Non-driving shaft rotating speed control switching method and system during driving shaft rotating speed fault of double-shaft gas turbine

Abstract

The invention discloses a non-driving shaft rotating speed control switching method and system during a double-shaft gas turbine driving shaft rotating speed fault, and belongs to the field of gas turbine driving control. The invention aims to solve the technical problem that if rotating speed sensors of driving shafts of an existing double-shaft gas turbine fail, the gas turbine can be shut down emergently, and operation of key facilities is affected. Comprising the following steps: S1, configuring and mounting a rotating speed acquisition system and a control system of the double-shaft gas turbine; s2, loading a starting mode and an operation mode, and starting the double-shaft gas turbine; s3, the rotating speed acquisition system transmits a low-pressure rotor rotating speed fault signal to the control system; s4, the control system detects whether a shaft vibration high signal or a low-pressure turbine exhaust temperature high signal exists at the same time or not; and S5, according to whether the shaft vibration high signal or the low-pressure turbine exhaust temperature high signal exists or not, the gas turbine is controlled to be shut down emergently or not. And the service life of high-pressure and low-pressure rotors is prolonged. The method is used for driving control of the double-shaft gas turbine.

Description

TECHNICAL FIELD

[0001] The application relates to a non-driving shaft speed control switching method and system when a driving shaft speed fault occurs in a dual-shaft gas turbine, and belongs to the field of gas turbine driving control. BACKGROUND

[0002] Multi-shaft gas turbines, such as dual-shaft or tri-shaft structures, are generally composed of a high-pressure rotor, a low-pressure rotor and a power turbine, and energy transmission is achieved through aerodynamic or mechanical coupling of the rotors. The control system needs to monitor the speed of each rotor in real time to adjust parameters such as fuel quantity and guide vane angle, and ensure stable operation. The speed sensor is a core feedback element, and 2-3 shafts are usually used to improve reliability.

[0003] In existing dual-shaft gas turbine control systems, 2-3 speed sensors are generally configured on each rotor. If all speed sensors on the driving shaft fail, the gas turbine will perform emergency shutdown, affecting the operation of critical facilities. However, in some special situations, such as emergency work of a marine gas turbine, insufficient power output or insufficient power output can easily cause dangerous situations, and at this time the gas turbine needs to continue to output load. At this time, the existing dual-shaft gas turbine control system cannot continue to provide corresponding load control in the case of driving shaft speed sensor failure.

[0004] In summary, if all speed sensors on the driving shaft of the existing dual-shaft gas turbine fail, the gas turbine will perform emergency shutdown, which has the technical problem of affecting the operation of critical facilities. SUMMARY

[0005] The application is to solve the technical problem that the existing dual-shaft gas turbine will perform emergency shutdown if all speed sensors on the driving shaft fail, which affects the operation of critical facilities, and further provides a non-driving shaft speed control switching method when a driving shaft speed fault occurs in a dual-shaft gas turbine. It includes the following steps:

[0006] S1, configure and install a dual-shaft gas turbine speed acquisition system and a control system;

[0007] S2, load start mode and operation mode into the control system, and start the dual-shaft gas turbine;

[0008] S3, the speed acquisition system acquires a low-pressure rotor speed fault signal and transmits the low-pressure rotor speed fault signal to the control system;

[0009] S4, the control system detects whether there are simultaneously high shaft vibration signals or low-pressure turbine exhaust temperature high signals;

[0010] S5, if the high signal of shaft vibration or the high signal of low pressure turbine exhaust temperature exists, the control system controls the gas turbine to emergency stop; if the high signal of shaft vibration and the high signal of low pressure turbine exhaust temperature do not exist, the control system controls the gas turbine to not stop.

[0011] As another improvement of the present application, the starting mode in step S2 includes normal starting and emergency starting, and the running mode includes low pressure rotating speed control mode and high pressure rotating speed control mode, and the dual-shaft gas turbine is started in the low pressure rotating speed control mode;

[0012] The step S5 that the control system controls the gas turbine to not stop includes the following steps:

[0013] S5-1, if the starting mode in the control system is normal starting, the control system is executed after manual operation; otherwise, the next step is executed;

[0014] S5-2, the low pressure rotating speed control mode of the dual-shaft gas turbine is switched to the running high pressure rotating speed control mode.

[0015] As another improvement of the present application, the step S5-1 that the control system is executed after manual operation includes executing emergency stop or executing the step S5-2.

[0016] As another improvement of the present application, the dual-shaft gas turbine rotating speed acquisition system includes rotating speed sensors and rotating speed cards; and the control system includes a controller.

