JPH01283431A - Controlling method for jacking mechanism and controlling device thereof - Google Patents

Abstract

PURPOSE:To correct the sliding characteristics by forming oil pockets on bearings of a stem turbine generator rotor and jacking up the rotor with the supply of oil pressure and/or adjusted flow of pressurized oil thereto. CONSTITUTION:Load on a turning device at starting and stopping is lessened by jacking up with the supply of pressurized oil from a jacking oil pump device A to oil pockets formed on bearings 4 of a steam turbine rotor 1. Adjustments are made in this case to see the pressure of a high pressure relief valve 13 of the jacking oil pump device and that of a low pressure relief valve 12 are set at such levels to enable to relieve the rotor 1 when it stops and to secure the maximum amount of relief for the rotor 1 within a range in which the pressurized oil being supplied will not cause any rotation to the rotor, respectively. Owing to the mechanism, no rotation is caused on the rotor 1, which is attributable to the action of the jacking mechanism, and the maximum relief is secured so that normal turning operation can be made possible with turning gears 7 and 6.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a jacking mechanism installed for the purpose of reducing the sliding resistance of a rotor support bearing in the low speed rotation range of a steam turbine, and in particular, to This relates to a method and a control device for controlling the state of pressure oil supply to a bearing so as to prevent excessive action and achieve a suitable action.6 [Prior Art] Bearings used in steam turbines are Since the rotor rotates at high speed during operation, sliding bearings are used because they cause less loss during operation.

The disadvantage of this sliding bearing is that the sliding friction is large in the low speed rotation range and during startup.

Therefore, in steam turbines for large thermal power plants and nuclear power plants, it is necessary to reduce the load on turning devices for turning operations performed during startup and shutdown, and to reduce wear and tear on bearings during turning operations. In order to prevent
A jacking mechanism is provided.

This jacking machine groove supplies pressurized oil into an oil pocket provided on the sliding surface of the bearing to levitate the rotor.

FIG. 4 is an explanatory diagram of the jacking mechanism. 4 is a bearing,
z4 is its inner diameter surface, and 23 is a journal.

Bearing supply oil is supplied as shown by arrow 30, circulated as shown by arrow 2G, and discharged as shown by arrow 31.

Port 25 is provided for pressure oil (jacking oil)
27 is supplied, and the journal 23 receives the push-up blade indicated by arrow 28.

The above-mentioned push-up blade 28 is generated corresponding to the oil pocket area of the port 25, and a peripheral push-up blade (arrow 29) smaller than the push-up blade 28 is generated around it.

As a result, the journal 23 is pushed up and floats,
Frictional resistance is kept at a minimum.

[Problem to be solved by the invention]

In the jacking mechanism according to the above-mentioned prior art, there is a problem in that the sliding resistance of the bearing portion of the rotor is extremely reduced, which may even cause problems.

For example, just by performing a jacking operation during startup, the rotor begins to rotate, making control difficult. FIG. 5 is an explanatory diagram of the above phenomenon, and depicts a state in which the journal 23 is floating.

Compared to the state before floating shown in FIG. 4, the push-up blade 28' corresponding to the boat 25 is slightly lowered, but the area around which the push-up blade 29' acts has become wider.

In this floating state, bearing oil supply (arrow 30) exerts a force (arrow 35) toward the left in the figure, and the journal 23 is moved to the left in the figure. Therefore, more jacking oil 27 flows in the direction of arrow 3:3 than in the direction of arrow 32. This jacking oil flow in the direction of arrow 33 is
An attempt is made to rotate the journal 23 in the direction of arrow 34.

Furthermore, the flow of lubrication oil (arrow 26) also facilitates this rotation.

Conventionally, in order to eliminate the above-mentioned problems, the action of the jacking mechanism is stopped for one or several bearings among the plurality of bearings that support the rotor, and the excessive action of the jacking mechanism is prevented. was suppressed.

However, it is extremely undesirable from the viewpoint of preventing wear and tear on the bearing parts that some bearing parts are completely floated and some bearing parts are not floated among the plurality of bearing parts.

The present invention was made in view of the above-mentioned circumstances, and does not control the action of the jacking mechanism in an all-or-nothing manner.

It is an object of the present invention to provide a control method and a control device that enable fine control of at least three stages.

