JP2005147426A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of preventing the shortening of service life of heat transfer pipes by uniforming the distribution of flow rate by preventing the drift generated in the fluid passing through the group of heat transfer pipes where the plurality of heat transfer pipes are arranged. <P>SOLUTION: In this heat exchanger 10 which has the group of heat transfer pipes comprising the heat transfer pipes 11 in a plurality of stages, and a box-shaped container 13 surrounding the group of heat transfer pipes 12 and forming a flow channel of the fluid flowing around each heat transfer pipe 11, and wherein the flowing-in direction from an inlet duct 14 of the fluid flowing into the box-shaped container 13 is substantially orthogonal to the flowing direction of the fluid in the group of heat transfer pipes 12, and baffle plates 15a, 15b are mounted on the orthogonal area 14a to guide the fluid flowing from the inlet duct 14 and to change its flowing direction, first small projecting parts 25a, 25b for partially disturbing the fluid are mounted on tip parts of the baffle plates 15a, 15b, to uniform the flow of the fluid passing in the group of heat transfer pipes 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a heat exchanger in which a flow velocity distribution of a fluid passing through a heat transfer tube group in which a plurality of heat transfer tubes are arranged is uniformed to prevent a decrease in the life of the heat transfer tubes.

In heat exchangers used in horizontal waste heat boilers, heat transfer tube groups in which a plurality of heat transfer tubes are arranged without changing the flow direction of the high-temperature waste heat gas, which is an example of the fluid flowing in from the inlet duct Heat exchange is performed with the heat exchange fluid (for example, water) that flows into the heat transfer tubes and passes through the heat transfer tubes, and the waste heat gas that has fallen in temperature is provided downstream of the heat exchanger. Had flowed out of the outlet duct.
In the horizontal waste heat boiler, the flow direction of the waste heat gas does not change in the heat exchanger, so there is no drift in the waste heat gas passing through the heat transfer tube group, and the horizontal cross section of the heat transfer tube group It was easy to homogenize the velocity distribution of waste heat gas. For this reason, each heat exchanger tube in the heat exchanger tube group can be made to receive a heat load equally in a cross section, and it was easy to extend the lifetime of a heat exchanger tube.
However, in order not to change the flow direction of the waste heat gas, in order to install the inlet side pipe of the waste heat gas flowing into the heat exchanger and the outlet side pipe of the waste heat gas flowing out of the heat exchanger A large area was required, which was a major limitation when a horizontal waste heat boiler was used.

Therefore, as a waste heat boiler that can be installed in a limited space, the flow direction of waste heat gas flowing in from the inlet duct of the heat exchanger is changed to a right angle direction to pass through the heat transfer tube group, and the heat exchanger An orthogonal waste heat boiler that discharges from an outlet duct provided on the downstream side is proposed.
However, in the orthogonal waste heat boiler, the flow direction of the waste heat gas is changed to a right angle in the heat exchanger before the waste heat gas passes through the heat transfer tube group, so there is a drift in the flow of the waste heat gas inside the heat exchanger. Occur. Then, when a drift occurs in the flow of the waste heat gas, the flow rate of the waste heat gas in the cross section of the heat transfer tube group becomes uneven, and the heat load of the heat transfer tube increases locally. For this reason, local corrosion of the heat transfer tube has progressed, and there has been a problem that the life of the heat transfer tube is shortened in the orthogonal waste heat boiler.
Therefore, a rectifying member that expresses a rectifying function that equalizes the flow of waste heat gas flowing into the heat transfer tube group is provided on the upstream side of the heat exchanger to extend the life of the heat transfer tubes of the orthogonal waste heat boiler. It has been proposed.

Here, as a rectifying member, for example, as described in Patent Document 1, it is known to use a porous plate. However, when a perforated plate is used, the waste heat gas flow is once blocked, and the pressure loss of the waste heat gas increases.
For this reason, in the orthogonal waste heat boiler using a perforated plate, there has been a problem that the operating cost increases with the occurrence of pressure loss. Furthermore, if a perforated plate is used, there is a high possibility that the holes will become clogged during use, and it will be necessary to perform regular maintenance, which reduces the operating rate of the orthogonal waste heat boiler. Along with this, there has been a problem that the operating cost increases.

