JPH11324997A - Axial fan device provided with sealed cooling mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with power source equipment, the foundation work and the laying work for power cable for independently installing an oil pump and a sealed cooling fan, by mounting a sealed cooling fan on a main shaft or an intermediate shaft, and supplying the cooling air into an inner cylinder in interlocking with the main shaft. SOLUTION: A sealed cooling fan 6 is mounted on an intermediate shaft 11 covered with a protective cylinder 14, and an oil pump 10 is mounted on a shaft end 50A of a main motor 5 located on the side opposite to the intermediate shaft 11. The clean and cool sealed air 12 of normal temperature sucked from the atmospheric air from the sealed cooling fan 6 through an air filter 7 is made to flow into the protective cylinder 14, and supplied to a main bearing 3 and a moving blade variable mechanism 2 through holes 13 formed on a vane 4A or the like. The sealed cooling fan 6 is operated without fail during the operation of the axial flow fan, so that the reliability is high. Thereby the power source equipment, the foundation work and the laying work for a power cable which are necessary when the sealed cooling fan 6 or the oil pump 10 are independently mounted, become unnecessary, and the cost and the installation space can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial flow fan device provided with a seal cooling mechanism, and more particularly to an axial flow fan attached to an axial flow fan using exhaust gas as a handling gas, such as an induced draft fan of a boiler. The present invention relates to an axial fan device having a seal cooling mechanism for sealing and cooling an internal structure of a fan.

[0002]

2. Description of the Related Art An axial flow fan is high efficiency and small in size, is suitable for a large air volume compared to a centrifugal fan, and improves the power economy under a partial load by adopting a variable pitch rotor blade. It is widely used in boilers and the like for power generation. The axial fan used in the boiler draws air at room temperature and blows air into the boiler for combustion, and the induced draft that plays the role of attracting boiler combustion gas and keeping the furnace pressure slightly negative. Machine exists.

[0003] When the axial fan is used as an induced draft fan, internal mechanisms such as a main bearing and a moving blade variable mechanism are provided with dust in combustion gas (exhaust gas). ) And a high temperature, and therefore, these axial fans are provided with a seal cooling mechanism for sealing and cooling the internal mechanism.

FIG. 2 shows an example of the conventional structure of an axial fan provided with such a seal cooling mechanism.
Is an axial fan main body, in which an inner cylinder 1A and an outer cylinder 1B are arranged concentrically, and a protection cylinder 14 of an intermediate shaft 11 is connected to one end of the inner cylinder 1A. Is the main motor 5
Extending to the shaft end. In the inner cylinder 1A, a pair of impellers 4 are provided on both sides of a main shaft 30 supported by a main bearing 3.
A and 4B are attached, and the main shaft 30 on the impeller 4A side is an intermediate shaft 1 penetrating through the inside of the coupling and the protective cylinder 14.
1 and is connected to the electric shaft 50B of the main motor 5 and the moving blade variable mechanism 2 is provided on the other impeller 4B side. 10
Is an oil pump provided on the other shaft end 50A of the main motor 5.

The seal cooling mechanism for sending the seal cooling air into the inner cylinder 1A comprises a seal cooling fan 6 and a seal cooling fan drive motor 8 mounted on a base 60 outside the axial fan body 1. By rotating the seal cooling fan 6 by the drive motor 8, the air filter 7
The cooling air 12 sucked through the inner pipe 1 is supplied to the main bearing 3 and the moving blade variable mechanism 2 in the inner cylinder 1A through the air pipe 9.

[0006]

However, in such a conventional seal cooling mechanism, since the seal cooling fan 6 is constructed as a fan facility independent of the axial flow fan main body 1, it is used exclusively for the seal cooling fan of about 10 to 20 kW. In addition to the electric motor 8, power supply equipment, foundation work, and power cable laying work were required. Also, in case of a power failure due to an accident or the like in the power supply system (normally 440V power supply) of the seal cooling fan 6, an emergency power supply of 440V AC must be provided. It was costly.

In order to solve this drawback, as shown in FIG. 3, a seal cooling fan 6 is directly connected to the other shaft end 50A of the main motor 5, and the cooling fan 6 is rotated by the driving force of the main motor 5. And the cooling air 12 is supplied to the air filter 7.
In addition, a seal cooling device driven by a five-axis driving of a main motor, which supplies the moving blade variable mechanism 2 and the main bearing 3 via an air pipe 9, has been developed.

However, an oil pump 10 for lubricating various parts of the axial fan 6 having the above-described structure must be installed together with the seal fan 6 at the other shaft end 50A of the main motor 5. Seal cooling fan 6
It was substantially impossible to attach both to the shaft end 50A of the main motor 5.

