CN115142913A

CN115142913A - Steam turbine emergency trip system and method

Info

Publication number: CN115142913A
Application number: CN202210770648.1A
Authority: CN
Inventors: 武茂松; 孟凡垟; 亓军锋; 吴喜; 张元舒
Original assignee: Huadian Electric Power Research Institute Co Ltd
Current assignee: Huadian Electric Power Research Institute Co Ltd
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2022-10-04

Abstract

The application relates to a steam turbine emergency interceptor system and a method, the steam turbine emergency interceptor system keeps a servomotor interceptor module in the related technology unchanged, and a high-pressure interceptor module is added, the servomotor interceptor module and the high-pressure interceptor module independently provide electrical protection for a steam turbine, one end of the high-pressure interceptor module is connected with a main engine EH oil supply main pipe, the other end of the high-pressure interceptor module is connected with a main engine EH oil return main pipe, and under the condition of emergency interruption, the high-pressure interceptor module unloads the oil pressure of the main engine EH oil supply main pipe so as to shut down the steam turbine.

Description

Steam turbine emergency trip system and method

Technical Field

The application relates to the technical field of steam turbines, in particular to a steam turbine emergency trip system and a steam turbine emergency trip method.

Background

The emergency interruption system of steam turbine is an indispensable safety protection device for ensuring normal operation of steam turbine generator set, and is characterized by that when some important operation parameters of steam turbine, such as overspeed, axial displacement, lubricating oil pressure, shaft vibration, differential expansion and vacuum protection value of condenser are out-of-limit, said system can send out emergency trip signal, and can quickly close all main valves and regulating valves of steam turbine by means of AST electromagnetic valve action so as to ensure safe operation of the steam turbine generator set.

At present, the emergency interruption system of the steam turbine generator unit in active service in China mostly adopts a mode of coexistence of electrical interruption and mechanical interruption (mechanical overspeed), and a mechanical emergency interruption device (mechanical overspeed device) is used as a backup means for preventing the unit from overspeed. After the unit is overhauled and during the unit operation, the mechanical overspeed device needs to perform oil injection test and overspeed test regularly, and needs to be stopped for adjustment and secondary test when necessary. In the test, the situations that the flyweight is jammed and cannot normally go out, a sliding valve of the breaker cannot normally and remotely hang a brake, the gap of the flyweight is improperly adjusted to cause the unit to trip and the like easily occur, the safety factor of the stable operation of the unit is greatly reduced, and the mechanical overspeed device has the inherent defects that the set value is inaccurate, the system is lack of diagnosis, the system is difficult to maintain, the test has difficulty and risk, the test cannot be performed in one fuel cycle, and the turbine blade and the generator rotor bear unnecessary stress in the test and the like.

With the high-speed development of digital control systems, 660MW and 1000MW grade full-cycle steam inlet turbine sets designed and manufactured by introducing siemens technology have appeared in the related art, the pure electric emergency shutdown system of the turbine cancels the traditional mechanical emergency shutdown module (mechanical overspeed), and the shutdown of the turbine set is mainly controlled by two shutdown solenoid valves configured by a main steam valve and a valve-regulating oil motor.

The overspeed protection system of the turboset manufactured by adopting the introduced siemens technology is composed of an electronic overspeed protection device consisting of two groups of coaxially mounted rotating speed probes, fig. 1 is a schematic diagram of the overspeed protection system principle in the related technology, as shown in fig. 1, the two sets of overspeed protection devices control a quick-closing electromagnetic valve on a steam turbine steam inlet valve servomotor, and after any one set of device is operated, the quick-closing electromagnetic valves of all the servomotors are operated, and the valve is quickly closed under the action of a closing spring, so that the turboset is shut down.

Fig. 2 is a schematic diagram of the principle of a related art servomotor, and as shown in fig. 2, the action of each valve (a high-pressure main steam valve, a high-pressure regulating valve, a medium-pressure main steam valve, a medium-pressure regulating valve, an air compensating valve, etc.) of the unit is controlled by a matched servomotor, each servomotor acts independently and independently, each servomotor is provided with two series-connected quick-closing solenoid valves (see (1) and (2) in fig. 1), and the valve is closed rapidly as long as one solenoid valve acts; each electromagnetic valve receives an action signal from ETS respectively and closes the valve rapidly; the electromagnetic valve is electrified normally and is not electrified; power was supplied at 24VDC directly from the ETS DO card.

