Heavy duty gas turbine control system

Abstract

The invention provides a heavy duty gas turbine control system which comprises a signal conditioning module and a plurality of parameter control modules, and a rotating speed control module, a load control module, a temperature limit control module and an acceleration control module in the parameter control modules are all used for achieving closed-loop control according to the deviation between a set value and a corresponding observation value; the starting control module is used for acquiring a starting fuel quantity instruction through a designed control strategy; the IGV and VGVs control module obtains an IGV and VGVs angle instruction according to the turbine inlet temperature set value, the turbine outlet temperature set value and the deviation maximum value of the corresponding observation value; the fuel quantity control module obtains a total fuel quantity instruction based on a full working condition range fuel quantity control strategy; the fuel gas distribution control module is used for obtaining an opening degree instruction of each fuel valve according to the total fuel quantity instruction; the adaptability, the reliability and the usability of the control system in application scenes such as autonomous design and technical improvement are improved.

Description

Technical Field

[0001] The present application relates to the technical field of heavy-duty gas turbine control, and in particular to a heavy-duty gas turbine control system. Background Art

[0002] Heavy-duty gas turbines are complex dynamic systems with strong coupling and nonlinearity, and their operating conditions are diverse and rapidly changing. Their control strategy design requires precise coordination and matching of the static and dynamic characteristics of various systems, components, and equipment. New heavy-duty gas turbines present numerous uncertainties in overall component design, manufacturing, process configuration, and equipment selection. The control strategy design phase must address numerous challenges, including consistency, completeness, and adaptability.

[0003] However, the existing gas turbine control system cannot overcome the many uncertainties in the design of new heavy-duty gas turbine components, processing and manufacturing, process configuration, equipment selection, etc. Summary of the Invention

[0004] This application provides a heavy-duty gas turbine control system to at least partially address one of the technical problems in the related art. The technical solution disclosed in this application is as follows: The present embodiment provides a heavy-duty gas turbine control system, comprising: a signal conditioning module and multiple parameter control modules, wherein the signal conditioning module is configured to perform signal conditioning on acquired system monitoring parameters and send the conditioned system monitoring parameters to the multiple parameter control modules; the multiple parameter control modules include: a starting control module configured to obtain an ignition fuel quantity, a warm-up fuel quantity, and an acceleration fuel quantity based on the conditioned system monitoring parameters, and to obtain a starting fuel quantity instruction based on the ignition fuel quantity, the warm-up fuel quantity, and the acceleration fuel quantity; A speed control module is used to obtain a fuel quantity instruction for a speed control loop based on a deviation between a set speed value and an observed speed value of the rotor when the rotor speed increases to a first speed, in combination with a PI control algorithm; The load control module is used to obtain the fuel quantity instruction of the load control loop according to the deviation between the load set value and the corresponding observed value in combination with the PI control algorithm during the grid connection stage; The IGV and VGVs control module is used to obtain the IGV angle command based on the maximum deviation between the set value and the observed value of the turbine inlet temperature T3 and the turbine outlet temperature T4 during the load increase phase, combined with the PI control algorithm. The VGV angle command is then obtained based on the characteristic relationship between the IGV and VGVs. The temperature limit control module is used to obtain the fuel quantity instruction of the temperature limit control loop based on the deviation between the set value and the corresponding observed value of the turbine inlet temperature T3 of the gas engine when the temperature limit value is reached, combined with the PI control algorithm; a fuel quantity control module, configured to obtain a total fuel quantity instruction based on the starting fuel quantity instruction, the fuel quantity instruction of the load control loop, the fuel quantity instruction of the speed control loop, and the fuel quantity instruction of the temperature limit control loop; The gas distribution control module is used to obtain the opening instruction of each fuel valve according to the total fuel quantity instruction and the fuel distribution ratio of each fuel valve.

[0005] In some implementations, the startup control module is specifically configured to: Obtaining a first correction coefficient according to the atmospheric temperature and the ISO operating condition atmospheric temperature, and obtaining the ignition fuel amount based on the first correction coefficient and the ignition fuel amount corresponding to the ISO; Obtaining a second correction coefficient based on the atmospheric temperature, the ISO operating atmospheric temperature, the atmospheric pressure, and the ISO operating atmospheric pressure, and obtaining the warm-up fuel amount based on the second correction coefficient and the ISO corresponding warm-up fuel amount; Obtaining a third correction coefficient based on the atmospheric temperature, the ISO operating atmospheric temperature, the atmospheric pressure, the ISO operating atmospheric pressure, the fuel lower heating value, and the ISO operating fuel lower heating value, and obtaining the speed-increasing fuel amount based on the third correction coefficient and the ISO corresponding speed-increasing fuel amount; Based on the ignition setting signal, the selector selects the ignition fuel amount and the first fuel amount to obtain a second fuel amount; Based on a warm-up setting signal, a selector selects the warm-up fuel amount and the second fuel amount to obtain a third fuel amount; Based on the speed-up setting signal, the speed-up fuel amount, the third fuel amount, the maximum fuel amount and the minimum fuel amount are selected by a selector to obtain the starting fuel amount instruction.

[0006] In some implementations, the fuel quantity control module is specifically configured to: Combining the fuel quantity instruction of the load control loop and the fuel quantity instruction of the speed control loop to obtain a combined load-speed-fuel quantity instruction; Based on the grid connection setting signal, the fuel quantity instruction of the speed control loop and the combined load speed fuel quantity instruction are selected by a selector to obtain the load speed control loop fuel quantity instruction; Based on the temperature limit control setting signal, the fuel quantity instruction of the temperature limit control loop and the total fuel quantity instruction are selected by a selector to obtain the fuel quantity instruction of the temperature limit control loop; Based on the speed control signal, the starting fuel quantity instruction and the total fuel quantity instruction are selected by a selector to obtain a starting process fuel quantity instruction; The starting process fuel quantity instruction, the load speed control loop fuel quantity instruction and the temperature limit control loop fuel quantity instruction are selected by a minimum value selector to obtain the total fuel quantity instruction.

