Coal dust stabilization system

Abstract

The utility model discloses a kind of coal powder stable combustion system, belong to power station boiler technical field.The system includes burner;Air separator, air is separated, and oxygen is obtained;Coal mill, raw coal is ground into predetermined fineness coal powder;Primary air control device, including primary air heating equipment, primary air is heated to obtain first predetermined temperature primary air, wherein first predetermined temperature primary air and predetermined fineness coal powder form primary air coal powder flow;Secondary air control device, including secondary air heating equipment, secondary air is heated to obtain second predetermined temperature secondary air, second predetermined temperature secondary air is blown into burner;Oxygen-rich control device, it includes oxygen heating equipment, oxygen heating equipment is heated to obtain third predetermined temperature oxygen flow to oxygen, wherein, third predetermined temperature oxygen flow and primary air coal powder flow are mixed and then enter burner.The utility model strengthens combustion reaction kinetics condition, improves combustion efficiency.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of power station boiler, especially relates to a pulverized coal stable combustion system. BACKGROUND

[0002] With the in-depth promotion of China's "double carbon" strategy, the power system is undergoing a structural change with new energy as the main body. As of 2023, the installed capacity of wind power and photovoltaic power has broken through 35%, but due to the intermittent output of wind power and photovoltaic power, the demand for grid peak regulation has surged. Traditional coal-fired units are forced to participate in deep peak regulation frequently, and more than 30% of the annual operating hours are in the 50% below load condition. Among them, when the supercritical unit operates at 40% load, the furnace temperature drops by 200-300℃, and the conventional combustion system appears flame pulsation, sudden drop of combustion efficiency (fly ash carbon content rises to 8-12%), NOx emission exceeds the standard (>300mg / Nm³) and other outstanding problems. Especially when mixed with high-ash lean coal or anthracite, the low-load stable combustion limit is generally higher than 35%BMCR (full name: Boiler Maximum Continuous Rating, Boiler Maximum Continuous Rating), which seriously restricts the progress of unit flexibility transformation. SUMMARY

[0003] In view of the above problems existing in the prior art, the utility model provides a pulverized coal stable combustion system.

[0004] In order to realize the above purpose, one technical scheme adopted by the utility model is to provide a pulverized coal stable combustion system, which comprises: a burner; an air separator which separates air to obtain oxygen; a coal mill which grinds raw coal into coal powder of a predetermined fineness; a primary air control device which comprises a primary air heating device, the primary air heating device heats the primary air to obtain primary air of a first predetermined temperature, wherein the primary air of the first predetermined temperature forms a primary air-pulverized coal flow with the coal powder of the predetermined fineness; a secondary air control device which comprises a secondary air heating device, the secondary air heating device heats the secondary air to obtain secondary air of a second predetermined temperature, and the secondary air of the second predetermined temperature is blown into the burner; an oxygen-enriched control device which comprises an oxygen heating device, the oxygen heating device heats the oxygen to obtain an oxygen flow of a third predetermined temperature, wherein the oxygen flow of the third predetermined temperature is mixed with the primary air-pulverized coal flow and then enters the burner.

[0005] The utility model discloses a beneficial effect is: the utility model provides a kind of coal powder stable combustion system, oxygen is obtained by air separation, and first air, secondary air and oxygen are heated respectively to form corresponding airflow with corresponding temperature, and the mixed flow of first air and coal powder is mixed with the oxygen flow obtained after heating before entering burner, and then injects combustion burner and burns, strengthens combustion reaction kinetics condition, to improve the load regulation capability of boiler combustion, reduce the load of stable combustion, also reduce the carbon content of fly ash, improve combustion efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 It is a specific embodiment of the utility model coal powder stable combustion system schematic diagram. Figure 2 It is a specific embodiment of the utility model coal powder stable combustion system schematic diagram. DETAILED DESCRIPTION

[0007] The preferred embodiments of the utility model are described in detail below in conjunction with the drawings, so that the advantages and features of the utility model can be more easily understood by those skilled in the art, and the protection scope of the utility model is more clearly defined.

[0008] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitation, the elements defined by the statement "include" do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0009] Next, the technical scheme of the utility model and how the technical scheme of the utility model solves the above technical problems will be described in detail with specific examples. The specific examples described below can be combined to form new examples. For the same or similar ideas or processes described in one example, they may not be described again in other examples. The embodiments of the utility model will be described below with reference to the drawings.

