A biomass gasification device and a biomass gasification method

Abstract

This invention discloses a biomass gasification device and a biomass gasification method. The biomass gasification device includes an upper pyrolysis chamber, a lower pyrolysis chamber, a first waste heat pipe, a second waste heat pipe, and a heat exchanger. An electric heating element is installed inside the upper pyrolysis chamber, and an upper hot air exhaust pipe is installed thereon. The lower pyrolysis chamber is located below the upper pyrolysis chamber, and a lower hot air exhaust pipe is installed thereon. A gas supply assembly is connected to the lower pyrolysis chamber. The first waste heat pipe is built into the upper pyrolysis chamber. The second waste heat pipe is built into the lower pyrolysis chamber. The heat exchanger contains a heat exchange hot air pipe and a heat exchange hot oil pipe. Both the first and second waste heat pipes are connected to the heat exchange hot oil pipe. The inlet end of the heat exchange hot air pipe is connected to both the upper and lower hot air exhaust pipes, and an induced draft fan is installed at the outlet end. The temperature of the upper pyrolysis chamber is lower than that of the lower pyrolysis chamber. By circulating the heat transfer oil and recovering the waste heat gas flow, the waste heat is reused to heat the reaction chamber, improving the overall thermal utilization efficiency and reducing external energy input.

Description

Technical Field

[0001] This invention relates to the field of combustible solid waste heat treatment equipment technology, and in particular to a biomass gasification device and a biomass gasification method. Background Technology

[0002] Pyrolysis gasification technology is a key technology that achieves low-energy consumption, low-pollution, and efficient utilization of waste resources and energy, and is an important way to realize the efficient utilization of biomass energy. Existing biomass gasification devices still have the following technical problems in practical applications: They use a single pyrolysis zone, where biomass feedstock undergoes drying, pyrolysis, and partial oxidation reactions sequentially within the same reaction zone. However, the temperature requirements for different reaction stages vary significantly, and a single temperature zone cannot simultaneously meet the optimal reaction conditions for each stage, resulting in incomplete biomass pyrolysis, unstable gas quality, and low gas production rate. Furthermore, the high-temperature flue gas waste heat is not effectively utilized, leading to serious energy waste, and the electric heating components are incompatible with the waste heat recycling system, making it impossible to effectively utilize waste heat. Summary of the Invention

[0003] The purpose of this invention is to provide a biomass gasification device to solve the technical problem of serious energy waste in the prior art.

[0004] To achieve the above objectives, embodiments of the present invention provide a biomass gasification device, including an upper pyrolysis chamber, a lower pyrolysis chamber, a first waste heat pipe, a second waste heat pipe, and a heat exchanger. An electric heating element is installed inside the upper pyrolysis chamber, and an upper hot air exhaust pipe is provided within the upper pyrolysis chamber. The lower pyrolysis chamber is located below the upper pyrolysis chamber, and a material discharge channel is provided between the lower and upper pyrolysis chambers for material passage. The material discharge channel is equipped with a material discharge valve to prevent backflow of airflow. A lower hot air exhaust pipe is provided within the lower pyrolysis chamber, and an air supply assembly is connected to the lower pyrolysis chamber. The first waste heat pipe is partially internal. The upper pyrolysis chamber is partially housed within the lower pyrolysis chamber. A heat exchanger contains a heat exchange hot air pipe and a heat exchange hot oil pipe, which exchange heat within the heat exchanger. The first and second waste heat pipes are both connected to the heat exchange hot oil pipe, forming a first waste heat cycle and a second waste heat cycle, respectively. The inlet of the heat exchange hot air pipe is connected to the upper and lower hot air exhaust pipes, and an induced draft fan is installed at the outlet of the heat exchange hot air pipe. The temperature of the upper pyrolysis chamber is lower than that of the lower pyrolysis chamber.

[0005] Preferably, a partition is provided between the upper pyrolysis chamber and the lower pyrolysis chamber, and the material discharge channel is provided on the partition.

[0006] Preferably, the portion of the first waste heat tube located in the upper pyrolysis chamber encloses the electric heating tube.

[0007] Preferably, an oil temperature sensor is provided at the oil outlet end of the heat exchange hot oil pipe, and the electric heating tube is electrically connected to the oil temperature sensor. When the temperature detected by the oil temperature sensor is lower than a preset threshold, the electric heating tube maintains maximum power; when the temperature detected by the oil temperature sensor is equal to or higher than the preset threshold, the electric heating tube reduces its heating power.

