CN113803713B

CN113803713B - Method and system for determining flame center in furnace during deep air classification

Info

Publication number: CN113803713B
Application number: CN202111013157.4A
Authority: CN
Inventors: 赵振宁
Original assignee: State Grid Corp of China SGCC; North China Electric Power Research Institute Co Ltd
Current assignee: State Grid Corp of China SGCC; North China Electric Power Research Institute Co Ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2023-06-16
Anticipated expiration: 2041-08-31
Also published as: CN113803713A

Abstract

The invention provides a method and a system for determining a flame center in a furnace during deep air classification. The method comprises the following steps: acquiring real-time heat release quantity of unit quantity of coal in a main combustion area and real-time heat release quantity of unit quantity of coal in an SOFA area in deep air staged combustion; acquiring the coal feeding amount and the central elevation of each burner in a main combustion zone, and acquiring the central elevation of an SOFA nozzle for supplementing combustion air in an SOFA zone; acquiring the total heat release amount of unit quantity of fire coal in the step combustion of the height and depth air of a hearth; and determining the relative height of the flame center based on the real-time heat release amount of the unit quantity of the coal in the main combustion area, the real-time heat release amount of the unit quantity of the coal in the SOFA area, the coal supply amount and the center elevation of each burner in the main combustion area, the center elevation of the SOFA nozzle for supplementing and burning air in the SOFA area, the height of a hearth and the total heat release amount of the unit quantity of the coal in the deep air staged combustion.

Description

Method and system for determining flame center in furnace during deep air classification

Technical Field

The invention belongs to the technical field of boiler combustion, and particularly relates to a method and a system for determining a flame center in a furnace during deep air classification.

Background

The deep air staged combustion technology is a technology developed in the century, and can effectively realize NO _x The emission is reduced, and the method is widely applied in China. The improvement of the deep air classification technology is completed in over 90% of the boilers in China at present, and the safe and reliable application of the deep air classification technology is very important. The deep air staged combustion technology is to make combustion firstly carried out under the condition of deep oxygen deficiency to inhibit NO _x And let the generated NO _x Reduction to N ₂ Thereby minimizing NO _x Is a concentration of (2); then oxygen supplementation is carried out, so that the subsequent combustion is completed in an oxygen-enriched environment; since the temperature of this region has been reduced, newly generated NO _x The amount is very limited, so that overall NO _x The discharge amount of the catalyst is obviously reduced.

The construction method of the deep air staged combustion technology comprises the following steps:

1) The air is sent in a grading way through a low NOx burner, such as concentration separation, wind powder packing technology and the like, and a local oxygen-lack combustion environment is constructed at an outlet of the burner;

2) By utilizing the cooperation among different burners, air distribution is graded on the vertical height of a hearth, namely, only 75% -100% of the air quantity required by combustion is shared (the excess coefficient is controlled to be about 0.75-1.0) near the area of a main burner (the burner for feeding the pulverized coal), the pulverized coal is subjected to remarkable and large-scale under-oxygen combustion in the area, and then the residual air is introduced above the main burner, so that the residual pulverized coal is subjected to complete combustion under the oxygen-enriched condition in the area. Wherein the air fed against the main burner area is referred to as over fire OFA (over fire air), and if the over fire OFA is a significant distance from the main burner area is referred to as split over fire SOFA (Separated over fire air).

The deep air classification technology generally adopts separating fire upwind SOFA, expands the range to be close to the whole hearth by air classification combustion, controls the residence time of fuel in an oxygen-lack area more nearly to the limit, and reduces the temperature of the oxygen-rich area to be lower. A typical burner arrangement at this point is shown in figure 1.

From a design point of view, depth air fractionation is low in NO _x Compared with the traditional combustion technology, the combustion technology has obvious difference in the exothermic behavior of the pulverized coal in the hearth:

1) The oxygen amount of the main combustion zone of the traditional hearth is sufficient, and the pulverized coal is finely ground; in the traditional combustion technology, about 96% of components of the pulverized coal at the outlet of the main burner can be combusted; the combustion condition is slightly higher than 96% when good, and is slightly lower than 96% when poor; particularly on the combustible content of fly ash and large slag. The flame height at each burner outlet, i.e., the point in the combustion gas stream torch where the combustion temperature is highest, is typically slightly above the burner outlet;

2) Deep air fractionation of low NO _x In the combustion technology, although the pulverized coal is still finely ground, the main combustion is performed due to the serious lack of oxidant components for combustionThe burner outlets immediately complete combustion with a composition well below 96%, so that the highest point of flame temperature after each burner outlet is never slightly above the burner outlet;

The boiler furnace is a radiation type heat exchange surface, and flame temperature is very important for heat exchange of the furnace. The exothermic behavior of the pulverized coal entering the boiler is changed greatly, which is reflected by the design of the hearth, and unfortunately, the deep air classification is low in NO _x The development of the combustion technology is too fast, and the traditional design concept can only be used for corresponding work at present. To ensure compliance with practice, it is common practice to correct the calculation by empirical coefficients.

The position of the highest temperature point of the flame is very important and is the basis of the whole hearth design. In the design of boiler furnace, a factor M is used to represent the furnace flame height, which is related to the combustion mode, burner arrangement, etc., such as the furnace outlet temperature calculation formula in the widely used power station boiler thermal calculation standard (73 edition) in China:

in the formula ：θ"_f The method comprises the steps of solving and calculating the outlet temperature of a hearth; t (T) _a The theoretical combustion temperature of the coal, namely the temperature to which the flue gas generated by the coal can be heated without heat transfer after the coal is combusted, namely the theoretical combustion temperature; f (F) _f Is the heated area of the hearth; sigma (sigma) ₀ Is a sildenafil-bolman constant; a, a _f The comprehensive factors calculated by the parameters such as boiler structure, flame temperature and the like are hearth blackness; psi is the ash and dirt coefficient of the hearth, and is searched according to the structure and other data of the hearth; b (B) _j Subtracting the part discharged out of the furnace in the form of ash from the amount of fuel fed into the boiler in unit time;

the heat preservation coefficient, namely the ratio of the part of the flame heat energy which is transferred to the steam-water working medium to heat and boost the working medium; />

The average heat capacity of the flue gas generated by the unit mass fuel between the flame temperature in the furnace and the outlet temperature of the hearth; m is the part of the flame center in the hearth.

The furnace outlet temperature in the formula (1) is calculated as the heat transfer quantity in the furnace, which is equal to the heat transfer quantity in the furnace in terms of data

The hearth is the first-stage heating surface of the boiler along the flue gas flow, and the calculation accuracy is the basis of accurate calculation of all other heating surfaces, namely the basis of the design calculation of the whole boiler.

