Patent Description:
Some heat exchanger has been known that is provided with flat tubes, to improve heat exchange performance, that are each a heat transfer tube having a flat sectional shape with multiple holes. One example of such a heat exchanger is a heat exchanger where flat tubes are arranged at predetermined intervals from one another in the up-and-down direction with the direction of pipe axes extending in the lateral direction. In such a heat exchanger, plate-like fins are aligned in the direction of the pipe axes of the flat tubes, and heat is exchanged between air passing through between the fins and fluid flowing through the flat tubes.

Some fin has been known that is provided with a fin collar at the peripheral edge of a flat tube insertion portion. The fin collar ensures a separation between the fins by causing the distal end of the fin collar to be in contact with the next fin. In recent years, as the thickness of the flat tube has been reduced, the width of the flat tube insertion portion of the fin is small and hence, it is difficult to raise the fin collar, which is provided to the peripheral edge of the flat tube insertion portion, up to a predetermined height. To solve the problem, in Patent Literature <NUM>, spacers are provided to each fin to maintain intervals between fins disposed next to each other, and each spacer is formed by bending a portion of the fin at a portion other than the peripheral edge of the flat tube insertion portion. The fin has an insertion region where the flat tube is inserted, and an extension region formed downwind of the insertion region. The spacers are formed in the insertion region and the extension region. The spacer in the extension region is formed right behind the spacer in the insertion region (see Patent Literature <NUM>, for example).

The document <CIT> shows an heat exchanger with the features of the preamble of claim <NUM>.

However, in the heat exchanger disclosed in Patent Literature <NUM>, the spacer is formed by bending a portion of the fin, and the spacer is provided with a surface of the spacer directed in a direction of the flow of air passing through between the fins. A problem is consequently caused in that the area of an air passage between the fins decreases, so that ventilation properties of the heat exchanger are deteriorated. Further, in the case where the spacer is provided with the surface of the spacer extending along the direction of the flow of air, a problem lies in that, on the surface of the spacer, frost forms and stagnates and meltwater of frost stagnates, so that drainage properties and defrosting properties of the heat exchanger are reduced. Further, in the heat exchanger disclosed in Patent Literature <NUM>, the flat tubes are disposed with the longitudinal direction of the sectional shape of each flat tube extending in the horizontal direction and hence, a problem lies in that water stagnates on the flat tube, and is not easily drained.

The present disclosure has been made to solve the above-mentioned problems, and it is an object of the present disclosure to provide a heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus where a reduction of drainage properties and ventilation properties is prevented, and an air passage is not easily clogged when frost forms.

A heat exchanger according to claim <NUM> represents the invention.

A heat exchanger unit according to another embodiment of the present disclosure includes the above-mentioned heat exchanger, and a fan configured to send air to the heat exchanger.

A refrigeration cycle apparatus according to still another embodiment of the present disclosure includes the above-mentioned heat exchanger unit. Advantageous Effects of Invention.

According to an embodiment of the present disclosure, with the above-mentioned configuration, the spacer appropriately maintains the interval between the fins. It is therefore possible to prevent the clogging of the air passage when frost forms, and drainage properties of meltwater are ensured during the defrosting process. Further, the spacer is inclined in the same direction as the flat tube, so that it is possible to prevent the blockage of the flow of air along the flat tube, and the reduction of ventilation properties between the fin and the flat tube. Resistance against frost and drainage properties of the heat exchanger, the heat exchanger unit, and the refrigeration cycle apparatus are therefore enhanced while heat exchange performance is maintained.

Hereinafter, embodiments of a heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus are described. Hereinafter, the embodiments of the present disclosure are described with reference to drawings. In the drawings, components and portions given the same reference signs are the same or corresponding components and portions, and the reference signs are common in the entire specification. Further, forms of components described in the entire specification are merely examples, and the present disclosure is not limited to the description in the specification. In particular, the combination of the components is not limited to the combination in each embodiment, and components described in one embodiment may be applicable to another embodiment. Further, when it is not necessary to distinguish or specify a plurality of components or portions of the same kind that are, for example, differentiated by suffixes, the suffixes may be omitted. In the drawings, the relationship in size of the components and portions may differ from that of actual components and portions. It is noted that directions indicated by "x", "y", and "z" in the drawings indicate the same directions in the drawings.

