Front-back opposed firing boiler system for fully burning bituminous coal

Abstract

The utility model provides a front-back opposed firing boiler system capable of fully burning bituminous coal, and relates to the technical field of safe operation of coal-fired unit boiler systems. The utility model discloses a full-burning bituminous coal front-back opposed firing boiler system. The multiple sets of combustors are arranged in a hearth of the boiler in a layered mode, a given distance is formed between every two adjacent layers of combustors, and the combustors are used for igniting coal powder in the hearth to be combusted to generate high-temperature flue gas; the air supply device comprises a primary air assembly and a secondary air assembly, and the primary air assembly and the secondary air assembly selectively communicate with each group of combustors and are used for conveying primary air and secondary air to the combustors; and the pulverizing devices are the same as the combustors in number and are used for pulverizing pulverized coal and forming an air-powder mixture by carrying the pulverized coal through primary air, and the air-powder mixture enters the hearth to be combusted through the corresponding combustors. According to the front-back opposed firing boiler system, the problem that in the prior art, due to the fact that the amount of cold air fed into a burner which does not participate in operation is insufficient, the burner is prone to being damaged by high-temperature flue gas is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of safe operation of a boiler system of a coal-fired unit, and in particular to a front-to-back counter-combustion boiler system which burns all bituminous coal. Background Art

[0002] At present, due to economic benefit pressure and coal market shortage, power generation enterprises are generally forced to use economic coal and implement coal blending. The boilers are operating in a state that deviates from the designed coal quality range and tends to be inferior. After the coal type of many units is changed, the boilers have problems such as decreased efficiency, increased cooling water, increased flue gas temperature, high-temperature corrosion of water-cooled walls, and coking of heating surfaces. At present, boilers and auxiliary machines that burn lean coal are designed and selected based on lean coal, which cannot meet the requirements of full combustion or even large-scale blending of bituminous coal, especially the low-ash melting point Shenhun series coal cannot be burned. In addition, during the operation of the unit, due to the change of coal type, the working mode of the burner will change, resulting in changes in the temperature in the boiler. After the working mode of the burner is changed, the burner that is not involved in the operation is affected by the high temperature roasting in the boiler, and the risk of damage increases. After the coal type is changed, the risk of damage is difficult to control. Therefore, a device is urgently needed to solve at least one of the above problems. Utility Model Content

[0003] The purpose of the embodiment of the utility model is to provide a front and rear counter-combustion boiler system that burns all bituminous coal, which is used to solve the problem in the prior art that the burner that is not involved in the operation is easily damaged by the high-temperature flue gas due to insufficient cold air supply.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a front and rear counter-combustion boiler system for burning all bituminous coal, which is arranged in a coal-fired unit, and the front and rear counter-combustion boiler system for burning all bituminous coal comprises:

[0005] boiler;

[0006] A plurality of groups of burners are arranged in layers in the furnace of the boiler, with a given distance between two adjacent layers of burners, and the burners are used to ignite coal powder in the furnace of the boiler to generate high-temperature flue gas;

[0007] The air supply device comprises: a primary air component and a secondary air component, wherein the primary air component and the secondary air component are selectively connected to each group of burners and are used to supply the primary air and the secondary air to the burners;

[0008] There are the same number of pulverizing devices as the burners, each pulverizing device being selectively connected to the corresponding burner and the primary air assembly, the pulverizing device being used to grind coal powder, and using the primary air to carry the coal powder to form an air-powder mixture which enters the furnace of the boiler through the corresponding burner for combustion.

[0009] Specifically, the front-to-back counter-combustion boiler system burning all bituminous coal also includes: a platen superheater, which is arranged in the boiler and located at the top of the boiler, and is used to use the heat of high-temperature flue gas to preheat the steam sent to the turbine of the coal-fired unit.

