JP6928793B2 - Plate fin laminated heat exchanger and freezing system using it - Google Patents

Description

The present invention relates to a plate fin laminated heat exchanger and a freezing system using the same.

Generally, in a refrigerating system such as an air conditioner or a refrigerating machine, a refrigerant compressed by a compressor is circulated to a heat exchanger such as a condenser or an evaporator and heat exchanged with a second fluid to perform cooling or heating. The heat exchange performance of the heat exchanger greatly affects the performance as a system and energy saving. Therefore, heat exchangers are strongly required to have high performance.

Under such circumstances, as the heat exchanger of a refrigeration system such as an air conditioner or a refrigerator, a fin tube type heat exchanger configured by penetrating a heat transfer tube through a fin group is generally used. Therefore, the heat exchange performance is being improved and the size is being reduced by reducing the diameter of the heat transfer tube.

However, since there is a limit to the reduction in diameter of the heat transfer tube, improvement in heat exchange performance and miniaturization are approaching the limit.

Therefore, the applicant has proposed to use the fin tube type heat exchanger in place of the plate fin laminated heat exchanger (see, for example, Patent Document 1).

15 and 16 show the plate fin laminated heat exchanger described in Patent Document 1, in which the plate fin laminated heat exchanger has header flow paths 101 and 102 for inflow and outflow of refrigerant at one end of the plate fin 103. The heat transfer flow path 104 provided between the inflow and outflow header flow paths 101 and 102 is U-turned on the other end side and connected to the inflow and outflow header flow paths 101 and 102. Further, the heat transfer flow path 104 is further divided into a plurality of parts and connects the inflow and outflow header flow paths 101 and 102.

In the plate fin laminated heat exchanger configured in this way, the concave groove 104a serving as the heat transfer flow path 104 can be formed by pressing, so that the cross-sectional area of the heat transfer flow path 104 formed by the concave groove 104a is a conventional fin tube type. It can be made extremely small compared to the tube of the heat exchanger. Moreover, since the heat transfer flow path 104 between the header flow path 101 and the header flow path 102 is U-turned and divided into a plurality of parts, the heat transfer flow path 104 is lengthened without lengthening the plate fin 103 to transfer heat. The area can be increased. Therefore, the heat exchange performance between the refrigerant and the air can be improved, and at the same time, miniaturization can be promoted, and a compact and high-performance heat exchanger can be obtained.

JP-A-2018-66534

However, the plate fin laminated heat exchanger having the above configuration has a problem that the heat transfer flow path 101 is reduced in diameter and branched into a plurality of heat transfer channels, so that the flow path is clogged or the flow path is reduced at the time of brazing joining. That is, the plate fins of this plate fin laminated heat exchanger form a heat transfer flow path 101 by brazing and joining two plates having a concave groove 101a. At this time, the contents such as brazing material and flux are formed. If the amount is excessive, it solidifies while adhering to the inner wall of the heat transfer flow path 101, causing clogging of the flow path and shrinkage of the flow path. Therefore, the original high heat exchange performance may not be sufficiently obtained due to the reduced diameter of the heat transfer flow path 101.

The present invention has been made in view of these points, and the original high heat exchange performance obtained by reducing the diameter by preventing the flow path from clogging or shrinking the flow path due to the contents such as brazing material and flux. The purpose is to provide a high-performance plate fin laminated heat exchanger with and a refrigeration system using it.

In order to achieve the above object, the heat exchanger of the present invention is a heat exchanger configured by stacking a large number of plate fins having a heat transfer flow path connected to a pair of header flow paths for inflow and outflow. The plate fins are formed by joining plates having concave grooves, the heat transfer flow path is branched into a plurality of parts via a branch flow path, and the contents such as brazing material and flux are released to the branch flow path. It has a structure with a part.

As a result, at the time of brazing, if the plate fins are laminated and brazed so that the relief portion is located below, even if the contents such as the brazing material and the flux become excessive, the excess contents can be removed. Due to gravity, it will flow downward and accumulate in the escape part. Therefore, it is possible to prevent the heat transfer flow path from being clogged or reduced due to an excessive content such as a brazing material or a flux.

