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

Coal water ratio control method and system Download PDF

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Publication number
CN113359442B
CN113359442B CN202110587138.6A CN202110587138A CN113359442B CN 113359442 B CN113359442 B CN 113359442B CN 202110587138 A CN202110587138 A CN 202110587138A CN 113359442 B CN113359442 B CN 113359442B
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fuel supply
deviation
value
fuel
water supply
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CN113359442A (en
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刘磊
高明帅
邢智炜
尤默
秦天牧
康静秋
高爱国
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State Grid Corp of China SGCC
North China Electric Power Research Institute Co Ltd
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State Grid Corp of China SGCC
North China Electric Power Research Institute Co Ltd
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
    • G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
    • G05B13/04—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators
    • G05B13/042—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators in which a parameter or coefficient is automatically adjusted to optimise the performance
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
    • Y02P90/02—Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

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  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Control Of Steam Boilers And Waste-Gas Boilers (AREA)

Abstract

The invention provides a coal water ratio control method and a system. The method comprises the following steps: acquiring deviation of intermediate point temperature or enthalpy of the once-through boiler; when the deviation is within the first dead zone range, not adjusting the feedwater flow and not adjusting the fuel feed; when the deviation is not in the first dead zone range and the second dead zone range, adjusting the feedwater flow does not adjust the fuel feed; when the deviation is not in the second dead zone range and is in the third dead zone range, adjusting the water supply flow rate and the fuel supply amount, wherein the adjusting amount of the fuel supply amount is determined based on the first fuel correction function; when the deviation is not in the third dead zone range, adjusting the water supply flow and the fuel supply amount, wherein the adjusting amount of the fuel supply amount is determined based on the first fuel correction function and the second fuel correction function; 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; for the same deviation that is not within the third dead zone, the adjustment amount of the fuel supply amount determined based on the first and second fuel correction functions is larger than that determined based on the first fuel correction function alone.

Description

Coal water ratio control method and system
Technical Field
The invention relates to a coal water ratio control method and a system.
Background
Along with the change of global energy patterns, particularly the change of China energy policy, a large number of new energy power stations are connected into a power grid. The method provides higher technical requirements for upgrading and updating the conventional thermal power generating unit. In order to adapt to market change, the economic benefit and other factors are comprehensively considered, and the new unit, particularly the large coal-fired unit, tends to adopt a direct-current boiler unit with ultra-supercritical pressure, so that the overall operation efficiency of the unit is improved, and the economic benefit is increased.
In order to effectively absorb the peak-valley difference of the power grid caused by the access of the new energy power station, the energy bureau provides a scheme for flexibly modifying the thermal power unit. The method has higher requirements on the common coal-fired thermal power unit. When the load of the power grid is low, the coal-fired unit is required to be downwards regulated to lower load under the condition of ensuring the normal power generation of the new energy unit, so that the requirements of the power grid and users are met.
The normal load adjustment range of the conventionally designed coal-fired thermal power unit is 50% -100% Pe (namely the rated load of the unit), the peak regulation range of the unit with the deep peak regulation capability is 40% -100% Pe, and even reaches 30% -100% Pe, namely 20% -100% Pe. When the unit load is reduced to a lower load, the unit, particularly the unit characteristics, can change greatly. The requirements of the conventional operation interval are met, and the change of the low-load working condition is also met, so that higher requirements are put forward on the coordinated control of the unit. The supercritical once-through boiler intermediate point temperature control is an important component in the whole coordination control framework, and the control performance of the supercritical once-through boiler intermediate point temperature control not only relates to the stability performance of the steam temperature of the whole boiler side, but also influences the performance of the whole coordination control system, thereby influencing the overall AGC (automatic power generation control) performance of the unit. The high-level supercritical once-through boiler intermediate point temperature control not only relates to the safe operation of the unit, but also relates to the overall control level of the unit, and plays an important role in unit operation benefit, stable and safe power grid and economic benefit of a power plant.
Along with the great increase of the capacity of a unit, particularly the wide adoption of the supercritical (supercritical) once-through boiler in the recent years, along with the access of a great deal of new energy power stations such as spring bamboo shoots after rains to a power grid, higher technical requirements are provided for the supercritical (supercritical) once-through boiler, and particularly the requirements of on-site all working conditions are difficult to meet in the existing control strategy. The control of the middle point temperature (enthalpy value) in the coordinated control strategy of the supercritical (ultra) once-through boiler unit is an important component, and the middle point temperature is further changed by changing the coal water ratio, so that the boiler side steam temperature is controlled, and the safe, efficient and stable operation of the unit is ensured.
The coal water ratio (i.e. the fuel water ratio) of the supercritical (super) boiler is an important parameter index for unit operation. It marks the excellent running state of the machine set and represents an important sign of whether the water power circulation of the boiler is normal or not. The factors for generating temperature change are very complex, such as the condition of the hydrodynamic cycle of the unit, the change of the combustion of the boiler furnace, the disturbance of the water supply system, the change of the parameters of the steam side, the structural characteristics of the interior of the boiler, the water level, the installation position and the installation precision of the flow measuring system, the precision of the measuring transmitter and the like. So in general, the separator working medium temperature is an important monitoring parameter for the boiler. The control effect directly influences the safe operation of the unit. Especially, under the wide load working condition of the unit, the operation condition of main auxiliary machines of the unit is more disfigurement than that of the main auxiliary machines of the unit under the normal working condition, and the factors such as huge variation of the combustion characteristics of the boiler and the like generate huge disturbance to the system, so that the unit cannot safely and stably operate.
The typical technical scheme of the existing coal water ratio control mainly comprises the following three types:
1. technical solution one
The first technical scheme is a control mode that the control output of the coal water ratio is the water supply flow correction, and the specific principle is shown in figure 5. In FIG. 5, PID1 is intermediate point temperature control (or intermediate point enthalpy control), and the PID1 input is the separation steam temperature or enthalpy, and the set value SP Tsep For the separator temperature or enthalpy set point, the measurement value PV Tsep The separator vapor temperature or enthalpy calculated from the separator vapor pressure and temperature are used as control inputs to PID 1. The PID1 performs a control operation, and the control operation is performed to output a control amount FW_Corr, thereby correcting the water supply setting. Boiler master control instruction BMD is converted into a water supply flow main instruction after being processed by a given function Fx 1. The two instructions are added to obtain a water supply flow rate setting instruction FWMD, and the water supply system is controlled by the instruction.
The steam temperature of the direct current separator is selected according to different designs of manufacturers, different modes are adopted, and the direct current separator is designed to different positions such as an inlet, a middle part and an outlet of the separator, but the core purpose of the direct current separator is to represent the basic position of the phase change of working media.
In the first aspect, the control object of the intermediate point temperature (enthalpy value) is the feedwater flow. When the system is disturbed, for example, due to the change of media and the like, the heat absorption of the water-cooling wall of the boiler is changed, and the heating area and the evaporation area of working medium (water) in the water-cooling wall are changed, so that the water-working medium separation point is changed in the water-cooling wall pipeline, the change of the temperature of the working medium of the separator (and the change of the enthalpy value) is influenced, and the heat absorption of steam at the back is influenced. Therefore, the influence on the water supply flow is generated through the intermediate temperature controller PID1, for example, when the temperature of the separator is increased due to external factors, the PID1 generates increased water supply flow through operation output, the water-coal ratio is changed, the working medium in the water cooling wall is increased to take away the increased heat load, and the temperature (the enthalpy value is changed) of the working medium of the separator is further reduced, so that the working medium is restored to the original control value. However, in the process, the evaporation capacity is increased due to the increase of the water supply flow, and the working medium flow entering the turbine side is reduced by the turbine side to ensure the stability of the load of the unit, so that the valve of the turbine is closed down, and the pressure of the system is increased. When the external disturbance is serious, the system pressure change is severe, and the safety operation of the unit is greatly influenced.
2. Technical proposal II
The second technical scheme is a control mode that the control output of the coal-water ratio is the correction of the fuel supply amount, and the specific principle is shown in figure 6. The structure is similar to the first technical proposal, PID2 is intermediate point temperature control (or intermediate point enthalpy control), the input quantity of PID2 is separation steam temperature or enthalpy, and the set value SP Tsep For the separator temperature or enthalpy set point, the measurement value PV Tsep For separator steam temperature or from separator steam pressure and temperatureThe obtained enthalpy values are used as control inputs of PID 2. The control operation is performed by PID2, and the control operation output generation control amount FUEL_Corr is performed to correct the FUEL setting. The boiler master control command BMD is converted into a fuel master control command after passing through a given function Fx 2. The two instructions are added to obtain a fuel setting instruction FUELMD, and the fuel system is controlled by the fuel setting instruction FUELMD.
The second technical proposal is to change the water-coal ratio by controlling the fuel, and then change the temperature of the working medium of the separator. Compared with the first technical proposal, the flow rate of the working medium is not changed greatly because the water supply is not changed, which is favorable for controlling the pressure and ensures that the pressure control is stable. However, since the object of control is fuel, the fuel system of the unit enters the boiler to perform combustion heat exchange, which is a slow process (compared with a water supply system for balancing the internal heat of the boiler). Therefore, when the temperature of the working medium of the separator is changed severely, PID2 will generate larger fluctuation of coal quantity, and the temperature adjustment is not timely due to the hysteresis of fuel control, so that the steam temperature is changed severely.
3. Technical proposal III
The control strategy of the coal-water ratio in the third aspect is based on the above-mentioned control direction Gu Zhen, i.e. the correction is performed on the water supply system, or on the fuel system, or the fine adjustment is performed on the partial correction command.
In the third technical scheme, only the local correction of the first technical scheme and the second technical scheme is adopted, and the problems of the first technical scheme and the second technical scheme are not solved basically, so that the method cannot be applied in a large range.
Disclosure of Invention
At present, as a large number of new energy power stations are connected into a power grid, higher technical requirements are put forward for the supercritical (super) once-through boiler, so that the existing coal-water ratio (i.e. fuel-water ratio) control strategy is difficult to meet the requirements of on-site all-condition. Based on the above, the invention aims to provide a coal water ratio control method which can better meet the current field full-working condition requirements and is suitable for super (super) critical boilers.
The invention further aims to provide a coal water ratio control system which can better meet the current field full-working condition requirements and is suitable for the supercritical (super) boiler.
In order to achieve the above object, the present invention provides a coal water ratio control method for achieving coal water ratio control by controlling a feed water flow rate and a feed fuel amount, wherein the method comprises:
Deviation acquisition: acquiring deviation of intermediate point temperature or enthalpy of the once-through boiler;
feed water flow control and feed fuel amount control are performed based on the deviation: when the deviation is within the first dead zone range, not adjusting the feedwater flow (including the feedwater flow adjustment being 0) and not adjusting the fuel feed (including the fuel feed adjustment being 0);
when the deviation is not in the first dead zone range but in the second dead zone range, the water supply flow rate (excluding the water supply flow rate adjustment amount of 0) is adjusted and the fuel supply amount is not adjusted, thereby realizing the coal water ratio adjustment;
when the deviation is not in the second dead zone range, but in the third dead zone range, the feed water flow rate (excluding the feed water flow rate adjustment amount of 0) and the feed fuel amount (excluding the feed fuel amount adjustment amount of 0) are adjusted, thereby achieving the coal water ratio adjustment; wherein the adjustment amount of the fuel supply amount is determined based on the first fuel correction function;
when the deviation is not in the third dead zone range, the water supply flow rate (excluding the water supply flow rate adjustment amount of 0) and the fuel supply amount (excluding the fuel supply amount adjustment amount of 0) are adjusted, so that the coal water ratio adjustment is realized; wherein the adjustment amount of the fuel supply amount is determined based on the first fuel correction function and the second fuel correction function;
Wherein 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 (i.e., the first dead zone is contained in the second dead zone, and the second dead zone is contained 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 given fuel amount is determined based on the first fuel correction function and the second fuel correction function to be larger than the adjustment amount of the fuel amount determined based on the first fuel correction function alone.
In the above-described coal water ratio control method, the deviation of the intermediate point temperature or the enthalpy value refers to a deviation between a measured value of the intermediate point temperature or the enthalpy value and a set value of the intermediate point temperature or the enthalpy value, and may be represented by subtracting the set value of the intermediate point temperature or the enthalpy value from the measured value of the intermediate point temperature or the enthalpy value, or may be represented by subtracting the measured value of the intermediate point temperature or the enthalpy value from the set value of the intermediate point temperature or the enthalpy value. In the step of performing the water supply flow control and the fuel supply amount control based on the deviation, when the deviation reflects that the measured value of the intermediate point temperature or the enthalpy value is smaller than the deviation of the set value of the intermediate point temperature or the enthalpy value, the performed water supply amount adjustment should be to decrease the water supply amount, and the performed fuel supply amount adjustment should be to increase the fuel supply amount; when the deviation reflects a deviation in which the measured value of the intermediate point temperature or the enthalpy value is greater than the set value of the intermediate point temperature or the enthalpy value, the adjustment of the amount of feed water to be made should be an increase in the amount of feed water and the adjustment of the amount of feed fuel to be made should be a smaller amount of feed fuel.
