JP2003314803A - Waste heat recovery boiler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste heat recovery boiler performing steam separation of steam to be fed from a vaporizer to a heater even if eliminating a steam drum. <P>SOLUTION: This waste heat recovery boiler is provided with the vaporizer which heats water supply flowing inside multiple vaporizer pipes 34 by waste heat discharged from a waste heat generation source such as a gas turbine to generate the vapor, and comprises to collect two-phase flow of the steam and the water generated in the vaporizer pipes 34 into a vaporizer outlet pipe header 35. A rotational vane 50 as a rotational flow forming means is provided in a vaporizer outlet connecting pipe connected to the outlet side of the vaporizer outlet pipe header 35. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust heat recovery boiler which produces steam by utilizing exhaust heat of exhaust gas discharged from a gas turbine or the like.

[0002]

2. Description of the Related Art Exhaust heat recovery boilers are used in combined cycle power plants constructed in combination with, for example, gas turbines. In a combined cycle power plant, a gas turbine drives a generator to generate electric power, and exhaust heat of exhaust gas discharged from the gas turbine is used to generate steam. If this steam is supplied to a steam turbine, it can be used to drive a generator, so that power can also be generated by the steam turbine, and therefore it is attracting attention as a highly efficient and environmentally friendly power plant.

In such a combined cycle power plant, a heat recovery steam generator is known as a device for generating steam by utilizing exhaust heat discharged from an exhaust heat generating source such as a gas turbine. ing. Hereinafter, as an example of the exhaust heat recovery boiler, a combined three-pressure reheat natural circulation exhaust heat recovery boiler (hereinafter abbreviated as “HRSG”) will be briefly described with reference to FIG. 6.

In the conventional HRSG 10 shown in the same drawing, a high pressure evaporator 12 is introduced into a casing 11 which guides the exhaust gas G from the lower side to the upper side in order from the lower side to the upper side which is the flow direction of the exhaust gas G. A medium pressure evaporator 13 and a low pressure evaporator 14 are arranged. The high-pressure evaporator 12 heats the feed water supplied from the high-pressure steam drum 15 and flowing through the many evaporator tubes 16 by the gas turbine exhaust G to generate high-pressure steam SH. The water supply in this case is water that has been preheated by the exhaust heat of the gas turbine exhaust G by branching from the water supply W1 of the medium-pressure evaporator 13 described later and flowing through the water supply pipe 17 that passes through the inside of the casing 11.

The medium-pressure evaporator 13 heats the feed water W1 supplied from the medium-pressure steam drum 18 and flowing in a large number of evaporator pipes 19 by the gas turbine exhaust G to generate medium-pressure steam SI. The water supply pipe 20 of the water supply W1 passes through the inside of the casing 11, so that the water supply preheated by the gas turbine exhaust G is used. The low-pressure evaporator 14 heats the feed water W2 supplied from the low-pressure steam drum 21 and flowing in the many evaporator tubes 22 with the gas turbine exhaust G to generate the low-pressure steam SL. In addition, the water supply pipe 23 of the water supply W2 is the casing 1
1 through which the feed water preheated in the gas turbine exhaust G is used. In addition, the high pressure steam S described above
H, medium pressure steam SI and low pressure steam SL are casing 11
It is led to an internal superheater (not shown) and reheated to give a superheat degree before being supplied to a steam turbine or the like.

A standard system diagram of the above-described high-pressure evaporator 12, intermediate-pressure evaporator 13 and low-pressure evaporator 14 is shown in FIG. In the figure, reference numeral 30 is an evaporator, 31 is a steam drum, 32 is a downcomer, 33 is an evaporator inlet pipe,
34 is an evaporator pipe, 35 is an evaporator outlet pipe, 36L is a left evaporator outlet communication pipe, 36R is a right evaporator outlet communication pipe,
37 is a water supply pipe, 38 is a saturated steam pipe, and W is water supply.

