CN110553242B - Direct current furnace unit RB control method and device based on differentiation parameters - Google Patents
Direct current furnace unit RB control method and device based on differentiation parameters Download PDFInfo
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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- F22B35/00—Control systems for steam boilers
- F22B35/06—Control systems for steam boilers for steam boilers of forced-flow type
- F22B35/10—Control systems for steam boilers for steam boilers of forced-flow type of once-through type
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B35/00—Control systems for steam boilers
- F22B35/18—Applications of computers to steam boiler control
Abstract
The invention provides a direct current furnace unit RB control method and device based on differentiation parameters, and the device comprises the following steps: acquiring an RB trigger type, wherein the RB trigger type comprises at least one of the following types: a feeding/induced draft fan RB, a primary air fan RB, a water feeding pump RB and a coal mill RB; acquiring target control parameters according to the RB trigger type, wherein the target control parameters comprise: the method comprises the following steps of (1) obtaining a target pressure value, a variable pressure rate, a target load, a variable load rate, a coal mill jumping and grinding interval time, an override closing instruction of a fan movable blade in a wind and smoke system and a water supply inertia time of a water supply system; and executing RB control according to the target control parameter. According to the invention, differential parameter setting of variable pressure rate and variable load rate is carried out according to different RB types, so that stable and safe load reduction of the unit after RB triggering is realized.
Description
Technical Field
The invention relates to the field of power plant unit control, in particular to a direct current furnace unit RB control method and device based on differentiation parameters.
Background
The auxiliary machine fault load reduction (Runback, RB) is that when a unit has a fault trip of part of main auxiliary machines and the maximum theoretical output of the unit is lower than the current actual load, the unit coordination control system quickly reduces the unit load to the response output which can be actually achieved by all auxiliary machines, and can control unit parameters to keep the unit running continuously within an allowable range.
The main purpose of RB logic design is to maintain the allowable boiler output when the main auxiliary machine of the unit fails, and to ensure that the unit is quickly and automatically reduced in load, the main regulating system is ensured to work normally, and the main parameters of the unit are maintained within the allowable range. The qualification of the RB test needs to ensure that the action process is completely and automatically completed without manual intervention, and the parameter fluctuation range does not endanger the safety of the unit and cause the protective tripping of the unit. However, in the RB test process of each power plant, the control effect difference of main parameters such as steam temperature, steam pressure, water supply flow, hearth negative pressure and the like is large, and a large optimization space is provided.
The direct-current furnace has the characteristic of once-through steam and water, and has no large steam drum, so that the heat storage capacity of the direct-current furnace is small. The smaller heat storage capacity can realize faster response in the load lifting process, but the positions of a heating section, an evaporation section and a superheating section of the unit are obviously changed due to the change of the water-coal ratio in the process, so that the temperature and the pressure of the unit are greatly influenced.
For different RB types, the influence on the unit operation parameters is different, so that the setting of the control parameters after RB triggering is not a general parameter, and different characteristics of different types of RB types are fully considered for differential parameter setting. Therefore, a set of differentiated control schemes is provided for different types of RB tests, and the method has important significance for the success of the RB tests and the realization of good control of main operation parameters in the RB process.
In the prior art, after RB is triggered, the heat load of a boiler is generally reduced by rapidly jumping an upper coal mill, and the water supply flow is gradually reduced according to a water-coal ratio broken line function. The unit is switched to a steam turbine following mode from a coordination mode, the pressure is controlled by a steam turbine regulating valve, and the pressure is gradually reduced to a target pressure value according to a certain pressure reduction rate. In addition, there is a large difference in the effect of reducing the influence of fuel and water supply on the temperature, and in order to achieve stability of temperature control, means such as setting the inertia time of a water supply instruction and overriding the temperature reduction water control valve are taken.
The control means applied to the RB logic generally includes setting of target load, setting of target load change rate, setting of target pressure change rate after RB triggering, setting of interval time of upper layer grinding after RB, holding time of RB closing and reducing water temperature regulating valve, and setting of inertia time of water supply main control after RB.
In the RB logic in the above prior art, there are the following disadvantages:
1. after various types of RB are triggered, a fixed load reduction rate and a fixed pressure reduction rate are set, the total coal quantity is reduced through a coal feeder according to the fixed load reduction rate, and the main steam pressure is reduced through a steam turbine regulating valve according to the fixed pressure reduction rate. However, when the main steam pressure is controlled by closing the steam turbine regulating valve, the opening or closing of the regulating valve has direct influence on the main steam flow, so that the main steam temperature is greatly influenced, and in addition, the steam inlet flow of the steam turbine also has great influence on the steam extraction source of the small turbine. Therefore, a fixed pressure reduction rate is set, and when only the control of the main steam pressure is considered, the temperature of the main steam can fluctuate greatly, steam supply of a small steam source is influenced, and the operation safety of a unit is influenced.
