JP2017040439A - High-temperature exhaust tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-temperature exhaust tube capable of suppressing contact of a high-temperature exhaust gas without using a heat insulating material, and easily discharging water intruding inside to the external.SOLUTION: A high-temperature exhaust tube 1 includes exhaust tube units 2A, 2B configured by forming diameter-reduced portions 4A at tip sides of cylindrical portions 3A, 3B in which a high-temperature exhaust gas F2 is circulated, and then forming diameter-expanded portions 5B at rear end sides, and rectifiers disposed in the exhaust tube units 2A, 2B for circulating an exhaust gas and outside air F1 as laminar flow. A clearance S1 is formed between the diameter-reduced portion 4A of the first exhaust tube unit 2A as one of the exhaust tube units and the diameter-expanded portion 5B of the second exhaust tube unit 2B as another one of the exhaust tube units, the first exhaust tube unit and the second exhaust tube unit are arranged on the same axis C, and an end 3aB at a rear end side, of the cylindrical portion of the second exhaust tube unit is disposed at a radial outer side of the cylindrical portion with respect to an end 4bA at a tip side of the diameter-reduced portion of the first exhaust tube unit.SELECTED DRAWING: Figure 4

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 that uses an engine generator, the high-temperature exhaust gas generated when the engine generator is operated is generally released and diluted to the outside air using a high-temperature exhaust pipe including a chimney. . In order to reduce the influence of the exhaust gas on the surroundings of the facility, the discharge of the exhaust gas is often performed at a height as much as possible. For this reason, an elongated tubular thing is used as the high-temperature exhaust pipe.
Further, the temperature and exhaust pressure of the exhaust gas vary depending on the type of the motor generator, and the high temperature exhaust pipe needs to have specifications corresponding to each. Currently, since the generators that are becoming mainstream use gas turbine engines as the engines, the exhaust gas temperature and flow velocity are higher than those of conventional diesel engines, and in one example, the exhaust gas temperature is 600 The exhaust gas wind speed reaches 40 m / s.

  2. Description of the Related Art Conventionally, as a high-temperature exhaust pipe used for combustion exhaust gas of a gas turbine or the like, for example, an exhaust pipe unit in which a heat insulating material is loaded between metal double pipes is vertically stacked. The heat insulating material is made of, for example, a fibrous or foamed material made of an inorganic material. The high-temperature exhaust pipe is formed by connecting a plurality of metal double pipes sandwiching a heat insulating material in the vertical direction at a joint portion.

In other high-temperature exhaust pipes, 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 high-temperature exhaust pipe described in Patent Document 1 in which this is improved, the heat insulating material on the inner surface of the chimney cylinder is separated into a first layer and a second layer, and a spatial air flow passage is formed between them. An introduction space is formed between the lower inner surface of the chimney cylinder and the first layer of heat insulating material, and this introduction space is communicated 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, rainwater or the like is likely to enter the high-temperature exhaust pipe through an opening formed in the joint portion or the upper end, and thus there is a high possibility that the internal heat insulating material is wetted. 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 water does not stay inside the double pipe or 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, the water that has entered the high-temperature exhaust pipe of the double pipe It was easy to be impregnated in the heat insulating material. If the engine generator is operated intermittently in this state, moisture will evaporate due to a sudden rise in temperature, especially when high-temperature exhaust gas passes through the high-temperature exhaust pipe of the double pipe as in a gas turbine engine. There was a possibility that the high temperature stack could be damaged by a sudden pressure rise 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 high temperature exhaust stack is directly affected by the exhaust heat and the temperature rises to around 600 ° C., for example. To do. In this case, for example, when a metal such as steel is used, the strength of the high temperature exhaust pipe is reduced to about half, and the life of the high temperature exhaust pipe is reduced, or the high temperature exhaust pipe is destroyed due to the strength reduction.

  The present invention has been made in view of such circumstances, and provides a high-temperature exhaust pipe that suppresses contact of high-temperature exhaust gas without using a heat insulating material and easily discharges water that has entered inside to the outside. For the purpose.

