WO2001061263A1

WO2001061263A1 - Heat exchanger

Info

Publication number: WO2001061263A1
Application number: PCT/JP2000/000837
Authority: WO
Inventors: Soichi Kato; Akihiko Takano
Original assignee: Zexel Valeo Climate Control Corporation
Priority date: 2000-02-15
Filing date: 2000-02-15
Publication date: 2001-08-23

Abstract

A heat exchanger (1); comprising heat exchange tubes (2), (24), and (26) having refrigerant flow paths, fins (3) and (32) installed between the tubes, and header pipes (4) and (5) to which the tubes communicate and which supply and receive refrigerant; and performing the exchange of heat transferred to the tubes and fins; wherein the heat exchange tubes are provided with refrigerant flow paths of circular cross-section, each of the heat exchange tubes is formed in the same cross-section and is provided with a plurality of refrigerant flow paths (21) and (25) of circular cross-section, the diameter of the circular cross-section of the refrigerant flow paths is 1 mm or less, the refrigerant flow paths in the header pipes are formed in a circular cross-section, the diameter of the refrigerant flow paths in the header pipes does not exceed 10 mm and the wall thickness of the header pipes does not exceed 5 mm, and the heat exchange tubes are provided with the refrigerant flow paths of circular cross-section and a thick wall part not forming the refrigerant flow paths and a tube inserting part having a cross-section smaller than that of the other portions is formed in the heat exchange tubes at the longitudinal end part thereof.

Description

Description Heat exchanger Technical field

The present invention relates to a heat exchanger that performs heat exchange by heat transmitted from a medium to a heat exchanger tube.

Background art

2. Description of the Related Art Conventionally, there has been known a heat exchanger configured by connecting a heat exchange tube for exchanging heat of a refrigerant and a pair of header pipes for receiving and transmitting the refrigerant to each other.

That is, the refrigerant introduced from one header pipe flows through the refrigerant flow path inside the heat exchange tube, and then is discharged from the other header pipe, and the heat exchange of the refrigerant is performed by heat transmitted to the heat exchange tube. Is performed.

The heat exchange tube used in this type of heat exchanger is formed by using an aluminum alloy or the like as a material and using a manufacturing method such as extrusion.

Further, the heat exchanger includes a fin that is in contact with the heat exchange tube, and the heat exchange tube has a flat cross section so as to increase the contact area between the heat exchange tube and the fin. The flat tube has a configuration in which a plurality of medium flow paths are formed.

In recent years, fluorocarbon-based refrigerants have a global warming effect and the like. Therefore, there is an increasing demand for the ban on the use of these refrigerants and the direction of reduction. For this reason, Japanese Patent Publication No. 2850484 and Japanese Patent Application Laid-Open No. H10-92421 disclose, as substitute refrigerants for fluorinated refrigerants, Carbon dioxide does not destroy the ozone layer (C 0 ₂₎ discloses a refrigerating cycle using as a refrigerant.

When using the C 0 ₂ in the refrigeration cycle as a refrigerant, for dissipating heat from high temperature and high pressure and Do ivy refrigerant, the refrigerant when flowing through the heat exchanger conditions, the gas-liquid two-phase state Excessive pressure is assumed to be applied to the heat exchanger compared to the case where the refrigerant in the normal gas-liquid two-phase state flows through the heat exchanger in the supercritical region beyond the critical point. Is done.

For example, if a C 0 ₂ is used as a refrigerant, the heat exchanger to exert the action of heat radiation refrigerant which high temperature and high pressure, 6-fold compared to the case where refrigerant in a gas-liquid mixed state is flowing It is considered that the above pressure resistance is required.

When a supercritical refrigerant is used in a refrigeration system, the thickness of the heat exchange tube and header pipe through which the refrigerant flows can be made thick to ensure the pressure resistance required of the heat exchanger. Conceivable. However, if the thickness of the heat exchange tubes or header pipes is increased, the external shape of the heat exchanger itself will be enlarged, and the layout of the refrigeration system will be reduced in vehicles with limited installation space. Produces. Also, if the thickness of the heat exchanger tubes and header pipes constituting the heat exchanger is made thicker, the weight of the heat exchanger also increases. Is not preferred.

Usually, the heat exchange tube is used to increase the heat exchange capacity by causing turbulence in the medium and to increase the pressure resistance of the flat surface of the tube. There is. When a flat tube is partitioned by beads or the like, the cross section of the refrigerant flow path forms a rectangular shape, and when a refrigerant with high pressure resistance is required to flow, the refrigerant stress concentrates at this corner and the pressure This causes the problem of poor performance.

To secure the required pressure resistance, use the same volume header When the pipe is made thicker, the inner diameter of the medium flow path of the header pipe becomes smaller, and the tube insertion hole formed for connecting the medium flow path of the header pipe and the tube is provided with the medium flow path. It is as small as the inside diameter of the road.

Generally, the header pipe and the tube are connected to each other by inserting a tube end into a tube insertion hole formed in the header pipe. When a tube is formed, along with the size of the tube insertion hole formed in the header pipe, the tube width is reduced, the contact area between the tube and the fin is reduced, and heat exchange performance is reduced. The problem of lowering occurs.

Here, it is necessary to increase the tube width as much as possible using the effective space to improve the heat exchange performance in order to avoid the deterioration of the heat radiation performance.

In order to secure the tube width, for example, the invention described in Japanese Patent Laid-Open Publication No. HEI 1-1477287 discloses a tube insertion hole with respect to the axis X in the longitudinal direction of the header pipe 73 as shown in FIG. There is a long tube insertion hole formed by tilting the major axis Y at the angle S at 7 4. Also, in the tube connected to the pipe, the longitudinal end of the tube is twisted at an angle of 0 with respect to the center of the tube. 7 4

In this case, it is necessary to twist the tube end so as to match the tube insertion hole 74, which may be cumbersome in operation, and assembling the twisted tube end with the tube insertion hole. Was sometimes difficult.