JP-A-5-322473

Therefore, in an orthogonal waste heat boiler, as a method for preventing the drift of waste heat gas and suppressing the increase in pressure loss as much as possible, for example, baffle is used in a region where the waste heat gas flowing into the heat exchanger changes its flow direction. It is considered that it is effective to divide the flow path of the waste heat gas into a plurality of parallel small flow paths and make the flow rate of the waste heat gas flowing in each small flow path uniform.
However, in this method, the rectification effect of the waste heat gas is improved as the number of flow paths is increased, and it is possible to prevent the occurrence of drift, but at the same time the pressure loss is increased, The same problem as when it is installed will occur.

The present invention has been made in view of such circumstances, and prevents uneven flow generated in a fluid passing through a heat transfer tube group in which a plurality of heat transfer tubes are arranged to make the flow velocity distribution uniform and further increase pressure loss. It aims at providing the heat exchanger which can prevent the lifetime reduction of a heat exchanger tube.

The heat exchanger according to claim 1, which meets the above object, includes a heat transfer tube group including a plurality of stages of heat transfer tubes, and a box that surrounds the heat transfer tube group and forms a fluid flow path that flows around each of the heat transfer tubes. The flow direction of the fluid from the inlet duct of the fluid flowing into the box-shaped container and the flow direction of the fluid in the heat transfer tube group are substantially orthogonal to each other, In the heat exchanger provided with a baffle plate for guiding the fluid flowing in from the inlet duct and changing the flow direction thereof,
A first small protrusion that obstructs a part of the fluid is provided at the tip of the baffle plate, and the flow of the fluid passing through the heat transfer tube group is made uniform.

If the flow of the fluid that has flowed into the box-type container is forcibly changed using the baffle plate, the fluid will flow along the baffle plate, so that the fluid that has passed through the baffle plate should follow the baffle plate. Drift occurs.
Therefore, if a first small protrusion is provided at the tip of the baffle plate to obstruct part of this drift, a small vortex is formed at the tip of the baffle plate. Since the drift flows through the baffle plate while being agitated by the vortex, the magnitude of the drift in the fluid flowing out of the baffle plate is reduced and the flow is made uniform. For this reason, the fluid passing through the heat transfer tube group can be brought close to a uniform flow, and the velocity distribution of the fluid passing through the heat transfer tube group can be made uniform.
Further, even if the first small protrusion is provided at the tip of the baffle plate, the flow of the fluid is not greatly blocked, so that the pressure loss does not increase.

The heat exchanger according to claim 2 is the heat exchanger according to claim 1, wherein an inner wall surface of the box-shaped container which contacts the orthogonal region and collides with the fluid and changes its flow direction has the first A second small protrusion that obstructs a part of the fluid flowing along the inner wall surface is provided at a position substantially the same height as the small protrusion.

As a result, a part of the drift along the inner wall surface that occurs when the fluid flowing into the box-shaped container collides with the inner wall surface and changes the flow direction can be obstructed. Small vortices can be formed around the periphery.
As a result, the drift flowing along the inner wall surface is agitated, and the magnitude of the drift in the fluid can be reduced to make the flow uniform. For this reason, the flow of the fluid passing through the heat transfer tube group can be made more uniform, and the velocity distribution of the fluid passing through the heat transfer tube group can be made more uniform.

According to a third aspect of the present invention, in the heat exchanger according to the first and second aspects, a diffusion region that promotes diffusion of the fluid is provided between a tip of the baffle plate and the heat transfer tube group. .
The fluid diffuses while passing through the diffusion region and the drift remaining in the fluid gradually decreases, so that the fluid can be made more uniform when it reaches the heat transfer tube group. As a result, when the fluid passes through the heat transfer tube group, the velocity distribution of the fluid in the cross section of the heat transfer tube group can be made more uniform.