[0007] In some implementations, the gas distribution control module is specifically configured to: Obtaining a fuel quantity instruction for each fuel valve according to the total fuel quantity instruction and the fuel distribution ratio of each fuel valve; Obtaining a flow coefficient for each fuel valve according to the flow command of each fuel valve and a fuel correction coefficient for each fuel valve; wherein the fuel correction coefficient is determined based on natural gas density, gas pressure before the fuel valve, natural gas specific gravity, compressibility, Weber index design value, and Weber index calculated value; The opening instructions of the fuel valves are obtained according to the flow coefficients of the fuel valves and the valve characteristic curve interpolation functions of the fuel valves.

[0008] In some implementations, the IGV and VGVs control module is specifically configured to: Obtain a first deviation between a T3 set value and a corresponding observed value and a second deviation between a T4 set value and a corresponding observed value of the IGV system; obtaining a larger value of the first deviation and the second deviation; Obtaining an IGV angle command of the IGV system based on the larger value and a temperature closed-loop control proportional coefficient and a temperature closed-loop control integral coefficient corresponding to the larger value; Based on the IGV angle command and the characteristic relationship between the IGV and the VGVs, a VGV angle command is obtained.

[0009] In some implementations, the system further includes a secondary air control module, wherein the secondary air control module is specifically configured to: According to the open-loop setting signal, multiple open-loop opening control laws are selected through the selector to obtain the open-loop control opening instruction; According to the closed-loop setting signal, the open-loop control opening instruction and the closed-loop control opening instruction are selected by a selector to obtain a first control opening instruction; According to the fully closed setting signal, the first control opening instruction and the minimum opening instruction are selected by a selector to obtain a second control opening instruction; According to the full-open setting signal, the second control opening instruction and the maximum opening instruction are selected by a selector to obtain the turbine cooling valve opening instruction.

[0010] In some implementations, the system further includes a frequency response control module, wherein the frequency response control module is specifically configured to: Obtaining a grid frequency deviation according to a difference between the actual grid frequency and the grid reference frequency; Obtaining a inequality rate according to the grid frequency deviation, the grid actual frequency, and the power target value; Obtaining a compensation coefficient based on the inequality rate, the grid reference frequency, and the power target value; The product of the grid frequency deviation and the compensation coefficient is calculated to obtain a primary frequency modulation power compensation value; and the load instruction after the primary frequency modulation correction is obtained according to the primary frequency modulation power compensation value and the load instruction before the primary frequency modulation correction.

[0011] In some implementations, the system further includes an acceleration control module, wherein the acceleration control module is configured to: After entering the transition state, the fuel quantity instruction of the rotor acceleration control loop is obtained according to the deviation between the rotor acceleration set value and the acceleration observation value, combined with the PI control algorithm.

[0012] In some implementations, the system adopts a distributed control architecture, and the signal conditioning module and the multiple parameter control modules are dispersedly configured at multiple sites.

[0013] In some implementations, the system includes an information layer, a monitoring layer, a control layer, and an instrument layer; the signal conditioning module and the multiple parameter control modules belong to the control layer; the information layer adopts a redundant high-speed, high-capacity network; the monitoring layer includes a global distributed database; the control layer and the instrument layer are connected via IO cards, and the IO cards are used for data acquisition and command output; the instrument layer includes at least DI acquisition, DO analog output, AI acquisition, AO analog output, RTD analog output, TC analog output, SPD analog output, and LVDT analog output.

[0014] The heavy-duty gas turbine control system provided in this application, by dividing the functions of the heavy-duty gas turbine control system into a signal conditioning module and multiple parameter control modules, and designing flexible control strategies for each module, can overcome to the greatest extent the many uncertainties in the design of whole machine components, processing and manufacturing, process configuration, equipment selection, etc. of new-model heavy-duty gas turbines in the prior art, thereby obtaining a highly versatile heavy-duty gas turbine control system that can solve problems such as consistency, integrity and adaptability between the gas turbine unit and the control system, and provide a reference for the development of new-model gas turbine control systems and the technical transformation of mature gas turbine control systems; thereby improving the adaptability, reliability and availability of the heavy-duty gas turbine control system in application scenarios such as independent design and technical improvement.

[0015] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 A block diagram of a heavy-duty gas turbine control system provided in an embodiment of the present application; Figure 2 A functional block diagram of the start control module provided in an embodiment of the present application; Figure 3 This is a functional block diagram of a fuel quantity control module provided in an embodiment of the present application; Figure 4 This is a functional block diagram of the gas distribution control module provided in an embodiment of the present application; Figure 5 This is a functional block diagram of the secondary air control module provided in an embodiment of the present application; Figure 6 This is an example of an inter-module data interface provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0018] The following describes a heavy-duty gas turbine control system according to an embodiment of the present application with reference to the accompanying drawings.

