CN113359442B - Coal water ratio control method and system - Google Patents

Abstract

The invention provides a coal-water ratio control method and system. The method includes: obtaining the deviation of the midpoint temperature or enthalpy value of the once-through boiler; when the deviation is within the first dead zone, neither the feed water flow nor the fuel supply amount is adjusted; when the deviation is not within the first dead zone, the second dead zone is not adjusted. When the deviation is within the range of the second dead zone but within the third dead zone, the feed water flow and the fuel supply amount are adjusted, and the adjustment amount of the fuel supply is based on the first fuel correction The function is determined; when the deviation is not within the third dead zone, the feed water flow and the fuel supply amount are adjusted, and the adjustment amount of the fuel supply amount is determined based on the first and second fuel correction functions; the first dead zone is a sub-section of the second dead zone set, the second dead zone is a subset of the third dead zone; for the same deviation that is not within the third dead zone, the adjustment amount of the fuel supply determined based on the first and second fuel correction functions is greater than the adjustment amount based only on the first fuel The correction function is determined.

Description

A coal-water ratio control method and system

Technical field

The invention relates to a coal-water ratio control method and system.

Background technique

With the changes in the global energy landscape, especially changes in China's energy policy, a large number of new energy power stations have been connected to the power grid. This puts forward higher technical requirements for the upgrading and replacement of conventional thermal power units. In order to adapt to market changes and comprehensively consider economic benefits and other factors, new units, especially large coal-fired units, tend to use ultra-supercritical pressure once-through boiler units to improve the overall operating efficiency of the unit and increase economic benefits.

In order to effectively absorb the peak and valley differences in the power grid caused by the access of new energy power stations, the Energy Bureau proposed a plan for the flexibility transformation of thermal power units. This places higher demands on ordinary coal-fired thermal power units. That is, when the load of the power grid is low, coal-fired units are required to adjust downward to a lower load to meet the requirements of the power grid and users while ensuring normal power generation conditions of new energy units.

The normal load adjustment range of conventionally designed coal-fired thermal power units is between 50% and 100% Pe (i.e. the rated load of the unit). The peak adjustment range of units with deep peak shaving capabilities is between 40% and 100% Pe, even up to 30%. %-100%Pe or even within the range of 20%-100%Pe. When the load of the unit is reduced to a lower load, the unit, especially the characteristics of the unit, will change significantly. It must not only meet the requirements of the regular operating range, but also meet the changes in low-load operating conditions, which puts forward higher requirements for unit coordination and control. The supercritical once-through boiler midpoint temperature control is an important part of the entire coordinated control framework. Its control performance is not only related to the stability of the entire boiler side steam temperature, but also affects the performance of the entire coordinated control system, which in turn affects the overall AGC (i.e. automatic power generation) of the unit. control) performance. High-level supercritical once-through boiler midpoint temperature control is not only related to the safe operation of the unit, but also related to the overall control level of the unit. It plays an important role in the operating efficiency of the unit, the stability and security of the power grid, and the economic benefits of the power plant.

This year, with the massive increase in unit capacity, especially the widespread adoption of super (super)critical once-through boilers, and as a large number of new energy power stations have sprung up and connected to the power grid, higher technical requirements have been put forward for super (super)critical once-through boilers. , especially the existing control strategy is difficult to meet the requirements of all working conditions on site. The midpoint temperature (enthalpy value) control is an important part of the coordinated control strategy of super (super)critical once-through boiler units. By changing the coal-water ratio, the midpoint temperature is changed to control the boiler side steam temperature to ensure the safety, efficiency and stability of the unit. run.

The coal-to-water ratio of super (super) critical boilers (i.e. fuel-to-water ratio) is an important parameter for unit operation. It marks the excellent operating status of the unit and is an important symbol that reflects the normality of the boiler's hydrodynamic cycle. The factors that cause temperature changes are very complex, such as the status of the hydrodynamic cycle of the unit, changes in combustion in the boiler furnace, disturbances in the water supply system, changes in steam side parameters, internal structural characteristics of the boiler, installation locations of water level and flow measurement systems, Installation accuracy, measuring transmitter accuracy, etc. Therefore, under normal circumstances, the separator working fluid temperature is an important monitoring parameter of the boiler. Its control effect directly affects the safe operation of the unit. Especially when the unit is under wide load conditions, the operating conditions of the main auxiliary engines of the unit are worse than under normal conditions, and the boiler combustion characteristics change greatly. These factors have caused huge disturbances to the system, causing the unit to It cannot operate safely and stably.

Typical existing technical solutions for coal-to-water ratio control mainly include the following three types:

1. Technical solution one

The first technical solution is a control method in which the coal-water ratio control output is the feed water flow correction. The specific principle is shown in Figure 5. In Figure 5, PID1 is the midpoint temperature control (or midpoint enthalpy value control), and its PID1 input is the separation steam temperature or enthalpy value, and the set value SP _Tsep is the separator temperature or enthalpy value set value, and the measured value PV _Tsep is the separator steam temperature or the enthalpy value calculated from the separator steam pressure and temperature, both of which are used as the control input of PID1. The control calculation is performed through PID1, and the control calculation is performed to output the control variable FW_Corr to correct the water supply setting. The boiler main control command BMD is processed by the given function Fx1 and converted into a feed water flow main command. Add the above two instructions to obtain the water supply flow setting instruction FWMD, through which the water supply system is controlled.

Among them, the steam temperature of the DC separator is selected in different ways according to the manufacturer's design. It is designed to different positions such as the inlet, middle and outlet of the separator, but its core purpose is to represent the basic position of the phase change of the working fluid.

In the first technical solution, the control object of the intermediate point temperature (enthalpy value) is the feed water flow. When the system is disturbed, for example due to changes in the medium, etc., the heat absorption of the boiler water wall changes, resulting in changes in the heating area and evaporation area of the working fluid (water) in the water wall, resulting in the separation point of the water working fluid in the water wall. Changes occur in the pipeline, which in turn affects changes in the temperature of the working fluid in the separator (thus affecting changes in enthalpy), and affects the heat absorption of the steam behind it. Therefore, the intermediate temperature controller PID1 has an impact on the feed water flow. For example, when external factors cause the temperature of the separator to rise, PID1 generates an increase in the feed water flow through the calculation output, changes the water-coal ratio, and increases the working fluid in the water wall. The heat load is reduced, thereby reducing the temperature of the separator working fluid (changing the enthalpy value) and returning it to the original control value. However, due to the increase in feed water flow during the process, the evaporation amount increases. In order to ensure the stability of the unit load, the steam turbine side must reduce the flow of working fluid entering it, resulting in the turbine valve closing, resulting in an increase in system pressure. When the external disturbance is serious, the system pressure changes drastically, which has a huge impact on the safe operation of the unit.

2. Technical solution two

The second technical solution is a control method in which the coal-water ratio control output is a correction of the fuel supply amount. The specific principle is shown in Figure 6. Its structure is similar to the technical solution one. PID2 is the mid-point temperature control (or mid-point enthalpy value control). The input value of PID2 is the separation steam temperature or enthalpy value. The set value SP _Tsep is the separator temperature or enthalpy value setting. value, the measured value PV _Tsep is the separator steam temperature or the enthalpy value calculated from the separator steam pressure and temperature, both of which are used as the control input of PID2. The control calculation is performed through PID2, and the control calculation is performed to output the control variable FUEL_Corr to correct the fuel setting. The boiler main control instruction BMD is converted into a fuel main control instruction through the given function Fx2. The fuel setting command FUELMD is obtained by adding the above two commands, through which the fuel system is controlled.

The second technical solution is to change the water-to-coal ratio by controlling the fuel, and then change the separator working fluid temperature. Compared with the technical solution 1, since the water supply is not changed, the working fluid flow rate does not change much, which is conducive to pressure control and the pressure control is relatively stable. However, since the object of its control is fuel, the fuel system of the unit itself enters the boiler for combustion and heat exchange, which is a "slow" process (compared to the water supply system for heat balance in the furnace). Therefore, when the separator working fluid temperature changes drastically, PID2 will produce large coal quantity fluctuations. Due to the hysteresis of its fuel control, the temperature adjustment is not timely and the steam temperature changes drastically.

3. Technical solution three

The control strategy of the coal-water ratio in the third technical solution is based on the above-mentioned single control direction, that is, correction is made on the water supply system, or correction is made on the fuel system, or partial fine-tuning is made on partial correction instructions.

The third technical solution is only a partial modification of the first and second technical solutions and does not fundamentally solve the problems of the two solutions, so it cannot be widely used.

Contents of the invention

At present, as a large number of new energy power stations are connected to the power grid, higher technical requirements are put forward for super (super) critical once-through boilers, making it difficult for the existing coal-to-water ratio (i.e., fuel-to-water ratio) control strategy to meet the requirements of all working conditions on site. Based on this, the purpose of the present invention is to provide a coal-water ratio control method suitable for super (super)critical boilers that can better meet the current requirements of all working conditions on site.

Another object of the present invention is to provide a coal-water ratio control system suitable for super (super)critical boilers that can better meet the current requirements of all working conditions on site.

In order to achieve the above object, the present invention provides a coal-water ratio control method, which realizes coal-water ratio control by controlling the water supply flow rate and the fuel supply amount, wherein the method includes:

Deviation acquisition: Obtain the deviation of the midpoint temperature or enthalpy value of the once-through boiler;

Control the feed water flow rate and fuel feed amount based on the deviation: when the deviation is within the first dead zone range, the feed water flow rate is not adjusted (including the feed water flow adjustment amount is 0) and the fuel feed amount is not adjusted (including the fuel feed amount adjustment amount is 0) 0);

When the deviation is not within the first dead zone range but is within the second dead zone range, the feed water flow rate is adjusted (excluding the feed water flow rate adjustment amount is 0) and the fuel feed amount is not adjusted, thereby realizing the adjustment of the coal-water ratio;

When the deviation is not within the second dead zone range, but is within the third dead zone range, adjust the feed water flow (excluding the feed water flow adjustment amount to 0) and adjust the fuel supply amount (excluding the fuel supply amount adjustment amount to 0), Thus, the coal-to-water ratio adjustment is realized; wherein, the adjustment amount of the fuel supply amount is determined based on the first fuel correction function;

When the deviation is not within the third dead zone, the feed water flow rate is adjusted (excluding the feed water flow adjustment amount is 0) and the fuel supply amount is adjusted (excluding the fuel feed amount adjustment amount is 0), thereby realizing the adjustment of the coal-water ratio; where , the adjustment amount of the fuel supply amount is determined based on the first fuel correction function and the second fuel correction function;

Among them, the first dead zone is a subset of the second dead zone, and the second dead zone is a subset of the third dead zone (that is, the first dead zone is included in the second dead zone, and the second dead zone is included in the third dead zone. );

When the deviation is not within the third dead zone range, for the same deviation, the adjustment amount of the fuel amount is determined based on the first fuel correction function and the second fuel correction function compared to the determination based only on the first fuel correction function. The adjustment amount is larger.

In the above coal-water ratio control method, the deviation of the midpoint temperature or enthalpy value refers to the deviation of the measured value of the midpoint temperature or enthalpy value and the set value of the midpoint temperature or enthalpy value. The midpoint temperature or enthalpy value can be used The value is expressed by subtracting the set value of the midpoint temperature or enthalpy value from the measured value of the midpoint temperature or enthalpy value. It can also be expressed by subtracting the measured value of the midpoint temperature or enthalpy value from the set value of the midpoint temperature or enthalpy value. In the step of controlling the feed water flow rate and the fuel feed amount based on the deviation, when the deviation reflects the deviation that the measured value of the intermediate point temperature or enthalpy value is less than the set value of the intermediate point temperature or enthalpy value, the adjustment of the feed water amount should be is to reduce the water supply amount, the fuel supply amount adjustment should be to increase the fuel supply amount; when the deviation reflects that the measured value of the intermediate point temperature or enthalpy value is greater than the deviation of the set value of the intermediate point temperature or enthalpy value, The water supply amount adjustment should be to increase the water supply amount, and the fuel supply amount adjustment should be to a smaller fuel supply amount.