As can be seen from the explanation of the principle of the typical pure electric critical interruption system of the steam turbine designed and manufactured by introducing the siemens technology, although the system composition and the control mode of the electric critical interruption system are complex, the electric critical interruption system is finally controlled by two series-connected quick-closing electromagnetic valves on a steam turbine valve servomotor, and if the two electromagnetic valves are simultaneously blocked and cannot act, the valves cannot be closed, so that the unit overspeed is inevitably caused.

Aiming at the problems that the safety redundancy rate of the operation of a turbine emergency interruption system in the related technology is low and the safety risk exists in the operation process of a unit, an effective solution is not provided.

Disclosure of Invention

The embodiment of the application provides a steam turbine emergency trip system and a method, which at least solve the problems that an emergency trip system in the related technology is low in operation safety redundancy rate and has safety risks in the unit operation process.

In a first aspect, an embodiment of the present application provides a steam turbine emergency trip system, the steam turbine emergency trip system includes: servomotor interdiction module and high pressure interdiction module, wherein, servomotor interdiction module with high pressure interdiction module all independently provides electrical protection for the steam turbine, host computer EH oil feed female pipe is connected to high pressure interdiction module one end, and host computer EH oil return female pipe is connected to the other end, under the critical interdiction condition, host computer EH oil feed female pipe oil pressure is unloaded to high pressure interdiction module to make the steam turbine interdiction shut down.

In some embodiments, the turbine critical trip system further comprises: or the door component, the first signal confirmation module and the second signal confirmation module;

the first signal confirmation module and the second signal confirmation module are respectively connected with the input end of the OR gate assembly, the servomotor interruption module and the high-pressure interruption module are respectively connected with the output end of the OR gate assembly, and under the condition that the first signal confirmation module and/or the second signal confirmation module input action signals to the OR gate assembly, the servomotor interruption module and/or the high-pressure interruption module trigger emergency interruption actions.

In some of these embodiments, the first signal confirmation module comprises a first set of speed probes and the second signal confirmation module comprises a second set of speed probes; the first group of rotating speed probes are arranged in the front box of the machine head, and the second group of rotating speed probes are arranged at the position of the jigger or the generator rotor.

In some embodiments, the or gate assembly comprises a first or gate and a second or gate, and detection signals of the first group of probes and the second group of probes are respectively processed by a relay loop and two-out-of-three logic of hardware and are input into the first or gate; the detection signals of the first group of probes and the second group of probes are respectively processed by a two-out-of-three logic of a processor and software and input into the second OR gate, and under the condition that the action signals are input into the first OR gate and/or the second OR gate, the servomotor interruption module and/or the high-voltage interruption module trigger emergency interruption action.

In some embodiments, the action signal is obtained according to the detection signal processed by a two-out-of-three logic of a processor and software, and according to a protection signal, where the protection signal includes: vibration of the turbine, shaft displacement, high exhaust temperature, condenser vacuum and lube pressure signals.

In some embodiments, the high voltage interrupter module comprises a two-out-of-three high voltage interrupter unit; and under the condition of receiving the action signal, if at least two relays in the two-out-of-three high-pressure interruption unit are subjected to power-off action, the oil of the main machine EH is discharged to the oil return main pipe of the main machine EH, and the steam turbine is interrupted and shut down.

In a second aspect, an embodiment of the present application provides a method for emergency interruption of a steam turbine, which is applied to a system for emergency interruption of a steam turbine, where the system for emergency interruption of a steam turbine includes an servomotor interruption module and a high-pressure interruption module, one end of the high-pressure interruption module is connected to a main pipe for supplying EH oil to a main machine, and the other end of the high-pressure interruption module is connected to a main pipe for returning EH oil to the main machine; the method comprises the following steps:

under the critical interruption condition, the servomotor interruption module and the high-pressure interruption module both independently provide electrical protection for the steam turbine, wherein the high-pressure interruption module unloads the oil pressure of an EH oil supply main pipe of the main machine so as to stop the steam turbine in an interruption manner.