[0019] Figure 1 This is a block diagram of a heavy-duty gas turbine control system provided by an embodiment of the present application. Figure 1 The heavy-duty gas turbine control system may include a signal conditioning module and multiple parameter control modules. The signal conditioning module is used to perform signal conditioning on the acquired system monitoring parameters and send the conditioned system monitoring parameters to the multiple parameter control modules. The multiple parameter control modules may include a starting control module, a speed control module, a load control module, a temperature limit control module, a fuel quantity control module, and a gas distribution control module. a starting control module configured to obtain an ignition fuel quantity, a warm-up fuel quantity, and an acceleration fuel quantity based on the conditioned system monitoring parameters, and to obtain a starting fuel quantity instruction based on the ignition fuel quantity, the warm-up fuel quantity, and the acceleration fuel quantity; A speed control module is used to obtain a fuel quantity instruction for a speed control loop based on a deviation between a set speed value and an observed speed value of the rotor when the rotor speed increases to a first speed, in combination with a PI control algorithm; The load control module is used to obtain the fuel quantity instruction of the load control loop according to the deviation between the load set value and the corresponding observed value in combination with the PI control algorithm during the grid connection stage; The IGV and VGVs control module is used to obtain the IGV angle command based on the maximum deviation between the set value and the observed value of the turbine inlet temperature T3 and the turbine outlet temperature T4 during the load increase phase, combined with the PI control algorithm. The VGV angle command is then obtained based on the characteristic relationship between the IGV and VGVs. The temperature limit control module is used to obtain the fuel quantity instruction of the temperature limit control loop based on the deviation between the set value and the corresponding observed value of the turbine inlet temperature T3 of the gas engine when the temperature limit value is reached, combined with the PI control algorithm; a fuel quantity control module, configured to obtain a total fuel quantity instruction based on the starting fuel quantity instruction, the fuel quantity instruction of the load control loop, the fuel quantity instruction of the speed control loop, and the fuel quantity instruction of the temperature limit control loop; The gas distribution control module is used to obtain the opening instruction of each fuel valve according to the total fuel quantity instruction and the fuel distribution ratio of each fuel valve.

[0020] To ensure the flexibility of the signal conditioning module, in some embodiments, two-level modular processing is performed within the signal conditioning module, which is divided into speed signal conditioning, temperature signal conditioning, generator power signal conditioning, atmospheric pressure signal conditioning, etc. according to the type of monitoring parameters; the purpose of setting up the signal conditioning module is to perform quality judgment and preprocessing on the monitoring signals received by the I / O module, for example, processing redundant signals by calculating the average value or selecting the middle value, so as to improve the accuracy and reliability of the signal.

[0021] Based on the above structure, by dividing the functions of the heavy-duty gas turbine control system into a signal conditioning module and multiple parameter control modules, as well as the flexible control strategy design of each module, it is possible to overcome to the greatest extent the many uncertainties in the design of whole machine components, processing and manufacturing, process configuration, equipment selection, etc. of new-model heavy-duty gas turbines in the existing technology, and obtain a highly versatile heavy-duty gas turbine control system that can solve problems such as consistency, integrity and adaptability between the gas turbine unit and the control system, providing a reference for the development of new-model gas turbine control systems and the technical transformation of mature gas turbine control systems.

[0022] Driven by the SFC (Static Frequency Converter), the engine reaches the purge speed, ignites after the purge is complete, and then warms up and accelerates to the trip speed under the combined power of the SFC and fuel. The fuel is then used to increase the engine speed to full no-load speed. A design scheme for setting and switching the ignition fuel amount, warm-up fuel amount, acceleration fuel amount, maximum fuel amount, and minimum fuel amount is required. In some embodiments, the starting control module is specifically used to: A first correction coefficient is obtained according to the atmospheric temperature and the ISO operating atmospheric temperature, and the ignition fuel amount is obtained based on the first correction coefficient and the ignition fuel amount corresponding to the ISO; a second correction coefficient is obtained according to the atmospheric temperature, the ISO operating atmospheric temperature, the atmospheric pressure, and the ISO operating atmospheric pressure, and the warm-up fuel amount is obtained based on the second correction coefficient and the warm-up fuel amount corresponding to the ISO; a third correction coefficient is obtained according to the atmospheric temperature, the ISO operating atmospheric temperature, the atmospheric pressure, the ISO operating atmospheric pressure, the lower heating value of the fuel, and the lower heating value of the ISO operating fuel, and the speed-up fuel amount is obtained based on the third correction coefficient and the speed-up fuel amount corresponding to the ISO; based on the ignition setting signal, the ignition fuel amount and the first fuel amount are selected by a selector to obtain a second fuel amount; based on the warm-up setting signal, the warm-up fuel amount and the second fuel amount are selected by a selector to obtain a third fuel amount; based on the speed-up setting signal, the speed-up fuel amount, the third fuel amount, the maximum fuel amount, and the minimum fuel amount are selected by a selector to obtain the starting fuel amount instruction.

[0023] As an example, the schematic diagram of the starting control module is as follows Figure 2 As shown, it can be obtained by the following formula Figure 2 Correction coefficients 1, 2, and 3 and the corresponding ignition fuel amounts, warm-up fuel amounts, and speed-up fuel amounts:

[0024] in, Indicates the amount of ignition fuel, Indicates the amount of ignition fuel corresponding to ISO, Indicates the warm-up fuel quantity. Indicates the warm-up fuel quantity corresponding to ISO; Indicates the amount of fuel for increasing speed. Indicates the fuel quantity corresponding to the ISO speed increase. represents the atmospheric temperature, Indicates ISO working condition atmospheric temperature (thermodynamic temperature unit: K), Indicates atmospheric pressure, Indicates ISO working atmospheric pressure, Indicates the lower calorific value of the fuel. Indicates the lower heating value of fuel under ISO conditions.

