WO2013014899A1

WO2013014899A1 - Heat exchanger and heat pump using same

Info

Publication number: WO2013014899A1
Application number: PCT/JP2012/004636
Authority: WO
Inventors: 森田　健一; 長生木戸; 鈴木　基啓; 町田　和彦
Original assignee: パナソニック株式会社
Priority date: 2011-07-22
Filing date: 2012-07-20
Publication date: 2013-01-31
Also published as: CN103562665A; JP6037235B2; EP2735832B1; EP2735832A4; JPWO2013014899A1; CN103562665B; EP2735832A1

Abstract

This heat exchanger (100) is provided with multiple heat exchange segments (10). The heat exchange segments (10) are configured from an inner tube assembly (26), which comprises two inner tubes (24), and an outer tube (28). The gap width G expressed by ((Φin / 2) - Φout), i.e., the difference between half of the inner diameter (Φin) of the outer tube (28), and the outer diameter (Φout) of the inner tube (24), fulfills 0 < G ≦ 0.8 (unit: mm). The pass number N representing the number of heat exchange segments (10), and the inner diameter Φin (unit: mm) of the outer tube (28), satisfy one of the relations (1) to (5) below. (1) N=4 and 8.20 ≦ Φin ≦ 9.50, (2) N=5 and 7.58 ≦ Φin ≦ 8.90, (3) N=6 and 7.14 ≦ Φin ≦ 8.50, (4) N=7 and 6.78 ≦ Φin ≦ 8.20, and (5) N=8 and 6.52 ≦ Φin ≦ 7.90.

Description

Heat exchanger and heat pump using the same

The present invention relates to a heat exchanger and a heat pump using the heat exchanger.

A heat exchanger for exchanging heat between two types of fluids (for example, water and refrigerant, air and refrigerant) has been widely used.

For example, Patent Document 1 describes a double-tube heat exchanger having an inner tube and an outer tube. As described in FIG. 6 of Patent Document 1, the heat exchanger of Patent Document 1 includes two double tubes and a header. Two double pipes are connected in parallel by the header. Each double pipe is composed of one outer pipe and two inner pipes.

Patent Document 2 describes a heat exchanger including a casing having a rectangular flow path and a heat transfer tube disposed in a flow path inside the casing. The heat exchanger described in Patent Document 2 is common to the heat exchanger described in Patent Document 1 in that it has a structure in which a pipe having a flow path of the other fluid is arranged in the flow path of one fluid. ing.

In the present specification, a heat exchanger having a structure in which the flow path of one fluid is arranged in the flow path of one fluid is referred to as a “double flow heat exchanger”.

Patent No. 4414197 JP 2005-24109 A

The heat exchangers described in

Patent Documents

1 and 2 are very heavy because they are made of a metal such as copper or stainless steel. Therefore, a lighter double flow path heat exchanger is desired.

In view of the above circumstances, an object of the present invention is to provide a technique for reducing the weight of a double-channel heat exchanger.

That is, this disclosure
A heat exchanger for exchanging heat between the first fluid and the second fluid,
A plurality of heat exchange segments each having a first flow path and a second flow path;
A first header provided at one end of the plurality of heat exchange segments to guide the first fluid to the first flow path and collect the second fluid from the second flow path;
A second header provided at the other end of the plurality of heat exchange segments so as to collect the first fluid from the first flow path and guide the second fluid to the second flow path;
With
The heat exchange segment includes (i) two inner pipes each having the first flow path, and an inner pipe assembly formed by twisting the two inner pipes in a spiral shape; and (ii) It is constituted by an exterior body that houses the inner pipe assembly so that the second flow path is formed between the inner peripheral surface of the inner pipe and the outer peripheral surface of the inner pipe assembly.
The number of paths N representing the number of the heat exchange segments arranged between the first header and the second header is 4 to 8,
The gap G expressed by the difference between the half of the inner diameter Φin of the outer body and the outer diameter Φout of the inner tube ((Φin / 2) −Φout) is 0 <G ≦ 0.8 (unit: mm) The filling,
Provided is a heat exchanger in which the number of passes N and the inner diameter Φin (unit: mm) of the exterior body satisfy any of the following relationships (1) to (5).
(1) N = 4, 8.20 ≦ Φin ≦ 9.50
(2) N = 5 and 7.58 ≦ Φin ≦ 8.90
(3) N = 6 and 7.14 ≦ Φin ≦ 8.50
(4) N = 7 and 6.78 ≦ Φin ≦ 8.20
(5) N = 8, 6.52 ≦ Φin ≦ 7.90

