A method, system, device and medium for controlling the pressure of a gas-fired boiler furnace

Abstract

The application provides a full gas-fired boiler furnace pressure control method, system, equipment and medium, and the method comprises the following steps: obtaining the flow characteristics of the air inlet adjusting door of each layer of burner, and obtaining the corresponding opening degree instruction processing function according to the flow characteristics; obtaining the opening degree instruction of the air inlet adjusting door of each layer of burner, and performing nonlinear processing on the opening degree instruction according to the corresponding opening degree instruction processing function to obtain the corresponding relative control flow; obtaining the feedforward value of the induced draft fan regulator according to the relative control flow; obtaining the induced draft fan control instruction according to the feedforward value of the induced draft fan regulator and the preset variable structure PI controller, and controlling the full gas-fired boiler furnace pressure according to the induced draft fan control instruction. The method can effectively improve the control performance of the induced draft fan of the unit, is beneficial to improving the stability of the induced draft control system, can ensure the normal operation of the automatic regulation system of the induced draft fan when the boiler is abnormally operated, and has high practical value.

Description

Technical Field

[0001] This invention relates to the field of power industry technology, and in particular to a method, system, computer equipment, and storage medium for controlling furnace pressure in a fully gas-fired boiler. Background Technology

[0002] As one of the main pieces of equipment in a thermal power plant, the boiler's function is to ensure the complete and stable combustion of fuel within it. The primary task of boiler combustion control is to control the amount of fuel and air entering the furnace, as well as the furnace negative pressure, ensuring that the furnace negative pressure is maintained within a specified range and that the flame is stable and the fuel combustion is efficient. In other words, furnace pressure control is a crucial component of the boiler combustion control system in a thermal power generating unit. Ensuring stable furnace pressure is a critical and complex issue directly related to the economic efficiency and safety of operating a fully gas-fired boiler unit.

[0003] Current furnace pressure control technology for thermal power generating units typically employs a single-loop PI control system with furnace pressure as the controlled variable and the induced draft rate as a feedforward regulator to adjust the boiler's induced draft. The entire control process operates using fixed control parameters. However, when abnormal boiler conditions occur, such as a main fuel trip (MFT) or auxiliary equipment failure leading to runback (RB), requiring rapid gas cut-off or reduction, the furnace pressure will change drastically. If the induced draft fan's adjustment response cannot keep up with the rate of gas reduction, the air / fuel balance in and out of the furnace will be disrupted, inevitably exacerbating the negative pressure within the furnace. Furthermore, the limitations of the induced draft fan's installation location also result in significant inertia and hysteresis in furnace pressure control. Under abnormal conditions, the induced draft fan's inability to respond promptly to rapid changes in furnace pressure can lead to excessive negative pressure and potentially accidents. It is evident that existing furnace pressure control technologies struggle to achieve optimal control performance under turbulent operating conditions. This is especially true for boilers equipped with variable frequency induced draft fans. Enabling the control system to promptly track furnace pressure changes, quickly stabilize furnace pressure, and ensure the safe and stable operation of the boiler is a challenging problem that urgently needs to be solved and has significant practical implications. Summary of the Invention

[0004] The purpose of this invention is to provide a method for controlling furnace pressure in a fully gas-fired boiler. This method can effectively improve the control performance of the induced draft fan when the boiler is in abnormal operating condition, and can respond quickly to avoid unsafe operating conditions, thereby ensuring the normal operation of the automatic furnace pressure regulation system.

[0005] To achieve the above objectives, it is necessary to provide a method, system, computer equipment, and storage medium for controlling the furnace pressure of a fully gas-fired boiler, addressing the aforementioned technical problems.

[0006] In a first aspect, embodiments of the present invention provide a method for controlling furnace pressure in a fully gas-fired boiler, the method comprising the following steps:

[0007] The flow characteristics of the intake regulating valve of each burner are obtained, and the corresponding opening command processing function is obtained based on each flow characteristic; the flow characteristics include relative stroke and relative flow.

