JP6661880B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner including a parallel flow heat exchanger using a flat tube and a cross-fin tube heat exchanger using a circular tube.

  Conventionally, as an indoor heat exchanger of an air conditioner, a fin tube heat exchanger using a heat transfer tube having a circular cross section (hereinafter, referred to as a circular tube) has been used. A general fin tube heat exchanger includes a copper circular pipe through which a refrigerant flows, an aluminum fin group intersecting with the circular pipe, and a copper U-shaped pipe connecting ends of the circular pipe. .

  In recent years, in the heat exchangers installed in air conditioners, in order to reduce the cost of copper materials and improve heat exchange efficiency, there has been a change from conventional copper pipes to flat aluminum pipes. It is being studied (for example, see Patent Document 1). Aluminum heat exchangers generally use flat tubes as heat transfer tubes, and aluminum flat tubes through which a refrigerant flows and corrugated fins that are alternately stacked with the flat tubes. A parallel flow heat exchanger (hereinafter, referred to as a flat tube heat exchanger) including a flat tube and an aluminum header connected to an end of the flat tube is known.

  Some indoor heat exchangers mounted on the indoor unit of the air conditioner include a main heat exchanger and an auxiliary heat exchanger provided on a part of the windward side of the main heat exchanger. In the current main heat exchanger, since the refrigerant flow dividing structure is complicated, it is difficult to reproduce the current flow dividing structure with the header of the flat tube heat exchanger. However, if the branching structure is a simple auxiliary heat exchanger, it is easy to change to a flat tube heat exchanger. Therefore, an auxiliary heat exchanger composed of a flat tube heat exchanger is provided on a part of the windward side of a main heat exchanger composed of a conventional fin tube heat exchanger using a circular tube (hereinafter referred to as a circular tube heat exchanger). A provided indoor heat exchanger is proposed.

  6 to 10 show an indoor heat exchanger in which an auxiliary heat exchanger including a flat tube heat exchanger 200 is provided on a part of the windward side of a main heat exchanger including a circular tube heat exchanger 100. . At this time, as shown in FIG. 8, when the aluminum header 201 of the flat tube heat exchanger 200 and the copper hairpin tube 101 of the circular tube heat exchanger 100 are close to each other, electric erosion due to a bridge due to water droplets or the like occurs. 6 and 7, the header 201 of the flat tube heat exchanger 200 is electrically eroded with the hairpin tube 101 of the circular tube heat exchanger 100 as shown in FIGS. It is necessary to arrange them with no distance L1.

  As shown in FIG. 9, when fixing the auxiliary heat exchanger to the main heat exchanger, a method of fixing the side plates 102 and 202 provided respectively to each other is used. At this time, by adjusting the fixed position between the side plates 102 and 202, not only the above distance L can be secured, but also the side gap S1 generated by the distance L1 can be shielded by the side plates 102 and 202.

  However, in the flat tube heat exchanger 200, a gap S2 needs to be provided between the header 201 and the fin group 203 in the manufacturing stage. Since the gap S2 communicates with a large gap S3 existing between the fin group 203 of the flat tube heat exchanger 200 and the fin group 103 of the circular tube heat exchanger 100, the gap S2 is smaller than the installation range of the fin group 203. As a result, a large amount of air flows into the gap S3 via the gap S2, and the heat exchange efficiency of the flat tube heat exchanger 200 as the auxiliary heat exchanger is reduced. There was a problem. Furthermore, since the fin groups 203 are not communicated in the vertical direction, there is a problem that drainage of condensed water is not good.

  As shown in FIG. 10, it is conceivable to provide a seal member 204 for closing the gap S <b> 2 in the flat tube heat exchanger 200 as the auxiliary heat exchanger. Since it becomes difficult for air to flow into the leeward region R of 204, there has been a problem that the heat exchange efficiency of the tube heat exchanger 100 as the main heat exchanger is reduced.

