JP5775971B2 - Air heat exchanger - Google Patents

Description

  The present invention relates to an air heat exchanger comprising a flat tube through which a refrigerant flows and heat transfer fins for exchanging heat with air, and more particularly to an air heat exchanger having an inner fin inside the flat tube.

  Air heat exchangers are used in various industrial equipment, and are typically widely used as heat exchangers for air conditioners and heat pumps for water heaters. However, the present invention described below is not limited to these air heat exchangers.

  Such an air heat exchanger includes two tubular headers through which refrigerant flows, a plurality of flat tubes arranged to connect the two headers, and a plurality of flat tubes provided between each of the plurality of flat tubes. Heat transfer fins. Each of the flat tubes is fluidly connected orthogonally to the header, and is configured to flow a refrigerant from one header to the other header via the flat tube. The heat transfer fins are thermally connected so as to be orthogonal to the flat tubes, so that heat (high temperature) or cold heat (low temperatures) from the flat tubes is exchanged with air by the heat transfer fins. It is configured.

  A plurality of thin refrigerant channels communicating with the header are provided inside one flat tube, and the fine refrigerant channels are formed by inner fins having a wavy shape. The refrigerant flows through the refrigerant flow path from one header to the flat tube and further flows to the other header. The header, the flat tube, the heat transfer fin, and the inner fin are formed of a metal material having high thermal conductivity, such as aluminum. These members are joined to each other by a wax material or an adhesive. And heat exchange is performed by blowing air from the blower fan to the heat transfer fins and the flat tubes of the air heat exchanger having such a structure.

  The air heat exchanger performs heat exchange between the refrigerant and air, and the refrigerant is introduced into one header and then distributed to the flat tube. The heat or cold of the refrigerant introduced into the flat tube is transferred from the flat tube to the heat transfer fins that expand the heat transfer area, and exchanges heat with the air flowing between the heat transfer fins.

  As described above, a plurality of refrigerant flow paths are formed inside the flat tube in order to increase the contact area between the refrigerant and the flat tube. This refrigerant flow path is formed by incorporating a corrugated inner fin (hereinafter referred to as a corrugated shape) along the direction of the refrigerant in a flat tube.

The plurality of refrigerant flow paths formed in the conventional flat tube that has been proposed so far are formed as independent flow paths from one header to the other header by the inner fins, and the refrigerant flow in the flat pipe from one header The refrigerant that entered the channel flowed to the outlet of the flat tube without being mixed with the refrigerant in the other refrigerant channels. Therefore, when the distribution ratio of the refrigerant to each refrigerant passage becomes nonuniform at the inlet of the refrigerant flow path, the nonuniform distribution ratio flows to the outlet of the refrigerant flow path without being improved. Therefore, when the distribution ratio of the refrigerant becomes uneven for each refrigerant flow path, for example, a refrigerant flow path in which the refrigerant flows excessively and a refrigerant flow path in which the refrigerant flow is insufficient are generated in the flat tube. Recently, there has been a strong demand for larger heat exchangers. To meet this demand, it is necessary to lengthen the flat tube in the direction of refrigerant flow. For this reason, when the flat tube is lengthened, the influence of the non-uniform distribution ratio of the refrigerant flow path of the flat tube is further increased, and there is a problem that the amount of exchange heat of the heat exchanger cannot be increased.

  Considering the time when the outdoor unit of the air conditioner is in cooling operation, the temperature of the refrigerant flowing through the flat tube is high. For this reason, when heat exchange of the flat tube is considered, since the air temperature is lower on the windward side on the surface of the flat tube, the heat transfer efficiency tends to be higher than that on the leeward side. For this reason, even in the refrigerant flow path in the flat tube, there is a phenomenon that the heat exchange efficiency between the windward side and the leeward side becomes non-uniform.

  And in order to expand a heat transfer area, when a flat tube is lengthened in the ventilation direction, the heat exchange efficiency becomes low on the leeward side. For example, if there is a refrigerant channel with insufficient refrigerant on the windward side of the flat tube and excess refrigerant flows through the refrigerant channel on the leeward side, effective heat exchange cannot be performed and the entire heat exchanger is replaced. There was a problem that the amount of heat could not be increased.

  In order to solve such a problem, a structure that makes the distribution ratio of the refrigerant to the flat tube uniform has been studied. For example, in Japanese Patent Application Laid-Open No. 2004-61065 (Patent Document 1), a communication region in which a plurality of refrigerant flow paths merge with a corrugated inner fin arranged to form a refrigerant flow path in a flat tube. The structure which prevents the bias | inclination of the distribution ratio of the refrigerant | coolant in a flat pipe by forming is disclosed.

JP 2004-61065 A

  However, the flat tube disclosed in Patent Document 1 has a uniform corrugated width (pitch) of the inner fins on the upstream and downstream sides of the communication region, and the outlet of the upstream coolant channel facing the communication region. The inlets of the downstream refrigerant passages have the same shape and are opened symmetrically facing each other, and the imaginary line connecting these outlets and inlets is linear.

  For this reason, when the flow rate of the refrigerant is high, the refrigerant travels straight through the communication region due to inertial force and proceeds as it is, and the ratio of flowing along the mutually opposing refrigerant flow paths increases. For this reason, there has been a problem that the deviation of the distribution ratio of the refrigerant in the communication region is not improved so much.

  In order to improve the distribution ratio, it is conceivable to increase the length of the communication area, but if the length of the communication area is increased, there is no inner fin in this area. This method is not a good idea because the heat transfer between the two becomes worse and the heat exchange efficiency decreases.

  Further, since the flat tube has a high heat exchange efficiency on the windward side, the heat exchange efficiency becomes a problem particularly when a refrigerant mixed with a gas phase and a liquid phase flows in the refrigerant channel on the windward side. As disclosed in Patent Document 1, the corrugated width (pitch) of the upstream and downstream inner fins of the communication region is uniform, and the outlet of the upstream coolant channel and the downstream coolant channel facing each other across the communication region In the configuration in which the inlets of the two are of the same shape and are opened symmetrically facing each other, when a refrigerant mixed with a gas phase and a liquid phase flows in the refrigerant channel on the windward side, the refrigerant in this state reaches the outlet of the flat tube. As a result, there is a problem that the refrigerant containing a large amount of the gas phase flows on the windward side and cannot improve the heat exchange efficiency.

  The objective of this invention is providing the air heat exchanger which improved the heat exchange efficiency by improving the bias | inclination of the distribution ratio between the some refrigerant | coolant flow paths formed in the flat tube via the communicating area | region.