According to the above configuration, the present invention can prevent clogging or shrinkage of the heat transfer flow path, and has high-performance plate fin laminated heat having the original high heat exchange performance obtained by reducing the diameter of the heat transfer flow path. It can be a exchanger and a refrigeration system using it.

A perspective view showing the appearance of the plate fin laminated heat exchanger according to the first embodiment of the present invention. An exploded perspective view of the plate fin laminated heat exchanger Perspective view showing the main part of the plate fin laminated heat exchanger Top view showing the plate fins of the plate fin laminated heat exchanger A perspective view of the header flow path side showing the plate fins of the plate fin laminated heat exchanger disassembled. A perspective view showing the U-turn side of the plate fins of the plate fin laminated heat exchanger. An exploded perspective view of the plate fin laminated heat exchanger according to the second embodiment of the present invention. Explanatory drawing showing the installation state at the time of brazing in the furnace of the plate fin laminated type heat exchanger Top view showing the header flow path side of the plate fins of the plate fin laminated heat exchanger. Top view showing the U-turn side of the plate fin of the plate fin laminated heat exchanger. An exploded perspective view showing a plate fin laminated heat exchanger according to the third embodiment of the present invention. Top view showing the plate fins of the plate fin laminated heat exchanger The refrigerating cycle diagram of the air conditioner according to the fourth embodiment using the plate fin laminated heat exchanger of the present invention. Schematic cross-sectional view showing the indoor unit of the air conditioner Perspective view showing the appearance of the conventional plate fin laminated heat exchanger proposed by the applicant. Top view showing the plate fins of the plate fin laminated heat exchanger

The first invention is a heat exchanger, which is a heat exchanger configured by stacking a large number of plate fins having a heat transfer flow path connected to a pair of header flow paths for inflow and outflow. The plate fins are formed by joining plates having concave grooves, the heat transfer flow path is branched into a plurality of parts via a branch flow path, and the contents such as brazing material and flux are released to the branch flow path. It has a structure with a part.

As a result, at the time of brazing, if the plate fins are laminated and brazed so that the relief portion is located below, even if the contents such as the brazing material and the flux become excessive, the excess contents can be removed. Due to gravity, it will flow downward and accumulate in the escape part. Therefore, it is possible to prevent the heat transfer flow path from being clogged or reduced due to an excessive content such as a brazing material or a flux.

In the second invention, in the first invention, the heat transfer flow path is provided along the longitudinal direction of the plate fins, and relief portions are provided at both ends of the heat transfer flow path.

As a result, even if the plate fins are brazed with either side in the longitudinal direction facing downward, excess contents will flow downward due to gravity and accumulate in the relief portion. Therefore, it is possible to prevent clogging or shrinkage of the heat transfer flow path due to excessive contents such as brazing material and flux without restricting the installation direction of the plate fins at the time of brazing.

In the third invention, in the second invention, the plate fin has a substantially bow shape.

As a result, even if the plate fins are brazed with the longitudinal direction of the substantially bow shape horizontal, excess contents flow toward both ends due to gravity along the inclination of the substantially bow shape, and the relief portions at both ends. Will accumulate in. Therefore, the degree of freedom in installing the plate fins at the time of brazing is increased, and it is possible to prevent the heat transfer flow path from being clogged or reduced due to excessive contents such as brazing material and flux.

In the fourth aspect of the invention, in the first to third inventions, the total volume V of the relief portion is A for the surface area of the refrigerant flow path, H for the height of the refrigerant flow path, and N for the number of the refrigerant flow paths. Then, the configuration is defined in the range of the following formula.

A × H / 1200 × N ≦ V ≦ A × H / 300 × N
As a result, it is possible to reliably prevent clogging or shrinkage of the heat transfer flow path by accumulating all excess contents such as brazing material and flux generated during brazing in the relief portion.

A fifth invention is a refrigeration system, in which the heat exchanger constituting the refrigeration cycle is a plate fin laminated heat exchanger according to the first to fourth inventions.

As a result, this refrigeration system can be a high-performance and energy-saving refrigeration system because the plate fin laminated heat exchanger has high heat exchange performance without clogging of the heat transfer flow path.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to this embodiment.