Therefore, in view of the above problems, an object of the present invention is to provide a heat exchanger that has improved heat exchange performance while preventing a weight increase while maintaining a desired pressure resistance. Disclosure of the invention

The invention described in claim 1 of the present application is directed to a header pie that is connected to a heat exchange tube having a refrigerant flow path, a fin mounted between the tubes, and the tubes, and that sends and receives the refrigerant. A heat exchanger that performs heat exchange by heat transmitted to the tubes and the fins, wherein the heat exchange tube has a refrigerant flow path having a circular cross section. It is.

For example, when a refrigerant in a supercritical state exceeding the critical point of the gas-liquid two-phase state is used in a refrigeration cycle as the refrigerant flowing through the heat exchanger, the heat of the refrigerant at high temperature and high pressure is released. It is considered that the heat exchanger that exerts its function must have a pressure resistance that is at least six times that of the case where the refrigerant in the gas-liquid mixed state flows.

Therefore, in order to secure the required pressure resistance, it is conceivable to make the cross-sectional shape of the refrigerant channel circular. That is, by forming the refrigerant flow path into a circular cross section, the refrigerant pressure is uniformly applied to the outer wall of the flow path, and the pressure resistance of the tube can be improved.

The invention described in claim 2 of the present application is the heat exchanger according to claim 1, wherein each of the heat exchange tubes has the same cross-section and a plurality of refrigerant passages having circular cross-sections. It is a vessel.

When a refrigerant that requires high pressure resistance is used in a refrigeration cycle, the above-mentioned refrigerant flow path must have a circular cross section and the refrigerant flow path itself must be small in order to ensure the required pressure resistance. Conceivable. In other words, by reducing the size of the refrigerant channel, it is possible to increase the wall thickness of the tube in the same volume and secure pressure resistance. In this case, by providing a plurality of refrigerant flow paths, it is possible to secure a flow rate of the refrigerant flowing through the heat exchanger.

The invention described in claim 3 of the present application is the heat exchanger according to claim 1, wherein the diameter of the circular cross section of the refrigerant channel is 1 mm or less. The configuration of the heat exchanger.

In this way, by setting the diameter of the refrigerant passage having a circular cross section formed in the tube to 1 mm or less, required pressure resistance can be secured.

The invention described in claim 4 of the present application is the heat exchanger according to claim 2, wherein the diameter of the circular cross section of the refrigerant channel is 1 mm or less.

When the diameter of the refrigerant flow path having a circular cross section is 1 mm or less, by providing a plurality of the refrigerant flow paths in the tube, it is possible to secure the flow rate of the refrigerant flowing through the heat exchanger.

A fifth aspect of the present invention is the heat exchanger according to any one of the first to fourth aspects, wherein the refrigerant pipe of the header pipe has a circular cross section.

In this way, if the refrigerant flow path of the header pipe is circular in cross section, the pressure of the refrigerant flowing through the header pipe is evenly applied to the header pipe, and the pressure resistance of the header pipe is increased. The performance is improved.

The invention described in claim 6 of the present application is the invention according to claim 5, wherein the inner diameter of the header pipe does not exceed 10 mm, and the thickness of the header pipe exceeds 5 mm. In order to secure the required pressure resistance of the header pipe, which is not a heat exchanger, the thickness of the header pipe must be set by adjusting the internal pressure applied to the inside of the header pipe and pulling the material constituting the header pipe. It is necessary to consider the effects of stress and other factors.

When the refrigerant flow path diameter is 10 mm or more, the pressure applied to the header pipe increases, and the thickness of the header pipe needs to be increased accordingly. growing. Also, when the refrigerant flow path diameter is set to be small, the pressure applied to the header pipe by the flow of the refrigerant becomes small, so that the thickness of the header pipe becomes thinner and the weight increases. Addition problems are avoided. On the other hand, if the coolant flow path diameter is too small, the performance as a header pipe for sending and receiving the coolant is reduced. Accordingly, when the refrigerant flow path diameter is not larger than 10 mm, the outer diameter of the header pipe may be determined based on the expression (1) described in the embodiment of the invention described later. It is possible.

For example, when aluminum is used as a material for forming a header pipe, the tensile stress of aluminum is 10 kg / mm ² . The pressure on the high-pressure side of the refrigerant is about six times as high as the pressure of the refrigerant in a normal gas-liquid mixed state, so the internal pressure applied to the members also increases, and pressure resistance is required.

For this reason, the outer diameter of the header pipe can be set to about 20 mm according to equation (1) described later.

Therefore, when the refrigerant pipe diameter is set to a value not exceeding 10 mm, the required pressure resistance is set by setting the thickness of the header pipe to a value not exceeding 5 mm. Can be ensured.

In addition, if the header pipe is configured with the minimum inner and outer diameter values to ensure the required pressure resistance, the increase in weight is limited and the in-vehicle latability is improved. Wear.

In addition to the header pipe, in the case of a tube with a circular cross section, the wall thickness of the tube is taken into account in consideration of the tensile stress of the members constituting the tube, the diameter of the refrigerant flow path, and the internal pressure applied to the tube. Can be set.

