JP7051630B2 - Exhaust gas discharge structure and eaves unit - Google Patents

Description

The present invention relates to an exhaust structure for discharging exhaust gas sent from a motor into the atmosphere.

A drainage pump station will be installed as a hydraulic control facility in areas where floods due to rainfall are a concern. Rainwater overflowing from small and medium-sized rivers due to heavy rain is supplied to the underground drainage channel via a shaft and stored in the suction tank of the drainage pump station. When the water level in the suction tank exceeds the standard value, the pump is driven and rainwater is pumped up and discharged into a large river.

By the way, a gas turbine is used to drive a pump in a drainage pump station. Since this gas turbine generates gas from combustion exhaust, the exhaust gas is discharged to the outside through a duct and a chimney. A cap body is provided at the chimney outlet to prevent rainwater from entering.

When constructing such a pump facility, it is required to take measures against the exhaust noise of the gas turbine so as not to damage the surrounding living environment. Especially in urban areas, noise specifications are strictly set, so it is necessary to install a muffler of sufficient size in the exhaust path. However, if the muffler is enlarged to meet the specifications, there will be inconveniences such as difficulty in securing a flow line and maintenance space in the aircraft. Therefore, it is conceivable to dispose a sound absorbing material along the inner surface of the chimney and the cap body separately from the muffler to enhance the sound reducing effect (for example, Patent Document 1).

Utility model registration No. 3110176

However, according to the verification by the inventors, even if the sound reduction effect is enhanced in this way, airflow noise is generated when the exhaust gas passes between the chimney outlet and the cap body, which is a noise specification. It turned out to be a size that cannot be ignored. It should be noted that such a problem of noise countermeasures may occur not only in the pump equipment of the drainage pump station but also in the equipment for discharging the exhaust gas from the prime mover to the atmosphere through the duct.

The present invention has been made in view of such circumstances, and one of the objects thereof is to provide an emission structure capable of suppressing noise due to exhaust gas transmitted from a prime mover.

One aspect of the present invention is an exhaust structure for discharging the exhaust gas sent from the prime mover through a duct into the atmosphere. This exhaust gas discharge structure includes a chimney that communicates with the duct and an eaves unit that covers the open end of the chimney. The eaves unit includes an end member located above the open end of the chimney and a plurality of diffusers arranged between the end member and the open end. A plurality of diffusion plates form a plurality of upper and lower discharge passages, and each discharge passage communicates with the chimney.

Another aspect of the present invention is an eaves unit attached to the open end of a chimney that exhausts the exhaust gas of a motor. The eaves unit includes an end member located above the open end of the chimney and a plurality of diffusers arranged between the end member and the open end. A plurality of diffusion plates form a plurality of upper and lower discharge passages.

According to the present invention, it is possible to provide an exhaust gas discharge structure capable of suppressing the exhaust noise from the prime mover.

It is a figure which shows roughly the equipment to which the discharge structure which concerns on an Example is applied. It is a figure which shows the structure of the eaves unit. It is a figure which shows the structure of a diffuser plate. It is a partially enlarged view which shows the detail of a bird invasion prevention structure. It is sectional drawing which shows the upper part of an exhaust unit schematically. FIG. 5 is a cross-sectional view taken along the line BB in FIG. It is a figure which shows the rectifying effect by a discharge structure. It is a figure which shows the sound reduction effect by a discharge structure. It is sectional drawing which shows the exhaust structure which concerns on the modification.

One embodiment of the present invention is a discharge structure for discharging the exhaust gas of a prime mover installed in a building into the atmosphere through a chimney. This exhaust structure includes a structure for reducing the exhaust noise generated by the prime mover itself and the airflow noise generated when the exhaust gas passes through the chimney (collectively referred to as "exhaust noise" unless otherwise specified). .. The prime mover may be a gas turbine that drives a pump as described later, or may be an internal combustion engine or the like that drives another drive target. Exhaust gas sent from the prime mover is guided to the chimney through a duct and released into the atmosphere. In order to prevent rainwater from entering the chimney, an eaves unit is provided so as to cover the opening end (upper end opening).