[0025] It can be understood that since there is a certain deviation between the ISO operating condition design values ​​corresponding to the ignition fuel amount, warm-up fuel amount and speed-up fuel amount and the actual operating conditions, this embodiment corrects the design values ​​corresponding to the ISO operating conditions through the correction coefficient to obtain the ignition fuel amount, warm-up fuel amount and speed-up fuel amount corresponding to the current operating conditions.

[0026] By implementing this embodiment, flexible switching of the starting fuel amount is achieved through ignition setting, warm-up setting and speed-up setting; the ISO operating condition design values ​​corresponding to the ignition fuel amount, warm-up fuel amount and speed-up fuel amount are corrected respectively through three correction coefficients to ensure the accuracy and flexibility of the correction.

[0027] The gas turbine needs to be stabilized at full speed and no-load speed before being connected to the grid. Therefore, it is necessary to enter speed closed-loop control in advance in a certain speed range before reaching full speed and no-load speed. In this embodiment, the gas turbine enters speed closed-loop control when the speed reaches a certain speed (90-95% of the rated speed). The speed closed-loop control is implemented by the speed control module. In some embodiments, the speed closed-loop fuel quantity calculation formula implemented by the speed control module is as follows:

[0028] in, Indicates the amount of fuel output by the speed closed loop at a certain moment, Indicates the speed closed-loop control proportional coefficient, The deviation between the speed setting value and the observed value at a certain moment, Represents the integral coefficient of the speed closed-loop control. and First, the parameters are optimized through the simulator, and then during the whole machine test phase, a decision is made on whether to further optimize based on actual conditions.

[0029] It should be noted that the above formula does not consider dimension and is a pure mathematical calculation.

[0030] By implementing this embodiment, the PI control of the speed based on the deviation between the speed setting value and the observed value at each moment is realized by the speed control module, thereby achieving flexible adjustment of the speed closed-loop fuel amount and ensuring the accuracy of the speed control.

[0031] In some embodiments, the system further includes an acceleration control module, wherein the acceleration control module is configured to: After entering the transition state, the fuel quantity instruction of the rotor acceleration control loop is obtained according to the deviation between the rotor acceleration set value and the acceleration observation value, combined with the PI control algorithm.

[0032] It can be understood that after the warm-up period, the engine enters a transition state, where the fuel quantity is adjusted to accelerate the engine. During the control process, the speed change rate must reach a certain desired value to prevent transient rotor fatigue or excessive vibration. Therefore, this embodiment designs an acceleration control module to implement acceleration closed-loop control to control the speed change rate. As an example, the fuel quantity calculation formula for acceleration closed-loop control is as follows:

[0033] in, Indicates the amount of fuel output by the acceleration closed loop at a certain moment, Indicates the acceleration closed-loop control proportional coefficient, The deviation between the acceleration setting value and the observed value at a certain moment, Represents the acceleration closed-loop control integral coefficient. and First, the parameters are optimized through the simulator, and then during the whole machine test phase, a decision is made on whether to further optimize based on actual conditions.

[0034] It should be noted that the above formula does not consider dimension and is a pure mathematical calculation.

[0035] By implementing this embodiment, the acceleration control module implements PI control of acceleration based on the deviation between the acceleration setting value and the observed value at each moment, thereby achieving flexible adjustment of the acceleration closed-loop fuel quantity and ensuring the stability of the speed control.

[0036] The engine keeps its speed unchanged after being connected to the grid. In the embodiment of the present application, the engine load is increased or decreased through closed-loop control. As an example, in the embodiment of the present application, the load control module is used to obtain the fuel amount for the load closed-loop control through the following formula:

[0037] in, Indicates the amount of fuel output by the load closed loop at a certain moment, Indicates the load closed-loop control proportional coefficient, The deviation between the load setting value and the observed value at a certain moment, Indicates the load closed-loop control integral coefficient. and First, the parameters are optimized through the simulator, and then during the whole machine test phase, a decision is made on whether to further optimize based on actual conditions.

[0038] By implementing this embodiment, the PI control of the load based on the deviation between the load setting value and the observed value at each moment is realized by the speed control module, thereby achieving flexible adjustment of the load closed-loop fuel quantity and ensuring the accuracy of load control.

[0039] The gas turbine includes an IGV (Inlet Guide Vanes) system. During load ramp-up, as the temperatures of T3 and T4 increase, T4 reaches its control value first, entering IGV-T4 closed-loop temperature control. Subsequently, T3 reaches its control value, switching to IGV-T3 closed-loop temperature control. During closed-loop temperature control, the IGVs are opened or closed to control the T3 or T4 temperature. VGVs (Variable Geometry Vanes) follow the IGVs in a specific pattern. Therefore, the system of this application also includes an IGV and VGV control module, which is used to: Obtain a first deviation between a set value and a corresponding observed value of the turbine inlet temperature T3 of the IGV system, and a second deviation between a set value and a corresponding observed value of the turbine outlet temperature T4; obtain a larger value between the first deviation and the second deviation; obtain an IGV angle instruction of the IGV system based on the larger value and a temperature closed-loop control proportional coefficient and a temperature closed-loop control integral coefficient corresponding to the larger value; obtain a VGV angle instruction based on the IGV angle instruction and a characteristic relationship between the IGV and VGVs.

[0040] As an example, the IGV and VGVs control module obtains the IGV angle command through the following formula:

[0041]

[0042] in, Indicates a moment or IGV angle command output by temperature closed loop, express or The temperature closed-loop control proportional coefficient is a function of the IGV angle setting value. Indicates a moment The deviation between the set value and the observed value, Indicates a moment The deviation between the set value and the observed value, Indicates a moment and Take the larger value, express or Temperature closed-loop control integral coefficient. Parameter optimization is first performed using a simulator, and further optimization is then determined based on actual conditions during the full-machine test phase. This embodiment utilizes PI control of the IGV opening, based on the deviation between the set value and the observed value of T3 or T4, whichever is greater, implemented by the IGV and VGV control modules. This allows for flexible adjustment of the IGV and VGV angles, ensuring accurate system temperature control.

