DE112021003218T5 - heat exchanger - Google Patents

Abstract

A heat exchanger includes: a tube forming a flow path through which a first fluid is supplied; a pair of partition plates provided at an interval in an extending direction of the flow path to block the flow path to partition a closed space in a portion of the flow path; a plurality of heat transfer tubes having a tubular shape with both ends open, extending to penetrate the pair of partition plates, and arranged side by side with spaces therebetween; a supply part configured to supply a second fluid from an outside of the tube into the closed space; and an outlet part configured to discharge the second fluid in the closed space to the outside of the pipe.

Description

[Technical Field]

The present disclosure relates to a heat exchanger.
Priority will be for the Japanese Patent Application No. 2020-214438 filed December 24, 2020, the contents of which are incorporated herein by reference.

[State of the art]

In a heat engine including an internal combustion engine and an external internal combustion engine, thermal energy is generated by burning fuels, and the thermal energy is taken out as rotational energy of an output shaft, for example. At this time, high-temperature exhaust gas is generated in the heat engine. As a measure for effectively using the thermal energy of the exhaust gas, it is conceivable to install a heat exchanger in an exhaust gas flow path.

Conventionally, a heat exchanger consists of a plurality of heat transfer tubes and a fin provided in each heat transfer tube. In this type of heat exchanger, one heat medium flows inside the heat exchanger tube and the other medium flows outside the heat exchanger tube. The heat transfer between the two media therefore takes place via the fin.

[citation list]

[patent document]

[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2010-223520

[Summary of the Invention]

[Technical problem]

In recent years, there has been a demand for downsizing of various devices including the heat engine described above. Therefore, it is necessary to significantly reduce the size of the heat exchanger.

The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide a heat exchanger with a smaller size.

[The solution of the problem]

In order to solve the problems, a heat exchanger according to the present disclosure includes: a tube forming a flow path through which a first fluid is supplied; a pair of partition plates provided at an interval in an extending direction of the flow path to block the flow path to partition a closed space in a portion of the flow path; a plurality of heat transfer tubes having a tubular shape with both ends open, extending to penetrate the pair of partition plates, and arranged side by side with spaces therebetween; a supply part configured to supply a second fluid from an outside of the tube into the closed space; and an outlet part configured to discharge the second fluid in the closed space to the outside of the tube.

[Advantageous Effects of the Invention]

According to the present disclosure, it is possible to provide a heat exchanger with a smaller size.

character list

• 1 12 is a cross-sectional view showing a configuration of a heat exchanger according to a first embodiment of the present disclosure.
• 2 is a cross-sectional view taken along line II-II in FIG 1 .
• 3 is a cross-sectional view taken along line III-III in FIG 1 .
• 4 12 is a cross-sectional view showing a configuration of a heat exchanger according to a second embodiment of the present disclosure.
• 5 is a cross-sectional view taken along line VV in FIG 4 .
• 6 is a cross-sectional view taken along line VI-VI in FIG 4 .
• 7 13 is a cross-sectional view showing a configuration of a heat transfer tube according to a third embodiment of the present disclosure.
• 8th 14 is a cross-sectional view showing a configuration of a heat exchanger according to a fourth embodiment of the present disclosure.
• 9 is a cross-sectional view taken along the line IX-IX in 8th .
• 10 14 is an enlarged cross-sectional view of a heat transfer tube according to a fifth embodiment of the present disclosure.
• 11 14 is an enlarged cross-sectional view showing a modified example of the heat transfer tube according to the fifth embodiment of the present disclosure.
• 12 14 is a perspective view showing the modified example of the heat transfer tube according to the fifth embodiment of the present disclosure.

[Description of the Embodiments]

[First embodiment]

(configuration of the heat exchanger)

A heat exchanger 100 according to a first embodiment of the present disclosure is described below with reference to FIG 1 until 3 described. As in 1 shown, the heat exchanger 100 is arranged in the middle of a tube 1 . The pipe 1 forms a flow path through which the exhaust gas (first fluid) discharged from a heat engine such as an engine flows. In an example from 1 the pipe 1 comprises a straight tubular pipe body 11 and angle pieces 10 provided at both end portions of the pipe body 11, respectively. The angle part 10 forms a curved portion, and an inside of the angle part 10 is provided with a plurality of vanes 4 to guide a flow direction of the exhaust gas to the curved portion. Each blade 4 is curved along a curve of the angle part 10 . The plurality of vanes 4 are provided at an interval in a direction intersecting an extending direction of the angle part 10 .

