JP4874320B2 - Heat exchanger and air conditioner equipped with the heat exchanger - Google Patents

Description

  The present invention is used for air conditioning, refrigeration, refrigeration, etc., and is a finned tube type heat exchange composed of a plate-like fin that exchanges heat between a refrigerant and a fluid such as air and a heat transfer tube composed of a multi-hole tube. And an air conditioner equipped with the heat exchanger.

  A heat exchanger constituting a conventional air conditioner is called a fin tube heat exchanger. This heat exchanger is composed of plate-like fins that are arranged at regular intervals and through which gas (air) flows, and circular tube-shaped heat transfer tubes that are inserted perpendicularly to the plate-like fins and into which refrigerant flows. Therefore, a slit group is formed by cutting and raising a plate-like fin between adjacent heat transfer tubes. This slit group is provided so that the side end portion of the slit is opposed to the wind direction, and heat transfer is promoted by thinning the velocity boundary layer and the temperature boundary layer of the air flow at the side end portion. The crack heat exchange capacity is said to increase (see, for example, Patent Document 1).

  In addition, there are a part of pipes with almost the same thickness centering on the axis of the hole on the outer periphery of each hole, and a part of the many pipes are integrated to form a corrugated surface on the outer periphery. A heat exchanger provided with a heat transfer tube made of a multi-hole tube has been proposed (see, for example, Patent Document 2).

JP-A-2-33595 (page 3-4, FIG. 1-2) Japanese Patent Laid-Open No. 2004-233012 (page 3, FIG. 1)

  The heat exchanger of Patent Document 1 is not only troublesome to manufacture because a large number of cuts and raised portions are provided on both sides of the plate-like fins, but also has a large ventilation resistance. For this reason, it can be applied only to an air conditioner or the like that can secure a sufficient air flow rate, and there is a problem in the application range. Moreover, in this invention, when the heat exchanger tube which consists of a multi-hole tube which connected the some circular tube to the heat exchanger is used, the dead water area which generate | occur | produces in the constriction part formed in the connection part cannot be suppressed. There's a problem.

  In Cited Document 2, there is a problem that a dead water area is generated in a constricted portion of a corrugated surface formed on the outer periphery of a large number of pipes, thereby reducing heat transfer performance.

  The present invention has been made in order to solve the above-described problems, and is a fin-tube type heat composed of laminated plate-like fins and a heat transfer tube formed of a multi-hole tube provided therethrough. An object of the present invention is to provide a heat exchanger having a high heat exchanging capacity and an air conditioner equipped with the heat exchanger, in which a dead water area is prevented from being generated in a constricted portion formed in a heat transfer tube. It is what.

The heat exchanger according to the present invention includes a plurality of plate-like fins stacked at predetermined intervals and air flowing between them, and a plurality of circular pipes connected via a constriction in the air flow direction, and the air flow direction and a plurality of heat transfer tubes disposed through said plate fins in the laminating direction in the column direction at predetermined intervals perpendicular to the front on both sides of Kiden heat pipe, the cut and raised the plate fins One leg is positioned close to the constricted portion of the heat transfer tube, and the other leg is positioned inclined in a direction away from the heat transfer tube, and has a slit that is obliquely opposed to the air flow direction. It is provided.

  Moreover, the air conditioner which concerns on this invention is equipped with said heat exchanger.

  The present invention relates to a heat exchanger composed of laminated plate-like fins and a multi-hole tube passing through the plate-like fins, and cuts and raises the plate-like fins between the heat transfer tubes adjacent in the step direction. Therefore, since both legs are provided with slits located close to the constricted portion of the heat transfer tube, there is no dead water area in the constricted portion of the heat transfer tube, and the effective heat transfer area increases, so the heat exchange capacity is high. A heat exchanger and an air conditioner including the heat exchanger can be obtained.