  Still another object of the present invention is to provide air heat exchange with improved heat exchange efficiency in a refrigerant channel downstream of the communication region and in the upstream side of the plurality of refrigerant channels formed in the flat tube via the communication region. Is to provide a vessel

  A feature of the present invention is that a plurality of upstream refrigerant flow paths, a communication region, and a plurality of downstream refrigerant flow paths are formed in the flat tube along the flow of the refrigerant, and an outlet and a downstream side of at least one upstream refrigerant path It is in the place where the entrance of the refrigerant passage is shifted.

  Another feature of the present invention is that a plurality of upstream refrigerant flow paths, a communication region, and a plurality of downstream refrigerant flow paths are formed in the flat tube along the flow of the refrigerant, and at least one downstream side on the windward side of the flat tube The width of the inlet of the side refrigerant passage is narrower than the width of the outlet of the upstream refrigerant flow path.

  According to the present invention, since the outlet of the upstream refrigerant passage and the inlet of the downstream refrigerant passage are shifted in the communication region, even if the refrigerant has a high flow velocity and has passed through the refrigerant passage, The distribution ratio can be improved by disturbing the flow of the refrigerant by the collision action on the wall end face of the inlet.

  Further, according to the present invention, since the width of the inlet of the downstream refrigerant passage is narrower than the width of the outlet of the upstream refrigerant passage in the communication region, the gas phase contained in the flowing refrigerant has a narrow width in the downstream refrigerant passage. It is difficult to enter the inlet, and as a result, the refrigerant having a large liquid phase flows into the inlet of the narrow downstream side refrigerant passage, so that the heat exchange efficiency of the refrigerant channel on the windward side can be improved. .

It is an external appearance perspective view which shows the whole structure of the air heat exchanger with which this invention is applied. It is sectional drawing which shows the cross section of the flat tube of the air heat exchanger which becomes the 1st Embodiment (Example 1) of this invention. It is sectional drawing which shows the cross section of the flat tube of the z direction of FIG. It is explanatory drawing explaining the behavior of the refrigerant | coolant in the communication area | region shown in FIG. It is sectional drawing which shows the cross section of the flat tube of the air heat exchanger which becomes the 2nd Embodiment (Example 2) of this invention. It is sectional drawing which shows the cross section of the flat tube of the z direction of FIG. It is explanatory drawing explaining the behavior of the refrigerant | coolant in the communication area | region shown in FIG. It is sectional drawing which shows the cross section of the flat tube of the air heat exchanger which becomes the 3rd Embodiment (Example 3) of this invention. It is sectional drawing which shows the cross section of the flat tube of the z direction of FIG. It is sectional drawing which shows the cross section of the flat tube of the air heat exchanger which becomes the 4th Embodiment (Example 4) of this invention. It is sectional drawing which shows the cross section of the flat tube of the z direction of FIG. It is sectional drawing which shows the cross section of the flat tube of the air heat exchanger which becomes the 5th Embodiment (Example 5) of this invention. It is sectional drawing which shows the cross section of the flat tube of the z direction of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and application examples may be included in the technical concept of the present invention. It is included in the range.

  First, before describing the present invention, a basic configuration of an air heat exchanger to which the present invention is applied will be described with reference to FIG.

  As shown in FIG. 1, the air heat exchanger 1 is provided with headers 3 at the top and bottom in the drawing, and the headers 3 are connected by a flat flat tube 2. A plurality of flat tubes 2 are provided so as to be orthogonal to each other between the headers 3, and here, eight are provided. The header 3 and the flat tubes 2 communicate with each other through passages through which refrigerant flows so that the refrigerant flows inside. Has been. Each flat tube 2 is provided with a plurality of heat transfer fins 5, in this case, 15 heat transfer fins 5 so as to be orthogonal to these, and the header 3 and the heat transfer fins 5 are arranged in a substantially parallel state. Therefore, heat from the flat tube 2 or cold heat is transmitted to the heat transfer fin 5, and heat is exchanged from the heat transfer fin 5 to the air.

  In such an air heat exchanger 1, in this embodiment, the refrigerant is supplied from the lower header 3 to the flat tube 2, and the refrigerant is discharged to the upper header 3 while ascending the flat tube 2. In such a state, when air is sent to the heat exchanger 1 from the blower fan disposed in front of or behind the air heat exchanger 1, the air is heated to the refrigerant between the heat transfer fins 5 and the flat tubes 2. The heat exchange is performed by supplying heat or absorbing heat from the refrigerant.

  Next, specific embodiments of the present invention in such an air heat exchanger will be described in detail. In the present invention, a plurality of embodiments are proposed. Accordingly, components having the same reference numbers represent the same components or components having similar functions.

  A first embodiment of the present invention will be described in detail with reference to FIGS. In this embodiment, the width of at least one of the inlets of the downstream refrigerant flow path formed on the downstream side of the communication area formed in the middle as viewed from the direction of the refrigerant in the flat tube 2 is set upstream of the communication area. It shows a case where the width is different from the outlet of the formed upstream refrigerant flow path and the inlet of the downstream refrigerant flow path is shifted from the outlet of the upstream refrigerant flow path. Furthermore, in the present embodiment, a configuration is shown in which the width of the inlet of the downstream refrigerant flow path on the windward side and the leeward side is shorter than the width of the outlet of the upstream refrigerant flow path.

  2 and 3 show the flat tube 2 of the air heat exchanger 1 and the corrugated inner fins 21 and 22 installed in the flat tube 2. 2 shows a cross section of one flat tube 2 in a plane perpendicular to the refrigerant flow direction, and FIG. 3 shows a cross section of the flat tube 2 in a plane along the refrigerant flow direction, that is, a flat shape in the z direction of FIG. A cross section of the tube is shown. In addition, the arrow 10 in a figure represents the flow of the air sent with a ventilation fan.

  2 to 4, the x-axis direction indicates the width direction of the air heat exchanger 1, and similarly indicates the width direction of the heat transfer fins 5 and the header 3. In addition, the y-axis direction indicates the direction of gravity, and the z-axis direction indicates the air blowing direction by the blower fan.

  In addition, the expressions “upstream” and “downstream” used below relate to the refrigerant flow direction 11 and indicate the state positions of the refrigerant flowing from the lower header 3 toward the upper header 3. Accordingly, the side where the refrigerant flow begins at a certain position is expressed as “upstream”, and the side where the refrigerant flows is expressed as “downstream”.

  Similarly, also in the flow of air, the expressions “upwind” and “downwind” relate to the air blowing direction 10, and the side on which the air flow starts is expressed as “windward” and the side on which the air flows. Is expressed as “leeward”.

  2 and 3 show one flat tube 2 and an upstream inner fin 21 and a downstream inner fin 22 provided inside the flat tube 2. The flat tube 2 is a cylindrical cuboid whose section is formed in a hollow rectangular shape, and a plurality of upstream refrigerant channels 6 and a plurality of downstream refrigerant channels 7 and 8 are formed therein.