[0043] When the IGV is opened to the maximum opening, the temperature closed-loop control is exited and the fuel continues to increase until a certain temperature limit value is reached, and then the T3-fuel quantity closed-loop control is entered. As an example, the temperature limit control module obtains the fuel quantity of the temperature limit closed-loop control through the following formula:

[0044] in, Indicates the amount of fuel output by the temperature-limited closed loop at a certain moment, Indicates the temperature limit closed-loop control proportional coefficient, The turbine inlet temperature of the combustion engine at a certain moment The deviation between the set value and the observed value, Indicates the closed-loop integral coefficient of temperature limit control, and First, the parameters are optimized through the simulator, and then during the whole machine test phase, a decision is made on whether to further optimize based on actual conditions.

[0045] By implementing this embodiment, the temperature limit control module is based on the The PI control of the temperature based on the deviation between the set value and the observed value realizes the flexible adjustment of the fuel amount in the temperature closed-loop control and ensures the accuracy of temperature control.

[0046] In different stages of the combustion engine, such as starting, speed increase, grid connection, load increase, IGV temperature control, and temperature limit control, there are control law switching and selection. This application achieves the above switching and selection goals through the fuel quantity control module. In some embodiments, such as Figure 3As shown, the fuel quantity control module is specifically used to: merge the fuel quantity instruction of the load control loop and the fuel quantity instruction of the speed control loop to obtain a combined load-speed fuel quantity instruction; based on the grid-connected setting signal, select the fuel quantity instruction of the speed control loop and the combined load-speed fuel quantity instruction through a selector to obtain a load-speed control loop fuel quantity instruction; based on the temperature limit control setting signal, select the fuel quantity instruction of the temperature limit control loop and the total fuel quantity instruction through a selector to obtain a temperature limit control loop fuel quantity instruction; based on the speed control signal, select the starting fuel quantity instruction and the total fuel quantity instruction through a selector to obtain a starting process fuel quantity instruction; and select the starting process fuel quantity instruction, the load-speed control loop fuel quantity instruction, and the temperature limit control loop fuel quantity instruction through a minimum value selector to obtain the total fuel quantity instruction.

[0047] like Figure 3 As shown, the starting control module, speed control module, load control module, and temperature limit control module each output a corresponding fuel quantity command, and the final total fuel quantity command is output via the minimum selector MIN. The fuel quantity command for the load and speed control loop is switched based on the grid connection set signal. Before grid connection, the fuel quantity command output by the speed closed-loop control is selected, while after grid connection, the fuel quantity command output by the load closed-loop control is selected.

[0048] By implementing this embodiment, the fuel quantity control module flexibly switches the fuel quantities output by the starting control module, the speed control module, the load control module, and the temperature limit control module through the grid connection setting signal, the temperature limit control setting signal, and the speed control signal, thereby achieving flexibility and accuracy in fuel quantity control; that is, the fuel quantity control module can obtain a total fuel quantity instruction based on the fuel quantity control strategy for the entire operating range.

[0049] In some embodiments, the gas distribution control module is specifically used to: obtain the fuel quantity instruction of each fuel valve based on the total fuel quantity instruction and the fuel distribution ratio of each fuel valve; obtain the flow coefficient of each fuel valve based on the flow instruction of each fuel valve and the fuel correction coefficient of each fuel valve; wherein the fuel correction coefficient is determined based on the natural gas density, the gas pressure before the fuel valve, the natural gas specific gravity, the compression coefficient, the Weber index design value and the Weber index calculated value; obtain the opening instruction of each fuel valve based on the flow coefficient of each fuel valve and the valve characteristic curve interpolation function of each fuel valve.

[0050] As an example, Figure 4As shown, assuming the combustion chamber has five fuel valves (A, B, C, D, and E), the gas distribution control module calculates the flow distribution ratio of each fuel valve based on the speed / load ratio according to the combustion staging strategy. Combined with the total fuel quantity command, the flow command for each fuel valve is obtained. The fuel correction coefficient is used to calculate the Cg value of each fuel valve, and the opening command for each fuel valve is obtained based on the calculated Cg value and the characteristic curve of each fuel valve. Gas distribution control ensures that each fuel valve meets the combustion operation control requirements under different combustion modes. Taking A as an example, the specific calculation formula is given:

[0051]

[0052]

[0053]

[0054] in, Indicates the fuel quantity instruction of valve A. Indicates the total fuel quantity command, Indicates the fuel distribution ratio of valve A, Indicates the Cg value of valve A, Indicates the opening instruction of valve A. Represents the characteristic curve interpolation function of fuel valve A. Indicates the fuel correction coefficient of line A, Indicates the density of natural gas (kg / m3), Indicates the gas pressure before the fuel valve (psi), G indicates the specific gravity of natural gas, Z indicates the compression coefficient, represents the design value of the Weibull index, Represents the calculated value of the Weibull index.