[0008] Preferably, the gas supply assembly includes a guide pipe and a blower, with one end of the guide pipe connected to the blower and the other end extending into the lower pyrolysis chamber.

[0009] Preferably, one end of the guide pipe extending into the lower pyrolysis chamber is connected to a gas distributor. The gas distributor is annular and has multiple exhaust pipes. The multiple exhaust pipes are spaced apart around the gas distributor, wherein the exhaust pipes are inclined from the outside of the gas distributor toward the center of the gas distributor.

[0010] Preferably, the axis of the exhaust pipe is inclined upward relative to the horizontal plane.

[0011] Preferably, the guide pipe is equipped with a flow control valve, and the lower pyrolysis chamber is equipped with an oxygen concentration sensor, which is electrically connected to the flow control valve.

[0012] Preferably, the biomass gasification device further includes a gas purification chamber, wherein the upper hot air exhaust pipe and the lower hot air exhaust pipe are both connected to the air inlet side of the gas purification chamber, and the air inlet side of the heat exchange hot air pipe is connected to the air outlet side of the gas purification chamber.

[0013] Preferably, a tar chamber is provided below the gas purification chamber, and the tar chamber is connected to the gas purification chamber.

[0014] The biomass gasification device provided by this invention has the following advantages: by using a system of heat transfer oil circulation and waste heat gas recovery, waste heat is reused to heat the reaction chamber, which improves the overall heat utilization efficiency and reduces the input of external energy.

[0015] Embodiments of the present invention also provide a biomass gasification method, comprising the following steps: Step S1: The material enters the upper pyrolysis chamber; Step S2: The electric heating tube heats the upper pyrolysis chamber, and at the same time, heat transfer oil is introduced into the first waste heat tube, and the material is dried and baked at low temperature in the upper pyrolysis chamber; Step S3: The material enters the lower pyrolysis chamber from the upper pyrolysis chamber. At the same time, the heat transfer oil in the first waste heat pipe flows back into the heat exchange hot oil pipe, and the pyrolysis gas generated in the upper pyrolysis chamber is discharged to the heat exchange hot air pipe through the upper hot air exhaust pipe. Step S4: Use the gas supply assembly to supply gas to the lower pyrolysis chamber to promote the combustion of residual carbon in the lower pyrolysis chamber. At the same time, heat transfer oil is introduced into the second waste heat pipe to carry out deep pyrolysis of the material in the lower pyrolysis chamber. Step S5: Clean up the generated residue. At the same time, the heat transfer oil in the second waste heat pipe flows back into the heat exchange hot oil pipe, and the pyrolysis gas generated in the lower pyrolysis chamber is discharged into the heat exchange hot air pipe through the lower hot air exhaust pipe. Step S6: The pyrolysis gas in the heat exchange hot air pipe exchanges heat with the heat transfer oil in the heat exchange hot oil pipe; Step S7: The heat transfer oil that has completed heat exchange in the heat exchange hot oil pipe flows into the first waste heat pipe and the second waste heat pipe respectively, and the airflow that has completed heat exchange in the heat exchange hot air pipe is discharged into the external environment by the induced draft fan.