[Embodiment 1]
1 is a plan sectional view of a part of a heat exchanger according to Embodiment 1 of the present invention, and FIG. 2 is a longitudinal sectional view of FIG.
In the figure, a plurality of plate-like fins 1 are laminated in parallel with a predetermined gap (pitch Fp). A plurality of heat transfer tubes 10 that are flat multi-hole tubes having the same outer diameter on both sides and constricted in the center are arranged in the step direction of the plate fins 10 (between the plate fins 1 in the vertical direction in FIG. 1). The shape is similar to the outer shape of the heat transfer tube 10 provided at a predetermined interval (pitch p) in the direction perpendicular to the flow direction of the air flowing through the plate, and is guided by the fin collar 2 provided on each plate-like fin 1 to form a plate shape. The fins 1 are installed through the stacking direction. Then, both end portions of these adjacent heat transfer tubes 10 are alternately connected and integrated in the opposite direction so that the refrigerant flowing in from one inflow port flows out from the other discharge port. In the figure, the fin collar 2 and the heat transfer tube 10 are shown integrally (the same applies to the following drawings).

  An air flow direction indicated by an arrow (hereinafter referred to as a row) is provided on either the front surface or the back surface between adjacent fin collars 2 provided on the plate-like fins 1 (the surface is shown in the drawing). A plurality of cut-and-raised portions (hereinafter referred to as slits) are provided perpendicular to the direction). That is, the first slit 4 is located at the center of the plate-like fin 1 in the row direction, the second slit 5 is located upstream of the first slit 4, and the second slit 5 is located downstream of the first slit 4. A total of three rows of third slits 6 are provided at the positions.

  The first to third slits 4, 5, 6 are formed by cutting and raising one surface of the plate-like fin 1, and as shown in FIGS. 3A and 3B, the surface of the plate-like fin 1. Leg portions 4a, 5a, 6a inclined to each other, and cut-and-raised portions 4b, 5b, 6b parallel to the surface of the plate-like fin 1 bridging between the two leg portions. 5b and 6b are opened in the air flow direction.

  The leg 4a of the first slit 4 is formed substantially in parallel with the air flow direction, and the second slit 5 is narrowed so that the distance between the legs 5a is widened on the upstream side and widened on the downstream side. It is formed diagonally opposite the air flow direction. Further, the distance between both leg portions 6a of the third slit 6 is narrowed by narrowing the upstream side and widening the downstream side, and is formed so as to be diagonally opposed to the air flow direction. In addition, both the leg parts 4a of the first slit 4 are located close to the constricted parts 11 of the two adjacent heat transfer tubes 10. 3C is a cross-sectional view taken along the line CC of FIG. 1 (cross-section of the fin collar 2).

  In the present embodiment, the heat transfer tube 10 is formed by joining two circular tubes of the same diameter made of a metal material such as copper or a copper alloy, aluminum or an aluminum alloy, with a part in the axial direction cut and joined. A plate having a constricted part 11 at the center and a substantially bowl-shaped cross section, which is guided by the fin collar 2 with the constricted part 11 as a substantially central part in the column direction, and is laminated in parallel with the air flow direction. It is installed through the fin 1. In the above description, the case where the two heat exchanger tubes 10 are joined to form the heat transfer tube 10 that is a multi-hole tube is shown, but the heat transfer tube 10 that is a multi-hole tube may be manufactured by drawing.

  For example, 12.24 mm, 15.3 mm, and 20.4 mm are used as the arrangement pitch p in the step direction of the plate-like fins 1 of the heat transfer tubes 10. When a plurality of heat transfer tubes 10 are installed in the row direction of the plate-like fins 1, the pitch in the row direction is set to 10.7 mm, 12.7 mm, 18 mm, and 22 mm, for example. In addition, these numerical values show the example, It does not limit to this.

  In the present embodiment, as shown in FIG. 4, the leg portion 4 a of the first slit 4 is located close to the constricted portion 11 of the heat transfer tube 10, and the leg portion 5 a of the second slit 5 is The upstream side of the heat transfer tube 10 is widened and positioned on the inner side (center side of the large diameter portion) of the large diameter portion on the upstream side of the heat transfer tube 10, with a gap between the large diameter portion and the air flow direction. Oppositely inclined. For this reason, the air which flows in into the large diameter part side of the heat exchanger tube 10 from between the laminated plate-like fins 1 can be led to the downstream side along the peripheral wall of the heat exchanger tube 10, particularly the peripheral wall of the constricted part 11. For this reason, a dead water area does not occur in the vicinity of the constricted portion 11 of the heat transfer tube 10.

