JP2018109464A - Heat exchanger and vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger, a boiler, and a vessel which are improved in heat efficiency.SOLUTION: A heat exchanger 40 comprises a cylindrical casing 41 where working fluid flows inside from the upstream side to the downstream side, a plurality of heating tube blocks 43 which are respectively formed by laminating, along the flow direction, a plurality of heating tube layers 46 which is provided in the casing 41, the heating tube layers having respectively a plurality of heating tubes 47 arranged at an equivalent pitch P along the radial direction in the face perpendicular to the flow direction of the working fluid, the heating tube blocks being arranged at an interval along the flow direction, and downstream side guide parts 50 which are respectively provided in the downstream of the heating tube block 43, respectively protrude from an inner face S of the casing 41, and have respectively a first guide face 51 oriented to the upstream side.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat exchanger and a ship.

  There is an exhaust heat recovery device that includes a heat exchanger that performs heat exchange with exhaust gas and the like and recovers heat of the exhaust gas and the like. The exhaust heat recovery device is mounted on a power generation facility or a ship. The exhaust heat recovery apparatus includes a heat exchanger that performs heat exchange between exhaust gas and a heat medium (for example, water). The heat exchanger includes a plurality of heat transfer tubes in which a heat medium flows and a casing that covers the heat transfer tubes from the outside. The heat exchanger performs heat exchange between the exhaust gas and the heat medium via the heat transfer tube by being disposed in the flue through which the exhaust gas flows. In such a heat exchanger, foreign matter such as soot and lubricating oil contained in the exhaust gas may adhere to the surface of the heat transfer tube. Here, Patent Document 1 describes a heat exchanger including an exhaust heat recovery device having a heat transfer tube panel that recovers heat of a fluid flowing between a casing and a heat transfer tube and transmits the heat to the heat transfer tube.

Japanese Patent No. 5514690

  Here, in the heat exchanger composed of a plurality of heat transfer tubes, a gap is formed between the heat transfer tubes and the casing. The flow resistance to the exhaust gas in this gap is smaller than the flow resistance in the region between the plurality of heat transfer tubes. For this reason, when the exhaust gas flows into the gap between the heat transfer tube and the casing, a slip-through flow is formed.

  The heat exchanger described in Patent Document 1 is an exhaust heat recovery device, and can recover the heat of steam flowing through the gap between the inner surface of the casing and the heat transfer tube. However, in the apparatus described in Patent Document 1, since the heat transfer tube panel is attached to the heat transfer tube itself, a large space is still formed between the inner surface of the casing and the heat transfer tube. For this reason, sufficient heat recovery may not be possible. In addition, providing the heat transfer tube panel makes the structure complicated and large. As a result, it becomes difficult to adopt the structure in a ship that is particularly demanded for downsizing of the on-board equipment. That is, the device described in Patent Document 1 still has room for improvement.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a heat exchanger, a boiler, and a ship having improved heat exchange performance.

  The heat exchanger according to the present invention includes a cylindrical casing in which the working fluid flows from the upstream side toward the downstream side, and a plurality of the casings arranged in the flow direction of the working fluid. A plurality of heat transfer tube layers having a heat transfer tube stacked in a direction orthogonal to the flow direction, and a plurality of heat transfer tube blocks arranged at intervals in the flow direction; and A downstream guide portion provided on the downstream side and protruding from the inner surface of the casing and having a first guide surface facing the upstream side.

  According to this configuration, since the first guide surface of the downstream guide portion serves as a flow resistance against the working fluid, the working fluid is guided by the first guide surface, and is transmitted in the region upstream of the first guide surface. It flows toward the direction away from the inner surface of the casing in the region where the heat pipe block is disposed. Thereby, a working fluid can be reduced to the clearance gap formed between a heat exchanger tube block and the inner surface of a casing.

  In the heat exchanger according to the present invention, the first guide surface may overlap the heat transfer tube closest to the inner surface as viewed from the flow direction.

  According to this configuration, the possibility that the working fluid flows into the gap between the heat transfer tube block and the inner surface of the casing can be further reduced. In addition, the distance between the heat transfer tube block and the inner surface of the casing can be reduced.

  In the heat exchanger according to the present invention, the first guide surface may be inclined with respect to the flow direction when viewed from the direction in which the heat transfer tube extends.

