CN220302219U - Overspeed tripping protection device of gas turbine - Google Patents

Abstract

The utility model discloses an overspeed tripping protection device of a gas turbine, which comprises a control oil duct, an overspeed tripping oil duct and an oil return duct, wherein a first hydraulic throttle, a first main electromagnetic tripping valve group, a second hydraulic throttle, a third hydraulic throttle and a second bypass electromagnetic tripping valve group are sequentially connected in series between the control oil duct and the oil return duct through pipelines; the first branch of the overspeed trip oil duct is connected between the first hydraulic throttle and the first main electromagnetic trip valve group, the second branch is connected with the oil return duct, the first branch is connected with a gas quick-closing valve executing mechanism and a gas discharge valve executing mechanism in series, and a manual-automatic overspeed trip control valve is connected between the second branch and the oil return duct. When the overspeed tripping condition is met, all pipeline electromagnetic valves can be immediately and simultaneously powered off, so that overspeed tripping oil pressure is directly communicated with oil return through the pipeline electromagnetic valves to rapidly release pressure, intermediate links of hydraulic elements are reduced, and the problems of complex structure and slower response speed in the prior art are solved.

Description

Overspeed tripping protection device of gas turbine

Technical Field

The utility model relates to the technical field of gas turbines, in particular to an overspeed tripping protection device of a gas turbine.

Background

The overspeed trip protection device is very important safety protection equipment of the gas turbine, and the action rapidity of the overspeed trip protection device directly influences the reliability and the safety of the whole gas turbine, particularly in a low-pressure control oil system, because the control oil pressure is low and the oil consumption of the whole regulating system is large, the requirement on the action rapidity of the overspeed trip protection device is higher. However, since the conventional overspeed tripping protection device of the gas turbine is only designed and installed with one tripping electromagnetic valve, the safety risk of unit failure or misoperation caused by the failure of the single tripping electromagnetic valve exists, and accordingly, the reliability of the unit is poor.

In order to solve the technical problem, the patent document with the publication number of CN115573960A provides a high-pressure blocking device of a steam turbine with on-line monitoring and maintenance functions, which comprises a safety oil duct, a pressure oil duct, an oil return duct, an intermediate oil duct, an intelligent pressure switch transmitter, a safety oil hydraulic damper, an on-line verification hydraulic damper, a normally open electromagnetic stop valve and four blocking valve groups, wherein the pressure oil duct is communicated with the safety oil duct through the intermediate oil duct; the four shutoff valve groups are connected in parallel in pairs and then connected in series on the middle oil duct; the on-line verification hydraulic damper is respectively arranged at the rear ends of the two pairs of shutoff valve groups; the intelligent pressure switch transmitter is respectively arranged on the safety oil duct and the middle oil duct. Compared with an overspeed trip protection device with only a single trip electromagnetic valve, the overspeed trip protection device not only improves reliability and response speed, but also improves safety margin of the whole turbine unit. However, in practice, the trip protection can be realized by matching the threaded cartridge stop valve, the electromagnetic reversing valve and the unloading valve, so that the technical problems of complex structure and slower response speed still exist.

Therefore, it is imperative to develop an overspeed trip protection device with simpler structure and higher response speed.

Disclosure of Invention

Aiming at the technical problems in the prior art, the utility model provides the overspeed tripping protection device of the gas turbine, which can immediately and simultaneously de-energize all pipeline electromagnetic valves when the gas turbine meets overspeed tripping conditions, so that overspeed tripping oil pressure is directly communicated with oil return through the pipeline electromagnetic valves to rapidly release pressure, a pressure release mode requiring the cooperation of a traditional stop valve, an electromagnetic valve and an unloading valve is abandoned, and intermediate links of hydraulic elements are reduced, thereby effectively solving the technical problems of complex structure and slower response speed in the prior art.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows:

an overspeed trip protection device for a gas turbine, characterized in that: the hydraulic control system comprises a control oil duct, an overspeed trip oil duct and an oil return duct, wherein a first hydraulic throttle, a first main electromagnetic trip valve bank, a second hydraulic throttle, a third hydraulic throttle and a second bypass electromagnetic trip valve bank are sequentially connected in series between the control oil duct and the oil return duct through pipelines, and the first main electromagnetic trip valve bank and the second bypass electromagnetic trip valve bank are connected with each other; the overspeed trip oil duct comprises a first branch and a second branch which are connected in parallel, the first branch is connected between the first hydraulic throttle and the first main electromagnetic trip valve group, the second branch is connected with the oil return channel, the first branch is connected with a gas quick-closing valve executing mechanism and a gas discharge valve executing mechanism in series, and a manual-automatic overspeed trip control valve is connected between the second branch and the oil return channel.

