JPH0557323U - Exhaust gas temperature reduction device - Google Patents

Abstract

(57) [Summary] [Purpose] The temperature of exhaust gas can be reduced by mixing high-temperature exhaust gas with the outside air, and the exhaust gas temperature can be reduced because the mixing distance required for almost even mixing is short. Provide a device. [Structure] A plurality of outside air guide grooves 2 are formed in the circumferential wall of the exhaust pipe 1 from the outlet end downward to the center from the outer periphery toward the center, and the degree to which the concave enter gradually decreases downward. Exhaust pipe 1 formed at intervals
The exit is shaped like a petal. At the center of the outlet (opening) of the exhaust pipe 1, a disk-shaped shield member 3 is supported by a plurality of radial support fittings 4 arranged radially.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to an exhaust gas temperature reduction device having a function of reducing the temperature of high-temperature exhaust gas discharged from an exhaust pipe of a ship or a vehicle.

[0002]

[Prior Art]

 In particular, when a gas turbine engine is used, the exhaust gas becomes extremely hot (500 ° C or higher). Such exhaust gas is emitted from the chimney (exhaust pipe) in ships and the like, but when electronic devices such as radar are installed around the chimney, the electronic devices are thermally affected by the exhaust gas and normally operate. It may cause a malfunction or malfunction. Further, the hot exhaust gas also has a problem in that it emits a large amount of infrared rays.

Therefore, conventionally, a short pipe having a diameter slightly larger than that of the exhaust pipe is continuously provided at the outlet end of the exhaust pipe with a certain gap around the outlet pipe, and cooling air is supplied from the gap to the inner peripheral wall of the short pipe. There is proposed a device (No. Sho 63-19540) for preventing the temperature rise at the outlet of the exhaust pipe by cutting off the contact between the high-temperature exhaust gas and the inner peripheral wall of the short pipe by flowing it along the pipe.

[0004]

[Problems to be solved by the device]

 However, the device described in the above publication has room for improvement in the following points. That is, since the short pipe, which is the outlet from which the exhaust gas is discharged, is cooled by the cooling air, the temperature rise can be avoided, but the exhaust gas itself is hardly cooled. As a result, high-temperature exhaust gas is discharged, and the exhaust gas may have a bad thermal effect on the electronic device or emit a large amount of infrared rays.

The present invention has been made in view of the above points, and can mix the high temperature exhaust gas with the outside air uniformly to reduce the temperature of the exhaust gas as a whole. It is an object of the present invention to provide an exhaust gas temperature reduction device that requires a short mixing distance.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the exhaust gas temperature reduction device of the present invention comprises: a) a mixing pipe having a flare with a gradually increasing diameter toward the downstream side at the downstream end, In the exhaust gas temperature reduction device that is installed upstream from the vicinity of the outlet end of b), b) Enters a concave shape toward the center of the peripheral wall of the outlet part of the exhaust pipe, and gradually decreases the concave shape from the downstream side to the outlet end. The outside air guide grooves that increase in degree are formed at equal intervals in the circumferential direction, and c) a circular, substantially circular, or regular polygonal shielding member is seen at the center of the outlet of the exhaust pipe when viewed from above. It is arranged.

As described in claim 2, d) it is preferable that the shielding member is formed in an inverted conical shape.

As described in claim 3, e) a plurality of swivel fins may be provided in a spiral shape in the same direction at intervals around the shielding member at intervals.

[0009]

[Action]

 According to the exhaust gas temperature reducing device of the present invention having the above-mentioned configuration, the high-temperature exhaust gas flows at a relatively high speed in the exhaust pipe and flows from the outlet of the exhaust pipe into the mixing pipe above it. A kind of suction force is generated by this exhaust gas flow, the outside air is guided along each outside air guide groove around the outlet of the exhaust pipe, and together with the high temperature gas flowing out from the outlet of the exhaust pipe, A large amount of outside air is sucked into the mixing pipe through the gap between the flare and the outlet of the exhaust pipe. Since a shielding member is provided at the center of the outlet of the exhaust pipe, the exhaust gas flowing through the center (axial center) of the exhaust pipe hits the shielding member and spreads radially around the shielding member. Thus, the exhaust gas flowing in the mixing pipe and flowing in the peripheral portion of the exhaust pipe straightly passes through the opening around the shielding member and flows in the mixing pipe.

Since each of the outside air guiding grooves enters a concave shape from the outer circumference of the exhaust pipe toward the center and has an irregular shape (petal shape) around the outlet end, exhaust gas is exhausted from exhaust gas discharged from the exhaust pipe. The outside air is uniformly mixed from the periphery of the outlet of the pipe to near the center (shielding member), and while passing through the inside of the mixing pipe, the exhaust gas and the outside air are mixed uniformly. Therefore, the temperature of the exhaust gas discharged from the outlet of the mixing pipe is reduced uniformly throughout. Further, since the mixing efficiency is good, the mixing distance becomes short.

