JP2017040437A - High-temperature exhaust cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve strength and service life by suppressing contact of an exhaust gas of high temperature without using a heat insulating material.SOLUTION: A high-temperature exhaust cylinder unit 1 includes an exhaust cylinder 2 provided with a tapered portion 4 gradually reduced in a diameter at a tip side of a cylinder body 3 in which a high-temperature exhaust gas is circulated, and a skirt portion 5 at a rear end side, and a rectifier 7 disposed in the exhaust cylinder 2 for circulating the high-temperature exhaust gas and the outside air as laminar flow. The tapered portion 4 of the exhaust cylinder 2 at a lower side is opposed to the skirt portion 5 of the exhaust cylinder 2 at an upper side with a clearance 8, and, for example, three exhaust cylinders 2A, 2B, 2C are arranged in series. The high-temperature exhaust gas flowing into the exhaust cylinder 2A at a lower side is increased in speed by being passed through the tapered portion 4, and the outside air is introduced due to negative pressure of the clearance 8 by venturi effect, and flows along an inner face of the exhaust cylinder 2. In the exhaust cylinder 2, the outside air flow and the exhaust gas flow are rectified by the rectifier 7 and formed into two-layered laminar flow of the outside air flow at an outer peripheral side and the exhaust gas flow at a central side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a high-temperature exhaust pipe for discharging high-temperature exhaust gas by combustion of a gas turbine or the like used in a power plant such as an engine generator.

In a facility using an engine generator, high-temperature exhaust gas generated when the engine generator is operated is generally released and diluted to the outside air using an exhaust pipe including a chimney or the like. In order to reduce the influence on the surroundings of the facility, the discharge of the exhaust gas is often performed at a height as much as possible. Therefore, a long and narrow exhaust pipe is used.
Further, the temperature and exhaust pressure of the exhaust gas vary depending on the type of the motor generator, and it is necessary to make the exhaust tube specifications corresponding to each. At present, the generators that are becoming mainstream use a gas turbine engine as the engine. Therefore, the exhaust gas temperature and flow velocity are higher than those of the conventional diesel engines, and in one example, the exhaust gas temperature is 600 ° C. The exhaust gas wind speed reaches 40 m / s.

  As a high-temperature exhaust pipe used for combustion exhaust gas such as a gas turbine, conventionally, an exhaust pipe unit in which an exhaust pipe loaded with a heat insulating material between, for example, metal double pipes is vertically stacked is known. The heat insulating material is made of, for example, a fibrous or foamed material made of an inorganic material. In this high-temperature exhaust pipe, a plurality of metal double pipes sandwiching a heat insulating material are connected in the vertical direction at a joint portion to form an exhaust pipe unit.

Further, in other high-temperature exhaust gas chimneys, the chimney cylinder of the outer wall is formed of structural carbon steel, and the heat insulating material is formed on the inner surface thereof. Moreover, since the outer surface temperature of the chimney cylinder of carbon steel needs to be suppressed to 60 ° C. to 70 ° C. or less, the heat insulating material has to be lined thickly.
In the chimney for high-temperature exhaust gas described in Patent Document 1 improved in this manner, the heat insulating material on the inner surface of the chimney cylinder is separated into the first layer and the second layer, and a space air flow passage is formed between them, and the chimney cylinder An introduction space is formed between the lower inner surface of the first layer and the heat insulating material of the first layer to communicate with the space air flow passage. And since the outside air introduced from the space for introducing the chimney cylinder flows through the space air flow passage and can cool the inner and outer walls of the chimney, the thickness of the heat insulating material by the first layer and the second layer is reduced to make the chimney lighter It can be made.

Japanese Patent No. 3511216

  By the way, in the above-described conventional high-temperature exhaust pipe and high-temperature exhaust gas chimney, rainwater or the like is likely to enter through the joint portion or the upper end opening of the chimney. When the motor generator is continuously operating continuously, the water that has entered the heat insulating material evaporates immediately due to the exhaust heat, so that it does not stay inside the double pipe or the chimney or in the heat insulating material.