According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, the heat exchange tube includes a refrigerant flow path having a circular cross section, and a thick portion that does not form a refrigerant flow path. A heat exchanger in which a tube insertion portion having a smaller cross-sectional area than other portions is formed at a longitudinal end of the heat exchange tube. As described above, in a heat exchanger that requires high pressure resistance, the required pressure resistance is obtained by forming the refrigerant flow path into a circular cross section and forming a thick portion in the heat exchange tube. When the header pipe is made thick to ensure the required pressure resistance, the inside diameter of the refrigerant flow path flowing through the inside of the header pipe becomes small, As the inner diameter of the coolant channel decreases, the tube insertion hole formed for connecting the tube and the header pipe also becomes smaller. If, for example, the width of the tube having a flat cross section in the lateral direction is narrowed to match the tube insertion hole, the heat dissipation performance is reduced due to a decrease in the heat transfer area.

Here, the flat cross section refers to a cross sectional shape of a tube having at least flat surfaces on the upper and lower surfaces of the tube.

According to the present invention, since a tube insertion portion having a smaller cross-sectional area than other portions is formed at the longitudinal end of the heat exchange tube, the width of the tube having a flat cross section in the lateral direction is changed. In addition, the heat exchanger can be configured without securing the heat transfer area and reducing the heat exchange performance.

The invention described in claim 8 of the present application is the heat exchanger according to any one of claims 1 to 7, wherein the tubes and the fins are alternately stacked to form a multi-layer.

As described above, by forming multiple faults by alternately stacking tubes and fins, the heat exchange area is increased, the amount of refrigerant flowing through is increased, and the heat exchange performance is improved. It can be improved.

According to the ninth aspect of the present invention, in the invention according to the eighth aspect, a partition plate that partitions a refrigerant flow path flowing between the tube and the header pipe into a plurality of sections is provided at a key point of the header pipe. The heat exchanger is arranged and has the same total cross-sectional area in each section of each refrigerant flow path partitioned into the plurality of sections. For example, if c 02 is used as a refrigerant in a refrigeration cycle, CO 2

₂ is used in the gaseous area and does not cause a change in volume due to condensation unlike conventional refrigerants, so that the total cross-sectional area in each section of each refrigerant flow path is within a range that can ensure pressure resistance. Can be almost the same. This does not increase the size of the heat exchanger unnecessarily o

According to the tenth aspect of the present invention, in the invention of the eighth or ninth aspect, a fin is mounted between the tubes so as to be multi-tiered, and the end of the tube is connected to and connected to a header pipe. A heat exchanger body composed of tubes, fins, and header pipes such that the cross-sectional longitudinal direction of the multi-tiered tubes and fins is orthogonal to the direction of ventilation of external air. This is a heat exchanger in which a plurality of heat exchangers are arranged, and the header pipes of each heat exchanger body are connected and connected.

In this way, even in a heat exchanger in which the refrigerant flow path is made small in order to ensure pressure resistance, a plurality of tubes and fins stacked in multiple stages are arranged so as to be parallel to the ventilation direction. If the header pipes are connected and connected to form an integrated heat exchanger, it is possible to increase the flow rate of the refrigerant flowing through the heat exchanger and to increase the heat transfer area, thereby improving the heat exchange performance. Can be improved.

The invention described in claim 11 of the present application is the invention according to any one of claims 7 to 9, wherein a plurality of tubes and fins have a cross-sectional longitudinal direction orthogonal to the ventilation direction. A heat exchanger in which the heat exchangers are arranged in parallel and the header pipes of the respective heat exchangers are connected and connected to each other, and a plurality of media flow through each tube and the header pipe. This is a heat exchanger that passes between the heat exchangers in series or in parallel and performs heat exchange by heat transmitted to a plurality of tubes and fins. In this way, a plurality of heat exchangers are arranged in parallel, and the heat exchangers are connected and connected to form an integrated heat exchanger, and the refrigerant passes in series or in parallel inside the heat exchanger. If it is configured to flow, it is possible to regulate the flow of the refrigerant in the ventilation direction.

That is, when the refrigerant flows through the plurality of header pipes arranged in parallel, the refrigerant flows in parallel between the plurality of heat exchanger bodies, or the refrigerant flows into one of the plurality of header pipes arranged in parallel. When the refrigerant flows in series in such a way that the refrigerant flows through the other heat exchanger bodies in order, the cooling process and the direction of ventilation of the external air are taken into consideration, and the heat exchange rate is improved. It is possible to achieve this.

For example, when the refrigerant is configured to flow in series between a plurality of heat exchanger bodies in series, the refrigerant flows from the header pipe in the rear row in the ventilation direction, and the refrigerant follows the cooling process. When the heat exchange medium is configured to flow in the ventilation direction, the heat exchange medium, which has been cooled to some extent through the heat exchanger body, flows through the refrigerant flow path closest to the ventilation direction. It is further cooled and the heat exchange performance can be improved.

The invention according to claim 12 is the invention according to claim 10 or 11, wherein a plurality of heat exchanges are performed such that a longitudinal direction of a cross section of the tube and the fin is orthogonal to a ventilation direction. A heat exchanger in which a plurality of tube insertion portions are formed at an end of the heat exchange tube, wherein the heat exchanger tubes are arranged in parallel, and header pipes of the respective heat exchangers are connected and connected to each other. And a heat exchanger in which the tube ends are connected to the respective header pipes.

As described above, a plurality of tube insertion portions are formed at the end of the tube, and the tube insertion portions are inserted into the tube insertion holes formed in the header pipe, whereby each refrigerant flow of each heat exchanger body is formed. The roads can be connected and connected, and the heat transfer area can be increased. The invention according to claim 13 is the heat exchanger according to any one of claims 9 to 12, wherein a plurality of refrigerant flow paths are formed in the header pipe.

By forming a plurality of refrigerant flow paths in the header pipe, when a plurality of heat exchangers are arranged in parallel and integrated, the work such as connecting tubes between header pipes is reduced. In addition, it is easy to manufacture a heat exchanger integrated by connecting and connecting a plurality of heat exchanger bodies, and it is possible to improve work efficiency.