[Means to solve the problem]

The basic principle of the present invention, created to achieve the above object, is to adjust the hydraulic pressure of jacking pressure oil in a direction that reduces it.

When applying this principle to an actual jacking mechanism, the hydraulic pressure may be directly controlled (for example, by providing a pressure regulating valve).
. It is also possible to restrict the flow of oil (for example, to allow some of the oil flow to escape elsewhere), thereby reducing the oil pressure. This is because, in general, in a hydraulic system, oil pressure and oil flow rate vary in relation to each other.

[Effect]

By taking the above-mentioned measures and adjusting the jacking oil pressure after the rotor journal has been lifted, the amount of lifting of the rotor journal in the bearing portion can be arbitrarily changed.

Therefore, changing the amount of floating changes the thickness of the oil film on the bearing surface.

By changing the thickness of the oil film, it is possible to control fluid friction without causing direct metal-to-metal contact, apply braking force to rotor rotation, and change the braking force.

Therefore, the action of the jacking mechanism during turning can be controlled so as not to be excessive.

〔Example〕

FIG. 1 is a system diagram showing one embodiment of the present invention.

The steam turbine is constructed by connecting a plurality of rotors 1 with couplings 2, and directly drives a generator 3.

The plurality of rotors 1 are supported by a turbine frame via bearings 4 and bearing rings 5, respectively. 6 is a receiving gear for turning, and 7 is an original gear for turning.

A is a jacking oil pump device constructed by applying the device of the present invention.

The oil supply 16 is sucked into the high pressure pump 11 through the filter 14, and the check valve 9. It is supplied to the bearing 4 (more specifically, to an oil pocket provided in the bearing 4) via the tube 8. 10
is the motor for driving the pump.

Reference numerals 12 and 13 are relief valves, and the relief valve 12 is adjusted to the pressure PIT, and the relief valve 13 is adjusted to the pressure P2, and PI<P2.

41 is a relief valve as a safety device, and P3>p
The pressure is adjusted to P3, which is 2.

A shutoff valve 15 that can be remotely operated is connected in series with and upstream of the relief valve 12 on the low pressure side (pressure P+).

As a result, the hydraulic pressure for jacking becomes pressure P1 when the shutoff valve 15 is opened, and becomes pressure P2 when the shutoff valve 15 is closed.

Switching is controlled. Even if some kind of failure occurs, the pressure will not rise above 23 due to the action of the relief valve 41.

The shutoff valve 15 is opened and closed by turning on and off the power source 19 of the motor 10. Jacking oil pump installed by entering! iM
When starting operation of A, the shutoff valve 15 is switched from the closed state to the open state by a signal after the set time of the timer 21, and the low pressure relief valve 12 is switched from the relief state of the high pressure relief valve 13 to the low pressure relief valve 12.
Switching to the relief state is performed by. Furthermore, when the jacking oil pump operation results in no need for adjustment by the low pressure relief valve 12, the switch 40 closes the low pressure relief valve 12.
You can lock the line.

On the other hand, when the jacking oil pump system [A] is stopped by turning off the power supply 19 of the motor 10, the shutoff valve 15 is returned from open to closed by the relay 22.

According to this embodiment, the set pressure P2 of the high pressure relief valve 13 of the jacking oil pump device A is set to the pressure that allows the turbine rotor 1 to float when the turbine rotor 1 is stopped, and the set pressure P1 of the low pressure relief valve 12 is set to the pressure that allows the turbine rotor 1 to float when the turbine rotor 1 is stopped. By adjusting and setting the pressure to the maximum uplift within the range that does not rotate due to the operation of jacking oil pump device A,
During operation of the jacking oil pump device A, the turbine rotor 1 does not rotate due to the action of the jacking mechanism, and maximum lifting can be ensured, allowing normal turning operation.

In this embodiment (Fig. 1), the relief valve 13 on the high pressure side
If the operation reliability is high, the relief valve 41 can be omitted.

Although not shown, a different embodiment from the above will be described with reference to FIG.

By replacing the high pressure relief valve I3 in Fig. 1 with a variable orifice with a small diameter setting orifice and the low pressure relief valve 12 with a variable orifice with a large diameter setting, the same effect can be achieved through the same control as the jacking oil pump device A. is obtained.

