JPH02233881A - Hydraulic machinery - Google Patents

Abstract

PURPOSE:To make driving force smaller and stable idle running attainable by interconnecting an interval between the runner outer circumferential side and the more lower part time a rubber chamber through plural control pipelines, while installing each control valve in these control pipelines. CONSTITUTION:An interval between the outer circumferential end inside of a runner chamber 3 and a draft tube 5 are connected by plural pieces of control pipelines 10a, 10b and a filling pipeline 10c. Likewise, an interval between a lower part of the runner chamber 3 and the draft tube 5 is connected by plural pieces of control pipelines 11a, 11b and a filling pipeline 11c. Respective control valves 14a, 14b, 15a and 15b are interposed in each spot midway in these control pipelines 10a, 10b, 11a and 11b. Thus, driving force for runner rotation is small, and stable idle running is made possible to be done.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a method for forcibly adjusting the water level in a suction pipe during startup or harmonic operation in hydraulic machines such as water turbines, bombs, and bomb water turbines. This invention relates to a hydraulic machine that can cause a runner to idle by being pushed down.

(Prior art) In general, when hydraulic machines such as large-capacity pumps and pump-turbines are to be operated with bomb startup, or to stabilize the power system, harmonized operation is generally performed using hydraulic machines such as large-capacity pumps and pump-turbines. In this case, the flow rate adjustment guide vanes placed around the runner are completely idle, high-pressure air is injected into the runner chamber to drain water, and the runner is operated in the air, thereby increasing the runner's driving torque. efforts are being made to reduce the

In this case, water in the casing enters the runner chamber through the small gap between the completely closed guide vanes, and this intruding water or water that reaches the runner due to the water surface movement caused by the rotation of the runner is transferred to the rotating runner. Due to the centrifugal action, it sticks to the outer periphery of the runner chamber and is subjected to a stirring action.

As a result, loss of energy increases and the runner driving force increases, and a considerable amount of heat is generated, heating the runner and runner chamber, causing the temperature to rise over time and deforming due to thermal expansion. There were some problems.

In order to solve these problems, as shown in FIG. 6, a system has been proposed in which control piping is provided on the outer circumferential side of the runner to control drainage.

That is, in FIG. 6, the hydraulic machine includes a spiral casing 1, a guide vane 2 for adjusting flow rate disposed at the inner peripheral opening of the casing, and a runner with the outer peripheral end facing near the guide vane. It includes a runner 4 arranged inside the chamber 3 and a suction pipe 5 connected to the lower end of the runner chamber 3.

In addition, control piping 6 is provided between the outer peripheral end of the runner chamber 3 and the suction pipe 5, and between the lower part of the runner chamber 3 and the suction pipe 5.
, 7 are provided, and control valves 8, 9 are interposed in the middle of these control pipes. As a result, the runner chamber 3
The water that has entered the inside of the pump is forcibly flushed out to the suction pipe 5 through the control pipe 6.7.

As a result, the hot water stuck to the outer circumference of the runner chamber 3 is discharged, so that the runner driving force can be reduced and the generation of heat around the outer circumference of the runner chamber can be suppressed (JP-A-52-1
(See No. 35942 and No. 52-135943).

(Problem to be Solved by the Invention) In the conventional example described above, if the capacity of the control pipes 6 and 7 is small, a large amount of water will fill the outer periphery of the runner chamber 3 immediately after the water level in the suction pipe 5 is pushed down by high-pressure air. Because I am wearing
This water cannot be completely discharged, resulting in problems such as an increase in the driving force of the runner 4 and thermal expansion caused by heat generated by the stirring action of the runner 4.

On the other hand, when the capacity of the control pipes 6 and 7 is large, the amount of water stuck to the outer periphery of the runner chamber 3 becomes small. However, since this stuck water is stirred by the runner 4 rotating in the air and mixed with air, it becomes a high-pressure jet due to the centrifugal action caused by the rotation of the runner, and the control piping 6
．． 7 and is discharged to the suction pipe 5.

The high pressure air in the high pressure jet discharged into the suction pipe 5 is
It is also influenced by water surface agitation caused by the rotation of the runner 4, and leaks out through the bent portion of the suction pipe 5 to the downstream side. When the high-pressure air leaks downstream in this way, the water level inside the suction pipe 5 rises, making it impossible for the runner 4 to operate in the air, and when the high-pressure air flowing downstream is released into the atmosphere. , which will generate a lot of noise.

The present invention has been made to solve the problems of the prior art as described above.The driving force for rotating the runner is small, and stable idle operation is achieved by preventing leakage of high-pressure air to the downstream side of the suction pipe. The purpose is to provide a hydraulic machine that is possible.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the hydraulic machine of the present invention has a structure in which the water surface in the runner chamber is pushed down by high pressure air and the runner can be rotated in the air.
A plurality of control pipes communicate between the outer peripheral side of the runner and a lower part of the runner chamber, and the control pipes are provided with control valves so that their capacities can be changed. Immediately after the completion of lowering the water level, the control valves The control valve is opened to increase the capacity of the control pipe, and after a set time, these control valves are throttled to decrease the capacity of the control pipe.

