The present invention relates to a heat exchanger that performs heat exchange between a first refrigerant and a second refrigerant, one of which is a low temperature fluid and the other one of which is a high temperature fluid, and to a heat pump system having the heat exchanger installed therein.
A heat exchanger having the following configuration is available as an example of the related art. In the heat exchanger, a first heat exchanger pipe through which a low temperature fluid flows and a second heat exchanger pipe through which a high temperature fluid flows are alternately stacked on each other. The second heat exchanger pipe is placed so that the flowing direction of the high temperature fluid may be in parallel with the flowing direction of the low temperature fluid.
At least one of the first and second heat exchanger pipes is constituted by a plurality of heat exchanger pipes which are arranged in the stacking direction. Both ends of the plurality of heat exchanger pipes are bent in directions perpendicular to both of the flowing direction of the fluids and the stacking direction. The plurality of heat exchanger pipes form parallel flow channels, together with an inlet header and an outlet header.
One of the inlet header and the outlet header is constituted by a tubular header, and the plurality of heat exchanger pipes which form the parallel flow channels are bundled and are connected to the tubular header such that the pipe axis direction of the tubular header is perpendicular to the flowing direction of the fluids in the heat exchanger pipes (for example, see Patent Literature 1).
The heat exchanger disclosed in Patent Literature 1 is formed in a structure in which heat exchanger pipes are stacked on each other, thereby implementing high performance and high efficiency in space utilization. On the other hand, however, in this structure, at least one of the header pipes through which a refrigerant flows is connected to heat exchanger pipes which are bent in a direction perpendicular to the stacking direction. Accordingly, a step of bending the heat exchanger pipes in the widthwise direction is necessary, and also, a space which cannot be utilized is increased by the provision of a header pipe.
Patent Literature 2 and Patent Literature 3 are considered to be the closest prior art of the invention according to independent claim. Patent Literature 2 discloses a multichannel flat tube for a heat exchanger comprising a plurality of parallel channels arranged inside a metal casing for defining a path between at least one fluid inlet and at least one fluid outlet. Patent Literature 3 discloses heat exchanger headers used in natural gas liquefaction processes.
The present invention has been made to solve the above-described problems. It is an object of the present invention to obtain a stacked heat exchanger in which the need to provide a step of bending heat exchanger pipes is eliminated and a space which cannot be utilized because of the provision of a header pipe is not produced, and also to obtain a heat pump system having the heat exchanger installed therein.
According to the invention, the problem is solved by the subject-matter outlined in independent claim. Advantageous further developments of the invention are set forth in dependent claims.
A stacked heat exchanger according to the present invention includes:
According to the present invention, first refrigerant flow channels of first heat exchanger pipes are caused to communicate with each other through the use of a first port, which is an inlet of a first refrigerant, and second refrigerant flow channels of second heat exchanger pipes are caused to communicate with each other through the use of a second port, which is an inlet of a second refrigerant. With this configuration, the provision of a header pipe is made unnecessary, and thus, a space which cannot be utilized can be eliminated, and the entire stacked heat exchanger can be formed in a compact size.
The configuration of the heat exchanger 10, which is a stacked heat exchanger according to Embodiment 1, will be described below with reference to
As shown in
The first and second heat exchanger pipes 1 and 2 have substantially the same length in a direction in which refrigerants flow through the refrigerant flow channels and also have substantially the same width in the widthwise direction of the refrigerant flow channels.
Among the refrigerant flow channels, rectangular refrigerant flow channels which pass through first heat exchanger pipe end portions 5 positioned at both ends of the first heat exchanger pipes 1 are referred to as first refrigerant flow channels 1a, while rectangular refrigerant flow channels which pass through second heat exchanger pipe end portions 6 positioned at both ends of the second heat exchanger pipes 2 are referred to as second refrigerant flow channels 2a. The first refrigerant flow channels 1a positioned at the first heat exchanger pipe end portions 5 and the second refrigerant flow channels 2a positioned at the second heat exchanger pipe end portions 6 are each closed by a capping 8.
As shown in
When closing the first and second refrigerant flow channels 1a and 2a positioned at the first and second heat exchanger pipe end portions 5 and 6, respectively, with the covers 8, the heat-exchanger-pipe fitting portions 8a are fit into the first and second refrigerant flow channels 1a and 2a.
In this case, the heat-exchanger-pipe fitting portions 8a which will be fit into the first refrigerant flow channels 1a positioned at the first beat exchanger end portions 5 are fit into the first refrigerant flow channels 1a such that they are all displaced toward the same side from the center in the longitudinal direction of the capping 8.
In contrast, the heat-exchanger-pipe fitting portions 8a which will be fit into the second refrigerant flow channels 2a positioned at the second heat exchanger end portions 6 are fit into the second refrigerant flow channels 2a such that they are all displaced from the center in the longitudinal direction of the capping 8 toward the side opposite to the side in which the heat-exchanger-pipe fitting portions 8a are fit into the first refrigerant flow channels 1a.
The first and second heat exchanger pipes 1 and 2 have substantially the same length in a direction in which refrigerants flow through the refrigerant flow channels and also have substantially the same width in the widthwise direction of the refrigerant flow channels. However, the first and second heat exchanger pipes 1 and 2 are not restricted to this configuration, and may have different lengths and different widths.
The capping 8 and the heat exchanger 10 respectively correspond to "closing means" and "a stacked heat exchanger" of the present invention. The heat-exchanger-pipe fitting portions 8a fit into the second refrigerant flow channels 2a and the heat-exchanger-pipe fitting portions 8a fit into the first refrigerant flow channels 1a respectively correspond to "first blocking means" and "second blocking means" of the present invention.