[0008] The opening command of the intake regulating valve of each burner is obtained, and nonlinear processing is performed according to the corresponding opening command processing function to obtain the corresponding relative control flow.

[0009] The feedforward value of the induced draft fan regulator is obtained based on the relative control flow rates.

[0010] Based on the feedforward value of the induced draft fan regulator and the preset variable structure PI controller, the induced draft fan control command is obtained, and the furnace pressure of the all-gas-fired boiler is controlled according to the induced draft fan control command.

[0011] Furthermore, the step of obtaining the corresponding opening instruction processing function based on each flow characteristic includes:

[0012] Based on the relative travel and relative flow of each flow characteristic, the opening command processing function is obtained by plotting points or linear fitting.

[0013] Furthermore, the step of obtaining the opening command of the intake regulating valve of each burner layer and performing nonlinear processing according to the corresponding opening command processing function to obtain the corresponding relative control flow includes:

[0014] The opening command is converted into the corresponding relative control stroke;

[0015] The relative control stroke is input into the opening command processing function for nonlinear processing to obtain the relative control flow rate.

[0016] Furthermore, the step of obtaining the feedforward value of the induced draft fan regulator based on each relative control flow rate includes:

[0017] The sum of the individual relative control flows is obtained by accumulating and summing them.

[0018] Multiply the sum of the relative control flow rates by the gain coefficient to obtain the sum of the relative control flow rate gains;

[0019] The relative control flow gain and the input lead-lag module are subjected to lag processing to obtain the relative control flow lag value;

[0020] The feedforward value of the induced draft fan regulator is obtained by subtracting the relative control flow gain from the relative control flow hysteresis value.

[0021] Further, the step of obtaining the induced draft fan control command based on the feedforward value of the induced draft fan regulator and the preset variable structure PI controller includes:

[0022] The furnace pressure is obtained, and the proportional and integral coefficients of the preset variable structure PI controller are dynamically adjusted according to the real-time furnace pressure to obtain the real-time proportional coefficient and real-time integral coefficient.

[0023] The real-time control voltage of the preset variable structure PI controller is obtained based on the real-time proportional term coefficient and the real-time integral term coefficient.

[0024] The real-time control voltage is superimposed with the feedforward value of the induced draft fan regulator to obtain the induced draft fan control command.

[0025] Furthermore, the step of dynamically adjusting the proportional and integral coefficients of the preset variable structure PI controller based on the real-time furnace pressure includes:

[0026] The magnitude of the furnace pressure deviation is determined based on the real-time furnace pressure and the preset pressure range;

[0027] Based on the magnitude of the furnace pressure deviation, a dynamic adjustment rule is determined, and based on the dynamic adjustment rule, the proportional and integral coefficients of the preset variable structure PI controller are adjusted in real time.

[0028] Furthermore, the calculation formula for the preset variable structure PI controller is expressed as follows:

[0029]

[0030] In the formula,

[0031]

[0032]

[0033] in, , , , and It is a positive real number; This represents the controller input deviation at time t; Indicates the controller input deviation; and These represent the proportional term coefficient and the integral term coefficient, respectively; This indicates the control voltage of the preset variable structure PI controller.

[0034] Secondly, embodiments of the present invention provide a furnace pressure control system for a fully gas-fired boiler, the system comprising:

[0035] The preprocessing module is used to obtain the flow characteristics of the intake regulating valve of each burner layer, and to obtain the corresponding opening command processing function based on each flow characteristic; the flow characteristics include relative stroke and relative flow.

[0036] The instruction conversion module is used to obtain the opening instruction of the intake regulating valve of each burner layer, and perform nonlinear processing according to the corresponding opening instruction processing function to obtain the corresponding relative control flow.

[0037] The feedforward acquisition module is used to obtain the feedforward value of the induced draft fan regulator based on the relative control flow rates.

[0038] The pressure control module is used to obtain induced draft fan control commands based on the feedforward value of the induced draft fan regulator and the preset variable structure PI controller, and to control the furnace pressure of the all-gas-fired boiler according to the induced draft fan control commands.