[0016] The biomass gasification method provided by this invention has the following advantages: by using a system of heat transfer oil circulation and waste heat gas recovery, waste heat can be reused to heat the reaction chamber, thereby improving the overall heat utilization efficiency and reducing the input of external energy. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a biomass gasification device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a biomass gasification device according to an embodiment of the present invention; In the picture, 100. Upper pyrolysis chamber; 110. Electric heating element; 120. Upper hot air exhaust duct; 200. Lower pyrolysis chamber; 210. Material discharge channel; 211. Baffle plate; 220. Lower hot air exhaust pipe; 230. Air supply assembly; 231. Guide pipe; 232. Blower; 233. Gas distributor; 234. Exhaust pipe; 235. Flow control valve; 300. First waste heat pipe; 400. Second waste heat pipe; 500. Heat exchanger; 600. Exhaust fan; 700. Gas purification chamber; 710. Tar chamber; 810. Grate; 820. Ash pan; 830. Spiral slag remover; 910. Storage chamber; 920. Screw feeder; Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0020] In the description of this invention, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0021] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0022] Reference Figure 1 An embodiment of the present invention provides a biomass gasification device, comprising an upper pyrolysis chamber 100, a lower pyrolysis chamber 200, a first waste heat pipe 300, a second waste heat pipe 400, and a heat exchanger 500. The upper pyrolysis chamber 100 is equipped with an electric heating pipe 110 and an upper hot air exhaust pipe 120. The lower pyrolysis chamber 200 is located below the upper pyrolysis chamber 100. A material discharge channel 210 is provided between the lower pyrolysis chamber 200 and the upper pyrolysis chamber 100 for material passage. The material discharge channel 210 is equipped with a material discharge valve to prevent backflow of airflow. The lower pyrolysis chamber 200 is equipped with a lower hot air exhaust pipe 220 and is connected to a gas supply assembly 230. The first waste heat pipe 300... Part 00 is built into the upper pyrolysis chamber 100; part of the second waste heat pipe 400 is built into the lower pyrolysis chamber 200; the heat exchanger 500 has a heat exchange hot air pipe (not shown in the figure) and a heat exchange hot oil pipe (not shown in the figure), which can exchange heat in the heat exchanger 500; wherein, the first waste heat pipe 300 and the second waste heat pipe 400 are both connected to the heat exchange hot oil pipe, and respectively form the first waste heat cycle and the second waste heat cycle; the air inlet end of the heat exchange hot air pipe is connected to the upper hot air exhaust pipe 120 and the lower hot air exhaust pipe 220, and the air outlet end of the heat exchange hot air pipe is equipped with an induced draft fan 600; wherein, the temperature of the upper pyrolysis chamber 100 is lower than the temperature of the lower pyrolysis chamber 200.

[0023] The biomass gasification method used in the above-mentioned biomass gasification device includes the following steps: Step S1: The material enters the upper pyrolysis chamber 100; Step S2: The electric heating tube 110 heats the upper pyrolysis chamber 100. At the same time, heat transfer oil is introduced into the first waste heat tube 300, and the material is dried and baked at low temperature in the upper pyrolysis chamber 100. Step S3: The material enters the lower pyrolysis chamber 200 from the upper pyrolysis chamber 100. At the same time, the heat transfer oil in the first waste heat pipe 300 flows back into the heat exchange hot oil pipe, and the pyrolysis gas generated in the upper pyrolysis chamber 100 is discharged to the heat exchange hot air pipe through the upper hot air exhaust pipe 120. Step S4: Use the gas supply component 230 to supply gas to the lower pyrolysis chamber 200 to promote the combustion of residual carbon in the lower pyrolysis chamber 200. At the same time, heat transfer oil is introduced into the second waste heat pipe 400 to carry out deep pyrolysis of the material in the lower pyrolysis chamber 200. Step S5: The residue generated by the combustion of residual carbon is discharged through the grate and the slag discharge screw. At the same time, the heat transfer oil in the second waste heat pipe 400 flows back into the heat exchange hot oil pipe, and the pyrolysis gas generated in the lower pyrolysis chamber 200 is discharged into the heat exchange hot air pipe through the lower hot air exhaust pipe 220. Step S6: The pyrolysis gas in the heat exchange hot air pipe exchanges heat with the heat transfer oil in the heat exchange hot oil pipe; Step S7: The heat transfer oil that has completed heat exchange in the heat exchange hot oil pipe flows into the first waste heat pipe 300 and the second waste heat pipe 400 respectively, and the airflow that has completed heat exchange in the heat exchange hot air pipe is discharged into the external environment by the induced draft fan 600.