The invention described in claim 14 of the present application is the heat exchanger according to any one of claims 1 to 7, wherein a fin is mounted between the tubes that reciprocate in a meandering manner. It is.

In this way, the heat exchange tubes through which the refrigerant flows are reciprocated in a meandering manner, and the fins are mounted between the tubes, thereby increasing the heat exchange area and improving the heat exchange rate. This is possible.

The invention described in claim 15 of the present application is the invention according to claim 14, wherein a plurality of heat exchanger bodies are arranged in parallel, and each heat exchanger body is connected and connected to be integrated. It is a heat exchanger.

For example, when a heat exchanger is mounted on a vehicle body, the surface on which the heat exchanger can be installed is limited to a certain range due to the design of the car, etc., in the direction of external air flow.

According to the present invention, since a plurality of heat exchanger bodies are arranged in parallel and each of the heat exchanger bodies is connected and connected to each other, the heat exchange area in contact with the external air is enlarged to improve the heat exchange performance. Can be improved.

The invention described in claim 16 of the present application is the invention according to any one of claims 1 to 15, wherein the tube and the header pipe are formed by molding aluminum or an aluminum alloy. The heat exchanger has the following configuration.

Tubes and heads made of aluminum or aluminum alloy Forming a pipe has the advantage that tubes and header pipes can be easily formed at low cost. However, for example, when a refrigerant that is in a supercritical region when flowing through the heat exchanger is used as the refrigerant, the wall thickness of each member is increased in order to ensure the pressure resistance required of the heat exchanger. The problem is that the heat exchanger becomes thicker and the weight of the heat exchanger increases.

In the present invention, a structure is adopted in which the required pressure resistance is ensured and a weight increase is avoided, so that a tube or a header pipe can be formed using aluminum or an aluminum alloy. As a result, it is possible to form a heat exchanger at low cost.

The invention described in claim 17 of the present application is the heat exchanger according to any one of claims 1 to 16, wherein the refrigerant flowing into and out of the heat exchanger is in a gaseous state.

As described above, when the high-temperature and high-pressure medium in the gaseous state flows between the heat exchangers in the gaseous state, the heat exchanger is required to have high pressure resistance. According to the configuration of the heat exchanger of the present invention, even when a medium in a gaseous state requiring high pressure resistance is passed, a weight increase for securing pressure resistance and deterioration of the radiation property are prevented. Can be avoided.

Further, the heat exchanger of the present invention can be used in a refrigeration cycle using a refrigerant that requires high pressure resistance. The invention described in claim 18 of the present application is the invention according to any one of claims 1 to 17, wherein the refrigerant flowing through the heat exchanger is heat using carbon dioxide (C 0 ₂ ). It is an exchanger.

When carbon dioxide is used as the refrigerant in the refrigeration cycle, high-pressure refrigerant in the supercritical region exceeding the critical point of the gas-liquid two-phase state flows through the heat exchanger.

Therefore, the heat exchanger is required to have a pressure resistance that is at least six times higher than that in a case where a refrigerant in a gas-liquid mixed state flows. I mentioned earlier According to the heat exchanger of the present invention, since it is designed to satisfy high pressure resistance, it is possible to use carbon dioxide which is in a supercritical region as a refrigerant. Brief description of the drawings

【Figure 1】

FIG. 1 is a front view showing a multi-stage heat exchanger according to a specific example of the present invention.

【Figure 2】

FIG. 4 is a perspective view showing an end of a heat exchange tube according to a specific example of the present invention.

[Figure 3]

FIG. 2 is a perspective view showing a heat exchange tube and a fin according to a specific example of the present invention.

[Fig. 4]

According to a specific example of the present invention, a plurality of heat exchangers composed of a tube, a fin, and a header pipe are arranged in parallel, and the header pipes are connected and connected to form a heat exchange unit. It is a top view which shows schematic structure of a container.

[Figure 5]

According to an embodiment of the present invention, a plurality of heat exchangers composed of a tube, a fin, and a header pipe are arranged in parallel, and a pipe for flowing a medium in parallel to each header pipe is connected. It is a top view which shows the schematic structure of the heat exchanger of integral shape.

[Fig. 6]

FIG. 4 is a perspective view showing an end portion of a heat exchange tube in which a plurality of tube insertion portions are formed according to a specific example of the present invention.

[Fig. 7] FIG. 7 is a partial cross-sectional view showing a schematic configuration in a state where an end of the tube shown in FIG. 6 is inserted into a tube insertion hole of a header pipe.

[Fig. 8]

FIG. 7 is a partial cross-sectional view showing a schematic configuration in a state where a tube inlet shown in FIG. 6 is inserted into a header pipe in which a plurality of medium flow paths are formed.

[Fig. 9]

FIG. 4 is a partial cross-sectional view of a tube and a fin, showing a schematic configuration of a heat exchanger in which the same fin is mounted on a plurality of tubes arranged in parallel according to a specific example of the present invention.

[Fig. 10]

FIG. 1 is a plan view showing a pen-type heat exchanger according to a specific example of the present invention.

[Fig. 11]

FIG. 9 is a perspective view schematically showing a header pipe in which a long tube-shaped tube insertion hole inclined at an angle of 0 is formed according to a conventional example.

Best mode for carrying out the invention

Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing a schematic configuration of a stacked heat exchanger in which tubes and fins are alternately stacked in multiple stages.

As shown in FIG. 1, the heat exchanger 1 has a plurality of tubes 2 and fines 3 alternately stacked, and each end of each of the stacked tubes 2 and 2 has a header pipe 4. , 5 are inserted and connected to the tube insertion holes 6, 6. The header pipes 4 and 5 are formed such that the refrigerant passage through which the refrigerant flows has a circular cross section. The openings at the upper and lower ends of the header pipes 4 and 5 are closed by caps 7. Also, at the required location for header pipe 4 or 5. A partition plate 8 for dividing the refrigerant flow path into a plurality of sections and coupling members 9 and 10 for flowing in and out the refrigerant are provided. In the figure, reference numeral 11 denotes a side blade.

