A combined pneumatic conveying system for fly ash from a coal-fired power station and its operation method

Abstract

The present invention discloses a combined pneumatic conveying system for fly ash of a coal-fired power station, comprising a pneumatic dust collection and delivery system, a transfer system, a terminal ash unloading system and a fly ash loading system. The pneumatic dust collection and delivery system is connected to the transfer system through a first conveying pipe and a second conveying pipe, and the transfer system is connected to the fly ash loading system through a third conveying pipe, a fourth conveying pipe and a fifth conveying pipe. An air dispersion channel is formed between the first sleeve and the second sleeve, and the second sleeve is provided with a plurality of air dispersion holes arranged along the axial direction. An operation method is also disclosed. The combined pneumatic conveying system for fly ash of a coal-fired power station of the present invention utilizes various conveying pipes with air dispersion to combine the pneumatic dust collection and delivery system, the terminal ash unloading system and the fly ash loading system into a conveying system that is not prone to ash blockage and has low maintenance costs; the operation method of the present invention can ensure that various material conveying units using the same conveying line will not convey materials at the same time, and there will be no problem of overloading of the conveying pipeline.

Description

Technical Field

[0001] The invention relates to a combined pneumatic conveying system for fly ash from a coal-fired power station and an operating method thereof, belonging to the technical field of material conveying. Background Art

[0002] With the improvement of economic level, the development of industrial technology is getting faster and faster. Pneumatic conveying plays an important role in industrial growth. Pneumatic conveying is to use the power of airflow to convey granular materials along the airflow direction in a closed pipeline. It is a specific application of fluidization technology. With the continuous improvement of production scale, the requirements for conveying distance are getting higher and higher. However, with the growth of pipelines and the increase of height difference, the difficulty of conveying is getting greater and greater. When the length exceeds a certain limit, long ash plugs often appear in the material conveying pipeline, causing pipeline blockage. Summary of the invention

[0003] The object of the present invention is to provide a combined pneumatic conveying system for fly ash of a coal-fired power plant and an operating method thereof, which solves the problem of conveying pipe blockage by using each conveying pipe that can cut off a long ash plug.

[0004] In order to solve the above technical problems, the present invention adopts the following technical scheme: a combined pneumatic conveying system for fly ash of a coal-fired power plant, comprising a pneumatic dust collection and delivery system, a transfer system, a terminal ash unloading system and a fly ash loading system, the pneumatic dust collection and delivery system is connected to the transfer system through a first conveying pipe and a second conveying pipe, and the transfer system is connected to the fly ash loading system through a third conveying pipe, a fourth conveying pipe and a fifth conveying pipe; it also comprises a sixth conveying pipe, a seventh conveying pipe and an eighth conveying pipe, one end of the sixth conveying pipe is connected to the third conveying pipe, and the other end is connected to the terminal ash unloading system, one end of the seventh conveying pipe is connected to the fourth conveying pipe, and the other end is connected to the terminal ash unloading system, one end of the eighth conveying pipe is connected to the fifth conveying pipe, and the other end is connected to the terminal ash unloading system, the first conveying pipe, the second conveying pipe, the third conveying pipe, the fourth conveying pipe, the fifth conveying pipe, the sixth conveying pipe, the seventh conveying pipe and the eighth conveying pipe comprise a first sleeve and a second sleeve, the diameter of the second sleeve is smaller than that of the first sleeve, an air dispersion channel is formed between the first sleeve and the second sleeve, and a plurality of air dispersion holes arranged along the axial direction are arranged on the second sleeve.

[0005] In the aforementioned combined pneumatic conveying system of fly ash of a coal-fired power plant, the pneumatic dust collection and sending system includes a first group of dust collection and sending devices, a second group of dust collection and sending devices, a third group of dust collection and sending devices and a fourth group of dust collection and sending devices. The first group of dust collection and sending devices and the second group of dust collection and sending devices are connected to the transfer system through a first conveying pipe, and the third group of dust collection and sending devices and the fourth group of dust collection and sending devices are connected to the transfer system through a second conveying pipe.

[0006] In the aforementioned combined pneumatic conveying system for fly ash from a coal-fired power plant, the first group of dust collecting and sending devices, the second group of dust collecting and sending devices, the third group of dust collecting and sending devices and the fourth group of dust collecting and sending devices all include an electrostatic precipitator and a plurality of pneumatic ash removal pumps, a gasification air duct, a conveying compressed air duct and a compressed air storage tank arranged below the electrostatic precipitator. The plurality of pneumatic ash removal pumps are connected in series through an ash conveying pipe, the pneumatic ash removal pump is connected to the ash hopper of the electrostatic precipitator, the ash hopper is connected to the gasification air duct, the ash conveying pipe is connected to the conveying compressed air duct, and the conveying compressed air duct is connected to the compressed air storage tank.

