JP2008232600A - Heat exchanger and air conditioner equipped with the heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger and an air conditioner equipped with the heat exchanger reducing ventilation resistance to increase heat exchange capacity by using a heat transfer tube having excellent heat transfer performance without increasing a pressure loss in the tube even if making a diameter small. <P>SOLUTION: The heat transfer tube 3 is formed in laterally symmetrical uneven shape on the outer peripheral surface and provided with a plurality of cylindrical refrigerant passages 32 in an axial direction at predetermined spaces in a longitudinal direction. This heat transfer tube 3 is inserted in a mounting hole 21 provided in parallel with the inflow direction A of air of a plurality of fins 2 juxtaposed along the inflow direction A of air. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat exchanger 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 heat transfer tubes that are inserted orthogonally to the plate-like fins and through which refrigerant flows, and are adjacent to each other. A slit group is formed by cutting and raising a plate-like fin between the 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).

JP-A-2-33595 (page 3-4, FIG. 1-2)

In the heat exchanger of patent document 1, since the circular tube was used for the heat exchanger tube, there existed a problem that it was difficult to suppress the ventilation resistance in a heat exchanger tube part, or the dead water area produced in the downstream of a heat exchanger tube.
In addition, the heat exchange performance has been improved by increasing the groove shape in the heat transfer tube on the refrigerant side and devising the fin shape on the air side for the purpose of improving the performance of the heat exchanger. In order to achieve high performance, it is conceivable to reduce the diameter of the heat transfer tube. However, by reducing the diameter of the heat transfer tube, the heat transfer coefficient in the tube increases, but the pressure loss increases. Therefore, it is necessary to optimize them. In addition, the small-diameter heat transfer tube is advantageous in terms of heat transfer performance, but has a problem that the manufacturing cost of the heat transfer tube increases.

  The present invention has been made to solve the above-described problems. Even if the diameter is reduced, the pressure loss in the pipe does not increase, and the use of a heat transfer pipe with excellent heat transfer performance reduces the ventilation resistance and heat exchange. An object of the present invention is to provide a heat exchanger capable of increasing the capacity and an air conditioner equipped with the heat exchanger.

  The heat exchanger according to the present invention includes a heat transfer tube having an outer peripheral surface formed in a symmetrical uneven shape, and provided with a plurality of cylindrical refrigerant flow paths in the axial direction at predetermined intervals in the longitudinal direction, The heat transfer tube is inserted into a mounting hole provided in parallel with the air inflow direction of a plurality of fins arranged in parallel along the air inflow direction, and is fixed integrally.

  Moreover, the air conditioner which concerns on this invention uses a refrigerant | coolant for a working fluid, and uses said heat exchanger for both or one of an evaporator and a condenser.

  According to the present invention, since a heat transfer tube having a small diameter and excellent heat transfer performance is used without increasing the pressure loss in the tube, a heat exchanger capable of reducing the ventilation resistance and increasing the heat exchange capacity, and An air conditioner equipped with this heat exchanger can be obtained.

[Embodiment 1]
1 is a front view of a heat exchanger according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view of the heat transfer tube of FIG.
In FIG. 1, 2 is a fin made of a metal plate such as copper or copper alloy, or aluminum or aluminum alloy (the same applies to other embodiments), parallel to the air inflow direction A and in the vertical direction of the figure. A plurality of mounting holes 21 to which heat transfer tubes 3 to be described later are mounted are provided in parallel in the depth direction at predetermined intervals, and perpendicular to the fins 2 in the vertical direction. The mounting holes 21 are provided so as to extend in the horizontal direction perpendicular to the fins 2 arranged side by side, and as shown in FIG. 3, the end portions of the fins 2 facing the mounting holes 21 are bent so Holding.