  These refrigerant flow paths 6, 7 and 8 are formed by interposing two corrugated inner fins of the upstream inner fin 21 and the downstream inner fin 22 inside the flat tube 2. The number of flow paths is determined by the width (pitch) of the corrugated shape with respect to the length of 2 in the blowing direction.

  Here, the corrugated shape is to form a plurality of partition walls along the flow direction of the refrigerant, and to form a plurality of partition walls having a curved cross section perpendicular to the flow direction of the refrigerant, a triangle Is formed with a shape that forms a plurality of partition walls that are repeated, a shape that forms a plurality of partition walls that are repeated with a rectangle, etc. In short, a plurality of fine refrigerant flow paths 6, 7, and 8 are formed by the inner fins. It is good.

  As shown in FIG. 3, an upstream inner fin 21 is provided on the upstream side of the flat tube 2, a communication region 23 is provided on the downstream side of the upstream inner fin 21, and further downstream on the downstream side of the communication region 23. Side inner fins 22 are provided. The communication region 23 is formed so as to cross the flat tube 2 perpendicular to the flow direction of the refrigerant, and the communication region 23 is configured such that the fine refrigerant flow paths 6, 7, and 8 do not exist. . That is, the inner fin partition wall is not present.

  Therefore, the refrigerant flowing from the inlet 6A of the refrigerant flow path 6 formed by the upstream inner fin 21 passes through the refrigerant flow path 6 and communicates with the communication region 23 from the outlet 6B of the refrigerant flow path 6 formed by the upstream inner fin 21. It flows out and joins. The refrigerant that has flowed out to the communication region 23 passes through the refrigerant passages 7 and 8 from the inlets 7A and 8A of the refrigerant flow passages 7 and 8 formed by the downstream inner fins 22 and is formed by the downstream inner fins 22. 7 and 8 from the outlets 7B and 8B to the header 3 on the upper side. The upstream inner fin 21 and the downstream inner fin 22 are joined to the inside of the flat tube 2 by brazing.

  Here, the width (pitch) W of the plurality of refrigerant channels 6 formed by the corrugated upstream inner fins 22 is substantially uniform. On the other hand, in the present embodiment, the width (pitch) of the downstream inner fins 22 is the same width (pitch) as the corrugated shape of the upstream inner fins 21, but is arranged so as to be shifted by a half width. Accordingly, the refrigerant flow paths 7 on both sides formed in the flat tube 2 when viewed from the air blowing direction are half the width of the refrigerant flow path 8 therebetween, and the refrigerant flow area is narrowed.

  Thus, by disposing the downstream inner fins 22 by a half width, among the plurality of refrigerant channels 7, 8 formed by the downstream inner fins 22, the refrigerant channels 7 on both sides are interposed between them. And the inlet 7A of the refrigerant channels 7 and 8 formed by the outlet 6B of the refrigerant channel 6 and the downstream inner fin 22 formed by the upstream inner fins 21. , 8A do not face each other symmetrically, and are shifted from the flow direction of the refrigerant.

  That is, the inlets 7A and 8A of the refrigerant flow paths 7 and 8 formed by the downstream inner fins 22 are on the imaginary line obtained by extending the outlet 6B of the refrigerant flow path 6 formed by the upstream inner fins 21. It has been shifted so as not to overlap.

Here, if the width of the narrow refrigerant flow path 7 on both sides of the refrigerant flow path formed by the downstream inner fins 22 is r _1, and the width of the refrigerant flow path 8 therebetween is r ₂ , these relationships are r ₁ <r ₂ . Further, the widths of the downstream refrigerant flow path 8 and the upstream refrigerant flow path 6 are equal to each other, r ₂ = W.

  FIG. 4 is a diagram for explaining the behavior of the refrigerant flowing through the flat tube 2, in which the vicinity of the communication region 23 in the cross section of the yz plane along the flow direction of the refrigerant 11 in the flat tube 2 is enlarged. First, the refrigerant 11 flows into the flat tube 2 from the header 3. At this time, the distribution ratio of the refrigerant flowing into the plurality of refrigerant flow paths 6 depends on the environment when the refrigerant 11 flows in, and thus tends to be uneven. .

  However, when the refrigerant 11 reaches the communication area 23 formed between the downstream inner fin 22 and the upstream inner fin 21 after passing through the upstream refrigerant flow path 6, the downstream inner fin is formed in the communication area 23. Since 22 and the upstream inner fin 21 are not provided, the environment can move in the direction orthogonal to the refrigerant flow direction, that is, in the Z-axis direction.

  Since the outlet 6B of the upstream refrigerant flow path 6 and the outlets 7A and 8A of the downstream refrigerant flow paths 7 and 8 are shifted so that the opening portions do not overlap when viewed from the flow direction of the refrigerant, the upstream refrigerant flow The refrigerant 12 (including the liquid phase and the gas phase) flowing out from the outlet 6B of the path 6 collides with the wall end surfaces of the inlets 7A and 8A of the downstream refrigerant flow paths 7 and 8. In the collision portion of the wall end surfaces of the inlets 7A and 8A, the traveling direction of the refrigerant is changed by the presence of the wall end surfaces of the inlets 7A and 8A.

  The refrigerant whose direction has been changed becomes a turbulent flow by generating a vortex, and this turbulent flow further affects the flow of the adjacent refrigerant. Therefore, the flow of the refrigerant in the communication region 23 is compared with the structure of Patent Document 1. It will be greatly disturbed. For this reason, in the communication region 23, the variation in the flow velocity and pressure of the refrigerant flowing out from the outlet 6B of the upstream refrigerant flow path 6 is alleviated, and the distribution of the refrigerant flowing into the inlets 7A and 8A of the downstream refrigerant flow paths 7 and 8 is reduced. The non-uniformity of the ratio can be improved.

  Further, the flow of the refrigerant including the turbulent flow formed in the communication region 23 flows into the inlets 7A and 8A of the downstream refrigerant flow paths 7 and 8, but since it includes the turbulent flow, between the downstream inner fins 22 The effect of improving the heat exchange efficiency can also be expected.

  Furthermore, since the refrigerant 11 containing a large amount of gas phase tends to have a higher flow velocity than the liquid phase, the refrigerant 11 tends to flow into the wide refrigerant flow path 8. Therefore, the vapor phase of the refrigerant that has exchanged heat with air in the upstream refrigerant flow path 6 tends to flow into the wide refrigerant flow path 8. On the other hand, a refrigerant containing a large amount of liquid phase tends to flow into the narrow refrigerant flow path 7 by capillary force. By these synergistic actions, a large amount of refrigerant containing a large amount of liquid phase flows in the narrow downstream side refrigerant flow path 7.

