JP7375492B2 - Heat exchanger - Google Patents

Description

The present invention relates to a heat exchanger.

Generally, an outdoor unit and an indoor unit of an air conditioner are provided with a heat exchanger. A heat exchanger operates as an evaporator or a condenser by exchanging heat between a refrigerant flowing inside the heat exchanger tube and air flowing around fins arranged around the heat exchanger tube.

Some heat exchangers have a plurality of rows of heat exchanger tubes stacked in multiple stages at intervals, and reciprocate refrigerant between the rows. Specifically, two refrigerant inlets and outlets are provided at one end of the heat exchanger, and the refrigerant flowing from one outlet flows through one row of heat transfer tubes and reaches the other end of the heat exchanger, The heat exchanger tubes may be folded back to the other row of heat exchanger tubes by means of a folding header connecting the rows, and returned to one end where the other outlet and inlet are provided. By reciprocating the refrigerant in this manner, the refrigerant flow path length becomes longer, and a large amount of refrigerant can be sufficiently evaporated.

Japanese Patent Application Publication No. 2006-17442 Utility Model Publication No. 1991-109185

Incidentally, a folded header that connects rows of heat exchanger tubes is generally formed by joining two plates together by brazing. Specifically, two plates each having a flat peripheral edge and a recess formed in the center that is deeper than the surface of the flat plate are placed facing each other so that the recesses face each other, and the peripheral edge is A folded header is formed by pasting them together as a brazing allowance. Since the two plates are joined with their recesses facing each other, a space is formed by the opposing recesses. Such a space is formed for each stage of heat exchanger tubes stacked in multiple stages, and a pair of heat exchanger tubes located at the same stage in different rows are connected by one space.

That is, a pair of heat exchanger tubes on the same stage, which serve as flow paths for refrigerant flowing in opposite directions, are connected through one space formed by facing each other so that the concave portions of the two plates face each other. A through hole is provided at the bottom of the concave portion of one of the plates forming this space, through which the tips of a pair of heat exchanger tubes located in the same stage of different rows are inserted. The tips of the heat transfer tubes pass through the through holes in this plate and reach the space inside the folded header. The refrigerant flowing out from one of the pair of heat exchanger tubes flows into the other heat exchanger tube via the space formed in the folded header.

However, in the case where the heat exchanger tubes are connected by a folded header, there is a problem that the refrigerant flow path may be blocked. Specifically, when the tip of the heat exchanger tube that passes through the through hole formed in one plate constituting the folded header comes into contact with the inner wall surface of the other plate, the end surface of the tip of the heat exchanger tube is is covered. As a result, the refrigerant flow path is blocked at the end face of the heat exchanger tube, making it difficult for the refrigerant to flow in and out between the folded header and the heat exchanger tube.

The disclosed technology has been made in view of this point, and an object thereof is to provide a heat exchanger that can suppress clogging of the refrigerant flow path at the end face of the heat exchanger tube.

In one embodiment, the heat exchanger disclosed in the present application includes a heat exchanger tube having a refrigerant flow path and a flat cross section, and a header connected to the tip of the heat exchanger tube, and a plurality of heat exchanger tubes are stacked. A heat exchanger provided in the header includes a first plate-like member in which a through-hole is formed for passing a heat exchanger tube through, a second plate-like member joined to the first plate-like member, and a second plate-like member joined to the first plate-like member. a space formed between a first plate-like member and a second plate-like member, the second plate-like member being an inner wall surface facing the through hole through the space; The heat exchanger tube has an inner wall surface having a shape in which the distance from the end surface changes along the lateral direction of the end surface passing through the heat exchanger tube, and one end of the end surface in the lateral direction is brought into contact with the inner wall surface. The through hole is formed below the center position of the space in the vertical direction along the stacking direction of the plurality of heat exchanger tubes.

According to one aspect of the heat exchanger disclosed in the present application, it is possible to suppress clogging of the refrigerant flow path at the end surface of the heat exchanger tube.

FIG. 1 is a perspective view showing the configuration of a heat exchanger according to an embodiment. FIG. 2 is a diagram showing a cross section taken along line II. FIG. 3 is a diagram showing a cross section taken along line II-II. FIG. 4 is a diagram showing the configuration of the return header. FIG. 5 is a diagram showing a cross section taken along the line III-III. FIG. 6 is a diagram showing a specific example of the shape of the folded header. FIG. 7 is a diagram showing a modification of the folded header. FIG. 8 is a diagram showing the configuration of a return header according to another embodiment. FIG. 9 is a diagram showing the configuration of a return header according to still another embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the heat exchanger disclosed by this application will be described in detail with reference to the drawings. Note that the present invention is not limited to this embodiment.