In the evaporator 30, the water supply W is supplied into the steam drum 31 through the water supply pipe 37. This water supply W
Flows out from the pair of left and right downcomer pipes 32 to the evaporator inlet header 33, and is further distributed from the evaporator inlet header 33 to a large number of evaporator pipes 34. One end of the evaporator pipe 34 is connected to the evaporator inlet pipe 33, and the other end is connected to the evaporator outlet pipe 3
It is a U-shaped tube connected to 5. The water supply W is heated by the high temperature gas turbine exhaust G that rises from the bottom to the top of the evaporator pipe 34 by flowing in the evaporator pipe 34, and becomes a two-phase flow of steam and water. Outlet heading 35
Flow into. In addition, the evaporator pipes 34 are respectively arranged toward the center of the evaporator outlet pipe 35 on the same circumference.
Books or multiple books are connected.

After that, the two-phase flow of steam and water is split into the left evaporator outlet communication pipe 36L and the right evaporator outlet communication pipe 36R and returns to the steam drum 31. In the steam drum 31,
Saturated steam flows out through the saturated steam pipe 38, and the water merges with the feed water W flowing out of the downcomer pipe 32 and is recirculated. That is, the above-mentioned steam drum 31 is installed so that only steam is supplied to the superheater (not shown) without containing water.

[0009]

By the way, in the exhaust heat recovery boiler having the above-mentioned structure, it is required to reduce the device cost. From such a background, it is considered to abolish the steam drum 31, which is a pressure vessel and is expensive. However, the steam supplied from the evaporator 30 to the superheater needs to have a steam quality of 1 or more so as not to contain water, and therefore, some measure to replace the steam drum 30 is required. It is conceivable to install a brackish water separator as an apparatus replacing the steam drum 30. However, since the steam container is a pressure vessel like the steam drum 30, reduction in apparatus cost cannot be expected so much.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an exhaust heat recovery boiler capable of separating steam supplied from an evaporator to a superheater into brackish water even if the steam drum is abolished. I am trying.

[0011]

The present invention adopts the following means in order to solve the above problems. The exhaust heat recovery boiler according to claim 1 is provided with an evaporator that heats feed water flowing in a large number of evaporator tubes with exhaust heat discharged from an exhaust heat generation source such as a gas turbine to generate steam, In a heat recovery steam generator configured to collect the two-phase flow of steam and water generated in the evaporator pipe to the evaporator outlet pipe, inside the evaporator outlet communication pipe connected to the outlet side of the evaporator outlet pipe It is characterized in that a swirl flow forming means is provided in the.

According to such an exhaust heat recovery boiler, since the swirl flow forming means is provided in the evaporator outlet communication pipe connected to the outlet side of the evaporator outlet pipe, the two-phase flow is formed by the swirl flow forming means. By passing, it becomes a swirling flow along the inner wall of the pipe and flows toward the outlet side. For this reason, centrifugal force acts on the two-phase flow of steam and water, and the specific gravities of the two differ, so that water with a large specific gravity gathers outside, and steam with a small specific gravity conversely separates in the central part. To be done.

In the exhaust heat recovery boiler according to claim 1, swirl vanes or swirl ribbons are suitable as swirl flow forming means, and when the two-phase flow passes through the swirl vanes or swirl ribbons, swirl flow along the inner wall of the pipe is generated. Become. (Claims 2 and 3)

Further, in the exhaust heat recovery boiler according to the first aspect, the swirl flow forming means is formed in the evaporator outlet communication pipe and narrows the cross-sectional area of the pipe passage toward the pipe inner wall side in the outlet direction. It may be configured to include an inclined surface and a transverse outlet communication pipe connected to intersect with the evaporator outlet communication pipe, whereby the two-phase flow collected on the inner wall side of the pipe at the inclined surface. Flows in from the tangential direction of the transverse outlet connecting pipe.
Therefore, the two-phase flow that has flowed into the transverse outlet communication pipe becomes a swirl flow along the inner wall of the pipe. (Claim 4)

In the exhaust heat recovery boiler according to any one of claims 1 to 4, a saturated steam pipe in which a saturated steam inlet is opened substantially concentrically is provided inside the evaporator outlet communication pipe or the transverse outlet communication pipe. It suffices to arrange them in a double pipe structure, which ensures that the steam collected in the central portion flows out from the saturated steam pipe without containing water on the outside. (Claim 5)

