A dry-carbon biomass gasification system and its working method

Abstract

A dry-carbon biomass gasification system and its working method disclosed by the present invention belong to the technical field of biomass energy gasification utilization. An inner furnace body is arranged inside an outer furnace body, the upper part of the inner furnace body is connected to the top of the outer furnace body, and the bottom is separated; a feeding screw is arranged inside the inner furnace body, and the bottom extends out of the inner furnace body and is connected to the bottom of the outer furnace body; a material equalizer is arranged at the top inside the outer furnace body, and a feed inlet and a biomass gas outlet are also opened at the top of the outer furnace body, and a feeding system is connected to the feed inlet; a carbon cooling device is provided with a carbon inlet, a carbon outlet, a gasifying agent inlet and a gasifying agent outlet, the discharge outlet of the inner furnace body is connected to the carbon inlet through a carbon conveying pipeline, a biomass carbon bin is connected to the carbon outlet, and the gasifying agent outlet is connected to the air inlet of the inner furnace body through a gas conveying pipeline. The present invention realizes the recovery of the heat of biomass carbon while reducing water resource waste, and the produced biomass carbon contains almost no moisture, which is beneficial to subsequent transportation and utilization.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomass energy gasification utilization, and particularly relates to a dry-carbon discharging biomass gasification system and its working method. Background Art

[0002] Biomass gasification is a process in which agricultural and forestry biomass wastes such as straws, rice husks, and fruit woods are used as raw materials, and gasification operations such as drying, pyrolysis, reduction, and oxidation are carried out on them at high temperatures to produce high-quality combustible gas energy. The produced biomass gas is a green energy source, which plays a promoting role in reducing the greenhouse effect and achieving "carbon neutrality" and "carbon peak".

[0003] A large amount of biomass carbon is generated after biomass gasification. Its reasonable utilization is of great significance for the economy and sustainability of biomass gasification. At present, most biomass gasifiers adopt a wet slag discharging device with a water seal, which can effectively seal the gasifier to prevent the generated biomass gas from leaking from the bottom of the furnace, and can also cool the high-temperature biomass carbon. However, when the high-temperature biomass carbon contacts water, a large amount of water vapor will be generated, which will cause certain damage to the water seal device. At the same time, although the wet carbon discharging effectively cools the biomass carbon, the heat is wasted, and the discharged biomass carbon has a very high humidity, which is not conducive to subsequent utilization and transportation. Summary of the Invention

[0004] In order to solve the above existing problems, the purpose of the present invention is to provide a dry-carbon discharging biomass gasification system and its working method, which can recover the heat of biomass carbon while reducing water resource waste, and the produced biomass carbon contains almost no moisture, which is conducive to subsequent transportation and utilization.

[0005] The present invention is achieved through the following technical solutions:

[0006] A dry-carbon discharging biomass gasification system disclosed by the present invention includes a feeding system, an outer furnace body, an inner furnace body, a feeding screw, a material leveling device, a carbon cooling device, and a biomass carbon bin;

[0007] The inner furnace body is arranged inside the outer furnace body. The upper part of the inner furnace body is connected to the top of the outer furnace body, and the bottom is separated. The feeding screw is arranged inside the inner furnace body, and the bottom extends out of the inner furnace body and is connected to the bottom of the outer furnace body. The material leveling device is arranged at the top inside the outer furnace body. An inlet for feed and a biomass gas outlet are also opened at the top of the outer furnace body. The feeding system is connected to the inlet for feed. The carbon cooling device is provided with a carbon inlet, a carbon outlet, an inlet for gasifying agent, and an outlet for gasifying agent. The discharge port of the inner furnace body is connected to the carbon inlet through a carbon conveying pipeline, the biomass carbon bin is connected to the carbon outlet, and the outlet for gasifying agent is connected to the air inlet of the inner furnace body through a gas conveying pipeline.

