JPH10103211A - Hydraulic machine air supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the operation of an air supply device of hydraulic machinery and prevent a turning stream of filling water in a suction pipe securely by providing a control valve and an air storage chamber in a main shaft in which an air passage is drilled and providing a control part which gives an open and close signal to a valve body of the control valve. SOLUTION: An air passage 10 which suppresses a turning stream generated in filling water 9 in a suction pipe 8 is drilled in a main shaft 2 connected with a runner vane 4. The air passage 10 is provided with an air storage chamber 12 sealed by a packing 11, and a control valve 13 and an air introduction port 14 are provided in the air storage chamber 12. A valve open and close signal of the control valve 13 which is set is input as a drive signal from a control part 16 into a motor 15 to advance and retract a valve body of the control valve 13 by driving force of the motor 15, and atmospheric air suctioned through the air introduction port 14 is supplied to the filling water 9 in the suction pipe 8. Consequently, it is possible to shut off air securely when it is unnecessary to supply air into the suction pipe 8 and perform stable operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air supply device for a hydraulic machine, and more particularly, to an air supply device for a hydraulic machine that supplies an appropriate amount of air to a suction pipe according to an operation state of the hydraulic machine.

[0002]

2. Description of the Related Art In general, in a hydraulic machine, a suction pipe is provided at an outlet side of a runner vane, and the suction pipe is set to a negative pressure compared with the atmospheric pressure so that the velocity energy of hydraulic fluid flowing out of the runner vane can be effectively recovered. It is planned.

[0003] However, as in the case of partial load operation, when the flow rate of the hydraulic water jetted from the runner vanes decreases,
Since the swirling speed component is generated in the moving water, when the moving water having the swirling speed component blows out to the suction pipe having a negative pressure, the charged water in the suction pipe generates a swirling flow. The swirling flow generated in the water in the suction pipe is a combination of free vortices and Rankine vortices. At first, the elongated vortex becomes a spiral vortex with a dead water core (cavity) inside as it grows. To change the water supply due to the swing of the spiral vortex, and finally the output swing (power swing) of the hydraulic machine,
Vibration due to resonance with the natural frequency of the dead water core, or noise due to collision of the suction pipe with the elbow was generated.

[0004] As one means for preventing the generation of output fluctuation, vibration, and noise, an air supply operation for supplying air from outside the vessel to the charged water fluctuating in the suction pipe has been conventionally performed.

[0005] In this air supply operation, when air is supplied from the outside to the charged water fluctuating in the suction pipe, the air is collected in a dead water core under negative pressure due to the centrifugal force of the swirling charged water, and the dead water is collected. It focuses on the fact that the core and the spiral vortex are surrounded over the entire circumference and eventually disappear, and thus a stable flow of the water is ensured.

[0006]

SUMMARY OF THE INVENTION In recent hydraulic machines,
Today, it is not possible to take the high head of hydraulic water from the viewpoint of environmental destruction.In order to obtain high output even at a relatively low head, the speed of hydraulic water passing through the runner vanes has been increased. Therefore, it is very important for the suction pipe that recovers high-speed energy to reliably prevent surging of the charged water in order to maintain the high output of the hydraulic machine and ensure stable operation.

Conventionally, an air supply operation method of a hydraulic machine is performed by drilling a main shaft (rotating shaft) integrally connected to an air pipe or a runner vane disposed on one side or transversely between a runner vane and a suction pipe. The suctioned air is blown out to the suction pipe using the air passage that has been used to prevent the swirling flow of the charged water.

[0008] However, in this conventional air supply means, when the sucked air is guided to the filling of the suction pipe without any control, the hydraulic fluid ejected from the runner vane to the suction pipe as in the partial load operation is used. When it is relatively small, while maintaining its output almost as specified, it has excellent characteristics that can prevent swirling flow of charged water,
As in rated operation, when there is a large amount of hydraulic fluid spouting from the runner vane, the air supply increases the runner vane outlet pressure and the runner head (head difference between runner inlet and outlet) decreases.
For this reason, there has been a problem that the output of the hydraulic machine is reduced, which is inconvenient.