[0055] By implementing this embodiment, the gas distribution control module obtains the fuel quantity instruction of each fuel valve based on the total fuel quantity instruction and the fuel distribution ratio of each fuel valve; obtains the flow coefficient of each fuel valve based on the flow instruction of each fuel valve and the fuel correction coefficient of each fuel valve; obtains the opening instruction of each fuel valve based on the flow coefficient of each fuel valve and the valve characteristic curve interpolation function of each fuel valve; corrects the distribution of each fuel valve by the fuel correction coefficient, thereby improving the accuracy and flexibility of gas distribution; obtains the opening instruction of each fuel valve based on the flow coefficient of each fuel valve and the valve characteristic curve interpolation function of each fuel valve, thereby further improving the accuracy of the opening control of the fuel valve.

[0056] In some embodiments, the heavy-duty gas turbine control system of the present application also includes a secondary air control module, which is used to control the action of the turbine cooling valve. In order to achieve switching between different control modes under different operating conditions and achieve corresponding control openings at the same time, the secondary air control module of this embodiment is specifically used to: select multiple open-loop opening control laws through a selector according to an open-loop setting signal to obtain an open-loop control opening instruction; select the open-loop control opening instruction and the closed-loop control opening instruction through a selector according to a closed-loop setting signal to obtain a first control opening instruction; select the first control opening instruction and the minimum opening instruction through a selector according to a fully closed setting signal to obtain a second control opening instruction; select the second control opening instruction and the maximum opening instruction through a selector according to a fully open setting signal to obtain the turbine cooling valve opening instruction.

[0057] As an example, Figure 5 As shown in the figure, before ignition, the fully open setting signal opens the turbine cooling valve to the maximum opening. After successful ignition, when the speed increases to a certain speed, the open-loop setting selects a fixed opening, and the turbine cooling valve moves to the target opening. When the grid is connected and the load is increased to a certain load, the closed-loop setting is performed, and closed-loop control is performed according to the target value of the 2nd, 3rd, and 4th stage turbine supply pressure ratio. Pure proportional control is adopted, and the calculation formula is as follows:

[0058]

[0059]

[0060] in, , , Indicates the opening of the 2nd, 3rd and 4th stage turbine cooling valves at a certain moment; , , Respectively represent the closed-loop control proportional coefficients of the 2nd, 3rd and 4th level air supply pressure ratios. , , Respectively represent the deviation percentage of the 2nd, 3rd and 4th level air supply pressure ratio.

[0061] In order to avoid frequent operation of the turbine cooling valve when the turbine air supply pressure ratio is near the target value, a control hysteresis of ±1% is set for the air supply pressure ratio deviation percentage. When the air supply pressure ratio deviation percentage exceeds the hysteresis range, closed-loop control is put into use. In addition, a dead zone of ±0.5% is set for the air supply pressure ratio deviation percentage. When the air supply pressure ratio deviation percentage returns to the dead zone range, closed-loop control adjustment is stopped.

[0062] By implementing this embodiment, the secondary air control module switches to different control modes for different operating conditions based on the open-loop setting signal, the closed-loop setting signal, the fully closed setting signal, and the fully open setting signal, while achieving the corresponding control opening, thereby achieving flexibility and accuracy in turbine cooling valve control.

[0063] In some embodiments, the heavy-duty gas turbine control system of the present application further includes a frequency response control module, which is used to adjust the gas turbine power through proportional control according to the change of the grid frequency under partial load or basic load conditions. Partial load can perform frequency response by increasing or decreasing power, and basic load can only perform frequency response by reducing power. As an implementation method, the frequency response control module is specifically used to: obtain the grid frequency deviation according to the difference between the actual grid frequency and the grid reference frequency; obtain the inequality according to the grid frequency deviation, the actual grid frequency and the power target value; obtain the compensation coefficient based on the inequality, the grid reference frequency and the power target value; calculate the product of the grid frequency deviation and the compensation coefficient to obtain the primary frequency modulation power compensation value; obtain the load instruction after the primary frequency modulation correction according to the primary frequency modulation power compensation value and the load instruction before the primary frequency modulation correction. As an example, the frequency response power compensation amount (i.e., the primary frequency modulation power compensation value) is obtained by the following formula:

[0064]

[0065]

[0066]

[0067] in, Indicates the frequency response power compensation amount, represents the compensation coefficient, represents the inequality rate, Indicates the power target value, Indicates the reference grid frequency, Indicates the deviation between the actual frequency and the reference grid frequency.

[0068] When the primary frequency regulation function is enabled and exceeds the static dead zone, the unit load command output is the load command after primary frequency regulation correction. The correction formula is as follows:

[0069] in, is the load instruction before frequency modulation correction, is the primary frequency modulation power compensation value, It is the load instruction after the frequency modulation correction.

[0070] By implementing this embodiment, a frequency response power compensation amount is obtained according to the deviation between the actual frequency and the reference grid frequency and the power target value, and the frequency regulation load instruction is adjusted according to the frequency response power compensation amount, thereby improving the accuracy of frequency regulation.

[0071] In the embodiment of the present application, data transmission is realized between related modules through a data interface. The connection relationship between modules is described by taking the fuel quantity control module as an example. Figure 6 As shown, the fuel quantity control module receives input from the starting control module and outputs signals to the gas distribution control module. MI1-3 and MO1-3 are used to illustrate the input and output of the module, and do not represent the actual input or output quantity. The input and output quantities of modules in different functional groups are different, and the specific quantity is determined according to the data interaction between specific modules.