[0007] In the aforementioned combined pneumatic conveying system of fly ash in a coal-fired power plant, the transfer system includes a fine ash transfer warehouse, a first coarse ash transfer warehouse and a second coarse ash transfer warehouse, and dry ash bulkers are arranged at the bottom of the fine ash transfer warehouse, the bottom of the first coarse ash transfer warehouse and the second coarse ash transfer warehouse, a transfer ash conveying pump is arranged at the bottom of the fine ash transfer warehouse, and two transfer ash conveying pumps are arranged at the bottom of the first coarse ash transfer warehouse and the second coarse ash transfer warehouse. The transfer ash conveying pump arranged at the bottom of the fine ash transfer warehouse is connected to the third conveying pipe, the transfer ash conveying pump arranged at the bottom of the first coarse ash transfer warehouse is connected to the third conveying pipe, the other transfer ash conveying pump arranged at the bottom of the first coarse ash transfer warehouse is connected to the fourth conveying pipe, the transfer ash conveying pump arranged at the bottom of the second coarse ash transfer warehouse is connected to the fourth conveying pipe, and the other transfer ash conveying pump arranged at the bottom of the second coarse ash transfer warehouse is connected to the fifth conveying pipe.

[0008] In the aforementioned combined pneumatic conveying system for fly ash from a coal-fired power plant, the terminal ash unloading system includes a terminal fine ash bin, a first terminal coarse ash bin, and a second terminal coarse ash bin, the terminal fine ash bin is connected to the sixth conveying pipe, the first terminal coarse ash bin is connected to the sixth conveying pipe, the seventh conveying pipe and / or the eighth conveying pipe, and the second terminal coarse ash bin is connected to the eighth conveying pipe and / or the seventh conveying pipe.

[0009] In the aforementioned combined pneumatic conveying system for fly ash from a coal-fired power plant, the fly ash loading system includes a buffer tank and a screw ash loader, the screw ash loader is connected to the buffer tank, and the terminals of the third conveying pipe, the fourth conveying pipe and the fifth conveying pipe are connected to the buffer tank.

[0010] In the aforementioned combined pneumatic conveying system for fly ash from a coal-fired power plant, both the first conveying pipe and the second conveying pipe are provided with a top switching valve.

[0011] In the aforementioned combined pneumatic conveying system for fly ash from a coal-fired power station, a pipeline switching valve is provided on the ash conveying pipe.

[0012] In the aforementioned combined pneumatic conveying system for fly ash from a coal-fired power plant, the sixth conveying pipe, the seventh conveying pipe and the eighth conveying pipe are all provided with a storage top switching valve.

[0013] The operation method of the above-mentioned coal-fired power plant fly ash combined pneumatic conveying system comprises the following steps:

[0014] Step S01: Check whether the start interlock condition of the pneumatic dust collection and delivery system meets the set value;

[0015] Step S02: When the startup interlocking condition of the checked pneumatic dust collection and delivery system meets the set value, a material conveying cycle is run; the running of a material conveying cycle includes the following running steps:

[0016] Step S021: selecting a group of dust collecting and sending devices as a material conveying unit;

[0017] Open the switching valve of the conveying pipe corresponding to the dust collecting and sending device as the material conveying unit;

[0018] Close the switching valve on the conveying pipe corresponding to the unselected dust collecting and sending device;

[0019] Step S02: Open the feed port of the pneumatic ash removal pump on the material conveying line;

[0020] Open the exhaust valve of the ash conveying pump on the material conveying line;

[0021] Start the material filling delay timer;

[0022] Start the loop monitoring timer;

[0023] Starting a minimum cycle timer; and / or a maximum cycle timer;

[0024] Step S03: Real-time detection of the high material level meter in the ash conveying pump on the material conveying line,

[0025] When it is detected that the high material level member is covered, the overfilling timer of the pneumatic ash removal pump is started.

[0026] Step S04: closing the feed port of the ash conveying pump on the material conveying line;

[0027] Close the exhaust valve of the ash conveying pump on the material conveying line;

[0028] During the process of closing the feed port and the exhaust valve, if the material filling delay timer expires, a delay of 0.1S is applied to close the feed port and the exhaust valve of the ash conveying pump on the material conveying line;

[0029] Step S05: Start the delayed opening timer of the air delivery valve;

[0030] Step S06: Start the delivery air valve; start the air supply valve of the delivery pipe on the delivery line; start the safety delivery timer.

[0031] Step S07: Detect the pressure in the conveying pipe on the material conveying line; if the pressure in the conveying pipe on the material conveying line is less than 0.3 Barg and the safety conveying timer has expired, start the delayed conveying timer for 20 seconds, and when the delayed conveying timer expires, send a conveying completion signal, close the conveying air valve and the air supply valve of the conveying pipe on the conveying line; start the cycle reset timer;

[0032] Step S08: When the cycle reset timer expires, a material conveying cycle is completed.