<FIG> is a perspective view showing a heat exchanger <NUM> according to Embodiment <NUM>. <FIG> is an explanatory view of a refrigeration cycle apparatus <NUM> to which the heat exchanger <NUM> according to Embodiment <NUM> is applied. The heat exchanger <NUM> shown in <FIG> is a heat exchanger to be mounted on the refrigeration cycle apparatus <NUM>, such as an air-conditioning apparatus and a refrigerator. In Embodiment <NUM>, an air-conditioning apparatus is described as an example of the refrigeration cycle apparatus <NUM>. The refrigeration cycle apparatus <NUM> has a configuration in which a compressor <NUM>, a four-way valve <NUM>, an outdoor heat exchanger <NUM>, an expansion device <NUM>, and an indoor heat exchanger <NUM> are connected by a refrigerant pipe <NUM> to form a refrigerant circuit. In the refrigeration cycle apparatus <NUM>, refrigerant flows through the refrigerant pipe <NUM>. By switching the flows of the refrigerant by the four-way valve <NUM>, the operation of the refrigeration cycle apparatus <NUM> is switched to one of a heating operation, a refrigerating operation, and a defrosting operation.

The outdoor heat exchanger <NUM> is mounted on an outdoor unit <NUM>, the indoor heat exchanger <NUM> is mounted on an indoor unit <NUM>, and a fan <NUM> is disposed in the vicinity of each of the outdoor heat exchanger <NUM> and the indoor heat exchanger <NUM>. In the outdoor unit <NUM>, the fan <NUM> sends outside air into the outdoor heat exchanger <NUM> to exchange heat between the outside air and refrigerant. In the indoor unit <NUM>, the fan <NUM> sends indoor air into the indoor heat exchanger <NUM> to exchange heat between the indoor air and refrigerant, so that the temperature of the indoor air is conditioned. Further, in the refrigeration cycle apparatus <NUM>, the heat exchanger <NUM> may be used as the outdoor heat exchanger <NUM>, mounted on the outdoor unit <NUM>, or as the indoor heat exchanger <NUM>, mounted on the indoor unit <NUM>, and the heat exchanger <NUM> is used as a condenser or an evaporator. In the specification, a unit, such as the outdoor unit <NUM> and the indoor unit <NUM>, on which the heat exchanger <NUM> is mounted is particularly referred to as "heat exchanger unit".

The heat exchanger <NUM> shown in <FIG> includes two heat exchange parts <NUM>, <NUM>. The heat exchange parts <NUM>, <NUM> are arranged in series along the x direction shown in <FIG>. The x direction is a direction perpendicular to a direction along which flat tubes <NUM> of the heat exchange part <NUM> are arranged in parallel and to a direction along which the pipe axes of the flat tubes <NUM> extend. In Embodiment <NUM>, air flows into the heat exchanger <NUM> along the x direction. The heat exchange parts <NUM>, <NUM> are consequently arranged in series along a direction along which air flows through the heat exchanger <NUM>. The first heat exchange part <NUM> is disposed upwind, and the second heat exchange part <NUM> is disposed downwind. Headers <NUM>, <NUM> are disposed at both ends of the heat exchange part <NUM>, and the header <NUM> and the header <NUM> are connected with each other by the flat tubes <NUM>. The header <NUM> and a header <NUM> are disposed at both ends of the heat exchange part <NUM>, and the header <NUM> and the header <NUM> are connected with each other by the flat tubes <NUM>. Refrigerant flowing into the header <NUM> from a refrigerant pipe <NUM> passes through the heat exchange part <NUM>, flows into the heat exchange part <NUM> through the header <NUM>, and flows out to a refrigerant pipe <NUM> from the header <NUM>. The heat exchange part <NUM> and the heat exchange part <NUM> may have the same structure, or may have different structures.

<FIG> is an explanatory view of the sectional structure of the heat exchanger <NUM> shown in <FIG>. <FIG> is an explanatory view showing a portion of a section A of the heat exchange part <NUM> of the heat exchanger <NUM> shown in <FIG> as the portion is viewed from the lateral direction, and the section A is perpendicular to the y axis. The heat exchange part <NUM> has a configuration in which the plurality of flat tubes <NUM> are arranged in parallel in the z direction with the pipe axes of the flat tubes <NUM> extending in the y direction. Refrigerant flows through the flat tubes <NUM>, so that heat is exchanged between air sent into the heat exchanger <NUM> and the refrigerant flowing through the flat tubes <NUM>. Further, the heat exchange part <NUM> has a configuration in which fins <NUM> are attached to the flat tubes <NUM> with a plate surface <NUM> of each fin <NUM>, which is a plate, intersecting the pipe axes of the flat tubes <NUM>. The fin <NUM> has a rectangular shape having the longitudinal direction of the fin <NUM> extending in a direction along which the flat tubes <NUM> are arranged in parallel. In other words, the fin <NUM> is provided with the longitudinal direction of the fin <NUM> extending along the z direction. A first end edge <NUM>, which is one end edge in the x direction, of the fin <NUM> is positioned upwind, and a second end edge <NUM>, which is the other end edge, of the fin <NUM> is positioned downwind. Cut-out portions <NUM> are formed at the second end edge <NUM>. The flat tubes <NUM> are fitted in these cut-out portions <NUM>. The width direction of the fin <NUM> means a direction orthogonal to the longitudinal direction of the fin <NUM>, and aligns with the x direction. In <FIG>, two flat tubes <NUM> are shown. These two flat tubes <NUM> disposed next to each other along the longitudinal direction of the fin <NUM> may be referred to as "first flat tube" and "second flat tube".