The heat exchanger according to claim 4 is the heat exchanger according to claims 1 to 3, wherein the flow direction of the fluid in the heat transfer tube group and the axial direction of each heat transfer tube are substantially orthogonal to each other. ing.
Thereby, heat exchange between the fluid passing through the heat transfer tube group and the heat transfer tubes can be efficiently performed.

In the heat exchanger according to any one of claims 1 to 4, a first small protrusion that obstructs a part of the fluid is provided at the tip of the baffle plate, and the flow of the fluid passing through the heat transfer tube group is made uniform. Therefore, the velocity distribution of the fluid in the cross section of the heat transfer tube group can be made uniform, and the temperature distribution of the heat transfer tubes at each stage in the heat transfer tube group can be made uniform. As a result, the heat load of the heat transfer tubes in each stage of the heat transfer tube group can be made uniform to prevent the progress of local corrosion of the heat transfer tubes, and the life of the heat exchanger can be extended. Become.
In addition, since the first small protrusion is provided and only part of the fluid is disturbed, an increase in pressure loss can be prevented and an increase in operating cost can be suppressed.

In particular, in the heat exchanger according to claim 2, the second interfering part of the fluid flowing along the inner wall surface at a position substantially the same height as the first small protrusion on the inner wall surface of the box-shaped container. Since the small protrusions are provided, it is possible to suppress the drift that occurs when the fluid collides with the inner wall surface of the box-type container and changes the flow direction, thereby further reducing the velocity distribution of the fluid in the heat transfer tube group. It becomes possible to make uniform.

In the heat exchanger according to the third aspect, since the diffusion region is provided between the tip of the baffle plate and the heat transfer tube group, the drift remaining in the fluid gradually passes through the diffusion region. When the temperature reaches the heat transfer tube group, the fluid can be made more uniform and the fluid velocity distribution in the heat transfer tube group can be made more uniform, and the temperature distribution of the heat transfer tubes at each stage in the heat transfer tube group Can be made more uniform.

In the heat exchanger according to claim 4, since the direction of the flow path in the heat transfer tube group and the axial direction of each heat transfer tube are orthogonal, heat exchange between the fluid and the heat transfer tube is efficiently performed. And the performance of the heat exchanger can be improved.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is a partially cutaway perspective view of a heat exchanger according to an embodiment of the present invention, and FIG. 2 is a side sectional view of the heat exchanger.
As shown in FIGS. 1 and 2, a heat exchanger 10 according to an embodiment of the present invention surrounds a heat transfer tube group 12 including a plurality of heat transfer tubes 11, and the heat transfer tube group 12, and each heat transfer tube 11. Has a box-shaped container 13 that forms a flow path of high-temperature waste heat gas, which is an example of a fluid flowing around. Further, the inflow direction of the waste heat gas flowing into the box-shaped container 13 from the inlet duct 14 and the flow direction of the waste heat gas in the heat transfer tube group 12 are substantially orthogonal (for example, 80 to 100 °, preferably 85). In addition, a plurality of (two in FIG. 1 and FIG. 2) baffle plates 15a and 15b that guide the waste heat gas flowing from the inlet duct 14 and change the flow direction thereof are provided in the orthogonal region 14a. It has been. Hereinafter, these will be described in detail.

The box-shaped container 13 is formed of heat-resistant steel (for example, stainless steel). For example, a rectangular parallelepiped main body portion 16 having a rectangular cross section, and a trapezoidal shape as viewed from the side connected to the upper portion of the main body portion 16. It has the discharge part 17 which became. Further, an inlet duct 14 formed of heat-resistant steel is substantially perpendicular to the side portion (for example, 80 side walls) at a lower portion of one side portion (a narrow side wall portion in FIGS. 1 and 2) of the main body portion 16. The outlet duct 18 formed of heat-resistant steel is connected to the upper portion of the discharge portion 17.

