CN108150228B - Method and system for preventing steam turbine from being stopped due to oil drainage of servomotor - Google Patents
Method and system for preventing steam turbine from being stopped due to oil drainage of servomotor Download PDFInfo
- Publication number
- CN108150228B CN108150228B CN201611107522.7A CN201611107522A CN108150228B CN 108150228 B CN108150228 B CN 108150228B CN 201611107522 A CN201611107522 A CN 201611107522A CN 108150228 B CN108150228 B CN 108150228B
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- servomotor
- valve
- oil
- steam turbine
- closed
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D17/00—Regulating or controlling by varying flow
- F01D17/20—Devices dealing with sensing elements or final actuators or transmitting means between them, e.g. power-assisted
- F01D17/22—Devices dealing with sensing elements or final actuators or transmitting means between them, e.g. power-assisted the operation or power assistance being predominantly non-mechanical
- F01D17/26—Devices dealing with sensing elements or final actuators or transmitting means between them, e.g. power-assisted the operation or power assistance being predominantly non-mechanical fluid, e.g. hydraulic
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D21/00—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
- F01D21/14—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for responsive to other specific conditions
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2270/00—Control
- F05D2270/01—Purpose of the control system
- F05D2270/09—Purpose of the control system to cope with emergencies
Abstract
The invention provides a method and a system for preventing a steam turbine from stopping due to oil drainage of a servomotor, and the method and the system comprise the following steps: judging whether the running state of the servomotor is abnormal or not; when the operating condition of the servomotor is judged to be abnormal, judging whether a valve of the servomotor is closed abnormally; and when the valve of the servomotor is judged to be abnormally closed, closing an electro-hydraulic servo valve of the servomotor to avoid the shutdown of the steam turbine. The method and the system for preventing the shutdown of the steam turbine caused by the oil drainage of the servomotor avoid the false shutdown of the steam turbine caused by the fault of hardware equipment; the safety and reliability of the operation of the steam turbine are improved.
Description
Technical Field
The invention relates to the technical field of steam turbines, in particular to a method and a system for preventing a steam turbine from being stopped due to oil drainage of an oil servomotor.
Background
A steam turbine is a rotary power machine that converts the energy of steam into mechanical work, and is mainly used as a prime mover for power generation, and may directly drive various pumps, fans, compressors, ship propellers, and the like. The steam valve control of the steam turbine adopts an electro-hydraulic servo system, and the control medium adopts high-pressure fire-resistant oil. The core element of the electro-hydraulic servo system is an electro-hydraulic servo valve. The electro-Hydraulic servo valve controls the movement of the valve core according to a deviation signal formed by a given Electric signal and a feedback Electric signal of a Digital electro-Hydraulic Control System (DEH) of a steam turbine, so as to Control the movement of the piston of the servomotor. The oil engine piston drives a corresponding steam inlet valve so as to quickly adjust the steam quantity of the steam turbine.
Fig. 1 shows the working principle of the servomotor. As can be seen, the pressure oil from the oil supply system goes through the quick-closing solenoid valve 11 and the electro-hydraulic servo valve 12. The quick-closing solenoid valves 11 are two in number and are in redundant configuration and used for receiving signals from a steam turbine protection system. When the electromagnetic valve works normally, the quick-closing electromagnetic valve 11 is in an electrified state, and the valve is quickly closed after power is lost. When the quick-closing electromagnetic valve 11 receives a signal of the protection system and loses power, the quick-closing electromagnetic valve 11 connects the pressure oil for controlling the one-way valve 13 to return oil, so that the one-way valve 13 is opened. The check valve 13 connects the upper and lower chambers of the piston of the cylinder 14 to communicate the upper and lower chambers of the piston, so that the oil pressures on both sides of the piston are balanced. The valve 15 of the servomotor is closed rapidly under the action of the spring force, the oil at the lower part of the oil cylinder returns to the upper part rapidly, the oil return speed is accelerated, and the servomotor is closed more rapidly.
During the operation of the servomotor, the one-way valve is opened when the following three conditions occur:
1) when the quick-closing solenoid valve is broken or a control signal fails, the quick-closing solenoid valve is de-energized, pressure oil acting on the one-way valve is discharged to return oil, and the one-way valve is opened;
2) an oil inlet throttling hole of the quick-closing electromagnetic valve is blocked, and no pressure exists after the electromagnetic valve is closed quickly, so that the one-way valve is opened;
3) the check valve is blocked at the opening position in the action process and cannot be closed.
