| 摘要 |
PURPOSE:To provide positive separation between a flow of working liquid and a flow of vapor and to improve a thermal transmitting characteristic by a method wherein aeration holes formed at an inner pipe have a length longer than a Taylor wave length lambda and has a width less than the Taylor wave length lambda. CONSTITUTION:Aeration holes 16 are a longitudinal hole which is inclined by about 30 deg.-60 deg. in respect to an axis of an inner pipe 11, its length l is defined as one longer than a Taylor wave length lambda defined by an equation in such a way as a film of the working fluid may not be applied over an entire surface. A width (w) is set at a value less than the Taylor wave length lambda. The Taylor wave length lambda defined herein is a limit size where a liquid film is generated, sigmais a surface tension of the liquid phase working fluid, (g) is a gravity acceleration, rho1 is a density of liquid phase working fluid, rhov is a density of gas phase working fluid. A heat input Q is present at a heating part 13, the working fluid 12 is evaporated, its vapor is flowed at a lower pressure heat radiation part 14, radiated there and then condensed. The working fluid vapor is passed through aeration holes 16, flowed into the inner periphery of the inner pipe 11 and flowed toward the heat radiation part 14 in the fluid passage.
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