In a third aspect, an embodiment of the present application provides a method for modifying a turbine emergency trip system, where the turbine emergency trip system includes a servomotor trip module and a high-pressure trip module, where the servomotor trip module and the high-pressure trip module both independently provide electrical protection for a turbine, and the method includes:

the high pressure interdiction module one end is connected the female pipe of host computer EH oil feed oil, and the female pipe of host computer EH oil return oil is connected to the other end, under the critical interdiction condition, the high pressure interdiction module unloads host computer EH oil feed oil female pipe oil pressure to make the steam turbine interdiction shut down.

Compared with the prior art, the steam turbine emergency shutdown system provided by the embodiment of the application keeps a servomotor shutdown module in the prior art unchanged, and is additionally provided with a high-pressure shutdown module, the servomotor shutdown module and the high-pressure shutdown module independently provide electrical protection for a steam turbine, one end of the high-pressure shutdown module is connected with a main engine EH oil supply main pipe, and the other end of the high-pressure shutdown module is connected with a main engine EH oil return main pipe.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic diagram of the overspeed protection system principle of the related art;

fig. 2 is a schematic view of the principle of a related art servomotor;

FIG. 3 is a schematic view of a turbine emergency shutdown system according to an embodiment of the present application;

fig. 4 is a schematic view of an installation location of a high voltage interrupter module according to an embodiment of the present application;

FIG. 5 is a steam turbine according to an embodiment of the present application schematic diagram of the control principle of a critical interruption system;

fig. 6 is a schematic diagram of a two-out-of-three high-voltage interrupter unit according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments provided in the present application without any inventive step are within the scope of protection of the present application.

It is obvious that the drawings in the following description are only examples or embodiments of the application, and that it is also possible for a person skilled in the art to apply the application to other similar contexts on the basis of these drawings without inventive effort. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of ordinary skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments without conflict.

Unless defined otherwise, technical or scientific terms referred to herein shall have the ordinary meaning as understood by those of ordinary skill in the art to which this application belongs. Reference to "a," "an," "the," and similar words throughout this application are not to be construed as limiting in number, and may refer to the singular or the plural. The use of the terms "including," "comprising," "having," and any variations thereof herein, is meant to cover a non-exclusive inclusion; for example, a process, method, system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to only those steps or elements but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. Reference to "connected," "coupled," and the like in this application is not intended to be limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality" as referred to herein means two or more. "and/or" describes the association relationship of the associated object, indicating that there may be three relationships, for example, "a and/or B" may indicate: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. Reference herein to the terms "first," "second," "third," and the like, are merely to distinguish similar objects and do not denote a particular ordering for the objects.

The application provides a turbine emergency trip system, fig. 3 is a schematic diagram of the turbine emergency trip system according to the embodiment of the application, as shown in fig. 3, a 1 st group of rotation speed probes detect the rotation condition of a unit to obtain a rotation speed signal 1 to a rotation speed signal 3 (voltage signal), a rotation speed module converts the voltage signal into a rotation speed value and determines whether overspeed occurs, if yes, an action signal is generated, the action signal is confirmed by a relay and a two-out-of-three overspeed protector (hard loop) and then is transmitted to a servomotor trip module or a high-voltage trip module, the servomotor trip module comprises two fast-closing solenoid valves, the action signal enables the fast-closing solenoid valves to act to perform overspeed protection, the high-voltage trip module comprises a two-out-of-three high-voltage trip unit, and the action high-voltage trip solenoid valves adopt two-out-two-out interruption to perform overspeed protection; meanwhile, the action signals of the 1 st group are transmitted to a servomotor interruption module or a high-voltage interruption module after being processed by a two-out-of-three logic (soft loop) of a processor and software so as to carry out overspeed protection; meanwhile, the 2 nd group of rotating speed probes detect the rotation condition of the unit to obtain a rotating speed signal 4 to a rotating speed signal 6 (voltage signal), the rotating speed module converts the voltage signal into a rotating speed value and determines whether the unit is overspeed or not, if so, an action signal is generated, and the action signal is confirmed by a relay and a two-out-of-three overspeed protector (a hard loop) and then is transmitted to a servomotor interruption module or a high-voltage interruption module to perform overspeed protection; meanwhile, the action signals of the 2 nd group are transmitted to a servomotor interruption module or a high-voltage interruption module after being processed by a two-out-of-three logic (soft loop) of a processor and software so as to carry out overspeed protection.