JP 2014-88993 A

  Therefore, the present invention has been made in view of the above problems, and in providing a flat tube heat exchanger on the windward side of a tube heat exchanger, the hairpin tube and the flat tube heat exchange of the tube heat exchanger are provided. Even if the header of the flat tube heat exchanger is placed apart to prevent electrolytic corrosion, the gap between the fin group of the flat tube heat exchanger and the header, the fin group of the flat tube heat exchanger and the circular tube It is an object of the present invention to provide an air conditioner that can suppress a decrease in heat exchange efficiency due to a gap between a heat exchanger and a fin group. In addition, an object of the present invention is to provide an air conditioner that does not require a spacer for securing a gap between a hairpin tube and a header, and that can improve drainage of condensed water.

  The present invention has been proposed to achieve the above object.

(1) One aspect according to the present invention includes a plurality of first heat transfer tubes made of copper, through which a refrigerant flows, and a first fin group including a plurality of fins intersecting and stacking with the first heat transfer tubes. A main heat exchanger including a copper connecting portion connecting end portions of the first heat transfer tubes, a plurality of second heat transfer tubes through which a refrigerant flows, and intersecting and stacking the second heat transfer tubes; A second fin group including a plurality of fins, and an auxiliary heat exchanger including an aluminum header connected to an end of the second heat transfer tube and disposed on the windward side of the main heat exchanger. An air conditioner comprising: an auxiliary heat exchanger fixed to the main heat exchanger such that the second heat transfer tube is arranged in parallel with the first heat transfer tube; The group has a first side plate at both ends in the stacking direction of the fins, the header has a second side plate, and the first and second side plates are The header and the connection portion are fixed by a fixture so as to be arranged at a predetermined distance, and the second fin group extends so as to approach or contact the windward end of the first fin group. It has a leeward end.

(2) In the air conditioner according to the above (1), the second fin group has a leeward end that extends so that at least fins at both ends approach or contact the leeward end of the first fin group. You may have.

(3) In the air conditioner of (1) or (2), the gap between the header and the first fin group may be closed by the first side plate and the second side plate.

(4) In the air conditioners of (1) to (3) above, all the fins constituting the second fin group extend so as to approach or contact the windward end of the first fin group. It may have a leeward end.

  According to the present invention, in an air conditioner provided with an auxiliary heat exchanger using a flat tube on the windward side of a main heat exchanger using a circular tube, a hairpin tube of the main heat exchanger and a header of the auxiliary heat exchanger Even if the fins of the auxiliary heat exchanger and the fin of the main heat exchanger are separated from the gap between the fin of the auxiliary heat exchanger and the header, It is possible to suppress a decrease in heat exchange efficiency due to air flowing into the gap. In addition, a spacer for securing a gap between the hairpin tube and the header is not required, and the drainage of condensed water can be improved.

It is an explanatory view at the time of heating operation of an air conditioner concerning an embodiment of the present invention. It is an explanatory view at the time of cooling operation of an air conditioner concerning an embodiment of the present invention. It is a side view showing the composition of the indoor heat exchanger concerning an embodiment of the present invention. FIG. 4 is a view taken in the direction of arrow A in FIG. 3 and shows an example in which the entire second fin group is close to the first fin group side. FIG. 4 is a diagram viewed from an arrow A in FIG. 3 and illustrates an example in which only fins at both ends of a second fin group are close to the first fin group. It is a figure of the flat tube heat exchanger which concerns on embodiment of this invention, (a) is a top view of a flat tube heat exchanger, (b) is a front view of a flat tube heat exchanger, (c) is a flat tube heat exchanger. FIG. 2D is a side view of the exchanger, and FIG. It is a side view which shows the structure of the indoor heat exchanger which concerns on the reference example 1. FIG. 7 is a view taken in the direction of arrow A in FIG. 6. FIG. 9 is a view as seen from the direction of arrow A in Reference Example 2. FIG. 13 is a view as viewed from the direction of the arrow A in Reference Example 3. FIG. 14 is a view as viewed from the direction of the arrow A in Reference Example 4.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The same elements will be denoted by the same reference symbols throughout the description of the embodiments.

