WO2018123209A1

WO2018123209A1 - Heat exchanger and ship

Info

Publication number: WO2018123209A1
Application number: PCT/JP2017/037213
Authority: WO
Inventors: 森　匡史; 龍太中村; 英輝天野; 智末野; 浩市松下
Original assignee: 三菱重工業株式会社
Priority date: 2016-12-28
Filing date: 2017-10-13
Publication date: 2018-07-05
Also published as: JP2018109464A; KR20190005920A; CN110088554A

Abstract

Provided are: a heat exchanger having improved thermal efficiency; and a ship. This heat exchanger 40 is provided with: a cylindrical casing 41, through the inside of which operating fluid flows from the upstream side toward the downstream side; a plurality of blocks 43 of heat transfer pipes, the blocks 43 being provided within the casing 41, the blocks 43 being formed by stacking a plurality of layers 46 of heat transfer pipe in the flow direction of the operating fluid, the layers 46 having a plurality of heat transfer pipes 47 arranged at equal pitches P in the radial direction in a plane perpendicular to the flow direction, the blocks 43 being arranged at a distance from each other in the flow direction; and a downstream-side guide section 50 which is provided on the downstream side of the blocks 43 of heat transfer pipes, protrudes from the inner surface S of the casing 41, and has a first guide surface 51 facing the upstream side.

Description

Heat exchanger and ship

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

There is an exhaust heat recovery device that has a heat exchanger that exchanges heat with exhaust gas and the like and that recovers the 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 device has a heat exchanger that performs heat exchange between the exhaust gas and a heat carrier (for example, water). The heat exchanger includes a plurality of heat transfer pipes through which the heat medium flows, and a casing which covers the heat transfer pipes from the outside. The heat exchanger performs heat exchange between the exhaust gas and the heat medium via the heat transfer pipe by being disposed in the flue through which the exhaust gas flows. In such a heat exchanger, foreign matter such as lubricating oil may be adhered to the surface of the heat transfer tube, as it is contained in the exhaust gas. Here, Patent Document 1 describes a heat exchanger including an exhaust heat recovery device having a heat transfer pipe panel that recovers the heat of the fluid flowing between the casing and the heat transfer pipe and transfers the heat to the heat transfer pipe.

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. Therefore, the exhaust gas flows into the gap between the heat transfer pipe and the casing, thereby forming a slip-through flow.

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

The present invention was made in order to solve the above-mentioned subject, and it aims at providing a heat exchanger and a ship with which heat exchange performance improved.

The heat exchanger of the present invention includes a cylindrical casing in which the working fluid flows from the upstream side to the downstream side, and a plurality of casings provided inside the casing and arranged at an equal pitch in the flow direction of the working fluid. And a plurality of heat transfer tube blocks which are formed by laminating a plurality of heat transfer tube layers having heat transfer tubes in a direction orthogonal to the flow direction, and are spaced apart from each other in the flow direction; And a downstream guide portion provided on the downstream side and projecting 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 to the working fluid, the working fluid is guided by the first guide surface, and is a region upstream of the first guide surface. It flows in the direction away from the inner surface of the casing in the area where the heat pipe block is disposed. Thereby, the working fluid can be reduced to the gap formed between the heat transfer tube block and the inner surface of the casing.

Further, in the heat exchanger of the present invention, the first guide surface may overlap the heat transfer pipe closest to the inner surface when viewed in the flow direction.

According to this configuration, the possibility of the working fluid flowing 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.

Further, in the heat exchanger of the present invention, the first guide surface may be inclined with respect to the flow direction as viewed from the direction in which the heat transfer pipe 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 leading to the accumulation of foreign matter such as soot and droplets of lubricating oil accompanied in the working fluid.

Further, in the heat exchanger of the present invention, the first guide surface may be curved in a direction away from the inner surface as it goes from the upstream side to 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, stagnation and stagnation of the flow of the working fluid leading to the accumulation of foreign matter such as soot and droplets of lubricating oil accompanied in the working fluid can be further reduced.

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

According to this configuration, it is possible to reduce the possibility of the working fluid flowing into the gap between the heat transfer tube block and the inner surface of the casing. In addition, the downstream guide can be provided simply and inexpensively as compared with other complicated shapes.

Further, in the heat exchanger of the present invention, the dimension by which the downstream side guide portion protrudes from the inner surface may be one or more times and three or less times the pitch of the heat transfer tubes.