The baffle plates 15a and 15b are each provided with one end on the side of the opening 19 formed at a portion where the inlet duct 14 and the box-shaped container 13 are connected, and the other end is parallel to the inflow direction of the waste heat gas from the inlet duct 14. That is, the first guide portions 23 a and 23 b that extend into the main body portion 16 parallel to the bottom surface 20 of the main body portion 16 and that are in contact with the wide side walls 21 and 22 of the main body portion 16. have. Further, the baffle plates 15a and 15b are refracted and connected to the other end portions of the first guide portions 23a and 23b, respectively, and both sides abut against the side walls 21 and 22 of the main body portion 16 and flow from the inlet duct 14. It has the 2nd induction | guidance | derivation parts 24a and 24b which change the flow direction of waste heat gas into the flow direction parallel to the axial direction of the box-type container 13.

Furthermore, first small protrusions 25a and 25b are provided at the front portions of the second guide portions 24a and 24b so as to obstruct a part of the flow of the waste heat gas. In addition, the 1st induction | guidance | derivation part 23a, 23b, the 2nd induction | guidance | derivation part 24a, 24b, and the 1st small projection part 25a, 25b are formed using heat-resistant steel.
As a result, when the waste heat gas whose flow direction has been changed by each baffle plate 15a, 15b flows out from each baffle plate 15a, 15b, a small vortex is formed at the tip of each baffle plate 15, and each baffle plate 15a. , 15b, the amount of drift in the waste heat gas flowing out is reduced, and the flow becomes uniform. Further, even if the first small protrusions 25a and 25b are provided at the front portions of the baffle plates 15a and 15b, the flow of the waste heat gas is not greatly blocked, so that the pressure loss does not increase.

Here, when a plurality of, for example, N baffle plates are provided, the flow of waste heat gas flowing from the inlet duct 14 is divided into N + 1 flows by these baffle plates. At this time, if there is a difference between the flow rates of the divided waste heat gases, the flow of the waste heat gas that has passed through the baffle plates and joined again tends to be non-uniform.
For this reason, the position where one end side of each baffle plate provided on the opening 19 side is installed is made to coincide with the position where the cross-sectional area of the opening 19 is equally divided into N + 1. As a result, the flow rates of the divided waste heat gases can be made substantially the same, and the flow of the waste heat gases that have passed through the baffle plates and merged again in the heat transfer tube group 12 can be more uniformly flowed. Can be approached.

Also, the inner wall surface of the main body 16 changes the flow direction of the lowermost layer along the bottom surface 20 by changing the flow direction among the three waste heat gas flows formed by being divided by the two baffle plates 15a and 15b. A part of the flow of the waste heat gas flowing along the inner wall surface 26 is placed at a position where the inner surface of the side wall facing the opening 19 is substantially the same height as the first small protrusion 25. The 2nd small projection part 27 which disturbs is provided.
Accordingly, the flow of waste heat gas along the inner wall surface 26 can be agitated to reduce the size of the flow and make the flow uniform.

The heat transfer tube group 12 is provided between the tip of each baffle plate 15a15b via a diffusion region 28 that promotes diffusion of waste heat gas.
Here, the length H of the diffusion region 28 is affected by the temperature, flow rate, and pressure loss of the waste heat gas, but the temperature of the waste heat gas is 300 to 1000 ° C., and the flow rate of the waste heat gas is 10,000 to 100,000 Nm ³ / h, when the pressure loss is in the range of 200 to 1000 Pa, the length of the diffusion region 28 is set so that the time until it reaches the heat transfer tube group 12 through the baffle plate 15 is, for example, 0.01 to 0.2 seconds. The height H may be set.