Each flat tube <NUM> has the longitudinal axis of a section inclined to the width direction of the fin <NUM> by an inclination angle θ. A first end portion <NUM> positioned closer to the first end edge <NUM> of the fin <NUM> than is a second end portion <NUM> is positioned lower than is the second end portion <NUM> positioned closer to the second end edge <NUM> than is the first end portion <NUM>. Each cut-out portion <NUM> formed at the second end edge <NUM> of the fin <NUM> is also inclined to the width direction of the fin <NUM> by the inclination angle θ.

The plurality of fins <NUM> are arranged along a direction along which the pipe axes of the flat tubes <NUM> extend. The fins <NUM> disposed next to each other are disposed with a predetermined gap between the fins <NUM> so that air is allowed to pass through between the fins <NUM>. To ensure an interval between the fins <NUM> disposed next to each other, a first spacer 50a and a second spacer 50b are formed on the fins <NUM>. Hereinafter, the first spacer 50a and the second spacer 50b may be collectively referred to as "spacer <NUM>". The spacer <NUM> is formed by bending a portion of the fin <NUM>, which is a plate, and the spacer <NUM> is erected in a direction intersecting the plate surface <NUM>.

<FIG> includes enlarged views of the spacer <NUM> provided to the fins <NUM> of the heat exchanger <NUM> according to Embodiment <NUM>. <FIG> is an enlarged view as the spacer <NUM> is viewed from the direction illustrated by an arrow C in <FIG>, and is an enlarged view as the spacer <NUM> is viewed from a direction parallel to the plate surfaces <NUM> of the fins <NUM> and parallel to a standing surface <NUM> of the spacer <NUM>. <FIG> is an explanatory view of the structure of the spacer <NUM> as the spacer <NUM> is viewed from a direction perpendicular to a section taken along B-B in <FIG>. The spacer <NUM> is erected toward the next fin <NUM>, and the distal end of the spacer <NUM> is in contact with the plate surface <NUM> of the next fin <NUM>. The distal end of the spacer <NUM> is bent to form a contact portion <NUM>. In Embodiment <NUM>, the standing surface <NUM> of the spacer <NUM> extends substantially perpendicular to the plate surface <NUM> of the fin <NUM>. The spacer <NUM> is formed by bending a portion of the fin <NUM> in a direction intersecting the plate surface <NUM>. An opening port <NUM> is formed adjacent to the spacer <NUM> in the opposite direction of the z direction. An opening port 51a adjacent to the first spacer 50a may be referred to as "first opening port", and an opening port 51b adjacent to the second spacer 50b may be referred to as "second opening port". Further, a standing surface 53a of the first spacer 50a may be referred to as "first standing surface", and a standing surface 53b of the second spacer 50b may be referred to as "second standing surface".

<FIG> is an explanatory view of a spacer 150c that is a comparative example of the spacer <NUM> formed on the fins <NUM> of the heat exchanger <NUM> according to Embodiment <NUM>. <FIG> is an explanatory view as the spacer 150c is viewed in the same direction as <FIG>. The spacer 150c of the comparative example is formed by bending a portion of a fin <NUM> in the opposite direction of the z direction in <FIG>. In other words, when the heat exchanger <NUM> is installed with the opposite direction of the z direction in <FIG> aligning with the direction of gravity, the spacer 150c is formed by bending the portion of the fin <NUM> in the direction of gravity. A standing surface 153c is formed substantially perpendicular to the plate surface <NUM>. In this case, an opening port 151c is formed over the spacer 150c. When condensation water or meltwater of frost flows down to the spacer 150c, not only water stays on the standing surface 153c, but also water adheres to the edge of the opening port 151c because of capillarity. Further, water drops also adhere to a portion under the spacer 150c in such a manner that the water drops hang from the portion under the spacer 150c, so that the spacer 150c and the opening port 151c maintain water in a region surrounded by a dotted line <NUM> in <FIG>. In contrast, water drops adhere to the spacer <NUM> and the opening port <NUM> according to Embodiment <NUM> in such a manner that the water drops hang from a portion under the spacer <NUM> as shown by a dotted line <NUM> in <FIG>. The amount of water maintained at the spacer <NUM> and the opening port <NUM> is consequently small compared with that maintained at the spacer 150c and the opening port 151c of the comparative example. In other words, the spacer <NUM> and the opening port <NUM> according to Embodiment <NUM> maintains less amount of water and has higher drainage properties compared with the spacer 150c and the opening port 151c of the comparative example.

