WO2022137755A1 - Heat exchanger - Google Patents

Abstract

This heat exchanger comprises: piping that forms a flow path through which a first fluid is supplied; a pair of partition plates provided with a gap therebetween in the extension direction of the flow path so as to block the flow path, whereby the partition plates demarcate and form a closed space in part of the flow path; a plurality of heat transfer pipes that are formed in tubular shapes of which both ends are open, that extend so as to pass through the pair of partition plates, and that are provided in parallel with gaps therebetween; a supply unit that is capable of supplying a second fluid into the closed space from outside of the piping; and a discharge unit that is capable of discharging the second fluid in the closed space out of the piping.

Description

Heat exchanger

The present disclosure relates to heat exchangers.
The present application claims priority with respect to Japanese Patent Application No. 2020-214438 filed in Japan on December 24, 2020, the contents of which are incorporated herein by reference.

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

Conventionally, a heat exchanger has generally been configured to have a plurality of heat transfer tubes and fins provided in each heat transfer tube. In this type of heat exchanger, a heat medium is circulated inside the heat transfer tube, and another medium is circulated outside the heat transfer tube. As a result, heat exchange is performed between the two media via the fins.

Japanese Unexamined Patent Publication No. 2010-223520

By the way, in recent years, there has been a demand for miniaturization of various devices including the above-mentioned heat engine. 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 further miniaturized heat exchanger.

In order to solve the above problems, the heat exchanger according to the present disclosure has a space between the pipe forming the flow path to which the first fluid is supplied and the flow path in the extending direction so as to block the flow path. By providing a pair of partitions, a partition plate that forms a closed space in a part of the flow path and a tubular shape that opens at both ends are formed so as to extend through the pair of partition plates and are spaced from each other. A plurality of heat transfer tubes arranged side by side, a supply unit capable of supplying a second fluid into the closed space from the outside of the pipe, and the second fluid in the closed space to the outside of the pipe. It is equipped with a discharge unit that can discharge.

According to the present disclosure, it is possible to provide a heat exchanger that is further miniaturized.

It is sectional drawing which shows the structure of the heat exchanger which concerns on 1st Embodiment of this disclosure. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. It is sectional drawing which shows the structure of the heat exchanger which concerns on 2nd Embodiment of this disclosure. It is sectional drawing in the VV line of FIG. It is sectional drawing in the VI-VI line of FIG. It is sectional drawing which shows the structure of the heat transfer tube which concerns on 3rd Embodiment of this disclosure. It is sectional drawing which shows the structure of the heat exchanger which concerns on 4th Embodiment of this disclosure. It is sectional drawing in the IX-IX line of FIG. It is an enlarged sectional view of the heat transfer tube which concerns on 5th Embodiment of this disclosure. It is an enlarged sectional view which shows the modification of the heat transfer tube which concerns on 5th Embodiment of this disclosure. It is a perspective view which shows the modification of the heat transfer tube which concerns on 5th Embodiment of this disclosure.

[First Embodiment]
(Construction of heat exchanger)
Hereinafter, the heat exchanger 100 according to the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the heat exchanger 100 is provided at an intermediate position of the pipe 1. The pipe 1 forms a flow path through which exhaust gas (first fluid) discharged from a heat engine such as an engine flows. In the example of FIG. 1, the pipe 1 has a straight tubular pipe main body 11 and elbow portions 10 provided at both ends of the pipe main body 11. The elbow portion 10 forms a curved portion, and a plurality of vanes 4 for guiding the flow direction of the exhaust gas according to the curved portion are provided inside the elbow portion 10. Each vane 4 is curved along the curve of the elbow portion 10. A plurality of such vanes 4 are provided at intervals in a direction intersecting the extending direction of the elbow portion 10.