FIG. 1 is a perspective view showing the configuration of a heat exchanger 100 according to an embodiment. The heat exchanger 100 shown in FIG. 1 is provided, for example, in an outdoor unit of an air conditioner, and operates as an evaporator or a condenser. The heat exchanger 100 includes a heat exchange core 110 , a first header 120 , a first outlet 130 , a second header 140 , a second outlet 150 , and a folded header 170 .

The heat exchange core section 110 has an L-shape in plan view, and has two rows of heat exchanger tubes stacked in multiple stages. Moreover, the heat exchange core part 110 has a plurality of fins that guide air around the heat exchanger tubes and promote heat exchange with the refrigerant flowing inside the heat exchanger tubes. Specifically, FIG. 2 is a diagram showing a cross section taken along line II in FIG. 1, and FIG. 3 is a diagram showing a cross section taken along line II-II in FIG. Note that, in FIG. 1, detailed illustrations of the heat exchanger tubes and fins included in the heat exchange core section 110 are omitted.

As shown in FIG. 2, the heat exchange core section 110 includes heat exchanger tubes 111a, fins 112a, heat exchanger tubes 111b, and fins 112b. The heat exchange core section 110 has a row in which heat exchanger tubes 111a are stacked in multiple stages at intervals, and a row in which heat exchanger tubes 111b are stacked in multiple stages at intervals, and the heat exchanger tubes in the same stage of each row 111a and heat exchanger tube 111b are arranged side by side so as to be close to each other and extend in parallel. The heat exchanger tubes 111a and 111b are flat tubes having a flat cross section, and the heat exchanger tube 111a and the heat exchanger tube 111b have the same cross-sectional shape. That is, the cross sections of the heat exchanger tubes 111a and 111b have a shape in which the longitudinal direction and the lateral direction are perpendicular to each other.

In the cross section of the heat exchanger tubes 111a, 111b, a plurality of refrigerant flow paths are lined up in the longitudinal direction, and the row width direction (hereinafter simply referred to as "row width") is the direction in which the heat exchanger tubes 111a, 111b in the same stage as the longitudinal direction are lined up. (referred to as "direction") match. Further, the transverse direction of the cross section of the heat exchanger tubes 111a, 111b coincides with the direction in which the heat exchanger tubes 111a, 111b in each row are stacked (hereinafter simply referred to as "stacking direction"). The heat exchanger tube 111a extends from the first header 120 to the folded header 170, and the heat exchanger tube 111b extends from the second header 140 to the folded header 170.

The heat exchanger tubes 111a, 111b penetrate comb-shaped fins 112a, 112b extending in the stacking direction. That is, as shown in FIG. 3, for example, the heat exchanger tube 111a passes through a plurality of fins 112a, and the refrigerant flowing inside the heat exchanger tube 111a efficiently exchanges heat with the air passing between the plurality of fins 112a. It is supposed to be replaced. Similarly, the heat transfer tube 111b passes through the plurality of fins 112b, so that the refrigerant flowing inside the heat transfer tube 111b efficiently exchanges heat with the air passing between the plurality of fins 112b. .

The fins 112a, 112b extend in the stacking direction, and the heat exchanger tubes 111a, 111b are inserted between the comb-shaped teeth. That is, the fins 112a allow the plurality of heat exchanger tubes 111a arranged in a row in the stacking direction to be inserted therethrough, and the fins 112b allow the plurality of heat transfer tubes 111b arranged in a row in the stacking direction to be inserted therethrough. There is a space between adjacent fins 112a in the direction in which the heat exchanger tubes 111a extend, and the space partitioned by the stacked heat exchanger tubes 111a and the adjacent fins 112a becomes an air passage. Heat exchange occurs between the air passing through this passage and the refrigerant flowing within the heat transfer tubes 111a. Similarly, there is a gap between adjacent fins 112b in the direction in which the heat exchanger tubes 111b extend, and the space partitioned by the stacked heat exchanger tubes 111b and the adjacent fins 112b becomes an air passage. Heat exchange occurs between the air passing through this passage and the refrigerant flowing within the heat transfer tube 111b.

The first header 120 and the second header 140 are provided at one end of the heat exchanger 100. The first header 120 is connected to a plurality of heat transfer tubes 111a arranged in a row in the stacking direction, and the second header 140 is connected to a plurality of heat transfer tubes 111b arranged in a row in a stacking direction.