The same applies even if the small diameter setting orifice is eliminated and only one large diameter setting orifice is used.

FIG. 2 is a system diagram showing a further different embodiment.

B is a jacking oil pump device in this example.

The jacking oil pump device B of this embodiment has a bearing 4
Turbine rotor 1 by gap sensor 38 installed in
This jacking oil pump is equipped with a function to control the relief flow rate of oil discharged from the high-pressure pump 11 to an electric regulating valve 37 based on a detection signal indicating the floating state of the oil.

When applying the jacking oil pump device B of this example, a high pressure relief is set to ensure the hydraulic pressure of the jacking oil 27 that can lift the turbine rotor 1 even when the turbine rotor 1 is stopped. Valve 13
(adjustment pressure P2) is provided, and furthermore, a signal from a gap sensor 38 that detects the amount of lift of the turbine rotor 1 is sent via a relay 39 to operate an electric adjustment valve 37.

The setting of the relay 39 is such that when the lifting amount of the turbine rotor 1 is less than the specified value, the electric regulating valve 37 is closed, and the opening degree of the electric adjusting valve 37 is automatically adjusted so that the lifting amount is within the target lifting amount range.
adjust.

Further, this relay 39 operates the electric regulating valve 37 only during operation based on a signal from the power switch 19 of the operating motor 10 of the jacking oil pump device B. When the motor 10 is stopped, the electric regulating valve 37 is returned to the closed position. Further, when the pressure of the jacking oil 27 is below a specified value, in order to protect the bearing 4, the opening degree of the electric regulating valve 37 is limited by a signal from the pressure switch 36 to maintain the specified pressure.

In this example, if the electric regulating valve 37 does not need to operate, the switch 40 may be turned off.

According to this embodiment (FIG. 2), the amount of floating of the turbine rotor can be freely adjusted throughout the operation of the jacking oil pump, and rotation of the turbine rotor due to operation of the jacking oil pump can be prevented.

Furthermore, even if the high-pressure relief valve 13 shown in Fig. 2 is abolished and floating is started by supplying the bearing 4 with the set pressure of the protective safety relief valve of the discharge line of the high-pressure pump 11, the subsequent operation and effect will be the same as described above. It doesn't change.

Furthermore, the relief valves 13, 12, described in the embodiment in FIG.
. . are installed, and the relief valves 13, 12, . This makes it possible to freely set the amount of lift of the rotor 1. Furthermore, the same effect can be obtained even when three or more variable orifices with different set diameters are provided in place of the relief valve. FIG. 3 is a system diagram showing a further different embodiment.

In this example, when the turbine rotor 1 is stopped, the operation is started when the rotational speed is reduced to 50 to 60% of the rated rotation speed in order to prevent wear and tear on the bearings.

This jacking oil pump device C monitors the deceleration rate of the rotor 1 with a detector 43 based on the passage of time after the start of operation and the rotor rotation detector 42, and instructs the relay 45 to keep the deceleration rate within a predetermined range. The electric regulating valve 37 has a function of automatically regulating the relief oil 17.

According to this example, the rotational force to the rotor 1 due to the supply of excessive jacking pressure oil due to the start of operation of the jacking oil pump device C is added to the inertial rotational force of the rotor 1, and if the rotor 1 does not decelerate, the relief valve is activated. The relief flow rate is increased to obtain the effect of promoting stoppage of the rotor 1.

In addition, the jacking oil pump device C has a limit switch 47 that controls the operation of meshing the turning gear 7 with the turning receiving gear 6 on the rotor 1 side after starting the turning motor 46 in the subsequent turning operation after the rotor has stopped. Turning motor 4 after completion of meshing operation detected by
It also has a function of monitoring the load power of 6 with a detector 48 and instructing a relay 49 to automatically adjust the relief miscarriage of the electric regulating valve 37 so that the power is within a predetermined power range.

In this embodiment, the sliding resistance of the bearing 4 of the rotor 1 during turning operation is monitored via the power consumption of the turning motor 46, and the jacking pressure oil supply is automatically controlled so that the sliding resistance is within a predetermined range. This has excellent practical effects in that it enables normal turning operation and prevents wear and tear on the bearing as much as possible.