[0008] Preferably, the feeding system includes a biomass stockpile, a bucket elevator, a biomass silo, and a feeding pipeline connected in sequence. The feeding pipeline is connected to the feed inlet of the outer furnace body through an automatic bin gate; the cross-sectional area of the feeding pipeline gradually decreases.

[0009] Preferably, the carbon cooling device includes a top cover, a cooling chamber, and an air chamber connected in sequence from top to bottom. A chain conveyor is arranged between the cooling chamber and the air chamber. The carbon inlet is arranged above the starting end of the chain conveyor, the carbon outlet is arranged at the end of the chain conveyor, the gasifying agent outlet is arranged above the top cover, and the gasifying agent inlet is arranged on one side of the air chamber.

[0010] More preferably, the cross-sectional area of the top cover gradually decreases from bottom to top, the cross-sectional area of the air chamber gradually decreases, and the gasifying agent inlet is arranged on the side with the largest cross-sectional area.

[0011] Preferably, the front section of the carbon conveying pipeline has a downward-sloping structure, and the cross-section of the carbon conveying pipeline gradually decreases from the discharge port of the inner furnace body to the carbon inlet.

[0012] Preferably, the outer furnace body is connected with a large cylinder section, a conical transition section, and a small cylinder section in sequence from top to bottom. The small cylinder section is provided with a maintenance opening. A heat preservation layer is arranged outside the outer furnace body.

[0013] Preferably, the feeding screw is a full-face type, and the spiral radius R of the feeding screw is:

[0014]

[0015] In the formula, I v is the volumetric conveying capacity, m 3 / h; k2 is the conveying capacity coefficient; g is the acceleration of gravity, taking 9.81 m / s 2 ;

[0016] Among them, I V = k3·Q; in the formula, k3 is the biomass carbon conversion rate of the gasifier; Q is the feeding amount of the gasifier, m 3 / h.

[0017] Preferably, there is a gap between the outer edge of the blade of the feeding screw and the inner wall of the inner furnace body. The feeding screw is a variable pitch structure, and the pitch of the lower section of the feeding screw < the pitch of the middle section < the pitch of the upper section.

[0018] Preferably, a wind chamber is arranged at the bottom of the outer furnace body, and a wind distribution plate is arranged above the wind chamber; the feeding screw is a hollow structure, and a gasifying agent channel is arranged inside the hollow structure. The inlet of the gasifying agent channel is connected to the air inlet of the inner furnace body, and the outlet of the gasifying agent channel is communicated with the wind chamber.

[0019] The working method of the dry-discharged carbon biomass gasification system disclosed by the present invention includes

[0020] The biomass raw materials are conveyed to the outer furnace body by the feeding system, and the biomass raw materials are evenly spread in the outer furnace body through the material distributor. Under the action of gravity, the biomass raw materials gradually move downward to the bottom of the outer furnace body and are converted into biomass charcoal, which accumulates at the bottom of the outer furnace body. The feeding screw conveys the biomass charcoal from the bottom of the outer furnace body to the discharge port through the inner furnace body and enters the charcoal cooling device through the charcoal conveying pipeline. When the biomass charcoal is lifted in the inner furnace body, it provides heat for the pyrolysis and drying of the biomass raw materials in the outer furnace body through the furnace wall of the inner furnace body. The gasifying agent enters the charcoal cooling device from the gasifying agent inlet, cools the biomass charcoal and then heats up, enters the inner furnace body through the gas conveying pipeline, reacts with the biomass charcoal to release heat, and then moves upward from the lower part of the outer furnace body to transfer the heat to the biomass raw materials in the outer furnace body. The generated biomass gas is discharged from the biomass gas outlet.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] A dry discharge charcoal biomass gasification system disclosed by the present invention realizes the lifting of biomass charcoal through the feeding screw mechanism of the inner furnace body, discharges charcoal from the upper part of the gasification furnace, and designs a charcoal cooling device and a biomass charcoal bin for the upper part charcoal discharge. While realizing step-by-step sealing, the heat recovery of biomass charcoal is achieved. A material distributor is arranged on the upper part of the outer furnace, which can make the biomass raw materials fed from one side evenly distributed and at the same height in the gasification furnace, which is beneficial to the uniformity of reactions at different positions of the gasification furnace and the stability of the continuous operation of the gasification furnace. The oxidation section of biomass gasification is mainly realized in the inner furnace body. A large amount of heat generated by combustion is conducted to the outer furnace body through two parts: flue gas carrying and heat transfer through the partition wall, providing heat for the reduction reaction, pyrolysis reaction and drying, improving the heat transfer performance of the gasification furnace and increasing the processing capacity of biomass. Moreover, the setting of the inner furnace body makes the overall structure of the gasification furnace more compact and more convenient to arrange, suitable for building a miniaturized distributed biomass gasification furnace and promoting the distributed utilization of biomass energy.