The invention also provides a coal-water ratio control system, wherein the system includes:

Deviation acquisition module: used to obtain the deviation of the midpoint temperature or enthalpy value of the once-through boiler;

The first deviation correction module is used to process the deviation through a first correction function to obtain the first corrected deviation. The first correction function is a function that can set the first dead zone; when the deviation is within the first dead zone range The deviation after the first correction is 0, and when the deviation is not within the first dead zone, the deviation after the first correction is not 0;

The second deviation correction module is used to process the deviation through a second correction function to obtain the second corrected deviation. The second correction function is a function that can set the second dead zone; when the deviation is within the second dead zone range The deviation after the second correction is 0, and when the deviation is not within the second dead zone, the deviation after the second correction is not 0;

The third deviation correction module is used to process the deviation through a third correction function to obtain the third corrected deviation. The third correction function is a function that can set the third dead zone; when the deviation is within the third dead zone range The deviation after the third correction is 0, and when the deviation is not within the third dead zone, the deviation after the first correction is not 0;

The first PID controller includes a first logic control unit; the first logic control unit is used to determine the water supply flow correction value based on the first corrected deviation using the water supply flow correction function; wherein, the water supply performed by the first logic control unit The flow correction value is determined to meet the following requirements: when the first corrected deviation is 0, the determined feed water flow correction value has no ability to correct the feed water flow formed by the original boiler main control instruction. When the first corrected deviation is not 0, the feed water flow correction value is determined. The flow correction value has the ability to correct the feed water flow formed by the original boiler master control instruction;

Original feed water flow acquisition module: used to obtain the feed water flow formed by the original boiler master control instructions;

Feed water flow set value determination module: used to use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value;

The second PID controller includes a second logic control unit; the second logic control unit is used to determine the first fuel amount correction value based on the second corrected deviation using the first fuel correction function; wherein, the second logic The first fuel supply correction value determined by the control unit satisfies the following conditions: when the second corrected deviation is 0, the first fuel supply correction value determined has no ability to correct the fuel supply quantity formed by the original boiler main control instruction. , when the second corrected deviation is not 0, the first fuel supply amount correction value determined has the ability to correct the fuel supply amount formed by the original boiler main control instruction;

The third PID controller includes a third logic control unit; the third logic control unit is used to determine the second fuel amount correction value based on the third corrected deviation and using the second fuel correction function; wherein, the third logic The second fuel supply correction value determined by the control unit satisfies the following requirements: the second fuel supply correction value determined when the third corrected deviation is 0 has no ability to correct the fuel supply quantity formed by the original boiler main control instruction. , when the deviation after the third correction is not 0, the second fuel supply amount correction value determined has the ability to correct the fuel supply amount formed by the original boiler main control instruction;

Original fuel supply quantity acquisition module: used to obtain the fuel supply quantity formed by the original boiler master control instruction;

The fuel supply quantity set value determination module is used to correct the fuel supply quantity formed by the original boiler main control instruction using the first fuel supply quantity correction value and the second fuel supply quantity correction value to determine the fuel supply quantity set value, as Further provide set values for the fuel control circuit;

Among them, the first dead zone is a subset of the second dead zone, and the second dead zone is a subset of the third dead zone.

The technical solution provided by the present invention is based on meeting the existing conditions, the requirements of large thermal power units for the safety and stability of the water supply system, and adapting to the power grid's deep peak regulation of thermal power units under the conditions of new energy access, and the wide load operation of the units. According to the requirements, combining the advantages of the two control methods and avoiding their shortcomings, a double-wishbone-based coal-water ratio (fuel-water ratio) control method and control system are proposed.

The coal-to-water ratio (fuel-to-water ratio) of super (super)critical boilers is an important parameter for unit operation. It marks the excellent operating status of the unit and is an important symbol that reflects the normality of the boiler's hydrodynamic cycle. The factors that cause temperature changes are very complex, such as the status of the hydrodynamic cycle of the unit, changes in combustion in the boiler furnace, disturbances in the water supply system, changes in steam side parameters, internal structural characteristics of the boiler, installation locations of water level and flow measurement devices, Installation accuracy, measuring transmitter accuracy, etc. Therefore, under normal circumstances, the separator working fluid temperature is an important monitoring parameter of the boiler. Its control effect directly affects the safe operation of the unit. Especially when the unit is under wide load conditions, the operating conditions of the main auxiliary engines of the unit are worse than under normal conditions, and the boiler combustion characteristics change greatly. These factors have caused huge disturbances to the system, causing the unit to It cannot operate safely and stably. The technical solution provided by the present invention is to propose a safer and more reliable control solution for fuel-water ratio control under such working conditions, process characteristics and in combination with traditional control solutions. It can more effectively improve the situation of severe temperature fluctuations at the intermediate point, thereby ensuring that the steam temperature is within a safe range. This enables the unit to have the capability of wide load peak shaving, bringing certain economic benefits to the power plant. Provide more favorable support for deep peak shaving of the power grid.

Adopting the technical solution provided by the method of the present invention has the following beneficial effects:

(1) The technical solution provided by the present invention overcomes the shortcomings of the conventional coal-to-water ratio control method, solves the large temperature and pressure fluctuations of super (super)critical units under wide-load operating conditions, and provides technical guarantee for the safe production of the unit. .

(2) The technical solution provided by the present invention can more effectively solve the problem that the separator temperature of the super (super) critical DC furnace is difficult to control under all working conditions, large loads, and extreme working conditions, and provides advantages for the safe production of the unit. protection. At the same time, it greatly improves the economic benefits of the unit and provides necessary support for the grid to accept new energy.

(3) The technical solution provided by the invention can adapt to the working characteristics of the DCS system, obtain optimized parameters through external optimization, and realize the technical solution provided by the invention without changing the original DCS system structure, saving transformation costs.

(4) The technical solution provided by the present invention can improve the variable load capability and adaptability of the unit, improve the adjustment performance of various indicators of the unit, and at the same time meet the requirements of the power grid for AGC and primary frequency regulation management and assessment under ultra-wide load operation; thus It improves the safety and economy of the operation of the unit, ensures the environmental protection indicators of the unit, and enhances the economic and social benefits of thermal power generating units participating in power grid assessment.

Description of the drawings

Figure 1 is a schematic flowchart of a coal-to-water ratio control method provided by an embodiment of the present invention.

Figure 2 is a schematic structural diagram of a coal-to-water ratio control system provided by an embodiment of the present invention.

Figure 3 is a schematic diagram of the optimized structure of the deviation acquisition module in an embodiment of the present invention.

Figure 4 is a schematic diagram of the optimized structure of the deviation acquisition module in an embodiment of the present invention.

Figure 5 is a schematic flow chart of a control method in which the coal-to-water ratio control output is feed water flow correction.

Figure 6 is a schematic flow chart of a control method in which the coal-to-water ratio control output is a correction of the fuel supply amount.

Figure 7 is a schematic flow chart of the coal-to-water ratio control method in Embodiment 1.

Figure 8 is a schematic flowchart of the deviation acquisition step in Embodiment 1.

Figure 9 is a schematic flowchart of the deviation acquisition step in Embodiment 1.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

The principles and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

Referring to Figure 1, in order to achieve the above objectives, the present invention provides a coal-water ratio control method, wherein the method includes:

Step S1: Deviation acquisition: Obtain the deviation of the midpoint temperature or enthalpy value of the DC boiler;

Step S2: Control the feed water flow rate and fuel supply amount based on the deviation: when the deviation is within the first dead zone range, the feed water flow rate is not adjusted (including the feed water flow adjustment amount is 0) and the fuel supply amount is not adjusted (including the fuel feed amount). The adjustment amount is 0);

When the deviation is not within the first dead zone range but is within the second dead zone range, the feed water flow rate is adjusted (excluding the feed water flow rate adjustment amount is 0) and the fuel feed amount is not adjusted, thereby realizing the adjustment of the coal-water ratio;

When the deviation is not within the second dead zone range, but is within the third dead zone range, adjust the feed water flow (excluding the feed water flow adjustment amount to 0) and adjust the fuel supply amount (excluding the fuel supply amount adjustment amount to 0), Thus, the coal-to-water ratio adjustment is realized; wherein, the adjustment amount of the fuel supply amount is determined based on the first fuel correction function;

When the deviation is not within the third dead zone, the feed water flow rate is adjusted (excluding the feed water flow adjustment amount is 0) and the fuel supply amount is adjusted (excluding the fuel feed amount adjustment amount is 0), thereby realizing the adjustment of the coal-water ratio; where , the adjustment amount of the fuel supply amount is determined based on the first fuel correction function and the second fuel correction function;

Among them, the first dead zone is a subset of the second dead zone, and the second dead zone is a subset of the third dead zone (that is, the first dead zone is included in the second dead zone, and the second dead zone is included in the third dead zone. );

When the deviation is not within the third dead zone range, for the same deviation, the adjustment amount of the fuel amount is determined based on the first fuel correction function and the second fuel correction function compared to the determination based only on the first fuel correction function. The adjustment amount is larger.

The deviation of the intermediate point temperature or enthalpy value refers to the deviation between the measured value of the intermediate point temperature or enthalpy value and the set value of the intermediate point temperature or enthalpy value. The intermediate point temperature or enthalpy value can be subtracted from the measured value of the intermediate point temperature or enthalpy value. It can be expressed by the set value of the point temperature or enthalpy value, or it can be expressed by subtracting the measured value of the intermediate point temperature or enthalpy value from the set value of the intermediate point temperature or enthalpy value. In the step of controlling the feed water flow rate and the fuel feed amount based on the deviation, when the deviation reflects the deviation that the measured value of the intermediate point temperature or enthalpy value is less than the set value of the intermediate point temperature or enthalpy value, the adjustment of the feed water amount should be is to reduce the water supply amount, the fuel supply amount adjustment should be to increase the fuel supply amount; when the deviation reflects that the measured value of the intermediate point temperature or enthalpy value is greater than the deviation of the set value of the intermediate point temperature or enthalpy value, The adjustment of the water supply quantity should be to increase the water supply quantity, and the fuel supply quantity adjustment should be to a smaller fuel supply quantity.

In one implementation, step S2 is implemented in the following manner:

Feed water flow control based on deviation: Determine the feed water flow correction value based on the deviation, use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value, and provide set values for further feed water control loops ; Wherein, the determination of the feed water flow correction value based on the deviation includes: processing the deviation through a first correction function to obtain the first corrected deviation, and the first correction function is a function that can set the first dead zone; based on For the first corrected deviation, the feed water flow correction function is used to determine the feed water flow correction value; among them, when the deviation is within the first dead zone, the first corrected deviation is 0, and the feed water flow correction value is correct for the original boiler main The feed water flow formed by the control command has no correction ability; when the deviation is not within the first dead zone, the deviation after the first correction is not 0, and the feed water flow correction value has the ability to correct the feed water flow formed by the original boiler main control command;

Control the fuel supply quantity based on the deviation: determine the first fuel supply quantity correction value and the second fuel supply quantity correction value based on the deviation; use the first fuel supply quantity correction value and the second fuel supply quantity correction value to correct the original boiler master The fuel supply amount formed by the control command is used to determine the fuel supply amount set value, which provides a set value for further fuel control loop; wherein, determining the first fuel supply amount correction value and the second fuel supply amount correction value based on the deviation includes: A second corrected deviation is obtained by processing the deviation through a second correction function, which is a function capable of setting a second dead zone; based on the second corrected deviation, using the first fuel correction function, determine The first fuel amount correction value; the third corrected deviation is obtained by processing the deviation through a third correction function, and the third correction function is a function that can set the third dead zone; based on the third corrected deviation, Use the second fuel correction function to determine the second fuel supply amount correction value; where, when the deviation is within the second dead zone range, the second corrected deviation is 0, and the first fuel supply amount correction value is correct for the original boiler main The fuel supply amount formed by the control command has no correction ability; when the deviation is not within the second dead zone range, the deviation after the second correction is not 0, the first fuel supply amount correction value will correct the fuel supply amount formed by the original boiler main control command. The amount has the ability to be corrected; when the deviation is within the third dead zone, the deviation after the third correction is 0, and the second fuel amount correction value has no ability to correct the fuel amount formed by the original boiler main control instruction; when the deviation Not within the scope of the third dead zone, the deviation after the third correction is not 0, and the second fuel supply amount correction value has the ability to correct the fuel supply amount formed by the original boiler main control instruction.

In one embodiment, using the first fuel supply amount correction value and the second fuel supply amount correction value to correct the fuel supply amount formed by the original boiler main control instruction includes:

Multiply the second fuel supply amount correction value with the fuel supply amount formed by the original boiler main control instruction, and the resulting fuel amount is then superimposed with the first fuel supply amount correction value to determine the fuel supply amount setting value;

Furthermore, the second fuel supply amount correction value is 0.8-1.2. The farther the corrected deviation is from 0 (that is, the further the original deviation is away from the third dead zone), the closer the corresponding second fuel supply amount correction value is to 0.8 or 1.2. After correction The closer the absolute value of the deviation is to 0 (that is, the closer the original deviation is to the third dead zone), the closer the corresponding second fuel supply correction value is to 1, and the corrected deviation is 0 (that is, the original deviation is located in the third dead zone). The second fuel supply amount correction value is 1 (at this time, the second fuel supply amount correction value does not constitute a correction of the fuel supply amount).

In one embodiment, the feed water flow correction value is used to correct the feed water flow formed by the original boiler master control instruction in the following manner:

Superimpose the feed water flow correction value with the feed water flow formed by the original boiler master control command.

In one embodiment, the midpoint temperature or enthalpy is the separator vapor temperature or enthalpy.

In one embodiment, obtaining the deviation of the midpoint temperature of the once-through boiler includes:

Obtain the actual pressure of the separator, and then obtain the design temperature value corresponding to the actual pressure of the separator; superimpose the design temperature value and the temperature offset value, and then perform second-order inertia filtering to form the set value of the separator steam temperature; where , the inertia time used in the second-order inertia filter is determined based on the main steam flow rate of the boiler;

Obtain the actual temperature of the separator and perform first-order inertial filtering on the obtained actual temperature of the separator;

Determine the deviation between the set value of the separator steam temperature and the actual temperature of the separator after first-order inertia filtering, which is the deviation of the mid-point temperature of the once-through boiler;

This optimal technical solution simulates the energy changes of the micro-hot spots during the change of the boiler's heat load, and the set value of the separator steam temperature formed has the boiler heat load characteristics;

Furthermore, the algorithm used in each order of inertial filtering is where s is the Laplacian operator and T is the inertial time;

Furthermore, the inertia time can be determined based on the main steam flow of the boiler in a conventional manner, such as an actual engineering test;

Further, the temperature offset value is operator controllable;

The design temperature value corresponding to the actual pressure of the separator can be obtained by conventional methods in this field. For example, it can be determined based on the water vapor enthalpy value calculation table.

