CN1179509A

CN1179509A - Air feeder for hydraulic machinery

Info

Publication number: CN1179509A
Application number: CN97120507A
Authority: CN
Inventors: 能登尚子; 铃木敏晓
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 1996-09-30
Filing date: 1997-09-29
Publication date: 1998-04-22
Anticipated expiration: 2017-09-29
Also published as: JPH10103211A; CN1096563C

Abstract

The invention provides an air supply device of hydraulic machinery with simple structure which is easy to operate and prevent a turning stream of filling water in a suction pipe. In the air supply device of hydraulic machinery, the air passage 10 in a main shaft 2 is provided with an air storage chamber 12, and a control valve 13. 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.

Description

Hydraulic machinery give device of air

The present invention relates to a kind of device of air of giving of hydraulic machinery, especially relate to a kind of can be corresponding to the operating condition of hydraulic machinery to draft tube supply with appropriate amount gas hydraulic machinery give device of air.

Usually, on hydraulic machinery, be provided with draft tube, make this draft tube and barometric pressure be in a ratio of negative pressure, so that can reclaim the kinetic energy of the dynamic water that from impeller blade, flows out effectively at the outlet side of impeller blade.

But, under situation as the partial load running, when the flow of the dynamic water that sprays from impeller blade has tailed off, because of dynamically the rotational speed composition occurring in the water, so when the dynamic water with this rotational speed composition sprayed to the draft tube that becomes negative pressure, the water filling meeting in the draft tube produced rotating flow.Result from the rotating flow in the water filling in the draft tube,, combine by free vortex flow and rankine's vortex.Originally, the whirlpool core that becomes elongated is along with its continuous growth, can become inner spiral whirlpool with stagnant water core (cavity), make water filling change by the fluctuation in this spiral whirlpool, finally can occur hydraulic machinery output fluctuation (power swing), because of and the natural vibration of stagnant water core between vibration that resonance produced or because the noise that the elbow of impact draft tube produces etc.

As one of means that prevent output fluctuation, vibration and noise, situation always is from the water filling air supply of machine exterior to changing in draft tube, and to carry out changeing to fate.

The starting point that should change to fate is, when the water filling that the air supply is being changed in suction pipe from the outside, its air can and around full week in this stagnant water core and spiral whirlpool, can make their disappearances soon because the action of centrifugal force of the water filling of rotating is pooled in the stagnant water core that becomes negative pressure.Like this, just realized guaranteeing the steady flow of water filling.

On recent hydraulic machinery, in the today that can not adopt the high drop of dynamic water for the consideration that prevents environmental disruption, even for making lower drop also can obtain high output, people have considered to make the dynamic water speed up by impeller blade.Draft tube for reclaiming kinetic energy positively prevents the impact of water filling to it, to the height output of keeping hydraulic machinery with guarantee that stable running is very important.

In the past, hydraulic machinery give the fate shifting method, it is a side that utilizes between the water filling that is provided in impeller blade and draft tube, or the air duct that is laterally setting, or be arranged in air flue on the main shaft (running shaft) that is combined into one with impeller blade, make inhaled air spray to draft tube, thereby prevent the appearance of the rotating flow of its water filling.

But, on this existing setter, when the water filling of the atmosphere guiding draft tube that will suck, owing to do not carry out any control, so when as sub load running, spraying to the dynamic water of draft tube when fewer from impeller blade, its output can be maintained on the almost suitable level, and have the excellent specific property of the generation of the rotating flow that can prevent water filling with rating value; But then, when at the dynamic water that sprays from impeller blade like that as rated load running more for a long time, owing to the outlet pressure of impeller blade is risen to gas, impeller head (head difference between impeller eye and outlet) is reduced, therefore can occur making the output of hydraulic machinery to reduce such problem.