The eaves unit includes a cap-shaped end member (cap body) and a plurality of diffusion plates. A plurality of diffusers are arranged between the open end of the chimney and the end member. As a result, a plurality of discharge passages are formed at the top and bottom, and each discharge passage communicates with the chimney. That is, the eaves unit is formed with a plurality of stages of discharge passages for dividing the exhaust gas from the chimney. The space between the diffusers adjacent to the top and bottom serves as the discharge passage. By providing three or more diffusion plates, it is possible to form three or more stages of discharge passages and promote the diversion of exhaust gas. The end member may form the roof of the chimney by itself, or may form the roof integrally with the diffusion plate at the uppermost stage. The diffuser plate of each stage may have a cap-shaped main body and an opening in the center of the main body. As a result, a part of the exhaust gas discharged to the lower stage (upstream side) of the eaves unit can flow to the upper stage (downstream side). Alternatively, each stage may be composed of a plurality of diffusion plates, and an open region surrounded by the plurality of diffusion plates may be formed in the center of each stage.

According to this aspect, the exhaust gas is divided by a plurality of diffusion plates, so that the flow to the side of the eaves unit can be smoothed (rectified). That is, if only the roof is provided on the eaves unit as in the conventional case, the flow velocity of the exhaust gas is greatly biased in the eaves unit, and the airflow noise becomes loud in the portion where the flow velocity is high. In this respect, according to this aspect, it is possible to suppress the bias of the flow velocity and suppress the increase of the airflow sound by dividing the flow into the discharge passages of a plurality of stages. As a result, exhaust noise can be reduced.

In the present embodiment, the sound absorbing material is arranged inside the end member. Since the sound absorbing material is located on the axis of the chimney, the gas discharged from the chimney that is guided to the uppermost stage hits the sound absorbing material and the sound is reduced. As a result, the sound reduction effect of the exhaust gas can be further enhanced as a whole. In this case, the uppermost discharge passage may form a discharge passage for leading the exhaust gas whose direction is changed (obstructed) by the sound absorbing material to the atmosphere. If the roof of the eaves unit is constructed by the diffusion plate on the uppermost stage and the end members, it is easy to realize the lead-out passage. A sound absorbing material may be provided on the end member, while the sound absorbing material may not be provided on the uppermost diffusion plate. As a result, a sufficient area of the uppermost discharge passage can be secured, and the generation of airflow noise can be suppressed. All the diffuser plates may be configured not to be provided with a sound absorbing material.

Alternatively, conversely, a sound absorbing material may be provided on at least one of the upper and lower diffusion plates forming the discharge passage. Thereby, the sound absorbing material can be arranged in the discharge passage of each stage. The above-mentioned diversion effect suppresses the generation of airflow sound to some extent, and promotes sound reduction by the sound absorbing material. However, the provision of the sound absorbing material increases the total weight of the diffuser plate and thus the eaves unit. In addition, the cost increases with the installation of the sound absorbing material. Therefore, when the noise specifications are satisfied, it is preferable to omit the installation of the sound absorbing material on the diffuser plate.

As for the multi-stage diffuser plate, the upper one has a smaller central opening area. With such a configuration, the gas discharged from the opening of the chimney can be gradually distributed from below. In that case, it is preferable that the difference between the opening area of the chimney and the opening area of the lowermost diffuser plate, the difference in the opening area of the diffuser plates adjacent to the top and bottom, and the opening area of the uppermost diffuser plate are equal. The term "equal" here includes the case of being the same and the error range. Also, even if they are not equal, it is preferable to keep them within the range of ± 30%. As a result, the flow rate of the exhaust gas flowing through each discharge passage can be made uniform, and the sound reduction effect of the plurality of diffusion plates becomes good. Even if the flow of exhaust gas becomes uneven in a plurality of exhaust passages, the flow is improved by the diversion, so that the generation of airflow noise can be suppressed.

A shield may be provided so as to surround the periphery of the plurality of diffusion plates in an annular shape. The shielding body may be a shielding plate obtained by forming a plate material in an annular shape, or may be a shielding block in which blocks are arranged in an annular shape. With such a configuration, it is possible to regulate the outflow direction of the exhaust gas flowing toward the side of the eaves unit, such as to direct it upward or vertically. As a result, it is possible to suppress the radiation of sound in the horizontal direction of the eaves unit and reduce the noise level around the eaves unit. It is possible to prevent situations such as thermal deformation due to exposure of building structures installed around the eaves unit to exhaust gas. By disposing a sound absorbing material on the inner peripheral surface of the shield, sound radiation can be suppressed more effectively.

