Biomass powder pneumatic conveying system and commissioning method and shutdown method thereof

Abstract

The invention belongs to the technical field of fire coal coupling biomass power generation, and discloses a biomass powder pneumatic conveying system and a commissioning method and a shutdown method thereof. The biomass powder pneumatic conveying system comprises a pneumatic conveying piece, a feeding device, a gas-solid mixer, a gas-solid separation assembly and a circulating device. An inlet of the pneumatic conveying piece communicates with the outside atmosphere. The feeding device is used for supplying biomass powder; a gas inlet of the gas-solid mixer is communicated with an air outlet of the pneumatic conveying part, and a solid inlet of the gas-solid mixer is communicated with a discharge port of the feeding device; an inlet of the gas-solid separation assembly is communicated with an outlet of the gas-solid mixer, and the gas-solid separation assembly is used for carrying out gas-solid separation on gas flow carrying biomass powder; an inlet of the circulating device is communicated with the outlet section of the gas-solid separation assembly, a solid outlet of the circulating device is communicated with a feeding port of the feeding device, and a gas outlet of the circulating device is communicated with the inlet section of the pneumatic conveying part. High-concentration, large-output and strong-stability conveying of biomass powder can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of coal-fired coupled biomass power generation, and in particular to a biomass powder pneumatic conveying system and an operation method and a shutdown method thereof. Background Art

[0002] As society's demand for energy continues to grow, the utilization rate of resources such as biomass is also increasing. At present, direct biomass combustion power generation has the disadvantages of high investment and low efficiency. Therefore, coal-fired coupled biomass power generation is usually adopted. This is a technology that fully utilizes the value of existing coal-fired power assets and utilizes biomass for energy. The direct combustion of biomass in coal-fired boilers has the advantages of high consumption level, high cycle efficiency, and low construction and operation and maintenance costs. It is widely used in biomass coupling power generation projects. The biomass powder transportation method is the key to the direct combustion of biomass in coal-fired boilers. It determines the scale, stability and energy consumption level of biomass processing.

[0003] Due to the low bulk density and poor fluidity of biomass powder, as well as the fact that the biomass crushing area is relatively far from the boiler combustion area, the existing biomass powder transportation method generally uses pneumatic conveying to transport the crushed biomass powder. However, pneumatic conveying of biomass powder faces problems such as low powder concentration, small conveying volume, and poor stability, making it difficult to meet the needs of large-scale blending of biomass in coal-fired boilers. In addition, pneumatic conveying of low-concentration biomass powder will lead to a decrease in combustion performance in the furnace and a significant increase in the amount of cold air entering the furnace, which is not conducive to ignition / combustion in the furnace and NOx emission control. At the same time, it increases the heat loss of boiler exhaust and reduces the thermal efficiency of the boiler.

[0004] Therefore, there is an urgent need for a biomass powder pneumatic conveying system and an operation method and a shutdown method thereof to solve the above-mentioned technical problems. Summary of the invention

[0005] An object of the present invention is to provide a pneumatic conveying system for biomass powder, which can realize high-concentration, high-output and highly stable conveying of biomass powder.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] Biomass powder pneumatic conveying system includes:

[0008] A pneumatic conveying member, the inlet of which is connected to the outside atmosphere, and the pneumatic conveying member is used to supply air with a preset pressure to form an airflow with a preset pressure to convey the biomass powder;

[0009] A feeding device, the feeding device is used to supply biomass powder;

[0010] A gas-solid mixer, wherein the gas inlet of the gas-solid mixer is connected to the air outlet of the pneumatic conveying member, the solid inlet of the gas-solid mixer is connected to the discharge port of the feeding device, and the gas-solid mixer is used to mix biomass powder and air;

[0011] A gas-solid separation component, wherein the inlet of the gas-solid separation component is connected to the outlet of the gas-solid mixer, and the gas-solid separation component is used to perform gas-solid separation on the airflow carrying the biomass powder, so as to divide the airflow carrying the biomass powder into a dense phase airflow and a dilute phase airflow;

[0012] A circulation device, wherein the inlet of the circulation device is connected to the outlet section of the gas-solid separation component, the solid outlet of the circulation device is connected to the feed inlet of the feeding device, and the gas outlet of the circulation device is connected to the inlet section of the pneumatic conveying member, so as to suck in the dilute phase gas flow and circulate it.