[0010] Specifically, the front-to-back counter-combustion boiler system burning all bituminous coal also includes: a high-temperature reheater, which is arranged in the boiler and located at the top of the boiler, and is used to use the heat of the high-temperature flue gas to secondary heat the steam that is preheated and then sent to the turbine of the coal-fired unit.

[0011] Specifically, the front-to-rear counter-fired combustion boiler system that burns all bituminous coal also includes: multiple temperature detectors, which are arranged at the flue gas inlet and flue gas outlet of the high-temperature reheater, and are used to detect the temperature of the high-temperature flue gas flowing through the flue gas inlet and flue gas outlet of the high-temperature reheater.

[0012] Specifically, the temperature detector is a K-type thermocouple.

[0013] Specifically, the front-to-back counter-combustion boiler system burning all bituminous coal further includes: a plurality of carbon monoxide concentration detectors, which are arranged at the coal powder outlet of the pulverizing device and are used to detect the concentration of carbon monoxide in the air-powder mixture.

[0014] Specifically, the front and rear counter-fired boiler system that burns all bituminous coal also includes: a soot blower, which is arranged on the outer furnace wall of the boiler and is used to transport soot blowing steam to the boiler furnace and the surface of the platen superheater to blow away the attachments adhered to the boiler furnace and the surface of the platen superheater.

[0015] Specifically, the front-to-back counter-fired combustion boiler system burning all bituminous coal further includes: an air preheater having a primary inlet, a primary outlet, a secondary inlet and a secondary outlet;

[0016] The primary inlet is connected to the air outlet of the primary air group through a pipe, and the primary outlet is connected to the air inlet of the powder making device and the air inlet of each burner through a pipe; the secondary inlet is connected to the air outlet of the secondary air component through a pipe, and the secondary outlet is connected to the air inlet of each burner through a pipe, and the air preheater is used to heat the primary air and secondary air sent to the burner and the powder making device.

[0017] Specifically, the front and rear counter-fired combustion boiler system that burns all bituminous coal also includes: a cold air component, which is connected to the pipeline between the primary outlet and the air inlet of the pulverizing device, and is used to transport cold air to the pulverizing device to adjust the wind temperature of the primary air sent into the pulverizing device.

[0018] Specifically, the front-to-back counter-combustion boiler system burning all bituminous coal further includes: a flow detector, which is arranged at the high-temperature flue gas outlet of the boiler and is used to detect the flow of the high-temperature flue gas at the high-temperature flue gas outlet.

[0019] The utility model provides a front and rear counter-combustion boiler system for burning all bituminous coal. A plurality of burners are arranged in layers in the furnace of the boiler. The pulverizing device is connected with the air supply device and the corresponding burners. The primary air is delivered to the pulverizing device through the primary air component of the air supply device. The primary air carries the pulverized coal ground by the pulverizing device and enters the furnace of the boiler through the corresponding burner for combustion. The secondary air component delivers secondary air to the furnace of the boiler to assist the pulverized coal to burn in the furnace of the boiler. At the same time, in order to ensure that when the type of coal fed into the furnace of the boiler changes, the burner that is not involved in the operation can avoid high-temperature smoke. In order to prevent the burner from being damaged by the hot flue gas, the primary air component of the air supply device is directly connected to the air inlet of the burner. When the burner is not in operation, the primary air is directly delivered to the burner not in operation through the primary air component, so that the high-temperature flue gas around the burner can be blown away by the primary air delivered to the burner, thereby avoiding damage to the burner not in operation by the hot flue gas in the boiler. This solves the problem in the prior art that the burner not in operation is easily damaged by the hot flue gas due to insufficient amount of cold air supplied, thereby improving the safety of boiler operation and the flexibility of boiler coal combustion.

[0020] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the embodiments of the present utility model and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present utility model, but do not constitute a limitation on the embodiments of the present utility model. In the accompanying drawings:

[0022] Figure 1 It is a schematic diagram of the layout of a front-to-back counter-fired boiler system that burns all bituminous coal provided by an embodiment of the utility model;

[0023] Figure 2 It is a schematic diagram of the arrangement of burners in a boiler in a front-to-back counter-combustion boiler system that burns all bituminous coal provided by an embodiment of the utility model.