  As shown in FIG. 2, the heat transfer tube 3 is made of a metal material such as copper, a copper alloy, aluminum, or an aluminum alloy (the same applies to other embodiments), and is elongated along the air inflow direction A. The outer peripheral surface is formed by alternately forming arcuate curved surfaces 31 corresponding to the outer shape of the refrigerant flow path 32, which will be described later, so that the left and right sides (upper and lower sides in the figure) are symmetrically uneven. L is formed to be approximately equal to or slightly longer than the length of the fins 2 arranged side by side in the depth direction. In the longitudinal direction (width direction), a plurality of cylindrical refrigerant flow paths 32a, 32b, 32c, 32d (hereinafter simply referred to as 32) are provided in parallel in the axial direction at predetermined intervals. Yes. In addition, although the figure showed the case where the four refrigerant | coolant flow paths 32 were provided, what is necessary is just two or more.

  The inner diameter d of the refrigerant flow path 32 after the diameter expansion (described later) is 1 to 5 m (therefore, initially, the diameter is expected to be larger and smaller than this). If the inner diameter d is less than 1 mm, the amount of increase in pressure loss is greater than the amount of increase in heat transfer coefficient, resulting in a decrease in heat exchange performance. When the inner diameter d exceeds 5 mm, not only the heat exchange performance is lowered, but also the width (thickness) of the heat transfer tube 3 is increased, and the pressure loss of the air flow is increased. Therefore, the inner diameter d after the diameter expansion of the refrigerant flow path 32 in the present embodiment is set to 1 to 5 mm (the same applies to other embodiments).

Further, the interval t ₂ between the refrigerant flow paths 32 adjacent to the heat transfer tubes 3 is set to about 1.5 times the wall thickness t ₁ of the refrigerant flow path 32. Thereby, the pressure strength of the heat transfer tube 3 can be increased.
Further, the radius of curvature r of the arcuate curved surface 31 on the outer periphery of the heat transfer tube 3 was made smaller than ½ of the inner diameter d of the refrigerant flow path 32. Thereby, joining with the fin 2 after diameter expansion of the refrigerant | coolant flow path 32 becomes reliable, and heat exchange efficiency can be improved by reduction of contact thermal resistance.

  Such a heat transfer tube 3 is inserted into a mounting hole 21 provided in the fin 2 as shown in FIG. 3, and as shown in FIG. 3A, an expanded biuret ball 41 made of a metal material such as cemented carbide. As shown in FIG. 3B, the refrigerant flow passage 32 is expanded and the fin 2 is integrated with the fluid pressurization type pipe expansion apparatus that pressurizes the pipe expansion billet ball 41 with the liquid 42, as shown in FIG. Jointly. Thereby, the heat exchanger 1 is comprised.

  The heat exchanger 1 configured as described above is an HC single refrigerant or a mixed refrigerant containing HC, or a heat exchanger that uses any one of refrigerants such as R32, R410A, R407C, and carbon dioxide. It is provided in a condenser.

  According to the present embodiment, a plurality of refrigerant flow paths 32 are provided in the longitudinal direction at predetermined intervals in the longitudinal direction of the symmetrical heat transfer tube 3 in which the irregularities of the curved surface 31 are continuously formed on the outer periphery. Since the air flow resistance is reduced and the pressure loss in the refrigerant flow path 32 is not increased, the heat exchange efficiency can be improved. The heat exchanger 1 can be obtained.

[Embodiment 2]
FIG. 4 is a front view of the heat transfer tube 3 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, and description thereof is omitted.
In the present embodiment, a plurality of protrusions 33 having a substantially square cross section are extended in parallel to the axial direction at predetermined intervals on the inner wall surfaces of the respective refrigerant flow paths 32a to 32d having an inner diameter d. In this case, it is desirable that the height h (projection length) of the protrusion 33 is about 0.05 to 0.3 mm. In addition, the cross-sectional shape of the protrusion 33 is not limited to a quadrangular shape, and may be an appropriate cross-sectional shape such as a triangular shape, a trapezoidal shape, or a semicircular shape.