As another means for solving such problems and inconveniences, as disclosed in Japanese Patent Application Laid-Open No. 55-151177, a jet pump is used as an air drive device for guiding air to fill a suction pipe. The control valve is adjusted based on the effective drop between the upper pond and the runner vane, and air is supplied to the swirling charge using the jet effect. I was

However, this means is structurally complicated because a hydraulic mechanism is used for opening and closing the control valve, and in order to reliably suppress the swirling flow of the charged water,
A hydraulic mechanism for adjusting the opening and closing of multiple jet pumps and control valves was required around the suction pipe, which made it difficult for the operator to use the driving operation easily. .

The present invention has been made in view of the above circumstances, and has an air supply device for a hydraulic machine that has a simplified structure, is easy to operate, and can reliably prevent a swirling flow of water in a suction pipe. Is to provide.

[0012]

According to a first aspect of the present invention, there is provided an air supply apparatus for a hydraulic machine, comprising: a casing provided in an intermediate passage connecting a casing and a suction pipe; A guide shaft and a runner provided with a runner vane are sequentially installed along the flow direction of the hydraulic fluid supplied from the main shaft, and a main shaft integrally formed with the runner and having an air passage for guiding air to the filling of the suction pipe is provided. A control valve and an air storage chamber are provided on a main shaft provided with the air passage, and a control unit for giving an open / close signal to a valve body of the control valve.

According to a second aspect of the present invention, there is provided an air supply apparatus for a hydraulic machine, wherein an air storage chamber is provided at an upper end of a main shaft having an air passage. It is.

In order to achieve the above object, the air supply device for a hydraulic machine according to the present invention, as described in claim 3, is characterized in that the control unit includes an effective head prepared in advance from data of a model test or an installation field test. And a calculation unit for setting a valve opening / closing signal of a control valve for supplying air to the suction pipe with a signal calculated based on the actual operation signal.

According to a fourth aspect of the present invention, there is provided an air supply device for a hydraulic machine, wherein an operation signal includes an actual output, an actual effective head, an actual flow rate, and an actual value of a guide vane. One of the opening degrees is selected.

In order to achieve the above object, in the air supply device for a hydraulic machine according to the present invention, the control valve is provided with a motor for moving the valve body forward and backward.

According to a sixth aspect of the present invention, there is provided an air supply device for a hydraulic machine, wherein the control valve includes a cylinder accommodating a valve body and a valve opening / closing provided by a control unit. It is provided with a valve element drive unit for moving the valve element forward and backward by a signal.

According to a seventh aspect of the present invention, there is provided an air supply device for a hydraulic machine, comprising: a valve seat provided in an air passage formed in a valve body and a main shaft of a control valve. Are both formed in a conical shape.

In order to achieve the above object, in the air supply device for a hydraulic machine according to the present invention, the cylinder is provided with a bearing for rotatably supporting the valve element. is there.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an air supply device for a hydraulic machine according to an embodiment of the present invention.

FIG. 1 is a schematic diagram showing an example in which the air supply device for a hydraulic machine according to the present invention is applied to a Francis turbine.

The spiral casing 1 has a runner 3 at the center, which is integrally connected to a main shaft (rotating shaft) 2. The runner 3 is provided with a runner vane 4 which gradually expands from the inlet to the outlet, forms a flat box-shaped passage between the blade cascades at the outlet, and further increases the velocity energy of the hydraulic fluid as compared with the prior art. Have been. An intermediate passage 5 formed between the spiral casing 1 and the runner 3 is provided with a stay vane 6 for rectifying the hydraulic fluid in the casing 1 and an effective head variation between the upper pond (not shown) and the casing 1. Guide vanes 7 which can be variably adjusted correspondingly are provided.