In order to solve the above problems, the present invention proposes the following means.
The high-temperature exhaust pipe of the present invention includes an exhaust pipe unit in which a reduced diameter portion is formed on the front end side of a cylindrical portion through which high-temperature exhaust gas is circulated and an enlarged diameter portion is formed on the rear end side; A rectifier that is installed and circulates the exhaust gas and the outside air as a laminar flow, the reduced diameter portion of the first exhaust cylinder unit that is one of the exhaust cylinder units, and the other exhaust cylinder unit. The first exhaust cylinder unit and the second exhaust cylinder unit are arranged on the same axis line with a gap between the enlarged diameter portion of the second exhaust cylinder unit and the first exhaust cylinder unit. The rear end side of the cylindrical portion of the second exhaust cylinder unit is disposed on the outer side in the radial direction of the cylindrical portion than the end of the reduced diameter portion of the first exhaust cylinder unit. The outside air is introduced through a gap, and the exhaust gas and the exhaust gas are introduced into the exhaust cylinder unit. And outside of the outside air is characterized in that so as to flow as a laminar flow.

According to this invention, the high-temperature exhaust pipe is installed so that the tip side is upward. In the first and second exhaust stack units arranged on the axis, high-temperature exhaust gas combusted by, for example, a generator of an engine generator circulates, and the layer does not become a turbulent flow or a diffused flow through the rectifier. It flows upward as a stream. At that time, if the exhaust gas flows through the inside of the enlarged diameter portion of the second exhaust pipe unit installed above through the inside of the reduced diameter part of the first exhaust pipe unit installed below, the exhaust pipe is throttled by the reduced diameter part. Thus, the outside air flows from the gap created by the Venturi effect. Then, the flow of exhaust gas and the flow of outside air in the exhaust tube unit flow upward as a laminar flow by the rectifier, but the outside air is layered along the inner surface of the exhaust tube unit, and the exhaust gas is layered in the center region. Flowing. By contacting the inner surface of the exhaust cylinder unit with the low temperature outside air that has flowed in, it is possible to suppress contact with the high temperature exhaust gas.
The water that enters the inside of the second exhaust cylinder unit and flows downward along the inner surface of the cylinder part of the second exhaust cylinder unit falls down from the lower end of the cylinder part to the first exhaust cylinder unit. Falls to the outer surface of the reduced diameter part. This water flows from the outer surface of the reduced diameter portion along the outer surface of the cylindrical portion and the outer surface of the enlarged diameter portion, and falls downward. Therefore, the water that has entered the inside of the second exhaust cylinder unit can be easily discharged to the outside.

Further, in the above high-temperature exhaust pipe, an end of the second exhaust cylinder unit on the rear end side of the cylinder part is located on a front end side of the reduced diameter part of the first exhaust cylinder unit in a direction along the axis. The first exhaust pipe unit may be disposed on the rear end side with respect to the front end side of the reduced diameter portion.
According to the present invention, when the high-temperature exhaust pipe is installed so that the front end side is on the upper side, the end of the second exhaust cylinder unit on the rear end side of the second exhaust cylinder unit is contracted in the direction along the axis. It is installed at the same position as the distal end side of the diameter portion or below the distal end side end of the reduced diameter portion of the first exhaust pipe unit. Therefore, it is possible to more reliably suppress the water that has fallen downward from the lower end of the cylindrical portion of the second exhaust cylinder unit from entering the inside of the reduced diameter portion of the first exhaust cylinder unit.

In the above-described high-temperature exhaust pipe, in the first exhaust pipe unit, the inner surface of the cylindrical portion and the inner surface of the enlarged diameter portion may be smoothly connected in a direction along the axis.
According to this invention, it is difficult for water to concentrate and collect in one place in the connection portion between the inner surface of the cylindrical portion and the inner surface of the enlarged diameter portion, and the water is separated from the axis along the inner surface of the enlarged diameter portion. It becomes easy to flow. For this reason, the water that has flowed through the inner surface of the cylindrical portion of the second exhaust stack unit flows so as to be spaced radially outward along the inner surface of the enlarged diameter portion, and the water that has dropped downward from the second exhaust stack unit Can be more reliably suppressed from entering the reduced diameter portion of the first exhaust pipe unit.

  According to the high temperature exhaust pipe of the present invention, the contact of high temperature exhaust gas can be suppressed without using a heat insulating material, and the water that has entered the inside can be easily discharged outside.