Among the factors of formula (1), the three most primitive determinants are: the fuel, the structure and area of the hearth, and the location of the flame temperature within the hearth. The fuel being embodied at a theoretical combustion temperature T _a In the middle, the structure and the area of the hearth are expressed in F _f And hearth blackness alpha _f The location of the flame temperature within the furnace is represented by the value of M, which is typically related to the location of the burner.

A single burner cannot support the large capacity of a modern power plant boiler, typically a multiple burner arrangement. Burner arrangement and current depth air staging low NO for a conventional boiler main burner _x The burner arrangement mode of the combustion technology is shown in fig. 2 (wherein a is a schematic diagram of equal air distribution mode suitable for inflammable coal types, b is a schematic diagram of equal air distribution mode of deep air classification of inflammable coal types, c is a schematic diagram of graded air distribution mode suitable for fire-retardant coal types, and d is a schematic diagram of equal air distribution mode of deep air classification of fire-retardant coal types).

As can be seen from FIG. 2, the depth air classification is low in NO _x The differences of combustion technology from conventional burner arrangements are mainly:

1) The area of the primary air burner nozzle of the main combustion area is unchanged;

2) The width of the secondary air burner of the main combustion area is unchanged, but the height is reduced;

3) The area of the nozzle of the secondary air burner is reduced, so that the primary air burner is moved down as a whole.

When the traditional burners are arranged, all secondary air is injected from the adjacent primary air burners, so that the whole main combustion area is in an oxygen-enriched condition, and the position of each burner after a little outlet is the position where the smoke burning is most vigorous, so that the flame height of the hearth can be weighted and averaged by the position of each burner in the hearth.

In order to indicate the relative position of a burner at the height of the furnace by means of a datum, the burner is generally of the same height x _b To express:

in the formula ：h_b Is the elevation of the burner (as shown in fig. 3); h is a _F Is the furnace height (as shown in fig. 3).

For a plurality of burners, the relative heights of the whole burners formed by the burners are weighted and averaged according to the fuel quantity of the burners, namely

in the formula ：B_i The fuel quantity for the ith burner (i.e., each primary air burner labeled with numeral 1 on the left in fig. 2); h is a _bi The central elevation of the ith burner, m;

the combustion amount of each burner outlet is weighted and averaged, namely the weighted and averaged real-time heat release amount of each burner outlet is actually taken into consideration the heat release amount of the combustion immediately after the combustion is carried out.

The burner relative height is reacted to the flame center height as:

x _flm ＝x _b +Δx type (4)

in the formula ：x_flm Is the relative height of the flame center; x is x _b The relative height of the burner is the ratio of the central elevation of the burner to the height of the hearth, and is calculated by the formulas (2) and (3); Δx is the burner type and mode of operation that causes correction of the flame center. Δx is related to the combustion mode and the attemperation mode of the boiler; when (when)When the boiler adopts a tangential combustion mode, the temperature of reheat steam is regulated by a swinging burner, a screen type reheater, a high-temperature reheater and a high-temperature superheater (the high-temperature reheater or a wall type reheater are arranged in sequence at the outlet of a hearth), a low-temperature superheater and an economizer are arranged in a tail shaft flue from top to bottom, and at the moment, deltax is related to the swinging angle:

1) Δx is 0 when the burner is horizontal;

2) When the burner swings upwards, every 20 degrees of swinging, the delta x is increased by 0.1;

3) When the burner swings downwards, every 20 degrees of swinging, the delta x is reduced by 0.1;

4) When the burner swings up and down for other angles, deltax takes the insertion value.

If a front wall arrangement or a opposed firing mode is adopted, the burner cannot swing normally, a tail flue gas baffle is used for adjusting the temperature of reheat steam, a screen type high-temperature superheater, a medium-temperature reheater and a high-temperature superheater (the high-temperature reheater is arranged at the rear) are sequentially arranged at a hearth outlet, a low-temperature superheater and a low-temperature reheater are arranged side by side in a part of a tail shaft flue where the low-temperature superheater is arranged in tangential firing, but the low-temperature reheater and an economizer are arranged side by side, and the flame center at the moment is relatively fixed and mainly depends on the evaporation amount, namely:

1) At D is less than or equal to 116kg/s or 420t/h, Δx=0.1;

2) At D >116kg/s or 420t/h, Δx=0.05.

After the flame center height is obtained from the structural parameters of the burner, the M value can be obtained, and then the outlet temperature of the hearth is calculated by the formula (1). The method for determining the M value of 73 year version of the standard for calculating the heat of the power station boiler is as follows:

in the formula ：V_daf Is a dry ashless based volatile component of the fuel;

As can be seen from formula (5), when V of the fuel _daf After more than 20%, the flame length, the combustion center of which is at the higher position of the outlet of the burner nozzle, is reduced by 0.59,the calculated M value is larger; whereas when V is the fuel _daf After the flame is less than 20%, the flame is short and thick, and the combustion center of the flame is at the lower position of the outlet of the burner nozzle, so that the M value is reduced by 0.56, and the calculated M value is smaller; the M value reflects the relative position of the flame center in the furnace.

From the above description, it is clear that in the thermal calculation of the utility boiler, the acquisition of the variable of the central height of the flame of the furnace needs to be considered very carefully, and factors such as the swing angle and the like which have small differences in practice are fully considered. However, all implicit assumption in the above process is that the coal burns under oxygen-rich conditions, i.e. the heat release at each burner outlet is only related to its fuel quantity. In the case of the under-oxygen combustion, when the air at the burner outlet is insufficient, the combustion amount is as large as the amount fed, but the combustion actually occurs is very different: 1kg of carbon element is burnt into CO ₂ The heat release amount is 33727kJ, the heat release amount of the CO is 4635kJ, the CO is only 7.3 times of the CO which is completely combusted, and the model assuming that the fuel is completely combusted at one time is used for calculation, so that the influence on the flame center is subverted. If the burner outlet is assumed to be pure carbon powder, when the burner burns under the condition that the excess air coefficient is more than 1, the heat release amount is 33727kJ; when the excess air ratio is 0.8, the heat release amount at a point of the burner outlet is 0.6x33727+0.4x4635=22090 kJ, and only 65% of the heat release amount is performed under the oxygen-enriched condition.

Disclosure of Invention

The invention aims to provide a method and a system for determining the flame center in a furnace during deep air classification to determine that fuel is low in NO _x Under the condition of oxygen lack combustion (the combustion heat release quantity of the burner is greatly reduced at the moment), the flame height in the hearth is high.

