阅读说明：本技术 一种生物质燃料低氮燃烧装置及其低氮燃烧方法 (Biomass fuel low-nitrogen combustion device and low-nitrogen combustion method thereof ) 是由 张光义 王文燕 曾玺 王芳 张建岭 崔彦斌 于 2021-07-30 设计创作，主要内容包括：本发明提供了一种生物质燃料低氮燃烧装置及其低氮燃烧方法,所述生物质燃料低氮燃烧装置包括加热炉以及加热炉内部的筒体；所述筒体自上而下包括上段筒体、下段筒体以及辅助管；所述辅助管包括可调节溢流管、可伸缩供气管以及热解床供风管；所述上段筒体的内部设置有气化燃烧床；所述下段筒体的内部设置有热解床。所述低氮燃烧方法包括解耦燃烧和空气分级燃烧。本发明提供的生物质燃料低氮燃烧装置结构简单,能够同时对生物质燃料进行空气分级燃烧以及解耦燃烧,可以实现生物质燃料的低氮燃烧,使得燃烧后烟气具有较低的含氮量,实现了生物质燃料的高效、清洁,以及能源化利用。(The invention provides a biomass fuel low-nitrogen combustion device and a low-nitrogen combustion method thereof, wherein the biomass fuel low-nitrogen combustion device comprises a heating furnace and a cylinder body inside the heating furnace; the cylinder body comprises an upper section of cylinder body, a lower section of cylinder body and an auxiliary pipe from top to bottom; the auxiliary pipe comprises an adjustable overflow pipe, a telescopic air supply pipe and a pyrolysis bed air supply pipe; a gasification combustion bed is arranged in the upper section of the cylinder body; and a pyrolysis bed is arranged in the lower section of the cylinder body. The low-nitrogen combustion method comprises decoupling combustion and air staged combustion. The biomass fuel low-nitrogen combustion device provided by the invention is simple in structure, can be used for carrying out air staged combustion and decoupling combustion on biomass fuel at the same time, can realize low-nitrogen combustion of the biomass fuel, enables the combusted flue gas to have lower nitrogen content, and realizes high efficiency, cleanness and energy utilization of the biomass fuel.)

1. The biomass fuel low-nitrogen combustion device is characterized by comprising a heating furnace and a cylinder body inside the heating furnace;

the heating furnace comprises an upper section heating furnace and a lower section heating furnace from top to bottom;

the cylinder body comprises an upper section of cylinder body, a lower section of cylinder body and an auxiliary pipe from top to bottom;

the upper heating furnace provides heat for the upper cylinder, and the lower heating furnace provides heat for the lower cylinder;

the auxiliary pipe comprises an adjustable overflow pipe, a telescopic air supply pipe and a pyrolysis bed air supply pipe;

the upper section of the cylinder body, the lower section of the cylinder body and the adjustable overflow pipe are symmetrical along an axial line;

a gasification combustion bed is arranged in the upper section of the cylinder body;

a pyrolysis bed is arranged inside the lower section of the cylinder body;

and a secondary air supply pipe is arranged between the gasification combustion bed and the top of the upper section cylinder.

2. The biomass fuel low-nitrogen combustion device according to claim 1, wherein a crown cover with a flue gas discharge pipe arranged at the top center position is arranged at the top of the cylinder;

preferably, the crown cover and the upper section cylinder are connected together through a grinding opening.

3. The biomass fuel low-nitrogen combustion device according to claim 1 or 2, wherein the gasification combustion bed and the barrel are symmetrical along an axis;

preferably, the bottom of the gasification combustion bed is connected with a gasification combustion bed air supply pipe.

4. The biomass fuel low-nitrogen combustion device according to claim 3, wherein the gasification combustion bed air supply pipe comprises an L-shaped pipe;

preferably, one end of the gasification combustion bed air supply pipe is connected to the bottom of the gasification combustion bed, and the other end of the gasification combustion bed air supply pipe penetrates through the upper section heating furnace and the lower section heating furnace and is connected with external air.