Therefore, in the prior art shown in FIG. 3, even if the electric motor 8, the power supply equipment, the foundation work, and the cable laying work on the side of the seal cooling fan 6 become unnecessary, the oil pump 10 must be provided separately and independently. In order to avoid this, seal cooling fan 6
Power equipment, foundation work, and power cable laying work required for the oil pump are required.

[0010] In view of the drawbacks of the prior art, the present invention provides
Along with an oil pump for lubricating each part, a seal cooling fan that seals and cools internal mechanisms such as the main bearing and variable blade mechanism is configured as a main motor drive, so that the oil pump and seal cooling fan can be installed independently. It is an object of the present invention to provide an axial fan device equipped with a seal cooling mechanism that eliminates the need for power supply equipment, foundation work, and power cable laying work, reduces costs and saves installation space.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a seal for cooling an internal structure such as a main bearing portion and a moving blade variable mechanism included in an inner cylinder of an axial fan and a seal for cooling. In an axial fan device provided with a cooling mechanism, a seal cooling fan is mounted on a main shaft driven by a driving force of a main motor or an intermediate shaft transmitting the driving force to the main shaft, and a seal rotating in conjunction with the main shaft. The cooling fan is configured to be able to supply cooling air guided from an atmosphere opening portion on the main motor side into the inner cylinder by a cooling fan.

More specifically, as set forth in claim 2, the seal cooling fan is mounted on an intermediate shaft in a protection cylinder extending toward the electric motor while covering the intermediate shaft from the inner cylinder. At the same time, it is preferable to provide an air filter at the atmospheric opening of the protective tube.

According to the present invention, as shown in FIG. 1, the seal cooling fan 6 is connected to the main shaft 30 of the axial fan or the main motor 5 for transmitting the driving force to the main shaft 30.
By attaching to the intermediate shaft 11 between the
Since the seal cooling fan 6 is driven by the main shaft 30 of the axial flow fan, an electric motor and a power supply dedicated to the seal cooling fan 6 are not required, and the seal cooling fan 6 is always operated during the operation of the axial flow fan. Seal air,
The supply of the cooling air will be continued, and therefore an AC 440 V emergency power supply dedicated to the seal cooling fan 6 will not be provided.

Further, according to the present invention, it is possible to attach an oil pump because the other shaft end side of the main motor is free, so that power supply equipment for the oil pump, foundation work, and power cable laying work can be performed. Etc. become unnecessary.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, unless otherwise specified, dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the invention, but are merely illustrative examples. FIG. 1 shows an axial fan device according to an embodiment of the present invention in which an induction draft fan for a thermal power plant is a main fan, and a circle surrounded by an imaginary line in the drawing is enlarged in FIG.

In this embodiment, the gas handled by a large axial fan used as an induced draft fan is 120 to 15 gas.
0 ° C. boiler exhaust gas, always supplying room temperature cooling air 12 from the seal cooling fan 6 in order to protect the internal mechanism of the axial flow fan (main bearing 3, moving blade variable mechanism 2, etc.) from dust and high temperature in the exhaust gas. There is a need. Therefore, in the present embodiment, in FIG. 1, the seal cooling fan 6 is attached to the intermediate shaft 11 wrapped by the protective cylinder 14, and the shaft end 50A of the main motor 5 located on the opposite side to the intermediate shaft 11 is provided.
The oil pump 10 is attached to the pump.

That is, in FIG. 1, reference numeral 1 denotes an axial fan body in which an inner cylinder 1A and an outer cylinder 1B are arranged concentrically, and a protection cylinder 14 of an intermediate shaft 11 is connected to one end of the inner cylinder 1A. The protection cylinder 14 is extended to the shaft side 50B of the main motor 5 and the extension end of the protection cylinder 14 is formed as an open end 15 opened through the air filter 7 so that air can be introduced. Make up. The main motor 5 is provided in the protection cylinder 14.
An intermediate shaft 11 connected to the shaft via a coupling is penetrated, and the end of the intermediate shaft 11 is connected to the main shaft 30 via the coupling in the inner cylinder 1A.

According to this configuration, the protection cylinder 14 and the inner cylinder 1A are integrally connected, and the extension end of the protection cylinder 14 on the main motor 5 side is open to the atmosphere. Therefore, by attaching the cooling fan 6 for sealing to the intermediate shaft 11, the cooling air 12 at normal temperature can be introduced into the inner cylinder 1 </ b> A from the opening end 15 of the protection cylinder 14 through the protection cylinder 14. In this case, it is preferable to provide the air filter 7 at the protection cylinder opening end 15 so that a part of the dust in the combustion gas (exhaust gas) does not enter the inner cylinder 1A.