[0072] In summary, the heavy-duty gas turbine control system of the embodiment of the present application modularizes the host system in combination with the design characteristics of the gas turbine, and divides the subsystems with relatively independent functions into the same functional module or functional group. The functional module division can comprehensively consider the unit operation path, important subsystems and important parameters; for each functional module, the embodiment of the present application designs a relatively flexible operation control strategy as much as possible under the premise of meeting the operation control requirements; thereby, through reasonable control function modular design and relatively flexible operation control strategy design of each module and between modules, sufficient verification and debugging conditions are provided for subsequent software-in-the-loop verification, hardware-in-the-loop verification and whole machine debugging, and potential risks and mismatches at each stage are timely checked to the greatest extent possible; the embodiment of the present application can overcome the many uncertainties of the new model heavy-duty gas turbine in the whole machine component design, processing and manufacturing, process configuration, equipment selection and other aspects to the greatest extent possible. Functional modularization can reduce the impact range of single module errors and improve reliability. It can guide the design of new heavy-duty gas turbine control systems or the technical transformation of mature unit control systems, covering heavy-duty gas turbine host signal conditioning, starting control, acceleration control, speed control, load control, temperature limit control, fuel quantity control, IGV and VGVs control, secondary air control, gas distribution control and frequency response control; it can reduce the impact of single module errors and improve the availability and reliability of the control system.

[0073] In some embodiments, the heavy-duty gas turbine control system of the present application adopts a distributed control architecture, and the signal conditioning module and the multiple parameter control modules are dispersedly configured at multiple sites.

[0074] In this embodiment, the functions of the heavy-duty gas turbine control system are dispersed to multiple independent sites that can operate in parallel through a distributed control architecture, thereby avoiding interference from other events that affect system performance; improving fault tolerance at the hardware level and overcoming the uncertainty in the unit operation control process to the greatest extent possible.

[0075] Furthermore, the system includes an information layer, a monitoring layer, a control layer and an instrument layer. The signal conditioning module and the multiple parameter control modules belong to the control layer. The information layer adopts a redundant high-speed and high-capacity network. The monitoring layer includes a global distributed database. The control layer is connected to the instrument layer through an IO card, and the IO card is used for data acquisition and command output; the instrument layer includes at least DI acquisition, DO analog output, AI acquisition, AO analog output, RTD analog output, TC analog output, SPD analog output, and LVDT analog output.

[0076] In some embodiments, the control layer is divided into a control part and a protection part. There is data interaction between the control part and the protection part, while maintaining relative independence. The gas turbine and auxiliary equipment monitoring and control functions are designed according to the requirements of the operational control concept; based on the requirements of the gas turbine functional safety design benchmark, the design follows the principles of single fault criterion, fault safety criterion and protection against common cause failures. Separate designs are made for protection functions with high reliability requirements and high process safety time requirements. Redundant configurations are made for sensors at key measuring points at the instrument layer, and signal accuracy and reliability are improved by processing redundant signals. The above four-layer architecture design can maximize the safety and reliability of the unit, further overcome the uncertainty of new gas turbine models, and achieve consistency, integrity and adaptability between the control system and the unit's operational control requirements.

[0077] As an example, the control section is configured with at least one pair of redundant controllers, or three pairs, for example. Controller No. 1 runs the main engine control logic for the gas turbine, controller No. 2 runs the sequence control and auxiliary engine control logic, and controller No. 3 runs the electrical control logic. The controllers are connected via Ethernet to form a control network. The protection section is configured with at least one pair of redundant controllers, such as controller No. 4. Three pairs of redundant SIL3 safety-rated controllers are attached to controller No. 4 to run the main engine, auxiliary engines, and electrical protection logic for the gas turbine. The control and protection sections are connected via Ethernet at the control network layer. The control layer and monitoring layer are connected via Ethernet to form a real-time network. The control layer and instrumentation layer are connected via I / O cards for data acquisition and command output.

[0078] In the descriptions of the foregoing embodiments, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0080] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A heavy-duty gas turbine control system, characterized in that: include: a signal conditioning module and a plurality of parameter control modules, wherein the signal conditioning module is used to perform signal conditioning on the acquired system monitoring parameters and send the conditioned system monitoring parameters to the plurality of parameter control modules; The multiple parameter control modules include: a starting control module configured to obtain an ignition fuel quantity, a warm-up fuel quantity, and an acceleration fuel quantity based on the conditioned system monitoring parameters, and to obtain a starting fuel quantity instruction based on the ignition fuel quantity, the warm-up fuel quantity, and the acceleration fuel quantity; A speed control module is used to obtain a fuel quantity instruction for a speed control loop based on a deviation between a set speed value and an observed speed value of the rotor when the rotor speed increases to a first speed, in combination with a PI control algorithm; The load control module is used to obtain the fuel quantity instruction of the load control loop according to the deviation between the load set value and the corresponding observed value in combination with the PI control algorithm during the grid connection stage; The IGV and VGVs control module is used to obtain the IGV angle command based on the maximum deviation between the set value and the observed value of the turbine inlet temperature T3 and the turbine outlet temperature T4 during the load increase phase, combined with the PI control algorithm. The VGV angle command is then obtained based on the characteristic relationship between the IGV and VGVs. The temperature limit control module is used to obtain the fuel quantity instruction of the temperature limit control loop based on the deviation between the set value and the corresponding observed value of the turbine inlet temperature T3 of the gas engine when the temperature limit value is reached, combined with the PI control algorithm; a fuel quantity control module, configured to obtain a total fuel quantity instruction based on the starting fuel quantity instruction, the fuel quantity instruction of the load control loop, the fuel quantity instruction of the speed control loop, and the fuel quantity instruction of the temperature limit control loop; The gas distribution control module is used to obtain the opening instruction of each fuel valve according to the total fuel quantity instruction and the fuel distribution ratio of each fuel valve.