According to the present disclosure, by appropriately determining the relationship between the inner diameter Φin of the exterior body, the gap width G, and the number of passes N, the heat exchange capacity equivalent to that of a conventional double-channel heat exchanger is provided. In spite of this, a light weight heat exchanger can be provided.

The schematic plan view of the heat exchanger which concerns on one Embodiment of this invention. Sectional drawing of the heat exchange segment used for the heat exchanger shown in FIG. Schematic diagram of inner tube assembly Configuration of heat pump water heater Graph showing simulation results Another graph showing the results of the simulation Yet another graph showing simulation results Yet another graph showing simulation results

Since the heat exchanger of Patent Document 1 has a large space in the central portion, it has a large size for the heat exchange capacity (see FIG. 3 and the like). The dimensions of the heat exchanger of Patent Document 1 are greatly affected by, for example, the radius of curvature of the corner portion. The smaller the radius of curvature of the corner portion, the smaller the overall dimensions. However, the radius of curvature of the corner portion has an inevitable limit depending on the thickness of the double tube and the like. Therefore, it is almost impossible to reduce the size by devising the bent shape of the double pipe.

The present inventors have maintained the heat exchange capacity at a constant value, the number of channels of the double channel heat exchanger (corresponding to the number of double tubes of Patent Document 1), the inner diameter of the outer tube When the width of the gap between the outer tube and the inner tube was changed, how the weight of the heat exchanger changed was examined by computer simulation. As a result, it has been found that the weight of the heat exchanger can be reduced when the number of flow paths, the inner diameter of the outer tube, and the width of the gap take specific values. Based on these findings, the present inventors disclose the following.

The first aspect of the present disclosure is:
A heat exchanger for exchanging heat between the first fluid and the second fluid,
A plurality of heat exchange segments each having a first flow path and a second flow path;
A first header provided at one end of the plurality of heat exchange segments to guide the first fluid to the first flow path and collect the second fluid from the second flow path;
A second header provided at the other end of the plurality of heat exchange segments so as to collect the first fluid from the first flow path and guide the second fluid to the second flow path;
With
The heat exchange segment includes (i) two inner pipes each having the first flow path, and an inner pipe assembly formed by twisting the two inner pipes in a spiral shape; and (ii) It is constituted by an exterior body that houses the inner pipe assembly so that the second flow path is formed between the inner peripheral surface of the inner pipe and the outer peripheral surface of the inner pipe assembly.
The number of paths N representing the number of the heat exchange segments arranged between the first header and the second header is 4 to 8,
The gap width G expressed by the difference between the half of the inner diameter Φin of the exterior body and the outer diameter Φout of the inner tube ((Φin / 2) −Φout) is 0 <G ≦ 0.8 (unit: mm) The filling,
Provided is a heat exchanger in which the number of passes N and the inner diameter Φin (unit: mm) of the exterior body satisfy any of the following relationships (1) to (5).
(1) N = 4, 8.20 ≦ Φin ≦ 9.50
(2) N = 5 and 7.58 ≦ Φin ≦ 8.90
(3) N = 6 and 7.14 ≦ Φin ≦ 8.50
(4) N = 7 and 6.78 ≦ Φin ≦ 8.20
(5) N = 8, 6.52 ≦ Φin ≦ 7.90

The second aspect of the present disclosure provides, in addition to the first aspect, a heat exchanger in which the gap width G satisfies 0.16 ≦ G ≦ 0.8. Thereby, an inner pipe assembly can be smoothly put in an exterior body.

The third aspect of the present disclosure provides a heat exchanger in which, in addition to the first or second aspect, the inner tube and the exterior body are each formed of a copper tube. Thereby, heat exchange between the first fluid and the second fluid can be efficiently performed.