Inside the piping main body 11, a plurality of heat transfer tubes 3 are arranged side by side at intervals from each other. The above exhaust gas circulates inside the heat transfer tube 3. As shown in FIG. 2, the heat transfer tube 3 is a tube having a hexagonal cross-sectional shape, and both ends thereof are open. The inside of the heat transfer tube 3 is the first flow path F1. Further, the plurality of heat transfer tubes 3 are adjacent to each other so that their outer surfaces are parallel to each other, and are arranged so as to have a hexagonal shape as a whole. The space formed between the heat transfer tubes 3 is a second flow path F2 through which water as a second fluid flows.

A supply unit 21 as an inlet side header and a discharge unit 22 as an outlet side header are provided at both ends of the piping main body 11. The supply unit 21 supplies water guided from the outside into the pipe 1, and the discharge unit 22 is provided to discharge the water that has passed through the pipe 1 to the outside. More specifically, the discharge unit 22 is provided at the end of the pipe 1 on the upstream side (the side where the first fluid flows), and the supply unit 21 is provided at the end on the downstream side. The supply unit 21 and the discharge unit 22 have the same configuration as each other except for the flow direction of the fluid. Therefore, here, the configuration of the discharge unit 22 will be typically described with reference to FIG.

As shown in FIG. 3, the discharge unit 22 includes a cylindrical discharge unit main body 22H that covers the ends of the plurality of heat transfer tubes 3 from the outside, and a partition plate 20 that closes the opening of the discharge unit main body 22H. Have. An opening H for discharging water to the outside is formed in a part of the discharge portion main body 22H in the circumferential direction. The flow path formed by the piping main body 11 is blocked from both sides by the partition plate 20 of the discharge unit 22 and the partition plate 20 of the supply unit 21. The space partitioned by the pair of partition plates 20 is a closed space V. Further, 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 the gap between the heat transfer tubes 3 extend in parallel.

It is desirable that each component of the heat exchanger 100 having the above configuration is formed by a 3D printer technique typified by AM (Additive Modeling). Further, as a material for forming the heat exchanger 100, titanium or SUS is preferably used.

(Action effect)
Next, the operation of the heat exchanger 100 will be described. In operating the heat exchanger 100, first, water as a second fluid is supplied into the closed space V through the supply unit 21. At this time, since the heat engine is operated, high-temperature exhaust gas as the first fluid is circulated in the heat transfer tube 3. Further, water flows through the gap (second flow path F2) between the heat transfer tubes 3 inside the pipe main body 11 in the direction opposite to the direction in which the exhaust gas flows. While water is flowing through the second flow path F2, heat exchange occurs with the exhaust gas via the wall surface of the heat transfer tube 3. As a result, the water becomes hot and is supplied to an external device via the discharge unit 22. On the other hand, the exhaust gas becomes a low temperature state and flows away in the pipe 1 toward the downstream side. When such a phenomenon occurs continuously, heat exchange between water and exhaust gas is performed.

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. In this closed space V, heat exchange is performed between the first fluid flowing through the heat transfer tube 3 and the second fluid flowing outside the heat transfer tube 3. As described above, according to the above configuration, the heat exchanger 100 can be provided in the middle of the extension of the pipe 1 without changing the extending direction of the pipe 1 and without greatly expanding the outer diameter of the pipe 1. .. This makes it possible to save space for arranging the heat exchanger 100. As a result, the heat exchanger 100 can be easily installed even in a narrow area where it was difficult to install in the past.

Further, according to the above configuration, the heat transfer tube 3 has a polygonal (hexagonal) cross-sectional shape. Therefore, as compared with the case where the heat transfer tube 3 has a quadrangular cross section, for example, the wet spot area on the inner surface of the heat transfer tube 3 is expanded, so that the efficiency of heat exchange can be further improved. Further, more preferably, the wet spot area can be further expanded by making the cross-sectional shape of the heat transfer tube 3 circular. If the cross-sectional shape is circular, there is a demerit that the filling density of the fluid decreases, so it is desirable to determine the shape of the heat transfer tube according to the overall balance.

Further, according to the above configuration, since water as a second fluid flows at a distance between the heat transfer tubes 3, a large contact area with the heat transfer tubes 3 can be secured. This makes it possible to further improve the efficiency of heat exchange while reducing the size of the heat exchanger 100.