According to this configuration, since the gap between the heat transfer pipe block and the inner surface of the casing can be sufficiently covered by the downstream side guide portion, the working fluid flowing into the gap can be further reduced.

Further, in the heat exchanger of the present invention, the distance between the first guide surface and the heat transfer pipe 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.

Further, the heat exchanger of the present invention may further include an upstream guiding portion provided on the upstream side of the heat transfer pipe block and projecting from the inner surface of the casing and having a second guiding surface facing the upstream side. .

According to this configuration, the inflow of working fluid from the upstream side to the gap between the heat transfer tube block and the inner surface of the casing can be reduced.

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

According to this configuration, it is possible to provide a ship provided with the heat exchanger with improved efficiency.

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

FIG. 1 is a schematic view showing the configuration of a ship according to a 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 sectional view showing a modification of the heat exchanger according to the first embodiment of the present invention. FIG. 5 is an enlarged 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 a 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. Note that the present invention is not limited by the embodiments, and in the case where there are a plurality of embodiments, the present invention also includes those configured by combining the respective embodiments.

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 on which a 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 emits exhaust gas. In the present embodiment, the heat is recovered by the exhaust heat recovery device 10 from the exhaust gas discharged from the diesel engine 11 of the ship 100, but the high temperature gas to be recovered by the exhaust heat recovery device 10 is particularly limited. I will not. That is, the exhaust heat recovery apparatus 10 can be installed downstream of an apparatus that discharges high-temperature gas, such as a gas turbine, a boiler, a fuel cell, etc., and can recover the heat of the high-temperature gas. In the ship 100, an exhaust gas treatment device may be installed downstream of the exhaust heat recovery device 10 to remove and reduce harmful substances in the exhaust gas.

The heat exchanger 40 exchanges heat 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. The heat exchanger 40 has a casing 41 and a heat exchanger main body 42, as shown in FIG. The casing 41 is cylindrical, and the exhaust gas flows from the upstream side toward the downstream side in the inside. In the following description, the flow direction of the exhaust gas may be referred to as “flow direction”. The casing 41 is a part of an exhaust path through which the exhaust gas discharged from the diesel engine 11 flows. In the internal space of the casing 41, a heat exchanger main body 42 is provided.

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 for guiding the exhaust gas (working fluid) around each heat transfer tube block 43 And. In the present embodiment, a configuration in which two heat transfer tube blocks 43 are provided will be described, but the number of heat transfer tube blocks 43 is not limited to two, and may be three or more. The two heat transfer pipe blocks 43 have the same configuration, but in the following description, the heat transfer pipe block 43 located on the upstream side is called the first heat transfer pipe block 44, and the heat transfer pipe block 43 located on the downstream side Is referred to as a second heat transfer tube block 45, and the two may be distinguished.

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

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

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

In the heat exchanger 40, a gap G1 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 portion formed by the outer peripheral surfaces of the plurality of heat transfer tubes 47 located on the outermost peripheral side of the heat transfer tube block 43.

The downstream guide portion 50 is provided in the region of the inner surface S of the casing 41 on the downstream side of the heat transfer pipe block 43. 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 the area extending in the 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 portion 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 be configured to have an L-shaped cross section, one side of the L-shape facing the casing 41, and one side protruding from the casing 41. Further, the downstream guide portion 50 may have a structure in which the plate member is supported by the stay.

The downstream side guide portion 50 has a protrusion height, that is, a dimension between an end portion of the downstream side guide portion 50 on the side away from the inner surface S and the inner surface S is one or more times of the pitch P of the heat transfer tubes 47 described above. It is preferable that it is twice or less. It is more preferable that the downstream guide portion 50 has a protrusion height that is not less than 1 time and not more than 2 times the pitch P of the heat transfer tubes 47. Most preferably, the downstream guide portion 50 has a protrusion 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 guide portion 50 can have a shape overlapping the heat transfer tube 47 closest to the inner surface S of the casing 41 when viewed from the flow direction by setting the protrusion height in the above range. Thereby, the first guide surface 51, which is a surface facing the upstream side, of both surfaces of the downstream side guide portion 50 faces the gap G1 and the heat transfer tube block 43 from the downstream side in the flow direction. In other words, as viewed in the flow direction, the gap G1 is closed by the downstream guide portion 50. The first guide surface 51 is a surface that extends in a plane perpendicular 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 preferred.