[0010] Figure 1 It is a specific embodiment of the utility model coal powder stable combustion system schematic diagram. The utility model discloses a beneficial effect is: the utility model provides a kind of coal powder steady combustion system, oxygen is obtained by air separation, and first air, secondary air and oxygen are respectively heated to form corresponding airflow with corresponding temperature, and the mixed flow of first air and coal powder is with the oxygen flow obtained after heating before entering burner first mixed, and then injects combustion burner and burns, strengthens combustion reaction kinetics condition, to improve the boiler combustion load regulation capability, reduce the load of stable combustion, also reduce the carbon content of fly ash, improve combustion effciency.

[0011] Figure 1The pulverized coal stable combustion system shown comprises: a burner 101; an air separator 102 which separates air to obtain oxygen; a coal mill 103 which grinds raw coal into pulverized coal of a predetermined fineness; a primary air regulating device 104 which comprises a primary air heating device which heats primary air to obtain primary air of a first predetermined temperature, wherein the primary air of the first predetermined temperature forms a primary air-pulverized coal flow together with the pulverized coal of the predetermined fineness; a secondary air regulating device 105 which comprises a secondary air heating device which heats secondary air to obtain secondary air of a second predetermined temperature which is blown into the burner; and an oxygen-rich regulating device 106 which comprises an oxygen heating device which heats oxygen to obtain an oxygen flow of a third predetermined temperature, wherein the oxygen flow of the third predetermined temperature is mixed with the primary air-pulverized coal flow before entering the burner.

[0012] In the specific embodiment, oxygen is obtained by separating air using an air separator, and the primary air, the secondary air and the oxygen are heated respectively to form corresponding air flows with respective temperatures. By preparing ultrafine pulverized coal, and mixing the primary air and the pulverized coal before entering the burner, and then injecting the mixture into the burner for combustion, the combustion reaction kinetics conditions are strengthened, thereby improving the load regulation capability of the boiler combustion, reducing the load for stable combustion, reducing the carbon content of fly ash, improving the combustion efficiency, and solving the technical problems of combustion oscillation and efficiency drop of a traditional coal-fired unit under low load conditions.

[0013] In one specific embodiment of the present application, the pulverized coal stable combustion system comprises: a burner 101.

[0014] In one specific embodiment of the present application, the pulverized coal stable combustion system comprises: an air separator 102 which separates air to obtain oxygen.

[0015] In the specific embodiment, high-purity oxygen is obtained by separating air using an air separator, which facilitates further corresponding regulation and control of the oxygen.

[0016] In one specific embodiment of the present application, the pulverized coal stable combustion system comprises: the coal mill 103 which grinds raw coal into pulverized coal of a predetermined fineness.

[0017] In the specific embodiment, raw coal is ground by the coal mill to pulverized coal of a predetermined fineness, which can enable the pulverized coal to burn fully and efficiently in the boiler.

[0018] In one specific embodiment of the present application, the pulverized coal of the predetermined fineness is obtained by using a screening method.

[0019] In this embodiment, the fineness of the pulverized coal in the power plant boiler is measured by sieving, that is, a certain amount of pulverized coal sample is sieved on a sieve, specifically, a certain amount of pulverized coal is left on the sieve, and a certain amount of pulverized coal falls through the sieve holes, then the percentage of the remaining amount of pulverized coal on the sieve to the total amount of sieved pulverized coal is R x =a / (a+b)x100%, wherein the angle X represents the sieve number or the inner width of the sieve hole, and R X is larger, which indicates that the pulverized coal is coarser. The following Table 1 shows the sieve specifications and the pulverized coal fineness in China.

[0020] In one embodiment of the present application, the predetermined fineness is different according to the type of the raw coal.

[0021] In this embodiment, the grinder grinds the raw coal into pulverized coal with a predetermined fineness, wherein the predetermined fineness is different according to the type of the raw coal, and the recommended predetermined fineness of the pulverized coal is: bituminous coal R 90 =(25-40)%; anthracite and lean coal R 90 =(6-14)%. The predetermined fineness is different according to the type of the raw coal, which helps to improve the combustion efficiency, improve the combustion stability, and reduce the power consumption for preparing the pulverized coal.

[0022] In one embodiment of the present application, the predetermined fineness is the most economical pulverized coal fineness.