The outlet of the runner vane 4 is provided with an elbow-type suction pipe 8, and the suction pipe 8 is designed to recover the velocity energy of the hydraulic fluid that has given the runner vane 4 a rotational driving force.

On the other hand, an air passage 10 for guiding air and suppressing a swirling flow generated in the water 9 of the suction pipe 8 is formed in the main shaft 2 integrally connected to the runner vane 4 along the axial direction of the runner vane 4. It is drilled to extend to the exit.

As shown in FIG. 2, the air passage 10 has an air storage chamber 12 which is hermetically sealed by a packing 11 at an upper end thereof, and a control valve 13 and air are sucked into the air storage chamber 12. An air inlet 14 is provided.

The control valve 13 has a motor 15, and the driving force of the motor 15 controls the opening and closing of the control valve 13. Further, as shown in FIG. 4, the motor 15 has a parabolic function or step calculated for each variable effective head between the upper pond (not shown) and the runner vane 4 previously obtained through a model test or an installation field test. The control unit 16 includes a control unit 16 that selectively incorporates a shape-like function, and a calculation unit 17 that sets the valve opening of the control valve 13 by matching the actual effective head detected during actual operation with the function. Control valve 13 based on the valve opening signal set from
Is driven to open and close.

On the other hand, the parabolic functions incorporated in the control unit 16 and shown in FIG. 4 show a solid line when the effective head H is small and a broken line where the effective head H is large, respectively. Data for each variable effective head indicated by a dashed line is plotted in the booth.

In FIG. 4, the output signal indicated by the vertical axis indicates the valve opening of the valve body of the control valve 13, and the input signal indicated by the horizontal axis indicates the water turbine output P and the effective head H
, The effective head H and the flow rate Q passing through the runner vane 4,
Any one of the signal obtained from the −Q curve or the signal obtained from the so-called HA curve of the effective head H and the guide vane opening A is selectively used.

Further, it is selectively incorporated in the control unit 16,
The step-like function shown in FIG.
Small and dashed lines indicate the effective head H, respectively, and data for each variable head indicated by a dashed line is plotted between the effective heads H. In this case, the output signal indicated by the vertical axis indicates the valve opening of the valve body of the control valve 13 in the same manner as described above, and the input signal indicated by the horizontal axis also indicates the PH curve, PQ One of the curve and the HA curve is selectively used.

Next, the operation will be described.

When the Francis turbine enters partial load operation,
Using the detected effective head, the turbine output, the flow rate, and the guide vane opening degree, any one of the signals is used to calculate by the calculation unit 17;
The calculation signal is input to the control unit 16, where the control signal is matched with a parabolic function shown in FIG. 4 or a step-like function shown in FIG. 5, and the valve opening of the control valve 13 is automatically set.

The set valve opening / closing signal of the control valve 13 is inputted as a drive signal from the control unit 16 to the motor 15, and the valve of the control valve 13 is advanced and retracted by the driving force of the motor 15, and thus, from the air inlet 14. The suctioned atmosphere is supplied to the entire area of the water 9 of the suction pipe 8 through the air storage chamber 12 and the air passage 10.

As described above, in the present embodiment, the effective head,
A control unit 16 is provided for automatically setting a valve opening / closing signal of the control valve 13 by using any one signal of the water turbine output, the flow rate, and the guide vane opening degree. Therefore, the swirling flow generated in the filling of the suction pipe can be reliably suppressed according to the actual situation of the Francis turbine operation.

In this embodiment, when air is supplied to the water in the suction pipe, the structure is simply provided with a control valve and a control section, so that automatic supply can be performed. An air supply device can be realized.

FIG. 3 is a schematic view showing a second embodiment of an air supply device for a hydraulic machine according to the present invention. The same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

The control valve 13 according to the present embodiment
Is a cylinder 21 for accommodating the valve element 18, and a valve element driving section 22 for moving the valve element 18 forward and backward by a valve opening / closing signal from the control section 16.
The valve body 18 is formed in a conical shape, and the valve seat 19 of the main shaft 2 with respect to the valve body 18 is formed in a conical shape. It is provided.