In one embodiment, obtaining the deviation of the midpoint enthalpy value of the once-through boiler includes:

Obtain the load command of the separator, and then obtain the design enthalpy value corresponding to the load command of the separator; superimpose the design enthalpy value and the enthalpy offset value, and then perform second-order inertia filtering to form the set value of the separator steam enthalpy value ; Among them, the inertia time used in the second-order inertia filter is determined based on the main steam flow rate of the boiler;

Obtain the actual temperature and actual pressure of the separator, determine the actual enthalpy value of the separator based on the actual temperature and actual pressure of the separator, and perform first-order inertial filtering on the actual enthalpy value of the separator;

The deviation between the set value of the separator steam enthalpy value and the actual enthalpy value of the separator after first-order inertia filtering is the deviation of the mid-point enthalpy value of the once-through boiler;

This optimal technical solution realizes the simulation of the energy change of the micro-hot spot during the change of heat load of the boiler, and the set value of the separator steam enthalpy value formed has the boiler heat load characteristics;

Furthermore, the algorithm used in each order of inertial filtering is where s is the Laplacian operator and T is the inertial time;

Furthermore, the inertia time can be determined based on the main steam flow of the boiler in a conventional manner, such as an actual engineering test;

Furthermore, the enthalpy offset value is operator controllable.

In one embodiment, the method further includes:

When the water supply is not in the automatic state, the water supply flow control based on the deviation is suspended, and the water supply flow is controlled according to the first forced control of the water supply flow; among which, the first forced control of the water supply flow includes:

Track the difference between the feed water flow demand signal transformed by the boiler main control command and the engineering measuring point that actually controls the feed water flow to obtain the actual feed water flow of the boiler, and use this difference as the feed water flow adjustment amount to adjust the feed water flow;

This optimized technical solution can ensure disturbance-free switching of lower-level feedwater flow control;

Furthermore, the first forced control of feed water flow is achieved in the following ways:

Track the difference between the feed water flow demand signal transformed by the boiler main control command and the engineering measuring point that actually controls the feed water flow to obtain the actual feed water flow of the boiler, and determine the feed water flow correction value based on the difference;

Use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value;

Among them, the determined feed water flow set value is equal to the actual boiler feed water flow measured at the engineering measuring point that actually controls the feed water flow;

Furthermore, in the process of determining the feed water flow correction value based on the difference, the difference is used as the feed water flow correction value;

In the process of using the feed water flow correction value to correct the feed water flow formed by the original boiler master control instruction to determine the feed water flow set value, the feed water flow correction value is superimposed with the feed water flow formed by the original boiler master control instruction to determine the feed water flow rate. set value.

In one embodiment, the method further includes:

When the fueling automatic is not in the automatic state, the fueling amount control based on the deviation is suspended and the fueling amount is controlled according to the first forced control of the fueling amount; wherein the first forced control of the fueling amount includes:

Track the fuel supply demand signal transformed by the boiler main control command and measure the engineering measurement point that actually controls the fuel supply to obtain the difference in the actual fuel supply to the boiler, and use this difference as the fuel supply adjustment amount to adjust the fuel supply;

This preferred technical solution can ensure disturbance-free switching of lower-level fuel supply control;

Furthermore, the first forced control of the fuel supply amount is achieved in the following way:

The difference between the actual fuel supply amount of the boiler is obtained by tracking the fuel supply demand signal transformed by the boiler main control instruction and the actual control fuel supply amount measured at engineering measuring points. Based on the difference, the first fuel supply quantity correction value and the second fuel supply quantity are determined. quantity correction value;

Use the first fuel supply amount correction value and the second fuel supply amount correction value to correct the fuel supply amount formed by the original boiler main control instruction to determine the fuel supply amount set value;

Among them, the determined set value of the fuel supply amount is equal to the actual fuel supply amount of the boiler measured at the engineering measuring point that actually controls the fuel supply amount;

Furthermore, in the process of determining the first fuel supply amount correction value and the second fuel supply amount correction value based on the difference, the difference is used as the first fuel supply amount correction value; determine the second fuel supply amount correction value 1;

In the process of determining the fuel supply setting value by using the first fuel supply quantity correction value and the second fuel supply quantity correction value to correct the fuel supply quantity formed by the original boiler main control instruction, the second fuel supply quantity correction value is compared with the original fuel supply quantity correction value. The fuel supply amount formed by some boiler master control instructions is multiplied, and the resulting fuel amount is superimposed with the first fuel supply amount correction value to determine the fuel supply amount set value.

In one embodiment, the method further includes:

When the unit auxiliary machine failure trip condition (RunBack condition, RB condition) occurs, the water supply flow control is forced to take priority according to the forced water flow control of the RB condition (RunBack condition). Among them, the forced water flow control of the RB condition includes :

The water supply flow adjustment switches to the hold state, and the water supply flow adjustment plan in the water supply flow control at the previous moment is used to adjust the water supply flow;

Furthermore, the forced control of feed water flow under RB working condition is realized in the following ways:

Use the feed water flow correction value in the feed water flow control at the previous moment as the feed water flow correction value for this feed water flow adjustment;

Use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value;

Furthermore, in the process of determining the feed water flow set value by using the feed water flow correction value to correct the feed water flow formed by the original boiler master control instruction, the feed water flow correction value is superimposed on the feed water flow formed by the original boiler master control instruction. Determine the feed water flow set value.

In one embodiment, the method further includes:

When the unit auxiliary machine failure trip condition occurs, the fuel supply amount control is forced to take priority according to the fuel supply amount forced control under the RB working condition; among them, the fuel supply amount forced control under the RB working condition includes: the fuel supply amount adjustment switches to the holding state, using the above The fuel supply quantity adjustment scheme in the momentary fuel supply quantity control adjusts the fuel supply quantity;

Furthermore, the forced control of the fuel supply amount under RB operating conditions is implemented in the following ways:

The first fuel supply amount correction value in the fuel supply amount control at the previous time is used as the first fuel supply amount correction value for this fuel supply amount adjustment, and the second fuel supply amount correction value in the fuel supply amount control at the previous time is used as the first fuel supply amount correction value for this fuel supply amount adjustment. As the second fuel supply amount correction value for this fuel supply amount adjustment;

The first fuel supply amount correction value and the second fuel supply amount correction value are used to correct the fuel supply amount formed by the original boiler main control instruction to determine the fuel supply amount set value.

Furthermore, in the process of using the first fuel supply amount correction value and the second fuel supply amount correction value to correct the fuel supply amount formed by the original boiler main control instruction to determine the fuel supply amount set value, the second fuel supply amount is corrected. The value is multiplied by the fuel supply amount formed by the original boiler main control instruction, and the resulting fuel amount is then superimposed with the first fuel supply amount correction value to determine the fuel supply amount set value.

The settings of forced control of water supply flow under RB working conditions and forced control of fuel supply under RB working conditions can ensure that the fuel-water ratio (coal-to-water ratio) control during the entire RB process does not participate in the control of the entire accident process and prevent adverse effects.

In one embodiment, the unit's auxiliary machine failure trip (RunBack) operating condition signal is monitored and a falling edge delay processing is performed on it. When the unit's auxiliary machine failure trip (RunBack) operating condition occurrence signal is displayed after the falling edge delay processing If the unit's auxiliary machine failure tripping (RunBack) condition occurs, it is considered that the unit's auxiliary machine failure tripping (RunBack) condition occurs.

In one embodiment, the method includes:

Deviation acquisition: Obtain the deviation of the midpoint temperature or enthalpy value of the once-through boiler;

Optional water supply control status acquisition: Get the status of automatic water supply, which includes automatic status and non-automatic status;

Optional fueling control status acquisition: Obtain the automatic fueling status, which includes in the automatic state and not in the automatic state;

Optional unit auxiliary machine fault tripping (RunBack) condition occurrence status acquisition: Obtain the unit auxiliary machine fault tripping (RunBack) condition occurrence status, the occurrence status of the unit auxiliary machine fault tripping (RunBack) condition includes occurrence and non-occurrence ;

Feed water flow control: Feed water flow control is carried out by including a deviation-based feed water flow control step, an optional first forced control step of feed water flow, and an optional RB working condition forced water flow control step; among which, the RB working condition forced water flow control step The priority is higher than the first forced control of the feed water flow, and the priority of the first forced control of the feed water flow is higher than the feed water flow control based on the deviation;

Feed water flow control based on deviation: When the deviation is within the first dead zone, the feed water flow is not adjusted (including the feed water flow adjustment amount is 0); when the deviation is not within the first dead zone, the feed water flow is adjusted (excluding the feed water flow The adjustment amount is 0);

The first forced control of feed water flow: when the automatic water supply is not in the automatic state, the feed water flow control is carried out in the following manner: the actual feed water flow of the boiler is obtained by tracking the feed water flow demand signal converted by the boiler main control instruction and the engineering measurement point that actually controls the feed water flow. The difference is used as the feed water flow adjustment amount to adjust the feed water flow;

Forced control of water supply flow under RB working condition: When the unit auxiliary machine failure trip (RunBack) condition occurs, that is, when RB working condition occurs, the water supply flow control is carried out in the following way: the water supply flow adjustment is cut into the holding state, and the water supply at the previous moment is used. The feed water flow adjustment scheme in flow control regulates the feed water flow;

Fuel supply quantity control: The fuel supply quantity is controlled by including a fuel supply quantity control step based on the deviation, an optional first forced control step of the fuel supply quantity, and an optional fuel supply quantity forced control step under RB working condition; wherein, RB working condition In this case, the priority of the forced control of the fuel supply amount is higher than the first forced control of the fuel supply amount, and the priority of the first forced control of the fuel supply amount is higher than that of the fuel supply amount control based on the deviation;

Control the fuel supply amount based on the deviation: when the deviation is within the second dead zone range, the fuel supply quantity is not adjusted (including the fuel supply quantity adjustment amount is 0); when the deviation is not within the second dead zone range but within the third dead zone range, When the deviation is within the range of the third dead zone, adjust the fuel supply amount (excluding the fuel supply amount adjustment amount is 0), and the adjustment amount of the fuel supply amount is determined based on the first fuel correction function; when the deviation is not within the third dead zone, adjust the feed water flow (excluding the feed water flow adjustment amount is 0), the adjustment amount of the fuel supply amount is determined based on the first fuel correction function and the second fuel correction function;

The first forced control of the fuel supply amount: When the fuel supply automatic is not in the automatic state, the fuel supply quantity control is carried out in the following manner: tracking the fuel supply quantity demand signal converted by the boiler main control instruction and the engineering measurement point that actually controls the fuel supply quantity The difference in the actual fuel supply amount to the boiler is measured, and the difference is used as the fuel supply volume adjustment amount to adjust the fuel supply volume;

Forced control of the fuel supply amount under RB operating conditions: When the unit auxiliary machine fails to trip (RunBack), that is, when the RB operating condition occurs, the fuel supply amount control is prioritized and forced to proceed in the following manner: The unit auxiliary machine fails to trip (RunBack). ) working condition, the fuel supply amount adjustment switches to the holding state, and the fuel supply amount adjustment plan in the fuel supply amount control at the previous moment is used to adjust the fuel supply amount;

Among them, the first dead zone is a subset of the second dead zone, and the second dead zone is a subset of the third dead zone (that is, the first dead zone is included in the second dead zone, and the second dead zone is included in the third dead zone. );

When the deviation is not within the third dead zone range, for the same deviation, the adjustment amount of the fuel amount is determined based on the first fuel correction function and the second fuel correction function compared to the determination based only on the first fuel correction function. The adjustment amount is larger.