Hereinafter, examples in which the present embodiment is embodied will be described with reference to the drawings. In the following examples and variations thereof, almost the same components are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

[Example]
FIG. 1 is a diagram schematically showing equipment to which the discharge structure according to the embodiment is applied. The exhaust gas discharge structure of this embodiment is applied to the pump equipment 1 of the drainage pump station.
The drainage pump station is provided with a suction water tank 2 and a discharge water tank 4. Rainwater supplied from an underground drainage channel or the like is stored in the suction water tank 2. The discharge water tank 4 is connected to a large river via a drainage channel (not shown).

The pump equipment 1 discharges the pipe 10 connecting the suction water tank 2 and the discharge water tank 4, the pump 12 provided in the pipe 10, the gas turbine 14 for driving the pump 12, and the exhaust gas of the gas turbine 14 into the atmosphere. The exhaust unit 16 is provided. The pump 12 of this embodiment is a vertical diagonal flow pump, and includes a casing 20 extending in the vertical direction, a main shaft 22 extending along the axis of the casing 20, and an impeller 24 provided at the tip of the main shaft 22. A speed reducer 25 is provided between the gas turbine 14 and the main shaft 22. The casing 20 constitutes a part of the pipe 10 and has a bell mouth 26 as a suction port at the lower end.

The pipe 10 includes a bent pipe 28 arranged on the floor of the suction water tank 2, a hanging pipe 30 hanging from the lower end of the bent pipe 28 to the suction water tank 2, and a discharge extending from the tip of the bent pipe 28 to the discharge water tank 4. It has a tube 32. The suspension pipe 30 suspends the casing 20. The main shaft 22 penetrates the curved pipe 28 and is further connected to the speed reducer 25 upstairs. The discharge pipe 32 is provided with a check valve 34 and a discharge valve 36 from the upstream side thereof. The discharge valve 36 connects the water channel from the suction water tank 2 to the discharge water tank 4 when the pump 12 is driven, and enables the discharge of rainwater. The check valve 34 prevents backflow of rainwater from the discharge water tank 4 to the suction water tank 2.

The speed reducer 25 is an orthogonal axis type speed reducer and has a built-in bevel gear unit. The input shaft of the speed reducer 25 is connected to the output shaft of the gas turbine 14. The output shaft of the speed reducer 25 is connected to the spindle 22 of the pump 12.

The exhaust unit 16 includes a primary silencer 40, a connecting pipe 42, a secondary silencer 44, a chimney 46 and an eaves unit 48. The exhaust port of the gas turbine 14 is connected to the primary silencer 40, and the primary silencer 40 is connected to the secondary silencer 44 via a connecting pipe 42. The secondary silencer 44 is provided so as to support the chimney 46 from below. The chimney 46 opens on the roof, and an eaves unit 48 is provided so as to cover the open end. The primary silencer 40, the connecting pipe 42 and the secondary silencer 44 form a "duct" connecting the gas turbine 14 and the chimney 46. The exhaust gas of the gas turbine 14 is discharged into the atmosphere through the primary silencer 40, the connecting pipe 42, the secondary silencer 44, the chimney 46 and the eaves unit 48 (see the two-point chain line).

In the above configuration, when the water level of the suction water tank 2 exceeds the reference value, the gas turbine 14 operates and the pump 12 is driven. As a result, the stored water (rainwater) in the suction water tank 2 is sucked up from the bell mouth 26 and guided to the discharge water tank 4 through the pipe 10.

At this time, the exhaust gas sent out from the gas turbine 14 is decompressed in the process of sequentially passing through the primary silencer 40, the connecting pipe 42, the secondary silencer 44, the chimney 46, and the eaves unit 48. The reduction of the exhaust noise is realized not only by the two silencers 40 and 44 but also by the exhaust structure provided in the chimney 46 and the eaves unit 48.