Inside the tube body 11, a plurality of heat transfer tubes 3 are arranged side by side with spaces therebetween. The exhaust gas flows inside the heat transfer tubes 3. As in 2 As shown, the heat transfer tube 3 is a tube having a hexagonal cross section, and both ends of the heat transfer tube 3 are open. The inside of the heat transfer tube 3 is a first flow path F1. In addition, the plurality of heat transfer tubes 3 are juxtaposed so that their outer surfaces are parallel to each other and arranged so as to form a hexagonal shape as a whole. A space formed between the heat transfer tubes 3 is a second flow path F2 through which water as the second fluid flows.

At both end portions of the pipe body 11, a supply part 21 as an inlet-side header and an outlet part 22 as an outlet-side header are provided. The supply part 21 is for supplying water introduced into the tube 1 from the outside, and the outlet part 22 is for discharging the water flowing through the tube 1 to the outside. More specifically, the outlet part 22 is provided at an end portion on an upstream side (a side where the first fluid flows) of the tube 1 , and the supply part 21 is provided at an end portion on a downstream side of the tube 1 . The supply part 21 and the outlet part 22 have the same configuration as the other except for the flow direction of the fluid. Therefore, a configuration of the outlet part 22 is typically described herein with reference to FIG 3 described.

As in 3 1, the outlet part 22 includes a cylindrical outlet part body 22H that covers the end portions of the plurality of heat transfer tubes 3 from the outside, and a partition plate 20 that blocks an opening of the outlet part body 22H. A hole H for discharging water to the outside is formed in a portion of the outlet body part 22H in the circumferential direction. The flow path formed by the tubular body 11 is blocked by the partition plate 20 of the outlet part 22 and the partition plate 20 of the feed part 21 from both sides. A space partitioned by a pair of partition plates 20 is a closed space V. In addition, the heat transfer tube 3 extends so as to penetrate the partition plate 20 . That is, in the closed space V, the first flow path F1 formed by the heat transfer tube 3 and the second flow path F2 formed by a gap between the heat transfer tubes 3 are parallel to each other.

Each component of the heat exchanger 100 having the configuration described above is formed by a 3D printing technique represented by additive modeling (AM), which is advantageous. Furthermore, titanium or SUS is preferably used as the material for forming the heat exchanger 100 .

(Effect)

Next, an operation of the heat exchanger 100 will be described. When the heat exchanger 100 is in operation, water is first introduced as the second fluid through the feed part 21 into the closed space V. At this time, the heat engine is operated so that the high-temperature off-gas flows into the heat transfer tube 3 as the first fluid. In addition, the water flows inside the pipe body 11 in a direction opposite to the flow direction of the exhaust gas through the gap (second flow path F2) between the heat transfer tubes 3. While the water flows through the second flow path F2, heat transfer occurs with the exhaust gas through a wall surface of the heat transfer tube 3. As a result, the temperature of the water becomes high, and the water is discharged to an external device via the outlet part 22 . On the other hand, the temperature of the exhaust gas becomes low, and the exhaust gas flows out toward the downstream side of the pipe 1 . Since such a phenomenon constantly occurs, heat exchange takes place between water and exhaust gas.

According to the above configuration, the closed space V is formed by the partition plate 20 in the middle of the extension of the pipe 1. The heat transfer occurs between the first fluid flowing through the heat transfer tube 3 and the second fluid flowing outside the heat transfer tube 3 in the closed space V . As described above, according to the above configuration, the heat exchanger 100 can be provided in the middle of the extension of the tube 1 without changing the extending direction of the tube 1 and without greatly increasing the outer diameter of the tube 1 . Accordingly, it is possible to accommodate the heat exchanger 100 in a space-saving manner. As a result, the heat exchanger 100 can be easily provided even in a narrow area where the heat exchanger 100 in the related art is difficult to be provided.

Moreover, according to the above configuration, the heat transfer tube 3 has a cross section of a polygonal (hexagonal) shape. Therefore, it is possible to further improve heat transfer efficiency since the wetted area of an inner surface of the heat transfer tube 3 is increased compared to a case where the heat transfer tube 3 has a quadrangular cross section. In addition, it is preferably possible to further increase the wetted area when the cross section of the heat transfer tube 3 has a circular shape. When the cross section is circular, there is a disadvantage of lower filling density of the fluid, and therefore it is advantageous to determine the shape of the heat transfer tube according to the overall balance.

