A hydrogen mixing control device system and control method for a hydrogen mixing gas turbine

Abstract

The present invention provides a hydrogen doping control device system and control method for a hydrogen-blended gas turbine. The hydrogen doping control device system includes a unit DCS module, a gas turbine control TCS module, a combustible gas alarm control module, and a flame detection module connected to a remote control device. It also includes a regional fire alarm control device and a plant fire monitoring module connected in sequence to the combustible gas alarm control module. The control device system is fully functional, safe and reliable, and is suitable for hydrogen doping upgrades and modifications of existing gas turbine units. The control method adopts a cascade feedforward three-impulse control method, combined with variable parameters, deviation dead zone, non-disturbance switching, manual protection and other measures, to achieve precise control of the hydrogen doping ratio and rapid tracking of the hydrogen flow rate, meeting the control requirements of the hydrogen-blended gas turbine.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbines and hydrogen energy utilization, and in particular to a hydrogen mixing control device system and a control method for a hydrogen-mixed gas turbine. Background Art

[0002] Hydrogen, a clean, storable energy source, is a secondary energy source being actively developed in the new and renewable energy sectors and is a key component in achieving the transition to low-carbon and zero-carbon energy. Hydrogen energy has enormous potential for development, but due to the high cost of large-scale storage and inadequate hydrogen infrastructure, the utilization of pure hydrogen will take considerable time.

[0003] Compared to natural gas, hydrogen has a lower density and a much higher calorific value per unit mass. It also ignites more easily and has a much faster flame rate than natural gas. Blending hydrogen into natural gas fuel not only addresses domestic natural gas shortages but also reduces carbon dioxide emissions. Therefore, blending a certain percentage of hydrogen into natural gas for use in gas turbines is a promising solution for the transition from fossil fuels to hydrogen energy.

[0004] Currently, hydrogen-blended gas turbines and natural gas hydrogen blending systems are relatively new, both domestically and internationally. Numerous data indicators require reliable experimental verification, and the overall technical level of natural gas hydrogen blending is still in the experimental verification phase. Standards for material compatibility, operational and control safety, process advancement, and equipment reliability are yet to be standardized. In addition to addressing inherent gas turbine safety issues such as premixed combustion flashback and combustion chamber vibration, hydrogen-blended gas turbines also place high demands on the accuracy and stability of hydrogen blending control within the hydrogen blending system.

[0005] In order to ensure the safe and stable operation of hydrogen-blended gas turbines, the hydrogen blending control system needs to solve the following technical difficulties:

[0006] (1) Gas turbines have high requirements for hydrogen blending ratio control quality. The ratio must be large and adjustable within a certain range. To achieve safe and stable combustion, the control deviation of the hydrogen content and the hydrogen content change rate limit must be small.

[0007] (2) When the unit load changes, it will cause changes in the natural gas flow rate. In order to ensure the stability of the hydrogen blending ratio, the hydrogen flow rate needs to automatically and quickly follow the changes in the natural gas flow rate, and the control system needs to have good dynamic response characteristics.

[0008] (3) The measurement parameters of the hydrogen doping system and hydrogen analyzer have characteristics such as large delay and large lag, the dynamic quality of the system is poor, and the control is difficult.

[0009] (4) Hydrogen has a wider explosion limit than natural gas, and the safety requirements for hydrogen blending stations are higher, requiring complete safety monitoring and protection measures.

[0010] There are relatively few methods for controlling hydrogen blending in natural gas reported in existing technologies and published literature, and most of them are used for natural gas pipeline transportation. Currently, they generally use a fixed, small-ratio blending method. Due to the aforementioned difficulties in controlling hydrogen blending in gas turbines, traditional flow ratio control or single-loop PID control of hydrogen content is difficult to adapt to the control requirements of the unit under different load conditions. In particular, when the unit increases or decreases load, it suffers from shortcomings such as delayed tracking, large control deviations, and low control accuracy. Furthermore, the control characteristics of hydrogen blending in gas turbines vary under different load conditions. Conventional PID controllers often use single, fixed control parameters, making it difficult to effectively adapt to different operating conditions and suffering from poor parameter adaptability. Furthermore, the setpoint for traditional flow ratio control is calculated from the natural gas flow rate and the hydrogen blending ratio. When the control loop is switched to manual, it is difficult to achieve setpoint tracking of the measured value. The manual-to-automatic switching function is also lacking, and when the deviation is large, switching from manual to automatic mode can cause significant disturbances. In these cases, the operator typically relies on manually adjusting the controlled variable to a small deviation from the setpoint before switching to automatic mode. This is inconvenient and can easily lead to adverse consequences if operated improperly. Summary of the Invention

[0011] In view of the problems existing in the prior art, the present invention provides a hydrogen mixing control device system and control method for a hydrogen mixing gas turbine, which meets the control requirements of the hydrogen mixing gas turbine and provides favorable conditions for the safe and stable operation of the hydrogen mixing gas turbine.