  FIG. 1 is an explanatory diagram during a heating operation of the air conditioner according to the embodiment of the present invention, and FIG. 2 is an explanatory diagram during a cooling operation of the air conditioner according to the embodiment of the present invention. As shown in FIGS. 1 and 2, the air conditioner 1 includes an indoor unit 2 and an outdoor unit 3. The indoor unit 2 includes a main heat exchanger including a heat exchanger 10 (hereinafter, referred to as a circular tube heat exchanger 10) using a plurality of circular tubes 13 (first heat transfer tubes) described below, and a main heat exchanger. A plurality of flat tubes 21 (second heat transfer tubes) to be described later are used in a part of the windward side of the heat exchanger 20 (hereinafter, referred to as a heat exchanger 20) having a pair of headers 23 provided at both ends in the longitudinal direction of the plurality of flat tubes. , An indoor heat exchanger 4 provided with an auxiliary heat exchanger including the heat exchanger 20, and a blower 5 arranged on the leeward side of the indoor heat exchanger 4. The air sucked from the suction port 5a in response to the driving of the blower 5 passes through the indoor heat exchanger 4, and is discharged from the blow port 5b. The outdoor unit 3 is provided with a compressor 7, an expansion valve 8, and a four-way valve 9 in addition to the outdoor heat exchanger 6 configured by using an arbitrary heat exchanger. Note that, here, a circular tube heat exchanger is described as the main heat exchanger, and a flat tube heat exchanger is described as the auxiliary heat exchanger, but the shapes of the heat transfer tubes are not limited to these. , Various things can be adopted.

  As shown in FIG. 1, during the heating operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 7 of the outdoor unit 3 flows into the indoor heat exchanger 4 of the indoor unit 2 via the four-way valve 9. The refrigerant that has exchanged heat with air in the indoor heat exchanger 4 (condenser) condenses and liquefies. As described above, the indoor heat exchanger 4 functions as a condenser, exchanges heat with the refrigerant in the indoor heat exchanger 4, and the heated indoor air is blown out into the room, so that the indoor unit 2 is installed. Heating is performed. At this time, the refrigerant first flows into the leeward tube heat exchanger 10 that is the main heat exchanger, and then flows into the flat tube heat exchanger 20 that is the auxiliary heat exchanger. Thereafter, the high-pressure liquid refrigerant is reduced in pressure by passing through the expansion valve 8 of the outdoor unit 3, becomes a low-temperature low-pressure gas-liquid two-phase refrigerant, and flows into the outdoor heat exchanger 6. The refrigerant that has exchanged heat with the outside air in the outdoor heat exchanger 6 (evaporator) is gasified. Thereafter, the low-pressure gas refrigerant is sucked into the compressor 7 via the four-way valve 9.

  As shown in FIG. 2, during the cooling operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 7 of the outdoor unit 3 flows into the outdoor heat exchanger 6 via the four-way valve 9. The refrigerant that has exchanged heat with the outside air in the outdoor heat exchanger 6 (condenser) is condensed and liquefied. Thereafter, the high-pressure liquid refrigerant is reduced in pressure by passing through the expansion valve 8 of the outdoor unit 3, becomes a low-temperature low-pressure gas-liquid two-phase refrigerant, and flows into the indoor heat exchanger 4 of the indoor unit 2. The refrigerant that has exchanged heat with air in the indoor heat exchanger 4 (evaporator) is gasified. As described above, the indoor heat exchanger 4 functions as an evaporator, exchanges heat with the refrigerant in the indoor heat exchanger 4, and the cooled indoor air is blown into the room, whereby the indoor unit 2 is installed. Cooling is performed. At this time, the refrigerant first flows into the flat tube heat exchanger 20 on the windward side as the auxiliary heat exchanger, and then flows into the circular tube heat exchanger 10 as the main heat exchanger. Thereafter, the low-pressure gas refrigerant is sucked into the compressor 7 via the four-way valve 9.