2. After different types of RBs are triggered, the existing control scheme generally realizes the purpose of reducing the fuel quantity by setting the same jumping and grinding interval time to trip the coal mill. However, different RB types have different influence mechanisms on the control of combustion and main steam temperature in the boiler, so that the arrangement of the same coal mill jumping and grinding interval time is not beneficial to the control of unit operation parameters after RB triggering.
Disclosure of Invention
The embodiment of the invention provides a direct current furnace unit RB control method based on differential parameters, which aims at carrying out differential setting on control parameters of different types of RBs and realizes stable and safe load reduction of the unit after RB triggering, and comprises the following steps:
acquiring an RB trigger type, wherein the RB trigger type comprises at least one of the following types: a feeding/induced draft fan RB, a primary air fan RB, a water feeding pump RB and a coal mill RB;
acquiring target control parameters according to the RB trigger type, wherein the target control parameters comprise: the method comprises the following steps of (1) obtaining a target pressure value, a variable pressure rate, a target load, a variable load rate, a coal mill jumping and grinding interval time, an override closing instruction of a fan movable blade in a wind and smoke system and a water supply inertia time of a water supply system;
and executing RB control according to the target control parameter.
The embodiment of the invention also provides a direct current furnace unit RB control device based on the differentiation parameters, which comprises the following steps:
an RB trigger type obtaining module, configured to obtain an RB trigger type, where the RB trigger type includes at least one of: a feeding/induced draft fan RB, a primary air fan RB, a water feeding pump RB and a coal mill RB;
a target control parameter obtaining module, configured to obtain a target control parameter according to an RB trigger type, where the target control parameter includes: the method comprises the following steps of (1) obtaining a target pressure value, a variable pressure rate, a target load, a variable load rate, a coal mill jumping and grinding interval time, an override closing instruction of a fan movable blade in a wind and smoke system and a water supply inertia time of a water supply system;
and the RB control execution module is used for executing RB control according to the target control parameter.
The embodiment of the invention also provides computer equipment which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the processor executes the computer program to realize the direct current furnace unit RB control method based on the differentiation parameters.
An embodiment of the present invention further provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program for implementing the RB control method for a direct current furnace unit based on differentiation parameters.
According to the RB control method and device of the direct current furnace unit based on the differential parameters, after RB is triggered, the differential variable pressure rate and variable load rate parameter setting is carried out according to the difference of RB types, stable and safe load reduction of the unit after RB is triggered is achieved, meanwhile, the differential distinguishing setting is carried out on the jumping and grinding interval time of a coal mill, the water supply inertia time and the override closing instruction of a fan movable blade, the coordinated adjustment of wind, coal and water after RB is triggered is facilitated, and the gas temperature and the stability of a boiler during RB are maintained.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts. In the drawings:
fig. 1 is a schematic diagram of a RB control method of a direct current furnace unit based on differentiation parameters according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of RB action of a direct current furnace unit RB control method based on differentiation parameters according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of a target pressure and a variable pressure rate of a direct current furnace unit RB control method based on differentiation parameters according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of a target load and a variable load rate of a direct current furnace unit RB control method based on differentiation parameters according to an embodiment of the present invention.
Fig. 5 is a schematic diagram of the coal mill skip interval time of the direct current furnace unit RB control method based on the differentiation parameters in the embodiment of the present invention.
Fig. 6 is a schematic diagram of coal mill skip-grinding logic of a direct current furnace unit RB control method based on differentiation parameters according to an embodiment of the present invention.
Fig. 7 is a schematic diagram of the water supply inertia time of the RB control method of the dc furnace set based on the differentiation parameters according to the embodiment of the present invention.
Fig. 8 is a schematic diagram of a RB control device of a direct current furnace unit based on differentiated parameters according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention.
The embodiment of the invention provides a direct current furnace unit RB control method based on differential parameters, which aims at carrying out differential setting on control parameters of different types of RBs and realizes stable and safe load reduction of the unit after RB triggering, and comprises the following steps:
step 101: acquiring an RB trigger type, wherein the RB trigger type comprises at least one of the following types: a feeding/induced draft fan RB, a primary air fan RB, a water feeding pump RB and a coal mill RB;
step 102: acquiring target control parameters according to the RB trigger type, wherein the target control parameters comprise: the method comprises the following steps of (1) obtaining a target pressure value, a variable pressure rate, a target load, a variable load rate, a coal mill jumping and grinding interval time, an override closing instruction of a fan movable blade in a wind and smoke system and a water supply inertia time of a water supply system;
step 103: and executing RB control according to the target control parameter.
According to the RB control method of the direct current furnace unit based on the differential parameters, provided by the embodiment of the invention, after RB is triggered, the differential variable pressure rate and variable load rate parameter setting is carried out according to the difference of RB types, so that the stable and safe load reduction of the unit after RB is triggered is realized.