  According to the present embodiment, the plurality of protrusions 33 are provided on the inner wall surface of the refrigerant flow path 32 to increase the contact area with the refrigerant, and the height h of the protrusions 33 is 0.05 to 0.3 mm. Therefore, the heat transfer performance can be further improved without increasing the pressure in the flow path. In addition, what is necessary is just to provide the groove | channel corresponding to the protrusion 33 in the outer periphery of the pipe expansion billet ball 41 demonstrated in FIG. 3, when expanding the diameter of the refrigerant flow path 32 which concerns on this Embodiment.

[Embodiment 3]
FIG. 5 is a front view of a heat transfer tube of a heat exchanger according to Embodiment 3 of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the present embodiment, among the plurality of refrigerant channels 32a to 32d provided in the longitudinal direction of the heat transfer tube 3, the inner wall surfaces of the refrigerant channels 32c and 32d on the downstream side in the air inflow direction A are arranged on the inner wall surface of the second embodiment. As in the case of the above, a plurality of protrusions 33 extending in the axial direction are extended at predetermined intervals. The height h of the ridge 33 is desirably about 0.05 to 0.3 mm as in the case of the second embodiment.

  In the heat exchanger, the temperature difference between the downstream air and the refrigerant is smaller than the temperature difference between the upstream air and the refrigerant in the inflow direction A of the inflowing air. Since the plurality of protrusions 33 are provided in the downstream refrigerant flow paths 32c and 32d to increase the contact area with the refrigerant, the heat exchange efficiency can be increased in substantially the same manner as the upstream refrigerant flow paths 32a and 32b. Although the figure shows the case where the protrusions 33 are provided in the two downstream refrigerant flow paths 32c and 32d, the most downstream one refrigerant flow path 32d or three or more refrigerant flow paths are shown. The ridge 33 may be provided on the road (for example, 32b, 32c, 32d).

[Embodiment 4]
FIG. 6 is a front view of a heat transfer tube 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, and description thereof is omitted.
In the present embodiment, among the plurality of refrigerant flow paths 32a to 32d provided in the longitudinal direction of the heat transfer tube 3, the downstream refrigerant flow paths 32c and 32d (in the case of two refrigerant flow paths 32c and 32d in the figure). While there is shown, the inner diameter d ₁ of a may be) is one or three or more, the upstream side of the coolant channel 32a, less than 32b, is obtained by forming the d ₁ <d. In the present embodiment, the downstream refrigerant flow paths 32c and 32d have a small diameter, but the outer peripheral wall of the heat transfer tube 1 is the same outer peripheral wall as the upstream refrigerant flow paths 32a and 32b. The wall thickness t ₁ is increased, and the interval t ₂ between the refrigerant flow paths 32b and 32c, and 32c and 32d is also slightly increased.

  Since the present embodiment is configured as described above, the refrigerant circulation amount in the downstream refrigerant flow paths 32c and 32d is smaller than the refrigerant circulation amount in the upstream refrigerant flow paths 32a and 32b. The mass ratio of the gas phase and the liquid phase at the outlet side of the heat quantity 3 can be made substantially equal, and the efficiency of the entire heat exchanger can be increased.

FIG. 7 is a front view showing another example of the heat transfer tube of the present embodiment. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 3 and the heat exchanger tube of FIG.
In this example, the inner diameter d ₁ of the downstream refrigerant flow paths 32c and 32d is smaller than the inner diameter d of the upstream refrigerant flow paths 32a and 32b and d ₁ <d, as in the heat transfer tube 3 of FIG. In addition, the inner peripheral walls of the upstream refrigerant flow paths 32a and 32b and the inner peripheral walls of the downstream refrigerant flow paths 32c and 32d are axially spaced at predetermined intervals, as in the case of the third embodiment (FIG. 4). A plurality of protrusions 33, 33a parallel to the direction are provided. In this case, the height h ₁ of the protrusion 33a of the downstream refrigerant flow paths 32c and 32d is lower than the height h of the protrusion 33 of the upstream refrigerant flow paths 32a and 32b, and h ₁ <h. Is desirable.
According to this example configured as described above, it is possible to obtain an effect obtained by combining both the effect of the heat transfer tube 3 of the third embodiment and the effect of the heat transfer tube 3 of FIG.