[0024] Description of Reference Numerals

[0025] 1- boiler; 2- burner; 3- air supply device; 4- pulverizing device; 5- high temperature reheater; 6- flow detector; 7- carbon monoxide concentration detector; 8- screen superheater; 9- air preheater; 10- cold air assembly; 31- primary air assembly; 32- secondary air assembly. DETAILED DESCRIPTION

[0026] The specific implementation of the embodiment of the utility model is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the utility model, and is not used to limit the embodiment of the utility model.

[0027] Figure 1 This is a schematic diagram of the layout of a front-to-back counter-fired boiler system that burns all bituminous coal. Figure 2 This is a schematic diagram of the arrangement of burners in a boiler in a front-to-back counter-fired boiler system that burns all bituminous coal. Figure 1-Figure 2 As shown, the utility model provides a front and rear counter-fired combustion boiler system for burning all bituminous coal, which is arranged in a coal-fired unit. The front and rear counter-fired combustion boiler system for burning all bituminous coal includes:

[0028] Boiler 1;

[0029] A plurality of groups of burners 2 are arranged in layers in the furnace of the boiler 1, with a given distance between two adjacent layers of burners 2, and the burners 2 are used to ignite coal powder in the furnace of the boiler 1 to generate high-temperature flue gas;

[0030] The air supply device 3 includes: a primary air component 31 and a secondary air component 32, wherein the primary air component 31 and the secondary air component 32 are selectively connected to each group of burners 2, and are used to supply primary air and secondary air to the burners 2;

[0031] There are the same number of pulverizing devices 4 as the burners 2, and each pulverizing device 4 is selectively connected to the corresponding burner 2 and the primary air assembly 31. The pulverizing devices 4 are used to grind coal powder, and use the primary air to carry the coal powder to form an air-powder mixture, which enters the furnace of the boiler 1 through the corresponding burner 2 for combustion.

[0032] The utility model provides a front-to-back counter-combustion boiler system for burning all bituminous coal. In the furnace of the boiler 1, burners 2 are arranged in layers. The primary air component 31 and the secondary air component 32 of the air supply device 3 are selectively connected with each burner 2. At the same time, the pulverizing device 4 is selectively connected with the primary air component 31 and the corresponding burner 2. When the burner 2 is running, the primary air is delivered to the pulverizing device 4 through the primary air component 31. The primary air entering the pulverizing device 4 carries the coal powder ground by the pulverizing device 4 to form an air-powder mixture and enters the corresponding burner 2. The coal powder in the air-powder mixture is ignited by the corresponding burner 2 and burns in the furnace of the boiler 1. The secondary air component 32 of the air supply device 3 simultaneously delivers the primary air to the corresponding burner 2. The burner 2 delivers secondary air to assist the combustion of coal powder. After the type of coal fed into the furnace changes, some burners 2 do not participate in the operation. The primary air component 31 is connected to the burner 2 that does not participate in the operation, and primary air is delivered to the burner 2 that does not participate in the operation through the primary air component 31. The primary air sprayed by the burner 2 that does not participate in the operation dispels the high-temperature flue gas around the burner 2, avoiding the high-temperature flue gas from roasting the burner 2 that does not participate in the operation, thereby improving the cooling effect of the burner 2 that does not participate in the operation, solving the problem in the prior art that the burner that does not participate in the operation is easily damaged by high temperature roasting due to insufficient amount of cold air supplied, thereby improving the safety of boiler operation and the flexibility of boiler combustion coal types.