However, when the generator is operated intermittently, for example, when it is operated intermittently during emergency and inspection, such as an emergency generator, it has entered a high-temperature exhaust pipe or chimney of a double pipe Water was easily impregnated in the heat insulating material. If the engine generator is operated intermittently in this state, moisture will evaporate due to a rapid rise in temperature, especially when high-temperature exhaust gas passes through a double-tube high-temperature exhaust stack or chimney, as in a gas turbine engine. However, there was a possibility of causing explosive damage due to a sudden increase in pressure inside the heat insulating material.
On the other hand, when a simple metal exhaust stack or chimney is used without the heat insulating material, the portion supporting the structure of the exhaust stack or chimney is directly affected by the exhaust heat and the temperature is about 600 ° C., for example. If the metal is made of, for example, steel, the strength is lowered to about half, and the life is shortened, or it is broken due to the strength reduction.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a high-temperature exhaust pipe having high strength and a long life by suppressing contact with high-temperature exhaust gas without using a heat insulating material.

The high-temperature exhaust pipe according to the present invention includes an exhaust pipe in which a reduced diameter portion is formed on the front end side of the cylindrical portion through which the high-temperature exhaust gas is circulated, and an enlarged diameter portion is formed on the rear end side. It comprises a rectifier that circulates gas and outside air as a laminar flow, and a plurality of exhaust pipes are arranged by installing a reduced diameter part of another exhaust pipe with a gap in the enlarged diameter part of one exhaust pipe, Outside air is introduced through the gap so that the high-temperature exhaust gas and the outside air outside the exhaust tube circulate as a laminar flow.
According to the present invention, high-temperature exhaust gas combusted by, for example, a generator of an engine generator circulates in a plurality of exhaust tubes arranged in series, and the layers are formed without being turbulent or diffused through the rectifier. It flows upward as a stream. At that time, when exhaust gas flows through the diameter-reduced portion of the upper exhaust stack through the diameter-reduced portion of the lower exhaust stack, the exhaust gas is throttled at the reduced diameter portion to increase the speed, and from the gap that has become negative pressure due to the venturi effect Outside air will flow in. Then, the exhaust gas flow and the external airflow in the exhaust pipe flow upward as a laminar flow by the rectifier, but the external air flows along the inner surface of the exhaust pipe and the exhaust gas flows in layers in the central region. Therefore, since the inner surface of the exhaust tube does not contact the high temperature exhaust gas but contacts the low temperature external airflow, the exhaust tube can be prevented from becoming high temperature and high strength can be maintained.
Moreover, even if rainwater or the like enters the exhaust tube, it can be discharged to the outside through the enlarged diameter portion along the inner surface of the exhaust tube.

The reduced diameter portion is preferably a tapered portion that is reduced in diameter toward the front end side, and the enlarged diameter portion is preferably a skirt portion that is increased in diameter toward the rear end side.
Since there is a gap between the taper part of the lower exhaust stack and the skirt part facing it, when the laminar flow velocity flowing through the taper part becomes high, the gap part becomes negative pressure due to the venturi effect, and the outside air flows through the gap. However, since the external airflow flows along the inner surface of the exhaust tube and the exhaust gas flow is brought to the central region, the outer airflow on the outer peripheral side and the exhaust gas flow on the central side become a laminar flow at a high speed in the exhaust tube. Flowing. Therefore, it is possible to prevent the hot exhaust gas flow from coming into contact with the inner surface of the exhaust tube and becoming hot.

The rectifier is preferably formed by arranging plates in a lattice shape or concentric shape along the longitudinal direction of the exhaust pipe.
Since the rectifier is formed in a lattice or concentric shape along the longitudinal direction of the exhaust stack, the exhaust gas flow and the external air flow that are laminar flow are guided along the lattice of the rectifier and the concentric opening, respectively, and the flow is disturbed. It flows as a laminar flow at high speed.

According to the high-temperature exhaust pipe according to the present invention, the high-temperature exhaust gas flows through the plurality of exhaust pipes arranged in series, so that the reduced-diameter portion has a higher speed. Since the outside air can be introduced from the gap with the enlarged diameter part of the exhaust pipe and circulated as a laminar flow by the rectifier, the hot exhaust gas does not come into contact with the exhaust pipe, and the exhaust due to the contact with the hot exhaust gas comes into contact with the exhaust pipe. It is possible to extend the service life by suppressing the strength reduction of the cylinder.
Therefore, unlike conventional high-temperature exhaust pipes, heat insulation and double pipes are not used, so manufacturing costs can be reduced, and even if rainwater enters, it is discharged along the inner surface of the exhaust pipe, causing adverse effects due to rainwater. Since it is not, it can be installed outdoors.