5. The biomass fuel low-nitrogen combustion device according to any one of claims 1 to 4, wherein the pyrolysis bed comprises a reducer pipe and a straight pipe;

preferably, the reducer pipe is arranged at the top of the lower section cylinder;

preferably, the straight-through pipe is arranged at the bottom of the reducer pipe;

preferably, a sieve plate is arranged in the through pipe;

preferably, an adjustable overflow pipe is arranged at the central position of the sieve plate.

6. The biomass fuel low-nitrogen combustion device according to any one of claims 1 to 5, wherein the pyrolysis bed air supply pipe and the retractable air supply pipe are arranged at the bottom of the lower section cylinder.

7. A low-nitrogen combustion method of the biomass fuel low-nitrogen combustion device as claimed in any one of claims 1 to 6, wherein the low-nitrogen combustion method comprises air staged combustion and decoupled combustion.

8. The low-nitrogen combustion method according to claim 7, characterized by comprising the steps of:

(1) drying and pyrolyzing the biomass fuel in a pyrolysis bed or a gasification combustion bed in sequence to obtain semicoke and a reductive oil gas product;

(2) after the biomass fuel is combusted in the gasification combustion bed or the pyrolysis bed, semicoke and high-nitrogen flue gas are obtained;

(3) mixing and reacting the reducing oil gas product obtained in the step (1) with the high-nitrogen flue gas obtained in the step (2);

(4) sufficient air is supplied by a secondary air supply pipe, and combustible components in the biomass fuel low-nitrogen combustion device are fully combusted;

the step (1) and the step (2) are not in sequence.

9. The low-nitrogen combustion method according to claim 8, wherein the biomass fuel in the step (1) comprises any one or a combination of at least two of sawdust, fine wood chips, rice hulls, furfural residues, vinasse or traditional Chinese medicine residues;

preferably, the reducing hydrocarbon product of step (1) includes volatiles;

preferably, the temperature of the pyrolysis in the step (1) is 400-1000 ℃;

preferably, the pyrolyzing of step (1) comprises pyrolyzing under anaerobic conditions and/or pyrolyzing under anoxic conditions;

preferably, the oxygen-free conditions comprise an inert gas atmosphere;

preferably, the inert gas atmosphere includes an argon atmosphere and/or a helium atmosphere.

10. The low-nitrogen combustion method as claimed in claim 8 or 9, wherein the temperature of the combustion in the step (2) is 750-.

Technical Field

The invention belongs to the fields of efficient and clean energy utilization technology and thermal conversion analysis of biomass fuel, and particularly relates to a biomass fuel low-nitrogen combustion device and a low-nitrogen combustion method thereof.

Background

With the continuous development of world economy, an energy system mainly based on traditional fossil energy is more and more fragile due to the gradual exhaustion of the energy system, and meanwhile, the accumulated amount of pollutant emission caused by the utilization of the fossil energy is more and more large, so that more and more serious environmental problems are caused. Renewable energy sources such as biomass and the like are considered as inevitable choices for sustainable development of future society, and particularly, a large amount of solid residues such as sawdust, wood chips, rice hulls, furfural residues and waste biomass such as Chinese medicine residues generated in the processing and production process of wood and grains which take agricultural and forestry crops as raw materials are utilized, so that multiple social benefits are brought. The industrial biomass residue produced in China every year is more than 3 hundred million tons, the yield is large, the distribution range is wide, if the industrial biomass residue can be used as a resource to be intensively utilized, the method is a way for relieving the problems of energy shortage and continuous environmental deterioration in China at present, and the significance is great. However, most biomass has the characteristic of high nitrogen content, and high NO is easily generated in the process of thermal conversion such as combustion_xThe smoke with concentration is discharged, and secondary environmental pollution is caused. Therefore, it is necessary to develop a technology for clean and efficient utilization of biomass resources.