[0033] In one embodiment, six burners 2 are arranged in the furnace of the boiler 1, and the six burners are arranged in layers in groups of two. Figure 2 As shown, the six burners 2 are marked as A, B, C, D, E, and F, respectively, where D and F are arranged in one layer in the middle of the furnace, A and C are arranged in one layer above D and F, B and E are arranged in one layer below D and F, E is a micro-oil ignition burner, A and C are conventional burners, B, D, and F are bubble atomization small oil guns, the given spacing between the A and C layers and the D and F layers is 6742 mm, and the given spacing between the B and E layers and the D and F layers is 5242 mm. By adjusting the given spacing between the layers, the heat load on the wall of the burner 2 attachment area can be greatly reduced, so that the heat load in the furnace is reduced, the flame temperature level is reduced, and it is beneficial to prevent coking in the furnace. After the burners 2 are arranged in layers according to the given spacing, the heat load in the furnace has dropped to 1.39MW / m under the THA condition. 2 ; Under BMCR conditions, the heat load in the furnace has dropped to 1.43 MW / m 2 The design coal quality corresponds to a screen bottom smoke temperature of 1322°C and a furnace outlet smoke temperature of 1010°C. The verification coal quality corresponds to a screen bottom smoke temperature of 1320°C and a furnace outlet smoke temperature of 1012°C.

[0034] When the lower layers B and E are not in operation, the burner 2 is usually cooled and protected by inhaling the atmosphere through the cooling air system to avoid being roasted by high-temperature flue gas. However, the type of coal changes frequently and the temperature in the furnace changes greatly. The inhaled atmosphere is often unable to better disperse the high-temperature flue gas around the burner 2 that is not in operation. Therefore, in order to better protect the burner 2, a primary air channel is introduced from the primary air component 31 and directly sent to the burner 1. The air volume sent to the burner 2 that is not in operation is increased by the introduced primary air channel, thereby facilitating better dispersal of the high-temperature flue gas around the burner 2, so as to better cool and protect the burner 2 that is not in operation.

[0035] In order to improve the power generation efficiency of the steam turbine in the coal-fired unit, the front and rear counter-fired combustion boiler system that burns all bituminous coal also includes: a screen superheater 8, which is arranged in the boiler 1 and located at the top of the boiler 1, and is used to use the heat of the high-temperature flue gas to preheat the steam sent to the steam turbine of the coal-fired unit.

[0036] The front-to-back counter-fired boiler system for burning all bituminous coal also includes: a high-temperature reheater 5, which is arranged in the boiler 1 and located at the top of the boiler 1, and is used to use the heat of the high-temperature flue gas to secondary heat the steam that is preheated and then fed into the steam turbine of the coal-fired unit. Figure 1 As shown, the heat in the high-temperature flue gas is first absorbed by the screen superheater 8 to preheat the steam sent to the coal-fired unit. The preheated steam is then sent to the steam turbine after secondary heating by the high-temperature reheater 5. The steam turbine expands the higher-temperature steam to do work, driving the generator to generate electricity.

[0037] The front-to-back counter-fired boiler system that burns all bituminous coal also includes: a plurality of temperature detectors, which are arranged at the flue gas inlet and the flue gas outlet of the high-temperature reheater 5, and are used to detect the flue gas temperature flowing through the flue gas inlet and the flue gas outlet of the high-temperature reheater 5. The temperature detector is a K-type thermocouple. The high-temperature flue gas generated by the combustion of pulverized coal enters the high-temperature reheater 5 through the flue gas inlet of the high-temperature reheater 5. The high-temperature reheater 5 absorbs the heat in the high-temperature flue gas to preheat the steam sent to the steam turbine in the coal-fired unit after secondary heating, further increasing the temperature of the steam sent to the steam turbine in the coal-fired unit, and improving the power generation efficiency of the steam turbine. The flue gas temperature distribution and temperature change at the flue gas inlet and the flue gas outlet of the high-temperature reheater 5 can be obtained by using a plurality of K-type thermocouples arranged at the flue gas inlet and the flue gas outlet of the high-temperature reheater 5.

