JP7538991B2 - Heat exchanger - Google Patents

Description

The present invention relates to a plate-fin stacked type heat exchanger.

Patent Document 1 shows a conventional plate fin stack type heat exchanger. As shown in Figs. 7 and 8, this plate fin stack type heat exchanger includes a plate fin stack 102 in which plate fins 101 having a flow path through which a first fluid such as a refrigerant flows, end plates 103 arranged on both sides of the plate fin stack 102, and inlet and outlet pipes 104 and 105 through which the first fluid flows through the flow path of the plate fin stack 102. A second fluid is passed between the plate fin stacks of the plate fin stack 102 to exchange heat between the first fluid and the second fluid. Through holes 107 are provided at appropriate locations on the periphery of a header region 106, which is the inlet and outlet portion of the first fluid flow path of the plate fin stack 102, and bolts 109 are passed through the through holes 107 via a reinforcing plate 108 to connect and fix the header region.

International Publication No. 2018/074342

This disclosure provides a plate-fin stacked heat exchanger that simplifies the connection and fixing configuration of the header area while suppressing deformation due to insufficient connection and fixing strength.

The plate-fin stacked type heat exchanger disclosed herein has a configuration in which cylindrical sections are provided in through holes provided at appropriate locations on the periphery of the header area, and the header area is connected and fixed by fitting and brazing the cylindrical sections together.

The heat exchanger disclosed herein has a simple structure that joins the cylindrical sections together without using reinforcing plates or bolts, improving the connection strength of the header area and suppressing deformation of the plate fin stack, resulting in a highly reliable heat exchanger.

FIG. 1 is a perspective view showing the appearance of a plate fin stack type heat exchanger according to a first embodiment; FIG. 2 is an enlarged perspective view showing a header region of the heat exchanger. An enlarged cross-sectional view showing the header area of the heat exchanger. Enlarged cross-sectional view of the header area of the heat exchanger FIG. 5 is an enlarged cross-sectional view of part A in FIG. FIG. 1 is an exploded perspective view of a plate fin of a heat exchanger according to a first embodiment; A perspective view of a conventional plate fin stack type heat exchanger. FIG. 1 is a perspective view showing a state before the header region of a conventional plate fin stack type heat exchanger is connected and fixed;

(Knowledge and other information that forms the basis of this disclosure)
At the time when the inventors came up with the present disclosure, they had proposed a plate-fin stacked type heat exchanger described in Patent Document 1. In this heat exchanger, a header region 106 in which a first fluid such as a refrigerant flowing through a flow path gathers is easily deformed by the pressure of the first fluid, so a reinforcing plate 108 is applied to the outer surface of the header region 106 and connected and fixed with bolts 109. However, since the reinforcing plate 108 and bolts 109 are required, the structure is complicated, the weight of the entire heat exchanger increases, and the work of assembling them is required, which reduces productivity.

In light of these problems, the inventors have come up with the subject matter of this disclosure to solve these problems.

Therefore, this disclosure provides a highly reliable heat exchanger that simplifies the connection and fixing configuration of the header area while suppressing deformation of the header area.

Below, the embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of matters that are already well known, or configurations that are substantially the same even in modified examples may be given the same reference numerals and duplicate explanations may be omitted. This is to avoid the following explanation being unnecessarily redundant and to make it easier for those skilled in the art to understand.

The heat exchanger of the present invention is not limited to the plate-fin stacked heat exchanger configuration described in the following embodiment, but includes heat exchanger configurations equivalent to the technical ideas described in the following embodiment.

Furthermore, the embodiments described below are merely examples of the present invention, and the configurations, functions, operations, and the like shown in the embodiments are merely illustrative and do not limit the present disclosure.
(Embodiment 1)
Hereinafter, a first embodiment of a heat exchanger according to the present disclosure will be described with reference to FIGS. 1 to 6. FIG.

[1-1. Configuration]
FIG. 1 is a perspective view showing the appearance of a plate fin stack type heat exchanger (hereinafter simply referred to as heat exchanger) 1 of embodiment 1, FIG. 2 is an enlarged perspective view showing the header region of the plate fin stack type heat exchanger, FIG. 3 is an enlarged cross-sectional view showing the header region of the plate fin stack type heat exchanger, FIG. 4 is an enlarged cross-sectional view of a main portion of the header region of the plate fin stack type heat exchanger, FIG. 5 is an enlarged cross-sectional view of part A of FIG. 4, and FIG. 6 is an exploded perspective view of the plate fins of the plate fin stack type heat exchanger in embodiment 1.