As shown in <FIG>, in Embodiment <NUM>, the spacer <NUM> is provided at two positions between two flat tubes <NUM> arranged in the longitudinal direction of the fin <NUM>. The spacers <NUM> are aligned in the width direction of the fin <NUM>, and are disposed in such a manner that a stable interval between the fins <NUM> is ensured. The first spacer 50a is disposed close to the first end edge <NUM> of the fin <NUM>, and is positioned on a first imaginary line L1 connecting lower ends of the first end portions <NUM> of the flat tubes <NUM> aligned in the up-and-down direction.

When the fin <NUM> is viewed in the y direction, that is, when the fin <NUM> is viewed in a direction perpendicular to the plate surface <NUM>, the standing surface 53a of the first spacer 50a is inclined in the direction same as that of the inclination angle θ of the flat tube <NUM>, and the standing surface 53a is inclined by an inclination angle α1. Each of the inclination angle θ and the inclination angle α1 is an angle by which the flat tube <NUM> or the standing surface 53a is inclined to the x axis on a section perpendicular to the pipe axes of the flat tubes <NUM> and, in other words, is an angle by which the flat tube <NUM> or the standing surface 53a is inclined to a straight line horizontal to the width direction of the fin <NUM>. The inclination angle α1 of the standing surface 53a of the first spacer 50a is set to α1 = θ according to this invention but could be otherwise also just satisfy a mathematical formula of <NUM> < α1 ≤ θ.

The second spacer 50b is formed on the fin <NUM> in an intermediate region <NUM>, which is a region between the cut-out portions <NUM> into which the flat tubes <NUM> are inserted. The standing surface 53b of the second spacer 50b is also inclined in the same direction as the direction in which the flat tube <NUM> is inclined in the same manner as the standing surface 53b of the first spacer 50a. The second spacer 50b has an inclination angle α2, and is set to satisfy a mathematical formula of <NUM> < α2 ≤ θ. The inclination angle α2 is also an angle by which the standing surface 53b is inclined to the x axis on the section perpendicular to the pipe axes of the flat tubes <NUM> and, in other words, is an angle by which the standing surface 53b is inclined to a straight line horizontal to the width direction of the fin <NUM>.

<FIG> includes explanatory views of a spacer 150a that is a modification of the spacer <NUM> formed on the fins <NUM> of the heat exchanger <NUM> according to Embodiment <NUM>. <FIG> corresponds to <FIG>, and <FIG> corresponds to <FIG>. Each of the first spacer 50a and the second spacer 50b provided to the fins <NUM> of the heat exchanger <NUM> according to Embodiment <NUM> may have the structure of the spacer 150a as shown in <FIG>, for example. The spacer 150a is formed in such a manner that two slits are formed in a plate surface 148a of the fin <NUM>, and a portion between these slits is caused to protrude from the plate surface 148a. The spacer 150a is consequently connected with the plate surface 148a at two positions. In <FIG>, an upper surface of the spacer 150a is a standing surface 153a. In the same manner as the standing surface <NUM> of the spacer <NUM>, the standing surface 153a is inclined in the same direction as the flat tube <NUM> in the heat exchanger <NUM> when the standing surface 153a is viewed in the y direction.

<FIG> includes explanatory views of a spacer 150b that is a modification of the spacer <NUM> formed on the fins <NUM> of the heat exchanger <NUM> according to Embodiment <NUM>. <FIG> corresponds to <FIG>, and <FIG> corresponds to <FIG>. The spacer 150b is formed in such a manner that the spacer 150b is caused to protrude from a plate surface 148b of the fin <NUM> in a rectangular shape. In <FIG>, an upper surface of the spacer 150b is a standing surface 153b. In the same manner as the standing surface <NUM> of the spacer <NUM>, the standing surface 153b is inclined in the same direction as the flat tube <NUM> in the heat exchanger <NUM> when the standing surface 153b is viewed from the y direction.

Advantageous effects of the heat exchanger <NUM> according to Embodiment <NUM> are described below. To facilitate understanding of drainage properties of the heat exchanger <NUM> according to Embodiment <NUM>, hereinafter, the description is made for the operation of the heat exchanger <NUM> when the heat exchanger <NUM> is operated as an evaporator under the condition that outside air has a low temperature. Subsequently, the configuration of a heat exchanger <NUM> of a comparative example is described, and the draining action of the heat exchanger <NUM> according to Embodiment <NUM> is then described.