[0023] Furthermore, the automatic warehouse door can ensure the airtightness of the gasification furnace; the cross-sectional area of the feeding pipeline gradually shrinks, which can enable the biomass raw materials to achieve material sealing under the action of gravity, so that the biomass gas will not escape from the silo during the feeding process.

[0024] Furthermore, the charcoal cooling device can realize the waste heat recovery of high-temperature biomass charcoal through the chain conveyor belt and the bottom gas chamber, preheat the gasifying agent, and improve the gasification efficiency in the gasification furnace.

[0025] Even further, the cross-sectional area of the top cover gradually shrinks from bottom to top to increase the flow rate of the gasifying agent; the cross-sectional area of the gas chamber gradually shrinks, which can make the flow rate and pressure change of the upward blowing air flow not large, so that the flow field in the cooling chamber is uniform and stable, and the heat of the biomass charcoal can be evenly recovered.

[0026] Furthermore, the front section of the carbon conveying pipeline is of a downward-inclined structure, which is conducive to the movement of biomass carbon from the inner furnace body to the carbon cooling device; the cross-section of the carbon conveying pipeline gradually shrinks from the discharge port of the inner furnace body to the carbon inlet port. Under the action of the extrusion force provided by the feeding screw and gravity, simple material sealing can be achieved, improving the airtightness of the gasifier.

[0027] Furthermore, the outer furnace body is successively connected with a large cylinder section, a conical transition section, and a small cylinder section from top to bottom, which can enable the preliminary pyrolysis products to accumulate at the bottom of the gasifier. Under the action of gravity and the feeding screw, it is beneficial for the feeding screw to lift the material to the inner furnace. A heat insulation layer is provided around the outer furnace body to prevent heat loss.

[0028] Furthermore, there is a gap between the outer edge of the blade of the feeding screw and the inner wall of the inner furnace body, which enables the gasifying agent to pass through. At the same time, the gasifying agent can carry the heat generated by the biomass carbon and the oxidation zone to the outer furnace body. Through direct solid-phase heat transfer and indirect gas heat transfer, the thermal efficiency of the biomass gasifier is improved, which is beneficial for the gasifier to work efficiently, improving the continuous working ability and maximum output of the biomass gasifier. The variable pitch design can effectively improve the ability of the inner furnace body to convey biomass carbon and prevent the biomass carbon from flowing back or being blocked during transportation.

[0029] Furthermore, an air chamber is provided at the bottom of the outer furnace body, and a air distribution plate is provided above the air chamber. The feeding screw is hollow and communicates with the air chamber. At this time, the gasifying agent recovers the heat of the biomass carbon through the shaft body of the feeding screw. The reaction zone of the gasifier is mainly distributed inside the outer furnace body. The main function of the inner furnace body is to lift the generated biomass carbon to the top outlet of the inner furnace body and preheat the gasifying agent to improve the gasification efficiency. At the same time, when the high-temperature biomass carbon is sent into the carbon cooling device through the inner furnace, it can still transfer heat to the outer furnace through the furnace wall of the inner furnace, strengthening heat transfer and improving the thermal efficiency of the gasifier. In addition, under the condition of bearing the same torque, the hollow shaft body saves more materials.

