Method and system for automatically controlling high and low bypasses of generator set

Abstract

The invention relates to the technical field of power system control, in particular to a method and a system for automatically controlling high and low bypasses of a generator set. The invention provides a method for automatically controlling high and low bypasses of a generator set, which comprises the following steps: acquiring control parameters of the high and low bypasses of the generator set, the control parameters at least comprising the actual main steam pressure of the generator set and whether the impulse of a steam turbine is loaded; determining a control mode of a high-low bypass of the generator set according to the control parameters; and executing a corresponding control strategy according to the control mode, and adjusting the opening degree of the high bypass valve and / or the opening degree of the low bypass valve to realize whole-course automatic control of the high bypass and the low bypass of the generator set. A brand-new high-low bypass control strategy is adopted, high-low bypass whole-process automatic control is achieved, the operation intensity of operators is reduced, main steam pressure and temperature fluctuation in the starting stage is effectively controlled, the process of a unit from starting to grid connection is accelerated, and the operation efficiency is improved.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of power system control, and in particular to a method and system for automatic control of high and low bypass of a generator set. Background Art

[0002] During the startup and operation of the generator set, the bypass control system plays a vital role in shortening the startup time of the unit and ensuring the stability of operation. However, in the existing technology, the bypass automatic control system of most units cannot be put into use stably after commissioning. During the startup phase of the unit, the operator mainly relies on manual control of the opening of the bypass valve, resulting in large fluctuations in the main steam pressure and temperature. The speed of the steam turbine before grid connection fluctuates with the fluctuation of the main steam pressure. Since this pressure fluctuation will cause system resonance under certain working conditions, the parameters will show a wave-like trend, and long-term operation will seriously affect the life of various system equipment.

[0003] In addition, manual operation increases the workload of operators and prolongs the startup time of the unit. During the normal operation of the unit, if an unplanned shutdown occurs, the bypass cannot be operated in time according to the actual working conditions, which may cause accidents such as safety valve operation, affecting the safety of equipment and personnel.

[0004] Therefore, a new high and low bypass full-range automatic control method is urgently needed, which can stabilize the main steam pressure and temperature during the unit startup phase, keep their changes within a reasonable range, reduce the operating intensity of operators, and shorten the unit startup time. At the same time, when the unit is not shut down, the bypass can be activated in time to avoid accidents, meeting the requirements of high and low bypass full-range automatic control. Summary of the invention

[0005] The purpose of the present invention is to provide a method for automatic high and low bypass control of a generator set, so as to solve the problems in the prior art that the bypass automatic control cannot be stably put into operation, the main steam pressure fluctuates greatly, and the operating intensity of operators is high.

[0006] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0007] In order to achieve the above object, the present invention provides a method for automatic control of high and low bypass of a generator set, the method comprising:

[0008] Obtaining control parameters of high and low bypass of the generator set, wherein the control parameters at least include the actual main steam pressure of the generator set and whether the turbine is running with load;

[0009] Determining a control mode of high and low bypass of the generator set according to the control parameter;

[0010] According to the control mode, the corresponding control strategy is executed to adjust the opening degree of the high bypass valve and / or the opening degree of the low bypass valve, so as to realize the full-range automatic control of the high and low bypass of the generator set.

[0011] In some embodiments, the control modes include minimum pressure mode, boost mode, constant pressure mode and pressure tracking mode in sequence:

[0012] According to the actual main steam pressure value of the generator set, determine whether the control mode is in the minimum pressure mode, boosting mode or constant pressure mode;

[0013] Depending on whether the turbine is running with load, it is determined whether the control mode is switched from the constant pressure mode to the pressure tracking mode.

[0014] In some embodiments, when the actual main steam pressure value of the generator set is less than the minimum pressure setting value, the control mode is in the minimum pressure mode;

[0015] The corresponding control strategies include: igniting the boiler to maintain the steam flow, opening the high bypass valve to the first opening;

[0016] When the actual main steam pressure of the generator set is greater than the minimum pressure setting value, the opening degree of the high bypass valve is adjusted to the second opening degree at the set opening rate.

[0017] In some embodiments, when the opening degree of the high bypass valve reaches a second opening degree and the actual main steam pressure of the generator set is greater than the minimum pressure setting value, the control mode enters the boost mode from the minimum pressure mode.