The invention also provides a coal water ratio control system, wherein the system comprises:
the deviation acquisition module is used for: the method comprises the steps of obtaining deviation of intermediate point temperature or enthalpy value of a once-through boiler;
a first deviation correction module: the method comprises the steps of obtaining a first corrected deviation by processing the deviation through a first correction function, wherein the first correction function is a function capable of setting a first dead zone; when the deviation is within the first dead zone range, the first corrected deviation is 0, and when the deviation is not within the first dead zone range, the first corrected deviation is not 0;
a second deviation correction module: the deviation is processed through a second correction function to obtain a second corrected deviation, wherein the second correction function is a function capable of setting a second dead zone; when the deviation is within the second dead zone range, the second corrected deviation is 0, and when the deviation is not within the second dead zone range, the second corrected deviation is not 0;
a third deviation correction module: the deviation is processed through a third correction function to obtain a third corrected deviation, wherein the third correction function is a function capable of setting a 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 range, the deviation after the first correction is not 0;
The first PID controller comprises a first logic control unit; the first logic control unit is used for determining a water supply flow correction value by utilizing a water supply flow correction function based on the first corrected deviation; wherein, the water supply flow correction value determination performed by the first logic control unit meets the following conditions: the water supply flow correction value determined when the first corrected deviation is 0 has no correction capability on the water supply flow formed by the original boiler main control instruction, and the water supply flow correction value has correction capability on the water supply flow formed by the original boiler main control instruction when the first corrected deviation is not 0;
original water supply flow acquisition module: the method is used for acquiring the water supply flow formed by the original boiler main control instruction;
the water supply flow set value determining module: the method comprises the steps of correcting the water supply flow formed by an original boiler main control instruction by utilizing a water supply flow correction value so as to determine a water supply flow set value;
the second PID controller comprises a second logic control unit; the second logic control unit is used for determining a first fuel supply correction value by using a first fuel correction function based on the second corrected deviation; wherein the first fuel supply amount correction value determination by the second logic control unit satisfies: the first fuel supply quantity correction value determined when the second corrected deviation is 0 has no correction capability on the fuel supply quantity formed by the original boiler main control instruction, and the first fuel supply quantity correction value determined when the second corrected deviation is not 0 has correction capability on the fuel supply quantity formed by the original boiler main control instruction;
The third PID controller comprises a third logic control unit; the third logic control unit is used for determining a second fuel supply correction value by using a second fuel correction function based on the third corrected deviation; wherein the second fuel supply amount correction value determination by the third logic control unit satisfies: the second fuel supply amount correction value determined when the third corrected deviation is 0 has no correction capability on the fuel supply amount formed by the original boiler main control instruction, and the second fuel supply amount correction value determined when the third corrected deviation is not 0 has correction capability on the fuel supply amount formed by the original boiler main control instruction;
original fuel supply amount acquisition module: the method is used for acquiring fuel supply quantity formed by original boiler main control instructions;
a fuel quantity set value determining module: the method comprises the steps of determining a fuel supply set value by correcting the fuel supply formed by an original boiler main control instruction by using a first fuel supply correction value and a second fuel supply correction value, and providing a set value for a fuel control loop;
wherein 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 scheme provided by the invention is based on meeting the requirements of a large thermal power unit on safety and stability of a water supply system under the existing condition, meets the requirements of a power grid on wide load operation of the thermal power unit under the deep peak regulation condition of the thermal power unit under the new energy access condition, combines the advantages of two control methods, avoids the defects of the two control methods, and provides the control method and the control system based on the coal-water ratio (fuel-water ratio) of the double fork arms.
The coal water ratio (fuel water ratio) of the supercritical boiler is an important parameter index for unit operation. It marks the excellent running state of the machine set and represents an important sign of whether the water power circulation of the boiler is normal or not. The factors for generating temperature change are very complex, such as the condition of the hydrodynamic cycle of the unit, the change of the combustion of the boiler furnace, the disturbance of the water supply system, the change of the parameters of the steam side, the structural characteristics of the interior of the boiler, the water level, the installation position and the installation precision of the flow measuring device, the precision of the measuring transducer and the like. So in general, the separator working medium temperature is an important monitoring parameter for the boiler. The control effect directly influences the safe operation of the unit. Especially, under the wide load working condition of the unit, the operation condition of main auxiliary machines of the unit is more disfigurement than that of the main auxiliary machines of the unit under the normal working condition, and the factors such as huge variation of the combustion characteristics of the boiler and the like generate huge disturbance to the system, so that the unit cannot safely and stably operate. The technical scheme provided by the invention is to provide a safer and more reliable control scheme for controlling the water ratio under the working condition and the technological characteristics by combining with the traditional control scheme. The condition of severe temperature fluctuation of the middle point can be effectively improved, so that the steam temperature can be ensured to be in a safe range. The unit has the capacity of wide load peak regulation, and brings certain economic benefit to the power plant. And more favorable support is provided for deep peak shaving of the power grid.
The technical scheme provided by the method has the following beneficial effects:
(1) The technical scheme provided by the invention overcomes the defects of a conventional coal water ratio control mode, so that the temperature and pressure fluctuation of the supercritical (super) unit under the wide load operation working condition are solved, and technical assurance is provided for unit safety production.
(2) The technical scheme provided by the invention can more effectively solve the difficult problem that the temperature of the separator of the supercritical (super) direct current furnace is difficult to control under all working conditions, heavy load and extreme working conditions, and provides a favorable guarantee for the safe production of the unit. Meanwhile, the economic benefit of the unit is greatly improved, and necessary support is provided for the power grid to receive new energy.
(3) The technical scheme provided by the invention can adapt to the working characteristics of the DCS system, and the optimization parameters are obtained through external optimization, so that the technical scheme provided by the invention can be realized on the premise of not changing the original DCS system structure, and the transformation cost is saved.
(4) The technical scheme provided by the invention can improve the variable load capacity and adaptability of the unit, improve the adjustment performance of various indexes of the unit, and simultaneously meet the requirements of the power grid on AGC and primary frequency modulation management and assessment under the ultra-wide load operation condition; therefore, the operation safety and economy of the unit are improved, the environmental protection index of the unit is ensured, and the economic benefit and the social benefit of the thermal generator unit participating in the power grid examination are enhanced.
Drawings
Fig. 1 is a schematic flow chart of a method for controlling a coal water ratio according to an embodiment of the invention.
FIG. 2 is a schematic diagram of a coal water ratio control system according to an embodiment of the present invention.
FIG. 3 is a schematic diagram of an optimization structure of the deviation acquisition module according to an embodiment of the present invention.
FIG. 4 is a schematic diagram of an optimization structure of the deviation acquisition module according to an embodiment of the present invention.
Fig. 5 is a flow chart of a control method in which the coal water ratio control output is the feed water flow rate correction.
Fig. 6 is a schematic flow chart of a control method in which the control output of the coal water ratio is corrected for the fuel supply amount.
Fig. 7 is a schematic flow chart of the coal water ratio control method in example 1.
Fig. 8 is a flow chart of the deviation obtaining step in embodiment 1.
Fig. 9 is a flow chart of the deviation obtaining step in embodiment 1.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention.
The principles and spirit of the present invention are described in detail below with reference to several representative embodiments thereof.
Referring to fig. 1, in order to achieve the above object, the present invention provides a coal water ratio control method, wherein the method includes:
step S1: deviation acquisition: acquiring deviation of intermediate point temperature or enthalpy of the once-through boiler;
step S2: feed water flow control and feed fuel amount control are performed based on the deviation: when the deviation is within the first dead zone range, not adjusting the feedwater flow (including the feedwater flow adjustment being 0) and not adjusting the fuel feed (including the fuel feed adjustment being 0);
when the deviation is not in the first dead zone range but in the second dead zone range, the water supply flow rate (excluding the water supply flow rate adjustment amount of 0) is adjusted and the fuel supply amount is not adjusted, thereby realizing the coal water ratio adjustment;
when the deviation is not in the second dead zone range, but in the third dead zone range, the feed water flow rate (excluding the feed water flow rate adjustment amount of 0) and the feed fuel amount (excluding the feed fuel amount adjustment amount of 0) are adjusted, thereby achieving the coal water ratio adjustment; wherein the adjustment amount of the fuel supply amount is determined based on the first fuel correction function;
when the deviation is not in the third dead zone range, the water supply flow rate (excluding the water supply flow rate adjustment amount of 0) and the fuel supply amount (excluding the fuel supply amount adjustment amount of 0) are adjusted, so that the coal water ratio adjustment is realized; wherein the adjustment amount of the fuel supply amount is determined based on the first fuel correction function and the second fuel correction function;
Wherein 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 (i.e., the first dead zone is contained in the second dead zone, and the second dead zone is contained 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 given fuel amount is determined based on the first fuel correction function and the second fuel correction function to be larger than the adjustment amount of the fuel amount determined based on the first fuel correction function alone.
The deviation of the intermediate point temperature or the enthalpy value refers to the deviation between the measured value of the intermediate point temperature or the enthalpy value and the set value of the intermediate point temperature or the enthalpy value, and may be represented by subtracting the set value of the intermediate point temperature or the enthalpy value from the measured value of the intermediate point temperature or the enthalpy value, or may be represented by subtracting the measured value of the intermediate point temperature or the enthalpy value from the set value of the intermediate point temperature or the enthalpy value. In the step of performing the water supply flow control and the fuel supply amount control based on the deviation, when the deviation reflects that the measured value of the intermediate point temperature or the enthalpy value is smaller than the deviation of the set value of the intermediate point temperature or the enthalpy value, the performed water supply amount adjustment should be to decrease the water supply amount, and the performed fuel supply amount adjustment should be to increase the fuel supply amount; when the deviation reflects a deviation in which the measured value of the intermediate point temperature or the enthalpy value is greater than the set value of the intermediate point temperature or the enthalpy value, the adjustment of the amount of feed water to be made should be an increase in the amount of feed water and the adjustment of the amount of feed fuel to be made should be a smaller amount of feed fuel.
In one embodiment, step S2 is implemented by:
water supply flow control based on deviation: determining a water supply flow correction value based on the deviation, and correcting the water supply flow formed by the original boiler main control instruction by using the water supply flow correction value so as to determine a water supply flow set value and provide a set value for a further water supply control loop; wherein the deviation-based feedwater flow correction value determination includes: processing the deviation through a first correction function to obtain a first corrected deviation, wherein the first correction function is a function capable of setting a first dead zone; determining a feedwater flow correction value using a feedwater flow correction function based on the first corrected deviation; when the deviation is in the first dead zone range, the first corrected deviation is 0, and the water supply flow correction value has no correction capability on the water supply flow formed by the original boiler main control instruction; when the deviation is not in the first dead zone range, the first corrected deviation is not 0, and the water supply flow correction value has the capability of correcting the water supply flow formed by the original boiler main control instruction;
fuel supply amount control is performed based on the deviation: determining a first fuel supply correction value and a second fuel supply correction value based on the deviation; the fuel supply quantity formed by the original boiler main control instruction is corrected by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity set value, and a set value is further provided for a 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: processing the deviation through a second correction function to obtain a second corrected deviation, wherein the second correction function is a function capable of setting a second dead zone; determining a first fueling quantity correction value using a first fuel correction function based on the second corrected deviation; processing the deviation through a third correction function to obtain a third corrected deviation, wherein the third correction function is a function capable of setting a third dead zone; determining a second fueling quantity correction value using a second fuel correction function based on the third corrected deviation; when the deviation is in the second dead zone range, the second corrected deviation is 0, and the first fuel supply quantity correction value has no correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is not in the second dead zone range, the second corrected deviation is not 0, and the first fuel supply quantity correction value has correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is in the third dead zone range, the third corrected deviation is 0, and the second fuel supply quantity correction value has no correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is not in the third dead zone range, the deviation after the third correction is not 0, and the second fuel supply quantity correction value has the capability of correcting the fuel supply quantity formed by the original boiler main control instruction.
In one embodiment, correcting the fuel supply amount formed by the original boiler main control command by using the first fuel supply amount correction value and the second fuel supply amount correction value comprises:
multiplying the second fuel supply quantity correction value by the fuel supply quantity formed by the original boiler main control instruction, and superposing the obtained fuel quantity with the first fuel supply quantity correction value to determine a fuel supply quantity set value;
further, the second fuel supply amount correction value is 0.8 to 1.2, the more the corrected deviation is away from 0 (i.e., the more the original deviation is away from the third dead zone), the corresponding second fuel supply amount correction value is closer to 0.8 or 1.2, the more the absolute value of the corrected deviation is closer to 0 (i.e., the more the original deviation is closer to the third dead zone), the corresponding second fuel supply amount correction value is closer to 1, the corrected deviation is 0 (i.e., the original deviation is located in the third dead zone), and the second fuel supply amount correction value is 1 (at this time, the second fuel supply amount correction value does not constitute correction of the fuel supply amount).
In one embodiment, the correction of the original boiler master control command based on the feedwater flow correction is performed by:
and superposing the water supply flow correction value with the water supply flow formed by the original boiler main control instruction.
In one embodiment, the intermediate point temperature or enthalpy is the separator vapor temperature or enthalpy.
In one embodiment, obtaining the deviation of the mid-point temperature of the once-through boiler comprises:
acquiring the actual pressure of the separator, and further acquiring a design temperature value corresponding to the actual pressure of the separator; superposing the design temperature value and the temperature offset value, and performing second-order inertial filtering to form a set value of the steam temperature of the separator; wherein the inertia time used in the second order inertia filtering is determined based on the main steam flow of the boiler;
acquiring the actual temperature of the separator, and performing first-order inertial filtering on the acquired actual temperature of the separator;
determining the deviation between the set value of the steam temperature of the separator and the actual temperature of the separator after the first-order inertia filtering, namely the deviation of the middle point temperature of the once-through boiler;
the optimal technical scheme realizes the simulation of the energy change condition of micro hot spots of the boiler in the process of changing the heat load, and the formed set value of the steam temperature of the separator has the heat load characteristic of the boiler;
further, the algorithm adopted by each order of inertial filtering is thatWherein s is a Laplacian operator, and T is inertia time;
further, the inertia time is determined based on the main steam flow of the boiler in a conventional manner, for example, in a manner of actual engineering test;
Further, the temperature bias value is operator controllable;
the design temperature value corresponding to the actual pressure of the separator is obtained by a conventional method in the art, and may be determined according to a vapor enthalpy calculation table, for example.