Heat exchanger 1 of this embodiment, for example, when the C 0 ₂ with C 0 ₂ is used as the refrigerant in the refrigerant frozen cycle, exerts a heat radiation effect of high temperature, high pressure and summer were refrigerant It is considered that the heat exchanger is required to have a pressure resistance six times or more as compared with the case where the refrigerant in the gas-liquid mixed state flows.

The heat exchanger 1 of the present example is formed by the partition plate 8 so that the sectional area of each section (path) of the refrigerant flow path divided into a plurality of sections is substantially the same.

For example, when used in a refrigeration cycle by the C 0 ₂ as a refrigerant, CO

₂ is used in the gaseous region and does not cause a change in volume due to condensation unlike conventional fluorocarbon refrigerants, so that each section of each refrigerant flow path (each path) is in a range where pressure resistance can be ensured. The total cross-sectional area at can be made approximately the same. This does not increase the size of the heat exchanger.

Each medium channel formed to communicate in the longitudinal direction of the header pipes 4 and 5 has a circular cross section. When the refrigerant flow path is formed in a circular cross section, pressure is uniformly applied to the refrigerant flow path, and the pressure resistance of the refrigerant flow path is improved.

In this case, the refrigerant pipe diameter of the header pipe is preferably 10 mm or less, and the thickness of the header pipe is preferably 5 mm or less.

The relationship between the outer diameter of the header pipe and the inner diameter of the refrigerant channel formed in the header pipe depends on the internal pressure applied to the header pipe and the tensile stress of the material constituting the header pipe. In consideration of the above, it can be determined according to the following equation (1).

(1) and 2 P (r 2 ² + r 1 ² ) / (r 2 ² -r 1 ² ) Here, the tensile stress of the material constituting the tube, P is the pressure inside the header pipe, r2 is the outer radius of the header pipe, and r1 is the refrigerant flow path radius of the header pipe. .

For example, when aluminum is used as a material for forming a header pipe, the tensile stress of aluminum is 10 kg / mm ² . If the internal pressure of 6 0 O kg / cm ² which is loaded on Dzudapai flop to, when the refrigerant flow path diameter of Heddapai flop is 1 0 mm, calculates the outline diameter of header Dapai flop in accordance with the equation (1) Then, the outer diameter of the header pipe is 20 mm.

For example, in the case of using by a C 0 ₂ or the like requiring high pressure resistance and refrigerant Tsuryu frozen cycle, if you refrigerant flow path diameter and 1 0 mm or more, the amount of refrigerant flowing through multi It becomes bad. As the amount of refrigerant flowing increases, a higher pressure resistance is required for the header pipe, so that it is necessary to make the header pipe thicker. As a result, refrigeration cycles have the disadvantage of soaring material costs and increasing the weight of the heat exchanger.

In this sense, it is considered appropriate that the diameter of the refrigerant flow path of the header pipe does not exceed 10 mm.

Furthermore, the cormorants I mentioned above, C 0 heat exchangers _{when 2} Ru used as the refrigerant, the heat exchanger gas-liquid two-phase refrigerant which has been used conventionally is required when flowing It is assumed that a pressure resistance of 6 times or more is required.

Considering these conditions, if the refrigerant flow path diameter of the header pipe is 10 mm, the minimum outer diameter of the header pipe is calculated to be 20 mm by calculating the outer diameter of the header pipe according to the above equation (1). Become.

From this result, when the refrigerant pipe diameter of the header pipe is set to a value not exceeding 10 mm, if the thickness of the header pipe does not exceed 5 mm, the required pressure resistance is reduced. Secured, minimum wall thickness Thus, it is possible to form a header pipe in which the weight is set, and thus it is possible to prevent an increase in weight.

In addition to setting the thickness of the header pipe, when setting the thickness of the heat exchange tube and other members, the thickness can be set based on the above equation (1). You.

Next, the tube of the present example will be described in detail with reference to the drawings. FIG. 2 is a perspective view showing a tube end.

As shown in FIG. 2, the tube 2 of the present example is formed to have a flat cross section and a plurality of refrigerant channels 21 and 21 having a circular cross section. The portion has a thick portion 22 in which no refrigerant flow path is formed. The tube 2 in this example is formed in a thin, flat shape with a tube width of 20 mm or less.

When the refrigerant passage 21 of the tube is formed in a circular cross section, the refrigerant pressure is uniformly applied in the refrigerant passage, and, for example, the pressure resistance is lower than in the case where the refrigerant passage has a rectangular cross section. In addition, when the thick portion 22 is formed in the width direction of the tube, the pressure resistance of the tube is improved, and the area of the tube and the tube are reduced. The fin area to be installed is enlarged, and the heat exchange rate can be improved by increasing the heat exchange area.

Also, in the tube of this example, the tube insertion portion 23 having a small cross-sectional area compared with the cross-sectional area of other portions is obtained by cutting the thick portion 22 at the longitudinal end of the tube 2 in the width direction. Is formed.

In order to ensure the required pressure resistance, as the thickness of the header pipe increases, the inner diameter of the header pipe having a constant outer diameter decreases, and the tube and the header pipe become smaller. The width of the tube insertion hole formed for communication connection becomes smaller.

In other words, if the tube insertion hole becomes smaller, insert the tube end into this tube insertion hole in the case of a normal flat tube. The width of the tubing connected for communication is reduced. If this is done, the amount of heat transferred to the fins installed between the tubes will decrease, causing a problem that the heat exchange rate will decrease.