It is the perspective view which fractured | ruptured a part of high temperature exhaust pipe of 1st Embodiment of this invention. It is the perspective view which fractured | ruptured a part of 1st exhaust pipe unit of the same high temperature exhaust pipe. It is A1-A1 sectional view taken on the line of the high temperature exhaust pipe in FIG. It is A2-A2 sectional view taken on the line of the high temperature exhaust pipe in FIG. It is sectional drawing of the principal part of the high temperature exhaust pipe of the modification of 1st Embodiment of this invention. It is the perspective view which fractured | ruptured a part of high temperature exhaust pipe of 2nd Embodiment of this invention. It is A4-A4 sectional drawing of the high temperature exhaust pipe in FIG. It is sectional drawing of the principal part of the high temperature exhaust pipe in embodiment of the modification of this invention.

(First embodiment)
Hereinafter, a first embodiment of a high-temperature exhaust pipe according to the present invention will be described with reference to FIGS. 1 to 5.
A high-temperature exhaust pipe 1 shown in FIG. 1 has a plurality (three in the figure) of exhaust pipe units 2 shown in FIG. 2 arranged on the same axis C. The three exhaust cylinder units 2 are arranged in series in the vertical direction Z. That is, the direction along the axis C coincides with the vertical direction Z.
Hereinafter, the three exhaust cylinder units 2 may be referred to as the first exhaust cylinder unit 2A, the second exhaust cylinder unit 2B, and the third exhaust cylinder unit 2C in order from the lower Z1. Cylindrical body 3A, 3B, 3C, which will be described later, may be referred to as cylindrical body 3 without distinction. The same applies to the tapered portions 4A, 4B, 4C and the like.
The high-temperature exhaust pipe 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 has a high temperature and high pressure of, for example, about 650 ° C. to 600 ° C., which is higher than that of the outside air. The cylinder P is circulated at a high speed and is discharged to the outside air through the high temperature exhaust cylinder 1.

Although the configuration of the first exhaust cylinder unit 2A will be described in FIG. 2, the configurations of the exhaust cylinder units 2B and 2C are the cylinder body 3A, the taper portion 4A, and the skirt portion 5A described later of the first exhaust cylinder unit 2A. It is the same except for the outer diameter. In the following, for the configuration of the first exhaust stack unit 2A, a capital letter “A” is added to the numbers and lowercase letters, and for the corresponding configuration of the exhaust stack units 2B and 2C, the same capital letters “ This is indicated by adding “B” and “C”. Thereby, the overlapping description is omitted.
The first exhaust tube unit 2A includes a cylindrical tube body (tube portion) 3A, a tapered portion (reduced diameter portion) 4A formed on the front end side of the tube portion body 3A, and a rear end of the tube body 3A. And a skirt portion (expanded diameter portion) 5A formed on the side.
The outer diameter of the tube portion main body 3A is constant regardless of the position of the tube portion main body 3A in the axial direction.
The taper portion 4A is formed in a cylindrical shape whose outer diameter decreases toward the distal end side. The outer diameter on the rear end side of the tapered portion 4A is equal to the outer diameter of the cylindrical portion main body 3A. The outer diameter on the tip end side of the tapered portion 4A is smaller than the outer diameter of the cylindrical portion main body 3A. A relatively small diameter opening 4aA is formed on the tip end side of the taper portion 4A.

The skirt portion 5A is formed in a cylindrical shape whose outer diameter increases toward the rear end side. The outer diameter on the front end side of the skirt portion 5A is equal to the outer diameter of the cylindrical portion main body 3A. The outer diameter of the rear end side of the skirt portion 5A is larger than the outer diameter of the cylindrical portion main body 3A. A relatively large-diameter opening 5aA is formed on the rear end side of the skirt portion 5A.
The cylindrical body 3A, the tapered portion 4A, and the skirt portion 5A can be formed by bending and welding a steel plate having a constant thickness.
Since the taper portion 4A is gradually narrowed and reduced in diameter toward the opening 4aA on the front end side, the flow velocity at the taper portion 4A increases when high-temperature exhaust gas flows through the first exhaust cylinder unit 2A. . Since the inner diameter of the skirt portion 5A is gradually narrowed from the rear end side opening 5aA toward the front end side, the exhaust gas flowing through the skirt portion 5A also has a high flow velocity.