[0033] The aforementioned method for operating the combined pneumatic conveying system for fly ash from a coal-fired power plant, wherein the start-up interlocking conditions of the pneumatic dust collection and delivery system include:

[0034] Check whether the start / stop / purge switch on the main electronic control screen is in the "start" or "purge" position;

[0035] Check whether the manual / programmed button on the local gas control box is in the "programmed" position;

[0036] Check whether the gas supply pressure is greater than 5.5 Barg;

[0037] Check whether the main pump inlet and exhaust valves are closed and sealed;

[0038] Check whether the inlet and exhaust valves of all auxiliary pumps are closed and sealed;

[0039] Check whether the minimum cycle timer is off or the material level bypass button is pressed;

[0040] Check whether the delivery pipeline is available;

[0041] Check whether there is space available at the target transfer depot and / or target ash depot and / or target terminal depot and / or target buffer tank.

[0042] Compared with the prior art, the combined pneumatic conveying system for fly ash of a coal-fired power plant of the present invention utilizes various conveying pipes with air dispersion to combine the pneumatic dust collection and delivery system, the terminal ash unloading system and the fly ash loading system into a conveying system that is not easy to be blocked and has low maintenance cost; the combined pneumatic conveying system for fly ash of a coal-fired power plant of the present invention can be used to transport fly ash to the fly ash loading system and the terminal ash unloading system at a long distance (more than 2000 meters) by simply switching the conveying pipeline, and the fly ash is directly transported by water through the fly ash loading system, and the fly ash is graded and stored through the terminal ash unloading system, so as to realize the multi-channel comprehensive utilization of dry ash. The operation method of the present invention can ensure that the material conveying units using the same conveying line will not convey materials at the same time, and the problem of overloading of the conveying pipeline will not occur. The combined pneumatic conveying system for fly ash of a coal-fired power plant of the present invention and its operation method reduce the probability of fly ash blockage, reduce the system shutdown frequency, and have low system maintenance cost and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute an improper limitation to the present invention. In the accompanying drawings:

[0044] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0045] Figure 2 It is a schematic diagram of the structure of a cut pipe section of the delivery pipe of the present invention.

[0046] Figure numbers: 1-pneumatic dust collection and delivery system, 2-transfer system, 201-fine ash transfer warehouse, 202-first coarse ash transfer warehouse, 203-second coarse ash transfer warehouse, 204-transfer ash conveying pump, 3-terminal ash unloading system, 301-terminal fine ash warehouse, 302-first terminal coarse ash warehouse, 303-second terminal coarse ash warehouse, 4-powder ash loading system, 401-buffer tank, 402-screw ash loader, 5-first conveying pipe, 6-second conveying pipe, 7-third conveying pipe, 8-fourth conveying pipe, 9-fifth conveying pipe, 10-sixth conveying pipe , 11-the seventh conveying pipe, 12-the eighth conveying pipe, 13-the first sleeve pipe, 14-the second sleeve pipe, 15-air dispersion channel, 16-air dispersion holes, 17-the first group of dust collecting and sending devices, 18-the second group of dust collecting and sending devices, 19-the third group of dust collecting and sending devices, 20-the fourth group of dust collecting and sending devices, 21-ash hopper, 22-gasification air duct, 23-compressed air pipeline for conveying, 24-compressed air storage tank, 25-storage top switching valve, 26-pipeline switching valve, 27-storage top switching valve, 28-ash conveying pipe, 29-pneumatic ash removal pump.

[0047] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention is clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] Embodiment 1 of the present invention: A combined pneumatic conveying system for fly ash in a coal-fired power plant, comprising a pneumatic dust collection and delivery system 1, a transfer system 2, a terminal ash unloading system 3 and a fly ash loading system 4, wherein the pneumatic dust collection and delivery system 1 is connected to the transfer system 2 via a first delivery pipe 5 and a second delivery pipe 6, and the transfer system 2 is connected to the fly ash loading system 4 via a third delivery pipe 7, a fourth delivery pipe 8 and a fifth delivery pipe 9; further comprising a sixth delivery pipe 10, a seventh delivery pipe 11 and an eighth delivery pipe 12, wherein one end of the sixth delivery pipe 10 is connected to the third delivery pipe 8, and the other end is connected to the terminal ash unloading system 3, and one end of the seventh delivery pipe 11 is connected to the terminal ash unloading system 3. It is connected to the fourth conveying pipe 9, and the other end is connected to the terminal ash unloading system 3. One end of the eighth conveying pipe 12 is connected to the fifth conveying pipe 9, and the other end is connected to the terminal ash unloading system 3. The first conveying pipe 5, the second conveying pipe 6, the third conveying pipe 7, the fourth conveying pipe 8, the fifth conveying pipe 9, the sixth conveying pipe 10, the seventh conveying pipe 11, and the eighth conveying pipe 12 include a first sleeve 13 and a second sleeve 14. The diameter of the second sleeve 14 is smaller than that of the first sleeve 13. An air dispersion channel 15 is formed between the first sleeve 13 and the second sleeve 14. The second sleeve 14 is provided with a plurality of air dispersion holes 16 arranged along the axial direction.