(Embodiment 1)
FIG. 1 is a perspective view showing the appearance of the plate fin laminated heat exchanger according to the first embodiment of the present invention, FIG. 2 is an exploded perspective view of the plate fin laminated heat exchanger, and FIG. 3 is an exploded perspective view of the plate fin laminated heat exchanger. A perspective view showing a main part, FIG. 4 is a plan view showing the plate fins of the plate fin laminated heat exchanger, and FIG. 5 is a perspective view of the header flow path side showing the plate fins of the plate fin laminated heat exchanger disassembled. FIG. 6 is a perspective view showing the U-turn portion side of the plate fins of the plate fin laminated heat exchanger.

As shown in FIGS. 1 and 2, the heat exchanger 1 of the present embodiment has end plates 3a and 3b having substantially the same plan view on both sides of the plate fin laminate 2 in which the strip-shaped plate fins 2a are laminated. Is joined and integrated. On one end side thereof, there is a tube A4 which is an inlet when used as an evaporator and an outlet when used as a condenser, and a tube B5 which is the opposite.

The end plates 3a and 3b on both sides of the plate fin laminate 2 are brazed so as to sandwich the plate fin laminate 2, and both ends in the longitudinal direction are connected and fixed by fastening means 7 such as bolts, nuts or caulking pin shafts. However, it retains its rigidity as a heat exchanger.

Further, the plate fins 2a have a configuration in which the pair of plates 6a and 6b shown in FIG. 5 are joined by brazing or the like to have a heat transfer flow path 8 through which a first fluid such as a refrigerant (hereinafter referred to as a refrigerant) flows. As shown in FIG. 3, a large number of layers are laminated to form a stacking interval in which a second fluid such as air (hereinafter referred to as air) flows between the plate fins 2a. Then, heat is exchanged between the refrigerant flowing through the heat transfer flow path 8 provided in the plate fins 2a and the air flowing through the stacking gap between the plate fins 2a.

As shown in FIG. 6, the pair of plates 6a and 6b constituting the plate fins 2a are provided in the header flow paths A9 and the header flow paths B10 connected to the pipes A4 and B5 and the openings 9a and 10a and the opening edges thereof. Ring-shaped concave grooves 9b and 10b, connecting flow path concave grooves 11a and 11b derived from the ring-shaped concave grooves 9b and 10b, and branch flow path concaves provided at the ends of the connecting flow path concave grooves 11a and 11b. The grooves 12a and 12b and a plurality of parallel flow path forming concave grooves 8a branched from the diversion channel concave grooves 12a and 12b are provided.

Then, the pair of plates 6a and 6b are brazed to face each other, and as shown in FIG. 3, the header flow path A9 and the header flow path B10, the communication flow path 11, the branch flow path 12, and the plurality of heat transfer flow paths 8 Is forming.

As shown in the overall view of the plate fins of FIG. 4, the plate fins 2a having the above configuration have a shape in which the heat transfer flow path 8 is bent at the end side of the plate fins 2a to make a U-turn, and the header flow path A9 and the header flow. A branch flow path 13 is also provided at the end opposite to the path B10, and two heat transfer forward flow paths 8-1 connected to the header flow path A9 and six heat transfer return flow paths connected to the header flow path B10. It is divided into 8-2.

A relief portion 14 for allowing excess brazing material, flux, and other contents generated during brazing to escape into each of the header flow path A9, the branch flow path 12 on the header flow path B10 side, and the branch flow path 13 on the opposite side. Is provided as shown in FIGS. 5 and 6.

Here, the total volume V of the relief portion is as follows, assuming that the surface area of the refrigerant flow path 8 is A, the height of the refrigerant flow path 8 is H, and the number of the refrigerant flow paths 8 is N. The configuration is defined in the range of Equation 1 of.

The total volume V of the relief portion refers to the total volume of the number of heat transfer channels to which the brazing material and the flux are released, and is the same in other embodiments described later.

The plate fins 2a of the plate fin laminate 2 having the above configuration are formed with a stacking interval in which air flows by a plurality of protrusions 15 (see FIG. 4) appropriately provided along the longitudinal direction of the plate fins 2a.

Next, the operation and effect of the plate fin laminated heat exchanger configured as described above will be described.