A rectifier 7A that rectifies a gas such as exhaust gas that circulates therein is installed inside the cylinder body 3A of the first exhaust cylinder unit 2A. As shown in FIGS. 2 and 3, the rectifier 7A has a long plate-like plate portion 7aA incorporated in a lattice shape, and has a substantially rectangular opening 7bA on the front end surface and the rear end surface. A large number of 7cA is formed. Therefore, a gas such as exhaust gas flowing into the rectifier 7A from the rear end side is rectified by the rectifier 7A in which a plurality of rectangular tubes are arranged, and flows into the front end side in a layered manner.
The plate portions 7aA may have a constant thickness, and the openings 7bA and 7cA of the rectifier 7A may have the same area. By increasing the thickness of the plate portion 7aA toward the front end side and making the area of the opening portion 7bA on the front end side smaller than the area of the opening portion 7cA on the rear end side, the pressure loss of the rectifier 7A is reduced. May be.
The rectifier 7A can be formed of a steel plate, a ceramic plate, or the like.
In addition, these exhaust pipe units 2A, 2B, and 2C are arranged so that the front end side is the upper Z2 (see FIG. 1) and the rear end side is the lower Z1.

The rectifier 7A is fixed to the inner surface of the cylindrical body 3A by welding or the like. The rectifier 7A may be seated and locked in the opening 4a at the tip of the tapered portion 4 of the exhaust tube unit 2 installed in the lower Z1. The installation position of the rectifier 7A in the first exhaust pipe unit 2A can be installed at an arbitrary position.
Considering the manufacturing cost, it is preferable to form the rectifier 7A so that the outer side surface of the rectifier 7A is in contact with the inner surface of the cylindrical cylindrical body 3A. Install it. In the present embodiment, a rectifier 7A is installed and fixed on the rear end side of the cylinder portion main body 3A so that the outside air flowing into the first exhaust cylinder unit 2A is easily rectified.

  As shown in FIG. 1, in the present embodiment, the outer diameter of the cylinder body 3B of the second exhaust cylinder unit 2B is smaller than the outer diameter of the cylinder body 3A of the first exhaust cylinder unit 2A. The outer diameter of the cylinder body 3C of the third exhaust cylinder unit 2C is smaller than the outer diameter of the cylinder body 3B of the second exhaust cylinder unit 2B.

As shown in FIG. 4, in the high temperature exhaust pipe 1, the skirt part 5B of the second exhaust pipe unit 2B is installed on the outer side in the radial direction of the taper part 4A of the first exhaust pipe unit 2A installed in the lower Z1. Yes. The tapered portion 4A and the skirt portion 5B are not in contact with each other, and a gap S1 is opened over the entire circumference between the tapered portion 4A and the skirt portion 5B. The gap S1 becomes narrower toward the inner side in the radial direction. In other words, in the cross section taken along the plane T including the axis C, the distance L1 between the skirt portion 5B and the tapered portion 4A becomes shorter toward the inner side in the radial direction.
An end 3aB of the lower portion Z1 of the tubular portion main body 3B is disposed on an outer side in the radial direction of the tubular portion main body 3 with respect to an end 4bA of the upper portion Z2 of the tapered portion 4A. The end 3aB of the cylindrical portion main body 3B is disposed at a position equal to the end 4bA of the tapered portion 4A in the vertical direction Z.
As will be described later, the outside air F1 flows into the second exhaust cylinder unit 2B through the gap S1 between the tapered portion 4A and the skirt portion 5B.

Similarly, as shown in FIG. 1, the skirt portion 5C of the third exhaust pipe unit 2C is installed on the outer side in the radial direction of the tapered portion 4B of the second exhaust pipe unit 2B installed in the lower Z1. The tapered portion 4B and the skirt portion 5C are not in contact with each other, and a gap S2 is opened between the tapered portion 4B and the skirt portion 5C over the entire circumference. The gap S2 becomes narrower toward the inner side in the radial direction.
The exhaust cylinder units 2A, 2B, and 2C are not in contact with each other, and these exhaust cylinder units 2A, 2B, and 2C may be individually connected to and supported by an external casing, a wall surface, a support column, or the like that is not shown. Or you may connect the skirt part 5 of the exhaust pipe unit 2 of the upper Z2, and the taper part 4 of the exhaust pipe unit 2 of the lower Z1 in the circumferential direction at predetermined intervals.
In the high temperature exhaust pipe 1, unlike the conventional high temperature exhaust pipe, no heat insulating material is used.
Note that an exhaust outlet P1 of the cylinder P is provided in the lower Z1 of the skirt portion 5A of the first exhaust cylinder unit 2A with a gap S0 around the entire circumference. When exhaust gas is discharged to the high-temperature exhaust pipe 1, the outside air F1 flows from the gap S0.