[0018] In some embodiments, when the actual main steam pressure of the generator set is greater than the pressure setting value before the turbine is connected to the grid, the control mode changes from the boost mode to the constant pressure mode;

[0019] When the control mode is in the constant pressure mode, the minimum opening of the high bypass valve is set below the second opening value.

[0020] In some embodiments, when the steam turbine is running and the unit load is greater than a preset threshold, the control mode changes from the constant pressure mode to the pressure tracking mode:

[0021] When the control mode is in pressure tracking mode, the high bypass valve is closed, all steam enters the turbine, and the high and low bypass control modes are switched to manual.

[0022] In some embodiments, when the control mode is in constant pressure mode:

[0023] Adjust the pressure setting value before the steam turbine is connected to the grid so that the steam turbine can be started up when the actual main steam pressure of the generator set reaches the pressure setting value before the steam turbine is connected to the grid.

[0024] In some embodiments, when the control mode is in constant pressure mode:

[0025] After the steam turbine is connected to the grid, when the unit load is less than a preset threshold, the opening degree of the high bypass valve is reduced from the second opening to a third opening, wherein the third opening is greater than the first opening and less than the second opening, and when the unit load is greater than the preset threshold, the high bypass valve is closed;

[0026] After the turbine is connected to the grid, when the unit load is less than the preset threshold, the opening degree of the low bypass valve is within the set range to adjust the steam pressure in the reheater. When the unit load is greater than the preset threshold, the low bypass valve is closed after the high bypass valve is closed.

[0027] In some embodiments, the bypass valve opening and fuel supply amount are calculated based on the actual main steam pressure of the generator set, the main steam control pressure setting value and the boiler fuel amount;

[0028] The bypass valve opening degree includes the high bypass valve opening degree and / or the low bypass valve opening degree.

[0029] In order to achieve the above object, the present invention provides a system for automatic control of high and low bypass of a generator set, comprising:

[0030] a memory for storing instructions executable by a processor;

[0031] A processor is used to execute the instructions to implement the above method.

[0032] In order to achieve the above object, the present invention provides a computer readable medium storing a computer program code, wherein the computer program code implements the above method when executed by a processor.

[0033] The present invention proposes a method and system for automatic control of high and low bypass of a generator set, which adopt a new high and low bypass control strategy, realize full-process automatic control of high and low bypass, and reduce the operating intensity of operators; effectively control the main steam pressure and temperature fluctuations in the startup phase, avoid system resonance and parameter fluctuations, and extend the service life of the equipment; optimize the control strategy, speed up the process from startup to grid connection of the unit, and improve the operating efficiency; in the case of unplanned shutdown or abnormal operating conditions of the unit, the bypass system can respond in time to avoid accidents such as safety valve action. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein:

[0035] Figure 1 A flow chart of a method for automatic high and low bypass control of a generator set according to an embodiment of the present invention is disclosed;

[0036] Figure 2 A design principle logic diagram of high and low bypass automatic control of a generator set according to an embodiment of the present invention is disclosed;

[0037] Figure 3 A system principle block diagram of high and low bypass automatic control of a generator set according to an embodiment of the present invention is disclosed. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0040] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0041] Figure 1 A flow chart of a method for automatic high and low bypass control of a generator set according to an embodiment of the present invention is disclosed. Figure 1 As shown, the present invention provides a method for automatic control of high and low bypass of a generator set, comprising:

[0042] Obtaining control parameters of high and low bypass of the generator set, wherein the control parameters at least include the actual main steam pressure of the generator set and whether the turbine is running with load;

[0043] Determining a control mode of high and low bypass of the generator set according to the control parameter;

[0044] According to the control mode, the corresponding control strategy is executed to adjust the opening degree of the high bypass valve and / or the opening degree of the low bypass valve, so as to realize the full-range automatic control of the high and low bypass of the generator set.

[0045] In one embodiment, the following parameters are first defined:

[0046] The actual main steam pressure PV of the generator set is the main steam pressure measured by the pressure sensor in real time;

[0047] The main steam control pressure setting value PS of the generator set refers to the pre-set main steam pressure target value;

[0048] The minimum pressure setting value Pmin refers to the minimum main steam pressure required for safe operation of the boiler and system;

[0049] The maximum pressure setting value Pmax means that the boiler and system cannot operate safely above the maximum main steam pressure;

[0050] The pressure setting value Psync before the turbine is connected to the grid refers to the main steam pressure value set before the turbine is connected to the grid.