In one embodiment, the method includes:

Deviation acquisition: Obtain the deviation of the midpoint temperature or enthalpy value of the once-through boiler;

Optional water supply control status acquisition: Get the status of automatic water supply, which includes automatic status and non-automatic status;

Optional fueling control status acquisition: Obtain the automatic fueling status, which includes in the automatic state and not in the automatic state;

Optional unit auxiliary machine fault tripping (RunBack) condition occurrence status acquisition: Obtain the unit auxiliary machine fault tripping (RunBack) condition occurrence status, the occurrence status of the unit auxiliary machine fault tripping (RunBack) condition includes occurrence and non-occurrence ;

Feed water flow control: Feed water flow control is carried out by including a deviation-based feed water flow control step, an optional first forced control step of feed water flow, and an optional RB working condition forced water flow control step; among which, the RB working condition forced water flow control step The priority is higher than the first forced control of the feed water flow, and the priority of the first forced control of the feed water flow is higher than the feed water flow control based on the deviation;

Feed water flow control based on deviation: Determine the feed water flow correction value through the step of determining the feed water flow correction value based on the deviation; use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value, as The water supply control loop further provides a set value; wherein the step of determining the water supply flow correction value based on the deviation includes: processing the deviation through a first correction function to obtain a first corrected deviation, and the first correction function is capable of setting the first correction value. A function of the dead zone; based on the first corrected deviation, use the feed water flow correction function to determine the feed water flow correction value; where, when the deviation is within the first dead zone, the first corrected deviation is 0, and the feed water flow correction value The value has no ability to correct the feed water flow caused by the original boiler main control command; when the deviation is not within the first dead zone, the deviation after the first correction is not 0, and the feed water flow correction value has the ability to correct the original boiler main control command. The feed water flow rate has the ability to be corrected;

The first forced control of feed water flow: when the automatic water supply is not in the automatic state, the feed water flow control is carried out in the following manner: the actual feed water flow of the boiler is obtained by tracking the feed water flow demand signal converted by the boiler main control instruction and the engineering measurement point that actually controls the feed water flow. The difference is determined based on the difference, and the feed water flow correction value is determined. The feed water flow correction value is used to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value; where, the determined feed water flow set value is The actual feed water flow of the boiler is measured by the engineering measuring points that actually control the feed water flow;

Forced control of feed water flow in RB working condition: When the unit auxiliary machine failure trip (RunBack) condition occurs, that is, when RB working condition occurs, the feed water flow control is carried out in the following way: the feed water flow rate in the feed water flow control at the previous moment is corrected The value is used as the feed water flow correction value for this feed water flow adjustment. Based on the feed water flow correction value for this feed water flow adjustment, the feed water flow formed by the original boiler main control instruction is corrected to determine the feed water flow set value;

Fuel supply quantity control: The fuel supply quantity is controlled by including a fuel supply quantity control step based on the deviation, an optional first forced control step of the fuel supply quantity, and an optional fuel supply quantity forced control step under RB working condition; wherein, RB working condition In this case, the priority of the forced control of the fuel supply amount is higher than the first forced control of the fuel supply amount, and the priority of the first forced control of the fuel supply amount is higher than that of the fuel supply amount control based on the deviation;

Carry out fuel supply quantity control based on the deviation: determine the first fuel supply quantity correction value and the second fuel supply quantity correction value through the step of determining the fuel supply quantity correction value based on the deviation; use the first fuel supply quantity correction value and the second fuel supply quantity correction value. The fuel quantity correction value corrects the fuel supply quantity formed by the original boiler main control instruction to determine the fuel supply quantity set value, and provides a set value for further fuel control loop; wherein, the step of determining the fuel supply quantity correction value based on the deviation includes : The second corrected deviation is obtained by processing the deviation through the second correction function, and the second correction function is a function that can set the second dead zone; based on the second corrected deviation, using the first fuel correction function, Determine the first fuel supply correction value; process the deviation through a third correction function to obtain a third corrected deviation, and the third correction function is a function capable of setting a third dead zone; based on the third corrected deviation , use the second fuel correction function to determine the second fuel supply correction value; where, when the deviation is within the second dead zone range, the second corrected deviation is 0, and the first fuel supply correction value is correct for the original boiler The fuel supply amount formed by the main control instruction has no correction ability; when the deviation is not within the second dead zone range, the second corrected deviation is not 0, and the first fuel supply amount correction value will not correct the fuel supply amount formed by the original boiler main control instruction. The fuel quantity has the ability to be corrected; when the deviation is within the third dead zone, the deviation after the third correction is 0, and the second fuel quantity correction value has no correction capability for the fuel quantity formed by the original boiler main control instruction; when The deviation is not within the third dead zone, the deviation after the third correction is not 0, and the second fuel supply amount correction value has the ability to correct the fuel supply amount formed by the original boiler main control instruction;

The first forced control of the fuel supply amount: When the fuel supply automatic is not in the automatic state, the fuel supply quantity control is carried out in the following manner: tracking the fuel supply quantity demand signal converted by the boiler main control instruction and the engineering measurement point that actually controls the fuel supply quantity The difference between the actual fuel supply amount of the boiler is measured, and the first fuel supply quantity correction value and the second fuel supply quantity correction value are determined based on the difference; the original fuel supply quantity correction value and the second fuel supply quantity correction value are used to correct the original fuel supply quantity. Some boiler main control instructions form the fuel supply amount to determine the fuel supply amount set value; among them, the determined fuel supply amount set value is equal to the actual fuel supply amount of the boiler measured at the engineering measuring point that actually controls the fuel supply amount;

Forced control of the fuel supply amount under RB working condition: When the unit auxiliary machine failure trip (RunBack) condition occurs, that is, when the RB working condition occurs, the fuel supply quantity control is carried out in the following way: the fuel supply quantity control at the previous moment is The first fuel supply quantity correction value is used as the first fuel supply quantity correction value for this fuel supply quantity adjustment, and the second fuel supply quantity correction value in the fuel supply quantity control at the previous time is used as the second fuel supply quantity adjustment value for this time. The fuel supply quantity correction value; based on the first fuel supply quantity correction value and the second fuel supply quantity correction value of this fuel supply quantity adjustment, the fuel supply quantity formed by the original boiler main control instruction is corrected to determine the fuel supply quantity set value. ;

Among them, the first dead zone is a subset of the second dead zone, and the second dead zone is a subset of the third dead zone (that is, the first dead zone is included in the second dead zone, and the second dead zone is included in the third dead zone. );

When the deviation is not within the third dead zone range, for the same deviation, the adjustment amount of the fuel amount is determined based on the first fuel correction function and the second fuel correction function compared to the determination based only on the first fuel correction function. The adjustment amount is larger;

Furthermore, feed water flow control is achieved in the following ways:

The feed water flow correction value is determined by including a step of determining the feed water flow correction value based on the deviation, an optional first forced control step of the feed water flow correction value, and an optional forced control step of the feed water flow correction value of the RB operating condition; wherein, the RB operating condition The priority of the forced control of the feed water flow correction value is higher than the first forced control of the feed water flow correction value, and the priority of the first forced control of the feed water flow correction value is higher than the determination of the feed water flow correction value based on the deviation;

Use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value and provide set values for further feed water control loops;

Among them, the feed water flow correction value is determined based on the deviation: the deviation is processed through a first correction function to obtain the first corrected deviation, and the first correction function is a function that can set the first dead zone; based on the first corrected Deviation of the feed water flow correction function is used to determine the feed water flow correction value; among them, when the deviation is within the first dead zone range, the first corrected deviation is 0, and the feed water flow correction value is formed by the original boiler main control instruction. The feed water flow has no correction ability; when the deviation is not within the first dead zone, the deviation after the first correction is not 0, and the feed water flow correction value has the ability to correct the feed water flow formed by the original boiler main control instruction;

The first forced control of the feed water flow correction value: when the water supply is not in the automatic state, the feed water flow correction value is determined as follows: the feed water flow demand signal converted by tracking the boiler main control instruction and the engineering measurement point that actually controls the feed water flow are measured. The difference between the actual feed water flow of the boiler and the correction value of the feed water flow determined based on the difference. The correction value of the feed water flow determined based on the difference can be used to achieve the set value of the feed water flow determined in the subsequent steps and the actual control of the feed water flow. The actual feed water flow rate of the boiler measured at the engineering measuring points is equal;

Forced control of the feed water flow correction value under RB working condition: When the unit auxiliary machine failure trip (RunBack) condition occurs, that is, when the RB working condition occurs, the feed water flow correction value is determined in the following way: the feed water flow rate at the previous moment is controlled The feed water flow correction value is used as the feed water flow correction value for this feed water flow adjustment;

Further, the fuel supply amount control is achieved in the following ways:

The first fuel supply amount correction value is determined by including a step of determining the fuel supply amount correction value based on the deviation, an optional first forced control step of the fuel supply amount correction value, and an optional RB operating condition fuel supply amount correction value forced control step, The second correction value of the fuel supply amount is determined; among them, the forced control priority of the fuel supply amount correction value in the RB operating condition is higher than the first forced control of the fuel supply amount correction value, and the first forced control priority of the fuel supply amount correction value is higher than that based on the deviation. Determine the fuel supply correction value;

Use the first fuel supply amount correction value and the second fuel supply amount correction value to correct the fuel supply amount formed by the original boiler main control instruction to determine the fuel supply amount set value, and provide a set value for further fuel control loop;

The correction value of the fuel supply amount is determined based on the deviation: the deviation is processed through a second correction function to obtain a second corrected deviation, and the second correction function is a function that can set the second dead zone; based on the second corrected Deviation, use the first fuel correction function to determine the first fuel amount correction value; process the deviation through the third correction function to obtain the third corrected deviation, the third correction function is capable of setting the third dead zone function; based on the third corrected deviation, use the second fuel correction function to determine the second fuel supply amount correction value; where, when the deviation is within the second dead zone range, the second corrected deviation is 0, and the first fuel supply amount correction value is The fuel quantity correction value has no ability to correct the fuel supply quantity formed by the original boiler main control instruction; when the deviation is not within the second dead zone range, the second corrected deviation is not 0, and the first fuel supply quantity correction value has no correction ability to the original fuel quantity correction value. The fuel supply amount formed by some boiler master control instructions has the ability to be corrected; when the deviation is within the third dead zone, the deviation after the third correction is 0, and the second fuel supply amount correction value forms a correction value for the original boiler master control instruction. The fuel supply amount has no correction ability; when the deviation is not within the third dead zone, the deviation after the third correction is not 0, and the second fuel supply amount correction value has a correction to the fuel supply amount formed by the original boiler main control instruction ability;

The first forced control of the fuel supply amount correction value: when the fuel supply amount is not in the automatic state, the fuel supply amount correction value is determined as follows: tracking the fuel supply amount demand signal converted by the boiler main control command and the actual control fuel supply amount The difference in the actual fuel supply amount of the boiler is measured at the engineering measuring point, and the first fuel supply quantity correction value and the second fuel supply quantity correction value are determined based on the difference; wherein, the first fuel supply quantity correction value determined based on the difference The value and the second fuel supply amount correction value can realize that the actual fuel supply amount of the boiler obtained by using the fuel supply amount set value determined in the subsequent steps and the engineering measurement point that actually controls the fuel supply amount are equal;

Forced control of the fuel supply amount correction value under RB operating condition: When the unit auxiliary machine failure trip (RunBack) operating condition occurs, that is, when the RB operating condition occurs, the fuel supply amount correction value is determined in the following way: the fuel supply at the previous moment is The first fuel supply quantity correction value in the fuel supply quantity control is used as the first fuel supply quantity correction value for this fuel supply quantity adjustment, and the second fuel supply quantity correction value in the fuel supply quantity control at the previous time is used as the fuel supply quantity this time. Adjusted second fuel quantity correction value.

In one embodiment, when the deviation is the midpoint temperature deviation, the first dead zone is [-2,2] (unit: °C); the second dead zone is [-5,5] (unit: °C); The three dead zones are [-10,10] (unit: °C).

In one embodiment, the deviation of the midpoint temperature or enthalpy value is expressed by subtracting the measured value of the midpoint temperature or enthalpy value from the set value of the midpoint temperature or enthalpy value.

In one implementation, the first correction function is:

In the formula, error ₁ is the first corrected deviation; error ₀ is the original deviation.

In one implementation, the second correction function is:

In the formula, error ₂ is the second corrected deviation; error ₀ is the original deviation.

In one implementation, the third correction function is:

In the formula, error ₃ is the third corrected deviation; error ₀ is the original deviation.

In one implementation, the feed water flow correction function is a PID algorithm model:

In the formula, error ₁ is the deviation after the first correction; FW_Corr is the feed water flow correction value; kp ₁ is the proportional coefficient; T ₁ is the integration time.

In one implementation, the first fuel correction function is a PID algorithm model:

In the formula, error ₂ is the second corrected deviation; FUEL_Corr is the first fuel supply correction value; kp ₂ is the proportional coefficient; T ₂ is the integration time.

In one implementation, the second fuel correction function is a PID algorithm model:

The original default output is 1;

In the formula, error ₃ is the third corrected deviation; MU_Factor is the third fuel supply correction value; kp ₃ is the proportional coefficient; T ₃ is the integration time.

The PID algorithm model is actually an incremental operation model, and all calculated values increase or decrease from the original values; the original default output of the PID algorithm model used in the above water flow correction function and the first fuel correction function is 0, and the second The original default output of the PID algorithm model used by the fuel correction function is 1.

In one embodiment, the difference between the feed water flow demand signal converted by the boiler main control instruction and the actual boiler feed water flow measured at the engineering measuring point that actually controls the feed water flow is measured at the engineering measuring point that actually controls the feed water flow to obtain the actual boiler feed water flow minus The feed water flow demand signal converted by the boiler master control command is expressed.

In one embodiment, the difference between the fuel supply quantity demand signal converted by the boiler main control instruction and the actual fuel supply quantity of the boiler obtained by measuring the engineering measuring point that actually controls the fuel supply quantity is measured by the engineering measuring point that actually controls the fuel supply quantity. The actual fuel supply amount is expressed by subtracting the fuel supply demand signal converted by the boiler main control command.

The embodiment of the present invention also provides a coal-to-water ratio control system. Preferably, the system is used to implement the above method embodiment.