Next, the details of the exhaust structure will be described.
FIG. 2 is a diagram showing the configuration of the eaves unit 48. FIG. 2A is a perspective view of the eaves unit 48. FIG. 2B shows a state in which the shield is removed, and FIG. 2C shows a state in which the bird invasion prevention structure is further removed. FIG. 3 is a diagram showing the configuration of the diffuser plate. FIG. 3A is a perspective view of the diffusion plate, and FIG. 3B is a vertical sectional view. FIG. 3C shows the function of the diffuser plate. FIG. 4 is a partially enlarged view showing the details of the bird invasion prevention structure. FIG. 4A shows a front view. FIG. 4B is a cross-sectional view taken along the line AA of FIG. 4A.

As shown in FIG. 2A, the eaves unit 48 is configured by concentrically assembling the rectifying unit 50, the bird intrusion prevention structure 52, and the shield 54. As shown in FIG. 2C, the rectifying unit 50 has three diffusion plates 56 arranged one above the other and a cap-shaped end member 57 covering the center of the upper surface of the uppermost diffusion plate 56. Hereinafter, when distinguishing the three diffusion plates 56, the lower one is referred to as "first diffusion plate 56a", the middle one is referred to as "second diffusion plate 56b", and the upper one is referred to as "third diffusion plate 56c". Call it.

The three diffusion plates 56 are fixed by a plurality of columns 62. The end member 57 is attached so as to cover the opening 60 of the third diffusion plate 56c from above. A discharge passage for passing exhaust gas is formed between the diffusers 56 adjacent to the upper and lower sides.

As shown in FIGS. 3A and 3B, the diffuser plate 56 has a cap-shaped (conical) main body 58, and has an opening 60 in the center of the main body 58. The main body 58 has a circular shape in a plan view, and the opening 60 has a circular hole. The main body 58 is inclined downward toward the outside in the radial direction, and the inclined surface forms an inclination angle θ with respect to the horizontal plane. The inclination angle θ may be set in the range of, for example, 10 ° to 30 °. As shown in FIG. 3 (c), a part of the exhaust gas from below hits the inner surface of the diffuser plate 56 and is turned around and guided to the discharge passage (see the arrow). By making the inclined surface of the diffusion plate 56 a downward slope in this way, it is possible to suppress the accumulation of rain and snow.

The outer diameters of the main bodies 58 of the three diffusion plates 56 are almost the same, but the inner diameter of the opening 60 is as small as that of the upper diffusion plate 56. This is to adjust the flow rate of the exhaust gas in each stage, and the details will be described later.

As shown in FIG. 2B, a bird intrusion prevention structure 52 is provided so as to surround the rectifying unit 50. If a bird invades the eaves unit 48, a problem such as poor gas discharge may occur, which may hinder the normal operation of the gas turbine 14. The bird invasion prevention structure 52 avoids such a problem. The bird invasion prevention structure 52 is configured by arranging a plurality of stages of slats 68 (blades) between the upper plate 64 and the lower plate 66. Both the upper plate 64 and the lower plate 66 form an annular shape, and are fixed to each other by a plurality of columns 70 provided along the outer peripheral edge. The lower end of the support column 62 of the diffusion plate 56 is fixed to the lower plate 66.

The slats 68 are made of an arcuate flat plate having substantially the same curvature as the upper plate 64, and are provided in a plurality of stages between the columns 70. Both ends of the slats 68 are fixed to adjacent columns 70, respectively. That is, the plurality of columns 70 function as a "fixed structure" for fixing the plurality of slats 68. Although the example in which the slats 68 are set to 7 stages is shown in this embodiment, the number of stages can be appropriately set. The slats 68 are provided with a plurality of insertion holes 72 along the longitudinal direction thereof. The insertion holes 72 of the slats 68 of each stage are arranged coaxially, and the bird-proof wire 74 penetrates them vertically. The upper end of the bird-proof wire 74 is fixed to the upper plate 64, and the lower end is fixed to the lower plate 66.