[0012] To achieve this object, the present invention adopts the following technical solutions:

[0013] In a first aspect, the present invention provides a hydrogen mixing control device system for a hydrogen mixing gas turbine, the hydrogen mixing gas turbine hydrogen mixing control device system comprising a unit DCS module connected to a remote control device, a gas turbine control TCS module, a combustible gas alarm control module, and a flame detection module;

[0014] The unit DCS module is connected to the gas turbine control TCS module;

[0015] The hydrogen blending control device system for the hydrogen-combustion gas turbine further includes a regional fire alarm control device and a plant fire monitoring module which are sequentially connected to the combustible gas alarm control module;

[0016] The hydrogen mixing control device system for a hydrogen-mixed gas turbine includes a field device connected to a remote control device.

[0017] The remote control device in the hydrogen blending control device system for the hydrogen blending gas turbine described in the present invention is a control center, which is mainly used to collect and monitor the real-time operating data of the hydrogen blending gas turbine control device system, realize the hydrogen blending process control and protection functions, and measure, record, display and store the various process parameters of the entire system. It has two-way data transmission with the unit DCS module and the gas turbine control TCS module, realizing centralized monitoring of the entire plant. The regional fire alarm control device is mainly used for regional fire alarm monitoring of the hydrogen blending station, and is connected to the regional fire alarm control system to facilitate monitoring of the entire plant; the combustible gas alarm control module is mainly used to monitor hydrogen and natural gas leakage in the hydrogen blending station area and generate alarms. The hydrogen blending control device system for the hydrogen blending gas turbine described in the present invention can realize that the natural gas flow rate follows the changes in the unit load, and the hydrogen flow rate follows the changes in the natural gas flow rate according to the hydrogen blending ratio.

[0018] The remote control device in the present invention can be a distributed control system DCS remote station or a programmable logic controller PLC control device in the prior art.

[0019] The remote control device is connected to the unit DCS module and the gas turbine control TCS module via a high-speed Ethernet communication network to achieve two-way data transmission; it is also connected to the gas turbine control system (TCS) via hard contact signals to achieve interactive connectivity of important protection signals, thereby better ensuring the safe operation of the gas turbine and hydrogen blending system.

[0020] The hydrogen mixing control device system for a hydrogen-blended gas turbine of the present invention is fully functional, safe and reliable, and is suitable for hydrogen mixing upgrades and modifications of existing gas turbine units.

[0021] The unit DCS mentioned in the present invention is a well-known professional term in the art, which is a distributed control system that integrates execution components and data acquisition functions.

[0022] Preferably, the regional fire alarm control device is connected to the factory fire monitoring module via modbus communication.

[0023] The Modbus communication described in the present invention is a well-known professional term in the art, a serial communication protocol, and a commonly used connection method between industrial electronic devices.

[0024] Preferably, the regional fire alarm control device is connected to the flame detection module.

[0025] The flame detection module of the present invention can be equipped with an infrared / ultraviolet composite flame detector, which can effectively reduce interference from external light. The signal of the flame detection module is connected to the remote control device for monitoring. When an alarm signal is generated, the hydrogen mixing station can be stopped through protection logic.

[0026] Preferably, the combustible gas alarm control module is connected to the combustible gas detection module.

[0027] The combustible gas detection module of this invention can optionally use a catalytic combustion combustible gas probe, which can be connected to a combustible gas controller via a 4-20mA analog signal. The combustible gas controller can also be connected to a remote control device via analog signals, enabling monitoring within the DCS system. In the event of a gas leak, protection logic can be used to shut down the hydrogen blending station.

[0028] Preferably, the field equipment includes a flow meter, a pressure transmitter, a temperature transmitter, a regulating valve, an emergency shut-off valve, a manual shut-off ball valve, a check valve and a hydrogen analyzer.

[0029] The field equipment and devices in the present invention can be arranged according to the actual situation of the plant. A natural gas flow meter, a pressure transmitter, etc. are set on the natural gas pipeline to measure the natural gas volume flow rate and the pressure before mixing respectively; a first pressure transmitter, a second pressure transmitter, and a hydrogen flow meter are set on the hydrogen pipeline to measure the pressure before the hydrogen regulating valve, the pressure after the regulating valve, and the hydrogen volume flow rate respectively; an emergency shut-off valve is set on the hydrogen pipeline to cut off the hydrogen supply in emergency situations such as combustible gas leakage, fire, and gas turbine tripping; a hydrogen regulating valve is set on the hydrogen pipeline to adjust the hydrogen mixing amount; a manual shut-off ball valve, a check valve and other equipment are set on the bypass pipeline to switch between the gas turbine hydrogen mixing operation mode and the pure natural gas operation mode; a pressure transmitter, a temperature transmitter, a hydrogen analyzer and the like are set on the mixing pipeline to measure parameters such as the pressure, temperature and hydrogen volume content of the mixed gas.