Hereinafter, the operation of the heat exchanger 40 according to the first embodiment will be described. 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 subjected to heat exchange with water as a heat medium flowing in the heat transfer pipe 47 to become a low temperature, and then released to the atmosphere.

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

Specifically, as shown in FIG. 3, the exhaust gas having flowed through the gap G1 does not form a flow (broken line arrow F1) along the inner surface S, and the downstream guide portion on the downstream side of the first heat transfer tube block 44 The direction is changed by the 50 first guide surfaces 51. As a result, the exhaust gas flows along the first guide surface 51 in the direction away from the inner surface S as indicated by an arrow F2. Thereafter, the exhaust gas flows along the flow (arrow F3) of the exhaust gas flowing through the portion other than the gap G1 through the first heat transfer pipe block 44. 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. Therefore, more exhaust gases can be brought into contact with the first heat transfer tube block 44, so the efficiency of heat exchange can be improved. In addition, the exhaust gas guided by the downstream guide portion 50 flows from the position separated from the inner surface S of the casing 41 into the second heat transfer pipe block 45 located on the downstream side. In other words, by providing the downstream side guide portion 50 on the downstream side of the first heat transfer pipe block 44, the amount of inflow of exhaust gas into the gap G2 between the second heat transfer pipe block 45 and the casing 41 is reduced. Ru. 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 above-described heat exchanger 40, the first guide surface 51 overlaps the heat transfer tube 47 closest to the inner surface S when viewed in the flow direction. According to this configuration, the gap G1 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 side guide portion 50 can be sufficiently ensured, and the possibility of the exhaust gas flowing into the gap G1 between the heat transfer pipe block 43 and the inner surface S of the casing 41 is further reduced. it can.

In addition, the distance between the heat transfer tube block 43 and the inner surface S of the casing 41 can be reduced by providing the downstream side guide portion 50. In other words, when the downstream side guide portion 50 is provided, the dimension (that is, the number of heat transfer tube layers 46) of the heat transfer tube block 43 is increased without considering the decrease in thermal efficiency due to the formation of the gap G1. be able to. Therefore, the efficiency of the heat exchanger 40 can be further improved.

Furthermore, in the above-mentioned heat exchanger 40, the downstream guide part 50 is plate shape with constant thickness. According to this configuration, the downstream side guide portion 50 can be provided simply and inexpensively as compared with other complicated shapes.

Furthermore, in the above-described heat exchanger 40, the dimension (that is, the protrusion height) of the downstream side guide portion 50 protruding from the inner surface S is 1 or more and 3 or less 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 of exhaust gas flowing into the gap G1 between the heat transfer pipe block 43 and the inner surface S of the casing 41 can be further reduced, and the efficiency of the heat exchanger 40 can be sufficiently improved.

The first embodiment of the present invention has been described above. Note that various changes can be made to the above-described configuration without departing from the scope 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 the direction of being gradually separated from the inner surface S as it goes from the upstream side to the downstream side.

According to this configuration, the exhaust gas can be smoothly guided along the first guide surface 52 because the first guide surface 52 is inclined with respect to the flow direction. Therefore, the possibility of stagnation or stagnation in the exhaust gas flow can be reduced.

Furthermore, the first guide surface 51 can also be configured as shown in FIG. Specifically, in the example of FIG. 5, the first guide surface 53 is gradually curved in the direction away 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 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 pipe block 45. The upstream guide portion 60 is provided in the region of the inner surface S of the casing 41 on the upstream side of the heat transfer tube block 43. Specifically, the upstream guide portion 60 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 upstream guide portion 60 is formed so that the area 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. The upstream guide portion 60 can be installed by fixing a plate material to the inner surface S of the casing 41 by welding or the like, as with the downstream guide portion 50. Further, the upstream guide portion 60 may be configured to have an L-shaped cross section so that one side of the L-shape protrudes from the casing 41. Further, the upstream guide portion 60 may have a structure in which the plate member is supported by a stay.

