Fluidized bed gasification equipment

Abstract

The utility model provides fluidized bed gasification equipment which comprises a gasification furnace, a fly ash returning device and a tar returning device, and the gasification furnace is provided with a crude synthesis gas outlet; the fly ash returning device is provided with a crude synthesis gas inlet end, a primary synthesis gas outlet end and an ash returning end, the crude synthesis gas inlet end is communicated with the crude synthesis gas outlet of the gasification furnace, so that crude synthesis gas in the gasification furnace enters the fly ash returning device, and the ash returning end is communicated with the gasification furnace, so that fly ash is returned into the gasification furnace; the tar returning device is provided with a primary synthesis gas inlet end, a purified synthesis gas outlet end and a tar returning end, the primary synthesis gas inlet end is communicated with the primary synthesis gas outlet end of the fly ash returning device, so that primary synthesis gas enters the tar returning device from the fly ash returning device, and the purified synthesis gas outlet end is used for outputting purified synthesis gas; and the tar returning end is communicated with the gasification furnace so as to return the tar into the gasification furnace.

Description

Technical Field

[0001] The utility model relates to the technical field of biomass gasification, in particular to fluidized bed gasification equipment. Background Art

[0002] As the most promising renewable energy source, biomass energy has become the fourth largest energy source after coal, oil and natural gas. Promoting the resource utilization of abundant and environmentally friendly biomass materials is one of the effective technical approaches to achieve the "dual carbon" goals. It is of great significance to promoting my country's ecological civilization construction, energy revolution and low-carbon economic development.

[0003] Biomass gasification technology is a thermal decomposition technology that converts solid biomass feedstock into high-quality synthesis gas under certain thermodynamic conditions. The gaseous products produced during the biomass gasification process primarily include CO, H2, CH4, and CO2, which are primarily used to produce high-quality liquid fuels such as synthesis gas, hydrogen, and alcohol-ether solvents. Currently, the fluidized bed gasifier is the primary gasifier used on a large scale and boasts relatively mature technology. However, in the practical application of biomass gasification technology, fluidized bed gasifiers still face several challenges. For example, they commonly suffer from the high carbon content of the fly ash in the syngas they export. This fly ash has small particle size, a high degree of graphitization, and poor reactivity, thus reducing the gasification efficiency and carbon conversion rate of the biomass. Furthermore, the goal of biomass gasification is to produce as much syngas as possible. However, compared to coal, biomass with a higher volatile content inevitably produces a large amount of tar during the gasification process, which seriously affects the purity and composition of the syngas. Furthermore, biomass tar has complex composition, variable properties, and significant hazards. For example, biomass tar is primarily composed of benzene derivatives, which are solid at room temperature and difficult to combust with combustible gas. Furthermore, if the unburned biomass tar is sent to a solid waste treatment center, significant costs will be incurred, while the biomass tar's fuel value will be lost.

[0004] Therefore, reducing the carbon content of fly ash and the tar content of syngas during biomass gasification is a key factor in the economic operation of fluidized bed gasifiers and a technical problem that engineers and technicians in this field need to solve. Therefore, it is necessary to provide improved fluidized bed gasification equipment that overcomes or alleviates at least some of the shortcomings of the above-mentioned prior art. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a fluidized bed gasification equipment, which includes a gasifier, a fly ash return device and a tar return device. The gasifier has a crude synthesis gas outlet; the fly ash return device has a crude synthesis gas inlet end, a primary synthesis gas outlet end and an ash return end, the crude synthesis gas inlet end is connected with the crude synthesis gas outlet of the gasifier so that the crude synthesis gas in the gasifier enters the fly ash return device, and the ash return end is connected with the gasifier to return the fly ash into the gasifier; the tar return device has a primary synthesis gas inlet end, a clean synthesis gas outlet end and a tar return end, the primary synthesis gas inlet end is connected with the primary synthesis gas outlet end of the fly ash return device so that the primary synthesis gas enters the tar return device from the fly ash return device, the clean synthesis gas outlet end is used to output clean synthesis gas, and the tar return end is connected with the gasifier to return tar into the gasifier.

[0006] Optionally, the tar return device includes a decoker and an atomizer, wherein the air inlet end of the decoker is the primary synthesis gas inlet end, the outlet end of the decoker is the net synthesis gas outlet end, and the return end of the decoker is the tar return end, which is connected to the gasifier via the atomizer to atomize the tar and return it to the gasifier.

[0007] Optionally, the atomizer is a steam atomizer.

[0008] Optionally, the fly ash return device includes a cyclone separator and a dust collector, the air inlet end of the cyclone separator is the raw synthesis gas inlet end, the air outlet end of the cyclone separator is connected to the air inlet end of the dust collector, the air outlet end of the dust collector is the primary synthesis gas outlet end, and is used to output primary synthesis gas. The cyclone separator and the dust collector both have ash return ends, and the ash return ends of the cyclone separator and the dust collector are both connected to the gasifier; preferably, a return valve is provided between the cyclone separator and the gasifier, or a heat exchanger is provided between the cyclone separator and the dust collector, or an ash hopper is provided between the dust collector and the gasifier.