In order to achieve the above object, in a first aspect, the present invention provides a method for determining a flame center in a furnace in deep air classification, wherein the method comprises:

acquiring real-time heat release quantity of unit quantity of coal in a main combustion area and in a SOFA area (separated over-fire wind area) in deep air staged combustion;

acquiring the coal feeding amount and the central elevation of each burner in a main combustion zone, and acquiring the central elevation of an SOFA nozzle for supplementing combustion air in an SOFA zone;

acquiring the total heat release amount of unit quantity of fire coal in the step combustion of the height and depth air of a hearth;

and determining the relative height of the flame center (the elevation of the flame center relative to the height of the hearth) based on the real-time heat release amount of the unit quantity of the fire coal in the main combustion area, the real-time heat release amount of the unit quantity of the fire coal in the SOFA area, the coal supply amount and the central elevation of each burner in the main combustion area, the central elevation of the SOFA nozzle for supplementing and burning air in the SOFA area, the hearth height and the total heat release amount of the unit quantity of the fire coal in the deep air staged combustion.

In a second aspect, the present invention also provides a system for determining flame center in a furnace during deep air classification, wherein the system comprises:

a first acquisition module: the method is used for acquiring the real-time heat release quantity of the unit quantity of the coal in the main combustion area and the unit quantity of the coal in the SOFA area (separated fire upwind area) in the deep air staged combustion;

and a second acquisition module: the method comprises the steps of obtaining coal feeding quantity and central elevation of each burner in a main combustion zone, and obtaining central elevation of a SOFA nozzle for supplementing combustion air in the SOFA zone;

and a third acquisition module: the method is used for acquiring the total heat release of unit quantity of fire coal in the high and deep air staged combustion of the hearth;

flame center height determination module: the method is used for determining the relative height of the flame center (the elevation of the flame center relative to the height of the hearth) based on the real-time heat release amount of the unit quantity of the coal in the main combustion area, the real-time heat release amount of the unit quantity of the coal in the SOFA area, the coal supply amount and the central elevation of each burner in the main combustion area, the central elevation of the SOFA nozzle for supplementing and burning air in the SOFA area, the hearth height and the total heat release amount of the unit quantity of the coal in the deep air staged combustion.

The technical scheme provided by the invention can well realize the determination of the low NO of the fuel _x Flame height in furnace chamber under the condition of oxygen lack combustionThe method is used for design calculation and in-operation control of the deep air staged combustion hearth.

Drawings

FIG. 1 shows a depth air staged burner arrangement and NO in a furnace _x Concentration profile schematic.

FIG. 2 is a conventional combustor arrangement and deep air staged low NO _x The arrangement mode of the combustion technology is compared with that of the schematic diagram.

FIG. 3 is a schematic diagram of relative elevation of a burner.

FIG. 4 is a flow chart illustrating a method for determining flame center in a furnace during deep air classification according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of an optimized flow of a method for determining flame kernel in a furnace during deep air classification according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a system for determining the flame center in a furnace during deep air classification 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 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.

In the invention, the elevation refers to the height relative to the central line of the furnace ash cooling hopper, namely, the datum planes of the elevation are the central line of the furnace ash cooling hopper.

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

Referring to fig. 4, the present invention provides a method for determining a flame center in a furnace in deep air classification, wherein the method comprises:

step S1: acquiring real-time heat release quantity of unit quantity of coal in a main combustion area and in a SOFA area (separated over-fire wind area) in deep air staged combustion;

step S2: acquiring the coal feeding amount and the central elevation of each burner in a main combustion zone, and acquiring the central elevation of an SOFA nozzle for supplementing combustion air in an SOFA zone;

step S3: acquiring the total heat release amount of unit quantity of fire coal in the step combustion of the height and depth air of a hearth;

step S4: and determining the relative height of the flame center (the elevation of the flame center relative to the height of the hearth) based on the real-time heat release amount of the unit quantity of the fire coal in the main combustion area, the real-time heat release amount of the unit quantity of the fire coal in the SOFA area, the coal supply amount and the central elevation of each burner in the main combustion area, the central elevation of the SOFA nozzle for supplementing and burning air in the SOFA area, the hearth height and the total heat release amount of the unit quantity of the fire coal in the deep air staged combustion.

In deep air staged combustion, the SOFA area is used as a virtual burner using CO as fuel, the rapidity of CO combustion is far higher than that of coal dust, and the flame center of CO combustion is positioned near a SOFA nozzle for supplementing combustion air in the SOFA area.

The SOFA nozzle for supplementing combustion air in the SOFA region refers to a SOFA nozzle for supplementing combustion air, and does not include a SOFA nozzle for providing excessive fuel air used after supplementing combustion air.

In one embodiment, if the SOFA zone is supplemented with more than one SOFA nozzle for combustion air, each SOFA zone may be treated as a whole with the SOFA nozzles for combustion air, thereby determining the central elevation thereof.

In one embodiment, step S4 includes:

step S41: determining the relative height of the whole burner formed by each burner and the SOFA zone based on the real-time heat release amount of the unit quantity of the fire coal in the main combustion zone, the real-time heat release amount of the unit quantity of the fire coal in the SOFA zone, the coal supply amount and the central elevation of each burner in the main combustion zone, the central elevation of the SOFA nozzle for supplementing and burning air in the SOFA zone, the height of a hearth and the total heat release amount of the unit quantity of the fire coal in the deep air staged combustion;

step S42: determining the relative height of the flame center based on the relative heights of the burners, the SOFA zone, and the overall burner;

Further, step S41 includes:

based on the real-time heat release amount of the unit quantity of the coal in the main combustion zone, the real-time heat release amount of the unit quantity of the coal in the SOFA zone, the coal supply amount and central elevation of each burner in the main combustion zone, the central elevation of the SOFA nozzle for supplementing the combustion air in the SOFA zone, the hearth height and the total heat release amount of the unit quantity of the coal in the deep air staged combustion, each burner and each SOFA zone determine the relative height of the integral burner formed by each burner and each SOFA zone according to weighted average of the fuel quantity and the heat release amount;

further, the relative heights of the individual burners, the SOFA zone, and the overall burner are determined by the following equation:

in the formula ,x_b The relative heights of the integral burners formed for each burner, SOFA zone; b (B) _i Kg of coal feed for the ith burner; b (B) _J Kg, which is the total coal feeding amount of the hearth (namely the sum of the coal feeding amounts of the burners); q (Q) _i The real-time heat release amount of the unit quantity of the coal in the main combustion area is kJ/(kg of the coal); h is a _bi The central elevation of the ith burner, m; q (Q) _j The real-time heat release amount of the unit quantity of the coal in the SOFA zone is kJ/(kg of the coal); h is a _bj The SOFA area is supplemented with the central elevation, m of a SOFA nozzle for combustion air; h is a _b The height of the hearth is m;

kJ/(kg of fire coal) is the total heat release amount of the fire coal of unit quantity in the deep air staged combustion;