It is a partially broken perspective view of the high temperature exhaust pipe unit by 1st embodiment of this invention. It is a partially broken perspective view which shows the single exhaust pipe in the high temperature exhaust pipe unit shown in FIG. It is the sectional view on the AA line of the high temperature exhaust pipe unit in FIG. It is a BB sectional view showing an exhaust pipe and a rectifier in Drawing 1. The high temperature exhaust pipe unit by 2nd embodiment is shown, (a) is a partially broken perspective view of a high temperature exhaust pipe unit, (b) is a partially broken perspective view of a single exhaust pipe unit. The high temperature exhaust pipe unit by 3rd embodiment is shown, (a) is a partially broken perspective view of a high temperature exhaust pipe unit, (b) is a partially broken perspective view of a single exhaust pipe. The high temperature exhaust pipe unit by 4th embodiment is shown, (a) is a partially broken perspective view of a high temperature exhaust pipe unit, (b) is a partially broken perspective view of a single exhaust pipe unit.

Hereinafter, a high-temperature exhaust pipe unit according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.
First, a high-temperature exhaust stack unit 1 according to a first embodiment of the present invention will be described with reference to FIGS. A high-temperature exhaust pipe unit 1 shown in FIG. 1 has a plurality of (three in the figure) exhaust pipes 2 shown in FIG. 2 arranged in series in the vertical direction.
The high-temperature exhaust pipe unit 1 is a chimney for discharging exhaust gas after burning fuel with a gas turbine (not shown) as an engine generator, for example. The exhaust gas after burning in the gas turbine becomes a high temperature and high pressure of, for example, about 650 ° C. to 600 ° C., and an approximately L-shaped cylinder body connected to the high temperature exhaust cylinder unit 1 from a horizontal exhaust cylinder (not shown) is moved at high speed. It is distributed and released to the atmosphere.

A single exhaust cylinder 2 shown in FIG. 2 is a cylindrical truncated cone having a substantially cylindrical cylindrical body 3 and a small-diameter opening 4a which is formed on the upper part and is gradually reduced in diameter toward the distal end side. A tapered portion 4 having a shape, and a cylindrical frustoconical skirt portion having a large-diameter opening 5a which is formed at a lower portion of the cylindrical portion main body 3 and gradually increases in diameter toward the base end side (lower side). 5 is integrally formed.
Since the taper portion 4 is gradually narrowed and reduced in diameter toward the opening on the distal end side, the flow velocity at the taper portion 4 increases when hot exhaust gas flows through the exhaust tube 2. Since the inner diameter dimension of the skirt portion 5 is gradually narrowed from the opening on the rear end side toward the front end side, the exhaust gas flowing through the skirt portion 5 provided on the rear end side also improves the flow velocity.

A rectifier 7 that rectifies a gas such as exhaust gas that circulates inside the cylinder main body 3 of the exhaust cylinder 2 is installed. As shown in FIGS. 2 and 3, the rectifier 7 has long plate-like plate portions 7 a incorporated in a lattice shape, and a plurality of substantially rectangular openings 7 b and 7 c are formed on the upper and lower surfaces. Therefore, gas such as exhaust gas flowing into the rectifier 7 from below is rectified by the rectifier 7 in which a plurality of rectangular tubes are arranged, and flows out in a layered manner. The upper and lower openings 7b and 7c of the rectifier 7 have the same area or the plate thickness is changed so that the area of the upper opening 7b is smaller than the lower side to reduce the pressure loss.
The exhaust pipe 2 and the rectifier 7 are made of metal such as steel.