As shown in fig. 1, a schematic diagram of a RB control method for a direct current furnace unit based on differentiation parameters in an embodiment of the present invention is shown, the RB control method for a direct current furnace unit based on differentiation parameters in an embodiment of the present invention includes: acquiring an RB trigger type, wherein the RB trigger type comprises at least one of the following types: a feeding/induced draft fan RB, a primary air fan RB, a water feeding pump RB and a coal mill RB; acquiring target control parameters according to the RB trigger type, wherein the target control parameters comprise: the method comprises the following steps of (1) obtaining a target pressure value, a variable pressure rate, a target load, a variable load rate, a coal mill jumping and grinding interval time, an override closing instruction of a fan movable blade in a wind and smoke system and a water supply inertia time of a water supply system; and executing RB control according to the target control parameter.
After the direct current furnace unit generates RB, the purpose of quickly reducing the load of the unit is achieved through the coordinated action of subsystems such as fuel, wind, smoke, steam and water. The main actions of each subsystem are shown in fig. 2, which is a schematic diagram of the RB action of the direct current furnace set RB control method based on differentiation parameters according to the embodiment of the present invention:
when an important unilateral auxiliary machine has a fault and RB is triggered, a unit control system can cut a coordinated control mode (CCS), a turbine following mode (TF) is switched in, and the front main steam pressure is controlled by a turbine governor and adjusted according to the set target pressure and the pressure change rate.
The target load and the load change rate are set in the logic, the fuel system rapidly reduces fuel by rapidly tripping the coal mill, releases heat stored in the boiler, and adjusts the rotating speed of the coal mill according to the load reduction rate, so that the coal quantity change rate is controlled.
For the wind and smoke system, the three fans adjust the air supply volume, the primary air pressure and the furnace pressure of the boiler through PID operation, and interaction exists among the three fans, so that the furnace can be ensured to be in a stable combustion working condition by setting the override logic of the movable blades of the fans. When the single-side fan fails, the other side fan can instantly increase the output power, and the upper limit of the opening degree of the movable blade is limited in order to prevent the fan from generating excessive power and overcurrent.
For a water supply system, the inertia characteristics of water supply and coal firing are greatly different, so that the setting of inertia time after the coal-water ratio is compared with a broken line function plays an important role in controlling the steam temperature in the RB process. In addition, desuperheating water damper override is also an important means of controlling steam temperature after rapid fuel reduction.
In the production control of a power plant, the main auxiliary machines generally comprise a feeding/induced draft fan, a primary air fan, a water feeding pump, a coal mill and the like; after the main auxiliary machine of the direct current furnace unit has a single-side fault, generating RB after the RB triggering condition is met; in an embodiment, the aforementioned RBs are divided into: a feeding/induced draft fan RB, a primary air fan RB, a water feeding pump RB and a coal mill RB; in an embodiment, the aforementioned RB trigger condition includes: when an RB (reverse blocking) fan is fed/induced, a unit control system is put into a coordinated control mode, the RB is already put into the unit, and the actual load of the unit is higher than the first trigger load; when the primary fan RB is used, the coordinated control mode is put into use, the RB is already put into use, and the actual load of the unit is higher than the second trigger load; when a water pump RB is fed, the coordinated control mode is put into, the RB is already put into, and the actual load of the unit is higher than the third trigger load; and when the coal mills RB are used, the coordinated control mode is put into use, the RB is already put into use, and any one coal mill trips.
After obtaining the RB type, a target control parameter needs to be obtained according to the RB trigger type, where the target control parameter may include: at least one of parameters such as a target pressure value, a variable pressure rate, a target load, a variable load rate, a coal mill jumping and grinding interval time, an override command of a fan movable blade in a wind and smoke system, a water supply inertia time of a water supply system and the like; in order to solve the above problem, in the prior art, because the control parameters are fixed values during RB control, which may cause instability of RB control, in the embodiments of the present invention, different control parameters are set according to different RB types.
As shown in fig. 3, a schematic diagram of a target pressure and a variable pressure rate of a RB control method of a direct current furnace set based on differential parameters in an embodiment of the present invention is shown, in an embodiment, the target pressure is a pressure set value given by a sliding pressure curve; setting the target pressure and the variable pressure rate as follows according to the RB type: when the RB type is a draught fan RB, setting the target pressure and the variable pressure rate as a first target pressure and a first variable pressure rate; when the RB type is a primary air fan RB, setting the target pressure and the variable pressure rate as a second target pressure and a second variable pressure rate; when the RB type is a water feed pump RB, setting the target pressure and the variable pressure rate as a third target pressure and a third variable pressure rate; when the RB type is coal pulverizer RB, the target pressure and the variable pressure rate are set to a fourth target pressure and a fourth variable pressure rate. Because the control mode of the unit is switched to the TF mode after RB triggering, the pressure is controlled by the steam turbine regulating valve, and different pressure reduction rates are set for different RB types in the embodiment of the invention; in one embodiment, in order to ensure the stability of the small steam source, the variable pressure rate is segmented according to time, and a plurality of pulse times are set; the variable pressure rate remains constant during each pulse time, and the variable pressure rate varies between each pulse time. Because the pressure reduction rate is set with a plurality of pulse times in sections, a certain rate is maintained within the pulse time, and the pulse time is switched to another rate after the pulse time is finished, the requirements of the opening degree of the throttle on the main steam flow and the quick load reduction of the unit are ensured, the requirements of the opening degree of the throttle on the main steam temperature and the steam extraction on the steam source of the small turbine and the influence of RB triggering on the main steam pressure and the main steam temperature are considered, the stability of the steam source of the small turbine is ensured, and the safe and stable operation of the unit is facilitated.