[0051] Embodiment 2 of the present invention: A combined pneumatic conveying system for fly ash in a coal-fired power plant, comprising a pneumatic dust collection and delivery system 1, a transfer system 2, a terminal ash unloading system 3 and a fly ash loading system 4, wherein the pneumatic dust collection and delivery system 1 is connected to the transfer system 2 via a first conveying pipe 5 and a second conveying pipe 6, and the transfer system 2 is connected to the fly ash loading system 4 via a third conveying pipe 7, a fourth conveying pipe 8 and a fifth conveying pipe 9; further comprising a sixth conveying pipe 10, a seventh conveying pipe 11 and an eighth conveying pipe 12, wherein one end of the sixth conveying pipe 10 is connected to the third conveying pipe 8, and the other end is connected to the terminal ash unloading system 3, and one end of the seventh conveying pipe 11 is connected to the terminal ash unloading system 3. It is connected to the fourth conveying pipe 9, and the other end is connected to the terminal ash unloading system 3. One end of the eighth conveying pipe 12 is connected to the fifth conveying pipe 9, and the other end is connected to the terminal ash unloading system 3. The first conveying pipe 5, the second conveying pipe 6, the third conveying pipe 7, the fourth conveying pipe 8, the fifth conveying pipe 9, the sixth conveying pipe 10, the seventh conveying pipe 11, and the eighth conveying pipe 12 include a first sleeve 13 and a second sleeve 14. The diameter of the second sleeve 14 is smaller than that of the first sleeve 13. An air dispersion channel 15 is formed between the first sleeve 13 and the second sleeve 14. The second sleeve 14 is provided with a plurality of air dispersion holes 16 arranged along the axial direction.

[0052] Specifically, the pneumatic dust collecting and sending system 1 includes a first group of dust collecting and sending devices 17, a second group of dust collecting and sending devices 18, a third group of dust collecting and sending devices 19 and a fourth group of dust collecting and sending devices 20. The first group of dust collecting and sending devices 17 and the second group of dust collecting and sending devices 18 are connected to the transfer system 2 through a first conveying pipe 5, and the third group of dust collecting and sending devices 19 and the fourth group of dust collecting and sending devices 20 are connected to the transfer system 2 through a second conveying pipe 6.

[0053] Furthermore, the first group of dust collecting and sending devices 17, the second group of dust collecting and sending devices 18, the third group of dust collecting and sending devices 19 and the fourth group of dust collecting and sending devices 20 all include an electrostatic precipitator (not shown in the figure) and a plurality of pneumatic ash removal pumps 29, a gasification air duct 22, a conveying compressed air duct 23 and a compressed air storage tank 24 arranged below the electrostatic precipitator. The plurality of pneumatic ash removal pumps 29 are connected in series through an ash conveying pipe 28. The pneumatic ash removal pump 29 is connected to the ash hopper 21 of the electrostatic precipitator, the ash hopper 21 is connected to the gasification air duct 22, the ash conveying pipe 28 is connected to the conveying compressed air duct 23, and the conveying compressed air duct 23 is connected to the compressed air storage tank 24.

[0054] Specifically, the transfer system 2 includes a fine ash transfer warehouse 201, a first coarse ash transfer warehouse 202, and a second coarse ash transfer warehouse 203. The bottoms of the fine ash transfer warehouse 201, the first coarse ash transfer warehouse 202, and the second coarse ash transfer warehouse 203 are all provided with dry ash bulkers 205. The bottom of the fine ash transfer warehouse 201 is provided with a transfer ash pump 204, and the bottoms of the first coarse ash transfer warehouse 202 and the second coarse ash transfer warehouse 203 are provided with two transfer ash pumps 204, which are arranged at the bottoms of the fine ash transfer warehouse 201 and the first coarse ash transfer warehouse 202 and the second coarse ash transfer warehouse 203. The transfer ash conveying pump at the bottom of the transfer warehouse 201 is connected to the third conveying pipe 7, a transfer ash conveying pump arranged at the bottom of the first coarse ash transfer warehouse 202 is connected to the third conveying pipe 7, another transfer ash conveying pump arranged at the bottom of the first coarse ash transfer warehouse 202 is connected to the fourth conveying pipe 8, a transfer ash conveying pump arranged at the bottom of the second coarse ash transfer warehouse 203 is connected to the fourth conveying pipe 8, and another transfer ash conveying pump arranged at the bottom of the second coarse ash transfer warehouse 203 is connected to the fifth conveying pipe 9.