The heat transfer tube group 12 is substantially orthogonal to the axial direction of the box-shaped container 13 (for example, 80 to 100 °, preferably 85 to 95 °), and is arranged in multiple stages in the axial direction of the box-shaped container 13. The heat transfer tube 11 made of a plurality of heat-resistant steels is provided.
By setting it as such a structure, the flow direction of the waste heat gas in the heat exchanger tube group 12 and the axial direction of each heat exchanger tube 11 are substantially orthogonal (for example, 80-100 degrees, Preferably it is 85-95 degrees). ).
Further, the heat transfer tube group 12 is on one side of the heat transfer tubes 11 adjacent to the upper side with respect to the heat transfer tubes 11 excluding the uppermost and lowermost steps, and on the other end side of the heat transfer tubes 11 adjacent to the lower side. A connecting member 29 to be connected is provided. Further, the first pipe 30 is connected to the side where the connecting member 29 is not connected to the uppermost heat transfer tube 11, and the second side is connected to the side where the connecting member 29 is not connected with the lowermost heat transfer tube 11. A pipe 31 is connected.
By adopting such a configuration, for example, water is introduced from the second pipe 31, passed through the heat transfer pipe group 12 via each heat transfer pipe 11 and each connection member 29, and flows out from the first pipe 30. Can be made. Accordingly, the water can be heated by passing the waste heat gas into the box-type container 13 while supplying water into the heat transfer tube group 12 from the second pipe 31, and hot water from the first pipe 30 or Water vapor mixed with warm water can be obtained.

Next, the operation method of the heat exchanger 10 according to the embodiment of the present invention will be described in detail.
First, after passing through the second pipe 31, water having a temperature of 80 to 170 ° C. or pressurized water is supplied to the heat transfer tube group 12 at a flow rate of 1000 to 3000 kg / h. On the other hand, waste heat gas (for example, exhaust gas from the combustor) having a temperature of 300 to 1000 ° C. and a flow rate of 10,000 to 50000 Nm ³ / h is caused to flow into the lower portion of the main body 16 from the inlet duct 14.
Waste heat gas that has flowed into the main body 16 from the inlet duct 14 through the opening 19 flows through the first guide portions 23a and 23b of the baffle plates 15a and 15b provided in two stages horizontally in the opening 19. Is divided into three equal parts. The divided waste heat gas flowing above the upper first guiding portion 23a is guided into the main body 16 along the first guiding portion 23a, and collides with the second guiding portion 24a to change its flow direction. The direction is changed to a substantially right angle (for example, 80 to 100 °, preferably 85 to 95 °), and is directed upward of the main body portion 16.

Waste heat gas flowing between the first guide portions 23a and 23b of the upper and lower baffle plates 15a and 15b is also guided into the main body 16 along the upper and lower first guide portions 23a and 23b. It collides with the lower second guide portion 24b and changes its flow direction to a substantially right angle so as to be directed upward of the main body portion 16. At this time, in the flow of the waste heat gas whose flow direction is changed, a drift is generated along the second guide portions 24a and 24b of the baffle plates 15a and 15b.
Further, the waste heat gas flowing below the lower first guide portion 23b is also guided into the main body portion 16 along the lower first guide portion 23b and the bottom surface 20, and collides with the inner wall surface 26 of the main body portion 16. Then, the flow direction is changed to a substantially right angle and becomes a direction toward the upper side of the main body portion 16. At this time, a drift along the inner wall surface 26 is generated in the flow of the waste heat gas whose flow direction is changed.

Waste heat gas whose flow direction has been changed by being guided by the upper and lower baffle plates 15a and 15b is drifted by the first small protrusions 25a and 25b when passing through the front portions of the baffle plates 15a and 15b. Is partially obstructed, and a small vortex is formed at the tip of each baffle plate 15a, 15b.
For this reason, since the drift flows through the baffle plates 15a and 15b while being stirred by the vortex, the magnitude of the drift in the waste heat gas flowing out through the baffle plates 15a and 15b is reduced. Approaching a uniform flow.

