JP6735924B2 - Heat exchanger and refrigeration cycle device - Google Patents

Description

The present invention relates to a heat exchanger including a first pipe and a second pipe wound around the first pipe, and a refrigeration cycle apparatus including the heat exchanger.

Conventionally, a first pipe in which a flow path through which the first heat medium flows is formed, and a second pipe which is wound around the outer periphery of the first pipe and in which a flow path through which the second heat medium flows is formed. There is a heat exchanger provided. In such a heat exchanger, heat is exchanged between the first heat medium flowing through the first pipe and the second heat medium flowing through the second pipe. The first pipe may be referred to as a core pipe. The second pipe may be referred to as an outer pipe. Examples of the first heat medium include water and antifreeze liquid. A refrigerant is used as the second heat medium.

As such, as described in Patent Document 1, "a first fluid pipe which is formed by a twisting process and has a plurality of ridge-valley bottoms continuously provided in a spiral shape on an outer periphery of each ridge, A second fluid pipe spirally wound along the shape of the bottom of the first fluid pipe, and the second fluid pipe is fitted into the bottom of the first fluid pipe to transfer heat. A twisted tube heat exchanger having a structure capable of being joined to the ".

In the heat exchanger described in Patent Document 1, a peak portion protruding in the radial direction of the first pipe and a valley portion having an outer diameter smaller than that of the portion where the peak portion is formed are formed. The contact area between the pipe and the second pipe is enlarged. By doing so, in the heat exchanger described in Patent Document 1, the heat transfer area is expanded, and the water is the first heat medium flowing through the first pipe and the refrigerant is the second heat medium flowing through the second pipe. The heat exchange performance with is improved.

JP, 2010-91266, A

In the heat exchanger described in Patent Document 1, the flow of water, which is the first heat medium flowing through the first pipe, tends to stay at the mountain portion forming portion. Therefore, in the heat exchanger described in Patent Document 1, the heat transfer coefficient in the mountain portion forming portion is low, and the amount of heat exchange in the mountain portion forming portion is small. As a result, according to the heat exchanger described in Patent Document 1, the contact area between the first pipe and the second pipe is expanded, but the effect of improving the heat exchange performance is limited.

The present invention has been made in view of the above problems, and a heat exchanger configured to improve the heat exchange performance by suppressing the retention of the flow of the first heat medium in the first pipe. , And a refrigeration cycle apparatus including the heat exchanger.

In the heat exchanger according to the present invention, a first pipe in which a first flow path through which a first heat medium flows is formed and a second flow path through which a second heat medium flows are formed. And a second pipe wound around the first pipe, wherein the first pipe has a mountain portion protruding in a radial direction in which the diameter of the first pipe expands and a portion where the mountain portion is formed. Also has a small outer diameter, and includes a trough portion around which the second pipe is wound, and the crest portion is formed in a spiral shape in a direction in which the first heat medium of the first flow path flows, The portion is formed in a spiral shape along the peak portion, is formed in a spiral direction which is a formation direction of the valley portion, and includes a recessed portion that is recessed in a diameter reducing direction in which the diameter of the first pipe is reduced, A first mountain portion which is the mountain portion of the Nth lap of the spiral winding of the mountain portion, and a second mountain portion which is the mountain portion of the N+1th lap of the spiral winding of the mountain portion; Section which cut|disconnected along the flow direction of the said 1st heat medium the part of the said 1st piping containing the intermediate valley part which is the said valley part between the said 1st mountain part and the said 2nd mountain part. In a cross-sectional view, the recess is formed such that the apex of the recess is located on the downstream side in the flow direction of the first heat medium with respect to the central point of the intermediate valley.

According to the heat exchanger of the present invention, by specifying the formation position of the recess formed in the valley, the flow velocity of the first heat medium can be determined even in the retaining portion of the first heat medium in the mountain portion on the downstream side of the recess. It does not easily fall off, and heat exchange performance can be improved.

It is a schematic block diagram which shows roughly an example of a circuit structure of the refrigerating-cycle apparatus provided with the heat exchanger which concerns on Embodiment 1 of this invention. It is a perspective view which shows roughly the structure of the heat exchanger which concerns on Embodiment 1 of this invention. It is an external view which shows an example of a structure of the 1st piping of the heat exchanger which concerns on Embodiment 1 of this invention. It is the schematic which shows a part of one example of a structure of the 1st piping of the heat exchanger which concerns on Embodiment 1 of this invention roughly. It is the schematic which shows a part of one example of a structure of the heat exchanger which concerns on Embodiment 1 of this invention roughly. It is a schematic sectional drawing which expands and shows a partial cross section of the heat exchanger which concerns on Embodiment 1 of this invention. It is explanatory drawing of the flow velocity distribution of the 1st heat medium in the 1st piping in which the recessed part is not formed. It is explanatory drawing of the flow velocity distribution of the 1st heat medium in the 1st piping of the heat exchanger which concerns on Embodiment 1 of this invention. It is explanatory drawing as a comparative example of the streamline of the 1st heat medium in the 1st piping which formed the recessed part in the center part of the valley part. It is explanatory drawing of the streamline of the 1st heat medium in the 1st piping of the heat exchanger which concerns on Embodiment 1 of this invention. It is explanatory drawing of the streamline of the 1st heat medium in the 1st piping of the heat exchanger which concerns on Embodiment 1 of this invention. FIG. 9 is a cross-sectional view schematically showing a cross section of the first pipe of the heat exchanger according to Modification 1 taken along the flow direction of the first heat medium. FIG. 8 is a cross-sectional view schematically showing a cross section of the first pipe of the heat exchanger according to Modification Example 1 orthogonal to the flow direction of the first heat medium. FIG. 9 is a cross-sectional view schematically showing a cross section of the first pipe of the heat exchanger according to Modification 2 taken along the flow direction of the first heat medium. FIG. 8 is a cross-sectional view schematically showing a cross section of the first pipe of the heat exchanger according to Modification Example 1 orthogonal to the flow direction of the first heat medium. It is explanatory drawing of the streamline of the 1st heat medium in the 1st piping of the heat exchanger which concerns on Embodiment 2 of this invention. It is explanatory drawing as a comparative example of the streamline of the 1st heat medium in the 1st piping in which the planar view circular recessed part was formed. It is explanatory drawing of the streamline of the 1st heat medium in the 1st piping of the heat exchanger which concerns on Embodiment 3 of this invention. It is explanatory drawing of the recessed part in the 1st piping of the heat exchanger which concerns on Embodiment 4 of this invention. It is a schematic sectional drawing which expands and shows roughly the cross-sectional structure of the recessed part in the 1st piping of the heat exchanger which concerns on Embodiment 4 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings including FIG. 1, the relationship of the sizes of the respective constituent members may be different from the actual one. Further, in the following drawings including FIG. 1, the same reference numerals are the same or equivalent, and this is common to all the texts of the specification. Furthermore, the forms of the constituent elements shown in the entire text of the specification are merely examples, and the present invention is not limited to these descriptions.