Since the water flows into the space between the heat transfer tubes 3 as the second fluid, it is possible to ensure a large contact area with the heat transfer tube 3 . This makes it possible to further improve the heat transfer efficiency while reducing the size of the heat exchanger 100 .

The first embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure.

(Second embodiment)

A second embodiment of the present disclosure will be described below with reference to FIG 4 until 6 described. Components similar to those of the first embodiment are given the same reference numerals and repeated description is not given. As in 4 1, in the present embodiment, a blocking part 5 that blocks only part of the gap between the heat transfer tubes 3 is further provided. A plurality of the blocking parts 5 are provided at an interval in an extending direction of the tubular body 11 . In addition, the blocking parts 5 adjacent to each other have different areas to be blocked. More specifically, a blocking part 5 of adjacent blocking parts 5 blocks only an upper portion in the tubular body 11 as shown in FIG 5 shown. As in 6 shown, the other blocking part 5 blocks only a lower section in the tubular body 11. Due to the alternating arrangement of such blocking parts 5, the second flow path F2 in the tubular body 11 runs in a meandering manner. That is, the blocking part 5 functions as a baffle.

According to the above configuration, the blocking part 5 changes the flow direction of the water in the closed space V. Since the areas blocked by the adjacent blocking parts 5 are different, the water flows meanderingly while flowing through the plurality of blocking parts 5 . Since the water is evenly distributed in the closed space V, the contact area between the water and the heat transfer tube 3 is increased, so that the heat transfer efficiency between the water and the exhaust gas can be further improved.

The second embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure. For example, in the second embodiment, an example in which the blocking member 5 blocks the upper or lower portion in the closed space V has been described. However, the kind of the blocking part 5 is not limited to this, and it is possible to adopt a configuration in which the blocking part 5 blocks the left and right sides of the pipe 1 in the direction of extension of the pipe 1 . In this case, the water can be frictional flow while meandering in a horizontal direction without gravity, so that the heat transfer efficiency can be further improved. This configuration is particularly useful when the fluid is expected to contain a low-density component and remain in the middle of the flow path.

[Third Embodiment]

A third embodiment of the present disclosure will be described below with reference to FIG 7 described. Components similar to those of the above-described embodiments are given the same reference numerals and repeated description is not given. As in 7 1, a support member 6 is provided between the adjacent heat transfer tubes 3 in the present embodiment. The support part 6 connects the outer surfaces of the heat transfer tubes 3 to each other. In addition, the support member 6 is provided on a portion of the heat transfer tube 3 in the extending direction, although not illustrated in detail.

According to the above configuration, the support member 6 can prevent the heat transfer tube 3 from being displaced and deformed. As a result, the heat exchanger 100 can be operated stably over a longer period of time.

The third embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure. For example, a configuration can be adopted in which a through hole is formed in the support part 6 and the fluid flows through the through hole. In this case, the support member 6 can suppress obstruction of the fluid flow.

[Fourth embodiment]

Next, a fourth embodiment of the present disclosure will be described with reference to FIG 8th and 9 described. Components similar to those of the above-described embodiments are given the same reference numerals and repeated description is not given. As in 9 1, in the present embodiment, the plurality of heat transfer tubes 3 are configured such that the heat transfer tube 3 located in a region with a lower flow rate has a larger flow path cross-sectional area. In particular, in a case where the angle part 10 of the tube 1 is curved vertically, a heat transfer tube 3A has a larger flow path cross-sectional area when positioned upward, and a heat transfer tube 3B has a smaller flow path cross-sectional area when positioned downward is.

In a case where the tube 1 has a curved portion such as the elbow 10 on the upstream side of the tube 1, the flow rate of the exhaust gas tends to be larger due to the inertial force when the heat transfer tube 3 is toward an outer peripheral side of the curved portion is directed, and the flow rate tends to be smaller when the heat transfer tube 3 is directed to an inner peripheral side of the curved portion. According to the above configuration, the heat transfer tube 3 has a larger flow path cross-sectional area when it is arranged in the region with a smaller flow rate. Therefore, it is possible to correct the configuration and evenly flow the exhaust gas over all of the plurality of heat transfer tubes 3 even if the flow velocity is unevenly distributed as described above. As a result, the efficiency of the heat exchanger 100 can be further improved.

The fourth embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure.