  Therefore, the outlet 6B of the upstream refrigerant flow path 6, the communication region 23, the inlet 7A of the narrow downstream refrigerant flow path 7, and the inlet 8A of the wide downstream refrigerant flow path 8 are in a liquid phase and a gas phase. And a gas phase separation function for sending a refrigerant containing a large amount of liquid phase to the narrow downstream refrigerant flow path 7.

  In the present embodiment, the narrow downstream side refrigerant flow path 7 is formed on the windward side and the leeward side of the flat tube 2, but the narrow downstream side refrigerant flow path 7 is formed at least on the windward side. A large amount of refrigerant containing a large amount of liquid phase flows on the windward side. As a result, a refrigerant containing a large amount of liquid phase flows through the refrigerant channel 7 on the windward side with high heat exchange efficiency, so that heat exchange between the air and the refrigerant 11 as a whole of the heat exchanger 1 is performed efficiently.

  Here, when viewed from the flow direction of the refrigerant, the number of inner fins and the number of communication regions 23 housed in the flat tube 2 can be arbitrarily determined according to the length of the flat tube 2. Further, the corrugated width (pitch) of the downstream inner fins 22 may be narrower or wider than the width (pitch) of the upstream inner fins 21, but in practice it is more desirable to narrow.

On the other hand, if the communication region 23 formed between the upstream inner fin 21 and the downstream inner fin 22 is greatly expanded, the contact area between the flat tube 2 including the inner fins 21 and 22 and the refrigerant 11 is reduced. Exchange efficiency decreases. Therefore, the length of the communication region 23 formed inside the flat tube 2 is set to be substantially the same as or longer than the width w of the refrigerant flow path 6 and the width r ₂ of the refrigerant flow path 8. In the present embodiment, for example, it is about 5 mm to 10 mm. Further, the length of the upstream inner fin 21 and the downstream inner fin 22 in the refrigerant flow direction (Y-axis direction) may not be equal, and the upstream inner fin 21 may be longer than the downstream inner fin 22. In this case, since the refrigerant flows from the lower header 3, the overall heat exchange efficiency is improved by making the upstream inner fin 21 longer.

  According to this embodiment, the upstream inner fin 21 and the downstream inner fin 22 use the same inner fin having the same width (pitch), and one inner fin is wider than the other inner fin. This is advantageous from the viewpoint of manufacturing cost because it is only shifted by half.

  Next, an air heat exchanger according to a second embodiment of the present invention will be described in detail. This embodiment is different from the first embodiment in that an inner fin is used in which the width on the windward side of the downstream inner fin 22 is narrower than the width on the leeward side.

  5 and 6 show the flat tube 2 of the air heat exchanger 1 according to the second embodiment and the upstream inner fin 21 and the downstream inner fin 22 that are housed in the flat tube 2. 5 shows a cross section of the xz plane perpendicular to the refrigerant flow direction, and FIG. 6 shows a cross section of the yz plane along the refrigerant flow direction.

  As in the first embodiment, the flat tube 2 is provided with two corrugated inner fins, that is, an upstream inner fin 21 and a downstream inner fin 22, and includes a plurality of upstream refrigerant channels 6 and a plurality of downstream sides. Refrigerant channels 7 and 8 are formed.

  Here, in order to form the respective refrigerant flow paths 6, 7, 8 in the flat tube 2, a corrugated upstream inner fin 21 having a uniform width is provided on the upstream side when viewed from the flow direction of the refrigerant 11, and the downstream side In addition, at least one location with the upstream inner fin 21 is provided with a downstream inner fin 22 having a corrugated shape having a different width. A communication region 23 is provided between the upstream inner fin 21 and the downstream inner fin 22 as in the first embodiment.

Since the upstream inner fin 21 has a substantially uniform corrugated width (pitch), the width W of the coolant channel 6 formed by the upstream inner fin 21 is uniform. On the other hand, the downstream inner fins 22 have a corrugated-shaped windward side width (pitch) narrower than the leeward side width (pitch) in the refrigerant circulation area. Thus, the narrow coolant flow path 7 width is formed on the downstream side windward side in the refrigerant passage 7 and 8, the leeward side refrigerant flow path 8 of the same width r ₂ and the upstream side refrigerant passage 6 is formed The Therefore, similar to the first embodiment, r ₁ <r _{2 and} r ₂ = W are satisfied.

  Similarly to the first embodiment, on the imaginary line extending the outlet 6B of the refrigerant flow path 6 formed by the upstream inner fins 21, the inlets 7A of the refrigerant flow paths 7, 8 formed by the downstream inner fins 22, 8A is shifted so as not to overlap when viewed from the flow direction of the refrigerant.

  Here, it is possible to continuously and integrally form a narrow width (pitch) inner fin and a wide width (pitch) inner fin in the flat tube 2; It is also possible to individually form fins and wide inner fins having a wide width (pitch), and to combine them in the flat tube 2. Therefore, an appropriate method may be adopted in consideration of the manufacturing apparatus, manufacturing cost, and the like.

  In the configuration as described above, when the refrigerant 11 reaches the communication area 23 formed between the downstream inner fin 22 and the upstream inner fin 21 after passing through the upstream refrigerant flow path 6, the communication area 23 enters the communication area 23. Since there are no downstream inner fins 22 and upstream inner fins 21, it is an environment that can also move in the direction perpendicular to the refrigerant flow direction, that is, in the Z-axis direction.

  Since the outlet 6B of the upstream refrigerant flow path 6 and the outlets 7A and 8A of the downstream refrigerant flow paths 7 and 8 are shifted so that the opening portions do not overlap when viewed from the flow direction of the refrigerant, the upstream refrigerant flow The refrigerant (including the liquid phase and the gas phase) flowing out from the outlet 6B of the path 6 collides with the wall end surfaces of the inlets 7A and 8A of the downstream refrigerant flow paths 7 and 8. In the collision portion of the end surfaces of the inlets 7A and 8A, the traveling direction of the refrigerant is changed by the presence of the wall end surfaces of the inlets 7A and 8A.

  The refrigerant whose direction has been changed becomes a turbulent flow by generating a vortex and this turbulent flow further affects the flow of the adjacent refrigerant. Therefore, the flow of the refrigerant in the communication region 23 is compared with the structure of Patent Document 1. It will be greatly disturbed. For this reason, in the communication region 23, the variation in the flow velocity and pressure of the refrigerant flowing out from the outlet 6B of the upstream refrigerant flow path 6 is alleviated, and the distribution of the refrigerant flowing into the inlets 7A and 8A of the downstream refrigerant flow paths 7 and 8 is reduced. The non-uniformity of the ratio can be improved.

  Furthermore, in the structure of the present embodiment, the liquid-phase refrigerant flows to the windward side of the flat tube 2 having high heat exchange efficiency as described below, so that the heat exchange efficiency of the entire heat exchanger can be increased. FIG. 6 is a diagram for explaining the behavior of the refrigerant flowing through the flat tube 2, in which the vicinity of the communication region 23 in the cross section of the yz plane along the flow direction of the refrigerant 11 in the flat tube 2 is enlarged.