In the tube of this example, at the longitudinal end of the tube 2, the thick portions 22 formed at both ends in the width direction of the tube are cut, and the tube insertion holes formed in the header pipes 4 and 5 are formed. A tube insertion portion 23 having a cross-sectional shape substantially matching 6 is formed. Therefore, even if the header pipes 4 and 5 become thicker and the tube insertion hole 6 becomes smaller with the inner diameter of the header pipe, the width of the tube to which the fin is mounted can be changed. Instead, the tube insertion portion 23 is inserted into the tube insertion hole 6, the tube 2 and the header pipes 4 and 5 are assembled, and the tube 2 and the header pipes 4 and 5 can be connected and connected.

Also, since the tube 2 and the header pipes 4 and 5 can be assembled without changing the width of the tube 2, the amount of heat transfer to the fin 3 is secured and the heat exchange rate is improved. This is possible.

The tube and the header pipe of this example are formed by extruding and molding aluminum or aluminum alloy.

In this example, since the tube 2 is formed with the thick portion 22, the required pressure resistance is secured, and the heat exchanger 1 is made of aluminum or an aluminum alloy at a low cost and light weight. Can be manufactured.

In this example, a tube insertion portion 23 having a smaller cross-sectional area than other portions of the tube 2 is formed at the end of the tube 2, and the tube insertion hole 23 is inserted into the tube insertion hole of the header pipe. The tube 2 and the header pipes 4 and 5 were connected by inserting it into the tube 6, but the connection of the tube and the header pipe is not limited to this example, and it is also possible to connect the pipes and connectors.

In addition to heat exchange tubes with a flat cross section, heat exchange tubes The cross section of the valve itself can be circular.

FIG. 3 is a perspective view showing a schematic configuration of heat exchange tubes 24 and fins 30 according to another specific example.

As shown in FIG. 3, the heat exchange tube 24 of the present example is provided with a refrigerant passage 25 having a circular cross section, and the outer shape of the tube 24 itself is also circular.

If the outer shape of the tube 24 is circular, the minimum volume can be kept within the same range while maintaining the strength that can withstand the pressure load of the medium flowing through the inside. Can improve the layout.

When the outer shape of the heat exchange tube 24 is a circular cross section, the concave portion 31 having a curvature along the outer shape of the tube 24 is provided in the fin 30 so that the tubes 24 and the By increasing the contact area of the fin 30, the heat transfer rate to the fin 30 side can be improved, and the heat exchange rate of the tube 24 and the fin 30 can be improved. .

In this case, the wall thickness of the tube 24 is determined by the diameter of the refrigerant passage 25 formed in the tube, the internal pressure applied to the tube, and the material constituting the tube based on the expression (1). In consideration of stress

It can be calculated based on equation (1).

Next, another specific example of the heat exchanger for improving the pressure resistance will be described.

FIG. 4 is a plan view showing a schematic configuration of the heat exchanger of the present example, in which tubes 2 stacked in multiple stages with fins (not shown) mounted therebetween and the ends of the tubes 2 are connected. A plurality of heat exchangers consisting of header pipes 41, 51, header pipes 42, 52, and header pipes 43, 53 have a tube and fin in the longitudinal direction. Are arranged in parallel with each other at right angles to the header pipe 51 and the header pipe 52, and between the header pipe 42 and the header pipe 43. Is a heat exchanger 12 which is connected by pipes 60 and 61 and is integrated. The arrows in the figure indicate the ventilation direction. In the figure, reference numeral 13 denotes a refrigerant inlet, and reference numeral 14 denotes a refrigerant outlet.

The heat exchanger 12 of this example has the tubes 2, the fins and the header pipes 41, 42, so that the longitudinal directions of the tubes 2 and the fins are perpendicular to the ventilation direction. A plurality of heat exchangers composed of 4 3, 5 1, 5 2, 5 3 are arranged in parallel, and the header pipes 4 1 4 2, 4 3, 5 1, 5 2, 5 3 are connected and connected to form a unit. Since the heat exchangers 1 and 2 are configured, the flow rate of the refrigerant flowing through the heat exchanger can be increased and the heat transfer area can be increased, and the heat exchange performance can be improved. .

Further, in this example, the refrigerant flow path is formed so that the refrigerant flowing between the heat exchangers flows in series, for example, from the header pipe 41 which is a rear row in the ventilation direction. Flows through the heat exchanger in the direction of the ventilation according to the cooling process, and the refrigerant that has been cooled to some extent by passing through the heat exchanger sequentially from the rear row is the refrigerant flow path closest to the ventilation direction. By flowing the gas through it, it is further cooled and the heat exchange performance can be improved.

For example, excellent air-conditioning functions are required for umbox vehicles with large indoor spaces. In this case, the required air-conditioning function can be achieved by installing a heat exchanger with an increased heat transfer area and improved heat exchange performance.

In the vehicle, the range of the surface area facing the ventilation direction is limited to a certain range, but it is assumed that the space with the heat exchanger will also increase with the size of the vehicle body. Therefore, as in this example, if the heat transfer area is increased while keeping the same surface area in the ventilation direction, the heat exchange performance is improved. Therefore, the structure of this specific example is suitable for the case of mounting in a vehicle where the mounting space is narrow. Next, the heat exchanger 15 shown in FIG. 5 connects the header pipes 44, 45, 46 to the refrigerant inflow pipe 62, and connects the header pipes 54, 55, 56 to the refrigerant outflow pipe 63. The refrigerant flowing into the header pipes 41, 42, and 43 from the refrigerant inflow pipe 62 flows through the plurality of tubes 2 in parallel, and flows from the header pipes 51, 52, and 53. It is configured to flow out to the refrigerant outflow pipe 63.