As shown in Figures 1 to 6, the heat exchanger 1 of this embodiment has an inlet pipe (inlet header) 2 into which the first fluid, the refrigerant, flows, a plate fin stack 4 formed by stacking a plurality of rectangular plate-shaped plate fins 3, and an outlet pipe (outlet header) 5 that discharges the refrigerant that has flowed through the flow path in the plate fins 3.

In addition, end plates 6a, 6b having approximately the same shape as the plate fins 3 in a plan view are provided on both sides (upper and lower sides in FIG. 1) of the plate fin stack 4 in the stacking direction. The end plates 6a, 6b are made of rigid plate material, and are formed by metal processing such as grinding a metal material such as aluminum, aluminum alloy, or stainless steel.

The end plates 6a, 6b and the plate fins 3 are brazed together in a stacked state. They may also be joined using other heat-resistant fixing methods, such as chemical joining materials.

In addition, in this embodiment, the plate fin stack 4 formed by stacking the plate fins 3 has both ends in the longitudinal direction connected and fixed, and its configuration will be described later.

As shown in FIG. 6, the plate fin 3 is formed by brazing a pair of elongated plates 3a and 3b having grooves that become the flow paths 7, and is provided with an inflow header flow path 9 and an outflow header flow path 10 that are connected to the flow path 7 via a communication path 8 by the above-mentioned joining. The flow paths 7 provided on the plates 3a and 3b are arranged along the longitudinal direction and made U-turns at the ends, and the inflow header flow path 9 connected to the outflow flow path 7a and the outflow header flow path 10 connected to the return flow path 7b are provided together on one end side, and a slit 11 is formed between the outflow flow path 7a and the return flow path 7b to suppress the heat transfer of the first fluid flowing through both flow paths. The plate fins 3 are then stacked and brazed together with the end plates 6a and 6b as described above to form the plate fin stack 4, and the inflow header flow path 9 and the outflow header flow path 10 of the plate fin stack 4 are connected to the inflow pipe 2 and the outflow pipe 5 to form the heat exchanger.

Next, the connection and fixing configuration of both ends of the plate fin stack 4 will be described. In the heat exchanger of this embodiment, a through hole 12 is provided on the periphery of the header region X where the inflow header flow passage 9 and outflow header flow passage 10 of the plate fin 3 are located, and a cylindrical portion 13 is formed in the through hole 12, and the cylindrical portion 13 is fitted and brazed to the cylindrical portion 13 of another plate fin 3 adjacent in the stacking direction as shown in Figures 4 and 5, thereby connecting and fixing the header region X. The cylindrical portions 13, 13 are formed to protrude on the surface opposite to the brazing surface of the brazing material that has been applied to the plates 3a and 3b in advance, and by fitting the cylindrical portions 13, 13 together, the brazing material on the brazing surface of the inner peripheral surface of one of the cylindrical portions melts and solidifies, and the cylindrical portions 13, 13 are integrated with each other, connecting and fixing the header region X of the plate fin stack 4 formed by stacking a plurality of plate fins 3.

In addition, although not shown, the end of each plate fin 3 opposite the header region X has a through hole 12 similar to that described above to form a cylindrical portion 13, and these cylindrical portions 13, 13 are fitted together and soldered to connect and fix the ends of the plate fin stack 4 formed by stacking each plate fin 3.

The cylindrical portion 13 erected in the through hole 12 is provided so as to surround the inflow header flow passage 9 and outflow header flow passage 10, as shown in FIG. 6. In this example, each cylindrical portion 13 is provided so that the outer circumference of the cylindrical portion overlaps approximately on the center line of the inflow header flow passage 9 and outflow header flow passage 10, specifically, approximately on the center line of the outflow header flow passage 10 and outflow header flow passage 10. The fitting clearance between the two cylindrical portions 13, 13 is 0.2 mm or less, preferably 0.2 mm to 0.1 mm.

In addition, at least one of the tubular parts 13, 13 to be fitted together, in this example the tubular part 13 of the plate 3a on the upper side of the drawing, is formed in a tapered shape that narrows at the end.

[1-2. Operation]
The operation and function of the heat exchanger 1 constructed as above will now be described.

When the heat exchanger of this embodiment is incorporated into a refrigeration system and used under evaporation conditions, for example, the first fluid, a gas-liquid two-phase refrigerant, flows from the inlet pipe 2 into the inlet header flow passage 9 of the plate fin stack 4. The refrigerant that flows into the inlet header flow passage 9 flows to the forward flow passages 7a through the communication passages 8 of each plate fin 3. The refrigerant that flows into the forward flow passages 7a of each plate fin 3 makes a U-turn and flows out of the outlet pipe 5 in a gas phase through the return flow passage 7b into the refrigeration system refrigerant circuit. Then, while flowing through the forward flow passage 7a, the refrigerant exchanges heat with the air (second fluid) that passes through the plate fin stacking spaces of the plate fin stack 4.