The first embodiment of the present disclosure has been described above. It is possible to make various changes and modifications to the above configuration as long as it does not deviate from the gist of the present disclosure.

[Second Embodiment]
Next, the second embodiment of the present disclosure will be described with reference to FIGS. 4 to 6. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 4, in the present embodiment, a closing portion 5 that closes only a part of the space between the heat transfer tubes 3 is further provided. A plurality of closed portions 5 are provided at intervals in the extending direction of the piping main body 11. Further, the areas to be closed are different between the closed portions 5 adjacent to each other. More specifically, of the adjacent closing portions 5, the closing portion 5 on one side closes only the upper portion in the piping main body 11 as shown in FIG. As shown in FIG. 6, the closing portion 5 on the other side closes only the lower portion in the piping main body 11. By arranging such closing portions 5 alternately, the second flow path F2 in the piping main body 11 extends in a meandering manner. That is, the closed portion 5 functions as a baffle plate.

According to the above configuration, the water flow direction changes in the closed space V due to the closed portion 5. Since the areas to be closed are different between the adjacent closing portions 5, the water flows in a meandering manner while passing through the plurality of closing portions 5. As a result, the water is evenly distributed in the closed space V, so that the contact area between the water and the heat transfer tube 3 is expanded, and the efficiency of heat exchange between the water and the exhaust gas can be further improved.

The second embodiment of the present disclosure has been described above. It is possible to make various changes and modifications to the above configuration as long as it does not deviate from the gist of the present disclosure. For example, in the second embodiment, an example in which the closed portion 5 closes the upper part or the lower part in the closed space V has been described. However, the mode of the closed portion 5 is not limited to this, and it is possible to adopt a configuration in which the closed portion 5 closes the left side and the right side of the pipe 1 in the extending direction, respectively. In this case, since water can flow smoothly while meandering in the horizontal direction without resisting gravity, the efficiency of heat exchange can be further improved. In particular, this configuration is suitable when the fluid contains a component having a low density and is expected to stay in the middle of the flow path.

[Third Embodiment]
Subsequently, the third embodiment of the present disclosure will be described with reference to FIG. 7. The same components as those of the above embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 7, in the present embodiment, the support portion 6 is provided between the heat transfer tubes 3 adjacent to each other. The support portion 6 connects the outer surfaces of the heat transfer tubes 3 to each other. Further, although not shown in detail, the support portion 6 is provided in a part of the heat transfer tube 3 in the extending direction.

According to the above configuration, the support portion 6 can suppress the displacement and deformation of the heat transfer tube 3. This makes it possible to operate the heat exchanger 100 stably for a longer period of time.

The third embodiment of the present disclosure has been described above. It is possible to make various changes and modifications to the above configuration as long as it does not deviate from the gist of the present disclosure. For example, it is possible to form a through hole in the support portion 6 and allow the fluid to flow through the through hole. In this case, it is possible to prevent the support portion 6 from obstructing the flow of the fluid.

[Fourth Embodiment]
Next, a fourth embodiment of the present disclosure will be described with reference to FIGS. 8 and 9. The same components as those of the above embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 9, in the present embodiment, the heat transfer tube 3 in the region where the flow rate is small among the plurality of heat transfer tubes 3 is configured so that the cross-sectional area of the flow path becomes larger. Specifically, when the elbow portion 10 of the pipe 1 is curved in the vertical direction, the cross-sectional area of the flow path is larger as the heat transfer tube 3A is located above, and the flow path is interrupted as the heat transfer tube 3B is located below. The area becomes smaller.

For example, when a bent portion such as an elbow portion 10 is configured on the upstream side of the pipe 1, the flow rate of the exhaust gas tends to increase toward the outer peripheral side of the bent portion and decrease toward the inner peripheral side due to inertial force. be. According to the above configuration, the heat transfer tube 3 in the region where the flow rate is small has a larger cross-sectional area of the flow path. As a result, even when the flow rate distribution is non-uniform as described above, it is possible to correct this and allow the exhaust gas to flow uniformly over the entire plurality of heat transfer tubes 3. 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. It is possible to make various changes and modifications to the above configuration as long as it does not deviate from the gist of the present disclosure.