[0009] Optionally, the fluidized bed gasification equipment further comprises at least one air flow injection device, and the air flow injection device is configured to communicate with the fly ash return device and / or the tar return device so that the fly ash and / or tar are returned to the gasifier through the air flow injection device.

[0010] Optionally, the airflow injection device includes a first jet tube and a second jet tube arranged around the outer circumference of the first jet tube, the first jet tube defines a first airflow injection channel; the second jet tube defines a second airflow injection channel, and a first swirler is provided in the second airflow injection channel.

[0011] Optionally, the airflow injection device also includes a third jet tube, which defines a third airflow injection channel. The third jet tube is arranged around the outer periphery of the second jet tube, or the third jet tube is arranged between the first jet tube and the second jet tube; preferably, a second swirler is provided in the third airflow injection channel, and / or the first jet tube and the second jet tube are coaxially arranged, and / or the first jet tube, the second jet tube and the third jet tube are coaxially arranged, and / or the first swirler is arranged at the outlet end of the second airflow injection channel, and / or the second swirler is arranged at the outlet end of the third airflow injection channel.

[0012] Optionally, the fluidized bed gasification equipment includes a gasifying agent supply device, which is connected to any one of the first airflow injection channel, the second airflow injection channel and the third airflow injection channel to supply the gasifying agent into the gasifier.

[0013] Optionally, the ash return end is connected to any one of the first air flow injection channel, the second air flow injection channel and the third air flow injection channel; and / or, the tar return end of the tar return device is connected to any one of the first air flow injection channel, the second air flow injection channel and the third air flow injection channel via an atomizer to atomize the tar and transport it into the gasifier.

[0014] Optionally, the tar does not share the same air flow injection channel with the gasifying agent or fly ash.

[0015] According to the fluidized bed gasification equipment of the present invention, the tar and high-carbon fly ash produced during the biomass gasification process can be simultaneously returned to the high-temperature oxidation zone of the biomass gasifier for further reaction, thereby solving the problems of high carbon content in fly ash and the inability of tar to crack in the biomass fluidized bed. This improves the gasification efficiency and energy utilization of biomass with a simple process, reducing environmental pollution. Furthermore, the fluidized bed gasification equipment of the present invention, which includes both fly ash and tar return devices, significantly improves the mixing of fly ash, tar, and gasifying agent by providing an airflow injection device. This allows fly ash and tar to be directly transported to the high-temperature oxidation zone of the biomass gasifier, reducing the repeated and ineffective circulation of fine ash and increasing the fuel value of the tar and the purity of the syngas.

[0016] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Features, advantages and exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals indicate like elements, and in which:

[0018] Figure 1This is a structural diagram of a fluidized bed gasification device according to an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 A partial cross-sectional schematic diagram of a gasifier of a fluidized bed gasification apparatus shown in FIG;

[0020] Figure 3 yes Figure 1 An enlarged structural diagram of the air flow injection device of the fluidized bed gasification equipment shown in FIG; and

[0021] Figure 4 yes Figure 3 The air flow injection device shown in Figure 2 Cross-section along line AA. DETAILED DESCRIPTION

[0022] The following describes exemplary embodiments of the present invention in more detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and in no way limits the present invention, its applications, or uses. Furthermore, the dimensions and proportions of the components in the drawings are merely schematic and do not strictly correspond to actual products.

[0023] The utility model provides a fluidized bed gasification device 100. Figure 1 1 is a schematic structural diagram of a fluidized bed gasification device 100 according to an embodiment of the present invention; Figure 2 yes Figure 1 A partial cross-sectional schematic diagram of a gasifier of the fluidized bed gasification apparatus 100 is shown in FIG; Figure 3 yes Figure 1 , which is an enlarged structural diagram of the airflow injection device 5 of the fluidized bed gasification equipment 100, so as to more clearly illustrate the various jet channels in the airflow injection device 5; and Figure 4 yes Figure 3 The air flow injection device 5 shown in FIG. Figure 3 The cross-section of the AA line. Figures 1 to 4 The fluidized bed gasification apparatus 100 according to an embodiment of the present invention will be described in detail.

[0024] like Figure 1 As shown, the fluidized bed gasification equipment 100 includes a gasifier, a fly ash return device 110 and a tar return device 120 arranged outside the gasifier. Specifically, the gasifier is a biomass gasifier 1 in this embodiment.