  FIG. 3 is a side view showing the configuration of the indoor heat exchanger according to the embodiment of the present invention, and FIG. 4A is a view taken in the direction of arrow A in FIG. As shown in FIG. 3 and FIG. 4A, a circular pipe heat exchanger 10 provided as a main heat exchanger of the indoor heat exchanger 4 includes a copper circular pipe 11 through which a refrigerant flows, and a plurality of A first fin group 12 made of aluminum made of laminated fins, and a U-shaped tube 13 (connection portion) made of copper for connecting the ends of the circular tube 11 are provided. The U-shaped tube 13 includes one integrated with the circular tube 11.

  Note that the tube heat exchanger 10 of the present embodiment includes a first tube heat exchanger unit 10a that is disposed substantially vertically below the front side in the housing of the air conditioner 1, and an upper part that is rearward on the front side. A second tube heat exchanger unit 10b having a lower portion inclined forward and a third tube heat exchanger unit 10c having an upper portion arranged forward and a lower portion inclined rearward. Although it is configured by connecting these tube heat exchanger units 10a, 10b, and 10c, the tube heat exchanger 10 of the present invention may be configured by one tube heat exchanger unit. It may be configured by connecting four or more circular tube heat exchanger units.

  Drawing 5 is a figure of the flat tube heat exchanger concerning an embodiment of the present invention, (a) is a top view of a flat tube heat exchanger, (b) is a front view of a flat tube heat exchanger, (c) FIG. 2 is a side view of a flat tube heat exchanger. As shown in FIGS. 3 to 5, a flat tube heat exchanger 20 provided as an auxiliary heat exchanger of the indoor heat exchanger 4 includes an aluminum flat tube 21 through which a refrigerant flows, and an A second fin group 22 made of a plurality of fins stacked with a gap for allowing the air to pass therethrough, and an aluminum header 23 connected to both ends of the flat tube 21 are provided. Is provided on the windward side of the circular tube heat exchanger 10 (second circular tube heat exchanger unit 10b) with a distance L1 that does not cause electrolytic corrosion with the U-shaped tube 13.

  The flat tube 21 has a flat shape whose cross section extends in the air flow direction, and a plurality of refrigerant flow paths 21a arranged in the air flow direction are formed in parallel inside the flat tube 21. The flat tubes 21 are arranged in parallel with a gap through which air passes, and both ends thereof are connected to the pair of headers 23.

  The header 23 has a cylindrical shape. Inside the header 23, a refrigerant flow path (not shown) for dividing the flowing refrigerant into the plurality of flat tubes 21 and merging the refrigerant flowing from the plurality of flat tubes 21 is provided. (Shown). That is, the refrigerant supplied to one header 23 is divided and flows into the plurality of flat tubes 21. Then, the refrigerant flowing into the flat tube 21 flows through the internal refrigerant flow path 21a, reaches the other end, and flows out to the other header 23. At this time, in the flat tube 21, heat exchange is performed between the refrigerant flowing through the flat tube 21 and air passing through the gap between the flat tubes 21.

  The second fin group 22 allows air to pass through a flat fin 22a extending in a direction intersecting with the flat tube 21 in a plan view (FIG. 5A) or a front view (FIG. 5B). Are provided in parallel with each other. As shown in FIG. 5D, the fin 22a has a plurality of cutouts 22b fitted to the flat tube 21 at the windward end, and these cutouts 22b are fitted to the flat tube 21. By brazing in the combined state, the fins 22a and the flat tubes 21 are integrally joined.

