JPS5922081B2 - Hydroelectric power plant pressure oil equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure oil system equipped with a regular system and a standby system in a hydroelectric power plant, and particularly to a system for reliably replenishing pressure oil into a pressure oil tank even in the event of an unloader failure. Regarding the pressure device that can be used.

The pressure oil system in a water turbine power plant is installed as a hydraulic source for control equipment such as the opening and closing of the large mouth valve installed at the inlet of the water turbine casing, the guide vanes that control the flow rate adjustment of the water turbine, and related speed governors. .

FIG. 1 is a system diagram showing the configuration of a pressure oil device according to the present invention, and the prior art will first be explained using this diagram.

The oil accumulated in the sump tank 9 is removed by a strainer 2, and then is pumped by a pressure oil pump 1 to a stop pulp 3, a check valve 4, a pressure oil pipe 10, an unloader 5, pressure oil pipes 11 and 12, and a pressure oil tank 6. It is sent from the pressure oil tank to the control equipment through the pressure oil pipe 28.

The unloader 5 is maintained in the state shown in the figure in the pressure oil supply state, and when the pressure in the pressure oil tank 6 increases (the volume of the compressed air 30 decreases), the oil pressure in the pressure oil pipe 13 increases and the switching valve γ is switched from the state shown in the figure, and the pressure oil pipe 14.1
5, the pressure oil in the pressure oil tank 6 is supplied to the unloader 5 to operate it, and the oil from the pressure oil pump 1 is drained to the sump tank 9 through the oil drain pipe 16, and the oil is discharged to the pressure oil tank 6. Stop oil supply.

By repeating such operations, the amount of oil in the pressure oil tank 6 is maintained at a certain specified value.

Here, the pressure oil tank 6 is provided with the pressure oil pump 1.
This is to reduce the size of the device.

In other words, when starting or stopping a water turbine,
Since the guide vanes are opened and closed rapidly, a large amount of pressure oil is temporarily consumed, but on the other hand, the amount of movement of the guide vanes during steady operation is very small, and the pressure oil consumption is small, so the pressure oil pump 1 is made small enough for steady operation, and pressure oil is stored in a pressure oil tank 6 in preparation for starting or stopping the water turbine.

In addition, in consideration of reliability, the pump device is
In addition to the regular system consisting of 16, there is a standby system consisting of each of the constituent elements 1' to 16' of similar construction.

As described above, the unloader 5 (same as 5') performs a switching operation so that an amount of pressure oil within a certain specified range is secured in the pressure oil tank 6.

To explain in more detail, the method of operating the pressure oil pump 1 or 1' is generally different depending on whether the main engine of the water turbine or pump turbine is in operation or stopped, but when the main engine is in operation, it is operated continuously, When the main engine is stopped, most pumps operate intermittently depending on the pressure in the pressure oil tank, but when the pressure oil pump is operated continuously, when the pressure in the pressure oil tank reaches a specified value, the pressure oil pump 1 or This switching operation is necessary to prevent the pressure oil discharged from 1' from being sent to the pressure oil tank 6, and to replenish the pressure oil to the pressure oil tank 6 when it falls below the specified value. An unloader 5 or 5' is installed to perform this.

The unloader 5.5' is also used to start and stop the pressure oil pumps 1, 1' without any load, but its function is not directly related to the present invention and will not be described here.

In this way, the unloaders 5 and 5' perform extremely important movements, but if the unloaders do not operate even if the pressure in the pressure oil tank increases, the pressure oil supply from the pressure oil pump will continue. As a result, the pressure in the pressure oil tank 6 further increases, causing the pressure oil tank 60 safety valve (not shown in FIG. 1) to operate.

Approximately 273 of the total volume of the pressure oil tank 6 is compressed air 30, so when the above situation occurs, compressed air will initially be ejected from the safety valve, but then pressurized oil will be ejected, which is extremely dangerous. It becomes a state.

On the other hand, if the unloader 5 does not operate even if the pressure in the pressure oil tank 6 decreases (pressure oil from the pressure oil pump 1 continues to be discharged from the oil drain pipe 16), the amount of pressure oil in the pressure oil pump is not secured. Fear arises.