[0013] Optionally, the gas-solid separation component comprises a first main pipeline, the inlet of the first main pipeline is connected to the outlet of the gas-solid mixer, and the outlet of the first main pipeline is used to supply biomass powder to the outside;

[0014] The first main pipeline is provided with an arc-shaped bend, and the arc-shaped bend is used to perform a first-stage gas-solid separation on the airflow carrying the biomass powder;

[0015] A gas-solid separation block is also provided in the first main pipeline. Along the flow direction of the airflow in the first main pipeline, the gas-solid separation block is arranged downstream of the arc bend to perform a second-stage gas-solid separation on the airflow carrying biomass powder; the inlet of the circulation device is connected to the downstream of the gas-solid separation block to inhale the dilute phase airflow.

[0016] Optionally, the circulation device comprises:

[0017] a first circulation pipeline, wherein the inlet of the first circulation pipeline is connected to the outlet section of the gas-solid separation component;

[0018] A cyclone separator, wherein the inlet of the cyclone separator is connected to the outlet of the first circulation pipeline, and the cyclone separator has a gas outlet and a solid outlet;

[0019] a second circulation pipeline, wherein the inlet of the second circulation pipeline is connected to the gas outlet of the cyclone separator, and the outlet of the second circulation pipeline is connected to the inlet section of the pneumatic conveying member;

[0020] A return pipe, the inlet of which is connected to the solid outlet of the cyclone separator, and the outlet of which is connected to the feed inlet of the feeding device.

[0021] Optionally, the feeding device comprises:

[0022] A powder bin, the inlet of which is connected to the feeding device;

[0023] A first screw conveyor, the inlet of which is connected to the powder bin, and the first screw conveyor is arranged horizontally, and is used for screw conveying biomass powder;

[0024] The second screw conveyor, the inlet of the second screw conveyor is connected to the outlet of the first screw conveyor, the outlet of the second screw conveyor is connected to the solid inlet of the gas-solid mixer, and the second screw conveyor is inclined, and the second screw conveyor is used for spiral conveying of biomass powder.

[0025] Optionally, the outlet section of the pneumatic conveying member is provided with a check structure, and the check structure is used to prevent the biomass powder in the gas-solid mixer from flowing back to the pneumatic conveying member; and / or,

[0026] The discharge section of the feeding device is provided with a first air lock, and the first air lock is used to prevent the airflow in the gas-solid mixer from carrying the powder back into the feeding device; and / or,

[0027] The solid outlet section of the circulation device is provided with a second air lock, and the second air lock is used to prevent the airflow in the circulation device from flowing into the feeding device.

[0028] Optionally, the inlet section of the pneumatic conveying member is provided with a first regulating valve to adjust the amount of external air entering; and / or,

[0029] The outlet section of the circulation device is provided with a second regulating valve to adjust the amount of circulating air.

[0030] Optionally, the outlet section of the pneumatic conveying member is provided with swirl blades to increase the turbulence of the conveying air.

[0031] Optionally, the gas-solid mixer is a Venturi structure.

[0032] Another object of the present invention is to provide a method for operating a biomass powder pneumatic conveying system, which can achieve high-concentration, high-output and highly stable conveying of biomass powder.

[0033] To achieve this object, the present invention adopts the following technical solutions:

[0034] The biomass powder pneumatic conveying system operation method uses the above-mentioned biomass powder pneumatic conveying system, and the above-mentioned biomass powder pneumatic conveying system operation method comprises the following steps:

[0035] S110, closing the first regulating valve between the pneumatic conveying member and the outside atmosphere and the second regulating valve between the circulation device and the pneumatic conveying member, and starting the pneumatic conveying member;

[0036] S120, opening the first regulating valve and adjusting the conveying pressure of the pneumatic conveying member;

[0037] S130, sequentially operating the second screw conveyor, the first air lock and the first screw conveyor of the feeding device to start the feeding device;

[0038] S140, putting into operation the second air lock of the solid outlet of the circulation device, and opening the second regulating valve to start the circulation device;

[0039] S150, adjusting the opening of the first regulating valve and the second regulating valve to change the circulating air ratio;

[0040] S160, feeding biomass powder into the feed port of the feeding device, and adjusting the operating frequency of the first screw conveyor and the second screw conveyor to change the feeding amount of the biomass powder.

[0041] Another object of the present invention is to provide a method for shutting down a biomass powder pneumatic conveying system, which can achieve high-concentration, high-output and highly stable conveying of biomass powder.

[0042] To achieve this object, the present invention adopts the following technical solutions:

[0043] A method for shutting down a biomass powder pneumatic conveying system, using the above-mentioned biomass powder pneumatic conveying system, the above-mentioned method for shutting down a biomass powder pneumatic conveying system comprises the following steps:

[0044] S210, stop feeding the biomass powder into the feeding device, and observe the position of the biomass powder in the powder bin of the feeding device;

[0045] S220, after the biomass powder in the powder bin is consumed and maintained for a first preset time, the first screw conveyor, the first air lock, and the second screw conveyor are sequentially stopped to close the feeding device;

[0046] S230, closing the second regulating valve and stopping the second air lock to close the above-mentioned circulation device;

[0047] S240, maintaining the pneumatic conveying component for a second preset time, stopping the pneumatic conveying component, and closing the first regulating valve.