[0051] In this embodiment, the above parameter setting values ​​PS, Pmin, Pmax and Psync can be adjusted as needed to meet the starting requirements of the generator set.

[0052] In one embodiment, the control modes include a minimum pressure mode, a boost mode, a constant pressure mode, and a pressure tracking mode.

[0053] The above four modes are executed in sequence, and the control mode is determined to be in the minimum pressure mode, boost mode or constant pressure mode according to the actual main steam pressure value of the generator set;

[0054] At the same time, whether to switch the control mode from the constant pressure mode to the pressure tracking mode is determined according to whether the turbine is running with load.

[0055] Furthermore, in this embodiment, whether the steam turbine is running with load refers to whether the steam turbine is running and the unit load is greater than a preset threshold.

[0056] Figure 2 The following is a logic diagram of the design principle of the automatic high and low bypass control of a generator set according to an embodiment of the present invention. Figure 2 As shown, the actual main steam pressure of the generator set and the main steam control pressure setting value of the generator set are used as input parameters of the control system, which are compared by a comparator and transmitted to the PID controller for calculating the control output.

[0057] The switching between various control modes such as ignition mode, minimum mode (ie, minimum pressure mode), boost mode, constant pressure mode and follow mode (ie, pressure tracking mode) is implemented by the logic block.

[0058] The OR gate is used to determine the current mode and control entry into different logic branches.

[0059] The T flip-flop is used to determine whether to switch to the next mode. For example, when a mode meets the conditions, the flip-flop will switch to the next mode.

[0060] The output of the PID controller is used to adjust the opening of the high bypass valve so that the actual main steam pressure meets the set requirements. The opening calculated by the PID controller is limited by the minimum opening setting to prevent the valve from opening and closing excessively.

[0061] Among them, the minimum pressure mode is used to ensure the minimum opening; after the minimum mode conditions are met, the system enters the boost mode to gradually increase the actual main steam pressure of the generator set. When the pressure reaches the main steam control pressure setting value PS of the generator set, the system enters the constant pressure mode to keep the main steam pressure stable. After the startup is completed, it enters the pressure tracking mode and automatically switches to manual control.

[0062] like Figure 2 As shown, the opening of the high bypass valve and the low bypass valve is determined according to the input parameters, the current control mode and the output of the PID controller, thereby realizing automatic control of the high and low bypasses and ensuring smooth switching of the modes during the startup of the generator set.

[0063] Furthermore, bypass control logic allows the main control path to be bypassed in certain circumstances to protect equipment or respond to emergency situations.

[0064] Next, we will combine Figure 2 The control logic is further explained Figure 1 The high and low bypass automatic control method of the generator set is shown.

[0065] First, the minimum pressure mode among the control modes will be discussed.

[0066] When the actual main steam pressure value PV of the generator set is less than the minimum pressure setting value Pmin, the control mode is in the minimum pressure mode;

[0067] In this embodiment, when the boiler is ignited, the necessary steam flow is maintained to ensure that the boiler is safely heated and pressurized;

[0068] The high bypass valve is forced to open to the first opening, which is the minimum opening Ymin, to maintain the minimum steam flow and prevent overheating of the steam side of the boiler.

[0069] The actual main steam pressure PV of the generator set is monitored in real time. When the actual main steam pressure PV of the generator set reaches the minimum pressure setting value Pmin, the opening degree of the high bypass valve is adjusted to the second opening degree at the set opening rate. The second opening degree is the maximum opening degree Ymax.

[0070] In this embodiment, the minimum mode stage mainly completes the temperature and voltage increase of the generator set to ensure that the parameters meet the start-up requirements.

[0071] Next, the boost mode in the control mode will be introduced.

[0072] When the opening degree of the high bypass valve reaches the second opening degree and the actual main steam pressure of the generator set is greater than the minimum pressure setting value Pmin, the control mode changes from the minimum pressure mode to the boost mode.

[0073] In this embodiment, when the high bypass valve position reaches the maximum opening Ymax and the main steam pressure is greater than the minimum set pressure setting value Pmin, the control mode enters the pressure boost stage.

[0074] In the boost mode stage, the main task is to control the main steam pressure of the steam turbine at various speeds and ensure that the bypass valve is debugged within a certain range.