FIG. 8 is a front view showing still another example of the heat transfer tube of the present embodiment.
The heat transfer tube 3 according to this example is provided in the case of the refrigerant flow paths 32c and 32d on the downstream side of the heat transfer tube 3 in FIG. Similarly, a plurality of protrusions 33a parallel to the axial direction are provided at predetermined intervals.
Also in this example, as in the case of the heat transfer tube of FIG. 6, the heat exchange efficiency can be further increased by increasing the heat transfer area of the downstream refrigerant flow paths 32c and 32d.

[Embodiment 5]
FIG. 9 is an explanatory view of a heat exchanger according to Embodiment 5 of the present invention, and FIG. 10 is an explanatory view of a main part of FIG.
The plurality of fins 2 arranged in parallel along the air inflow direction A at predetermined intervals in the lateral direction are provided with four heat transfer tubes 3a, 3b, 3c, 3d in the vertical direction perpendicular to the fins 2. Yes. In addition, the figure has shown the case where the three refrigerant | coolant flow paths 32a-32c are provided in the heat exchanger tubes 3a-3d, respectively.

  The adjacent heat transfer tubes 3b, 3c in the middle in the up-down direction are connected to the heat transfer tubes 3b, which are the inlet portion and the outlet portion of the refrigerant, by a return vent tube 35 made of a metal material such as copper, copper alloy, aluminum, or aluminum alloy. A downstream refrigerant flow path 32c and an upstream refrigerant flow path 32a of the heat transfer pipe 3c, an intermediate refrigerant flow path 32b of the heat transfer pipe 3b, a downstream refrigerant flow path 32c of the heat transfer pipe 3c, and an upstream side of the heat transfer pipe 3b. The refrigerant flow path 32b and the refrigerant flow path 32b in the middle of the heat transfer tube 3c are respectively connected. The heat transfer tube 3a provided in the upper part is connected to a refrigerant pipe (not shown), for example, as a refrigerant outlet, and the heat transfer pipe 3d provided in the lower part is used as a refrigerant inlet.

  By configuring as described above, it is possible to balance the heat exchange capacity on the upstream side in the air inflow direction A and the heat exchange capacity on the downstream side, so that a highly efficient heat exchanger can be obtained. .

FIG. 11 is an explanatory view showing another example of the heat exchanger according to the present embodiment, and FIG. 12 is an explanatory view of a main part of FIG.
In this example, the refrigerant flow passages 32a and 32a on the upstream side, which are the inlet portion and the outlet portion of the refrigerant, of the adjacent heat transfer tubes 3b and 3c provided in the middle in the vertical direction of the fin 2, and the intermediate refrigerant flow passage 32b. And 32b, and downstream refrigerant flow paths 32c and 32c are connected by a return vent pipe 35, respectively.

  By comprising in this way, the mass ratio of the gaseous phase and liquid phase in the exit side of the refrigerant flow paths 32a-32c of the heat exchanger tube (for example, 3a) of an exit side becomes substantially equal, The heat exchanger of the other stage direction Since it flows into the refrigerant inlet of the heat transfer tube 3d, the heat exchange capacity on the upstream side and the heat exchange capacity on the downstream side of the heat transfer tube 3 can be balanced, so that a high capacity heat exchanger can be obtained. .

Next, examples of the heat exchanger according to the present invention will be described.
In the heat exchanger of the first embodiment, the refrigerant flow path 32 has an inner diameter d of 5 mm and a wall thickness t ₁ of 0.2 mm, an inner diameter d of 3 mm, a wall thickness t ₁ of 0.2 mm, and an inner diameter d of 2 mm. Heat transfer tubes 3 each having t ₁ of 0.2 mm, an inner diameter d of 1 mm, and a wall thickness t ₁ of 0.2 mm are manufactured, and an inner diameter d of 7 mm, a wall thickness t ₁ of 0.25 mm, and an inner diameter d of 0.1 mm. A heat transfer tube 3 having a thickness t ₁ of 0.25 mm and a thickness of 6 mm was manufactured.