  According to this configuration, since the first guide surface is inclined with respect to the flow direction, the working fluid can be smoothly guided along the first guide surface. In other words, it is possible to reduce stagnation and stagnation in the flow of the working fluid that leads to the accumulation of foreign matter such as soot and splashes of lubricating oil accompanying the working fluid.

  In the heat exchanger of the present invention, the first guide surface may be curved in a direction away from the inner surface from the upstream side toward the downstream side.

  According to this configuration, since the first guide surface is curved, the working fluid can be guided more smoothly along the first guide surface. In other words, it is possible to further reduce the stagnation and stagnation of the flow of the working fluid that leads to the accumulation of foreign matters such as soot and splashes of lubricating oil accompanying the working fluid.

  In the heat exchanger of the present invention, the downstream guide portion may have a plate shape in which the region extending in the direction away from the inner surface does not change in thickness.

  According to this structure, possibility that a working fluid will flow into the clearance gap between a heat exchanger tube block and the inner surface of a casing can be reduced. In addition, the downstream guide portion can be provided simply and inexpensively as compared with other complicated shapes.

  Moreover, in the heat exchanger of this invention, the dimension which the said downstream side guide part protrudes from the said inner surface may be 1 to 3 times the said pitch of the said heat exchanger tube.

  According to this structure, since the downstream guide part can fully cover the gap between the heat transfer tube block and the inner surface of the casing, the working fluid flowing into the gap can be further reduced.

  In the heat exchanger according to the present invention, the distance between the first guide surface and the heat transfer tube closest to the first guide surface may be 10 mm or more and 50 mm or less.

  According to this configuration, heat exchange in the heat transfer tube can be performed more efficiently.

  The heat exchanger according to the present invention may further include an upstream guide portion provided on the upstream side of the heat transfer tube block, having a second guide surface that protrudes from the inner surface of the casing and faces the upstream side. .

  According to this configuration, it is possible to reduce the inflow of the working fluid from the upstream side with respect to the gap between the heat transfer tube block and the inner surface of the casing.

  Moreover, the ship of this invention is equipped with the above-mentioned heat exchanger, the flue where the said heat exchanger is arrange | positioned, and the main engine which supplies waste gas to the said flue.

  According to this structure, the ship provided with the heat exchanger with improved efficiency can be provided.

  According to the present invention, the efficiency of heat exchange can be improved.

FIG. 1 is a schematic diagram showing the configuration of a ship according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of the heat exchanger of the exhaust heat recovery apparatus according to the first embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of the heat exchanger according to the first embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view showing a modification of the heat exchanger according to the first embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view showing another modification of the heat exchanger according to the first embodiment of the present invention. FIG. 6 is an enlarged cross-sectional view of a heat exchanger according to the second embodiment of the present invention.

[First embodiment]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, and when there are two or more embodiments, what comprises combining each embodiment is also included.

  A first embodiment of the present invention will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the ship 100 includes a hull 1, a diesel engine 11, and an exhaust heat recovery device 10.

  The hull 1 is a housing in which a cargo passenger or the like can be mounted. The diesel engine 11 is a main engine. The main engine may be an internal combustion engine other than the diesel engine 11. The diesel engine 11 generates power for driving a propeller shaft, for example, and discharges exhaust gas. In the present embodiment, heat is recovered from the exhaust gas discharged from the diesel engine 11 of the ship 100 by the exhaust heat recovery device 10, but the high-temperature gas that the exhaust heat recovery device 10 recovers heat is particularly limited. Not. That is, the exhaust heat recovery device 10 can be installed downstream of a device that discharges high-temperature gas such as a gas turbine, a boiler, or a fuel cell, and can recover the heat of the high-temperature gas. Further, the ship 100 may be provided with an exhaust gas treatment device that removes and reduces harmful substances in the exhaust gas downstream of the exhaust heat recovery device 10.

  The heat exchanger 40 performs heat exchange between the exhaust gas discharged from the diesel engine 11 and water as a heat medium. Water heated by heat exchange becomes superheated steam and is used to drive other devices (not shown) such as a steam turbine.

  Hereinafter, the detailed configuration of the heat exchanger 40 will be described with reference to FIG. As shown in FIG. 2, the heat exchanger 40 includes a casing 41 and a heat exchanger body 42. The casing 41 has a cylindrical shape, and exhaust gas flows from the upstream side toward the downstream side. In the following description, the direction in which the exhaust gas flows may be referred to as the “flow direction”. The casing 41 becomes a part of the exhaust path through which the exhaust gas discharged from the diesel engine 11 flows. A heat exchanger body 42 is provided in the internal space of the casing 41.