[0048] Beneficial effects of the present invention:

[0049] The present invention provides a biomass powder pneumatic conveying system and its operation method and shutdown method. By setting a gas-solid separation component, a resistance to the airflow carrying the biomass powder is formed to impact the airflow, achieve gas-solid mixing and separation, thereby forming a dense phase airflow and a dilute phase airflow. The dense phase airflow is used for output, which improves the concentration, delivery volume and stability of the biomass powder in the airflow output by the biomass powder pneumatic conveying system, improves the ignition / combustion performance of the biomass and the stable combustion capacity of the boiler, reduces the emission of pollutants such as NOx, and reduces the amount of air entering the boiler, reduces the heat loss of boiler exhaust, and improves the thermal efficiency of the boiler. In addition, the dilute phase airflow is recycled again through a circulation device, which improves the utilization rate of the biomass powder pneumatic conveying system and helps to save energy and reduce emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a working principle diagram of a biomass powder pneumatic conveying system provided in a specific embodiment of the present invention.

[0051] In the figure:

[0052] 10. Pneumatic conveying parts; 11. High-pressure fan; 12. Second main pipeline; 13. Third main pipeline; 14. Swirl blades;

[0053] 20. Feeding device; 21. Powder bin; 22. First screw conveyor; 23. Second screw conveyor; 24. Cone structure;

[0054] 30. Gas-solid mixer;

[0055] 40. gas-solid separation assembly; 41. first main pipeline; 42. arc-shaped bend; 43. gas-solid separation block;

[0056] 50. Circulation device; 51. First circulation pipeline; 52. Cyclone separator; 53. Second circulation pipeline; 54. Return pipe;

[0057] 60. Check structure; 70. First air lock; 80. Second air lock; 90. First regulating valve; 100. Second regulating valve. DETAILED DESCRIPTION

[0058] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0059] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0061] In the description of this embodiment, the terms "upper", "lower", "left", "right", etc., and the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplified operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0062] Refer to the following Figure 1 The invention introduces a biomass powder pneumatic conveying system and its operation method and shutdown method.

[0063] It should be noted that Figure 1 The direction of the arrow in the biomass powder pneumatic conveying system is the flow direction of the airflow for conveying the biomass powder.

[0064] This embodiment provides a biomass powder pneumatic conveying system, which conveys biomass powder by pneumatic means.

[0065] Please refer to Figure 1Specifically, the biomass powder pneumatic conveying system includes a pneumatic conveying member 10, a feeding device 20, a gas-solid mixer 30, a gas-solid separation component 40 and a circulation device 50. Among them, the inlet of the pneumatic conveying member 10 is connected to the outside atmosphere, and the pneumatic conveying member 10 is used to supply air with a preset pressure to form an airflow with a preset pressure to convey biomass powder; the feeding device 20 is used to supply biomass powder; the gas inlet of the gas-solid mixer 30 is connected to the air outlet of the pneumatic conveying member 10, and the solid inlet of the gas-solid mixer 30 is connected to the discharge port of the feeding device 20, and the gas-solid mixer 30 is used to mix the biomass powder and air; the inlet of the gas-solid separation component 40 is connected to the outlet of the gas-solid mixer 30, and the gas-solid separation component 40 is used to perform gas-solid separation on the airflow carrying the biomass powder to divide the airflow carrying the biomass powder into a dense phase airflow and a dilute phase airflow; the inlet of the circulation device 50 is connected to the outlet section of the gas-solid separation component 40, the solid outlet of the circulation device 50 is connected to the feed port of the feeding device 20, and the gas outlet of the circulation device 50 is connected to the inlet section of the pneumatic conveying member 10 to inhale the dilute phase airflow and recycle it.

[0066] When in use, the air with a preset pressure output by the pneumatic conveying component 10 forms an airflow, which flows into the gas-solid mixer 30 to mix with the biomass powder, and carries the biomass powder to the gas-solid separation component 40 to realize the formation of dense phase airflow and dilute phase airflow. The dense phase airflow flows out to the output port to increase the concentration of biomass powder in the output airflow and reduce the output of gas; while the dilute phase airflow returns the air and biomass powder to the corresponding pneumatic conveying component 10 and feeding device 20 respectively through the circulation device 50 for recycling.