  The rectifier 7 is fixed to the inner surface of the cylindrical body 3 by welding or the like. Alternatively, it may be seated and locked in the opening 4a at the tip of the tapered portion 4 of the exhaust pipe 2 installed on the lower side. The installation position of the rectifier 7 in the exhaust pipe 2 can be installed at an arbitrary position. Considering the manufacturing cost, it is preferable that the outer side surface of the rectifier 7 is formed so as to contact the inner side surface of the cylindrical tube body 3, and the rectifier 7 is installed on any surface in the longitudinal direction of the inner surface of the tube body 3. That's fine. In this embodiment, it is installed and fixed to the lower part of the cylinder part main body 3 so that the external air which flowed in the exhaust cylinder 2 is easy to be rectified.

Next, an assembly structure of the high-temperature exhaust stack unit 1 in which a plurality of exhaust stacks 2 having the above-described configuration are assembled in the vertical direction will be described with reference to FIGS. 1 and 4. In the example shown in FIG. 1, three exhaust cylinders 2 are connected in series, and these exhaust cylinders 2 are referred to as exhaust cylinders 2A, 2B, and 2C from the lower side to the upper side for convenience.
In the high temperature exhaust pipe unit 1, the skirt part 5 of the second exhaust pipe 2B is installed on the taper part 4 of the first exhaust pipe 2A installed on the lower side. Moreover, the first exhaust cylinder 2A and the second exhaust cylinder 2B are not in contact with each other as shown in FIG. 4, and the tapered portion 4 and the skirt portion 5 are arranged with a gap 8 of a predetermined distance a over the entire circumference. Has been. For this reason, the tapered portion 4 and the skirt portion 5 are installed substantially in parallel in the cross-sectional view of FIG. To do.
The tapered portion 4 and the skirt portion 5 that form the gap 8 do not need to be substantially parallel to each other. For example, the distance a between the tapered portion 4 and the skirt portion 5 may be smaller on the upper end side than the lower side, or It may be reversed.

And the 3rd exhaust pipe 2C is installed in the upper part of the 2nd exhaust pipe 2B. Similarly to the above, a gap 8 having a distance a is formed over the entire circumference between the skirt portion 5 of the upper third exhaust cylinder 2C and the tapered portion 4 of the second exhaust cylinder 2B.
The exhaust pipes 2A, 2B, and 2C are not in contact with each other, and the exhaust pipes 2A, 2B, and 2C may be individually connected to and supported by an external housing, a wall surface, a support column, or the like that is not shown. Alternatively, the skirt portion 5 of the upper exhaust tube 2 and the taper portion 4 of the lower exhaust tube 2 may be connected to each other at a predetermined interval in the circumferential direction by an arm or the like through a gap 8.
In addition, an exhaust outlet 6 of a horizontal exhaust pipe of the gas turbine is provided on the lower side of the skirt portion 5 of the first exhaust pipe 2A with a gap 8 around the entire circumference, and exhaust gas is discharged to the high-temperature exhaust pipe unit 1 Sometimes outside air flows in.

The high-temperature exhaust pipe unit 1 according to the first embodiment has the above-described configuration. Next, a method for discharging high-temperature exhaust gas will be described.
First, high-temperature exhaust gas after burning fuel in a gas turbine (not shown) as an engine generator flows into the first exhaust cylinder 2A of the high-temperature exhaust cylinder unit 1 from an exhaust outlet 6 of a horizontal exhaust cylinder (not shown). Then, in the first exhaust cylinder 2 </ b> A, high-temperature exhaust gas flows through the skirt portion 5 whose diameter is reduced upward, so that the flow velocity is increased and collected and flows into the cylinder body 3.
In addition, by increasing the exhaust gas flow velocity at the skirt portion 5, the outside air flows into the first exhaust cylinder 2A from the gap 8 with the exhaust outlet 6 and flows upward along the inner surface thereof. Since the rectifier 7 is installed in the tube body 3, the outside air flows along the inner surface of the tube body 3, and the exhaust gas is rectified in a state of being concentrated in the center.