[0025] like Figure 1As shown, the biomass gasifier 1 includes a gasifier shell 106 having an inner cavity 105. The inner cavity 105 can form a storage space in which biomass feedstock, fly ash returned by a fly ash return device 110, tar returned by a tar return device 120, a gasifying agent, steam, etc. can undergo a gasification reaction. Specifically, in this embodiment, the gasifier shell 106 is a generally hollow cylindrical shell having an upper shell section 108, a tapered section S, and a lower shell section 109. The upper shell section 108 is located at the upper portion of the gasifier shell 106, the lower shell section 109 is located at the lower portion of the gasifier shell 106, and the tapered section S is fixedly connected between the upper shell section 108 and the lower shell section 109. A dilute phase zone 3 is formed in the upper shell section 108, and a dense phase zone 2 is formed in the lower shell section 109. The dense phase zone 2 has a high-temperature flame zone capable of ejecting jet flames. The temperature of the center of the jet flame is as high as 1000°C to 1500°C, so that the temperature of the dense phase zone 2 is between 800°C and 1500°C. Biomass raw materials, fly ash returned through the fly ash return device 110, tar returned through the tar return device 120, gasifying agent, steam, etc. undergo gasification reaction in the dense phase zone 2 of the biomass gasifier 1. In addition, a biomass inlet 107, a steam inlet 103 and a gasifier slag discharge hole 102 are formed on the lower shell section 109, wherein the biomass inlet 107 is connected to the feeding device 130, so that the biomass can enter the dense phase zone 2 of the biomass gasifier 1 through the biomass inlet 107 through the feeding device 130; and the steam inlet 103 is connected to the steam supply device (not shown), so that the steam transported by the steam supply device enters the dense phase zone 2 of the biomass gasifier 1 through the steam inlet 103. More specifically, in this embodiment, the lower shell section 109 is provided with a plurality of steam inlets 103, such as Figures 1 to 2As shown, three layers of steam inlets 103 are uniformly distributed along the circumference of the transverse cross section of the gasifier are provided on the lower shell section 109. It should be noted that, although in the present embodiment, a separate steam nozzle can be provided at the steam inlet 103, and the steam nozzle only transports steam into the biomass gasifier 1, in other embodiments not shown in the present invention, an air flow injection device 5, which will be described in detail later, can also be provided at the steam inlet 103, so that the fly ash and / or tar generated in the fluidized bed gasification equipment 100 can be transported to the biomass gasifier 1 through the steam inlet 103 at the same time as the steam, and the present invention does not impose any restrictions on this; and wherein, the gasifier slag discharge hole 102 is connected to the dense phase zone 2 of the biomass gasifier 1, and the gasifier slag discharge hole 102 is provided with an air flow injection device 5, which will be described in detail later, so that The fly ash and tar produced in the fluidized bed gasification equipment 100 can be simultaneously returned to the dense phase zone 2 of the biomass gasifier 1 through the air flow injection device 5. The arrangement is made in this way so that the biomass raw materials transported by the feeding device 130, the steam transported by the steam supply device, the fly ash returned by the fly ash return device 110, the tar returned by the tar return device 120, and the gasifying agent, such as oxygen, transported by the gasifying agent supply device 140 of the fluidized bed gasification equipment 100 can undergo gasification reaction in the inner cavity 105 of the biomass gasifier 1 at conditions of 800°C to 1500°C, thereby generating a raw synthesis gas containing CO, H2, CH4, CO2, tar, etc. It should be noted that although the airflow injection device 5 is disposed at the bottom of the biomass gasifier 1, within the gasifier slag discharge hole 102, an annular gap exists between the gasifier slag discharge hole 102 and the airflow injection device 5, allowing the coarse waste residue produced during the gasification process to be discharged from the biomass gasifier 1 through this gap. In addition, the gasifier has a crude syngas outlet 104. Specifically, in this embodiment, the gasifier shell 106 is provided with a crude syngas outlet 104, which is disposed at the upper end of the upper shell section 108, so that the crude syngas produced in the biomass gasifier 1 can be discharged from the biomass gasifier 1 through the crude syngas outlet 104 of the biomass gasifier 1.

[0026] like Figure 1As shown, the fly ash return device 110 has a raw synthesis gas inlet end 111, a primary synthesis gas outlet end 112 and an ash return end. The raw synthesis gas inlet end 111 of the fly ash return device 110 is configured to be connected to the raw synthesis gas outlet 104 of the biomass gasifier 1 so that the raw synthesis gas in the biomass gasifier 1 enters the fly ash return device 110. The ash return end is connected to the biomass gasifier 1 to return the fly ash to the biomass gasifier 1. Specifically, in this embodiment, the crude synthesis gas inlet end 111 of the fly ash return device 110 is connected to the crude synthesis gas outlet 104 of the biomass gasifier 1 via the crude synthesis gas pipeline 30, so that the crude synthesis gas generated in the biomass gasifier 1 can enter the fly ash return device 110 via the crude synthesis gas pipeline 30 for gas-solid separation and form primary synthesis gas, and the formed primary synthesis gas is discharged from the fly ash return device 110 from the primary synthesis gas outlet end 112, wherein, during the gas-solid separation process in the fly ash return device 110, the separated fly ash particles are returned to the dense phase zone 2 of the biomass gasifier 1 through the ash return end for further combustion, thereby improving the carbon conversion rate in the gasification process.