As other device that solves above-mentioned such problem, as open the Japan Patent spy in the clear 55-151177 communique disclosed, adopt Jet injector as the air driven device in the water filling that air is imported in the draft tube, it adjusts the aperture of control valve according to the change available head of water between upper pool and impeller blade of inducing that imports from the hydraulic pressure iron pipe, utilize the jet effect to supply air in the water filling of rotating.

But this device is owing to having adopted hydraulic mechanism, so complex structure when carrying out the switch drive of control valve; In addition, in order positively to restrain the rotating flow of water filling, around draft tube, need the hydraulic mechanism of the open and close of a plurality of Jet injectors and adjustment control valve, this is concerning the operator, the performance easy to use of running operation degenerates, and people wish to have the device of air of giving of easy running operation.

The present invention is based on above-mentioned such situation and proposes, its purpose be to provide a kind of simple in structure, operation running easily and can positively prevent the water filling in the draft tube rotating flow hydraulic machinery to device of air.

Hydraulic machinery of the present invention give device of air, in order to achieve the above object, as first scheme was put down in writing, on the via intermedia that connects volute and draft tube, the edge was disposed with guide vane and the impeller with impeller blade by the flow direction of the dynamic water that volute is supplied with; And, also have the main shaft that is combined into one with impeller and be equipped with the air flue in the water filling that air can be imported in the above-mentioned draft tube, this hydraulic machinery to device of air on: be equipped with on the main shaft of above-mentioned air flue and be provided with control valve; And has the control device that sends the open and close signal to the spool of control valve.

Hydraulic machinery of the present invention give device of air, in order to achieve the above object, as alternative plan is put down in writing, be provided with air-storage chamber in the upper end of the main shaft that is equipped with air flue.

Water conservancy machinery of the present invention give device of air, in order to achieve the above object, as third party's case is put down in writing; Its control device will contrast according to real-world operation signal signal of calculating and the available head function that is drawn by model test or erecting bed test for data in advance; And has the calculating part that the open and close signal of the control valve that supplies air to draft tube is set.

Hydraulic machinery of the present invention give device of air, in order to achieve the above object, as cubic case was put down in writing, its CRANK PULSES can be selected any one in the actual aperture of actual output, actual available head, actual flow and guide vane.

Hydraulic machinery of the present invention give device of air, in order to achieve the above object, as the 5th scheme was put down in writing, its control valve has can make spool advance or jibber reaches.

Hydraulic machinery of the present invention give device of air, in order to achieve the above object, as the 6th scheme was put down in writing, its control valve had the ram of taking in spool and by from valve open and close signal that control device sent and the spool drive portion that spool is advanced or retreat.

Hydraulic machinery of the present invention give device of air, in order to achieve the above object, as the 7th scheme was put down in writing, the spool of its control valve was all done taper shape with the valve seat that is arranged on the air flue that is arranged in main shaft.

Hydraulic machinery of the present invention give device of air, in order to achieve the above object, case was put down in writing from all directions as the, its ram had the bearing that spool is supported in rotation freely.

Fig. 1 is to be the sketch of example with the Francis turbine of giving device of air of having used hydraulic machinery of the present invention.

Fig. 2 is the part figure that has represented the 1st embodiment who gives device of air of hydraulic machinery of the present invention briefly.

Fig. 3 is the part figure that has represented the 2nd embodiment who gives device of air of hydraulic machinery of the present invention briefly.

Fig. 4 be shown hydraulic machinery of the present invention to device of air on, enroll the plotted curve of the parabolic function of control device.

Fig. 5 be shown hydraulic machinery of the present invention to device of air on, enroll the plotted curve of the step function of control device.

Below, the embodiment who gives device of air to hydraulic machinery of the present invention describes with reference to accompanying drawing.

Fig. 1 has represented hydraulic machinery of the present invention is applied to the sketch of an example on the Francis turbine to device of air.