  Since the heat transfer coefficient on the surface of the flat tube 2 is higher on the leeward side than on the leeward side, the amount of exchange heat is higher on the leeward side than on the leeward side. For this reason, even if a refrigerant having a uniform distribution ratio is introduced into the upstream refrigerant flow path 6 of the flat tube 2, heat exchange with the windward refrigerant 11 easily proceeds when flowing through the refrigerant flow path 6. On the upper side, heat exchange between the refrigerant 11 and the air is efficiently advanced.

  For example, when the heat exchanger 1 is used as an evaporator, when the refrigerant passes through the upstream-side refrigerant flow path 6 on the windward side, the refrigerant 11 in the liquid phase 14 changes to the gas phase 15 and the gas phase 15 is large. The communication area 23 is reached in a state. On the other hand, the refrigerant 11 passing through the upstream-side refrigerant flow path 6 on the leeward side does not have high heat exchange efficiency, and therefore reaches the communication region 23 with a large amount of the liquid phase 14.

  The refrigerant 11 that has reached the communication region 23 can also move in a direction orthogonal to the refrigerant flow path 6, that is, in the z-axis direction. Further, in the downstream refrigerant flow paths 7 and 8 formed by the downstream inner fins 22, the windward side is a refrigerant flow path 7 having a narrow width, that is, a refrigerant flow area narrowed. Here, since the refrigerant 11 that has become the gas phase 15 has a higher flow velocity than the liquid phase 14, it tends to easily flow into the wide refrigerant flow path 8 on the leeward side rather than the narrow refrigerant flow path 7. .

  For this reason, the gas phase 15 in which heat exchange with the air has been completed easily flows into the leeward downstream refrigerant passage 8 having a low heat transfer coefficient. On the other hand, the liquid phase 14 easily flows into the narrow downstream side refrigerant flow path 7 by capillary force. By these synergistic actions, a large amount of refrigerant containing a large amount of liquid phase flows in the narrow downstream side refrigerant flow path 7. Accordingly, a large amount of the liquid phase 14 flows through the upstream-side downstream refrigerant passage 7 having high heat exchange efficiency, so that heat exchange between the air and the refrigerant 11 as a whole is efficiently performed.

  The downstream side refrigerant flow path 7 having a narrow width on the windward side is not limited to one, but can be an arbitrary number, but in this embodiment, it is about 1/3 of the flat tube 2 when viewed from the blowing direction. It is provided over the length. According to the knowledge of the inventors, the heat exchange efficiency is not so high on the leeward side when viewed from the blowing direction of the flat tube 2, and up to about half of the flat tube 2 has high heat exchange efficiency. Therefore, it is desirable to provide the narrow downstream side refrigerant flow path 7 between about a half of the flat tube 2 from the windward side toward the leeward side.

  Accordingly, the flat pipe 2 is formed with at least a narrow downstream refrigerant passage 7 (in which the refrigerant circulation area is narrow) and a wide downstream refrigerant passage 8 in the air blowing direction. Will be.

  Next, an air heat exchanger according to a third embodiment of the present invention will be described in detail. This embodiment is different from the second embodiment in that the width of the downstream inner fin 22 is gradually increased from the windward side toward the leeward side.

  8 and 9 show a flat tube 2 and an upstream inner fin 21 and a downstream inner fin 22 housed in the flat tube 2 of the air heat exchanger 1 according to the third embodiment. 7 shows a cross section of the xz plane perpendicular to the refrigerant flow direction, and FIG. 8 shows a cross section of the yz plane along the refrigerant flow direction.

Similarly to the second embodiment, since the upstream inner fin 21 has a corrugated width (pitch) that is substantially constant, the width of the upstream refrigerant flow path 6 is constant. On the other hand, the downstream inner fin 22 has a corrugated width that is narrower on the leeward side than the leeward side, and further widens gradually toward the leeward side. That is, when the widths of the downstream refrigerant flow paths 7 and 8 are set to the width x ₁ , the width x ₂ , and the width x ₃ from the windward side, they are configured to have a relationship of x ₁ <x ₂ <x ₃ . The relationship with the width W of the upstream inner fin 1 is x1 <x2 = W <x3.

  Here, inner fins 22 having different widths (pitch) such as width x1, width x2, and width x can be continuously and integrally formed in the flat tube 2, but the width (pitch) It is also possible to individually form different inner fins and combine them in the flat tube 2. Therefore, an appropriate method may be adopted in consideration of the manufacturing apparatus, manufacturing cost, and the like.

  The behavior of the refrigerant shows the same behavior as that of the air heat exchanger 1 having the structure as in the second embodiment, and the effect thereof is substantially the same.

  That is, the outlet 6B of the upstream refrigerant flow path 6 and the inlets 7A and 8A of the downstream refrigerant flow paths 7 and 8 are shifted so that the opening portions do not overlap when viewed from the flow direction of the refrigerant. The refrigerant (including the liquid phase and the gas phase) flowing out from the outlet 6B of the path 6 collides with the wall end surfaces of the inlets 7A, 8A, and 8C of the downstream refrigerant flow paths 7 and 8. In the collision portion of the wall end surfaces of the inlets 7A, 8A, and 8C, the traveling direction of the refrigerant is changed by the presence of the wall end surfaces of the inlets 7A, 8A, and 8C.

  The refrigerant whose direction has been changed becomes a turbulent flow by generating a vortex, and this turbulent flow further affects the flow of the adjacent refrigerant, so that the flow of the refrigerant is greatly disturbed in the communication region 23. For this reason, in the communication area 23, the flow velocity and pressure variations of the refrigerant flowing out from the outlet 6B of the upstream refrigerant flow path 6 are alleviated, and the refrigerant flows into the inlets 7A, 8A, 8C of the downstream refrigerant flow paths 7, 8 This can improve the non-uniform distribution ratio.

  Furthermore, in the structure of the present embodiment, as described in the second embodiment, since the liquid-phase refrigerant flows on the windward side of the flat tube 2 having a high heat exchange efficiency, the heat exchange efficiency of the entire heat exchanger can be increased. it can. In the downstream refrigerant flow paths 7 and 8 formed by the downstream inner fins 22, the refrigerant flow path 7 is narrow on the windward side. Here, since the gas phase of the refrigerant 11 has a higher flow velocity than the liquid phase, it tends to easily flow into the inlets 8A and 8C of the wide refrigerant flow path 8 on the leeward side rather than the narrow refrigerant flow path 7. is there.