[0023] In this embodiment, although the finer the pulverized coal is, the easier it is to burn, but the fineness of the pulverized coal is related to the coal power consumption and the boiler efficiency. If the pulverized coal is too coarse, it is not easy to burn out in the furnace, which increases the incomplete combustion heat loss. If the pulverized coal is too fine, it will increase the power consumption and metal wear of the pulverizing system. Therefore, in actual application, the fineness of the pulverized coal should be appropriate, and the economic factors of the pulverized coal fineness should be fully considered. The predetermined fineness of the pulverized coal obtained by the coal mill can be the most economical pulverized coal fineness.

[0024] In one embodiment of the present application, in actual use, for bituminous coal and anthracite, the fineness of the pulverized coal is only R 90 and R 200 , and since the fineness of the pulverized coal is related to the coal power consumption and the boiler efficiency, the most economical pulverized coal fineness is: wherein n is a coal particle distribution uniformity coefficient, which is related to the type and operating condition of the coal mill and the separator; V r is the combustible base volatile matter value of the pulverized coal. The coal particles of the coal with a high combustible base volatile matter value can be relatively coarser to reduce the power consumption for preparing the pulverized coal, and the coal particles of the coal with a low combustible base volatile matter value should be relatively finer to reduce the incomplete combustion heat loss.

[0025] In one specific embodiment of the present application, the pulverized coal stable combustion system comprises: a primary air regulating device 104, which comprises a primary air heating device, the primary air heating device heats the primary air to obtain primary air at a first predetermined temperature, wherein the primary air at the first predetermined temperature forms a primary air-pulverized coal flow with the pulverized coal of a predetermined fineness.

[0026] In this specific embodiment, the primary air regulating device comprises a primary air heating device, the primary air regulating device heats the primary air to obtain primary air at a first predetermined temperature through the primary air system and by using the primary air heating device, and then the primary air at the first predetermined temperature enters the coal mill to dry the pulverized coal and make the pulverized coal have a corresponding temperature, and in this process, a mixed flow of the primary air and the pulverized coal, i.e., the primary air-pulverized coal flow, is formed. By drying the pulverized coal with the primary air at the first predetermined temperature, the pulverized coal also has a certain temperature, and a mixed flow of the primary air and the pulverized coal is formed, which helps to carry the pulverized coal into the boiler and quickly start combustion.

[0027] In one specific embodiment of the present application, the primary air heating device comprises: a first preheater, which preheats the primary air by using the tail gas of the pulverized coal stable combustion system; and a first heater, which secondarily heats the preheated primary air to heat the primary air to the first predetermined temperature.

[0028] In this specific embodiment, the primary air heating device comprises the first preheater and the first heater, wherein the first preheater preheats the primary air by using the tail gas of the pulverized coal stable combustion system, the heat energy of the tail gas can be recycled, and energy consumption is saved, and the first heater secondarily heats the preheated primary air to heat the primary air to the first predetermined temperature, so that after the primary air at the first predetermined temperature enters the coal mill, the primary air at the first predetermined temperature can dry the pulverized coal and carry and deliver the pulverized coal, and the pulverized coal also has a corresponding temperature, thereby promoting quick start of combustion.

[0029] In one specific embodiment of the present application, the pulverized coal stable combustion system comprises: a secondary air regulating device 105, which comprises a secondary air heating device, the secondary air heating device heats the secondary air to obtain secondary air at a second predetermined temperature, and the secondary air at the second predetermined temperature is blown into the burner.

[0030] In this specific embodiment, the secondary air regulating device comprises a secondary air heating device, the secondary air regulating device heats the secondary air to obtain secondary air at a second predetermined temperature through the secondary air system and by using the secondary air heating device, thereby facilitating subsequent entry of the secondary air into the burner to quickly start combustion of the pulverized coal.

[0031] In one specific embodiment of the present application, the secondary air heating device comprises: a second preheater which preheats the secondary air by using the tail gas of the pulverized coal stable combustion system; and a second heater which heats the preheated secondary air for the second time to obtain the secondary air of the second predetermined temperature.

[0032] In the specific embodiment, the secondary air heating device comprises the second preheater and the second heater, wherein the second preheater preheats the secondary air by using the tail gas of the pulverized coal stable combustion system, the heat energy of the tail gas can be recycled, the energy consumption is saved, the second heater heats the preheated secondary air for the second time to make the secondary air increase in temperature to the second predetermined temperature, so that the secondary air injected into the burner has the corresponding temperature, and the stable and efficient combustion of the pulverized coal is promoted.