[0039] Thirdly, embodiments of the present invention also provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0040] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-described method.

[0041] This application provides a method, system, computer equipment, and storage medium for controlling the furnace pressure of a fully gas-fired boiler. The method achieves the following: obtaining corresponding opening command processing functions based on the flow characteristics of each burner inlet regulating valve; performing nonlinear processing on the opening commands of each burner inlet regulating valve to obtain the corresponding relative control flow; obtaining the induced draft fan regulator feedforward value based on each relative control flow; and obtaining the induced draft fan control command based on the induced draft fan regulator feedforward value and a preset variable structure PI controller. Finally, the furnace pressure of the fully gas-fired boiler is controlled according to the induced draft fan control command. Compared with existing technologies, this fully gas-fired boiler furnace pressure control method, through nonlinear processing of the burner inlet regulating valve commands and the use of a variable structure PI controller, effectively improves the control performance of the unit's induced draft fan. This not only enhances the stability of the induced draft control system but also effectively ensures the normal operation of the induced draft fan automatic adjustment system under abnormal boiler operating conditions, demonstrating high practical value. Attached Figure Description

[0042] Figure 1 This is a schematic flowchart of the furnace pressure control method for a fully gas-fired boiler in an embodiment of the present invention.

[0043] Figure 2 This is a schematic diagram of the curve of the opening command processing function corresponding to the intake regulating valve of a certain layer of burner in an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the logic for obtaining the feedforward value of the induced draft fan burner in an embodiment of the present invention;

[0045] Figure 4 The figure in the middle is a simulation curve diagram of the feedforward value of the induced draft fan burner generated according to the opening command in an embodiment of the present invention;

[0046] Figure 5 The figure in the middle is a schematic diagram of the proportional coefficient variation curve of the preset variable structure PI controller in an embodiment of the present invention;

[0047] Figure 6 The figure in the middle is a schematic diagram of the integral term coefficient change curve of the preset variable structure PI controller in an embodiment of the present invention;

[0048] Figure 7 This is a schematic diagram of the furnace pressure control system of a coal gas-fired boiler in an embodiment of the present invention;

[0049] Figure 8 This is an internal structural diagram of the computer device in an embodiment of the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and beneficial effects of this application clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Obviously, the embodiments described below are only part of the embodiments of the present invention and are used to illustrate the present invention, but are not intended to limit the scope of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0051] The furnace pressure control method for a fully gas-fired boiler provided by this invention is a furnace pressure control method that balances the contradiction between the economic operation of the generator set and the effective improvement of the induced draft fan control performance under harsh operating conditions. It is specifically designed for fully gas-fired boilers equipped with variable frequency speed-regulating induced draft fans. This method not only effectively improves the induced draft fan control performance when the boiler experiences abnormal operating conditions, but also facilitates rapid response, preventing unsafe operating conditions and ensuring the normal operation of the automatic furnace pressure regulation system, thereby ensuring the safe and stable operation of the boiler. The following embodiments will provide a detailed description of the furnace pressure control method for fully gas-fired boilers of this invention.

[0052] In one embodiment, such as Figure 1 As shown, a method for controlling furnace pressure in a fully gas-fired boiler is provided, comprising the following steps:

[0053] S11. Obtain the flow characteristics of each burner inlet regulating valve and, based on each flow characteristic, obtain the corresponding opening command processing function; the flow characteristics include relative stroke and relative flow rate; wherein, the flow characteristics of each burner inlet regulating valve can be obtained from relevant manufacturer equipment data or from experiments, such as based on the percentage of the current burner inlet flow rate (m3 / h) to the design flow rate at different opening degrees (%), obtain the flow characteristic data of a certain burner inlet regulating valve shown in Table 1, and find that there is a certain nonlinear mapping relationship between relative stroke and relative flow rate; it should be noted that there is a certain correspondence between relative stroke and opening command, that is, based on the opening command, it can be converted into the corresponding relative stroke data.