[0030] In a second aspect, the present invention further provides a method for controlling hydrogen doping in a hydrogen-mixed gas turbine, wherein the method for controlling hydrogen doping in a hydrogen-mixed gas turbine is performed using the hydrogen doping control device system for the hydrogen-mixed gas turbine described in the first aspect;

[0031] The hydrogen blending control method for a hydrogen-blended gas turbine is a three-impulse follow-up control method for hydrogen blending ratio based on cascade feedforward control, wherein the three impulses include hydrogen content, hydrogen flow rate and natural gas flow rate.

[0032] The hydrogen mixing control method for a hydrogen-mixed gas turbine is realized by a main regulating loop controller, a sub-regulating loop controller, a feedforward compensation block, a variable parameter block, a disturbance-free switching block and a manual protection block.

[0033] The control method described in the present invention adopts a cascade feedforward control mode combined with variable parameters, deviation dead zone, disturbance-free switching, manual protection and other measures, which can achieve precise control of the hydrogen blending ratio and rapid tracking of the hydrogen flow rate, meeting the control requirements of the hydrogen-blended gas turbine.

[0034] Preferably, the main control loop controller is a hydrogen content PID controller for fine-tuning the hydrogen blending ratio.

[0035] Preferably, the feedback signal of the main control loop controller is the hydrogen content, and the set value of the main control loop controller is the hydrogen blending ratio set value. The deviation between the two is calculated and output by the main control loop PID1 controller as the secondary control loop hydrogen flow set value.

[0036] The hydrogen content of the present invention can be measured in real time by a hydrogen analyzer, and the set value of the hydrogen blending ratio can be set by an operator through a human-machine interface within the set value limit according to the operating conditions.

[0037] PID, as used in this article, is a well-known technical term in the art. It stands for "proportional, integral, and derivative" and is a very common control algorithm. In thermal power plants and other fields, it uses proportional (P), integral (I), and derivative (D) functions to change the characteristics of the actuator based on the changing characteristics of the controlled variable to achieve stable regulation.

[0038] Preferably, the hydrogen doping ratio is set to 5-100%, for example, 5%, 10%, 20%, 40%, 50%, 80% or 100%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] Preferably, the secondary regulation loop controller is a hydrogen flow PID controller, which adjusts the deviation between the hydrogen flow feedback signal and the set value.

[0040] Preferably, the feedback signal of the auxiliary regulation loop controller is the hydrogen flow rate, and the set value of the auxiliary regulation loop controller is the main regulation loop deviation calculated by the auxiliary regulation loop PID2 operation and the output value of the feedforward compensation block superimposed on the operation value, and the deviation between the two is calculated by the auxiliary regulation loop PID2 controller and output to control the opening of the regulating valve.

[0041] Preferably, the feedforward compensation block comprises a feedforward compensation function:

[0042] Where f(x) is the feedforward compensation, F NG is the natural gas volume flow rate under standard conditions, H2SP is the set value of hydrogen blending ratio, and K is the feedforward compensation coefficient.

[0043] The feedforward compensation block described in the present invention is a static feedforward compensation method. It calculates the required hydrogen flow rate according to the static proportional function relationship between the hydrogen blending ratio and the natural gas flow rate, and quickly tracks the changes in the unit load. It mainly achieves the purpose of preliminary adjustment of the hydrogen blending ratio and rapid tracking of the hydrogen flow rate, eliminating external disturbances of the unit load and natural gas flow rate.

[0044] Preferably, the variable parameter block includes adjusting the main regulating loop PID1 controller according to the main regulating loop deviation piecewise function and adjusting the auxiliary regulating loop PID2 parameters according to the unit load piecewise function.

[0045] The variable parameter block of the present invention realizes online adjustment of the PID parameters of the main control loop PID1 controller, completes the flow following and hydrogen blending ratio fine adjustment switching functions; realizes online optimization adjustment of the PID parameters of the auxiliary control loop PID2 controller, and better adapts to system characteristics.

[0046] The auxiliary regulation loop PID2 parameters are adjusted according to the unit load segmentation function, so that the auxiliary regulation loop PID2 parameters are better adapted to the unit load control characteristics, thereby obtaining a precise hydrogen flow regulation effect;

[0047] The adjustment of the main regulating loop PID1 controller according to the main regulating loop deviation piecewise function means that when the unit load causes the natural gas flow rate to change or the hydrogen blending ratio to be adjusted, the main regulating loop PID1 parameters are automatically adjusted to weaken the effect of the main regulating loop PID1 controller, so that the output of the main regulating controller is mainly acted upon by the feedforward compensation block, and the initial adjustment of the hydrogen blending ratio and the rapid flow tracking function are mainly completed through the feedforward compensation effect based on the functional relationship between the hydrogen flow rate and the natural gas flow rate ratio; when the unit load is relatively stable and the main regulating loop deviation enters the fine adjustment setting range, the main regulating loop PID1 parameters are adjusted to enhance the effect of the main regulating loop PID1 controller. At this time, the feedforward compensation effect has been weakened, and the purpose of fine adjustment of the hydrogen blending ratio is mainly achieved through the effect of the main regulating loop PID1 controller.