If the shielding member arranged at the center of the outlet is omitted in the exhaust pipe of the present invention, the temperature distribution of the exhaust gas discharged from the outlet of the mixing pipe becomes slightly higher at the center. It is recognized that the shielding member has the function of mixing exhaust gas and outside air uniformly. Further, when the outlet of the exhaust pipe is formed into a simple conical shape, the temperature of the exhaust gas will not be uniform even if a shielding member is provided at the center of the outlet.

According to the exhaust gas temperature reducing device of the second aspect, the resistance of the exhaust gas flow to the shielding member is suppressed to be small, and the pressure loss is small.

Further, according to the exhaust gas temperature reducing device of the third aspect, the exhaust gas flows into the mixing pipe so as to be twisted spirally along the plurality of swirl fins of the conical shielding member. The exhaust gas becomes a swirling flow in the mixing pipe, and is mixed with the outside air more efficiently.

[0014]

【Example】

 An embodiment of an exhaust gas temperature reduction device of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an exhaust gas temperature reducing device according to an embodiment of the present invention, and FIG. 2 is a view taken along the line II-II of FIG. As shown in these figures, from the outlet of the exhaust pipe 1, that is, from the outlet end of the exhaust pipe 1 downward, the peripheral wall of the exhaust pipe 1 is recessed (arc-shaped) from the outer periphery toward the center and from below. A plurality of outside air guide grooves 2 having a progressively increasing degree of concave entry toward the outlet end are formed at equal intervals in the circumferential direction, and the peripheral wall of the outlet 1a of the exhaust pipe 1 has a petal shape. At the center of the outlet (opening) 1a of the exhaust pipe 1, a disk-shaped shield member 3 is supported by a plurality of radial support fittings 4 arranged radially.

A mixing pipe 5 having the same diameter as that of the exhaust pipe 1 extends from near the outlet end of the exhaust pipe 1 toward the upper side. Further, a flare 6 whose diameter is gradually enlarged downward is integrally attached to the lower end of the mixing tube 5.

In the above-mentioned exhaust pipe 1, as shown in FIG. 1, the exhaust gas a at 500 ° C. is discharged through the outlet 1 a into the upper mixing pipe 5, and the exhaust gas a discharged from the outlet of the mixing pipe 5 is mixed. The distance L was set to 2D (D: diameter of the exhaust pipe 1), and the temperature distribution of the exhaust gas (a + b) at the same distance was measured by an experiment. The flow rate of the exhaust gas a at this time was 300 m ³ / min, and the flow rate was 43 m / sec. As a result of the experiment, the temperature distribution was about 390 ° C and the maximum temperature was about 415 ° C, and a uniform temperature distribution was obtained. Further, when the exhaust gas a is discharged from the exhaust pipe 1, the outside air b is guided along each outside air guiding groove 2 around the outlet portion, and a large amount of the outside air b is discharged together with the exhaust gas a at the lower end of the mixing pipe 5. It was confirmed that the flare 6 was sucked into the mixing pipe 5 through the gap between the flare 6 and the outlet end of the exhaust pipe 1.

On the other hand, in order to compare with the exhaust pipe 1 of the present invention, although not shown, a device is manufactured in which the outlet of the exhaust pipe is squeezed into a conical shape with the outlet end facing the outlet end. When the above-mentioned shielding member 3 is arranged and an experiment is conducted under the same conditions as above, the temperature distribution of the exhaust gas (a + b) discharged from the mixing pipe 5 becomes a mountain shape, and the maximum temperature thereof is 497 ° C, which is almost the same temperature. Was not recognized. This is because when the outlet of the exhaust pipe is narrowed toward the outlet end in a conical shape, even if the shielding member 3 is provided at the center of the outlet, the exhaust gas flowing out of the exhaust pipe hits the shielding member 3 and the exhaust gas flows out as a whole. Although it spreads radially, since the outlet of the exhaust pipe is conical, mixing with the surrounding outside air is not promoted, and exhaust gas gathers near the center after passing through the shielding member 3, so it is as if there was no shielding member 3. It is presumed that such a flow occurs, and the effect of providing the shielding member 3 does not occur.

FIGS. 3A to 3C are perspective views showing another embodiment of the above-mentioned shielding member. First, the shielding member 13 of FIG. 1A is formed in an inverted conical shape, and is disposed at the outlet of the exhaust pipe 1 (FIG. 1) with its top portion 13a facing downward. Therefore, there is an advantage that the flow path resistance of the exhaust gas flowing in the exhaust pipe 1 is smaller than that of the shielding member 3 of the above embodiment, and therefore the pressure loss is reduced.