Figure 2 is a structural block diagram of a coal-to-water ratio control system according to an embodiment of the present invention. As shown in Figure 2, the system includes:

Deviation acquisition module 21: used to obtain the deviation of the midpoint temperature or enthalpy value of the once-through boiler;

The first deviation correction module 22 is used to process the deviation through a first correction function to obtain the first corrected deviation. The first correction function is a function that can set the first dead zone; when the deviation is in the first dead zone The deviation after the first correction within the range is 0. When the deviation is not within the first dead zone range, the deviation after the first correction is not 0;

The second deviation correction module 23 is used to process the deviation through a second correction function to obtain a second corrected deviation. The second correction function is a function that can set the second dead zone; when the deviation is in the second dead zone The deviation after the second correction is 0 within the range. When the deviation is not within the second dead zone range, the deviation after the second correction is not 0;

The third deviation correction module 24 is used to process the deviation through a third correction function to obtain the third corrected deviation. The third correction function is a function that can set the third dead zone; when the deviation is in the third dead zone The deviation after the third correction within the range is 0. When the deviation is not within the third dead zone, the deviation after the first correction is not 0;

The first PID controller 25 includes a first logic control unit; the first logic control unit is used to determine the feed water flow correction value based on the first corrected deviation using the feed water flow correction function; wherein, the first logic control unit performs The feed water flow correction value is determined to meet the following requirements: when the first corrected deviation is 0, the determined feed water flow correction value has no ability to correct the feed water flow formed by the original boiler main control instruction; when the first corrected deviation is not 0 The feed water flow correction value has the ability to correct the feed water flow formed by the original boiler main control command;

Original feed water flow acquisition module 26: used to obtain the feed water flow formed by the original boiler master control instruction;

Feed water flow set value determination module 27: used to use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value;

The second PID controller 28 includes a second logic control unit; the second logic control unit is used to determine the first fuel amount correction value based on the second corrected deviation using the first fuel correction function; wherein, the The determination of the first fuel supply amount correction value carried out by the second logic control unit satisfies: when the second corrected deviation is 0, the first fuel supply amount correction value determined has no influence on the fuel supply amount formed by the original boiler main control instruction. Correction ability: when the second corrected deviation is not 0, the first fuel supply correction value determined has the ability to correct the fuel supply quantity formed by the original boiler main control instruction;

The third PID controller 29 includes a third logical control unit; the third logical control unit is used to determine the second fuel supply amount correction value based on the third corrected deviation and using the second fuel correction function; wherein, the third The determination of the second fuel supply amount correction value carried out by the three logic control units satisfies: when the third corrected deviation is 0, the second fuel supply amount correction value determined has no influence on the fuel supply amount formed by the original boiler main control instruction. Correction ability. When the deviation after the third correction is not 0, the second fuel supply amount correction value determined has the ability to correct the fuel supply amount formed by the original boiler main control instruction;

Original fuel supply quantity acquisition module 30: used to obtain the fuel supply quantity formed by the original boiler master control instruction;

The fuel supply amount set value determination module 31 is used to correct the fuel supply amount formed by the original boiler main control instruction using the first fuel supply amount correction value and the second fuel supply amount correction value to determine the fuel supply amount set value, To further provide set values for the fuel control circuit.

In one embodiment, the fuel supply amount set value determination module 31 includes a first fuel supply amount correction sub-module and a second fuel supply amount correction sub-module; the first fuel supply amount correction sub-module is used for the second fuel supply amount correction sub-module. The fuel supply quantity correction value corrects the fuel supply quantity formed by the original boiler main control instruction to obtain the first corrected fuel supply quantity; the second fuel supply quantity correction sub-module is used to correct the first fuel supply quantity correction value to the first fuel supply quantity correction value. The corrected fuel quantity is used to determine the fuel quantity setting value.

In one embodiment, the system further includes:

Water supply control status acquisition module: used to obtain the status of automatic water supply. The status of automatic water supply includes automatic status and not automatic status;

The first difference acquisition module: used to track the feed water flow demand signal transformed by the boiler main control instruction and the engineering measurement point that actually controls the feed water flow to obtain the difference between the actual feed water flow of the boiler;

The first PID controller 25 includes a fourth logic control unit: when the water supply control state acquisition module acquires that the water supply is not in the automatic state, start determining the feed water flow correction value based on the difference obtained by the first difference acquisition module. ;The fourth logical control unit has a higher priority than the first logical control unit;

The water supply control state acquisition module and the first difference acquisition module are respectively connected to the first PID controller 25;

Further, the fourth logical control unit includes a fourth logical trigger subunit and a fourth logical operation subunit, the water supply control state acquisition module is connected to the fourth logical trigger subunit, and the first difference acquisition module is connected to the fourth logical operation subunit. , thereby realizing that the automatic water supply control state signal obtained by the water supply control state acquisition module is transmitted to the fourth logic trigger subunit, and the fourth logic trigger subunit is used to trigger the fourth logic operation when receiving a signal that the water supply is not in the automatic state. After the subunit is started, the fourth logical operation subunit is used to determine the feed water flow correction value based on the difference obtained by the first difference acquisition module.

In one embodiment, the system further includes:

Fueling control status acquisition module: used to acquire the status of automatic fueling. The status of automatic fueling includes automatic status and non-automatic status;

The second difference acquisition module: used to track the fuel supply demand signal transformed by the boiler main control instruction and the engineering measurement point that actually controls the fuel supply volume to obtain the difference between the actual fuel supply volume of the boiler;

The second PID controller 28 includes a fifth logic control unit: when the fueling control state acquisition module acquires that the fueling automatic is not in the automatic state, start determining the first value based on the difference acquired by the second difference acquisition module. Give the fuel amount correction value; the fifth logical control unit has a higher priority than the second logical control unit 281;

The third PID controller 29 includes a sixth logic control unit configured to start determining the second value based on the difference value obtained by the second difference value acquisition module when the fuel supply control state acquisition module obtains that the fuel supply automatic is not in the automatic state. Give the fuel amount correction value; the sixth logic control unit has a higher priority than the third logic control unit;

The fuel control state acquisition module is connected to the second PID controller 28 and the third PID controller 29 respectively, and the second difference acquisition module is connected to the second PID controller 28 and the third PID controller 29 respectively;

Further, the fifth logical control unit includes a fifth logical trigger subunit and a fifth logical operation subunit, and the fuel control state acquisition module is connected to the fifth logical trigger subunit, and the second difference acquisition module is connected to the fifth logical operation subunit. connection, thereby transmitting the automatic fueling control status signal acquired by the fueling control status acquisition module to the fifth logical triggering subunit. The fifth logical triggering subunit is used to trigger when receiving a signal that the fueling automatic is not in the automatic state. The fifth logical operation subunit is started. After the fifth logical operation subunit is started, it is used to determine the first fuel flow correction value based on the difference obtained by the second difference acquisition module;

Further, the sixth logic control unit includes a sixth logic trigger subunit and a sixth logic operation subunit, and the fuel control state acquisition module is connected to the sixth logic trigger subunit, and the second difference acquisition module is connected to the sixth logic operation subunit. connection, thereby transmitting the automatic fueling control state signal acquired by the fueling control state acquisition module to the sixth logical triggering subunit. The sixth logical triggering subunit is used to trigger when receiving a signal that the fueling automatic is not in the automatic state. The sixth logic operation subunit is started. After the sixth logic operation subunit is started, it is used to determine the second fuel flow correction value based on the difference obtained by the second difference acquisition module.

In one embodiment, the system further includes:

RB operating condition occurrence status acquisition module: used to obtain the occurrence status of the unit's auxiliary engine fault trip (RunBack) condition. The occurrence status of the unit's auxiliary engine fault trip (RunBack) condition includes occurrence and non-occurrence;

The first PID controller 25 includes a seventh logical control unit: used to start the water supply in the water supply flow control at the previous moment when the RB operating condition occurrence status acquisition module 36 acquires the unit auxiliary machine failure trip (RunBack) operating condition. The flow correction value is used as the feed water flow correction value for this feed water flow adjustment; the seventh logical control unit has a higher priority than the first logical control unit and the fourth logical control unit;

The second PID controller 28 includes an eighth logic control unit: used for when the RB operating condition occurrence status acquisition module acquires the unit auxiliary machine failure trip (RunBack) operating condition, start to give the last moment to the third unit in the fuel quantity control. A fuel supply amount correction value is used as the first fuel supply amount correction value for this fuel supply amount adjustment; the eighth logic control unit has a higher priority than the second logic control unit and the fifth logic control unit;

The third PID controller 29 includes a ninth logic control unit: used for when the RB operating condition occurrence status acquisition module 36 acquires the unit auxiliary machine failure trip (RunBack) operating condition, start to give the last moment to the fuel quantity control. The second fuel supply amount correction value is used as the second fuel supply amount correction value for this fuel supply amount adjustment; the ninth logic control unit has a higher priority than the third logic control unit and the sixth logic control unit;

Further, the RB operating condition occurrence status acquisition module includes: a sequentially connected RB operating condition occurrence signal monitoring sub-module and a TOF sub-module; wherein the sequentially connected RB operating condition occurrence signal monitoring sub-module is used to detect unit auxiliary machine fault tripping. (RunBack) working condition occurrence signal, the TOF sub-module is used for unit auxiliary machine fault trip (RunBack) working condition occurrence signal falling edge delay processing.

In one embodiment, referring to Figure 3, the deviation acquisition module 21 includes a separator actual pressure corresponding to the design temperature acquisition sub-module 211, a temperature offset value acquisition sub-module 212, a first superposition calculation sub-module 213, and a first LAG sub-module 214 , the second LAG sub-module 215, the fifth LAG sub-module 216 and the first difference calculation sub-module 217; among them, the actual pressure of the separator corresponds to the design temperature acquisition sub-module 211 and the temperature offset value acquisition sub-module 212 are respectively related to the first difference calculation sub-module 217. The superposition calculation sub-module 213 is connected. The first superposition calculation module 213, the first LAG sub-module 214 and the second LAG sub-module 215 are connected in series in sequence. The second LAG sub-module 215 and the fifth LAG sub-module 216 are respectively calculated with the first difference value. Submodule 217 is connected; where,

The actual pressure of the separator corresponds to the design temperature acquisition sub-module 211: used to determine the design temperature value corresponding to the actual pressure of the separator based on the actual pressure of the separator; the temperature offset value acquisition sub-module 212: used to obtain the temperature offset value; A superposition calculation sub-module 213: used to superimpose the design temperature value corresponding to the actual pressure of the separator and the temperature offset value; the first LAG sub-module 214 and the second LAG sub-module 215 in series: used to calculate the first superposition The superposition value determined by the sub-module 213 is subjected to second-order inertial filtering to obtain the set value of the separator steam temperature; the fifth LAG sub-module 216 is used to perform first-order inertial filtering processing on the actual temperature of the separator; the first difference calculation sub-module 217 is used to determine the difference between the set value of the separator steam temperature and the actual temperature of the separator after first-order inertia filtering, which is the deviation of the mid-point temperature of the once-through boiler;

Further, the deviation acquisition module 21 also includes a first inertia time determination sub-module 218, which is used to determine the inertia time used by the first LAG sub-module 214 and the second LAG sub-module 215 when performing inertial filtering based on the main steam flow rate of the boiler.

In one embodiment, referring to Figure 4, the deviation acquisition module 21 includes a design enthalpy value acquisition sub-module 2111 corresponding to the separator load instruction, an enthalpy offset value acquisition sub-module 2121, a second superposition calculation sub-module 2131, a third LAG sub-module 2111. Module 2141, separator actual enthalpy value determination sub-module 2151, fourth LAG sub-module 2161, sixth LAG sub-module 2171 and second difference calculation sub-module 2181; among them, the separator load instruction corresponds to the design enthalpy value acquisition sub-module 2111 , the enthalpy offset value acquisition sub-module 2121 is connected to the second superposition calculation sub-module 2131 respectively, and the second superposition calculation module 2131, the third LAG sub-module 2141 and the fourth LAG sub-module 2161 are connected in series in sequence; the actual enthalpy value of the separator is determined The sub-module 2151 is connected to the fourth LAG sub-module 2161, and the fourth LAG sub-module 2161 and the sixth LAG sub-module 2171 are respectively connected to the second difference calculation sub-module 2181; wherein,

The sub-module 2111 for obtaining the design enthalpy value corresponding to the load instruction of the separator: used to determine the design enthalpy value corresponding to the load instruction of the separator based on the load instruction of the separator; the sub-module 2121 for obtaining the enthalpy offset value: used to obtain the enthalpy offset value; the second superposition calculation sub-module 2131: used to superimpose the design enthalpy value corresponding to the load instruction of the separator and the enthalpy offset value; the third LAG sub-module 2141 and the fourth LAG sub-module 2161 connected in series: used to calculate The superposition value determined by the second superposition calculation sub-module 2131 is subjected to second-order inertial filtering to obtain the set value of the separator steam temperature; the separator actual enthalpy value determination sub-module 2151 is used to determine the separator based on the actual temperature and actual pressure of the separator. Actual enthalpy value; the sixth LAG sub-module 2171 is used to perform first-order inertia filtering processing on the actual enthalpy value of the separator; the second difference calculation sub-module 2181 is used to determine the set value of the separator steam enthalpy value and the first-order inertia The difference in the actual enthalpy value of the filtered separator is the deviation of the mid-point enthalpy value of the once-through boiler;

Further, the deviation acquisition module 21 also includes a second inertia time determination sub-module 2191, which is used to determine the inertia time used by the third LAG sub-module 2141 and the fourth LAG sub-module 2161 when performing inertial filtering based on the main steam flow rate of the boiler.

In one implementation, the first difference calculation sub-module 217, the second difference calculation sub-module 2181, the first difference acquisition module, and the second difference acquisition module may all use a subtraction block.

In one embodiment, the first superposition calculation sub-module 213, the second superposition calculation sub-module 2131, the water supply flow set value determination module 27, and the second fuel supply amount correction sub-module can all use addition blocks.

In one embodiment, the first fuel amount correction sub-module may use a multiplication block.