[0055] Embodiment 3 of the present invention: A combined pneumatic conveying system for fly ash in a coal-fired power plant, comprising a pneumatic dust collection and delivery system 1, a transfer system 2, a terminal ash unloading system 3 and a fly ash loading system 4, wherein the pneumatic dust collection and delivery system 1 is connected to the transfer system 2 via a first delivery pipe 5 and a second delivery pipe 6, and the transfer system 2 is connected to the fly ash loading system 4 via a third delivery pipe 7, a fourth delivery pipe 8 and a fifth delivery pipe 9; further comprising a sixth delivery pipe 10, a seventh delivery pipe 11 and an eighth delivery pipe 12, wherein one end of the sixth delivery pipe 10 is connected to the third delivery pipe 8, and the other end is connected to the terminal ash unloading system 3, one end of the seventh delivery pipe 11 is connected to the fourth delivery pipe 9, and the other end is connected to the terminal unloading system 3 The ash system 3 is connected, one end of the eighth conveying pipe 12 is connected to the fifth conveying pipe 9, and the other end is connected to the terminal ash unloading system 3. The first conveying pipe 5, the second conveying pipe 6, the third conveying pipe 7, the fourth conveying pipe 8, the fifth conveying pipe 9, the sixth conveying pipe 10, the seventh conveying pipe 11, and the eighth conveying pipe 12 include a first sleeve 13 and a second sleeve 14. The diameter of the second sleeve 14 is smaller than that of the first sleeve 13. By utilizing this double sleeve type consisting of the first sleeve 13 and the second sleeve 14 embedded in the first sleeve 13, an air dispersion channel 15 is formed between the first sleeve 13 and the second sleeve 14, and a plurality of air dispersion holes 16 arranged along the axial direction are provided on the second sleeve 14.

[0056] Specifically, the pneumatic dust collecting and sending system 1 includes a first group of dust collecting and sending devices 17, a second group of dust collecting and sending devices 18, a third group of dust collecting and sending devices 19 and a fourth group of dust collecting and sending devices 20. The first group of dust collecting and sending devices 17 and the second group of dust collecting and sending devices 18 are connected to the transfer system 2 through a first conveying pipe 5, and the third group of dust collecting and sending devices 19 and the fourth group of dust collecting and sending devices 20 are connected to the transfer system 2 through a second conveying pipe 6.

[0057] Furthermore, the first group of dust collecting and sending devices 17, the second group of dust collecting and sending devices 18, the third group of dust collecting and sending devices 19 and the fourth group of dust collecting and sending devices 20 all include an electrostatic precipitator and a plurality of pneumatic ash removal pumps 29, a gasification air duct 22, a conveying compressed air duct 23 and a compressed air storage tank 24 arranged below the electrostatic precipitator. The plurality of pneumatic ash removal pumps 29 are connected in series through an ash conveying pipe 28. The pneumatic ash removal pump 29 is connected to the ash hopper 21 of the electrostatic precipitator, the ash hopper 21 is connected to the gasification air duct 22, the ash conveying pipe 28 is connected to the conveying compressed air duct 23, and the conveying compressed air duct 23 is connected to the compressed air storage tank 24.

[0058] Specifically, the transfer system 2 includes a fine ash transfer warehouse 201, a first coarse ash transfer warehouse 202, and a second coarse ash transfer warehouse 203. The bottoms of the fine ash transfer warehouse 201, the first coarse ash transfer warehouse 202, and the second coarse ash transfer warehouse 203 are all provided with dry ash bulkers 205. The bottom of the fine ash transfer warehouse 201 is provided with a transfer ash pump 204, and the bottoms of the first coarse ash transfer warehouse 202 and the second coarse ash transfer warehouse 203 are provided with two transfer ash pumps 204, which are arranged at the bottoms of the fine ash transfer warehouse 201 and the first coarse ash transfer warehouse 202 and the second coarse ash transfer warehouse 203. The transfer ash conveying pump at the bottom of the transfer warehouse 201 is connected to the third conveying pipe 7, a transfer ash conveying pump arranged at the bottom of the first coarse ash transfer warehouse 202 is connected to the third conveying pipe 7, another transfer ash conveying pump arranged at the bottom of the first coarse ash transfer warehouse 202 is connected to the fourth conveying pipe 8, a transfer ash conveying pump arranged at the bottom of the second coarse ash transfer warehouse 203 is connected to the fourth conveying pipe 8, and another transfer ash conveying pump arranged at the bottom of the second coarse ash transfer warehouse 203 is connected to the fifth conveying pipe 9.

[0059] Specifically, the terminal ash unloading system 3 includes a terminal fine ash bin 303, a first terminal coarse ash bin 302, and a second terminal coarse ash bin 301. The terminal fine ash bin 303 is connected to the sixth conveying pipe 10, the first terminal coarse ash bin 302 is connected to the sixth conveying pipe 10, the seventh conveying pipe 11 and / or the eighth conveying pipe 12, and the second terminal coarse ash bin 301 is connected to the eighth conveying pipe 12 and / or the seventh conveying pipe 11.

[0060] Specifically, the fly ash loading system 4 includes a buffer tank 401 and a spiral ash loader 402 . The spiral ash loader 402 is connected to the buffer tank 401 . The terminals of the third conveying pipe 7 , the fourth conveying pipe 8 and the fifth conveying pipe 9 are connected to the buffer tank 401 .

[0061] Furthermore, the first conveying pipe 5 and the second conveying pipe 6 are both provided with a top switching valve 25 ; the ash conveying pipe 28 is provided with a pipeline switching valve 26 .