The upstream guide portion 60 has a protrusion height, that is, a dimension between the end portion of the upstream guide portion 60 on the side away from the inner surface S and the inner surface S is at least one time the pitch P of the heat transfer tubes 47 described above. It is preferable that it is twice or less. More preferably, the upstream guide portion 60 has a protrusion height of at least one time and at most two times the pitch P of the heat transfer tubes 47. Most preferably, the upstream guide portion 60 has a protrusion 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 G2 narrower than the pitch P. The upstream guide portion 60 can have a shape overlapping the heat transfer tube 47 closest to the inner surface S of the casing 41 when viewed from the flow direction by setting the protrusion height to the above range. As a result, the second guide surface 61, which is a surface facing the upstream side, of both surfaces of the upstream guide portion 60 faces the gap G1 and the second heat transfer tube block 45 from the upstream side in the flow direction. In other words, as viewed in the flow direction, the gap G1 is closed by the upstream guide portion 60. The second guide surface 61 is a surface extending in a plane perpendicular to the inner surface S of the casing 41.

The distance between the second guiding surface 61 and the heat transfer tube 47 closest to the second guiding surface 61 is preferably 10 mm or more and 50 mm or less. It is more preferable that the distance between the second guide surface 61 and the heat transfer tube 47 closest to the second guide surface 61 be 10 mm or more and 30 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 most preferably 10 mm.

According to this configuration, the working fluid flowing from the upstream side can be reduced with respect to the gap G2 between the second heat transfer pipe block 45 and the inner surface S of the casing 41. More specifically, the exhaust gas has been circulated in the first heat transfer pipe block 44 after being guided in a direction away from the inner surface S by the downstream guide portion 50 provided on the downstream side of the first heat transfer pipe block 44 It joins with the mainstream of the exhaust gas, that is, the flow of the exhaust gas flowing through the portion other than the gap G1, and flows toward the downstream side. The exhaust gas guided by the downstream side guiding portion 50 flows into the second heat transfer pipe block 45 located downstream from the position separated from the inner surface S of the casing 41 by the upstream side guiding portion 60 being provided. . In other words, the downstream guide portion 50 is provided on the downstream side of the first heat transfer pipe block 44, and the upstream guide portion 60 is provided on the upstream side of the second heat transfer pipe block 45. It is possible to further reduce the inflow of the exhaust gas into the gap G2 between 45 and the casing 41. Therefore, 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 changes can be made to the above-described configuration without departing from the scope 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 it is also possible to adopt the configuration as shown in FIG. 4 or FIG. 5 similarly to the downstream guide portion 50. Specifically, it is possible to adopt a configuration in which the second guide surface 61 is inclined with respect to the flow direction, and a configuration in which the second guide surface 61 is curved.

Moreover, the application object of the heat exchanger 40 is not limited to the exhaust heat recovery apparatus 10, For example, it is also possible to apply the structure demonstrated in each embodiment to the superheater, evaporator, economizer etc. of a waste heat recovery boiler It is.

100 Vessel 1 Hull 10 Exhaust Heat Recovery Device 11 Diesel Engine 40 Heat Exchanger 41 Casing 42 Heat Exchanger Body 43 Heat Transfer Tube Block 44 First Heat Transfer Tube Block 45 Second Heat Transfer Tube Block 50 Downstream Guide 46 Heat Transfer Tube Layer 47 Transfer 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

A cylindrical casing in which the working fluid flows from the upstream side to the downstream side;
It is formed by laminating a plurality of heat transfer tube layers provided inside the casing and having a plurality of heat transfer tubes arranged at 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 spaced apart in the flow direction;
A downstream guiding portion provided on the downstream side of the heat transfer tube block and having a first guiding surface that protrudes from the inner surface of the casing and faces the upstream side;
Heat exchanger provided with
The heat exchanger according to claim 1, wherein the first guide surface overlaps the heat transfer pipe closest to the inner surface when viewed in the flow direction.
The heat exchanger according to claim 1, wherein the first guide surface is inclined with respect to the flow direction when viewed from the direction in which the heat transfer tubes extend.
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 as it goes from upstream to downstream.
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 in which the downstream side guide portion protrudes from the inner surface is one time or more and three times or less of the pitch of the heat transfer tube.
The heat exchanger according to any one of claims 1 to 6, wherein a distance between the first guide surface and the heat transfer pipe closest to the first guide surface is 10 mm or more and 50 mm or less.
The upstream guide portion according to any one of claims 1 to 7, further comprising: an upstream guide portion provided on the upstream side of the heat transfer tube block and projecting from the inner surface of the casing and having a second guide surface facing the upstream side. Heat exchanger.
A heat exchanger according to any one of the preceding claims,
A flue in which the heat exchanger is arranged;
A main engine supplying exhaust gas to the flue;
Ships equipped with