[0030] The working method of the dry-carbon-discharging biomass gasification system disclosed by the present invention has a high degree of automation, realizes the recovery of the heat of biomass carbon while reducing water resource waste, and the produced biomass carbon contains almost no moisture, which is beneficial for subsequent transportation and utilization. Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the overall structure of the system in Embodiment 1;

[0032] Figure 2 It is a schematic diagram of the structures of the outer furnace body, inner furnace body, and feeding screw in Embodiment 2;

[0033] Figure 3 For Figure 2 The enlarged view of the partial structure of A;

[0034] Figure 4 Schematic diagram of different reaction zones in the gasifier in Embodiment 1;

[0035] Figure 5 Schematic diagram of different reaction zones in the gasifier in Embodiment 2.

[0036] In the figure: 1 is the biomass material pile, 2 is the bucket elevator, 3 is the biomass material bin, 4 is the feeding pipeline, 5 is the outer furnace body, 6 is the inspection port, 7 is the heat insulation layer, 8 is the inner furnace body, 9 is the feeding screw, 10 is the material distributor, 11 is the biomass gas outlet, 12 is the carbon conveying pipeline, 13 is the gas conveying pipeline, 14 is the top cover, 15 is the cooling chamber, 16 is the chain conveyor, 17 is the gasifying agent inlet, 18 is the gas chamber, 19 is the biomass carbon bin, 20 is the bin door, 21 is the air chamber, and 22 is the air distribution plate. Specific implementation manner

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The content is an explanation of the present invention rather than a limitation:

[0038] Embodiment 1

[0039] As Figure 1 , a dry carbon-discharging biomass gasification system of the present invention includes a feeding system, an outer furnace body 5, an inner furnace body 8, a feeding screw 9, a material distributor 10, a carbon cooling device, and a biomass carbon bin 19;

[0040] The inner furnace body 8 is arranged inside the outer furnace body 5. The upper part of the inner furnace body 8 is connected to the top of the outer furnace body 5 and the bottom is separated. The feeding screw 9 is arranged inside the inner furnace body 8 and the bottom extends out of the inner furnace body 8 and is connected to the bottom of the outer furnace body 5. The material distributor 10 is arranged at the top inside the outer furnace body 5. An inlet and a biomass gas outlet 11 are also opened at the top of the outer furnace body 5. The feeding system is connected to the inlet. The carbon cooling device is provided with a carbon inlet, a carbon outlet, a gasifying agent inlet 17, and a gasifying agent outlet. The discharge port of the inner furnace body 8 is connected to the carbon inlet through a carbon conveying pipeline 12, the biomass carbon bin 19 is connected to the carbon outlet, and the gasifying agent outlet is connected to the air inlet of the inner furnace body 8 through a gas conveying pipeline 13.

[0041] As a further optimized solution of this embodiment, the feeding system includes a biomass material pile 1, a bucket elevator 2, a biomass material bin 3, and a feeding pipeline 4 connected in sequence. The feeding pipeline 4 is connected to the inlet of the outer furnace body 5 through an automatic bin door; the cross-sectional area of the feeding pipeline 4 gradually decreases.

[0042] As a further optimized solution of this embodiment, the carbon cooling device includes a top cover 14, a cooling chamber 15, and a gas chamber 18 that are connected in sequence from top to bottom. A chain conveyor 16 is arranged between the cooling chamber 15 and the gas chamber 18. The carbon inlet is arranged above the starting end of the chain conveyor 16, and the carbon outlet is arranged at the end of the chain conveyor 16. The gasifying agent outlet is arranged above the top cover 14, and the gasifying agent inlet 17 is arranged on one side of the gas chamber 18. Preferably, the cross-sectional area of the top cover 14 gradually decreases from bottom to top, the cross-sectional area of the gas chamber 18 gradually decreases, and the gasifying agent inlet 17 is arranged on the side with the largest cross-sectional area.