The fourth aspect of the present disclosure provides a heat exchanger in which, in addition to the first or second aspect, the inner tube is made of a copper tube, and the exterior body is made of resin. If the exterior body is made of resin, there is a possibility that a lighter heat exchanger can be provided.

According to a fifth aspect of the present disclosure, in addition to any one of the first to fourth aspects, the inner tube includes an inner surface smooth tube and an inner grooved tube provided outside the inner surface smooth tube. A heat exchanger that is a leak detection tube is provided. According to the leak detection tube, even if the inner surface smooth tube is damaged, the first fluid can be prevented from flowing into the second flow path.

The sixth aspect of the present disclosure provides the heat exchanger according to any one of the first to fifth aspects, in which the first fluid is carbon dioxide and the second fluid is water. When carbon dioxide is used as a refrigerant, water can be heated to a temperature close to the boiling point.

The seventh aspect of the present disclosure is:
A compressor for compressing the refrigerant;
A heat radiator configured by any one of the first to sixth heat exchangers for cooling the compressed refrigerant;
An expansion mechanism for expanding the cooled refrigerant;
An evaporator for evaporating the expanded refrigerant;
A water circuit for circulating water through the radiator;
A heat pump is provided.

The heat pump efficiency can be increased by using any one of the first to sixth heat exchangers.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by the following embodiment.

As shown in FIG. 1, the heat exchanger 100 of this embodiment includes a plurality of heat exchange segments 10, a first header 16, and a second header 22. The first header 16 and the second header 22 are provided at one end and the other end of the plurality of heat exchange segments 10, respectively.

As shown in FIG. 2, the heat exchange segment 10 is composed of an inner tube assembly 26 and an outer tube 28 (exterior body). The inner tube assembly 26 includes two inner tubes 24. The two inner tubes 24 each have a first flow path 24h. As shown in FIG. 3, the inner tube assembly 26 is formed by twisting these two inner tubes 24 in a spiral shape. The inner tube assembly 26 is disposed in the outer tube 28. As a result, a second flow path 28 h is formed between the inner peripheral surface of the outer tube 28 and the outer peripheral surface of the inner tube assembly 26. The cross-sectional shape of the first flow path 24h and the cross-sectional shape of the second flow path 28h are typically circular.

Regarding the inner tube assembly 26, the helical pitch and the helical angle are not particularly limited. The spiral pitch is adjusted to a range of 20 to 65 mm, for example. The spiral angle is adjusted to a range of 13 to 26 °, for example. Although it is desirable that the spiral angle is large to some extent, there is a processing limit depending on the outer diameter of the inner tube 24. As shown in FIG. 3, “spiral pitch” means the length of one cycle of the twisted inner tube 24. “Helix angle” is an angle defined as follows. When the inner tube assembly 26 is viewed in plan, the center line L ₁ of the inner tube assembly 26 and the contact point P of the two inner tubes 24 at the antinode position of the inner tube assembly 26 are defined. Further, a tangent line L _{2 of the} inner tube 24 is defined so as to pass through the contact point P. An angle formed by the center line L ₁ and the tangent line L ₂ is defined as a “spiral angle”.

As shown in FIG. 1, the first header 16 includes an exit header 12 and an entrance header 14. The first header 16 serves to collect the second fluid from the second flow path 28h and guide the first fluid to the first flow path 24h. The second header 22 includes an inlet header 18 and an outlet header 20. The second header 22 guides the second fluid to the second flow path 28h and collects the first fluid from the first flow path 24h. When the second fluid is caused to flow through the second passage 28h while the first fluid is caused to flow through the first passage 24h, heat exchange is performed between the first fluid and the second fluid.

An example of the first fluid is a refrigerant such as carbon dioxide, and an example of the second fluid is water. Carbon dioxide is suitable for a heat pump as a refrigerant having a low GWP (Global Warming Potential). When carbon dioxide is used as a refrigerant, water can be heated to a temperature close to the boiling point. However, the two types of fluids to be heat-exchanged are not limited to these. Instead of water, oil, brine, etc. can be used as the second fluid. In addition, a fluorine refrigerant such as hydrofluorocarbon can be used as the refrigerant.