The gas quick-closing valve actuating mechanism and the gas discharge valve actuating mechanism are respectively connected to the first branch through a one-way throttle hydraulic valve.

And a pressure switch, a first pressure transmitter and a second pressure transmitter are also connected in series between the control oil duct and the oil return duct, the first pressure transmitter and the pressure switch are sequentially connected in series between the control oil duct and the first branch, and the second pressure transmitter is connected in series between the second hydraulic throttle and the third hydraulic throttle.

The first main electromagnetic tripping valve group and the second bypass electromagnetic tripping valve group comprise two pipeline electromagnetic valves, the two pipeline electromagnetic valves in the first main electromagnetic tripping valve group are connected in parallel at the front end of the second hydraulic throttle, the two pipeline electromagnetic valves in the second bypass electromagnetic tripping valve group are connected in parallel at the rear end of the third hydraulic throttle, and the pipeline electromagnetic valves in the first main electromagnetic tripping valve group and the pipeline electromagnetic valves in the second bypass electromagnetic tripping valve group are connected in one-to-one correspondence.

The pipeline electromagnetic valve comprises a valve body, a valve cover, a valve seat and an electromagnetic control assembly, wherein a flow passage and the valve seat are arranged in the valve body, the valve cover is fixed on the valve body in a sealing manner, the electromagnetic control assembly is vertically fixed above the valve seat through the valve cover, and the electromagnetic control assembly is matched with the valve seat to control the on-off of the flow passage.

The electromagnetic control assembly comprises a core tube, a supporting ring, a valve core spring, an extension spring, a supporting washer, a diaphragm, a valve clack and an electromagnetic assembly, wherein the lower end of the core tube is fixed on a valve cover through the supporting ring, the electromagnetic assembly is fixed at the upper end of the core tube, the upper end of the valve core is movably arranged in the core tube, the lower end of the valve core penetrates through a valve cover to extend into a valve body, the valve core spring is arranged between the electromagnetic assembly and the core tube, the extension spring, the supporting washer, the diaphragm and the valve clack are sequentially arranged at the lower end of the valve core through threaded sleeves, the periphery of the diaphragm is fixed between the valve cover and the valve body in a sealing manner, the periphery of the supporting washer is propped against the valve cover, the valve clack is positioned right above a valve seat, and the electromagnetic assembly can control the valve clack to act through the valve core.

The electromagnetic assembly comprises an electromagnetic coil, a shielding coil, a fixing cap and a screw plug, wherein the electromagnetic coil is sleeved on the core tube and is positioned above the supporting ring, the screw plug axially fixes the electromagnetic coil through the core tube, the fixing cap radially fixes the electromagnetic coil through the core tube, the shielding coil is fixed on the end face of the lower end of the screw plug, and the electromagnetic coil and the shielding coil are matched to generate electromagnetic force to control the valve core to act.

And a sealing ring is fixed between the supporting ring and the valve cover.

A sealing ring is fixed between the valve body and the valve cover.

By adopting the technical scheme, the utility model has the beneficial technical effects that:

1. according to the utility model, through the first main electromagnetic trip valve group and the second bypass electromagnetic trip valve group which are sequentially connected in series between the control oil duct and the oil return duct, when the gas turbine meets the overspeed trip condition, all the electromagnetic trip valve groups can be immediately and simultaneously powered off, so that overspeed trip oil pressure is directly communicated with oil return through the electromagnetic trip valve groups to rapidly release pressure. Compared with the prior art, the utility model eliminates the pressure relief mode which needs the cooperation of the traditional stop valve, the electromagnetic valve and the unloading valve, reduces the intermediate links of the hydraulic element, is beneficial to simplifying the structure of the device and improving the response speed of the device.