[0024] Among them, steps S1 to S7 above include airflow circulation and heat transfer oil circulation; Specifically, airflow circulation includes the following processes: A1: The material is dried and pyrolyzed at low temperature in the upper pyrolysis chamber 100, and the generated primary pyrolysis gas is discharged through the upper hot air exhaust pipe 120. A2: The dried material enters the lower pyrolysis chamber 200 through the material discharge channel 210, where it undergoes deep pyrolysis and coke combustion. The high-temperature pyrolysis gas generated is discharged through the lower hot air exhaust pipe 220. A3: The pyrolysis gas discharged from the upper hot air exhaust pipe 120 and the lower hot air exhaust pipe 220 is respectively introduced into the heat exchange hot air pipe of the heat exchanger 500 for heat exchange. A4: The airflow that has completed heat exchange is discharged from the induced draft fan 600; The heat transfer oil circulation includes the following processes: B1: The material is dried and pyrolyzed at low temperature in the upper pyrolysis chamber 100. The heat transfer oil in the built-in first waste heat pipe 300 absorbs the heat of the upper pyrolysis chamber 100 and flows to the heat exchanger 500. B2: The dried material enters the lower pyrolysis chamber 200 through the material discharge channel 210. Deep pyrolysis and coke combustion are carried out in the lower pyrolysis chamber 200. The heat transfer oil in the built-in second waste heat pipe 400 absorbs the heat of the lower pyrolysis chamber 200 and flows to the heat exchanger 500. B3: The heat transfer oil in the first waste heat pipe 300 in step P1 and the heat transfer oil in the second waste heat pipe 400 in step P2 are combined; B4: The combined heat transfer oils flow into the heat exchange oil pipe for heat exchange; B5: After heat exchange, the heat transfer oil is pumped back to the first waste heat pipe 300 and the second waste heat pipe 400 respectively, and releases heat through the pipe wall to the upper pyrolysis chamber 100 and the lower pyrolysis chamber 200 to maintain the pyrolysis temperature. In steps A4 and B4, the heat transfer oil in the heat exchange hot oil pipe and the airflow in the heat exchange hot air pipe exchange heat.

[0025] In summary, during actual use, the material enters from the top of the upper pyrolysis chamber 100 and begins to heat up under the action of the electric heating tube 110. The pyrolysis gas generated in the upper pyrolysis chamber 100 is discharged through the upper hot air exhaust pipe 120; in the lower pyrolysis chamber 200, the material undergoes further pyrolysis and partial combustion with the help of the gas supply component 230, and the generated high-temperature flue gas is discharged through the lower hot air exhaust pipe 220. The first waste heat pipe 300 and the second waste heat pipe 400 respectively absorb the heat in the upper pyrolysis chamber 100 and the lower pyrolysis chamber 200, and transfer the heat to the heat exchange hot oil pipe in the heat exchanger 500, forming two independent waste heat cycles. The heat exchange hot air pipe then recovers the waste heat from the pyrolysis gas (or flue gas) collected from the upper hot air exhaust pipe 120 and the lower hot air exhaust pipe 220.

[0026] It is important to emphasize that the function of the induced draft fan 600 is to provide suction power to ensure smooth gas flow. Since the upper pyrolysis chamber 100 is mainly heated externally, while the lower pyrolysis chamber 200 is heated by combustion, the temperature of the upper pyrolysis chamber 100 is naturally lower than that of the lower pyrolysis chamber 200.

[0027] In summary, the system, which uses heat transfer oil circulation and waste heat gas recovery, reuses waste heat to heat the reaction chamber, improving overall heat utilization efficiency and reducing external energy input. At the same time, the function of preventing backflow of airflow through the discharge valve on the discharge channel 210 also enables independent waste heat recovery of the upper and lower pyrolysis chambers 200, avoiding unnecessary heat transfer from the high-temperature zone to the low-temperature zone.

[0028] Specifically, the temperature in the upper pyrolysis chamber 100 is stably maintained at 300–400℃, and the temperature in the lower pyrolysis chamber 200 is maintained at 500–800℃. During operation, the internal temperature of the upper pyrolysis chamber 100 is consistently controlled within the range of 300–400℃ by adjusting the power of the electric heating tube 110, the flow rate of the heat transfer oil in the first waste heat pipe 300, and the feeding speed of the upper pyrolysis chamber 100. The temperature of the lower pyrolysis chamber 200 is maintained at 500–800℃ by controlling the air supply of the air supply component 230, the flow rate of the heat transfer oil in the second waste heat pipe 400, and the intensity of residual carbon combustion.

[0029] It is understandable that 300-400℃ is the optimal temperature range for biomass drying and preliminary pyrolysis. At this temperature, volatiles in biomass begin to be released, but tar does not decompose in large quantities, which is beneficial for subsequent separation and utilization. 500-800℃ is the ideal range for semi-coke gasification and deep pyrolysis, which can completely decompose large molecular organic matter into small molecular combustible gases, while the heat released by the combustion of residual carbon can maintain the high temperature.