The detailed structure of the first header 16 and the second header 22 is described in, for example, Patent Document 1 (FIG. 6).

In the present embodiment, the inner tube 24 and the outer tube 28 are each formed of a copper tube. Thereby, heat exchange between the first fluid and the second fluid can be efficiently performed.

The second flow path 28h may be formed of a member having a shape other than a pipe. Such a member may be made of metal or may be made of a material other than metal. For example, the inner tube 24 may be made of a copper tube, and a member (exterior body) corresponding to the outer tube 28 may be made of resin. If the member corresponding to the outer tube 28 is made of resin, there is a possibility that a lighter heat exchanger can be provided.

The member corresponding to the outer tube 28 is made of, for example, a resin such as polyphenylene sulfide, polyether ether ketone, polytetrafluoroethylene, polysulfone, polyether sulfone, polyarylate, polyamideimide, polyetherimide, liquid crystal polymer, or polypropylene. It may be done. These resins (thermoplastic resins) have excellent heat resistance and chemical durability, and do not easily deteriorate even when exposed to water. The outer tube 28 may also be made of a resin containing a reinforcing material such as a glass filler.

As shown in FIG. 2, the inner tube 24 is a leak detection tube composed of an inner surface smooth tube 32 and an inner surface grooved tube 30 provided outside the inner surface smooth tube 32. The outer diameter of the inner smooth tube 32 is equal to the inner diameter of the inner grooved tube 30. According to the leak detection tube, even if the inner surface smooth tube 32 is damaged, the first fluid can be prevented from flowing into the second flow path 28h. However, it is not essential that the inner tube 24 is a leak detection tube. The inner tube 24 may be composed only of the inner smooth tube 32. Further, dimples (unevenness) may be formed on the surface of the inner tube 24. Such dimples improve the heat transfer coefficient at the surface of the inner tube 24.

As shown in FIG. 1, in this embodiment, the number of passes N representing the number of heat exchange segments 10 arranged between the first header 16 and the second header 22 is four. Depending on the inner diameter of the outer tube 28 and the outer diameter of the inner tube 24, the number of passes N can be appropriately changed within the range of 4-8.

As described in FIG. 6 of Patent Document 1 (Japanese Patent No. 4414197), the number of passes N of the conventional double-channel heat exchanger is, for example, two. When the number of passes N is increased, the flow path area increases in proportion to the number of passes, so that the pressure loss is greatly reduced. However, the heat transfer rate decreases as the fluid flow rate decreases. In order to compensate for a decrease in heat exchange capacity due to a decrease in heat transfer coefficient, it is necessary to appropriately design the length of the flow path per pass. Even if the number of passes N is doubled, the length per pass cannot be halved. Therefore, the effect of reducing the weight of the double flow path heat exchanger cannot be obtained by simply increasing the number of passes.

The present inventors examined in detail the relationship between the number of flow paths (number of passes), the inner diameter of the outer tube, and the width of the gap by computer simulation. As a result, when these parameters take specific values, it is possible to provide a heat exchanger that is reduced in weight even though it has a heat exchange capacity equivalent to that of a conventional double-channel heat exchanger. I found out.

Specifically, the heat exchanger 100 of the present embodiment satisfies the following relationship. First, the number of passes N is in the range of 4-8. The inner diameter Φin of the outer tube 28 is in the range of 6.52 to 9.50 mm. The gap G expressed by the difference between the half of the inner diameter Φin of the outer tube 28 and the outer diameter Φout of the inner tube 24 ((Φin / 2) −Φout) is 0 <G ≦ 0.8 (unit: mm) Meet. Further, the number of passes N and the inner diameter Φin (unit: mm) of the outer tube 28 satisfy any of the following relationships (1) to (5). As can be understood from FIG. 2, the outer diameter of the inner tube assembly 26 is equal to twice the outer diameter Φout of the inner tube 24.
(1) N = 4, 8.20 ≦ Φin ≦ 9.50
(2) N = 5 and 7.58 ≦ Φin ≦ 8.90
(3) N = 6 and 7.14 ≦ Φin ≦ 8.50
(4) N = 7 and 6.78 ≦ Φin ≦ 8.20
(5) N = 8, 6.52 ≦ Φin ≦ 7.90

As the number of passes N increases, the number of brazing points increases and the structure of the

headers

16 and 22 becomes complicated. If the number of passes N exceeds 8, even if weight reduction can be achieved, mass production is difficult. If the number of passes N is too large, it is difficult to flow the first fluid and the second fluid uniformly through each of the heat exchange segments 10. Therefore, the number of passes N is desirably in the range of 4-8.