In addition, the utility model can form a four-out-two and series-parallel structure type through the first main electromagnetic tripping valve group, the second hydraulic throttle device, the third hydraulic throttle device and the second bypass electromagnetic tripping valve group, and form a redundant protection structure with the manual-automatic overspeed tripping control valve again. The design not only meets the reliability requirement of the long-term operation of the gas turbine, but also can realize the multiple redundancy tripping function under critical working conditions and can realize the on-line test function of a single electromagnetic valve.

In addition, the utility model can also control the manual-automatic overspeed trip control valve manually or remotely and automatically so that overspeed trip oil pressure is directly communicated with oil return through the manual-automatic overspeed trip control valve, thereby achieving the purpose of overspeed trip. And the manual-automatic overspeed trip control valve is provided with a valve position feedback device, so that the valve position state of the manual-automatic overspeed trip control valve can be monitored in real time, and the safety and reliability of the gas turbine are greatly improved.

Finally, the gas quick-closing valve actuating mechanism and the gas discharge valve actuating mechanism can also control the gas discharge valve to be quickly opened and control the gas quick-closing valve to be quickly closed when overspeed trip oil pressure disappears, and finally, the gas before entering each gas flow control valve of the gas turbine is quickly discharged and cut off the gas from entering, so that the purpose of quick and safe shutdown of the gas turbine is achieved.

2. The utility model can respectively control the overspeed trip oil to slowly enter the gas quick-closing valve executing mechanism and the gas discharge valve executing mechanism through the unidirectional throttle hydraulic valve, and can control the overspeed trip oil to be rapidly discharged from the gas quick-closing valve executing mechanism and the gas discharge valve executing mechanism when the gas turbine needs emergency shutdown, thereby realizing the quick action of the gas quick-closing valve and the gas discharge valve under the shutdown working condition.

3. According to the utility model, the pressure switch, the first pressure transmitter and the second pressure transmitter are matched, so that the device has an on-line test function, and the reliability and stability of the device are improved.

4. The pipeline electromagnetic valve mainly comprises a valve body, a valve cover, a valve seat and an electromagnetic control assembly, and the pipeline electromagnetic valve with the structure has a direct driving mode, can directly control the establishment and disappearance of overspeed limiting oil pressure, and is beneficial to further improving the response speed of overspeed tripping action.

5. The electromagnetic force control device can generate magnetic force lines opposite to the electromagnetic coil through the shielding coil, is beneficial to improving the strength of electromagnetic force generated by the electromagnetic coil, and improves the control stability of the pipeline electromagnetic valve.

Drawings

FIG. 1 is a schematic diagram of the present utility model;

fig. 2 is a schematic structural diagram of a pipeline electromagnetic valve in the utility model.

Marked in the figure as: 1. the control oil duct, 2, overspeed trip oil duct, 3, return oil duct, 4, first hydraulic throttle, 5, second hydraulic throttle, 6, third hydraulic throttle, 7, pressure switch, 8, first pressure transmitter, 9, second pressure transmitter, 10, pipeline electromagnetic valve, 11, manual overspeed trip control valve, 12, gas quick-closing valve actuating mechanism, 13, gas discharge valve actuating mechanism, 14, unidirectional throttle hydraulic valve;

3.1, a first branch, 3.2 and a second branch;

10.1, electromagnetic coil, 10.2, shielding coil, 10.3, core tube, 10.4, support ring, 10.5, valve cap, 10.6, extension spring, 10.7, diaphragm, 10.8, valve body, 10.9, valve clack, 10.10, fixed cap, 10.11, screw plug, 10.12, valve core spring, 10.13, valve core, 10.14, sealing ring, 10.15, fastener, 10.16, support gasket, 10.17, valve seat.

Detailed Description

Example 1

The present embodiment provides a gas turbine overspeed trip protection apparatus, as shown in fig. 1, which includes a control oil passage 1, an overspeed trip oil passage, and an oil return passage 3. Wherein,

the first hydraulic throttle 4, the first main electromagnetic tripping valve group, the second hydraulic throttle 5, the third hydraulic throttle 6 and the second bypass electromagnetic tripping valve group are sequentially connected in series through pipelines between the control oil duct 1 and the oil return duct 3, and the first main electromagnetic tripping valve group and the second bypass electromagnetic tripping valve group are mutually connected.