FIG. 13 is a diagram showing a coefficient of performance COP (heat exchanger capacity / compressor input) of a cycle using the inner diameter d of the refrigerant flow path 32 of each of the heat transfer tubes 3 as a parameter. As shown in the figure, when the inner diameter d of the refrigerant flow path 32 is about 1.5 to 2 mm, the COP becomes the maximum value, and when the inner diameter d is in the range of about 0.8 mm to about 5 mm, the maximum COP is obtained. It was within 5% of the value, and it was found that the target value was reliably obtained and the heat exchange capacity was sufficiently large. In addition, COP falls rapidly when the internal diameter d of the refrigerant flow path 32 is less than 1 mm, and will fall gradually when it exceeds 5 mm.
For this reason, in the present invention, the inner diameter of the refrigerant flow path 32 of the heat transfer tube 3 is set to 1 to 5 mm as described above.

[Embodiment 6]
FIG. 14 is an explanatory diagram of an air conditioner cycle of an air conditioner according to Embodiment 6 of the present invention, and FIG. 15 is an explanatory diagram of an indoor unit of the air conditioner according to the present invention, which is provided with a heat exchanger according to the present invention. Provided with an evaporator and a condenser.

  As shown in FIG. 14, the air-conditioning cycle of the air conditioner according to the present embodiment contains refrigeration oil and flows through the refrigerant flow path 32 of the heat transfer tube 3 of the heat exchanger 1 according to the present invention. An evaporator 51 that cools air, water, and the like by vaporization heat at that time, a compressor 52 that compresses the refrigerant discharged from the evaporator 51 and supplies the refrigerant 53 to a condenser 53 at a high temperature and a high pressure, A condenser 53 that flows into the refrigerant flow path 32 of the heat transfer tube 3 of the heat exchanger 1 according to the present invention and heats air, water, or the like by the heat of the high-temperature refrigerant, and expands the refrigerant discharged from the condenser 53. The expansion valve 54 is supplied to the evaporator 51 at a low temperature.

  As shown in FIG. 15, the indoor air sucked from the air inlet 62 provided in the front panel by the air blower 61 in the indoor area is driven by the heat according to the present invention provided on the downstream side of the air inlet 62. Heat is exchanged by the evaporator 51 including the exchangers 1a, 1b, and 1c, and the air is blown into the room from the blowout port 65 formed by the duct 63 and the casing 64 as hot air or cold air.

  According to this Embodiment, since the heat exchanger 1 which concerns on this invention was provided in the evaporator 51 and the condenser 53, the air conditioner excellent in the air conditioning capability can be obtained. In addition, the indoor unit of the air conditioner provided with the heat exchanger 1 according to the present invention is not limited to the illustrated structure, and may have another structure. Moreover, although the case where the heat exchanger 1 which concerns on this invention was provided in both the evaporator 51 and the condenser 53 was shown, this heat exchanger is provided only in any one, and the heat exchanger from which the structure differs in the other May be provided.