[0067] The biomass powder pneumatic conveying system in this embodiment forms resistance to the airflow carrying the biomass powder by setting up the gas-solid separation component 40 to impact the airflow, achieve gas-solid mixing and separation, thereby forming dense phase airflow and dilute phase airflow. The dense phase airflow is used for output, which improves the concentration, delivery volume and stability of the biomass powder in the airflow output by the biomass powder pneumatic conveying system, improves the ignition / combustion performance of the biomass and the stable combustion capacity of the boiler, reduces the emission of pollutants such as NOx, and reduces the amount of air entering the boiler, reduces the heat loss of boiler exhaust, and improves the thermal efficiency of the boiler. In addition, the dilute phase airflow is recycled again through the circulation device 50, which improves the utilization rate of the biomass powder pneumatic conveying system and helps to save energy and reduce emissions.

[0068] It should be noted that the above-mentioned preset pressure is the required pressure, that is, it is set according to the required air flow rate in the biomass powder pneumatic conveying system, and is not specifically limited here.

[0069] Please continue to refer to Figure 1In this embodiment, the pneumatic conveying member 10 includes a high-pressure blower 11, a second main pipeline 12 and a third main pipeline 13. The inlet of the second main pipeline 12 is connected to the outside atmosphere, the inlet of the high-pressure blower 11 is connected to the second main pipeline 12, the outlet of the high-pressure blower 11 is connected to the inlet of the third main pipeline 13, and the outlet of the third main pipeline 13 is connected to the gas-solid mixer 30. When in use, the high-pressure blower 11 drives the second main pipeline 12 to absorb air from the outside atmosphere and transport it to the third main pipeline 13, so that the third main pipeline 13 is circulated with air with a preset pressure.

[0070] Specifically, the high-pressure fan 11 is equipped with a variable frequency, explosion-proof motor to achieve the change of the operating frequency of the high-pressure fan 11, and has an explosion-proof function to improve safety.

[0071] Optionally, the pressure head of the high-pressure blower 11 has a pressure range of 10 kPa to 70 kPa to meet the transportation requirements of biomass powder in common boilers and other structures.

[0072] Furthermore, the inlet section of the pneumatic conveying member 10 is provided with a first regulating valve 90 . Specifically, the first regulating valve 90 is arranged in the second main pipeline 12 to adjust the amount of external air entering, thereby adjusting the supply amount of the airflow.

[0073] Optionally, the first regulating valve 90 is an electric explosion-proof valve or a pneumatic explosion-proof valve, that is, it can realize the opening, closing or regulation of the second main pipeline 12, which is not specifically limited here.

[0074] Furthermore, the outlet section of the pneumatic conveying component 10 is provided with a check structure 60. Specifically, the check structure 60 is arranged on the third main pipeline 13. The check structure 60 is used to prevent the biomass powder in the gas-solid mixer 30 from flowing back to the pneumatic conveying component 10, thereby avoiding the backflow of airflow when the pressure of the output structure such as the boiler is too high, thereby causing damage to various structures such as the high-pressure fan 11 in the pneumatic conveying component 10, thereby improving the reliability and safety of the use of various structures in the pneumatic conveying component 10.

[0075] Furthermore, the outlet section of the pneumatic conveying member 10 is provided with a swirl blade 14. Specifically, the swirl blade 14 is arranged on the third main pipeline 13 to increase the turbulence of the conveying air, to strengthen the mixing of the biomass powder and air in the gas-solid mixer 30, and to prevent the accumulation of the biomass powder.

[0076] In this embodiment, the feeding device 20 includes a powder bin 21, a first screw conveyor 22, and a second screw conveyor 23. The inlet of the powder bin 21 is connected to the feeding device; the inlet of the first screw conveyor 22 is connected to the powder bin 21, and the first screw conveyor 22 is horizontally arranged, and the first screw conveyor 22 is used for the spiral conveying of biomass powder; the inlet of the second screw conveyor 23 is connected to the outlet of the first screw conveyor 22, and the outlet of the second screw conveyor 23 is connected to the solid inlet of the gas-solid mixer 30, and the second screw conveyor 23 is inclined, and the second screw conveyor 23 is used for the spiral conveying of biomass powder. When in use, the operator can put biomass powder into the powder bin 21, and the biomass powder is mixed by the two screw conveyors in turn through the outlet of the powder bin 21, so as to improve the mixing uniformity and convey the biomass powder, thereby achieving more uniform transportation of the biomass powder. Furthermore, the first screw conveyor 22 is arranged horizontally, and the second screw conveyor 23 is arranged obliquely, which greatly reduces the accumulation and clogging of the biomass powder and improves the conveying effect of the biomass powder.