As shown in FIGS. 4A and 4B, the slats 68 are provided so as to incline downward toward the outside, and form an inclination angle θ with respect to the horizontal plane like the diffusion plate 56. The distance p1 of the adjacent bird-proof wires 74 is set to be about the same as the distance p2 of the adjacent slats 68. In this embodiment, the intervals p1 and p2 are set to about 50 to 100 mm, respectively. Further, the thickness of the slats 68 is 6 mm, and the diameter of the bird-proof wire 74 is about 1 mm. The plurality of slats 68 and the plurality of bird-proof wires 74 form a lattice structure. The distance p2 between the upper and lower slats 68 is considerably smaller than the distance between the upper and lower diffuser plates 56. Therefore, where the slat 68 becomes the ventilation resistance of the exhaust gas, the ventilation resistance is reduced by setting the inclination angle of the slat 68 to be about the same as that of the diffusion plate 56.

As shown in FIG. 2A, a shield 54 (shield plate) is provided so as to further surround the bird invasion prevention structure 52. The shield 54 is obtained by molding a metal plate into an annular shape. The shield 54 is supported by a plurality of beams extending from the columns 70 (see beam 76 in FIG. 5). A ventilation passage 78 is formed between the shield 54 and the bird intrusion prevention structure 52. The ventilation passage 78 is open upward and downward. With such a configuration, the exhaust gas discharged laterally from the rectifying unit 50 can be turned upward or downward. As a result, it is possible to prevent the structures and the like around the eaves unit 48 from being exposed to the exhaust gas. The shield 54 itself also has a bird invasion prevention effect.

FIG. 5 is a cross-sectional view schematically showing the upper part of the exhaust unit 16. FIG. 6 is a cross-sectional view taken along the line BB of FIG.
As shown in FIG. 5, three diffusion plates 56 are arranged between the open end 47 of the chimney 46 and the end member 57 to form a three-stage discharge passage 80. That is, the first discharge passage 80a is between the opening end 47 and the first diffusion plate 56a, the second discharge passage 80b is between the first diffusion plate 56a and the second diffusion plate 56b, and the second diffusion plate 56b and the third are. A third discharge passage 80c is formed between the diffusion plate 56c and the diffusion plate 56c.

A sound absorbing material 82 is provided in the center of the lower surface of the end member 57, and a glass cloth 84 and a punching metal 86 are arranged on the lower surface thereof. The sound absorbing material 82 is made of, for example, rock wool or glass wool. The glass cloth 84 and the punching metal 86 function as a "protective material" for preventing the sound absorbing material 82 from scattering. That is, the sound absorbing material 82 is arranged on the axis of the chimney 46 in the end member 57. As shown in the figure, the outer peripheral edge of the punching metal 86 is set to be substantially the same height as the inner peripheral edge of the opening 60c of the third diffusion plate 56c.

A punching metal 86 is fitted in the opening 60c of the third diffusion plate 56c. The opening 60b of the second diffusion plate 56b is smaller than the opening 60a of the first diffusion plate 56a. Therefore, a step is formed along the axis of the eaves unit 48 by the three diffusion plates 56 and their peripheral members. As a result, the exhaust gas from the chimney 46 is gradually divided into the three-stage discharge passages 80a to 80c. The exhaust gas traveling straight along the axis of the chimney 46 is reduced in sound by the sound absorbing material 82, and most of the exhaust gas is guided to the third discharge passage 80c. That is, the uppermost third discharge passage 80c forms a "out-out passage" for leading the exhaust gas whose direction is changed by the sound absorbing material 82 to the atmosphere.

As shown in FIG. 6, the chimney 46 has a square cylinder shape (square cross section), the upper end portion thereof protrudes into the eaves unit 48, and the lower end portion is flange-joined to the casing of the secondary silencer 44. .. The chimney 46 has a diameter-expanded portion 90 between its upper end and lower end. A sound absorbing material 92 is internally attached to the enlarged diameter portion 90. A glass cloth 94 and a punching metal 96 (protective material) are arranged inside the sound absorbing material 92.

Next, the action and effect of the discharge structure will be described. FIG. 7 is a diagram showing a rectifying effect due to the discharge structure. FIG. 8 is a diagram showing a sound reduction effect due to the discharge structure.
As shown in FIG. 7, assuming that the area of the opening end 47 of the chimney 46 is S1, the area of the opening 60a of the first diffusion plate 56a is S2, and the area of the opening 60b of the second diffusion plate 56b is S3, S1- It is set so that S2 = S2-S3 = S3. As a result, when the average flow velocity of the exhaust gas passing through each portion is equal, the flow rates Q1 to Q3 guided to the respective discharge passages 80a to 80c are made to be substantially equal. It should be noted that these values may be generally equal and may be within the range of the margin ± 30%.