When the gap width G is zero, the inner tube assembly 26 cannot be inserted into the outer tube 28. It is therefore essential that the gap width G is greater than zero. The gap width G is preferably 0.16 mm or more. On the other hand, if the gap width G exceeds 0.8 mm, the heat transfer coefficient on the surface of the inner tube 24 is lowered, and there is a possibility that the deterioration of the heat exchange performance becomes obvious. Therefore, the upper limit value of the gap width G is preferably 0.8 mm.

When the inner diameter Φin of the outer tube 28 and the gap width G are determined, the outer diameter Φout of the inner tube 24 is determined. The weight reduction of the heat exchanger 100 can reduce the inner diameter Φin of the outer tube 28 and / or the outer diameter Φout of the inner tube 24, and further reduce the thickness of the outer tube 28 and / or the thickness of the inner tube 24. Can be achieved due to that. However, in consideration of safety, the inner tube 24 and the outer tube 28 each require a certain thickness. Considering the corrosion resistance, the thickness of the detection tube 30 (the thickness of the portion without the groove) is adjusted to a range of 0.5 to 0.7 mm, for example. From the same viewpoint, the thickness of the outer tube 28 is adjusted to a range of 0.5 to 0.7 mm, for example. The wall thickness of the inner smooth tube 32 is adjusted to a range of 0.2 to 0.4 mm, for example. As for the inner smooth tube 32 (refrigerant tube), a thickness that can withstand the pressure of the refrigerant (first fluid) is required. If the thickness of the inner smooth tube 32 is excessive, the weight, cost, refrigerant pressure loss, etc. of the heat exchanger 100 are affected. Therefore, the thickness of the inner surface smooth tube 32 can be set in a range of, for example, 12 to 20% (preferably 12 to 16%) of the outer diameter of the inner surface smooth tube 32 itself.

The heat exchange capacity of the heat exchanger 100 is not particularly limited, but is, for example, in the range of 4.5 to 6.0 kW. When the heat exchanger 100 has such a heat exchange capacity, the heat exchanger 100 can be suitably used for a heat pump for general households. Of course, when more heat exchange capability is required, two heat exchangers 100 can be used in parallel.

As shown in FIG. 1, in this embodiment, the heat exchange segment 10 is not bent. Depending on the number of passes N, the heat exchange segment 10 has a length of 2-5 meters. Therefore, in the heat exchanger 100 of the present embodiment, the heat exchange segment 10 may be bent in a spiral shape. By using a thin tube for the heat exchange segment 10, the bending radius can be reduced, and the dead space may be reduced.

Next, the use of the heat exchanger 100 will be described. FIG. 4 is a configuration diagram of a heat pump water heater 200 that can employ the heat exchanger 100.

The heat pump water heater 200 includes a heat pump unit 201 and a tank unit 203. Hot water produced by the heat pump unit 201 is stored in the tank unit 203. Hot water is supplied from the tank unit 203 to the hot-water tap 204. The heat pump unit 201 includes a compressor 205 that compresses the refrigerant, a radiator 207 that cools the refrigerant, an expansion mechanism 209 that expands the refrigerant, an evaporator 211 that evaporates the refrigerant, and a refrigerant pipe that connects these devices in this order. 213. The expansion mechanism 209 is typically an expansion valve. Instead of the expansion valve, a positive displacement expander that can recover the expansion energy of the refrigerant may be used. The heat exchanger 100 can be used as the radiator 207. The tank unit 203 includes a hot water storage tank 215 and a water circuit 217. The water circuit 217 plays a role of circulating water through the radiator 207.