[0075] Afterwards, the constant pressure mode in the control mode will be explained.

[0076] When the actual main steam pressure of the generator set is greater than the pressure setting value Psync before the turbine is connected to the grid, the control mode changes from the boost mode to the constant pressure mode;

[0077] When the control mode is in the constant pressure mode, the minimum opening of the high bypass valve is set at the second opening value (ie, the maximum opening Ymax).

[0078] Optionally, when the actual main steam pressure of the generator set is greater than the pressure setting value Psync of 0.5 MPa before the turbine is connected to the grid, the control mode changes from the boost mode to the constant pressure mode.

[0079] When the control mode is in constant pressure mode:

[0080] Adjust the pressure setting value Psync before the turbine is connected to the grid so that when the actual main steam pressure of the generator unit reaches the pressure setting value Psync before the turbine is connected to the grid, the turbine can be started up.

[0081] In this embodiment, the actual main steam pressure PV of the unit is automatically adjusted, and the opening degree of the high bypass valve is limited to the second opening value. The operator can change the pressure setting value Psync before the turbine is connected to the grid to meet the start-up parameter requirements.

[0082] When the actual main steam pressure PV of the unit reaches the pressure setting value Psync before the turbine is connected to the grid, the turbine starts to run, and the high and low bypasses are adjusted normally to maintain the run parameters. After the turbine unit is connected to the grid, the high bypass valve can only be closed slightly and cannot be opened widely.

[0083] Furthermore, when the control mode is in constant pressure mode:

[0084] After the steam turbine is connected to the grid, when the unit load is less than a preset threshold, the opening degree of the high bypass valve is reduced from the second opening to a third opening, wherein the third opening is greater than the first opening and less than the second opening, and when the unit load is greater than the preset threshold, the high bypass valve is closed;

[0085] After the turbine is connected to the grid, when the unit load is less than the preset threshold, the opening degree of the low bypass valve is within the set range to adjust the steam pressure in the reheater. When the unit load is greater than the preset threshold, the low bypass valve is closed after the high bypass valve is closed.

[0086] In this embodiment, the preset threshold value of the unit load is 90MW, and the third opening of the high bypass valve is 30% of the second opening (ie, the maximum opening Ymax).

[0087] When the turbine unit is running with a load of less than 90MW, the high bypass valve is closed to 30% of the opening and no longer closed downward; when the turbine unit is running with a load of more than 90MW, the high bypass valve is quickly closed.

[0088] At the same time, after the low bypass is connected to the grid, when the turbine unit is running with a load less than 90MW, the low bypass valve adjusts the reheater pressure within a certain range; when the turbine unit is running with a load greater than 90MW, the low bypass valve closes quickly after the high bypass valve is closed.

[0089] In constant pressure mode, ensure that the steam turbine unit meets the starting curve pressure and temperature requirements under load.

[0090] Finally, the pressure tracking mode in the control mode will be explained.

[0091] When the turbine is running and the unit load is greater than the preset threshold, the control mode changes from constant pressure mode to pressure tracking mode:

[0092] When the control mode is in pressure tracking mode, the high bypass valve is closed, all steam enters the turbine, the high and low bypass control modes are switched to manual, the high and low bypasses are automatically cut off, the high and low bypass valves open to 0, and the generator set start-up process is completed.

[0093] The tracking mode ensures that the high and low bypasses are opened in time according to the actual operating conditions when the unit is not shut down or in normal shutdown state, ensuring the safety of equipment and personnel.

[0094] In this embodiment, the main steam control pressure setting value PS of the generator set is gradually increased according to a predetermined pressure increase curve, so that the actual main steam pressure PV of the generator set increases along with the main steam control pressure setting value PS.

[0095] Furthermore, the actual main steam pressure PV can be gradually increased by adjusting the high bypass valve opening and the boiler fuel quantity until it exceeds the pressure setting value Psync before the turbine is connected to the grid.

[0096] In this embodiment, while the bypass is adjusting the main steam pressure, the fuel supply amount of the boiler is also adjusted.

[0097] According to the actual main steam pressure PV of the generator set, the main steam control pressure setting value PS and the boiler fuel quantity, the reasonable bypass valve opening and fuel supply quantity are calculated.

[0098] In this embodiment, the bypass valve opening degree includes the opening degree of the high bypass valve and / or the low bypass valve.