  The heat exchanger main body 42 includes a plurality of (two) heat transfer tube blocks 43 arranged at intervals in the flow direction, and a downstream guide portion 50 that guides the exhaust gas (working fluid) around each heat transfer tube block 43. Have. In addition, although this embodiment demonstrates the structure provided with two heat exchanger tube blocks 43, the number of the heat exchanger tube blocks 43 is not limited to two, Three or more may be sufficient. The two heat transfer tube blocks 43 have the same configuration. In the following description, the heat transfer tube block 43 located on the upstream side is referred to as a first heat transfer tube block 44 and is located on the downstream side. Is referred to as the second heat transfer tube block 45, and they may be distinguished from each other.

  In the heat transfer tube block 43, a plurality of heat transfer tube layers 46 are laminated in the flow direction. The heat transfer tube layer 46 has a plurality of heat transfer tubes 47 arranged at an equal pitch P in a direction orthogonal to the flow direction. Here, the pitch P of the heat transfer tubes 47 indicates the distance between the center points of the adjacent heat transfer tubes 47. Each heat transfer tube 47 is formed by turning back a plurality of tubes that extend continuously in the flow direction at intervals in the flow direction. That is, the heat transfer tube 47 is disposed across the plurality of heat transfer tube layers 46.

  Each heat transfer tube 47 has a circular cross-sectional shape and extends in a direction perpendicular to the flow direction. In the heat transfer tube 47, water as a heat medium flows through the inside from the downstream side in the flow direction to the upstream side. In the heat transfer tubes 47 between the adjacent heat transfer tube layers 46, the directions in which the water flows are opposite to each other.

  In the heat transfer tube block 43 of the present embodiment, the heat transfer tubes 47 are arranged in a staggered manner when viewed from the direction orthogonal to the flow direction and from the direction in which the heat transfer tubes 47 extend in one heat transfer tube layer. In other words, in the heat transfer tube layers 46 adjacent to each other, the plurality of heat transfer tubes 47 are arranged at different positions in the direction orthogonal to the flow direction. In the heat transfer tube block 43, the heat transfer tubes 47 may be arranged in a lattice shape instead of a staggered shape.

  In the heat exchanger 40, a gap G <b> 1 is formed between the outer peripheral edge of the heat transfer tube block 43 and the inner surface S of the casing 41. The outer peripheral edge of the heat transfer tube block 43 is an edge formed by the outer peripheral surfaces of the plurality of heat transfer tubes 47 located on the outermost periphery side in the heat transfer tube block 43.

  The downstream guide portion 50 is provided in a region on the downstream side of the heat transfer tube block 43 on the inner surface S of the casing 41. Specifically, the downstream guide portion 50 has a plate shape that protrudes from the inner surface S of the casing 41 in a direction orthogonal to the inner surface S. The downstream guide portion 50 is formed so that a region extending in a direction away from the inner surface S does not change in thickness. In other words, the thickness of the downstream guide portion 50 is constant. The downstream guide unit 50 can be installed by fixing the plate material to the inner surface S of the casing 41 by welding or the like. Further, the downstream side guide portion 50 may have a shape with a L-shaped cross section, a structure in which one side of the L shape faces the casing 41 and one side protrudes from the casing 41. Moreover, the downstream guide part 50 is good also as a structure which supported the plate-shaped member with the stay.

  The downstream guide portion 50 has a protruding height, that is, a dimension between the end portion of the downstream guide portion 50 on the side away from the inner surface S and the inner surface S is 1 or more times the pitch P of the heat transfer tubes 47 described above. It is preferable that it is less than 2 times. As for the downstream side guide part 50, it is more preferable that protrusion height is 1 time or more and 2 times or less of the pitch P of the heat exchanger tube 47. FIG. Most preferably, the downstream guide portion 50 has a protruding height that is one time the pitch P of the heat transfer tubes 47. The heat exchanger 40 can increase the efficiency of heat exchange by making the gap G1 narrower than the pitch P. The downstream side guide part 50 can be made into the shape which overlaps with the heat exchanger tube 47 nearest to the inner surface S of the casing 41, when it sees from a flow direction by making protrusion height into the said range. Thereby, the 1st guide surface 51 which is a surface which faces an upstream among the both surfaces of the downstream guide part 50 is facing the clearance gap G1 and the heat exchanger tube block 43 from the flow direction downstream. In other words, when viewed from the flow direction, the gap G <b> 1 is blocked by the downstream guide portion 50. The first guide surface 51 is a surface that extends in a plane orthogonal to the inner surface S of the casing 41.