As shown in fig. 4, in an embodiment of the present invention, a schematic diagram of a target load and a variable load rate of a RB control method for a dc furnace unit based on differentiation parameters is shown, in which the target load and the variable load rate are set according to an RB type as follows: when the RB type is a draught fan RB, setting a target load and a variable load rate as a first target load and a first variable load rate; when the RB type is a primary air fan RB, setting the target load and the variable load rate as a second target load and a second variable load rate; when the RB type is a water supply pump RB, setting the target load and the variable load rate as a third target load and a third variable load rate; when the RB type is a coal mill RB, setting the target load and the variable load rate as a fourth target load and a fourth variable load rate; due to the fact that different RB types have different influences on the unit, particularly the difference of hearth heat storage, different target loads can be set, and the load change rate can be better matched.
As shown in fig. 5, in an embodiment of the present invention, a schematic diagram of coal mill skip interval time of a RB control method for a direct current boiler unit based on differentiated parameters is shown, in which the coal mill skip interval time is set according to RB types as: when the RB type is a draught fan/induced draft fan RB, carrying out jumping grinding on the coal mill according to the first jumping grinding interval time; when the RB type is a primary air fan RB, carrying out jumping grinding on the coal mill according to a second jumping grinding interval time; when the RB type is a water feeding pump RB, carrying out jump grinding on the coal mill according to a third jump grinding interval time; when the RB type is a coal mill RB, the coal mill does not jump, and except for a fault coal mill causing the tripping of the coal mill RB, other coal mills normally operate.
As shown in fig. 6, in an embodiment of the present invention, as a schematic diagram of a coal mill trip logic of a RB control method for a direct current boiler unit based on differentiated parameters, in the embodiment, different trip logic settings are performed on the coal mill trip according to different RB types, and an upper coal mill trip at a certain time interval after RB triggering is realized in the logic, where the method includes: when the RB type is a feeding/induced draft fan RB, a primary air fan RB or a water feeding pump RB, the number of running grinding groups is more than 3.5, and the RB jumps to an upper coal mill A; when the RB type is a feeding/induced draft fan RB, a primary air fan RB or a water feeding pump RB, the number of the grinding groups is more than 3.5, the coal mill A stops delaying, and the RB jumps to the upper coal mill B; when the RB type is a feeding/induced draft fan RB, a primary air fan RB or a water feeding pump RB, the number of the grinding groups is more than 3.5, the coal mill A stops delaying, the coal mill B stops delaying, and the RB jumps to the upper coal mill C; and when the RB type is a primary fan, the number of the grinding groups is more than 3.5, the coal mill A stops delaying, the coal mill B stops delaying, and the RB jumps to the upper coal mill D. For a water feeding pump RB and a primary air fan RB, differential setting is carried out on the jumping and grinding interval time for ensuring the success of the test. In addition, after the primary air fan RB is triggered, in order to guarantee primary air pressure of the coal mills, the logic setting is different from RB logic setting of other types, and two coal mills which trip at last do not set time intervals and trip at the same time.
As shown in fig. 7, in an embodiment of the present invention, a schematic diagram of a feedwater inertia time of a RB control method of a direct current boiler unit based on differentiation parameters is shown, in which the feedwater inertia time of a feedwater system is set according to RB types as: and when the RB type is a feeding/induced draft fan RB, controlling the water supply system to delay water supply according to the first water supply inertia time. And when the RB type is the primary air fan RB, controlling the water supply system to delay water supply according to the second water supply inertia time. And when the RB type is a water feeding pump RB, controlling the water feeding system to delay water feeding according to a third water feeding inertia time. When the RB type is a coal mill RB, controlling the water supply system to delay water supply according to fourth water supply inertia time; because the response time characteristics of the fuel and the water supply are different, the water supply function is delayed through third-order inertia after the fuel corresponds to the water-coal ratio function of the water supply, and the setting of the water supply instruction in different RB types is adjusted through setting the water supply inertia time in a differentiation mode.