[0048] Preferably, the bumpless switching block includes three parts: first, when the M / A station is switched to manual, the set value of the main control loop controller tracks its measured value, and the rate limiting function of the main loop set value rate limit block is eliminated; when the M / A station is switched to automatic, the set value rate limiting function is restored; second, when the M / A station is switched to manual, the output of the main control loop controller tracks the measured value of the auxiliary control loop controller; third, when the M / A station is switched to manual, the output of the auxiliary control loop controller follows the manual output value of the M / A station.

[0049] The M / A station in the present invention is a professional term well known in the art, and refers to a manual-automatic switching station.

[0050] Preferably, the manual switching protection block is a protection measure when the M / A station cannot be normally put into automatic control. When the protection manual switching condition is met, the M / A station is switched to manual.

[0051] Preferably, the protective cut-off conditions include bad quality of hydrogen content, bad quality of hydrogen flow, bad quality of natural gas flow, closed ESD valve of the gas mixing skid, large deviation between the set value and the measured value, and large deviation between the output value of the regulating valve and the feedback value.

[0052] In the present invention, there is no clear numerical range limit for bad quality, large deviation between set value and measured value, and large deviation between control valve output value and feedback value. Those skilled in the art can set appropriate ranges according to actual conditions.

[0053] Preferably, the hydrogen blending control method for a hydrogen-mixed gas turbine further includes deviation deadband control.

[0054] Preferably, the deviation dead zone control includes that when the absolute value of the deviation is less than the set dead zone width, the error output is forced to 0; when the absolute value of the deviation is greater than the set dead zone width, the input and output of the dead zone are in a linear relationship and controlled according to the normal PID law.

[0055] Preferably, a deviation dead zone is set for the main control loop PID1 to eliminate PID operation within the system control accuracy range to prevent frequent transition adjustment of the system; a suitable deviation dead zone width is introduced into the auxiliary control loop PID2 to eliminate the influence of large delay and lag caused by hydrogen content.

[0056] Compared with the prior art, the present invention has at least the following beneficial effects:

[0057] (1) The hydrogen doping control device system for a hydrogen-blended gas turbine provided by the present invention uses a remote control device to realize the control and protection functions of the hydrogen doping system of the hydrogen-blended gas turbine, thereby saving daily maintenance costs; the combustible gas alarm control module and the plant fire monitoring module therein improve the safety of the hydrogen doping system; the control system is characterized by being fully functional, safe and reliable, and is suitable for the upgrade and transformation of existing gas turbine units for hydrogen doping;

[0058] (2) The hydrogen blending control method for a hydrogen-blended gas turbine provided by the present invention adopts a three-impulse follow-up control method of the hydrogen blending ratio with cascade feedforward control, realizes fine adjustment of the hydrogen blending ratio through the main control loop controller, realizes preliminary adjustment of the hydrogen blending ratio and rapid tracking of the hydrogen flow rate through feedforward compensation, and accurately controls the hydrogen flow rate through the auxiliary control loop controller. Combined with control measures such as variable parameters, disturbance-free switching, manual protection, and deviation dead zone, the method can overcome the shortcomings of the existing technology, solve the control difficulties of the hydrogen-blended gas turbine, and better meet the hydrogen blending control requirements of the hydrogen-blended gas turbine;

[0059] (3) The hydrogen mixing control method for the hydrogen-mixed gas turbine provided by the present invention is simple and easy to be programmed and implemented in the existing mainstream DCS or PLC system, and has the prospect of large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is a structural schematic diagram of the hydrogen mixing control device system of the hydrogen mixing gas turbine provided by the present invention.

[0061] Figure 2 Schematic diagram of a gas mixing skid of a hydrogen blending system in a specific embodiment of the present invention.

[0062] Figure 3 This is a schematic diagram of the hydrogen blending process of a hydrogen-blended gas turbine in a specific embodiment of the present invention.

[0063] Figure 4 This is a logical diagram of the hydrogen blending control method for a hydrogen-blended gas turbine provided by the present invention.