<FIG> is an explanatory view of the sectional structure of the heat exchanger <NUM> that is the comparative example of the fin <NUM> of the heat exchanger <NUM> which does not fall under this invention. In the same manner as <FIG>, <FIG> shows a section perpendicular to the pipe axes of the flat tubes <NUM>. Also in a fin <NUM> of the heat exchanger <NUM> of the comparative example, spacers 1050a, 1050b are formed in a region between the flat tubes <NUM>. Each of the spacers 1050a, 1050b is formed by bending a portion of the fin <NUM>, and standing surfaces 1053a, 1053b are formed to be horizontal to the width direction of the fin <NUM>. Further, opening ports 1051a, 1051b are respectively formed below and adjacently to the spacers 1050a, 1050b.

During the operation of the refrigeration cycle apparatus <NUM>, condensation water or meltwater of frost flows down onto the fin <NUM> from above. In such a case, water flows down also onto the standing surfaces 1053a, 1053b of the spacers 1050a, 1050b. In the heat exchanger <NUM> of the comparative example, the spacers 1050a, 1050b are formed to be horizontal, so that water stagnates on the standing surfaces 1053a, 1053b, and is not drained. Water on the standing surfaces 1053a, 1053b is consequently frozen, and a frozen portion expands using the frozen water as a base point and thus becomes a cause of clogging of an air passage, or breakage of the heat exchanger <NUM>.

In contrast, in the heat exchanger <NUM> according to Embodiment <NUM>, the first spacer 50a and the second spacer 50b are inclined, so that water on the standing surfaces 53a, 53b is rapidly drained by gravity and flows downward. With such a configuration, in the heat exchanger <NUM>, an appropriate gap is ensured between the fins <NUM> disposed next to each other, and water flowing down onto the standing surface <NUM> of the first spacer 50a does not stagnate. The heat exchanger <NUM> consequently has high drainage properties, and has no clogging of an air passage between the fins <NUM> and hence, no possibility remains that heat exchange performance of the heat exchanger <NUM> is impaired.

To prevent ventilation resistance in the heat exchanger <NUM>, and to reduce the amount of refrigerant filled in the refrigeration cycle apparatus <NUM> for lessening an effect on global warming, the transverse axis of the flat tube <NUM> is set to have a small value, that is, the thickness of the flat tube <NUM> is reduced. With such a reduction in thickness, in providing a fin collar to the peripheral edge of the cut-out portion <NUM> for appropriately ensuring intervals between the fins <NUM>, the cut-out portion <NUM> into which the fin <NUM> is to be inserted has a small width and hence, it is difficult to raise the fin collar, which is provided to the peripheral edge of the cut-out portion <NUM>, up to a predetermined height. However, by providing the spacer <NUM> to the fin <NUM> as in the case of the heat exchanger <NUM> according to Embodiment <NUM>, it is possible to appropriately ensure intervals between the fins <NUM>.

<FIG> is an explanatory view of the sectional structure of a heat exchanger 100a that is a modification of the heat exchanger <NUM> according to Embodiment <NUM>. In the heat exchanger 100a of the modification, the first spacer 50a is disposed in a region close to the first end edge <NUM> of the fin <NUM>, and no cut-out portion <NUM> is provided at the first end edge <NUM>. In other words, the first spacer 50a, disposed close to the first end edge <NUM> of the fin <NUM>, is disposed in such a manner that the first spacer 50a at least does not overlap with the first imaginary line L1 connecting the first end portions <NUM> of the flat tubes <NUM> aligned in the z direction.

In the heat exchanger 100a of the modification, the first spacer 50a is disposed away from the first imaginary line L1 by <NUM> or more, for example. By disposing the first spacer 50a as described above, when water on the flat tube <NUM> flows down from the first end portion <NUM> of the flat tube <NUM>, water flows through a drainage region h formed between the first spacer 50a and the first end portions <NUM> of the flat tubes <NUM>. In the case where the direction of gravity aligns with the longitudinal direction of the fin <NUM>, no object that blocks the flow of water is disposed in the drainage region h and hence, the heat exchanger 100a of the modification has further improved drainage properties compared with the heat exchanger <NUM>.

<FIG> is an explanatory view of the sectional structure of a heat exchanger 100b that is a modification of the heat exchanger <NUM> according to Embodiment <NUM>. In the heat exchanger 100b of the modification, the first spacer 50a is disposed in the intermediate region <NUM> of the fin <NUM>, and the intermediate region <NUM> is disposed between two cut-out portions <NUM> disposed next to each other. In other words, the first spacer 50a, disposed close to the first end edge <NUM> of the fin <NUM>, is disposed in the intermediate region <NUM> in such a manner that the first spacer 50a does not overlap with the first imaginary line L1 connecting the first end portions <NUM> of the flat tubes <NUM> aligned in the z direction in <FIG>.