[0030] In some embodiments, a partition 211 is provided between the upper pyrolysis chamber 100 and the lower pyrolysis chamber 200, and a material discharge channel 210 is provided on the partition 211. The partition 211 divides the upper pyrolysis chamber 100 and the lower pyrolysis chamber 200 into two independent spaces. After the material has finished passing through the upper pyrolysis chamber 100, it enters the lower pyrolysis chamber 200 through the material discharge channel 210 on the partition 211. The material discharge channel 210 is only opened when material passes through, and remains closed or only allows material to pass through in one direction at other times. This separates the two reaction zones with different temperatures and atmospheres, preventing the low-temperature oxygen-deficient atmosphere of the upper pyrolysis chamber 100 from interfering with the high-temperature oxidizing atmosphere of the lower pyrolysis chamber 200.

[0031] Among them, reference Figure 1 A storage chamber 910 is provided above the upper pyrolysis chamber 100. Material can fall from the storage chamber 910 into the upper pyrolysis chamber 100. The storage chamber 910 is connected to a screw feeder 920, which is used to transport material to the storage chamber 910 for later use.

[0032] In some embodiments, the portion of the first waste heat pipe 300 located in the upper pyrolysis chamber 100 encloses the electric heating pipe 110. When the electric heating pipe 110 heats up, the heat is first transferred to the heat transfer oil in the adjacent first waste heat pipe 300, and the heated heat transfer oil flows to the heat exchanger 500; simultaneously, the first waste heat pipe 300 itself also radiates heat to the upper pyrolysis chamber 100. When the waste heat circulation is started, the heat transfer oil heated by the heat exchange hot air pipe flows back from the heat exchanger 500 to the first waste heat pipe 300, and supplies heat to the upper pyrolysis chamber 100 again.

[0033] It should be mentioned that both the upper hot air exhaust pipe 120 and the lower hot air exhaust pipe 220 are equipped with one-way valves to ensure that the airflow carrying residual heat can only flow to the heat exchanger 500. This ensures that the airflow will not backflow and guarantees that the residual heat airflow can exchange heat with the heat transfer oil.

[0034] Furthermore, an oil temperature sensor is installed at the oil outlet of the heat exchange hot oil pipe. The electric heating tube 110 is electrically connected to the oil temperature sensor. When the temperature detected by the oil temperature sensor is lower than a preset threshold, the electric heating tube 110 maintains maximum power; when the temperature detected by the oil temperature sensor is equal to or higher than the preset threshold, the electric heating tube 110 reduces its heating power. In a specific embodiment, the temperature threshold is set at 250℃. The oil temperature sensor monitors the temperature of the heat transfer oil at the outlet of the heat exchange hot oil pipe in real time. When the detected temperature is lower than 250℃, the control system (not shown in the figure) determines that the residual heat is insufficient, and the electric heating tube 110 operates at maximum power to provide the main heat for the upper pyrolysis chamber 100. When the detected temperature reaches or exceeds 250℃, the control system determines that the residual heat is sufficient and automatically reduces the heating power of the electric heating tube 110 (or even shuts it off completely), prioritizing the use of residual heat in the heat transfer oil to maintain the temperature of the upper pyrolysis chamber 100. In the above control process, the heating logic of "residual heat priority, electric heating supplement" is realized, maximizing the utilization of flue gas waste heat and reducing power consumption. It should be emphasized that using a control system (not shown in the figure) in conjunction with an oil temperature sensor and an electrically connected electric heating tube 110 to control the heating power is a standard configuration in this field and will not be described in detail here. Only the heating logic of "waste heat priority and electric heating supplement" will be explained.

[0035] In some embodiments, the air supply assembly 230 includes a guide pipe 231 and a blower 232. One end of the guide pipe 231 is connected to the blower 232, and the other end extends into the lower pyrolysis chamber 200. The blower 232 draws air from the environment and delivers it into the lower pyrolysis chamber 200 through the guide pipe 231. Specifically, the airflow can be adjusted by the speed of the blower 232 or by a subsequent flow control valve 235. In the lower pyrolysis chamber 200, the internal pyrolysis reaction requires a certain amount of air to partially oxidize and burn the residual carbon, thereby releasing heat to maintain a high temperature of 500-800°C. The guide pipe 231 directly delivers air into the lower pyrolysis chamber 200 to ensure that the temperature of the pyrolysis reaction reaches the target.