[0043] As a further optimized solution of this embodiment, the front section of the carbon conveying pipeline 12 has a downward-inclined structure, and the cross-section of the carbon conveying pipeline 12 gradually decreases from the discharge port of the inner furnace body 8 to the carbon inlet.

[0044] As a further optimized solution of this embodiment, the outer furnace body 5 includes a large cylinder section, a conical transition section, and a small cylinder section that are connected in sequence from top to bottom. The small cylinder section is provided with a maintenance port 6, and a heat insulation layer 7 is arranged outside the outer furnace body 5.

[0045] As a further optimized solution of this embodiment, there is a gap between the outer edge of the blade of the feeding screw 9 and the inner wall of the inner furnace body 8. The feeding screw 9 has a variable pitch structure, and the pitch of the lower section of the feeding screw 9 < the pitch of the middle section < the pitch of the upper section. Preferably, through holes can be evenly opened on the blade of the feeding screw 9 to facilitate the flow of the gasifying agent.

[0046] As a further optimized solution of this embodiment, the helix of the feeding screw 9 is a full-face type. The screw is designed according to the feeding amount, and the feeding amount is related to the input biomass quality and its gasification efficiency. After determining the power and size of the gasifier, the carbon conveying amount of the feeding screw is determined by the average feeding amount of the biomass and the gasification efficiency. The biomass carbon particles are extruded towards the bottom of the outer furnace body 5 under the action of gravity and enter the inner furnace body 8 from below. Under the action of multiple forces such as centripetal force, friction force, and gravity, the biomass carbon particles begin to move along the helical surface and gradually accelerate. When the centrifugal force received by the biomass carbon is greater than the frictional force of the helical surface, the biomass carbon moves towards the inner wall surface of the inner furnace body 8. Then, as the contact pressure between the biomass carbon and the wall surface increases, the frictional force between the two also gradually increases. Under the action of this frictional force, the biomass carbon near the wall surface decelerates, generates relative movement with the helix, and finally moves upward and is discharged from the discharge port.

[0047] During the process of the feeding screw 9 in the inner furnace body 8 conveying biomass carbon, it moves upward according to the state of the material group. Its design needs to first determine the friction coefficients μ1 and μ2 between the biomass carbon and the helical surface and the inner wall surface of the inner furnace body 8; the pitch coefficient β1 is the ratio of the pitch S (m) to the helical radius R (m):

[0048]

[0049] In this case, the screw has a variable pitch design, and the pitch coefficient is selected according to the following conditions. In the formula, L (m) is the screw length:

[0050]

[0051] Refer to the "Design Manual of Continuous Conveying Machinery" according to μ1, μ2 and β1 to obtain the corresponding filling coefficient ψ and rotational speed coefficient k1, and then query to obtain the conveying capacity coefficient k2.

[0052] According to the feeding rate Q (m 3 / h) of the gasifier and the biomass carbon conversion rate k3, the volumetric conveying capacity I v (m 3 / h) of the screw is obtained:

[0053] I V = k3·Q(3)

[0054] The spiral radius R can be obtained through the following formula:

[0055]

[0056] In the formula, g = 9.81 m / s 2 , which is the acceleration due to gravity.

[0057] The calculated value of R is rounded up to obtain the standard value; furthermore, the pitch parameter S can be determined through formula (1).

[0058] The shaft diameter d (m) of the spiral center axis is determined according to the following formula:

[0059] d = β2·D (5);

[0060] In the formula, D (m) is the spiral diameter, which is 2 times the spiral radius R. β2 is the diameter ratio coefficient. According to the rigidity requirement, it can be taken as 0.3 - 0.4. The larger the value, the better the rigidity of the rotating shaft, but the lower the efficiency.