Further, in step S42, the relative height of the flame center is determined by the following formula:

x _flm ＝x _b +Δx

in the formula ,x_flm Is the relative height of the flame center; x is x _b The relative heights of the integral burners formed for each burner, SOFA zone; Δx isA correction of the relative height of the flame center;

still further, Δx is related to the swing angle:

1) Δx is 0 when the burner is horizontal;

In one embodiment, the total heat release amount of the unit amount of the coal in the deep air staged combustion is determined by using the heat release amount of the complete combustion of the unit amount of the coal into carbon dioxide in the deep air staged combustion;

further, the total heat release amount per unit amount of fire coal in the deep air staged combustion is determined using the following formula:

in the formula ,

the calorific value of the carbon dioxide is obtained by completely burning a unit amount of coal in deep air staged combustion, kJ/(kg of coal); />

kJ/(kg of fire coal) is the total heat release amount of the fire coal of unit quantity in the deep air staged combustion.

In one embodiment, step S1 includes:

Step S11: acquiring total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion;

step S12: the method comprises the steps of obtaining the heating value of the complete combustion of unit quantity of coal into carbon dioxide in deep air staged combustion;

step S13: determining the real-time heat release amount of the unit-quantity fire coal in the main combustion zone in the deep air staged combustion based on the total heat released by the complete combustion of the CO obtained by the unit-quantity fire coal in the main combustion zone in the deep air staged combustion and the heat release amount of the carbon dioxide obtained by the complete combustion of the unit-quantity fire coal in the deep air staged combustion;

step S14: determining the real-time heat release amount of the unit-quantity coal in the SOFA zone based on the total heat released by the complete combustion of the CO obtained by the unit-quantity coal combustion in the main combustion zone in the deep air staged combustion;

further, the real-time heat release amount of the unit amount of coal in the main combustion zone in the deep air staged combustion is determined based on the following formula:

in the formula ,q_CO The total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion is kJ/(kg coal);

the calorific value of unit amount of coal is completely burned into carbon dioxide in deep air staged combustion, kJ/(kg of coal); q (Q) _i The method is characterized in that the method is the real-time heat release quantity of unit quantity coal in a main combustion zone in deep air staged combustion, kJ/(kg coal);

further, the real-time heat release amount of the unit amount of fire coal in the SOFA zone is determined based on the following formula:

Q _j ＝q _CO

in the formula ,q_CO The total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion is kJ/(kg coal); q (Q) _j The real-time heat release amount of the unit quantity of the fire coal in the SOFA zone is kJ/(kg of fire coal).

Referring to fig. 5, in a specific embodiment, step S11 includes:

step S111: acquiring an excess air coefficient of a main combustion zone in deep air staged combustion;

step S112: acquiring the content of carbon element actually burnt by the coal-fired receiving base;

step S113: determining total heat released by complete combustion of CO obtained by unit-quantity coal combustion in the main combustion zone in the deep air staged combustion based on the excess air coefficient of the main combustion zone in the deep air staged combustion and the mass content of carbon element actually burnt by the coal;

further, step S113 includes:

step S1131: when the excess air coefficient is larger than 1, the total heat released by complete combustion of CO obtained by unit-quantity coal combustion in the main combustion zone in the deep air staged combustion is 0;

Step S1132: when the excess air coefficient is not more than 1, determining the total heat released by complete combustion of CO obtained by single-unit-quantity coal combustion in the main combustion zone in the deep air staged combustion by the following formula:

the mass content percentage of carbon element which is actually burnt by the fuel coal receiving base is percent; q (Q) _CO The calorific value of carbon monoxide per unit mass, kJ/kg; alpha is the excess air coefficient of the main combustion zone; k is a coefficient;

further, the value of k is determined by utilizing the mass content of carbon element actually burnt by the coal, the excess air coefficient of a main combustion zone in deep air staged combustion, the combustion rate and the theoretical dry air quantity; for example, the number of the cells to be processed,

wherein alpha is the excess air coefficient of a main combustion zone in the deep air staged combustion;

the mass content percentage of carbon element which is practically burnt for the coal is receivedRate,%; />

For theoretical dry air quantity, m ³ /kg; lambda is the combustion rate (e.g., 96%).

The actual combustion heat release of coal under the condition of oxygen deficiency has a great relationship with the excess air coefficient for the coal; the excess air ratio means the ratio of the air actually involved in combustion to the air required for complete combustion, low NO in the deep air classification _x The combustion technology is based on design, is an important means of operation control in operation control and is also a control target, so that the determination of the actual heat release amount through the excess air coefficient at the outlet of the burner is feasible; when the preferable technical scheme is used, the k value of the same coal type can be regarded as a fixed value, and after the k value is determined, the heat release quantity of the main combustion zone and the SOFA zone can be determined according to the preferable technical scheme, so that the flame center of the hearth can be determined better.

Wherein the carbon element content of the coal which is actually burnt is preferably determined based on the following formula:

in the formula ,C_ar The mass content percentage,%; c (C) _f,as Percent of carbon element mass content in fly ash; c (C) _s,as The mass percent of carbon element in the large slag is; r is (r) _f,as The mass fraction of ash in fly ash to the total ash content of coal is percent; r is (r) _s,as The ash content in the large slag accounts for the mass fraction of the total ash content of the coal; a is that _ar Percentage by mass of base ash received for the coal;

the mass percent of carbon element which is actually burnt by the fuel coal is calculated.

Wherein the theoretical dry air amount is preferably determined based on the following formula:

wherein ,

in the formula ,

For the theoretical dry air quantity (theoretical dry air quantity required for combustion of coal per kg), m ³ /kg；H _ar The mass content percentage,%; o (O) _ar The mass percent of the oxygen-based element is received by the coal; s is S _ar The mass percent of the sulfur element is the mass percent of the sulfur element received by the coal; />

The mass content percentage,% > of carbon element is calculated for the fuel coal received by the fuel coal to be actually burnt; c (C) _ar The mass content percentage,%; c (C) _f,as The mass percent of carbon element in fly ash; c (C) _s,as The mass percent of carbon element in the large slag is; r is (r) _f,as The mass fraction of ash in fly ash to the total ash content of coal is percent; r is (r) _s,as The ash content in the large slag accounts for the mass fraction of the total ash content of the coal; a is that _ar The mass percent of the base ash content received by the coal is percent;

the preferred embodiment requires on-line instrumentation for elemental analysis of coal quality to be provided in operation, or elemental analysis data results of the design coal during the design phase.

