Thermosyphon device, cooling and heating device and method using the thermosyphone device, and plant cultivating method

A double tube type thermosyphon device in which an inner tube is disposed to be longitudinally passed through an outer tube disposed to be horizontally long, in which a working space defined between the outer tube and the inner tube is provided with an operating liquid and is hermetically closed, and in which heat exchange is performed between an outside and an inside of the outer tube while allowing a thermal source fluid to flow through the inner tube, the double tube- type thermosyphon device wherein:

• a large number of circumferentially formed narrow concave grooves are formed both in an inner wall surface of the outer tube facing the working space and in an outer wall surface of the inner tube facing the working space;
• the operating liquid is contained in the working space, and has such a liquid surface height as to soak the inner tube in the operating liquid in a state in which a part of the inner tube appears above a liquid surface of the operating liquid;
• and
• the operating liquid is raised in a circumferential direction of the wall surface by capillary attraction via the narrow concave grooves, and is evaporated on an evaporating portion of either of the inner wall surface of the outer tube and the outer wall surface of the inner tube, whereas the operating liquid is condensed on the other wall surface, so that the outside of the outer tube is cooled or heated.