Specifically, the first main electromagnetic trip valve group and the second bypass electromagnetic trip valve group both comprise two pipeline electromagnetic valves 10, the two pipeline electromagnetic valves 10 in the first main electromagnetic trip valve group are connected in parallel at the front end of the second hydraulic throttle device 5, the two pipeline electromagnetic valves 10 in the second bypass electromagnetic trip valve group are connected in parallel at the rear end of the third hydraulic throttle device 6, and the pipeline electromagnetic valves 10 in the first main electromagnetic trip valve group and the pipeline electromagnetic valves 10 in the second bypass electromagnetic trip valve group are connected in one-to-one correspondence (two by two respectively). The two parallel pipeline electromagnetic valves 10 in the first main electromagnetic tripping valve group, the second hydraulic throttle 5, the third hydraulic throttle 6 and the two parallel pipeline electromagnetic valves 10 in the second bypass electromagnetic tripping valve group can form a structure type of four-out-of-two and series-parallel connection, and a redundant protection structure is formed with the manual-automatic integrated overspeed tripping control valve 11 again. The design not only meets the reliability requirement of the long-term operation of the gas turbine, but also can realize the multiple redundancy tripping function under critical working conditions.

A pressure switch 7, a first pressure transmitter 8 and a second pressure transmitter 9 are further connected in series between the control oil duct 1 and the oil return duct 3, the first pressure transmitter 8 and the pressure switch 7 are sequentially connected in series between the control oil duct 1 and the first branch 3.1, and the second pressure transmitter 9 is connected in series between the second hydraulic throttle 5 and the third hydraulic throttle 6. Preferably, the number of the pressure switches 7 is three, and the device can perform logic selection of three or two according to the action signals of the three pressure switches 7, so that whether the overspeed tripping oil pressure is established (namely, the overspeed tripping oil pressure is already hung) can be automatically judged. In addition, the overspeed trip oil pressure value can be remotely transmitted to the control system of the gas turbine by means of the first pressure transmitter 8, and the oil pressure value between the second hydraulic throttle 5 and the third hydraulic throttle 6 can be monitored by means of the second pressure transmitter 9.

It should be noted that, in this embodiment, the four pipeline solenoid valves 10 all have an online test function, and in order to meet the reliability of the device, the control power sources of the first main electromagnetic trip valve group and the second bypass electromagnetic trip valve group are required to be in different power supply loops.

The over-speed tripping oil duct comprises a first branch 3.1 and a second branch 3.2 which are connected in parallel, the first branch 3.1 is connected between the first hydraulic throttle 4 and the first main electromagnetic tripping valve group, and the second branch 3.2 is connected with the oil return duct 3. In addition, the first branch 3.1 is connected in series with a gas quick-closing valve executing mechanism 12 and a gas discharge valve executing mechanism 13, the gas quick-closing valve executing mechanism 12 and the gas discharge valve executing mechanism 13 are respectively connected to the first branch 3.1 through a one-way throttling hydraulic valve 14, and the gas quick-closing valve executing mechanism 12 and the gas discharge valve executing mechanism 13 are respectively used for controlling the on-off of a gas quick-closing valve and the on-off of a gas discharge valve in the gas turbine. An automatic overspeed trip control valve 11 is connected between the second branch 3.2 and the oil return channel 3, the automatic overspeed trip control valve 11 can be controlled manually or remotely and automatically, and the overspeed trip oil pressure can be directly connected with oil return through the automatic overspeed trip control valve 11 so as to achieve the purpose of overspeed trip. In addition, the manual-automatic overspeed trip control valve 11 is provided with a valve position feedback device, so that the valve position state of the manual-automatic overspeed trip control valve 11 can be monitored in real time, and the safety and reliability of the gas turbine can be improved.

The structure of the device is described in further detail below in connection with fig. 1.

The control oil in this embodiment is serially connected with the first hydraulic restrictor 4, the second hydraulic restrictor 5 and the third hydraulic restrictor 6 through the control oil passage 1 and then is communicated with the return oil passage 3 to finally form a closed-loop hydraulic circuit, wherein the resistance value of the first hydraulic restrictor 4 is small, and the resistance values of the second hydraulic restrictor 5 and the third hydraulic restrictor 6 are equal and large. Under normal conditions, the oil from the control oil passing through the first hydraulic restrictor 4 to the second hydraulic restrictor 5 is called overspeed trip oil, the overspeed trip oil pressure value is basically equal to the control oil pressure value through the combined design of the first hydraulic restrictor 4, the second hydraulic restrictor 5 and the third hydraulic restrictor 6, and the overspeed trip oil pressure value can be remotely transmitted to a control system through the first pressure transmitter 8 by performing two-out-of-three logic selection through action signals of three pressure switches 7 arranged on the overspeed trip oil duct 2.