The first header 120 serves as a refrigerant inlet header when the heat exchanger 100 functions as an evaporator, and sends out the gas-liquid two-phase refrigerant flowing from the first inlet/outlet 130 to the heat transfer tube 111a. Further, the first header 120 serves as a refrigerant outlet header when the heat exchanger 100 functions as a condenser, and sends out the gas-liquid two-phase refrigerant flowing from the heat transfer tube 111a to the first inlet/outlet 130.

The second header 140 serves as a refrigerant outlet header when the heat exchanger 100 functions as an evaporator, and sends out the gas-liquid two-phase refrigerant flowing from the heat transfer tube 111b to the second inlet/outlet 150. Further, the second header 140 serves as a refrigerant inlet header when the heat exchanger 100 functions as a condenser, and sends out the gas-liquid two-phase refrigerant flowing from the second inlet/outlet 150 to the heat transfer tube 111b.

The folded header 170 is provided at an end of the heat exchanger 100 opposite to one end where the first header 120 and the second header 140 are provided, and connects the heat exchanger tube 111a and the heat exchanger tube 111b. That is, the folding header 170 has a space where the ends of the pair of heat exchanger tubes 111a and 111b on the same stage are commonly connected, and folds back the refrigerant flowing out from the tips of the heat exchanger tubes 111a to the heat exchanger tubes 111b. The refrigerant flowing out from the tip of the heat exchanger tube 111b is turned back and flows into the heat exchanger tube 111a.

FIG. 4 is a diagram showing the structure of the folded header 170. FIG. 4 is a perspective view of the folded header 170 viewed from the side of the heat exchanger tubes 111a and 111b (that is, from the inside of the heat exchanger 100).

The folded header 170 is formed by joining two plate-like members 171 and 172 by, for example, brazing. In the center of the plate member 171, a recess 171a is formed for each stage of the heat exchanger tubes 111a, 111b, and in the center of the plate member 172, a recess 172a is formed for each stage of the heat exchanger tubes 111a, 111b. The plate members 171 and 172 are arranged such that the recesses 171a and 172a corresponding to the same stage of the heat exchanger tubes 111a and 111b face each other, and a space 170a shown in FIG. 5 is formed by the recesses 171a and 172a facing each other. is joined to. The brazing material that joins the plate-like members 171 and 172 is contained in a cladding layer formed on the surface of the plate-like member 172, and when this cladding layer is heated, the brazing material melts and joins the plate-like member 172. 171 and plate member 172 are joined. On the other hand, no cladding layer is formed on the surface of the plate member 171. That is, the inner wall surface of the recess 171a that forms a space within the folded header 170 is not provided with a cladding layer that melts when heated. Note that, for example, the plate-like member 171 corresponds to a "second plate-like member" in the claims, and, for example, the plate-like member 172 corresponds to a "first plate-like member" in the claims.

A through hole is formed in the recess 172a, and the tips of the heat exchanger tubes 111a and 111b pass through this through hole and reach the space 170a formed by the recesses 171a and 172a. The refrigerant can be turned back between the heat exchanger tubes 111a and 111b via the space 170a formed by the recesses 171a and 172a. That is, the end faces of the tips of the heat exchanger tubes 111a and 111b are not covered by the inner wall surface of the recess 171a, and the refrigerant flow path is not blocked. This point will be specifically explained below.

FIG. 5 is a cross-sectional view taken along the line III--III in FIG. 4. As shown in FIG. 5, the tip of the heat transfer tube 111a passes through a through hole 172b formed in a recess 172a of the plate member 172, and reaches a space 170a inside the folded header 170. The through hole 172b is formed at a position offset from the center height C in the stacking direction of the space 170a (below the center height C in FIG. 5). Therefore, the heat exchanger tube 111a passes through the recess 172a at a position shifted downward from the center height C.

At a position facing the through hole 172b, the inner wall surface 171b of the recess 171a is not perpendicular to the direction in which the heat exchanger tube 111a extends, but has an arc shape in side view. That is, the distance of the inner wall surface 171b from the end surface 115 of the tip of the heat exchanger tube 111a is not constant, and the distance to the inner wall surface 171b is different between the upper end 115a and the lower end 115b of the end surface 115. As a result, one end (lower end 115b here) of the end surface 115 of the heat exchanger tube 111a in the lateral direction comes into contact with the inner wall surface 171b, thereby positioning the heat exchanger tube 111a in the insertion direction into the space 170a.