2. The system according to claim 1, wherein: The starting control module is specifically used to: Obtaining a first correction coefficient according to the atmospheric temperature and the ISO operating condition atmospheric temperature, and obtaining the ignition fuel amount based on the first correction coefficient and the ignition fuel amount corresponding to the ISO; Obtaining a second correction coefficient based on the atmospheric temperature, the ISO operating atmospheric temperature, the atmospheric pressure, and the ISO operating atmospheric pressure, and obtaining the warm-up fuel amount based on the second correction coefficient and the ISO corresponding warm-up fuel amount; Obtaining a third correction coefficient based on the atmospheric temperature, the ISO operating atmospheric temperature, the atmospheric pressure, the ISO operating atmospheric pressure, the fuel lower heating value, and the ISO operating fuel lower heating value, and obtaining the speed-increasing fuel amount based on the third correction coefficient and the ISO corresponding speed-increasing fuel amount; Based on the ignition setting signal, the selector selects the ignition fuel amount and the first fuel amount to obtain a second fuel amount; Based on a warm-up setting signal, a selector selects the warm-up fuel amount and the second fuel amount to obtain a third fuel amount; Based on the speed-up setting signal, the speed-up fuel amount, the third fuel amount, the maximum fuel amount and the minimum fuel amount are selected by a selector to obtain the starting fuel amount instruction.

3. The system according to claim 1, wherein: The fuel quantity control module is specifically configured to: Combining the fuel quantity instruction of the load control loop and the fuel quantity instruction of the speed control loop to obtain a combined load-speed-fuel quantity instruction; Based on the grid connection setting signal, the fuel quantity instruction of the speed control loop and the combined load speed fuel quantity instruction are selected by a selector to obtain the load speed control loop fuel quantity instruction; Based on the temperature limit control setting signal, the fuel quantity instruction of the temperature limit control loop and the total fuel quantity instruction are selected by a selector to obtain the fuel quantity instruction of the temperature limit control loop; Based on the speed control signal, the starting fuel quantity instruction and the total fuel quantity instruction are selected by a selector to obtain a starting process fuel quantity instruction; The starting process fuel quantity instruction, the load speed control loop fuel quantity instruction and the temperature limit control loop fuel quantity instruction are selected by a minimum value selector to obtain the total fuel quantity instruction.

4. The system according to claim 1, wherein: The gas distribution control module is specifically used to: Obtaining a fuel quantity instruction for each fuel valve according to the total fuel quantity instruction and the fuel distribution ratio of each fuel valve; Obtaining a flow coefficient for each fuel valve according to the flow command of each fuel valve and a fuel correction coefficient for each fuel valve; wherein the fuel correction coefficient is determined based on natural gas density, gas pressure before the fuel valve, natural gas specific gravity, compressibility, Weber index design value, and Weber index calculated value; The opening instructions of the fuel valves are obtained according to the flow coefficients of the fuel valves and the valve characteristic curve interpolation functions of the fuel valves.

5. The system according to claim 1, wherein: The IGV and VGVs control modules are specifically used to: Obtain a first deviation between a T3 set value and a corresponding observed value and a second deviation between a T4 set value and a corresponding observed value of the IGV system; obtaining a larger value of the first deviation and the second deviation; Obtaining an IGV angle command of the IGV system based on the larger value and a temperature closed-loop control proportional coefficient and a temperature closed-loop control integral coefficient corresponding to the larger value; Based on the IGV angle command and the characteristic relationship between the IGV and the VGVs, a VGV angle command is obtained.

6. The system according to claim 1, wherein: The system further includes a secondary air control module, wherein the secondary air control module is specifically configured to: According to the open-loop setting signal, multiple open-loop opening control laws are selected through the selector to obtain the open-loop control opening instruction; According to the closed-loop setting signal, the open-loop control opening instruction and the closed-loop control opening instruction are selected by a selector to obtain a first control opening instruction; According to the fully closed setting signal, the first control opening instruction and the minimum opening instruction are selected by a selector to obtain a second control opening instruction; According to the full-open setting signal, the second control opening instruction and the maximum opening instruction are selected by a selector to obtain a turbine cooling valve opening instruction.

7. The system according to claim 1, wherein: The system further includes a frequency response control module, wherein the frequency response control module is specifically configured to: The grid frequency deviation is obtained according to the difference between the actual grid frequency and the grid reference frequency; Obtaining a inequality rate according to the grid frequency deviation, the grid actual frequency, and the power target value; Obtaining a compensation coefficient based on the inequality rate, the grid reference frequency, and the power target value; The product of the grid frequency deviation and the compensation coefficient is calculated to obtain a primary frequency modulation power compensation value; and a load instruction after primary frequency modulation correction is obtained according to the primary frequency modulation power compensation value and the load instruction before primary frequency modulation correction.

8. The system according to claim 1, wherein: The system further includes an acceleration control module, wherein the acceleration control module is configured to: After entering the transition state, the fuel quantity instruction of the rotor acceleration control loop is obtained according to the deviation between the rotor acceleration set value and the acceleration observation value, combined with the PI control algorithm.

9. The system according to claim 1, wherein: The system adopts a distributed control architecture, and the signal conditioning module and the multiple parameter control modules are dispersedly configured at multiple sites.

10. The system according to claim 1 or 9, characterized in that The system includes an information layer, a monitoring layer, a control layer and an instrument layer. The signal conditioning module and the multiple parameter control modules belong to the control layer. The information layer adopts a redundant high-speed and high-capacity network. The monitoring layer includes a global distributed database. The control layer and the instrument layer are connected through an IO card, and the IO card is used for data acquisition and command output; the instrument layer includes at least DI acquisition, DO analog output, AI acquisition, AO analog output, RTD analog output, TC analog output, SPD analog output, and LVDT analog output.

Images