PURPOSE: To effectively enhance the coefficient of heat transfer at the inside surface of a pipe, by arranging inside surface projections in a spiral form to induce turbulent flows in a flow of a fluid.
CONSTITUTION: A plurality of inside surface projections 6 are provided on the inside surface of the pipe in a spiral form, so that turbulent flows are induced when a heat-transmitting fluid passes over the projections 6. In addition, the flow of the fluid in the axial direction of the pipe along the inside surface of the pipe is divided into left and right portions by each of the projections 6. Further, a spiral flow effect on the fluid flowing near the inside surface of the pipe is also produced by the spiral arrangement of the projections, resulting in complicate and delicate turbulent flows on the inside surface of the pipe. Accordingly, a boundary film liable to be formed in proximity to the inside surface of the pipe is effectively broken, and the coefficient of heat transfer at the inside surface is effectively enhanced.
TAKEDA IWAO
HASHIMOTO HIROMI
HIRAMATSU YOSHIHIRO
| JPS54157369A | 1979-12-12 |