At this time, the slits 11 suppress the heat transfer between the forward flow paths 7a and the return flow path 7b, so high heat exchange efficiency is achieved. When the heat exchanger is used as a condenser, the flow of the first fluid is reversed, and the inflow pipe 2 and the inflow header flow path 9 become the outflow pipe and the outflow header flow path, and the outflow pipe 5 and the outflow header flow path 10 become the inflow pipe and the inflow header flow path.

In the above heat exchanger, the opening area of the header flow path 9 is larger than that of the other flow paths, so stress is concentrated in the header region X, which tends to cause significant deformation in the stacking direction. However, in the heat exchanger of this embodiment, the header region X is firmly connected and fixed, so deformation is suppressed and the heat exchanger can be used as a highly reliable heat exchanger.

In more detail, the heat exchanger of this embodiment has cylindrical sections 13, 13 provided in the header region X of each plate 3a, 3b that forms the plate fin 3, and these cylindrical sections 13, 13 are fitted together and brazed to connect and fix the header regions X of adjacent plate fins 3.

As a result, the cylindrical portions 13, 13 of each plate fin 3 are connected together in a cylindrical shape in the stacking direction while being fitted together, and the cylindrical portions 13, 13 are joined together with solder, and the joining strength of the solidified solder is added to make the heat exchanger robust. This greatly improves the connection strength of the header area, and improves the rigidity of the plate fin stack, resulting in a highly reliable heat exchanger.

In addition, there is no need for reinforcing plates, bolts, etc. to ensure the connection strength of the header area, and the structure can be simplified compared to those that use reinforcing plates, bolts, etc.

Moreover, workability is improved, and productivity can be increased. In other words, the header region X can be connected and fixed simply by inserting the through holes 12 into a guide pin jig, stacking the plates 3a, 3b, and then placing them in a melting furnace and soldering them. This reduces the number of steps required for assembly using reinforcing plates and bolts in addition to the conventional soldering process, and greatly improves workability. As a result, productivity is greatly improved.

In addition, in the heat exchanger of this embodiment, the cylindrical portions 13, 13 are provided so as to surround the inflow header flow passage 9 and the outflow header flow passage 10, respectively. Therefore, even if a large amount of the first fluid is concentrated and a high pressure is applied around the inflow header flow passage 9 and the outflow header flow passage 10 of each plate 3a, 3b, i.e., the header region X portion, the pressure resistance of the entire header region X portion can be improved approximately evenly around the inflow header flow passage 9 and the outflow header flow passage 10. In this example, each cylindrical portion 13 is provided so that at least the outer periphery of each cylindrical portion 13 overlaps on the approximate center line of each of the outflow header flow passage 10 and the outflow header flow passage 10. Therefore, the vicinity of the approximate center line of each of the outflow header flow passage 10 and the outflow header flow passage 10 is connected by the cylindrical portion 13, and the pressure resistance of the header region X portion can be improved more uniformly and reliably and deformation can be prevented.

In addition, at least one of the cylindrical portions 13, 13 provided on the pair of plates 3a, 3b is tapered, so even if there is a dimensional tolerance in the fitted cylindrical portions 13, 13, at least a portion of the cylindrical portions 13, 13 can be reliably contacted with each other and reliably fixed together with solder. This makes the connection strength of the header region X stronger, and the pressure resistance can be more reliably improved.

The fitting clearance between the two cylindrical sections 13, 13 is set to 0.2 mm or less, in this example, in the range of 0.2 mm to 0.1 mm, so that the molten solder fills the entire circumference of the cylindrical sections 13, 13 and solidifies almost uniformly. This reliably improves the strength of the joint between the cylindrical sections 13, 13, including the solder, and further improves the pressure resistance of the header region X.

Other Embodiments
As described above, the first embodiment has been described as an example of the technology disclosed in the present invention. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. In addition, it is also possible to combine the components described in the first embodiment to create a new embodiment.

Therefore, other embodiments are given below as examples.

In the first embodiment, a heat exchanger is illustrated in which the flow path through which the first fluid flows is turned around and an inflow header flow path 9 connected to the forward flow path 7a and an outflow header flow path 10 connected to the return flow path 7b are provided at one end. However, the flow path 7 may be linear, with the inflow header flow path 9 provided at one end of the plate fin 3 and the outflow header flow path 10 provided at the other end, and cylindrical sections 13, 13 provided to surround the inflow header flow path 9 and the outflow header flow path 10 and connected and fixed.