In conventional devices, when the drive motor of the regular pump 1 fails, a thermal relay is generally used to detect the temperature rise and start the standby pump 1', but the above-mentioned protection against unloader failure is Not taken.

Since the capacity of water turbines and pump-turbines will continue to increase in the future, and power plants are increasingly being controlled remotely or unmanned, measures to protect against unloader failures are an extremely important issue when operating power plants. be.

Based on the above-mentioned background, an object of the present invention is to provide a highly reliable pressure oil system that can automatically switch from the regular system to the standby system in the event of a failure of the unloader in the regular system of the pressure oil system. It is in.

In order to achieve the above-mentioned object, the present invention solves the following problems: (1) When the oil level or oil pressure of the pressure oil tank decreases even though the unloader is in an unloaded state (pressure oil is not supplied to the pressure oil tank), or (2) If the oil level or oil pressure in the pressure oil tank rises above the specified value even though the unloader is on-load (pressure oil is supplied to the pressure oil tank), the regular pump system is stopped and the standby pump system is activated. It is characterized by the following.

Next, one embodiment of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, 8at8bt8a't8b', 1γ,
18 is added according to the present invention, and 8at8
a' is an unload detector attached to each unloader 5, 5', which closes when these unloaders are in the unload position (see Fig. 2);
Similarly, on-load detectors b and 8b' are attached to the unloaders 5 and 5', and are closed when these unloaders are in the on-load position.

Further, 1γ is an oil level drop detector that outputs an output when the oil level in the pressure oil tank 6 is abnormally low, and 18 is an oil level rise detector that outputs an output when the oil level is abnormally high.

FIG. 2 is a circuit diagram showing an example of a circuit according to the present invention that controls switching from the regular system to the standby system related to the unload or on-load detector and oil level drop or rise detector.

Reference numeral 19 denotes a contactor for a motor that drives the pump 1, and when this is energized, the pump 1 is operated.

Reference numeral 20 denotes a contactor for the pump 1', and when this is energized, the pump 1' is operated.

21 and 22 are start and stop command contacts for the pumps 1 and 1', respectively, which are opened and closed manually or automatically in conjunction with the pressure of the pressure oil tank 6.

23 is a contactor energized or deenergized by the combination of the unload detector 8a and the oil level rise detector 18 of the unloader 5, or the combination of the on-load detector 8b and the oil level drop detector 110 of the unloader 5; 24-25; 21 indicates the auxiliary contact, and 21 indicates the alarm device (buzzer or indicator light).

Next, the operation of the embodiment shown in FIGS. 1 and 2 will be explained.

For ease of explanation, it is assumed that the regular pump 1 is continuously operated.

That is, it is assumed that the start and stop contacts 21 and 22 are closed.

Here, when the unloader 5 is normal, the contactor 23 is not energized, so the auxiliary contact 24 is closed (contactor 19 is energized), and the auxiliary contact 25 is open (contactor 20 is deenergized).

When the pressure in the pressure oil tank 6 is below the specified value, as shown in FIG. ．．
The pressure oil tank 6 is supplied with oil through the lL12.

When the pressure in the pressure oil tank 6 exceeds the specified value, the oil pressure switching valve γ operates, and the pressure oil 14 is transferred to the unloader 5 through the pressure oil pipe 15.
It acts on

As a result, the pressure oil from the pressure oil pump 1 is communicated to the oil drain pipe 16, and the oil supply to the pressure oil tank 6 is cut off.

Under normal conditions, the above operation is repeated and the pressure oil tank 6
The oil amount is kept at a certain specified value.

Such operation is no different from the conventional example.

Next, the operation when the unloader 5 breaks down will be explained.

Regarding unloader failures, we must consider cases where the unloader continues to unload and cases where the unloader continues to load.

We will discuss these two cases below.

(1) In the case of unloading for as long as it is left unloaded This may be caused by the internal valve of the unloader 5 being stiff or malfunctioning of the hydraulic switching valve I. In this case, the pressure oil from the pressure oil pump 1 is discharged. Since the oil is discharged to the sump tank 9 through the oil pipe 16, the pressure oil tank 6 is not supplied with oil.

However, since the oil is supplied from the pressure oil tank 6 to the control equipment through the pressure oil pipe 28, the oil pressure and oil level in the pressure oil tank decrease.