In this way, since the inner wall surface 171b facing the through hole 172b has a shape in which the distance from the end surface 115 changes along the lateral direction of the end surface 115 of the heat exchanger tube 111a, one end of the end surface 115 in the lateral direction Even if the end surface 115 (for example, the lower end 115b) comes into contact with the inner wall surface 171b, the entire end surface 115 is not covered by the inner wall surface 171b. Therefore, the refrigerant flow path is not blocked at the end face 115, and the inflow and outflow of the refrigerant is not obstructed. Further, as described above, no cladding layer is formed on the inner wall surface of the recess 171a including the inner wall surface 171b. Therefore, even if the plate members 171 and 172 are heated and brazed with the heat exchanger tube 111a penetrating the through hole 172b, the brazing material will not adhere to the end surface 115 of the heat exchanger tube 111a, and the flow path blockage can be prevented.

In addition, in FIG. 5, the through hole 172b is formed below the center height C in the stacking direction of the space 170a, and the lower end 115b of the end surface 115 of the heat exchanger tube 111a is in contact with the inner wall surface 171b. However, the through hole of the recess 172a may be formed above the center height C, and the upper end 115a of the end surface 115 of the heat exchanger tube 111a may contact the inner wall surface 171b. However, by forming the through hole 172b below the center height C of the space 170a, the tip of the heat transfer tube 111a is located below the space 170a, and the refrigerant in a liquid phase flows below the space 170a. flows into the heat exchanger tube 111a at an early stage. Therefore, it is possible to prevent the refrigerant from stagnation in the space 170a.

For example, even if the through hole of the recess 172a is formed near the center height C, the inner wall surface 171b facing the through hole has a shape in which the distance from the end surface 115 changes along the short direction of the end surface 115. It's good to have. In short, if the distance between the end surface 115 and the inner wall surface 171b facing the through hole of the recess 172a via the space 170a changes along the short direction of the end surface 115, the entire end surface 115 is covered by the inner wall surface 171b. Therefore, clogging of the refrigerant flow path can be suppressed.

FIG. 6 is a diagram showing a cross section of the folded header 170 taken along a plane perpendicular to the stacking direction. As shown in FIG. 6, the heat exchanger tubes 111a and 111b penetrate the plate member 172 at the recess 172a and reach the space 170a inside the folded header 170. Since one end of the end surface 115 at the tip of the heat exchanger tube 111a in the lateral direction contacts the inner wall surface 171b, the tip of the heat exchanger tube 111a is positioned without the entire end surface 115 being covered by the recess 171a. Similarly, the tip of the heat exchanger tube 111b is also positioned without the end surface being covered. In this way, by positioning the heat exchanger tubes 111a, 111b by bringing one end in the lateral direction of the end surface of the heat exchanger tubes 111a, 111b into contact with the inner wall surface 171b of the recess 171a, the folded header 170 of the heat exchanger tubes 111a, 111b is fixed. The insertion depth can be adjusted to the same depth.

As described above, according to the present embodiment, the tip of the heat exchanger tube passes through one plate member of the folded header formed by joining two plate members, and faces the end face of the tip of the heat exchanger tube. The inner wall surface of the other plate-like member has a shape in which the distance from the end surface changes along the width direction of the end surface. Therefore, when one end of the end surface of the heat exchanger tube comes into contact with the inner wall surface of the plate-shaped member and the tip of the heat exchanger tube is positioned, the entire end surface is not covered by the inner wall surface. As a result, clogging of the refrigerant flow path at the tip of the heat transfer tube can be suppressed.

In the above embodiment, the recesses 171a and 172a are formed in both the plate members 171 and 172, but the plate members through which the heat exchanger tubes 111a and 111b pass may be flat plates. good. That is, for example, as shown in FIG. 7, a folded header 170 may be formed by joining a plate-like member 171 and a flat plate-like member 173. In FIG. 7, the same parts as in FIG. 5 are given the same reference numerals.

In the structure shown in FIG. 7, a through hole 173a is formed in the plate member 173, and the tip of the heat transfer tube 111a passes through the through hole 173a to reach the space inside the folded header 170. Since the inner wall surface 171b of the recess 171a facing the through hole 173a has a shape in which the distance from the end surface 115 changes along the short direction of the end surface 115 of the heat exchanger tube 111a, even in the configuration of FIG. is not covered by the inner wall surface 171b. Therefore, the refrigerant flow path is not blocked at the tip of the heat transfer tube 111a, and the refrigerant can flow in and out. Moreover, since one plate member 173 is a flat plate, processing for forming the through hole 173a is facilitated, and the folding header 170 can be manufactured easily.