Embodiment 1.
FIG. 1 is a schematic configuration diagram schematically showing an example of a circuit configuration of a refrigeration cycle apparatus 200 including a heat exchanger 100 according to Embodiment 1 of the present invention. The refrigeration cycle apparatus 200 will be described with reference to FIG.
In addition, in Embodiment 1, it is assumed that the first heat medium is water and the second heat medium is a refrigerant.

<Overall configuration of refrigeration cycle apparatus 200>
The refrigeration cycle device 200 has a refrigerant circuit A1 and a heat medium circuit A2. The refrigerant circuit A1 and the heat medium circuit A2 are thermally connected via the heat exchanger 100. The heat medium circuit A2 is connected to the water supply circuit A3 via the hot water storage tank 207. The water supply circuit A3 is connected to the hot water supply utilization unit U, and is configured to supply hot water to the hot water supply utilization unit U. As the hot water supply utilization unit U, at least one of various loads that require hot water, such as a faucet and a bath of a domestic water supply, can be mentioned. The water supply circuit A3 is connected to a water pipe or the like so that water can be supplied.

The refrigerant circulates in the refrigerant circuit A1 via the refrigerant pipe 20A. Carbon dioxide can be used as the refrigerant. The refrigerant circuit A1 is formed by including a compressor 201 that compresses a refrigerant, a heat exchanger 100 that functions as a condenser, a throttle device 202, and a heat exchanger 203 that functions as an evaporator.

The compressor 201 compresses a refrigerant. The refrigerant compressed by the compressor 201 is discharged from the compressor 201 and sent to the heat exchanger 100. The compressor 201 can be configured by, for example, a rotary compressor, a scroll compressor, a screw compressor, a reciprocating compressor, or the like.

The heat exchanger 100 functions as a condenser, performs heat exchange between the high-temperature and high-pressure refrigerant flowing through the refrigerant circuit A1 and the water flowing through the heat medium circuit A2, heats the water, and condenses the refrigerant. is there. The heat exchanger 100 is a water-refrigerant heat exchanger that exchanges heat between water and a refrigerant. The heat exchanger 100 will be described in detail later.
The heat exchanger 100 corresponds to the heat exchanger of the present invention.

The expansion device 202 expands the refrigerant flowing from the heat exchanger 100 to reduce the pressure. The expansion device 202 may be composed of, for example, an electric expansion valve capable of adjusting the flow rate of the refrigerant. As the expansion device 202, not only an electric expansion valve, but also a mechanical expansion valve having a diaphragm as a pressure receiving portion, a capillary tube, or the like can be applied.

The heat exchanger 203 functions as an evaporator, performs heat exchange between the low-temperature low-pressure refrigerant discharged from the expansion device 202 and the air supplied by the blower 203A, and evaporates the low-temperature low-pressure liquid refrigerant or two-phase refrigerant. It is a thing. The heat exchanger 203 is, for example, a fin-and-tube heat exchanger, a microchannel heat exchanger, a shell-and-tube heat exchanger, a heat pipe heat exchanger, a double-tube heat exchanger, or a plate heat exchanger. It can be configured with a container or the like.
A blower 203A is attached to the heat exchanger 203.

Water circulates in the heat medium circuit A2 via the heat medium pipe 10A. The heat medium circuit A2 is formed including the heat exchanger 100 and a pump 205 that conveys water.

Further, the refrigeration cycle apparatus 200 includes a control device 60 that integrally controls the entire refrigeration cycle apparatus 200. The control device 60 controls the drive frequency of the compressor 201. Further, the control device 60 controls the opening degree of the expansion device 202 according to the operating state. Further, the control device 60 controls driving of the blower 203A and the pump 205. That is, the control device 60 uses the information sent from each temperature sensor (not shown) and each pressure sensor (not shown) based on the operation instruction, and uses the compressor 201, the expansion device 202, the blower 203A, the pump 205, and the like. Control each actuator of.

Each functional unit included in the control device 60 is configured by dedicated hardware or an MPU (Micro Processing Unit) that executes a program stored in the memory.