[0077] Specifically, the powder bin 21 is an inverted trapezoidal structure, and a large opening at the top serves as a feed inlet to enable external feeding or input of recycled materials from the circulation device 50 .

[0078] Optionally, a cone structure 24 is provided in the powder bin 21 to prevent the biomass powder from arching, thereby improving the flow effect of the biomass powder in the powder bin 21 .

[0079] Specifically, the side wall of the discharge port of the first screw conveyor 22 is an inclined wall to prevent the accumulation and blockage of the biomass powder, so that all the biomass powder can be put into the second screw conveyor 23.

[0080] Optionally, the first screw conveyor 22 and the second screw conveyor 23 are both equipped with variable frequency, explosion-proof motors to dynamically and accurately adjust the feeding amount of the biomass powder.

[0081] Furthermore, the first screw conveyor 22 and the second screw conveyor 23 adopt a shaftless screw conveying structure, which greatly improves the anti-winding performance of the screw conveying and avoids blockage.

[0082] Furthermore, the discharge section of the feeding device 20 is provided with a first air lock 70, which is used to prevent the airflow in the gas-solid mixer 30 from carrying powder back into the feeding device 20. Specifically, the first air lock 70 is arranged between the first screw conveyor 22 and the second screw conveyor 23 to prevent the airflow from carrying powder back into the feeding device 20.

[0083] In this embodiment, the gas-solid mixer 30 is a Venturi structure, that is, a structure in which the diameter at the throat is smaller than the diameter of the main body, which can increase the air flow rate at the throat and improve the mixing effect of biomass powder and air. At the same time, it can reduce the static pressure at the throat and prevent the return of biomass powder, thereby improving the reliability of the gas-solid mixer 30.

[0084] Optionally, the air velocity at the throat of the gas-solid mixer 30 is selected to be 50 m / s to 100 m / s, which can meet the requirements of improving the gas-solid mixing effect and preventing the return of biomass powder.

[0085] In this embodiment, the gas-solid separation component 40 includes a first main pipeline 41, the inlet of the first main pipeline 41 is connected to the outlet of the gas-solid mixer 30, and the outlet of the first main pipeline 41 is used to supply biomass powder to the outside; the first main pipeline 41 is provided with an arc bend 42, and the arc bend 42 is used to perform the first-stage gas-solid separation on the airflow carrying the biomass powder; the first main pipeline 41 is also provided with a gas-solid separation block 43, and along the flow direction of the airflow in the first main pipeline 41, the gas-solid separation block 43 is arranged downstream of the arc bend 42 to perform the second-stage gas-solid separation on the airflow carrying the biomass powder; the inlet of the circulation device 50 is connected to the downstream of the gas-solid separation block 43 to inhale the dilute phase airflow. In this arrangement, when the airflow carrying the biomass powder flows through the first main pipeline 41, it is subjected to two gas-solid separations by the pipe wall of the arc bend 42 and the gas-solid separation block 43, thereby realizing the concentration and separation of the biomass powder in the airflow, so as to realize the separation of the dense phase airflow and the dilute phase airflow. In addition, the arc bend 42, the gas-solid separation block 43 and the circulation device 50 are arranged in sequence along the flow direction of the airflow in the first main pipeline 41, so that the airflow carrying the biomass powder is separated twice and the dense phase airflow and the dilute phase airflow are directly separated and flowed out to avoid the airflow from mixing again.

[0086] Specifically, the air flow velocity in the first main pipeline 41 is 14 m / s to 30 m / s, which can realize the flow of the air flow in the first main pipeline 41, ensure the transportation, separation and recycling of the biomass powder, and avoid deposition.

[0087] Optionally, the arc-shaped bend 42 adopts a wear-resistant elbow with a large curvature radius, which can reduce the friction resistance during flow, has good wear resistance, and is better for separating the dense phase and the dilute phase in the airflow.

[0088] Further optionally, the gas-solid separation block 43 is made of wear-resistant parts, and the cross-sectional area of ​​the gas-solid separation block 43 accounts for 1 / 4 to 1 / 3 of the cross-sectional area of ​​the pipeline; such a configuration better realizes the separation of gas and solid, and realizes the separation of dense phase gas flow and dilute phase.

[0089] Optionally, the gas-solid separation block 43 is in a trapezoidal shape, an arc shape, a triangle shape, etc., which is not specifically limited herein. Exemplarily, the gas-solid separation block 43 is in a trapezoidal shape, which has a better separation effect.