The outside air and the exhaust gas flow in the second exhaust cylinder 2B at an increased flow velocity by passing through the tapered part 4 that gradually decreases in diameter from the cylinder part main body 3. At this time, since the outside air and the exhaust gas become high speed at the taper portion 4, negative pressure is caused by the venturi effect, and the inside of the gap 8 between the taper portion 4 of the first exhaust cylinder 2A and the skirt portion 5 of the second exhaust cylinder 2B. Therefore, the outside air flows into the second exhaust pipe 2B through the gap 8 over the entire circumference.
Moreover, since the outside air that flows in is cooler than the exhaust gas and flows along the inner surface of the second exhaust cylinder 2B, the high-temperature exhaust gas is brought to the center. These external airflow and exhaust gas flow are further rectified by passing through the rectifier 7 of the second exhaust cylinder 2B, and a two-layer laminar flow is formed by the ring-shaped external airflow and the central exhaust gas flow. Into the taper portion 4.

  Then, since the laminar flow of the external air flow and the exhaust gas flow is further accelerated by the tapered portion 4 having a reduced diameter of the second exhaust cylinder 2B, negative pressure is caused by the Venturi effect, and the skirt part of the third exhaust cylinder 2C. As the outside air flows in from the gap 8 with the air 5 and passes through the rectifier 7, the two-layer laminar flow is further rectified and discharged to the outside air through the tapered portion 4.

In this way, the high-temperature exhaust gas flow flowing from the lower side to the upper side in the high-temperature exhaust pipe unit 1 has a layer of a relatively low-temperature external airflow close to normal temperature on the outside thereof, so that contact with each exhaust pipe 2 is suppressed. It can suppress that each exhaust pipe 2 becomes high temperature.
Even if rainwater or the like enters or condenses in the high-temperature exhaust pipe unit 1, water drops such as rainwater descend along the inner surfaces of the first, second, and third exhaust pipes 2A, 2B, and 2C. Then, it is discharged from the inner surface of each skirt portion 5 to the outside. Further, since the skirt portion 5 that covers the gap 8 is provided in each exhaust pipe 2, rainwater or the like can be prevented from entering the inside from the gap 8.

As described above, according to the high-temperature exhaust pipe unit 1 according to the present embodiment, the high-temperature exhaust gas passes through the tapered portion 4 of each exhaust pipe 2 through the first, second, and third exhaust pipes 2A, 2B, and 2C. In addition, since the outside air can flow in from the gap 8 because the speed is increased, the outside air flow and the exhaust gas flow become laminar, and the high temperature exhaust gas flow does not contact the inner surface of each exhaust tube 2, so a heat insulating material is used. Even if not, it is possible to reduce the adverse effect due to the heat of each exhaust pipe 2 and to suppress the strength from being lowered.
In addition, the high-temperature exhaust stack unit 1 according to the present embodiment does not require the use of a heat insulating material, a double pipe, or the like, so that manufacturing costs can be reduced.
Even if rainwater enters or condenses in the high temperature exhaust pipe unit 1, the water is transferred to the external environment from the skirt portion 5 through the inner surface of each exhaust pipe 2. Even in the case of intermittent use, it is not necessary to consider the adverse effects of rainwater.

  The present invention is not limited to the high-temperature exhaust stack unit 1 according to the first embodiment described above, and can be appropriately changed or replaced without departing from the gist of the present invention. Included in the invention. Hereinafter, other embodiments and modifications of the present invention will be described, but the same or similar parts and members as those of the above-described embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

Next, a high-temperature exhaust pipe unit 1A according to a second embodiment of the present invention will be described with reference to FIG.
In the high-temperature exhaust pipe unit 1A according to the second embodiment, the configuration and combination of each exhaust pipe 2 are the same as those in the first embodiment. In this embodiment, the rectifier 10 installed and fixed in each exhaust pipe 2 is different from the rectifier 7 of the first embodiment.
5 (a) and 5 (b), the rectifier 10 according to the present embodiment includes a plurality of concentric circular rectifying tube portions 11 along the cylindrical inner surface of the tube portion main body 3 in each exhaust tube 2 (see FIG. 5). 4 in the example shown in FIG. 4) are arranged at substantially equal or unequal intervals in the radial direction. In addition, since only the exhaust gas flow flows through the central rectifying cylinder portion 11, the inner diameter may be relatively large.
In addition, the connecting plates 9 extending in the radial direction are installed at a predetermined interval, for example, approximately 90 degrees, and intersected with the plurality of concentric rectifying tube portions 11, so that the connecting plate 9 and the inner surface of the tube portion main body 3 meet each other. The intersecting portion between the contact portion and each rectifying cylinder portion 11 is fixed by welding or the like.