In the embodiment, two pipeline electromagnetic valves 10 are connected in parallel at the front end of the second hydraulic throttle 5, two pipeline electromagnetic valves 10 are connected in parallel at the rear end of the third hydraulic throttle 6 as redundant bypasses, and the oil pressure value between the second hydraulic throttle 5 and the third hydraulic throttle 6 is monitored through a second pressure transmitter 9; in normal operation of the unit, all the pipeline electromagnetic valves 10 are kept in an electrified state, and the oil pressure value between the second hydraulic throttle 5 and the third hydraulic throttle 6 is one half of the overspeed trip oil pressure value; as in the two line solenoid valves 10 at the front end of the second hydraulic throttle 5, the failure of one of the line solenoid valves 10 or the failure of both of the line solenoid valves 10 together shorts the second hydraulic throttle 5 connected in parallel therewith, thereby rapidly increasing the oil pressure value between the second hydraulic throttle 5 to the third hydraulic throttle 6 from one half of the overspeed trip oil pressure value to equal the overspeed trip oil pressure value. As in the two line solenoid valves 10 at the rear end of the third hydraulic throttle 6, wherein a failure of one line solenoid valve 10 or a failure of both line solenoid valves 10 together short-circuits the third hydraulic throttle 6 connected in parallel therewith, thereby rapidly reducing the oil pressure value between the second hydraulic throttle 5 to the third hydraulic throttle 6 from half the overspeed trip oil pressure value to a gauge pressure value equal to zero. The overspeed trip oil pressure value does not change basically in the process.

The present embodiment can also perform an operation test for each of the pipe solenoid valves 10 on the overspeed trip protection apparatus during the operation of the gas turbine, and can automatically determine whether or not the operation test of the pipe solenoid valve 10 is successful by a change in the pressure value of the second pressure transmitter 9 installed in the second to third hydraulic restrictors 5 to 6 when any one of the pipe solenoid valves 10 performs the operation test.

In this embodiment, two pipeline electromagnetic valves 10 are connected in parallel to the front end of the second hydraulic throttle 5, two pipeline electromagnetic valves 10 are connected in parallel to the rear end of the third hydraulic throttle 6, and the first main electromagnetic trip valve group and the second bypass electromagnetic trip valve group form a series connection relationship with each other. When the gas turbine reaches an overspeed tripping condition, the control system at least causes any one of the two pipeline electromagnetic valves 10 connected in parallel at the front end of the second hydraulic throttle 5 and any one of the two pipeline electromagnetic valves 10 connected in parallel at the rear end of the third hydraulic throttle 6 to lose electricity at the same time, so that overspeed tripping oil pressure can be directly connected with return oil through the corresponding pipeline electromagnetic valve 10 to achieve the purpose of overspeed tripping.

In the embodiment, the manual or remote automatic control of the manual-automatic overspeed trip control valve 11 can also enable overspeed trip oil pressure to be directly communicated with the oil return duct 3 through the manual-automatic overspeed trip control valve 11, so that the purpose of overspeed trip is achieved.

The gas quick-closing valve actuator 12 in the embodiment is of a hydraulic opening and spring closing type, and the gas discharge valve actuator 13 is of a hydraulic closing and spring opening type. When the overspeed trip oil pressure is established, the gas discharge valve actuating mechanism 13 overcomes the spring force to close the gas discharge valve under the action of the overspeed trip oil pressure, and meanwhile, the gas quick-closing valve actuating mechanism 12 overcomes the spring force to open the gas quick-closing valve under the action of the overspeed trip oil pressure, so that the gas finally enters the front of each gas flow control valve of the gas turbine, and the gas turbine is ready for smooth starting. When overspeed trip oil pressure disappears, the spring force of the gas discharge valve actuating mechanism 13 controls the gas discharge valve to be opened quickly, meanwhile, the spring force of the gas quick closing valve actuating mechanism 12 controls the gas quick closing valve to be closed quickly, finally, the gas before entering each gas flow control valve of the gas turbine is discharged quickly, and meanwhile, the gas is cut off from entering, so that the aim of quick and safe shutdown of the gas turbine is achieved.