[0064] In the figure: 01-Emergency shut-off valve; 02-Second pressure transmitter; 03-Hydrogen flowmeter; 04-Hydrogen regulating valve; 05-Third pressure transmitter; 06-Mixing tank; 07-Fourth pressure transmitter; 08-Temperature transmitter; 09-Hydrogen analyzer; 10-Natural gas flowmeter; 11-First pressure transmitter; 12-Manual shut-off ball valve; 13-Check valve; 14-Long tube trailer; 15-Gas unloading column; 16-Hydrogen pressure regulating skid; 17-Natural gas pressure regulating skid; 18-Mixing skid; 19-Gas turbine front module. DETAILED DESCRIPTION

[0065] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0066] The present invention is further described in detail below. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0067] As a specific embodiment of the present invention, a hydrogen mixing control device system for a hydrogen mixed gas turbine is provided, and its structural schematic diagram is as follows: Figure 1 shown.

[0068] Taking the hydrogen blending of a certain type of F-class gas turbine power plant as an example, it is possible to achieve high-proportion and high-flow hydrogen blending operation of the gas turbine at 5%-100%, with two operating modes: hydrogen blending operation and pure natural gas operation.

[0069] The hydrogen mixing control device system of the hydrogen mixing gas turbine includes a unit DCS module connected to a remote control device, a gas turbine control TCS module, a combustible gas alarm control module and a flame detection module;

[0070] The unit DCS module is connected to the gas turbine control TCS module;

[0071] The hydrogen blending control device system for the hydrogen-combustion gas turbine further includes a regional fire alarm control device and a plant fire monitoring module which are sequentially connected to the combustible gas alarm control module;

[0072] The hydrogen mixing control device system for a hydrogen-mixed gas turbine includes a field device connected to a remote control device.

[0073] The regional fire alarm control device is connected to the factory fire monitoring module via Modbus communication to achieve fire monitoring of the entire factory.

[0074] The regional fire alarm control device is connected to the flame detection module and is used to monitor the fire alarm conditions of each process skid of the hydrogen blending system.

[0075] In this specific embodiment, the flame detector module is an infrared and ultraviolet composite flame detector, which can effectively reduce the interference of external light.

[0076] The signal of the flame detection module is connected to the remote control device for monitoring. When an alarm signal is generated, the operation of the hydrogen blending station can be stopped through protection logic.

[0077] In this embodiment, the combustible gas detection module can optionally utilize a catalytic combustion-type combustible gas probe, which can be connected to a combustible gas controller via a 4-20mA analog signal. The combustible gas controller can also be connected to a remote control device via analog signals, enabling monitoring within the DCS system. When a gas leak occurs, protection logic can be used to shut down the hydrogen blending station.

[0078] The field equipment device includes a flow meter, a pressure transmitter, a temperature transmitter, a regulating valve, an emergency shut-off valve, a manual shut-off ball valve, a check valve and a hydrogen analyzer.

[0079] The on-site equipment and devices constitute the hydrogen mixing station gas mixing skid 18, and its schematic diagram is as follows Figure 2 shown.

[0080] A natural gas flow meter 10 and a first pressure transmitter 11 are sequentially provided on the natural gas pipeline for measuring the natural gas volume flow rate and the pressure before gas mixing, respectively;

[0081] The second pressure transmitter 02, the third pressure transmitter 05 and the hydrogen flowmeter 03 are sequentially arranged on the hydrogen pipeline to measure the pressure before the hydrogen regulating valve, the pressure after the regulating valve and the hydrogen volume flow rate respectively;

[0082] An emergency shut-off valve 01 is installed on the hydrogen pipeline to cut off the hydrogen supply in emergency situations such as combustible gas leakage, fire, or gas turbine tripping. A hydrogen regulating valve 04 is installed on the hydrogen pipeline to adjust the hydrogen blending amount.

[0083] Natural gas and hydrogen enter the mixing tank 06 and are mixed;

[0084] A manual shut-off ball valve 12 and a check valve 13 are provided on the bypass pipeline for switching between the gas turbine's hydrogen-blended operation mode and pure natural gas operation mode.

[0085] The fourth pressure transmitter 07, temperature transmitter 08 and hydrogen analyzer 09 are provided on the mixed gas pipeline, which are used to measure parameters such as the pressure, temperature and hydrogen volume content of the mixed gas respectively.

[0086] In this specific embodiment, the diaphragm material of the pressure transmitter on each pipeline is gold-plated film to eliminate the damage to the transmitter diaphragm caused by hydrogen embrittlement.

[0087] The hydrogen flowmeter 03 uses a mass flowmeter based on the Coriolis force principle, which outputs the volume flow rate under standard conditions with an accuracy of up to 0.35%.

[0088] The natural gas flow meter 10 uses a turbine flow meter, which is temperature-pressure compensated by instruments such as a volume corrector to output the volume flow rate under standard conditions, with an accuracy of 0.5%.

[0089] Hydrogen Analyzer 09 uses thermal conductivity principle hydrogen analyzer TCD, with an accuracy of up to 0.4%.

[0090] The hydrogen mixing devices in this embodiment are all skid-mounted equipment, and the hydrogen mixing process is as shown in the attached figure. Figure 3 shown.