The theoretical dry air quantity is preferably determined by the low-level calorific value of coal according to DL/904-2015 method for calculating economic and technical index of thermal power plant; specifically based on the following formula:

in the formula ,

for the theoretical dry air quantity (theoretical dry air quantity required for combustion of coal per kg), m ³ /kg; k is a coefficient related to the coal type, and the value of the K is referenced to the power industry standard DL/T904-2015; q (Q) _net.ar The coal receives basic low-grade heating value, kJ/kg.

Wherein the amount of heat generated by complete combustion of a unit amount of coal into carbon dioxide in the deep air staged combustion is preferably determined based on the following formula:

in the formula ,

the calorific value of the unit amount of the coal is the calorific value of the carbon dioxide completely combusted, kJ/(kg of the coal); q (Q) _net.ar The base low-position heating value is received for the fire coal, kJ/(kg fire coal); c (C) _f,as The mass percent of carbon element in fly ash; c (C) _s,as The mass percent of carbon element in the large slag is; r is (r) _f,as The mass parts of ash in the fly ash accounting for the total ash content of the coal are percent; r is (r) _s,as The ash content in the large slag accounts for the mass fraction of the total ash content of the coal; a is that _ar The mass percent of the base ash is received for the coal.

In one embodiment, the excess air ratio of each burner of the main combustion zone in the progressive combustion is uniform, typically between 0.8 and 0.95. The air excess factor means the ratio of the air actually involved in combustion to the air required for complete combustion, low NO in the deep air classification _x The combustion technology is based on design, and is an important means of operation control and a control target in operation control.

In a specific embodiment, the mass content percentage of the base hydrogen element received by the coal, the mass content percentage of the base oxygen element received by the coal, the mass content percentage of the base sulfur element received by the coal, the mass content percentage of the base carbon element received by the coal, the mass content percentage of the base nitrogen element received by the coal, the mass content percentage of the base ash received by the coal and the mass content percentage of the base ash received by the coal are obtained through a coal sample test.

In a specific embodiment, the mass percentage of carbon elements in the fly ash, the mass percentage of carbon elements in the large slag, the mass fraction of ash in the fly ash to the total ash content of the fire coal and the mass fraction of ash in the large slag to the total ash content of the fire coal are measured by a loss-of-ignition method.

In a specific embodiment, the heating value per unit mass of carbon monoxide is 10108kJ/kg.

The embodiment of the invention also provides a system for determining the flame center in the furnace during deep air classification, and the system is preferably used for realizing the method embodiment.

FIG. 6 is a block diagram of a system for determining flame center in a furnace during deep air staging according to an embodiment of the invention, as shown in FIG. 6, the system comprising:

the first acquisition module 51: the method is used for acquiring the real-time heat release quantity of the unit quantity of the coal in the main combustion area and the unit quantity of the coal in the SOFA area (separated fire upwind area) in the deep air staged combustion;

The second acquisition module 52: the method comprises the steps of obtaining coal feeding quantity and central elevation of each burner in a main combustion zone, and obtaining central elevation of a SOFA nozzle for supplementing combustion air in the SOFA zone;

the third acquisition module 53: the method is used for acquiring the total heat release amount of unit quantity of fire coal in the step combustion of the height and depth air of the hearth;

flame center height determination module 54: the method is used for determining the relative height of the flame center (the elevation of the flame center relative to the height of the hearth) based on the real-time heat release amount of the unit quantity of the coal in the main combustion area, the real-time heat release amount of the unit quantity of the coal in the SOFA area, the coal supply amount and the central elevation of each burner in the main combustion area, the central elevation of the SOFA nozzle for supplementing and burning air in the SOFA area, the hearth height and the total heat release amount of the unit quantity of the coal in the deep air staged combustion.

In one embodiment, the flame center height determination module 54 includes:

the first altitude determination submodule 541: the method comprises the steps of determining the relative height of an integral burner formed by each burner and an SOFA zone based on the real-time heat release amount of unit quantity of fire coal in a main combustion zone, the real-time heat release amount of unit quantity of fire coal in the SOFA zone, the coal supply amount and central elevation of each burner in the main combustion zone, the central elevation of a SOFA nozzle for supplementing and burning air in the SOFA zone, the height of a hearth and the total heat release amount of unit quantity of fire coal in deep air staged combustion;

A second altitude determination submodule 542: for determining the relative height of the flame centre based on the relative heights of the burners, the SOFA zones, forming the whole burner;

further, the first elevation determination submodule 541 is configured to determine, based on the real-time heat release amount of the unit amount of the fire coal in the main combustion area, the real-time heat release amount of the unit amount of the fire coal in the SOFA area, the coal supply amount and the central elevation of each burner in the main combustion area, the central elevation of the SOFA nozzle for the SOFA area to supplement the combustion air, the height of the furnace, and the total heat release amount of the unit amount of the fire coal in the deep air staged combustion, the relative elevation of the integral burner formed by each burner and the SOFA area according to the weighted average of the fuel amount and the heat release amount;

still further, the first height determining submodule 541 is configured to determine the relative heights of the burners, the SOFA area, and the overall burner by the following formula:

is of depthTotal heat release of unit quantity of fire coal in air staged combustion, kJ/(kg of fire coal);

further, the second height determination sub-module 542 is configured to determine the relative height of the flame center by the following equation:

x _flm ＝x _b +Δx

in the formula ,x_flm Is the relative height of the flame center; x is x _b The relative heights of the integral burners formed for each burner, SOFA zone; Δx is the correction of the relative height of the flame center;

still further, Δx is related to the swing angle:

1) Δx is 0 when the burner is horizontal;

In one embodiment, the third obtaining module 53 is configured to determine a total heat release amount of the unit amount of the coal in the deep air staged combustion by using a heat release amount of the unit amount of the coal in the deep air staged combustion to be fully combusted into carbon dioxide;

further, the third acquisition module 53 is configured to determine the total heat release amount of a unit amount of fire coal in the deep air staged combustion using the following formula:

in the formula ,

In a specific embodiment, the first obtaining module 51 includes:

the CO heat capture submodule 511: the method is used for obtaining total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion;

coal heating value acquisition sub-module 512: the method is used for obtaining the heating value of the complete combustion of the unit quantity of coal into carbon dioxide in the deep air staged combustion;

main combustion zone heat determination submodule 513: the method comprises the steps of determining real-time heat release of unit-quantity coal in a main combustion zone in deep air staged combustion based on total heat released by complete combustion of CO obtained by unit-quantity coal combustion in the main combustion zone in deep air staged combustion and heat release of the unit-quantity coal in the deep air staged combustion to form carbon dioxide;