At present, the most rapid and effective way for utilizing biomass is combustion, and particularly, harmless and quantitative reduction treatment can be realized on biomass waste. The above method is often used abroad for the treatment of aqueous solid waste including biomass. At the present stage, the biomass combustion technology is not mature, the problems of small scale and large pollutant discharge amount exist in application, and the research on the combustion technology with high efficiency, low pollution, simplicity, applicability and low cost is very important.

The renewable carbon-neutral biomass resource has obvious advantage over the internal diameter benefit of fossil fuel combustion utilization, and the nitrogen control/NO reduction in the combustion process_xThe discharge is critical.

Currently, air staged combustion is most widely applied in the nitrogen-controlled combustion technology. CN 111593156a discloses a low-nitrogen combustion process of a blast furnace hot blast stove, which utilizes the air staged combustion principle to complete low-nitrogen combustion of fuel. The air staged combustion technology divides the combustion process into two stages of combustion: the primary combustion area is mainly incomplete combustion under the anoxic condition; formation of CH under the action of high temperature_iAnd CO, H₂Reducing gases, above the second combustion zone, a proportion of secondary air completely reignites the unburnt fuel and the insufficiently combusted gases, in the process of which not only new NO is suppressed_xGenerating, also enabling NO already generated_xIs reduced. It is generally believed that in air staged combustion, increasing the proportion of secondary air helps to create a stronger reducing atmosphere, and increasing the distance between the primary and secondary air ports helps to increase the residence time of the fuel and gas in the reduction zone, both of which further reduce NO_xAnd (5) discharging. In general, NO in gas boilers after air staged combustion techniques_xThe emission amount shows a significant reduction tendency, thereby realizing a clean combustion control technique.

Currently, an advanced low NO_xThe exhaust heat conversion technology-decoupling combustion technology is emerging and is widely applied to various high-nitrogen-content fuels. CN 101270875A discloses a biomass briquette decoupling combustion device and a combustion method thereof; CN 212805615U discloses a biomass fuel decoupling combustion device.

The decoupling combustion technology is to decompose the fuel combustion process into two parts of pyrolysis and combustion, and adopts a graded thermal conversion mode, so that the problems of unstable direct combustion, low burnout rate and the like of high-water-content fuel are avoided, and the two parts are coupled together through the regulation and control of a certain process. The decoupling combustion technology is originally proposed based on medium and small coal-fired boilers, and aims to release heat from semicoke combustion for drying and pyrolysis processes through heat carrier circulation and utilize volatile components of semicoke and NO generated by semicoke reduction combustion_xThis technique makes full use of the fuel products themselves to reduce NO_xAnd (5) discharging. With the research and application trialIt presents unique advantages in terms of high water content, high volatile biomass.

Therefore, the device capable of simultaneously carrying out decoupling combustion and air staged combustion is provided, and NO after high-nitrogen fuel combustion is reduced_xDischarge and has good application prospect.

Disclosure of Invention

The invention aims to provide a biomass fuel low-nitrogen combustion device which can simultaneously carry out air staged combustion and decoupling combustion on biomass fuel, realize low-nitrogen combustion of the biomass fuel, enable the combusted flue gas to have lower nitrogen content, and realize high efficiency, cleanness and energy utilization of the biomass fuel.

The low-nitrogen combustion of the invention refers to: NO in flue gas after biomass fuel combustion_xThe discharge concentration is lower than 200mg/m³。

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a biomass fuel low-nitrogen combustion device, which comprises a heating furnace and a cylinder inside the heating furnace;

the heating furnace comprises an upper section heating furnace and a lower section heating furnace from top to bottom;

the cylinder body comprises an upper section of cylinder body, a lower section of cylinder body and an auxiliary pipe from top to bottom;

the upper heating furnace provides heat for the upper cylinder, and the lower heating furnace provides heat for the lower cylinder;

the auxiliary pipe comprises an adjustable overflow pipe, a telescopic air supply pipe and a pyrolysis bed air supply pipe;

the upper section of the cylinder body, the lower section of the cylinder body and the adjustable overflow pipe are symmetrical along an axial line;

a gasification combustion bed is arranged in the upper section of the cylinder body;

a pyrolysis bed is arranged inside the lower section of the cylinder body;

and a secondary air supply pipe is arranged between the gasification combustion bed and the top of the upper section cylinder.