[0099] When the fuel is insufficient, the system promptly reminds the operator to add fuel without reducing the opening of the high and low bypass valves; when the fuel is excessive, the system reminds the operator to reduce fuel without increasing the opening of the high and low bypass valves.

[0100] By coordinating the bypass valve and the amount of fuel, the main steam pressure can be accurately controlled to avoid pressure fluctuations. When the fuel is insufficient or excessive, the operator is reminded to adjust the fuel amount to maintain a stable valve opening, thereby improving control accuracy, ensuring system safety, and optimizing fuel usage.

[0101] The present invention also proposes a system for automatic high and low bypass control of a generator set, comprising a memory and a processor, wherein the memory is used to store instructions executable by the processor; the processor is used to execute the instructions to implement the method for automatic high and low bypass control of a generator set as described above.

[0102] At any stage before the start-up bypass sends a start-up completion signal, the generator set high and low bypass automatic control system can be put into use and automatically enter the corresponding control mode.

[0103] Figure 3 This is a system block diagram of the automatic high and low bypass control of a generator set according to an embodiment of the present invention. Figure 3As shown, the system 300 for automatic control of high and low bypass of the generator set may include an internal communication bus 301, a processor 302, a read-only memory (ROM) 303, a random access memory (RAM) 304, and a communication port 305. When applied on a personal computer, the system 300 for automatic control of high and low bypass of the generator set may also include a hard disk 307. The internal communication bus 301 can realize data communication between components of the system 300 for automatic control of high and low bypass of the generator set. The processor 302 can make judgments and issue prompts. In some embodiments, the processor 302 can be composed of one or more processors. The communication port 305 can realize data communication between the system 300 for automatic control of high and low bypass of the generator set and the outside. In some embodiments, the system 300 for automatic control of high and low bypass of the generator set can send and receive information and data from the network through the communication port 305. The system 300 for automatic control of high and low bypass of the generator set may also include different forms of program storage units and data storage units, such as a hard disk 307, a read-only memory (ROM) 303 and a random access memory (RAM) 304, which can store various data files used for computer processing and / or communication, and possible program instructions executed by the processor 302. The processor executes these instructions to implement the main part of the method. The results of the processor processing are transmitted to the user device through the communication port and displayed on the user interface.

[0104] The above-mentioned method for automatic control of high and low bypass of a generator set can be implemented as a computer program, stored in the hard disk 307, and loaded into the processor 302 for execution to implement the data processing method of the present application.

[0105] The present invention also includes a computer readable medium storing computer program code, which, when executed by a processor, implements the method for automatic high and low bypass control of a generator set as described above.

[0106] When the method for automatic control of high and low bypass of a generator set is implemented as a computer program, it can also be stored in a computer-readable storage medium as a product. For example, a computer-readable storage medium may include, but is not limited to, a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic strip), an optical disk (e.g., a compact disk (CD), a digital versatile disk (DVD)), a smart card, and a flash memory device (e.g., an electrically erasable programmable read-only memory (EPROM), a card, a stick, a key drive). In addition, the various storage media described herein can represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media (and / or storage media) that can store, contain and / or carry code and / or instructions and / or data.

[0107] The invention provides a method and system for automatic control of high and low bypass of a generator set, which achieves the following beneficial effects:

[0108] 1) It realizes full automatic control of high and low bypass, reducing the operating intensity of operators;

[0109] 2) Effectively control the main steam pressure and temperature fluctuations during the startup phase, avoid system resonance and parameter fluctuations, and extend the service life of the equipment;

[0110] 3) The control strategy was optimized, which accelerated the process from unit startup to grid connection and improved operation efficiency;

[0111] 4) In the event of unplanned shutdown or abnormal operating conditions of the unit, the bypass system can respond in time to avoid accidents such as safety valve actuation.

[0112] It should be understood that the embodiments described above are only illustrative. The embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For hardware implementation, the processor may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and / or other electronic units designed to perform the functions described herein, or a combination thereof.

[0113] Some aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor may be one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, various aspects of the present application may be expressed as computer products located in one or more computer-readable media, which include computer-readable program codes. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes ...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs ...), smart cards, and flash memory devices (e.g., cards, sticks, key drives ...).