[0033] In one specific embodiment of the present application, the first preheater and the second preheater are the same preheater.

[0034] In the specific embodiment, the primary air heating device and the secondary air heating device share the same preheater, the preheater heats the primary air and the secondary air for the first time respectively, so that the temperature of the primary air and the secondary air increases respectively.

[0035] In one specific embodiment of the present application, the pulverized coal stable combustion system comprises: an oxygen-rich control device 106 which comprises an oxygen heating device, the oxygen heating device heats the oxygen to obtain the oxygen flow of the third predetermined temperature, wherein the oxygen flow of the third predetermined temperature is mixed with the primary air pulverized coal flow and then enters the burner.

[0036] In the specific embodiment, the oxygen obtained by separating the air separator is heated to have the third predetermined temperature, forming the oxygen flow of the third predetermined temperature, so that the oxygen flow is fully mixed with the primary air pulverized coal flow, then enters the burner through the air pipe of the primary air, and the combustion in the burner reaches the oxygen-rich state, thereby helping to ignite and accelerating the combustion process, and significantly improving the combustion efficiency.

[0037] In one specific embodiment of the present application, the oxygen heating device comprises: a third heater which heats the oxygen to the third predetermined temperature.

[0038] In the specific embodiment, the oxygen is heated to have a higher temperature, which helps to accelerate the combustion process and improve the combustion efficiency.

[0039] In one specific embodiment of the present application, the first predetermined temperature, the second predetermined temperature and the third predetermined temperature are respectively taken as different temperatures according to the different types of raw coal.

[0040] In the specific embodiment, the first predetermined temperature, the second predetermined temperature and the third predetermined temperature are respectively taken as corresponding different temperatures according to different types of raw coal, different first predetermined temperature, second predetermined temperature and third predetermined temperature are set according to the characteristics of different coal, so as to improve the combustion efficiency.

[0041] In one specific example of the utility model, the heating parameter design of the primary air can refer to the following table 2, wherein, the design primary air temperature is the temperature of the primary air after the first preheater, the low load 10% air temperature is the temperature of the primary air after the first preheater when the boiler operating load is 10% BMCR, and the temperature after heating is the temperature of the primary air after heating by the primary air heating equipment in the primary air control device of the utility model. When the boiler is full load and the boiler operating load is 10% BMCR, the temperature of the primary air after the first preheater is low, and if the primary air temperature cannot support the full and stable combustion of the coal powder in the burner without the second heating by the first heater, the primary air after the first preheater needs to be heated for the second time to increase the temperature of the primary air to the first predetermined temperature, so that the coal powder in the burner can be fully and stably combusted. When the coal type is bituminous coal, the first predetermined temperature is 330 DEG C; when the coal type is lean coal, the first predetermined temperature is 400 DEG C; and when the coal type is anthracite, the first predetermined temperature is 600 DEG C.

[0042] In one specific example of the utility model, the heating parameter design of the secondary air can refer to the following table 3, wherein, the design secondary air temperature is the temperature of the secondary air after the second preheater, the low load 10% air temperature is the temperature of the secondary air after the second preheater when the boiler operating load is 10% BMCR, and the temperature after the heating is the temperature of the secondary air after heating by the secondary air heating equipment in the secondary air control device of the utility model. When the boiler is full load and the boiler operating load reaches 10% BMCR, the temperature of the secondary air after the second preheater is low, and if the secondary air temperature cannot support the full and stable combustion of the coal powder in the burner without the second time heating by the second heater, the secondary air after the second preheater needs to be heated for the second time to increase the temperature of the secondary air to the second predetermined temperature, so that the coal powder in the burner can be fully and stably combusted, When the coal type is bituminous coal, the second predetermined temperature is 350 DEG C; when the coal type is lean coal, the second predetermined temperature is 400 DEG C; and when the coal type is anthracite, The second predetermined temperature is 600 DEG C.

[0043] In one specific example of the utility model, the heating parameter design of the secondary air can be referred to the following table 3, wherein, the design secondary air temperature is the temperature of the second air after the second preheater, the low load 10% air temperature is the temperature when the boiler operating load is 10% BMCR, and the temperature after heating is the secondary air temperature after heating by the secondary air heating equipment in the secondary air control device of the utility model.In one specific example of the present application, the heating parameter design for oxygen can refer to Table 4 as shown below, when the coal type is bituminous coal, the third predetermined temperature is 340℃; when the coal type is lean coal, the third predetermined temperature is 390℃; and when the coal type is anthracite, the third predetermined temperature is 590℃.