On the other hand, when the waste heat gas that has collided with the inner wall surface 26 and changed its flow direction flows out along the inner wall surface 26, a part of the drift is generated by the second small protrusions 27 provided on the inner wall surface 26. The passage is obstructed, and a small vortex is formed around the second small protrusion 27.
For this reason, since the drift flows through the second small protrusion 27 while being stirred by the vortex, the magnitude of the drift in the waste heat gas flowing out through the second small protrusion 27 is reduced. As a result, the flow becomes uniform.
Here, since the first small protrusions 25a and 25b and the second small protrusion 27 are provided at substantially the same height, each of the three baffle plates 15a and 15b is divided into three parts. The magnitude of the drift generated in the flow can be reduced and flow into the diffusion region 28. As a result, it is possible to prevent the influence of the drift from being strongly transmitted into the diffusion region 28.

The waste heat gases flowing into the diffusion region 28 are diffused and mixed with each other to form a single waste heat gas flow. At this time, in each waste heat gas, the magnitude of the remaining drift gradually decreases with diffusion. For this reason, at the time of passing through the diffusion region 28 and reaching the heat transfer tube group 12, the drift remaining in each waste heat gas is greatly reduced and approaches a more uniform flow.
Accordingly, since the waste heat gas having a uniform flow can be passed through the heat transfer tube group 12, the velocity distribution of the waste heat gas passing through the heat transfer tube group 12 is made uniform. .

In the heat transfer tube group 12, the flow direction of the waste heat gas and the axial direction of each heat transfer tube 11 are substantially orthogonal to each other, so that heat exchange between the waste heat gas and each heat transfer tube 11 is efficiently performed. This can be performed, and the surface of each heat transfer tube 11 can be efficiently heated.
Here, since the velocity distribution of the waste heat gas passing through the heat transfer tube group 12 is made uniform, the surface temperature of the heat transfer tube 11 at each stage of the heat transfer tube group 12 becomes uniform. For this reason, the heat load on the heat transfer tube 11 does not increase locally, and the progress of local corrosion of the heat transfer tube 11 is prevented, and the life of the heat transfer tube 11 can be extended.
The waste heat gas whose temperature has decreased after passing through the heat transfer tube group 12 flows into the discharge part 17 and is discharged to the outside from an outlet duct 18 provided at the upper part thereof.
Even if the first small protrusions 25a and 25b are provided at the front ends of the baffle plates 15a and 15b, and the second small protrusion 27 is provided on the inner wall surface 26 of the main body 16, the flow of waste heat gas is large. Since it is not stopped, the pressure loss does not increase.

Next, examples carried out for confirming the effects of the present invention will be described.
Here, FIGS. 3 to 5 are perspective views of the heat exchanger of the first embodiment of the present invention, the heat exchanger of the second embodiment of the present invention, and the heat exchanger of the comparative example, respectively. 6 to 8 show the inside of the heat transfer tube group during operation of the heat exchanger of the first embodiment of the present invention, the heat exchanger of the second embodiment of the present invention, and the heat exchanger of the comparative example, respectively. It is a perspective view which shows temperature distribution.

[Example 1]
As shown in FIG. 3, the heat exchange of the first embodiment is performed with the body portion 16 having a width of 2140 mm, a depth of 900 mm, and a height of 3800 mm (both are inner dimensions, the same applies hereinafter), a lower base width of 2140 mm, and an upper base width of 750 mm. , Having a discharge portion 17 having a depth of 900 mm and a height of 390 mm, the main body portion 16 includes an orthogonal region 14a having a width of 2140 mm, a depth of 900 mm, and a height of 1000 mm, a diffusion region having a width of 2140 mm, a depth of 900 mm, and a height of 1000 mm, and A heat transfer tube group 12 having a width of 2140 mm, a depth of 900 mm, and a height of 1650 mm is provided.
Here, two baffle plates 15a and 15b are provided in the orthogonal region 14a, and the tip ends of the baffle plates 15a and 15b are provided in accordance with positions where the width of the orthogonal region 14a is equally divided into three. The protruding lengths of the first and second small protrusions 25a, 25b, and 27 are all 80 mm. The inner diameters of the inlet duct 14 and the outlet duct 18 are both 762 mm, the upper baffle plate 15 a is 279.5 mm from the upper end of the opening 19, and the lower baffle plate 15 b is spaced from the upper baffle plate 15 a by 203 mm. And horizontally arranged.

