Biomass fuel pretreatment system for fire coal coupling biomass fuel power generation

Abstract

The invention belongs to the technical field of fire coal coupled biomass fuel power generation, and particularly relates to a biomass fuel pretreatment system for fire coal coupled biomass fuel power generation. And an off-factory granulation process is canceled, so that the biomass fuel bulk material can be conveniently and directly prepared into the biomass fuel powder material. A cyclone separation device and a dust removal device behind a three-stage crushing device in a traditional process are omitted, and a first pipeline connecting a discharge port of the three-stage crushing device and a feed port of a pneumatic conveying device is adjusted to operate at negative pressure. The processing cost of the biomass fuel is reduced, and the use efficiency of equipment and the economical efficiency of system operation are improved. And by arranging the drying device, free water in separated biomass fuel second-stage particles is removed, the crushing performance of the biomass fuel is improved, and the energy consumption of a downstream third-stage crushing device and a pneumatic conveying device is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of coal-fired coupled biomass fuel power generation, and in particular relates to a biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation. Background Art

[0002] Common technologies for coupling biomass fuel with pulverized coal boilers for power generation include co-grinding technology, co-pipe technology and independent combustion technology.

[0003] The co-grinding process is to premix the biomass fuel with coal upstream of the coal feeder, make the biomass fuel and coal into powder together through the coal mill, and then send the mixed powder of biomass fuel and coal to the coal powder combustion device. It has the advantages of simple process and no need to modify the unit equipment. However, the blending ratio of biomass fuel is low, usually 5-10%. Due to the high moisture content of biomass fuel and the different grindability of biomass fuel and coal. When the blending ratio of biomass fuel is greater than 5%, it is easy to have problems such as a significant decrease in the output of the coal mill, a high volatile matter of biomass fuel, and easy spontaneous combustion.

[0004] The co-pipe process is to process the biomass fuel through a special biomass fuel hammer mill and then spray it into the coal powder pipeline or into the coal powder combustion device. The blending ratio of biomass fuel can be increased to more than 20%. The co-pipe process requires the transformation of existing unit equipment, which has problems such as complex pipelines and control systems and increased costs.

[0005] The independent injection process is to crush the biomass fuel separately and then inject it into the biomass fuel special combustion device in the main combustion area of ​​the boiler for combustion. This process requires the original boiler combustion device to be updated, and the investment cost is relatively high, but the blending ratio of biomass fuel can be increased to 100%.

[0006] At present, the domestic coal-fired coupled biomass fuel power generation process requires the pretreatment of biomass fuel. The biomass fuel pretreatment system includes an off-site pelletizing process and an in-site crushing process. The off-site pelletizing process is mainly responsible for converting biomass fuel bulk into biomass fuel pellets, while the in-site crushing process is mainly responsible for converting biomass fuel pellets into biomass fuel powder. Specifically, the in-site crushing process includes an in-plant unloading device, a screening device, a silo storage device, a primary crushing device, an intermediate storage device, a secondary crushing device, a tertiary crushing device, a cyclone separation device, a dust removal device, and a positive pressure pneumatic conveying device. The existing biomass fuel pretreatment system has problems such as many intermediate production links, large initial equipment investment, high energy consumption in the production of biomass fuel powder, and poor economy. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation, which eliminates the off-site granulation process and facilitates direct conversion of biomass fuel bulk into biomass fuel powder.