The emergency trip system of the steam turbine in the embodiment of the application is provided with two sets of electronic overspeed protection devices, the two sets of electronic overspeed protection devices are mutually independent, and any one set of overspeed protection device can enable two quick-closing electromagnetic valves on a steam inlet valve hydraulic motor of the steam turbine and three trip electromagnetic valves of a high-pressure trip module to act simultaneously. When any one set of device acts, all the quick-closing solenoid valves of the hydraulic motors lose electricity or three interruption solenoid valves of the high-voltage interruption module lose electricity, and further the EH oil pressure is discharged, and the valves are quickly closed under the action of the closing springs, so that the steam turbine set is interrupted and stopped.

Specifically, the hard circuit overspeed protection is characterized in that an action signal sent by a rotating speed module passes through a relay circuit to perform hardware three-to-two logic processing, and two sets of processing systems are respectively connected in series with a power supply circuit of two fast-closing electromagnetic valves of a gas turbine valve oil engine and a power supply circuit of three interruption electromagnetic valves of a high-voltage interruption module, so that the power supply of the electromagnetic valves is directly cut off, and the engine is rapidly stopped. The soft loop overspeed protection is characterized in that an action signal sent by a rotating speed module is sent to a processor of a protection system, logic processing of two out of three is carried out in software, and two quick-closing electromagnetic valves of a turbine valve servomotor and three interruption electromagnetic valves of a high-pressure interruption module are controlled through output clamping pieces together with other protection signals (vibration, shaft displacement, high exhaust temperature, condenser vacuum, lubricating oil pressure and the like), the electromagnetic valves are de-energized to discharge EH oil pressure, and the unit is rapidly stopped.

Specifically, fig. 4 is a schematic diagram of an installation position of a high-pressure blocking module according to an embodiment of the present application, and as shown in fig. 4, the high-pressure blocking module is connected to a main engine EH oil supply main pipe, and oil drainage of the high-pressure blocking module is connected to a main engine EH oil return main pipe. Compared with the related technology, the steam turbine emergency trip system provided by the embodiment of the application keeps an oil motor trip module in the related technology unchanged, and is additionally provided with a high-pressure trip module, the oil motor trip module and the high-pressure trip module independently provide electrical protection for a steam turbine, one end of the high-pressure trip module is connected with a main engine EH oil supply main pipe, the other end of the high-pressure trip module is connected with a main engine EH oil return main pipe, and under the condition of emergency trip, the high-pressure trip module unloads the oil pressure of the main engine EH oil supply main pipe so as to shut down the steam turbine in a trip way, the two stop electromagnetic valves arranged on the oil engine are used for draining the oil pressure of EH oil, but if the two electromagnetic valves are simultaneously clamped and cannot act, the valves cannot be closed, so that the unit is forced to overspeed, the risk of the unit is caused by the situation, the high-pressure blocking module is added, the oil supply pressure is drained from the source through the high-pressure blocking module under the condition that the steam turbine unit needs to be blocked and stopped, and therefore even if the two electromagnetic valves are clamped and do not act, the main steam valve and the regulating valve of the steam turbine can be closed due to the loss of the oil supply pressure, the problems that in the related technology, the safety redundancy rate of operation of a steam turbine emergency blocking system is low, and safety risks exist in the operation process of the unit are solved, and the effect of improving the operation safety of the steam turbine is achieved.