In the exhaust heat recovery boiler according to any one of claims 1 to 3, a diameter expansion outlet communication pipe is provided on the downstream side of the swirl flow forming means and outside the evaporator outlet communication pipe. A tube structure may be provided with a slit for communicating between the evaporator outlet communication pipe and the expanded outlet communication pipe, and the evaporator outlet communication pipe on the downstream side of the slit may be used as a saturated vapor pipe. The outer water flows out from the slit to the expanded diameter outlet communication pipe, and the steam collected in the central portion surely flows out from the evaporator outlet communication pipe used as a saturated steam pipe without containing the outer water. (Claim 6)

Further, in the exhaust heat recovery boiler according to any one of claims 1 to 6, when the evaporator outlet pipe or the transverse outlet connecting pipe is installed horizontally, the saturated steam pipe is directed upward. It is preferable that the evaporator outlet pipe is guided downward, whereby it is possible to prevent water with a large specific gravity from being included in the steam with a small specific gravity that is guided upward. Can be reliably separated. (Claim 7)

Further, in the exhaust heat recovery boiler according to any one of claims 1 to 6, when the evaporator outlet pipe or the transverse outlet communication pipe is installed vertically or inclined, the saturated steam It is preferable that the pipe is opened to the upper end side of the evaporator outlet pipe side and guided upward, so that it becomes difficult for water having a large specific gravity to flow upward from the upper end side opening. And water can be reliably separated. (Claim 8)

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an exhaust heat recovery boiler according to the present invention will be described below with reference to the drawings. In each of the following embodiments, the evaporator 3 shown in FIG. 7 as a conventional example is used.
No. 0 and the evaporator outlet pipe header 35 will be described with reference to the enlarged main drawings.

<First Embodiment> FIG. 1 (a) is an enlarged cross-sectional view of an essential portion of the vicinity of an outlet of an evaporator pipe, in which reference numeral 34 is an evaporator tube and 35 is an evaporator. Outlet heading, 3
6 is an evaporator outlet communication pipe, 40 is a saturated steam pipe, and 50 is a swirl vane. In this embodiment, a configuration example of a horizontally placed header in which the evaporator outlet header 35 is installed horizontally is shown. In the illustrated example, as shown in FIG.
The four evaporator tubes 34 are connected on the same circumference.

In the evaporator outlet header 35, the feed water which is heated in the process of passing through a large number of evaporator tubes 34 and becomes a two-phase flow of steam and water is collected, and only saturated steam is superheated (not shown). Supply to. On the outer peripheral surface of the evaporator outlet pipe header 35, four evaporator pipes 34 directed toward the pipe center are radially connected on the same circumference and communicate with the inside of the pipe. As described above, the structure in which the four evaporator tubes 34 are connected on the same circumference is generally referred to as “four-piece take”.
A large number of main arrangements are arranged in the axial direction of the evaporator outlet pipe head 35. Although FIG. 1 shows an example in which four evaporator tubes 4 are taken, the number is not limited to four and can be appropriately selected from one and plural.

Now, in the present invention, the evaporator outlet pipe head 35
Outlet connection pipe 3 connected to the outlet (downstream) side of the
A swirl vane 50 is installed inside the straight pipe portion 6 as a swirl flow forming means. The swirl vane 50 is, for example, a plurality of plate-shaped blades or blades arranged in the circumferential direction, and swirls by rotating the two-phase flow flowing from the evaporator outlet header 35 to the evaporator outlet communication pipe 36. It has the function of converting into a flow.

With such a structure, the two-phase flow of steam and water flowing into the evaporator outlet pipe 35 passes through the swirl vanes 50 installed in the evaporator outlet communication pipe 36, and thereby the swirl flow is generated. Becomes As a result, the two-phase flow is guided in the outlet direction while swirling along the inner wall of the evaporator outlet communication pipe 36, and due to the centrifugal force, water having a large specific gravity gathers on the inner wall side which is the outer side, and the specific gravity is small. Since steam collects on the center side of the pipe, the steam and water are separated in the evaporator outlet communication pipe 36 downstream of the swirl vanes 50. Therefore, if only the steam collected at the center of the evaporator outlet communication pipe 36 is guided to the superheater, it is possible to supply steam having a steam quality of 1 or more to the superheater even if the steam drum 31 is eliminated. Become.