[0054] Table 1 Flow characteristics of the burner inlet regulating valve

[0055]

[0056] The valve opening command processing function can be understood as a function that processes the nonlinear relationship between the valve opening change and the gas flow rate change to make the valve opening command proportional to the gas flow rate, thereby improving the linearity between the valve opening command and the relative flow rate. Specifically, the step of obtaining the corresponding valve opening command processing function based on each flow characteristic includes:

[0057] Based on the relative travel and relative flow of each flow characteristic, the opening command processing function is obtained through either the point plotting method or the linear fitting method. The point plotting method can be understood as plotting each set of relative travel and relative flow data shown in Table 1 as X-axis and Y-axis coordinates in a two-dimensional coordinate system, and then connecting these coordinate points with smooth line segments. Figure 2 The process of the piecewise function shown is illustrated; the linear fitting method can be understood as fitting each set of relative travel and relative flow data shown in Table 1 as the explanatory variable and the explained variable, respectively, to obtain the corresponding linear relationship function; it should be noted that the linear fitting in this embodiment can be implemented using existing technology, and can obtain the same result as... Figure 2 Similar curves will not be described further here.

[0058] S12. Obtain the opening command of the intake regulating valve of each burner layer, and perform nonlinear processing according to the corresponding opening command processing function to obtain the corresponding relative control flow.

[0059] The steps of obtaining the opening command of the intake regulating valve of each burner layer and performing nonlinear processing according to the corresponding opening command processing function to obtain the corresponding relative control flow include:

[0060] The opening command is converted into the corresponding relative control stroke;

[0061] The relative control stroke is input into the opening command processing function for nonlinear processing to obtain the relative control flow rate. The relative control flow rate can be understood as the function value obtained by inputting the relative control stroke corresponding to the opening command into the opening command processing function. It should be noted that a fully gas-fired boiler unit is equipped with multiple burners, and each burner inlet has a flow regulating valve to control the gas intake. The opening command of each regulating valve needs to be nonlinearly processed using the corresponding opening command processing function to obtain the corresponding relative control flow rate. That is, the number of relative control flow rates is the same as the number of burner inlet regulating valves in the fully gas-fired boiler unit. For example, a 135MW subcritical fully gas-fired boiler unit equipped with 5 layers of BFG gas burners (A13, A46, B13, B46, and C13 layers) will yield 5 corresponding relative control flow rates.

[0062] S13. Obtain the feedforward value of the induced draft fan regulator based on each relative control flow; wherein the number of relative control flow rates is the same as the number of burner inlet regulating valves in a fully gas-fired boiler unit; wherein the process of obtaining the feedforward value of the induced draft fan regulator is as follows: Figure 3 The above can be understood as follows: the output values ​​obtained after nonlinear processing of the opening command of each burner regulating valve through the opening command processing function F(x) are first summed and then multiplied by the gain coefficient to obtain the relative control flow gain. One path is sent to the lead-lag module (LEADLAG) for lag processing, and the other path is sent directly to the summation module (SUM) to obtain the feedforward value by subtracting the output value from the lead-lag module. Specifically, the step of obtaining the feedforward value of the induced draft fan regulator based on each relative control flow includes:

[0063] The sum of the individual relative control flows is obtained by accumulating and summing them.

[0064] The sum of the relative control flow rates is multiplied by the gain coefficient to obtain the relative control flow rate gain. The gain coefficient can be selected according to actual needs in principle. In this embodiment, the gain coefficient is preferably set to K=0.21.

[0065] The relative control flow gain and input lead-lag module are subjected to lag processing to obtain the relative control flow lag value. The lead-lag module has both lead and lag functions. When the lead time constant (LEAD) is greater than the lag time constant (LAG), the module's output changes faster than the input; when the lead time constant is less than the lag time constant, the module's output changes slower than the input. In this embodiment, preferably only the lag function is used, with the lead time constant set to LEAD=0 and the lag time constant set to LAG=3.

