JPH0125894B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sand discharge valve control circuit in a cooling water system of a hydraulic machine such as a water turbine, a pump water turbine, or a pump.

[Conventional technology]

A conventional cooling water system will be explained with reference to FIG.

In FIG. 1, a runner 2 is arranged to rotate synchronously with the main shaft 1. A guide vane 3 for controlling the rotation of the runner 2 is arranged near the casing 4. Flowing water from the runner 2 is guided to a suction pipe 5. A cooling water supply pipe 7 is opened at the bottom of the suction pipe 5 at an intermediate position through a screen 6 for removing foreign matter.

The cooling water supply pipe 7 is equipped with a pump 8 and a strainer 9 that collects sand and foreign matter in the cooling water. Part 13, main shaft water sealing device 16, water turbine bearing 1
7. Cooling water is pumped to each device that requires cooling water, such as the thrust bearing 18, the main transformer 19, the air cooler 20, the generator bearing 21, and the liquid resistor 22. The cooling water used to cool each device is
The temperature is raised and the water is discharged to the suction pipe 5 again via the drain pipe 23 shown by the broken line in the figure. In addition, if the amount of cooling water decreases for some reason, flow relays 24 and 2 are installed to prevent accidents caused by this.
5 and 26 are installed, for example, in the runner seal cooling water pipe, the main shaft water sealing device cooling water pipe, and the cooling water drain pipe 23, respectively, and are configured to stop the main engine when the amount of cooling water drops below a predetermined level. .

[Problem to be solved by the invention]

However, the above configuration has the following drawbacks.

That is, regardless of the operating state of the main engine, the sand discharge valve 10 is automatically opened, for example, by a time-limited relay, after a certain period of time has elapsed, or after a certain cumulative operating time has elapsed, and the strainer 9 is drained and cleaned. . For example, the diameter of this sand discharge valve needs to be as large as 200 mm compared to the 350 mm cooling water supply pipe 7. Therefore, once the sand discharge valve 10 is opened, a considerable amount of cooling water flows into the sand discharge pipe. As a result, the amount of cooling water flowing into each cooler decreases, and the flow rate relays 24, 25, and 26 are activated, stopping the main engine, making the power supply from the main engine unstable. .

An object of the present invention is to provide a cooling water system for hydraulic machinery that prevents hydraulic machinery in operation from stopping due to lack of cooling water, stabilizes the power supply, and allows for good cooling of various equipment. The purpose of the present invention is to provide a sand discharge valve control circuit.

[Means to solve the problem]

The sand removal valve control circuit of the present invention includes an opening circuit 50 that opens the sand removal valve by closing the opening switch 88SR' when the opening excitation coil 88SR is excited, and an opening circuit 50 that opens the sand removal valve by energizing the opening excitation coil 88SR'. When the opening auxiliary B contact 88SRB and the opening auxiliary B contact are closed, the closing excitation coil 88SL is energized,
A closing circuit 51 that closes the closing switch 88SL' to close the sand discharge valve; and a relay 5X that closes only when the hydraulic machine and electrical system connected to the opening circuit are disconnected. It is in.

[Effect]

As a result, the relay 5X only operates when the main engine is stopped, and does not remove sand during operation, so it does not have to stop the main engine for sand removal work and can always provide stable power from the main engine. Therefore, the power can be stably supplied.

〔Example〕

Hereinafter, an embodiment of the present invention will be explained using a control circuit shown in FIG. FIG. 2 explains the case where the movable contactor 43S is switched to the automatic operation circuit side.

A disconnector 49B, a thermal relay 49C, and opening and closing switches 88SR' and 88SL' are connected between the electric motor power supply 49A and the electric motor 11. A control circuit 1 is provided between the opening switch 88SR' and the closing switch 88SL' and the disconnecting switch 49B.
00 is connected. The control circuit 100 mainly consists of an opening circuit 50 and a closing circuit 51, and operates as follows. Incidentally, the invention portions of the present invention are shown surrounded by chain lines in the drawings.

(1) When the main engine, such as a generator or a water turbine, is in operation, when the relay 5X and the sand removal valve 10 are opened, the opening excitation coil 88 provided in the opening circuit 50
The a contact of the SR (relay that is energized from the time the main engine is disconnected until the next startup operation) is open, but
The other sand discharge valve protection relay 86S, keep auxiliary contact 88SX, and position switch 33Shb are closed.
Therefore, since the sand discharge valve 10 is closed, cooling water is being supplied to the cooling water system of the main engine.