As shown in
This will be discussed later. One first port 3 is provided at a refrigerant inlet and the other first port 3 is provided at a refrigerant outlet. One second port 4 is provided at the refrigerant inlet and the other second port 4 is provided at the refrigerant outlet. The first and second ports 3 and 4 are connected to, for example, a refrigerant circuit, disposed in a heat pump system.
As shown in
As shown in
A description will now be given, with reference to
As shown in part (b) of
That is, the first port 3 communicates with the first refrigerant flow channel 1a of the topmost first heat exchanger pipe 1, and this first refrigerant flow channel 1a communicates with, via the second heat exchanger pipe 2 positioned immediately under this first refrigerant flow channel 1a, the first refrigerant flow channel 1a of the first heat exchanger pipe 1 under the second heat exchanger pipe 2. The lower layers of the first and second heat exchanger pipes 1 and 2 have a structure similar to the above-described structure. That is, the first port 3 and the first refrigerant flow channels 1a of the first heat exchanger pipes 1 sequentially communicate with each other, but they are shielded from the second refrigerant flow channels 2a of the second heat exchanger pipes 2 by the provision of the heat-exchanger-pipe fitting portions 8a of the covers 8. However, a first communication hole 3a is formed only on the top surface of the bottommost first heat exchanger pipe 1 (the second bottommost heat exchanger pipe in part (b) of
Second communication holes 4a pass through the top and bottom surfaces of the topmost first heat exchanger pipe 1, and the second port 4 communicates with the first refrigerant flow channel 1a through the second communication hole 4a formed on the top surface of the first heat exchanger pipe 1. Here, the above-stated heat-exchanger-pipe fitting portion 8a of the capping 8 is fit into the first refrigerant flow channel 1a of the first heat exchanger pipe 1 which communicates with this second communication hole 4a. However, as shown in
That is, the second port 4 communicates with the second refrigerant flow channel 2a of the second heat exchanger pipe 2 immediately under the topmost first heat exchanger pipe 1, and this second refrigerant flow channel 2a communicates with, via the first heat exchanger pipe 1 positioned immediately under this second refrigerant flow channel 2a, the second refrigerant flow channel 2a of the second heat exchanger pipe 2 under this first heat exchanger pipe 1. The lower layers of the first and second heat exchanger pipes 1 and 2 have a structure similar to the above-described structure. That is, the second port 4 and the second refrigerant flow channels 2a of the second heat exchanger pipes 2 sequentially communicate with each other, but they are shielded from the first refrigerant flow channels 1a of the first heat exchanger pipes 1 by the provision of the heat-exchanger-pipe fitting portions 8a of the covers 8. However, a second communication hole 4b is formed only on the top surface of the bottommost second heat exchanger pipe 1 (the bottommost heat exchanger pipe in part (b) of
The stacking structure of the first and second heat exchanger pipes 1 and 2 is configured, as shown in
Additionally, the number of first heat exchanger pipes 1 and the number of second heat exchanger pipes 2 stacked on each other do not have to be the same. For example, the number of first heat exchanger pipes 1 may be smaller than or may be larger than the number of second heat exchanger pipes 2 by one.
As shown in part (b) of
As shown in
As shown in
As shown in
However, these holes are not restricted to this configuration. Instead, they may be formed such that they do not have the same diameter or such that they are not concentric in the stacking direction, and they may be formed in any manner as long as the first refrigerant flow channels 1a of the first heat exchanger pipes 1 can communicate with each other.
Also, the second communication holes 4a formed in the first heat exchanger pipes 1, the second communication holes 4b formed in the second heat exchanger pipes 2, and the communication holes 8b of the heat-exchanger-pipe fitting portions 8a fit into the first refrigerant flow channels 1a have the same diameter and are formed concentrically in the stacking direction.
Similarly, however, these holes are not restricted to this configuration. Instead, they may be formed such that they do not have the same diameter or such that they are not concentric in the stacking direction, and they may be formed in any manner as long as the second refrigerant flow channels 2a of the second heat exchanger pipes 2 can communicate with each other. Additionally, the above-described holes are not restricted to a circular shape, and may be formed in another shape, such as a rectangular shape.
The communication hole 8b corresponds to a "fitting-portion communication hole" of the present invention.
The first and second heat exchanger pipes 1 and 2 of the heat exchanger 10 of Embodiment 1 shown in
In the stacking structure of the first and second heat exchanger pipes 1 and 2 shown in
As shown in part (a) of
In this case, the heat-exchanger-pipe fitting portions 8a are brazed to the inner surfaces of the first refrigerant flow channels 1a and the second refrigerant flow channels 2a by using a brazing filler material 21, and also, the bonding surfaces of the first and second heat exchanger pipe end portions 5 and 6 and the covers 8 are bonded to each other by means of brazing utilizing a brazing filler material 21.
With this configuration, refrigerants do not leak from the first and second heat exchanger pipe end portions 5 and 6. Additionally, by brazing the heat-exchanger-pipe fitting portions 8a to the inner surfaces of the first and second refrigerant flow channels 1a and 2a, the first refrigerant flow channels 1a and the second refrigerant flow channels 2a are preventing from communicating with each other, and thus, the first refrigerant flowing through the first refrigerant flow channels 1a and the second refrigerant flowing through the second refrigerant flow channels 2a are not mixed with each other.
As shown in part (b) of
Then, as stated above, the first ports 3 are configured such that they communicate with all the first refrigerant flow channels 1a of the first heat exchanger pipes 1, and the second ports 4 are configured such that they communicate with all the second refrigerant flow channels 2a of the second heat exchanger pipes 2.