<Structure of heat exchanger 100>
FIG. 2 is a perspective view schematically showing the configuration of the heat exchanger 100.
The heat exchanger 100 includes a first pipe 1 in which a first flow path FP1 through which water as a first heat medium flows is formed, and a second flow path FP2 through which a refrigerant as a second heat medium flows. And a second pipe 2. The second pipe 2 is wound around the outer periphery of the first pipe 1 in a single line or a plurality of lines and is in contact with the first pipe 1. The first pipe 1 constitutes a part of the heat medium pipe 10A. The second pipe 2 constitutes a part of the refrigerant pipe 20A.

A water inlet 1a and a water outlet 1b that communicate with the first flow path FP1 are formed in the first pipe 1. Further, the second pipe 2 is formed with a refrigerant inlet 2a and a refrigerant outlet 2b which communicate with the second flow path FP2.
The heat exchanger 100 can be connected to the refrigerant circuit A1 and the heat medium circuit A2 so that the direction of the water flowing through the first pipe 1 and the direction of the refrigerant flowing through the second pipe 2 face each other. This improves the heat exchange efficiency between the heat medium and the refrigerant.

<Operation of Refrigeration Cycle Device 200>
Here, returning to FIG. 1, the operation of the refrigeration cycle apparatus 200 will be described.
The refrigeration cycle apparatus 200 is capable of hot water supply operation based on an instruction from the load side.
The operation of each actuator is controlled by the control device 60.

The low-temperature low-pressure refrigerant is compressed by the compressor 201, becomes a high-temperature high-pressure gas refrigerant, and is discharged from the compressor 201. The high-temperature and high-pressure gas refrigerant discharged from the compressor 201 flows into the heat exchanger 100. The refrigerant flowing into the heat exchanger 100 flows through the second pipe 2 and exchanges heat with the water flowing through the first pipe 1. At this time, the refrigerant is condensed into a low-temperature and high-pressure liquid refrigerant and flows out from the heat exchanger 100. When carbon dioxide is used as the refrigerant, the temperature of the refrigerant changes while the refrigerant remains in the supercritical state.
On the other hand, the water flowing into the first pipe 1 is heated by the refrigerant flowing through the second pipe 2 and supplied to the load side.

The low-temperature high-pressure liquid refrigerant flowing out of the heat exchanger 100 becomes a low-temperature low-pressure liquid refrigerant or two-phase refrigerant by the expansion device 202, and flows into the heat exchanger 203. The refrigerant flowing into the heat exchanger 203 exchanges heat with the air supplied by the blower 203A attached to the heat exchanger 203 to become a low-temperature low-pressure gas refrigerant and flows out from the heat exchanger 203. The refrigerant flowing out of the heat exchanger 203 is sucked into the compressor 201 again.

In FIG. 1, the case where the flow of the refrigerant in the refrigerant circuit A1 is in a fixed direction is shown as an example, but a flow path switching device is provided on the discharge side of the compressor 201 so that the flow of the refrigerant can be reversed. You may. When the flow path switching device is provided, the heat exchanger 100 also functions as an evaporator, and the heat exchanger 203 also functions as a condenser. As the flow path switching device, for example, a combination of two-way valves, a combination of three-way valves, or a four-way valve can be adopted.

Although carbon dioxide is desirable as the refrigerant used in the refrigeration cycle apparatus 200, it is not limited to using carbon dioxide. Besides carbon dioxide, natural refrigerants such as hydrocarbons or helium, chlorine-free alternative refrigerants such as HFC410A, HFC407C or HFC404A, or CFC-based refrigerants used in existing products such as R22 or R134a are also used. It is possible.

<Detailed configuration of heat exchanger 100>
FIG. 3 is an external view showing an example of the configuration of the first pipe 1 of the heat exchanger 100. FIG. 4 is a schematic diagram schematically showing a part of an example of the configuration of the first pipe 1 of the heat exchanger 100. FIG. 5 is a schematic diagram schematically showing a part of an example of the configuration of the heat exchanger 100. FIG. 6 is a schematic cross-sectional view showing an enlarged cross-section of a part of the heat exchanger 100. The configuration of the heat exchanger 100 will be described in detail with reference to FIGS.

In FIG. 6, a part of the cross section obtained by cutting the first pipe 1 and the second pipe 2 of the heat exchanger 100 along the flow direction of the first heat medium is schematically illustrated in an enlarged manner. Further, in FIG. 6, the inner peripheral surface S1 of the first pipe 1, the outer peripheral surface S2 of the first pipe 1, the diameter expansion direction DR1, the diameter reduction direction DR2, the first flow path FP1, and the retention portion T are shown. Is shown.

The radial expansion direction DR1 is a direction from the inner peripheral surface S1 side of the first pipe 1 toward the outer peripheral surface S2 of the first pipe 1. The diameter reducing direction DR2 is a direction from the outer peripheral surface S2 side of the first pipe 1 toward the inner peripheral surface S1 of the first pipe 1. The first flow path FP1 is the flow path of the first pipe 1. The inner peripheral surface S1 of the first pipe 1 is an inner surface forming the inner wall of the first pipe 1. The outer peripheral surface S2 of the first pipe 1 is an outer surface forming an outer wall of the first pipe 1. The retention part T is a region in the first flow path FP1 where the flow velocity of the first heat medium becomes slow.

The first pipe 1 has a mountain portion 3a protruding in the radial expansion direction DR1 in which the diameter of the first pipe 1 expands. The mountain portion 3a is formed in a spiral shape in the direction in which the water in the first flow path FP1 flows.
Further, the first pipe 1 has a valley portion 3b having an outer diameter smaller than that of the portion where the peak portion 3a is formed. The valley portion 3b is formed in a spiral shape along the mountain portion 3a.
That is, the peaks 3a and the valleys 3b are formed in parallel. As shown in FIGS. 5 and 6, the second pipe 2 is wound around the valley 3b. Therefore, the second pipe 2 is also spirally wound around the first pipe 1.