The cylindrical portions 13, 13 provided on the pair of plates 3a, 3b that constitute the plate fin 3 are cylindrical portions with a circular cross section, but they may be any shape, such as a polygonal cylinder such as a hexagonal cylinder, or an elliptical cylinder. Also, as shown in Figure 6, they may be discontinuous cylindrical portions with a break, such as the cylindrical portion 13a provided midway through the slit 11.

In addition, while at least one of the cylindrical portions 13, 13 is shown as being tapered, neither of them need be tapered. In addition, both cylindrical portions 13, 13 may be tapered, in which case it is preferable to make the taper angles of both slightly different. Alternatively, although not shown, the tip of one of the cylindrical portions 13, 13 may be nested.

[1-3. Effects, etc.]
As described above, the heat exchanger of the present disclosure comprises a plate fin stack comprising plate fins having a flow path through which a first fluid such as a refrigerant flows, end plates stacked on both sides of the plate fin stack, and an inlet header flow path and an outlet header flow path through which the first fluid flows through the flow path of the plate fin stack, and is a heat exchanger that exchanges heat between the first fluid and the second fluid by flowing a second fluid between the plate fin stacks of the plate fin stack, and the plate fins are configured by brazing a pair of plates to form a flow path between them, and cylindrical portions are provided at appropriate locations on the periphery of a header region where an inlet header flow path and an outlet header flow path connected to the flow paths are provided, and the cylindrical portions are fitted together and brazed to connect and fix the header region.

This improves the connection strength of the header area with a simple configuration without using reinforcing plates or bolts, improving the rigidity of the plate fin stack and creating a highly reliable heat exchanger.

The heat exchanger disclosed herein has the above-mentioned configuration and effects, but it is preferable that the cylindrical portion is arranged to surround the inflow header flow path and the outflow header flow path, which can more reliably improve the pressure resistance of the header area.

In addition, in each of the heat exchangers disclosed herein, it is preferable that at least one of the cylindrical portions provided on the pair of plates is tapered or has a nested shape, thereby ensuring a secure connection between the cylindrical portions and more reliably improving the pressure resistance of the header area.

In addition, in the heat exchanger disclosed herein, it is preferable to set the fitting clearance between the cylindrical portions to 0.2 mm or less, which ensures a secure connection between the cylindrical portions as described above and further improves the pressure resistance of the header area.

The plate-fin stacked heat exchanger according to the present invention has been described above using the above-mentioned embodiments, but the present invention is not limited to these. In other words, the embodiments disclosed here are illustrative in all respects and are not restrictive, and the scope of the present invention is indicated by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

The heat exchanger disclosed herein has a simple configuration that improves the connection strength of the header area and improves the rigidity of the plate fin laminate, making it a highly reliable heat exchanger. Therefore, it can be widely used in heat exchangers for home and commercial air conditioners, various types of refrigeration equipment, etc., and has great industrial value.

REFERENCE SIGNS LIST 1 heat exchanger 2 inlet pipe 3 plate fins 3a, 3b plate 4 plate fin stack 5 outlet pipe 6a, 6b end plate 7 flow path 7a forward flow path 7b return flow path 8 communication path 9 inlet header flow path 10 outlet header flow path 11 slit 12 through hole 13 cylindrical portion

Claims (4)

1. A heat exchanger comprising: a plate fin stack comprising plate fins having flow paths through which a first fluid such as a refrigerant flows; end plates stacked on both sides of the plate fin stack; and an inlet header flow path and an outlet header flow path through which the first fluid flows through the flow paths of the plate fin stack, wherein a second fluid is flowed between the plate fin stacks of the plate fin stack to exchange heat between the first and second fluids, the plate fins being configured by brazing a pair of plates to form a flow path between them, and a cylindrical portion being provided at an appropriate location on the periphery of a header region where an inlet header flow path and an outlet header flow path connected to the flow paths are provided and away from the header flow paths , and the cylindrical portions are fitted together and brazed to connect and fix the header region. The heat exchanger according to claim 1, in which the cylindrical portion is arranged to surround the inflow header flow path and the outflow header flow path. A heat exchanger according to claim 1 or 2, in which at least one of the cylindrical portions provided on the pair of plates is tapered or has a nested shape. A heat exchanger according to any one of claims 1 to 3, in which the fitting clearance between the cylindrical portions is 0.2 mm or less.

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