The high-temperature exhaust pipe unit 1A according to the second embodiment has the above-described configuration, and a method for discharging the exhaust gas after the gas turbine burns will be described.
In FIG. 5A, when the high-temperature exhaust gas after burning the fuel in the gas turbine flows into the first exhaust cylinder 2A of the high-temperature exhaust cylinder unit 1A, the high-temperature exhaust gas is reduced in diameter upward. The flow rate is increased because it flows through the portion 5, and outside air flows from the gap 8 with the exhaust outlet 6, exhaust gas collects from the center, and the outside air flows into the cylinder body 3 along the inner surface of the skirt portion 5. . In the cylindrical body 3, the outside air and the exhaust gas are rectified as a concentric laminar flow by the rectifier 10 and flow upward, and the exhaust gas flow velocity is improved by the taper portion 4.

  When passing the skirt portion 5 of the second exhaust cylinder 2B from the taper portion 4 of the first exhaust cylinder 2A, the outside air and the exhaust gas increase in flow speed by passing through the tapered section 4 having a reduced diameter. The area of the gap 8 between the skirt portion 4 and the skirt portion 5 becomes negative pressure, and outside air flows into the cylinder body 3 of the second exhaust cylinder 2B through the gap 8 and travels along the inner surface thereof.

Moreover, since the rectifier 10 installed on the inner surface of the tube portion main body 3 is formed by a plurality of concentric flow rectifying tube portions 11, the outside air flows from the inner surface of the tube portion main body 3 to the outermost side or the rectifier tube inside thereof. It flows along the part 11 as a ring-shaped laminar flow. Therefore, the exhaust gas flow is drawn to the center side in the tube body 3 and flows upward in the plurality of rectifying tube portions 11 on the center side.
The flow of the outside air and the exhaust gas thus formed into a two-layer laminar flow is increased in flow velocity by the taper portion 4 of the second exhaust cylinder 2B, and the outside air flows from the gap 8 with the skirt portion 5 of the third exhaust cylinder 2C. By flowing in and passing through the rectifier 10, the two-layer laminar flow is further rectified and discharged to the outside air through the tapered portion 4.

  As described above, in the high-temperature exhaust pipe unit 1A according to the second embodiment, the high-temperature exhaust gas flow that flows from the lower side to the upper side and the outside flows relatively by the gap 8 and the rectifier 10 of the connecting portion of each exhaust pipe 2. Since it flows as a two-layer laminar flow with a low-temperature external airflow, the contact between the high-temperature exhaust gas flow and the inner surface of each exhaust tube 2 can be suppressed, and the exhaust tubes 2 can be prevented from becoming hot.

Next, a high-temperature exhaust pipe unit 1B according to a third embodiment of the present invention will be described with reference to FIG.
In the high-temperature exhaust pipe unit 1B according to the third embodiment, each exhaust pipe 12 has a substantially rectangular cylindrical shape in a horizontal sectional view. Each exhaust cylinder 12 according to the present embodiment includes a substantially rectangular tubular body 14, a tapered portion 15 formed on the upper portion thereof, and a skirt portion 16 attached to the lower portion thereof. Moreover, the rectifier 13 installed on the inner surface of each exhaust cylinder 12 is also formed in a substantially rectangular cylinder shape, and a long plate-like plate portion 13a is incorporated in a lattice shape.

Also in the present embodiment, a plurality of exhaust cylinders 12 are connected with a gap 8 between the upper and lower sides, and the exhaust gas flow and the exhaust gas flowing from the skirt portion 16 of the lower first exhaust cylinder 12A through the exhaust outlet 6 are exhausted. The outside airflow flowing in from the gap 8 with the outlet 6 is rectified by the rectifier 13, and the outside air flows in by the venturi effect from the gap 8 between the taper portion 15 and the skirt portion 16 of the second exhaust cylinder 12 </ b> B. The two-layer laminar flow is also controlled in the third exhaust cylinder 12C so that the same two-layer laminar flow is controlled as a high-speed flow, and is discharged from the upper opening 4a to the outside air.
Therefore, also in the high temperature exhaust pipe unit 1B according to the present embodiment, the exhaust pipe 12 can be protected by the laminar flow of the outside air while suppressing the high temperature exhaust gas from contacting the inner surface of each exhaust pipe 12.