  For this reason, the gas phase in which heat exchange with the air has been completed easily flows into the inlets 8A and 8C of the downstream refrigerant flow path 8 on the leeward side having a low heat transfer coefficient. On the other hand, the liquid phase easily flows into the narrow downstream side refrigerant flow path 7 by capillary force. By these synergistic actions, a large amount of refrigerant containing a large amount of liquid phase flows in the narrow downstream side refrigerant flow path 7. Therefore, a large amount of liquid phase flows through the upstream-side downstream refrigerant flow path 7 with high heat exchange efficiency, so that heat exchange between the air and the refrigerant 11 as a whole is efficiently performed.

  In the present embodiment, the downstream refrigerant flow path 8 having the widest inlet 8C is arranged on the most leeward side of the flat tube 2 because the gas phase in the refrigerant flows through a passage having a large opening area. It was hoped that the gas phase would be gathered more on the leeward side that does not contribute much to heat exchange. As a result, it is possible to flow a refrigerant containing a large amount of liquid phase toward the downstream refrigerant flow path 7 having a narrow width on the windward side when viewed from the whole refrigerant. Therefore, heat exchange between the air and the refrigerant 11 as the entire heat exchanger 1 is efficiently performed.

  Next, an air heat exchanger according to a fourth embodiment of the present invention will be described in detail. The present embodiment is different from the second embodiment in that the communication area 23A is inclined by a predetermined angle from the windward side toward the leeward side. In the present embodiment, the upstream side refrigerant flow path 6 and the downstream side refrigerant path 8 having the same width are opposed to each other so that the outlet 6B and the inlet 8A overlap each other.

  10 and 11 show a flat tube 2 and an upstream inner fin 21 and a downstream inner fin 22 housed in the flat tube 2 of the air heat exchanger 1 according to the fourth embodiment. 10 shows a cross section of the xz plane orthogonal to the refrigerant flow direction, and FIG. 11 shows a cross section of the yz plane along the refrigerant flow direction.

  Similarly to the second embodiment, since the upstream inner fin 21 has a corrugated width (pitch) that is substantially constant, the width of the upstream refrigerant flow path 6 is constant. On the other hand, the downstream inner fin 22 has a corrugated width that is narrower on the leeward side than on the leeward side. Therefore, the refrigerant behaves in the same manner as in the second embodiment in the downstream side refrigerant flow path 7 having at least the narrow inlet 7A.

  That is, the outlet 6B of the upstream refrigerant flow path 6 and the inlet 7A of the downstream refrigerant flow path 7 are offset so that the opening portions do not overlap when viewed from the refrigerant flow direction. The refrigerant (including the liquid phase and the gas phase) flowing out from 6B collides with the wall end surface of the inlet 7A of the downstream refrigerant flow path 7. In the collision portion of the wall end surface of the inlet 7A, the traveling direction of the refrigerant is changed by the presence of the wall end surface of the inlet 7A.

  The refrigerant whose direction has been changed becomes a turbulent flow by generating a vortex, and this turbulent flow further affects the flow of the adjacent refrigerant, so that the flow of the refrigerant is greatly disturbed in the communication region 23A. For this reason, in the communication area 23A, variations in the flow velocity and pressure of the refrigerant flowing out from the outlet 6B of the upstream refrigerant flow path 6 are alleviated, and the distribution ratio of the refrigerant flowing into the inlet 7A of the downstream refrigerant flow path 7 is uneven. Can be improved.

  Furthermore, in the structure of the present embodiment, as described in the second embodiment, since the liquid-phase refrigerant flows on the windward side of the flat tube 2 having a high heat exchange efficiency, the heat exchange efficiency of the entire heat exchanger can be increased. it can. In the downstream refrigerant flow path 7 formed by the downstream inner fins 22, the windward side is a narrow refrigerant flow path 7. Here, since the gas phase of the refrigerant 11 has a higher flow velocity than the liquid phase, the refrigerant 11 tends to easily flow into the inlet 8A of the refrigerant passage 8 having a wide width on the leeward side instead of the narrow refrigerant passage 7.

  For this reason, the gas phase in which the heat exchange with the air has been completed easily flows into the inlet 8A of the downstream-side refrigerant flow path 8 on the leeward side having a low heat transfer coefficient. On the other hand, the liquid phase easily flows into the narrow downstream side refrigerant flow path 7 by capillary force. By these synergistic actions, a large amount of refrigerant containing a large amount of liquid phase flows in the narrow downstream side refrigerant flow path 7. Therefore, a large amount of liquid phase flows through the upstream-side downstream refrigerant flow path 7 with high heat exchange efficiency, so that heat exchange between the air and the refrigerant 11 as a whole is efficiently performed.

  Since the upstream refrigerant flow path 6 and the downstream refrigerant passage 8 having the same width are opposed to each other so that the outlet 6B and the inlet 8A overlap each other when viewed from the flow direction of the refrigerant, the refrigerant does not slow down. However, since the heat exchange efficiency is not so high on the leeward side as described above, it does not become a big problem. Instead, since the flow velocity of the refrigerant is high in this portion, the effect of taking in the gas phase of the refrigerant 11 separated at the narrow inlet 7A can be expected, and the liquid phase is put into the downstream refrigerant passage 7 having the narrow inlet 7A. A refrigerant containing a large amount can be sent.

  In the present embodiment, the communication region 23A is formed to be inclined at a predetermined angle from the windward side to the leeward side in the direction of the refrigerant. For this reason, since the communication area 23A is gradually displaced in the traveling direction of the air flowing through the uppermost communication area 23A flowing by the blower fan, the local heat exchange efficiency of the flat tube 2 is prevented from being lowered. be able to. That is, since the contact area between the refrigerant 11 and the flat tube 2 is small in the communication region 23A, the heat exchange efficiency is not high. For this reason, when the flow of the communication region 23A and the air 10 is parallel as in the second embodiment, the heat exchange efficiency between the air 10 and the flat tube 2 is locally reduced. However, since the communication flow path 23A is inclined with respect to the flow direction of the air 10 as in the present embodiment, it is possible to prevent the local heat exchange efficiency of the flat tube 2 from being lowered.

  The wide downstream side refrigerant flow path 8 shown in FIG. 11 is on the downstream side on the imaginary line extending the outlet 6B of the refrigerant flow path 6 formed by the upstream inner fins 21 as in the second embodiment. You may comprise so that the inlet 8A of the wide refrigerant | coolant flow path 8 formed by the inner fin 22 may be shifted so that it may not overlap, seeing from the flow direction of a refrigerant | coolant.

  Next, an air heat exchanger according to a fifth embodiment of the present invention will be described in detail. In this embodiment, a narrow downstream refrigerant passage 7, a downstream refrigerant passage 8 having the same width as the outlet 6B of the upstream refrigerant passage 6, and an upstream refrigerant passage and a downstream refrigerant passage are formed continuously. The second embodiment is different from the second embodiment in that the continuous refrigerant flow path 9 is provided.