Here, a case where the first pipe 1 is formed with one ridge 3a is described as an example. Therefore, in FIGS. 3 to 5, four ridges 3 a are shown above and below the first pipe 1 so that the formation locations of the ridges 3 a can be easily understood. However, the first pipe 1 is not formed with a plurality of ridges 3a, but the first pipe 1 is formed with one ridge 3a so as to extend spirally. However, when forming a plurality of ridges 3a, a plurality of ridges 3a are formed so as to extend in a spiral shape.

Since the mountain portion 3a is formed in a spiral shape, it makes a plurality of rounds around the first pipe 1. Further, the valley portion 3b is also formed so as to make a plurality of rounds around the first pipe 1. Since the valley portion 3b is formed along the mountain portion 3a, the valley portion 3b is formed between the mountain portion 3a of the Nth turn of the spiral winding and the mountain portion 3a of the N+1th rotation of the spiral winding. Will be formed. In other words, the mountain portion 3a is formed between the valley portion 3b of the Nth round of the spiral winding and the mountain portion 3a of the N+1th round of the spiral winding. Note that N is a natural number. In addition, it is assumed that the Nth turn of the spiral turn is near the inflow port 1a, and the N+1th turn of the spiral turn is near the outflow port 1b.

A recess 3c is formed in the valley 3b. A plurality of recesses 3c are formed so as to be lined up in the spiral direction that is the forming direction of the valleys 3b, and are recessed in the diameter reduction direction DR2 in which the diameter of the first pipe 1 is reduced.

Here, the recess 3c will be described in detail with reference to FIG. In FIG. 6, a part of the heat exchanger 100 is located, that is, the N-th ridge 3a of the spiral winding, the N+1-th ridge 3a of the spiral winding, and the portion between them. A portion including a valley portion 3b which is an intermediate valley portion of the Nth turn is illustrated. In addition, for convenience, in FIG. 6, the mountain portion 3a of the Nth turn of the spiral winding is referred to as a first mountain portion 3a-1, and the mountain portion 3a of the N+1th rotation of the spiral winding is referred to as a second mountain portion 3a-1. It is referred to as mountain portion 3a-2. In addition, in FIG. 6, a part of the heat exchanger 100 is further illustrated by being divided into a first region R1 and a second region R2.

The first region R1 passes through the apex B1 of the first mountain portion 3a-1, passes through a straight line D1 orthogonal to the first flow passage FP1, and passes through the center point B4 of the valley portion 3b, and passes through the first flow passage FP1. It is a region between the straight line D2 and the orthogonal straight line D2. That is, the first region R1 means a region on the upstream side in the flow direction of the first heat medium in the first flow path FP1 with respect to the central point B4 of the valley portion 3b in the cross section shown in FIG.
The second region R2 is a region between the straight line D2 and a straight line D3 that passes through the apex B2 of the second mountain portion 3a-2 and is orthogonal to the first flow path FP1. That is, the second region R2 means a region on the downstream side in the flow direction of the first heat medium in the first flow path FP1 with respect to the central point B4 of the valley portion 3b in the cross section shown in FIG.
The central point B4 of the valley 3b means a point located in the middle of the valley 3b in the flow direction of the first heat medium in the first flow path FP1.

Further, in FIG. 6, a line segment connecting the apex B3 of the concave portion 3c and the apex B1 of the first mountain portion 3a-1 is defined as a line segment L1, and the apex B3 of the concave portion 3c and the second mountain portion 3a-2. The line segment connecting the apex B2 of FIG.
The apex B3 of the recess 3c is the most recessed portion of the recess 3c in the diameter reduction direction DR2.

As shown in FIG. 6, the recess 3c is formed in the second region R2. That is, the recess 3c is formed such that the apex B3 of the recess 3c is located on the downstream side in the flow direction of the first heat medium in the first flow path FP1 with respect to the central point B4 of the valley 3b. In other words, the recess 3c is formed at a position where the line segment L2 is shorter than the line segment L1. That is, in a state in which a section including the first crest portion 3a-1, the second crest portion 3a-2, and the trough portion 3b, which is an intermediate trough portion therebetween, is viewed in cross section, the first heat The first peak portion 3a-1, the valley portion 3b, the recessed portion 3c, and the second peak portion 3a-2 are arranged in this order from the upstream side in the medium flow direction.

As shown in FIG. 6, the wall surface of the recess 3c on the downstream side in the flow direction of the first heat medium is the inside of the first pipe 1 forming the wall surface of the valley 3b in which the recess 3c is formed. It is formed by extending the peripheral surface S1 and the outer peripheral surface S2. That is, when the apex B3 of the concave portion 3c is seen from the apex B2 of the second mountain portion 3a-2, the line segment L2 of the concave portion 3c is directed toward the upstream side in the flow direction of the first heat medium and in the radial direction. It is formed to face DR2. When the vertex B2 of the second mountain portion 3a-2 is viewed from the vertex B3 of the concave portion 3c, the concave portion 3c has a line segment L2 toward the downstream side in the flow direction of the first heat medium and in the radial direction. It is heading to DR1.

Generally, in the heat exchanger 100 having the structure in which the peaks 3a and the valleys 3b are formed, the flow of the first heat medium tends to be stagnant particularly in the peaks 3a. That is, as shown in FIG. 6, the flow of the first heat medium tends to be stagnated at the first crest portion 3a-1 and the second crest portion 3a-2, and the retention portion T is formed. Therefore, the heat exchange performance in the retention section T becomes low.
Therefore, in the heat exchanger 100, since the concave portion 3c is formed in the valley portion 3b, it is possible to suppress the decrease in the flow velocity of the first heat medium in the retention portion T and improve the heat exchange performance. Hereinafter, suppression of the decrease in the flow velocity of the first heat medium will be described.