Spiral helicine volute 1 has the impeller 3 that is combined into one with main shaft (running shaft) 2 in the central.Do not have impeller blade 4 on this impeller 3, to slowly expansion of outlet, the impeller clearance of outlet forms the rectangular passageway of flat to this impeller blade 4 from inlet, the kinetic energy that makes dynamic water higher than in the past.In addition, on the via intermedia 5 that is formed between Vorticose volute 1 and the impeller 3, be respectively equipped with the stator blade 6 of the dynamic water in the rectification volute 1, and can change the guide vane of adjusting freely 7 according to the change of the available head between upper pool (not shown) and the volute 1.

In addition, the draft tube 8 that has the elbow shape in the outlet of impeller blade 4 is given rotary driving force and the kinetic energy of dynamic water of impeller blade 4 to reclaim by this suction pipe 8.

On the other hand, on the main shaft 2 that is combined into one with impeller blade 4, be equipped with and import air suppressing to result from the air flue 10 of the rotating flow in the water filling 9 in the draft tube 8, and it is extended axially to the outlet of impeller blade 4 along it.

As shown in Figure 2, air flue 10 has the air-storage chamber 12 that is obtained water-tight closure by sealing material 11 in the top, and this air-storage chamber 12 has the air introducing port 14 of control valve 13 and suction air respectively.

In addition, control valve 13 has motor 15, is controlled the open and close of control valve 13 by the driving force of this motor 15.And, as shown in Figure 4, motor 15 has control device 16 and calculating part 17 respectively, wherein, parabolic function or step function that preliminary election is tried to achieve by model test or erecting bed test, that calculate according to the unit change available head between upper pool (figure does not show) and the impeller blade 4 have been enrolled selectively 16 li of this control devices; And calculating part 17 detected actual available head and above-mentioned function by with real-world operation the time contrast, and sets the aperture of control valve 13.Motor 15 according to from the setting of control device 16 the open and close that come the spool of drive control valve 13 of valve opening signal.

On the other hand, enroll the parabolic function shown in Figure 4 of 16 li of control devices, its solid line is represented the little occasion of available head H, and dotted line is represented the big occasion of available head H; In addition, the data that are in the unit that represents with the dot and dash line change available head between the large and small available head H also are shown on the figure.

Again, on Fig. 4, the output signal representative that the longitudinal axis is represented the spool aperture of control valve 13; And the represented input signal of transverse axis has used any one following signal selectively: promptly export the signal that the so-called P-H curve (カ-Block) between P and the available head H is tried to achieve by water turbine, by the available head H and the signal of being tried to achieve, the perhaps signal of being tried to achieve by the so-called H-A cap between available head H and the guide vane aperture A by the so-called H-Q curve between the flow Q of impeller blade 4.

In addition, enroll the step function shown in Figure 5 of 16 li of control devices selectively, its solid line is represented the little occasion of available head H, and dotted line is represented the big occasion of available head H; In addition, the data with the represented unit change available head of dot and dash line that are between the large and small available head H also are shown on the figure.In this case, the represented output signal of the longitudinal axis is represented the spool aperture of control valve 13 with above-mentioned identical; The represented input signal of transverse axis also with above-mentioned identical, has used one of any one signal of being tried to achieve by P-H curve, H-Q curve and H-A curve selectively.

Below its effect is described.

When Francis turbine entering part load running state, calculate at calculating part 17 with any one signal in detected available head, water turbine output, flow and the guide vane aperture, then its signal calculated is input to control device 16, contrast at this and parabolic function shown in Figure 4 or step function shown in Figure 5, thereby automatically set the aperture of control valve 13.

The open and close signal of the control valve 13 that sets, be imported into motor 15 as drive signal from control device 16, the spool of control valve 13 is advanced or retreat by the driving force of motor 15, so that will be supplied in the whole zone of the water filling 9 in the draft tube 8 from the atmosphere of air introducing port 14 inspirations through air-storage chamber 12 and air flue 10 thus.

Like this, be provided with control device 16 in the present embodiment, any one signal that this control device 16 adopts in available heads, water turbine output, flow and the guide vane aperture is automatically set the open and close signal of control valve 13.Because on the air whole zone that supplies to the water filling in the draft tube insufficiently within reason, so can positively restrain the rotating flow that takes place in the water filling in draft tube according to the actual conditions of Francis turbine running.