[0027] like Figure 1 As shown, the fly ash return device 110 includes a cyclone separator and a dust collector. The dust collector in this embodiment is a low-temperature dust collector 9, which has a primary synthesis gas outlet end 112 and an ash return end. The low-temperature dust collector 9 is configured to be in communication with the biomass gasifier 1, and the ash return end of the low-temperature dust collector 9 is configured to be in communication with the air flow injection device 5 of the biomass gasifier 1. Specifically, in this embodiment, the fluidized bed gasification equipment 100 also includes a heat exchanger 8 arranged between the cyclone separator and the low-temperature dust collector 9. In this embodiment, the cyclone separator is a high-temperature cyclone separator 6, and the heat exchanger 8 is arranged between the high-temperature cyclone separator 6 and the low-temperature dust collector 9. The raw synthesis gas outlet 104 of the biomass gasifier 1 is connected to the air inlet end of the high-temperature cyclone separator 6, that is, the raw synthesis gas inlet end 111, via the raw synthesis gas pipeline 30, so that the raw synthesis gas generated in the biomass gasifier 1 can first enter the high-temperature cyclone separator via the raw synthesis gas pipeline 30. 6 for gas-solid separation, and the ash return end of the high-temperature cyclone separator 6 is connected to the biomass gasifier 1, so that the fly ash particles larger than 100 μm captured in the high-temperature cyclone separator 6 are directly transported to the dense phase zone 2 of the biomass gasifier 1 through the ash return end of the high-temperature cyclone separator 6, specifically through the first feed leg 31 and the second feed leg 32, for further reaction, wherein a return valve 7 is provided between the high-temperature cyclone separator 6 and the biomass gasifier 1, specifically, a return valve 7 is provided between the first feed leg 31 and the second feed leg 32, so that the transportation of the circulating fly ash can be controlled by the return valve 7 as needed. In addition, as Figure 1As shown, the outlet of the high-temperature cyclone separator 6 is connected to the inlet of the low-temperature dust collector 9 via a first pipe 33. Specifically, the outlet of the high-temperature cyclone separator 6 is connected to the inlet of the low-temperature dust collector 9 via a heat exchanger 8 through the first pipe 33. In this manner, the synthesis gas after preliminary gas-solid separation in the high-temperature cyclone separator 6 enters the heat exchanger 8 for heat exchange, thereby reducing the temperature of the synthesis gas after preliminary gas-solid separation to 300°C to 400°C. Furthermore, the heat exchanger 8 is configured to be connected to the low-temperature dust collector 9 via a second pipe 34, so that the synthesis gas after the temperature reduction can enter the low-temperature dust collector 9 via the second pipe 34 for further gas-solid separation. As a result, fly ash particles below 100 μm are captured in the low-temperature dust collector 9 and then transported to the dense phase zone 2 of the biomass gasifier 1 via the airflow injection device 5 for further reaction. This solves the problem that fly ash in existing fluidized bed gasification equipment cannot reach the high-temperature oxidation zone, thereby improving the gasification efficiency and carbon conversion rate in the biomass gasification process.

[0028] Preferably, the fluidized bed gasification equipment 100 is also provided with an ash hopper 10, and the ash hopper 10 is located downstream of the low-temperature dust collector 9 and between the low-temperature dust collector 9 and the biomass gasifier 1, so that the fly ash particles captured by the low-temperature dust collector 9 can be transported to the ash hopper 10 for storage, wherein 10% to 30% of the fly ash particles stored in the ash hopper 10 are discharged from the ash hopper 10 via the ash discharge channel 40 and are no longer returned to the biomass gasifier 1, and the remaining 70% to 90% of the fly ash particles stored in the ash hopper 10 are returned to the dense phase zone 2 of the biomass gasifier 1 with the help of the CO2 / N2 conveying gas conveyed via the CO2 / N2 conveying end 300. It should be noted that, in the present embodiment, 70% to 90% of the fly ash particles stored in the ash hopper 10 are returned to the biomass gasifier 1. However, in other embodiments not shown in the present invention, the amount of fly ash particles stored in the ash hopper 10 that are returned to the biomass gasifier 1 can be adjusted to less than 70% or more than 90% of the total amount of fly ash particles according to actual needs.

[0029] In addition, the upper end of the low-temperature dust collector 9 is provided with a gas outlet end, specifically, a primary synthesis gas outlet end 112, and the primary synthesis gas outlet end 112 of the low-temperature dust collector 9 is connected to the tar return device 120 via the primary synthesis gas pipeline 35. It is arranged in this way so that the primary synthesis gas output through the gas outlet end of the low-temperature dust collector 9 after gas-solid separation through the low-temperature dust collector 9 can enter the tar return device 120 through the primary synthesis gas pipeline 35 to remove the tar in the primary synthesis gas and thus form a net synthesis gas.