In the three cases, the pressure oil and the return oil from the electro-hydraulic servo valve are communicated, and the valve is closed under the action of the spring force. Meanwhile, because the valve opening instruction from the control system is still in, the output instruction of a valve controller in the control system will be maximum under the action of the PID controller, so that the opening of the electro-hydraulic servo valve is maximum flow, and a large amount of pressure oil is discharged to return oil. The flow rate of the electro-hydraulic servo valve far exceeds the oil supply amount of the oil pump, so that the pressure of EH oil (fire resistant oil) of the system is low, and further the steam turbine unit is stopped and cannot normally operate.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present invention provides a method and system for preventing the shutdown of a steam turbine caused by oil drainage of a servomotor, wherein when a valve of the servomotor is abnormally closed, an electro-hydraulic servo valve is closed to cut off pressure oil and return oil, thereby preventing the shutdown of the steam turbine.
To achieve the above and other related objects, the present invention provides a method for preventing shutdown of a steam turbine caused by oil drainage from a servomotor, comprising the steps of: judging whether the running state of the servomotor is abnormal or not; when the operating condition of the servomotor is judged to be abnormal, judging whether a valve of the servomotor is closed abnormally; and when the valve of the servomotor is judged to be abnormally closed, closing an electro-hydraulic servo valve of the servomotor to avoid the shutdown of the steam turbine.
According to the method for preventing the stop of the steam turbine caused by the oil drainage of the servomotor, the method comprises the following steps: and when the valve position control instruction received by the servomotor and/or the actual opening of the servomotor valve is larger than a preset threshold value, judging that the running condition of the servomotor is abnormal.
According to the method for preventing the stop of the steam turbine caused by the oil drainage of the servomotor, the method comprises the following steps: when the operation condition of the servomotor is abnormal, and one or more of the following conditions exist, judging that the servomotor valve is abnormally closed:
1) the servomotor does not receive a valve quick closing instruction;
2) the actual opening degree of the valve of the servomotor is smaller than a valve position control instruction received by the servomotor;
3) the fuel-resistant oil pressure of the servomotor decreases.
According to the method for preventing the stop of the steam turbine caused by the oil drainage of the servomotor, the method comprises the following steps: when the hydraulic servomotor valve is judged to be abnormally closed, the output of a valve controller in the steam turbine control system is set to zero so as to close the electro-hydraulic servo valve.
Meanwhile, the invention also provides a system for preventing the stop of the steam turbine caused by the oil drainage of the servomotor, which comprises a first judgment module, a second judgment module and a processing module which are sequentially connected;
the first judgment module is used for judging whether the running state of the servomotor is abnormal or not;
the second judging module is used for judging whether the valve of the servomotor is closed abnormally or not when the operating condition of the servomotor is judged to be abnormal;
and the processing module is used for closing the electro-hydraulic servo valve of the servomotor when judging that the servomotor valve is abnormally closed so as to avoid the shutdown of the steam turbine.
According to the above-mentioned system for preventing servomotor draining from causing the steam turbine to shut down, wherein: in the first judgment module, when the valve position control instruction received by the servomotor and/or the actual opening degree of the servomotor valve is larger than a preset threshold value, the operating condition of the servomotor is judged to be abnormal.
According to the above-mentioned system for preventing servomotor draining from causing the steam turbine to shut down, wherein: in the second judgment module, when the running condition of the servomotor is abnormal, and one or more of the following conditions exist, judging that the servomotor valve is abnormally closed:
1) the servomotor does not receive a valve quick closing instruction;
2) the actual opening degree of the valve of the servomotor is smaller than a valve position control instruction received by the servomotor;
3) the fuel-resistant oil pressure of the servomotor decreases.
According to the above-mentioned system for preventing servomotor draining from causing the steam turbine to shut down, wherein: in the processing module, when the servomotor valve is judged to be abnormally closed, the output of a valve controller in the steam turbine control system is set to zero so as to close the electro-hydraulic servo valve.
As described above, the method and system for preventing the stop of the steam turbine caused by the oil drainage of the servomotor of the present invention have the following beneficial effects:
(1) the error shutdown of the steam turbine caused by hardware equipment failure is avoided;
(2) the safety and reliability of the operation of the steam turbine are improved.
Drawings
FIG. 1 is a schematic diagram of the operation of a servomotor;
FIG. 2 is a flow chart of a method of the present invention for preventing steam turbine shutdown due to servomotor drainage;
fig. 3 is a schematic structural diagram of the system for preventing the stop of the steam turbine caused by the oil drainage of the servomotor of the invention.
Description of the element reference numerals
11 quick-closing electromagnetic valve
12 electro-hydraulic servo valve
13 one-way valve
14 oil cylinder
15 valve
31 first judging module
32 second judging module
33 processing module
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
Referring to fig. 2, the method for preventing the stop of the steam turbine caused by the oil drainage of the servomotor of the invention comprises the following steps:
step S1 is to determine whether the operating state of the servomotor is abnormal.