In the heat exchanger 100b of the modification, the first spacer 50a is not disposed in the region close to the first end edge <NUM> of the fin <NUM>, and no cut-out portion <NUM> is provided at the first end edge <NUM>. No possibility consequently remains that the first spacer 50a blocks the flow of water from above shown in <FIG>. Further, when water staying on an upper surface <NUM> of the flat tube <NUM> flows down from the first end portion <NUM> of the flat tube <NUM>, the water flows through the drainage region h positioned closer to the first end edge <NUM> than the first end portion <NUM> of the flat tube <NUM>. In the case where the direction of gravity aligns with the longitudinal direction of the fin <NUM>, that is, the direction of gravity aligns with the z direction in <FIG>, no object that blocks the flow of water is disposed in the drainage region h and hence, the heat exchanger 100b of the modification has further improved drainage properties compared with the heat exchanger <NUM>.

<FIG> is an explanatory view of the sectional structure of a heat exchanger 100c that is a modification of the heat exchanger <NUM> according to Embodiment <NUM>. The heat exchanger 100c of the modification is obtained by causing the fin <NUM> to extend farther in the downwind direction than the second end portions <NUM> of the flat tubes <NUM>. As the shape of the fin <NUM> is caused to extend in the downwind direction, the cut-out portions <NUM> are also formed to extend in the downwind direction. Nothing is disposed in a region of the cut-out portion <NUM> at a portion close to the second end edge <NUM>. In the heat exchanger <NUM> according to Embodiment <NUM>, the second end edge <NUM> and the second end portions <NUM> of the flat tubes <NUM> are disposed at substantially the same position in the x direction. In contrast, in the heat exchanger 100c of the modification, the second end edge <NUM> of the fin <NUM> is positioned away from the second end portions <NUM> of the flat tubes <NUM> in the x direction. Further, in the intermediate region <NUM>, the second spacer 50b is disposed in a region between the second end portions <NUM> and the second end edge <NUM> of the fin <NUM>, and each second end portion <NUM> is the end portion of the flat tube <NUM> disposed downwind in the width direction of the fin <NUM>. By disposing the second spacer 50b further downstream than is the flat tube <NUM>, it is possible to prevent the reduction of heat exchange performance of the heat exchanger 100c caused by the provision of the second spacer 50b.

In the heat exchanger <NUM>, 100a, 100b, 100c according to Embodiment <NUM>, the second spacer 50b is formed in the intermediate region <NUM> of the fin <NUM>. However, as long as intervals between the fins <NUM> are appropriately ensured, the second spacer 50b may not be provided. Further, it is not always necessary to provide the spacer <NUM> in every space provided between the flat tubes <NUM>, and the positions where spacers <NUM> are installed may be suitably changed. In addition to the above, it is not always necessary to provide the first spacer 50a and the second spacer 50b as a set, and only either one of the first spacer 50a or the second spacer 50b may be provided at some positions.

<FIG> is an explanatory view of the flow of air passing through the heat exchanger <NUM> which does not fall under this invention. <FIG> shows a state where the first end edge <NUM> of the fin <NUM> of the heat exchanger <NUM> is disposed upwind. In the heat exchanger <NUM>, the first spacer 50a and the second spacer 50b are provided, so that intervals between the fins <NUM> are appropriately maintained. Air consequently passes through between the fins <NUM> and the flat tubes <NUM>, so that heat is exchanged between the air and fluid flowing through the flat tubes <NUM>. Each flat tube <NUM> is inclined to the direction of the flow of air flowing into the heat exchanger <NUM> and hence, the air that enters the heat exchanger <NUM> comes into contact with the upper surface <NUM> of the flat tube <NUM>, so that the direction of the flow changes.

The first spacer 50a and the second spacer 50b are provided between the fins <NUM> of the heat exchanger <NUM>. The standing surface 53a of the first spacer 50a and the standing surface 53b of the second spacer 50b are inclined in a direction same as that of the inclination angle θ of the flat tube <NUM> and hence, the flow of air is not easily blocked. Further, the inclination angle α1 of the standing surface 53a of the first spacer 50a is smaller than the inclination angle θ of the flat tube <NUM>, so that the direction of the flow of air is gently changed and hence, no possibility remains that ventilation properties are impaired. Further, the inclination angle α2 of the standing surface 53b of the second spacer 50b is set to a value close to the value of the inclination angle θ of the flat tube <NUM>, so that the flow of air is not blocked in the intermediate region <NUM> between the flat tubes <NUM> disposed next to each other.

In the heat exchanger 100a of the modification shown in <FIG>, the first spacer 50a is positioned upwind of the flat tube <NUM>. By setting the inclination angle α1 to a small value (which is not in accordance with this invention), ventilation properties are consequently not impaired. In the heat exchanger 100b of the modification shown in <FIG>, the first spacer 50a is positioned in the intermediate region <NUM>, and is thus positioned downwind of the first end portion <NUM> of the flat tube <NUM>. It is consequently preferable and in line with this invention to set the inclination angle α1 to a value of the inclination angle θ of the flat tube <NUM>.