It is a front view of the heat exchanger which concerns on Embodiment 1 of this invention. It is a perspective view of the heat exchanger tube of FIG. It is explanatory drawing of the diameter expansion means of the refrigerant flow path of the heat exchanger tube of FIG. It is a front view of the heat exchanger tube of the heat exchanger which concerns on Embodiment 2 of this invention. It is a front view of the heat exchanger tube of the heat exchanger which concerns on Embodiment 3 of this invention. It is a front view of the heat exchanger tube of the heat exchanger which concerns on Embodiment 4 of this invention. It is explanatory drawing which shows the other example of the heat exchanger tube of Embodiment 4. FIG. It is explanatory drawing which shows the other example of the heat exchanger tube of Embodiment 4. FIG. It is explanatory drawing of the heat exchanger which concerns on Embodiment 5 of this invention. It is explanatory drawing of the principal part of FIG. It is explanatory drawing of the other example of the heat exchanger which concerns on Embodiment 5. FIG. It is explanatory drawing of the principal part of FIG. It is a diagram which shows the relationship between the internal diameter of the refrigerant flow path of a heat exchanger tube, and COP. It is explanatory drawing of the air conditioning cycle of the air conditioner which concerns on Embodiment 6 of this invention. It is explanatory drawing of the indoor unit of the air conditioner which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Heat exchanger, 2 fins, 3 heat exchanger tubes, 32 refrigerant | coolant flow path, 33 protrusion, 35 return vent pipe, 41 expanded pipette ballet, 51 evaporator, 52 compressor, 53 condenser, 54 expansion valve.

Claims (13)

  The outer peripheral surface has a heat transfer tube that is formed in a symmetric uneven shape and is provided with a plurality of cylindrical refrigerant channels in the axial direction at predetermined intervals in the longitudinal direction, and the heat transfer tube is arranged in the air inflow direction. A heat exchanger characterized by being inserted into a mounting hole provided in parallel with the air inflow direction of a plurality of fins arranged side by side and fixed integrally.   The heat exchanger according to claim 1, wherein the refrigerant flow path of the heat transfer tube is expanded by a mechanical tube expansion device or a liquid pressurization tube expansion device, and is joined and fixed to the fin.   The heat exchanger according to claim 1 or 2, wherein a plurality of ridges extending in parallel in the axial direction at predetermined intervals are provided on an inner peripheral wall of a refrigerant flow path provided in the heat transfer tube.   4. The heat exchanger according to claim 3, wherein the protrusion is provided in a refrigerant flow path downstream in an air inflow direction among the plurality of refrigerant flow paths provided in the heat transfer tube.   3. The refrigerant flow path on the downstream side in the air inflow direction among the plurality of refrigerant flow paths provided in the heat transfer tube is formed to have a smaller diameter than the refrigerant flow path on the upstream side. Heat exchanger.   A plurality of ridges extending in parallel in the axial direction at predetermined intervals are provided on the inner peripheral wall of the refrigerant flow path provided on the upstream side of the heat transfer tube and the refrigerant flow path provided on the downstream side. The heat exchanger according to claim 5.   7. The heat exchanger according to claim 6, wherein the height of the protrusion provided in the refrigerant flow path on the downstream side of the heat transfer tube is lower than the height of the protrusion provided in the refrigerant flow path on the upstream side. .   6. The heat according to claim 5, wherein a plurality of ridges extending in parallel in the axial direction at predetermined intervals are provided on an inner peripheral wall of a downstream small-diameter refrigerant channel provided in the heat transfer tube. Exchanger.   The heat exchanger according to any one of claims 1 to 8, wherein an inner diameter of each of the plurality of refrigerant channels provided in the heat transfer tube after being expanded is 1 to 5 mm.   In the vertical direction of the plurality of fins arranged side by side, a plurality of heat transfer tubes are provided orthogonal to the fins, the refrigerant inlet portion of the refrigerant flow path on the downstream side of one adjacent heat transfer tube, and the other heat transfer tube The heat exchanger according to any one of claims 1 to 9, wherein a return vent pipe is connected to the refrigerant outlet portion of the upstream refrigerant flow path.   A plurality of heat transfer tubes are provided in the vertical direction of the plurality of fins arranged side by side perpendicularly to the fins, and the refrigerant flow paths facing the adjacent heat transfer tubes are respectively connected by return vent tubes. Item 10. The heat exchanger according to any one of Items 1 to 9.   An air conditioner using a refrigerant as a working fluid and using the heat exchanger according to any one of claims 1 to 11 for both or one of an evaporator and a condenser.   The air conditioner according to claim 12, wherein any one of HC single refrigerant, a mixed refrigerant containing HC, R32, R410A, R407C, and carbon dioxide is used as the refrigerant.

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