A method for constructing a module of a modular cooling unit includes acquiring a plurality of tubes, each tube having a first end and a second end, and overmolding a first header onto the first ends of the plurality of tubes to form a watertight connection between the first header and the first ends of the plurality of tubes, the first header having a plurality of parallel first slots, each slot of the parallel first slots having an extended surface configured to receive and retain the first end of the tube.

A method for constructing a module of a modular cooling unit includes acquiring a plurality of tubes, each tube having a first end and a second end, and overmolding a first header onto the first ends of the plurality of tubes to form a watertight connection between the first header and the first ends of the plurality of tubes, the first header having a plurality of parallel first slots, each slot of the parallel first slots having an extended surface configured to receive and retain the first end of the tube.

A heat exchange tube (51) for a heat exchanger, heat exchanger and assembly method thereof. The heat exchange tube (51) is a combined heat exchange tube having a space (55) at its center, and the space (55) is configured to accommodate an insertion member (57), such that the combined heat exchange tube is expanded in and joined with a corres-ponding fin hole (53) in a heat exchanger. The solution addresses the problem of expansion and assembly between a fin and a heat ex-change tube that is minute or has a small inner diameter without employing a brazing process, thus reducing manufacturing costs.

The present invention addresses the problem of providing an apparatus for inserting flattened tubes into heat exchanger fins that is capable of assembling a heat exchanger core efficiently and with a high yield. As a solution, the invention includes: a fin stack arranging unit that disposes a fin stack, in which heat exchanger fins are stacked in the thickness direction and a guide is inserted into at least cutaway portion; a flattened tube arranging unit that holds flattened tubes in an intermittent arrangement with respect to the cutaway portions into which the guide has not been inserted; a flattened tube insertion driving unit for inserting the flattened tubes into the cutaway portions; a contact plate for producing a reactive force when the flattened tubes are inserted into the cutaway portions; and a flattened tube intermittently inserted fin stack arranging unit that aligns the positions of cutaway portions into which the flattened tubes have not been inserted to the positions of the flattened tubes on the flattened tube arranging unit and is used in place of the fin stack arranging unit.

The present invention addresses the problem of providing an apparatus for inserting flattened tubes into heat exchanger fins that is capable of assembling a heat exchanger core efficiently and with a high yield. As a solution, the invention includes: a fin stack arranging unit that disposes a fin stack, in which heat exchanger fins are stacked in the thickness direction and a guide is inserted into at least cutaway portion; a flattened tube arranging unit that holds flattened tubes in an intermittent arrangement with respect to the cutaway portions into which the guide has not been inserted; a flattened tube insertion driving unit for inserting the flattened tubes into the cutaway portions; a contact plate for producing a reactive force when the flattened tubes are inserted into the cutaway portions; and a flattened tube intermittently inserted fin stack arranging unit that aligns the positions of cutaway portions into which the flattened tubes have not been inserted to the positions of the flattened tubes on the flattened tube arranging unit and is used in place of the fin stack arranging unit.

A heat transfer tube of a heat exchanger is provided with a first and a second annular convex portions of which outer diameters are partially expanded. The first annular convex portion is positioned on an inner face side of a side plate portion of a case of the heat exchanger and is engaged with a circumferential edge portion of a first hole portion provided for the side plate portion, or the first annular convex portion contacts under pressure with an inner circumferential face of the first hole portion. The second annular convex portion is positioned on an outer face side of a header constituting member and is engaged with a circumferential edge portion of a second hole portion. Thus the side plate portion, the heat transfer tube, and a header are relatively fixed by a simple means.

A heat transfer tube of a heat exchanger is provided with a first and a second annular convex portions of which outer diameters are partially expanded. The first annular convex portion is positioned on an inner face side of a side plate portion of a case of the heat exchanger and is engaged with a circumferential edge portion of a first hole portion provided for the side plate portion, or the first annular convex portion contacts under pressure with an inner circumferential face of the first hole portion. The second annular convex portion is positioned on an outer face side of a header constituting member and is engaged with a circumferential edge portion of a second hole portion. Thus the side plate portion, the heat transfer tube, and a header are relatively fixed by a simple means.

A laminated header includes a plate-like unit including: bare members having first flow passages formed therein with no brazing material being applied to each of the bare members; and cladding members having second flow passages formed therein with a brazing material being applied to at least a front surface and a back surface of each of the cladding members. The bare members and the cladding members are alternately laminated so that the first flow passages and the second flow passages communicate with each other. A pipe is joined to the plate-like unit under a state in which an end portion of the pipe is inserted into at least one of the first flow passages or the second flow passages. One of the bare members is laminated on an outermost side of the plate-like unit in a laminating direction of the bare members and the cladding members.

A laminated header includes a plate-like unit including: bare members having first flow passages formed therein with no brazing material being applied to each of the bare members; and cladding members having second flow passages formed therein with a brazing material being applied to at least a front surface and a back surface of each of the cladding members. The bare members and the cladding members are alternately laminated so that the first flow passages and the second flow passages communicate with each other. A pipe is joined to the plate-like unit under a state in which an end portion of the pipe is inserted into at least one of the first flow passages or the second flow passages. One of the bare members is laminated on an outermost side of the plate-like unit in a laminating direction of the bare members and the cladding members.

Plate-shaped fins of a heat exchanger each include, at circumferential portions thereof defining a notch in which a heat transfer tube having a flattened shape is disposed, fin collars formed by being raised from the circumferential portions. Each of the fin collars includes, in a position that faces a long axis side surface of the heat transfer tube, at least one reflare section bent in a direction opposite to the side surface. At least one of the reflare sections defining fin pitches between the adjoining plate-shaped fins is formed so that a reflare tip portion, which is a tip portion of the reflare section, is drawn apart from a contact side surface of the plate-shaped fin with which the reflare section comes into contact.