By using the above-described method, the heat exchanger 10, which is a stacked heat exchanger, is fabricated.
The heat exchanger 10, which is a stacked heat exchanger according to Embodiment 1, is installed in a heat pump system utilizing heating energy or cooling energy. For example, in the case of an operation utilizing heating energy, a heat exchange operation is performed as follows, A high-temperature first refrigerant flowing from a refrigerant circuit flows into the heat exchanger 10 through one of the first ports 3, flows through the first refrigerant flow channels 1a of the first heat exchanger pipes 1, and then, flows out of the other first port 3. A second refrigerant flowing from a use side circuit flows into the heat exchanger 10 through one of the second ports 4, flows through the second refrigerant flow channels 2a of the second heat exchanger pipes 2, and then, flows out of the other second port 4.
In this case, the first refrigerant and the second refrigerant flow through the first refrigerant flow channels 1a of the first heat exchanger pipes 1 and the second refrigerant flow channels 2a of the second heat exchanger pipes 2, respectively, in opposite directions or in parallel with each other, thereby performing heat exchange between the first refrigerant and the second refrigerant at wall surfaces of the first and second heat exchanger pipes 1 and 2.
In the heat exchanger 10 according to Embodiment 1, the flow channel area of the first refrigerant flow channels 1a of the first heat exchanger pipes 1 and the flow channel area of the second refrigerant flow channels 2a of the second heat exchanger pipes 2 do not necessarily have to be the same.
If there is a difference in the thermal physical property value, such as specific heat or density, the flow rate, pressure conditions, or cleanliness level between the first refrigerant and the second refrigerant, the flow channel area may be made different between the first refrigerant flow channels 1a and the second refrigerant flow channels 2a.
For example, if a carbon dioxide or fluorocarbon refrigerant is used as the first refrigerant, and if, for example, tap water which is not subjected to sufficient water quality control, is used as the second refrigerant, the flow channel area of the second refrigerant flow channels 2a may be made larger than that of the first refrigerant flow channels 1a in order to improve beat exchange performance or to inhibit an increase in a pressure drop caused by the adhesion of scale to the inner surfaces of the refrigerant flow channels.
The heat exchanger disclosed in Patent Literature 1 has a space which cannot be utilized because of the provision of a header pipe used for distributing a refrigerant over heat exchanger pipes, thereby decreasing efficiency in space utilization. However, as in the above-described configuration, the first refrigerant flow channels 1a of the first heat exchanger pipes 1 communicate with each other through the first ports 3, while the second refrigerant flow channels 2a of the second heat exchanger pipes 2 communicate with each other through the use of the second ports 4. Accordingly, it is not necessary to provide a header pipe, thereby making it possible to eliminate a space which cannot be utilized and to form the entire heat exchanger 10 in a compact size.
In the heat exchanger disclosed in Patent Literature 1, it is necessary to bend heat exchanger pipes bonded to the header pipe. However, concerning the heat exchanger pipes (first and second heat exchanger pipes 1 and 2) of the heat exchanger 10 according to Embodiment 1, bending is not necessary, and only hole drilling is sufficient, thereby implementing high machinability,
By alternately stacking the first heat exchanger pipes 1 and the second heat exchanger pipes 2 on each other, heat exchange efficiency between the first refrigerant and the second refrigerant can be improved. Moreover, by setting the lengths of the first heat exchanger pipes 1 and the second heat exchanger pipes 2 in a direction in which refrigerants flow through their refrigerant flow channels to be substantially the same and by setting the widths of the first heat exchanger pipes 1 and the second heat exchanger pipes 2 in the widthwise direction of the refrigerant flow channels to be substantially the same, heat exchange between the first refrigerant and the second refrigerant can be more effectively performed, and also, the entire heat exchanger 10 can be formed in a compact size.
On the top surface of the topmost heat exchanger pipe (the first heat exchanger pipe 1 in
Accordingly, the flow channel lengths of the first and second refrigerant flow channels 1a and 2a through which refrigerants flow can be substantially maximized, thereby further enhancing heat exchange efficiency between the first refrigerant and the second refrigerant.
However, the positions of the first ports 3 and the second ports 4 are not restricted to the above-described positions, and may be changed appropriately depending on the position of the heat exchanger 10 installed in, for example, a heat pump system. In this case, it is necessary that the first ports 3 communicate with the communication holes 8b of the heat-exchanger-pipe fitting portions 8a fit into the second refrigerant flow channels 2a and that the second ports 4 communicate with the communication holes 8b of the heat-exchanger-pipe fitting portions 8a fit into the first refrigerant flow channels 1a.
As shown in
As in the two first ports 3, the positions of the two second ports 4 are not restricted, either. Moreover, the first ports 3 and the second ports 4 do not have to be disposed on the same surface. For example, the two first ports 3 may be disposed on the top surface of the topmost heat exchanger pipe of the stacking structure, while the two second ports 4 may be disposed on the bottom surface of the bottommost heat exchanger pipe of the stacking structure.
By brazing the heat-exchanger-pipe fitting portions 8a to the inner surfaces of the first and second refrigerant flow channels 1a and 2a, the first refrigerant flow channels 1a and the second refrigerant flow channels 2a are shielded from each other and do not communicate with each other, and thus, the first refrigerant flowing through the first refrigerant flow channels 1a and the second refrigerant flowing through the second refrigerant flow channels 2a can be prevented from being mixed with each other.