[0030] like Figure 1As shown, the tar return device 120 includes a decoking device 11, and has a primary synthesis gas inlet end 121, a clean synthesis gas outlet end 122 and a tar return end 123. The air inlet end of the decoking device 11 is the primary synthesis gas inlet end 121, and the return end of the decoking device 11 is the tar return end 123. The primary synthesis gas inlet end 121 of the tar return device 120 is configured to be connected to the primary synthesis gas outlet end 112 of the low-temperature dust collector 9 of the fly ash return device 110, so that the primary synthesis gas enters the tar return device 120 from the fly ash return device 110. The clean synthesis gas outlet end 122 is used to output the clean synthesis gas, and the tar return end 123 of the tar return device 120 is configured to be connected to the biomass gasifier 1 to return the tar to the biomass gasifier 1. Specifically, in this embodiment, the primary synthesis gas inlet end 121 of the tar return device 120 is connected to the primary synthesis gas outlet end 112 of the low-temperature dust collector 9 of the fly ash return device 110 via the primary synthesis gas pipeline 35, that is, the air inlet end of the decoker 11 is connected to the primary synthesis gas outlet end 112 of the fly ash return device 110, and the outlet end of the decoker 11 is the clean synthesis gas outlet end 122, which is used to output clean synthesis gas, so that the primary synthesis gas discharged from the low-temperature dust collector 9 can enter the tar return device 120 via the primary synthesis gas pipeline 35 to remove tar in the primary synthesis gas to form clean synthesis gas, and the formed clean synthesis gas is discharged from the clean synthesis gas outlet end 122 and then transported to the downstream process via the clean synthesis gas pipeline 36 for the production of chemical products. The tar return device 120 also includes an atomizer 12. The tar return end 123 of the tar return device 120 is connected to the biomass gasifier 1 via the atomizer 12 to atomize the tar and return it to the biomass gasifier 1. The liquid tar formed during the tar removal process is transported to the atomizer 12 via the tar pipe 37 through the tar return end 123. In the atomizer 12, the tar is mixed with the steam transported from the outside via the steam transport end 400 and then returned to the jet flame center of the biomass gasifier 1 via the tar / steam pipe 38 and the air flow injection device 5 for further combustion. Since the temperature of the jet flame center is as high as 1000°C to 1500°C, the mixed tar steam atomized gas undergoes a cracking reaction in the high-temperature flame zone of 1000°C to 1500°C and is converted into C m H y , CO, H2 and other gaseous products. The tar return device 120 provided in the present invention makes it possible to fully utilize the fuel value of the tar produced during the gasification process without increasing the additional tar processing costs. This not only improves the purity of the synthesis gas with a simple process, but also increases the generation rate of synthesis gas during the biomass gasification process, reducing pollution to the environment.

[0031] Regarding the atomization process of liquid tar in the atomizer 12, it should be noted that tar is gaseous above 350°C and condenses into a liquid below 350°C. Based on this characteristic of tar, high-temperature, high-pressure steam can atomize the liquid tar discharged from the tar return device 120 in the atomizer 12, thereby forming a mixed tar vapor atomized gas. It should also be noted that for the atomization process of liquid tar, an atomizing device known in the art can be used, without the need for special configuration of existing atomizing devices. For example, the atomization operation can be medium-type atomization, in which the tar is atomized by the energy of an additional atomizing medium (steam, etc.). The kinetic energy of the high-speed sprayed atomizing medium impacts the tar, causing it to be broken up and blown away into fine oil droplets. An atomizer using high-pressure steam as the atomizing medium is called a steam-type atomizer. That is, in this embodiment, the atomizer 12 can be a steam-type atomizer; however, in some other embodiments, a mechanical atomizer can also be used for the atomization operation.

[0032] In addition, as described above, the fluidized bed gasification equipment 100 with a fly ash return device and a tar return device in the present invention can simultaneously return the fly ash with a high carbon content and the biomass tar collected in the later stage of gasification to the dense phase zone 2 of the biomass gasifier 1 for further reaction, thereby solving the problems of high carbon content in fly ash and inability of tar to crack in the biomass fluidized bed, thereby improving the gasification efficiency and energy utilization rate of biomass with a simple process and reducing pollution to the environment.

[0033] like Figures 1 to 4 As shown, the fluidized bed gasification equipment 100 with a fly ash return device and a tar return device further includes at least one air flow injection device 5, the first end of which is arranged in the inner cavity 105 of the biomass gasifier 1 and communicated with the biomass gasifier 1, and the air flow injection device 5 is arranged to communicate with the fly ash return device 110 and / or the tar return device 120, so that the fly ash and / or tar are returned to the biomass gasifier 1 through the air flow injection device 5. Specifically, in this embodiment, as shown in Figure 3As shown in more detail in FIG, the air flow injection device 5 has a first end 501 and a second end 502, wherein the first end 501 is arranged in the gasification furnace slag discharge hole 102 of the biomass gasification furnace 1, and the second end 502 is connected to the low-temperature dust collector 9, the tar return device 120 and the gasification agent supply device 140. More specifically, the second end 502 is connected to the ash hopper 10, the atomizer 12 and the gasification agent supply device 140. In this way, the fly ash particles separated by the low-temperature dust collector 9 can be transported to the fly ash return pipe 39 by means of the fly ash return pipe 39. The CO2 / N2 transport gas is returned to the dense phase zone 2 of the biomass gasifier 1 via the airflow injection device 5, and the tar removed by the tar return device 120 is mixed with steam transported from the outside in the atomizer 12 and can be returned to the dense phase zone 2 of the biomass gasifier 1 via the airflow injection device 5 with the help of the tar / steam pipe 38. As a result, the separated fly ash particles and tar, as well as the oxygen supplied by the gasifying agent supply device 140, can be transported to the center of the jet flame of the biomass gasifier 1 through the airflow injection device 5 for further reaction. It should be noted that there is a gap 510 between the gasifier slag discharge hole 102 and the composite injection burner of the airflow injection device 5, so that the coarse waste slag generated in the biomass gasifier 1 during the gasification process can be discharged from the biomass gasifier 1 through the gap 510.