[0066] The feedforward value of the induced draft fan regulator is obtained by subtracting the relative control flow gain from the relative control flow lag value. The feedforward value can be either negative or positive. Specifically: when the boiler is reducing fuel, the burner inlet regulating valve closes downwards. The value after passing through the lead-lag module changes more slowly than the value without the lead-lag module, resulting in a negative feedforward value. Conversely, when the boiler is adding fuel, the feedforward value is positive. When the inlet regulating valve opening stops changing, the feedforward value becomes zero after a period of time. It should be noted that the magnitude of the feedforward value of the induced draft fan regulator is determined by the gain coefficient K and the lag time constant LAG. Its impact on the entire control system can be adjusted by adjusting the gain coefficient K and the lag time constant LAG according to actual needs.

[0067] In addition, this embodiment also uses Matlab simulation software to build a system in the Simulink environment. Figure 3 The logic model shown is simulated and output to obtain... Figure 4 The simulated output curve of the feedforward response of the induced draft fan regulator is shown.

[0068] S14. Based on the feedforward value of the induced draft fan regulator and the preset variable structure PI controller, obtain the induced draft fan control command, and control the furnace pressure of the all-gas-fired boiler according to the induced draft fan control command; wherein, the preset variable structure PI controller can be understood as a controller that sets the proportional term coefficient and integral term coefficient as non-fixed value parameters that are dynamically adjusted according to the furnace pressure deviation of the all-gas-fired boiler equipped with a variable frequency speed-regulating induced draft fan;

[0069] In furnace pressure control, the proportional term is used for error regulation. Increasing the proportional term can reduce error and speed up response, but in areas with large deviations, a large proportional term coefficient can cause system instability. The integral term is used to eliminate steady-state error, but in areas with large deviations, integration often leads to integral saturation, resulting in excessive overshoot and longer settling time. Based on these control characteristics, if the proportional and integral term coefficients are set to fixed parameters, the following problems will inevitably occur:

[0070] Due to the large inertia and lag characteristics of the controlled object, significant deviations between the target value and the actual negative pressure value are prone to occur under abnormal operating conditions. On one hand, the large deviation causes the proportional output to be too fast. However, because the induced draft fan frequency converter has acceleration and deceleration time limits, the actual frequency feedback cannot keep up with the controller's output command in a timely manner. As the adjustment process progresses, the deviation between the command and feedback increases, causing the controller to switch to manual mode and adversely affecting the stability of the negative pressure control system. On the other hand, as the adjustment time increases, the large deviation amplifies the effect of the integral term, leading to significant overshoot or integral saturation in the control system, slowing down the system response and prolonging the adjustment time. Therefore, it is difficult to meet the control requirements of the furnace pressure regulation process in a fully gas-fired boiler using a fixed-parameter controller.

[0071] Considering the characteristics of the furnace pressure regulation process in a fully gas-fired boiler and the shortcomings of using a fixed-parameter controller, this embodiment preferably employs a preset variable-structure PI controller to regulate the furnace pressure, and combines its output control voltage with the feedforward value of the induced draft fan regulator obtained in the above steps to generate the required induced draft fan control command; specifically, the step of obtaining the induced draft fan control command based on the feedforward value of the induced draft fan regulator and the preset variable-structure PI controller includes:

[0072] The furnace pressure is obtained, and the proportional and integral coefficients of the preset variable structure PI controller are dynamically adjusted according to the real-time furnace pressure to obtain the real-time proportional coefficient and real-time integral coefficient.

[0073] The step of dynamically adjusting the proportional and integral coefficients of the preset variable structure PI controller based on the real-time furnace pressure includes:

[0074] The magnitude of the furnace pressure deviation is determined based on the real-time furnace pressure and the preset pressure range. The preset pressure range can be understood as the normal allowable range of furnace pressure, which can be determined according to the equipment protection and alarm settings of the furnace operation process. For example, if the operation process requires the furnace operating pressure to be around -100Pa, the pressure between ±500Pa is acceptable, exceeding ±500Pa is a first-level alarm value, exceeding ±1500Pa is a second-level alarm value, and exceeding ±3000Pa is a protection value, requiring interlocking to stop the blower. Therefore, when the furnace pressure exceeds ±500Pa, it is considered that the deviation is large. The specific value can only be obtained through field experience or commissioning tests, and no specific restrictions are made here.