  Further, the leg portion 6a of the third slit 6 is widened on the downstream side and is located on the inner side of the outer periphery of the large-diameter portion on the downstream side of the heat transfer tube 10, and the air is separated from the large-diameter portion with a gap. It is provided to be inclined to face the flow direction. For this reason, since the air which flows out along the surrounding wall of the large diameter part downstream from the constriction part 11 of the heat exchanger tube 10 can be guide | induced to the center part side of the step direction of the heat exchanger tube 10, the downstream of the heat exchanger tube 10 It is possible to greatly reduce the dead water area that is formed.

  FIG. 5 is an explanatory view of a heat exchanger provided with a heat transfer tube 10 composed of a multi-hole tube not provided with a slit for comparison with the present embodiment. In this case, since the laminated plate-like fins 1 are not provided with slits, the temperature boundary layer is not divided or renewed, and the constricted portion 11 of the heat transfer tube 10 and a large dead water area are formed on the downstream side. As a result, the heat transfer performance is significantly reduced.

Next, the relationship between the width SL in the column direction of the first slit 4 in FIG. 1 and the width L in the column direction of the constricted portion 11 of the heat transfer tube 10 (the distance between the center portions of the joined circular tubes). Consider.
The first slit 4 is formed in the constricted portion 11 of the heat transfer tube 10 by forming the width SL in the row direction of the first slit 4 smaller (narrower) than the width L in the column direction of the constricted portion 11 of the heat transfer tube 10. They can be provided close to each other, thereby preventing a dead water area from being generated in the constricted portion 11 and suppressing a decrease in heat transfer.

  When the width SL of the first slit 4 in the row direction is substantially equal to or larger than the width L of the constricted portion 11 of the heat transfer tube 10 in the row direction, both ends of the first slit 4 are close to the constricted portion 11. Therefore, a dead water area is formed in the constricted part 11 and heat transfer is reduced. Therefore, it is necessary to make the width SL of the first slit 4 in the column direction smaller than the width L of the constricted portion 11 of the heat transfer tube 10.

  According to the present embodiment, in a heat exchanger constituted by stacked plate-like fins 1 and a multi-hole pipe 10 having a substantially bowl-shaped cross section penetrating therethrough, heat transfer adjacent in the step direction is performed. The plate-like fin 1 between the heat tubes 10 is provided with a first slit 4 whose legs are located close to the constricted portions 11 of the heat transfer tubes 10 by cutting and raising, and the upstream side and the downstream side are symmetrical. Since the second and third slits 5 and 6 whose both legs are diagonally opposed to the air flow direction are provided at the positions, air flow vortices are generated by these first to third slits 4 to 6 and are disturbed. While the flow is promoted, heat transfer is promoted by thinning the velocity boundary layer and the temperature boundary layer of the air flow at the side ends thereof.

Further, by providing the first to third slits 4 to 6, particularly the first slit 4, it is possible to prevent a dead water boundary from occurring near the constricted portion 11 of the heat transfer tube 10, and The dead water area generated on the downstream side can be greatly reduced, and the effective heat transfer area can be increased.
As a result, a heat exchanger having a high heat exchange capability can be obtained.

[Embodiment 2]
FIG. 6 is a plan sectional view of a part of the heat exchanger according to Embodiment 2 of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals.
In the present embodiment, between the adjacent heat transfer tubes 10 of the first embodiment, instead of the first slit 4 provided at the center in the column direction of the plate-like fins 1, leg portions are provided at both ends. Two first slits 41 a and 41 b that are short in the step direction are provided, and the first slits 41 a and 41 b are provided on both sides of the constricted portion 11 of the heat transfer tube 10 and close to the constricted portion 11.

  Even in the present embodiment, substantially the same effect as in the case of Embodiment 1 can be obtained, but furthermore, there is a region where no slit is provided in the central portion between adjacent heat transfer tubes 10. As compared with the first embodiment, a heat exchanger having high heat transfer performance and low ventilation resistance can be obtained.

[Embodiment 3]
FIG. 7 is a partial cross-sectional plan view of a heat exchanger according to Embodiment 3 of the present invention. The same parts as those in the second embodiment are denoted by the same reference numerals.
In the present embodiment, the first slits 41a and 41b that are short in the step direction in the second embodiment are provided close to the constricted portion 11 of the heat transfer tube 10 and obliquely opposed to the air flow direction. It is.