(Other embodiments)
In addition to the embodiment described above, the shape of the folded header 170 can be changed in various ways. FIG. 8 is a diagram showing the configuration of a return header 170 according to another embodiment. Similar to FIG. 6, FIG. 8 is a diagram showing a cross section of the folded header 170 taken along a plane perpendicular to the stacking direction, and the same parts as in FIG. 6 are given the same reference numerals. The folded header 170 shown in FIG. 8 has an inclined portion 171c at the end of the recessed portion 171a in the column width direction. That is, an inclined part 171c whose distance from the end face 115 of the heat exchanger tube 111a changes along the longitudinal direction of the end face 115 of the heat exchanger tube 111a is formed at the end of the recessed part 171a in the row width direction. One longitudinal end of the end surface 115 comes into contact with the inner wall surface of the inclined portion 171c.

One end of the end surface 115 in the lateral direction contacts the inner wall surface 171b of the recess 171a whose distance from the end surface 115 changes along the lateral direction of the end surface 115, as in the above embodiment. That is, in the structure shown in FIG. 8, one short side of the end surface 115 in the longitudinal direction is in contact with the inner wall surface of the inclined part 171c, and one long side of the end surface in the short direction of the end surface 115 is in contact with the inner wall surface 171b of the recessed part 171a. By abutting, the tip of the heat exchanger tube 111a is positioned. In this way, by positioning the heat exchanger tube 111a by the two sides of the end face 115, the positional relationship between the folded header 170 and the heat exchanger tube 111a can be made more accurate. The same applies to the heat exchanger tube 111b.

FIG. 9 is a diagram showing the configuration of a return header 170 according to still another embodiment. Similar to FIGS. 6 and 8, FIG. 9 is a diagram showing a cross section of the folded header 170 taken along a plane perpendicular to the stacking direction, and the same parts as in FIGS. 6 and 8 are given the same reference numerals. A folding header 170 shown in FIG. 9 has an interposed plate-like member 175 sandwiched between plate-like members 171 and 172. The interposed plate-like member 175 is sandwiched and joined between the flat parts of the plate-like members 171 and 172 other than the recesses 171a and 172a. By joining the plate-like members 171 and 172 with the interposed plate-like member 175 in between, it is possible to widen the space 170a formed by the recesses 171a and 172a.

Further, the end face of the interposed plate member 175 is exposed to the space 170a formed by the recesses 171a and 172a, and a refrigerant flow path different from that of the heat exchanger tubes 111a and 111b is formed inside the interposed plate member 175. It's okay. By doing so, the refrigerant can flow in and out at the end face of the intervening plate-like member 175 exposed to the space 170a, and a refrigerant circulation path different from that of the heat transfer tubes 111a and 111b can be formed.

110 Heat exchange core portion 111a, 111b Heat exchanger tube 112a, 112b Fin 115 End face 120 First header 130 First inlet/outlet 140 Second header 150 Second outlet/outlet 170 Folded header 170a Space 171, 172, 173 Plate member 171a, 172a Recessed portion 171b Inner wall surface 171c Inclined portion 172b, 173a Through hole 175 Interposed plate-like member

Claims (4)

A heat exchanger comprising a heat exchanger tube having a refrigerant flow path and a flat cross section, and a header connected to a tip of the heat exchanger tube , and in which a plurality of the heat exchanger tubes are stacked ,
The header is
a first plate member in which a through hole is formed to penetrate the heat exchanger tube;
a second plate member joined to the first plate member;
a space formed between the first plate member and the second plate member,
The second plate member is
An inner wall surface facing the through hole through the space, the inner wall surface having a shape such that a distance from the end surface of the heat exchanger tube passing through the through hole changes along the width direction of the end surface. ,
The heat exchanger tube is
one end of the end surface in the lateral direction is brought into contact with the inner wall surface ,
The through hole is
Formed below the center position of the space in the vertical direction along the stacking direction of the plurality of heat exchanger tubes.
A heat exchanger characterized by: The first plate member is
It has a flat plate shape,
The second plate member is
The heat exchanger according to claim 1, further comprising a recess that is recessed in a direction away from the first plate member. The second plate member is
The inner wall surface facing the through-hole through the space further includes an inclined part whose distance from the end surface of the heat exchanger tube that passes through the through-hole changes along the longitudinal direction of the end surface. The heat exchanger according to claim 1 or 2 . The first plate member is
a cladding layer containing a bonding material on a bonding surface to be bonded to the second plate-like member;
The second plate member is
The heat exchanger according to any one of claims 1 to 3 , wherein at least an inner wall surface facing the space does not have the cladding layer.

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