The biomass fuel low-nitrogen combustion device provided by the invention is simple in structure, can be used for carrying out air staged combustion and decoupling combustion on biomass fuel at the same time, and can realize low-nitrogen combustion of the biomass fuel, so that the flue gas after combustion has lower nitrogen content.

When low-nitrogen combustion is carried out in the biomass fuel low-nitrogen combustion device provided by the invention, volatile gas generated by pyrolysis reaction interacts with high-nitrogen flue gas generated by combustion reaction, and NO is reduced and inhibited_xAfter the secondary air is introduced into the device, combustible substances in the burnout device are burned to obtain low-nitrogen smoke, so that the high efficiency, cleanness and energy utilization of the biomass fuel are realized.

Preferably, the top of the cylinder is provided with a crown cover with a smoke discharge pipe at the top center.

Preferably, the crown cover and the upper section cylinder are connected together through a grinding opening.

Preferably, the gasification combustion bed is axially symmetric with the barrel.

The gasification combustion bed has a certain fluidization height, so that gas generated by combustion or pyrolysis of the biomass fuel in the gasification fluidized bed cannot directly overflow into the lower section of the cylinder body, and sufficient reactants are provided for gas reaction in the upper section of the cylinder body.

Preferably, the bottom of the gasification combustion bed is connected with a gasification combustion bed air supply pipe.

Preferably, the gasification combustion bed air supply pipe comprises an L-shaped pipe.

Preferably, one end of the gasification combustion bed air supply pipe is connected to the bottom of the gasification combustion bed, and the other end of the gasification combustion bed air supply pipe penetrates through the upper section heating furnace and the lower section heating furnace and is connected with external air.

The area between the secondary air supply pipe, the gasification combustion bed and the outer pipe of the upper section cylinder body is an in-situ nitrogen control area. High-nitrogen flue gas generated by combustion of biomass in a gasification combustion bed interacts with volatile gas generated by pyrolysis of a pyrolysis bed in an in-situ nitrogen control region to reduce and inhibit NO_xAnd (4) generating.

Preferably, the area between the secondary air supply pipe, the gasification combustion bed and the outer pipe of the upper section cylinder is an in-situ nitrogen control area.

Preferably, the pyrolysis bed comprises a reducer pipe and a straight pipe.

Preferably, the reducer pipe is arranged at the top of the lower section cylinder.

Preferably, the straight pipe is arranged at the bottom of the reducer pipe.

Preferably, a sieve plate is arranged in the through pipe.

Preferably, an adjustable overflow pipe is arranged at the central position of the sieve plate.

The area between the pyrolysis bed and the outer pipe of the lower section cylinder body forms a gas preheating cavity, and gas introduced into the device from the auxiliary pipe is uniformly preheated by the gas preheating cavity and is used for pyrolyzing and burning biomass fuel in the pyrolysis bed.

Preferably, the pyrolysis bed air supply pipe and the telescopic air supply pipe are arranged at the bottom of the lower section cylinder.

In a second aspect, the invention provides a low-nitrogen combustion method which is carried out by adopting the biomass fuel low-nitrogen combustion device in the first aspect, wherein the low-nitrogen combustion method comprises air staged combustion and decoupling combustion.

The low-nitrogen combustion method comprises the following steps:

(1) drying and pyrolyzing the biomass fuel in a pyrolysis bed or a gasification combustion bed in sequence to obtain semicoke and a reductive oil gas product;

(2) after the biomass fuel is combusted in the gasification combustion bed or the pyrolysis bed, semicoke and high-nitrogen flue gas are obtained;

(3) mixing and reacting the reducing oil gas product obtained in the step (1) with the high-nitrogen flue gas obtained in the step (2);

(4) sufficient air is supplied by a secondary air supply pipe, and combustible components in the biomass fuel low-nitrogen combustion device are fully combusted;

the step (1) and the step (2) are not in sequence.