As shown in
Among the refrigerant flow channels, rectangular refrigerant flow channels which pass through first heat exchanger pipe end portions 5 positioned at both ends of the first heat exchanger pipes 1 are referred to as first refrigerant flow channels 1a, while rectangular refrigerant flow channels which pass through second heat exchanger pipe end portions 6 positioned at both ends of the second heat exchanger pipes 2 are referred to as second refrigerant flow channels 2a.
The first and second heat exchanger pipes 1 and 2 have substantially the same length in a direction in which refrigerants flow through the refrigerant flow channels and also have substantially the same width in the widthwise direction of the refrigerant flow channels. However, the first and second heat exchanger pipes 1 and 2 are not restricted to this configuration, and may have different lengths and different widths.
The heat exchanger 10a corresponds to "a stacked heat exchanger" not forming part of the present invention.
The first heat exchanger pipe 1 has a pressed portion 9a in an area having a predetermined length from the first heat exchanger pipe end portion 5 toward inward of the first heat exchanger pipe 1. As viewed from the penetrating direction of the first refrigerant flow channel 1a, the pressed portion 9a is formed by pressing, in the vertical direction in
By the provision of this pressed portion 9a, part of the opening of the first refrigerant flow channel 1a is closed. In the first heat exchanger pipe end portion 5 positioned opposite to the first heat exchanger pipe end portion 5 in which this pressed portion 9 is formed, another pressed portion 9a is formed in a similar manner. In this case, the two pressed portions 9a are formed at positions diagonal to each other, as viewed from the top surface of the first heat exchanger pipe 1.
A central portion sandwiched between the two pressed portions 9a of the first heat exchanger pipe 1 is pressed in the vertical direction in
This projecting portion 9b is formed for each of the two pressed portions 9a, and the two projecting portions 9b are disposed at positions diagonal to each other, as viewed from the top surface of the first heat exchanger pipe 1. In a manner similar to the first heat exchanger pipe 1, concerning the second heat exchanger pipe 2, a pressed portion 9c and a projecting portion 9d are formed at each side of the second heat exchanger pipe end portions 6. As stated above, part of the opening of the first refrigerant flow channel 1a of the first heat exchanger pipe 1 is closed by the pressed portion 9a.
However, the first refrigerant flow channel 1a corresponding to the projecting portion 9b is opened, and inside of this opening, a first refrigerant auxiliary flow channel 1b which communicates with the first refrigerant flow channel 1a is formed.
Similarly, part of the opening of the second refrigerant flow channel 2a of the second heat exchanger pipe 2 is closed by the pressed portion 9c, while the second refrigerant flow channel 2a corresponding to the projecting portion 9d is opened, and inside of this opening, a second refrigerant auxiliary flow channel 2b which communicates with the second refrigerant flow channel 2a is formed,
Concerning the stacking structure of the first heat exchanger pipes 1 and the second heat exchanger pipes 2, the first heat exchanger pipe 1 and the second heat exchanger pipe 2 are stacked on each other such that the pressed portion 9a of the first heat exchanger pipe 1 and the projecting portion 9d of the second heat exchanger pipe 2 overlap each other and such that the projecting portion 9b of the first heat exchanger pipe 1 and the pressed portion 9c of the second heat exchanger pipe 2 overlap each other. In this case, the pressed portion 9a and the projecting portion 9d are brazed to each other by using a brazing filler material 21, and similarly, the projecting portion 9b and the pressed portion 9c are brazed to each other by using a brazing filler material 21.
As shown in
One first port 3 is provided at a refrigerant inlet and the other first port 3 is provided at a refrigerant outlet. One second port 4 is provided at the refrigerant inlet and the other second port 4 is provided at the refrigerant outlet. The first and second ports 3 and 4 are connected to, for example, a refrigerant circuit, disposed in a heat pump system.
A description will now be given, with reference to
As shown in part (b) of
The first communication hole 3c formed on the bottom surface of the projecting portion 9b communicates with a first communication hole 3d formed through the pressed portion 9c of the second heat exchanger pipe 2 positioned right under the projecting portion 9b of the first heat exchanger pipe 1.
As stated above, this pressed portion 9c closes part of the opening of the second refrigerant flow channel 2a of the second heat exchanger pipe 2, and thus, the first communication hole 3d does not communicate with the second refrigerant flow channel 2a. Further, as in the projecting portion 9b formed on the topmost heat exchanger pipe 1, first communication holes 3c pass through the top and bottom surfaces of the projecting portion 9b of the first heat exchanger pipe 1 positioned right under the pressed portion 9c of this second heat exchanger pipe 2.
The above-described first communication hole 3d communicates with, via the first communication hole 3c formed on the top surface of the projecting portion 9b, the first refrigerant auxiliary flow channel 1b formed inside the projecting portion 9b, and also communicates with the first refrigerant flow channel 1a of the first heat exchanger pipe 1.
That is, the first port 3 communicates with the first refrigerant flow channel 1a of the topmost first heat exchanger pipe 1, and this first refrigerant flow channel 1a communicates with, via the second heat exchanger pipe 2 positioned immediately under this first refrigerant flow channel 1a, the first refrigerant flow channel 1a of the first heat exchanger pipe 1 under the second heat exchanger pipe 2. The lower layers of the first and second heat exchanger pipes 1 and 2 have a structure similar to the above-described structure.
That is, the first port 3 and the first refrigerant flow channels 1a of the first heat exchanger pipes 1 sequentially communicate with each other, but they are shielded from the second refrigerant flow channels 2a of the second heat exchanger pipes 2 by the provision of the pressed portions 9c formed in these second heat exchanger pipes 2. However, a first communication hole 3c is formed only on the top surface of the pressed portion 9a of the bottommost first heat exchanger pipe 1 (the second bottommost heat exchanger pipe in part (b) of
In this structure, a first refrigerant flowing from one of the two first ports 3 flows through the first refrigerant auxiliary flow channels 1b and the first refrigerant flow channels 1a of the first heat exchanger pipes 1 of the stacking structure and flows out of the other first port 3.