[0061] The screw rotational speed n (r / min) is usually calculated through formula (6):

[0062]

[0063] The working method of the above dry - discharged carbon biomass gasification system:

[0064] The collected biomass raw materials such as straw, fruit tree branches, and waste wood boards are stacked at the biomass material pile 1 and lifted to the biomass silo 3 by the bucket elevator 2. The biomass silo 3 is connected to the outer furnace body 5 of the gasifier by the feeding pipeline 4. A hatch is provided on the feeding pipeline 4. After being remotely controlled to open, the biomass raw materials in the silo are fed into the gasifier under the action of gravity. Since the biomass silo 3 is arranged on one side of the gasifier, a material distributor 10 is provided at the top of the outer furnace body 5. The material distributor 10 is a trapezoidal deflector made of metal and is driven by an external motor to rotate, evenly spreading the biomass raw materials fed from one side on the top of the outer furnace body 5. As the gasification reaction continues, the biomass raw materials in the outer furnace body 5 gradually descend under the action of gravity, successively passing through the drying zone, pyrolysis zone, and reduction zone, and falling to the bottom of the outer furnace body 5. The middle and lower part of the outer furnace body is frustum-shaped. The volume of the biomass after drying and pyrolysis becomes smaller and accumulates in the small cylinder area at the bottom under the action of the slope.

[0065] The inner furnace body 8 is connected to the top of the outer furnace body 5 and does not touch the bottom. The feeding screw 9 is arranged in the middle of the inner furnace body and is driven by an external motor to rotate and is connected to the bottom of the outer furnace body 5. The biomass after drying, pyrolysis, and partial reduction accumulates at the bottom of the outer furnace body. Under the dual action of gravity extrusion and the feeding screw 9, the biomass enters the inner furnace body 8 and gradually ascends against gravity under the drive of the feeding screw 9. During the ascending process, the biomass encounters the conveyed gasifying agent and undergoes an oxidation reaction, releasing a large amount of heat. After being transformed into biomass charcoal, it continues to move upward to the top of the inner furnace body 8 under the action of the feeding screw and then falls into the charcoal cooling device through the carbon conveying pipeline 12 on one side. At this time, the gasifying agent is conveyed into the gasifier from the top of the inner furnace body 8, and the main oxidation reaction occurs in the inner furnace body 8. The heat generated by the reaction is transferred to the outer furnace body 5 in two parts. One part is through the furnace wall of the inner furnace body 8, and the heat is transferred to the external biomass through solid heat conduction; the other part is through the gasifying agent. The gasifying agent flows through the high-temperature biomass charcoal and the oxidation reaction zone, and after being heated, the gasifying agent carries heat and transfers it to the external biomass. Through the setting of the inner and outer furnace bodies, the heat generated in the oxidation zone and the heat carried by the biomass charcoal are effectively utilized, improving the thermal efficiency of the gasifier and making the structure of the gasifier more compact. The distribution of different reaction zones during the operation of the gasifier is as Figure 4 shown. The oxidation zone is distributed in the upper and middle part of the inner furnace body 8, the reduction zone is distributed at the bottom of the inner furnace body 8 and the outer furnace body 5, the pyrolysis zone is mainly distributed in the middle of the outer furnace body 5, and the drying zone is distributed in the upper part of the outer furnace body 5.

[0066] The carbon delivery pipeline 12 is of a tapered type. Biomass carbon is continuously lifted to the top by the feeding screw 9 and moves under the action of extrusion and gravity. A simple material seal can be achieved when passing through the tapered section to ensure the airtightness of the gasifier. After the biomass carbon falls into the carbon cooling device, it is conveyed from one side to the other side by the chain conveyor 16. An air chamber 18 is provided at the bottom of the chain conveyor 16, and a gasifying agent inlet 17 is provided on one side of the air chamber 18. Along the flowing direction of the gasifying agent, the air chamber 18 is of a tapered type to balance the upward blowing air flow. The biomass carbon is driven by the chain conveyor 16 and cooled by the air flow blown out from the lower air chamber 18. The cooled biomass carbon is transported outside the cooling device; the gasifying agent cools the biomass carbon and recovers the waste heat in the biomass carbon, and then passes through the middle of the conical top cover 14 and is conveyed into the gasifier through the gas transmission pipeline 13.