[0091] Hydrogen is transported to the power plant by a long tube trailer 14. To ensure a continuous supply of hydrogen, four hydrogen unloading positions and four gas unloading columns 15 are set up. Both the long tube trailer 14 and the gas unloading columns 15 are designed with three in use and one in reserve.

[0092] Hydrogen enters hydrogen pressure-regulating skid 16 via gas unloading column 14. Hydrogen pressure-regulating skid 16 is divided into three parallel routes. The hydrogen pressure before regulation is 20 MPa(g) to 4.0 MPa(g), and the pressure after regulation is 3.5 MPa(g). The blending point is located behind pressure-regulating skid 17 at the existing natural gas pressure-regulating station.

[0093] Natural gas is drawn out from the pipeline behind the natural gas pressure regulating skid 17 and enters the gas mixing skid 18 with the hydrogen pipeline for static premixing. The premixed fuel enters the hydrogen-mixed natural gas pipeline and is transported to the gas turbine front module 19.

[0094] This specific embodiment also provides a method for controlling hydrogen doping in a hydrogen-mixed gas turbine. The method for controlling hydrogen doping in a hydrogen-mixed gas turbine is performed using the above-mentioned hydrogen doping control device system for a hydrogen-mixed gas turbine.

[0095] The hydrogen blending control method for a hydrogen-blended gas turbine is a three-impulse follow-up control method for hydrogen blending ratio based on cascade feedforward control, wherein the three impulses include hydrogen content, hydrogen flow rate and natural gas flow rate.

[0096] The hydrogen mixing control method for a hydrogen-mixed gas turbine is realized by a main regulating loop controller, a sub-regulating loop controller, a feedforward compensation block, a variable parameter block, a disturbance-free switching block and a manual protection block.

[0097] The main control loop is the hydrogen content control loop, which mainly realizes the precise adjustment of the hydrogen blending ratio. The calculation function of the natural gas flow rate and the set value of the hydrogen blending ratio constitutes the hydrogen flow feedforward compensation instruction, which mainly realizes the functions of preliminary adjustment of the hydrogen blending ratio and rapid follow-up of the hydrogen flow rate.

[0098] The secondary control loop is the hydrogen flow control loop, primarily responsible for precise hydrogen flow adjustment. The hydrogen blending ratio three-impulse control system uses the sum of the calculated value of the primary control loop and the feedforward compensation as the hydrogen flow setting command for the secondary control loop. If the hydrogen flow signal deviates from this command, the secondary control loop causes the actuator to change the opening of the hydrogen control valve, thereby regulating the hydrogen flow.

[0099] The logic diagram of the hydrogen mixing control method of the hydrogen mixed gas turbine in this specific embodiment is as follows: Figure 4 shown.

[0100] The main control loop PID1 controller is a hydrogen content PID controller, and its main function is to fine-tune the hydrogen blending ratio. The feedback signal of the main control loop PID1 controller is the hydrogen content, and the set value is the hydrogen blending ratio setting SP, with a setting range of 0 to 30%. The deviation between the two is obtained by superimposing the output of the main control loop PID1 controller and the feedforward compensation FF as the hydrogen flow setting value SP of the sub-control loop. The hydrogen content can be measured in real time by a hydrogen analyzer (thermal conductivity meter TCD) as the measurement value of the main control loop PID1 controller. The hydrogen blending ratio setting value can be obtained by the operator through the human-machine interface within the set value limit according to the operating conditions, and is used as the setting value of the main control loop PID1 controller after passing through the rate limiting block.

[0101] The auxiliary control loop controller PID2 is a hydrogen flow PID controller, whose main function is to adjust the deviation between the hydrogen flow feedback signal and the set value, so as to achieve the purpose of accurate adjustment of the hydrogen flow and eliminate the internal disturbance of the hydrogen flow and the regulating valve. The feedback signal of the auxiliary control loop PID2 controller is the hydrogen volume flow (05), and the set value is the superposition calculation value of the main control loop deviation calculated by PID1 and the output value FF of the feedforward compensation block. The deviation between the hydrogen volume flow measurement value and the set value SP is calculated by the auxiliary control loop PID2 controller and output to control the opening of the hydrogen regulating valve.

[0102] The feedforward compensation block is a feedforward compensation function of the natural gas volume flow rate and the set value of the hydrogen blending ratio. It is a static feedforward compensation method. It calculates the required hydrogen flow rate according to the static proportional function relationship between the hydrogen blending ratio and the natural gas flow rate, and quickly tracks the changes in the unit load. It mainly achieves the purpose of preliminary adjustment of the hydrogen blending ratio and rapid tracking of the hydrogen flow rate, eliminating external disturbances of the unit load and natural gas flow rate.