<Regarding the flow velocity distribution of the first heat medium in the first pipe 1>
FIG. 7 is an explanatory diagram of the flow velocity distribution of the first heat medium in the first pipe 1 in which the recess 3c is not formed. FIG. 8 is an explanatory diagram of the flow velocity distribution of the first heat medium in the first pipe 1 of the heat exchanger 100.
Although FIG. 7 is a comparative example, the same reference numerals as those of the heat exchanger 100 are added for convenience of description. In FIG. 7 and FIG. 8, the flow of the first heat medium in the first pipe 1 is shown by arrows as a flow FL1, a flow FL2, and a flow FL3. Further, in FIGS. 7 and 8, it is assumed that the flow rate of the first heat medium is slow in the order of the flow FL1, the flow FL2, and the flow FL3.

As shown in FIG. 7, the flow FL1 is formed in the central portion of the first pipe 1 and the flow velocity is high.
Further, as shown in FIG. 7, the flow FL2 is formed in the portion along the inner peripheral surface S1 of the first pipe 1, and the flow velocity is lower than that of the flow FL1.
Further, as shown in FIG. 7, the flow FL3 is formed in the portion where the retention portion T of the first pipe 1 is formed, and the flow velocity is lower than that of the flow FL2.

On the other hand, as shown in FIG. 8, the flow FL2 is formed in the portion along the inner peripheral surface S1 of the first pipe 1, but the flow FL2 has a flow velocity close to the flow FL1 as compared with FIG. .. That is, the first heat medium flows in the direction of the ridges 3a while avoiding the concave portions 3c, and the flow velocity of the flow FL2 increases accordingly.
Further, as shown in FIG. 8, the flow FL3 is formed in the portion where the retention portion T of the first pipe 1 is formed, but compared with FIG. 7, the flow FL3 has a flow velocity close to the flow FL2. That is, the first heat medium flows in the direction of the mountain portion 3a while avoiding the concave portion 3c, and the flow velocity of the flow FL3 in the retaining portion T increases accordingly.

Therefore, comparing the heat exchanger 100 in which the recess 3c is formed with the heat exchanger in which the recess 3c is not formed, in the heat exchanger 100 in which the recess 3c is formed, the inner peripheral surface of the first pipe 1 is Even on the S1 side, the flow velocity is less likely to drop. As described above, in the heat exchanger 100, since the concave portion 3c is formed, it is difficult for the flow velocity to drop even in the retention portion T, and the heat exchange performance can be improved.

<Regarding the streamline of the first heat medium in the first pipe 1>
FIG. 9 is an explanatory diagram as a comparative example of streamlines of the first heat medium in the first pipe 1 in which the recess 3c is formed in the center of the valley 3b. 10 and 11 are explanatory diagrams of streamlines of the first heat medium in the first pipe 1 of the heat exchanger 100. FIG. 10 schematically shows the internal state of the first pipe 1. Further, FIG. 11 schematically shows a state in which the inside of the first pipe 1 is viewed from the outside.
Note that, although FIG. 9 is a comparative example, for convenience of description, the same reference numerals as those of the heat exchanger 100 are added. In FIG. 9, a partial flow of the first heat medium in the first pipe 1 is shown as an eddy flow FL4 by an arrow. 10 and 11, the partial flow of the first heat medium in the first pipe 1 is shown as an eddy flow FL5 by an arrow.

As shown in FIG. 9, the vortex flow FL4 is retained along the inner peripheral surface S1 of the first pipe 1 on the downstream side in the flow direction of the first heat medium in the recess 3c. Due to this vortex flow FL4, there is a concern that corrosion may occur in the first pipe 1. It is considered that this is because one of the factors is that the corrosion resistance of the portion where the vortex flow FL4 is generated is not formed on the inner peripheral surface S1 of the first pipe 1 and the corrosion resistance of the portion is reduced. When the concave portion 3c is formed in the central portion of the valley portion 3b, the inner peripheral surface S1 of the first pipe 1 forming the valley portion 3b that is continuous with the concave portion 3c exists on the downstream side of the concave portion 3c. become. Therefore, the vortex flow FL4 generated by the concave portion 3c is generated along the inner peripheral surface S1 of the first pipe 1 forming the valley portion 3b, which causes the formation of an oxide film in this portion. ing.

10 and 11, the vortex flow FL5 is generated on the downstream side in the flow direction of the first heat medium in the recess 3c. However, in the heat exchanger 100, the inner peripheral surface S1 of the first pipe 1 does not exist immediately after the downstream side of the recess 3c in the flow direction of the first heat medium. Further, the vortex FL5 is not generated due to the flow of the mountain portion 3a. That is, the vortex flow FL5 generated by the recess 3c does not stay near the inner peripheral surface S1 of the first pipe 1 forming the valley 3b, and becomes like the flow FL5a shown in FIG. It does not interfere with the formation of an oxide film on the part.

As described above, in the heat exchanger 100, since the concave portion 3c is formed in the second region R2, the vortex flow FL5 generated on the downstream side of the concave portion 3c in the flow direction of the first heat medium is the inner circumference of the first pipe 1. Since it does not stay in the vicinity of the surface S1, it is possible to suppress the deterioration of the corrosion resistance even in this portion.

The recess 3c can be formed by dimple processing. That is, the recess 3c is recessed in a circular shape in plan view. The recess 3c is not limited to the dimple processing. The recess 3c may be recessed in a plan view shape. That is, the recess 3c may be formed in a groove shape.
Further, although the concave portion 3c has been described as having a circular shape in a plan view, it is not limited thereto, and may have a polygonal shape such as a triangular shape or a quadrangular shape in a plan view.
Further, although the concave portions 3c have been described as having the same shape, the concave portions 3c are not limited thereto and may have different shapes.