NO in high-nitrogen flue gas of high-nitrogen flue gas_xThe discharge concentration of the catalyst is 350-600mg/m³。

The invention provides low-nitrogen fuelThe combustion method can not only carry out decoupling combustion on the biomass fuel, but also carry out air staged combustion. The biomass fuel pyrolysis bed generates pyrolysis reaction, and the generated volatile gas product spontaneously diffuses upwards in the device or flows upwards under the carrying of fluidized gas, interacts with a high-nitrogen smoke product generated by the gasification combustion of biomass fuel in the gasification combustion bed in an in-situ nitrogen control region, reduces and inhibits NO_xAnd after secondary air is introduced into the secondary air supply pipe, the fuel realizes air staged combustion, and finally the low-nitrogen flue gas is discharged by the flue gas discharge pipe.

Preferably, the biomass fuel in step (1) comprises any one or a combination of at least two of sawdust, fine wood chips, rice hulls, furfural residues, vinasse or Chinese medicine residues, and typical but non-limiting combinations comprise a combination of sawdust and fine wood chips, a combination of rice hulls and furfural residues, a combination of vinasse and Chinese medicine residues, a combination of sawdust, fine wood chips and rice hulls, a combination of sawdust, furfural residues and vinasse, or a combination of sawdust, fine wood chips, vinasse and Chinese medicine residues.

Preferably, the pyrolysis temperature in step (1) is 400-.

Preferably, the reducing hydrocarbon product of step (1) includes volatiles.

Preferably, the pyrolyzing of step (1) comprises pyrolyzing under anaerobic conditions and/or pyrolyzing under anoxic conditions.

Preferably, the oxygen-free conditions include an inert gas atmosphere.

Preferably, the inert gas atmosphere includes an argon atmosphere and/or a helium atmosphere.

The oxygen-deficient condition of the invention is that the oxygen content in the air is lower than 12%.

Preferably, the temperature of the combustion in step (2) is 750-1000 ℃, such as 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃ or 1000 ℃, but not limited to the recited values, and other unrecited values within the range of values are equally applicable.

When the biomass fuel low-nitrogen combustion device provided by the invention is used for low-nitrogen combustion, the gas in the device is not limited to the gas flow direction from bottom to top, by adopting the device provided by the invention, the biomass fuel can also be conveyed to the gasification combustion bed from the flue gas discharge pipe, high-temperature flue gas generated after the biomass fuel is combusted in the gasification combustion bed flows to the pyrolysis bed in the lower section cylinder under the pressure effect to react with semicoke obtained by pyrolysis in the pyrolysis bed, and the low-nitrogen flue gas in the device is discharged out of the device through the pyrolysis bed air supply pipe.

Compared with the prior art, the invention has the following beneficial effects:

the biomass fuel low-nitrogen combustion device provided by the invention is simple in structure, can be used for carrying out air staged combustion and decoupling combustion on biomass fuel at the same time, can realize low-nitrogen combustion of the biomass fuel, enables the combusted flue gas to have lower nitrogen content, and realizes high efficiency, cleanness and energy utilization of the biomass fuel.

Drawings

Fig. 1 is a schematic structural diagram of a biomass fuel low-nitrogen combustion device provided in embodiment 1 of the present invention.