The description has been made above for a state where air flows into the heat exchanger <NUM> from a direction perpendicular to the first end edge <NUM> of the fin <NUM> of the heat exchanger <NUM>. However, there may be also a case where the heat exchanger <NUM> is disposed and inclined to the direction of gravity, for example. The inclination angle of each of the flat tubes <NUM>, the first spacer 50a, and the second spacer 50b is only required to be suitably set corresponding to an environment where the heat exchanger <NUM> is disposed.

In the heat exchanger <NUM>, 100a, 100b according to Embodiment <NUM>, the first spacer 50a is inclined in the same direction as the flat tube <NUM> and hence, it is possible to prevent stagnation, on the first spacer 50a, of water flowing from an upper portion of the fin <NUM>. Further, the inclination angle α1 of the standing surface 53a of the first spacer 50a has the relationship of the mathematical formula of <NUM> < α1 ≤ θ, so that the flow of air flowing into the heat exchanger <NUM>, 100a, 100b is not easily blocked. As a consequence, the angle α1 of the standing surface is set to the value of angle θ in accordance with this invention.

Resistance against frost and drainage properties of the heat exchanger <NUM>, 100a, 100b are consequently enhanced while heat exchange performance is maintained. Further, even in the case where the transverse axis of the flat tube <NUM> is shorter than the interval between the arranged fins <NUM>, it is also possible to appropriately ensure a gap between the fins <NUM> by the first spacer 50a.

A heat exchanger <NUM> according to Embodiment <NUM> is a heat exchanger obtained by changing the disposition of the first spacer 50a from that in the heat exchanger <NUM> according to Embodiment <NUM>. The description of the heat exchanger <NUM> according to Embodiment <NUM> is made below mainly for points different from Embodiment <NUM>. In the drawings, portions of the heat exchanger <NUM> according to Embodiment <NUM> having the same functions as those in Embodiment <NUM> are given the same reference signs as used in the drawings for describing Embodiment <NUM>.

<FIG> is an explanatory view of the sectional structure of the heat exchanger <NUM> according to Embodiment <NUM>. <FIG> shows a section perpendicular to the pipe axes of the flat tubes <NUM> shown in <FIG>. A first spacer 250a is provided to a fin <NUM> of the heat exchanger <NUM> and positioned close to a first end edge <NUM>. The first spacer 250a is disposed and positioned closer to the first end edge <NUM> than the first imaginary line L1 connecting the first end portions <NUM> of the flat tubes <NUM> aligned in the up-and-down direction. Further, the first spacer 250a is positioned between an imaginary line La and an imaginary line Lb. The imaginary line La extends in the longitudinal direction of the sectional shape of the flat tube <NUM> from the upper surface <NUM> of the flat tube <NUM>. The imaginary line Lb extends in the longitudinal direction of the section of the flat tube <NUM> from a lower surface <NUM> of the flat tube <NUM>. In other words, the first spacer 250a is disposed in a region obtained by projecting the flat tube <NUM> in a direction along the longitudinal direction of the section of the flat tube <NUM>.

The first spacer 250a and the first end portion <NUM> of the flat tube <NUM> are positioned with a predetermined separation. The cut-out portion <NUM> is formed in the fin <NUM> at a portion where the flat tube <NUM> is disposed and hence, the cut-out portion <NUM> and the first spacer 250a are formed to be spaced apart from each other. In Embodiment <NUM>, the inclination angle α1 of the first spacer 250a is set to a value substantially equal to the value of the inclination angle θ of the flat tube <NUM>. However, the inclination angle α1 is not limited to the above, and any value within the mathematical formula of <NUM> < α1 ≤ θ may be used.

In the heat exchanger <NUM> according to Embodiment <NUM>, the first spacer 250a is disposed in the vicinity of the extension of the upper surface <NUM> of the flat tube <NUM> where water easily stagnates. When water on the upper surface <NUM> of the flat tube <NUM> reaches the first end portion <NUM>, the water is consequently guided toward the first spacer 250a because of capillarity, and is drained from the flat tube <NUM>. Further, the first spacer 250a is inclined by the inclination angle α1, so that the water guided from the flat tube <NUM> is easily drained also from the first spacer 250a. In the heat exchanger <NUM>, water on the upper surface <NUM> and the lower surface <NUM> of the flat tube <NUM> is easily guided toward the first end edge <NUM> by the first spacer 250a. Compared with the heat exchanger <NUM>, 100a, 100b according to Embodiment <NUM>, the heat exchanger <NUM> therefore has an advantageous effect that the amount of water remaining on the upper surface <NUM> and the lower surface <NUM> of the flat tube <NUM> easily reduces. Further, the first spacer 250a is disposed in a region obtained by projecting the flat tube <NUM> in the longitudinal direction of the section of the flat tube <NUM>, and is formed in such a manner that the flow of air passing across the first end edge <NUM> of the fin <NUM> is caused to flow to the upper surface <NUM> of the flat tube <NUM>. No possibility consequently remains that ventilation properties of the heat exchanger <NUM> are impaired.