[0062] The sixth delivery pipe 10 , the seventh delivery pipe 11 and the eighth delivery pipe 12 are all provided with a reservoir top switching valve 27 .

[0063] Embodiment 4 of the present invention: An operation method of a combined pneumatic conveying system for fly ash of a coal-fired power station, characterized in that it comprises the following steps:

[0064] Step S01: Check whether the start interlock condition of the pneumatic dust collection and delivery system meets the set value;

[0065] Step S02: When the startup interlocking condition of the checked pneumatic dust collection and delivery system meets the set value, a material conveying cycle is run; the running of a material conveying cycle includes the following running steps:

[0066] Step S021: select a group of dust collecting and sending devices as the material conveying unit; open the switching valve of the conveying pipe corresponding to the dust collecting and sending device as the material conveying unit; close the switching valve on the conveying pipe corresponding to the unselected dust collecting and sending device;

[0067] Step S02: Open the feed port of the pneumatic ash removal pump on the material conveying line; open the exhaust valve of the ash conveying pump on the material conveying line; start the material filling delay timer; start the cycle monitoring timer; start the minimum cycle timer; and / or the maximum cycle timer;

[0068] Step S03: Real-time detection of the high material level gauge in the ash conveying pump on the material conveying line; when it is detected that the high material level gauge is covered, the overfilling timer of the pneumatic ash removal pump is started.

[0069] Step S04: closing the feed port of the ash conveying pump on the material conveying line; closing the exhaust valve of the ash conveying pump on the material conveying line; in the process of closing the feed port and the exhaust valve, if the material filling delay timer expires, delay 0.1S and close the feed port and the exhaust valve of the ash conveying pump on the material conveying line;

[0070] Step S05: Start the delayed opening timer of the air delivery valve;

[0071] Step S06: Start the delivery air valve; start the air supply valve of the delivery pipe on the delivery line; start the safety delivery timer.

[0072] Step S07: Detect the pressure in the conveying pipe on the material conveying line; if the pressure in the conveying pipe on the material conveying line is less than 0.3 Barg and the safety conveying timer has expired, start the delayed conveying timer for 20 seconds, and when the delayed conveying timer expires, send a conveying completion signal, close the conveying air valve and the air supply valve of the conveying pipe on the conveying line; start the cycle reset timer;

[0073] Step S08: When the cycle reset timer expires, a material conveying cycle is completed.

[0074] Among them, the start-up interlocking conditions of the pneumatic dust collection and delivery system include:

[0075] Check whether the start / stop / purge switch on the main electronic control screen is in the "start" or "purge" position;

[0076] Check whether the manual / programmed button on the local gas control box is in the "programmed" position;

[0077] Check whether the gas supply pressure is greater than 5.5 Barg;

[0078] Check whether the main pump inlet and exhaust valves are closed and sealed;

[0079] Check whether the inlet and exhaust valves of all auxiliary pumps are closed and sealed;

[0080] Check whether the minimum cycle timer is off or the material level bypass button is pressed;

[0081] Check whether the delivery pipeline is available;

[0082] Check whether there is space available at the target transfer depot and / or target ash depot and / or target terminal depot and / or target buffer tank.

[0083] The working principle of the system of the present invention:

[0084] The pneumatic dust collection and delivery system 1 is transported to the fine ash transfer warehouse 201, the first coarse ash transfer warehouse 202 or the second coarse ash transfer warehouse 203 of the transfer system 2 through the pneumatic ash removal pump 29 arranged below the ash hopper 21 through the ash conveying pipe 28, and the fly ash is transferred out of the transfer system 2 through the transfer ash conveying pump 204, and the fly ash in each transfer warehouse is transported to its corresponding conveying pipe by the transfer ash conveying pump 204 arranged at the bottom of each transfer warehouse, and the fly ash in the transfer system can be directly transported out by tank truck by using the dry ash bulker arranged at the bottom of each transfer warehouse. The fly ash in the transfer system 2 is transported to the wharf through the third conveying pipe 7, the fourth conveying pipe 8, and the fifth conveying pipe 9 (the length can exceed 2000 meters) which are not easy to be blocked, and transported out through the fly ash loading system 4, and can also be transported to the terminal ash unloading system 3 located in the power plant through the sixth conveying pipe 10 and the seventh conveying pipe 11 for graded storage for reuse.

[0085] The fly ash in the fine powder transfer warehouse 201 is blown into the third conveying pipe 7 through the transfer ash pump 204 arranged at the bottom of the fine powder transfer warehouse 201, and the fly ash in the fine powder transfer warehouse 201 is transported over a long distance (greater than 2000 meters) by the third conveying pipe 7 and the sixth conveying pipe 10, so that the fly ash in the fine powder transfer warehouse 201 is transported to the buffer tank 401 of the fly ash loading system 4, and the fly ash is loaded onto the ash ship docked at the dock by the spiral ash loader 402 connected to the buffer tank 401.

