JPS6054515B2 - hydraulic machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pump water turbine and a hydraulic machine that drains leakage water accumulated on the outer periphery of a runner during idle running of a hydraulic machine such as a pump.

Figure 1 shows a conventional hydraulic machine such as a pump-turbine and a pump, in which 1 is a runner, 2 is a guide vane, 3 is an upper cover,
4 is a lower cover, 5 is a suction pipe, 6 is a first drain pipe that communicates the side pressure chamber between the runner 1 and the lower cover 4 to the suction pipe 5, and 7
8 is a second drain pipe that connects the gap between the guide vane 2 and the runner 1 to the suction pipe 5, 8 is a first drain valve provided in the first drain pipe 6, and 9 is a second drain pipe. This is a second drain valve provided in the drain pipe 7.

In order to reduce the shaft input during startup or idling, such hydraulic machines are driven by fully closing the guide vanes 2 and sending compressed air into the runner chamber to push down the water surface of the suction pipe 5. . In this case, in order to reduce the agitation loss caused by stirring water leaking from the guide vane 2 with the runner 1, the runner outer circumferential pressure P is slightly smaller than the pressure Po on the suction pipe 5 side, so that the first drainage is The water is drained from the pipe 6 and the second drain pipe to the suction pipe 5, and is brought into contact with the idling runner 1 to cool it and suppress the temperature rise during idling. As the rotational speed of the sumo wrestler increases and the circumferential speed of runner 1 gradually increases, leakage water drained into the lateral pressure chamber through the gap at the outer circumference of the runner is affected by centrifugal force due to the circumferential speed of the runner. As a result, the leakage water in the side pressure chamber is pushed to the outside side of the side pressure chamber, so the pressure difference is reduced, and the amount of water drained into the suction pipe 5 through the runner outer peripheral gap is drastically reduced.

In addition, since the distance between the guide vane 2 and the runner 1 is small, the opening area of the second drain pipe 7 that opens between them is inevitably small, and even a slight pressure difference between pressure P and P2 cannot sufficiently drain water. If some of the water leaks and enters into the runner 1 as shown in 10, there will be no cooling effect on the runner 1, and as the runner 1 stirs the water, the idling shaft input will suddenly increase. Not only does this increase consume a large amount of power, but the consumed energy is converted into heat and increases the temperature inside the runner chamber. Therefore, if the operation continues as it is, the sudden increase in shaft input will cause fluctuations in the power system, and thermal expansion caused by excessive temperature rise will cause contact damage between the rotating and stationary parts. Therefore, there has been a demand for a drainage device that can stabilize the shaft input by controlling the leakage amount to a constant value that does not increase the import power rapidly, and can also perform a cooling action on the runner 1. The present invention was developed in view of the above-mentioned drawbacks, and when the shaft input suddenly increases, the leakage water accumulated between the guide vane and the runner outer circumference is efficiently discharged into the atmosphere by using the pressure difference between the atmospheric pressure and the runner chamber. It is an object of the present invention to provide a hydraulic machine that controls the amount of accumulated leakage water to a constant value.

In order to achieve the above object, the present invention aims to prevent water leakage that accumulates between the guide vane and the outer periphery of the runner when the guide vane is fully closed and compressed air is sent into the runner chamber to push down the water surface and idle. A drain pipe is installed to drain leakage water that accumulates around the runner to the atmosphere through a drain valve, and the agitation loss that changes depending on the amount of leakage that accumulates around the runner is fixed. Detected by input detection device,
The drain valve is opened and closed according to the value of the shaft input, which makes it possible to keep the amount of water leaking around the runner constant, thereby stabilizing the idling shaft input and preventing abnormal temperatures inside the runner chamber. be able to.

An embodiment of the present invention will be described below with reference to FIG.

Reference numeral 1 denotes a runner, and a guide vane 2 is rotatably supported by an upper cover 3 and a lower cover 4 and is provided on the outer periphery of the runner 1, and a suction pipe 5 is connected to the lower cover 4.