[0038] In one embodiment, the pulverizing device 4 is a coal mill, and each burner 2 is connected to a corresponding coal mill. In order to ensure safe production, the front and rear counter-fired combustion boiler system that burns all bituminous coal also includes: multiple carbon monoxide concentration detectors 7, which are arranged at the coal powder outlet of the pulverizing device 4, and are used to detect the concentration of carbon monoxide in the air-powder mixture.

[0039] A carbon monoxide concentration detector 7 is provided at the coal powder outlet of each coal mill to detect the concentration of carbon monoxide in the air-powder mixture sent into the furnace through the burner 2, so as to avoid the risk of explosion caused by excessive carbon monoxide concentration in the air-powder mixture.

[0040] In order to avoid coking in the furnace of the boiler 1 and on the surface of the platen superheater 8, the front and rear counter-fired boiler system burning all bituminous coal also includes: a soot blower, which is arranged on the outer furnace wall of the boiler 1 and is used to transport soot blowing steam to the furnace of the boiler 1 and the surface of the platen superheater 8 to purge the attachments adhered to the furnace of the boiler 1 and the surface of the platen superheater 8. The number and position of the soot blowers are set according to actual applications, and the soot blowing steam is blown to the furnace and the surface of the platen superheater 8 by the soot blowers. The soot blowing steam can remove the coking on the furnace and the surface of the platen superheater 8, thereby reducing the impact of coking and contamination on the heating surface in the furnace and on the surface of the platen superheater 8, and reducing the exhaust gas temperature.

[0041] In order to ensure the combustion effect of pulverized coal, the front and rear counter-fired combustion boiler system for burning all bituminous coal further includes: an air preheater 9 having a primary inlet, a primary outlet, a secondary inlet and a secondary outlet;

[0042] The primary inlet is connected to the air outlet of the primary air group 31 through a pipe, and the primary outlet is connected to the air inlet of the powder making device 4 and the air inlet of each burner 2 through a pipe; the secondary inlet is connected to the air outlet of the secondary air component 32 through a pipe, and the secondary outlet is connected to the air inlet of each burner 2 through a pipe, and the air preheater 9 is used to heat the primary air and secondary air sent to the burner 2 and the powder making device 4.

[0043] like Figure 1As shown, the primary air sent out by the primary air component 31 enters the air preheater 9 through the primary inlet through the pipeline, the air preheater 9 heats the entering primary air, and the heated primary air is discharged from the primary outlet of the air preheater 9. One path of the heated primary air is sent to the powder making device 4 through the pipeline, and the other path of the heated primary air is sent to the burner 2. The secondary air sent out by the secondary air component 32 enters the air preheater 3 through the secondary inlet through the pipeline, the air preheater 9 heats the secondary air and is discharged from the secondary outlet and sent to the burner 2 through the pipeline. In actual application, the order of heating the primary air and the secondary air by the air preheater 9 can be changed by controlling the forward and reverse rotation of the air preheater 9. Usually, the air preheater 9 rotates forward to heat the primary air first. The secondary air is then heated, and the temperature of the primary air after heating is 356°C. With the change of the type of coal sent into the furnace, the corresponding temperature requirement of the primary air will also change accordingly. For example, when the type of coal burned is changed to full combustion of Shenhua coal, the outlet temperature of the pulverizer is required to be controlled at 65°C-70°C. At this time, it is necessary to cool the primary air by increasing the volume of cold air, but increasing the volume of cold air is not conducive to lowering the exhaust gas temperature. In order to improve the adaptability of the coal type, the air preheater 9 can be controlled to reverse at this time, so that the air preheater 9 heats the secondary air first, so that the secondary air absorbs more heat, thereby lowering the temperature of the primary air heated later, reducing the demand for cold air, and helping to lower the exhaust gas temperature.