  The distance between the first guide surface 51 and the heat transfer tube 47 closest to the first guide surface 51 is preferably 10 mm or more and 50 mm or less, more preferably 10 mm or more and 30 mm or less, and 10 mm. Most preferably.

  Hereinafter, the operation of the heat exchanger 40 according to the first embodiment will be described. The exhaust gas discharged from the diesel engine 11 flows into the heat exchanger 40. The exhaust gas flowing into the heat exchanger 40 contacts the heat transfer tube block 43. The exhaust gas is heat-exchanged with water as a heat medium flowing through the heat transfer tube 47 and becomes a low temperature, and then released into the atmosphere.

  The downstream guide unit 50 regulates and guides the flow of exhaust gas, and reduces the amount of exhaust gas that flows into the gap G1. The downstream side guide part 50 is demonstrated with reference to FIG. The downstream guide portion 50 has a flow resistance against the exhaust gas, and the area around the first guide surface 51 that is in the downstream portion of the first heat transfer tube block 44 and in the vicinity of the inner surface S is a region where the exhaust gas hardly flows. As a result, the exhaust gas flowing in the vicinity of the inner surface S or in the gap G1 is likely to flow away from the inner surface S while flowing in the region where the first heat transfer tube block 44 is disposed.

  Specifically, as shown in FIG. 3, the exhaust gas flowing through the gap G <b> 1 does not form a flow along the inner surface S (broken line arrow F <b> 1), and downstream of the first heat transfer tube block 44. The direction is changed by 50 first guide surfaces 51. As a result, the exhaust gas flows as indicated by an arrow F <b> 2 in the direction away from the inner surface S along the first guide surface 51. Thereafter, the exhaust gas flows along the flow (arrow F3) of the exhaust gas that has circulated through the first heat transfer tube block 44 and a portion other than the gap G1. As a result, the amount of exhaust gas flowing is greater on the arrow F3 side closer to the center of the casing 41 than on the gap G1 side. Accordingly, since more exhaust gas can be brought into contact with the first heat transfer tube block 44, the efficiency of heat exchange can be improved. In addition, the exhaust gas guided by the downstream guide unit 50 flows from the position away from the inner surface S of the casing 41 into the second heat transfer tube block 45 positioned on the downstream side. In other words, since the downstream guide portion 50 is provided on the downstream side of the first heat transfer tube block 44, the amount of exhaust gas flowing into the gap G2 between the second heat transfer tube block 45 and the casing 41 is reduced. The Therefore, the efficiency of the heat exchanger 40 can be improved as compared with the configuration in which the downstream guide portion 50 is not provided.

  Furthermore, in the heat exchanger 40 described above, the first guide surface 51 overlaps the heat transfer tube 47 closest to the inner surface S as viewed from the flow direction. According to this configuration, the gap G <b> 1 can be sufficiently covered from the downstream side by the downstream guide portion 50. Therefore, the flow resistance to the exhaust gas by the downstream guide portion 50 can be sufficiently secured, and the possibility of exhaust gas flowing into the gap G1 between the heat transfer tube block 43 and the inner surface S of the casing 41 can be further reduced. it can.

  In addition, by providing the downstream guide portion 50, the distance between the heat transfer tube block 43 and the inner surface S of the casing 41 can be reduced. In other words, when the downstream side guide part 50 is provided, the dimension (namely, the number of the heat exchanger tube layers 46) of the heat exchanger tube block 43 is increased, without considering the thermal efficiency fall by forming the clearance gap G1. be able to. For this reason, the efficiency of the heat exchanger 40 can be further improved.

  Furthermore, in the above-described heat exchanger 40, the downstream guide portion 50 has a plate shape with a constant thickness. According to this structure, the downstream side guide part 50 can be provided simply and cheaply compared with the case where it is set as another complicated shape.