[0034] like Figures 1 to 4As shown, the airflow injection device 5 includes a first jet tube that defines a first airflow injection channel; and a second jet tube disposed around the periphery of the first jet tube that defines a second airflow injection channel. Furthermore, the airflow injection device 5 also includes a third jet tube that defines a third airflow injection channel, and the third jet tube is disposed around the periphery of the second jet tube. Specifically, in this embodiment, the first jet tube is a tar / steam jet tube 191, the second jet tube is a gasifying agent jet tube 181, and the third jet tube is a fly ash jet tube 171, wherein the fly ash jet tube 171 is used to return the fly ash generated in the fluidized bed gasification equipment 100 to the biomass gasifier 1, the gasifying agent jet tube 181 is used to transport the gasifying agent to the biomass gasifier 1, and the tar / steam jet tube 191 is used to return the tar generated in the fluidized bed gasification equipment 100 to the biomass gasifier 1, that is, the tar and the gasifying agent or fly ash do not share the same airflow injection channel to avoid the atomized tar being condensed into liquid by the gasifying agent or fly ash. Specifically, in this embodiment, the fly ash jet pipe 171 is arranged to surround the gasifier jet pipe 181, and the gasifier jet pipe 181 is arranged to surround the tar / steam jet pipe 191, that is, the gasifier jet pipe 181 is arranged outside the tar / steam jet pipe 191, and the fly ash jet pipe 171 is arranged outside the gasifier jet pipe 181, so that a gasifier jet channel 18 is formed between the gasifier jet pipe 181 and the tar / steam jet pipe 191, a fly ash jet channel 17 is formed between the fly ash jet pipe 171 and the gasifier jet pipe 181, and a tar / steam jet channel 19 is formed inside the tar / steam jet pipe 191. In this way, the gasifier jet can not only provide the oxygen required for the combustion of fly ash and tar, but also play a role in disturbing and mixing the airflow. In addition, as Figure 1 and Figure 2As shown, the longitudinal length of the fly ash jet pipe 171 is smaller than the longitudinal length of the gasifying agent jet pipe 181, and the longitudinal length of the gasifying agent jet pipe 181 is smaller than the longitudinal length of the tar / steam jet pipe 191. The fly ash jet pipe 171 is provided with a fly ash inlet end 13 at the second end portion 502 of the air flow injection device 5, so that the fly ash particles separated by the low-temperature dust collector 9 can be transported to the fly ash jet channel 17 via the fly ash inlet end 13 through the fly ash return pipe 39. The tar / steam jet pipe 191 A tar inlet end 14 is provided at the second end portion 502 of the air flow injection device 5, so that the tar removed by the tar return device 120 can be transported to the tar / steam jet channel 19 via the tar inlet end 14 through the tar / steam pipe 38, and a gasifying agent inlet end 15 is provided on the gasifying agent jet pipe 181 at the second end portion 502 of the air flow injection device 5, so that the gasifying agent from the gasifying agent supply device 140 can be transported to the gasifying agent jet channel 18 via the gasifying agent inlet end 15. Designed in such a way, the fly ash particles separated by the low-temperature dust collector 9, the tar removed by the tar return device 120, and the gasifying agent supplied by the gasifying agent supply device 140 can enter the airflow injection device 5 through the second end 502 of the airflow injection device 5, and be discharged from the first end 501 of the airflow injection device 5 to the jet flame center of the biomass gasifier 1 for further reaction, so that the returned fly ash and tar can directly enter the high-temperature oxidation zone with the gasifying agent, and due to the presence of the airflow injection device 5, the mixing effect of the fly ash, tar and gasifying agent is significantly improved, thereby reducing the repeated and ineffective circulation of fine ash and improving the fuel value of the tar and the purity of the synthesis gas.

[0035] Preferably, the first jet tube and the second jet tube are coaxially arranged. More preferably, the first jet tube, the second jet tube and the third jet tube are coaxially arranged. Specifically, Figures 1 to 3 As shown, the fly ash jet pipe 171, the gasifying agent jet pipe 181, and the tar / steam jet pipe 191 are coaxially arranged. This arrangement allows the fly ash in the fly ash jet channel 17, the gasifying agent in the gasifying agent jet channel 18, and the tar steam atomized gas in the tar / steam jet channel 19 to be evenly transported to the dense phase zone 2 of the biomass gasifier 1, thereby preventing the efficiency of the gasification reaction from being affected by uneven distribution of the various gas components in the dense phase zone 2.