[0008] The technical solution adopted by the present invention to solve the technical problem is: a biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation, comprising a primary crushing device, a first conveying device, a secondary crushing device, a second conveying device, a sorting device, a sorting material conveying mechanism, a drying device, a third conveying device, a third crushing device, a pneumatic conveying device and a biomass fuel combustion device;

[0009] The first conveying device is used to convey the first-level biomass fuel particles from the discharge port of the first-level crushing device to the feed port of the second-level crushing device; the second conveying device is used to convey the second-level biomass fuel particles from the discharge port of the second-level crushing device to the feed port of the sorting device; the feed end of the sorting and unloading conveying mechanism is adjacent to and corresponding to the discharge port of the sorting device, and the discharge end of the sorting and unloading conveying mechanism is adjacent to and corresponding to the feed port of the drying device; the third conveying device is used to convey the sorted and dried second-level biomass fuel particles from the discharge port of the drying device to the feed port of the tertiary crushing device; the discharge port of the tertiary crushing device is connected to the feed port of the pneumatic conveying device through a first pipeline, and the discharge port of the pneumatic conveying device is connected to the feed port of the biomass fuel combustion device through a second pipeline.

[0010] Further, the first conveying device includes a first belt conveying mechanism, a silo, a silo unloading conveying mechanism, and a second belt conveying mechanism;

[0011] The feed end of the first belt conveyor mechanism is adjacent to and corresponding to the discharge port of the primary crushing device, and the discharge end of the first belt conveyor mechanism is adjacent to and corresponding to the feed port of the silo;

[0012] The silo unloading conveying mechanism and the second belt conveying mechanism are arranged in sequence along the material conveying direction L, the feed end of the silo unloading conveying mechanism is adjacent to and corresponding to the discharge port of the silo, the discharge end of the silo unloading conveying mechanism is adjacent to and corresponding to the feed end of the second belt conveying mechanism, and the discharge end of the second belt conveying mechanism is adjacent to and corresponding to the feed port of the secondary crushing device.

[0013] Furthermore, it also includes a magnet device, which is arranged above the discharge end of the first belt conveyor mechanism.

[0014] Furthermore, the second conveying device includes a secondary crushing and unloading conveying mechanism and a lifting and conveying mechanism;

[0015] The feed end of the secondary crushing material feeding and conveying mechanism is adjacent to and corresponding to the discharge port of the secondary crushing device, the discharge end of the secondary crushing material feeding and conveying mechanism is adjacent to and corresponding to the lower feed port of the lifting and conveying mechanism, and the upper discharge port of the lifting and conveying mechanism is adjacent to and corresponding to the feed port of the sorting device.

[0016] Furthermore, the drying device includes a tank body and a heating mechanism disposed on a side wall of the tank body;

[0017] The discharging end of the sorting and unloading conveying mechanism is adjacent to and corresponding to the feeding port of the tank body.

[0018] Furthermore, the heating mechanism is a steam heating coil, and the steam heating coil is installed around the outer circumferential surface of the tank body.

[0019] Furthermore, it also includes a drain pump, the inlet of which is connected to the inner cavity of the tank body through a drain pipe.

[0020] Furthermore, it also includes a pneumatic partition device; the second pipeline includes a first connecting pipe and a second connecting pipe that are connected to each other, the inlet end of the first connecting pipe is connected to the discharge port of the pneumatic conveying device, the outlet end of the first connecting pipe is connected to the inlet of the pneumatic partition device, the inlet end of the second connecting pipe is connected to the outlet of the pneumatic partition device, and the outlet end of the second connecting pipe is connected to the feed port of the biomass fuel combustion device.

[0021] Furthermore, it also includes a metering device, which is arranged on the third conveying device.

[0022] Furthermore, the sorting material discharging and conveying mechanism, the silo material discharging and conveying mechanism, the secondary crushing material discharging and conveying mechanism and the lifting and conveying mechanism are all screw conveyors.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation, which eliminates the off-site granulation process and facilitates the direct production of biomass fuel bulk into biomass fuel powder. The cyclone separation device and the dust removal device after the three-stage crushing device in the traditional process are eliminated, and the first pipeline connecting the discharge port of the three-stage crushing device and the feed port of the pneumatic conveying device is adjusted to negative pressure operation. The processing cost of biomass fuel is reduced, and the equipment utilization efficiency and the economy of system operation are improved. By setting up a drying device, the free water in the sorted biomass fuel secondary granular material is removed, the crushability of the biomass fuel is improved, and the energy consumption of the downstream three-stage crushing device and the pneumatic conveying device is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the present invention;