12 and 13 show a flat tube 2 and an upstream inner fin 21 and a downstream inner fin 22 housed in the flat tube 2 of the air heat exchanger 1 according to the fifth embodiment. 12 shows a cross section of the xz plane perpendicular to the refrigerant flow direction, and FIG. 13 shows a cross section of the yz plane along the refrigerant flow direction.
Here, the upstream side refrigerant flow path 6 and the downstream side refrigerant flow path 7 do not have to be formed separately using two inner fins, and the inner fin 20 has a predetermined shape from the windward side toward the leeward side. A continuous communication region 23 is formed over the range. At this time, the communication region 23 is formed on the windward side of the inner fin 20 to form the upstream refrigerant flow path 6 and the downstream refrigerant flow path 7. The leeward side communicates from the lower end to the upper end of the flat tube 2 and forms independent coolant channels 9. The downstream refrigerant flow path 7 is configured as a refrigerant flow path 8 having a narrow width on the windward side and a wider width on the leeward side. In the present embodiment, the upstream side refrigerant flow path 6 and the downstream side refrigerant path 8 having the same width are opposed to each other so that the outlet 6B and the inlet 8A overlap each other.

  In this embodiment, the upstream inner fin 21 has a corrugated width (pitch) that is substantially constant, so the upstream refrigerant flow path 6 has a constant width. On the other hand, the corrugated width of the inner fin 20 is narrower on the leeward side than on the leeward side. Therefore, the refrigerant behaves in the same manner as in the second embodiment in the downstream side refrigerant flow path 7 having at least the narrow inlet 7A.

  That is, the outlet 6B of the upstream refrigerant flow path 6 and the inlet 7A of the downstream refrigerant flow path 7 are offset so that the opening portions do not overlap when viewed from the refrigerant flow direction. The refrigerant (including the liquid phase and the gas phase) flowing out from 6B collides with the wall end surface of the inlet 7A of the downstream refrigerant flow path 7. In the collision portion of the wall end surface of the inlet 7A, the traveling direction of the refrigerant is changed by the presence of the wall end surface of the inlet 7A.

  The refrigerant whose direction has been changed becomes a turbulent flow by generating a vortex, and this turbulent flow further affects the flow of the adjacent refrigerant, so that the flow of the refrigerant is greatly disturbed in the communication region 23. For this reason, in the communication region 23, the variation in the flow velocity and pressure of the refrigerant flowing out from the outlet 6B of the upstream refrigerant flow path 6 is alleviated, and the distribution ratio of the refrigerant flowing into the inlet 7A of the downstream refrigerant flow path 7 is uneven. Can be improved.

  Furthermore, in the structure of the present embodiment, as described in the second embodiment, since the liquid-phase refrigerant flows on the windward side of the flat tube 2 having a high heat exchange efficiency, the heat exchange efficiency of the entire heat exchanger can be increased. In the downstream refrigerant flow path 7 formed by the inner fins 20 that can be formed, the windward side is a refrigerant flow path 7 having a narrow width. Here, since the gas phase of the refrigerant 11 has a higher flow velocity than the liquid phase, the refrigerant 11 tends to easily flow into the inlet 8A of the refrigerant passage 8 having a wide width on the leeward side instead of the narrow refrigerant passage 7.

  For this reason, the gas phase in which the heat exchange with the air has been completed easily flows into the inlet 8A of the downstream-side refrigerant flow path 8 on the leeward side having a low heat transfer coefficient. On the other hand, the liquid phase easily flows into the narrow downstream side refrigerant flow path 7 by capillary force. By these synergistic actions, a large amount of refrigerant containing a large amount of liquid phase flows in the narrow downstream side refrigerant flow path 7. Therefore, a large amount of liquid phase flows through the upstream-side downstream refrigerant flow path 7 with high heat exchange efficiency, so that heat exchange between the air and the refrigerant 11 as a whole is efficiently performed.

Since the upstream refrigerant flow path 6 and the downstream refrigerant passage 8 having the same width are opposed to each other so that the outlet 6B and the inlet 8A overlap each other when viewed from the flow direction of the refrigerant, the refrigerant remains as it is without reducing the speed. Although the rate of progress increases, the leeward side does not have a large problem because the heat exchange efficiency is not so high as described above. Instead, since the flow rate of the refrigerant is high in this portion, the effect of taking in the gas phase of the refrigerant 11 separated at the narrow inlet 7A can be expected, and the liquid phase is introduced into the downstream refrigerant passage 7 having the narrow inlet 7A. It becomes possible to send a refrigerant containing a large amount.
In addition, since the heat transfer efficiency is low on the leeward side of the flat tube 2, even if the distribution ratio is not uniform with respect to the refrigerant 11 flowing through the refrigerant channel 7 on the windward side, the heat exchange efficiency for the entire heat exchanger 1 can be improved. The impact is small so it doesn't matter much.

  In the present embodiment, since the inner fins 20 provided in the flat tube 2 are integrally formed, handling when the inner fins 20 are brazed to the flat tubes 2 is facilitated, and the upstream side refrigerant flow path 6 and The width of the communicating region 23 formed between the downstream refrigerant flow paths 7 can be kept uniform, and the quality of the plurality of flat tubes 2 arranged in the heat exchanger 1 can be kept uniform. At this time, the number of the refrigerant flow paths 9 communicating with the inside of the flat tube 2 can be arbitrarily determined at one or more places.

  Finally, although a plurality of embodiments have been proposed in the present invention, each embodiment may be implemented alone, or two or more embodiments may be appropriately combined to form a more suitable embodiment. Is possible.

  DESCRIPTION OF SYMBOLS 1 ... Air heat exchanger, 2 ... Flat tube, 3 ... Header, 5 ... Heat transfer fin, 6 ... Upstream refrigerant flow path, 6A ... Inlet, 6B ... Outlet, 7 ... Narrow downstream refrigerant flow path, 8 ... Wide downstream refrigerant flow path, 7A, 8A ... Inlet, 7B, 8B ... Inlet, 9 ... Independent communication refrigerant flow path, 10 ... Air blowing direction, 11, 12 ... Refrigerant, 14 ... Liquid phase refrigerant, 15 ... Gas Phase refrigerant, 20 ... continuous inner fin, 21 ... upstream inner fin, 22 ... downstream inner fin, 23 ... communication region.