In one embodiment, obtaining the deviation of the mid-point enthalpy value of the once-through boiler includes:
acquiring a load instruction of the separator, and further acquiring a design enthalpy value corresponding to the load instruction of the separator; superposing the design enthalpy value and the enthalpy value offset value, and then performing second-order inertial filtering to form a set value of the vapor enthalpy value of the separator; wherein the inertia time used in the second order inertia filtering is determined based on the main steam flow of the boiler;
acquiring the actual temperature and the actual pressure of the separator, determining the actual enthalpy value of the separator based on the actual temperature and the actual pressure of the separator, and performing first-order inertial filtering on the actual enthalpy value of the separator;
determining the deviation between the set value of the vapor enthalpy value of the separator and the actual enthalpy value of the separator after the first-order inertia filtering, namely the deviation of the intermediate point enthalpy value of the once-through boiler;
the optimal technical scheme realizes the simulation of the energy change condition of micro hot spots of the boiler in the heat load change process, and the formed set value of the vapor enthalpy value of the separator has the heat load characteristic of the boiler;
Further, the algorithm adopted by each order of inertial filtering is thatWherein s is a Laplacian operator, and T is inertia time;
further, the inertia time is determined based on the main steam flow of the boiler in a conventional manner, for example, in a manner of actual engineering test;
further, the enthalpy bias value is operator controllable.
In one embodiment, the method further comprises:
when the water supply is automatically not in an automatic state, stopping water supply flow control based on the deviation, and performing water supply flow control according to the first forced water supply flow control; wherein the first forced control of the feedwater flow includes:
tracking a water supply flow demand signal converted by a main control instruction of the boiler and measuring engineering measuring points for actually controlling the water supply flow to obtain a difference value of the actual water supply flow of the boiler, and taking the difference value as a water supply flow regulating quantity to regulate the water supply flow;
the optimized technical scheme can ensure undisturbed switching of lower-stage water supply flow control;
further, the first forced control of the feed water flow rate is realized by the following means:
tracking a difference value of the actual water supply flow of the boiler obtained by measuring a water supply flow demand signal converted by a main control instruction of the boiler and an engineering measuring point for actually controlling the water supply flow, and determining a water supply flow correction value based on the difference value;
Correcting the water supply flow formed by the original boiler main control instruction by utilizing the water supply flow correction value so as to determine a water supply flow set value;
the set value of the water supply flow is equal to the actual water supply flow of the boiler obtained by measuring engineering measuring points which actually control the water supply flow;
further, in the process of determining the water supply flow correction value based on the difference value, the difference value is used as the water supply flow correction value;
in the process of determining the water supply flow set value by correcting the water supply flow formed by the original boiler main control instruction by using the water supply flow correction value, the water supply flow correction value is overlapped with the water supply flow formed by the original boiler main control instruction so as to determine the water supply flow set value.
In one embodiment, the method further comprises:
suspending the fuel supply amount control based on the deviation from the first forced fuel supply amount control when the fuel supply automatic is not in the automatic state; wherein the first forced control of the fuel amount includes:
tracking a fuel supply quantity demand signal converted by a main control instruction of the boiler and measuring engineering measuring points for actually controlling the fuel supply quantity to obtain a difference value of the actual fuel supply quantity of the boiler, and taking the difference value as a fuel supply quantity regulating quantity to regulate the fuel supply quantity;
The optimized technical scheme can ensure the undisturbed switching of the lower-level fuel supply quantity control;
further, the first forced control of the fuel amount is achieved by:
tracking a fuel supply quantity demand signal converted by a boiler main control instruction and measuring engineering measuring points for actually controlling the fuel supply quantity to obtain a difference value of the actual fuel supply quantity of the boiler, and determining a first fuel supply quantity correction value and a second fuel supply quantity correction value based on the difference value;
correcting the fuel supply quantity formed by the original boiler main control instruction by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity set value;
the set value of the fuel supply amount is equal to the actual fuel supply amount of the boiler obtained by measuring engineering measuring points for actually controlling the fuel supply amount;
further, in the process of determining the first fuel supply amount correction value and the second fuel supply amount correction value based on the difference value, the difference value is used as the first fuel supply amount correction value; determining a second fuel supply correction value 1;
in the process of determining a fuel supply set value by correcting the fuel supply formed by the original boiler main control instruction by using the first fuel supply correction value and the second fuel supply correction value, multiplying the second fuel supply correction value by the fuel supply formed by the original boiler main control instruction, and then superposing the obtained fuel quantity with the first fuel supply correction value to determine the fuel supply set value.
In one embodiment, the method further comprises:
when the fault tripping working condition (RunBack working condition and RB working condition) of the auxiliary machine of the unit occurs, the forced priority is to control the water supply flow according to the forced control of the water supply flow of the RB working condition (RunBack working condition), wherein the forced control of the water supply flow of the RB working condition comprises the following steps:
the water supply flow rate is adjusted to be switched into a holding state, and the water supply flow rate is adjusted by adopting a water supply flow rate adjusting scheme in water supply flow rate control at the last moment;
further, the forced control of the RB working condition water supply flow is realized by the following modes:
the water supply flow correction value in the water supply flow control at the previous moment is used as the water supply flow correction value for the water supply flow adjustment at the present time;
correcting the water supply flow formed by the original boiler main control instruction by utilizing the water supply flow correction value so as to determine a water supply flow set value;
further, in the process of correcting the water supply flow formed by the original boiler main control instruction by using the water supply flow correction value to determine the water supply flow set value, the water supply flow correction value is overlapped with the water supply flow formed by the original boiler main control instruction to determine the water supply flow set value.
In one embodiment, the method further comprises:
when the fault tripping working condition of the auxiliary machine of the unit occurs, the forced control of the fuel feeding quantity is carried out by forcing priority according to the RB working condition; wherein, RB working condition fuel quantity forced control includes: the fuel supply amount is adjusted to be switched into a holding state, and the fuel supply amount adjustment scheme in the fuel supply amount control at the previous moment is adopted for fuel supply amount adjustment;
Further, the forced control of the RB working condition to the fuel quantity is realized by the following modes:
taking the first fuel supply correction value in the fuel supply control at the previous moment as the first fuel supply correction value for the fuel supply adjustment at the present time, and taking the second fuel supply correction value in the fuel supply control at the previous moment as the second fuel supply correction value for the fuel supply adjustment at the present time;
and correcting the fuel supply quantity formed by the original boiler main control instruction by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity set value.
In the process of determining the fuel supply set value by correcting the fuel supply formed by the original boiler main control instruction by using the first fuel supply correction value and the second fuel supply correction value, multiplying the second fuel supply correction value by the fuel supply formed by the original boiler main control instruction, and then superposing the obtained fuel supply with the first fuel supply correction value to determine the fuel supply set value.
The arrangement of the RB working condition water supply flow forced control and the RB working condition fuel quantity forced control can ensure that the control of the fuel-water ratio (coal-water ratio) in the whole RB process does not participate in the control of the whole accident process, and adverse effects are prevented.
In one embodiment, a fault tripping (RunBack) working condition occurrence signal of the auxiliary machine of the unit is monitored, falling edge time delay processing is carried out on the fault tripping (RunBack) working condition occurrence signal of the auxiliary machine of the unit after the falling edge time delay processing shows that the fault tripping (RunBack) working condition of the auxiliary machine of the unit is generated, and then the fault tripping (RunBack) working condition of the auxiliary machine of the unit is considered to be generated.
In one embodiment, the method comprises:
deviation acquisition: acquiring deviation of intermediate point temperature or enthalpy of the once-through boiler;
optional feedwater control status acquisition: acquiring an automatic water supply state, wherein the automatic water supply state comprises an automatic state and a non-automatic state;
optional fuel control status acquisition: acquiring an automatic fuel feeding state, wherein the automatic fuel feeding state comprises an automatic state and a non-automatic state;
and acquiring the occurrence state of the fault tripping (RunBack) working condition of the optional auxiliary machine set: acquiring the occurrence state of a fault tripping (RunBack) working condition of the auxiliary machine of the unit, wherein the occurrence state of the fault tripping (RunBack) working condition of the auxiliary machine of the unit comprises occurrence and non-occurrence;
and (3) water supply flow control: the water supply flow control is carried out by comprising a water supply flow control step based on deviation, a first forced water supply flow control step capable of selecting and a forced water supply flow control step capable of selecting RB working conditions; the control method comprises the steps that the control priority of the RB working condition water supply flow forced control is higher than that of the water supply flow first forced control, and the control priority of the water supply flow first forced control is higher than that of the water supply flow control based on deviation;
Water supply flow control based on deviation: when the deviation is within the first dead zone range, not adjusting the feedwater flow (including the feedwater flow adjustment of 0); when the deviation is not within the first dead zone range, adjusting the feedwater flow (excluding the feedwater flow adjustment of 0);
first forced control of water supply flow: when the water supply is not automatically in an automatic state, the water supply flow control is performed in the following manner: tracking a water supply flow demand signal converted by a main control instruction of the boiler and measuring engineering measuring points for actually controlling the water supply flow to obtain a difference value of the actual water supply flow of the boiler, and taking the difference value as a water supply flow regulating quantity to regulate the water supply flow;
RB working condition feedwater flow forced control: when a fault trip (RunBack) condition of the auxiliary machine of the unit occurs, namely when an RB condition occurs, the water supply flow control is carried out according to the following mode: the water supply flow rate is adjusted to be switched into a holding state, and the water supply flow rate is adjusted by adopting a water supply flow rate adjusting scheme in water supply flow rate control at the last moment;
controlling the fuel amount: the fuel supply amount control is carried out by comprising a fuel supply amount control step based on deviation, a selectable fuel supply amount first forced control step and a selectable RB working condition fuel supply amount forced control step; the control method comprises the steps that the control priority of the forced fuel supply quantity under the RB working condition is higher than that of the first forced fuel supply quantity control, and the control priority of the first forced fuel supply quantity is higher than that of the control of the fuel supply quantity based on deviation;
Fuel supply amount control is performed based on the deviation: when the deviation is within the second dead zone range, the fuel supply amount is not adjusted (including the fuel supply amount adjustment amount being 0); when the deviation is not within the second dead zone range but within the third dead zone range, the fuel supply amount (excluding the fuel supply amount adjustment amount of 0) is adjusted, the adjustment amount of which is determined based on the first fuel correction function; when the deviation is not within the third dead zone range, the feedwater flow (excluding the feedwater flow adjustment of 0) is adjusted, the adjustment of the amount of the given fuel being determined based on the first fuel correction function and the second fuel correction function;
first forced control of fuel quantity: when the fuel supply automation is not in the automatic state, the fuel supply amount control is performed as follows: tracking a fuel supply quantity demand signal converted by a main control instruction of the boiler and measuring engineering measuring points for actually controlling the fuel supply quantity to obtain a difference value of the actual fuel supply quantity of the boiler, and taking the difference value as a fuel supply quantity regulating quantity to regulate the fuel supply quantity;
and (3) forced control of the fuel quantity under the RB working condition: when a fault trip (RunBack) working condition of auxiliary machines of the unit occurs, namely when an RB working condition occurs, the control of the fuel quantity is preferably and forcedly carried out according to the following mode: when a fault tripping (RunBack) working condition of auxiliary machinery of the unit occurs, the fuel supply is adjusted to be cut into a holding state, and the fuel supply is adjusted by adopting a fuel supply adjusting scheme in the fuel supply control at the previous moment;
Wherein 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 (i.e., the first dead zone is contained in the second dead zone, and the second dead zone is contained 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 given fuel amount is determined based on the first fuel correction function and the second fuel correction function to be larger than the adjustment amount of the fuel amount determined based on the first fuel correction function alone.