Example 1

This embodiment provides a coal-to-water ratio control method, the flow of which is shown in Figures 7-9, specifically including:

1. Get deviation error ₀

1.1. Obtain the set value SP _Tsep of the separator steam temperature (or enthalpy value) of the once-through boiler and the measured value PV _Tsep of the separator steam temperature (or enthalpy value);

Among them, obtaining the set value SP _Tsep of the separator steam temperature (or enthalpy value) of the once-through boiler is achieved in the following way:

The actual pressure at the separator outlet is processed by the given function Fx6 (which can be determined according to the conventional method of calculating the water vapor enthalpy value of the separator of the once-through boiler) to obtain the design temperature value corresponding to the actual pressure of the separator; obtain the temperature deviation Set the value Bias (can be manually set according to the specific type of unit); use the addition block (i.e. the first superposition calculation sub-module) to superimpose the design temperature value corresponding to the actual pressure of the separator and the temperature offset value Bias; after superposition The value is sequentially passed through two LAG blocks (i.e., the first LAG sub-module and the second LAG sub-module) for second-order inertial filtering to form the set value SP _Tsep of the separator steam temperature; among them, the values used in the two LAG blocks are The inertia time is determined in the following way: use the given function Fx7 (which can be determined in a conventional way according to the specific type of unit) to process the main steam flow of the boiler to determine the inertia time used in the two LAG blocks;

Through the given function Fx8 (which can be determined in a conventional way according to the specific type of unit), the actual load command at the separator outlet is processed to obtain the design enthalpy value corresponding to the actual load command of the separator; the enthalpy bias value Bias (according to The specific type of unit can be set manually); use the addition block (i.e. the second superposition calculation sub-module) to superimpose the design enthalpy value corresponding to the actual load command of the separator and the enthalpy bias value Bias; the superimposed values are sequentially passed through The two LAG blocks (i.e., the third LAG sub-module and the fourth LAG sub-module) perform second-order inertia filtering to form the set value SP _Tsep of the separator steam enthalpy; among them, the inertia time used in the two LAG blocks Determine it in the following way: use the given function Fx9 (which can be determined in a conventional way according to the specific type of unit) to process the main steam flow of the boiler to determine the inertia time used in the two LAG blocks;

Among them, obtaining the measured value PV _Tsep of the separator steam temperature (or enthalpy value) of the once-through boiler is achieved in the following way:

Obtain the actual temperature of the separator, and perform first-order inertial filtering on the obtained actual temperature of the separator through a LAG block (i.e., the fifth LAG sub-module) to obtain the measured value PV _Tsep of the separator steam temperature;

Obtain the actual temperature and actual pressure of the separator, and use the Cal block to perform calculations based on the actual temperature and actual pressure of the separator (obtained through table lookup or fitting calculation) to determine the actual enthalpy value of the separator; use the determined actual enthalpy value of the separator The enthalpy value undergoes first-order inertial filtering through a LAG block (i.e., the sixth LAG sub-module) to obtain the measured value PV _Tsep of the separator steam enthalpy value;

Among them, the algorithm used in each order of inertial filtering is where s is the Laplacian operator and T is the inertial time.

When the boiler is a certain unit type, the given function Fx6 satisfies the following table 1, the given function Fx7 satisfies the following table 2, and the given function Fx8 (the enthalpy value is expressed by temperature; for example, when the load is 400t/h, the actual value of the separator The design enthalpy value corresponding to the load command (the enthalpy value corresponding to 362°C) satisfies the following table 3. The given function Fx9 satisfies the following table 4:

Table 1

Pressure(Mpa) 14.51 17.4 19.1 21.5 23.01 26.38 26.62 27.8 28.5 Temperature(℃) 362 367 372 383 386 403.9 406.6 409 410

Table 2

Main steam flow (t/h) 1044 1588 1869 2136 2403 2675 3000 Inertia time(s) 15 12 8 5 5 5 5

table 3

Load(t/h) 400 450 550 650 750 850 900 950 1000 Temperature(℃) 362 365 367 374 386 403.9 406.6 409 410

Table 4

Main steam flow (t/h) 1044 1588 1869 2136 2403 2675 3000 Inertia time(s) 18 15 12 8 8 7 5

1.2. Determine the difference between the set value SP _Tsep of the separator steam temperature (or enthalpy value) and the measured value PV _Tsep of the separator steam temperature (or enthalpy value) to obtain the control deviation error ₀ , error ₀ = SP _Tsep -PV _Tsep .

2. Get the status of automatic water supply. The status of automatic water supply includes automatic status and not automatic status.

3. Monitor the unit's auxiliary machine fault trip (i.e. RB) signal and use the tof block (i.e. TOF sub-module) to perform falling edge delay processing (falling edge delay is more than 10s). When the unit after falling edge delay processing If the auxiliary engine failure trip condition signal indicates that the unit auxiliary engine failure trip condition has occurred, it is considered that the unit auxiliary engine failure trip condition has occurred.

4. Obtain the boiler main control command BMD; the boiler main control command BMD is processed through the given function Fx1 (which can be determined in a conventional way according to the specific type of the unit) to obtain the feed water flow FW_MD formed by the original boiler main control command; the boiler main control command The command BMD is processed through the given function Fx2 (which can be determined in a conventional way according to the specific type of unit) to obtain the fuel supply amount FUEL_MD formed by the original boiler master control command.

When the boiler is a certain unit type, the given function Fx1 satisfies the following table 5, and the given function Fx2 satisfies the following table 6:

table 5

Main control command BMD 0% 40% 53% 80% 100% 110% Feed water flow (t/h) 940 1080 1440 2150 2710 3000

Table 6

Main control command BMD 0% 40% 53% 80% 100% 110% Fuel volume (t/h) 0 160 1440 315 375 430

5. Obtain the feed water flow demand signal (i.e., feed water flow FW_MD) converted from the boiler main control instruction and measure the engineering measuring point that actually controls the feed water flow to obtain the actual feed water flow of the boiler (i.e., the actual feed water flow); and use the subtraction block to determine the boiler main control instruction. The difference between the converted feed water flow demand signal and the engineering measuring point that actually controls the feed water flow is measured to obtain the actual feed water flow of the boiler;

Obtain the fuel supply demand signal (i.e., feed water flow rate FUEL_MD) converted from the boiler master control instruction and measure the actual control feed water flow at the engineering measurement point to obtain the actual fuel supply volume of the boiler (i.e., the actual fuel supply volume); and use the subtraction block to determine the boiler master control The difference between the command-converted fuel supply demand signal and the engineering measuring point that actually controls the fuel supply volume is the actual feed water flow rate of the boiler.

6. Feed water flow control (first fork arm control):

6.1. Determine the feed water flow correction value FW_Corr

Use the method given in step 6.1.1, step 6.1.2 or step 6.1.3 to determine the feed water flow correction value FW_Corr; where step 6.1.3 has a higher priority than step 6.1.2, and step 6.1.2 has a higher priority. In step 6.1.1;

6.1.1. The first correction function fx3 performs deviation processing on the control deviation error ₀ to obtain the first corrected deviation; after the first corrected deviation enters the controller PID1 (i.e. the first PID controller), it passes through the controller PID1 The SP unit (i.e. the first logical control unit) uses the feed water flow correction function to perform calculations to determine the feed water flow correction value FW_Corr; where,

The first correction function fx3 is: In the formula, error ₁ is the first corrected deviation; error ₀ is the original deviation;

When the control deviation error ₀ is the separator steam temperature deviation, use the first correction function fx3 to perform deviation processing on the control deviation error ₀ to obtain the first corrected deviation as shown in Table 7;

Table 7

Input(℃) -20 -10 -5 -2 2 5 10 20 Output(℃) -20 -10 -5 0 0 5 10 20

The feed water flow correction function is The original default output is 0; in the formula, error ₁ is the first corrected deviation; FW_Corr is the feed water flow correction value; kp ₁ is the proportional coefficient; T ₁ is the integration time;

6.1.2. When it is obtained that the water supply is not in the automatic state, that is, it is in the manual state of water supply control, use the TRSF unit (i.e., the fourth logical trigger subunit) of the controller PID1 to trigger the controller PID1 according to the TR unit (i.e., the fourth logical operation subunit). ) starts, and the TR unit of the controller PID1 uses the feed water flow demand signal converted by the boiler main control command (i.e., the feed water flow FW_MD) and the engineering measuring point that actually controls the feed water flow to obtain the difference between the actual feed water flow of the boiler and determines the feed water flow correction value. FW_Corr, FW_Corr=actual feed water flow-FW_MD;

6.1.3. When the unit auxiliary machine failure trip (RunBack) condition is obtained, that is, when the RB condition occurs, the HOLD unit of the controller PID1 (i.e., the seventh logical control unit) is used to determine the feed water flow correction value FW_Corr, and The feed water flow correction value FW_Corr(t-1) in the feed water flow control at the previous moment is used as the feed water flow correction value FW_Corr(t) for this feed water flow adjustment.

6.2 Use the adder to superpose the feed water flow correction value FW_Corr with the feed water flow FW_MD formed by the original boiler main control instruction to determine the feed water flow set value FWMD.

7. Fuel supply control (second fork arm control):

7.1. Determine the first fuel supply amount correction value FUEL_Corr and the second fuel supply amount correction value MU_Factor

Determine the first fuel supply correction value FUEL_Corr using the method given in step 7.1.1, step 7.1.2 or step 7.1.3; among them, step 7.1.3 has a higher priority than step 7.1.2, step 7.1.2 has a higher priority than step 7.1.1;

7.1.1. The second correction function fx4 performs deviation processing on the control deviation error ₀ to obtain the second corrected deviation; after the second corrected deviation enters the controller PID2 (i.e. the second PID controller), it passes through the controller PID2 The SP unit (i.e., the second logical control unit) uses the first fuel supply amount correction function to perform calculations to determine the first fuel supply amount correction value FUEL_Corr; where,

The second correction function fx4 is: In the formula, error ₂ is the second corrected deviation; error ₀ is the original deviation;

When the control deviation error ₀ is the separator steam temperature deviation, use the second correction function fx4 to perform deviation processing on the control deviation error ₀ to obtain the second corrected deviation as shown in Table 8;

Table 8

Input(℃) -30 -15 -10 -5 5 10 15 30 Output(℃) -30 -15 -10 0 0 10 15 30

The first fuel quantity correction function is The original default output is 0; in the formula, error ₂ is the second corrected deviation; FUEL_Corr is the first fuel supply correction value; kp ₂ is the proportional coefficient; T ₂ is the integration time;

7.1.2. When it is obtained that the automatic fueling is no longer in the automatic state, that is, it is in the manual fueling control state, use the TRSF unit (i.e., the fifth logical trigger subunit) of the controller PID2 to trigger the controller PID2 according to the TR unit (i.e., the fifth logical operation Subunit) is started, and the difference between the fuel supply demand signal (i.e. feed water flow rate FUEL_MD) converted by the boiler main control instruction and the engineering measurement point that actually controls the fuel supply amount is measured by the TR unit of the controller PID2 to obtain the actual fuel supply amount of the boiler. Determine the fuel supply correction value FUEL_Corr, FUEL_Corr=actual fuel quantity-FUEL_MD;

7.1.3. When the unit auxiliary machine failure trip (RunBack) operating condition is obtained, that is, when the RB operating condition occurs, the HOLD unit (i.e., the eighth logical control unit) of the controller PID2 is used to determine the fuel amount correction value FUEL_Corr, The first fuel supply amount correction value FUEL_Corr(t-1) in the fuel supply amount control at the previous time is used as the fuel supply amount correction value FUEL_Corr(t) for this first fuel supply amount adjustment.

7.2. Determine the second fuel supply correction value MU_Factor

Determine the second fuel supply correction value MU_Factor using the method given in step 7.2.1, step 7.2.2 or step 7.2.3; among them, step 7.2.3 has a higher priority than step 7.2.2, step 7.2.2 has a higher priority than step 7.2.1;

7.2.1. The third correction function fx5 performs deviation processing on the control deviation error ₀ to obtain the third corrected deviation; after the third corrected deviation enters the controller PID3 (that is, the third PID controller), it passes through the controller PID3 The SP unit (i.e., the third logical control unit) uses the second fuel supply amount correction function to perform calculations to determine the second fuel supply amount correction value MU_Factor; where,

The third correction function fx5 is: In the formula, error ₃ is the third corrected deviation; error ₀ is the original deviation;

When the control deviation error ₀ is the separator steam temperature deviation, use the third correction function fx5 to perform deviation processing on the control deviation error ₀ to obtain the third corrected deviation, as shown in Table 9;

Table 9

Input(℃) -30 -15 -10 -5 5 10 15 30 Output(℃) -30 -15 0 0 0 0 15 30

The second fuel correction function is: The original default output is 1; in the formula, error ₃ is the third corrected deviation; MU_Factor is the third fuel supply correction value; kp ₃ is the proportional coefficient; T ₃ is the integration time;

The second fuel supply amount correction value is 0.8-1.2. The farther the corrected deviation is from 0, the closer the corresponding second fuel supply amount correction value is to 0.8 or 1.2. The closer the corrected deviation absolute value is to 0, the corresponding second fuel supply amount correction value is. The closer the fuel supply amount correction value is to 1, the corrected deviation is 0 and the second fuel supply amount correction value is 1.

7.2.2. When it is obtained that the fueling automatic is no longer in the automatic state, that is, it is in the fueling control manual state, use the TRSF unit (i.e., the sixth logical trigger subunit) of the controller PID3 to trigger the controller PID3 according to the TR unit (i.e., the sixth logical operation Subunit) is started, and the fuel amount correction value FUEL_Corr is determined to be 1 through the TR unit of controller PID3;

7.2.3. When the unit auxiliary machine failure trip (RunBack) operating condition is obtained, that is, when the RB operating condition occurs, the HOLD unit (i.e., the ninth logical control unit) of the controller PID3 is used to determine the fuel amount correction value MU_Factor, The second fuel supply amount correction value MU_Factor(t-1) in the fuel supply amount control at the previous time is used as the fuel supply amount correction value MU_Factor(t) for this second fuel supply amount adjustment.