As long as at least one of the first spacer 250a and an opening port 251a is disposed between the imaginary line La and the imaginary line Lb, the heat exchanger <NUM> according to Embodiment <NUM> obtains an advantageous effect of draining water on the upper surface <NUM> of the flat tube <NUM>.

A heat exchanger <NUM> according to Embodiment <NUM> is a heat exchanger obtained by changing the disposition of the second spacer 50b from that in the heat exchanger <NUM> according to Embodiment <NUM>. The description of the heat exchanger <NUM> according to Embodiment <NUM> is made below mainly for points different from Embodiment <NUM>. In the drawings, portions of the heat exchanger <NUM> according to Embodiment <NUM> having the same functions as those in Embodiment <NUM> are given the same reference signs as used in the drawings for describing Embodiment <NUM>.

<FIG> is an explanatory view of the sectional structure of the heat exchanger <NUM> according to Embodiment <NUM>. <FIG> shows a section perpendicular to the pipe axes of the flat tubes <NUM> shown in <FIG>. A second spacer 350b is formed on a fin <NUM> of the heat exchanger <NUM> in an intermediate region <NUM> that is a region between the cut-out portions <NUM> into which the flat tubes <NUM> are inserted. The flat tubes <NUM> of the heat exchanger <NUM> are inclined and hence, when air flows into the heat exchanger <NUM> across the first end edge <NUM> of the fin <NUM> as shown in <FIG>, air passes through the heat exchanger <NUM> along the flat tubes <NUM>.

When the second spacer 350b is viewed from the first end edge <NUM>, that is, when the second spacer 350b is viewed in a direction along which air flows into the heat exchanger <NUM> in <FIG>, the second spacer 350b is disposed in a region shielded by the flat tube <NUM>. In other words, the second spacer 350b is disposed in a shielded region <NUM> disposed behind the flat tube <NUM> as the second spacer 350b is viewed from the first end edge <NUM> of the fin <NUM>. Still further, in the intermediate region <NUM> between two cut-out portions <NUM>, the second spacer 350b is disposed in the shielded region <NUM> that is a region between a second imaginary line L2 and the lower surface <NUM> of the flat tube <NUM>, and the second imaginary line L2 is drawn horizontal to the width direction of the fin <NUM> from the lower end of the first end portion <NUM> of the flat tube <NUM>.

In the heat exchanger <NUM> according to Embodiment <NUM>, the first spacer 50a may be disposed in the same manner as the heat exchanger <NUM>, 100a, 100b of Embodiment <NUM>, or the first spacer 250a may be disposed in the same manner as the heat exchanger <NUM> of Embodiment <NUM>. Alternatively, in an example which does not fall under this invention, the heat exchanger <NUM> may have a configuration in which only the second spacer 350b is provided to the fin <NUM>.

Claim 1:
A heat exchanger (<NUM>, 100a, 100b, 100c, <NUM>, <NUM>), comprising:
a flat tube (<NUM>); and
a plurality of fins (<NUM>, <NUM>, <NUM>, <NUM>) each comprising a plate having a plate surface (<NUM>) extending in a longitudinal direction and in a width direction orthogonal to the longitudinal direction, the plate surface (<NUM>) intersecting a pipe axis of the flat tube (<NUM>), the plurality of fins (<NUM>, <NUM>, <NUM>, <NUM>) being arranged at an interval from one another,
the plurality of fins (<NUM>, <NUM>, <NUM>, <NUM>) each having a first spacer (50a, 150a, 250a) formed in the plate and maintaining the interval, the plurality of fins each having a first end edge (<NUM>) that is one end edge in the width direction, a second end edge (<NUM>) that is an other end edge in the width direction, and a cut-out portion (<NUM>) is formed at the second end edge (<NUM>),
the flat tube (<NUM>) inserted into the cut-out portion (<NUM>) and having a longitudinal axis of a section perpendicular to the pipe axis, the longitudinal axis being inclined to the width direction by an inclination angle θ,
each first spacer (50a, 150a, 250a) having a standing surface (<NUM>, 153a, 153b) extending in a direction intersecting the plate surface (<NUM>),
each standing surface (<NUM>, 153a, 153b) being inclined in a direction same as that of the inclination angle θ, characterized in that each first spacer is formed in the plate other than a peripheral edge of the cut-out portion (<NUM>) and in that an opening port (<NUM>) is formed adjacent to each spacer.