As shown by the arrows in the figure, the exhaust gas that has passed through the secondary silencer 44 and the chimney 46 is sequentially changed in direction by each diffusion plate 56, and flows outward in the radial direction along each discharge passage 80. When the exhaust gas is discharged from each discharge passage 80, the exhaust gas passes through the bird intrusion prevention structure 52. Then, it is turned around on the inner surface of the shield 54, guided above or below the ventilation passage 78, and discharged into the atmosphere. The cross-sectional area of the ventilation passage 78 is equal to or larger than the opening area S1 of the chimney 46.

In this way, the flow is divided by the three-stage discharge passage 80, and the flow velocity of the exhaust gas is made uniform, so that the generation of airflow noise is suppressed. As described above, since the inclination angle of the slats 68 in the bird intrusion prevention structure 52 is adjusted to the inclination angle of the diffusion plate 56, the generation of airflow noise when the exhaust gas passes through the bird intrusion prevention structure 52 is also suppressed.

Further, as shown in FIG. 8, when the exhaust gas passes through the chimney 46, the exhaust sound is absorbed by the sound absorbing material 92 (see the two-dot chain arrow). Further, since the sound absorbing material 82 is provided on the axis of the chimney 46, that is, at the end of the exhaust gas in the traveling direction, the exhaust noise of the gas flowing into the exhaust passage 80 can be effectively reduced. Since the exhaust gas traveling straight along the chimney 46 can be applied substantially vertically to the sound absorbing material 82, it is possible to prevent an increase in the sound pressure level due to reflection. At the stage where the exhaust gas is discharged from above or below the ventilation passage 78, the exhaust noise is considerably reduced.

As described above, according to the present embodiment, the exhaust gas is divided by the plurality of diffusion plates 56, so that the flow to the side of the eaves unit 48 can be smoothed. That is, by dividing the exhaust gas into a plurality of stages of discharge passages 80, it is possible to suppress the bias of the flow velocity and suppress the increase of the air flow noise. Further, the exhaust sound can be absorbed (reduced) by lining the chimney 46 and the end member 57 with a sound absorbing material. As a result, the exhaust noise can be effectively reduced as a whole. Since the sound reducing effect can be expected from the sound absorbing material, it is not necessary to increase the size of the silencers 40 and 44.

Even if a plurality of diffusion plates are not provided in this way to divide the flow, it is conceivable to increase the roof (eaves) of the eaves unit to reduce the flow velocity of the exhaust gas and suppress the generation of airflow noise. However, increasing the size of the roof leads to an increase in the size of the entire eaves unit and an increase in the total weight, which causes problems in installation space and strength. According to this embodiment, the exhaust noise can be reduced without causing such a problem.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and it goes without saying that various modifications can be made within the scope of the technical idea of the present invention. Nor.

FIG. 9 is a cross-sectional view showing an exhaust structure according to a modified example.
In this modification, in the eaves unit 148, the sound absorbing material 82 is internally attached not only to the end member 57 but also to each diffusion plate 56 and the shielding body 54. Similar to the end member 57, a glass cloth 84 and a punching metal 86 (protective material) are arranged inside the sound absorbing material 82.

According to this modification, the exhaust noise can be expected to be further reduced by the sound reduction by the sound absorbing material 82 in addition to the suppression of the airflow noise by the multi-stage exhaust passage 80. However, by providing the sound absorbing material 82 also on the diffusion plate 56 and the shielding body 54, the total weight of the eaves unit 148 increases. In addition, the cost of parts increases with the installation of the sound absorbing material 82. Therefore, whether the sound absorbing material 82 is arranged on both the diffuser plate 56 and the shield 54 or only on one of them is appropriately adjusted according to the noise specifications. In other words, if the noise specifications are sufficiently satisfied by the effect of suppressing the airflow sound by the plurality of diffuser plates 56, it is not necessary to provide the sound absorbing material on the diffuser plate 56 or the shield 54, or it can be kept to a minimum. As a result, the weight of the eaves unit can be reduced.