[0086] The fly ash in the first coarse ash transfer warehouse 202 is blown into the third conveying pipe 7 or the fourth conveying pipe 8 through a transfer ash pump 204 arranged at the bottom of the first coarse ash transfer warehouse 202. The third conveying pipe 7 or the fourth conveying pipe 8 is used to transport the fly ash in the first coarse ash transfer warehouse 202 over a long distance (greater than 2000 meters), so that the fly ash in the first coarse ash transfer warehouse 202 can be transported to the fly ash loading system 4, in order to enable the fly ash in the first coarse ash transfer warehouse 202 to be transported to the terminal ash unloading system 3 arranged in the power plant.

[0087] The fly ash in the second coarse ash transfer warehouse 203 is pumped into the third ash conveying pipe 14 through a transfer ash pump 204 arranged at the bottom of the first coarse ash transfer warehouse 202, and the fly ash in the second coarse ash transfer warehouse 203 is transported to the fly ash loading system 4 by the third ash conveying pipe 14, so that the fly ash in the second coarse ash transfer warehouse 203 can be transported to the terminal ash unloading system 3 in the power plant.

[0088] When fly ash accumulates in each conveying pipe in the present invention to form long ash plugs and affect transportation, compressed air can enter the air dispersion channel 15 through a certain air dispersion hole 16 on the second sleeve 14, and then come out from the next air dispersion hole 16 thereafter. The compressed air coming out of the air dispersion hole 16 (the compressed air is provided by the air compression tank connected to each conveying pipe) can separate the accumulated long ash plugs into short ash plugs. The short ash plugs can continue to move under the push of compressed air, thereby preventing the blockage of each conveying pipe. Therefore, the present invention is more suitable for long-distance transportation of fly ash, reduces the frequency of ash blockage, reduces the maintenance cost of equipment, improves the transportation efficiency of fly ash, and improves economic benefits.