In the above description, the case where one mountain portion 3a and one valley portion 3b are formed in the first pipe 1 is taken as an example, but the number of the mountain portions 3a and the valley portions 3b is not particularly limited. .. As described in Modification 1 and Modification 2, a plurality of ridges 3a and valleys 3b may be formed in the first pipe 1.

[Modification 1 of the first pipe 1]
FIG. 12 is a cross-sectional view schematically showing a cross section of the first pipe 1 of the heat exchanger 100 according to Modification Example 1 taken along the flow direction of the first heat medium. FIG. 13 is a cross-sectional view schematically showing a cross section of the first pipe 1 of the heat exchanger 100 according to the first modification, which is orthogonal to the flow direction of the first heat medium.
12 and 13 show the first pipe 1 in which three peaks 3a and three valleys 3b are formed.

In FIG. 12, three peaks 3a and valleys 3b are formed. That is, the first pipe 1 is formed with the mountain portion 3a1, the mountain portion 3a2, and the mountain portion 3a3. Further, the first pipe 1 also has a valley portion 3b1, a valley portion 3b2, and a valley portion 3b3.
Then, the valley portion 3b1 is located between the mountain portion 3a1 and the mountain portion 3a2. Further, the valley portion 3b2 is located between the mountain portion 3a2 and the mountain portion 3a3. Further, the valley portion 3b3 is located between the mountain portion 3a3 and the mountain portion 3a1.

The protrusion amount of the mountain portion 3a in the radial direction DR1 decreases as the number of threads increases. That is, when the number of threads of the crest portion 3a increases, the first heat medium is less likely to stay in the stay portion T, and it is easy to suppress the decrease in the flow velocity in the stay portion T in addition to the formation position of the recess 3c. As a result, when the mountain portion 3a has three threads, the heat exchange performance can be further improved.

[Modification 2 of the first pipe 1]
FIG. 14: is sectional drawing which shows roughly the cross section which cut|disconnected the 1st piping 1 of the heat exchanger 100 which concerns on the modification 2 along the flow direction of a 1st heat medium. FIG. 15 is a cross-sectional view schematically showing a cross section of the first pipe 1 of the heat exchanger 100 according to Modification 1 orthogonal to the flow direction of the first heat medium.
14 and 15 show the first pipe 1 in which four ridges 3a and valleys 3b are formed.

In FIG. 14, four peaks 3a and valleys 3b are formed. That is, the first pipe 1 is formed with the mountain portion 3a1, the mountain portion 3a2, the mountain portion 3a3, and the mountain portion 3a4. Further, the first pipe 1 is formed with the valley portion 3b1, the valley portion 3b2, the valley portion 3b3, and the peak portion 3a4.
Then, the valley portion 3b1 is located between the mountain portion 3a1 and the mountain portion 3a2. Further, the valley portion 3b2 is located between the mountain portion 3a2 and the mountain portion 3a3. Further, the valley portion 3b3 is located between the mountain portion 3a3 and the mountain portion 3a4. Further, the valley portion 3b4 is located between the mountain portion 3a4 and the mountain portion 3a1.

As in the first modification, when the number of threads of the mountain portion 3a increases, the shape of the first heat medium is less likely to stay in the retaining portion T, and the decrease in the flow velocity in the retaining portion T is suppressed in addition to the formation position of the recess 3c. Easier to do. As a result, when the mountain portion 3a has four threads, the heat exchange performance can be further improved.

[Effects of Heat Exchanger 100 and Refrigeration Cycle Device 200]
As described above, in the heat exchanger 100, since the concave portion 3c is formed in the second region R2, it is difficult for the flow velocity to drop even in the retention portion T, and heat exchange performance can be improved.
Further, in the heat exchanger 100, since the concave portion 3c is formed in the second region R2, the vortex flow FL5 generated on the downstream side of the concave portion 3c in the flow direction of the first heat medium is generated in the first pipe 1. It is possible not to follow the peripheral surface S1. Therefore, according to the heat exchanger 100, it is possible to suppress a decrease in corrosion resistance even on the downstream side in the flow direction of the first heat medium in the recess 3c.

In the heat exchanger 100, since the concave portion 3c is formed at a position where the line segment L2 is shorter than the line segment L1, the concave portion 3c is formed in the second region R2, and the retention portion is formed. The decrease in the flow velocity at T can be suppressed.

In the heat exchanger 100, when the recess 3c sees the vertex B3 of the recess 3c from the vertex B2 of the second mountain portion 3a-2, the line segment L2 is directed toward the upstream side in the flow direction of the first heat medium, and , Are formed so as to extend in the diameter reduction direction DR2. Therefore, it becomes clear that the recessed portion 3c is recessed further in the diameter reduction direction DR2 than the valley portion 3b, and it is possible to suppress the decrease in the flow velocity in the retention portion T without forming the recessed portion 3c into a complicated shape.

According to the heat exchanger 100, since the concave portion 3c is formed in a circular shape in plan view, the concave portion 3c can be formed by dimple processing, and it is not necessary to form the concave portion 3c by a complicated and expensive mechanism.

According to the heat exchanger 100, since the plurality of peaks 3a and the plurality of valleys 3b are formed, the retention of the first heat medium in the retention section T can be further suppressed.

According to the refrigeration cycle apparatus 200, since the above heat exchanger is provided as the condenser, improvement in heat exchange performance in the condenser can be expected.

