POROUS BODY MATERIAL

PURPOSE:To improve the thermal conduction performance of a porous body material by a method wherein a space having no porous material inside is surrounded by the porous material and a direction along which the central axis of the longitudinal direction of the space extends is made to coincide with a temperature gradient. CONSTITUTION:A liquid-phase electrolyte (e.g. a phosphoric acid) 3 transfers through gaps of a large number of porous bodies 2 due to a capillary phenomenon. When the phosphoric acid 3 reaches the edge part on the upstream side of a space 30, it is evaporated and penetrates as vapor (the arrow J) into the space 30. The phosphoric acid 3 transfers as the vapor through the space 30 in the direction (the arrow TM) of a temperature gradient. When the vapor reaches the edge part on the downstream side, it is condensed into a liquid-phase phosphoric acid G and transfers through the gaps of the porous bodies 2 in the direction of the arrow JM due to the capillary phenomenon. In other words, the phosphoric acid 3 being the electrolyte transfers in the direction (the arrow TM) of the temperature gradient while repeating evaporation, vapor transfer and condensation, and heat transfers also with it. Since the heat transfer by the vapor is larger than that by a solid or liquid phase herein, the efficiency of the heat transfer is improved.