When the heat exchanger of the present embodiment is used, for example, under evaporation conditions, a liquid refrigerant in a gas-liquid two-phase state flows from the pipe A4 into the header flow path A9 on the inlet side of the plate fin laminate 2. The liquid refrigerant that has flowed into the header flow path A9 flows to the heat transfer flow path 8-1 group of the heat transfer flow path 8 via the communication flow path 11 and the branch flow path 12 of each plate fin 2a. The refrigerant flowing into the heat transfer outflow flow path 8-1 group of each plate fin 2a makes a U-turn in the branch flow path 13 on the other end side, and from the pipe B5 via the heat transfer return flow path 8-2 group and the header flow path B10. It flows out to the refrigerant circuit of the refrigeration system.

Then, when the refrigerant flows from the heat transfer flow path 8-1 of the heat transfer flow path 8 to the pipe B5 via the heat transfer return flow path 8-2 group, the refrigerant is gasified and the plate fins of the plate fin laminate 2 are used. It exchanges heat with the air that passes through the stacking interval.

Here, in the plate fin laminated heat exchanger, a large number of plate fins 2a in a state where the plates 6a and 6b face each other are laminated between the end plates 3a and 3b, and the plate fins 2a and the end in the laminated state are laminated. The plates 3a and 3b are arranged in the vertical direction, for example, the header flow path A9 and the header flow path B10 are located downward, and brazed in the furnace.

At this time, if the wax material applied to the joint surfaces of the plates 6a and 6b is excessive, the contents such as the molten wax material and the flux flow down in the heat transfer flow path 8 under the influence of gravity, and the branch flow path 12 As it is, it flows into the relief portion 14 as it is, accumulates, and solidifies.

Therefore, it is possible to prevent the heat transfer flow path 8 from being clogged or reduced due to an excessive content such as a brazing material or flux, and the original high heat obtained by reducing the diameter of the heat transfer flow path 8 can be obtained. It can be a heat exchanger with exchange performance.

Further, in the present embodiment, the relief portion 14 has U-turns on both ends of the plate fin 2a, that is, the side provided with the header flow path A9 and the header flow path B10, and the opposite side, that is, the heat transfer flow path 8. Since it is provided on both sides of the furnace, brazing in the furnace is performed downward on the header flow path A9 and the header flow path B10 as described above, as well as on the side where the heat transfer flow path 8 makes a U-turn. Can also be done downward. Therefore, the installation direction of the plate fins 2a at the time of brazing in the furnace is not restricted, and the workability is improved.

Further, the total volume V of the relief portion falls within the range of the following equation 1 assuming that the surface area of the refrigerant flow path 8 is A, the height of the refrigerant flow path 8 is H, and the number of the refrigerant flow paths 8 is N. Since the configuration is specified, all excess contents such as brazing material and flux generated during brazing in the furnace are stored in the relief portion 14 without increasing the ventilation resistance of the air flowing through the stacking interval of the plate fins 2a. It is possible to reliably prevent clogging and shrinkage of the heat transfer flow path.

（実施の形態２）
図７は実施の形態２のプレートフィン積層型熱交換器を示す分解斜視図、図８は同プレートフィン積層型熱交換器の炉中ロウ付け時の設置状態を示す説明図、図９はプレートフィン積層型熱交換器のプレートフィンのヘッダ流路側を示す平面図、図１０はプレートフィン積層型熱交換器のプレートフィンのＵターン部側を示す平面図である。

(Embodiment 2)
FIG. 7 is an exploded perspective view showing the plate fin laminated heat exchanger of the second embodiment, FIG. 8 is an explanatory view showing the installation state of the plate fin laminated heat exchanger at the time of brazing in the furnace, and FIG. 9 is a plate. A plan view showing the header flow path side of the plate fins of the fin laminated heat exchanger, and FIG. 10 is a plan view showing the U-turn portion side of the plate fins of the plate fin laminated heat exchanger.

The plate fins 2a of the present embodiment are formed in a substantially bow shape, and a plurality of heat transfer channels 8 are provided along the bow shape. The heat transfer flow path 8 is provided by making a U-turn so as to connect the header flow path A9 provided on one end side of the plate fin 2a and the header flow path B10, and the heat transfer flow path is provided at both ends of the heat transfer flow path. 12 and 13 divide the heat transfer flow path 8-1 connected to the header flow path A9 into two heat transfer return flow paths 8-2 connected to the header flow path B10. On top of that, the respective branch channels 12 and 13 are provided with relief portions 14 for letting out excess brazing material, flux and other contents generated during brazing.