[Fifth Embodiment]
Subsequently, the fifth embodiment of the present disclosure will be described with reference to FIG. The same components as those of the above embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 10, in the present embodiment, a plurality of fins 3F are further provided on the inner surface of the heat transfer tube 3. The fins 3F project from the inner surface of the heat transfer tube 3 toward the inner peripheral side, and extend over the entire extending direction of the heat transfer tube 3. A plurality of such fins 3F are arranged at intervals along the inner surface. Further, 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 the hexagon forming the cross section of the heat transfer tube 3 is 6 mm as an example, it is desirable that the protruding height of the fin 3F is about 2 mm and the width is about 1 mm.

According to the above configuration, since the contact area between the exhaust gas and the heat transfer tube 3 is expanded by providing the fin 3F, the efficiency of heat exchange can be further improved. Further, since the fin 3F has a minute size as described above, it is difficult for dust and 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 for a longer period of time.

The fifth embodiment of the present disclosure has been described above. It is possible to make various changes and modifications to the above configuration as long as it does not deviate from the gist of the present disclosure.

For example, in the fifth embodiment described above, an example in which the fin 3F extends linearly has been described. However, as shown in FIGS. 11 and 12, the fin 3F'may extend so as to swivel along the inner surface from the upstream side to the downstream side in the extending direction of the heat transfer tube 3. In FIGS. 11 and 12, the tip A1 and the base end A2 of the fin 3F'extend so as to swivel from one side in the circumferential direction toward the other side about the central axis of the heat transfer tube 3. Similar to the fifth embodiment, it is possible to adopt a configuration in which a plurality of such fins 3F'are arranged at intervals along the inner surface.

According to the above configuration, since the fin 3F'extends so as to swirl along the inner surface, a swirling flow component is added to the flow of the exhaust gas inside the heat transfer tube 3. As a result, the residence time of the exhaust gas inside the heat transfer tube 3 becomes long, so that the efficiency of heat exchange can be further improved. Further, since it is accompanied by a swirling flow component, it is possible to suppress the generation of deposits such as dust and soot on the fin 3F'. This makes it possible to operate the heat exchanger 100 stably for a longer period of time.

[Additional Notes]
The heat exchanger 100 described in each embodiment is grasped as follows, for example.

(1) The heat exchanger 100 according to the first aspect is spaced from the pipe 1 forming the flow path to which the first fluid is supplied in the extending direction of the flow path so as to block the flow path. By providing the pair, the partition plate 20 that partitions the closed space V in a part of the flow path and the partition plate 20 that forms a tubular shape with both ends open and extends so as to penetrate the pair of partition plates 20 and each other. A plurality of heat transfer tubes 3 arranged side by side at intervals, a supply unit 21 capable of supplying a second fluid into the closed space V from the outside of the pipe 1, and the second in the closed space V. A discharge unit 22 capable of discharging the fluid to the outside of the pipe 1 is provided.

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. In this closed space V, heat exchange is performed between the first fluid flowing through the heat transfer tube 3 and the second fluid flowing outside the heat transfer tube 3. As described above, according to the above configuration, the heat exchanger 100 can be provided in the middle of the extension of the pipe 1 without changing the extending direction of the pipe 1 and without greatly expanding the outer diameter of the pipe 1. can. This makes it possible to save space for arranging the heat exchanger 100.

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

According to the above configuration, the wet spot area on the inner surface of the heat transfer tube 3 is expanded, so that the efficiency of heat exchange can be further improved.

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

According to the above configuration, since the second fluid flows through the space between the heat transfer tubes 3, a large contact area with the heat transfer tubes 3 can be secured. This makes it possible to further improve the efficiency of heat exchange while reducing the size of the heat exchanger 100.