Due to the drop in oil pressure, the oil pressure switching valve γ and the unloader 5 must operate, but because the unloader 5 is not in the on-load position due to the failure, the oil pressure and oil level in the pressure oil tank 5 further drop.

Therefore, the oil level drop detector 17 is closed.

That is, in FIG. 2, the oil pressure drop detector 1T is closed while the unload detector 8a is closed.

Therefore, the contactor 23 is energized, so the contact 24 is opened, the contact 25 is closed, and the contact 26 is closed.

As a result, the contactor 19 is deenergized and the pressure oil pump 1
At the same time, the contactor 20 is energized and the backup pump 1' is activated, and at the same time, the alarm device 21 issues an alarm.

By starting the reserve pump 1', the stop pulp (normally open) 3', check valve 4', unloader 5', and pressure oil pipe 10' are activated.
, 11', and 12, pressure oil is supplied to the pressure oil tank 6.

Thereafter, as in the case of the regular pump system described above, the pressure oil tank 6 is moved by the operation of the hydraulic switching valve 13' and the unloader 5'.
pressure is maintained at a specified value.

(2) When left on-load In this case, pressure oil from the pressure oil pump 1 is continuously supplied regardless of the pressure in the pressure oil tank 6, so the oil level in the pressure oil tank 6 , the oil pressure increases.

As a result, the oil level rise detector 18 is closed.

That is, in FIG. 2, the oil level rise detector 18 is closed while the on-load detector 8b is closed, so the contactor 23 is energized and the same procedure as described for the unloading case is followed. The reserve pump 1' is started, and pressure oil is supplied to the pressure oil tank 6 by this reserve pump 1'.

In this way, a failure is detected in both cases where the pump is left unloaded and left unloaded, and the regular pump is switched to the standby pump.

Note that the above explanation assumes that the system related to pump 1 is the regular system,
Although the system related to the pump 1' was referred to as the standby system, the same applies to the case where the pump 1' side is the regular system.

In addition, in the above configuration in which the pressure oil tank 6 is filled with compressed air 30, the height of the oil level corresponds one to one to the magnitude of the pressure, so the oil level drop detector 11 and the oil level rise detector vessel 18
Alternatively, an oil pressure drop detector and an oil pressure rise detector may be used, respectively.

As described above, according to the present invention, in the event of a failure of the unloader of the regular pump system, automatic switching is quickly performed, so that the pressure in the pressure oil tank can be maintained within a specified value.

Therefore, in hydroelectric power plants in recent years where there is a trend towards remote control or unmanned operation, even in the event of an unloader failure, it is possible to continue operating without any problems, which has a great economic effect.

[Brief explanation of the drawing]

The attached drawings are diagrams illustrating an embodiment of the present invention, in which Fig. 1 is a system diagram of a pressure oil system, and Fig. 2 is a circuit diagram showing a circuit for switching between a regular system and a standby system in the event of an unloader failure. It is. 1.1'--...Pressure oil pump, 5,5'...
・Unloader, 6...Pressure oil tank, 7,7'・
...Hydraulic switching valve, 8a, 8a'...Unload detector, 8b. 8b'...On-road detector, 1γ...
・Oil level drop detector, 18...Oil level rise detector,
19... Contactor for starting pump 1, 20...
...Pump 1' starting contactor, 28...
Pressure oil pipe connected to control equipment, 30... Compressed air.

Claims (1)

[Claims] 1. A regular pump system, a backup pump system, a pressure oil tank installed on the outlet side of both pump systems, and a pressure oil tank installed in both pump systems to keep the amount of pressure oil in the pressure oil tank within a specified range. Equipped with an unloader that controls the supply of oil from the pump,
In a pressure oil system of a hydroelectric power plant configured to supply pressure oil from the pressure oil tank to each control device, an abnormal decrease or an abnormal increase in the oil amount in the pressure oil tank is detected. A drop detector, an oil amount increase detector, and an unload detector and an on-load detector installed at least on the unloader of the regular pump system, and the unload detector and the oil amount drop detector operate simultaneously. A pressure oil system for a hydroelectric power plant, characterized in that the regular pump system is switched to a standby pump system when the on-load detector and the oil amount increase detector operate at the same time.