A second communication hole 4c passes through the pressed portion 9a formed in the topmost first heat exchanger pipe 1, and the second port 4 communicates with this second communication hole 4c. Second communication holes 4d are formed on the top and bottom surfaces of the projecting portion 9d formed on the second heat exchanger pipe 2 positioned immediately under the pressed portion 9a of the first heat exchanger pipe 1, and the second communication hole 4c of the pressed portion 9a formed in the first heat exchanger pipe 1 immediately above this second heat exchanger pipe 2 communicates with, via the second communication hole 4d formed on the top surface of this projecting portion 9d, the second refrigerant auxiliary flow channel 2b formed inside the projecting portion 9d.
This second refrigerant auxiliary flow channel 2b communicates with the second refrigerant flow channel 2a of the second heat exchanger pipe 2. The second communication hole 4d formed on the bottom surface of the projecting portion 9d communicates with a second communication hole 4c formed through the pressed portion 9a of the first heat exchanger pipe 1 positioned right under the projecting portion 9d of the second heat exchanger pipe 2.
Further, second communication holes 4d pass through the top and bottom surfaces of the projecting portion 9d of the second heat exchanger pipe 2 positioned right under the pressed portion 9a of this first heat exchanger pipe 1. The above-described second communication hole 4c communicates with, via the second communication hole 4d formed on the top surface of the projecting portion 9d, the second refrigerant auxiliary flow channel 2b formed inside the projecting portion 9d, and also communicates with the second refrigerant flow channel 2a of the second heat exchanger pipe 2.
That is, the second port 4 communicates with the second refrigerant flow channel 2a of the second heat exchanger pipe 2 immediately under the topmost first heat exchanger pipe 1, and this second refrigerant flow channel 2a communicates with, via the first heat exchanger pipe 1 positioned immediately under this second refrigerant flow channel 2a, the second refrigerant flow channel 2a of the second heat exchanger pipe 2 under the first heat exchanger pipe 1. The lower layers of the first and second heat exchanger pipes 1 and 2 have a structure similar to the above-described structure.
That is, the second port 4 and the second refrigerant flow channels 2a of the second heat exchanger pipes 2 sequentially communicate with each other, but they are shielded from the first refrigerant flow channels 1a of the first heat exchanger pipes 1 by the provision of the pressed portions 9a formed in these first heat exchanger pipes 1. However, a second communication hole 4d is formed only on the top surface of the pressed portion 9c of the bottommost second heat exchanger pipe 2 (the bottommost heat exchanger pipe in part (b) of
In this structure, a second refrigerant flowing from one of the two second ports 4 flows through the second refrigerant auxiliary flow channels 2b and the second refrigerant flow channels 2a of the second heat exchanger pipes 2 of the stacking structure and flows out of the other second port 4.
As shown in
As shown in
Similarly, the second communication holes 4c formed in the pressed portions 9a and the second communication holes 4d formed in the projecting portions 9d have the same diameter and are formed concentrically in the stacking direction. However, these holes are not restricted to this configuration. Instead, they may be formed such that they do not have the same diameter or such that they are not concentric in the stacking direction, and they may be formed in any manner as long as the second refrigerant flow channels 2a of the second heat exchanger pipes 2 can communicate with each other. Additionally, the above-described holes are not restricted to a circular shape, and may be formed in another shape, such as a rectangular shape.
The first and second heat exchanger pipes 1 and 2 of the heat exchanger 10a of Embodiment 2 shown in
A sheet is bended by means of, for example, roll-forming, and then, joints, which are both ends of this sheet, are electric-resistance welded (welded). Alternatively, a cylinder is processed by means of roll-forming or press-forming or is processed by means of extrusion forming or pultrusion forming.
Then, in an area having a predetermined length from the first heat exchanger pipe end portion 5 toward inward of the first heat exchanger pipe 1, as viewed from the penetrating direction of the first refrigerant flow channel 1a, a portion from one end to a point on the way to the other end in the longitudinal direction of the first refrigerant flow channel 1a is pressed in the vertical direction in
By the provision of this pressed portion 9a, part of the opening of the first refrigerant flow channel 1a is closed. In the first heat exchanger pipe end portion 5 positioned opposite to the first heat exchanger pipe end portion 5 in which this pressed portion 9 is formed, another pressed portion 9a is formed in a similar manner. In this case, the two pressed portions 9a are disposed at positions diagonal to each other, as viewed from the top surface of the first heat exchanger pipe 1.
A central portion sandwiched between the two pressed portions 9a of the first heat exchanger pipe 1 is pressed in the vertical direction in
As a result, the other end which has not been pressed when forming the pressed portion 9a projects to a level higher than the central portion, thereby forming a projecting portion 9b. This projecting portion 9b is formed for each of the two pressed portions 9a, and the two projecting portions 9b are disposed at positions diagonal to each other, as viewed from the top surface of the first heat exchanger pipe 1.
In a manner similar to the first heat exchanger pipe 1, concerning the second heat exchanger pipe 2, a pressed portion 9c corresponding to the pressed portion 9a and a projecting portion 9d corresponding to the projecting portion 9b are formed at each side of the second heat exchanger pipe end portions 6.
At this stage, the pressed portion 9a closes part of the opening of the first refrigerant flow channel 1a of the first heat exchanger pipe 1. In contrast, the first refrigerant flow channel 1a corresponding to the projecting portion 9b is opened, and inside of this opening, the first refrigerant auxiliary flow channel 1b which communicates with the first refrigerant flow channel 1a is formed.
