| 摘要 |
PURPOSE:To prevent the damage of the heat pipe upon freezing and increase the reliability of the solar heat collector by providing a capillary acting part and a smoothened part for absorbing volmetric expansion of water upon freezing within the heat pipe. CONSTITUTION:The heat collecting part of the heat pipe 1 is constituted by a grooved part 4 and a smoothened part 5. The grooved part 4 causes a capillary operation and improves heat transfer characteristic of the heat pipe 1. The smoothened part 5 is selected to have in inner volume approximately 1.1-1.3 times the volume of water so that water is accumulated upon stopping the operation of the pipe 1. Even when the volume of water expands upon freezing of the smoothened part 5, so far as the volume of water expands over a space 7, the frictional resistance between ice and the smooth face is small, and no large stress is applied upon the pipe, and hence the pipe 1 is not damaged even though water freezes. |