[0044] When the type of coal fed into the furnace changes, there will be corresponding requirements for the temperature of the primary air. In order to adapt to the change of coal type, the front and rear counter-fired combustion boiler system for burning all bituminous coal also includes: a cold air component 10, which is connected to the pipeline between the primary outlet and the air inlet of the pulverizing device 4, and is used to deliver cold air to the pulverizing device 4 to adjust the temperature of the primary air fed into the pulverizing device 4. For example, the pulverizing device 4 is a coal mill. When burning bituminous coal, in order to ensure the safety of the coal mill, the outlet temperature of the coal mill needs to be controlled at 65-75°C, which is lower than the current actual operating value (about 120°C). Therefore, a certain amount of cold air needs to be increased. At this time, cold air can be fed into the primary air fed into each coal mill through the cold air component 10, and the temperature of the primary air finally fed into the coal mill is adjusted by the fed cold air; when Shenhua coal is fed into the furnace, because the water content of Shenhua coal is higher than the current coal quality, a greater drying output is required. Therefore, it is necessary to determine the required amount of cold air and calculate whether the diameter of the cold air duct needs to be modified.

[0045] In order to better utilize the flue gas discharged from the boiler 1, the front and rear counter-combustion boiler system that burns all bituminous coal also includes: a flow detector 6, which is arranged at the high-temperature flue gas outlet of the boiler 1 and is used to detect the flow of the high-temperature flue gas at the high-temperature flue gas outlet.

[0046] The utility model provides a front and rear counter-combustion boiler system for burning all bituminous coal. A plurality of burners are arranged in layers in the furnace of the boiler. The pulverizing device is connected with the air supply device and the corresponding burners. The primary air is delivered to the pulverizing device through the primary air component of the air supply device. The primary air carries the pulverized coal ground by the pulverizing device and enters the furnace of the boiler through the corresponding burner for combustion. The secondary air component delivers secondary air to the furnace of the boiler to assist the pulverized coal to burn in the furnace of the boiler. At the same time, in order to ensure that when the type of coal fed into the furnace of the boiler changes, the burner that is not involved in the operation can avoid high-temperature smoke. In order to prevent the burner from being damaged by the hot flue gas, the primary air component of the air supply device is directly connected to the air inlet of the burner. When the burner is not in operation, the primary air is directly delivered to the burner not in operation through the primary air component, so that the high-temperature flue gas around the burner can be blown away by the primary air delivered to the burner, thereby avoiding damage to the burner not in operation by the hot flue gas in the boiler. This solves the problem in the prior art that the burner not in operation is easily damaged by the hot flue gas due to insufficient amount of cold air supplied, thereby improving the safety of boiler operation and the flexibility of boiler coal combustion.

[0047] The optional implementation modes of the embodiments of the utility model are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the utility model are not limited to the specific details in the above implementation modes. Within the technical concept of the embodiments of the utility model, the technical scheme of the embodiments of the utility model can be subjected to various simple modifications, and these simple modifications all belong to the protection scope of the embodiments of the utility model.

[0048] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the utility model will not further describe various possible combinations.

[0049] In addition, various implementations of the embodiments of the present utility model can also be arbitrarily combined, as long as they do not violate the concept of the embodiments of the present utility model, they should also be regarded as the contents disclosed in the embodiments of the present utility model.

Claims

1. A front-to-back counter-fired boiler system burning all bituminous coal, arranged in a coal-fired unit, characterized in that: The front and rear counter-fired boiler system for burning all bituminous coal comprises: Boiler (1); A plurality of groups of burners (2) are arranged in layers in the furnace of the boiler (1), with a given spacing between two adjacent layers of burners (2), and the burners (2) are used to ignite coal powder in the furnace of the boiler (1) to generate high-temperature flue gas; An air supply device (3) comprises: a primary air component (31) and a secondary air component (32), wherein the primary air component (31) and the secondary air component (32) are selectively connected to each group of burners (2) and are used to supply primary air and secondary air to the burners (2); The number of pulverizing devices (4) is the same as that of the burners (2), each pulverizing device (4) being selectively connected to a corresponding burner (2) and a primary air assembly (31), the pulverizing devices (4) being used to grind coal powder, and to use primary air to carry coal powder to form an air-powder mixture which enters the furnace of the boiler (1) through the corresponding burner (2) for combustion.