Similarly, the pressed portion 9c closes part of the opening of the second refrigerant flow channel 2a of the second heat exchanger pipe 2, while the second refrigerant flow channel 2a corresponding to the projecting portion 9d is opened, and inside of this opening, the second refrigerant auxiliary flow channel 2b which communicates with the second refrigerant flow channel 2a is formed.
Then, in the state in which the pressed portion 9a and the projecting portion 9b are formed in the first heat exchanger pipe 1, as stated above, and in the state in which the pressed portion 9c and the projecting portion 9d are formed in the second heat exchanger pipe 2, as stated above, a stacking structure of the first beat exchanger pipes 1 and the second heat exchanger pipes 2 is formed in the following manner.
The first heat exchanger pipe 1 and the second heat exchanger pipe 2 are stacked on each other such that the pressed portion 9a of the first heat exchanger pipe 1 and the projecting portion 9d of the second heat exchanger pipe 2 overlap each other and such that the projecting portion 9b of the first heat exchanger pipe 1 and the pressed portion 9c of the second heat exchanger pipe 2 overlap each other.
In this case, the central portions of the first and second heat exchanger pipes 1 and 2 are bonded to each other by brazing utilizing a brazing filler material 21. Then, the pressed portion 9a and the projecting portion 9d are brazed to each other by using a brazing filler material 21, and similarly, the projecting portion 9b and the pressed portion 9c are brazed to each other by using a brazing filler material 21.
As stated above, if a gap is produced between the pressed portion 9a and the projecting portion 9d or between the projecting portion 9b and the pressed portion 9c when bonding the central portions of the first and second heat exchanger pipes 1 and 2, the pressed portion 9a and the projecting portion 9d or the projecting portion 9b and the pressed portion 9c may be brazed by filling this gap with a brazing filler material 21.
Similarly, if a gap is produced between the central portions of the first and second heat exchanger pipes 1 and 2 when bonding the pressed portion 9a and the projecting portion 9d and the projecting portion 9b and the pressed portion 9c, the central portions of the first and second heat exchanger pipes 1 and 2 may be brazed by filling this gap with a brazing filler material 21.
As shown in part (a) of
When closing the openings of the projecting portions 9b of the first heat exchanger pipes 1 and the openings of the projecting portions 9d of the second heat exchanger pipes 2 with the covers 13, as stated above, the heat-exchanger-pipe fitting portions 13a of the covers 13 are fit into the openings, and then, the covers 13 are bonded to the openings by using a brazing filler material 21, thereby closing the openings. With this configuration, refrigerants do not leak from the openings of the projecting portions 9b and 9d.
As shown in part (b) of
As stated above, the first ports 3 communicate with the first refrigerant auxiliary flow channels 1b and the first refrigerant flow channels 1a of all the first heat exchanger pipes 1, and the second ports 4 communicate with the second refrigerant auxiliary flow channels 2b and the second refrigerant flow channels 2a of all the second heat exchanger pipes 2.
By using the above-described method, the heat exchanger 10a, which is a stacked heat exchanger, is fabricated.
The projecting portion 9b of the first heat exchanger pipe 1 is formed by pressing a central portion sandwiched between the two pressed portions 9a of the first heat exchanger pipe 1 in the vertical direction in
When the pressed portion 9a is formed, the opening of the first refrigerant flow channel 1a, which has not been closed, positioned at the first heat exchanger pipe end portion 5 may be expanded from inward to outward, thereby forming the projecting portion 9b. The same applies to the formation of the projecting portion 9d of the second heat exchanger pipe 2.
As shown in part (a) of
The same applies to the formation of the projecting portion 9d of the second heat exchanger pipe 2. In this case, when stacking the first heat exchanger pipe 1 and the second heat exchanger pipe 2 on each other, a gap is produced between the pressed portion 9a and the projecting portion 9d and between the projecting portion 9b and the pressed portion 9c. However, the pressed portion 9a and the projecting portion 9d and the projecting portion 9b and the pressed portion 9c may be bonded to each other by filling the gaps with a brazing filler material 21.
As shown in part (a) of
The same applies to the opening of the projecting portion 9d of the second heat exchanger pipe 2. With this configuration, the provision of the covers 13 is not necessary, thereby making it possible to decrease the number of parts and to reduce the weight of the heat exchanger 10a.
The covers 13 correspond to "closing means" of the present invention.
The heat exchanger 10a, which is a stacked heat exchanger according to Embodiment 2, is installed in a heat pump system utilizing heating energy or cooling energy. For example, in the case of an operation utilizing heating energy, a heat exchange operation is performed as follows.
A high-temperature first refrigerant flowing from a refrigerant circuit flows into the heat exchanger 10a through one of the first ports 3 and further into the first refrigerant auxiliary flow channels 1b inside the projecting portions 9b of the first heat exchanger pipes 1, flows through the first refrigerant flow channels 1a of the first heat exchanger pipes 1 and the first refrigerant auxiliary flow channels 1b inside the projecting portions 9b positioned on the other side, and then, flows out of the other first port 3.
A second refrigerant flowing from a use side circuit flows into the heat exchanger 10a through one of the second ports 4 and further into the second refrigerant auxiliary flow channels 2b inside the projecting portions 9d of the second heat exchanger pipes 2, flows through the second refrigerant flow channels 2a and the second refrigerant auxiliary flow channels 2b inside the projecting portions 9d positioned on the other side, and then, flows out of the other second port 4.