In addition, in the present embodiment, when the water filling that supplies air to draft tube owing to can automatically supply with the simple structure that only has control valve and control device, so can realize concerning operator processing ease to device of air.

Fig. 3 is the 2nd embodiment's who gives device of air of an expression hydraulic machinery of the present invention sketch.In addition, the part identical with the 1st embodiment's structure member is marked with identical label, and omits repeat specification it.

Control valve 13 in the present embodiment has the ram 21 of taking in spool 18 and the spool drive portion 22 that makes spool 18 generations advance or retreat by the valve open and close signal of control device 16; Simultaneously, spool 18 is made coniform, further the valve seat 19 of main shaft 2 that will be relative with spool 18 is also made coniform; On the other hand, have bearing 20 on the ram 21, while so that use core 18 to rotate to advance or retreat.

Like this, in the present embodiment, owing to all make spool 18 and valve seat 19 coniform, but also possesses the bearing 20 that when closing spool 18, can rotate freely, so in the time giving gas needn't for draft tube 8, can positively cut off air, can not rise, thereby can carry out stable running owing to gas leakage makes the impeller head of impeller blade 4.

As mentioned above, hydraulic machinery of the present invention is given device of air, owing on the air flue of the main shaft in the whole zone of the water filling that atmosphere is supplied to draft tube, be provided with control valve, but also be provided with control device, the parabola or the step function that draw according to available head, water turbine output, flow and guide vane aperture in this control device, have been enrolled as the switching signal of the valve of giving above-mentioned control valve, so can not supply air in the draft tube too insufficiently and accurately and automatically according to operating condition.

In addition, hydraulic machinery of the present invention give device of air, because supplying air to the spool of the control valve in the water filling in the draft tube is made into coniform, and being provided with rotation in air-storage chamber supports the bearing of this spool freely and makes its watertight ground throttle down, so in the time needn't giving gas, can positively cut off its gas leakage to draft tube.

Claims

A hydraulic machinery give device of air, its formation comprises: on the via intermedia that connects volute and draft tube, be disposed with guide vane and have the impeller of impeller blade along the flow direction of the dynamic water of supplying with from volute; And, also have the main shaft that is combined into one with impeller, be equipped with the air flue in the water filling that air can be imported in the above-mentioned draft tube; It is characterized in that: be provided with control valve being equipped with on the main shaft of above-mentioned air flue; And has the control device that sends the open and close signal to the spool of control valve.
The hydraulic machinery of putting down in writing as claim 1 give device of air, it is characterized in that: the upper end at the main shaft that is equipped with air flue is provided with air-storage chamber.
3. as the device of air of giving of claim 1 or 2 hydraulic machinerys of being put down in writing, it is characterized in that: control device makes the signal calculated according to the real-world operation signal and the available head function coupling that is drawn by model test or erecting bed test for data in advance, and has the calculating part that the open and close signal of the control valve that supplies air to draft tube is set.
The hydraulic machinery of putting down in writing as claim 3 give device of air, it is characterized in that: CRANK PULSES can be selected any one in the actual aperture of actual output, actual available head, actual flow and guide vane.
The hydraulic machinery of putting down in writing as claim 1 give device of air, it is characterized in that: control valve has can make spool advance or jibber reaches.
The hydraulic machinery of putting down in writing as claim 1 give device of air, it is characterized in that: control valve has the ram of taking in spool and by the spool drive portion that spool is advanced or retreat from the valve open and close signal of control device.
The hydraulic machinery of putting down in writing as claim 6 give device of air, it is characterized in that: the spool of control valve and the valve seat that is arranged on the air flue that is arranged in the main shaft all are made into taper shape.
The hydraulic machinery of putting down in writing as claim 6 give device of air, it is characterized in that: ram has the bearing that rotation supports spool freely.