Claims

1. An operating method of a combined pneumatic conveying system for fly ash in a coal-fired power station, characterized in that: The steps include: Step S01: Check whether the start interlocking condition of the pneumatic dust collection and delivery system meets the set value; Step S02: When the start interlocking condition of the checked pneumatic dust collection and delivery system meets the set value, a material conveying cycle is run; the running of a material conveying cycle includes the following running steps; Step S021: selecting a group of dust collecting and sending devices as a material conveying unit; Open the switching valve of the conveying pipe corresponding to the dust collecting and sending device as the material conveying unit; Close the switching valve on the conveying pipe corresponding to the unselected dust collecting and sending device; Step S02: Open the feed port of the pneumatic ash removal pump on the material conveying line; Open the exhaust valve of the ash conveying pump on the material conveying line; Start the material filling delay timer; Start the loop monitoring timer; Start the minimum cycle timer; and / or maximum cycle timer; Step S03: Real-time detection of the high material level meter in the ash conveying pump on the material conveying line, When it is detected that the high material level meter is covered, an overfill timer of the pneumatic ash removal pump is started; Step S04: closing the feed port of the ash conveying pump on the material conveying line; Close the exhaust valve of the ash conveying pump on the material conveying line; During the process of closing the feed port and the exhaust valve, if the material filling delay timer expires, a delay of 0.1S is applied to close the feed port and the exhaust valve of the ash conveying pump on the material conveying line; Step S05: Start the delayed opening timer of the air delivery valve; Step S06: start the air delivery valve; start the air supply valve of the delivery pipe on the delivery line; Start the safety conveying timer; Step S07: Detect the pressure in the conveying pipe on the material conveying line; if the pressure in the conveying pipe on the material conveying line is less than 0.3 Barg and the safety conveying timer has expired, start the delayed conveying timer for 20 seconds, and when the delayed conveying timer expires, send a conveying completion signal, and close the conveying air valve and the air supply valve of the conveying pipe on the conveying line; Start the cycle reset timer; Step S08: When the cycle reset timer expires, a material conveying cycle is completed; Among them, the startup interlock conditions of the pneumatic dust collection and delivery system include: Check whether the start / stop / purge switch on the main electronic control screen is in the "start" or "purge" position; Check whether the manual / programmed button on the local gas control box is in the "programmed" position; Check that the delivery gas supply pressure is greater than 5.5 Barg; Check whether the main pump inlet and exhaust valves are closed and sealed; Check whether the inlet and exhaust valves of all auxiliary pumps are closed and sealed; Check whether the minimum cycle timer is off or the material level bypass button is pressed; Check whether the delivery pipeline is available; Check whether there is space available at the target transfer depot and / or target ash depot and / or target terminal depot and / or target buffer tank; A combined pneumatic conveying system for fly ash of a coal-fired power plant comprises a pneumatic dust collection and delivery system (1), a transfer system (2), a terminal ash unloading system (3) and a fly ash loading system (4), wherein the pneumatic dust collection and delivery system (1) is connected to the transfer system (2) via a first conveying pipe (5) and a second conveying pipe (6), and the transfer system (2) is connected to the fly ash loading system (4) via a third conveying pipe (7), a fourth conveying pipe (8) and a fifth conveying pipe (9); and further comprises a sixth conveying pipe (10), a seventh conveying pipe (11) and an eighth conveying pipe (12), wherein one end of the sixth conveying pipe (10) is connected to the third conveying pipe (7), and the other end is connected to the terminal ash unloading system (3), and one end of the seventh conveying pipe (11) is connected to the fourth conveying pipe ( 8) is connected, and the other end is connected to the terminal ash unloading system (3); one end of the eighth conveying pipe (12) is connected to the fifth conveying pipe (9), and the other end is connected to the terminal ash unloading system (3); the first conveying pipe (5), the second conveying pipe (6), the third conveying pipe (7), the fourth conveying pipe (8), the fifth conveying pipe (9), the sixth conveying pipe (10), the seventh conveying pipe (11), and the eighth conveying pipe (12) include a first sleeve (13) and a second sleeve (14); the diameter of the second sleeve (14) is smaller than that of the first sleeve (13); an air dispersion channel (15) is formed between the first sleeve (13) and the second sleeve (14); and the second sleeve (14) is provided with a plurality of air dispersion holes (16) arranged along the axial direction; The pneumatic dust collecting and sending system (1) comprises a first group of dust collecting and sending devices (17), a second group of dust collecting and sending devices (18), a third group of dust collecting and sending devices (19) and a fourth group of dust collecting and sending devices (20); the first group of dust collecting and sending devices (17) and the second group of dust collecting and sending devices (18) are connected to the transfer system (2) via a first conveying pipe (5); the third group of dust collecting and sending devices (19) and the fourth group of dust collecting and sending devices (20) are connected to the transfer system (2) via a second conveying pipe (6); The first group of dust collecting and sending devices (17), the second group of dust collecting and sending devices (18), the third group of dust collecting and sending devices (19) and the fourth group of dust collecting and sending devices (20) all comprise an electrostatic precipitator, a plurality of pneumatic ash removal pumps (29) arranged below the electrostatic precipitator, a gasification air duct (22), a conveying compressed air duct (23) and a compressed air storage tank (24); the plurality of pneumatic ash removal pumps (29) are connected in series via an ash conveying pipe (28); the pneumatic ash removal pump (29) is connected to an ash hopper (21) of the electrostatic precipitator; the ash hopper (21) is connected to the gasification air duct (22); the ash conveying pipe (28) is connected to a conveying compressed air duct (23); and the conveying compressed air duct (23) is connected to a compressed air storage tank (24); The transfer system (2) comprises a fine ash transfer warehouse (201), a first coarse ash transfer warehouse (202) and a second coarse ash transfer warehouse (203); a dry ash bulker (205) is arranged at the bottom of each of the fine ash transfer warehouse (201), the first coarse ash transfer warehouse (202) and the second coarse ash transfer warehouse (203); a transfer ash conveying pump (204) is arranged at the bottom of the fine ash transfer warehouse (201); and two transfer ash conveying pumps (204) are arranged at the bottom of each of the first coarse ash transfer warehouse (202) and the second coarse ash transfer warehouse (203). The transfer ash conveying pump at the bottom of the fine ash transfer storehouse (201) is connected to the third conveying pipe (7), a transfer ash conveying pump arranged at the bottom of the first coarse ash transfer storehouse (202) is connected to the third conveying pipe (7), another transfer ash conveying pump arranged at the bottom of the first coarse ash transfer storehouse (202) is connected to the fourth conveying pipe (8), a transfer ash conveying pump arranged at the bottom of the second coarse ash transfer storehouse (203) is connected to the fourth conveying pipe (8), and another transfer ash conveying pump arranged at the bottom of the second coarse ash transfer storehouse (203) is connected to the fifth conveying pipe (9); The terminal ash unloading system (3) comprises a terminal fine ash storage (303), a first terminal coarse ash storage (302), and a second terminal coarse ash storage (301); the terminal fine ash storage (303) is connected to the sixth conveying pipe (10); the first terminal coarse ash storage (302) is connected to the sixth conveying pipe (10), the seventh conveying pipe (11), and / or the eighth conveying pipe (12); and the second terminal coarse ash storage (301) is connected to the eighth conveying pipe (12) and / or the seventh conveying pipe (11); The fly ash loading system (4) comprises a buffer tank (401) and a spiral ash loading machine (402), the spiral ash loading machine (402) and the buffer tank (401) are connected, and the terminals of the third conveying pipe (7), the fourth conveying pipe (8) and the fifth conveying pipe (9) are connected to the buffer tank (401); The first conveying pipe (5) and the second conveying pipe (6) are both provided with a silo top switching valve; the ash conveying pipe (28) is provided with a pipeline switching valve (26); The sixth delivery pipe (10), the seventh delivery pipe (11) and the eighth delivery pipe (12) are all provided with a reservoir top switching valve.

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