In one embodiment, the method comprises:
deviation acquisition: acquiring deviation of intermediate point temperature or enthalpy of the once-through boiler;
optional feedwater control status acquisition: acquiring an automatic water supply state, wherein the automatic water supply state comprises an automatic state and a non-automatic state;
optional fuel control status acquisition: acquiring an automatic fuel feeding state, wherein the automatic fuel feeding state comprises an automatic state and a non-automatic state;
and acquiring the occurrence state of the fault tripping (RunBack) working condition of the optional auxiliary machine set: acquiring the occurrence state of a fault tripping (RunBack) working condition of the auxiliary machine of the unit, wherein the occurrence state of the fault tripping (RunBack) working condition of the auxiliary machine of the unit comprises occurrence and non-occurrence;
and (3) water supply flow control: the water supply flow control is carried out by comprising a water supply flow control step based on deviation, a first forced water supply flow control step capable of selecting and a forced water supply flow control step capable of selecting RB working conditions; the control method comprises the steps that the control priority of the RB working condition water supply flow forced control is higher than that of the water supply flow first forced control, and the control priority of the water supply flow first forced control is higher than that of the water supply flow control based on deviation;
Water supply flow control based on deviation: determining the water supply flow correction value by performing a water supply flow correction value determination step based on the deviation; correcting the water supply flow formed by the original boiler main control instruction by utilizing the water supply flow correction value so as to determine a water supply flow set value and provide a set value for a further water supply control loop; wherein the step of determining the correction value of the water supply flow rate based on the deviation comprises the steps of: processing the deviation through a first correction function to obtain a first corrected deviation, wherein the first correction function is a function capable of setting a first dead zone; determining a feedwater flow correction value using a feedwater flow correction function based on the first corrected deviation; when the deviation is in the first dead zone range, the first corrected deviation is 0, and the water supply flow correction value has no correction capability on the water supply flow formed by the original boiler main control instruction; when the deviation is not in the first dead zone range, the first corrected deviation is not 0, and the water supply flow correction value has the capability of correcting the water supply flow formed by the original boiler main control instruction;
first forced control of water supply flow: when the water supply is not automatically in an automatic state, the water supply flow control is performed in the following manner: tracking a difference value of the actual water supply flow of the boiler obtained by measuring a water supply flow demand signal converted by a main control instruction of the boiler and an engineering measuring point for actually controlling the water supply flow, determining a water supply flow correction value based on the difference value, and correcting the water supply flow formed by the original main control instruction of the boiler by utilizing the water supply flow correction value so as to determine a water supply flow set value; the set value of the water supply flow is equal to the actual water supply flow of the boiler obtained by measuring engineering measuring points which actually control the water supply flow;
RB working condition feedwater flow forced control: when a fault trip (RunBack) condition of the auxiliary machine of the unit occurs, namely when an RB condition occurs, the water supply flow control is carried out according to the following mode: the water supply flow correction value in the water supply flow control at the previous moment is used as the water supply flow correction value for the water supply flow adjustment at the present time, and the water supply flow formed by the original boiler main control instruction is corrected based on the water supply flow correction value for the water supply flow adjustment at the present time so as to determine a water supply flow set value;
controlling the fuel amount: the fuel supply amount control is carried out by comprising a fuel supply amount control step based on deviation, a selectable fuel supply amount first forced control step and a selectable RB working condition fuel supply amount forced control step; the control method comprises the steps that the control priority of the forced fuel supply quantity under the RB working condition is higher than that of the first forced fuel supply quantity control, and the control priority of the first forced fuel supply quantity is higher than that of the control of the fuel supply quantity based on deviation;
fuel supply amount control is performed based on the deviation: determining a first fuel supply amount correction value and a second fuel supply amount correction value by performing a fuel supply amount correction value determination step based on the deviation; the fuel supply quantity formed by the original boiler main control instruction is corrected by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity set value, and a set value is further provided for a fuel control loop; wherein the fuel supply amount correction value determining step based on the deviation includes: processing the deviation through a second correction function to obtain a second corrected deviation, wherein the second correction function is a function capable of setting a second dead zone; determining a first fueling quantity correction value using a first fuel correction function based on the second corrected deviation; processing the deviation through a third correction function to obtain a third corrected deviation, wherein the third correction function is a function capable of setting a third dead zone; determining a second fueling quantity correction value using a second fuel correction function based on the third corrected deviation; when the deviation is in the second dead zone range, the second corrected deviation is 0, and the first fuel supply quantity correction value has no correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is not in the second dead zone range, the second corrected deviation is not 0, and the first fuel supply quantity correction value has correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is in the third dead zone range, the third corrected deviation is 0, and the second fuel supply quantity correction value has no correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is not in the third dead zone range, the third corrected deviation is not 0, and the second fuel supply quantity correction value has correction capability on the fuel supply quantity formed by the original boiler main control instruction;
First forced control of fuel quantity: when the fuel supply automation is not in the automatic state, the fuel supply amount control is performed as follows: tracking a fuel supply quantity demand signal converted by a boiler main control instruction and measuring engineering measuring points for actually controlling the fuel supply quantity to obtain a difference value of the actual fuel supply quantity of the boiler, and determining a first fuel supply quantity correction value and a second fuel supply quantity correction value based on the difference value; correcting the fuel supply quantity formed by the original boiler main control instruction by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity set value; the set value of the fuel supply amount is equal to the actual fuel supply amount of the boiler obtained by measuring engineering measuring points for actually controlling the fuel supply amount;
and (3) forced control of the fuel quantity under the RB working condition: when a fault trip (RunBack) condition of the auxiliary machine of the unit occurs, namely when an RB condition occurs, the fuel quantity is controlled in the following manner: taking the first fuel supply correction value in the fuel supply control at the previous moment as the first fuel supply correction value for the fuel supply adjustment at the present time, and taking the second fuel supply correction value in the fuel supply control at the previous moment as the second fuel supply correction value for the fuel supply adjustment at the present time; correcting the fuel supply quantity formed by the original boiler main control instruction based on the first fuel supply quantity correction value and the second fuel supply quantity correction value of the fuel supply quantity adjustment so as to determine a fuel supply quantity set value;
Wherein 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 (i.e., the first dead zone is contained in the second dead zone, and the second dead zone is contained 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 given fuel amount is determined based on the first fuel correction function and the second fuel correction function to be larger than the adjustment amount of the fuel amount determined based on the first fuel correction function alone;
further, the feedwater flow control is achieved by:
the method comprises the steps of determining the water supply flow correction value based on deviation, the first forced control step of the selectable water supply flow correction value and the forced control step of the selectable RB working condition water supply flow correction value; the RB working condition water supply flow correction value forced control priority is higher than the water supply flow correction value first forced control, and the water supply flow correction value first forced control priority is higher than the water supply flow correction value determination based on deviation;
correcting the water supply flow formed by the original boiler main control instruction by utilizing the water supply flow correction value so as to determine a water supply flow set value and provide a set value for a further water supply control loop;
Wherein, based on the deviation, the feed water flow correction value is determined: processing the deviation through a first correction function to obtain a first corrected deviation, wherein the first correction function is a function capable of setting a first dead zone; determining a feedwater flow correction value using a feedwater flow correction function based on the first corrected deviation; when the deviation is in the first dead zone range, the first corrected deviation is 0, and the water supply flow correction value has no correction capability on the water supply flow formed by the original boiler main control instruction; when the deviation is not in the first dead zone range, the first corrected deviation is not 0, and the water supply flow correction value has the capability of correcting the water supply flow formed by the original boiler main control instruction;
first forced control of water supply flow correction value: when the water supply is not automatically in an automatic state, the water supply flow correction value is determined according to the following mode: tracking a difference value of the actual water supply flow of the boiler obtained by measuring a water supply flow demand signal converted by a main control instruction of the boiler and an engineering measuring point for actually controlling the water supply flow, and determining a water supply flow correction value based on the difference value; the water supply flow correction value determined based on the difference value can be used for realizing that the water supply flow set value determined in the subsequent step is equal to the actual water supply flow of the boiler obtained by measuring engineering measuring points for actually controlling the water supply flow;
And (3) forcibly controlling the correction value of the feed water flow under the RB working condition: when a fault trip (RunBack) condition of the auxiliary machine of the unit occurs, namely when an RB condition occurs, the water supply flow correction value is determined according to the following manner: the water supply flow correction value in the water supply flow control at the previous moment is used as the water supply flow correction value for the water supply flow adjustment at the present time;
further, the fuel supply amount control is realized by the following means:
the first fuel supply amount correction value and the second fuel supply amount correction value are determined by the steps of determining the fuel supply amount correction value based on deviation, the first forced control step of the selectable fuel supply amount correction value and the forced control step of the selectable RB working condition fuel supply amount correction value; the RB working condition is higher than the first forced control of the fuel supply correction value, and the first forced control of the fuel supply correction value is higher than the determination of the fuel supply correction value based on deviation;
the fuel supply quantity formed by the original boiler main control instruction is corrected by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity set value, and a set value is further provided for a fuel control loop;
and determining a fuel feeding amount correction value based on the deviation: processing the deviation through a second correction function to obtain a second corrected deviation, wherein the second correction function is a function capable of setting a second dead zone; determining a first fueling quantity correction value using a first fuel correction function based on the second corrected deviation; processing the deviation through a third correction function to obtain a third corrected deviation, wherein the third correction function is a function capable of setting a third dead zone; determining a second fueling quantity correction value using a second fuel correction function based on the third corrected deviation; when the deviation is in the second dead zone range, the second corrected deviation is 0, and the first fuel supply quantity correction value has no correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is not in the second dead zone range, the second corrected deviation is not 0, and the first fuel supply quantity correction value has correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is in the third dead zone range, the third corrected deviation is 0, and the second fuel supply quantity correction value has no correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is not in the third dead zone range, the third corrected deviation is not 0, and the second fuel supply quantity correction value has correction capability on the fuel supply quantity formed by the original boiler main control instruction;
First forcing control for fuel quantity correction value: when the fuel supply automation is not in the automatic state, the fuel supply amount correction value is determined as follows: tracking a fuel supply quantity demand signal converted by a boiler main control instruction and measuring engineering measuring points for actually controlling the fuel supply quantity to obtain a difference value of the actual fuel supply quantity of the boiler, and determining a first fuel supply quantity correction value and a second fuel supply quantity correction value based on the difference value; the first fuel supply quantity correction value and the second fuel supply quantity correction value determined based on the difference value can be used for realizing that the fuel supply quantity set value determined in the subsequent step is equal to the actual fuel supply quantity of the boiler obtained by measuring engineering measuring points for actually controlling the fuel supply quantity;
and (3) forcibly controlling the correction value of the fuel quantity under the RB working condition: when a fault trip (RunBack) condition of the auxiliary machine of the unit occurs, namely when an RB condition occurs, the fuel quantity correction value is determined according to the following mode: the first fuel supply correction value in the fuel supply control at the previous moment is used as the first fuel supply correction value for the fuel supply adjustment at the present time, and the second fuel supply correction value in the fuel supply control at the previous moment is used as the second fuel supply correction value for the fuel supply adjustment at the present time.
In one embodiment, when the deviation is a midpoint temperature deviation, the first dead zone is [ -2,2] (in degrees Celsius); the second dead zone is [ -5,5] (in degrees Celsius); the third dead zone is [ -10,10] (in degrees Celsius).
In one embodiment, the deviation of the intermediate point temperature or enthalpy value is represented by subtracting a measured value of the intermediate point temperature or enthalpy value from a set value of the intermediate point temperature or enthalpy value.
In one embodiment, the first correction function is:
wherein error is of the formula 1 Is the first corrected deviation; error (error) 0 Is the original deviation.
In one embodiment, the second correction function is:
wherein error is of the formula 2 Is the second corrected deviation; error (error) 0 Is the original deviation.
In one embodiment, the third correction function is:
wherein error is of the formula 3 Is the third corrected deviation; error (error) 0 Is the original deviation.
In one embodiment, the feedwater flow correction function is a PID algorithm model:
wherein error is of the formula 1 Is the first corrected deviation; FW_Corr is the feed water flow correction value; kp (kP) 1 Is a proportionality coefficient; t (T) 1 Is the integration time.
In one embodiment, the first fuel correction function is a PID algorithm model:
wherein error is of the formula 2 Is the second corrected deviation; fuel_corr is the first FUEL supply amount correction value; kp (kP) 2 Is a proportionality coefficient; t (T) 2 Is the integration time.
In one embodiment, the second fuel correction function is a PID algorithm model:
wherein the original default output is 1;
wherein error is of the formula 3 Is the third corrected deviation; MU_Factor is the third fuel supply correction value; kp (kP) 3 Is a proportionality coefficient; t (T) 3 Is the integration time.
The PID algorithm model is actually an incremental algorithm model, and all calculated values are increased or decreased from original values; the original default output of the PID algorithm model used by the water supply flow correction function and the first fuel correction function is 0, and the original default output of the PID algorithm model used by the second fuel correction function is 1.
In one embodiment, the difference between the water supply flow demand signal converted by the boiler main control instruction and the actual water supply flow of the boiler obtained by measuring the engineering measuring point of the actual water supply flow is represented by subtracting the water supply flow demand signal converted by the boiler main control instruction from the actual water supply flow of the boiler obtained by measuring the engineering measuring point of the actual water supply flow.
In one embodiment, the difference between the fuel supply demand signal converted by the boiler main control command and the actual fuel supply measured by the engineering measuring point of the actual fuel supply is represented by subtracting the fuel supply demand signal converted by the boiler main control command from the actual fuel supply of the boiler measured by the engineering measuring point of the actual fuel supply.
The embodiment of the invention also provides a coal water ratio control system, and the system is preferably used for realizing the method embodiment.
FIG. 2 is a block diagram of a coal water ratio control system according to an embodiment of the present invention, as shown in FIG. 2, including:
the deviation acquisition module 21: the method comprises the steps of obtaining deviation of intermediate point temperature or enthalpy value of a once-through boiler;
the first deviation correction module 22: the method comprises the steps of obtaining a first corrected deviation by processing the deviation through a first correction function, wherein the first correction function is a function capable of setting a first dead zone; when the deviation is within the first dead zone range, the first corrected deviation is 0, and when the deviation is not within the first dead zone range, the first corrected deviation is not 0;
the second deviation correction module 23: the deviation is processed through a second correction function to obtain a second corrected deviation, wherein the second correction function is a function capable of setting a second dead zone; when the deviation is within the second dead zone range, the second corrected deviation is 0, and when the deviation is not within the second dead zone range, the second corrected deviation is not 0;
the third deviation correction module 24: the deviation is processed through a third correction function to obtain a third corrected deviation, wherein the third correction function is a function capable of setting a 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 range, the deviation after the first correction is not 0;
The first PID controller 25 comprises a first logic control unit; the first logic control unit is used for determining a water supply flow correction value by utilizing a water supply flow correction function based on the first corrected deviation; wherein, the water supply flow correction value determination performed by the first logic control unit meets the following conditions: the water supply flow correction value determined when the first corrected deviation is 0 has no correction capability on the water supply flow formed by the original boiler main control instruction, and the water supply flow correction value has correction capability on the water supply flow formed by the original boiler main control instruction when the first corrected deviation is not 0;
original feed water flow acquisition module 26: the method is used for acquiring the water supply flow formed by the original boiler main control instruction;
the feedwater flow set point determination module 27: the method comprises the steps of correcting the water supply flow formed by an original boiler main control instruction by utilizing a water supply flow correction value so as to determine a water supply flow set value;
a second PID controller 28 comprising a second logic control unit; the second logic control unit is used for determining a first fuel supply correction value by using a first fuel correction function based on the second corrected deviation; wherein the first fuel supply amount correction value determination by the second logic control unit satisfies: the first fuel supply quantity correction value determined when the second corrected deviation is 0 has no correction capability on the fuel supply quantity formed by the original boiler main control instruction, and the first fuel supply quantity correction value determined when the second corrected deviation is not 0 has correction capability on the fuel supply quantity formed by the original boiler main control instruction;
A third PID controller 29, comprising a third logical control unit; the third logic control unit is used for determining a second fuel supply correction value by using a second fuel correction function based on the third corrected deviation; wherein the second fuel supply amount correction value determination by the third logic control unit satisfies: the second fuel supply amount correction value determined when the third corrected deviation is 0 has no correction capability on the fuel supply amount formed by the original boiler main control instruction, and the second fuel supply amount correction value determined when the third corrected deviation is not 0 has correction capability on the fuel supply amount formed by the original boiler main control instruction;
original fuel supply amount obtaining die 30: the method is used for acquiring fuel supply quantity formed by original boiler main control instructions;
to the fuel quantity set point determination module 31: the method is used for correcting the fuel supply quantity formed by the original boiler main control instruction by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity set value and further provide a set value for a fuel supply control loop.