[0075] Based on the magnitude of the furnace pressure deviation, a dynamic adjustment rule is determined, and the proportional and integral coefficients of the preset variable structure PI controller are adjusted in real time according to the dynamic adjustment rule. The dynamic adjustment rule, in principle, only needs to satisfy the following: when the furnace pressure deviation is large, a smaller proportional coefficient and a larger integral coefficient are selected to prevent integral saturation, reduce overshoot, and shorten the adjustment time; while when the furnace pressure deviation is small, a larger proportional coefficient is selected to avoid the actual frequency output of the induced draft fan failing to track the controller command in time, preventing excessive overshoot and ensuring system stability, while a smaller integral coefficient is selected to eliminate steady-state error. That is, the basic design idea of ​​the preset variable structure PI controller in this embodiment is: when the target value deviates significantly from the controlled variable, a smaller proportional coefficient and a larger integral coefficient are used; when the target value deviates significantly from the controlled variable, a larger proportional coefficient and a smaller integral coefficient are used. During the adjustment process, the proportional term coefficient can be automatically adjusted according to the change of the deviation value, thereby improving the response speed and preventing the controller from generating excessive output control quantity, ensuring system stability. Preferably, a preset variable structure PI controller structure that satisfies the following calculation formula is adopted:

[0076] (1)

[0077] In the formula,

[0078] (2)

[0079] (3)

[0080] in, , , , and It is a positive real number; This represents the controller input deviation at time t; Indicates the controller input deviation; and These represent the proportional term coefficient and the integral term coefficient, respectively; This indicates the control voltage of the preset variable structure PI controller;

[0081] From equations (1) to (3), it can be seen that when the deviation When it is large, the proportional term coefficient Take the maximum value as coefficient of integral term Take the maximum value ;When the deviation When it is small, the proportional term coefficient Take the minimum value coefficient of integral term Take the minimum value of 0.

[0082] In equation (2), the proportional term coefficient can be automatically adjusted as the deviation value changes. The magnitude of the adjustment and the slope of the change are determined by... , , Three parameters determine the outcome. for The minimum value, for The range of variation, Decide Rate of change; in the example, , , The values ​​of are set to 1.0, 1.2, and 0.005 respectively, and then the result can be obtained from formula (2). Figure 5 The proportionality coefficient shown The curve showing the change. Figure 5 The horizontal axis represents the furnace pressure deviation. The range of variation, i.e., the maximum allowable deviation of the induced draft fan, is ±500Pa, with the vertical axis representing the proportional coefficient. The range of variation is 1.0 to 2.2.

[0083] Similarly, for equation (3), for The range of values ​​for , Decide There is a rate of change; in the example, it will... The value is 300. The value is taken as 0.006, and the coefficient of the integral term is obtained from equation (3). The change curve is as follows Figure 6 As shown;

[0084] based on Figure 5 and Figure 6 As can be seen from the example, this embodiment can adjust the proportional term coefficient and integral term coefficient in a timely manner according to the real-time furnace pressure deviation, so that the PI controller can effectively track and control the furnace pressure based on the dynamically adjusted proportional term coefficient and integral term coefficient through the following method steps.

[0085] The real-time control voltage of the preset variable structure PI controller is obtained based on the real-time proportional term coefficient and the real-time integral term coefficient.

[0086] The real-time control voltage is superimposed with the feedforward value of the induced draft fan regulator to obtain the induced draft fan control command.

[0087] The induced draft fan control commands generated through the above methods and steps can be directly used to control the induced draft fan to work normally and effectively. The specific method of using the induced draft fan control commands to control the operation of the induced draft fan can be implemented using existing technologies, and will not be elaborated here.