(Function) In the hydraulic machine of the present invention configured as described above, in order to drain the water remaining in the runner chamber as quickly as possible immediately after pressing down the water level in the runner chamber, as shown in FIG. The control valve is opened at time to, and the capacity of the control pipe is set to vl.
increase to After time 11 has elapsed in this state, the control valve is throttled to reduce the capacity of the control pipe to ν2, thereby suppressing an increase in the amount of air leakage.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and the same parts as in FIG. 6 are given the same reference numerals, and only the differences will be explained.

The inside of the outer peripheral end of the runner chamber 3 and the suction pipe 5 are connected by a plurality of control pipes 10a, 10b and the injection pipe 10c, and the lower part of the runner chamber 3 and the suction pipe 5 are connected by a plurality of control pipes. 11a, 11b and injection pipe 11C
connected by.

Control piping 10a. , 10b are connecting pipes 12a, 12b.
The control pipes 11a and 1lb are connected by connecting pipes 13a and 13b.

Control valves 14a, 14b, 15a, 15b are inserted in the middle of the control pipes 10a, 10b, lla, llb, respectively. Control valve 14a. The diameter of the control valve 15a is small, and the diameter of the control valves 14b and 15b is large.

In the hydraulic machine configured as described above, when the water surface in the suction pipe 5 is pushed down by high-pressure air to cause the runner 4 to idle, the water surface is pushed down completely t as shown in FIG.
o and control valves 14a, 14b. 15a and 15b are fully opened, the capacity (opening area) of the control pipe is set to v1, and after a preset time 11 has elapsed, the large diameter control valves 14b and 15b are closed to reduce the capacity of the control pipe to v2.

The method of determining the time t1 at which the control piping capacity is changed is as follows.

That is, as shown in FIG. 3, when the water surface is pushed down and the control piping capacity is set to v1 at the same time and the runner continues to idle, the amount of leakage air increases rapidly after time t1. Therefore, the optimum time for changing the capacity of the control piping from ■1 to v2 is t1, just before the leakage amount rapidly increases.

Furthermore, as shown in FIG. 4, when the horizontal axis represents the control piping capacity and the vertical axis represents the amount of air leakage, the amount of air leakage increases rapidly when the predetermined control piping capacity ffiv2 is exceeded. Therefore, v2 is optimal as the control piping capacity to be switched after time tl after completion of lowering the water surface.

By performing the water surface pressing operation of the hydraulic machine as described above, a large amount of water stuck to the outer periphery of the runner chamber immediately after completion of the water surface pressing is discharged to the suction pipe through the control pipe. Therefore, the runner driving force does not increase due to the water around the outer periphery of the runner chamber, and the temperature of the water around the outer periphery of the runner chamber does not rise to cause thermal deformation of the structure.

In addition, after the water around the outer periphery of the runner chamber is sufficiently drained, the control valves 14b and 15b are closed to reduce the capacity of the control piping, thereby reducing the force of high-pressure water mixed with air flowing through the control piping to the suction pipe. Since it can be suppressed, this air can be prevented from flowing downstream of the suction pipe.

Therefore, it is possible to obtain a hydraulic machine that has little air leakage, a small runner driving force, and a small rise in the temperature of water around the outer periphery of the runner chamber, and is capable of stable water press operation.

In addition, as another embodiment of the present invention, a hydraulic machine having the structure shown in FIG. 5 can also be used.

That is, the control piping 1 connected by the connecting pipe 13a
A large-diameter control valve 14b is inserted between 0a, 10b and the injection pipe 10c.

A small-diameter control valve 14a is inserted between both ends of the control valve 14b via a bypass pipe 14c.

In addition, control piping 11a connected by a connecting pipe 12a,
A large-diameter control valve 15b is inserted between the injection pipe llb and the injection pipe 11c. A small diameter control valve 15a is inserted between both ends of the control valve 15b via a bypass pipe 15c.

In the embodiment with such a configuration, all the control valves 14a, 14b, 15a, and 15b are opened immediately after the water surface is lowered to make the control piping capacity a large capacity ■1, and after a predetermined time tl, the large-diameter pipe is opened. Control valves 14b, 15b
is closed and only the small diameter control valves 14a and 15a are opened to reduce the control piping capacity to v2. This provides the same effect as the previous embodiment.

〔Effect of the invention〕

According to the present invention configured as described above, during idling operation in which the water surface in the runner chamber is pushed down by high-pressure air and the runner rotates in the air, the runner driving force is small, the temperature rise in the runner chamber is small, and the suction pipe It is possible to obtain a stable and highly reliable hydraulic machine with a small amount of air leakage.

a, 10b, lla, llb--control piping, 8, 14
a, 14b, 15a, 15b---control valve, 12a, 1
2b, 13a, 13b--Connecting pipe, 14c, 15
C...Bypass pipe.

Claims (1)

[Claims] 1. In a hydraulic machine that is capable of rotating the runner in the air by pushing down the water surface in the runner chamber with high-pressure air, a plurality of control pipes communicate between the outer peripheral side of the runner and a lower part of the runner chamber, and The control pipes are provided with control valves so that their capacities can be changed,
Immediately after completion of pushing down the water surface, the control valves are opened to increase the capacity of the control piping, and after a set time, these control valves are throttled to reduce the capacity of the control piping. .