Next, a high-temperature exhaust pipe unit 1C according to a fourth embodiment of the present invention will be described with reference to FIG.
In the high-temperature exhaust pipe unit 1C according to the fourth embodiment, as shown in FIG. 7A, each exhaust pipe 18 has a substantially square cylindrical shape as in the third embodiment. The difference is that the tapered portion 15 and the skirt portion 16 are not provided.
That is, as shown in FIG. 7B, each exhaust cylinder 18 according to the fourth embodiment has a cylindrical enlarged diameter portion 19 that forms a substantially rectangular cylindrical enlarged diameter portion, a stepped portion 20, and a cylindrical shape. And a cylindrical reduced-diameter portion 21 having a substantially quadrangular cylindrical shape that is reduced in diameter from the enlarged-diameter portion 19. The cylindrical enlarged diameter portion 19 has a lower opening, and the cylindrical reduced diameter portion 21 has an upper opening. A rectifier 13 similar to that of the third embodiment is installed in the cylindrical reduced diameter portion 21 by welding or the like.

  The high-temperature exhaust pipe unit 1C according to the fourth embodiment has a cylindrical enlarged diameter portion of the second exhaust cylinder 18B installed on the upper cylindrical reduced diameter portion 21 of the first exhaust cylinder 18A. The cylindrical enlarged diameter portion 19 of the second exhaust cylinder 18B is installed with a gap 8 of a predetermined distance a above the stepped portion 20 and the cylindrical reduced diameter portion 21 of the exhaust cylinder 18A. A cylindrical diameter-enlarged portion 19 of the third exhaust cylinder 18C is also provided with a gap 8 of a predetermined distance a above the stepped portion 20 and the cylindrical reduced diameter portion 21 of the second exhaust cylinder 18B.

Also in this embodiment, the high-temperature exhaust pipe unit 1C has a plurality of (three in the example shown in the figure) exhaust pipes 18 connected to each other with a gap 8 between the upper and lower sides. The exhaust gas flow flowing at high speed from the lower exhaust outlet 6 through the cylindrical enlarged portion 19 of the first exhaust cylinder 18 </ b> A and the external airflow flowing from the gap 8 between the exhaust outlet 6 are rectified by the rectifier 13. . Even if the flow velocity is not increased in the vicinity of the stepped portion 20 of the first exhaust cylinder 18A, even if the initial exhaust gas flow velocity is high, the air pressure decreases without reducing the diameter, and the cylindrical reduced diameter portion of the first exhaust cylinder 18A. The outside air can be sucked from the gap 8 between the reduced diameter portion 21 and the stepped portion 20 of the second exhaust cylinder 18B.
The outside air that flows in through the gap 8 flows along the inner surface of the cylindrical reduced diameter portion 21 of the second exhaust cylinder 18B, and the high-temperature exhaust gas flow is drawn to the center side and passes through the rectifier 13 so that the outside air flows outside. It is rectified as a two-layer laminar flow of an air flow and a central exhaust gas flow.

Since the exhaust gas flow is faster than the two-layer laminar flow flowing through the cylindrical reduced diameter portion 21 of the second exhaust cylinder 18B at a high speed, the cylindrical reduced diameter portion 21 of the second exhaust cylinder 18B and Outside air also flows from the region of the gap 8 between the cylindrical enlarged diameter portion 19 and the stepped portion 20 of the third exhaust cylinder 18C.
The outside air that flows in through the gap 8 flows along the inner surface of the cylindrical reduced diameter portion 21 of the third exhaust cylinder 18C, and the high-temperature exhaust gas flow is drawn to the center side and passes through the rectifier 13 so that the outside air flows outside. Rectified as a two-layer laminar flow of the air flow and the central exhaust gas flow, and is discharged from the third exhaust cylinder 18C to the outside air through the upper opening.