Wherein: 1 is the upper segment barrel, 2 is the gasification burning bed, 3 is the hypomere barrel, 4 is the pyrolysis bed, 5 is the sieve, 6 is the pyrolysis bed air feed pipe, 7 is scalable air supply pipe, 8 is adjustable overflow pipe, 9 is the hypomere heating furnace, 10 is the gasification burning bed air feed pipe, 11 is the upper segment heating furnace, 12 is the secondary air feed pipe, 13 is the crown cover, 14 is the flue gas delivery pipe.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The embodiment provides a biomass fuel low-nitrogen combustion device as shown in fig. 1, which comprises a heating furnace and a cylinder inside the heating furnace; the heating furnace comprises an upper section heating furnace 11 and a lower section heating furnace 9 from top to bottom; the cylinder body comprises an upper section cylinder body 1, a lower section cylinder body 3 and an auxiliary pipe from top to bottom; the upper heating furnace 11 provides heat for the upper cylinder 1, and the lower heating furnace 9 provides heat for the lower cylinder 3.

The auxiliary pipe comprises an adjustable overflow pipe 8, a telescopic air supply pipe 7 and a pyrolysis bed air supply pipe 6; the upper section cylinder 1, the lower section cylinder 3 and the adjustable overflow pipe 8 are symmetrical along the axis.

A gasification combustion bed 2 is arranged in the upper section cylinder 1; a pyrolysis bed 4 is arranged in the lower section of the cylinder 3; a secondary air supply pipe 12 is arranged between the gasification combustion bed 2 and the top of the upper section cylinder 1.

The top of the cylinder body is provided with a crown-shaped cover 13 provided with a flue gas discharge pipe 14 at the center of the top; the crown cover 13 is connected with the upper section cylinder body 1 through a ground.

The gasification combustion bed 2 has a certain fluidization height; the bottom of the gasification combustion bed 2 is connected with a gasification combustion bed air supply pipe 10; the air supply pipe 10 of the gasification combustion bed is an L-shaped pipeline; one end of the gasification combustion bed air supply pipe 10 is connected to the bottom of the gasification combustion bed 2, and the other end penetrates through the upper section heating furnace 11 and the lower section heating furnace 9 and is connected with external air.

And the area between the secondary air supply pipe 12, the gasification combustion bed 2 and the outer pipe of the upper section cylinder 1 is an in-situ nitrogen control area.

The pyrolysis bed 4 comprises a reducer pipe and a straight pipe; the reducer pipe is arranged at the top of the lower section cylinder 3; the straight-through pipe is arranged at the bottom of the reducer pipe; a sieve plate 5 is arranged in the straight-through pipe; an adjustable overflow pipe 8 is arranged at the central position of the sieve plate 5; the area between the pyrolysis bed 4 and the outer pipe of the lower section cylinder 3 is a gas preheating cavity.

The pyrolysis bed air supply pipe 6 and the telescopic air supply pipe 7 are arranged at the bottom of the lower section cylinder.

Example 2

This example provides a biomass fuel low-nitrogen combustion apparatus which is the same as that of example 1 except that the fluidization height of the gasification combustion bed 2 is omitted.

Comparative example 1

This comparative example provides a biomass fuel combustion apparatus which is the same as that of example 1 except that the secondary air supply duct 12 is omitted.

Comparative example 2

This comparative example provides a biomass fuel combustion apparatus which is the same as that of example 1 except that the adjustable overflow pipe 8 is omitted.

Application example 1

The biomass fuel low-nitrogen combustion device provided in example 1 is used for low-nitrogen combustion of biomass fuel, the biomass fuel is a combination of sawdust, fine wood chips and rice hulls, and the mass ratio of the sawdust to the fine wood chips to the rice hulls is 2:3: 1.

The low-nitrogen combustion method comprises the following steps:

(1) the lower heating furnace 9 is heated to 700 ℃, and the biomass fuel is dried and pyrolyzed in the pyrolysis bed 4 in sequence to obtain semicoke and volatile components;

(2) the upper-section heating furnace 11 is heated to 800 ℃, biomass fuel is pyrolyzed in the gasification combustion bed 2 to obtain semicoke, the pyrolysis atmosphere is helium atmosphere, and the helium is provided by an air supply pipe 10 of the gasification combustion bed; burning the obtained semicoke in an air atmosphere to obtain high-nitrogen flue gas, wherein the burning atmosphere is an air atmosphere, and the air is provided by an air supply pipe 10 of a gasification combustion bed;

(3) pushing the volatile components generated in the step (1) to an in-situ nitrogen control area by a pyrolysis bed air supply pipe 6 to react with the high-nitrogen flue gas obtained in the step (2);

(4) sufficient air is supplied through the secondary air supply duct 12 to burn out the combustible components and obtain low nitrogen flue gas which is discharged from the device through the flue gas discharge duct 14.