[0025] Figure markings: 1-primary crushing device; 2-first belt conveyor mechanism; 3-magnet device; 4-silo; 5-silo unloading conveying mechanism; 6-second belt conveyor mechanism; 7-secondary crushing device; 8-secondary crushing unloading conveying mechanism; 9-lifting conveying mechanism; 10-sorting device; 11-sorting unloading conveying mechanism; 12-drying device; 1201-tank body; 1202-heating mechanism; 13-metering device; 14-third conveying device; 15-third-stage crushing device; 16-pneumatic conveying device; 17-pneumatic partition device; 18-biomass fuel combustion device; 19-drain pump; 20-air compressor; 21-boiler. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0027] The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation includes a primary crushing device 1, a first conveying device, a secondary crushing device 7, a second conveying device, a sorting device 10, a sorting and unloading conveying mechanism 11, a drying device 12, a third conveying device 14, a tertiary crushing device 15, a pneumatic conveying device 16 and a biomass fuel combustion device 18.

[0028] The first conveying device is used to convey the first-level biomass fuel particles from the discharge port of the first-level crushing device 1 to the feed port of the second-level crushing device 7; the second conveying device is used to convey the second-level biomass fuel particles from the discharge port of the second-level crushing device 7 to the feed port of the sorting device 10; the feed end of the sorting and unloading conveying mechanism 11 is adjacent to and corresponding to the discharge port of the sorting device 10, and the discharge end of the sorting and unloading conveying mechanism 11 is adjacent to and corresponding to the feed port of the drying device 12; the third conveying device 14 is used to convey the sorted and dried second-level biomass fuel particles from the discharge port of the drying device 12 to the feed port of the tertiary crushing device 15; the discharge port of the tertiary crushing device 15 is connected to the feed port of the pneumatic conveying device 16 through a first pipeline, and the discharge port of the pneumatic conveying device 16 is connected to the feed port of the biomass fuel combustion device 18 through a second pipeline.

[0029] The bulk biomass fuel is fed into the primary crushing device 1 by a cantilever feeder. The bulk biomass fuel is crushed by the primary crushing device 1 to form the primary biomass fuel pellets. The particle size of the primary biomass fuel pellets is controlled within ≤100mm. The primary biomass fuel pellets are transported to the secondary crushing device 7 by the first conveying device. The primary biomass fuel pellets are crushed by the secondary crushing device 7 to form the secondary biomass fuel pellets. The particle size of the secondary biomass fuel pellets is controlled within ≤30mm. The secondary biomass fuel pellets are transported to the sorting device 10 by the second conveying device. The sorting device 10 separates impurities such as sand and gravel in the secondary biomass fuel pellets. The sorting device 10 is a prior art, and specifically uses an air duct and a suction fan to absorb impurities such as sand and gravel in the secondary biomass fuel pellets. The sorted biomass fuel secondary granules are transported to the drying device 12 through the sorting feeding conveying mechanism 11. The drying device 12 dries the sorted biomass fuel secondary granules, so that the moisture content in the sorted biomass fuel secondary granules is reduced to about 10%. At this time, the free water in the sorted biomass fuel secondary granules has been basically removed. By setting the drying device 12, the free water in the sorted biomass fuel secondary granules is removed, the crushability of the biomass fuel is improved, and the energy consumption of the downstream tertiary crushing device 15 and the pneumatic conveying device 16 is reduced. Furthermore, the latent heat loss of water vaporization after the coupled combustion of biomass fuel and coal powder is also reduced, which improves the economy of the system operation. The sorted and dried biomass fuel secondary granules are transported to the tertiary crushing device 15 through the third conveying device 14. The sorted and dried biomass fuel secondary granules are crushed by the tertiary crushing device 15 to form biomass fuel powder, and the particle size of the biomass fuel powder is controlled within ≤3mm. Finally, the pneumatic conveying device 16 pumps the biomass fuel powder into the biomass fuel dedicated combustion device 18. The biomass fuel dedicated combustion device 18 extends into the boiler 21. Specifically, the first pipeline connecting the discharge port of the three-stage crushing device 15 and the feed port of the pneumatic conveying device 16 operates at negative pressure, and the second pipeline connecting the discharge port of the pneumatic conveying device 16 and the feed port of the biomass fuel combustion device 18 operates at positive pressure, which facilitates the smooth discharge of the three-stage crushing device 15.