As described above, in the present embodiment, the valve element 18 and the valve seat 19 are both formed in a conical shape, and the bearing 20 is provided so as to be rotatable when the valve element 18 is closed. When the air supply is not required, the air can be reliably cut off, and the runner head of the runner vane 4 can be stably operated without raising the runner head due to the leakage.

[0038]

As described above, the air supply device for a hydraulic machine according to the present invention is provided with the air storage chamber and the control valve in the air passage of the main shaft for supplying the atmosphere over the entire area of the suction pipe. The control unit incorporates a parabolic or step-like function based on the effective head, turbine output, flow rate, and guide vane opening as a valve opening / closing signal given to the control valve. The air can be supplied to the suction pipe automatically without any shortage.

In the air supply apparatus for a hydraulic machine according to the present invention, the valve body of the control valve for supplying water to the suction pipe is formed in a conical shape, and a bearing for rotatably supporting the valve body is stored. Since the valve is provided in the air chamber and closed in a water-tight manner, the leakage can be reliably cut off when the supply of air to the suction pipe is not required.

[Brief description of the drawings]

FIG. 1 is a schematic view of a Francis turbine to which an air supply device for a hydraulic machine according to the present invention is applied.

FIG. 2 is a partial view schematically showing a first embodiment of an air supply device for a hydraulic machine according to the present invention.

FIG. 3 is a partial view schematically showing a second embodiment of an air supply device for a hydraulic machine according to the present invention.

FIG. 4 is a graph showing a parabolic curve function incorporated in the control unit in the air supply device for a hydraulic machine according to the present invention.

FIG. 5 is a graph showing a step-like function incorporated in a control unit in the air supply device for a hydraulic machine according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Main shaft 3 Runner 4 Runner vane 5 Intermediate passage 6 Stay vane 7 Guide vane 8 Suction pipe 9 Filling water 10 Air passage 11 Packing 12 Gas storage room 13 Control valve 14 Air introduction port 15 Motor 16 Control part 17 Calculation part 18 Valve body 19 Valve seat 20 Bearing 21 Cylinder 22 Valve drive unit

Claims (8)

[Claims] A runner having a guide vane and a runner vane is sequentially installed in an intermediate passage connecting a casing and a suction pipe along a flow direction of hydraulic fluid supplied from the casing. In the air supply device for a hydraulic machine provided with a main shaft having an air passage for guiding the water to the suction pipe, a control valve and an air storage chamber are provided on the main shaft having the air passage, and a valve of the control valve is provided. An air supply device for a hydraulic machine, comprising: a control unit for giving an opening / closing signal to a body. 2. The air supply device for a hydraulic machine according to claim 1, wherein the air storage chamber is provided at an upper end of a main shaft provided with an air passage. 3. The control unit according to claim 1, wherein the control unit compares a signal calculated based on an actual operation signal with a function of an effective head created from data of a model test or an installation field test in advance to supply air to the suction pipe. The air supply device for a hydraulic machine according to claim 1, further comprising a calculation unit that sets an open / close signal. 4. The air supply device for a hydraulic machine according to claim 3, wherein the operation signal is selected from one of an actual output, an actual effective head, an actual flow rate, and an actual opening degree of the guide vane. 5. The air supply device for a hydraulic machine according to claim 1, wherein the control valve includes a motor that moves the valve body forward and backward. 6. The hydraulic machine according to claim 1, wherein the control valve includes a cylinder accommodating the valve element, and a valve element driving section that moves the valve element forward and backward according to a valve opening / closing signal given from the control section. Air supply device. 7. The air supply device for a hydraulic machine according to claim 6, wherein the valve body of the control valve and the valve seat provided in the air passage formed in the main shaft are both formed in a conical shape. 8. The air supply device for a hydraulic machine according to claim 6, wherein the cylinder includes a bearing that rotatably supports the valve element.