As shown in FIG. 1 (a), as a concrete structural example for surely guiding the steam and water separated in the radial direction in the evaporator outlet communication pipe 36 to the desired equipment as described above. There is a double pipe structure in which a saturated steam pipe 40 is arranged in the evaporator outlet communication pipe 36 so as to be opened substantially concentrically. The saturated steam pipe 40 has an opening 41, which is one end thereof, opened downstream of the swirl vane 50 with an appropriate distance.
Then, the saturated steam pipe 40 penetrates through the evaporator outlet communication pipe 36, and is turned around by 90 degrees from the horizontally installed evaporator outlet pipe header 35 to be guided upward. On the other hand, the evaporator outlet communication pipe 36 connected to the evaporator outlet pipe 35 forms a straight pipe portion required for swirling flow formation and steam / water separation on the downstream side of the opening 41, and then the saturated vapor is formed. It is turned downward from the evaporator outlet pipe head 35 by about 90 degrees in the opposite direction to the pipe 40.

In this way, the steam having a small specific gravity flowing from the opening 41 into the saturated steam pipe 40 easily forms an upward flow and is guided to the superheater, and the water having a large specific gravity flowing outside is evaporated. Since the downward flow is formed by being guided to the outlet communication pipe 36, even if water with a large specific gravity is mixed with the steam flowing in the saturated steam pipe 40, it cannot follow the upward flow and is separated. Therefore, the separation of steam and water becomes more reliable, and high-quality steam can be stably supplied to the superheater. It is to be noted that the above-described two-phase flow of steam and water is likely to occur in the evaporator 30 when the gas turbine exhaust gas temperature is not stable when the engine is started or when the load changes. For example, even in such a case, the steam drum can be eliminated.

By the way, as the swirl vane 50 of the swirl flow forming means described above, a swirl ribbon 55 can be adopted as in the first modification shown in FIG. 2, for example.
The swirling ribbon 55 is, for example, a thin metal plate twisted to form a spiral shape substantially matching the inner diameter of the evaporator outlet communication pipe 36, and is fixed in the pipe by an appropriate means. When such a swirl ribbon 55 is installed, the two-phase flow passing through the swirl ribbon 55 becomes a swirl flow and is subjected to the action of centrifugal force. Therefore, the two-phase flow can be separated into steam and water in the same manner as the swirl vane 50 described above.

The saturated steam pipe 4 for guiding the separated steam
0 and the evaporator outlet communication pipe 36 that guides water, if the same configuration as that of the embodiment shown in FIG. 1 is adopted to more reliably separate steam and water, the quality of the superheater is improved. High steam can be supplied stably.

Next, a second modification shown in FIG. 3 will be described. In the second modified example, the structure of the saturated steam pipe 40 that guides the steam collected in the central portion of the pipe downstream of the swirl vane 50 to a superheater (not shown) is different. In this modification, a double-walled pipe in which a diameter-expanded outlet communication pipe 36A formed by expanding the evaporator outlet communication pipe 36 is provided substantially concentrically on the downstream side of the swirl vane 50 and outside the evaporator outlet communication pipe 36. The structure is adopted.
Then, a slit 37 is provided to connect the inside evaporator outlet communication pipe 36 and the outside diameter expansion outlet communication pipe 36A,
The evaporator outlet communication pipe 36 on the downstream side of the slit 37 is used as a saturated steam pipe 40. A straight pipe portion having an appropriate length is provided between the swirl vane 50 and the slit 37 so that swirl flow is sufficiently formed and steam and water are sufficiently separated.

For this reason, the evaporator outlet communication pipe 36 used as the saturated steam pipe 40 is provided with a suitable straight pipe portion on the downstream side of the slit 37 so as not to disturb the flow, and then the direction is changed by about 90 degrees to expand the diameter. It is guided upward through the outlet communication pipe 36A. Further, the diameter expansion outlet communication pipe 36A is provided with the slit 37.
On the downstream side, the direction of the saturated steam pipe 40 is changed from the horizontal direction downward by about 90 degrees.