[0017] The present application also provides a dual-shaft gas turbine rotating speed acquisition system and control system, which includes a low pressure rotor, a high pressure rotor, low pressure rotor rotating speed sensors, rotating speed cards, a controller, a combustion chamber and a fuel emergency shut-off valve; the low pressure rotor and the high pressure rotor are linked and run, and are driven by high temperature gas generated by the combustion chamber; the input end of the combustion chamber is provided with the fuel emergency shut-off valve; the low pressure rotor is provided with a plurality of low pressure rotor rotating speed sensors; the output end of each low pressure rotor rotating speed sensor is correspondingly provided with a rotating speed card; the input end of the rotating speed card is electrically connected with the low pressure rotor rotating speed sensor; the output end of the rotating speed card is electrically connected with the controller; and the fuel emergency shut-off valve is electrically connected with the controller.

[0018] As another improvement of the present application, it further includes high pressure rotor rotating speed sensors and a fuel adjusting valve group; the high pressure rotor is provided with a plurality of high pressure rotor rotating speed sensors; the output end of each high pressure rotor rotating speed sensor is correspondingly provided with a rotating speed card; and the fuel adjusting valve group is electrically connected with the controller.

[0019] As another improvement of the present application, the low pressure rotor rotating speed sensors are provided with three.

[0020] As another improvement of the present application, the high pressure rotor rotating speed sensors are provided with three.

[0021] As another improvement of the present application, the controller is a PLC controller. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a flow chart of a method for controlling switching of the non-driving shaft rotation speed when the driving shaft rotation speed of a dual-shaft gas turbine fails.

[0023] Figure 2 is a structural schematic diagram of a rotation speed acquisition system and a control system of a dual-shaft gas turbine. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all the embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0025] Specific implementation one: combined with Figure 1 and Figure 2 The present embodiment provides a method for controlling switching of the non-driving shaft rotation speed when the driving shaft rotation speed of a dual-shaft gas turbine fails, which is characterized in that it comprises the following steps:

[0026] S1, configuring and installing a rotation speed acquisition system and a control system of a dual-shaft gas turbine;

[0027] S2, loading a start mode and a running mode into the control system, and starting the dual-shaft gas turbine;

[0028] S3, the rotation speed acquisition system acquires a low-pressure rotor rotation speed failure signal, and sends the low-pressure rotor rotation speed failure signal to the control system;

[0029] S4, the control system detects whether there are simultaneously an axial vibration high signal or a low-pressure turbine exhaust temperature high signal;

[0030] S5, if there is an axial vibration high signal or a low-pressure turbine exhaust temperature high signal, the control system controls the gas turbine to stop urgently; if there are neither an axial vibration high signal nor a low-pressure turbine exhaust temperature high signal, the control system controls the gas turbine not to stop.

[0031] The dual-shaft gas turbine rotation speed signal acquisition and control system, wherein three rotation speed sensors are configured for the low-pressure rotor, three rotation speed sensors are configured for the high-pressure rotor, and the rotation speed signal is sent to the controller after being acquired by a rotation speed card. The dual-shaft gas turbine is connected to a generator for power output at the cold end of the low-pressure rotor, or connected to a compressor or an impeller for power output.

[0032] Before the dual-shaft gas turbine is started, the operator can select a start mode, which is respectively "normal start" and "emergency start". In the "normal start" mode, after the dual-shaft gas turbine is started, runs at full speed and is unloaded, and then runs under load, if a "low-pressure rotor speed fault" signal appears, the control system does not control the gas turbine to directly enter an emergency shutdown protection process. Instead, the control system continues to judge whether the gas turbine has other emergency shutdown signals, such as high shaft vibration emergency shutdown and low-pressure turbine exhaust temperature high emergency shutdown. If there is other emergency shutdown signal, such as high shaft vibration emergency shutdown and low-pressure turbine exhaust temperature high emergency shutdown, the gas turbine is shut down. If the control system judges that only the "low-pressure rotor speed fault" signal exists, the state of the gas turbine is maintained, until the operator operates the gas turbine "emergency shutdown" or switches to a "high-pressure speed control mode" to enter a normal shutdown process, thereby preventing the high-pressure rotor and the low-pressure rotor of the gas turbine from being locked, and prolonging the service life of the high-pressure rotor and the low-pressure rotor.