[0088] This application embodiment improves the control performance of the induced draft fan by performing nonlinear processing on the burner intake regulating valve command and using a variable structure PI controller with dynamically adjusted proportional and integral coefficients based on furnace pressure deviation to regulate furnace pressure. This enhances the stability of the induced draft control system and ensures the normal operation of the induced draft fan automatic adjustment system under abnormal boiler operating conditions. Consequently, it achieves effective control of the furnace pressure in a fully gas-fired generator boiler equipped with a variable frequency speed-regulating induced draft fan, demonstrating high practical value.

[0089] In one embodiment, such as Figure 7 As shown, a furnace pressure control system for a fully gas-fired boiler is provided, the system comprising:

[0090] Preprocessing module 1 is used to acquire the flow characteristics of the intake regulating valve of each burner layer, and obtain the corresponding opening command processing function according to each flow characteristic; the flow characteristics include relative stroke and relative flow.

[0091] Command conversion module 2 is used to obtain the opening command of the intake regulating valve of each burner and perform nonlinear processing according to the corresponding opening command processing function to obtain the corresponding relative control flow.

[0092] Feedforward acquisition module 3 is used to obtain the feedforward value of the induced draft fan regulator based on each relative control flow rate;

[0093] Pressure regulation module 4 is used to obtain induced draft fan control commands based on the feedforward value of the induced draft fan regulator and the preset variable structure PI controller, and to control the furnace pressure of the all-gas-fired boiler according to the induced draft fan control commands.

[0094] Specific limitations regarding the furnace pressure control system for fully gas-fired boilers can be found in the above description of the furnace pressure control method for fully gas-fired boilers, and will not be repeated here. Each module in the aforementioned furnace pressure control system for fully gas-fired boilers can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0095] Figure 8 An internal structural diagram of a computer device is shown in one embodiment. This computer device may specifically be a terminal or a server. Figure 8As shown, the computer device includes a processor, memory, network interface, display, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for controlling the furnace pressure of a fully gas-fired boiler. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0096] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computing devices may include more or fewer components than those shown in the figure, or combine certain components, or have the same component arrangement.

[0097] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described above.

[0098] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0099] In summary, the present invention provides a method, system, computer equipment, and storage medium for controlling the furnace pressure of a fully gas-fired boiler. The method achieves this by obtaining a corresponding opening command processing function based on the flow characteristics of the inlet regulating valves of each burner layer. After nonlinearly processing the opening commands of each burner inlet regulating valve through the opening command processing function to obtain the corresponding relative control flow, the method obtains the feedforward value of the induced draft fan regulator based on each relative control flow. Furthermore, it obtains the induced draft fan control command based on the feedforward value of the induced draft fan regulator and a preset variable structure PI controller. Finally, it controls the furnace pressure of the fully gas-fired boiler according to the induced draft fan control command. This method, through nonlinear processing of the burner inlet regulating valve commands and the use of a designed variable structure PI controller based on dynamic adjustment of the proportional and integral term coefficients of the furnace pressure deviation to regulate the furnace pressure, effectively improves the control performance of the induced draft fan. This not only enhances the stability of the induced draft control system but also effectively ensures the normal operation of the automatic adjustment system of the induced draft fan under abnormal boiler operating conditions, demonstrating high practical value.