[0044] In one specific example of the present application, the pulverized coal stable combustion system further comprises an intelligent temperature control module, which automatically adjusts the first predetermined temperature, the second predetermined temperature and / or the third predetermined temperature according to the different types of raw coal through a pre-established database representing the matching relationship between different types of raw coal and the corresponding first predetermined temperature, the second predetermined temperature and the third predetermined temperature with different values.

[0045] In this specific example, the pre-established database representing the matching relationship between different types of raw coal and the corresponding first predetermined temperature, the second predetermined temperature and the third predetermined temperature with different values in the intelligent temperature control module can automatically adjust the first predetermined temperature, the second predetermined temperature and / or the third predetermined temperature according to the different types of raw coal, thereby reducing manual control, and by increasing the temperature of the corresponding fluid to the first predetermined temperature, the second predetermined temperature and / or the third predetermined temperature, the combustion process is accelerated and the combustion efficiency is improved. For example, bituminous coal: 150℃±10℃, lean coal: 230℃±10℃, anthracite: 300℃±10℃, and the temperature values of the above examples are the temperature of the mixed flow of primary air and pulverized coal (i.e. the temperature after the coal mill).

[0046] In one specific example of the present application, the intelligent temperature control module automatically adjusts the heating power of the first heater, the second heater and / or the third heater according to the different types of raw coal, and then adjusts the first predetermined temperature, the second predetermined temperature and / or the third predetermined temperature accordingly.

[0047] In this specific example, the intelligent temperature control module automatically adjusts the heating power of the first heater, the second heater and / or the third heater according to the different types of raw coal, and then adjusts the first predetermined temperature, the second predetermined temperature and / or the third predetermined temperature accordingly, and by intelligently adjusting the heating power of the first heater, the second heater and / or the third heater, the temperature of the corresponding fluid can be appropriately adjusted according to the different types of raw coal, and increased to the first predetermined temperature, the second predetermined temperature and / or the third predetermined temperature, thereby accelerating the combustion process and improving the combustion efficiency.

[0048] In one specific embodiment of the present application, the oxygen-rich regulating device further comprises: an oxygen air volume regulator arranged at the front end of the oxygen heating device, which adjusts the amount of oxygen to be heated by the oxygen heating device, so as to regulate the concentration of oxygen in the burner.

[0049] In this specific embodiment, the oxygen concentration has various influences on the combustion process, mainly including changes in combustion efficiency, temperature, pollutant emission and energy utilization, etc. The oxygen air volume regulator in the oxygen-rich regulating device controls the amount of oxygen to be heated by the oxygen heating device, so as to control the concentration of oxygen in the burner, so as to realize the staged regulation of the oxygen concentration in the burner according to the coal type, temperature and actual load in the burner, etc., thereby improving the combustion efficiency and reducing the emission of pollutants.

[0050] In one specific embodiment of the present application, the concentration of oxygen in the burner is about 30%.

[0051] In this specific embodiment, the concentration of oxygen in the burner is in an oxygen-rich state, so that the pulverized coal can be fully combusted, the boiler combustion efficiency is improved, and the generation of NO X is reduced.

[0052] Figure 2 is a schematic view of one specific embodiment of the pulverized coal stable combustion system of the present application.

[0053] As shown in Figure 2 , the working process of the pulverized coal stable combustion system of the present application is as follows: first, the primary air system passes through the air preheater and the secondary heating of the primary air reheater, so that the temperature of the primary air is increased to a first predetermined temperature, and the primary air at the first predetermined temperature enters the coal mill, drying the coal powder while making the coal powder have a corresponding temperature, and forming a mixed flow of primary air and coal powder; the secondary air system passes through the air preheater and the secondary heating of the secondary air reheater, so that the secondary air is heated to a second predetermined temperature and then enters the burner; the air is separated by the air separator to obtain oxygen, and then the oxygen is heated by the heater to obtain an oxygen flow at a third predetermined temperature, and then the mixed flow of primary air and coal powder and the oxygen flow at the third predetermined temperature are mixed and injected into the burner together, so that the pulverized coal can be quickly and stably combusted in the burner. The present application can improve the load regulation capability of the pulverized coal stable combustion system through this embodiment, so that the minimum stable combustion load can be reduced to 10% BMCR, and the combustion efficiency is optimized, the carbon content of fly ash is reduced, and the boiler efficiency is improved.