Next, the operation when the high-temperature exhaust stack 1 configured as described above does not exhaust exhaust gas and exhaust gas will be described.
When the high-temperature exhaust pipe 1 does not discharge exhaust gas, as shown in FIG. 1, water droplets (water) W1 such as rainwater enter the third exhaust pipe unit 2C from the opening 4aC. A part of the water droplet W1 flows downward Z1 along the inner surface of the cylinder body 3B of the second exhaust cylinder unit 2B as shown in FIG. This water droplet W1 may fall from the end 3aB of the cylindrical body 3B downward Z1 due to the action of gravity. At this time, since the end 3aB of the cylindrical body 3B is disposed on the outer side in the radial direction than the end 4bA of the tapered portion 4A, the water droplet W1 falls on the outer surface of the tapered portion 4A and becomes the water droplet W2. Since the end 3aB of the cylindrical portion main body 3B is disposed at the same position as the end 4bA of the tapered portion 4A in the vertical direction Z, the water droplet W1 that has dropped from the end 3aB of the cylindrical portion main body 3B to the lower Z1 is the first exhaust cylinder unit. Intrusion into the 2A tapered portion 4A is more reliably suppressed.
The water droplet W2 flows along the outer surface of the tapered portion 4A, the outer surface of the cylindrical portion main body 3A, and the outer surface of the skirt portion 5A in the gap S1, and falls to the lower side Z1.

Even when condensation occurs in the high-temperature exhaust pipe 1, water droplets flow in the same manner and are discharged to the outside.
In addition, since the skirt portion 5B is disposed so as to cover the gap S1, it is possible to prevent the water droplets W1 from entering the exhaust pipe units 2A and 2B through the gap S1.

On the other hand, when the high-temperature exhaust stack 1 discharges exhaust gas, the following occurs.
First, the high-temperature exhaust gas F2 (see FIG. 1) after the fuel is combusted by a gas turbine (not shown) as an engine generator passes through the exhaust outlet P1 of the cylindrical body P from the horizontal exhaust cylinder (not shown) to the first of the high-temperature exhaust cylinder 1. It flows into the exhaust tube unit 2A. Then, in the first exhaust cylinder unit 2A, the high-temperature exhaust gas F2 flows through the skirt part 5A whose diameter is reduced toward the upper Z2, so that the flow velocity is increased and collected and flows into the cylinder part body 3A.
Moreover, by increasing the flow rate of the exhaust gas F2 at the skirt portion 5A, the outside air F1 is introduced (inflowed) into the first exhaust cylinder unit 2A through the gap S0 with the exhaust outlet P1. The outside air F1 flows upward Z2 along the inner surface of the cylinder body 3A. Since the rectifier 7A is installed in the cylinder main body 3A, the outside air F1 flows along the inner surface of the cylinder main body 3A as a laminar flow, and the exhaust gas F2 forms a layer in the central area of the cylinder main body 3A. It circulates as a stream. For this reason, it is suppressed that the hot exhaust gas F2 contacts the first exhaust cylinder unit 2A.

  Then, by passing through the tapered portion 4A that gradually decreases in diameter from the cylindrical portion main body 3A, the outside air F1 and the exhaust gas F2 increase in flow rates and flow into the second exhaust cylinder unit 2B. At this time, since the outside air F1 and the exhaust gas F2 become high speed at the taper portion 4A, negative pressure is caused by the Venturi effect. Since the inside of the gap S1 between the taper portion 4A of the first exhaust pipe unit 2A and the skirt part 5B of the second exhaust pipe unit 2B also becomes negative pressure, the outside air F1 passes through the gap S1 over the entire circumference, and the second exhaust pipe unit. Flows into 2B.

The inflowing outside air F1 is at a lower temperature than the exhaust gas F2, and the outside air F1 flows in along the inner surface of the tube portion main body 3B, so that the high temperature exhaust gas F2 is drawn to the center of the tube portion main body 3B. The flow of the outside air F1 and the flow of the exhaust gas F2 are further rectified by passing through the rectifier 7B of the second exhaust cylinder unit 2B. In the cylinder body 3B, the flow of the central exhaust gas F2 and the flow of the ring-shaped outside air F1 outside the exhaust gas F2 circulate as a two-layer laminar flow and flow into the tapered portion 4B.
Since the gap S1 becomes narrower toward the inner side in the radial direction, the flow rate of the outside air F1 flowing through the gap S1 is efficiently increased. And the internal surface of the cylinder part main body 3B is cooled reliably by the external air F1 whose flow velocity was raised.