[0090] In this embodiment, the circulation device 50 includes a first circulation pipe 51, a cyclone separator 52, a second circulation pipe 53 and a return pipe 54. The inlet of the first circulation pipe 51 is connected to the outlet section of the gas-solid separation component 40; the inlet of the cyclone separator 52 is connected to the outlet of the first circulation pipe 51, and the cyclone separator 52 has a gas outlet and a solid outlet; the inlet of the second circulation pipe 53 is connected to the gas outlet of the cyclone separator 52, and the outlet of the second circulation pipe 53 is connected to the inlet section of the pneumatic conveying member 10, that is, the second main pipe 12; the inlet of the return pipe 54 is connected to the solid outlet of the cyclone separator 52, and the outlet of the return pipe 54 is connected to the feed port of the feeding device 20, that is, the feed port of the powder bin 21. The dilute phase airflow enters the cyclone separator 52 through the first circulation pipe 51 for gas-solid separation, wherein the residual biomass powder flows into the return pipe 54 through the solid outlet of the cyclone separator 52 and flows to the feeding device 20 for secondary utilization, and the residual air flows into the second circulation pipe 53 through the gas outlet of the cyclone separator 52 and flows back to the inlet section of the pneumatic conveying member 10 for secondary utilization.

[0091] Optionally, the air flow rate in the first circulation duct 51 is 10 m / s to 30 m / s, which can achieve the suction and transportation of dilute phase airflow.

[0092] Furthermore, a second air lock 80 is provided at the solid outlet section of the circulation device 50 , that is, a second air lock 80 is provided on the return pipe 54 , and the second air lock 80 is used to prevent the airflow in the circulation device 50 from flowing into the feeding device 20 .

[0093] Furthermore, the outlet section of the circulation device 50 is provided with a second regulating valve 100 to adjust the amount of air to be circulated. In addition, the first regulating valve 90 and the second regulating valve 100 cooperate to adjust the circulating air ratio.

[0094] It should be noted that the circulating air ratio is the percentage of the air volume of the circulating air flow to the total transported air volume.

[0095] Optionally, the circulating air ratio is usually selected to be 20% to 60%, which can meet the use of common biomass powder pneumatic conveying systems.

[0096] Optionally, the second regulating valve 100 is an electric explosion-proof valve or a pneumatic explosion-proof valve, that is, it can realize the opening, closing or regulation of the second circulating pipeline, which is not specifically limited here.

[0097] This embodiment also provides a method for commissioning a biomass powder pneumatic conveying system to realize the operation of the biomass powder pneumatic conveying system and the conveying of biomass powder.

[0098] Specifically, the biomass powder pneumatic conveying system described in any of the above schemes is used, and the operation method of the biomass powder pneumatic conveying system includes the following steps:

[0099] Step S110, close the first regulating valve 90 between the pneumatic conveying member 10 and the outside atmosphere and the second regulating valve 100 between the circulation device 50 and the pneumatic conveying member 10, and start the pneumatic conveying member 10; that is, first check whether it has entered the fully closed state, and then start the pneumatic conveying member 10, which also avoids the residual biomass powder in the pipeline and other structures from flowing to the inlet section of the pneumatic conveying member 10 and causing damage.

[0100] Step S110 is followed by step S120, opening the first regulating valve 90 and adjusting the conveying pressure of the pneumatic conveying member 10; thus, the input of air with a preset pressure is realized, thereby forming an airflow with a preset pressure to purge each pipeline.

[0101] Step S120 also includes step S130, sequentially operating the second screw conveyor 23, the first air lock 70 and the first screw conveyor 22 of the feeding device 20 to start the feeding device 20; this arrangement avoids blockage of the two screw conveyors during the conveying process when there is material stored in the powder bin 21, thereby improving safety of use.

[0102] After step S130, the process further includes step S140, in which the second air lock 80 at the solid outlet of the circulation device 50 is put into operation, and the second regulating valve 100 is opened to start the circulation device 50; that is, the circulation device 50 is opened and used.

[0103] Step S140 is followed by step S150, in which the openings of the first regulating valve 90 and the second regulating valve 100 are adjusted to change the circulating air ratio; the ratio is adjusted to meet the usage demand value so as to better transport the biomass powder to the outside.

[0104] After step S150, the process further includes step S160, in which biomass powder is fed into the feed port of the feeding device 20, and the operating frequencies of the first screw conveyor 22 and the second screw conveyor 23 are adjusted to change the feeding amount of the biomass powder. After each device is opened and air is purged, the biomass powder can be fed in to transport the biomass powder.