As shown in fig. 3 to 7, in the case that the RB trigger type is a draught fan RB, the performing RB control according to the target control parameter may include: according to the first target pressure and the first variable pressure rate, regulating the main steam pressure to the first target pressure according to the first variable pressure rate; according to the first target load and the first variable load rate, adjusting the load of the direct current furnace unit to the first target load according to the first variable load rate; controlling the coal mill to jump and grind according to the first jumping and grinding interval time; controlling water supply of a water supply system according to the first water supply inertia time; and controlling the closing rate and the opening value of the movable blade of the primary fan according to an override command of the movable blade of the fan in the air-smoke system. In an embodiment, the first variable pressure rate may be divided into a first pulse time and a second pulse time, the second variable pressure rate may be divided into a first pulse time and a second pulse time, the third variable pressure rate may be divided into a first pulse time and a second pulse time, and the fourth variable pressure rate may be divided into a first pulse time and a second pulse time.
As shown in fig. 3 to 7, in the case that the RB trigger type is a primary air blower RB, the performing RB control according to the target control parameter may include: according to the second target pressure and the second variable pressure rate, regulating the main steam pressure to a second target pressure according to the second variable pressure rate; according to the second target load and the second variable load rate, the load of the direct current furnace unit is adjusted to the second target load according to the second variable load rate; controlling the coal mill to jump and grind according to the second jumping and grinding interval time; controlling water supply of the water supply system according to the second water supply inertia time; and controlling the closing speed and the opening value of the movable blade of the induced draft fan according to the override closing instruction of the movable blade of the induced draft fan in the air and smoke system.
As shown in fig. 3 to 7, in the case where the RB trigger type is the feed pump RB, the aforementioned performing of RB control according to the target control parameter may include: according to the third target pressure and the third variable pressure rate, regulating the main steam pressure to a third target pressure according to the third variable pressure rate; according to the third target load and the third variable load rate, the load of the direct current furnace unit is adjusted to the third target load according to the third variable load rate; controlling the coal mill to jump and grind according to the third jumping and grinding interval time; controlling water supply of the water supply system according to the third water supply inertia time; and controlling the closing rate and the opening value of the movable blade of the primary fan according to an override command of the movable blade of the fan in the air-smoke system.
As shown in fig. 3 to 7, in the case that the RB trigger type is the coal mill RB, the performing RB control according to the target control parameter may include: according to the fourth target pressure and the fourth variable pressure rate, regulating the main steam pressure to the fourth target pressure according to the fourth variable pressure rate; according to the fourth target load and the fourth variable load rate, the load of the direct current furnace unit is adjusted to the fourth target load according to the fourth variable load rate; controlling the coal mill not to jump for grinding; and controlling the water supply of the water supply system according to the fourth water supply inertia time.
After the RB control is executed, if the fault of the main auxiliary machine is eliminated, and the reset condition is met, the RB reset is needed, and in one embodiment, when the supply/induced draft fan RB, the primary air fan RB, the feed pump RB or the coal mill RB reaches the RB reset condition, the direct current furnace set is controlled to reset.
The aforementioned reset condition, in one embodiment, may include: when an RB (reverse circulation) air supply/induced draft fan is used, the actual load of the direct current furnace unit is lower than a first reset load; when the primary fan RB is used, the actual load of the direct current furnace unit is lower than a second reset load; when a water feeding pump RB is used, the actual load of the direct current furnace unit is lower than a third reset load; and when the coal mill RB is used, the boiler main control output is lower than the maximum fuel capacity increase corresponding to the number of the running mills, and the set reset percentage is reached.
The embodiment of the invention also provides an example of performing RB control by using the RB control method of the direct current furnace set based on the differentiation parameters when the direct current furnace set triggers RB, which comprises the following steps:
1. RB triggering:
1) the unit control system is put into a coordinated control mode, RB is put into the unit control system, the actual load of the unit is higher than the first trigger load 580MW, and a delivery/induced draft fan RB is triggered;
2) a coordination control mode is put into, RB is put into, the actual load of the unit is higher than the second trigger load 580MW, and the primary air fan RB is triggered;
3) c, a coordinated control mode is put into, RB is put into, the actual load of the unit is higher than the third trigger load of 550MW, and a water feeding pump RB is triggered;
4) and (4) putting in a coordinated control mode, wherein RB is already put in, tripping any one coal mill, and triggering the coal mill RB.