In one embodiment, the fueling setting value determination module 31 includes a first fueling correction sub-module and a second fueling correction sub-module; the first fuel supply quantity correction submodule is used for correcting the fuel supply quantity formed by the original boiler main control instruction by the second fuel supply quantity correction value to obtain a first corrected fuel supply quantity; the second fuel supply amount correction submodule is used for correcting the first corrected fuel supply amount by the first fuel supply amount correction value so as to determine a fuel supply amount set value.
In one embodiment, the system further comprises:
the water supply control state acquisition module: for acquiring the state of automatic water supply, the state of automatic water supply including an automatic state and a non-automatic state;
a first difference value acquisition module: the system comprises a boiler main control instruction, a boiler water supply flow demand signal acquisition module, a boiler main control instruction acquisition module, a boiler water supply flow control module and a boiler water supply flow control module, wherein the boiler main control instruction acquisition module is used for acquiring a boiler water supply flow;
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 automatically in an automatic state, starting to determine a water supply flow correction value based on the difference acquired by the first difference acquisition module; the fourth logic control unit has a higher priority than the first logic control unit;
the water supply control state acquisition module and the first difference acquisition module are respectively connected with the first PID controller 25;
further, the fourth logic control unit comprises a fourth logic triggering subunit and a fourth logic operation subunit, the water supply control state acquisition module is connected with the fourth logic triggering subunit, and the first difference acquisition module is connected with the fourth logic operation subunit, so that the water supply automatic control state signal acquired by the water supply control state acquisition module is transmitted to the fourth logic triggering subunit, the fourth logic triggering subunit is used for triggering the fourth logic operation subunit to start when receiving a signal that the water supply is not in an automatic state, and the fourth logic operation subunit is used for determining a water supply flow correction value based on the difference acquired by the first difference acquisition module after being started.
In one embodiment, the system further comprises:
and (3) feeding the fuel control state acquisition module with: for acquiring an automatic fuel-feeding state, the automatic fuel-feeding state including an automatic state and a non-automatic state;
and a second difference value acquisition module: the method comprises the steps of obtaining a difference value of actual fuel supply quantity of a boiler by measuring engineering measuring points for tracking fuel supply quantity demand signals converted by a main control instruction of the boiler and the actual fuel supply quantity;
the second PID controller 28 comprises a fifth logical control unit: the fuel supply control state acquisition module is used for starting to determine a first fuel supply amount correction value based on the difference value acquired by the second difference value acquisition module when the fuel supply control state acquisition module acquires that the fuel supply is automatically in an automatic state; the fifth logic control unit has a higher priority than the second logic control unit 281;
the third PID controller 29 comprises a sixth logical control unit: the fuel supply control state acquisition module is used for starting to determine a second fuel supply amount correction value based on the difference value acquired by the second difference value acquisition module when the fuel supply control state acquisition module acquires that the fuel supply is automatically in an automatic state; the sixth logic control unit has a higher priority than the third logic control unit;
the fuel supply control state acquisition module is respectively connected with the second PID controller 28 and the third PID controller 29, and the second difference acquisition module is respectively connected with the second PID controller 28 and the third PID controller 29;
Further, the fifth logic control unit comprises a fifth logic triggering subunit and a fifth logic operation subunit, the fuel supply control state acquisition module is connected with the fifth logic triggering subunit, the second difference acquisition module is connected with the fifth logic operation subunit, so that the fuel supply automatic control state signal acquired by the fuel supply control state acquisition module is transmitted to the fifth logic triggering subunit, the fifth logic triggering subunit is used for triggering the starting of the fifth logic operation subunit when receiving the signal that the fuel supply is not in an automatic state automatically, and the fifth logic operation subunit is used for determining a first fuel flow correction value based on the difference acquired by the second difference acquisition module after being started;
further, the sixth logic control unit comprises a sixth logic triggering subunit and a sixth logic operation subunit, the fuel supply control state acquisition module is connected with the sixth logic triggering subunit, and the second difference acquisition module is connected with the sixth logic operation subunit, so that the fuel supply automatic control state signal acquired by the fuel supply control state acquisition module is transmitted to the sixth logic triggering subunit, the sixth logic triggering subunit is used for triggering the start of the sixth logic operation subunit when receiving the signal that the fuel supply is not in an automatic state, and the sixth logic operation subunit is used for determining a second fuel flow correction value based on the difference acquired by the second difference acquisition module after the start.
In one embodiment, the system further comprises:
RB working condition occurrence state acquisition module: the method comprises the steps of acquiring the occurrence state of a fault tripping (RunBack) working condition of the auxiliary machine of the unit, wherein the occurrence state of the fault tripping (RunBack) working condition of the auxiliary machine of the unit comprises occurrence and non-occurrence;
the first PID controller 25 includes a seventh logic control unit: when the RB condition occurrence state obtaining module 36 obtains a fault trip (RunBack) condition of an auxiliary machine of the generator set, starting to use the water supply flow correction value in water supply flow control at the previous moment as the water supply flow correction value for the water supply flow adjustment at the present time; the seventh logic control unit has a higher priority than the first logic control unit and the fourth logic control unit;
the second PID controller 28 comprises an eighth logic control unit: when the RB working condition occurrence state acquisition module acquires a fault trip (RunBack) working condition of an auxiliary machine of the generator set, starting to take a first fuel supply quantity correction value in the fuel supply quantity control at the previous moment as a first fuel supply quantity correction value for regulating the fuel supply quantity at the current time; 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: when the RB condition occurrence state obtaining module 36 obtains a fault trip (RunBack) condition of the generator set auxiliary machine, starting to use the second fuel supply correction value in the fuel supply control at the previous moment as the second fuel supply correction value for the current fuel supply 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 condition occurrence state acquisition module includes: the RB working condition generation signal monitoring sub-module and the TOF sub-module are sequentially connected; the monitoring submodule for the RB working condition generation signals is used for detecting the fault tripping (RunBack) working condition generation signals of the auxiliary machines of the unit, and the TOF submodule is used for carrying out falling edge time delay processing on the fault tripping (RunBack) working condition generation signals of the auxiliary machines of the unit.
In an embodiment, referring to fig. 3, the deviation obtaining module 21 includes a separator actual pressure corresponding design temperature obtaining sub-module 211, a temperature offset value obtaining sub-module 212, a first superposition calculating sub-module 213, a first LAG sub-module 214, a second LAG sub-module 215, a fifth LAG sub-module 216, and a first difference calculating sub-module 217; the separator actual pressure corresponding design temperature obtaining sub-module 211 and the temperature bias value obtaining sub-module 212 are respectively connected with the first superposition calculating sub-module 213, the first superposition calculating module 213, the first LAG sub-module 214 and the second LAG sub-module 215 are sequentially connected in series, and the second LAG sub-module 215 and the fifth LAG sub-module 216 are respectively connected with the first difference calculating sub-module 217; wherein,
the actual separator pressure corresponds to the design temperature acquisition sub-module 211: a design temperature value corresponding to the actual pressure of the separator is determined based on the actual pressure of the separator; temperature bias value acquisition sub-module 212: the method comprises the steps of obtaining a temperature bias value; the first superposition calculation sub-module 213: the design temperature value corresponding to the actual pressure of the separator is overlapped with the temperature offset value; a first LAG submodule 214 and a second LAG submodule 215 in series: the second order inertial filter is used for carrying out second order inertial filtering on the superposition value determined by the first superposition calculation sub-module 213 to obtain a set value of the steam temperature of the separator; the fifth LAG submodule 216 is configured to perform first-order inertial filtering on an actual temperature of the separator; the first difference calculation sub-module 217 is configured to determine that a difference between a set value of a steam temperature of the separator and an actual temperature of the separator after the first-order inertia filtering is a deviation of a middle point temperature of the once-through boiler;
Further, the deviation acquisition module 21 further comprises a first inertia time determination sub-module 218 for determining an inertia time used when the first LAG sub-module 214 and the second LAG sub-module 215 perform the inertia filtering process based on the main steam flow of the boiler.
In an embodiment, referring to fig. 4, the deviation obtaining module 21 includes a separator load command corresponding design enthalpy obtaining submodule 2111, an enthalpy offset obtaining submodule 2121, a second superposition calculating submodule 2131, a third LAG submodule 2141, a separator actual enthalpy determining submodule 2151, a fourth LAG submodule 2161, a sixth LAG submodule 2171, and a second difference calculating submodule 2181; the separator load instruction corresponds to the design enthalpy value obtaining submodule 2111 and the enthalpy value offset obtaining submodule 2121 are respectively connected with the second superposition computing submodule 2131, and the second superposition computing module 2131, the third LAG submodule 2141 and the fourth LAG submodule 2161 are sequentially connected in series; the separator actual enthalpy value determining submodule 2151 is connected with the fourth LAG submodule 2161, and the fourth LAG submodule 2161 and the sixth LAG submodule 2171 are respectively connected with the second difference value calculating submodule 2181; wherein,
the separator load command corresponds to the design enthalpy acquisition submodule 2111: the method comprises the steps of determining a design enthalpy value corresponding to a load instruction of a separator based on the load instruction of the separator; enthalpy bias value acquisition submodule 2121: the method comprises the steps of obtaining an enthalpy value bias value; a second overlay calculation sub-module 2131: the design enthalpy value corresponding to the load instruction of the separator is overlapped with the enthalpy value bias value; third LAG submodule 2141 and fourth LAG submodule 2161 in series: the second order inertial filter is used for carrying out second order inertial filtering on the superposition value determined by the second superposition calculation submodule 2131 to obtain a set value of the steam temperature of the separator; the separator actual enthalpy determination submodule 2151 is configured to determine an actual enthalpy of the separator based on an actual temperature and an actual pressure of the separator; the sixth LAG submodule 2171 is used for performing first-order inertial filtering processing on the actual enthalpy value of the separator; the second difference value calculating sub-module 2181 is configured to determine that a difference value between a set value of the vapor enthalpy value of the separator and an actual enthalpy value of the separator after the first-order inertia filtering is a deviation of the intermediate point enthalpy value of the once-through boiler;
Further, the deviation obtaining module 21 further includes a second inertia time determining sub-module 2191 for determining an inertia time used when the third LAG sub-module 2141 and the fourth LAG sub-module 2161 perform the inertia filtering process based on the main steam flow of the boiler.
In an embodiment, 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 each use a subtraction block.
In one embodiment, the first stack calculation sub-module 213, the second stack calculation sub-module 2131, the feedwater flow set point determination module 27, and the second fueling correction sub-module may each use an adder block.
In one embodiment, the first fueling quantity correction submodule may use a multiplication block.
Example 1
The embodiment provides a coal water ratio control method, the flow of which is shown in fig. 7-9, and specifically includes:
1. obtaining deviation error 0
1.1 obtaining a setpoint SP for a separator steam temperature (or enthalpy) of a once-through boiler Tsep And a measurement value PV of the separator steam temperature (or enthalpy) Tsep ；
Wherein the set value SP of the separator steam temperature (or enthalpy) of the once-through boiler is obtained Tsep The method is realized by the following steps:
the actual pressure at the outlet of the separator is processed through a given function Fx6 (which is determined according to the conventional mode of a water vapor enthalpy value calculation table of the separator of the once-through boiler) to obtain a design temperature value corresponding to the actual pressure of the separator; obtaining a temperature Bias value Bias (which is manually set according to the specific type of the unit); using addition blocks (i.e. first superposition A calculation sub-module) superimposes a design temperature value corresponding to the actual pressure of the separator with a temperature Bias value Bias; the superimposed values are sequentially subjected to second-order inertial filtering by two LAG blocks (namely a first LAG sub-module and a second LAG sub-module) to form a set value SP of the steam temperature of the separator Tsep The method comprises the steps of carrying out a first treatment on the surface of the Wherein the inertia time used in the two LAG blocks is determined by: processing the main steam flow of the boiler by using a given function Fx7 (which is determined in a conventional manner according to the specific type of the unit) to determine the inertia time used in obtaining the two LAG blocks;
the actual load instruction of the outlet of the separator is processed through a given function Fx8 (which is determined in a conventional manner according to the specific type of the unit), so as to obtain a design enthalpy value corresponding to the actual load instruction of the separator; obtaining an enthalpy value Bias (which is manually set according to the specific type of the unit); superposing a design enthalpy value corresponding to an actual load instruction of the separator and an enthalpy value Bias by using an adding block (namely a second superposition computing sub-module); the overlapped values are sequentially subjected to second-order inertial filtering by two LAG blocks (namely a third LAG sub-module and a fourth LAG sub-module) to form a set value SP of the vapor enthalpy value of the separator Tsep The method comprises the steps of carrying out a first treatment on the surface of the Wherein the inertia time used in the two LAG blocks is determined by: processing the main steam flow of the boiler by using a given function Fx9 (which is determined in a conventional manner according to the specific type of the unit) to determine the inertia time used in obtaining the two LAG blocks;
wherein a measurement value PV of the separator steam temperature (or enthalpy) of the once-through boiler is obtained Tsep The method is realized by the following steps:
acquiring the actual temperature of the separator, and performing first-order inertial filtering on the acquired actual temperature of the separator through a LAG block (namely a fifth LAG sub-module) to obtain a measured value PV of the steam temperature of the separator Tsep ；
Acquiring the actual temperature and the actual pressure of the separator, and determining the actual enthalpy value of the separator by utilizing a Cal block to perform calculation (obtained by table lookup or fitting calculation) based on the actual temperature and the actual pressure of the separator; passing the determined actual enthalpy value of the separator through a LAG blockThe first-order inertia filtering is carried out (namely, the sixth LAG sub-module) to obtain a measurement value PV of the vapor enthalpy value of the separator Tsep ；
Wherein, the algorithm adopted by each order of inertial filtering is thatWhere s is the Laplacian and T is the inertia time.