According to this structure, the two-phase flow passing through the swirl vane 50 becomes a swirl flow and a centrifugal force acts, so that water having a large specific gravity gathered on the outer pipe wall side passes through the slit 37. The steam having a small specific gravity, which has flowed out to the diameter expansion outlet communication pipe 36A and has gathered in the center of the pipe, goes straight into the saturated steam pipe 40. Therefore, the two-phase steam and water are reliably separated, and the saturated steam of high quality can be stably supplied to the superheater through the saturated steam pipe 40.

In the above-described embodiment and its modified example, the application to the horizontal placement of the evaporator outlet header 35 is shown, but the vertical placement of the evaporator outlet pipe 35 is explained. Needless to say, it can be applied to a pipe head or a tilted pipe head installed at an angle. In the case of such a vertical pipe arrangement or an inclined pipe arrangement, the saturated vapor pipe 40 has a double pipe structure in which the saturated vapor pipe 40 opens to the upper end side of the evaporator outlet pipe 35, and the separated saturated vapor is guided upward. Good. Also,
The water separated from the two-phase flow may be provided with the evaporator outlet communication pipe 36 or the expanded diameter outlet communication pipe 36A so as to flow downward as it is.

<Second Embodiment> FIGS. 4A and 4B.
Is an enlarged cross-sectional view of an essential part of the vicinity of the evaporator outlet pipe,
(A) is a front view and (b) is a plan view. In addition,
In the figure, reference numeral 34 is an evaporator pipe, 35 is an evaporator outlet pipe,
36 is an evaporator outlet connecting pipe, 40 is a saturated steam connecting pipe, 45 is a transverse outlet connecting pipe, 60 is an inclined surface, and 61 is a block.

In this embodiment, the evaporator outlet pipe header 35
Shows a configuration example of horizontal placement of a horizontal pipe. In the illustrated example, four evaporator pipes 34 are connected on the same circumference. The swirl flow forming means of this embodiment is formed in the evaporator outlet communication pipe 36 connected to the evaporator outlet pipe head 35, and is an inclined surface that narrows the cross-sectional area of the pipe flow passage toward the pipe inner wall 36a in the outlet direction. 60 and a transverse outlet communication pipe 45 connected to intersect with the evaporator outlet communication pipe 36.

The inclined surface 60 in FIG. 4 is the evaporator outlet communication pipe 3
6 is formed by a block 61 fixedly installed. The illustrated transverse outlet communication pipe 45 is a pipe of the same diameter connected to one end of the evaporator outlet communication pipe 36 in a T shape, and is installed vertically to the horizontal evaporator outlet communication pipe 36. . A saturated steam pipe 40 is arranged substantially concentrically on the upper end side of the transverse outlet pipe 45, and an opening 41 thereof is opened as an inlet for saturated steam. In addition, crossing exit connection pipe 4
5 does not necessarily have the same diameter as the evaporator outlet communication pipe 36, and can be appropriately selected.

With such a structure, the two-phase flow of steam and water flowing into the evaporator outlet communication pipe 36 approaches the transverse outlet pipe 45 along the inclined surface 60 along the pipe inner wall 3
6a is collected in one direction (in the illustrated example, the upper side of the plane of the drawing). As a result, the two-phase flow comes to flow from the substantially tangential direction along the inner pipe wall 45a of the transverse outlet communication pipe 45, so that the two-phase flow in the transverse outlet communication pipe 45 becomes a swirl flow and acts by centrifugal force. Receive. For this reason, steam and water are separated into the inside and outside of the pipe due to the difference in specific gravity, so that steam with a small specific gravity gathers on the pipe center side and is guided from the saturated steam pipe 40 to a superheater (not shown), and water with a large specific gravity Crossing exit connecting pipe 4
It falls in 5 and is guided downward. Therefore, the two-phase steam and water are reliably separated, and the saturated steam of high quality can be stably supplied to the superheater through the saturated steam pipe 40.