In this case, the first refrigerant and the second refrigerant flow through the first refrigerant flow channels 1a of the first heat exchanger pipes 1 and the second refrigerant flow channels 2a of the second heat exchanger pipes 2, respectively, in opposite directions or in parallel with each other, thereby performing heat exchange between the first refrigerant and the second refrigerant at wall surfaces of the first and second heat exchanger pipes 1 and 2.
The heat exchanger disclosed in Patent Literature 1 has a space which cannot be utilized because of the provision of a header pipe used for distributing a refrigerant over heat exchanger pipes, thereby decreasing efficiency in space utilization. However, as in the above-described configuration, the first refrigerant flow channels 1a of the first heat exchanger pipes 1 communicate with each other through the use of the first ports 3, while the second refrigerant flow channels 2a of the second heat exchanger pipes 2 communicate with each other through the use of the second port 4.
Accordingly, it is not necessary to provide a header pipe, thereby making it possible to reduce the generation of a space which cannot be utilized and to form the entire heat exchanger 10a in a compact size.
By alternately stacking the first heat exchanger pipes 1 and the second heat exchanger pipes 2 on each other, heat exchange efficiency between the first refrigerant and the second refrigerant can be improved. Moreover, by setting the lengths of the first heat exchanger pipes 1 and the second heat exchanger pipes 2 in a direction in which refrigerants flow through their refrigerant flow channels to be substantially the same and by setting the widths of the first heat exchanger pipes 1 and the second heat exchanger pipes 2 in the widthwise direction of the refrigerant flow channels to be substantially the same, heat exchange between the first refrigerant and the second refrigerant can be more effectively performed, and also, the entire heat exchanger 10a can be formed in a compact size.
On the topmost heat exchanger pipe (the first heat exchanger pipe 1 in
Accordingly, the flow channel lengths of the first and second refrigerant flow channels 1a and 2a through which refrigerants flow can be substantially maximized, thereby further enhancing heat exchange efficiency between the first refrigerant and the second refrigerant.
However, the positions of the first ports 3 and the second ports 4 are not restricted to the above-described positions, and may be changed appropriately depending on the position of the heat exchanger 10a installed in, for example, a heat pump system.
As shown in
As in the two first ports 3, the positions of the two second ports 4 are not restricted, either. Moreover, the first ports 3 and the second ports 4 do not have to be disposed on the same surface. For example, the two first ports 3 may be disposed on the top surface of the topmost heat exchanger pipe of the stacking structure, while the two second ports 4 may be disposed on the bottom surface of the bottommost heat exchanger pipe of the stacking structure.
By forming the pressed portions 9a for the openings of the first refrigerant flow channels 1a of the first heat exchanger pipes 1 and by forming the pressed portions 9c for the openings of the second refrigerant flow channel 2a of the second heat exchanger pipes 2, the first refrigerant flow channels 1a and the second refrigerant flow channels 2a are shielded from each other and do not communicate with each other.
Thus, the first refrigerant flowing through the first refrigerant flow channels 1a and the second refrigerant flowing through the second refrigerant flow channels 2a can be prevented from being mixed with each other.
The cross sections of all the heat exchanger pipes shown in parts (a) through (d) of
The top surfaces and the bottom surfaces of both the heat exchanger pipes 14a and 14b are flat, and when a stacking structure of the heat exchanger pipes 14a or 14b is formed, the heat exchanger pipes 14a or 14b can be bonded in close contact with each other, thereby improving heat exchange efficiency.
Both ends of a longitudinal heat exchanger pipe 14c shown in part (c) of
By the formation of these grooves 15, the area of the inner wall surface of the heat exchanger pipe 14c is increased, thereby improving efficiency in heat exchange with a refrigerant flowing through an adjacent heat exchanger pipe. Additionally, as stated above, the grooves 15 are formed in a direction from one opening to the other opening of the heat exchanger pipe 14c, thereby reducing a pressure drop in a refrigerant. Needless to say, the above-described advantages obtained by the heat exchanger pipes 14a and 14b are also obtained by the heat exchanger pipe 14c.
As stated above, on the inner wall surface of the refrigerant flow channel of the heat exchanger pipe 14c, the grooves 15 are formed in a direction from one opening to the other opening of the heat exchanger pipe 14c. However, the grooves 15 are not restricted to this configuration. For example, the grooves 15 may be formed in a wavy line shape or an oblique lines shape. With this configuration, the area of the inner wall surface of the heat exchanger pipe 14c is increased, thereby improving efficiency in heat exchange with a refrigerant flowing through an adjacent heat exchanger pipe. At the same time, turbulence is generated in the flow of a refrigerant, thereby improving heat exchange efficiency.
Both ends of a longitudinal heat exchanger pipe 14d shown in part (d) of
The projections of the waveforms of the corrugated plate 16 abut against the inner wall surface of the heat exchanger pipe 14d. By inserting this corrugated plate 16, a refrigerant flowing through a refrigerant flow channel contacts the corrugated plate 16 as well as the inner wall surface, thereby transferring heating energy or cooling energy to the inner wall surface via this corrugated plate 16.
Thus, advantages similar to those obtained by an increased area of the inner surface wall of the heat exchanger pipe 14c, that is, the effect of improving efficiency in heat exchange with a refrigerant flowing through an adjacent heat exchanger pipe, is obtained. Needless to say, the above-described advantages obtained by the heat exchanger pipes 14a and 14b are also obtained by the heat exchanger pipe 14d.
Any one of the heat exchanger pipes 14a through 14d shown in
The heat exchanger 10b based on the heat exchanger 10 according to Embodiment 1 corresponds to a "stacked heat exchanger" of the present invention.