When the boiler is of a certain unit type, the given function Fx6 satisfies the following table 1, the given function Fx7 satisfies the following table 2, the given function Fx8 (the enthalpy value is expressed by temperature; for example, when the load is 400t/h, the design enthalpy value corresponding to the actual load instruction of the separator is 362 ℃) satisfies the following table 3, and 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 (. Degree. C.) 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 Table 3
Load (t/h) 400 450 550 650 750 850 900 950 1000
Temperature (. Degree. C.) 362 365 367 374 386 403.9 406.6 409 410
TABLE 4 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, determination of the temperature (or enthalpy) of the steam to be separatedConstant SP Tsep And a measurement value PV of the separator steam temperature (or enthalpy) Tsep The difference of the control deviation error is obtained 0 ，error 0 ＝SP Tsep -PV Tsep 。
2. The automatic water supply state is acquired, and the automatic water supply state includes an automatic state and a non-automatic state.
3. And monitoring a fault tripping (namely RB) occurrence signal of the auxiliary machine of the unit, carrying out falling edge time delay processing (more than 10s in falling edge time delay) on the fault tripping (namely TOF submodule) occurrence signal by utilizing the TOF block, and displaying a fault tripping working condition of the auxiliary machine of the unit by the fault tripping working condition occurrence signal of the auxiliary machine of the unit after the falling edge time delay processing, so that the fault tripping working condition of the auxiliary machine of the unit is considered to be generated.
4. Acquiring a main control instruction BMD of a boiler; the boiler main control instruction BMD is processed through a given function Fx1 (which is determined in a conventional manner according to the specific type of the unit) to obtain the water supply flow FW_MD formed by the original boiler main control instruction; the boiler main control instruction BMD is processed through a given function Fx2 (which is determined in a conventional manner according to the specific type of the unit) to obtain the FUEL supply quantity fuel_MD formed by the original boiler main control instruction.
When the boiler is of 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 instruction BMD 0％ 40％ 53％ 80％ 100％ 110％
Water supply flow (t/h) 940 1080 1440 2150 2710 3000
TABLE 6
Main control instruction BMD 0％ 40％ 53％ 80％ 100％ 110％
Fuel supply quantity (t/h) 0 160 1440 315 375 430
5. Acquiring a water supply flow demand signal (i.e. water supply flow FW_MD) converted by a boiler main control instruction and measuring engineering measuring points for actually controlling the water supply flow to obtain the actual water supply flow (i.e. actual water supply flow) of the boiler; determining a difference value between a water supply flow demand signal converted by a main control instruction of the boiler and an engineering measuring point for actually controlling the water supply flow by using a subtracting block to obtain the actual water supply flow of the boiler;
acquiring a FUEL supply quantity demand signal (namely a water supply flow quantity fuel_MD) converted by a boiler main control instruction and measuring engineering measuring points for actually controlling the water supply flow quantity to obtain the actual FUEL supply quantity (namely the actual FUEL supply quantity) of the boiler; and determining a difference value between a fuel supply quantity demand signal converted by the main control instruction of the boiler and an engineering measuring point for actually controlling the fuel supply quantity by using a subtracting block to obtain the actual water supply flow of the boiler.
6. Feedwater flow control (first fork arm control):
6.1 determining the feed water flow correction FW_Corr
Determining a feedwater flow correction fw_corr using the method set forth in step 6.1.1, step 6.1.2 or step 6.1.3; wherein the step 6.1.3 has a higher priority than the step 6.1.2, and the step 6.1.2 has a higher priority than the step 6.1.1;
6.1.1, first correction function fx3 vs. control deviation error 0 Performing deviation processing to obtain a first corrected deviation; after the first corrected deviation enters the controller PID1 (namely a first PID controller), the SP unit (namely a first logic control unit) of the controller PID1 utilizes the water supply flow correction function to calculate and determine a water supply flow correction value FW_Corr; wherein,
the first correction function fx3 is:wherein error is of the formula 1 Is the first corrected deviation; error (error) 0 Is the original deviation;
when controlling deviation error 0 For the deviation of the separator steam temperature, the first correction function fx3 is used to control the deviation error 0 Performing deviation processing to obtain a first corrected deviation as shown in table 7;
TABLE 7
Input (DEG C) -20 -10 -5 -2 2 5 10 20
Output (. Degree. C.) -20 -10 -5 0 0 5 10 20
The water supply flow correction function isWherein the original default output is 0; wherein error is of the formula 1 Is the first corrected deviation; FW_Corr is the feed water flow correction value; kp (kP) 1 Is a proportionality coefficient; t (T) 1 Is the integration time;
6.1.2, when the obtained water supply is automatically not in an automatic state, namely in a water supply control manual state, triggering the controller PID1 by using a TRSF unit (namely a fourth logic triggering subunit) of the controller PID1, starting the controller PID1 according to the TR unit (namely a fourth logic operation subunit), and determining a water supply flow correction value FW_Corr and FW_Corr=actual water supply flow-FW_MD by using a difference value between a water supply flow demand signal (namely water supply flow FW_MD) converted by a boiler main control instruction and an engineering measurement point for actually controlling the water supply flow, which is obtained by measuring the actual water supply flow of the boiler, by using the TR unit of the controller PID 1;
6.1.3, when the fault tripping (RunBack) working condition of the auxiliary machine of the unit is obtained, namely, when the RB working condition is generated, determining a water supply flow correction value FW_Corr by using a HOLD unit (namely, a seventh logic control unit) of the controller PID1, and taking the water supply flow correction value FW_Corr (t-1) in water supply flow control at the last moment as the water supply flow correction value FW_Corr (t) of water supply flow regulation at the moment.
And 6.2, utilizing an addition speed to superpose the water supply flow correction value FW_Corr with the water supply flow FW_MD formed by the original boiler main control instruction so as to determine the water supply flow set value FWMD.
7. Fuel amount control (second fork arm control):
7.1 determining a first FUEL supply correction value FUEL_Corr, a second FUEL supply correction value MU_Factor
Determining a first FUEL supply correction value fuel_corr in the manner specified in step 7.1.1, step 7.1.2 or step 7.1.3; wherein, the priority of the step 7.1.3 is higher than that of the step 7.1.2, and the priority of the step 7.1.2 is higher than that of the step 7.1.1;
7.1.1, second correction function fx4 vs. control deviation error 0 Performing deviation processing to obtain a second corrected deviation;after the second corrected deviation enters the controller PID2 (namely a second PID controller), the SP unit (namely a second logic control unit) of the controller PID2 utilizes the first FUEL supply quantity correction function to calculate and determine a first FUEL supply quantity correction value fuel_Corr; wherein,
The second correction function fx4 is:wherein error is of the formula 2 Is the second corrected deviation; error (error) 0 Is the original deviation;
when controlling deviation error 0 For the deviation of the separator steam temperature, the second correction function fx4 is used for controlling the deviation error 0 Performing deviation processing to obtain a second corrected deviation as shown in table 8;
TABLE 8
Input (DEG C) -30 -15 -10 -5 5 10 15 30
Output (. Degree. C.) -30 -15 -10 0 0 10 15 30
The first fuel supply quantity correction function isWherein the original default output is 0; wherein error is of the formula 2 Is the second corrected deviation; fuel_corr is the first FUEL supply amount correction value; kp (kP) 2 Is a proportionality coefficient; t (T) 2 Is the integration time;
7.1.2, when the automatic FUEL feeding state is not obtained, namely, the automatic FUEL feeding state is in a manual FUEL feeding control state, the TRSF unit (namely, the fifth logic triggering subunit) of the controller PID2 is utilized to trigger the controller PID2 to start according to the TR unit (namely, the fifth logic operation subunit), and the difference value of the actual FUEL feeding amount of the boiler is determined by the TR unit of the controller PID2, which is obtained by measuring the FUEL feeding amount demand signal (namely, the water feeding flow quantity fuel_MD) converted by the boiler main control instruction and the engineering measuring point which is used for actually controlling the FUEL feeding amount;
7.1.3 determining a FUEL supply correction value fuel_corr by using a HOLD unit (namely an eighth logic control unit) of the controller PID2 when a fault trip (RunBack) working condition of the auxiliary machinery of the machine set is obtained, namely when an RB working condition is generated, and taking a first FUEL supply correction value fuel_corr (t-1) in the previous FUEL supply control as a FUEL supply correction value fuel_corr (t) for the first FUEL supply adjustment.
7.2 determining a second fuel supply correction value MU_Factor
Determining a second fueling correction value mu_factor using the manner set forth in step 7.2.1, step 7.2.2, or step 7.2.3; wherein, the priority of the step 7.2.3 is higher than that of the step 7.2.2, and the priority of the step 7.2.2 is higher than that of the step 7.2.1;
7.2.1, third correction function fx5 vs. control deviation error 0 Performing deviation processing to obtain a third corrected deviation; after the third corrected deviation enters the controller PID3 (namely a third PID controller), the SP unit (namely a third logic control unit) of the controller PID3 utilizes the second fuel supply quantity correction function to calculate and determine a second fuel supply quantity correction value MU_factor; wherein,
the third correction function fx5 is:wherein error is of the formula 3 Is the third corrected deviation; error (error) 0 Is the original deviation;
when controlling deviation error 0 For the deviation of the separator steam temperature, the third correction function fx5 is used to control the deviation error 0 The deviation processing is performed to obtain a third corrected deviation as shown in table 9;
TABLE 9
Input (DEG C) -30 -15 -10 -5 5 10 15 30
Output (. Degree. C.) -30 -15 0 0 0 0 15 30
The second fuel correction function is:wherein the original default output is 1; wherein error is of the formula 3 Is the third corrected deviation; MU_Factor is the third fuel supply correction value; kp (kP) 3 Is a proportionality coefficient; t (T) 3 Is the integration time;
the second fuel supply amount correction value is 0.8-1.2, the corresponding second fuel supply amount correction value is 0.8 or 1.2 when the corrected deviation is far away from 0, and the corresponding second fuel supply amount correction value is 1 when the absolute value of the corrected deviation is close to 0, and the corrected deviation is 0 and the second fuel supply amount correction value is 1.
7.2.2, when the FUEL supply automatic state is not acquired, namely, the FUEL supply control manual state is acquired, the TRSF unit (namely, the sixth logic trigger subunit) of the controller PID3 is utilized to trigger the controller PID3 to start according to the TR unit (namely, the sixth logic operation subunit), and the FUEL supply correction value fuel_Corr is determined to be 1 through the TR unit of the controller PID 3;
and 7.2.3, when a fault trip (RunBack) working condition of the auxiliary machine of the unit is obtained, namely, when an RB working condition is generated, determining a fuel supply quantity correction value MU_factor by using a HOLD unit (namely, a ninth logic control unit) of the controller PID3, and taking a second fuel supply quantity correction value MU_factor (t-1) in the fuel supply quantity control at the last moment as a fuel supply quantity correction value MU_factor (t) for regulating the second fuel supply quantity.
And 7.3, multiplying the second FUEL supply quantity correction value MU_Factor by the FUEL supply quantity FUEL_MD formed by the original boiler main control instruction by using the multiplication block MUL, and superposing the obtained FUEL quantity with the first FUEL supply quantity correction value FUEL_Corr by using the addition block to determine a FUEL supply quantity set value FUELMD.
Preferred embodiments of the present invention are described above with reference to the accompanying drawings. The many features and advantages of the embodiments are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the embodiments which fall within the true spirit and scope thereof. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the embodiments of the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope thereof.