In the modification shown in FIG. 5, an inclined plate 62 is fixedly installed in the evaporator outlet communication pipe 36 instead of the block 60, and the inclined surface 60 is formed. Even in this case, the same effect as that of the inclined surface 60 by the block 61 described above can be obtained. Moreover, in the embodiment of FIGS. 4 and 5 described above, an example is shown in which the evaporator outlet pipe header 35 and the evaporator outlet communication pipe 36 are horizontally installed and the transverse outlet communication pipe 45 is connected in the vertical direction. However, the present invention is not limited to this. For example, the cross outlet pipe 36 may be inclined,
Alternatively, various modifications are possible in which a two-phase swirl flow is formed in the transverse outlet communication pipe 45 by using the inclined surface 60, such as inclining the evaporator outlet header 35 and the evaporator outlet communication pipe 36. .

As described above, according to each of the embodiments of the present invention, a swirl flow forming means installed in the evaporator outlet communication pipe 36 forms a swirl flow of a two-phase flow, and vapor is generated from this two-phase flow. Since saturated steam can be separated and supplied to the superheater, the steam drum installed for the purpose of brackish water separation becomes unnecessary. It should be noted that the configuration of the present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of the present invention.

[0038]

The exhaust heat recovery boiler of the present invention has the following effects. According to the invention described in claim 1, since the swirl flow forming means is provided in the evaporator outlet communication pipe connected to the outlet side of the evaporator outlet pipe, the two-phase flow passing through the swirl flow forming means is It becomes a swirling flow along the inner wall of the pipe. As a result, the steam and water of the two-phase flow have different specific gravities, so the steam and water are separated by centrifugal force, the water with a large specific gravity gathers outside, and the steam with a small specific gravity gathers in the central part. Brackish water can be separated even if it is abolished.

In such an exhaust heat recovery boiler, if a swirl vane or swirl ribbon is used as the swirl flow forming means, the two-phase flow can be made into a swirl flow and separated into steam and water in a relatively small space. In addition, an inclined surface that is formed in the evaporator outlet communication pipe and narrows the cross-sectional area of the pipe flow path toward the pipe inner wall in the outlet direction, and a transverse outlet communication pipe that is connected to intersect the evaporator outlet communication pipe If the swirl flow forming means configured as described above is adopted, the two-phase flow flowing in from the tangential direction of the transverse outlet communication pipe can be swirled and separated into steam and water.

According to the invention described in any one of claims 1 to 4, a double pipe in which a saturated steam pipe having a saturated steam inlet opening substantially concentrically is arranged inside the evaporator outlet communication pipe or the transverse outlet communication pipe. Since the structure is adopted, the steam collected in the central portion of the pipe comes to flow out from the saturated steam pipe without containing water on the outside, and the saturated steam can be reliably recovered and supplied to the superheater.

According to the invention described in any one of claims 1 to 3, a double-pipe structure is provided in which a diameter-increasing outlet communication pipe is provided on the downstream side of the swirl flow forming means and outside the evaporator outlet communication pipe. Since a slit that connects the evaporator outlet communication pipe and the diameter expansion outlet communication pipe is provided, and the evaporator outlet communication pipe on the downstream side of the slit is used as a saturated steam pipe, the water separated outside expands from the slit. The steam that flows out to the diameter outlet communication pipe and collects in the center part will surely flow out from the evaporator outlet communication pipe that will become a saturated steam pipe as it is without containing water, and will surely recover saturated steam and superheat it. Can be supplied to the vessel.

According to the invention described in any one of claims 1 to 6, when the evaporator outlet header or the transverse outlet connecting pipe is installed horizontally, the saturated steam pipe is guided upward, and the evaporator outlet is directed. If the header is guided downward, it is possible to prevent the steam having a small specific gravity guided upward and containing water having a large specific gravity from flowing, so that the steam and the water can be reliably separated. Further, according to the invention of any one of claims 1 to 6, when the evaporator outlet pipe header or the transverse outlet communication pipe is installed vertically or inclined,
If the saturated steam pipe is opened to the upper end side of the evaporator outlet pipe and guided upward, it will be difficult for water with a large specific gravity to flow upward from the upper end side opening. It can be reliably separated from water.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part showing a first embodiment of an exhaust heat recovery boiler according to the present invention, where (a) is a front view showing an enlarged side view of a horizontal pipe holder, and (b) is ( It is sectional drawing which follows the AA line of a).