  As shown in FIG. 5C, the second fin group 22 is formed so as to extend such that the leeward end thereof is located on the leeward side with a distance L2 from the leeward side outline of the header 23 in a side view. Is done. The distance L2 can be set based on the distance L3 from the windward end of the first fin group 12 of the circular tube heat exchanger 10 to the windward end of the U-shaped tube 13, and the distance L1 described above. it can. For example, a value obtained by subtracting the distance L3 from the distance L1 is set as the distance L2. In this way, when the flat tube heat exchanger 20 is disposed on the windward side of the circular tube heat exchanger 10 with the distance L1 at which the header 23 does not cause electrolytic corrosion from the U-shaped tube 13, the leeward side of the second fin group 22 The end can be close to or in contact with the windward end of the first fin group 12.

  As shown in FIG. 4A, the tube heat exchanger 10 has first side plates 14 outside both ends in the stacking direction of the first fin group 12, and the flat tube heat exchanger 20 is located on the leeward side of the header 23. It has a second side plate 24. The leeward end of the first side plate 14 and the leeward end of the second side plate 24 overlap with each other and are fixed by bolts B as fixing tools. In this way, the flat tube heat exchanger 20 can be fixed to the circular tube heat exchanger 10 while securing the predetermined distance L1 at which the header 23 does not cause electrolytic corrosion with the U-shaped tube 13, and the distance L1 Is closed by the first side plate 14 and the second side plate 24, so that air can be prevented from flowing into the space between the circular tube heat exchanger 10 and the flat tube heat exchanger 20 from the space.

  The flat tube heat exchanger 20 has a gap S2 between the header 23 and the second fin group 22 due to the manufacturing method. Here, when there is a large gap S3 (see Reference Example 3 shown in FIG. 9) between the second fin group 22 of the flat tube heat exchanger 20 and the first fin group 12 of the circular tube heat exchanger 10. Since the gap S2 communicates with the gap S3 and becomes an air inflow path having a smaller air resistance than the installation range of the second fin group 22, a large amount of air flows into the gap S3 via the gap S2 and becomes flat. Although the heat exchange efficiency of the tube heat exchanger 20 may decrease, in the flat tube heat exchanger 20 according to the embodiment of the present invention, the leeward end of the second fin group 22 is Since the space S3 is formed so as to extend close to or be in contact with the windward side end, the air injected from the space S2 can be guided to the first fin group 12 located downstream thereof. Here, FIG. 4A shows an example in which all the fins forming the second fin group 22 are close to the first fin group 12 side, but the configuration of the second fin group 22 is not limited to this. Instead, for example, as shown in FIG. 4B, only the fins at both ends of the second fin group 22 may be made to approach or contact the first fin group 12. However, in this case, air flows into the gap formed between the second fin group 22 and the first fin group 12 from above and below (in the drawing, perpendicular to the paper surface). Therefore, as shown in FIG. 4A, it is preferable that the entire second fin group 22 is brought close to or in contact with the first fin group 12 side.

  According to the embodiment of the present invention described above, the air conditioner 1 includes a plurality of copper circular pipes 11 through which the refrigerant flows, and a plurality of the circular pipes 11 intersecting the circular pipes 11 and provided with a gap for allowing air to pass therethrough. A main heat exchanger 10 including a first fin group 12 composed of fins and a copper U-shaped tube 13 connecting the ends of the circular tube 11, a flat tube 21 through which a refrigerant flows, and an intersection with the flat tube 21 A flat tube including a second fin group 22 composed of a plurality of stacked fins and an aluminum header 23 connected to an end of the flat tube 21 and arranged on the windward side of the circular tube heat exchanger 10 The first fin group 12 has a first side plate 14 at both ends in the stacking direction of the fins, the header 23 has a second side plate 24, and the first side plate 14 and the second side plate 24 , So that the header 23 and the U-shaped tube 13 are arranged at a predetermined distance. B, and the second fin group 22 has a leeward end that extends so that at least both fins are close to or in contact with the leeward end of the first fin group 12, so that the flat tube heat exchanger Even if there is a gap S2 between the first fin group 12 and the header 23, a lot of air flows between the first fin group 12 and the second fin group 22 through the gap S2. As a result, the heat exchange efficiency of the flat tube heat exchanger 20 can be improved. Furthermore, a spacer for securing a gap between the U-shaped tube 13 and the header 23 is not required, and the drainage of condensed water can be improved.