In this modification, the sound absorbing material 82 is arranged on the lower surface of each diffusion plate 56, but if it is arranged in the discharge passage 80, it may be provided on any of the upper and lower surfaces of the diffusion plate 56. For example, in the configuration shown in FIG. 9, the sound absorbing material 82 may be arranged on both the upper surface and the lower surface of the second diffusion plate 56b, and the sound absorbing material 82 of the third diffusion plate 56c may be omitted. Exhaust gas reduced by the sound absorbing material 82 provided on the end member 57 is introduced into the third discharge passage 80c. Therefore, the installation of the sound absorbing material 82 may be omitted for the third discharge passage 80c.

Further, in this modification, the configuration in which the sound absorbing material 82 is arranged on the entire inner side surface of each of the shielding body 54 and the diffusion plate 56 is illustrated, but the sound absorbing material 82 is divided into a plurality of parts and appropriately spaced apart from each other. May be placed. The same applies to the sound absorbing material 92 of the chimney 46.

In the above embodiment, the main body of the diffuser plate has a circular shape in a plan view, but it may have a polygonal shape in a plan view. Further, the main body of the diffusion plate may be formed in a cap shape by arranging a plurality of members in an annular shape instead of a single member.

In the above embodiment, an example in which a three-stage discharge passage is formed by three diffusion plates is shown. In the modified example, four or more diffusion plates may be provided and four or more discharge passages may be provided. However, when only the number of discharge passages is increased without increasing the height of the eaves unit 48, the flow velocity of the exhaust gas increases due to the smaller cross-sectional area of the discharge passages, and the effect of reducing the airflow noise becomes smaller. There is. On the contrary, if the number of exhaust passages is too large, the cross section of each exhaust passage becomes small, so that the ventilation resistance becomes large and the exhaust performance may be deteriorated. Therefore, an appropriate number is set according to the height of the eaves unit 48.

In the above embodiment, the chimney has a square cross section, but it may have a polygonal cross section such as a hexagonal cross section. Further, although the chimney has a stepped square tube shape, it may be simply a square tube shape and a sound absorbing material may be attached inside. In that case, a step is formed on the inner surface of the chimney. Alternatively, it may have a cylindrical shape or a stepped cylindrical shape (circular cross-sectional shape). When the shape of the sound absorbing material is plate-shaped, it is easier to construct the chimney with a polygonal cross section.

In the above embodiment, as the configuration of the bird invasion prevention structure 52, a lattice structure consisting of a slats 68 and a bird prevention wire 74 is adopted. In the modified example, the lattice structure may be realized by supporting the slats with a plurality of partition plates (flat plates, etc.). Alternatively, a net-like structure made of a bird-proof wire mesh (for example, a clamp wire mesh having a 25 mm square mesh) may be adopted. When the flow velocity of the exhaust gas is relatively small, it is considered that the influence of the airflow noise generated in the wire mesh body and the mounting steel material is small. When the flow velocity of the exhaust gas is large, it is preferable to adopt the configuration of the above embodiment.

In the above embodiment, as shown in FIGS. 2A and 7 and the like, an example is shown in which the ventilation passage 78 between the shield 54 and the bird invasion prevention structure 52 is opened upward and downward. In the modified example, the ventilation passage 78 may be opened only upward.

In the above-mentioned examples and modifications, the bird invasion prevention structure 52 is exemplified as the “foreign matter invasion prevention structure”, but its use is not limited to “bird invasion prevention”. Needless to say, it can be applied to other foreign matter intrusion prevention (foreign matter contamination prevention) such as prevention of invasion of small animals other than birds and invasion of flying objects during storms.

In the above embodiment, the centrifugal pump is exemplified as the driving target of the prime mover, but a centrifugal pump, an axial flow pump or other pump may be targeted. The prime mover is not limited to the gas turbine, but may be a diesel engine or other internal combustion engine. The target of the prime mover is not limited to the drainage pump station, but may be a steel mill, a factory, a farm or other equipment. The exhaust structure of the above embodiment can be applied to equipment having a chimney that exhausts the exhaust gas of the prime mover.