Claims (13)

An upstream inner fin which is provided in the flat tube and forms a plurality of upstream refrigerant flow paths by a plurality of partition walls arranged along the flow direction of the refrigerant;
A communication region that is provided in the flat tube and connects an outlet of each upstream refrigerant flow path downstream of each upstream refrigerant flow path and does not have the partition wall;
It is provided in the flat tube, and comprises downstream inner fins that form a plurality of downstream refrigerant flow paths by a plurality of partition walls arranged along the refrigerant flow direction downstream of the communication region,
The inlet of at least one of the downstream refrigerant flow paths and the outlet of the upstream refrigerant flow path of the downstream refrigerant flow path are arranged at positions that do not overlap with each other when viewed from the flow of the refrigerant,
The air heat exchanger, wherein the downstream refrigerant flow path on the windward side of the flat tube is configured to be narrower than the downstream refrigerant flow path on the leeward side . The air heat exchanger according to claim 1 ,
The width (pitch) of the partition walls of the upstream inner fin and the downstream inner fin is substantially the same, and the downstream inner fin is arranged so as to be displaced from the refrigerant flow with respect to the upstream inner fin. An air heat exchanger characterized by that . In the air heat exchanger according to claim 1 or 2 ,
The upstream inner fin and the downstream inner fin have a shape that forms a plurality of wavy partition walls having a curved cross section perpendicular to the refrigerant flow direction, a shape that forms a plurality of partition walls in which triangles are repeated, An air heat exchanger, wherein the air heat exchanger is at least one of shapes forming a plurality of partition walls in which a rectangle is repeated . The air heat exchanger according to claim 2,
The air heat exchanger according to claim 1, wherein the downstream inner fin is disposed so as to be shifted from the upstream inner fin by half the width of the downstream inner fin as viewed from the flow of the refrigerant . An upstream inner fin which is provided in the flat tube and forms a plurality of upstream refrigerant flow paths by a plurality of partition walls arranged along the flow direction of the refrigerant ;
A communication region that is provided in the flat tube and connects an outlet of each upstream refrigerant flow path downstream of each upstream refrigerant flow path and does not have the partition wall ;
It is provided in the flat tube, and comprises downstream inner fins that form a plurality of downstream refrigerant flow paths by a plurality of partition walls arranged along the refrigerant flow direction downstream of the communication region ,
The air heat exchanger characterized in that the downstream refrigerant flow path on the windward side of the flat tube is configured to be narrower than the downstream refrigerant flow path on the leeward side and the upstream refrigerant flow path . The air heat exchanger according to claim 5 ,
The upstream inner fin and the downstream inner fin have a shape that forms a plurality of wavy partition walls having a curved cross section perpendicular to the refrigerant flow direction, a shape that forms a plurality of partition walls in which triangles are repeated, An air heat exchanger, wherein the air heat exchanger is at least one of shapes forming a plurality of partition walls in which a rectangle is repeated . The air heat exchanger according to claim 6 ,
The downstream refrigerant flow path in the range of 1/3 to 1/2 of the flat pipe as viewed from the windward side of the flat pipe is narrower than the downstream refrigerant flow path and the upstream refrigerant flow path on the leeward side. An air heat exchanger characterized by comprising . The air heat exchanger according to claim 5 ,
The air heat exchanger according to claim 1, wherein the downstream-side refrigerant passage and the upstream-side refrigerant passage on the leeward side have substantially the same size . An upstream inner fin which is provided in the flat tube and forms a plurality of upstream refrigerant flow paths by a plurality of partition walls arranged along the flow direction of the refrigerant ;
A communication region that is provided in the flat tube and connects an outlet of each upstream refrigerant flow path downstream of each upstream refrigerant flow path and does not have the partition wall ;
It is provided in the flat tube, and comprises downstream inner fins that form a plurality of downstream refrigerant flow paths by a plurality of partition walls arranged along the refrigerant flow direction downstream of the communication region ,
The downstream refrigerant flow path is composed of a first downstream refrigerant flow path with a narrow refrigerant flow passage area and a second downstream refrigerant flow path with a large refrigerant flow passage area, and the first downstream refrigerant flow. The path is arranged on the windward side of the flat tube ,
The inlets of the first downstream refrigerant flow path, the second downstream refrigerant flow path, and the outlet of the upstream refrigerant flow path are disposed at positions that do not overlap with each other when viewed from the flow of the refrigerant. Features an air heat exchanger . An upstream inner fin which is provided in the flat tube and forms a plurality of upstream refrigerant flow paths by a plurality of partition walls arranged along the flow direction of the refrigerant ;
A communication region that is provided in the flat tube and connects an outlet of each upstream refrigerant flow path downstream of each upstream refrigerant flow path and does not have the partition wall ;
Provided in front Symbol flat tube becomes more downstream side inner fin which forms a plurality of downstream side refrigerant channel by a plurality of partition walls which are arranged along the flow direction of the refrigerant downstream of the communication area,
The downstream refrigerant flow path is composed of a first downstream refrigerant flow path with a narrow refrigerant flow passage area and a second downstream refrigerant flow path with a large refrigerant flow passage area, and the first downstream refrigerant flow. The path is arranged on the windward side of the flat tube ,
The second downstream refrigerant flow path and the upstream refrigerant flow path are substantially the same size, and the inlet of the second downstream refrigerant flow path and the outlet of the upstream refrigerant flow path are refrigerant flows. An air heat exchanger, which is arranged at a position overlapping when viewed from above . The air heat exchanger according to claim 9 or 10 ,
The air heat exchanger is characterized in that the communication region is formed to be inclined at a predetermined angle in the flow direction of the refrigerant from the windward side to the leeward side of the flat tube . An upstream inner fin which is provided in the flat tube and forms a plurality of upstream refrigerant flow paths by a plurality of partition walls arranged along the flow direction of the refrigerant ;
A communication region that is provided in the flat tube and connects an outlet of each upstream refrigerant flow path downstream of each upstream refrigerant flow path and does not have the partition wall ;
It is provided in the flat tube, and comprises downstream inner fins that form a plurality of downstream refrigerant flow paths by a plurality of partition walls arranged along the refrigerant flow direction downstream of the communication region ,
The downstream refrigerant flow path is formed continuously with a first downstream refrigerant flow path with a narrow refrigerant flow passage area, a second downstream refrigerant flow path with a large refrigerant flow passage area, and the upstream refrigerant flow. The continuous refrigerant flow path is arranged in the order of the first downstream refrigerant flow path, the second downstream refrigerant flow path, and the continuous refrigerant flow path as viewed from the windward side of the flat tube. With
The second downstream refrigerant flow path, the continuous flow path, and the upstream refrigerant flow path are substantially the same size, and the inlet of the second downstream refrigerant flow path and the outlet of the upstream refrigerant flow path Is an air heat exchanger characterized in that it is arranged in an overlapping position as seen from the refrigerant flow . The air heat exchanger according to any one of claims 9, 10, and 12 ,
The upstream inner fin and the downstream inner fin have a shape that forms a plurality of wavy partition walls having a curved cross section perpendicular to the refrigerant flow direction, a shape that forms a plurality of partition walls in which triangles are repeated, An air heat exchanger, wherein the air heat exchanger is at least one of shapes forming a plurality of partition walls in which a rectangle is repeated .

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