7.3 Use the multiplication block MUL to multiply the second fuel supply amount correction value MU_Factor with the fuel supply amount FUEL_MD formed by the original boiler master control instruction. The resulting fuel amount is then superimposed with the first fuel supply amount correction value FUEL_Corr through the addition block to determine Set the fuel quantity setting value FUELMD.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. The many features and advantages of these embodiments are apparent from this detailed description, and thus it is intended by the claims to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since many modifications and changes will readily occur to those skilled in the art, the embodiments of the invention are not intended to be limited to the precise structure and operation illustrated and described, but rather to cover all suitable modifications and equivalents falling within its scope. things.

Claims (27)

1. A coal-water ratio control method, which realizes coal-water ratio control by controlling the water supply flow rate and the fuel supply amount, wherein the method includes: Deviation acquisition: Obtain the deviation of the midpoint temperature or enthalpy value of the once-through boiler; Control the feed water flow and fuel supply quantity based on the deviation: when the deviation is within the first dead zone range, the feed water flow rate and the fuel supply quantity are not adjusted; when the deviation is not within the first dead zone range but within the second dead zone range When the deviation is not within the second dead zone but within the third dead zone, the feed water flow is adjusted without adjusting the fuel supply, thereby realizing the adjustment of the coal-to-water ratio. Coal-water ratio adjustment, in which the adjustment amount of the fuel supply amount is determined based on the first fuel correction function; when the deviation is not within the third dead zone range, the feed water flow rate and the fuel supply amount are adjusted, thereby realizing the coal-water ratio adjustment, in which the fuel supply amount is adjusted. The adjustment amount of the fuel amount is determined based on the first fuel correction function and the second fuel correction function; Among them, the first dead zone is a subset of the second dead zone, and the second dead zone is a subset of the third dead zone; When the deviation is not within the third dead zone range, for the same deviation, the adjustment amount of the fuel amount is determined based on the first fuel correction function and the second fuel correction function compared to the determination based only on the first fuel correction function. The adjustment amount is larger; Among them, the water supply flow control and fuel supply amount control based on the deviation are realized in the following ways: Feed water flow control based on deviation: determine the feed water flow correction value based on the deviation, use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value; wherein, the feed water flow rate is determined based on the deviation Determining the correction value includes: processing the deviation through a first correction function to obtain a first corrected deviation, the first correction function being a function capable of setting a first dead zone; based on the first corrected deviation, using the feed water flow rate The correction function determines the correction value of the feed water flow; among them, when the deviation is within the first dead zone, the deviation after the first correction is 0, and the feed water flow correction value has no ability to correct the feed water flow formed by the original boiler main control instruction; When the deviation is not within the first dead zone, the deviation after the first correction is not 0, and the feed water flow correction value has the ability to correct the feed water flow formed by the original boiler main control instruction; Control the fuel supply quantity based on the deviation: determine the first fuel supply quantity correction value and the second fuel supply quantity correction value based on the deviation; use the first fuel supply quantity correction value and the second fuel supply quantity correction value to correct the original boiler master The fuel supply amount formed by the control command is used to determine the fuel supply amount set value; wherein, determining the first fuel supply amount correction value and the second fuel supply amount correction value based on the deviation includes: processing the deviation through the second correction function to obtain The second corrected deviation, the second correction function is a function capable of setting the second dead zone; based on the second corrected deviation, the first fuel correction function is used to determine the first fuel supply correction value; through the third The correction function processes the deviation to obtain a third corrected deviation, and the third correction function is a function capable of setting a third dead zone; based on the third corrected deviation, the second fuel correction function is used to determine the second feed Fuel quantity correction value; among them, when the deviation is within the second dead zone range, the second corrected deviation is 0, and the first fuel quantity correction value has no ability to correct the fuel quantity formed by the original boiler main control instruction; When the deviation is not within the second dead zone and the second corrected deviation is not 0, the first fuel supply correction value has the ability to correct the fuel supply amount formed by the original boiler main control instruction; when the deviation is within the third dead zone Within the range of the third dead zone, the deviation after the third correction is 0, and the second fuel supply amount correction value has no ability to correct the fuel supply amount formed by the original boiler main control instruction; when the deviation is not within the third dead zone, the third correction value The final deviation is not 0, and the second fuel supply amount correction value has the ability to correct the fuel supply amount formed by the original boiler main control command; Among them, the first fuel correction function is the PID algorithm model: The original default output is 0; In the formula, error ₂ is the second corrected deviation; FUEL_Corr is the first fuel supply correction value; kp ₂ is the proportional coefficient; T ₂ is the integration time; The second fuel correction function is the PID algorithm model: The original default output is 1; In the formula, error ₃ is the third corrected deviation; MU_Factor is the third fuel supply correction value; kp ₃ is the proportional coefficient; T ₃ is the integration time. 2. The control method according to claim 1, wherein obtaining the deviation of the midpoint temperature of the once-through boiler includes: Obtain the actual pressure of the separator, and then obtain the design temperature value corresponding to the actual pressure of the separator; superimpose the design temperature value and the temperature offset value, and then perform second-order inertia filtering to form the set value of the separator steam temperature; where , the inertia time used in the second-order inertia filter is determined based on the main steam flow rate of the boiler; Obtain the actual temperature of the separator and perform first-order inertial filtering on the obtained actual temperature of the separator; The deviation between the set value of the separator steam temperature and the actual temperature of the separator after first-order inertia filtering is determined to be the deviation of the mid-point temperature of the once-through boiler. 3. The control method according to claim 1, wherein obtaining the deviation of the midpoint enthalpy value of the once-through boiler includes: Obtain the load command of the separator, and then obtain the design enthalpy value corresponding to the load command of the separator; superimpose the design enthalpy value and the enthalpy offset value, and then perform second-order inertia filtering to form the set value of the separator steam enthalpy value ; Among them, the inertia time used in the second-order inertia filter is determined based on the main steam flow rate of the boiler; Obtain the actual temperature and actual pressure of the separator, determine the actual enthalpy value of the separator based on the actual temperature and actual pressure of the separator, and perform first-order inertial filtering on the actual enthalpy value of the separator; The deviation between the set value of the separator steam enthalpy value and the actual enthalpy value of the separator after first-order inertia filtering is the deviation of the mid-point enthalpy value of the once-through boiler. 4. The control method according to claim 1, wherein, The first correction function is: In the formula, error ₁ is the first corrected deviation; error ₀ is the original deviation; The second correction function is: In the formula, error ₂ is the second corrected deviation; error ₀ is the original deviation; The third correction function is: In the formula, error ₃ is the third corrected deviation; error ₀ is the original deviation; The water supply flow correction function is the PID algorithm model: The original default output is 0; In the formula, error ₁ is the deviation after the first correction; FW_Corr is the feed water flow correction value; kp ₁ is the proportional coefficient; T ₁ is the integration time. 5. The control method according to claim 1, wherein the method further comprises: When the automatic water supply is not in the automatic state, the feed water flow control based on the deviation is suspended, and the feed water flow is controlled according to the first forced control of the feed water flow. Among them, the first forced control of the feed water flow includes: tracking the feed water flow demand signal transformed by the boiler main control instruction. The difference between the actual feed water flow of the boiler and the engineering measuring point that actually controls the feed water flow is measured, and the difference is used as the feed water flow adjustment amount to adjust the feed water flow. 6. The control method according to claim 5, wherein the difference between the feed water flow demand signal converted by the boiler main control instruction and the actual control feed water flow measured at the engineering measuring point of the boiler is used as the actual control feed water flow. The actual feed water flow of the boiler measured at the engineering measuring point is subtracted from the feed water flow demand signal converted by the boiler main control instruction to represent it; When the automatic fuel supply is not in the automatic state, the fuel supply quantity control based on the deviation is suspended and the fuel supply quantity control is carried out according to the first forced control of the fuel supply quantity; wherein the first forced control of the fuel supply quantity includes: tracking the transformation of the boiler main control command The difference between the fuel supply quantity demand signal and the engineering measuring point that actually controls the fuel supply quantity is measured to obtain the actual fuel supply quantity of the boiler, and the difference is used as the fuel supply quantity adjustment amount to adjust the fuel supply quantity. 7. The control method according to claim 5, wherein the difference between the fuel supply quantity demand signal converted by the boiler main control instruction and the actual control fuel supply quantity measured at the engineering measuring point is used to calculate the actual fuel supply quantity of the boiler. It is expressed by subtracting the actual fuel supply quantity of the boiler from the actual fuel supply quantity measured at the engineering measuring point of the boiler main control instruction and converting it into the fuel supply quantity demand signal. 8. The control method according to claim 5, wherein, The first forced control of feed water flow is achieved in the following ways: Track the difference between the feed water flow demand signal transformed by the boiler main control command and the engineering measuring point that actually controls the feed water flow to obtain the actual feed water flow of the boiler, and determine the feed water flow correction value based on the difference; Use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value; Among them, the determined feed water flow set value is equal to the actual boiler feed water flow measured at the engineering measuring point that actually controls the feed water flow; The first forced control of the fuel supply amount is achieved in the following ways: Track the difference between the fuel supply demand signal transformed by the boiler main control command and the engineering measurement point that actually controls the fuel supply to obtain the actual fuel supply to the boiler. Based on the difference, the first fuel supply correction value and the second fuel supply are determined. quantity correction value; Use the first fuel supply amount correction value and the second fuel supply amount correction value to correct the fuel supply amount formed by the original boiler main control instruction to determine the fuel supply amount set value; Among them, the determined set value of the fuel supply amount is equal to the actual fuel supply amount of the boiler measured at the engineering measuring point that actually controls the fuel supply amount. 9. The control method according to claim 1, wherein the method further comprises: When the unit's auxiliary machine fails and trips, the water supply flow control is forced to take priority according to the forced water flow control under the RB working condition. Among them, the forced water flow control under the RB working condition includes: the water supply flow adjustment switches to the holding state, and the water supply flow rate at the previous moment is used. The feed water flow adjustment scheme under control regulates the feed water flow; When the unit auxiliary machine failure trip condition occurs, the fuel supply amount control is forced to take priority according to the fuel supply amount forced control under the RB working condition; among them, the fuel supply amount forced control under the RB working condition includes: the fuel supply amount adjustment switches to the holding state, using the above The fuel supply amount adjustment scheme in the momentary fuel supply amount control adjusts the fuel supply amount. 10. The control method according to claim 9, wherein the fault tripping condition signal of the auxiliary machine of the unit is monitored and the falling edge delay processing is performed on it. When the fault tripping condition of the auxiliary machine of the unit occurs after the falling edge delay processing. If the signal indicates that the unit's auxiliary machine failure and tripping conditions have occurred, it is considered that the unit's auxiliary machine failure and tripping conditions have occurred. 11. The control method according to claim 9, wherein, Forced control of feed water flow under RB working condition is achieved in the following ways: Use the feed water flow correction value in the feed water flow control at the previous moment as the feed water flow correction value for this feed water flow adjustment; Use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value; The forced control of fuel supply quantity under RB operating condition is realized in the following ways: The first fuel supply amount correction value in the fuel supply amount control at the previous time is used as the first fuel supply amount correction value for this fuel supply amount adjustment, and the second fuel supply amount correction value in the fuel supply amount control at the previous time is used as the first fuel supply amount correction value for this fuel supply amount adjustment. As the second fuel supply amount correction value for this fuel supply amount adjustment; The first fuel supply amount correction value and the second fuel supply amount correction value are used to correct the fuel supply amount formed by the original boiler main control instruction to determine the fuel supply amount set value. 12. The control method according to any one of claims 4, 8, and 11, wherein, Using the first fuel supply quantity correction value and the second fuel supply quantity correction value to correct the fuel supply quantity formed by the original boiler master control instruction includes: combining the second fuel supply quantity correction value with the fuel supply quantity formed by the original boiler master control instruction. The fuel quantity is multiplied, and the obtained fuel quantity is superimposed with the first fuel supply quantity correction value to determine the fuel supply quantity setting value. 13. The control method according to claim 12, wherein the second fuel supply amount correction value is 0.8-1.2. The farther the corrected deviation is from 0, the closer the corresponding second fuel supply amount correction value is to 0.8 or 1.2. The closer the absolute value of the deviation is to 0, the closer the corresponding second fuel supply amount correction value is to 1. The corrected deviation is 0 and the second fuel supply amount correction value is 1. 14. The control method according to claim 12, wherein when the coal-to-water ratio control method includes the first forced control of the fuel supply amount, during the first forced control of the fuel supply amount, the boiler main control command is transformed into the fuel supply The difference between the quantity demand signal and the actual control fuel quantity is measured at the engineering measuring point and the actual fuel quantity of the boiler is measured as the first fuel quantity correction value; the second fuel quantity correction value is determined as 1. 15. The control method according to any one of claims 4, 8, and 11, wherein the feed water flow correction value is used to correct the feed water flow formed by the original boiler main control instruction in the following manner: the feed water flow correction value is It is superimposed with the feed water flow formed by the original boiler master control command. 16. The control method according to claim 15, wherein when the coal-water ratio control method includes the first forced control of the feed water flow, during the first forced control process of the feed water flow, the boiler main control command is converted into the feed water flow demand signal The difference between the actual boiler feed water flow measured at the engineering measuring points that actually control the feed water flow is used as the feed water flow correction value. 