JP2003065199A - Hydraulic power generator provided with mixed or axial water turbine runner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve power generation efficiency by feeding water prewhirled by a volute casing through a guide vane to a water turbine runner and rotating, and increasing water turbine efficiency of a water turbine with a low specific speed, and to provide a hydraulic power generator provided with a mixed or axial water turbine runner capable of easing a restriction on an installation space by reducing a size, and enhancing cooling capacity of a generator. SOLUTION: An axial flow type volute casing 1 for housing the generator 3 in a casing main body 1A and forming a vortex chamber 1C extending in an axial direction, and a water turbine casing 2 with an annular water passage 2C communicating with the vortex chamber 1C by continuing in a direction of a vertical axis C on a downstream side in a flow direction of water W for power generation are provided. The guide vane 4 is arranged in the annular water passage 2C, the mixed or axial flow water turbine runner 5, which rotates by the water W for power generation flowing out of the guide vane 4, is rotatably housed in an inside of the water turbine casing 2 on a downstream side of the annular water passage 2C, and the water turbine runner 5 is mounted on a water turbine shaft 6 simultaneously rotating with a rotator 3B of the generator 3 so as to rotate simultaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydroelectric generator equipped with a mixed flow or axial flow turbine runner.

[0002]

2. Description of the Related Art Conventionally, a mixed flow turbine shown in FIG. 3 is known as a turbine having a large head and a low specific speed. In this mixed flow turbine, a guide vane (guide vane) 52 and a stay vane 53 are provided on the outer periphery of a mixed flow turbine runner 51 fixed to a turbine shaft 50.
Are arranged in a double structure, and the centrifugal spiral casing 54 is arranged so as to surround the outer periphery thereof. Therefore, by connecting the generator 55 to the water wheel shaft 50, the hydraulic power generation device 56 can be configured. In this hydroelectric power generation device 56, the centrifugal swirl casing 54 pre-swirls the water, and this pre-swirl flow is sent to the mixed flow turbine runner 51 via the stay vanes 53 and the guide vanes 52 for rotation, so that an oblique flow with a low specific speed is used. Increase the efficiency of the water wheel,
Power generation efficiency can be improved.

[0003]

However, the structure in which the centrifugal swirl casing 54 is arranged on the outer periphery of the guide vane 52 and the stay vane 53, that is, the centrifugal swirl casing 54 is largely outside in the radial direction of the guide vane 52 and the stay vane 53. In the structure in which the hydrodynamic power generation device 56 is installed, the outer diameter D of the centrifugal spiral casing 54 increases, and the space for installing the hydroelectric generator 56 increases accordingly. ing.

On the other hand, since the generator 55 is installed outside, cooling of the generator 55 is limited to natural heat radiation, and a large cooling effect cannot be expected. In order to obtain a large cooling effect, a cooling device must be additionally provided, which hinders downsizing of the hydroelectric power generation device 56, and has a problem that the structure is complicated and the equipment cost increases. . In FIG. 3, the hydroelectric power generator 56 using the mixed flow turbine runner 51 is described, but the same can be said for the hydraulic power generator 56 using the axial flow turbine runner.

Therefore, according to the present invention, the water is pre-swirled by the spiral casing, and then the pre-swirl flow is sent to the water turbine runner through the guide vanes to be rotated, whereby the water turbine efficiency of the water turbine having a low specific speed is improved. It is possible to raise the power generation efficiency to increase the power generation efficiency, and in particular, it is possible to reduce the installation space restrictions by compacting it for small hydropower generation, and further improve the cooling capacity of the generator. It is an object of the present invention to provide a hydroelectric power generator having a mixed flow or axial flow turbine runner.

[0006]

In order to achieve the above-mentioned object, a hydraulic power generator having a mixed flow or axial flow turbine runner according to the present invention accommodates at least a part of a generator in a cylindrical casing body. And an axial flow type spiral casing that forms a spiral chamber extending in the axial direction, and an outer peripheral cylinder portion and an inner peripheral cylinder that are continuously provided in the axial direction of the axial flow spiral casing on the downstream side in the flow direction of power generation water. Section and a water turbine casing formed by extending an annular water channel communicating with the swirl chamber in the axial direction, guide vanes are arranged in the annular water channel, and the inside of the outer peripheral tubular portion is located downstream of the guide vanes. A turbulent or axial flow turbine runner that is rotated by the power generation water that has flowed out from the guide vanes is rotatably accommodated in the turbine, and the turbine runner is attached to the turbine shaft that rotates at the same time as the rotor of the generator so as to rotate simultaneously. The It is characterized in that.