The present invention is not limited to the above examples and modifications, and the components can be modified and embodied within a range that does not deviate from the gist. Various inventions may be formed by appropriately combining a plurality of components disclosed in the above examples and modifications. In addition, some components may be deleted from all the components shown in the above embodiment and modifications.

1 Pump equipment, 2 Suction water tank, 4 Discharge water tank, 10 Piping, 12 Pump, 14 Gas turbine, 16 Exhaust unit, 25 Reducer, 34 Check valve, 36 Discharge valve, 40 Primary silencer, 42 Connection pipe, 44 2 Next silencer, 46 chimney, 47 open end, 48 eaves unit, 50 rectifying unit, 52 bird intrusion prevention structure, 54 shield, 56 diffuser, 57 end member, 62 stanchion, 64 upper plate, 66 lower plate, 68 slats , 70 stanchions, 72 insertion holes, 74 check valve wires, 78 ventilation passages, 80 exhaust passages, 82 sound absorbing materials, 84 glass cloth, 86 punching metal, 92 sound absorbing materials, 94 glass cloth, 96 punching metal, 148 eaves units.

Claims (13)

It is an exhaust structure for exhausting the exhaust gas sent from the prime mover through the duct to the atmosphere.
The chimney that communicates with the duct
The eaves unit that covers the open end of the chimney,
Equipped with
The eaves unit is
An end member located above the open end of the chimney and
A plurality of diffusion plates arranged between the end member and the open end,
A shield that surrounds the plurality of diffusers in a ring shape, and
A grid-like or net-like foreign matter intrusion prevention structure that surrounds the periphery of the plurality of diffusion plates inside the shield.
Including
An exhaust gas discharge structure characterized in that a plurality of upper and lower discharge passages are formed by the plurality of diffusion plates, and each discharge passage communicates with the chimney. The exhaust gas discharge structure according to claim 1, further comprising three or more diffusion plates. The exhaust gas discharge structure according to claim 1 or 2, wherein the sound absorbing material is arranged on the axis of the chimney in the end member. The exhaust gas discharge structure according to claim 3, wherein the uppermost discharge passage is a lead-out passage for leading out the exhaust gas whose direction is changed by the sound absorbing material to the atmosphere. The exhaust gas discharge structure according to claim 3 or 4, wherein at least the uppermost diffusion plate is not provided with a sound absorbing material. The exhaust gas discharge structure according to any one of claims 1 to 5, wherein a sound absorbing material is provided on at least one of the upper and lower diffusion plates forming the discharge passage. The exhaust gas discharge structure according to any one of claims 1 to 6, wherein a sound absorbing material is disposed on the inner surface of the chimney. The exhaust gas discharge structure according to any one of claims 1 to 7, wherein the diffusion plate has a cap-shaped main body and an opening in the center of the main body. The difference between the opening area of the chimney and the opening area of the lowermost diffuser plate, the difference in the opening area of the diffuser plates adjacent to the top and bottom, and the opening area of the uppermost diffuser plate are equal to each other, or the margin is ± 30. The exhaust gas discharge structure according to claim 8, wherein the exhaust gas is set in the range of%. The exhaust gas discharge structure according to any one of claims 1 to 9, wherein a sound absorbing material is disposed on the inner surface of the shield. The exhaust gas discharge structure according to any one of claims 3 to 7, wherein the sound absorbing material is prevented from scattering by a protective material. The foreign matter intrusion prevention structure is
A plurality of flat plates arranged in the vertical direction around the plurality of diffusion plates, and
A fixed structure for fixing the plurality of flat plates and
Including
The exhaust gas discharge structure according to any one of claims 1 to 11 , wherein the inclination angle of the flat plate is set substantially equal to the inclination angle of the diffusion plate. An eaves unit attached to the open end of a chimney that exhausts the exhaust gas of a prime mover.
An end member arranged above the open end of the chimney and
A plurality of diffusion plates arranged between the end member and the open end,
A shield that surrounds the plurality of diffusers in a ring shape, and
A grid-like or net-like foreign matter intrusion prevention structure that surrounds the periphery of the plurality of diffusion plates inside the shield.
Including
An eaves unit characterized in that a plurality of upper and lower discharge passages are formed by the plurality of diffusion plates.

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