On the other hand, a main shaft 30 extending into the inner cylinder 1A is supported by a main bearing 3. A pair of impellers 4A and 4B are attached to both sides of the main shaft 30, and the main shaft 30 is located on the opposite side to the main motor 5. The moving blade variable mechanism 2 is provided in the rotating impeller 4B. In addition, each of the impellers 4A and 4B has a protective cylinder 14
In order to supply the seal air 12 to the main bearing 3 and the moving blade variable mechanism 2 from the side, a hole 13 for passing the seal air 12 is provided.

The oil pump 1 for lubricating each part
2 is provided at the other shaft end 50A of the main motor 5 as in FIG.

According to the seal cooling structure having such a configuration, the seal cooling fan 6 rotates the space 18 between the intermediate shaft 11 and the protection cylinder 14 and introduces the normal temperature seal air 12 from the protection cylinder opening end 15. . At this time, since the air filter 7 is provided at the opening end 15 of the protection cylinder so as not to suck impurities and the like, only clean air is introduced. As a result, the normal temperature and clean seal air 12 sucked from the atmosphere by the seal cooling fan 16 through the air filter 7 flows through the protection cylinder 14 as a passage of the seal air 12, and the impeller 4
It can be supplied to the main bearing 3 and the moving blade variable mechanism 2 through the holes 13 penetrating through A and 4B. Also, the seal cooling fan 6 operates during the operation of the induction ventilator 1, that is, the main motor 5 (the intermediate shaft 1).
While 1) is rotating, the seal cooling fan 6 is also operated at the same rotational speed, so that the seal air 12 can be supplied stably.

The capacity of the main motor 5 of the induction fan for a normal thermal power plant is several thousand kW (approximately 8000 kW for a 1000 MW class power plant), whereas the required power of the seal cooling fan 6 is 10 to 20 k.
W (18 kW for a 1000 MW class power plant), and the required power ratio of the cooling fan 6 to the rated load of the main motor 5 is 1
%, There is no effect on the main motor 5 main body and the power supply side, including cost effects. In the past, in the event of an accident in the power supply system of the seal air fan, etc., the backup operation was performed by the emergency AC power supply equipment. The seal cooling fan 6 is always operated, and from the viewpoint of reliability, the same as when there is an emergency power supply, or if the possibility of an accident or defect in the emergency power supply system itself cannot be denied, furthermore It can be said that it has reliability.

As a result, it is possible to reduce the incidental costs required for the seal cooling fan 6 or the oil pump driving motor, the power supply equipment, the foundation work, the laying of the power cable, the laying of the seal air pipe, etc., which were required in the conventional method. it can.
In consideration of the reduction in the number of emergency power supply facilities, the cost advantage of the present embodiment is further increased.

[0024]

As described above, according to the present invention, an oil pump for lubricating various parts and a seal cooling fan for sealing and cooling internal mechanisms such as a main bearing and a moving blade variable mechanism are configured as a main motor drive. , Power supply equipment, foundation work,
In addition, the construction work for laying the power cable becomes unnecessary, and the cost is reduced and the installation space is reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an axial fan device according to an embodiment of the present invention in which an induction draft fan for a thermal power plant is a main fan.

FIG. 2 is an explanatory diagram showing an axial fan device according to a first related art.

FIG. 3 is an explanatory view showing an axial fan device according to a second conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Axial flow fan main body 2 Moving blade variable mechanism 3 Main bearing 4A, 4B impeller 5 Main motor 6 Seal cooling fan 7 Air filter 10 Oil pump 11 Intermediate shaft 12 Cooling seal air 14 Protection cylinder 15 Protection cylinder opening end

Claims (2)

[Claims] An axial fan device having a seal cooling mechanism for sealing and cooling an internal structure such as a main bearing portion and a moving blade variable mechanism included in an inner cylinder of an axial fan. A seal cooling fan is attached to the main shaft driven by the main shaft or an intermediate shaft transmitting the driving force to the main shaft, and the cooling guided by the seal cooling fan rotating in conjunction with the main shaft from the atmosphere opening portion on the main motor side. An axial fan device wherein air is supplied into the inner cylinder. 2. The seal cooling fan is mounted on an intermediate shaft in a protection cylinder extending toward the electric motor while enclosing the intermediate shaft from the inner cylinder, and an air filter is provided at an atmospheric opening of the protection cylinder. The axial fan device according to claim 1, wherein the axial fan device is provided.