Embodiment 2.
FIG. 16: is explanatory drawing of the streamline of the 1st heat medium in the 1st piping 1 of the heat exchanger which concerns on Embodiment 2 of this invention. Based on FIG. 16, a streamline of the first heat medium in the first pipe 1 of the heat exchanger according to the second embodiment will be described.
In the second embodiment, differences from the first embodiment will be mainly described, and the same parts as those in the first embodiment will be designated by the same reference numerals and the description thereof will be omitted.

In the second embodiment, the shape of the recess 3c is different from the shape of the recess 3c described in the first embodiment. Specifically, the shape of the recess 3c is a streamline shape in cross section as shown in FIG. That is, the portion of the concave portion 3c along the flow direction of the first heat medium is made longer than the portion of the concave portion 3c orthogonal to the flow direction of the first heat medium, and the elongated portion is formed into a shape that is smoothly curved to form the concave portion 3c. Is composed of. By forming the concave portion 3c to have a streamlined shape in cross section, it is possible to suppress the generation of eddy currents in the concave portion 3c. Therefore, according to the heat exchanger according to the second embodiment, it is possible to expect further suppression of the decrease in corrosion resistance.

Also in this case, the recess 3c can be formed by dimple processing. That is, the recess 3c may be formed by making the mold of the recess 3c formed by the dimple processing into a streamlined shape in cross section.
Further, all of the concave portions 3c may have a cross-sectional streamlined shape, or may not all have a cross-sectional streamlined shape.
Further, it is assumed that the modified example 1 or modified example 2 described in the first embodiment can be applied to the second embodiment.

[Effects of Heat Exchanger According to Second Embodiment]
According to the heat exchanger according to the second embodiment, since the recess 3c is formed in a streamlined shape in cross section, it is possible to further suppress the generation of a vortex in the recess 3c and further suppress the reduction in corrosion resistance. Can be expected.

Embodiment 3.
FIG. 17 is an explanatory diagram as a comparative example of streamlines of the first heat medium in the first pipe 1 in which the concave portion 3c having a circular shape in plan view is formed. FIG. 18: is explanatory drawing of the streamline of the 1st heat medium in the 1st piping 1 of the heat exchanger which concerns on Embodiment 3 of this invention. The streamlines of the first heat medium in the first pipe 1 of the heat exchanger according to the third embodiment will be described with reference to FIGS. 17 and 18.
The third embodiment will be described focusing on the differences from the first and second embodiments, and the same parts as those of the first and second embodiments will be designated by the same reference numerals and the description thereof will be omitted. It shall be.

In FIG. 17, the configuration of the first pipe 1 of the heat exchanger 100 according to the first embodiment is shown as a comparative example. In FIG. 17, the flow of the first heat medium in the first pipe 1 is shown as a flow FL6 by an arrow. In FIG. 18, the flow of the first heat medium in the first pipe 1 is shown by an arrow as a flow FL7.

In the third embodiment, the shape of the recess 3c is different from the shape of the recess 3c described in the first embodiment. Specifically, the shape of the recess 3c is an elliptical shape in plan view as shown in FIG. That is, the concave portion 3c is formed in an elliptical shape with the minor axis ma1 as the spiral direction of the concave portion 3c and the major axis ma2 as the direction perpendicular to the spiral direction of the concave portion 3c. Here, the spiral direction means a direction parallel to the straight line L3 shown in FIG. The straight line L3 is a straight line that connects the vertices of the mountain portions 3a that are connected to each other at the top and bottom of the paper.

When the recess 3c has an elliptical shape in plan view, the recess 3c functions more as a weir for the flow of the first heat medium along the spiral direction. That is, the recess 3c serves as a wall of the flow of the first heat medium along the spiral direction with the width of the major axis ma2. Therefore, when the concave portion 3c has an elliptical shape in plan view, the effect of the flow FL7 guided to the mountain portion 3a shown in FIG. 18 is larger than that of the flow FL6 shown in FIG. That is, since the flow velocity of the first heat medium at the retention portion T is unlikely to drop, improvement in heat exchange performance can be expected.

Also in this case, the recess 3c can be formed by dimple processing. That is, the recess 3c may be formed by making the mold of the recess 3c formed by the dimple processing into an elliptical shape in plan view.
Further, all of the concave portions 3c may have an elliptical shape in plan view or may not have an elliptical shape in plan view.
In addition, it is assumed that the first modification or the second modification described in the first embodiment can be applied to the third embodiment.

[Effects of Heat Exchanger According to Third Embodiment]
In the heat exchanger 100, since the concave portion 3c is formed in an elliptical shape in plan view having the minor axis ma1 in the spiral direction and the major axis ma2 in the direction perpendicular to the spiral direction, the first heat medium along the spiral direction is formed. The concave portion 3c functions as a weir against the flow. Therefore, according to the heat exchanger according to the third embodiment, the effect of the flow guided to the mountain portion 3a becomes great.

Fourth Embodiment
FIG. 19: is explanatory drawing of the recessed part 3c in the 1st piping 1 of the heat exchanger which concerns on Embodiment 4 of this invention. FIG. 20 is a schematic sectional view schematically enlarging and showing the sectional configuration of the recess 3c in the first pipe 1 of the heat exchanger according to Embodiment 4 of the present invention. The recess 3c in the first pipe 1 of the heat exchanger according to the fourth embodiment will be described with reference to FIGS. 19 and 20.
Note that the fourth embodiment will be described focusing on the differences from the first, second, and third embodiments, and the first, second, and third embodiments will be described. The same parts are designated by the same reference numerals and the description thereof will be omitted.