2. The unit control system executes RB control after RB triggering:
1) cutting off a coordination control mode, switching to a machine following mode, and controlling the front main steam pressure by a steam turbine regulating valve;
2) maintaining a sliding pressure mode, wherein the target pressure is a pressure set value given by a sliding pressure curve, and reducing the pressure according to a variable pressure rate;
3) pressure rate of change setpoint:
when the RB trigger type is a draught fan/induced draft fan RB, the first pulse time (the first 85 seconds) is 0.5MPa/min, and the second pulse time is 2.4 MPa/min;
when the RB trigger type is a primary air fan RB, the first pulse time (the first 100 seconds) is 0.4MPa/min, and the second pulse time is 2.4 MPa/min;
when the RB trigger type is a water supply pump RB, the first pulse time (the first 100 seconds) is 2MPa/min, and the second pulse time is 1 MPa/min;
when the RB trigger type is a coal mill RB, the pressure is 0.6 MPa/min;
4) after RB is triggered, a target coal amount is given according to a target load, and the coal amount is reduced according to a load reduction rate; maintaining the main control instruction of the boiler as the current actual fuel quantity during RB grinding;
5) RB target load:
when the RB trigger type is a draught fan RB, the first target load is 550 MW;
when the RB trigger type is a primary air fan RB, the second target load is 520 MW;
when the RB trigger type is a water feed pump RB, the third target load is 520 MW;
when the RB trigger type is a coal mill RB, the fourth target load is a load corresponding to the maximum fuel capacity of the number of operating grinding platforms;
6) RB load reduction rate:
when the RB trigger type is a draught fan RB, the first load reduction rate is 300 MW/min;
when the RB trigger type is a primary air fan RB, the second load reduction rate is 300 MW/min;
when the RB trigger type is a water supply pump RB, the third load reduction rate is 260 MW/min;
when the RB trigger type is a coal mill RB, the fourth load reduction rate is 200 MW/min;
7) after RB is triggered, the fuel main control is prohibited to increase for 60 seconds;
8) and after RB is triggered, three layers of running coal mills are sequentially jumped, three coal mills on the lower layer are reserved, and the jumping and grinding interval time is as follows:
the RB trigger type is a draught fan/induced draft fan RB, and the first jump grinding interval time is 12 seconds;
the RB trigger type is a primary air fan RB, and the second jump grinding interval time is 10 seconds;
the RB trigger type is a water supply pump RB, and the third jump grinding interval time is 15 seconds;
the RB trigger type is a coal mill RB, and the coal mill does not jump to be ground;
9) when the coal mill is not RB, the output of the intermediate point temperature control loop is prohibited to increase or decrease, and the correction of the intermediate point temperature control loop on the boiler main control is kept unchanged; the effect of the mid-point temperature control loop on the total fuel command has been offset during the coal pulverizer RB;
10) the water supply inertia time of the water supply system set by the water supply master control is as follows:
the RB trigger type is a draught fan/air feeder RB, and the first water supply inertia time is 10 seconds;
the RB trigger type is a primary air fan RB, and the second water supply inertia time is 8 seconds;
the RB trigger type is a water supply pump RB, and the inertia time of third water supply is 15 seconds;
the RB triggering type is a coal mill RB, and the fourth water supply inertia time is 18 seconds;
11) when the primary fan RB is used, an induced draft fan movable blade override switch instruction is sent, the induced draft fan movable blade controls the induced draft fan movable blade to override according to 20% of a neutral value in the override switch instruction, the switching rate is 100%/s when the induced draft fan movable blade is triggered, and the recovery rate after the action is 0.01%/s;
12) when a fan RB and a water pump RB are fed/induced, a movable blade of a primary fan is shut over for 5 openings, the shut-off rate is 100%/s when triggered, and the recovery rate after action is 0.01%/s;
13) after RB triggers, the output upper limit of the auxiliary machine is set: the upper limit of the rotating speed instruction of the feed pump is 5700rpm, the upper limit of the moving blade instruction of the induced draft fan is 70%, the upper limit of the blower instruction is 77%, and the upper limit of the primary air fan instruction is 80%;
3. resetting RB:
1) when the RB is fed/induced, the actual load of the unit is lower than the first reset load of 550MW, or the unit is manually reset;
2) when the primary fan RB is adopted, the actual load of the unit is lower than the second reset load 550MW, or the unit is reset manually;
3) when the water pump RB is used, the actual load of the unit is lower than the third reset load 520MW, or the unit is manually reset;
4) and when the coal mill RB is used, the main control output of the boiler is lower than the maximum fuel capacity + 2% corresponding to the number of the operating mills, and the reset is delayed for 300 seconds or manually reset.
The embodiment of the invention also provides computer equipment which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the processor executes the computer program to realize the direct current furnace unit RB control method based on the differentiation parameters.
An embodiment of the present invention further provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program for implementing the RB control method for a direct current furnace unit based on differentiation parameters.
The embodiment of the invention also provides a direct current furnace unit RB control device based on the differentiation parameters, and the device is described in the following embodiment. Because the principle of the device for solving the problems is similar to the RB control method of the direct current furnace set based on the differentiation parameters, the implementation of the device can refer to the implementation of the RB control method of the direct current furnace set based on the differentiation parameters, and repeated parts are not described again.
As shown in fig. 8, an embodiment of the present invention provides a schematic diagram of a RB control apparatus of a direct current furnace unit based on differentiation parameters, and an embodiment of the present invention further provides a RB control apparatus of a direct current furnace unit based on differentiation parameters, including:
an RB trigger type obtaining module 801, configured to obtain an RB trigger type, where the RB trigger type includes at least one of: a feeding/induced draft fan RB, a primary air fan RB, a water feeding pump RB and a coal mill RB;
a target control parameter obtaining module 802, configured to obtain a target control parameter according to an RB trigger type, where the target control parameter includes: the method comprises the following steps of (1) obtaining a target pressure value, a variable pressure rate, a target load, a variable load rate, a coal mill jumping and grinding interval time, an override closing instruction of a fan movable blade in a wind and smoke system and a water supply inertia time of a water supply system;
an RB control execution module 803, configured to execute RB control according to the target control parameter.