[0036] Optionally, a second swirler may be provided in the third airflow injection channel, and the second swirler is provided at the outlet end of the third airflow injection channel. Figures 1 to 3As shown, the airflow injection device 5 is provided with a second cyclone 16. Specifically, in this embodiment, the second cyclone 16 is disposed at the first end 501 of the airflow injection device 5 in the fly ash jet channel 17 between the fly ash jet pipe 171 and the gasifying agent jet pipe 181. That is, the second cyclone 16 is disposed outside the gasifying agent jet pipe 181, and the fly ash jet pipe 171 is disposed outside the second cyclone 16. Preferably, the second cyclone 16 is fixedly arranged in the outlet end of the fly ash jet channel 17 in a detachable manner, so that the fly ash jet in the fly ash jet channel 17 can enter the jet flame center of the dense phase zone 2 of the biomass gasifier 1 in the form of a swirl jet after flowing through the second cyclone 16. More specifically, the fly ash particles discharged into the biomass gasifier 1 through the fly ash jet channel 17 can form a recirculation zone in the airflow center of the dense phase zone 2 to strongly mix the airflow after being ejected from the airflow injection device 5. This recirculation zone is called an inner recirculation zone. The inner recirculation zone draws in the high-temperature flue gas in the furnace to heat the fly ash jet. When the fly ash jet has a certain amount of heat and reaches the ignition temperature, it can burn again. At the same time, a recirculation zone is also formed on the periphery of the swirl jet. This recirculation zone is called an outer recirculation zone. The outer recirculation zone also draws in high-temperature flue gas to heat the fly ash jet and the gasifying agent jet. Swirling jets have a larger expansion angle than straight jets, significantly enhancing the mixing of airflow and high-temperature flue gas, further facilitating fly ash combustion. Therefore, the provision of the second cyclone 16 addresses the problem of fly ash's poor reactivity and inability to enter the high-temperature oxidation zone. This facilitates fluidization of the biomass and the stable operation of the biomass gasifier 1, further improving the gasification efficiency and carbon conversion rate of the biomass gasifier 1.

[0037] like Figure 1 As shown, the biomass gasifier 1 is provided with a slag discharge pipe 150 at its bottom, at the slag discharge hole 102 of the gasifier. The slag discharge pipe 150 surrounds the airflow injection device 5 and is arranged outside the airflow injection device 5 to form a slag discharge channel between the slag discharge pipe 150 and the airflow injection device 5. Specifically, the slag discharge pipe 150 is arranged to surround the fly ash jet pipe 171 at the first end 501 of the airflow injection device 5. That is, the slag discharge pipe 150 is arranged outside the fly ash jet pipe 171, so that a gap 510 is formed between the slag discharge pipe 150 and the fly ash jet pipe 171. The longitudinal length of the slag discharge pipe 150 is smaller than the longitudinal length of the airflow injection device 5, specifically, smaller than the longitudinal length of the fly ash jet pipe 171 of the airflow injection device 5. Therefore, the waste slag generated during the gasification process can be smoothly discharged from the biomass gasifier 1 through this gap.

[0038] It should be noted that the first jet tube, the second jet tube and the third jet tube cited in this article are not intended to limit the order in which the first jet tube, the second jet tube and the third jet tube are arranged in a ring, but are only used to distinguish the various jet tubes. That is to say, although in the embodiment shown in the present invention, the second jet tube is arranged in a ring between the first jet tube and the third jet tube, that is, the various jet channels in the air flow injection device 5 are, from the inside to the outside, the tar / steam jet channel 19, the gasifying agent jet channel 18 and the fly ash jet channel 17, and the gasifying agent supply device 140 is connected to the second air flow injection channel, but in other embodiments not shown in the present invention, the third jet tube can be arranged in a ring between the first jet tube and the second jet tube, for example, the gasifying agent supply device 140 can be connected to the first air flow injection channel, the second air flow injection channel and the third air flow injection channel. Any one of them is connected to supply gasifying agent to the biomass gasifier 1; the ash return end of the cyclone separator and the low-temperature dust collector 9 can be connected to any one of the first air flow injection channel, the second air flow injection channel and the third air flow injection channel; the tar return end 123 of the tar return device 120 can be connected to any one of the first air flow injection channel, the second air flow injection channel and the third air flow injection channel via the atomizer 12 to atomize the tar and transport it to the biomass gasifier 1. Preferably, the tar and the gasifying agent or fly ash do not share the same air flow injection channel to avoid the atomized tar being condensed into a liquid by the gasifying agent or fly ash. That is to say, the arrangement order of the tar / steam jet channel 19, the gasifying agent jet channel 18 and the fly ash jet channel 17 can be changed according to actual conditions. For example, the gasifying agent jet channel 18 or the fly ash jet channel 17 can be set in the innermost channel. Furthermore, a first swirler can be provided in the second airflow injection channel, and the first swirler is located at the outlet end of the second airflow injection channel. In other words, the swirler can be placed in the outermost layer or the middle layer, or in both layers, depending on the gas flow rate, to form a larger recirculation zone within the furnace.