Application example 2

The biomass fuel low-nitrogen combustion device provided in example 1 is used for low-nitrogen combustion of biomass fuel, the biomass fuel is a combination of sawdust, fine wood chips and rice hulls, and the mass ratio of the sawdust to the fine wood chips to the rice hulls is 2:3: 1.

The low-nitrogen combustion method comprises the following steps:

(1) the lower heating furnace 9 is heated to 900 ℃, and the biomass fuel is dried and pyrolyzed in the pyrolysis bed 4 in sequence to obtain semicoke and volatile components;

(2) the upper-section heating furnace 11 is heated to 950 ℃, biomass fuel is combusted in the gasification combustion bed 2 to obtain high-nitrogen flue gas, the combustion atmosphere is air atmosphere, and the air is provided by an air supply pipe 10 of the gasification combustion bed;

(3) under the pushing of the air pressure generated by the expansion of the high-nitrogen flue gas obtained in the step (2), the high-nitrogen flue gas reacts with the semicoke generated in the step (1) to reduce the high-nitrogen flue gas;

(4) and (3) introducing sufficient air into the pyrolysis bed 4 by adopting an adjustable overflow pipe 8, decoupling the semicoke obtained in the combustion step (1), and discharging the flue gas in the device through a flue gas discharge pipe 14.

Application example 3

The biomass fuel low-nitrogen combustion device provided in example 1 is used for low-nitrogen combustion of biomass fuel, the biomass fuel is a combination of sawdust, fine wood chips and rice hulls, and the mass ratio of the sawdust to the fine wood chips to the rice hulls is 2:3: 1.

The low-nitrogen combustion method comprises the following steps:

(1) the lower heating furnace 9 is heated to 900 ℃, and the biomass fuel is dried and pyrolyzed in the pyrolysis bed 4 in sequence to obtain semicoke and volatile components;

(2) providing sufficient air through a telescopic air supply pipe 7, and burning the volatile component obtained in the step (1);

(3) supplying biomass fuel to the gasification combustion bed 2 through a flue gas discharge pipe 14, heating the upper-section heating furnace 11 to 950 ℃, and combusting the biomass fuel in the gasification combustion bed 2 to obtain high-nitrogen flue gas, wherein the combustion atmosphere is an air atmosphere, and the air is supplied by an air supply pipe 10 of the gasification combustion bed and a secondary air supply pipe 12;

(4) and (3) under the pushing of the air pressure generated by the expansion of the high-nitrogen flue gas obtained in the step (2), the high-nitrogen flue gas reacts with the semicoke generated in the step (1), the high-nitrogen flue gas is reduced, and the high-nitrogen flue gas is discharged out of the device through an air supply pipe 6 of the pyrolysis bed.

Application example 4

The biomass fuel low-nitrogen combustion device provided in example 2 is used for low-nitrogen combustion of biomass fuel, the biomass fuel is a combination of sawdust, fine wood chips and rice hulls, and the mass ratio of the sawdust to the fine wood chips to the rice hulls is 2:3: 1.

The low-nitrogen combustion method was the same as in application example 1.

Application example 5

The biomass fuel low-nitrogen combustion device provided in example 2 is used for low-nitrogen combustion of biomass fuel, the biomass fuel is a combination of sawdust, fine wood chips and rice hulls, and the mass ratio of the sawdust to the fine wood chips to the rice hulls is 2:3: 1.

The low-nitrogen combustion method was the same as in application example 2.