In the plate fin laminated heat exchanger of the present embodiment configured as described above, as shown in FIG. 8, the laminated plate fins 2a can be horizontally installed horizontally and brazed in the furnace. .. That is, when the heat transfer flow path 8 of the horizontally installed plate fin 2a is horizontally installed, it descends toward both left and right ends of the plate fin 2a, that is, toward the header flow path A9 and the header flow path B10 side and the U-turn side of the heat transfer flow path. It will be tilted. Therefore, at the time of brazing in the furnace, excess brazing material, flux, and other contents flow in the heat transfer flow path 8 along the inclination, and flow into the relief portion 14 via the branch flow paths 12 and 13. Become. Therefore, even with this configuration, it is possible to prevent the heat transfer flow path 8 from being clogged or shrunk due to excessive contents such as brazing material and flux, and the plate fins 2a are installed sideways and brazed in the furnace. The degree of freedom in installing the plate fin 2a is increased, and workability is further improved.

Other configurations and actions and effects are the same as those in the first embodiment, and the same drawing numbers are added to the same parts and the description thereof will be omitted.

(Embodiment 3)
FIG. 11 is an exploded perspective view showing the plate fin laminated heat exchanger of the third embodiment, and FIG. 12 is a plan view showing the plate fins of the plate fin laminated heat exchanger.

In the plate fin laminated heat exchanger of the present embodiment, the header flow path A9 is provided on one end side of the plate fin 2a and the header flow path B10 is provided on the opposite side, and the heat transfer flow path 8 connecting between them is provided in only one direction. The relief portion 14 is provided in the left and right branch flow paths 12 and 13 connected to the header flow path A9 and the header flow path B10.

Even in the plate fin laminated heat exchanger having such a configuration, it is possible to prevent the heat transfer flow path 8 from being clogged, and the heat transfer flow path 8 has a small diameter, as in the first and second embodiments. It is possible to obtain a heat exchanger having the original high heat exchange performance obtained by the conversion.

Other configurations and actions and effects are the same as those in the first embodiment, and the same drawing numbers are added to the same parts and the description thereof will be omitted.

(Embodiment 4)
FIG. 13 is a refrigeration cycle diagram of an air conditioner configured by using the plate fin laminated heat exchanger described in any one of the above embodiments, and FIG. 14 is a schematic cross-sectional view showing an indoor unit of the air conditioner. ..

In FIGS. 13 and 14, the air conditioner is composed of an outdoor unit 51 and an indoor unit 52 connected to the outdoor unit 51. The outdoor unit 51 includes a compressor 53 for compressing the refrigerant, a four-way valve 54 for switching the refrigerant circuit during cooling and heating operation, an outdoor heat exchanger 55 for exchanging heat between the refrigerant and the outside air, a decompressor 56 for reducing the refrigerant, and an outdoor unit. A blower 59 is arranged. Further, the indoor unit 52 is provided with an indoor heat exchanger 57 for exchanging heat between the refrigerant and the indoor air, and an indoor blower 58. Then, the compressor 53, the four-way valve 54, the indoor heat exchanger 57, the decompressor 56, and the outdoor heat exchanger 55 are connected by a refrigerant circuit to form a heat pump type refrigeration cycle.

In the refrigerant circuit according to the present embodiment, a refrigerant in which tetrafluoropropene or trifluoropropene, difluoromethane or pentafluoroethane or tetrafluoroethane is used alone, or a mixture of two components or three components, respectively, is used.

The air conditioner having the above configuration switches the four-way valve 54 so that the discharge side of the compressor 53 and the outdoor heat exchanger 55 communicate with each other during the cooling operation. As a result, the refrigerant compressed by the compressor 53 becomes a high-temperature and high-pressure refrigerant and is sent to the outdoor heat exchanger 55 through the four-way valve 54. Then, it exchanges heat with the outside air to dissipate heat, becomes a high-pressure liquid refrigerant, and is sent to the decompressor 56. In the decompressor 56, the pressure is reduced to become a low-temperature low-pressure two-phase refrigerant, which is sent to the indoor unit 52. In the indoor unit 52, the refrigerant enters the indoor heat exchanger 57, exchanges heat with the indoor air, absorbs heat, evaporates and vaporizes, and becomes a low-temperature gas refrigerant. At this time, the indoor air is cooled to cool the room. Further, the refrigerant returns to the outdoor unit 51 and is returned to the compressor 53 via the four-way valve 54.