Furthermore, the servomotor interruption module in the related art is designed in a non-redundant manner, and although two sets of overspeed protection devices are arranged in the emergency interruption system in the related art, the emergency interruption system finally controls two series-connected quick-closing electromagnetic valves on the steam turbine valve servomotor, so that the emergency interruption system belongs to one set of system in terms of control principle, the safety redundancy of operation is low, and safety risks exist in the operation process of a unit. The embodiment of the application shows redundancy design everywhere, increases the redundancy degree of emergency interruption of the system, and effectively improves the safety of the operation of the steam turbine set for the following reasons:

firstly, the turbine emergency trip system provided by the invention is provided with two sets of overspeed protection devices (a set of rotation speed signals 1-3 corresponds to one set, and a set of rotation speed signals 4-6 corresponds to the other set), and under the condition that one set of devices fails, the other set of devices can still function;

secondly, the turbine emergency trip system of the invention has two sets of independent hard loop overspeed protection: firstly, action signals sent by two sets of rotating speed modules are subjected to two-out-of-three logic processing of hardware through a relay circuit and then are connected in series into a power supply circuit of two quick-closing electromagnetic valves of a steam turbine valve oil engine; second, after the action signal that two sets of rotational speed modules send out carries on the logical processing of two out of three of the hardware through the relay circuit, connect in series into the power supply circuit of three interdiction solenoid valves of high-pressure interdiction module, these two hard circuits can both finish the overspeed protection of the hard circuit of the steam turbine, under the situation that a hard circuit breaks down among them, another hard circuit can still function;

thirdly, the turbine emergency trip system of the invention has two sets of mutually independent soft loop overspeed protection: the soft loop overspeed protection is characterized in that an action signal sent by a rotating speed module is sent to a processor of a protection system, logical processing of two out of three is carried out in software, and together with other protection signals (vibration, shaft displacement, high exhaust temperature, condenser vacuum, lubricating oil pressure and the like), two quick-closing electromagnetic valves of a turbine valve servomotor and three interruption electromagnetic valves of a high-pressure interruption module are controlled through an output clamping piece, the electromagnetic valves lose power and discharge EH oil pressure, a unit is rapidly stopped, the two soft loops can both complete the turbine soft loop overspeed protection, and under the condition that one soft loop fails, the other soft loop can still function;

fourthly, the hard loop and the soft loop of the steam turbine emergency trip system coexist, and the action signal can still be transmitted to the servomotor trip-out module and the high-pressure trip-out module through the soft loop under the condition that the hard loop has all faults, and similarly, the action signal can still be transmitted to the servomotor trip-out module and the high-pressure trip-out module through the hard loop under the condition that the soft loop has all faults;

fifth, the turbine emergency shutdown system of the present invention has two independent turbine emergency shutdown modes: one is to realize the interruption of the steam turbine through 2 quick-closing solenoid valves of the valve configuration of the steam turbine, and the other is to carry out the interruption through a high-pressure interruption module of the system configuration, and the two modes can realize the emergency interruption of the steam turbine, and under the condition that one mode has a fault, the other mode still can function.

According to the steam turbine emergency trip system provided by the embodiment of the application, through two mutually independent electric overspeed protections (firstly, through the action of two electromagnetic valves of a valve servomotor and secondly, through the action of a high-pressure trip module), any one of the servomotor trip module and the two-out-of-three high-pressure trip module can effectively trip a steam turbine, and the independence is embodied; any one of the two groups of rotating speed probes can enable the two electromagnetic valves of the oil engine valve and the high-pressure blocking module to block the electromagnetic valves to act so as to block the steam turbine, thereby embodying the integration.

Fig. 5 is a schematic diagram of a control principle of a turbine emergency trip system according to an embodiment of the present application, and as shown in fig. 5, the turbine emergency trip system in the embodiment of the present application receives important turbine protection signals (vibration, shaft displacement, overspeed, high exhaust temperature, condenser vacuum, lubricating oil pressure, and the like) such as sensors and thermocouples, the protection signals are sent to a controller through an input fastener, redundant protection signals are distributed to different fasteners, two-out-of-three logic processing is performed in the controller, and finally, an action signal is output through a fail-safe Fastener (FDO) to control 2 fast-closing solenoid valves configured for each servomotor. When the parameter variation exceeds the interruption value, an interruption signal is sent out, the electromagnetic valve is stopped by action to block the steam turbine set.