SOFA zone heat determination submodule 514: the method is used for determining the real-time heat release amount of the unit-quantity coal in the SOFA zone based on the total heat released by complete combustion of CO obtained by unit-quantity coal combustion in the main combustion zone in deep air staged combustion;

Further, the main combustion zone heat determination submodule 513 is configured to determine the real-time heat release amount of the main combustion zone unit amount of coal in the deep air staged combustion based on the following formula:

further, the SOFA zone heat determination submodule 514 is configured to determine the real-time heat release of a unit amount of fire coal in the SOFA zone based on the following formula:

Q _j ＝q _CO

In one embodiment, the CO heat capture sub-module 511 comprises:

excess air ratio acquisition unit 5111: the method is used for obtaining the excess air coefficient of a main combustion zone in deep air staged combustion;

combustion carbon content acquisition unit 5112: the method is used for obtaining the content of carbon element actually burnt by the coal-fired receiving base;

CO heat determination unit 5113: the method is used for determining total heat released by complete combustion of CO obtained by single-unit-quantity coal combustion in the main combustion zone in the deep air staged combustion based on the excess air coefficient of the main combustion zone in the deep air staged combustion and the mass content of carbon elements actually burnt by the coal;

further, the CO heat amount determination unit 5113 includes:

first CO heat determination subunit 51131: when the excess air coefficient is larger than 1, determining that the total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in the deep air staged combustion is 0;

second CO heat determination subunit 51132: for determining the total heat released by complete combustion of CO obtained by unit-amount coal combustion in the main combustion zone in the deep air stage combustion by the following formula when the excess air ratio is not more than 1:

for the coal to receive the base actual combustionThe mass percent of the burned carbon element; q (Q) _CO The calorific value of carbon monoxide per unit mass, kJ/kg; alpha is the excess air coefficient of the main combustion zone; k is a coefficient;

Further, the second CO heat determining subunit 51132 is configured to determine the value of k by using the mass content of carbon element actually burned by the coal, the excess air coefficient of the main combustion zone in the deep air staged combustion, the combustion rate and the theoretical dry air amount; for example, the number of the cells to be processed,

the mass percent of carbon element which is obtained by burning coal and is practically burnt; />

for burning coal to obtain carbon elementPercentage of the amount,%.

wherein ,

in the formula ,

in the formula ,

/>

in the formula ,

In a specific embodiment, the mass content percentage of the basic hydrogen element received by the coal, the mass content percentage of the basic oxygen element received by the coal, the mass content percentage of the basic sulfur element received by the coal, the mass content percentage of the basic carbon element received by the coal, the mass content percentage of the basic nitrogen element received by the coal, the mass content percentage of the basic ash received by the coal and the mass content percentage of the basic ash received by the coal are obtained through a coal sample test.

Example 1

The embodiment provides a method for determining a flame center in a furnace during deep air classification, wherein the furnace during deep air classification is shown in (b) of fig. 2, and the method comprises the following steps:

1. acquiring real-time heat release quantity of unit quantity of coal in a main combustion area and in a SOFA area (separated fire upwind area) in deep air staged combustion;

The real-time heat release amount of the unit amount of the coal in the main combustion area and the unit amount of the coal in the SOFA area (separated over-fire wind area) in the deep air staged combustion is determined by the following method:

in the formula ,C_f,as The mass percent of carbon element in fly ash; c (C) _s,as The mass percent of carbon element in the large slag is; r is (r) _f,as The mass fraction of ash in fly ash to the total ash content of coal is percent; r is (r) _s,as The ash content in the large slag accounts for the mass fraction of the total ash content of the coal; a is that _ar The mass percent of the base ash content received by the coal is percent;

the mass content percentage of carbon element which is obtained by the actual combustion of the coal，％；Q _i The method is characterized in that the method is the real-time heat release quantity of single-unit-quantity coal in a main combustion zone in deep air staged combustion, kJ/(kg coal); q (Q) _CO The calorific value of carbon monoxide per unit mass, kJ/kg; alpha is the excess air coefficient of the main combustion zone; k is a coefficient; q (Q) _net.ar The base low-position heating value, kJ/kg, is received for the coal;

wherein the content of carbon element actually burnt by the coal is determined based on the following formula:

the mass content percentage of carbon element which is actually burnt by the fuel coal receiving base is percent;

the value of k is determined by using the mass content of carbon element actually burnt by the coal, the excess air coefficient of a main combustion area in deep air staged combustion, the combustion rate and the theoretical dry air amount, and specifically:

For theoretical dry air quantity, m ³ /kg; lambda is the combustion rate;

wherein the theoretical dry air amount is determined based on the following formula:

in the formula ,

The mass content percentage,% > of carbon element is calculated for the fuel coal received by the fuel coal to be actually burnt;

The data are shown in table 1.

2. Acquiring the coal feeding amount and the central elevation of each burner in a main combustion zone, and acquiring the central elevation of an SOFA nozzle for supplementing and burning air in an SOFA zone;

the results are shown in Table 1.

3. Acquiring the total heat release amount of unit quantity of fire coal in the step combustion of the height and depth air of a hearth;

wherein, the total heat release amount of the unit amount of coal in the deep air staged combustion is determined by the following formula:

in the formula ,

kJ/(kg of fire coal) is the total heat release amount of the fire coal of unit quantity in the deep air staged combustion; q (Q) _net.ar The base low-position heating value is received for the fire coal, kJ/(kg fire coal); c (C) _f,as The mass percent of carbon element in fly ash is,%; c (C) _s,as The mass percent of carbon element in the large slag is; r is (r) _f,as The mass fraction of ash in fly ash to the total ash content of coal is percent; r is (r) _s,as The ash content in the large slag accounts for the mass fraction of the total ash content of the coal; a is that _ar The mass percent of the base ash is received by the fire coal.