To sum up, according to the RB control method and device for the direct current furnace unit based on the differentiation parameters provided by the embodiment of the present invention, after RB is triggered, parameter settings of differential variable pressure rate and variable load rate are performed according to the difference of RB types, so that stable and safe load reduction of the unit after RB is triggered is realized; and the variable pressure rate of each RB type is set in a segmented mode according to time, so that the influence of RB triggering on the main steam pressure and the main steam temperature can be considered, the stability of a small steam source is guaranteed, and the safe and stable operation of a unit is facilitated. According to the influence of RB of different types on primary air and feed water flow of the coal mill and combustion in the boiler, the jump grinding interval time and the feed water inertia time are set in a differentiated mode, and matching adjustment of the RB triggered air, coal and water is facilitated.
Based on the consideration of negative pressure and stable combustion of the hearth, the override switch control logic of the draught fan or the primary fan is set for different RB types, and the boiler is kept stable by realizing fast switch and slow switch through different rates. Therefore, the RB control method and device of the direct current furnace unit based on the differentiation parameters, provided by the embodiment of the invention, can ensure that the unit can quickly reduce the load and safely operate in the RB test process, and realize better control effect on main operation parameters such as steam temperature and steam pressure
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (11)
1. A direct current furnace unit RB control method based on differentiation parameters is characterized by comprising the following steps:
acquiring an RB trigger type, wherein the RB trigger type comprises at least one of the following types: a feeding/induced draft fan RB, a primary air fan RB, a water feeding pump RB and a coal mill RB;
acquiring target control parameters according to the RB trigger type, wherein the target control parameters comprise: the method comprises the following steps of (1) obtaining a target pressure value, a variable pressure rate, a target load, a variable load rate, a coal mill jumping and grinding interval time, an override closing instruction of a fan movable blade in a wind and smoke system and a water supply inertia time of a water supply system;
executing RB control according to the target control parameter;
wherein, RB triggers the type and sends/draught fan RB, according to the said target control parameter, carries out RB control, including:
according to the first target pressure and the first variable pressure rate, regulating the main steam pressure to the first target pressure according to the first variable pressure rate;
according to the first target load and the first variable load rate, adjusting the load of the direct current furnace unit to the first target load according to the first variable load rate;
controlling the coal mill to jump and grind according to the first jumping and grinding interval time;
controlling water supply of a water supply system according to the first water supply inertia time;
and controlling the closing rate and the opening value of the movable blade of the primary fan according to an override command of the movable blade of the fan in the air-smoke system.
2. The RB control method of the direct current furnace set based on the differentiation parameters as claimed in claim 1, wherein the RB trigger type is a primary air fan RB, and the execution of RB control according to the target control parameters comprises:
according to the second target pressure and the second variable pressure rate, regulating the main steam pressure to a second target pressure according to the second variable pressure rate;
according to the second target load and the second variable load rate, the load of the direct current furnace unit is adjusted to the second target load according to the second variable load rate;
controlling the coal mill to jump and grind according to the second jumping and grinding interval time;
controlling water supply of the water supply system according to the second water supply inertia time;
and controlling the closing speed and the opening value of the movable blade of the induced draft fan according to the override closing instruction of the movable blade of the induced draft fan in the air and smoke system.
3. The RB control method of the direct current furnace set based on the differentiation parameters as claimed in claim 1, wherein the RB trigger type is a feed pump RB, and the RB control is performed according to the target control parameters, comprising:
according to the third target pressure and the third variable pressure rate, regulating the main steam pressure to a third target pressure according to the third variable pressure rate;
according to the third target load and the third variable load rate, the load of the direct current furnace unit is adjusted to the third target load according to the third variable load rate;
controlling the coal mill to jump and grind according to the third jumping and grinding interval time;
controlling water supply of the water supply system according to the third water supply inertia time;
and controlling the closing rate and the opening value of the movable blade of the primary fan according to an override command of the movable blade of the fan in the air-smoke system.
4. The RB control method of the direct current furnace unit based on the differentiation parameters as claimed in claim 1, wherein the RB trigger type is a coal mill RB, and the RB control is executed according to the target control parameters, and comprises the following steps:
according to the fourth target pressure and the fourth variable pressure rate, regulating the main steam pressure to the fourth target pressure according to the fourth variable pressure rate;
according to the fourth target load and the fourth variable load rate, the load of the direct current furnace unit is adjusted to the fourth target load according to the fourth variable load rate;
controlling the coal mill not to jump for grinding;
and controlling the water supply of the water supply system according to the fourth water supply inertia time.