In this way, by flowing the refrigerant in parallel to the plurality of heat exchangers, the flow rate of the refrigerant flowing through the heat exchanger is increased, and the heat transfer area is increased by increasing the heat transfer area. The efficiency can be improved and the heat exchange of the refrigerant can be performed all at once.

FIG. 6 is a perspective view showing another specific example of the tube. As shown in FIG. 6, the tube 26 has a tube width capable of accommodating a plurality of header pipes arranged in parallel, and the refrigerant flow path 27 and the refrigerant flow path 27 each having a circular cross section are formed. It has a thick portion 28 that is not formed. At the end of the tube 26, a tube having a smaller cross-sectional area than other portions of the tube 26 is provided in order to allow the refrigerant flowing through the refrigerant passage 27 having the circular cross section to communicate with the header pipe. A plurality of insertion portions 29 and 29 are formed.

Thus, a plurality of tube insertion portions 29, 29 are formed at the end of the tube 26, and the tube insertion portions 29, 29 are inserted into the tube insertion holes formed in the header pipe, It can be connected to each of the refrigerant flow passages, whereby the tube width can be increased and the heat transfer area can be increased.

FIG. 7 is a partial cross-sectional view showing a schematic configuration in a state where the tube insertion portions 29 and 29 of the tube 26 are inserted into the tube insertion holes of a plurality of header pipes 47 and 48.

By forming a plurality of tube insertion portions 2992 at the end of the tube 26, the tube width can be increased. In other words, the heat transfer area between the tube and the fin can be increased, and the heat exchange performance can be improved.

FIG. 8 shows a state in which a plurality of refrigerant channels 71 and 72 are formed in the header pipe 70, and the tube insertion portion 23 of the tube 2 is inserted into a tube insertion hole formed in the header pipe 70. FIG. 2 is a partial cross-sectional view schematically showing the structure of FIG.

When a plurality of refrigerant flow paths 71 and 72 are formed in the header pipe 70, a plurality of heat exchangers composed of a plurality of tubes, fins, and header pipes are arranged in parallel to the direction of air flow. In this case, the number of assembling steps such as connection of header pipes arranged in parallel is reduced, and the number of parts is reduced as compared with the case where a plurality of header pipes are arranged in parallel. Work efficiency can be improved.

Also, as shown in Fig. 9, it is possible to arrange a plurality of tubes in parallel and to attach the same fin to each tube to form a heat exchanger.

In this case, a plurality of heat exchangers shown in Fig. 4 or Fig. 5 are arranged in parallel, and the force has the same configuration as an integrated heat exchanger. By mounting the same fins 32 on the tubes, the heat exchange area can be increased and the heat exchange performance can be improved.

Further, in the specific example described above, the stacked heat exchanger in which the tubes with the fins mounted therebetween are stacked in multiple stages has been described. However, the present invention is not limited to this example, and as shown in FIG. In the serpentine heat exchanger 16 in which the tubes are reciprocated in a meandering manner and the fins are mounted between the reciprocating tubes, the structure of the tube and the heat exchanger of the present example can be used. is there. Industrial applicability The heat exchanger according to the present invention is a heat exchanger in which the pressure resistance and heat exchange rate of the heat exchange tube are improved, and is suitable for a high-pressure medium such as carbon dioxide gas instead of the conventional heat exchange medium. It is particularly suitable for automotive and consumer refrigeration cycles.

Claims

The scope of the claims

1. A heat exchange tube having a refrigerant flow path, a fin mounted between the tubes, and a header pipe connected and connected to the tubes to transmit and receive a refrigerant, the tubes and the fins being provided in the tubes and the fins. In a heat exchanger that exchanges heat by transferring heat,

The heat exchanger, wherein the heat exchange tube has a refrigerant flow path having a circular cross section.

2. The heat exchanger according to claim 1,

The heat exchanger, wherein each of the heat exchange tubes has a refrigerant passage having the same cross section and a plurality of circular cross sections.

3. The heat exchanger according to claim 1,

A heat exchanger characterized in that the diameter of the circular cross section of the refrigerant channel is 1 mm or less.

4. The heat exchanger according to claim 2,

5. The heat exchanger according to any one of claims 1 to 4, wherein the refrigerant pipe of the header pipe has a circular cross section.

6. The heat exchanger according to claim 5, wherein the diameter of the refrigerant channel of the header pipe does not exceed 10 mm, and the thickness of the header pipe does not exceed 5 mm. .

7. The heat exchange tube includes a refrigerant channel having a circular cross section, and a thick portion that does not form a refrigerant channel.

The heat exchange according to any one of claims 1 to 6, wherein a tube insertion portion having a smaller cross-sectional area than other portions is formed at a longitudinal end portion of the heat exchange tube. vessel.

8. The heat exchange tubes and fins are alternately stacked to form a multi-stage layer. The heat exchanger according to claim 1, wherein the heat exchanger is formed.

9. A partition plate that partitions a plurality of refrigerant flow paths flowing between the tube and the header pipe is arranged at a key point of the header pipe,

9. The heat exchanger according to claim 8, wherein the total cross-sectional area of each of the refrigerant flow paths partitioned into the plurality of sections is the same.

10 ・ Fin mounted between the tubes and multi-layered, the end of the tube is connected to the header pipe,

The heat exchanger body including the tubes, the fins, and the header pipes is configured such that the cross-sectional longitudinal direction of the multi-tiered tubes and the fins is orthogonal to the direction of the external air flow. 10. The heat exchanger according to claim 8, wherein a plurality of the heat exchangers are arranged, and header pipes of the respective heat exchanger bodies are connected to each other and are integrated.

