Abstract: The invention relates to a heat exchanger, comprising a closed chamber in which are arranged ribbed welded plates (40) defining therebetween independent and mutually penetrating circuits in which fluids flow, the side walls defining said chamber being attached onto vertical rails, characterized in that said plates comprise at each angle an edge (41) that fits into apertures formed on vertical angle corners (60), said rails being inserted into said corners. The use of angle corners for receiving the edges of the plates improves the assembly and the retention of the plates therebetween.

Abstract: Each tube and a corresponding fin satisfy all of the following relationships: Lp?t?0.03Tr+0.22; Lp?t?0.115Tr2?1.14Tr+2.35; and Lp?t?5Tr2?8.3Tr+3, where Lp denotes a width of a sub-passages, Tr denotes a refrigerant passage height, and t denotes a plate thickness of the fin. The amount of a brazing material, which is present through an entire extent of the width of the sub-passage, is set to satisfy a relationship of 0.005?S/L<0.5, where S denotes a size of a cross-sectional area of the brazing material, and L denotes a length of a center line of a corresponding portion of the fin, which is present through the entire extent of the width of the sub-passage.

Abstract: A heat exchanger including a casing including aluminum nitride impregnated alumina-silica cloth. The heat exchanger includes a hot fluid flowpath positioned inside the casing for carrying a hot fluid from an inlet to an outlet downstream from the inlet. The hot fluid flowpath is formed at least in part by a thermally conductive wall permitting thermal energy to transfer from hot fluid flowing through the hot fluid flowpath. The heat exchanger includes a cold fluid flowpath for carrying a cold fluid from an inlet to an outlet downstream from the inlet. At least a downstream portion of the cold fluid flowpath is formed by the thermally conductive wall permitting thermal energy to transfer from hot fluid flowing through the hot fluid flowpath to the cold fluid. At least a portion of the cold fluid flowpath upstream from the thermally conductive wall is formed by ceramic foam.