The top surfaces and the bottom surfaces of all the heat exchanger pipes 14a through 14d shown in
As shown in part (c) of
If the grooves 15 are formed in a wavy line shape or an oblique line shape, the area of the inner wall surface of the heat exchanger pipe 14c is increased. As a result, efficiency in heat exchange with a refrigerant flowing through an adjacent heat exchanger pipe is improved, and at the same time, turbulence is generated in the flow of a refrigerant, thereby improving heat exchange efficiency.
As shown in part (d) of
As shown in
The first refrigerant circuit 100 is formed by sequentially connecting a compressor 31, the heat exchanger 10, an expansion valve 33, and an outdoor heat exchanger 34 through the use of refrigerant pipes. A fan 39 is disposed near the outdoor heat exchanger 34. The fan 39 sends outside air to the outdoor heat exchanger 34 so that heat exchange between the outside air and the first refrigerant flowing through the outdoor heat exchanger 34 can be performed. As the first refrigerant flowing through the first refrigerant circuit 100, for example, R410A, another fluorocarbon refrigerant, or a natural refrigerant, such as carbon dioxide or hydrocarbon, may be used.
The second refrigerant circuit 101 is formed by sequentially connecting a pump 36, a use side heat exchanger 35, and the heat exchanger 10 through the use of refrigerant pipes. Among these elements, the use side heat exchanger 35 is used as a radiator, a floor heater, or the like. As the second refrigerant flowing through the second refrigerant circuit 101, for example, a fluorocarbon refrigerant, a natural refrigerant, such as carbon dioxide or hydrocarbon, tap water, distilled water, or brine may be used.
The outdoor heat exchanger 34 corresponds to a "heat source side heat exchanger" of the present invention.
An operation of the heat pump system according to Embodiment 4 will now be described below with reference to
The first refrigerant flowing out of the heat exchanger 10 flows into the expansion valve 33 and is expanded and decompressed by this expansion valve 33, thereby being transformed into a low-temperature low-pressure first refrigerant. This low-temperature low-pressure first refrigerant flows into the outdoor heat exchanger 34 and performs heat exchange with outside air which is sent from the fan 39 through the rotation operation of the fan 39, thereby being transformed into a low-temperature low-pressure gaseous first refrigerant and then flowing out of the outdoor heat exchanger 34. The gaseous first refrigerant flowing out of the outdoor heat exchanger 34 flows into the compressor 31 and is compressed again.
Meanwhile, in the second refrigerant circuit 101, the second refrigerant flowing into the heat exchanger 10 performs heat exchange, within the heat exchanger 10, with the first refrigerant which flows in a direction opposite to or in parallel with the flowing direction of the second refrigerant, thereby being heated by the first refrigerant and then flowing out of the heat exchanger 10.
The second refrigerant flowing out of the heat exchanger 10 circulates within the second refrigerant circuit 101 through the use of the pump 36 and flows into the use side heat exchanger 35. The second refrigerant flowing into the use side heat exchanger 35 transfers heat to the outside and then flows out of the use side heat exchanger 35. The second refrigerant flowing out of the use side heat exchanger 35 flows into the heat exchanger 10 and is heated again.
If water is used as the second refrigerant flowing through the second refrigerant circuit 101, it is desirable that portions of the heat exchanger 10 which contact water have a corrosion resistance to water, for example, the second heat exchanger pipes 2 and the second ports 4 of the heat exchanger 10 be formed of a corrosion-resistant material.
In the heat pump system shown in
As in the above-described configuration, by mounting the heat exchanger 10, 10a, or 10b having a stacking structure of the first heat exchanger pipes 1 and the second heat exchanger pipes 2, it is possible to obtain a heat pump system in which heat exchange efficiency between a first refrigerant and a second refrigerant is improved.
Needless to say, advantages discussed in Embodiment 1 through Embodiment 3 can also be obtained by Embodiment 4.
The heat pump system according to Embodiment 4 is not restricted to the configuration shown in
In the heat pump system shown in
As in the heat pump system shown in
In the heat pump system shown in
In the heat pump system shown in
The first refrigerant flowing out of the outdoor heat exchanger 34 flows into the expansion valve 33 and is expanded and decompressed by this expansion valve 33, thereby being transformed into a low-temperature low-pressure first refrigerant. This low-temperature low-pressure first refrigerant flows into the heat exchanger 10 and performs heat exchange, within the heat exchanger 10, with a second refrigerant which flows in a direction opposite to or in parallel with the flowing direction of the first refrigerant, thereby receiving heat from the second refrigerant and being transformed into a low-temperature low-pressure gaseous first refrigerant.
The gaseous first refrigerant then flows out of the heat exchanger 10. This gaseous first refrigerant flowing out of the heat exchanger 10 flows into the compressor 31 and is compressed again.
In the second refrigerant circuit 101, the second refrigerant flowing into the heat exchanger 10 performs heat exchange, within the heat exchanger 10, with the first refrigerant which flows in a direction opposite to or in parallel with the flowing direction of the second refrigerant. The second refrigerant is cooled by the first refrigerant and then flows out of the heat exchanger 10.
The second refrigerant flowing out of the heat exchanger 10 circulates within the second refrigerant circuit 101 through the use of the pump 36 and flows into the use side heat exchanger 35. The second refrigerant flowing into the use side heat exchanger 35 cools, for example, outside air, and then flows out of the use side heat exchanger 35. The second refrigerant flowing out of the use side heat exchanger 35 flows into the heat exchanger 10 and is cooled again.
In a manner similar to the heat pump system shown in
In the heat pump system shown in
In a manner similar to the heat pump system shown in
In the heat pump systems shown in
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.