(2) In this state, when the generator is disconnected from the power system by stopping the main engine, the relay 5X closes, current flows through the opening excitation coil 88SR, and the opening excitation coil 88SR is excited. The opening switch 88SR' is closed. Then, the electric motor 11 rotates, for example, clockwise, and
Close the opening auxiliary A contact 88SRA and open the opening auxiliary B contact 88SRB. As a result,
In response to the rotation of the electric motor 11, the sand removal valve 10 starts an opening operation, and when it reaches the fully open position, the opening excitation coil 88SR is demagnetized to open the opening position switch 33Shb, and the sand removal valve 10 opens. 10 is at rest in the fully open position. The electric motor 11 rotates and stops by energizing and demagnetizing the opening switch 88SR'. In addition, the excitation coil 8 for opening
When 8SR is demagnetized, the opening auxiliary B contact 88
SRB changes from open state to closed state.

On the other hand, when the opening auxiliary A contact 88SRA closes, the timer 88ST starts the sand discharge valve 1 for the set time.
0 open state (at this time, the opening auxiliary A contact 88SRA opens and the self-holding contact 88
ST′ is closed and forms a self-holding circuit. ). During this time, the cooling water is drained from the strainer 9 in the direction shown by the chain line, so that foreign matter such as sand in the strainer is removed and cleaned.

(3) When the timer 88ST has elapsed the set time, the timer auxiliary contact 88STA of the timer 88ST closes and the closing excitation coil 88SL provided in the closing circuit 51 is excited, and the closing switch 88
SL′ closes. Then, the electric motor 11 rotates counterclockwise, for example, and the closing auxiliary A contact 88SLA closes. As a result, the sand discharge valve 10 starts to close in accordance with the rotation of the electric motor 11, and when it reaches the fully closed position, the closing position switch 33SlA is opened, so that the closing excitation coil 88SL is demagnetized. The sand discharge valve 10 is stationary in the fully closed position. The electric motor 11 is powered off by demagnetizing the closing excitation coil 88SL.

On the other hand, the closing auxiliary A contact 88SLA closes,
When the keep close contact 88SXO is energized, the keep auxiliary contact 88SX is opened. Therefore, it is possible to prevent the second opening operation of the sand discharge valve 10 from being performed.

(4) Next, when operating the main engine again, close the starting contact 5X' and energize the starting switch 88SXR, and the auxiliary keep contact 88SX will close.
Return to the above state and perform the same operation.

In this way, the relay 5X of the present invention is configured to perform a closing operation in response to the stoppage of the main engine. As a result, when the main engine is stopped, the cooling water is drained through the strainer 9, and while the main engine is in operation, cooling water can be supplied to various devices without stopping unlike conventional technology, making it safe and stabilizing the power supply. You can do it by doing this. Furthermore, since it is only necessary to provide the relay 5X in the control circuit, the structure is simple and the existing control circuit can be easily improved.

In addition, the control circuit has a closing contact 88SXO for keeping.
And its auxiliary contact 88SX is provided, so
Since the second opening operation of the sand removal valve is prevented after the first opening operation of the sand removal valve is performed, it is possible to eliminate the waste of operating the sand removal valve many times.

〔Effect of the invention〕

As described above, the control circuit of the present invention has a simple structure in which a relay is provided, and sand is removed at times other than during operation, so there is no shortage of cooling water while the main engine is operating, and it is safe. At the same time, power can be stably supplied.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a conventional water turbine cooling water supply and drainage system, and FIG. 2 is a control circuit diagram of a sand discharge valve showing an embodiment of the present invention. 10... Sand discharge valve, 11... Electric motor, 5X... Relay,
33Shb and 33Sla...position switches for opening and closing, 88SR and 88SL...excitation coils for opening and closing, 50 and 51...circuits for opening and closing.

Claims (1)

[Claims] 1. A strainer with a sand discharge valve that pumps up the cooling water with the cooling water pump 8 of the suction pipe 5, supplies the cooling water to the cooling water system of the hydraulic machine, cools the cooling part, and removes foreign matter from the cooling water system. 9 is installed, an electric motor 11 is connected to the sand removal valve 10, and a control circuit is provided between the power source 49A and the electric motor 11 for controlling the opening and closing of the sand removal valve according to the rotation of the motor. The opening circuit 50 excites the opening excitation coil 88SR, closes the opening switch 88SR' and opens the sand removal valve, and the opening auxiliary B contact 88SRB opens when the opening excitation coil is excited. When the opening auxiliary B contact is closed, the closing excitation coil 88SL is energized,
It is equipped with a closing circuit 51 that closes the closing switch 88SL' to close the sand discharge valve, and a relay 5X that closes only when the hydraulic machine and electrical system connected to the opening circuit are disconnected. Features a sand discharge valve control circuit for hydraulic machinery.