That is, the leg portions on the heat transfer tube 10 side of the first slits 41a and 41b provided on both sides of the heat transfer tube 10 are positioned close to the constricted portion 11 of the heat transfer tube 10 toward the oblique upstream side, and the other leg. The portion is positioned so as to move away from the heat transfer tube 10 toward the oblique downstream side, and the opening is provided obliquely opposite the air flow direction.
According to the present embodiment, substantially the same effect as in the first and second embodiments can be obtained, but the air flow can be more reliably guided to the constricted portion 11 of the heat transfer tube 10.

[Embodiment 4]
FIG. 8 is a partial cross-sectional plan view of a heat exchanger according to Embodiment 4 of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals.
In the present embodiment, between the heat transfer tubes 10 having a substantially bowl-shaped cross section adjacent to each other in the step direction, between the second slit 5 and the third slit 6 provided in the plate-like fin 1, parallel to these. Two first slits 42a and 42b are provided.

  The first slit 42a on the upstream side is formed obliquely with the leg portion being widened at the downstream side, and the slit 42b on the downstream side is formed obliquely with the leg portion being widened at the upstream side. Each leg portion is provided obliquely along the upstream and downstream outer walls of the constricted portion 11 of the heat transfer tube 10.

  According to the present embodiment, substantially the same effect as in the first embodiment can be obtained. However, since the area where the slit is further provided is large, a heat exchanger having a larger heat exchange capability can be obtained. However, since the area where the slit is provided is increased, the ventilation resistance is increased. Therefore, the present invention is particularly effective when implemented in an air conditioner that can secure the air flow rate even when the ventilation resistance of the heat exchanger is large.

[Embodiment 5]
FIG. 9 is a partial cross-sectional plan view of a heat exchanger according to Embodiment 5 of the present invention. In addition, the same code | symbol is attached | subjected to the part of the same or same function as Embodiment 1. FIG.
In the present embodiment, three circular tubes made of a metal material are joined in the row direction to form the heat transfer tube 10, and two constricted portions 11 are formed in the row direction.

  Since the heat transfer tubes 10 are thus elongated in the row direction, the width of the plate fins 1 in the row direction is increased, and the second slit 5 provided between the heat transfer tubes 10 adjacent in the step direction and the second Two first slits 4, 4 having both end portions (leg portions) close to the constricted portion 11 of the heat transfer tube 10 are provided between the three slits 6.

  According to the present embodiment, it is possible to obtain substantially the same effect as in the first embodiment, but furthermore, since the heat transfer area of the plate-like fin 1 is larger than that in the first embodiment, more heat exchange is performed. A heat exchanger having a large capacity can be obtained. Although the figure shows a case in which three circular tubes are connected to form a multi-hole heat transfer tube 10, four, five or more circular tubes are further connected to form a heat transfer tube 10. Thus, it is possible to obtain a heat exchanger having a larger heat exchange capability.

  As mentioned above, although Embodiment 1-5 of the heat exchanger which concerns on this invention was demonstrated, the heat exchanger which concerns on each of these embodiment may each be implemented independently, and may be implemented combining it suitably. Further, depending on the situation, the second and third slits 5 and 6 may be omitted and only the first slit 4 (including 41a, 41b, 42a and 42b) may be provided.

[Embodiment 6]
FIG. 10 is an explanatory diagram of an example of a refrigeration cycle of an air conditioner according to Embodiment 6 of the present invention.
The refrigeration cycle 30 of the air conditioner according to the present embodiment includes a compressor 31, a four-way valve 32, an indoor heat exchanger 33 that functions as a condenser, an expansion valve 34, and an outdoor heat exchanger 35 that functions as an evaporator. The heat exchangers of the first to fifth embodiments are used for both or any one of the indoor heat exchanger 33 and the outdoor heat exchanger 35, which are sequentially connected by refrigerant piping. Reference numerals 36 and 37 denote blowers.

  In the refrigeration cycle 30 configured as described above, the refrigerant flow during the heating operation is in the direction indicated by the solid line arrow. That is, the high-temperature and high-pressure refrigerant in the gas state compressed by the compressor 31 is guided to the indoor heat exchanger 33 through the four-way valve 32 and is radiated by heat exchange with the air sent by the blower 36 to heat the room. To do. The refrigerant heat-exchanged by the indoor heat exchanger 33 becomes a supercooled liquid refrigerant and is sent to the expansion valve 34. The low-temperature and low-pressure refrigerant expanded by the expansion valve 34 enters a two-phase state with a low dryness and is led to the outdoor heat exchanger 35. The refrigerant in the outdoor heat exchanger 35 exchanges heat with the outdoor air sent by the blower 37, and the absorbed refrigerant enters the compressor 31 in a gas state.

