The present invention reduces and mitigates thermal stress generated at joint portions between a header plate and a flat tube of a heat exchanger. In a direction of a vertical center axis passing the center of the inside of a flat tube, positions of first brazing parts are set to be closer to the center of the flat tube in the direction of the vertical center axis than positions of edge brazing parts. Accordingly, the thermal stress concentrated at the joint portions between short sides of the flat tube and the header plate is dispersed to other portions.

A heat exchange apparatus includes a heat exchanger, a refrigerant adjustment component, and a first connecting member. The heat exchanger includes a first pipe, a second pipe, a plurality of heat exchange tubes connecting the first pipe and the second pipe, and an edge plate located on an outer side of the plurality of heat exchange tubes in a length direction of the first pipe. At least part of the refrigerant adjustment component is located on an outer side of the edge plate in the length direction of the first pipe. An included angle between an axis in a length direction of at least part of an outer wall of the refrigerant adjustment component and an axis in the length direction of the first pipe is greater than 0° and less than or equal to 90°.

The present invention relates to a pipe connection assembly of a heat exchanger for connecting a header tank and a pipe of the heat exchanger, in which a means for preventing a welding ring that fixes a manifold and a pipe from entering into a hollow at one end of the manifold before welding is disposed, and a space is formed between the inner surface of the one end of the manifold and the outer surface of the pipe, thereby preventing the molten welding ring from flowing out.

A heat exchanger satisfies Expression (1) below, where the number of the main heat transfer tubes is represented as N.sub.1, and the number of the sub-heat transfer tubes is represented as N.sub.2. In this heat exchanger, the main heat exchanger satisfies Expressions (2) and (3) below, while the sub-heat exchanger satisfies Expressions (4) and (5) below.

0.1<N.sub.2(N.sub.1+N.sub.2)<0.4  (1)

0.03<Ta.sub.1/Ha.sub.1<0.3  (2)

0.03<Ta.sub.2/Ha.sub.2<0.3  (3)

AT.sub.1<Gr.sub.1/(G×D.sub.1(ρL.sub.1−ρG.sub.1)).sup.(1/2)×(X.sub.1.sup.(1/2)×ρG.sub.1.sup.(−1/4)+(1−X.sub.1).sup.(1/2)×ρL.sub.1.sup.(−1/4)).sup.2  (4)

AT.sub.2<Gr.sub.2/(G×D.sub.2(ρL.sub.2−ρG.sub.2)).sup.(1/2)×(X.sub.2.sup.(1/2)×ρG.sub.2.sup.(−1/4)+(1−X.sub.2).sup.(1/2)×ρL.sub.2.sup.(−1/4)).sup.2  (5)

A heat exchanger includes a plurality of heat exchange units each including a plurality of flat tubes, a plurality of fins, an upper header, and a lower header. In the plurality of heat exchange units, the upper headers are connected such that the upper headers communicate with each other, and the lower headers are connected such that the lower headers communicate with each other through an opening-closing valve. The heat exchanger has a configuration in which when the heat exchanger serves as a condenser, the opening-closing valve is controlled such that refrigerant in at least one of the plurality of heat exchange units flows in an upward direction, and refrigerant in the other one or the other ones of the plurality of heat exchange units flows in a downward direction.

A heat exchanger has an upper manifold with a first curved section; a lower manifold spaced from and extending parallel to the upper manifold and having a second curved section; a plurality of refrigerant tubes, and a plurality of corrugated fins. Each corrugated fin is formed by a strip having radiused portions alternating with planar portions, and the radiused portions are in contact with the respective adjacent refrigerant tubes. Each of the fins has a curve-inner edge and a curve outer edge and at least one edge of the curve-inner edge and the curve outer edge of at least one fin has a recessed portion in the planar portions that is recessed inward toward a center of the core.

A spacer device for incorporation into a bent-tube heat exchanger that includes a spine and a plurality of fingers that protrude from one side of the spine. The number of fingers in the spacer device is less than the number of tubes that are folded in a region to form the bent-tube heat exchanger. The plurality of fingers are configured to exert a force against the tubes and to provide and maintain a separation between the tubes in the folded region. A heat exchanger that includes the spacer device may also include a coating on the tubes in the folded region in order to reduce corrosion and increase the life-time of the heat exchanger. The method of forming the heat exchanger includes placing the spacer device between the tubes, such that the fingers lay on the tubes in the region to be folded and assist in the folding process.

A plurality of spacer devices for incorporation into a bent-tube heat exchanger that includes a spine and one or more fingers that protrude from opposite sides of the spine. The fingers are configured to exert a force against the tubes and to provide and maintain a separation between the tubes in the folded region. A heat exchanger includes a plurality of the spacer devices, such that one spacer device is positioned on every two tubes. The tubes may also include a coating in the folded region in order to reduce corrosion and increase the life-time of the heat exchanger. The method of forming the heat exchanger includes placing one of the spacer devices on every other tube, such that the fingers lay on the tubes in the region to be folded and assist in the folding process.

Embodiments of the present invention disclose a heat exchanger and an air-conditioning system. The heat exchanger includes heat exchange tubes. The heat exchange tubes have first heat exchange tubes configured to form a first circuit, and second heat exchange tubes configured to form a second circuit. With the heat exchanger and the air-conditioning system according to the embodiments of the present invention, for example, a heat exchange capacity of the heat exchanger in a part load condition is improved.

Some embodiments relate to constructing a heat exchanger using nanoink as a thermal bond interface between portions of the heat exchanger. The heat exchanger may comprise fins and at least one base. A nanoink may be applied to at least a portion of the fins. The pieces of the heat exchanger may be sintered such that the nanoink melts and forms a bond between the pieces of the heat exchanger. Some embodiments include a second base. Some embodiments incorporate dissimilar materials within the heat exchanger construction.