Claims (27)

1. A coal water ratio control method that achieves coal water ratio control by feed water flow rate and feed fuel amount control, wherein the method comprises:
deviation acquisition: acquiring deviation of intermediate point temperature or enthalpy of the once-through boiler;
feed water flow control and feed fuel amount control are performed based on the deviation: when the deviation is within the first dead zone range, not adjusting the feedwater flow and not adjusting the fuel feed; when the deviation is not in the first dead zone range but in the second dead zone range, the water supply flow rate is regulated, and the fuel supply amount is not regulated, so that the coal-water ratio is regulated; when the deviation is not in the second dead zone range but in the third dead zone range, adjusting the feed water flow rate and adjusting the feed fuel amount, thereby realizing the coal water ratio adjustment, wherein the adjustment amount of the feed fuel amount is determined based on the first fuel correction function; when the deviation is not in the third dead zone range, adjusting the water supply flow rate and the fuel supply amount, thereby realizing the coal water ratio adjustment, wherein the adjustment amount of the fuel supply amount is determined based on the first fuel correction function and the second fuel correction function;
Wherein 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 given fuel amount is determined based on the first fuel correction function and the second fuel correction function to be larger than the adjustment amount of the fuel amount determined based on the first fuel correction function alone;
wherein, the water supply flow control and the fuel supply flow control based on the deviation are realized by the following modes:
water supply flow control based on deviation: determining a water supply flow correction value based on the deviation, and correcting the water supply flow formed by the original boiler main control instruction by using the water supply flow correction value so as to determine a water supply flow set value; wherein the deviation-based feedwater flow correction value determination includes: processing the deviation through a first correction function to obtain a first corrected deviation, wherein the first correction function is a function capable of setting a first dead zone; determining a feedwater flow correction value using a feedwater flow correction function based on the first corrected deviation; when the deviation is in the first dead zone range, the first corrected deviation is 0, and the water supply flow correction value has no correction capability on the water supply flow formed by the original boiler main control instruction; when the deviation is not in the first dead zone range, the first corrected deviation is not 0, and the water supply flow correction value has the capability of correcting the water supply flow formed by the original boiler main control instruction;
Fuel supply amount control is performed based on the deviation: determining a first fuel supply correction value and a second fuel supply correction value based on the deviation; correcting the fuel supply quantity formed by the original boiler main control instruction by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity 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 a second correction function to obtain a second corrected deviation, wherein the second correction function is a function capable of setting a second dead zone; determining a first fueling quantity correction value using a first fuel correction function based on the second corrected deviation; processing the deviation through a third correction function to obtain a third corrected deviation, wherein the third correction function is a function capable of setting a third dead zone; determining a second fueling quantity correction value using a second fuel correction function based on the third corrected deviation; when the deviation is in the second dead zone range, the second corrected deviation is 0, and the first fuel supply quantity correction value has no correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is not in the second dead zone range, the second corrected deviation is not 0, and the first fuel supply quantity correction value has correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is in the third dead zone range, the third corrected deviation is 0, and the second fuel supply quantity correction value has no correction capability on the fuel supply quantity formed by the original boiler main control instruction; when the deviation is not in the third dead zone range, the third corrected deviation is not 0, and the second fuel supply quantity correction value has correction capability on the fuel supply quantity formed by the original boiler main control instruction;
Wherein the first fuel correction function is a PID algorithm model:
wherein the original default output is 0;
wherein error is of the formula 2 Is the second corrected deviation; fuel_corr is the first FUEL supply amount correction value; kp (kP) 2 Is a proportionality coefficient; t (T) 2 Is the integration time;
the second fuel correction function is a PID algorithm model:
wherein the original default output is 1;
wherein error is of the formula 3 Is the third corrected deviation; MU_Factor is the third fuel supply correction value; kp (kP) 3 Is a proportionality coefficient; t (T) 3 Is the integration time.
2. The control method according to claim 1, wherein obtaining the deviation of the intermediate point temperature of the once-through boiler comprises:
acquiring the actual pressure of the separator, and further acquiring a design temperature value corresponding to the actual pressure of the separator; superposing the design temperature value and the temperature offset value, and performing second-order inertial filtering to form a set value of the steam temperature of the separator; wherein the inertia time used in the second order inertia filtering is determined based on the main steam flow of the boiler;
acquiring the actual temperature of the separator, and performing first-order inertial filtering on the acquired actual temperature of the separator;
and determining the deviation between the set value of the steam temperature of the separator and the actual temperature of the separator after the first-order inertia filtering to be the deviation of the middle point temperature of the once-through boiler.
3. The control method according to claim 1, wherein obtaining the deviation of the intermediate point enthalpy value of the once-through boiler comprises:
acquiring a load instruction of the separator, and further acquiring a design enthalpy value corresponding to the load instruction of the separator; superposing the design enthalpy value and the enthalpy value offset value, and then performing second-order inertial filtering to form a set value of the vapor enthalpy value of the separator; wherein the inertia time used in the second order inertia filtering is determined based on the main steam flow of the boiler;
acquiring the actual temperature and the actual pressure of the separator, determining the actual enthalpy value of the separator based on the actual temperature and the actual pressure of the separator, and performing first-order inertial filtering on the actual enthalpy value of the separator;
and determining the deviation between the set value of the vapor enthalpy value of the separator and the actual enthalpy value of the separator after the first-order inertia filtering, namely the deviation of the intermediate point enthalpy value of the once-through boiler.
4. The control method according to claim 1, wherein,
the first correction function is:
wherein error is of the formula 1 Is the first corrected deviation; error (error) 0 Is the original deviation;
the second correction function is:
wherein error is of the formula 2 Is the second corrected deviation; error (error) 0 Is the original deviation;
the third correction function is:
wherein error is of the formula 3 Is the third corrected deviation; error (error) 0 Is the original deviation;
the water supply flow correction function is a PID algorithm model:
wherein the original default output is 0;
wherein error is of the formula 1 Is the first corrected deviation; FW_Corr is the feed water flow correction value; kp (kP) 1 Is a proportionality coefficient; t (T) 1 Is the integration time.
5. The control method according to claim 1, wherein the method further comprises:
when the water supply is automatically not in an automatic state, stopping water supply flow control based on the deviation, and performing water supply flow control according to the first forced water supply flow control; wherein the first forced control of the feedwater flow includes: tracking a water supply flow demand signal converted by a boiler main control instruction and measuring engineering measuring points for actually controlling the water supply flow to obtain a difference value of the actual water supply flow of the boiler, and taking the difference value as a water supply flow regulating quantity to regulate the water supply 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 feed water flow obtained by measuring the engineering measuring point of the actual control feed water flow is represented by subtracting the feed water flow demand signal converted by the boiler main control instruction from the actual feed water flow of the boiler obtained by measuring the engineering measuring point of the actual control feed water flow;
Suspending the fuel supply amount control based on the deviation from the first forced fuel supply amount control when the fuel supply automatic is not in the automatic state; wherein the first forced control of the fuel amount includes: and tracking a fuel supply quantity demand signal converted by a boiler main control instruction and measuring engineering measuring points for actually controlling the fuel supply quantity to obtain a difference value of the actual fuel supply quantity of the boiler, and taking the difference value as a fuel supply quantity regulating quantity to regulate the fuel supply quantity.
7. The control method according to claim 5, wherein the difference between the fuel supply demand signal converted by the boiler main control command and the actual fuel supply of the boiler measured at the engineering site for actually controlling the fuel supply is represented by subtracting the fuel supply demand signal converted by the boiler main control command from the actual fuel supply of the boiler measured at the engineering site for actually controlling the fuel supply.
8. The control method according to claim 5, wherein,
the first forced control of the water supply flow is realized by the following modes:
tracking a difference value of the actual water supply flow of the boiler obtained by measuring a water supply flow demand signal converted by a main control instruction of the boiler and an engineering measuring point for actually controlling the water supply flow, and determining a water supply flow correction value based on the difference value;
Correcting the water supply flow formed by the original boiler main control instruction by utilizing the water supply flow correction value so as to determine a water supply flow set value;
the set value of the water supply flow is equal to the actual water supply flow of the boiler obtained by measuring engineering measuring points which actually control the water supply flow;
the first forced control of the fuel quantity is realized by the following modes:
tracking a fuel supply quantity demand signal converted by a boiler main control instruction and measuring engineering measuring points for actually controlling the fuel supply quantity to obtain a difference value of the actual fuel supply quantity of the boiler, and determining a first fuel supply quantity correction value and a second fuel supply quantity correction value based on the difference value;
correcting the fuel supply quantity formed by the original boiler main control instruction by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity set value;
the determined fuel supply quantity set value is equal to the actual fuel supply quantity of the boiler obtained by measuring engineering measuring points which actually control the fuel supply quantity.
9. The control method according to claim 1, wherein the method further comprises:
when the fault tripping working condition of the auxiliary machine of the unit occurs, the forced priority is to control the water supply flow according to the forced control of the water supply flow of the RB working condition, wherein the forced control of the water supply flow of the RB working condition comprises the following steps: the water supply flow rate is adjusted to be switched into a holding state, and the water supply flow rate is adjusted by adopting a water supply flow rate adjusting scheme in water supply flow rate control at the last moment;
When the fault tripping working condition of the auxiliary machine of the unit occurs, the forced control of the fuel feeding quantity is carried out by forcing priority according to the RB working condition; wherein, RB working condition fuel quantity forced control includes: the fuel supply amount adjustment is switched into the holding state, and the fuel supply amount adjustment is performed by adopting a fuel supply amount adjustment scheme in the fuel supply amount control at the previous time.
10. The control method according to claim 9, wherein the unit auxiliary machine fault tripping condition occurrence signal is monitored and subjected to falling edge delay processing, and the unit auxiliary machine fault tripping condition occurrence signal after the falling edge delay processing shows that the unit auxiliary machine fault tripping condition occurs, and the unit auxiliary machine fault tripping condition is considered to occur.
11. The control method according to claim 9, wherein,
the forced control of the RB working condition water supply flow is realized by the following modes:
the water supply flow correction value in the water supply flow control at the previous moment is used as the water supply flow correction value for the water supply flow adjustment at the present time;
correcting the water supply flow formed by the original boiler main control instruction by utilizing the water supply flow correction value so as to determine a water supply flow set value;
the forced control of the RB working condition to the fuel quantity is realized by the following steps:
Taking the first fuel supply correction value in the fuel supply control at the previous moment as the first fuel supply correction value for the fuel supply adjustment at the present time, and taking the second fuel supply correction value in the fuel supply control at the previous moment as the second fuel supply correction value for the fuel supply adjustment at the present time;
and correcting the fuel supply quantity formed by the original boiler main control instruction by using the first fuel supply quantity correction value and the second fuel supply quantity correction value so as to determine a fuel supply quantity set value.
12. The control method according to any one of claims 4, 8, 11, wherein,
the method for correcting the fuel supply quantity formed by the original boiler main control instruction by using the first fuel supply quantity correction value and the second fuel supply quantity correction value comprises the following steps: and multiplying the second fuel supply correction value by the fuel supply formed by the original boiler main control instruction, and superposing the obtained fuel quantity with the first fuel supply correction value to determine a fuel supply set value.
13. The control method according to claim 12, wherein the second fuel supply amount correction value is 0.8 to 1.2, the more the corrected deviation is away from 0, the corresponding second fuel supply amount correction value is closer to 0.8 or 1.2, the more the absolute value of the corrected deviation is closer to 0, the corresponding second fuel supply amount correction value is closer to 1, and 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 water ratio control method includes the first forced control of the fuel supply amount, a difference between a fuel supply amount demand signal converted by the boiler main control command and an engineering measurement point actually controlling the fuel supply amount is measured to obtain an actual fuel supply amount of the boiler as the first fuel supply amount correction value in the first forced control of the fuel supply amount; a second fuel supply amount correction value 1 is determined.
15. The control method according to any one of claims 4, 8, and 11, wherein correcting the feedwater flow formed by the original boiler master control command with the feedwater flow correction value is performed by: and superposing the water supply flow correction value with the water supply flow formed by the original boiler main control instruction.
16. The control method according to claim 15, wherein when the coal water ratio control method includes the first forced control of the feedwater flow, a difference between the feedwater flow demand signal converted by the boiler master control command and the engineering measurement point actually controlling the feedwater flow is measured as the feedwater flow correction value in the first forced control of the feedwater flow.
17. The control method according to claim 1, wherein,
When the deviation is a midpoint temperature deviation, 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 is the separator steam temperature or enthalpy;
the deviation of the intermediate point temperature or the enthalpy value is represented by subtracting a measured value of the intermediate point temperature or the enthalpy value from a set value of the intermediate point temperature or the enthalpy value.
18. A coal-to-water ratio control system, wherein the system comprises:
the deviation acquisition module is used for: the method comprises the steps of obtaining deviation of intermediate point temperature or enthalpy value of a once-through boiler;
a first deviation correction module: the method comprises the steps of obtaining a first corrected deviation by processing the deviation through a first correction function, wherein the first correction function is a function capable of setting a first dead zone; when the deviation is within the first dead zone range, the first corrected deviation is 0, and when the deviation is not within the first dead zone range, the first corrected deviation is not 0;
a second deviation correction module: the deviation is processed through a second correction function to obtain a second corrected deviation, wherein the second correction function is a function capable of setting a second dead zone; when the deviation is within the second dead zone range, the second corrected deviation is 0, and when the deviation is not within the second dead zone range, the second corrected deviation is not 0;
A third deviation correction module: the deviation is processed through a third correction function to obtain a third corrected deviation, wherein the third correction function is a function capable of setting a 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 range, the deviation after the first correction is not 0;
the first PID controller comprises a first logic control unit; the first logic control unit is used for determining a water supply flow correction value by utilizing a water supply flow correction function based on the first corrected deviation; wherein, the water supply flow correction value determination performed by the first logic control unit meets the following conditions: the water supply flow correction value determined when the first corrected deviation is 0 has no correction capability on the water supply flow formed by the original boiler main control instruction, and the water supply flow correction value has correction capability on the water supply flow formed by the original boiler main control instruction when the first corrected deviation is not 0;
original water supply flow acquisition module: the method is used for acquiring the water supply flow formed by the original boiler main control instruction;
the water supply flow set value determining module: the method comprises the steps of correcting the water supply flow formed by an original boiler main control instruction by utilizing a water supply flow correction value so as to determine a water supply flow set value;
The second PID controller comprises a second logic control unit; the second logic control unit is used for determining a first fuel supply correction value by using a first fuel correction function based on the second corrected deviation; wherein the first fuel supply amount correction value determination by the second logic control unit satisfies: the first fuel supply quantity correction value determined when the second corrected deviation is 0 has no correction capability on the fuel supply quantity formed by the original boiler main control instruction, and the first fuel supply quantity correction value determined when the second corrected deviation is not 0 has correction capability on the fuel supply quantity formed by the original boiler main control instruction;
the third PID controller comprises a third logic control unit; the third logic control unit is used for determining a second fuel supply correction value by using a second fuel correction function based on the third corrected deviation; wherein the second fuel supply amount correction value determination by the third logic control unit satisfies: the second fuel supply amount correction value determined when the third corrected deviation is 0 has no correction capability on the fuel supply amount formed by the original boiler main control instruction, and the second fuel supply amount correction value determined when the third corrected deviation is not 0 has correction capability on the fuel supply amount formed by the original boiler main control instruction;
Original fuel supply amount acquisition module: the method is used for acquiring fuel supply quantity formed by original boiler main control instructions;
a fuel quantity set value determining module: the method comprises the steps of determining a fuel supply set value by correcting the fuel supply formed by an original boiler main control instruction by using a first fuel supply correction value and a second fuel supply correction value, and providing a set value for a fuel control loop;
wherein 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;
wherein the first fuel correction function is a PID algorithm model:
wherein the original default output is 0;
wherein error is of the formula 2 Is the second corrected deviation; fuel_corr is the first FUEL supply amount correction value; kp (kP) 2 Is a proportionality coefficient; t (T) 2 Is the integration time;
the second fuel correction function is a PID algorithm model:
wherein the original default output is 1;
wherein error is of the formula 3 Is the third corrected deviation; MU_Factor is the third fuel supply correction value; kp (kP) 3 Is a proportionality coefficient; t (T) 3 Is the integration time.