For the heat exchanger described with reference to FIGS. 1 to 3, the inner diameter Φin of the outer tube was fixed to 7.06 mm or 8.6 mm, and the weight when the number of passes N was changed was calculated by computer simulation. . The gap width G was fixed at 0.4 mm. As a reference example, a calculation result of a heat exchanger in which the number of passes N is 2 and the inner diameter Φin of the outer tube is 10.8 mm was prepared. The number of passes N was changed while maintaining the heat exchange capacity at the value of the reference example (about 4.7 kW). That is, the length of the heat exchange segment (the length of the outer tube) was set so that the same heat exchange capability as in the reference example was exhibited. The simulation conditions are as follows.

Analysis software: REFPROP Version 7.0
Water flow rate: 1.4 kg / min Water temperature: 17 ° C
Refrigerant type: CO ₂
Refrigerant temperature (inlet): 87 ° C
Refrigerant temperature (outlet): 20 ° C
Refrigerant pressure: 9.6 MPa
Material of outer tube and inner tube: Copper

Results are shown in Tables 1 and 2. Table 1 shows the results for Φin = 7.06 mm. Table 2 shows the results for Φin = 8.6 mm.

As shown in the item of total weight in Table 1, when Φin = 7.06 mm, only the 8-pass heat exchanger was lighter than the reference example. As shown in the item of total weight in Table 2, when Φin = 8.6 mm, only the 4-pass heat exchanger was lighter than the reference example.

Next, the gap width G was fixed to 0.4 mm, and various combinations of the inner diameter Φin of the outer tube and the number of passes N were examined. Then, a combination of the inner diameter Φin of the outer tube and the number of passes N in the heat exchanger lighter than the reference example was picked up. The results are shown in Table 3.

The results of Table 3 are shown in the graphs of FIGS. In the graph of FIG. 5, the horizontal axis represents the number of passes N, and the vertical axis represents the weight. In FIG. 5, the leftmost mark corresponds to the reference example. In the graph of FIG. 6, the horizontal axis represents the inner diameter Φin of the outer tube, and the vertical axis represents the number of passes N. As shown in FIG. 6, in order to reduce the weight while maintaining the heat exchange capability equivalent to that of the reference example, it is necessary to appropriately select the inner diameter Φin of the outer tube according to the number of passes N.

As shown in Table 3 and FIG. 5, when the gap width G was 0.4 mm, the weight of the heat exchanger was minimized under the conditions of Φin = 6.82 mm and 9 passes. However, when the number of passes N exceeds 8, there is a concern that the productivity is lowered.

Next, (a) When the gap width G is 0.8 mm, (b) When the gap width G is 0 mm, (c) Under the conditions when the gap width G is optimized Thus, various combinations of the inner diameter Φin of the outer tube and the number of passes N were examined. Table 4 shows the results in the case of (a). The results in the case of (b) are shown in Table 5. The results in the case of (c) are shown in Table 6. Further, the results of Tables 3 to 6 are shown in the graph of FIG.

When the gap width G exceeds 0.8 mm, the heat transfer coefficient on the surface of the inner tube is lowered, and there is a possibility that the deterioration of the heat exchange performance becomes obvious. Therefore, no simulation is performed for a range exceeding 0.8 mm. On the other hand, the lower limit value of the gap width G is not particularly limited. However, as shown in Table 6, when the gap width G is optimized, the weight of the heat exchanger is reduced to the maximum as compared with the reference example. Can do.

That is, the data when the gap width G is optimized in a range where the pressure loss of the second fluid (water) does not exceed a certain value represents the gap width G that can minimize the weight of the heat exchanger. ing. Therefore, data when the gap width G is optimized can be handled as a suitable lower limit value. In Table 6, the smallest value of the gap width G is 0.16 mm, and the number of passes N at that time is 8.

As can be understood from the data when the gap width G is 0 mm, when the gap width G approaches 0 mm, it is necessary to suppress the pressure loss on the water side, so it is necessary to increase the inner diameter Φin of the outer tube. is there. As a result, the inner diameter Φin of the outer tube when the gap width G is 0 mm is larger than the inner diameter Φin of the outer tube when the gap width G is 0.4 mm.

