m2 and 470 kW/m2, respectively; the difference in the influence of thread structure parameters on heat transfer under full cycle heating and half cycle heating conditions was compared, and the heat transfer enhancement mechanism caused by changes in screw structure parameters was revealed. The results show that compared with the full cycle heating, the screw thread structure parameters under the half cycle heating condition enhance the influence on the heat transfer performance of the heating side, and weaken the influence on the overall average heat transfer performance. The cold side wall temperature is mainly affected by the circumferential heat conduction, only related to the heat flow density, and the cold side temperature distribution has almost no change under different screw thread structure parameters; when the buoyancy criterion number Bo>10-5, optimizing the threaded structure has a more prominent effect on improving the heat transfer performance of supercritical water. Increasing the threaded height and reducing the pitch can enhance heat transfer, and the heat transfer performance of rectangular rifled tubes is better than that of trapezoidal rifled tubes; swirl flow is the main factor for heat transfer enhancement of supercritical water in rifled tubes. The structural parameters mainly enhance the swirling strength in the 30<y+<100 region of the boundary layer, and ultimately improve the heat transfer performance of supercritical water in tubes.

TK124

山东大学青年学者未来计划资助项目(2015WLJH33)