Waste heat gas having a temperature of 410 ° C. was supplied from the inlet duct 14 at a flow rate of 25200 Nm ³ / h and discharged from the outlet duct 18. On the other hand, pressurized water having a temperature of 160 ° C. was supplied from the second pipe 31 at a flow rate of 2100 kg / h to perform heat exchange, and the obtained water vapor having a temperature of 320 ° C. and a pressure of 1.25 MPa was recovered from the first pipe 30. The temperature of the waste heat gas discharged from the outlet duct 18 was 234 ° C., and the pressure loss was 848 Pa.
The state of the temperature distribution in the heat transfer tube group 12 at this time is shown in FIG.

[Comparative example]
As shown in FIG. 5, the heat exchange of the comparative example includes a main body portion 16 a having a width of 2140 mm, a depth of 900 mm, and a height of 2800 mm, and a lower bottom width of 2140 mm, an upper bottom width of 750 mm, a depth of 900 mm, and a height of 390 mm. The body portion 16a is provided with an orthogonal region 14a having a width of 2140 mm, a depth of 900 mm, and a height of 1000 mm, and a heat transfer tube group 12 having a width of 2140 mm, a depth of 900 mm, and a height of 1650 mm.
The configuration of the two baffle plates 32a and 32b provided in the orthogonal region 14a is the same as that of the first embodiment, and includes the first guide portions 33a and 33b and the second guide portions 34a and 34b. The first small protrusions are not provided at the tip portions of the second guide portions 34 a and 34 b, and the second small protrusions are not provided on the inner wall surface 26.
Waste heat gas was introduced from the inlet duct 14 under the same conditions as in Example 1, and water was supplied from the second pipe 31 under the same conditions as in Example 1 to exchange heat. The water vapor obtained at this time had a temperature of 325 ° C. and a pressure of 1.26 MPa, the temperature of the waste heat gas discharged from the outlet duct 18 was 233 ° C., and the pressure loss was 842 Pa.
The state of the temperature distribution in the heat transfer tube group 12 at this time is shown in FIG.

As shown in FIG. 4, the heat exchange of Example 2 includes a main body portion 16 a having a width of 2140 mm, a depth of 900 mm, and a height of 2800 mm, and a discharge portion 17 having a lower bottom width of 2140 mm, an upper bottom width of 750 mm, a depth of 900 mm, and a height of 390 mm. And the diffusion region 28 is omitted from the heat exchanger of the first embodiment.
Then, waste heat gas was introduced from the inlet duct 14 under the same conditions as in Example 1, and water was supplied from the second pipe 31 under the same conditions as in Example 1 to exchange heat. The water vapor obtained at this time had a temperature of 320 ° C. and a pressure of 1.25 MPa, the temperature of the waste heat gas discharged from the outlet duct 18 was 234 ° C., and the pressure loss was 852 Pa.
The state of the temperature distribution in the heat transfer tube group 12 at this time is shown in FIG.