The two unidirectional throttle hydraulic valves 14 in the embodiment are respectively used for controlling the overspeed trip oil to slowly enter the gas quick-closing valve executing mechanism 12 and the gas discharge valve executing mechanism 13, and can also control the overspeed trip oil to be rapidly discharged from the gas quick-closing valve executing mechanism 12 and the gas discharge valve executing mechanism 13 when the gas turbine needs emergency shutdown, so that the gas quick-closing valve and the gas discharge valve can rapidly act under the shutdown working condition.

In summary, the device in this embodiment abandons the pressure release mode that needs the cooperation of traditional stop valve, solenoid valve and unloading valve, has reduced the intermediate link of hydraulic component, is favorable to not only simplifying the device structure, is favorable to improving the response speed of device, has promoted the reliability of device simultaneously, and the practicality is better.

Example 2

The present embodiment further defines the structure of the pipeline electromagnetic valve 10 on the basis of embodiment 1, and the pipeline electromagnetic valve 10 has a direct driving function, and can directly control the establishment and disappearance of the overspeed limit oil pressure, thereby improving the response speed. As shown in fig. 2, the pipeline electromagnetic valve 10 comprises a valve body 10.8, a valve cover 10.5, a valve seat 10.17 and an electromagnetic control assembly, wherein the structure and the connection relation of the components are as follows:

the valve body 10.8 is internally provided with a flow passage and a valve seat 10.17, the valve cover 10.5 is fixed on the valve body 10.8 in a sealing way through a bolt fastener 10.15 and a sealing ring 10.14, the electromagnetic control assembly is vertically fixed above the valve seat 10.17 through the valve cover 10.5, and the electromagnetic control assembly is matched with the valve seat 10.17 to control the flow passage to be opened and closed.

The electromagnetic control assembly comprises a core tube 10.3, a support ring 10.4, a valve core 10.13, a valve core spring 10.12, a tension spring 10.6, a support gasket 10.16, a diaphragm 10.7, a valve clack 10.9 and an electromagnetic assembly. The support ring 10.4 is installed in the middle of the upper portion of the valve cover 10.5 through threaded fit, a sealing ring 10.14 is arranged between the support ring 10.4 and the valve cover 10.5, the core tube 10.3 is a hollow insulating tube, the lower end of the core tube 10.3 is fixed on the valve cover 10.5 through the support ring 10.4, the electromagnetic component is fixed at the upper end of the core tube 10.3, and electromagnetic force can be generated when the electromagnetic component is electrified. The valve core 10.13 is a metal rod which can be pushed by electromagnetic force, the upper end of the valve core 10.13 is movably arranged in the core tube 10.3, and the lower end of the valve core 10.13 penetrates through the valve cover 10.5 and stretches into the valve body 10.8. The upper end of the valve core 10.13 is provided with a concave hole matched with the valve core spring 10.12, the valve core spring 10.12 is arranged between the electromagnetic component and the core pipe 10.3, one end of the valve core spring 10.12 is positioned in the concave hole, and the other end is abutted with the electromagnetic component. The lower end of the valve core 10.13 is fixedly provided with a screw sleeve, the extension spring 10.6, the support gasket 10.16, the diaphragm 10.7 and the valve clack 10.9 are sequentially arranged at the lower end of the valve core 10.13 from top to bottom through the screw sleeve, and under the action of the screw sleeve and the valve cover 10.5, the extension spring 10.6, the support gasket 10.16, the diaphragm 10.7 and the valve clack 10.9 are restrained to be incapable of freely moving. It should be noted that, the extension spring 10.6, the support washer 10.16, the diaphragm 10.7 and the valve clack 10.9 are all located between the valve cover 10.5 and the screw sleeve, the support washer 10.16 is a disc-shaped structure with a concave portion, the opening faces the valve cover 10.5, and the peripheral edge of the support washer abuts against the lower surface of the valve cover 10.5. The peripheral edge of the diaphragm 10.7 is sealingly secured between the bonnet 10.5 and the valve body 10.8, and the diaphragm 10.7 prevents fluid within the valve body 10.8 from entering above the diaphragm 10.7, both to prevent fluid leakage and to prevent fluid from affecting the solenoid control assembly. The flap 10.9 is located directly above the valve seat 10.17, and the flap 10.9 is sealed against the valve seat 10.17 by surface contact. When the electromagnetic assembly is electrified, electromagnetic force is generated, the valve clack 10.9 can be controlled to move downwards through the valve core 10.13 and press the valve seat 10.17, so that the flow passage is controlled to be disconnected, and the pipeline electromagnetic valve 10 is in a closed state. When the electromagnetic assembly is powered off, the electromagnetic force disappears, the valve clack 10.9 moves upwards and resets by the restoring force of the extension spring 10.6, the valve clack 10.9 is separated from the valve seat 10.17, the control flow passage is communicated, and the pipeline electromagnetic valve 10 is in an open state.