  Then, since the laminar flow of the outside air F1 and the exhaust gas F2 is further accelerated by the tapered portion 4B having a reduced diameter of the second exhaust cylinder unit 2B, a negative pressure is generated due to the venturi effect. The outside air F1 flows from the gap S2 between the tapered portion 4B of the second exhaust pipe unit 2B and the skirt portion 5C of the third exhaust pipe unit 2C and passes through the rectifier 7C, thereby further rectifying the two-layer laminar flow. And discharged to the outside through the tapered portion 4C.

  As described above, according to the high-temperature exhaust pipe 1 of the present embodiment, the high-temperature exhaust pipe 1 is installed so that the tip side is the upper Z2. In the exhaust cylinder units 2A and 2B arranged on the axis C, the high-temperature exhaust gas F2 combusted by, for example, the generator of the generator generator circulates and becomes a turbulent flow or a diffusion flow through the rectifiers 7A and 7B. Instead, it flows upward Z2 as a laminar flow. At that time, when the exhaust gas F2 flows in the skirt portion 5B of the second exhaust cylinder unit 2B installed in the upper Z2 through the tapered part 4A of the first exhaust cylinder unit 2A installed in the lower Z1. The outside air F1 flows in from the gap S1 which is throttled by the taper portion 4A and becomes high speed and becomes negative pressure by the Venturi effect. The exhaust gas F2 flow and the external air F1 flow in the second exhaust cylinder unit 2B flow to the upper Z2 as a laminar flow by the rectifier 7B. The exhaust gas F2 flows in a layered manner in the central region. By contacting the inner surface of the second exhaust cylinder unit 2B with the low temperature outside air F1 that has flowed in, it is possible to suppress contact with the high temperature exhaust gas F2.

The water droplet W1 that enters the inside of the second exhaust cylinder unit 2B and flows downward Z1 along the inner surface of the cylinder body 3B of the second exhaust cylinder unit 2B has an end 3aB of the cylinder body 3B at the end of the taper part 4A. Since it is arranged on the outer side in the radial direction with respect to 4bA, it falls on the outer surface of the tapered portion 4A of the first exhaust tube unit 2A when it falls from the end 3aB of the tube portion main body 3B to the lower Z1. This water droplet W1 flows from the outer surface of the taper portion 4A along the outer surface of the cylindrical portion main body 3A and the outer surface of the skirt portion 5A, and falls downward Z1. Therefore, the water droplet W1 that has entered the inside of the second exhaust cylinder unit 2B can be easily discharged to the outside.
In this high temperature exhaust pipe 1, it can suppress that the high temperature exhaust gas F2 contacts the high temperature exhaust pipe 1 without using a heat insulating material.
Since the end 3aB of the cylindrical portion main body 3B is disposed at the same position as the end 4bA of the tapered portion 4A in the vertical direction Z, the water droplet W1 that has dropped from the end 3aB of the cylindrical portion main body 3B to the lower Z1 is the first exhaust cylinder unit. It is possible to more reliably suppress the intrusion into the 2A tapered portion 4A.

In the present embodiment, the end 3aB of the cylindrical portion main body 3B is disposed at a position equal to the end 4bA of the tapered portion 4A in the vertical direction Z. However, the end 3aB of the cylindrical portion main body 3B is the end of the tapered portion 4A. It is good also as arrange | positioning below Z1 rather than 4bA. Further, as in the high temperature exhaust cylinder 11 shown in FIG. 5, the end 3aB of the cylinder body 3B may be disposed above the end 4bA of the tapered portion 4A.
Even if comprised in this way, since the water droplet W2 falls on the outer surface of the taper part 4A from the end 3aB of the cylinder part main body 3B, there can exist an effect similar to this embodiment.