[0114] A computer-readable medium may include a propagated data signal containing computer program code, such as in baseband or as part of a carrier wave. The propagated signal may have a variety of manifestations, including electromagnetic, optical, etc., or a suitable combination. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium, which may be connected to an instruction execution system, device or apparatus to communicate, propagate or transmit a program for use. The program code on the computer-readable medium may be propagated via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above mediums.

[0115] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0116] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0117] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

Claims

1. A method for automatic control of high and low bypass of a generator set, characterized in that: The method comprises: Obtaining control parameters of high and low bypass of the generator set, wherein the control parameters at least include the actual main steam pressure of the generator set and whether the turbine is running with load; Determining a control mode of high and low bypass of the generator set according to the control parameter; According to the control mode, the corresponding control strategy is executed to adjust the opening degree of the high bypass valve and / or the opening degree of the low bypass valve, so as to realize the full automatic control of the high and low bypass of the generator set.

2. The method for automatic control of high and low bypass of a generator set according to claim 1, characterized in that: The control modes include minimum pressure mode, boost mode, constant pressure mode and pressure tracking mode in sequence: According to the actual main steam pressure value of the generator set, determine whether the control mode is in the minimum pressure mode, boosting mode or constant pressure mode; Depending on whether the turbine is running with load, it is determined whether the control mode is switched from the constant pressure mode to the pressure tracking mode.

3. The method for automatic control of high and low bypass of a generator set according to claim 2, characterized in that: When the actual main steam pressure value of the generator set is less than the minimum pressure setting value, the control mode is in the minimum pressure mode; The corresponding control strategies include: igniting the boiler to maintain the steam flow, opening the high bypass valve to the first opening; When the actual main steam pressure of the generator set is greater than the minimum pressure setting value, the opening degree of the high bypass valve is adjusted to the second opening degree at the set opening rate.

4. The method for automatic control of high and low bypass of a generator set according to claim 2, characterized in that: When the opening degree of the high bypass valve reaches the second opening degree and the actual main steam pressure of the generator set is greater than the minimum pressure setting value, the control mode enters the boost mode from the minimum pressure mode.

5. The method for automatic control of high and low bypass of a generator set according to claim 2, characterized in that: When the actual main steam pressure of the generator set is greater than the pressure setting value before the turbine is connected to the grid, the control mode changes from the boost mode to the constant pressure mode; When the control mode is in the constant pressure mode, the minimum opening of the high bypass valve is set below the second opening value.

6. The method for automatic control of high and low bypass of a generator set according to claim 2, characterized in that: When the steam turbine is running and the unit load is greater than the preset threshold, the control mode changes from the constant pressure mode to the pressure tracking mode: When the control mode is in pressure tracking mode, the high bypass valve is closed, all steam enters the turbine, and the high and low bypass control modes are switched to manual.

7. The method for automatic control of high and low bypass of a generator set according to claim 5, characterized in that: When the control mode is in constant pressure mode: Adjust the pressure setting value before the steam turbine is connected to the grid so that the steam turbine can be started up when the actual main steam pressure of the generator set reaches the pressure setting value before the steam turbine is connected to the grid.

8. The method for automatic control of high and low bypass of a generator set according to claim 7, characterized in that: When the control mode is in constant pressure mode: After the steam turbine is connected to the grid, when the unit load is less than a preset threshold, the opening degree of the high bypass valve is reduced from the second opening to a third opening, wherein the third opening is greater than the first opening and less than the second opening, and when the unit load is greater than the preset threshold, the high bypass valve is closed; After the turbine is connected to the grid, when the unit load is less than the preset threshold, the opening degree of the low bypass valve is within the set range to adjust the steam pressure in the reheater. When the unit load is greater than the preset threshold, the low bypass valve is closed after the high bypass valve is closed.

9. The method for automatic control of high and low bypass of a generator set according to claim 1, characterized in that: The bypass valve opening and fuel supply are calculated based on the actual main steam pressure of the generator set, the main steam control pressure setting value and the boiler fuel quantity; The bypass valve opening degree includes the high bypass valve opening degree and / or the low bypass valve opening degree.

10. A system for automatic control of high and low bypass of a generator set, comprising: a memory for storing instructions executable by a processor; A processor, configured to execute the instructions to implement the method according to any one of claims 1 to 9.

11. A computer readable medium storing computer program code, wherein the computer program code, when executed by a processor, implements the method according to any one of claims 1 to 9.

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