2A and 2B are cross-sectional views of a main part showing a first modified example according to the first embodiment shown in FIG. 1, where FIG. 2A is an enlarged front view of a horizontal placement pipe vicinity, and FIG. FIG. 7A is a sectional view taken along line BB of FIG.

3A and 3B are cross-sectional views of a main part showing a second modified example according to the first embodiment shown in FIG. 1, where FIG. 3A is an enlarged front view showing the vicinity of a horizontal placement pipe holder, and FIG. FIG. 7A is a sectional view taken along line CC of FIG.

[Fig. 4] Fig. 4 is a cross-sectional view of an essential part showing a second embodiment of an exhaust heat recovery boiler according to the present invention, (a) is an enlarged front view of a horizontal placement pipe vicinity, and (b) is ( a) plan view,
(C) is sectional drawing which follows the DD line | wire of (a).

FIG. 5 is a cross-sectional view of main parts of a modified example according to the second embodiment shown in FIG. 4, and is a front view showing an enlarged periphery of a horizontal placement header.

FIG. 6 shows an example of an exhaust heat recovery boiler (HRSG).
It is a figure which shows schematic structure of the triple pressure reheat natural circulation exhaust heat recovery boiler for combined use.

FIG. 7 is a standard systematic diagram showing a conventional example of an evaporator of an exhaust heat recovery boiler.

[Explanation of symbols]

30 evaporator 31 steam drum 34 Evaporator tube 35 Evaporator outlet pipe 36 Evaporator outlet connection pipe 36A Expanding outlet connecting pipe 37 slits 40 Saturated steam pipe 41 opening 45 Crossing exit connecting pipe 50 swirl vanes (swirl flow forming means) 55 Swirling Ribbon (Swirl Flow Forming Means) 60 inclined surface 61 blocks 62 inclined plate

Claims (8)

[Claims] 1. An evaporator that heats feed water flowing in a large number of evaporator pipes with exhaust heat discharged from an exhaust heat generation source such as a gas turbine to generate steam, and the steam generated in the evaporator pipes And a waste heat recovery boiler configured to collect a two-phase flow of water into the evaporator outlet pipe, wherein a swirling flow forming means is provided in the evaporator outlet communication pipe connected to the outlet side of the evaporator outlet pipe. Exhaust heat recovery boiler characterized by 2. The exhaust heat recovery boiler according to claim 1, wherein the swirl flow forming means is a swirl vane. 3. The exhaust heat recovery boiler according to claim 1, wherein the swirl flow forming means is a swirl ribbon. 4. The swirl flow forming means intersects with the evaporator outlet communication pipe, with an inclined surface formed in the evaporator outlet communication pipe to narrow the cross-sectional area of the pipe flow passage toward the pipe inner wall side in the outlet direction. The exhaust heat recovery boiler according to claim 1, wherein the exhaust heat recovery boiler is configured by including a transverse outlet communication pipe connected to each other. 5. A double-pipe structure is provided by arranging a saturated steam pipe having a saturated steam inlet opened substantially concentrically inside the evaporator outlet communication pipe or the transverse outlet communication pipe. The exhaust heat recovery boiler according to any one of 1 to 4. 6. A double-pipe structure is provided by providing a diameter expansion outlet communication pipe on the downstream side of the swirl flow forming means and outside the evaporator outlet communication pipe, and the evaporator outlet communication pipe and the diameter expansion outlet communication are connected. The exhaust heat recovery boiler according to any one of claims 1 to 3, wherein a slit for communicating with the pipe is provided, and the evaporator outlet communication pipe on the downstream side of the slit is used as a saturated steam pipe. 7. The saturated steam pipe is guided upward and the evaporator outlet pipe is guided downward when the evaporator outlet header or the transverse outlet connecting pipe is installed horizontally. The exhaust heat recovery boiler according to any one of claims 1 to 6. 8. When the evaporator outlet header or the transverse outlet connecting pipe is installed vertically or inclined, the saturated steam pipe opens upward to the upper end side of the evaporator outlet header. Guided by:
The exhaust heat recovery boiler according to any one of 1.