2024 年 32 巻 3 号 p. 541-545
Magnetic fluids have their many industrial applications in field of thermo-fluid engineering. Particularly there is one that has the strong temperature dependence on the magnetization at room temperature range, so called temperature sensitive magnetic fluid, TSMF. TSMF whose magnetic constituent that contains high pyromagnetic coefficient can also be extended to various applications in thermo-fluid engineering, by controlling both magnetic and temperature filed simultaneously. Present report describes some representative systems those produce power or refrigeration by cycling a ferromagnetic material or TSMF itself, thermally through a range of temperatures such that its magnetization changes appreciably. The present report also introduces and discuss some representative devices in such magnetic heat transport and refrigeration device in conjunction with development of permanent magnet. Hybrid combination with the magnetic material itself and magnetic field distribution in the devices are discussed for further development of engineering utilization.