[0033] In the "emergency start" mode, after the dual-shaft gas turbine is started, runs at full speed and is unloaded, and then runs under load, if a "low-pressure rotor speed fault" signal appears, the control system judges whether the gas turbine has other emergency shutdown signals, such as high shaft vibration emergency shutdown and low-pressure turbine exhaust temperature high emergency shutdown. If there is other emergency shutdown signal, such as high shaft vibration emergency shutdown and low-pressure turbine exhaust temperature high emergency shutdown, the gas turbine is shut down. If not, the control system automatically switches to a "high-pressure speed control mode", the control system controls the load adjustment of the gas turbine to continue to provide power output according to the corresponding relationship curve of the high-pressure speed and the load obtained from the design document or the historical trend curve, the operator can adjust the output power or control the gas turbine to enter a normal shutdown process, thereby preventing the high-pressure rotor and the low-pressure rotor of the gas turbine from being locked, and prolonging the service life of the high-pressure rotor and the low-pressure rotor.

[0034] DETAILED DESCRIPTION Figure 1 and Figure 2 The embodiment is described. The embodiment is different from the first embodiment in that the start mode in step S2 includes normal start and emergency start, and the operation mode includes a low-pressure speed control mode and a high-pressure speed control mode. The dual-shaft gas turbine is started in the low-pressure speed control mode.

[0035] In step S5, the control system controls the gas turbine not to be shut down, including the following steps:

[0036] S5-1, if the start mode in the control system is normal start, the control system is executed after being manually operated; otherwise, the next step is executed.

[0037] S5-2, switching the low-pressure rotating speed control mode of the dual-shaft gas turbine to the high-pressure rotating speed control mode.

[0038] In the "normal start" mode, if only the "low-pressure rotating speed fault" signal exists after the control system judges, the gas turbine state remains unchanged until the operator operates, preventing the high and low-pressure rotors of the gas turbine from being locked due to emergency shutdown, and prolonging the service life of the high and low-pressure rotors. In the "emergency start" mode, if only the "low-pressure rotating speed fault" signal exists after the control system judges, the control system automatically switches to the "high-pressure rotating speed control mode", and the control system controls the gas turbine load adjustment to continue to provide power output according to the corresponding relationship curve between the high-pressure rotating speed and the load obtained from the design file or the historical trend curve, and the operator can adjust the output power or control the gas turbine to enter the normal shutdown process, preventing the high and low-pressure rotors of the gas turbine from being locked due to emergency shutdown, and prolonging the service life of the high and low-pressure rotors.

[0039] Specific implementation method three: in combination with Figure 1 and Figure 2 This embodiment is described, and the difference between this embodiment and the specific implementation method one is that the step S5-1 to be executed after manual operation includes executing emergency shutdown or switching the low-pressure rotating speed control mode of the dual-shaft gas turbine to the high-pressure rotating speed control mode. The operator operates the gas turbine "emergency shutdown" or switches to the "high-pressure rotating speed control mode" to enter the normal shutdown process.

[0040] Specific implementation method four: in combination with Figure 1 and Figure 2 This embodiment is described, and the difference between this embodiment and the specific implementation method one is that the dual-shaft gas turbine rotating speed acquisition system includes a rotating speed sensor and a rotating speed card; and the control system includes a controller. Such a design is used to realize a dual-shaft gas turbine driving shaft rotating speed fault non-driving shaft rotating speed control switching method.

[0041] Specific implementation method five: in combination with Figure 1 and Figure 2The embodiment is illustrated. The embodiment provides a dual-shaft gas turbine speed acquisition system and control system, which comprises a low-pressure rotor, a high-pressure rotor, a low-pressure rotor speed sensor, a speed card, a controller, a combustion chamber and a fuel emergency shutdown valve; the low-pressure rotor and the high-pressure rotor are linked and operated, the low-pressure rotor and the high-pressure rotor are driven by high-temperature gas generated by the combustion chamber, the input end of the combustion chamber is provided with the fuel emergency shutdown valve, a plurality of low-pressure rotor speed sensors are arranged on the low-pressure rotor, the output end of each low-pressure rotor speed sensor is correspondingly provided with a speed card, the input end of the speed card is electrically connected with the low-pressure rotor speed sensor, the output end of the speed card is electrically connected with the controller, and the fuel emergency shutdown valve is electrically connected with the controller. Such a design is used to realize a dual-shaft gas turbine driving shaft speed fault non-driving shaft speed control switching method.

[0042] Specific embodiment six: in combination with Figure 1 and Figure 2 The embodiment is illustrated. The difference between the embodiment and the fifth specific embodiment is that the embodiment further comprises a high-pressure rotor speed sensor and a fuel regulating valve group; a plurality of high-pressure rotor speed sensors are arranged on the high-pressure rotor, the output end of each high-pressure rotor speed sensor is correspondingly provided with a speed card, and the fuel regulating valve group is electrically connected with the controller. The other components and connection modes are the same as those of the fifth specific embodiment.