Further, the shielding member 23 of FIG. 2B is the same as the shielding member 13 of FIG. 2A, in which a plurality of spiral swirl fins 24 are provided at equal intervals in the same direction. .. In the shielding member 23 of this embodiment, the pressure loss is reduced similarly to the shielding member 13, and the exhaust gas flowing out from the exhaust pipe 1 is swirled by the swirling fins 24 so as to be spirally twisted into the mixing pipe. Since it flows in, the exhaust gas becomes a swirling flow in the mixing pipe 5 (FIG. 1) and is efficiently mixed with the outside air.

Further, the shielding member 33 of FIG. 2C is a circular plate shape like the shielding member 3 of FIG. 1, but after making notches at equal intervals in the circumferential direction to form a plurality of blades, The blades 34 are twisted in the same direction to form a windmill. Therefore, the shielding member 33 of the present embodiment has a larger pressure loss than the shielding members 13 and 23, but the exhaust gas becomes a swirling flow in the mixing pipe 5 (FIG. 1) like the shielding member 23. Since it flows in, the mixing efficiency with the outside air is very high.

By the way, although the exhaust pipe 1 is integrally formed in the above-mentioned embodiment, the outlet portion of the exhaust pipe 1 is separated from the lower body portion thereof, and the outlet portion side is replaced via a flange (not shown) or the like. The connection may be possible. Further, although the exhaust pipe 1 and the mixing pipe 5 are arranged in the vertical direction, the present invention is not limited to this, and it goes without saying that the same can be done by arranging them in an oblique direction or a horizontal direction.

[0023]

EFFECTS OF THE INVENTION As is clear from the above description, the exhaust gas temperature reduction device of the present invention has the following effects.

(1) Since the high temperature gas discharged from the outlet of the exhaust pipe is uniformly mixed with the outside air, the temperature of the high temperature gas can be reduced uniformly and the large amount of outside air can be introduced into the mixing pipe. Since it is mixed with the high temperature gas, the mixing distance required for uniform mixing can be short. In particular, the height of the chimney can be reduced in ships because the mixing distance becomes shorter.

Further, in the conventional apparatus described in the above publication, the vicinity of the inner peripheral wall of the short pipe connected to the upper end of the exhaust pipe is cooled by the outside air to suppress the temperature rise at the exhaust pipe outlet, whereas the present invention Since the device reduces the temperature of the hot gas itself, not only the area around the outlet of the exhaust pipe, but also the thermal effect of the gas after discharge is reduced, and the infrared radiation from the gas is also reduced.

Furthermore, since the intake of the outside air is performed by a kind of suction action by the exhaust gas flow discharged from the exhaust pipe, no equipment such as a fan is required, the structure of the device is simplified, and compactness can be achieved. It is easy to install the device on a ship or vehicle.

(2) In the exhaust gas temperature reducing device according to the second aspect, the resistance of the exhaust gas flow to the shielding member is suppressed as much as possible, so the pressure loss becomes small.

(3) In the exhaust gas temperature reduction device according to the third aspect, the exhaust gas is introduced into the mixing pipe so as to be spirally twisted along a plurality of swirl fins of the conical shielding member, and the mixture is mixed. Since it becomes a swirling flow in the pipe, it is more efficiently mixed with the outside air.

[Brief description of drawings]

FIG. 1 is a perspective view showing an exhaust gas temperature reduction device according to an embodiment of the present invention.

FIG. 2 is a view taken along the line II-II of FIG.

3 (a) to 3 (c) are perspective views showing another embodiment of the shielding member used in the device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust pipe 2 Outside air guide groove 3/13/23/33 Shielding member 4 Support metal fitting 5 Mixing pipe 6 Flare 24 Swivel fin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Nishikami 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries Ltd. Kobe factory (72) Yoshimasa Sakai Higashi-kawasaki, Chuo-ku, Kobe-shi, Hyogo 3-1, 1-1, Kawasaki Heavy Industries Ltd. Kobe factory

Claims (3)

[Scope of utility model registration request] 1. An exhaust gas temperature obtained by extending a mixing pipe having a flare whose downstream diameter is gradually increased toward the downstream end from the vicinity of the outlet end of the exhaust pipe for high-temperature exhaust gas to the upstream side. In the reducing device, on the peripheral wall of the outlet portion of the exhaust pipe, outside air guide grooves that enter a concave shape toward the center and gradually increase in degree from the downstream side to the outlet end are formed at equal intervals in the circumferential direction. An exhaust gas temperature reduction device, characterized in that a circular, substantially circular, or regular polygonal shielding member as viewed from above is arranged in the center of the outlet of the exhaust pipe. 2. The exhaust gas temperature reducing device according to claim 1, wherein the shielding member is formed in an inverted conical shape. 3. A plurality of swirl fins are provided in a spiral shape in the same direction at intervals around the shielding member.
Exhaust gas temperature reduction device described.