  Further, according to the configuration of the present embodiment, it is not necessary to close the gap S2, so that the air flow in the leeward region of the gap S2 is improved, and the heat exchange efficiency of the tubular heat exchanger 10 can be improved.

  Further, according to the configuration of the present embodiment, the flat tube heat exchanger 20 is not only provided on the windward side of the circular tube heat exchanger 10 with the distance L1 at which the header 23 does not cause electrolytic corrosion with the U-shaped tube 13, Since the gap generated by the distance L1 is closed by the first side plate 14 and the second side plate 24, air may flow between the flat tube heat exchanger 20 and the circular tube heat exchanger 10 from the gap. Can be avoided.

  Further, since the first side plate 14 and the second side plate 24 are fixed by the bolts B, which are fixing tools, the flat tube heat exchange is performed while securing the distance L1 at which the header 23 and the U-shaped tube 13 do not cause electrolytic corrosion. The vessel 20 can be fixed to the tube heat exchanger 10.

  In addition, since all the fins forming the second fin group 22 have the leeward side end portions that extend to approach or contact the leeward side end portions of the first fin group 12, the flat tube heat exchanger 20 It is possible to eliminate a gap between the cylindrical heat exchanger 10 and the heat exchanger 10 over a wide area, and to prevent turbulence of airflow in the gap. Furthermore, since the second fin group 22 communicates vertically on the leeward side, even with the flat tube heat exchanger 20, the drainage of condensed water can be improved. In particular, this point is a more remarkable effect than the flat tube heat exchanger using corrugated fins.

  As described above, the preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiments, and various modifications and changes may be made within the scope of the present invention described in the appended claims. Changes are possible.

DESCRIPTION OF SYMBOLS 1 ... Air conditioner, 2 ... Indoor unit, 3 ... Outdoor unit, 4 ... Indoor heat exchanger, 5 ... Blower, 5a ... Inlet, 5b ... Outlet, 6 ... Outdoor heat exchanger, 7 ... Compressor, 8 ... expansion valve, 9 ... four-way valve, 10 ... circular pipe heat exchanger, 11 ... circular pipe, 12 ... first fin group, 13 ... hairpin pipe, 14 ... first side plate, 20 ... flat pipe heat exchanger, 21 ... Flat tube, 21a refrigerant channel, 22 second fin group, 22a fin, 22b notch, 23 header, 24 second side plate,

Claims (4)

A plurality of first heat transfer tubes made of copper through which a refrigerant flows;
A first fin group including a plurality of fins that intersect with the first heat transfer tube and are stacked;
A main heat exchanger including a copper connecting portion for connecting an end of the first heat transfer tube;
A plurality of second heat transfer tubes through which the refrigerant flows;
A second fin group including a plurality of fins that intersect with the second heat transfer tube and are stacked;
An aluminum header connected to an end of the second heat transfer tube;
An auxiliary heat exchanger arranged on the windward side of the main heat exchanger, and an air conditioner comprising:
The auxiliary heat exchanger is fixed to the main heat exchanger such that the second heat transfer tube is arranged in parallel with the first heat transfer tube,
The first fin group has first side plates at both ends in the stacking direction of the fins,
The header has a second side plate,
The first side plate and the second side plate are fixed by a fixture such that the header and the connection portion are arranged at a predetermined distance,
The second fin group has a leeward end portion extending more leeward than the leeward end of the header so as to approach or contact the leeward end of the first fin group. Air conditioner. 2. The air according to claim 1, wherein the second fin group has a leeward end that extends so that at least both fins are close to or in contact with the leeward end of the first fin group. 3. Harmony machine. 3. The air conditioner according to claim 1, wherein a gap between the header and the first fin group is closed by the first side plate and the second side plate. 4. The fins constituting the second fin group all have a leeward side end extending so as to approach or contact the leeward side end of the first fin group. The air conditioner according to any one of the above.

Images