[0043] Specific embodiment seven: in combination with Figure 1 and Figure 2 The embodiment is illustrated. The difference between the embodiment and the fifth specific embodiment is that the low-pressure rotor speed sensor is provided with three. The other components and connection modes are the same as those of the fifth or sixth specific embodiment.

[0044] Specific embodiment eight: in combination with Figure 1 and Figure 2 The embodiment is illustrated. The difference between the embodiment and the fifth specific embodiment is that the high-pressure rotor speed sensor is provided with three. The other components and connection modes are the same as those of any one of the fifth to seventh specific embodiments.

[0045] Specific embodiment nine: in combination with Figure 1 and Figure 2 The embodiment is illustrated. The difference between the embodiment and the fifth specific embodiment is that the controller is a PLC controller. The other components and connection modes are the same as those of any one of the fifth to eighth specific embodiments.

[0046] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for switching the speed control of the non-driving shaft when the driving shaft speed of a dual-shaft gas turbine fails, characterized in that It includes the following steps: S1. Configure and install dual-shaft gas turbine speed acquisition system and control system; S2. Loading the start-up mode and the operation mode into the control system and starting the dual-shaft gas turbine; S3, the speed acquisition system collects the low-pressure rotor speed fault signal and transmits the low-pressure rotor speed fault signal to the control system; S4. The control system detects whether there is a high shaft vibration signal or a high low-pressure turbine exhaust temperature signal at the same time; S5. If there is a high shaft vibration signal or a high low-pressure turbine exhaust temperature signal, the control system controls the gas turbine to shut down urgently; if neither the high shaft vibration signal nor the high low-pressure turbine exhaust temperature signal exists, the control system controls the gas turbine to continue shutting down.

2. The method for switching the speed control of the non-driving shaft when the driving shaft speed of a dual-shaft gas turbine fails according to claim 1, characterized in that: In step S2, the startup mode includes normal startup and emergency startup, and the operation mode includes low-pressure speed control mode and high-pressure speed control mode, and the dual-shaft gas turbine is started in the low-pressure speed control mode; In step S5, the control system controls the gas turbine to not shut down, including the following steps: S5-1. If the startup mode in the control system is normal startup, the control system will execute after human operation; Otherwise, proceed to the next step; S5-2. Switch the low-pressure speed control mode of the dual-shaft gas turbine to the high-pressure speed control mode.

3. The method for switching the speed control of the non-driving shaft when the driving shaft speed of a dual-shaft gas turbine fails according to claim 2, characterized in that: The execution after the human operation in step S5-1 includes executing an emergency shutdown or switching the low-pressure speed control mode of the dual-shaft gas turbine to the high-pressure speed control mode.

4. The method for switching the speed control of the non-driving shaft when the driving shaft speed of a dual-shaft gas turbine fails according to claim 1 is characterized in that The dual-shaft gas turbine speed acquisition system includes a speed sensor and a speed card; the control system includes a controller.

5. A dual-shaft gas turbine speed acquisition and control system, characterized in that It includes a low-pressure rotor, a high-pressure rotor, a low-pressure rotor speed sensor, a speed card, a controller, a combustion chamber and a fuel emergency shut-off valve; the low-pressure rotor and the high-pressure rotor operate in conjunction, and the low-pressure rotor and the high-pressure rotor are driven by the high-temperature combustion gas generated by the combustion chamber. A fuel emergency shut-off valve is installed at the input end of the combustion chamber, and multiple low-pressure rotor speed sensors are arranged on the low-pressure rotor. A speed card is correspondingly arranged at the output end of each low-pressure rotor speed sensor. The input end of the speed card is electrically connected to the low-pressure rotor speed sensor, the output end of the speed card is electrically connected to the controller, and the fuel emergency shut-off valve is electrically connected to the controller.

6. A dual-shaft gas turbine speed acquisition and control system according to claim 5, characterized in that It also includes a high-pressure rotor speed sensor and a fuel regulating valve group; multiple high-pressure rotor speed sensors are arranged on the high-pressure rotor, and a speed card is arranged corresponding to the output end of each high-pressure rotor speed sensor, and the fuel regulating valve group is electrically connected to the controller.

7. A dual-shaft gas turbine speed acquisition and control system according to claim 6, characterized in that: There are three low-pressure rotor speed sensors.

8. The dual-shaft gas turbine speed acquisition and control system according to claim 6, characterized in that: There are three high-pressure rotor speed sensors.

9. The dual-shaft gas turbine speed acquisition and control system according to claim 5, characterized in that: The controller is a PLC controller.

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