Abstract: Heat exchange device with a boiling surface comprising a porous surface layer arranged on a solid substrate, the porous surface layer comprises a porous wall structure defining and separating macro-pores that are interconnected in the general direction normal to the surface of the substrate and have a diameter greater than 5 ?m and less than 1000 ?m wherein the diameter of the pores gradually increases with distance from the substrate wherein the porous wall structure is a continuous branched structure.

Abstract: Heat exchange device with a boiling surface comprising porous surface layer arranged on a solid substrate, the porous surface layer comprises a porous wall structure defining and separating macro-pores that are interconnected in the general direction normal to the surface of the substrate and have a diameter greater than 5 ?m and less than 1000 ?m wherein the diameter of the pores gradually increases with distance from the substrate wherein the porous wall structure is a continuous branched structure.

Abstract: A cooling system, especially for electronic components, having a hermetically closed pipe conduit including an evaporator and a condenser, and utilizing thermosiphon circulation of the refrigerant used in the pipe conduit. The evaporator is in heat conducting contact with a heat emitting component to be cooled and absorbs heat therefrom. The heat is transported through the pipe conduit by the refrigerant to the condenser and dissipated therein. The pipe conduit includes a plurality of evaporators in series, each being in heat conducting contact with a heat emitting component, and the condenser is placed so that the liquid level of the condensed refrigerant is below the upper-most situated evaporator in the pipe conduit. This is rendered possible by the increased pumping action achieved by the evaporators connected together in series in the circulation direction after the evaporators partly evaporated refrigerant used in the pipe conduit.

Abstract: A heat exchanger wall incorporates a partition wall (11-12), one side of which is in contact with a heat exchange medium. A mechanically stable part (11) of the partition wall (11-12) has provided on one surface thereof a thin metal foil (12), which is provided with a large number of small through-passing holes (121) and which is attached directly to the said part (11), such as to form a minute gap (13) between the foil and the mechanically stable part. According to one embodiment the element comprises a tube (11) and the foil has provided therein a longitudinally extending slot (122) and/or a plurality of folds or bends (31, 32) directed towards the stable part (11), and/or a fold or bend (51) facing away from the stable part (11).