[Fifth Embodiment]

A fifth embodiment of the present disclosure will be described below with reference to FIG 10 described. Components similar to those of the above-described embodiments are given the same reference numerals and repeated description is not given. As in 10 1, a plurality of fins 3F are provided on the inner surface of the heat transfer tube 3 in the present embodiment. The fins 3F protrude from the inner surface toward the inner peripheral side of the heat transfer tube 3 and extend over the entire area of the heat transfer tube 3 in the extending direction. The plurality of such ribs 3F are spaced along the inner surface. Also, in the present embodiment, the fin 3F extends linearly in the extending direction of the heat transfer tube 3. When the length of one side of a hexagon forming the cross section of the heat transfer tube 3 is 6 mm, for example, it is preferable that the protruding height of the fin 3F about 2 mm and the width of the rib 3F is about 1 mm.

According to the above configuration, since the contact area between the exhaust gas and the heat transfer tube 3 is increased by the inclusion of the fins 3F, the heat transfer efficiency can be further improved. In addition, since the fins 3F have a minute dimension as described above, it is difficult for dust or soot contained in the exhaust gas flowing in the heat transfer tube 3 to accumulate. As a result, the heat exchanger 100 can be operated stably over a longer period of time.

The fifth embodiment of the present disclosure has been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure.

For example, an example of the linearly extending rib 3F in the fifth embodiment has been described. As in the 11 and 12 However, as shown, a fin 3F' may extend so as to turn along the inner surface from the upstream side to the downstream side of the heat transfer tube 3 in the direction of extension. In the 11 and 12 a tip A1 and a base end A2 of the fin 3F' extend so as to rotate around the central axis of the heat transfer tube 3 from one side of the heat transfer tube 3 in the circumferential direction to the other side. Similar to the fifth embodiment, a configuration may be adopted in which a plurality of such ribs 3F' are arranged at an interval along the inner surface.

According to the above configuration, since the fin 3F' extends to rotate along the inner surface, a rotating flow component is added to the flow of exhaust gas inside the heat transfer tube 3 . This increases the residence time of the exhaust gas in the heat transfer tube 3, so that the heat transfer efficiency can be further improved. In addition, since the exhaust gas accompanies the rotating flow component, it is possible to prevent the formation of deposits such as dust and soot on the fin 3F'. As a result, the heat exchanger 100 can be operated stably over a longer period of time.

[Attachment]

The heat exchanger 100 described in each embodiment is constructed as follows, for example.

(1) A heat exchanger 100 according to a first aspect comprises: a tube 1 forming a flow path through which a first fluid is supplied; a pair of partition plates 20 provided at an interval in an extending direction of the flow path to block the flow path to partition a closed space V in a portion of the flow path; a plurality of heat transfer tubes 3 having a tubular shape with both ends open, extending to penetrate the pair of partition plates 20 and arranged side by side with spaces therebetween; a supply part 21 arranged to supply a second fluid from an outside of the pipe 1 into the closed space V; and an outlet part 22 arranged to discharge the second fluid in the closed space V to the outside of the pipe 1.

According to the above configuration, the closed space V is formed by the partition plate 20 in the middle of the extension of the pipe 1. The heat transfer occurs between the first fluid flowing through the heat transfer tube 3 and the second fluid flowing outside the heat transfer tube 3 in the closed space V . As described above, according to the above configuration, the heat exchanger 100 can be provided in the middle of extending the tube 1 without changing the extending direction of the tube 1 and without greatly increasing an outer diameter of the tube 1 . Accordingly, it is possible to accommodate the heat exchanger 100 in a space-saving manner.

(2) In the heat exchanger 100 according to a second aspect, the heat transfer tube 3 may have a cross section of a polygonal shape when viewed in the extending direction.

According to the above configuration, since a wetted area in an inner surface of the heat transfer tube 3 is increased, it is possible to further improve heat transfer efficiency.

(3) In the heat exchanger 100 according to a third aspect, the second fluid may be configured to flow through the gap between the plurality of heat transfer tubes 3 in the closed space V.

According to the above configuration, since the second fluid flows into the space between the heat transfer tubes 3 , it is possible to ensure a large contact area with the heat transfer tube 3 . This makes it possible to further improve the heat transfer efficiency while reducing the size of the heat exchanger 100 .

(4) The heat exchanger 100 according to a fourth aspect may further comprise a blocking part 5 blocking only a part of the gap between the heat transfer tubes 3, wherein a plurality of the blocking parts 5 may be provided at an interval in the extending direction and the blocking parts 5 blocking each other are adjacent may have different blocking areas.