Therefore, also in the high temperature exhaust pipe unit 1C according to the fourth embodiment, the exhaust gas 18 is prevented from coming into contact with the inner surface of each exhaust pipe 18 and the exhaust pipe 18 is heated to the high temperature of the exhaust gas by the laminar flow of the outside air. It can protect against exposure.
Moreover, in the high-temperature exhaust pipe unit 1C according to the fourth embodiment, each exhaust pipe 18 is configured in a simplified shape in which the cylindrical diameter-expanded portion 19 and the cylindrical diameter-reduced portion 21 are connected via the stepped portion 20. The configuration for narrowing down the exhaust gas flow and the external air flow can be further simplified, and the manufacturing cost can be reduced.

Further, in the first and second exhaust cylinders 18A and 18B, the inner surface of the cylindrical reduced diameter portion 21 forming the gap 8 is cooled by a laminar external air flow and the outer surface is absorbed by an external air current sucked through the gap 8. Since it can cool, both the inner and outer surfaces of the cylindrical reduced diameter portion 21 can be cooled. Moreover, since the cylindrical enlarged diameter portion 19 is positioned outside the cylindrical reduced diameter portion 21 with the gap 8 interposed therebetween, heat transfer due to the exhaust gas flow can be reliably prevented.
Therefore, in the high-temperature exhaust pipe unit 1C according to the fourth embodiment, since the cooling effect of each exhaust pipe 18 can be further exhibited, the strength reduction due to the high-temperature exhaust gas flow can be further suppressed.

In each of the above-described embodiments of the present invention, the tapered portion 4 and the cylindrical reduced diameter portion 21 are included in the reduced diameter portion, and the skirt portion 5 and the cylindrical expanded diameter portion 19 are included in the expanded diameter portion. . Moreover, the cylinder main bodies 3 and 14 and the step part 20 are included in the cylinder.
Moreover, in each embodiment mentioned above, the clearance gap 8 between the taper parts 4 and 15 and the skirt parts 5 and 16 and the clearance gap 8 between the cylindrical reduced diameter part 21 and the cylindrical enlarged diameter part 19 are respectively the perimeter. However, it is not necessary to allow the outside air to flow from the entire circumference. For example, an arm portion may be provided in the gap 8 between the tapered portions 4 and 15 and the skirt portions 5 and 16 or between the cylindrical reduced diameter portion 21 and the cylindrical enlarged diameter portion 19 to be connected. The gap 8 may be shielded.
Moreover, the high temperature exhaust pipe units 1, 1A, 1B, and 1C according to the above-described embodiments are included in the high temperature exhaust pipe according to the present invention. Moreover, the high-temperature stack according to the present invention includes a chimney for discharging high-temperature exhaust gas.

1, 1A, 1B, 1C High temperature exhaust cylinder unit 2, 12, 18 Exhaust cylinder 2A, 12A, 18A First exhaust cylinder 2B, 12B, 18B Second exhaust cylinder 2C, 12C, 18C Third exhaust cylinder 3 cylinder Main part 4 Taper part 5 Skirt part 7, 10, 13 Rectifier 7b, 7c Opening part 8 Clearance 19 Cylindrical diameter-increasing part 20 Step part 21 Cylindrical diameter-reducing part

Claims (3)

An exhaust cylinder in which a reduced diameter portion is formed on the front end side of the cylindrical portion through which the high-temperature exhaust gas is circulated and an enlarged diameter portion is formed on the rear end side;
A rectifier that is installed in the exhaust pipe and circulates the high-temperature exhaust gas and outside air as a laminar flow;
A plurality of the exhaust pipes are arranged by installing a reduced diameter part of the other exhaust pipe with a gap in the enlarged diameter part of the one exhaust pipe,
The high-temperature exhaust pipe, wherein the outside air is introduced through the gap so that the high-temperature exhaust gas and the outside air outside the exhaust pipe circulate as a laminar flow.   2. The high-temperature exhaust pipe according to claim 1, wherein the reduced diameter portion is a tapered portion that is reduced in diameter toward a front end side, and the enlarged diameter portion is a skirt portion that is increased in diameter toward a rear end side.   The high-temperature exhaust pipe according to claim 1 or 2, wherein the rectifier is configured by arranging plates in a lattice shape or a concentric shape along a longitudinal direction of the exhaust pipe.

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