[0039] According to the fluidized bed gasification equipment 100 of the present invention, which has a fly ash return device 110 and a tar return device 120, the tar and fly ash with a high carbon content generated during the gasification process can be simultaneously returned to the dense phase zone 2 of the biomass gasifier 1 for further reaction, thereby solving the problems of high carbon content in the fly ash and the inability of tar to crack in the biomass fluidized bed. Thus, the gasification efficiency and energy utilization rate of the biomass are improved with a simple process, and environmental pollution is reduced. In addition, the fluidized bed gasification equipment 100 of the present invention, which has a fly ash return device 110 and a tar return device 120, significantly improves the mixing effect of the fly ash, tar, and gasifying agent by providing an airflow injection device 5. It can directly transport the fly ash and tar to the high-temperature oxidation zone of the biomass gasifier, reducing the repeated and ineffective circulation of fine ash and improving the fuel value of the tar and the purity of the synthesis gas.

[0040] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "one example," "some examples," or "preferred embodiment" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0041] The embodiments of the present invention are described in detail above. However, aspects of the present invention are not limited to the above embodiments. Various modifications and substitutions can be applied to the above embodiments without departing from the scope of the present invention.

Claims

1. A fluidized bed gasification device, characterized in that: include: a gasifier having a raw synthesis gas outlet; a fly ash return device having a crude synthesis gas inlet end, a primary synthesis gas outlet end, and an ash return end, wherein the crude synthesis gas inlet end is communicated with the crude synthesis gas outlet of the gasifier so that the crude synthesis gas in the gasifier enters the fly ash return device, and the ash return end is communicated with the gasifier so as to return the fly ash into the gasifier; And a tar return device, having a primary synthesis gas inlet end, a net synthesis gas outlet end and a tar return end, the primary synthesis gas inlet end is connected with the primary synthesis gas outlet end of the fly ash return device, so that the primary synthesis gas enters the tar return device from the fly ash return device, the net synthesis gas outlet end is used to output the net synthesis gas, and the tar return end is connected with the gasifier to return the tar to the gasifier.

2. The fluidized bed gasification equipment according to claim 1, characterized in that: The tar return device includes a decoker and an atomizer, wherein the air inlet end of the decoker is the primary synthesis gas inlet end, the outlet end of the decoker is the clean synthesis gas outlet end, and the return end of the decoker is the tar return end. The tar return end is connected to the gasifier via the atomizer to atomize the tar and return it to the gasifier.

3. The fluidized bed gasification equipment according to claim 2, characterized in that: The atomizer is a steam atomizer.

4. The fluidized bed gasification equipment according to claim 1, characterized in that: The fly ash return device includes a cyclone separator and a dust collector. The air inlet end of the cyclone separator is the raw synthesis gas inlet end, the air outlet end of the cyclone separator is connected to the air inlet end of the dust collector, and the air outlet end of the dust collector is the primary synthesis gas outlet end, which is used to output primary synthesis gas. The cyclone separator and the dust collector both have ash return ends, and the ash return ends of the cyclone separator and the dust collector are both connected to the gasifier.

5. The fluidized bed gasification equipment according to claim 4, characterized in that: A return valve is provided between the cyclone separator and the gasifier, or a heat exchanger is provided between the cyclone separator and the dust collector, or an ash hopper is provided between the dust collector and the gasifier.

6. The fluidized bed gasification equipment according to any one of claims 1 to 5, characterized in that: The fluidized bed gasification equipment also includes at least one air flow injection device, and the air flow injection device is configured to be connected to the fly ash return device and / or the tar return device so that the fly ash and / or the tar are returned to the gasifier through the air flow injection device.

7. The fluidized bed gasification equipment according to claim 6, characterized in that: The airflow injection device comprises: a first jet tube, wherein the first jet tube defines a first airflow jet channel; and a second jet tube annularly arranged on the outer periphery of the first jet tube, wherein the second jet tube defines a second airflow injection channel, and a first swirler is provided in the second airflow injection channel.

8. The fluidized bed gasification equipment according to claim 7, characterized in that: The airflow injection device further includes a third jet tube, which defines a third airflow injection channel. The third jet tube is arranged around the outer circumference of the second jet tube, or the third jet tube is arranged between the first jet tube and the second jet tube.

9. The fluidized bed gasification equipment according to claim 8, characterized in that: A second swirler is provided in the third airflow injection channel, and / or the first jet tube and the second jet tube are coaxially arranged, and / or the first jet tube, the second jet tube and the third jet tube are coaxially arranged, and / or the first swirler is provided at the outlet end of the second airflow injection channel, and / or the second swirler is provided at the outlet end of the third airflow injection channel.

10. The fluidized bed gasification equipment according to claim 9, characterized in that: The fluidized bed gasification equipment includes a gasifying agent supply device, which is connected to any one of the first airflow injection channel, the second airflow injection channel, and the third airflow injection channel to supply the gasifying agent into the gasifier.

11. The fluidized bed gasification equipment according to claim 10, characterized in that: The ash return end is in communication with any one of the first airflow injection channel, the second airflow injection channel, and the third airflow injection channel; And / or, the tar return end of the tar return device is connected to any one of the first airflow injection channel, the second airflow injection channel and the third airflow injection channel via an atomizer to atomize the tar and transport it into the gasifier.

12. The fluidized bed gasification equipment according to claim 11, characterized in that: The tar does not share the same air flow injection channel with the gasifying agent or the fly ash.

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