[0103] The feedforward compensation block includes the feedforward compensation function:

[0104] Where f(x) is the feedforward compensation, F NG is the natural gas volume flow rate under standard conditions, H2SP is the set value of hydrogen blending ratio, and K is the feedforward compensation coefficient;

[0105] The variable parameter block realizes online adjustment of the PID parameters of the main control loop PID1 controller, completes the flow following and hydrogen blending ratio fine adjustment switching functions; and realizes online optimization adjustment of the PID parameters of the auxiliary control loop PID2 controller to better adapt to system characteristics.

[0106] The implementation steps include two parts: first, adjusting the PID2 parameters of the auxiliary control loop according to the unit load segmented function, so that the auxiliary control loop PID2 parameters better adapt to the unit load control characteristics and achieve a precise hydrogen flow regulation effect; second, adjusting the main control loop PID1 controller according to the main control loop deviation segmented function. When the unit load causes the natural gas flow to change or the hydrogen blending ratio to be adjusted, the main control loop PID1 parameters are automatically adjusted, weakening the effect of the main control loop PID1 controller, so that the main control controller output is mainly affected by the feedforward compensation block. The feedforward compensation function mainly achieves the initial adjustment of the hydrogen blending ratio and the rapid flow tracking function based on the functional relationship between the hydrogen flow rate and the natural gas flow rate. When the unit load is relatively stable and the main control loop deviation enters the fine adjustment setting range, the main control loop PID1 parameters are adjusted to enhance the effect of the main control loop PID1 controller. At this time, the feedforward compensation effect has weakened, and the purpose of fine adjustment of the hydrogen blending ratio is mainly achieved through the action of the main control loop PID1 controller.

[0107] The bumpless switching block is a functional block that implements bumpless switching of the controller from manual to automatic. It consists of three parts: First, when the M / A station switches to manual mode, the main control loop controller setpoint tracks its measured value, while simultaneously eliminating the rate limiting function of the main loop setpoint rate limit block and setting its enable EN value to 0. When the M / A station switches to automatic mode, the setpoint rate limiting function is restored and its enable EN value is set to 1. Second, when the M / A station switches to manual mode, the main control loop controller output tracks the measured value of the auxiliary control loop controller. Third, when the M / A station switches to manual mode, the auxiliary control loop controller output follows the manual output value of the M / A station.

[0108] The manual switching protection block is a protection measure when the M / A station cannot be put into automatic control normally. When the protection manual switching condition is met, the M / A station is switched to manual.

[0109] The protection cut-off conditions include bad hydrogen content, bad hydrogen flow, bad natural gas flow, closed ESD valve of gas mixing skid, large deviation between set value and measured value, and large deviation between output value and feedback value of regulating valve.

[0110] The hydrogen blending control method for a hydrogen-blended gas turbine also includes deviation dead band control; the deviation dead band control includes forcing the error output to 0 when the absolute value of the deviation is less than the set dead band width; when the absolute value of the deviation is greater than the set dead band width, the input and output of the dead band are in a linear relationship and are controlled according to normal PID rules.

[0111] The main control loop PID1 is set with a deviation dead zone to eliminate PID operation within the system control accuracy range to prevent frequent transition adjustment of the system; the auxiliary control loop PID2 is introduced with a suitable deviation dead zone width to eliminate the influence of large delay and lag caused by hydrogen content.

[0112] The hydrogen analyzer measures hydrogen content with significant delay and hysteresis. When the primary control loop, PID1, fine-tunes the hydrogen blending ratio, the secondary control loop, PID2, adjusts too frequently within a small deviation range. This over-adjustment of the hydrogen flow rate can cause significant hydrogen content overshoot. The selection of the deadband value requires consideration of both system characteristics and control accuracy.

[0113] In summary, the hydrogen doping control device system for a hydrogen-blended gas turbine provided by the present invention uses a remote control device to implement control and protection functions for the hydrogen doping system of the hydrogen-blended gas turbine. It seamlessly connects with the unit's DCS and TCS systems, facilitates centralized monitoring, and improves the safety of the hydrogen doping system. The control device system is fully functional, safe and reliable, and is suitable for upgrading and modifying existing gas turbine units for hydrogen doping.

[0114] The hydrogen blending control method for a hydrogen-blended gas turbine provided by the present invention adopts a three-impulse follow-up control method for the hydrogen blending ratio with cascade feedforward control, which can overcome the shortcomings of the existing technology, solve the control difficulties of the hydrogen-blended gas turbine, and better meet the hydrogen blending control requirements of the hydrogen-blended gas turbine. Compared with the traditional flow ratio control method, the control method is easier to implement the manual-automatic non-disturbance switching function. The non-disturbance switching can be achieved through the tracking algorithm of the main and auxiliary loops. The implementation method is simple and effective. The implementation of manual-automatic non-disturbance switching can greatly facilitate the operation of the operator and also enhance the safety of the system.