  In addition, in the heat exchanger 40 described above, the dimension (that is, the protruding height) at which the downstream guide portion 50 protrudes from the inner surface S is 1 to 3 times the pitch P of the heat transfer tubes 47. Further, the distance between the first guide surface 51 and the heat transfer tube 47 closest to the first guide surface 51 is 10 mm or more and 50 mm or less. According to this configuration, the possibility that exhaust gas flows into the gap G1 between the heat transfer tube block 43 and the inner surface S of the casing 41 can be further reduced, and the efficiency as the heat exchanger 40 can be sufficiently improved.

  The first embodiment of the present invention has been described above. Note that various modifications can be made to the above-described configuration without departing from the gist of the present invention.

  For example, in the first embodiment, the configuration in which the first guide surface 51 of the downstream guide unit 50 is a surface orthogonal to the inner surface S of the casing 41 has been described. However, the configuration of the first guide surface 51 is not limited to this, and a configuration as shown in FIG. 4 can also be adopted. Specifically, in the example of FIG. 4, the first guide surface 52 is inclined with respect to the flow direction of the exhaust gas. In other words, the first guide surface 52 extends in a direction of gradually separating from the inner surface S as it goes from the upstream side to the downstream side.

  According to this configuration, since the first guide surface 52 is inclined with respect to the flow direction, the exhaust gas can be smoothly guided along the first guide surface 52. Therefore, it is possible to reduce the possibility of stagnation and stagnation in the flow of exhaust gas.

  Further, the first guide surface 51 may have a configuration as shown in FIG. Specifically, in the example of FIG. 5, the first guide surface 53 is gradually curved toward the direction away from the inner surface S from the upstream side toward the downstream side.

  According to this configuration, since the first guide surface 51 is curved, the exhaust gas can be guided more smoothly along the first guide surface 53.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, an upstream guide portion 60 is further provided on the upstream side of the second heat transfer tube block 45. The upstream guide portion 60 is provided in a region on the upstream side of the heat transfer tube block 43 on the inner surface S of the casing 41. Specifically, the upstream guide portion 60 has a plate shape protruding from the inner surface S of the casing 41 in a direction orthogonal to the inner surface S. The upstream guide portion 60 is formed so that the region extending in the direction away from the inner surface S does not change in thickness. In other words, the thickness of the upstream guide portion 60 is constant. Similarly to the downstream guide unit 50, the upstream guide unit 60 can be installed by fixing a plate material to the inner surface S of the casing 41 by welding or the like. Further, the upstream guide portion 60 may have a shape with a L-shaped cross section and a structure in which one side of the L shape protrudes from the casing 41. Further, the upstream guide part 60 may have a structure in which a plate-like member is supported by a stay.

  The upstream guide portion 60 has a protruding height, that is, a dimension between the end portion on the side away from the inner surface S of the upstream guide portion 60 and the inner surface S is 1 or more times the pitch P of the heat transfer tubes 47 described above. It is preferable that it is less than 2 times. As for the upstream guide part 60, it is more preferable that protrusion height is 1 time or more and 2 times or less of the pitch P of the heat exchanger tube 47. FIG. As for the upstream guide part 60, it is most preferable that the protrusion height is 1 time the pitch P of the heat transfer tubes 47. The heat exchanger 40 can increase the efficiency of heat exchange by making the gap G2 narrower than the pitch P. The upstream side guide part 60 can be made into the shape which overlaps with the heat exchanger tube 47 nearest to the inner surface S of the casing 41, when it sees from the flow direction by making protrusion height into the said range. Thereby, the 2nd guide surface 61 which is a surface which faces an upstream among the both surfaces of the upstream guide part 60 is facing the clearance gap G1 and the 2nd heat exchanger tube block 45 from the flow direction upstream. In other words, when viewed from the flow direction, the gap G <b> 1 is blocked by the upstream guide portion 60. The second guide surface 61 is a surface that extends in a plane orthogonal to the inner surface S of the casing 41.

  The distance between the second guide surface 61 and the heat transfer tube 47 closest to the second guide surface 61 is preferably 10 mm or more and 50 mm or less. The distance between the second guide surface 61 and the heat transfer tube 47 closest to the second guide surface 61 is more preferably 10 mm or greater and 30 mm or less. Most preferably, the distance between the second guide surface 61 and the heat transfer tube 47 closest to the second guide surface 61 is 10 mm.