[0054] The present application is particularly suitable for the modification of 300MW and above units with mixed burning of multiple coal types and the need for rapid peak shaving, and through the material flow-energy flow collaborative optimization, the technical bottlenecks such as combustion shock and sudden drop in efficiency under the low load working condition of the traditional coal-fired unit are solved.

[0055] In the pulverized coal stable combustion system, oxygen is obtained by air separation, and the primary air, the secondary air and the oxygen are heated to form corresponding air flows with corresponding temperatures, the mixed flow of the primary air and the pulverized coal is mixed with the oxygen flow obtained after heating before entering the burner, and then is injected into the burner for combustion, the combustion reaction kinetics condition is strengthened, the load regulation capacity of the boiler combustion is improved, the load of the stable combustion is reduced, the carbon content of the fly ash is reduced, and the combustion efficiency is improved.

[0056] In several embodiments provided by the utility model, it should be understood that the disclosed device and method can be realized by other ways. For example, the device embodiment described above is only illustrative, for example, the division of the unit is only a logical function division, and another division mode can be used in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0057] The unit described as a separate component can or can not be physically separated, and the component shown as a unit can or can not be a physical unit, that is, it can be located in one place, or it can be distributed on a plurality of network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment scheme.

[0058] The above is only an embodiment of the utility model, and does not limit the patent range of the utility model, and any equivalent structural transformation or direct or indirect application in other related technical fields according to the content of the utility model specification and drawings is also included in the patent protection range of the utility model.

Claims

1. A pulverized coal combustion stabilization system, characterized in that, include: Burner; An air separator separates air to obtain oxygen; A coal mill grinds raw coal into coal powder of a predetermined fineness; A primary air control device includes a primary air heating device, which heats the primary air to obtain primary air at a first predetermined temperature, wherein the primary air at the first predetermined temperature and the coal powder of the predetermined fineness form a primary air-coal powder flow. A secondary air control device includes a secondary air heating device, which heats the secondary air to obtain secondary air at a second predetermined temperature, and the secondary air at the second predetermined temperature is blown into the burner. An oxygen enrichment control device includes an oxygen heating device that heats the oxygen to obtain an oxygen stream at a third predetermined temperature, wherein the oxygen stream at the third predetermined temperature is mixed with the primary air pulverized coal stream and then enters the burner.

2. The pulverized coal combustion stabilization system according to claim 1, characterized in that, The primary air heating equipment includes: The first preheater uses the exhaust gas from the pulverized coal combustion stabilization system to preheat the primary air; A first heater reheats the preheated primary air to the first predetermined temperature.

3. The pulverized coal combustion stabilization system according to claim 2, characterized in that, The secondary air heating equipment includes: The second preheater uses the exhaust gas from the pulverized coal combustion stabilization system to preheat the secondary air; The second heater heats the preheated secondary air a second time to obtain secondary air at the second predetermined temperature.

4. The pulverized coal combustion stabilization system according to claim 1, characterized in that, The oxygen heating device includes: A third heater heats the oxygen to the third predetermined temperature.

5. The pulverized coal combustion stabilization system according to claim 1, characterized in that, The first predetermined temperature, the second predetermined temperature, and the third predetermined temperature are respectively taken as different temperatures depending on the type of raw coal.

6. The pulverized coal combustion stabilization system according to claim 5, characterized in that, Also includes: The intelligent temperature control module automatically adjusts the first, second, and / or third predetermined temperatures according to the type of raw coal by using a pre-established database that represents the matching relationship between different types of raw coal and the corresponding first, second, and third predetermined temperatures.

7. The pulverized coal combustion stabilization system according to claim 6, characterized in that, The intelligent temperature control module automatically adjusts the heating power of the first heater, the second heater, and / or the third heater according to the type of raw coal, thereby adjusting the first predetermined temperature, the second predetermined temperature, and / or the third predetermined temperature accordingly.

8. The pulverized coal combustion stabilization system according to claim 1, characterized in that, The oxygen enrichment control device also includes: An oxygen flow regulator is located at the front end of the oxygen heating equipment to regulate the amount of oxygen to be heated by the oxygen heating equipment, thereby enabling graded control of the oxygen concentration in the burner.

9. The pulverized coal combustion stabilization system according to claim 1, characterized in that, The predetermined fineness varies depending on the type of raw coal.

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