Application example 6

The biomass fuel low-nitrogen combustion device provided in example 2 is used for low-nitrogen combustion of biomass fuel, the biomass fuel is a combination of sawdust, fine wood chips and rice hulls, and the mass ratio of the sawdust to the fine wood chips to the rice hulls is 2:3: 1.

The low-nitrogen combustion method was the same as in application example 3.

Comparative application example 1

This comparative application example employed a biomass fuel combustion apparatus as provided in comparative example 1 for combustion of biomass fuel, which was a combination of sawdust, fine wood chips, and rice hulls.

The method of combustion comprises the steps of:

(1) the lower heating furnace 9 is heated to 700 ℃, and the biomass fuel is dried and pyrolyzed in the pyrolysis bed 4 in sequence to obtain semicoke and volatile components;

(2) the upper-section heating furnace 11 is heated to 800 ℃, biomass fuel is combusted in the gasification combustion bed 2 to obtain semicoke, the combustion atmosphere is helium atmosphere, and the helium is provided by an air supply pipe 10 of the gasification combustion bed; then, after burning in an air atmosphere, obtaining high-nitrogen flue gas, wherein the burning atmosphere is the air atmosphere, and the air is provided by an air supply pipe 10 of a gasification burning bed;

(3) pushing the volatile components generated in the step (1) to an in-situ nitrogen control area by a pyrolysis bed air supply pipe 6 to react with the high-nitrogen flue gas obtained in the step (2);

(4) air is supplied through the gasification combustion bed air supply pipe 10, so that the combustible components are burnt out, low-nitrogen smoke is obtained, and the low-nitrogen smoke is discharged out of the device through the smoke discharge pipe 14.

This contrast application example can know with the contrast of application example 1, and this contrast application example adopts gasification combustion bed air feed pipe 10 to provide the air for the device is inside, and its purpose is the combustible substance in the ashes device, but the one end of gasification combustion bed air feed pipe 10 sets up in the bottom of gasification bed, and the air that is provided by gasification combustion bed air feed pipe 10 can not in time contact with the combustible substance in the device for partial combustible substance can not contact sufficient air, produces gaseous pollutants.

Comparative application example 2

This comparative application example employed a biomass fuel combustion apparatus as provided in comparative example 2 for combustion of biomass fuel, which was a combination of sawdust, fine wood chips, and rice hulls.

The method of combustion comprises the steps of:

(1) the lower heating furnace 9 is heated to 900 ℃, and the biomass fuel is dried and pyrolyzed in the pyrolysis bed 4 in sequence to obtain semicoke and volatile components;

(2) the upper-section heating furnace 11 is heated to 950 ℃, biomass fuel is combusted in the gasification combustion bed 2 to obtain high-nitrogen flue gas, the combustion atmosphere is air atmosphere, and the air is provided by an air supply pipe 10 of the gasification combustion bed;

(3) under the pushing of the air pressure generated by the expansion of the high-nitrogen flue gas obtained in the step (2), the high-nitrogen flue gas reacts with the semicoke generated in the step (1) to reduce the high-nitrogen flue gas;

(4) and (3) introducing sufficient air into the pyrolysis bed 4 by adopting a telescopic air supply pipe 7, decoupling the semicoke obtained in the burning step (1), and discharging the flue gas in the device through a flue gas discharge pipe 14.

As can be seen from the comparison between the comparative application example and the application example 2, the air supply pipe 7 is adopted to supply air to the pyrolysis bed 4, and the purpose of the air supply pipe is to burn the semicoke generated in the step (1), but the air supply pipe 7 cannot directly contact with the semicoke inside the pyrolysis bed 4, so that the semicoke cannot contact with sufficient air and generate polluted gas.

In summary, the biomass fuel low-nitrogen combustion device provided by the invention can simultaneously perform air staged combustion and decoupling combustion on biomass fuel, can realize low-nitrogen combustion of biomass fuel, enables the combusted flue gas to have lower nitrogen content, and realizes high efficiency, cleanness and energy utilization of biomass fuel.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.