[0036] Furthermore, referring to Figure 1 and Figure 2A gas distributor 33 is connected to one end of the guide pipe 231 that extends into the lower pyrolysis chamber 200. The gas distributor 33 is annular and has multiple exhaust pipes 234 spaced around it. The exhaust pipes 234 are inclined from the outside of the gas distributor 33 towards its center. Air enters the annular gas distributor 33 from the guide pipe 231 and is then distributed to the multiple exhaust pipes 234. Because the exhaust pipes 234 are inclined from the outside of the ring towards the center, the air is ejected in a converging direction, forming a rotating or intersecting airflow field at the bottom of the lower pyrolysis chamber 200, which thoroughly mixes with the material inside the lower pyrolysis chamber 200. It can be understood that the axis of the exhaust pipe 234 is inclined upward relative to the horizontal plane, forming an angle of 30° to 45° with the horizontal plane. When air is ejected from the exhaust pipe 234, the direction is obliquely upward (elevation angle 30°-45°). In this way, after the air enters the lower pyrolysis chamber 200, it will diffuse and further mix with the volatiles and semi-coke in the upper part of the lower pyrolysis chamber 200.

[0037] Understandably, the upward airflow direction utilizes the buoyancy of the air to rise naturally, prolonging the residence time of the gas in the reaction zone; on the other hand, it avoids blowing directly downwards onto the grate 810, which would cause ash and slag to splash.

[0038] In summary, the annular distributor, in conjunction with the inclined exhaust pipe 234, prevents air from being simply injected vertically or horizontally, instead creating a swirling or radial airflow. This airflow penetrates the material more evenly, avoiding localized oxygen-deficient / oxygen-rich areas and ensuring the uniformity of the pyrolysis reaction.

[0039] In some embodiments, the guide pipe 231 is equipped with a flow control valve 235, and an oxygen concentration sensor is installed in the lower pyrolysis chamber 200, which is electrically connected to the flow control valve 235. The oxygen concentration sensor monitors the oxygen content in the lower pyrolysis chamber 200 in real time and transmits the signal to the controller. The controller automatically adjusts the opening of the flow control valve 235 according to a preset oxygen concentration range (e.g., 5-8%): when the oxygen concentration is too high, the valve is closed to reduce the air supply; when the oxygen concentration is too low, the valve is opened to increase the air supply.

[0040] In some embodiments, the biomass gasification device further includes a gas purification chamber 700. The upper hot air exhaust pipe 120 and the lower hot air exhaust pipe 220 are both connected to the air inlet side of the gas purification chamber 700, and the air inlet side of the heat exchange hot air pipe is connected to the air outlet side of the gas purification chamber 700. The pyrolysis gas discharged from the upper pyrolysis chamber 100 and the high-temperature flue gas discharged from the lower pyrolysis chamber 200 mix and first enter the gas purification chamber 700 to remove impurities such as tar and dust. The purified clean gas (still at a relatively high temperature) then enters the heat exchange hot air pipe of the heat exchanger 500, transferring residual heat to the heat transfer oil in the heat exchange hot oil pipe, and finally is discharged via the induced draft fan 600.

[0041] In some embodiments, a tar chamber 710 is disposed below the gas purification chamber 700, and the tar chamber 710 is connected to the gas purification chamber 700. Inside the gas purification chamber 700, when the pyrolysis gas is cooled or passes through the purification medium, the tar in it condenses into a liquid or solid state, flows downward by gravity, and falls into the tar chamber 710, which is connected to the bottom of the purification chamber, and is periodically discharged and collected.

[0042] Those skilled in the art can make several improvements and substitutions without departing from the technical principles of this invention, and these improvements and substitutions should also be considered within the scope of protection of this invention.

Claims

1. A biomass gasification device, characterized in that, include: The upper pyrolysis chamber is equipped with an electric heating tube and an upper hot air exhaust pipe. The lower pyrolysis chamber is located below the upper pyrolysis chamber. A material discharge channel is provided between the lower pyrolysis chamber and the upper pyrolysis chamber for material to pass through. The material discharge channel is equipped with a material discharge valve to prevent backflow of airflow. The lower pyrolysis chamber is equipped with a lower hot air exhaust pipe and is connected to an air supply assembly. The first waste heat tube is partially built into the upper pyrolysis chamber; The second waste heat pipe is partially built into the lower pyrolysis chamber; A heat exchanger has a built-in heat exchange hot air pipe and a heat exchange hot oil pipe, which can exchange heat in the heat exchanger. The first waste heat pipe and the second waste heat pipe are both connected to the heat exchange hot oil pipe, and respectively form the first waste heat cycle and the second waste heat cycle. The air inlet of the heat exchange hot air pipe is connected to the upper hot air exhaust pipe and the lower hot air exhaust pipe, and an exhaust fan is provided at the air outlet of the heat exchange hot air pipe. The temperature of the upper pyrolysis chamber is lower than the temperature of the lower pyrolysis chamber.