[0067] The biomass carbon bin 19 is arranged on one side at the end of the chain conveyor 16. The top of the biomass carbon bin 19 is connected to the cooling chamber 15. The cooled biomass carbon falls into the biomass carbon bin 19 under the action of gravity. A bin door 20 is provided at the bottom of the biomass carbon bin 19, which can be remotely controlled by a computer and is only opened for discharging when the biomass carbon capacity is almost full and is normally closed at other times to ensure the airtightness of the whole system.

[0068] Example 2

[0069] As Figure 2 and Figure 3 , in this embodiment, a wind chamber 21 is provided at the bottom of the outer furnace body 5, and a wind distribution plate 22 is provided above the wind chamber 21; the feeding screw 9 is of a hollow structure, and a gasifying agent channel is provided inside the hollow structure. The inlet of the gasifying agent channel is connected to the air inlet of the inner furnace body 8, and the outlet of the gasifying agent channel is communicated with the wind chamber 21. The structures, positions and connection relationships of the other components are the same as those in Example 1.

[0070] In this embodiment, the gasifying agent flows through the inner furnace body 8 and the wind chamber 21 through the hollow structure of the feeding screw 9 and is evenly dispersed into the outer furnace body 5 through the holes on the wind distribution plate 22. At this time, the gasifying agent recovers the heat of the biomass carbon through the gasifying agent channel inside the feeding screw 9. The distribution of the reaction zone in the gasifier is as Figure 5 shown. The reaction intervals of the gasifier are mainly distributed inside the outer furnace body 5. The oxidation zone, reduction zone, pyrolysis zone and drying zone of the gasification reaction are distributed from bottom to top inside the outer furnace body 5 in sequence. The main function of the inner furnace body 8 is to lift the generated biomass carbon to the top outlet of the inner furnace body 8 and preheat the gasifying agent to improve the gasification efficiency. At the same time, when the high-temperature biomass carbon is sent into the carbon cooling device after passing through the inner furnace body 8, heat can also be transferred from the furnace wall of the inner furnace body 8 to the outer furnace, strengthening the heat transfer and improving the thermal efficiency of the gasifier.

[0071] The above are only embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention, or equivalent structural or equivalent process transformations made by using the content of the specification and drawings of the present invention, or direct or indirect applications in other related technical fields shall all be covered within the protection scope of the present invention.

Claims

1. A dry-feed charcoal biomass gasification system, characterized in that, It includes a feeding system, an outer furnace body (5), an inner furnace body (8), a feeding screw (9), a material leveling device (10), a carbon cooling device, and a biomass carbon bin (19); The lower part of the inner furnace body (8) is arranged inside the outer furnace body (5), the bottom of the inner furnace body (8) is separated from the bottom of the outer furnace body (5), the upper part of the inner furnace body (8) is connected to the top of the outer furnace body (5) and extends out of the outer furnace body (5); the feeding screw (9) is arranged inside the inner furnace body (8), and the bottom extends out of the inner furnace body (8) and is connected to the bottom of the outer furnace body (5); the material leveling device (10) is arranged at the top inside the outer furnace body (5), and a feeding port and a biomass gas outlet (11) are also opened at the top of the outer furnace body (5), and the feeding system is connected to the feeding port; the carbon cooling device is provided with a carbon inlet, a carbon outlet, a gasifying agent inlet (17), and a gasifying agent outlet. The discharge port at the upper part of the inner furnace body (8) is connected to the carbon inlet through a carbon conveying pipeline (12), the biomass carbon bin (19) is connected to the carbon outlet, and the gasifying agent outlet is connected to the air inlet at the top of the inner furnace body (8) through a gas conveying pipeline (13).