When FIG. 7 and FIG. 8 are compared, it can be seen that the temperature distribution in the heat transfer tube group 12 in Example 2 shows a flat distribution compared to the temperature distribution in the heat transfer tube group 12 in the comparative example. Accordingly, the first small protrusions 25a and 25b are provided at the front portions of the baffle plates 15a and 15b, and the second small protrusion 27 is provided on the inner wall surface 26, whereby the cross section of the heat transfer tube group 12 is increased. It was confirmed that the temperature distribution could be made uniform.
Further, comparing FIG. 6 with FIG. 8, the first and second small protrusions 25a, 25b, and 27 are provided, and the diffusion region 28 is provided between the tips of the baffle plates 15a and 15b and the heat transfer tube group 12. As a result, it was confirmed that the temperature distribution in the cross section of the heat transfer tube group 12 could be made very uniform.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The change in the range which does not change the summary of invention is possible, Each above-mentioned embodiment is possible. The case where the heat exchanger of the present invention is configured by combining some or all of the forms and modifications is also included in the scope of the right of the present invention.
For example, although two baffle plates are provided, one or three or more baffle plates may be used depending on the cross-sectional area of the box-type container. Moreover, although the 1st small projection part was attached to the front part of the 2nd guide plate, you may fold the front part of a 2nd guide plate and comprise a 1st small projection part. Although the first guide plate and the second guide plate are connected so as to be refracted, the first and second guide portions may be configured by bending so that one heat-resistant steel plate is bent. Good.
Furthermore, the lower part of the inner wall surface facing the inlet duct in the main body part of the box-shaped container may be curved and smoothly connected to the bottom surface of the main body part. By curving, the waste heat gas can easily flow and the pressure loss can be further reduced.
Moreover, although waste heat gas was made to flow into the lower part of a heat exchanger and was discharged | emitted from the upper part, you may make it invert a heat exchanger, make waste heat gas flow in from an upper part, and make it flow out from a lower part.
In addition, although the high temperature waste heat gas was used for the fluid, a low temperature fluid (for example, gas) can also be used. In this case, the heat exchange fluid (for example, water) flowing through the heat transfer tube can be cooled.

It is a partially cutaway perspective view of a heat exchanger according to an embodiment of the present invention. It is a sectional side view of the same heat exchanger. It is a perspective view of the heat exchanger of the 1st example of the present invention. It is a perspective view of the heat exchanger of the 2nd Example of this invention. It is a perspective view of the heat exchanger of a comparative example. It is a perspective view which shows the temperature distribution in the heat exchanger tube group in the driving | operation of the heat exchanger of 1st Example of this invention. It is a perspective view which shows the temperature distribution in the heat exchanger tube group in the driving | operation of the heat exchanger of the 2nd Example of this invention. It is a perspective view which shows the temperature distribution in the heat exchanger tube group in the driving | operation of the heat exchanger of a comparative example.

Explanation of symbols

10: heat exchanger, 11: heat transfer tube, 12: heat transfer tube group, 13: box-type container, 14: inlet duct, 14a: orthogonal region, 15a, 15b: baffle plate, 16, 16a: main body, 17: discharge Part, 18: outlet duct, 19: opening, 20: bottom surface, 21, 22: side wall, 23a, 23b: first guiding part, 24a, 24b: second guiding part, 25a, 25b: first small Projection part, 26: inner wall surface, 27: second small projection part, 28: diffusion region, 29: connecting member, 30: first pipe, 31: second pipe, 32a, 32b: baffle plate, 33a, 33b: 1st guide part, 34a, 34b: 2nd guide part

Claims (4)

A heat transfer tube group including a plurality of stages of heat transfer tubes, and a box-shaped container that surrounds the heat transfer tube group and forms a fluid flow path that flows around each of the heat transfer tubes, and flows into the box-shaped container The inflow direction of the fluid from the inlet duct and the flow direction of the fluid in the heat transfer tube group are substantially orthogonal, and the fluid flowing in from the inlet duct is guided to the orthogonal region. In heat exchangers with baffle plates to change,
A heat exchanger characterized in that a first small protrusion that obstructs a part of the fluid is provided at the tip of the baffle plate, and the flow of the fluid passing through the heat transfer tube group is made uniform. . 2. The heat exchanger according to claim 1, wherein an inner wall surface of the box-type container that is in contact with the orthogonal region and changes the flow direction by colliding with the fluid has substantially the same height as the first small protrusion. The heat exchanger is characterized in that a second small protrusion that obstructs a part of the fluid that flows along the inner wall surface is provided at the position. The heat exchanger according to any one of claims 1 and 2, wherein a diffusion region that promotes diffusion of the fluid is provided between a tip of the baffle plate and the heat transfer tube group. Heat exchanger. The heat exchanger according to any one of claims 1 to 3, wherein the flow direction of the fluid in the heat transfer tube group and the axial direction of the heat transfer tubes are substantially orthogonal to each other. Heat exchanger.

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