[0105] Through the above-mentioned biomass powder pneumatic conveying system operation method, its use safety is improved, the damage of residual powder to various structures and pipelines in the conveying system is avoided, the reliability of the operation of the biomass powder pneumatic conveying system is improved, and high-concentration, high-output and highly stable conveying of biomass powder can be achieved.

[0106] This embodiment also provides a method for shutting down a biomass powder pneumatic conveying system, so as to shut down the equipment of the biomass powder pneumatic conveying system and clean the equipment.

[0107] Specifically, the method for shutting down a biomass powder pneumatic conveying system uses the biomass powder pneumatic conveying system described in any of the above schemes, and the method for shutting down a biomass powder pneumatic conveying system comprises the following steps:

[0108] Step S210, stop feeding biomass powder into the feeding device 20, and observe the position of the biomass powder in the powder bin 21 of the feeding device 20; and stop the operation of the feeding device 20 after all the biomass powder in the feeding device 20 is delivered as much as possible.

[0109] Step S210 also includes step S220, after the biomass powder in the powder bin 21 is consumed and maintained for a first preset time, the first screw conveyor 22, the first air lock 70 and the second screw conveyor 23 are stopped in sequence to close the feeding device 20; after all the powder is delivered, they are stopped in sequence in the opposite direction of the order when they were opened to avoid residual biomass powder and the occurrence of material suffocation.

[0110] Step S220 also includes step S230, closing the second regulating valve 100, stopping the second air lock 80 to close the circulation device 50; and after the feeding device 20, the biomass powder in the pipeline of the conveying system is gradually emptied, so the circulation device 50 is also purged by the airflow, so that the circulation device 50 can be closed.

[0111] After step S230, the method further includes step S240, maintaining the pneumatic conveying member 10 for a second preset time, stopping the pneumatic conveying member 10, and closing the first regulating valve 90. The main pipeline of the conveying system is purged to clean the conveying system, avoid residual powder, and avoid the occurrence of material return in the boiler.

[0112] Through the above-mentioned biomass powder pneumatic conveying system commissioning method, the conveying system is shut down and cleaned, the safety of its use is improved, the damage of residual powder to various structures and pipelines in the conveying system is avoided, and the reliability of the operation of the biomass powder pneumatic conveying system is improved.

[0113] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Biomass powder pneumatic conveying system, characterized in that: include: A pneumatic conveying member (10), wherein the inlet of the pneumatic conveying member (10) is connected to the outside atmosphere, and the pneumatic conveying member (10) is used to supply air with a preset pressure to form an airflow with a preset pressure to convey the biomass powder; A feeding device (20), the feeding device (20) being used to supply biomass powder; A gas-solid mixer (30), wherein the gas inlet of the gas-solid mixer (30) is connected to the air outlet of the pneumatic conveying member (10), and the solid inlet of the gas-solid mixer (30) is connected to the discharge port of the feeding device (20), and the gas-solid mixer (30) is used to mix biomass powder and air; A gas-solid separation component (40), wherein the inlet of the gas-solid separation component (40) is connected to the outlet of the gas-solid mixer (30), and the gas-solid separation component (40) is used to perform gas-solid separation on the airflow carrying the biomass powder, so as to divide the airflow carrying the biomass powder into a dense phase airflow and a dilute phase airflow; A circulation device (50), wherein the inlet of the circulation device (50) is connected to the outlet section of the gas-solid separation component (40), the solid outlet of the circulation device (50) is connected to the feed inlet of the feeding device (20), and the gas outlet of the circulation device (50) is connected to the inlet section of the pneumatic conveying member (10), so as to suck in the dilute phase gas flow and circulate it.

2. The biomass powder pneumatic conveying system according to claim 1, characterized in that: The gas-solid separation component (40) comprises a first main pipeline (41), the inlet of the first main pipeline (41) is connected to the outlet of the gas-solid mixer (30), and the outlet of the first main pipeline (41) is used to supply biomass powder to the outside; The first main pipeline (41) is provided with an arc-shaped bend (42), and the arc-shaped bend (42) is used to perform a first-stage gas-solid separation on the airflow carrying the biomass powder; A gas-solid separation block (43) is also provided in the first main pipeline (41). The gas-solid separation block (43) is arranged downstream of the arc-shaped bend (42) along the flow direction of the airflow in the first main pipeline (41) to perform a second-stage gas-solid separation on the airflow carrying biomass powder; the inlet of the circulation device (50) is connected to the downstream of the gas-solid separation block (43) to inhale the dilute phase airflow.