2. The dry-carbon biomass gasification system according to claim 1, wherein, The feeding system includes a biomass material pile (1), a bucket elevator (2), a biomass material bin (3), and a feeding pipeline (4) connected in sequence. The feeding pipeline (4) is connected to the feeding port of the outer furnace body (5) through an automatic warehouse door; the cross-sectional area of the feeding pipeline (4) gradually decreases.

3. The dry-feed carbon biomass gasification system according to claim 1, wherein, The carbon cooling device includes a top cover (14), a cooling chamber (15), and a gas chamber (18) connected in sequence from top to bottom. A chain conveyor belt (16) is arranged between the cooling chamber (15) and the gas chamber (18). The carbon inlet is arranged above the starting end of the chain conveyor belt (16), the carbon outlet is arranged at the end of the chain conveyor belt (16), the gasifying agent outlet is arranged above the top cover (14), and the gasifying agent inlet (17) is arranged on one side of the gas chamber (18).

4. The dry carbon biomass gasification system according to claim 3, wherein, The cross-sectional area of the top cover (14) gradually decreases from bottom to top. Along the flowing direction of the gasifying agent, the cross-sectional area of the gas chamber (18) perpendicular to the ground gradually decreases, and the gasifying agent inlet (17) is arranged on the side with the largest cross-sectional area.

5. The dry-carbon biomass gasification system according to claim 1, characterized in that, The front section of the carbon conveying pipeline (12) is of a downward-inclined structure, and the cross-section of the carbon conveying pipeline (12) gradually decreases from the discharge port of the inner furnace body (8) to the carbon inlet.

6. The dry-carbon biomass gasification system according to claim 1, characterized in that, The outer furnace body (5) includes a large cylinder section, a conical transition section, and a small cylinder section connected in sequence from top to bottom. The small cylinder section is provided with a maintenance port (6); a heat preservation layer (7) is arranged outside the outer furnace body (5).

7. The dry-carbon biomass gasification system according to claim 1, wherein, There is a gap between the outer edge of the blade of the feeding screw (9) and the inner wall of the inner furnace body (8); the feeding screw (9) is of a variable pitch structure, and the pitch of the lower section of the feeding screw (9) < the pitch of the middle section < the pitch of the upper section.

8. The dry-carbon biomass gasification system according to claim 1, characterized in that A wind chamber (21) is arranged at the bottom of the outer furnace body (5), and a wind distribution plate (22) is arranged above the wind chamber (21); the feeding screw (9) is of a hollow structure, and a gasifying agent channel is arranged inside the hollow structure. The inlet of the gasifying agent channel is connected to the air inlet of the inner furnace body (8), and the outlet of the gasifying agent channel is communicated with the wind chamber (21).

9. The working method of the dry-carbonized biomass gasification system according to any one of claims 1 to 7, characterized in that, It includes: The biomass raw material is conveyed by the feeding system to the outer furnace body (5), and the biomass raw material is evenly spread in the outer furnace body (5) through the material distributor (10). Under the action of gravity, the biomass raw material gradually moves downward and reaches the bottom of the outer furnace body (5), and is converted into biomass charcoal and accumulates at the bottom of the outer furnace body (5); the feeding screw (9) lifts the biomass charcoal from the bottom of the outer furnace body (5) through the inner furnace body (8) to the discharge port, and enters the charcoal cooling device through the charcoal conveying pipeline (12); when the biomass charcoal is lifted in the inner furnace body (8), heat is provided for the pyrolysis and drying of the biomass raw material in the outer furnace body (5) through the furnace wall of the inner furnace body (8); the gasifying agent enters the charcoal cooling device through the gasifying agent inlet (17) to cool the biomass charcoal and then heats up, and enters the inner furnace body (8) through the gas conveying pipeline (13), reacts with the biomass charcoal to release heat, and then moves upward from the lower part of the outer furnace body (5) to transfer the heat to the biomass raw material in the outer furnace body (5); the generated biomass gas is discharged from the biomass gas outlet (11).

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