Further, it is preferable that the guide vanes are configured to secondarily swirl the pre-swirl flow of the power-generating water flowing out of the spiral chamber of the axial-flow spiral casing.

According to the first aspect of the invention, since the turbine casing is continuously provided in the axial direction of the axial flow type spiral casing on the downstream side in the flow direction of the power generation water, the outer diameter of the axial flow type spiral casing is increased. Can be reduced to the same extent as the outer diameter of the turbine casing. Therefore, it is possible to reduce the restrictions on the installation space in a compact size for small hydropower generation. Further, since the axial flow type spiral casing accommodates at least a part of the generator in the cylindrical casing body to form a spiral chamber extending in the axial direction, the power generation water passing through the spiral chamber cools the power generation. The machine can be actively cooled.

According to the second aspect of the present invention, the pre-swirl flow of the power generation water flowing out of the spiral chamber of the axial-flow spiral casing is secondarily swirled by the guide vanes, and the secondary swirl flow causes a diagonal flow. Or by rotating the axial flow turbine runner, the turbine efficiency of the mixed flow or axial flow turbine with a low specific speed is further increased,
The power generation efficiency can be further increased.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional front view showing an embodiment of the present invention, and FIG. 2 is a plan view of FIG. 1. In these drawings, a hydroelectric power generation device equipped with a mixed flow turbine runner is
The axial flow type spiral casing 1 has an axial flow type spiral casing 1 and a water turbine casing 2, and the axial flow type spiral casing 1 has a substantially cylindrical casing body 1 accommodating a generator 3 except for an upper end portion in the vertical axis C direction.
A, and a water inlet 1B provided extending from the upper end of the casing body 1A in the direction of the vertical axis C in the tangential direction or a direction close to the tangent, and the generator casing 3A of the generator 3 is an inner peripheral wall portion, And cylindrical casing body 1A
Is formed as an outer peripheral wall, the upper end of the spiral chamber 1C is closed in a watertight and openable manner by the lid 1D, and the lower end of the spiral chamber 1C is open.

The turbine casing 2 is provided continuously to the axial flow type spiral casing 1 on the downstream side in the flow direction of the power-generating water indicated by the arrow W and on the lower side in the vertical axis C direction. The cylindrical casing body 1A of the axial-flow spiral casing 1 is detachably and watertightly connected to the outer peripheral cylindrical portion 2A, the stator 3B and the rotor 3 of the generator 3.
The lower end of the generator casing 3A accommodating C is equipped with an inner peripheral cylindrical portion 2B which is detachably and watertightly connected via the bearing box 7, and has a double structure in which both ends in the vertical axis C direction are opened. And the inner peripheral surface of the outer peripheral cylindrical portion 2A and the inner peripheral cylindrical portion 2B.
An annular water channel 2C surrounded by the outer peripheral surface of is formed extending in the direction of the vertical axis C. The upper end of the annular water passage 2C communicates with the swirl chamber 1C, and the diameter is gradually reduced from the center to the lower end in the direction C of the vertical axis.

In the annular water channel 2C of the water turbine casing 2, there are circumferentially spaced guide vanes 4 for converting the pressure energy of the power generation water W flowing out from the swirl chamber 1C with a pre-swirl component into velocity energy for outflow. Are arranged in multiple numbers. In these guide vanes 4, the upper end inlet portion 4a faces the lower end opening portion of the spiral chamber 1C in the axial flow type spiral casing 1, and the reduced lower end outlet portion 4b faces the lower end opening portion of the water turbine casing 2, The angle of attack of the upper end inlet portion 4a is set so as to match the pre-swirl flow of the power generation water W flowing out of the spiral chamber 1C, and smoothly receive the pre-swirl flow without resistance.

