Abstract: A heat exchanger includes a plurality of plate-shaped heat exchanger units and a plurality of flat fins arranged on the units, respectively. Each of the units has a first planar fluid communication chamber for receiving the flat fin. The flat fin has a first end provided with a first recess and a second end opposing to the first end and provided with a second recess. The first recess includes a circular opening and a cutout part. The second recess includes a circular opening and a cutout part. A clearance is defined between an edge of the first end and an inner periphery of the chamber, while another clearance is defined between an edge of the second end and the inner periphery. Consequently, a fluid can flow along the edge of the first end after being introduced into the first planar fluid communication chamber through the first recess.

Abstract: A heat exchanger includes a plurality of plate-shaped heat exchanger units and a plurality of flat fins arranged on the units, respectively. Each of the units has a first planar fluid communication chamber for receiving the flat fin. The flat fin has a first end provided with a first recess and a second end opposing to the first end and provided with a second recess. The first recess includes a circular opening and a cutout part. The second recess includes a circular opening and a cutout part. A clearance is defined between an edge of the first end and an inner periphery of the chamber, while another clearance is defined between an edge of the second end and the inner periphery. Consequently, a fluid can flow along the edge of the first end after being introduced into the first planar fluid communication chamber through the first recess.

Abstract: A plurality of heat transfer tube elements 17 are laminated with outer fins disposed between the heat transfer tube elements 17 in order to form a core. A gas flows between the outer fins. A passage 24 allowing flow of a cooling medium in a direction orthogonal to the direction of gas flow is formed in each heat transfer tube element 17. The passage 24 has a large passage 31 having a large width disposed upstream with respect to the direction a of gas flow and a small passage group 33 comprising a plurality of small passages 32 being more narrow than the large passage 31 and being disposed downstream with respect to the direction of gas flow. This arrangement allows non-uniformity in the temperature distribution of a gas flow to be suppressed to a low level with a downsizing, low-weight and low-cost device.

Abstract: A heat exchanger with catalyst is provided with a plurality of cooling membrane portions for circulation of cooling water, which are piled up and communicated with each other, first tank portions respectively communicated with first ends of the cooling membrane portions, second tank portions respectively communicated with second ends of the cooling membrane portions, cavities respectively held between the cooling membrane portions, fins disposed in the cavities and an air flow path communicating with the cavities. The first tank portions are communicated with each other and the second tank portions are communicated with each other. The reformed gas flows through the cavities. The catalyst is supported on the respective fins. The air supplied from an outside and the reformed gas are mixed in the cavities and oxidized on the catalyst.

Abstract: A plurality of heat transfer tube elements 17 are laminated with outer fins disposed between the heat transfer tube elements 17 in order to form a core. A gas flows between the outer fins. A passage 24 allowing flow of a cooling medium in a direction orthogonal to the direction of gas flow is formed in each heat transfer tube element 17. The passage 24 has a large passage 31 having a large width disposed upstream with respect to the direction a of gas flow and a small passage group 33 comprising a plurality of small passages 32 being more narrow than the large passage 31 and being disposed downstream with respect to the direction of gas flow. This arrangement allows non-uniformity in the temperature distribution of a gas flow to be suppressed to a low level with a downsizing, low-weight and low-cost device.