Specifically, in the steam turbine control system, when a valve position control command and/or an actual opening degree of a valve is larger than a preset threshold value, it is determined that the operating condition of the servomotor is abnormal. For example, when the valve position control command received by the servomotor and/or the actual opening of the turbine valve is greater than the set opening by 5%, it is determined that the operating condition of the servomotor is abnormal.
And step S2, when the operation condition of the servomotor is judged to be abnormal, judging whether the servomotor valve is abnormally closed.
Specifically, when the operating condition of the servomotor is determined to be abnormal, the steam turbine control system determines that the servomotor valve is abnormally closed if one or more of the following conditions occur:
(1) the servomotor does not receive a valve quick closing instruction;
(2) the actual opening degree of the valve of the servomotor is smaller than a valve position control instruction received by the servomotor;
(3) the fuel-resistant oil pressure of the servomotor decreases.
And step S3, when the servomotor valve is judged to be abnormally closed, closing the electro-hydraulic servo valve to cut off the pressure oil and the return oil so as to avoid the shutdown of the steam turbine.
Specifically, when the servomotor valve is judged to be abnormally closed, the steam turbine control system sends a command to set the output of a valve level controller on the steam turbine control system to zero so as to close the electro-hydraulic servo valve, thereby intercepting pressure oil and return oil and avoiding the shutdown of the steam turbine.
Referring to fig. 3, the system for preventing the stop of the steam turbine caused by the oil drainage of the servomotor of the present invention includes a first judging module 31, a second judging module 32 and a processing module 33 which are connected in sequence.
The first judging module 31 is used for judging whether the running condition of the servomotor is abnormal.
Specifically, in the steam turbine control system, when the valve position control command and/or the actual opening degree of the valve is greater than a preset threshold value, the first judgment module 31 judges that the operating condition of the servomotor is abnormal. For example, when the valve position control instruction received by the servomotor and/or the actual opening of the servomotor valve is greater than the set opening by 5%, it is determined that the operating condition of the servomotor is abnormal.
The second determination module 32 is configured to determine whether the servomotor valve is abnormally closed when the servomotor operation condition is determined to be abnormal.
Specifically, when the operating condition of the servomotor is determined to be abnormal, the steam turbine control system determines that the servomotor valve is abnormally closed if one or more of the following conditions occur:
(1) the servomotor does not receive a valve quick closing instruction;
(2) the actual opening degree of the valve of the servomotor is smaller than a valve position control instruction received by the servomotor;
(3) the fuel-resistant oil pressure of the servomotor decreases.
The processing module 33 is configured to close the electro-hydraulic servo valve to block the pressure oil and the return oil when it is determined that the servomotor valve is abnormally closed, so as to prevent the turbine from shutdown.
Specifically, when the servomotor valve is judged to be abnormally closed, the steam turbine control system sends a command to set the output of a valve level controller on the steam turbine control system to zero so as to close the electro-hydraulic servo valve, thereby intercepting pressure oil and return oil and avoiding the shutdown of the steam turbine.
In conclusion, the method and the system for preventing the steam turbine from stopping due to the oil drainage of the servomotor avoid the error stop of the steam turbine caused by the fault of hardware equipment; the safety and reliability of the operation of the steam turbine are improved. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (8)
1. A method for preventing oil drainage of a servomotor from causing shutdown of a steam turbine is characterized in that: the method comprises the following steps:
judging whether the running state of the servomotor is abnormal or not;
when the operating condition of the servomotor is judged to be abnormal, judging whether a valve of the servomotor is closed abnormally; wherein, the pressure oil from the oil supply system goes to the fast-closing electromagnetic valve and the electro-hydraulic servo valve; when the quick-closing electromagnetic valve receives a signal of the protection system and loses power, the quick-closing electromagnetic valve connects pressure oil for controlling the one-way valve to return oil, so that the one-way valve is opened; the one-way valve is connected with the upper chamber and the lower chamber of the piston of the oil cylinder, so that the upper chamber and the lower chamber of the piston are communicated, and the oil pressures on two sides of the piston are balanced; the servomotor valve is closed rapidly under the action of the spring force, the oil at the lower part of the oil cylinder returns to the upper part rapidly, the oil return speed is accelerated, and the servomotor is closed more rapidly;
and when the valve of the servomotor is judged to be abnormally closed, closing an electro-hydraulic servo valve of the servomotor to avoid the shutdown of the steam turbine.
2. The method for preventing the oil drain of the servomotor from causing the shutdown of the steam turbine according to claim 1, characterized in that: and when the valve position control command received by the servomotor and/or the actual opening of the electrohydraulic servo valve of the servomotor are larger than a preset threshold value, judging that the running condition of the servomotor is abnormal.