During the heating operation, the four-way valve 54 is switched so that the discharge side of the compressor 53 and the indoor unit 52 communicate with each other. As a result, the refrigerant compressed by the compressor 53 becomes a high-temperature and high-pressure refrigerant, passes through the four-way valve 54, and is sent to the indoor unit 52. The high-temperature and high-pressure refrigerant enters the indoor heat exchanger 57, exchanges heat with the indoor air to dissipate heat, and is cooled to become a high-pressure liquid refrigerant. At this time, the indoor air is heated to heat the room. After that, the refrigerant is sent to the compressor 56, decompressed in the compressor 56 to become a low-temperature low-pressure two-phase refrigerant, sent to the outdoor heat exchanger 55 to exchange heat with the outside air, evaporate and vaporize, and pass through the four-way valve 54. Then, it is returned to the compressor 53.

The air conditioner configured as described above has high performance and energy saving by using the heat exchanger having high heat exchange performance shown in the above embodiment for the outdoor heat exchanger 55 or the indoor heat exchanger 57. It can be a highly efficient refrigeration system.

The plate fin laminated heat exchanger according to the present invention and the refrigeration system using the same have been described above using the above-described embodiment, but the present invention is not limited thereto. For example, in the present embodiment, the relief portion 14 is provided in each of the branch channels 12 and 13 at both ends of the heat transfer flow path, but this may be provided in only one of them. Further, an example in which the branch flow path 13 is also provided on the U-turn side of the heat transfer flow path 8 is illustrated, but this is a form in which the heat transfer flow path 8 is U-turned several times and there is no branch flow path on the U-turn side. It is also good. That is, the embodiments disclosed this time are exemplary and not restrictive in all respects, and the scope of the present invention is indicated by the claims, meaning and within the same meaning and scope as the claims. All changes are included.

As described above, the present invention uses a plate fin laminated heat exchanger having high heat exchange performance obtained by preventing clogging or shrinkage of the heat transfer flow path and reducing the diameter of the heat transfer flow path. The refrigeration system that was available can be provided. Therefore, it can be widely used in heat exchangers and various refrigeration equipment used for home and commercial air conditioners, and has great industrial value.

1 Heat exchanger 2 Plate fin laminate 2a Plate fin 3a, 3b End plate 4 Tube A
5 Tube B
6a plate 6b plate 7 fastening means (bolts and nuts)
8 Heat transfer flow path 8-1 Heat transfer forward flow path 8-2 Heat transfer return flow path 9 Header flow path A
10 Header flow path B
11 Communication flow path 12, 13 Minute flow path 14 Relief part 15 Protrusion 51 Outdoor unit 52 Indoor unit 53 Compressor 54 Four-way valve 55 Outdoor heat exchanger 56 Decompressor 57 Indoor heat exchanger 58 Indoor blower

Claims (5)

A heat exchanger composed of a large number of plate fins provided with heat transfer channels connected to a pair of header flow paths for inflow and outflow, and the plate fins are formed by joining plates having concave grooves. A plate fin laminated heat exchanger in which the heat transfer flow path is branched into a plurality of parts via a branch flow path, and the branch flow path is provided with a relief portion for contents such as brazing material and flux. The plate fin laminated heat exchanger according to claim 1, wherein the heat transfer flow path is provided along the longitudinal direction of the plate fins, and relief portions are provided at both ends of the heat transfer flow path. The plate fin laminated heat exchanger according to claim 2, wherein the plate fins have a substantially bow shape. The total volume V of the relief portion, the surface area of the heat transfer passage A, the height of the Dennetsuryuro H, When the number of the Dennetsuryuro N, claim where the structure specified in the scope of the following formula The plate fin laminated heat exchanger according to any one of 1 to 3.
A × H / 1200 × N ≦ V ≦ A × H / 300 × N A refrigeration system in which the heat exchanger constituting the refrigeration cycle is the plate fin laminated heat exchanger according to any one of claims 1 to 4.

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