The turbine trip protection conditions are measured by analog measurements, and the signals are monitored and compared without interruption. The standard interrupt protection signal includes a two-out-of-three configuration (two-out-of-two for vibration signal). And (3) performing signal processing through a digital automatic system, and after the signals are gathered, forming a steam turbine protection shutdown signal and sending the steam turbine protection shutdown signal to the ETS system for processing. The ETS system receives protective switching value signals including overspeed protection, generator protection, boiler protection MFT, emergency stop button and turbine protection signals, and sends the signals to a processor through a failure safety input module (FAILSAFE DI) to perform operation processing on the processor. And forming a final shutdown signal, and outputting the shutdown signal through a FAILSAFE output module (FAILSAFE DO). The shutdown signal output by the fail safe output module (FAILSAFE DO) is sent to 2 series redundant quick-closing solenoid valves configured for the turbine valve, and the valve is quickly closed as long as one quick-closing solenoid valve acts, so that the unit is quickly interrupted. The other path of the shutdown signal output by the fail-safe output module (FAILSAFE DO) is sent to 3 electromagnetic valves configured by the high-pressure critical interruption module, the three-taking-two redundant interruption function can be realized by the 3 electromagnetic valves through oil circuit connection, namely EH oil supply pressure can be released by the action of any 2 electromagnetic valves in the 3 electromagnetic valves, so that the steam turbine valve is quickly closed under the action of a spring, and the quick interruption of a unit is realized.

Consider that two sets of rotational speed probes are if coaxial arrangement, the rotational speed protection device that two sets of rotational speed probes correspond after the axle fracture can all lose the guard action to lead to the too big and unable risk of shutting down of unit rotational speed, consequently, the mounted position of the 1 st group rotational speed probe, and the mounted position of the 2 nd group rotational speed probe need satisfy non-coaxial arrangement form. For example, group 1 rotational speed probes are typically mounted in the nose front box, and group 2 rotational speed probes are typically mounted at the barring or generator rotor, thereby ensuring non-coaxial arrangement requirements. The rotating speed signals of the two sets of overspeed protection devices are arranged at different bearing bush positions, and the rotating speed signals meet ' 8.1.9 clauses in ' twenty-five key requirements for preventing electric power production accidents ' (2014) of the national energy agency: the shafting of the turbo generator set is required to be provided with two sets of rotating speed monitoring devices which are respectively arranged on different rotors.

Considering that the probability of misoperation of a mechanical overspeed device in the related technology is high, the cost of non-stop of a steam turbine generator unit caused by one misoperation is high, the cost of re-starting and stopping caused by one non-stop and the total cost of a power grid for checking the non-stop of the unit are more than 150 ten thousand yuan, and the probability of non-stop caused by the misoperation of the original mechanical overspeed device on a heating and heating unit easily causes important influence on the aspect of civil conservation and supply; the non-stop of the industrial heat supply unit can cause the stagnation of the production process of a subsequent factory, so that the default economic loss caused by the stagnation is huge, and in order to improve the fault tolerance of the system, the high-voltage interruption module comprises a two-out-of-three high-voltage interruption unit; and under the condition of receiving the action signal, if at least two relays in the two-out-of-three high-voltage interruption unit are in power failure action, the EH oil is discharged to an EH oil return pipe, and the steam turbine is interrupted and stopped.

Fig. 6 is a schematic diagram of a two-out-of-three high-pressure blocking unit according to an embodiment of the present application, and as shown in fig. 6, the two-out-of-three high-pressure blocking unit is provided with three electromagnetic valves, and a two-out-of-three emergency blocking function can be realized by connecting oil pipelines: the three electromagnetic valves are electrified in normal operation, and the oil pressure of the EH oil main pipe cannot be discharged when any one of the electromagnetic valves is electrified; the three electromagnetic valves normally run and are electrified, and the oil pressure of the EH oil bus pipe can be discharged by the power-off action of any two electromagnetic valves, so that the steam turbine valve is quickly closed under the action of the spring; the three solenoid valves normally operate and are electrified, the EH oil bus pipe oil pressure can be drained by the action of the three solenoid valves simultaneously losing electricity, and then the steam turbine valve is rapidly closed under the action of the spring. The design of an overspeed protection system of a steam turbine set is required to have measures for preventing false operation and refusal operation according to the existing relevant regulations, the redundancy design of the two-out-of-three high-voltage interruption unit added in the embodiment of the application is reliable, the risk that a flyweight (a flyring) of mechanical overspeed protection in the relevant technology is easily jammed, cannot normally act and has false operation is reduced, and the safety and stability of the operation of the turbine set are improved.