Outer peripheral cylindrical portion 2A immediately downstream of the annular water channel 2C
The water for power generation W flowing out from the plurality of guide vanes 4
A water turbine runner 5 composed of a mixed flow turbine rotating by is rotatably accommodated. The water turbine runner 5 is attached to a lower end portion of a water turbine shaft 6 which rotates simultaneously with the rotor 3C of the generator 3 so as to be simultaneously rotatable. ing. In addition, the water axle 6
The bearing 8 is rotatably supported by a bearing 8 incorporated in a bearing box 7 interposed between the generator casing 3A and the inner cylindrical portion 2B, and a bearing is provided by a mechanical seal 9 provided at the lower end of the inner cylindrical portion 2B. 8 and generator casing 3A
Prevents ingress of water. In the figure, 10 indicates a lubricant supply system, and the lubricant supply system 10 can supply the lubricant to the bearing 8. Further, 11 is a discharge bell.

In the above structure, the power-generating water W that has been introduced straight into the spiral chamber 1C from the water inlet 1B of the axial-flow spiral casing 1 descends while swirling in the circumferential direction inside the spiral chamber 1C. It is converted into SW (see the dashed arrow in FIG. 2). The power generation water W flowing downward from the swirl chamber 1C with a pre-swirl component is converted from pressure energy into velocity energy by the guide vanes 4 while flowing down the annular water channel 2C of the turbine casing 2, and reaches the turbine runner 5, where Rotating the runner 5 and the water wheel shaft 6 causes the rotor 3 of the generator 3 to rotate.
By rotating B, power can be generated and power can be supplied to the outside.

In particular, the straight-moving power generation water W is converted by the spiral chamber 1C of the axial-flow spiral casing 1 into a pre-swirling flow SW that descends while swirling in the circumferential direction, and then the guide vanes 4 are formed.
Since the pressure energy of the water W for power generation is converted into velocity energy and the turbine runner 5 is rotated, the turbine efficiency of the mixed flow turbine having a low specific speed can be increased, and the power generation efficiency can be increased.

Further, since the turbine casing 2 is continuously provided in the direction of the longitudinal axis C of the axial flow type spiral casing 1 on the downstream side in the flow direction of the power generation water W, the outer diameter D1 of the axial flow type spiral casing 1 is set to the turbine. It can be reduced to the same extent as the outer diameter D2 of the casing 2. That is, compared with the structure of the conventional hydroelectric generator equipped with the mixed flow turbine shown in FIG. 3, in which the centrifugal spiral casing 54 largely projects outward in the radial direction of the guide vanes 52 and the stay vanes 53, The equipment can be compactly integrated for small hydropower generation, and restrictions on the installation space can be relaxed.

Further, the generator 3 is housed in the cylindrical casing body 1A of the axial flow type spiral casing 1 leaving the upper end portion in the vertical axis C direction, and the inner peripheral wall portion of the spiral chamber 1C extending in the axial direction. Therefore, the power generation water W passing through the spiral chamber 1C is actively cooled by the water cooling action. Therefore, it is possible to reliably prevent the occurrence of an inconvenience such as burn-in damage to the generator 3 due to poor cooling.

On the other hand, the upper end inlet portion 4 with respect to the axial length from the upper end inlet portion 4a of the guide vane 4 to the lower end outlet portion 4b.
By using a three-dimensional guide vane whose displacement amount from a to the lower end outlet portion 4b in one circumferential direction is set to be larger than that of the guide vane 4 which is normally used, the spiral chamber of the axial flow type spiral casing 1 is The pre-swirl flow SW of the power generation water W flowing out from 1C is secondarily pre-swirled in the same direction by the three-dimensional guide vanes, and the mixed flow turbine runner 5 can be rotated by this second pre-swirl flow. The turbine efficiency of the low mixed-flow turbine can be further enhanced, and the power generation efficiency can be further enhanced.

Further, the axial flow type spiral casing 1 has a simple structure in which the cylindrical casing body 1A is used as the outer peripheral wall portion and the generator casing 3A of the generator 3 is used as the inner peripheral wall portion to form the spiral chamber 1C. Since the cylindrical casing body 1A having the water inlet 1B can be manufactured by the can manufacturing process using the steel pipe and the steel plate without relying on casting, it is easy to manufacture the axial flow spiral casing 1. have.