3. The biomass powder pneumatic conveying system according to claim 1, characterized in that: The circulation device (50) comprises: a first circulation pipeline (51), wherein the inlet of the first circulation pipeline (51) is connected to the outlet section of the gas-solid separation component (40); a cyclone separator (52), wherein the inlet of the cyclone separator (52) is connected to the outlet of the first circulation pipeline (51), and the cyclone separator (52) has a gas outlet and a solid outlet; a second circulation pipeline (53), wherein the inlet of the second circulation pipeline (53) is connected to the gas outlet of the cyclone separator (52), and the outlet of the second circulation pipeline (53) is connected to the inlet section of the pneumatic conveying member (10); A return pipe (54), the inlet of the return pipe (54) is connected to the solid outlet of the cyclone separator (52), and the outlet of the return pipe (54) is connected to the feed port of the feeding device (20).

4. The biomass powder pneumatic conveying system according to claim 1, characterized in that: The feeding device (20) comprises: A powder bin (21), the inlet of which is connected to a feeding device; A first screw conveyor (22), wherein the inlet of the first screw conveyor (22) is connected to the powder bin (21), and the first screw conveyor (22) is arranged horizontally, and the first screw conveyor (22) is used for screw conveying biomass powder; A second screw conveyor (23), wherein the inlet of the second screw conveyor (23) is connected to the outlet of the first screw conveyor (22), the outlet of the second screw conveyor (23) is connected to the solid inlet of the gas-solid mixer (30), and the second screw conveyor (23) is arranged at an angle, and the second screw conveyor (23) is used for screw conveying of biomass powder.

5. The biomass powder pneumatic conveying system according to claim 1, characterized in that: The outlet section of the pneumatic conveying member (10) is provided with a check structure (60), and the check structure (60) is used to prevent the biomass powder in the gas-solid mixer (30) from flowing back to the pneumatic conveying member (10); and / or, The discharge section of the feeding device (20) is provided with a first air lock (70), and the first air lock (70) is used to prevent the airflow in the gas-solid mixer (30) from carrying powder back into the feeding device (20); and / or, The solid outlet section of the circulation device (50) is provided with a second air lock (80), and the second air lock (80) is used to prevent the air flow in the circulation device (50) from flowing into the feeding device (20).

6. The biomass powder pneumatic conveying system according to claim 1, characterized in that: The inlet section of the pneumatic conveying member (10) is provided with a first regulating valve (90) to adjust the amount of external air entering; and / or, The outlet section of the circulation device (50) is provided with a second regulating valve (100) to adjust the amount of circulating air.

7. The biomass powder pneumatic conveying system according to claim 1, characterized in that: The outlet section of the pneumatic conveying member (10) is provided with swirl blades (14) to increase the turbulence of the conveying air.

8. The biomass powder pneumatic conveying system according to claim 1, characterized in that: The gas-solid mixer (30) is a Venturi structure.

9. The operation method of the biomass powder pneumatic conveying system is characterized in that: Using the biomass powder pneumatic conveying system as described in any one of claims 1 to 8, the operation method of the biomass powder pneumatic conveying system comprises the following steps: S110, closing the first regulating valve (90) between the pneumatic conveying member (10) and the outside atmosphere and the second regulating valve (100) between the circulation device (50) and the pneumatic conveying member (10), and starting the pneumatic conveying member (10); S120, opening the first regulating valve (90) and adjusting the conveying pressure of the pneumatic conveying member (10); S130, sequentially operating the second screw conveyor (23), the first air lock (70) and the first screw conveyor (22) of the feeding device (20) to start the feeding device (20); S140, putting into operation the second air lock (80) at the solid outlet of the circulation device (50), and opening the second regulating valve (100) to start the circulation device (50); S150, adjusting the openings of the first regulating valve (90) and the second regulating valve (100) to change the circulating air ratio; S160, feeding biomass powder into the feed port of the feeding device (20), adjusting the operating frequency of the first screw conveyor (22) and the second screw conveyor (23) to change the feeding amount of the biomass powder.

10. A method for shutting down a biomass powder pneumatic conveying system, characterized in that: Using the biomass powder pneumatic conveying system as described in any one of claims 1 to 8, the method for shutting down the biomass powder pneumatic conveying system comprises the following steps: S210, stopping feeding biomass powder into the feeding device (20), and observing the position of the biomass powder in the powder bin (21) of the feeding device (20); S220, after the biomass powder in the powder bin (21) is consumed and maintained for a first preset time, the first screw conveyor (22), the first air lock (70) and the second screw conveyor (23) are stopped in sequence to close the feeding device (20); S230, closing the second regulating valve (100), stopping the second air lock (80), and closing the circulation device (50); S240, maintaining the purge of the pneumatic conveying component (10) for a second preset time, stopping the pneumatic conveying component (10), and closing the first regulating valve (90).

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