2. The biomass gasification device according to claim 1, characterized in that, A partition is provided between the upper pyrolysis chamber and the lower pyrolysis chamber, and the material discharge channel is provided on the partition.

3. The biomass gasification device according to claim 1, characterized in that, The portion of the first waste heat tube located in the upper pyrolysis chamber encloses the electric heating tube.

4. The biomass gasification device according to claim 1 or 3, characterized in that, An oil temperature sensor is installed at the oil outlet end of the heat exchange hot oil pipe. The electric heating tube is electrically connected to the oil temperature sensor. When the temperature detected by the oil temperature sensor is lower than a preset threshold, the electric heating tube maintains maximum power. When the temperature detected by the oil temperature sensor is equal to or higher than the preset threshold, the electric heating tube reduces its heating power.

5. The biomass gasification device according to claim 1, characterized in that, The gas supply assembly includes a guide pipe and a blower. One end of the guide pipe is connected to the blower, and the other end extends into the lower pyrolysis chamber.

6. The biomass gasification device according to claim 5, characterized in that, One end of the guide pipe extending into the lower pyrolysis chamber is connected to a gas distributor. The gas distributor is annular and has multiple exhaust pipes. The multiple exhaust pipes are spaced apart around the gas distributor, and the exhaust pipes are inclined from the outside of the gas distributor toward the center of the gas distributor.

7. The biomass gasification device according to claim 6, characterized in that, The axis of the exhaust pipe is inclined upward relative to the horizontal plane.

8. The biomass gasification device according to claim 5, characterized in that, The guide pipe is equipped with a flow control valve, and the lower pyrolysis chamber is equipped with an oxygen concentration sensor, which is electrically connected to the flow control valve.

9. The biomass gasification device according to claim 1, characterized in that, It also includes a gas purification chamber, wherein the upper hot air exhaust pipe and the lower hot air exhaust pipe are both connected to the air inlet side of the gas purification chamber, and the air inlet side of the heat exchange hot air pipe is connected to the air outlet side of the gas purification chamber.

10. A biomass gasification method, used in the biomass gasification apparatus according to any one of claims 1 to 9, characterized in that, Includes the following steps: Step S1: The material enters the upper pyrolysis chamber; Step S2: The electric heating tube heats the upper pyrolysis chamber, and at the same time, heat transfer oil is introduced into the first waste heat tube, and the material is dried and baked at low temperature in the upper pyrolysis chamber; Step S3: The material enters the lower pyrolysis chamber from the upper pyrolysis chamber. At the same time, the heat transfer oil in the first waste heat pipe flows back into the heat exchange hot oil pipe, and the pyrolysis gas generated in the upper pyrolysis chamber is discharged to the heat exchange hot air pipe through the upper hot air exhaust pipe. Step S4: Use the gas supply assembly to supply gas to the lower pyrolysis chamber to promote the combustion of residual carbon in the lower pyrolysis chamber. At the same time, heat transfer oil is introduced into the second waste heat pipe to carry out deep pyrolysis of the material in the lower pyrolysis chamber. Step S5: Clean up the generated residue. At the same time, the heat transfer oil in the second waste heat pipe flows back into the heat exchange hot oil pipe, and the pyrolysis gas generated in the lower pyrolysis chamber is discharged into the heat exchange hot air pipe through the lower hot air exhaust pipe. Step S6: The pyrolysis gas in the heat exchange hot air pipe exchanges heat with the heat transfer oil in the heat exchange hot oil pipe; Step S7: The heat transfer oil that has completed heat exchange in the heat exchange hot oil pipe flows into the first waste heat pipe and the second waste heat pipe respectively, and the airflow that has completed heat exchange in the heat exchange hot air pipe is discharged into the external environment by the induced draft fan.

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