  In the present embodiment, the gap S1 is narrowed toward the inner side in the radial direction. However, the gap S1 may be constant regardless of the position in the radial direction, or may be wider toward the inner side in the radial direction. It may be.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. 6 and FIG. 7, but the same parts as those in the above-described embodiment will be denoted by the same reference numerals and the description thereof will be omitted, and only differences will be described. explain.
The high temperature exhaust cylinder 21 shown in FIG. 6 replaces the exhaust cylinder units 2A, 2B, and 2C of the high temperature exhaust cylinder 1 of the first embodiment with a first exhaust cylinder unit 22A, a second exhaust cylinder unit 22B, Three exhaust cylinder units 22C are provided. Hereinafter, the configuration of the first exhaust cylinder unit 22A will be described. The configuration of the exhaust cylinder units 22B and 22C includes a cylinder main body 23A, a taper portion 24A, and a skirt portion 25A described later of the first exhaust cylinder unit 22A. It is the same except for the outer diameter.

The first exhaust cylinder unit 22A includes a rectangular tubular body 23A, a tapered portion 24A formed on the distal end side of the tubular body 23A, and a skirt portion 25A formed on the rear end side of the tubular body 23A. And have.
In the present embodiment, the cross section of the cylinder body 23A has a square edge shape. The outer diameter of the cylinder main body 23A is constant regardless of the position of the cylinder main body 23A in the axial direction.
The taper portion 24 </ b> A is formed in a rectangular tube shape whose outer diameter decreases toward the distal end side. The outer diameter on the rear end side of the tapered portion 24A is equal to the outer diameter of the cylindrical portion main body 23A. The outer diameter of the taper portion 24A on the front end side is smaller than the outer diameter of the cylindrical portion main body 23A.
The skirt portion 25A is stepped so that the tip extends radially outward. The outer diameter on the rear end side with respect to the front end of the skirt portion 25A is constant regardless of the position of the skirt portion 25A in the axial direction. The cross section on the rear end side of the skirt portion 25A has a square edge shape.
In the present embodiment, the outer diameter of the cylinder body 23B of the second exhaust cylinder unit 22B is smaller than the outer diameter of the cylinder body 23A of the first exhaust cylinder unit 22A. The outer diameter of the cylinder main body 23C of the third exhaust cylinder unit 22C is smaller than the outer diameter of the cylinder main body 23B of the second exhaust cylinder unit 22B.

Between the taper portion 24A and the skirt portion 25B, a gap S11 is opened over the entire circumference. As shown in FIG. 7, in the cross section taken along the plane T including the axis C, the distance L3 at the radially outer end between the skirt portion 25B and the tapered portion 24A is the radial distance between the skirt portion 25B and the tapered portion 24A. The distance L4 at the inner end is also long. The distance between the skirt portion 25B and the taper portion 24A as used herein means a distance between the opposing portions of the skirt portion 25B and the taper portion 24A. A distance L5 at the intermediate portion in the radial direction between the skirt portion 25B and the tapered portion 24A is longer than both the distance L3 and the distance L4.
An end 23aB of the lower portion Z1 of the cylindrical portion main body 23B is disposed on an outer side in the radial direction from an end 24bA of the upper portion Z2 of the tapered portion 24A. The end 23aB of the cylindrical portion main body 23B is disposed at a position equal to the end 24bA of the tapered portion 24A in the vertical direction Z.
Between the taper portion 24B and the skirt portion 25C, a gap S12 is opened over the entire circumference (see FIG. 6).

When the high-temperature exhaust pipe 21 thus configured does not discharge exhaust gas, the flow of water droplets is as described above.
On the other hand, when the high-temperature exhaust cylinder 21 discharges the exhaust gas, the high-temperature exhaust gas flows as described above. The outside air F1 passing through the gap S11 flows as follows.
The outside air F1 that has passed through the radially outer portion that is the distance L3 in the gap S11 between the tapered portion 24A and the skirt portion 25B has a low flow velocity when passing through the intermediate portion in the radial direction that is the distance L5. For this reason, the water vapor contained in the outside air F1 tends to adhere to the lower surface of the stepped portion of the skirt portion 25B as water droplets W4. The outside air F1 that has passed through the intermediate portion in the radial direction in the gap S11 has the highest flow velocity when passing through the radially inner portion that is the distance L4, and flows into the second exhaust cylinder unit 22B.

As described above, according to the high temperature exhaust cylinder 21 of the present embodiment, the contact of the high temperature exhaust gas F2 can be suppressed without using a heat insulating material, and water droplets entering the inside can be easily discharged to the outside.
Further, the distance L5 in the radial intermediate portion of the gap S11 is longer than both the distance L3 of the radially outer end portion and the distance L4 of the radially inner end portion, thereby passing through the gap S11. It is possible to prevent water droplets from entering the high temperature exhaust cylinder 21 due to the outside air F1 flowing into the second exhaust cylinder unit 22B.