17. The control method according to claim 1, wherein, When the deviation is the temperature deviation of the midpoint, the first dead zone is [-2,2]; the second dead zone is [-5,5]; the third dead zone is [-10,10]; The intermediate point temperature or enthalpy value is the separator steam temperature or enthalpy value; The deviation of the intermediate point temperature or enthalpy value is expressed by subtracting the measured value of the intermediate point temperature or enthalpy value from the set value of the intermediate point temperature or enthalpy value. 18. A coal-water ratio control system, wherein the system includes: Deviation acquisition module: used to obtain the deviation of the midpoint temperature or enthalpy value of the once-through boiler; The first deviation correction module is used to process the deviation through a first correction function to obtain the first corrected deviation. The first correction function is a function that can set the first dead zone; when the deviation is within the first dead zone range The deviation after the first correction is 0, and when the deviation is not within the first dead zone, the deviation after the first correction is not 0; The second deviation correction module is used to process the deviation through a second correction function to obtain the second corrected deviation. The second correction function is a function that can set the second dead zone; when the deviation is within the second dead zone range The deviation after the second correction is 0, and when the deviation is not within the second dead zone, the deviation after the second correction is not 0; The third deviation correction module is used to process the deviation through a third correction function to obtain the third corrected deviation. The third correction function is a function that can set the third dead zone; when the deviation is within the third dead zone range The deviation after the third correction is 0, and when the deviation is not within the third dead zone, the deviation after the first correction is not 0; The first PID controller includes a first logic control unit; the first logic control unit is used to determine the water supply flow correction value based on the first corrected deviation using the water supply flow correction function; wherein, the water supply performed by the first logic control unit The flow correction value is determined to meet the following requirements: when the first corrected deviation is 0, the determined feed water flow correction value has no ability to correct the feed water flow formed by the original boiler main control instruction. When the first corrected deviation is not 0, the feed water flow correction value is determined. The flow correction value has the ability to correct the feed water flow formed by the original boiler master control instruction; Original feed water flow acquisition module: used to obtain the feed water flow formed by the original boiler master control instructions; Feed water flow set value determination module: used to use the feed water flow correction value to correct the feed water flow formed by the original boiler main control instruction to determine the feed water flow set value; The second PID controller includes a second logic control unit; the second logic control unit is used to determine the first fuel amount correction value based on the second corrected deviation using the first fuel correction function; wherein, the second logic The first fuel supply correction value determined by the control unit satisfies the following conditions: when the second corrected deviation is 0, the first fuel supply correction value determined has no ability to correct the fuel supply quantity formed by the original boiler main control instruction. , when the second corrected deviation is not 0, the first fuel supply amount correction value determined has the ability to correct the fuel supply amount formed by the original boiler main control instruction; The third PID controller includes a third logic control unit; the third logic control unit is used to determine the second fuel amount correction value based on the third corrected deviation and using the second fuel correction function; wherein, the third logic The second fuel supply correction value determined by the control unit satisfies the following requirements: the second fuel supply correction value determined when the third corrected deviation is 0 has no ability to correct the fuel supply quantity formed by the original boiler main control instruction. , when the deviation after the third correction is not 0, the second fuel supply amount correction value determined has the ability to correct the fuel supply amount formed by the original boiler main control instruction; Original fuel supply quantity acquisition module: used to obtain the fuel supply quantity formed by the original boiler master control instruction; The fuel supply quantity set value determination module is used to correct the fuel supply quantity formed by the original boiler main control instruction using the first fuel supply quantity correction value and the second fuel supply quantity correction value to determine the fuel supply quantity set value, as Further provide set values for the fuel control circuit; Among them, the first dead zone is a subset of the second dead zone, and the second dead zone is a subset of the third dead zone; Among them, the first fuel correction function is the PID algorithm model: The original default output is 0; In the formula, error ₂ is the second corrected deviation; FUEL_Corr is the first fuel supply correction value; kp ₂ is the proportional coefficient; T ₂ is the integration time; The second fuel correction function is the PID algorithm model: The original default output is 1; In the formula, error ₃ is the third corrected deviation; MU_Factor is the third fuel supply correction value; kp ₃ is the proportional coefficient; T ₃ is the integration time. 19. The system of claim 18, further comprising: Water supply control status acquisition module: used to obtain the status of automatic water supply. The status of automatic water supply includes automatic status and non-automatic status; The first difference acquisition module: used to track the feed water flow demand signal transformed by the boiler main control instruction and the engineering measurement point that actually controls the feed water flow to obtain the difference between the actual feed water flow of the boiler; The first PID controller includes a fourth logic control unit: configured to start determining the feed water flow correction value based on the difference obtained by the first difference acquisition module when the water supply control state acquisition module obtains that the water supply is not in the automatic state; The fourth logical control unit has a higher priority than the first logical control unit; The water supply control state acquisition module and the first difference acquisition module are respectively connected to the first PID controller. 20. The system according to claim 19, wherein the fourth logic control unit includes a fourth logic trigger subunit and a fourth logic operation subunit, and the water supply control state acquisition module is connected to the fourth logic trigger subunit, and the first difference The value acquisition module is connected to the fourth logical operation subunit, thereby transmitting the automatic water supply control status signal acquired by the water supply control status acquisition module to the fourth logical trigger subunit. The fourth logical trigger subunit is used to automatically terminate the water supply when receiving the water supply control status acquisition module. The fourth logical operation subunit is triggered to start when the signal of the automatic state is started. After the fourth logical operation subunit is started, it is used to determine the feed water flow correction value based on the difference obtained by the first difference acquisition module. 21. The system of claim 18, further comprising: Fueling control status acquisition module: used to acquire the status of automatic fueling. The status of automatic fueling includes automatic status and non-automatic status; The second difference acquisition module: used to track the fuel supply demand signal transformed by the boiler main control instruction and the engineering measurement point that actually controls the fuel supply volume to obtain the difference between the actual fuel supply volume of the boiler; The second PID controller includes a fifth logic control unit: configured to start determining the first fuel supply based on the difference value obtained by the second difference value acquisition module when the fuel supply control state acquisition module obtains that the fuel supply automatic state is not in the automatic state. Fuel quantity correction value; the fifth logical control unit has a higher priority than the second logical control unit; The third PID controller includes a sixth logic control unit: configured to start determining the second fuel supply based on the difference value obtained by the second difference value acquisition module when the fuel supply control state acquisition module obtains that the fuel supply automatic state is not in the automatic state. Fuel quantity correction value; the sixth logical control unit has a higher priority than the third logical control unit; The fuel supply control state acquisition module is connected to the second PID controller and the third PID controller respectively, and the second difference acquisition module is connected to the second PID controller and the third PID controller respectively. 22. The system according to claim 21, wherein the fifth logic control unit includes a fifth logic trigger subunit and a fifth logic operation subunit, and the fuel control state acquisition module is connected to the fifth logic trigger subunit, and the second logic trigger subunit is connected to the fuel control state acquisition module. The difference acquisition module is connected to the fifth logical operation sub-unit, thereby realizing the automatic fuel supply control state signal acquired by the fuel supply control state acquisition module to be transmitted to the fifth logical trigger sub-unit. The fifth logical trigger sub-unit is used to when receiving The fifth logical operation subunit is triggered to start when the fueling automatic is not in the automatic state signal. After the fifth logical operation subunit is started, it is used to determine the first fuel flow correction value based on the difference obtained by the second difference acquisition module. 23. The system according to claim 21, wherein the sixth logic control unit includes a sixth logic trigger subunit and a sixth logic operation subunit, and the fuel control state acquisition module is connected to the sixth logic trigger subunit, and the second logic trigger subunit is connected to the fuel control state acquisition module. The difference acquisition module is connected to the sixth logic operation subunit, thereby transmitting the automatic fuel control state signal acquired by the fuel control state acquisition module to the sixth logic trigger subunit. The sixth logic trigger subunit is used when receiving The sixth logical operation subunit is triggered to start when the fueling automatic is not in the automatic state signal. After the sixth logical operation subunit is started, it is used to determine the second fuel flow correction value based on the difference obtained by the second difference acquisition module. 24. The system of any one of claims 18-23, further comprising: RB operating condition trigger state acquisition module: used to obtain the trigger state of the unit's auxiliary engine fault trip condition. The trigger state of the unit's auxiliary engine fault trip condition includes triggering and non-triggering; The first PID controller includes a seventh logic control unit: used for when the RB working condition triggering state acquisition module acquires the triggering unit auxiliary machine fault tripping condition, start to use the feed water flow correction value in the feed water flow control at the previous moment as this The feed water flow correction value of the secondary feed water flow adjustment; the seventh logical control unit has a higher priority than the first logical control unit and the fourth logical control unit; The second PID controller includes an eighth logic control unit: used to start controlling the first fuel supply amount at the previous moment when the RB operating condition triggering state acquisition module acquires the triggering unit auxiliary machine fault trip operating condition. The correction value is used as the first fuel supply amount correction value for this fuel supply amount adjustment; the eighth logic control unit has a higher priority than the second logic control unit and the fifth logic control unit; The third PID controller includes a ninth logic control unit: used to start the second fuel supply amount in the fuel supply control at the previous moment when the RB working condition trigger state acquisition module acquires the triggering unit auxiliary machine fault trip condition. The correction value is used as the second fuel supply amount correction value for this fuel supply amount adjustment; the ninth logic control unit has a higher priority than the third logic control unit and the sixth logic control unit. 25. The system according to claim 24, wherein the RB operating condition occurrence status acquisition module includes: a sequentially connected RB operating condition occurrence signal monitoring sub-module and a TOF sub-module; wherein the sequentially connected RB operating condition occurrence signal monitoring sub-module The monitoring sub-module is used to detect the signal of the unit's auxiliary machine fault tripping condition, and the TOF sub-module is used to process the falling edge delay of the unit's auxiliary machine fault tripping condition signal. 26. The system of claim 18, wherein the deviation acquisition module includes: The actual pressure of the separator corresponds to the design temperature acquisition sub-module, the temperature offset value acquisition sub-module, the first superposition calculation sub-module, the first LAG sub-module, the second LAG sub-module, the fifth LAG sub-module and the first difference calculation sub-module module; wherein, the actual pressure of the separator corresponds to the design temperature acquisition sub-module and the temperature offset value acquisition sub-module are respectively connected to the first superposition calculation sub-module, and the first superposition calculation module, the first LAG sub-module and the second LAG sub-module are sequentially In series, the second LAG sub-module and the fifth LAG sub-module are respectively connected to the first difference calculation sub-module; where, The actual pressure of the separator corresponds to the design temperature acquisition sub-module: used to determine the design temperature value corresponding to the actual pressure of the separator based on the actual pressure of the separator; the temperature offset value acquisition sub-module: used to obtain the temperature offset value; first superposition Calculation sub-module: used to superimpose the design temperature value corresponding to the actual pressure of the separator and the temperature offset value; the first LAG sub-module and the second LAG sub-module in series: used to superimpose the determined superposition of the first superposition calculation sub-module The value is subjected to second-order inertial filtering to obtain the set value of the separator steam temperature; the fifth LAG sub-module is used to perform first-order inertial filtering on the actual temperature of the separator; the first difference calculation sub-module is used to determine the separator steam temperature The difference between the set value and the actual temperature of the separator after first-order inertia filtering is the deviation of the mid-point temperature of the once-through boiler. 27. The system of claim 18, wherein the deviation acquisition module includes: The separator load command corresponds to the design enthalpy value acquisition sub-module, the enthalpy offset value acquisition sub-module, the second superposition calculation sub-module, the third LAG sub-module, the separator actual enthalpy value determination sub-module, the fourth LAG sub-module, Six LAG sub-modules and the second difference calculation sub-module; among them, the separator load command corresponding to the design enthalpy value acquisition sub-module and the enthalpy offset value acquisition sub-module are respectively connected to the second superposition calculation sub-module, and the second superposition calculation module , the third LAG sub-module and the fourth LAG sub-module are connected in series in sequence; the actual enthalpy value determination sub-module of the separator is connected to the fourth LAG sub-module, and the fourth LAG sub-module and the sixth LAG sub-module are respectively connected to the second difference calculation sub-module. Module connection; where, The sub-module for obtaining the design enthalpy value corresponding to the load instruction of the separator: used to determine the design enthalpy value corresponding to the load instruction of the separator based on the load instruction of the separator; the sub-module for obtaining the enthalpy offset value: used to obtain the enthalpy offset value; The second superposition calculation sub-module: used to superimpose the design enthalpy value and enthalpy offset value corresponding to the load command of the separator; the third LAG sub-module and the fourth LAG sub-module connected in series: used to superimpose the second superposition calculation sub-module The superposition value determined by the module is subjected to second-order inertial filtering to obtain the set value of the separator steam temperature; the separator actual enthalpy value determination sub-module is used to determine the actual enthalpy value of the separator based on the actual temperature and actual pressure of the separator; the sixth LAG The sub-module is used to perform first-order inertia filtering on the actual enthalpy value of the separator; the second difference calculation sub-module is used to determine the set value of the separator steam enthalpy value and the actual enthalpy value of the separator after first-order inertia filtering The difference is the deviation of the midpoint enthalpy value of the once-through boiler.