5. The RB control method of the direct current furnace set based on the differentiation parameters as claimed in claim 1,
segmenting the variable pressure rate according to time, and setting a plurality of pulse times;
the variable pressure rate remains constant during each pulse time, and the variable pressure rate varies between each pulse time.
6. The RB control method of the direct current furnace set based on the differentiation parameters as claimed in claim 1,
further comprising: and after RB is triggered, limiting the upper limit of the output of the air feeding/inducing fan, the primary air fan and the water feeding pump.
7. The RB control method based on the differentiation parameters of the direct current furnace set according to claim 1, further comprising: and when the air feeding/induced draft fan RB, the primary air fan RB, the water feeding pump RB or the coal mill RB reach the RB resetting condition, the direct current furnace unit is controlled to reset.
8. The RB control method of the direct current furnace set based on the differentiation parameters as claimed in claim 7, wherein the RB reset condition comprises:
when an RB (reverse circulation) air supply/induced draft fan is used, the actual load of the direct current furnace unit is lower than a first reset load;
when the primary fan RB is used, the actual load of the direct current furnace unit is lower than a second reset load;
when a water feeding pump RB is used, the actual load of the direct current furnace unit is lower than a third reset load;
and when the coal mill RB is used, the boiler main control output is lower than the maximum fuel capacity increase corresponding to the number of the running mills, and the set reset percentage is reached.
9. The utility model provides a direct current stove unit RB controlling means based on differentiation parameter which characterized in that includes:
an RB trigger type obtaining module, configured to obtain an RB trigger type, where the RB trigger type includes at least one of: a feeding/induced draft fan RB, a primary air fan RB, a water feeding pump RB and a coal mill RB;
a target control parameter obtaining module, configured to obtain a target control parameter according to an RB trigger type, where the target control parameter includes: the method comprises the following steps of (1) obtaining a target pressure value, a variable pressure rate, a target load, a variable load rate, a coal mill jumping and grinding interval time, an override closing instruction of a fan movable blade in a wind and smoke system and a water supply inertia time of a water supply system;
the RB control execution module is used for executing RB control according to the target control parameters;
wherein, the RB control execution module is further configured to: when the RB trigger type is a fan/draught RB,
according to the first target pressure and the first variable pressure rate, regulating the main steam pressure to the first target pressure according to the first variable pressure rate;
according to the first target load and the first variable load rate, adjusting the load of the direct current furnace unit to the first target load according to the first variable load rate;
controlling the coal mill to jump and grind according to the first jumping and grinding interval time;
controlling water supply of a water supply system according to the first water supply inertia time;
and controlling the closing rate and the opening value of the movable blade of the primary fan according to an override command of the movable blade of the fan in the air-smoke system.
10. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method for controlling the direct current furnace set RB based on the differentiation parameters according to any one of claims 1 to 8 when executing the computer program.
11. A computer-readable storage medium storing a computer program for executing the RB control method of the dc furnace set based on the differentiation parameters according to any one of claims 1 to 8.
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| CN111981459A (en) * | 2020-07-10 | 2020-11-24 | 华电电力科学研究院有限公司 | Optimization control method of multi-fuel co-combustion coal-fired unit under RB working condition |
| CN112540537B (en) * | 2020-12-04 | 2022-05-31 | 浙江浙能技术研究院有限公司 | Unit RB target load self-adaptive generation method based on auxiliary machine state |
| CN114153239B (en) * | 2021-11-15 | 2023-09-15 | 国网山东省电力公司电力科学研究院 | RB sliding pressure instruction adjusting method and device based on unit load and computer equipment |
| CN114296341B (en) * | 2021-12-30 | 2024-03-08 | 华润电力技术研究院有限公司 | Control method of generator set and related equipment |
| CN114253315B (en) * | 2022-03-02 | 2022-05-27 | 天津国能津能滨海热电有限公司 | Control method for reheating steam temperature of boiler, electronic equipment and storage medium |
| CN114811570B (en) * | 2022-04-20 | 2023-06-13 | 华北电力科学研究院有限责任公司 | High-load-adding and disconnecting fault load-reducing method and device suitable for coal-fired unit |
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| CN203285709U (en) * | 2013-05-21 | 2013-11-13 | 国家电网公司 | Auxiliary breakdown load reducing RB device of booster fan in power plant |
| CN104179704B (en) * | 2013-05-21 | 2016-05-04 | 国家电网公司 | Method and the device of a kind of booster fan runback RB of power plant |
| CN104296156B (en) * | 2013-07-19 | 2016-10-05 | 国家电网公司 | A kind of method and system of desulfurization fume heat exchanger RB |
| CN104654269B (en) * | 2014-12-18 | 2016-08-24 | 山东中实易通集团有限公司 | The method that in thermal power generation unit, calorific value correction coefficient adjusts RB desired value automatically |
| CN106090872B (en) * | 2016-06-17 | 2018-08-07 | 华电电力科学研究院 | A kind of overcritical coal-fired level pressure unit RB optimal control methods |
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