According to the above configuration, the blocking part 5 changes the flow direction of the second fluid in the closed space V. Since the areas blocked by the adjacent blocking parts 5 are different, the second fluid flows meanderingly while passing the plural blocking parts 5 . Since the second fluid is evenly distributed in the closed space V, the heat transfer efficiency can be further improved.

(5) The heat exchanger 100 according to a fifth aspect may further include a support member 6 provided between the heat transfer tubes 3 .

According to the above configuration, the support member 6 can suppress displacement and deformation of the heat transfer tube.

(6) In the heat exchanger 100 according to a sixth aspect, the plurality of heat transfer tubes 3 may be configured such that the heat transfer tube 3 arranged in a region with a smaller flow rate has a larger flow path cross-sectional area.

For example, in a case where the tube 1 has a curved portion on the upstream side of the tube 1, the flow rate of the first fluid tends to be larger when the heat transfer tube 3 is directed to an outer peripheral side of the curved portion due to the inertial force, and the Flow rate tends to be smaller when the heat transfer tube 3 is directed to an inner peripheral side of the curved portion. According to the above configuration, the heat transfer tube 3 has a larger flow path cross-sectional area when it is arranged in the region with a smaller flow rate. As a result, it is possible to correct the configuration and flow the first fluid evenly over all of the plurality of heat transfer tubes 3 even if the flow rate distribution is uneven as described above.

(7) The heat exchanger 100 according to a seventh aspect may further include a plurality of fins 3F that protrude from an inner surface of the heat transfer tube 3, extend in the extending direction, and are provided at an interval along the inner surface.

According to the above configuration, since a contact area with the first fluid is expanded by the fin 3F, it is possible to further improve heat transfer efficiency.

(8) In the heat exchanger 100 according to an eighth aspect, the fin 3F' may be extended so as to turn along the inner surface from an upstream side to a downstream side in the extending direction.

According to the above configuration, since the fin 3F' extends to rotate along the inner surface, a rotating flow component is added to the first fluid inside the heat transfer tube 3 . As a result, the residence time of the first fluid in the heat transfer tube 3 becomes long, so that the heat transfer efficiency can be further improved. In addition, since the exhaust gas accompanies the rotating flow component, it is possible to suppress the formation of deposits such as dust on the fin 3F'.

[Industrial Applicability]

According to the present disclosure, it is possible to provide a heat exchanger with a smaller size.

Reference List

100

heat exchanger

1

Pipe

3, 3A, 3B

heat transfer tube

3F, 3F'

rib

4

shovel

5

blocking part

6

support part

10

angle part

11

tubular body

20

partition plate

21

feeding part

22

outlet part

22H

outlet part body

F1

First flow path

F2

Second flow path

H

opening

V

Closed room

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• JP 2020214438 [0001]

Claims (8)

Heat exchanger comprising: a tube forming a flow path through which a first fluid is supplied; a pair of partition plates provided at an interval in an extending direction of the flow path to block the flow path to partition a closed space in a portion of the flow path; a plurality of heat transfer tubes having a tubular shape with both ends open, extending to penetrate the pair of partition plates, and arranged side by side with spaces therebetween; a supply part configured to supply a second fluid from an outside of the tube into the closed space; and an outlet part configured to discharge the second fluid in the closed space to the outside of the tube. heat exchanger claim 1 wherein the heat transfer tube has a cross section of a polygonal shape as viewed in the extending direction. heat exchanger claim 1 or 2 , wherein the second fluid is configured to flow into the closed space through the gap between the plurality of heat transfer tubes. Heat exchanger according to one of Claims 1 until 3 , further comprising: a blocking member that blocks only a portion of the gap between the heat transfer tubes, a plurality of the blocking members being provided at an interval in the extending direction, and the blocking members adjacent to each other having different blocking areas from each other. Heat exchanger according to one of Claims 1 until 4 , further comprising: a support member provided between the heat transfer tubes. Heat exchanger according to one of Claims 1 until 5 wherein the plurality of heat transfer tubes are configured such that the heat transfer tube located in a region with a smaller flow rate has a larger cross-sectional area of the flow path. Heat exchanger according to one of Claims 1 until 6 , further comprising: a plurality of fins protruding from an inner surface of the heat transfer tube, extending in the extending direction, and provided at an interval along the inner surface. heat exchanger claim 7 , wherein the rib extends to turn in the direction of extension along the inner surface from an upstream side to a downstream side.

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