The electromagnetic assembly comprises an electromagnetic coil 10.1, a shielding coil 10.2, a fixing cap 10.10 and a screw plug 10.11. The electromagnetic coil 10.1 is formed by winding an insulated copper wire according to a certain number of turns according to a required voltage level, the electromagnetic coil 10.1 is sleeved on the core tube 10.3 and is positioned above the supporting ring 10.4, and the supporting ring 10.4 can axially position the electromagnetic coil 10.1. The screw plug 10.11 is inserted and fixed in the upper end of the core tube 10.3, so that the electromagnetic coil 10.1 can be axially fixed. The fixing cap 10.10 is fixed at the upper end of the screw plug 10.11 through the core tube 10.3, so that radial fixation of the electromagnetic coil 10.1 can be realized. The shielding coil 10.2 is embedded and fixed on the lower end face of the screw plug 10.11, and the electromagnetic coil 10.1 and the shielding coil 10.2 are matched to generate electromagnetic force to control the action of the valve core 10.13. Specifically, since the magnetic force lines generated after the shielding coil 10.2 is energized are opposite to the magnetic force lines generated by the electromagnetic coil 10.1, the electromagnetic force generated by the electromagnetic coil 10.1 can be stronger. In addition, the spool spring 10.12 is pressed by the plug 10.11 between the plug 10.11 and the spool 10.13.

In the implementation of the embodiment, the electromagnetic force generated by electrification of the electromagnetic coil 10.1 directly pushes the valve core 10.13 to move downwards, so that the valve clack 10.9 is always kept in a pressed state with the valve seat 10.17. When the electromagnetic coil 10.1 is de-energized, the electromagnetic force is removed and the valve flap 10.9 rapidly moves away from the valve seat 10.17 under the restoring force of the tension spring 10.6. The actions are all direct driving, and the safety of the whole gas turbine is improved rapidly and reliably.

While the utility model has been described with reference to certain embodiments, it is understood that any feature disclosed in this specification may be replaced by alternative features serving the equivalent or similar purpose, unless expressly stated otherwise; all of the features disclosed, or all of the steps in a method or process, except for mutually exclusive features and/or steps, may be combined in any manner.

Claims (9)

1. An overspeed trip protection device for a gas turbine, characterized in that: the hydraulic control system comprises a control oil duct (1), an over-speed tripping oil duct and an oil return duct (3), wherein a first hydraulic throttle (4), a first main electromagnetic tripping valve group, a second hydraulic throttle (5), a third hydraulic throttle (6) and a second bypass electromagnetic tripping valve group are sequentially connected in series between the control oil duct (1) and the oil return duct (3) through pipelines, and the first main electromagnetic tripping valve group and the second bypass electromagnetic tripping valve group are mutually connected; the over-speed tripping oil duct comprises a first branch (3.1) and a second branch (3.2) which are connected in parallel, the first branch (3.1) is connected between the first hydraulic throttle (4) and the first main electromagnetic tripping valve group, the second branch (3.2) is connected with the oil return duct (3), the first branch (3.1) is connected with a gas quick-closing valve executing mechanism (12) and a gas discharging valve executing mechanism (13) in series, and a manual-automatic overspeed tripping control valve (11) is connected between the second branch (3.2) and the oil return duct (3).

2. The gas turbine overspeed trip protection apparatus of claim 1, wherein: the gas quick-closing valve actuating mechanism (12) and the gas discharge valve actuating mechanism (13) are respectively connected to the first branch (3.1) through a one-way throttling hydraulic valve (14).