[0100] The various embodiments in this specification are described in a progressive manner. For directly identical or similar parts of the embodiments, refer to each other. Each embodiment focuses on its differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0101] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this invention, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A method for controlling furnace pressure in a fully gas-fired boiler, characterized in that, The method includes the following steps: The flow characteristics of the intake regulating valve of each burner are obtained, and the corresponding opening command processing function is obtained based on each flow characteristic; the flow characteristics include relative stroke and relative flow. The opening command of the intake regulating valve of each burner is obtained, and nonlinear processing is performed according to the corresponding opening command processing function to obtain the corresponding relative control flow. Based on each relative control flow, the feedforward value of the induced draft fan regulator is obtained, including: summing up each relative control flow to obtain the total relative control flow; Multiply the sum of the relative control flow rates by the gain coefficient to obtain the sum of the relative control flow rate gains; The relative control flow gain and the input lead-lag module are subjected to lag processing to obtain the relative control flow lag value; The feedforward value of the induced draft fan regulator is obtained by subtracting the relative control flow gain from the relative control flow hysteresis value. Based on the feedforward value of the induced draft fan regulator and the preset variable structure PI controller, the induced draft fan control command is obtained, and the furnace pressure of the all-gas-fired boiler is controlled according to the induced draft fan control command; the preset variable structure PI controller is a controller that sets the proportional term coefficient and integral term coefficient to non-fixed value parameters that are dynamically adjusted according to the furnace pressure deviation of the all-gas-fired boiler equipped with a variable frequency speed-regulating induced draft fan. The step of obtaining the induced draft fan control command based on the feedforward value of the induced draft fan regulator and the preset variable structure PI controller includes: The furnace pressure is obtained, and the proportional and integral coefficients of the preset variable structure PI controller are dynamically adjusted according to the real-time furnace pressure to obtain the real-time proportional and integral coefficients. The real-time control voltage of the preset variable structure PI controller is obtained based on the real-time proportional term coefficient and the real-time integral term coefficient. The real-time control voltage is superimposed with the feedforward value of the induced draft fan regulator to obtain the induced draft fan control command.

2. The method for controlling furnace pressure in a fully gas-fired boiler as described in claim 1, characterized in that, The step of obtaining the corresponding opening instruction processing function based on each flow characteristic includes: Based on the relative travel and relative flow of each flow characteristic, the opening command processing function is obtained by plotting points or linear fitting.

3. The method for controlling furnace pressure in a fully gas-fired boiler as described in claim 1, characterized in that, The steps of obtaining the opening command of the intake regulating valve of each burner layer and performing nonlinear processing according to the corresponding opening command processing function to obtain the corresponding relative control flow include: The opening command is converted into the corresponding relative control stroke; The relative control stroke is input into the opening command processing function for nonlinear processing to obtain the relative control flow rate.

4. The method for controlling furnace pressure in a fully gas-fired boiler as described in claim 1, characterized in that, The step of dynamically adjusting the proportional and integral coefficients of the preset variable structure PI controller based on the real-time furnace pressure includes: The magnitude of the furnace pressure deviation is determined based on the real-time furnace pressure and the preset pressure range; Based on the magnitude of the furnace pressure deviation, a dynamic adjustment rule is determined, and based on the dynamic adjustment rule, the proportional and integral coefficients of the preset variable structure PI controller are adjusted in real time.

5. The method for controlling furnace pressure in a fully gas-fired boiler as described in claim 1, characterized in that, The calculation formula for the preset variable structure PI controller is expressed as follows: In the formula, in, , , , and It is a positive real number; This represents the controller input deviation at time t; Indicates the controller input deviation; and These represent the proportional term coefficient and the integral term coefficient, respectively; This indicates the control voltage of the preset variable structure PI controller.

6. A furnace pressure control system for a fully gas-fired boiler, characterized in that, The system, employing the furnace pressure control method for a fully gas-fired boiler as described in claim 1, comprises: The preprocessing module is used to obtain the flow characteristics of the intake regulating valve of each burner layer, and to obtain the corresponding opening command processing function based on each flow characteristic; the flow characteristics include relative stroke and relative flow. The instruction conversion module is used to obtain the opening instruction of the intake regulating valve of each burner layer, and perform nonlinear processing according to the corresponding opening instruction processing function to obtain the corresponding relative control flow. The feedforward acquisition module is used to obtain the feedforward value of the induced draft fan regulator based on the relative control flow rates. The pressure control module is used to obtain induced draft fan control commands based on the feedforward value of the induced draft fan regulator and the preset variable structure PI controller, and to control the furnace pressure of the all-gas-fired boiler according to the induced draft fan control commands.

7. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

Images