In the above embodiment, the generator 3 is left in the cylindrical casing body 1A, leaving the upper end in the vertical axis C direction.
To form a spiral chamber 1C extending in the axial direction, that is, a part of the generator 3 is housed in a cylindrical casing body 1A to form a spiral chamber 1C extending in the axial direction. Although the axial flow type spiral casing 1 has been described above, the axial flow type spiral casing 1 in which the whole generator 3 is housed in the cylindrical casing body 1A to form the spiral chamber 1C extending in the axial direction is also applicable. Good.

Further, in the above-described embodiment, the hydroelectric power generator having the water turbine runner 5 composed of the mixed flow turbine is explained, but the present invention is also applied to the hydraulic power generator having the axial flow turbine runner. be able to.

Furthermore, by using an existing mass-produced mixed flow or axial flow pump, the axial flow type spiral casing 1 described in the above embodiment is arranged at a position immediately upstream of the discharge bend (pump casing). As a result, it is possible to construct a hydraulic power generation device equipped with a diagonal flow or axial flow turbine runner that achieves the same actions and effects as those of the above-described embodiment, without using the time and effort of production, and can be used for power generation.

[0023]

As described above, since the hydroelectric power generator having the mixed flow or axial flow turbine runner according to the present invention is configured, the following special effects are exhibited.

That is, according to the first aspect of the invention, since the turbine casing is continuously provided in the axial direction of the axial flow type spiral casing on the downstream side in the flow direction of the power generation water, the axial flow type spiral casing has The outer diameter can be reduced to the same extent as the outer diameter of the turbine casing. Therefore, compared to the conventional example using the centrifugal spiral casing, the hydroelectric power generation device can be compactly arranged for small hydroelectric power generation and the restrictions on the installation space can be eased. Further, since the axial flow type spiral casing accommodates at least a part of the generator in the cylindrical casing body to form a spiral chamber extending in the axial direction, the power generation water passing through the spiral chamber cools the power generation. The machine can be actively cooled. As a result, it is possible to reliably prevent the occurrence of inconvenience such as burn-in damage to the generator due to poor cooling.

According to the second aspect of the invention, the pre-swirl flow of the power generation water flowing out from the spiral chamber of the axial-flow spiral casing is secondarily swirled by the guide vanes, and this second swirl flow is used. By rotating the diagonal or axial turbine runner,
The turbine efficiency of a mixed flow or axial flow turbine with a low specific speed can be further increased to further increase the power generation efficiency.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a schematic configuration diagram showing an example of a conventional hydroelectric power generator using a mixed-flow turbine.

[Explanation of symbols]

1 Axial flow type spiral casing 1A Cylindrical casing body 1C swirl chamber 2 turbine casing 2A Turbine casing outer cylinder 2B Turbine casing inner cylinder 2C ring waterway 3 generator 3C generator rotor 4 guide vanes 5 turbine runners (diagonal or axial flow turbine runners) 6 water axle C vertical axis (axial direction) W power generation water

Claims (2)

[Claims] 1. An axial flow type spiral casing in which at least a part of a generator is housed in a cylindrical casing body to form a spiral chamber extending in the axial direction, and the axial flow type spiral casing is located downstream in the flow direction of power generation water. A turbine casing formed by continuously extending in the axial direction an annular water passage that is continuously provided in the axial direction of the casing and communicates with the spiral chamber by an outer peripheral tubular portion and an inner peripheral tubular portion, and the annular water channel A guide vane is arranged, and on the downstream side of the guide vane, a mixed flow or axial flow turbine runner that is rotated by the power generation water flowing out from the guide vane is rotatably accommodated inside the outer peripheral tubular portion. A hydroelectric generator equipped with a mixed-flow or axial-flow turbine runner, which is attached to a turbine shaft that rotates simultaneously with the rotor of the generator so as to be rotatable simultaneously. 2. The mixed flow or axial flow water according to claim 1, wherein the guide vanes are configured to secondarily prerotate the pre-rotation flow of the power generation water flowing out from the spiral chamber of the axial flow type spiral casing. A hydroelectric generator equipped with a car runner.