19. The system of claim 18, wherein the system further comprises:
the water supply control state acquisition module: for acquiring the state of automatic water supply, the state of automatic water supply including an automatic state and a non-automatic state;
A first difference value acquisition module: the system comprises a boiler main control instruction, a boiler water supply flow demand signal acquisition module, a boiler main control instruction acquisition module, a boiler water supply flow control module and a boiler water supply flow control module, wherein the boiler main control instruction acquisition module is used for acquiring a boiler water supply flow;
the first PID controller includes a fourth logic control unit: when the water supply control state acquisition module acquires that the water supply is automatically in an automatic state, starting to determine a water supply flow correction value based on the difference acquired by the first difference acquisition module; the fourth logic control unit has a higher priority than the first logic control unit;
the water supply control state acquisition module and the first difference acquisition module are respectively connected with the first PID controller.
20. The system of claim 19, wherein the fourth logic control unit includes a fourth logic trigger subunit, a fourth logic operator subunit, the feedwater control state acquisition module being connected to the fourth logic trigger subunit, the first difference acquisition module being connected to the fourth logic operator subunit to enable the feedwater automatic control state signal acquired by the feedwater control state acquisition module to be delivered to the fourth logic trigger subunit, the fourth logic trigger subunit being configured to trigger activation of the fourth logic operator subunit when receiving a signal that the feedwater is not in an automatic state automatically, the fourth logic operator subunit being configured to determine a feedwater flow correction value based on the difference acquired by the first difference acquisition module after activation.
21. The system of claim 18, wherein the system further comprises:
and (3) feeding the fuel control state acquisition module with: for acquiring an automatic fuel-feeding state, the automatic fuel-feeding state including an automatic state and a non-automatic state;
and a second difference value acquisition module: the method comprises the steps of obtaining a difference value of actual fuel supply quantity of a boiler by measuring engineering measuring points for tracking fuel supply quantity demand signals converted by a main control instruction of the boiler and the actual fuel supply quantity;
the second PID controller comprises a fifth logical control unit: the fuel supply control state acquisition module is used for starting to determine a first fuel supply amount correction value based on the difference value acquired by the second difference value acquisition module when the fuel supply control state acquisition module acquires that the fuel supply is automatically in an automatic state; the fifth logic control unit has a higher priority than the second logic control unit;
the third PID controller includes a sixth logical control unit: the fuel supply control state acquisition module is used for starting to determine a second fuel supply amount correction value based on the difference value acquired by the second difference value acquisition module when the fuel supply control state acquisition module acquires that the fuel supply is automatically in an automatic state; the sixth logic control unit has a higher priority than the third logic control unit;
the fuel supply control state acquisition module is respectively connected with the second PID controller and the third PID controller, and the second difference acquisition module is respectively connected with the second PID controller and the third PID controller.
22. The system of claim 21, wherein the fifth logic control unit includes a fifth logic trigger subunit, a fifth logic operator subunit, the fuel supply control state acquisition module is connected to the fifth logic trigger subunit, the second difference acquisition module is connected to the fifth logic operator subunit, so as to realize that the fuel supply automatic control state signal acquired by the fuel supply control state acquisition module is transmitted to the fifth logic trigger subunit, the fifth logic trigger subunit is used for triggering the fifth logic operator subunit to start when receiving the signal that the fuel supply automatic is not in the automatic state, and the fifth logic operator subunit is used for determining the fuel supply correction value based on the difference acquired by the second difference acquisition module after starting.
23. The system of claim 21, wherein the sixth logic control unit includes a sixth logic trigger subunit, a sixth logic operator subunit, the fuel supply control state acquisition module being connected to the sixth logic trigger subunit, the second difference acquisition module being connected to the sixth logic operator subunit to enable the fuel supply automatic control state signal acquired by the fuel supply control state acquisition module to be delivered to the sixth logic trigger subunit, the sixth logic trigger subunit being configured to trigger a start of the sixth logic operator subunit when a signal that the fuel supply automatic is not in an automatic state is received, the sixth logic operator subunit being configured to determine the fuel supply second flow correction value based on the difference acquired by the second difference acquisition module after the start of the sixth logic operator subunit.
24. The system of any of claims 18-23, wherein the system further comprises:
RB working condition triggering state acquisition module: the method comprises the steps of acquiring a trigger state of a fault tripping working condition of an auxiliary machine of the unit, wherein the trigger state of the fault tripping working condition of the auxiliary machine of the unit comprises triggering and non-triggering;
the first PID controller includes a seventh logic control unit: when the RB working condition triggering state acquisition module acquires the fault tripping working condition of the auxiliary machine of the trigger unit, starting to take the water supply flow correction value in water supply flow control at the last moment as the water supply flow correction value for water supply flow regulation at the moment; the seventh logic control unit has a higher priority than the first logic control unit and the fourth logic control unit;
the second PID controller includes an eighth logic control unit: when the RB working condition triggering state acquisition module acquires the fault tripping working condition of the auxiliary machine of the trigger unit, starting to take the first fuel supply quantity correction value in the fuel supply quantity control at the previous moment as the first fuel supply quantity correction value for the current fuel supply quantity 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 logical control unit: when the RB working condition triggering state acquisition module acquires the fault tripping working condition of the auxiliary machine of the trigger unit, starting to take the second fuel supply quantity correction value in the fuel supply quantity control at the previous moment as the second fuel supply quantity correction value for the current fuel supply quantity 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 of claim 24, wherein the RB condition occurrence state acquisition module includes: the RB working condition generation signal monitoring sub-module and the TOF sub-module are sequentially connected; the monitoring sub-module of the RB working condition generation signal is used for detecting the generation signal of the auxiliary machine fault tripping working condition of the unit, and the TOF sub-module is used for carrying out the falling edge delay processing of the generation signal of the auxiliary machine fault tripping working condition of the unit.
26. The system of claim 18, wherein the bias acquisition module comprises:
the actual pressure of the separator corresponds to the design temperature acquisition sub-module, the temperature bias 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; the separator actual pressure corresponding design temperature acquisition submodule and the temperature offset value acquisition submodule are respectively connected with the first superposition calculation submodule, the first LAG submodule and the second LAG submodule are sequentially connected in series, and the second LAG submodule and the fifth LAG submodule are respectively connected with the first difference calculation submodule; wherein,
the actual pressure of the separator corresponds to the design temperature and obtains the submodule: a design temperature value corresponding to the actual pressure of the separator is determined based on the actual pressure of the separator; temperature offset value acquisition submodule: the method comprises the steps of obtaining a temperature bias value; a first superposition calculation sub-module: the design temperature value corresponding to the actual pressure of the separator is overlapped with the temperature offset value; the first LAG sub-module and the second LAG sub-module are connected in series: the second-order inertial filtering is used for carrying out second-order inertial filtering on the superposition value determined by the first superposition calculation sub-module to obtain a set value of the steam temperature of the separator; the fifth LAG submodule is used for carrying out first-order inertial filtering treatment on the actual temperature of the separator; the first difference value calculation submodule is used for determining that the difference value between the set value of the steam temperature of the separator and the actual temperature of the separator after the first-order inertia filtering is the deviation of the intermediate point temperature of the once-through boiler.
27. The system of claim 18, wherein the bias acquisition module comprises:
the separator load instruction corresponds to a design enthalpy acquisition sub-module, an enthalpy bias value acquisition sub-module, a second superposition calculation sub-module, a third LAG sub-module, a separator actual enthalpy determination sub-module, a fourth LAG sub-module, a sixth LAG sub-module and a second difference calculation sub-module; the separator load instruction corresponds to the design enthalpy value acquisition submodule and the enthalpy value offset value acquisition submodule, and are respectively connected with the second superposition calculation submodule, and the second superposition calculation module, the third LAG submodule and the fourth LAG submodule are sequentially connected in series; the separator actual enthalpy value determining submodule is connected with a fourth LAG submodule, and the fourth LAG submodule and the sixth LAG submodule are respectively connected with a second difference value calculating submodule; wherein,
the separator load command corresponds to a design enthalpy value acquisition sub-module: the method comprises the steps of determining a design enthalpy value corresponding to a load instruction of a separator based on the load instruction of the separator; enthalpy value offset value acquisition sub-module: the method comprises the steps of obtaining an enthalpy value bias value; a second superposition calculation sub-module: the design enthalpy value corresponding to the load instruction of the separator is overlapped with the enthalpy value bias value; third and fourth LAG sub-modules in series: the second-order inertial filtering is used for carrying out second-order inertial filtering on the superposition value determined by the second superposition calculation sub-module to obtain a set value of the steam temperature of the separator; the separator actual enthalpy value determining submodule is used for determining the actual enthalpy value of the separator based on the actual temperature and the actual pressure of the separator; the sixth LAG submodule is used for carrying out first-order inertial filtering treatment on the actual enthalpy value of the separator; the second difference value calculation sub-module is used for determining that the difference value between the set value of the vapor enthalpy value of the separator and the actual enthalpy value of the separator after the first-order inertia filtering is the deviation of the intermediate point enthalpy value of the once-through boiler.
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Publication number Priority date Publication date Assignee Title
CN114115367B (en) * 2021-11-24 2024-05-07 国能河北沧东发电有限责任公司 Control method and device for water supply flow of direct-current furnace
CN116359275B (en) * 2023-04-18 2024-09-20 南方电网电力科技股份有限公司 Method, system, equipment and medium for determining hydrodynamic phase transition point of boiler

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006071166A (en) * 2004-09-01 2006-03-16 Babcock Hitachi Kk Steam temperature control device for once-through boiler
JP2010243016A (en) * 2009-04-03 2010-10-28 Hitachi Ltd Oxygen burning boiler plant and method of operating the oxygen burning boiler plant
CN102323748A (en) * 2011-04-25 2012-01-18 上海迪吉特控制系统有限公司 Direct current stove monoblock directly can matter balance coordination control system
CN105588122A (en) * 2015-12-22 2016-05-18 山东中实易通集团有限公司 Fuel control method and system applied to circulating fluidized bed boiler
CN106919053A (en) * 2017-04-12 2017-07-04 东南大学 A kind of fired power generating unit coordinated control system based on Variable structure prediction control algorithm
CN109737378A (en) * 2018-12-05 2019-05-10 中国大唐集团科学技术研究院有限公司火力发电技术研究院 The whole-process control method of supercritical DC furnace water supply correction amount under varying load condition
CN111878796A (en) * 2020-07-13 2020-11-03 内蒙古京能康巴什热电有限公司 Supercritical once-through boiler unit intermediate point temperature four-quadrant control method and control loop thereof
CN112412558A (en) * 2020-11-17 2021-02-26 广西电网有限责任公司电力科学研究院 Thermal power generating unit control system with quick load shedding function

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006071166A (en) * 2004-09-01 2006-03-16 Babcock Hitachi Kk Steam temperature control device for once-through boiler
JP2010243016A (en) * 2009-04-03 2010-10-28 Hitachi Ltd Oxygen burning boiler plant and method of operating the oxygen burning boiler plant
CN102323748A (en) * 2011-04-25 2012-01-18 上海迪吉特控制系统有限公司 Direct current stove monoblock directly can matter balance coordination control system
CN105588122A (en) * 2015-12-22 2016-05-18 山东中实易通集团有限公司 Fuel control method and system applied to circulating fluidized bed boiler
CN106919053A (en) * 2017-04-12 2017-07-04 东南大学 A kind of fired power generating unit coordinated control system based on Variable structure prediction control algorithm
CN109737378A (en) * 2018-12-05 2019-05-10 中国大唐集团科学技术研究院有限公司火力发电技术研究院 The whole-process control method of supercritical DC furnace water supply correction amount under varying load condition
CN111878796A (en) * 2020-07-13 2020-11-03 内蒙古京能康巴什热电有限公司 Supercritical once-through boiler unit intermediate point temperature four-quadrant control method and control loop thereof
CN112412558A (en) * 2020-11-17 2021-02-26 广西电网有限责任公司电力科学研究院 Thermal power generating unit control system with quick load shedding function

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
1000 MW机组给水系统控制策略分析研究;陈立岩,韩希昌;沈阳工程学院学报 （自然科学版）;第第16卷卷(第第4期期);第75-77、91页 *

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