RECOVERY OF THERMAL ENERGY

PURPOSE:To obtain thermal energy from an evaporated high-pressure working fluid, by a method wherein a slurry form heat-accumulating medium consisting of a powder of a transition substance or microcapsules filled with a phase change substance is heated by a thermosiphon through an upright-type heat exchanger. CONSTITUTION:The slurry form heat-accumulating medium 2 is sucked from a bottom part of a heat-accumulating medium storing tank 1 into a bottom part of the upright- type heat exchanger 3 by a thermosiphon action, and is heated while moving upward through heat exchanger tubes 4. The powder in the medium 2 absorbs heat of fusion or heat of transition, and the temperature of the medium 2 remains at the melting or transition temperature of the powder until the powder is completely melted or completely undergoes transition. Thus, heat is absorbed from a heat source fluid while maintaining a fixed temperature. The medium 2 thus heated is automatically returned into the tank 1 by the thermosiphon action. The heat of transition of the powder of the transition substance or the heat of phase change of the microcapsules filled with the phase change substance is utilized according to the conditions and purpose of the use, and thermal energy is recovered by taking off the vapor of a refluxed heat-transmitting medium or by subjecting the vapor to heat exchange.