  According to this configuration, the working fluid flowing from the upstream side can be reduced with respect to the gap G <b> 2 between the second heat transfer tube block 45 and the inner surface S of the casing 41. More specifically, the exhaust gas has been circulated through the first heat transfer tube block 44 after being guided in the direction away from the inner surface S by the downstream guide portion 50 provided on the downstream side of the first heat transfer tube block 44. The main flow of exhaust gas, that is, the flow of exhaust gas that has circulated through the portion other than the gap G1, joins and flows toward the downstream side. The exhaust gas guided by the downstream guide portion 50 flows into the second heat transfer tube block 45 located on the downstream side from a position separated from the inner surface S of the casing 41 by providing the upstream guide portion 60. . In other words, the downstream side guide portion 50 is provided on the downstream side of the first heat transfer tube block 44, and the upstream side guide portion 60 is provided on the upstream side of the second heat transfer tube block 45, whereby the second heat transfer tube block is provided. The amount of exhaust gas flowing into the gap G2 between the casing 45 and the casing 41 can be further reduced. For this reason, the efficiency of the heat exchanger 40 can be further improved.

  The second embodiment of the present invention has been described above. Note that various modifications can be made to the above-described configuration without departing from the gist of the present invention.

  For example, in the second embodiment, the configuration in which the second guide surface 61 of the upstream guide portion 60 is a surface orthogonal to the inner surface S of the casing 41 has been described. However, the configuration of the second guide surface 61 is not limited to this, and the configuration as shown in FIG. 4 or FIG. Specifically, it is possible to adopt a configuration in which the second guide surface 61 is inclined with respect to the flow direction, or a configuration in which the second guide surface 61 is curved.

  In addition, the application target of the heat exchanger 40 is not limited to the exhaust heat recovery device 10, and for example, the configuration described in each embodiment can be applied to a superheater, an evaporator, a economizer, or the like of an exhaust heat recovery boiler. It is.

DESCRIPTION OF SYMBOLS 100 Ship 1 Hull 10 Waste heat recovery apparatus 11 Diesel engine 40 Heat exchanger 41 Casing 42 Heat exchanger main body 43 Heat exchanger tube block 44 First heat exchanger tube block 45 Second heat exchanger tube block 50 Downstream guide part 46 Heat exchanger tube layer 47 Heat pipe 51 First guide surface 52 First guide surface 53 First guide surface 60 Upstream guide portion 61 Second guide surface G1 Gap G2 Gap P Pitch S Inner surface

Claims (9)

A cylindrical casing in which the working fluid flows from the upstream side toward the downstream side;
It is formed by laminating a plurality of heat transfer tube layers provided in the casing and having a plurality of heat transfer tubes arranged at an equal pitch in a plane orthogonal to the flow direction of the working fluid in the flow direction, A plurality of heat transfer tube blocks arranged at intervals in the flow direction;
A downstream guide portion provided on the downstream side of the heat transfer tube block, protruding from the inner surface of the casing and having a first guide surface facing the upstream side;
A heat exchanger.   2. The heat exchanger according to claim 1, wherein the first guide surface overlaps the heat transfer tube closest to the inner surface when viewed from the flow direction.   The heat exchanger according to claim 1 or 2, wherein the first guide surface is inclined with respect to the flow direction when viewed from a direction in which the heat transfer tube extends.   The heat exchanger according to any one of claims 1 to 3, wherein the first guide surface is curved in a direction away from the inner surface from the upstream side toward the downstream side.   The heat exchanger according to any one of claims 1 to 4, wherein the downstream guide portion has a plate shape in which a region extending in a direction away from the inner surface does not change in thickness.   The heat exchanger according to any one of claims 1 to 5, wherein a dimension of the downstream guide portion protruding from the inner surface is 1 to 3 times the pitch of the heat transfer tubes.   The heat exchanger according to any one of claims 1 to 6, wherein a distance between the first guide surface and the heat transfer tube closest to the first guide surface is 10 mm or more and 50 mm or less.   The upstream guide part which is provided in the upstream of the said heat exchanger tube block, protrudes from the inner surface of the said casing, and has a 2nd guide surface which faces an upstream is further provided as described in any one of Claim 1 to 7 Heat exchanger. The heat exchanger according to any one of claims 1 to 8,
A flue in which the heat exchanger is arranged;
A main engine for supplying exhaust gas to the flue;
Ship equipped with.

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