4. Determining the relative height of the center of the flame (the elevation of the center of the flame relative to the height of the hearth) based on the real-time heat release amount of the unit quantity of the fire coal in the main combustion zone, the real-time heat release amount of the unit quantity of the fire coal in the SOFA zone, the coal supply amount and the center elevation of each burner in the main combustion zone, the center elevation of the SOFA nozzle for supplementing and burning air in the SOFA zone, the hearth height and the total heat release amount of the unit quantity of the fire coal in the deep air staged combustion; specifically:

4.1, determining the relative height of the whole burner formed by each burner and the SOFA zone according to weighted average of fuel quantity and heating value based on the real-time heat release quantity of the unit quantity fire coal of the main combustion zone, the real-time heat release quantity of the unit quantity fire coal of the SOFA zone, the coal supply quantity and central elevation of each burner in the main combustion zone, the central elevation of SOFA nozzles for the SOFA zone to supplement combustion air, the height of a hearth and the total heat release quantity of the unit quantity fire coal in deep air staged combustion; wherein, the relative height of the whole burner formed by each burner and the SOFA zone is determined by the following formula:

in the formula ,x_b The relative heights of the integral burners formed for each burner, SOFA zone; b (B) _i Kg of coal feed for the ith burner; b (B) _J Kg, which is the total coal feeding amount of the hearth (namely the sum of the coal feeding amounts of the burners); q (Q) _i Is the unit quantity of the main combustion areaReal-time heat release of fire coal, kJ/(kg fire coal); h is a _bi The central elevation of the ith burner, m; q (Q) _j The real-time heat release amount of the unit quantity of the coal in the SOFA zone is kJ/(kg of the coal); h is a _bj The SOFA area is supplemented with the central elevation, m of a SOFA nozzle for combustion air; h is a _b The height of the hearth is m;

4.2, determining the relative height of the flame center based on the relative heights of the burners and the SOFA zone; wherein the relative height of the flame center is determined by the following formula:

x _flm ＝x _b +Δx

Δx is related to the swing angle:

1) Δx is 0 when the burner is horizontal;

The results are shown in Table 1.

The relative height of the flame center determined by determination 4 of the present embodiment determines a coefficient M representing the height of the furnace flame:

wherein: vdaf is the dry ashless based volatile component of the fuel; x is x _flm Is the relative height of the flame center;

the results are shown in Table 1.

If calculated conventionally, the relative height of the flame center is 0.275, and the corresponding coefficient M representing the height of the furnace flame is 0.56.

TABLE 1

The principles and embodiments of the present invention have been described in detail with reference to specific examples, which are provided to facilitate understanding of the method and core ideas of the present invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.

Claims

1. A method for determining flame center in a furnace during deep air classification, wherein the method comprises the following steps:

acquiring real-time heat release quantity of unit quantity of coal in a main combustion area and real-time heat release quantity of unit quantity of coal in an SOFA area in deep air staged combustion;

acquiring the total heat release amount of unit quantity of fire coal in the step combustion of the height and depth air of a hearth; the total heat release amount of the unit amount of the coal in the deep air staged combustion is determined by using the heat release amount of the unit amount of the coal in the deep air staged combustion to be completely combusted into carbon dioxide;

determining the relative height of a flame center based on the real-time heat release amount of the unit quantity of the coal in the main combustion area, the real-time heat release amount of the unit quantity of the coal in the SOFA area, the coal supply amount and the center elevation of each burner in the main combustion area, the center elevation of the SOFA nozzle for supplementing and burning air in the SOFA area, the height of a hearth and the total heat release amount of the unit quantity of the coal in the deep air staged combustion;

the step of determining the relative height of the flame center based on the real-time heat release amount of the unit quantity of the coal in the main combustion area, the real-time heat release amount of the unit quantity of the coal in the SOFA area, the coal supply amount and the center elevation of each burner in the main combustion area, the center elevation of the SOFA nozzle for the supplementary firing air in the SOFA area, the hearth height and the total heat release amount of the unit quantity of the coal in the deep air staged combustion comprises the following steps:

determining the relative height of the flame center based on the relative heights of the burners, the SOFA zone, and the overall burner; wherein, the relative height of the whole burner formed by each burner and the SOFA zone is determined by the following formula:

in the formula ,x_b The relative heights of the integral burners formed for each burner, SOFA zone; b (B) _i Kg of coal feed for the ith burner; b (B) _J The total coal feeding amount of the hearth is kg; q (Q) _i The real-time heat release amount of the unit quantity coal in the main combustion zone is kJ/kg; h is a _bi The central elevation of the ith burner, m; q (Q) _j The real-time heat release amount of unit quantity coal in the SOFA zone is kJ/kg; h is a _bj The SOFA area is supplemented with the central elevation, m of a SOFA nozzle for combustion air; h is a _b The height of the hearth is m;

kJ/kg, the total heat release amount of unit amount of coal in deep air staged combustion;

Wherein, obtain the real-time calorific value of main combustion zone unit volume fire coal among the deep air staged combustion, the real-time calorific value of SOFA district unit volume fire coal includes:

acquiring total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion;

the method comprises the steps of obtaining the heating value of the complete combustion of unit quantity of coal into carbon dioxide in deep air staged combustion;

determining the real-time heat release amount of the unit-quantity fire coal in the main combustion zone in the deep air staged combustion based on the total heat released by the complete combustion of the unit-quantity fire coal in the main combustion zone in the deep air staged combustion and the heat release amount of the carbon dioxide generated by the complete combustion of the unit-quantity fire coal in the deep air staged combustion;

and determining the real-time heat release amount of the unit-quantity coal in the SOFA zone based on the total heat released by complete combustion of CO obtained by the unit-quantity coal combustion in the main combustion zone in the deep air staged combustion.

2. The determination method according to claim 1, wherein,

the real-time heat release amount of the unit quantity coal of the main combustion area in the deep air staged combustion is determined based on the following formula:

in the formula ,q_CO The total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion is kJ/kg;

The calorific value of the carbon dioxide is kJ/kg generated by the complete combustion of unit amount of coal in deep air staged combustion; q (Q) _i The method is the real-time heat release quantity of unit quantity coal in a main combustion zone in deep air staged combustion, kJ/kg.

3. The determination method according to claim 1, wherein the real-time heat release amount per unit amount of fire coal in the SOFA zone is determined based on the following formula:

Q _j ＝q _CO

in the formula ,q_CO The total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion is kJ/kg; q (Q) _j The real-time heat release amount of unit quantity of coal in the SOFA zone is kJ/kg.

4. The determination method according to claim 1, wherein obtaining total heat released by complete combustion of CO obtained by unit-amount coal combustion in the main combustion zone in the deep air stage combustion comprises:

acquiring an excess air coefficient of a main combustion zone in deep air staged combustion;

acquiring the content of carbon element actually burnt by the coal-fired receiving base;

and determining total heat released by complete combustion of CO obtained by unit-quantity coal combustion in the main combustion area in the deep air staged combustion based on the excess air coefficient of the main combustion area in the deep air staged combustion and the mass content of carbon element actually burnt by the coal.