The three-out-of-two high-voltage interruption unit in the embodiment of the application has an online test function, the electromagnetic valve in the device can be ensured to operate reliably through a periodic online operation test, the protection device is safe, stable and reliable, and the online test principle of the high-voltage interruption unit is as follows: during an online test, an online test signal is sent to enable the solenoid valve 1YV to be de-energized to operate, oil ways A-P and B-T of the solenoid valve 1YV are both communicated, at the moment, oil in the EH oil main pipe cannot be discharged to an EH oil return pipeline, and the pressure displayed by a 1YV solenoid valve test pressure gauge is equal to the pressure of the EH oil main pipe, so that the normal operation of the solenoid valve 1YV is proved; the online tests of the electromagnetic valves 2YV and 3YV are the same as those of the electromagnetic valve 1YV.

It should be understood by those skilled in the art that various technical features of the above-described embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described, however, so long as there is no contradiction between the combinations of the technical features, they should be considered as being within the scope of the present description.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A turbine trip system, comprising: servomotor interdiction module and high pressure interdiction module, wherein, servomotor interdiction module with high pressure interdiction module all independently provides electrical protection for the steam turbine, host computer EH oil feed female pipe is connected to high pressure interdiction module one end, and host computer EH oil return female pipe is connected to the other end, under the critical interdiction condition, host computer EH oil feed female pipe oil pressure is unloaded to high pressure interdiction module to make the steam turbine interdiction shut down.

2. The turbine critical trip system of claim 1, further comprising: or the door component, the first signal confirmation module and the second signal confirmation module;

3. The turbine trip system of claim 2, wherein the first signal validation module comprises a first set of speed probes and the second signal validation module comprises a second set of speed probes; the first group of rotating speed probes are arranged in the nose front box, and the second group of rotating speed probes are arranged at the jigger or the generator rotor.

4. The turbine emergency trip system according to claim 3, wherein the or gate assembly comprises a first or gate and a second or gate, and the detection signals of the first group of probes and the second group of probes are respectively input into the first or gate through a relay loop and a two-out-of-three logic process of hardware; the detection signals of the first group of probes and the second group of probes are respectively processed by a two-out-of-three logic of a processor and software and input into the second OR gate, and under the condition that the action signals are input into the first OR gate and/or the second OR gate, the servomotor interruption module and/or the high-voltage interruption module trigger emergency interruption action.

5. The turbine emergency trip system of claim 4, wherein the action signal is derived from the detection signal after being processed by a two-out-of-three logic of a processor and software, and from a protection signal, wherein the protection signal comprises: vibration of the turbine, shaft displacement, high exhaust temperature, condenser vacuum and lube pressure signals.

6. The turbine critical trip system of claim 2, wherein the high pressure trip module comprises a two out of three high pressure trip unit; and under the condition of receiving the action signal, if at least two relays in the two-out-of-three high-pressure interruption unit are subjected to power-off action, the oil of the main machine EH is discharged to the oil return main pipe of the main machine EH, and the steam turbine is interrupted and shut down.

7. The emergency trip method of the steam turbine is characterized by being applied to a steam turbine emergency trip system, wherein the steam turbine emergency trip system comprises an servomotor trip module and a high-pressure trip module, one end of the high-pressure trip module is connected with a main engine EH oil supply main pipe, and the other end of the high-pressure trip module is connected with a main engine EH oil return main pipe; the method comprises the following steps:

8. The utility model provides a steam turbine emergency trip system's transformation method which characterized in that, steam turbine emergency trip system includes, servomotor interdiction module and high pressure interdiction module, wherein, servomotor interdiction module with high pressure interdiction module all independently provides electrical protection for the steam turbine, the method includes:

the main engine EH oil supply main pipe is connected to high pressure interdiction module one end, and the main engine EH oil return main pipe is connected to the other end, under the critical interdiction condition, the main engine EH oil supply main pipe oil pressure is unloaded to the high pressure interdiction module to make the steam turbine interdiction shut down.