  The flow of the refrigerant during the cooling operation is in the direction of the dashed arrow, and the room is cooled by the indoor heat exchanger 33 by the action opposite to that during the heating operation. As the refrigerant as the working fluid of the refrigeration cycle 30, any one of HC single refrigerant, a mixed refrigerant containing HC, R32, R407C, and carbon dioxide is used.

  Since the heat exchanger according to any one of the first to fifth embodiments is used for both or one of the indoor heat exchanger 33 and the outdoor heat exchanger 35 of the air conditioner having the refrigeration cycle as described above, An air conditioner with high exchange capacity can be obtained. In addition to the air conditioner, the heat exchanger according to the present invention can be used for a freezer dedicated to freezing, a dryer for generating hot air, and the like.

It is a one part flat sectional view of the heat exchanger which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view of FIG. It is AA sectional drawing of FIG. 1, BB sectional drawing, and CC sectional drawing. FIG. 3 is an operation explanatory diagram of the heat exchanger according to the first embodiment. It is operation | movement explanatory drawing of the heat exchanger which is a comparative example. It is a one part flat sectional view of the heat exchanger which concerns on Embodiment 2 of this invention. It is a one part flat sectional view of the heat exchanger which concerns on Embodiment 3 of this invention. It is a one part flat sectional view of the heat exchanger which concerns on Embodiment 4 of this invention. It is a one part flat sectional view of the heat exchanger which concerns on Embodiment 5 of this invention. It is explanatory drawing of an example of the refrigerating cycle of the air conditioner which concerns on Embodiment 6 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Plate-like fin, 2 Fin collar, 4 41a, 41b, 42a, 42b 1st slit, 5 2nd slit, 6 3rd slit, 4a, 5a, 6a Leg part, 4b, 5b, 6b Cut and raised part 10 heat transfer tubes, 11 constricted sections, 20 dead water areas, 30 refrigeration cycles.

Claims (7)

A plurality of plate-like fins that are stacked at a predetermined interval and through which air flows, and a plurality of circular pipes are connected via a constriction in the air flow direction, and a predetermined interval in a step direction orthogonal to the air flow direction A plurality of heat transfer tubes installed through the plate fins in the stacking direction,
Before each side of Kiden heat pipes, wherein the one leg cut and raised plate fins is positioned in proximity to the neck portion of the heat transfer tube, the other leg portion is inclined in a direction away from the heat transfer tube Position to,
A heat exchanger characterized in that a slit is provided obliquely opposite to the air flow direction . The width of the flow direction of air in the slit, heat exchanger according to claim 1, characterized in that narrower than the distance between the center of each side of the circular tube portion of the constricted portion of the heat transfer tube. The heat exchanger according to claim 1 or 2 , wherein one leg portion of the slit is provided between the center portions of the circular tube portions on both sides of the constricted portion of the heat transfer tube. The plate-shaped fin is cut and raised on the upstream side of the slit, and a second slit is provided in the vicinity of the upstream side of the constricted portion of the heat transfer tube adjacent in the step direction, and the downstream side of the slit the plate-like any one of claims 1 to 3 in which the legs by cutting and raising the fins, characterized in that a third slit located near the downstream side of the constricted portion of the heat transfer tube of the adjacent The heat exchanger according to item . The upstream side of both leg portions of the second slit is widened, and the downstream side of both leg portions of the third slit is widened so as to be opposed obliquely to the air flow direction. 4. The heat exchanger according to 4 . A compressor, an indoor heat exchanger, a throttle valve, and an outdoor heat exchanger are sequentially connected by a refrigerant pipe, a refrigerant is used as a working fluid, and both the indoor heat exchanger and the outdoor heat exchanger are charged. Item 6. An air conditioner using the heat exchanger according to any one of Items 1 to 5 . The air conditioner according to claim 6 , wherein any one of HC single refrigerant, a mixed refrigerant containing HC, R32, R410A, R407C, or carbon dioxide is used as the refrigerant.

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