As mentioned above, although 1st Embodiment and 2nd Embodiment of this invention were explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The structure of the range which does not deviate from the summary of this invention Changes, combinations, deletions, etc. are also included. Furthermore, it goes without saying that the configurations shown in the embodiments can be used in appropriate combinations.
For example, in the first embodiment, as in the high temperature exhaust pipe 1 shown in FIG. 8, in the second exhaust pipe unit 2B, the inner surface of the cylinder body 3B and the inner surface of the skirt part 5B are in the direction along the axis C. In FIG. 2, the connection may be smooth so that there is no corner. The term “smooth” as used herein means that, for example, the inclination of the tangent line on the inner surface is continuous.
By comprising in this way, it becomes difficult for the water drop W1 to fall from the end 3aB of the cylinder part main body 3B, and the water drop W1 of the end 3aB of the cylinder part main body 3B flows to the outer side of radial direction along the inner surface of the skirt part 5B. Therefore, the water droplet W1 can be discharged to the outside more easily.

  Further, groove portions 3bB and 5aB extending on the plane T and communicating with each other may be formed on the inner surface of the cylindrical portion main body 3B and the inner surface of the skirt portion 5B. The water droplet W2 flowing in the groove portion 3bB of the tube portion main body 3B is guided by the groove portions 3bB and 5aB and is difficult to fall from the end 3aB of the tube portion main body 3B.

In the first embodiment and the second embodiment, the gaps may not be formed over the entire circumference. For example, the gap may be partially shielded by providing an arm portion between the tapered portion and the skirt portion for connection.
The high temperature exhaust pipe is assumed to be composed of three exhaust pipe units. However, the number of the exhaust pipe units 2 constituting the high temperature exhaust pipe is not limited to this, and may be two or four or more.

1, 11, 21 High temperature exhaust cylinder 2 Exhaust cylinder unit 2A, 22A First exhaust cylinder unit (exhaust cylinder unit)
2B, 22B Second exhaust cylinder unit (exhaust cylinder unit)
2C, 22C Third exhaust cylinder unit (exhaust cylinder unit)
3aB, 4bB, 23aB, 24bB End 3A, 3B, 3C, 23A, 23B, 23C Tube body (tube portion)
4A, 4B, 4C, 24A, 24B, 24C Tapered part (reduced diameter part)
5A, 5B, 5C, 25A, 25B, 25C Skirt part (expanded part)
7A, 7B, 7C Rectifier C Axis F1 Outside air F2 Exhaust gas S1, S11 Gap

Claims (3)

An exhaust cylinder unit in which a reduced diameter portion is formed on the front end side of the cylindrical portion through which the high-temperature exhaust gas flows and an enlarged diameter portion is formed on the rear end side;
A rectifier that is installed in the exhaust pipe unit and circulates the exhaust gas and outside air as a laminar flow;
While opening a gap between the reduced diameter part of the first exhaust pipe unit which is one of the exhaust pipe units and the enlarged diameter part of the second exhaust pipe unit which is the other one of the exhaust pipe units The first exhaust stack unit and the second exhaust stack unit are arranged on the same axis,
The end of the cylindrical portion of the second exhaust cylinder unit on the rear end side is disposed on the outer side in the radial direction of the cylindrical portion than the end of the reduced diameter portion of the first exhaust cylinder unit. ,
A high-temperature exhaust pipe, wherein the outside air is introduced through the gap so that the exhaust gas and the outside air outside the exhaust pipe unit circulate as a laminar flow.   The end on the rear end side of the cylindrical portion of the second exhaust cylinder unit is equal to the end on the front end side of the reduced diameter portion of the first exhaust cylinder unit in the direction along the axis, or the first The high-temperature exhaust pipe according to claim 1, wherein the high-temperature exhaust pipe is disposed on the rear end side with respect to the front end side of the reduced diameter portion of the exhaust pipe unit.   3. The high-temperature exhaust pipe according to claim 1, wherein in the second exhaust pipe unit, the inner surface of the cylindrical portion and the inner surface of the enlarged diameter portion are smoothly connected in a direction along the axis.

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