As shown in FIG. 7, when N = 4, if 8.20 ≦ Φin ≦ 9.50 is satisfied, the weight of the double-channel heat exchanger is reduced while maintaining the heat exchange capability equivalent to that of the reference example. Can be reduced. Similarly, when N = 5, 7.58 ≦ Φin ≦ 8.90, when N = 6, 7.14 ≦ Φin ≦ 8.50, when N = 7, 6.78 ≦ Φin ≦ 8.20, N By satisfying 6.52 ≦ Φin ≦ 7.90 when = 8, the weight of the double-channel heat exchanger can be reduced.

In this simulation, since the detection tube and the inner tube are handled as an integral tube, the presence of the detection tube does not affect the result of the simulation. The wall thickness of the detector tube is constant at 0.68 mm. However, when the detector tube does not exist, it is necessary to increase the wall thickness of the inner smooth tube in order to increase the corrosion resistance.

Next, the material of the outer tube was changed to polyphenylene sulfide (PPS) containing glass filler at a ratio of 30% by weight, and the same simulation as that obtained in Table 3 was performed. The results are shown in Table 7 and FIG. As in Table 3 and FIG. 5, the leftmost column in Table 7 and the leftmost mark in FIG. 8 correspond to reference examples.

As shown in Table 7 and FIG. 8, even when a resin outer tube is used, the heat exchanger is used under the conditions of Φin = 6.82 mm and 9 passes as in the case of using a copper outer tube. Weight is minimized. The graph of FIG. 8 showed the same tendency as the graph of FIG. This means that the conclusion derived with respect to the heat exchanger using the copper outer tube (see FIG. 7) also applies to the heat exchanger using the resin outer tube.

The heat exchanger of the present invention can be used for devices such as a heat pump type hot water heater and a hot water heater.

Claims

A heat exchanger for exchanging heat between the first fluid and the second fluid,
A plurality of heat exchange segments each having a first flow path and a second flow path;
A first header provided at one end of the plurality of heat exchange segments to guide the first fluid to the first flow path and collect the second fluid from the second flow path;
A second header provided at the other end of the plurality of heat exchange segments so as to collect the first fluid from the first flow path and guide the second fluid to the second flow path;
With
The heat exchange segment includes (i) two inner pipes each having the first flow path, and an inner pipe assembly formed by twisting the two inner pipes in a spiral shape; and (ii) It is constituted by an exterior body that houses the inner pipe assembly so that the second flow path is formed between the inner peripheral surface of the inner pipe and the outer peripheral surface of the inner pipe assembly.
The number of paths N representing the number of the heat exchange segments arranged between the first header and the second header is 4 to 8,
The gap G expressed by the difference between the half of the inner diameter Φin of the outer body and the outer diameter Φout of the inner tube ((Φin / 2) −Φout) is 0 <G ≦ 0.8 (unit: mm) The filling,
A heat exchanger in which the number of passes N and the inner diameter Φin (unit: mm) of the exterior body satisfy any of the following relationships (1) to (5).
(1) N = 4, 8.20 ≦ Φin ≦ 9.50
(2) N = 5 and 7.58 ≦ Φin ≦ 8.90
(3) N = 6 and 7.14 ≦ Φin ≦ 8.50
(4) N = 7 and 6.78 ≦ Φin ≦ 8.20
(5) N = 8, 6.52 ≦ Φin ≦ 7.90
The heat exchanger according to claim 1, wherein the gap width G satisfies 0.16 ≦ G ≦ 0.8.
The heat exchanger according to claim 1, wherein each of the inner tube and the outer body is made of a copper tube.
The heat exchanger according to claim 1, wherein the inner tube is made of a copper tube, and the exterior body is made of a resin.
The heat exchanger according to claim 1, wherein the inner tube is a leak detection tube composed of an inner surface smooth tube and an inner grooved tube provided outside the inner surface smooth tube.
The heat exchanger according to claim 1, wherein the first fluid is carbon dioxide and the second fluid is water.
A compressor for compressing the refrigerant;
A heat radiator configured to cool the compressed refrigerant composed of the heat exchanger according to claim 1;
An expansion mechanism for expanding the cooled refrigerant;
An evaporator for evaporating the expanded refrigerant;
A water circuit for circulating water through the radiator;
With a heat pump.