3. The gas turbine overspeed trip protection apparatus of claim 1, wherein: the control oil duct (1) is also connected in series with a pressure switch (7), a first pressure transmitter (8) and a second pressure transmitter (9) between the oil return duct (3), the first pressure transmitter (8) and the pressure switch (7) are sequentially connected in series between the control oil duct (1) and the first branch (3.1), and the second pressure transmitter (9) is connected in series between the second hydraulic throttle (5) and the third hydraulic throttle (6).

4. A gas turbine overspeed trip protection apparatus according to any one of claims 1-3, wherein: the first main electromagnetic tripping valve group and the second bypass electromagnetic tripping valve group comprise two pipeline electromagnetic valves (10), the two pipeline electromagnetic valves (10) in the first main electromagnetic tripping valve group are connected in parallel at the front end of the second hydraulic throttle (5), the two pipeline electromagnetic valves (10) in the second bypass electromagnetic tripping valve group are connected in parallel at the rear end of the third hydraulic throttle (6), and the pipeline electromagnetic valves (10) in the first main electromagnetic tripping valve group and the pipeline electromagnetic valves (10) in the second bypass electromagnetic tripping valve group are connected in one-to-one correspondence.

5. The overspeed trip protection apparatus of a gas turbine of claim 4, wherein: the pipeline solenoid valve (10) comprises a valve body (10.8), a valve cover (10.5), a valve seat (10.17) and an electromagnetic control assembly, wherein a flow passage and the valve seat (10.17) are arranged in the valve body (10.8), the valve cover (10.5) is fixed on the valve body (10.8) in a sealing mode, the electromagnetic control assembly is vertically fixed above the valve seat (10.17) through the valve cover (10.5), and the electromagnetic control assembly is matched with the valve seat (10.17) to control the flow passage to be opened and closed.

6. The gas turbine overspeed trip protection apparatus of claim 5, wherein: the electromagnetic control assembly comprises a core tube (10.3), a supporting ring (10.4), a valve core (10.13), a valve core spring (10.12), a tension spring (10.6), a supporting gasket (10.16), a diaphragm (10.7), a valve clack (10.9) and an electromagnetic assembly, wherein the lower end of the core tube (10.3) is fixed on a valve cover (10.5) through the supporting ring (10.4), the electromagnetic assembly is fixed at the upper end of the core tube (10.3), the upper end of the valve core (10.13) is movably arranged in the core tube (10.3), the lower end of the valve core (10.13) penetrates through the valve cover (10.5) to stretch into a valve body (10.8), the valve core spring (10.12) is arranged between the electromagnetic assembly and the core tube (10.3), the tension spring (10.6), the supporting gasket (10.16), the diaphragm (10.7) and the valve clack (10.9) are sequentially arranged at the lower end of the valve core (10.13) through threaded sleeves, the periphery of the diaphragm (10.7) is fixed between the valve cover (10.5) and the valve cover (10.8) in a sealing mode, the periphery of the valve core (10.13) is arranged on the valve seat (10.8), and the valve core (10.8) can be controlled to move around the valve core (10.9) through the valve core.

7. The gas turbine overspeed trip protection apparatus of claim 6, wherein: the electromagnetic assembly comprises an electromagnetic coil (10.1), a shielding coil (10.2), a fixing cap (10.10) and a screw plug (10.11), wherein the electromagnetic coil (10.1) is sleeved on a core tube (10.3) and is located above a supporting ring (10.4), the screw plug (10.11) axially fixes the electromagnetic coil (10.1) through the core tube (10.3), the fixing cap (10.10) radially fixes the electromagnetic coil (10.1) through the core tube (10.3), the shielding coil (10.2) is fixed on the end face of the lower end of the screw plug (10.11), and the electromagnetic coil (10.1) and the shielding coil (10.2) are matched to generate electromagnetic force to control the action of a valve core (10.13).

8. The gas turbine overspeed trip protection apparatus of claim 6, wherein: a sealing ring (10.14) is fixed between the supporting ring (10.4) and the valve cover (10.5).

9. The gas turbine overspeed trip protection apparatus of claim 5, wherein: a sealing ring (10.14) is fixed between the valve body (10.8) and the valve cover (10.5).