2. The front-to-back counter-fired boiler system for burning all bituminous coal according to claim 1 is characterized in that: The front-to-back counter-combustion boiler system that burns all bituminous coal also includes: a platen superheater (8) arranged in the boiler (1) and located at the top of the boiler (1), which is used to use the heat of high-temperature flue gas to preheat the steam sent to the turbine of the coal-fired unit.

3. The front-to-back counter-fired boiler system for burning all bituminous coal according to claim 1, characterized in that: The front-to-back counter-combustion boiler system that burns all bituminous coal also includes: a high-temperature reheater (5) arranged in the boiler (1) and located at the top of the boiler (1), which is used to use the heat of the high-temperature flue gas to secondary heat the steam that is preheated and then fed into the turbine of the coal-fired unit.

4. The front-to-back counter-fired boiler system for burning all bituminous coal according to claim 3 is characterized in that In, The front-to-back counter-fired boiler system that burns all bituminous coal also includes: a plurality of temperature detectors, which are arranged at the flue gas inlet and the flue gas outlet of the high-temperature reheater (5) and are used to detect the temperature of the high-temperature flue gas flowing through the flue gas inlet and the flue gas outlet of the high-temperature reheater (5).

5. The front-to-back counter-fired boiler system for burning all bituminous coal according to claim 4, characterized in that: The temperature detector is a K-type thermocouple.

6. The front-to-back counter-fired boiler system for burning all bituminous coal according to claim 3, characterized in that: The front-to-back counter-combustion boiler system for burning all bituminous coal further comprises: a plurality of carbon monoxide concentration detectors (7) arranged at the coal powder outlet of the pulverizing device (4) for detecting the concentration of carbon monoxide in the air-powder mixture.

7. The front-to-back counter-fired boiler system for burning all bituminous coal according to claim 2, characterized in that: The front and rear counter-fired boiler system for burning all bituminous coal further comprises: a soot blower, which is arranged on the outer furnace wall of the boiler (1) and is used to transport soot blowing steam to the furnace of the boiler (1) and the surface of the platen superheater (8) to blow away the attachments adhered to the furnace of the boiler (1) and the surface of the platen superheater (8).

8. The front-to-back counter-fired boiler system for burning all bituminous coal according to claim 1, characterized in that: The front-to-back counter-fired combustion boiler system for burning all bituminous coal further comprises: an air preheater (9) having a primary inlet, a primary outlet, a secondary inlet and a secondary outlet; The primary inlet is connected to the air outlet of the primary air component (31) via a pipeline, and the primary outlet is connected to the air inlet of the pulverizing device (4) and the air inlet of each burner (2) via a pipeline; the secondary inlet is connected to the air outlet of the secondary air component (32) via a pipeline, and the secondary outlet is connected to the air inlet of each burner (2) via a pipeline; the air preheater (9) Used for heating the primary air and secondary air fed into the burner (2) and the powder making device (4).

9. The front-to-back counter-fired boiler system for burning all bituminous coal according to claim 8, characterized in that: The front-to-rear counter-fired combustion boiler system burning all bituminous coal further comprises: a cold air component (10) connected to a pipeline between the primary outlet and the air inlet of the pulverizing device (4), and used for delivering cold air to the pulverizing device (4) to adjust the wind temperature of the primary air delivered to the pulverizing device (4).

10. The front-to-back counter-fired boiler system for burning all bituminous coal according to claim 1, characterized in that: The front-to-back counter-combustion boiler system that burns all bituminous coal further comprises: a flow detector (6) arranged at the high-temperature flue gas outlet of the boiler (1) and used to detect the flow of the high-temperature flue gas at the high-temperature flue gas outlet.

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