〔Effect of the invention〕

According to the jacking mechanism control method of the present invention, the sliding resistance of the steam turbine rotor bearing is controlled to be appropriate without the risk of premature wear and tear, and the rotor is oiled by excessive action of the jacking mechanism. Rotate with pressure,
It is possible to prevent loss of control due to insufficient sliding resistance.

Further, according to the control device of the present invention, the above-described method of the invention can be easily and safely implemented to exhibit its effects.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 are system diagrams showing embodiments of a jacking mechanism control device according to the present invention. Figures 4 and 5 are explanatory diagrams of the jacking mechanism.
The figure depicts a state in which the journal is not floating, and FIG. 5 depicts a state in which the journal is floating. 1... Steam turbine rotor, 2... Coupling,
4... Bearing, 5... Bearing ring, 6... Turning receiving gear, 7... Turning original gear, 9... Check valve, 10... Drive motor, II... High pressure pump,■
2...Low pressure relief valve, 13...High pressure relief valve, 1
4...Filter, 15...Remotely controllable shutoff valve,
16...Refueling. Representative Patent Attorney Tadashi Akimoto Minoru 11': :f6; j? ,・ 2nd 3V 4th- dent

Claims (1)

[Scope of Claims] 1. In a method for controlling a mechanism for jacking up the rotor by providing an oil pocket in a bearing that supports a rotor of a steam turbine generator, and supplying pressure oil to the oil pocket, the pressure oil A method for controlling a jacking mechanism, the method comprising adjusting at least one of oil pressure and flow rate. 2. According to claim 1, the oil pressure and flow rate of the pressure oil are adjusted by switching one or more flow resistance imparting means provided in the middle of the pressure oil supply pipeline. A method of controlling the jacking mechanism described. 3. The jacking mechanism according to claim 1, wherein the oil pressure and flow rate of the pressure oil are adjusted by adjusting the flow rate of the oil released from the middle of the pressure oil supply pipe. control method. 4. In a device that controls a mechanism for jacking up the rotor by providing an oil pocket in a bearing that supports the rotor of a steam turbine generator and supplying pressure oil to the oil pocket, the pressure oil supply pipe is provided with an oil pocket. 1. A control device for a jacking mechanism, comprising means for adjusting at least one of oil pressure and flow rate. 5. According to claim 4, the hydraulic pressure and oil amount adjusting means is an orifice that releases pressure oil to the low pressure side, and a remotely operated shutoff valve is provided in series with the orifice. control device for the jacking mechanism. 6. The hydraulic pressure and oil amount adjusting means is provided with a plurality of relief valves having different set pressures in parallel, and
The jacking mechanism according to claim 4, characterized in that a remote control shutoff valve is provided in series with a relief valve other than the relief valve with the highest set pressure among the plurality of relief valves. Control device. 7. The jacking mechanism control device according to claim 4, wherein the oil pressure and oil amount adjusting means is a remotely controllable relief valve. 8. The remote control shutoff valve is equipped with an automatic control device equipped with a timer, and the automatic control device is given a signal indicating the start of operation of the pressure oil pump, 7. The jacking mechanism control device according to claim 5, wherein the control device controls opening and closing of the remote control shutoff valve according to a predetermined program. 9. The remote control shutoff valve is equipped with an automatic control device, and the automatic control device receives the amount of lift of the rotor and controls the remote control so that the amount of lift falls within a predetermined range. 7. The jacking mechanism control device according to claim 5 or 6, wherein the control device controls opening and closing of a shutoff valve. 10. The jack according to claim 5 or 6, wherein the remote control shutoff valve is equipped with an automatic control device, and the automatic control device has the following functions. control device for the mechanical mechanism. (a) A function that detects the start of operation of the pump that pumps the pressure oil and starts counting when the turbine is stopped. (b) A function that continuously detects the relationship between the above count time and the inertial rotation speed of the rotor. (c) When the speed reduction rate is about to deviate from the set range, the remote control shutoff valve is operated to control the speed reduction rate to be within the set range. 11. The remote control shutoff valve is equipped with an automatic control device, and the automatic control device has a sensor that detects the load power of the drive motor for turning the rotor, and the automatic control device has a sensor that detects the load power of the drive motor for turning the rotor. 7. The jacking mechanism control device according to claim 5, further comprising a function of controlling the remote control shutoff valve so as to monitor and keep it within a set range.