3. The method for preventing the oil drain of the servomotor from causing the shutdown of the steam turbine according to claim 1, characterized in that: when the operation condition of the servomotor is abnormal, and one or more of the following conditions exist, judging that the servomotor valve is abnormally closed:
1) the servomotor does not receive a valve quick closing instruction;
2) the actual opening degree of the valve of the servomotor is smaller than a valve position control instruction received by the servomotor;
3) the fuel-resistant oil pressure of the servomotor decreases.
4. The method for preventing the oil drain of the servomotor from causing the shutdown of the steam turbine according to claim 1, characterized in that: when the hydraulic servomotor valve is judged to be abnormally closed, the output of a valve controller in the steam turbine control system is set to zero so as to close the electro-hydraulic servo valve.
5. The utility model provides a system for prevent that servomotor draining from arousing steam turbine shutdown which characterized in that: the device comprises a first judgment module, a second judgment module and a processing module which are connected in sequence;
the first judgment module is used for judging whether the running state of the servomotor is abnormal or not;
the second judging module is used for judging whether the valve of the servomotor is closed abnormally or not when the operating condition of the servomotor is judged to be abnormal; wherein, the pressure oil from the oil supply system goes to the fast-closing electromagnetic valve and the electro-hydraulic servo valve; when the quick-closing electromagnetic valve receives a signal of the protection system and loses power, the quick-closing electromagnetic valve connects pressure oil for controlling the one-way valve to return oil, so that the one-way valve is opened; the one-way valve is connected with the upper chamber and the lower chamber of the piston of the oil cylinder, so that the upper chamber and the lower chamber of the piston are communicated, and the oil pressures on two sides of the piston are balanced; the servomotor valve is closed rapidly under the action of the spring force, the oil at the lower part of the oil cylinder returns to the upper part rapidly, the oil return speed is accelerated, and the servomotor is closed more rapidly;
and the processing module is used for closing the electro-hydraulic servo valve of the servomotor when judging that the servomotor valve is abnormally closed so as to avoid the shutdown of the steam turbine.
6. The system for preventing drain oil of a servomotor from causing a turbine to stop according to claim 5, characterized in that: in the first judgment module, when the valve position control instruction received by the servomotor and/or the actual opening of the electrohydraulic servo valve of the servomotor are larger than a preset threshold value, the operating condition of the servomotor is judged to be abnormal.
7. The system for preventing drain oil of a servomotor from causing a turbine to stop according to claim 5, characterized in that: in the second judgment module, when the running condition of the servomotor is abnormal, and one or more of the following conditions exist, judging that the servomotor valve is abnormally closed:
1) the servomotor does not receive a valve quick closing instruction;
2) the actual opening degree of the valve of the servomotor is smaller than a valve position control instruction received by the servomotor;
3) the fuel-resistant oil pressure of the servomotor decreases.
8. The system for preventing drain oil of a servomotor from causing a turbine to stop according to claim 5, characterized in that: in the processing module, when the servomotor valve is judged to be abnormally closed, the output of a valve controller in the steam turbine control system is set to zero so as to close the electro-hydraulic servo valve.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201611107522.7A CN108150228B (en) | 2016-12-06 | 2016-12-06 | Method and system for preventing steam turbine from being stopped due to oil drainage of servomotor |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201611107522.7A CN108150228B (en) | 2016-12-06 | 2016-12-06 | Method and system for preventing steam turbine from being stopped due to oil drainage of servomotor |
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| CN108150228A CN108150228A (en) | 2018-06-12 |
| CN108150228B true CN108150228B (en) | 2020-06-09 |
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| CN201611107522.7A Active CN108150228B (en) | 2016-12-06 | 2016-12-06 | Method and system for preventing steam turbine from being stopped due to oil drainage of servomotor |
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| CN109268347B (en) * | 2018-11-26 | 2024-02-13 | 湖北华电江陵发电有限公司 | Generator set and steam turbine interruption early warning system thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201786395U (en) * | 2010-09-20 | 2011-04-06 | 上海电气电站设备有限公司 | Oil servo motor of steam valve for steam turbine |
| CN102268497A (en) * | 2011-07-12 | 2011-12-07 | 西安陕鼓动力股份有限公司 | Safety control method for TRT (Blast Furnace Top Gas Recovery Turbine Unit) fixed blade servo control system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3341511B2 (en) * | 1995-01-13 | 2002-11-05 | 富士電機株式会社 | Stem-free test equipment for main steam stop valve |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201786395U (en) * | 2010-09-20 | 2011-04-06 | 上海电气电站设备有限公司 | Oil servo motor of steam valve for steam turbine |
| CN102268497A (en) * | 2011-07-12 | 2011-12-07 | 西安陕鼓动力股份有限公司 | Safety control method for TRT (Blast Furnace Top Gas Recovery Turbine Unit) fixed blade servo control system |
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