The lateral pressure chamber below the runner 1 and the suction pipe 5 are connected to the first drain pipe 6.
In addition, the space formed by the runner 1 and the guide vane 2 and the suction pipe 5 are communicated through a second drain pipe 7, and a first drain pipe 7 is connected to the first drain pipe 6 and the second drain pipe 7, respectively. A drain valve 8 and a second drain valve 9 are arranged. A third drain pipe 11 branching from below the first drain pipe 9 is connected to the first drain pipe 7, and a third drain pipe 11 is connected to the first drain pipe 7. It is communicated with the drain bit 12 via a water valve 13. This third drain valve 1
3 is connected to a power conversion relay 15 that converts the input of the generator motor 14 coupled to the runner 1, and is controlled by fluctuations in the idling shaft input. In addition, a check valve 16 is provided below the branch of the second drain pipe 7 to the third drain pipe 11.
is provided to close the flow from the suction pipe 5 when the drain valve 13 is opened. Then, PO is atmospheric pressure,
When P1 is the water pressure on the outer periphery of the runner 1 and P2 is the pressure inside the suction pipe 5, the respective pressures have a relationship of P1>P2>PO. Next, the effect will be explained.

During idle running such as startup, the guide vane 2 is fully closed, and compressed air is sent into the runner chamber from a device not shown to push down the water surface and at the same time open the first drain valve 8 and the second drain valve 9. . Then, when runner 1 is started after pushing down the water surface,
Water leaking from the guide vane 2 comes into contact with the runner 1 and is blown to the outer circumference by centrifugal action, producing pressure P1, and a portion of the water flows through the outer circumferential gap of the runner 1 and through the first drain pipe 6. The remaining water is passed through the second drain pipe 7 to the suction pipe 5.
The water is discharged by the pressure difference between P1 and P2, and the water that accumulates around the outer periphery of the runner 1 is kept constant. However, the amount of water leaking from the guide vane 2 increases and the first drain pipe 6, second drain pipe
When the drainage capacity of the drain pipe 7 is exceeded, the amount of leakage water that collects in the outer peripheral space of the runner 1 increases and enters into the runner 1. Therefore, the runner 1 stirs the water that has entered, causing a sudden increase in the idling shaft input. This change in the idling shaft input is detected by the power conversion relay 15, and when it reaches a predetermined value, the third drain valve 13 is opened and the water leakage is removed from the third drain valve by the pressure difference P1-PO with the atmosphere. It is discharged through a drain pipe 11 to a drain bit 12. Since the pressure difference P1-PO with the atmosphere is much larger than the pressure difference P1-P2 with the suction pipe 5, the drainage capacity increases, and when the idling shaft input decreases and drops to a predetermined value, the third drainage Valve 1
3 is closed to prevent compressed air from being released into the atmosphere. This operation is repeated during idling to maintain the amount of water leaking around the outer periphery of the runner 1 at a constant value. Therefore, according to this embodiment, even if the amount of water leaking from the guide vane 2 increases due to aging etc., fluctuations in the idling shaft input can be suppressed to a minimum, thereby stabilizing the power system. Since it is possible to suppress the temperature rise associated with stirring of water, it is possible to prevent contact accidents between the rotating part and the stationary part due to thermal expansion, and it is possible to perform stable idling operation for a long time.

In addition, the third drain valve 13 opens only when the input of the idling shaft increases when the amount of leakage water accumulated on the outer circumference of the runner 1 becomes excessive.
Release of compressed air can be prevented by the amount of water leakage that accumulates around the runner, and problems such as increasing the capacity of compressed air equipment will not occur. In addition, in the above, the third drain pipe 11 is replaced with the second drain pipe 11.
However, the third drain pipe 11 may be directly discharged into the atmosphere from between the outer periphery of the runner and the guide vane 2 in parallel with the second drain pipe 7.

As explained above, according to the present invention, the leakage water that accumulates on the outer periphery is efficiently drained by using the pressure difference with the atmosphere, so the amount of leakage water can be kept constant, and the temperature inside the runner chamber can be It is possible to perform stable idling operation by suppressing the rise.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional hydraulic machine, and FIG. 2 is a longitudinal sectional view showing an embodiment of the hydraulic machine of the present invention. 1...Runner, 2...Guide vane,
5...Suction pipe, 7...Second drain pipe, 9...Second drain valve, 11...Third
Drain pipe, 12... Drain bit, 13...
...Third drain valve, 14... Generator motor, 15...
...Power conversion relay, 16...Check valve.

Claims (1)

[Claims] 1. When the guide vane is fully closed and compressed air is sent into the runner chamber to push down the water surface and idle, a drain pipe is provided to drain leakage water accumulated between the guide vane and the outer periphery of the runner to a suction pipe. In this system, a drain pipe is installed to drain leakage water that accumulates around the runner's outer circumference to the atmosphere via a drain valve, and a shaft input detection device detects the stirring loss that changes with the amount of leakage that accumulates around the runner's outer circumference, and the drain valve is activated. A hydraulic machine characterized by opening and closing operations based on shaft input values.