1 1. A plurality of heat exchangers are arranged in parallel so that the cross-sectional longitudinal directions of the tubes and fins are orthogonal to the ventilation direction, and the header pipes of each heat exchanger are connected to each other. Heat exchanger that is integrated

The medium flowing through each tube and header pipe flows in series or in parallel between a plurality of heat exchanger bodies, and performs heat exchange by heat transferred to a plurality of tubes and fins. The heat exchanger according to any one of claims 7 to 9.

12 2. A plurality of heat exchangers are arranged in parallel so as to be orthogonal to the ventilation direction in the cross-sectional longitudinal direction of the tubes and the fins, and the header pipes of the heat exchangers are connected and connected. Heat exchanger,

A plurality of tube insertion portions are formed at the end of the heat exchange tube, and the tube end is connected to each of the header pipes. The heat exchanger according to claim 10 or 11, wherein:

13. The heat exchanger according to any one of claims 9 to 12, wherein a plurality of refrigerant channels are formed in the header pipe.

14. The heat exchanger according to any one of claims 1 to 7, wherein a fin is mounted between the tubes that reciprocate in a meandering manner.

15. The heat exchanger according to claim 14, wherein a plurality of heat exchanger bodies are arranged in parallel, and each heat exchanger body is connected and integrated.

16. The heat exchanger according to any one of claims 1 to 15, wherein the tube and the header pipe are made of an aluminum or aluminum alloy.

17. The heat exchanger according to any one of claims 1 to 16, wherein the refrigerant flowing into and out of the heat exchanger is in a gaseous state.

1 8. Refrigerant Tsuryu to the heat exchanger, carbon dioxide (C 0 ₂₎ the claims 1 to 1 7 heat exchanger according to any one, characterized in that it is a.

Claims for amendment harm

[July 17, 2000 (17.7.00) Accepted by the International Bureau: Claims 1, 5, 7, 8, 1, 4, 16, 17, and 18 at the time of filing were amended Claims 2, 3 and 4 at the beginning of the application have been withdrawn. (Page 3)]

1. (after correction) a heat exchange tube having a refrigerant flow path, a fin mounted between the tubes, and a header pipe connected and connected to the tubes to transmit and receive the refrigerant, In a heat exchanger that performs heat exchange by heat transmitted to tubes and fins,

The heat exchange tube includes a refrigerant passage having a circular cross section,

Each of the heat exchange tubes has the same cross-section and a plurality of circular cross-section refrigerant flow paths,

Further, the heat exchanger is characterized in that the diameter of the circular cross section of the refrigerant channel is lmm or less.

2. (Delete)

3. (Delete)

4. (Delete)

5. (After correction) The heat exchanger according to claim 1, wherein the refrigerant flow passage of the header pipe has a circular cross section. .

6. The heat exchanger according to claim 5, wherein the diameter of the refrigerant flow path of the header pipe does not exceed 10 mm, and the thickness of the header pipe does not exceed 5 mm.

7. (After correction) The heat exchange tube includes a refrigerant flow path having a circular cross section, and a thick portion that does not form a refrigerant flow path,

7. The heat exchanger according to claim 1, wherein a tube insertion portion having a smaller cross-sectional area than other portions is formed at a longitudinal end portion of the heat exchange tube. .

8. (After collection) Paper with the heat exchange tubes and fins laminated alternately and corrected (about Article 19) 8. The heat exchanger according to claim 1, wherein the heat exchanger forms a multi-stage layer.

9. A partition plate for partitioning the refrigerant flow path flowing between the tube and the header pipe into a plurality of sections is arranged at a key point of the header pipe,

9. The heat exchange according to claim 8, wherein the total cross-sectional area of each of the refrigerant flow paths divided into the plurality of sections is the same.

10. A fin is mounted between the tubes to form a multi-stage stack, and the tube end is connected to a header pipe,

A plurality of heat exchanger bodies composed of tubes, fins, and header pipes are arranged so that the cross-sectional longitudinal direction of the multi-tiered tubes and fins is orthogonal to the direction of external air flow. 10. The heat exchanger according to claim 8, wherein the header pipes of the heat exchanger bodies are connected and integrated.

1 1. A plurality of heat exchangers are arranged in parallel so that the cross-sectional longitudinal directions of the tubes and the fins are orthogonal to the ventilation direction, and the header pipes of each heat exchanger are connected and connected. Heat exchanger,

A medium flowing through each tube and the header pipe flows in series or in parallel between a plurality of heat exchanger bodies, and performs heat exchange by heat transferred to the plurality of tubes and the fins. The heat exchanger according to any one of claims 7 to 9.

12 2. A plurality of heat exchangers are arranged in parallel so that the cross-sectional longitudinal direction of the tubes and fins is orthogonal to the ventilation direction, and the header pipes of each heat exchanger are connected and connected. A heat exchanger that is

A plurality of tube insertion portions are formed at the end of the heat exchange tube, and the tube end is connected to each of the header pipes. Corrected paper (Article 19 of the Convention) The heat exchanger according to claim 10 or 11, wherein:

13. Heat exchange according to any one of claims 9 to 12, characterized in that a plurality of refrigerant channels are formed in the header pipe. 14. (After correction) The heat exchanger reciprocates in a meandering manner. The heat exchanger according to claim 1, 5, 6, or 7, wherein a fin is mounted between the tubes.

16. The heat exchanger according to any one of claims 1, 5 to 15, wherein the tube and the header pipe are formed by molding aluminum or aluminum alloy. .

17. The heat exchanger according to any one of claims 1, 5 to 16, wherein the refrigerant flowing into and out of the heat exchanger is in a gaseous state.

1 8. Refrigerant Tsuryu the (corrected) the heat exchanger, carbon dioxide (CO ₂₎ claim 1, 5 to 1 7 have heat exchanger deviation or wherein that it is a.

Corrected paper (Article 19 of the Convention)