FIG. 20 is a schematic enlarged view of a cross section of the first pipe 1 including the recess 3 c in the spiral direction. Further, in FIG. 20, a flow along the spiral direction of the first heat medium from the inflow port 1a to the outflow port 1b of the first flow path FP1 is indicated by an arrow as a flow FL8.

In the fourth embodiment, the shape of the recess 3c is different from the shape of the recess 3c described in the first embodiment. Specifically, as shown in FIGS. 19 and 20, the position of the apex B3 of the recess 3c is displaced upstream of the center of the recess 3c with respect to the traveling direction in the spiral direction.
By shifting the apex B3 of the concave portion 3c to the upstream side of the center with respect to the traveling direction of the spiral direction, the concave portion 3c has a streamlined shape with respect to the flow FL8 shown in FIG. Therefore, similarly to the second embodiment, it is possible to suppress the generation of the vortex flow in the recess 3c. Therefore, according to the heat exchanger according to the fourth embodiment, it is possible to expect further suppression of the reduction in corrosion resistance.

It should be noted that the first modification or the second modification described in the first embodiment can be applied to the fourth embodiment.

[Effects of Heat Exchanger According to Fourth Embodiment]
In the heat exchanger according to Embodiment 4, the apex B3 of the recess 3c is formed on the upstream side of the central portion with respect to the traveling direction of the spiral direction in the flow direction of the first heat medium of the first pipe 1. ing. Therefore, according to the heat exchanger according to the fourth embodiment, similarly to the heat exchanger according to the second embodiment, it is possible to further suppress the generation of the eddy current in the recess 3c and further suppress the decrease in the corrosion resistance. Can be expected.

Although the present invention has been described above by dividing the embodiments, the specific configuration is not limited to the embodiments described above, and can be modified without departing from the gist of the invention.

1 1st piping, 1a inlet, 1b outlet, 2nd piping, 2a inlet, 2b outlet, 3a mountain part, 3a-1 1st mountain part, 3a-2 2nd mountain part, 3a1 mountain Section, 3a2 crest section, 3a3 crest section, 3a4 crest section, 3b trough section, 3b1 trough section, 3b2 trough section, 3b3 trough section, 3b4 trough section, 3c recessed section, 10A heat medium piping, 20A refrigerant piping, 60 control device, 100 heat exchanger, 200 refrigeration cycle device, 201 compressor, 202 expansion device, 203 heat exchanger, 203A blower, 205 pump, 207 hot water storage tank, A1 refrigerant circuit, A2 heat medium circuit, A3 water supply circuit, B1 first mountain Apex of the portion, B2 apex of the second mountain portion, B3 apex of the concave portion, B4 center point of the intermediate valley portion, DR1 first pipe diameter expansion direction, DR2 first pipe diameter reduction direction, FP1 first flow Channel, FP2 second flow path, R1 first area, R2 second area, S1 inner peripheral surface, S2 outer peripheral surface, T retention section, U hot water supply utilization section.

Claims (10)

A first pipe in which a first flow path through which the first heat medium flows is formed;
A second flow path in which a second heat medium flows is formed, and a second pipe wound around the first pipe;
Have
The first pipe is
A mountain portion projecting in a diameter expanding direction in which the diameter of the first pipe expands;
An outer diameter smaller than a portion where the peak portion is formed, and a valley portion around which the second pipe is wound,
The mountain part is
A spiral shape is formed in a direction in which the first heat medium of the first flow path flows,
The valley is
It is formed in a spiral shape along the mountain portion,
The groove is formed in a spiral direction that is a direction of forming the valley portion, and includes a recessed portion that is recessed in a diameter reducing direction in which the diameter of the first pipe becomes small,
A first mountain portion which is the mountain portion of the Nth lap of the spiral winding of the mountain portion, and a second mountain portion which is the mountain portion of the N+1th lap of the spiral winding of the mountain portion; Section which cut|disconnected along the flow direction of the said 1st heat medium the part of the said 1st piping containing the intermediate valley part which is the said valley part between the said 1st mountain part and the said 2nd mountain part. In a cross-sectional view,
The recess is
The heat exchanger formed so that the apex of the recess is located downstream of the central point of the intermediate valley in the flow direction of the first heat medium. The recess is
Rather than a straight line connecting the apex of the recess and the apex of the first mountain portion,
The heat exchanger according to claim 1, wherein a straight line connecting the apex of the recess and the apex of the second mountain portion is shorter than the straight line. The recess is
The heat exchanger according to claim 1 or 2, wherein the wall surface on the downstream side in the flow direction of the first heat medium is formed by extending a part of the wall surface of the intermediate valley portion. The recess is
The heat exchanger according to claim 1, wherein the heat exchanger has a circular shape in plan view. The recess is
The heat exchanger according to claim 1, wherein the heat exchanger is formed in a streamlined shape in cross section. The recess is
The heat exchanger according to claim 1, wherein the heat exchanger has an elliptical shape in plan view. The recess is
The heat exchanger according to any one of claims 1 to 3, which is formed in an elliptical shape in a plan view having a spiral direction as a short axis and a direction perpendicular to the spiral direction as a long axis. The recess is
The apex
The heat exchange according to any one of claims 1 to 3, which is formed on an upstream side of a central portion with respect to a traveling direction of a spiral direction in a flow direction of the first heat medium of the first pipe. vessel. The heat exchanger according to any one of claims 1 to 8, wherein a plurality of the peaks and the valleys are formed. A heat exchanger according to any one of claims 1 to 9 is provided as a condenser,
In the heat exchanger,
The first heat medium flowing through the first flow path of the first pipe constituting the heat exchanger,
Refrigeration cycle device is warmed by the second heat medium flowing through the second flow path of the second pipe constituting the heat exchanger.

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