5. The determination method according to claim 1, wherein determining total heat released by complete combustion of CO per unit amount of coal combustion in the main combustion zone in the depth air staged combustion based on an excess air ratio of the main combustion zone in the depth air staged combustion and a mass content of carbon element that is actually burned off by the coal comprises:

when the excess air coefficient is larger than 1, the total heat released by complete combustion of CO obtained by unit-quantity coal combustion in the main combustion zone in the deep air staged combustion is 0;

when the excess air ratio is not more than 1, the total heat released by complete combustion of CO obtained by unit-quantity coal combustion in the main combustion zone in the deep air staged combustion is determined by the following formula:

the mass content percentage,% > of carbon element is calculated for the fuel coal received by the fuel coal to be actually burnt; q (Q) _CO The calorific value of carbon monoxide per unit mass, kJ/kg; alpha is the excess air coefficient of the main combustion zone; k is a coefficient.

6. The determination method according to claim 5, wherein the value of k is determined by using the mass content of carbon element actually burned by the coal, the excess air ratio of the main combustion zone in the deep air staged combustion, the combustion rate and the theoretical dry air amount; wherein,

the mass content percentage,% > of carbon element is calculated for the fuel coal received by the fuel coal to be actually burnt; v (V) _a ⁰ For theoretical dry air quantity, m ³ /kg; lambda is the combustion rate.

7. An in-furnace flame center determination system for depth air staging, wherein the system comprises:

a first acquisition module: the method is used for acquiring the real-time heat release quantity of the unit quantity of the coal in the main combustion area and the SOFA area in the deep air staged combustion;

and a third acquisition module: the method is used for acquiring the total heat release amount of unit quantity of fire coal in the step combustion of the height and depth air of the hearth;

flame center height determination module: the method comprises the steps of determining the relative height of a flame center based on the real-time heat release amount of unit quantity of fire coal in a main combustion zone, the real-time heat release amount of unit quantity of fire coal in an SOFA zone, the coal supply amount and center elevation of each burner in the main combustion zone, the center elevation of a SOFA nozzle for supplementing and burning air in the SOFA zone, the height of a hearth and the total heat release amount of unit quantity of fire coal in deep air staged combustion;

Wherein the flame center height determination module comprises:

a first height determination submodule: the method comprises the steps of determining the relative heights of the burners and the SOFA areas according to weighted average of fuel quantity and heating value, wherein the relative heights are used for determining the relative heights of the integral burners formed by the burners and the SOFA areas according to the real-time heat release quantity of unit quantity of fire coal in a main combustion area, the real-time heat release quantity of unit quantity of fire coal in the SOFA area, the coal supply quantity and central elevation of each burner in the main combustion area, the central elevation of a SOFA nozzle for supplementing and burning air in the SOFA area, the hearth height and the total heat release quantity of unit quantity of fire coal in deep air staged combustion;

a second height determination submodule: for determining the relative height of the flame centre based on the relative height of the burners, the SOFA zone, forming the whole burner;

wherein, the first altitude determining submodule is used for determining the relative altitude of the whole burner formed by each burner and the SOFA zone through the following formula:

in the formula ,x_b The relative heights of the integral burners formed for each burner, SOFA zone; b (B) _i Kg of coal feed for the ith burner; b (B) _J The total coal feeding amount of the hearth is kg; q (Q) _i The real-time heat release amount of the unit quantity coal in the main combustion zone is kJ/kg; h is a _bi The central elevation of the ith burner, m; q (Q) _j The real-time heat release amount of unit quantity coal in the SOFA zone is kJ/kg; h is a _bj The SOFA area is supplemented with the central elevation, m of a SOFA nozzle for combustion air; h is a _b The height of the hearth is m; q (Q) _n ^r _et,ar kJ/kg, the total heat release amount of unit amount of coal in deep air staged combustion;

the third acquisition module is used for determining the total heat release amount of the unit quantity of the coal in the deep air staged combustion by utilizing the heat release amount of the unit quantity of the coal in the deep air staged combustion to be completely combusted into carbon dioxide;

wherein, the first acquisition module includes:

CO heat acquisition sub-module: the method is used for obtaining total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion;

a coal heating value acquisition sub-module: the method is used for obtaining the heating value of the complete combustion of the unit quantity of coal into carbon dioxide in the deep air staged combustion;

main combustion zone heat determination submodule: the method comprises the steps of determining real-time heat release of unit-quantity fire coal in a main combustion zone in deep air staged combustion based on total heat released by complete combustion of CO obtained by unit-quantity fire coal in the main combustion zone in deep air staged combustion and heat release of the carbon dioxide obtained by complete combustion of the unit-quantity fire coal in the deep air staged combustion;

SOFA zone heat determination submodule: the method is used for determining the real-time heat release amount of the unit-quantity coal in the SOFA zone based on the total heat released by complete combustion of CO obtained by the unit-quantity coal combustion in the main combustion zone in the deep air staged combustion.

8. The system of claim 7, wherein the main combustion zone heat determination submodule is configured to determine the real-time heat release of a unit amount of coal from the main combustion zone in the progressive air-staged combustion based on the following equation:

wherein qCO is total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion, and kJ/kg;

9. The system of claim 7, wherein the SOFA zone heat determination submodule is configured to determine the real-time heat release of a unit amount of fire coal of the SOFA zone based on the following equation:

Q _j ＝q _CO

wherein qCO is total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in deep air staged combustion, and kJ/kg; q (Q) _j The real-time heat release amount of unit quantity of coal in the SOFA zone is kJ/kg.

10. The system of claim 7, wherein the CO heat capture submodule comprises:

excess air ratio acquisition unit: the method is used for acquiring the excess air coefficient of a main combustion zone in the deep air staged combustion;

a carbon content obtaining unit: the method is used for obtaining the content of carbon element actually burnt by the coal-fired receiving base;

CO heat determination unit: the method is used for determining total heat released by complete combustion of CO obtained by unit-quantity coal combustion in the main combustion zone in the deep air staged combustion based on the excess air coefficient of the main combustion zone in the deep air staged combustion and the mass content of carbon elements actually burnt by the coal.

11. The system of claim 10, wherein the CO heat determination unit comprises:

a first CO heat determination subunit: when the excess air coefficient is larger than 1, determining that the total heat released by complete combustion of CO obtained by unit-quantity coal combustion in a main combustion zone in the deep air staged combustion is 0;

a second CO heat determination subunit: for determining the total heat released by complete combustion of CO obtained by unit-amount coal combustion in the main combustion zone in the deep air stage combustion by the following formula when the excess air ratio is not more than 1:

12. The system of claim 11, wherein the second CO heat determination subunit is configured to determine the value of k using the mass content of carbon element that is actually burned off by the coal, the excess air ratio of the main combustion zone in the deep air staged combustion, the combustion rate, and the theoretical dry air amount; wherein,

the mass content percentage,% > of carbon element is calculated for the fuel coal received by the fuel coal to be actually burnt; />

For theoretical dry air quantity, m ³ /kg; lambda is the combustion rate.