(4) The heat exchanger 100 according to the fourth aspect further has a closing portion 5 that closes only a part of the space between the heat transfer tubes 3, and the closing portion 5 is in the extending direction. A plurality of closed portions 5 are provided at intervals, and the closed regions may be different between the closed portions 5 adjacent to each other.

According to the above configuration, the flow direction of the second fluid changes in the closed space V due to the closed portion 5. Since the regions to be closed are different between the adjacent closing portions 5, the second fluid flows in a meandering manner while passing through the plurality of closing portions 5. As a result, the second fluid is evenly distributed in the closed space V, so that the efficiency of heat exchange can be further improved.

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

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

(6) In the heat exchanger 100 according to the sixth aspect, among the plurality of heat transfer tubes 3, the heat transfer tube 3 in the region where the flow rate is small may be configured so that the cross-sectional area of the flow path becomes larger.

For example, when a bent portion or the like is configured on the upstream side of the pipe 1, the flow rate of the first fluid tends to increase toward the outer peripheral side of the bent portion due to inertial force, and decrease toward the inner peripheral side. According to the above configuration, the heat transfer tube 3 in the region where the flow rate is small has a larger cross-sectional area of the flow path. As a result, even when the flow rate distribution is non-uniform as described above, this can be corrected and the first fluid can be uniformly flowed over the entire plurality of heat transfer tubes 3.

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

According to the above configuration, since the contact area with the first fluid is expanded by the fin 3F, the efficiency of heat exchange can be further improved.

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

According to the above configuration, since the fin 3F'extends so as to swirl along the inner surface, a swirling flow component is added to the first fluid inside the heat transfer tube 3. As a result, the residence time of the first fluid inside the heat transfer tube 3 becomes long, so that the efficiency of heat exchange can be further improved. Further, since it is accompanied by a swirling flow component, it is possible to suppress the generation of deposits such as dust on the fin 3F'.

According to the present disclosure, it is possible to provide a heat exchanger that is further miniaturized.

100 Heat exchanger 1 Piping 3,3A, 3B Heat transfer tube 3F, 3F'Fin 4 Vane 5 Closure part 6 Support part 10 Elbow part 11 Piping body 20 Partition plate 21 Supply part 22 Discharge part 22H Discharge part body F1 First flow path F2 Second flow path H Opening V Closed space

Claims (8)

The piping that forms the flow path to which the first fluid is supplied,
A partition plate that partitions a closed space in a part of the flow path by providing a pair at intervals in the extending direction of the flow path so as to block the flow path.
A plurality of heat transfer tubes having a tubular shape with both ends open and extending so as to penetrate the pair of partition plates, and a plurality of heat transfer tubes arranged side by side at intervals from each other.
A supply unit capable of supplying the second fluid from the outside of the pipe into the closed space,
A discharge portion capable of discharging the second fluid in the closed space to the outside of the pipe, and a discharge portion.
A heat exchanger equipped with. The heat exchanger according to claim 1, wherein the heat transfer tube has a polygonal cross-sectional shape when viewed from the extending direction. The heat exchanger according to claim 1 or 2, wherein the second fluid is configured to circulate between the plurality of heat transfer tubes in the closed space. Further, it has a closed portion that closes only a part of the space between the heat transfer tubes.
The heat exchanger according to any one of claims 1 to 3, wherein a plurality of the closed portions are provided at intervals in the extending direction, and the closed regions are different between the closed portions adjacent to each other. .. The heat exchanger according to any one of claims 1 to 4, further comprising a support portion provided between the heat transfer tubes. The heat exchanger according to any one of claims 1 to 5, which is configured such that the cross-sectional area of the flow path becomes larger as the flow rate becomes smaller in the region of the plurality of heat transfer tubes. The heat exchanger according to any one of claims 1 to 6, which protrudes from the inner surface of the heat transfer tube, extends in the extending direction, and further has a plurality of fins provided at intervals along the inner surface. The heat exchanger according to claim 7, wherein the fin extends so as to swivel along the inner surface from the upstream side to the downstream side in the extending direction.

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