[0115] The implementation of manual-automatic disturbance-free switching can bring great convenience to operators, while also enhancing the safety of the system. It is easy to program and implement in existing mainstream DCS or PLC systems, and is suitable for large-scale promotion and application.

[0116] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for controlling hydrogen mixing in a hydrogen-mixed gas turbine, characterized in that: The hydrogen mixing gas turbine hydrogen mixing control method is performed using the following hydrogen mixing gas turbine hydrogen mixing control device system; The hydrogen mixing control device system of the hydrogen mixing gas turbine includes a unit DCS module connected to a remote control device, a gas turbine control TCS module, a combustible gas alarm control module and a flame detection module; The unit DCS module is connected to the gas turbine control TCS module; The hydrogen blending control device system for the hydrogen-combustion gas turbine further includes a regional fire alarm control device and a plant fire monitoring module which are sequentially connected to the combustible gas alarm control module; The hydrogen mixing control device system for the hydrogen mixing gas turbine includes a field device connected to a remote control device; The hydrogen blending control method for a hydrogen-blended gas turbine is a three-impulse follow-up control method for the hydrogen blending ratio based on cascade feedforward control, wherein the three impulses include hydrogen content, hydrogen flow rate, and natural gas flow rate; The hydrogen mixing control method for a hydrogen-blended gas turbine is implemented by a main control loop controller, a sub-control loop controller, a feedforward compensation block, a variable parameter block, a non-disturbance switching block and a manual protection block. The main control loop controller is a hydrogen content PID controller, which fine-tunes the hydrogen blending ratio; The feedback signal of the main control loop controller is the hydrogen content, and the set value of the main control loop controller is the hydrogen blending ratio set value. The deviation between the two is calculated and output by the main control loop PID1 controller as the hydrogen flow set value of the auxiliary control loop; the hydrogen blending ratio set value is 5-100%; The auxiliary regulation loop controller is a hydrogen flow PID controller, which adjusts the deviation between the hydrogen flow feedback signal and the set value; The feedback signal of the auxiliary control loop controller is the hydrogen flow rate. The set value of the auxiliary control loop controller is the main control loop deviation calculated by the auxiliary control loop PID2 operation and the output value of the feedforward compensation block superimposed on the operation value. The deviation between the two is calculated by the auxiliary control loop PID2 controller and output to control the opening of the regulating valve.

2. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 1, characterized in that: The regional fire alarm control device is connected to the factory area fire monitoring module via Modbus communication.

3. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 1, characterized in that: The regional fire alarm control device is connected to the flame detection module.

4. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 1, characterized in that: The combustible gas alarm control module is connected to the combustible gas detection module.

5. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 1, characterized in that: The field equipment device includes a flow meter, a pressure transmitter, a temperature transmitter, a regulating valve, an emergency shut-off valve, a manual shut-off ball valve, a check valve and a hydrogen analyzer.

6. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 1, characterized in that: The feedforward compensation block includes the feedforward compensation function: Where f(x) is the feedforward compensation, F NG is the natural gas volume flow rate under standard conditions, H2SP is the set value of hydrogen blending ratio, and K is the feedforward compensation coefficient.

7. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 1, characterized in that: The variable parameter block includes adjusting the main control loop PID1 controller according to the main control loop deviation piecewise function and adjusting the auxiliary control loop PID2 parameters according to the unit load piecewise function.

8. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 1, characterized in that: The bumpless switching block includes three parts: first, when the M / A station is switched to manual, the set value of the main control loop controller tracks its measured value, and the rate limiting function of the main loop set value rate limit block is eliminated; when the M / A station is switched to automatic, the set value rate limiting function is restored; second, when the M / A station is switched to manual, the output of the main control loop controller tracks the measured value of the auxiliary control loop controller; third, when the M / A station is switched to manual, the output of the auxiliary control loop controller follows the manual output value of the M / A station.

9. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 1, characterized in that: The manual switching protection block is a protection measure when the M / A station cannot be put into automatic control normally. When the protection manual switching condition is met, the M / A station is switched to manual.

10. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 1, characterized in that: The hydrogen blending control method for a hydrogen-mixed gas turbine further includes deviation deadband control.

11. The hydrogen mixing control method for a hydrogen-mixed gas turbine according to claim 10, characterized in that: The deviation dead zone control includes that when the absolute value of the deviation is less than the set dead zone width, the error output is forced to 0; when the absolute value of the deviation is greater than the set dead zone width, the input and output of the dead zone are in a linear relationship and controlled according to the normal PID law.

12. The hydrogen blending control method for a hydrogen-mixed gas turbine according to claim 11, characterized in that: The main control loop PID1 is set with a deviation dead zone to eliminate PID operation within the system control accuracy range to prevent frequent transition adjustment of the system; the auxiliary control loop PID2 is introduced with a suitable deviation dead zone width to eliminate the influence of large delay and lag caused by hydrogen content.

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