[0030] The first conveying device may only include the first belt conveying mechanism 2. Preferably, the first conveying device includes the first belt conveying mechanism 2, the silo 4, the silo unloading conveying mechanism 5 and the second belt conveying mechanism 6; the feeding end of the first belt conveying mechanism 2 is adjacent to and corresponding to the discharge port of the primary crushing device 1, and the discharging end of the first belt conveying mechanism 2 is adjacent to and opposite to the feeding port of the silo 4; the silo unloading conveying mechanism 5 and the second belt conveying mechanism 6 are sequentially arranged along the material conveying direction L, the feeding end of the silo unloading conveying mechanism 5 is adjacent to and corresponding to the discharge port of the silo 4, the discharging end of the silo unloading conveying mechanism 5 is adjacent to and corresponding to the feeding end of the second belt conveying mechanism 6, and the discharging end of the second belt conveying mechanism 6 is adjacent to and corresponding to the feeding port of the secondary crushing device 7. The silo 4 has a buffering function, which is convenient for uniform feeding to the secondary crushing device 7. The primary biomass fuel particles are transported to the silo 4 through the first belt conveyor mechanism 2 , discharged from the discharge port of the silo 4 , and transported to the secondary crushing device 7 through the silo unloading conveyor mechanism 5 and the second belt conveyor mechanism 6 .

[0031] Preferably, it also includes a magnet device 3, which is arranged above the discharge end of the first belt conveyor mechanism 2. When the primary biomass fuel granules fall into the silo 4 from the discharge end of the first belt conveyor mechanism 2, the magnet device 3 absorbs the iron-containing metal impurities in the primary biomass fuel granules. Specifically, the magnet device 3 includes a bracket and a magnet block mounted on the bracket. The lower surface of the magnet block is located above the discharge end of the first belt conveyor mechanism 2.

[0032] The second conveying device may only include a secondary crushing and discharging conveying mechanism 8. Preferably, the second conveying device includes a secondary crushing and discharging conveying mechanism 8 and a lifting conveying mechanism 9; the feed end of the secondary crushing and discharging conveying mechanism 8 is adjacent to and corresponding to the discharge port of the secondary crushing device 7, the discharge end of the secondary crushing and discharging conveying mechanism 8 is adjacent to and corresponding to the lower feed port of the lifting conveying mechanism 9, and the upper discharge port of the lifting conveying mechanism 9 is adjacent to and corresponding to the feed port of the sorting device 10. The installation elevation of the secondary crushing device 7 can be lowered. The secondary particulate material of the biomass fuel is transported to the sorting device 10 through the secondary crushing and discharging conveying mechanism 8 and the lifting conveying mechanism 9.

[0033] Specifically, the drying device 12 includes a tank body 1201 and a heating mechanism 1202 disposed on the side wall of the tank body 1201; the discharge end of the sorting and unloading conveying mechanism 11 is adjacent to and corresponding to the feed inlet of the tank body 1201. The feed inlet of the tank body 1201 is the feed inlet of the drying device 12.

[0034] The heating mechanism 1202 may be an electric heating tube, and preferably, the heating mechanism 1202 is a steam heating coil, which is wound and installed on the outer circumference of the tank body 1201. The steam passed into the steam heating coil may come from the auxiliary steam system of the unit.

[0035] Preferably, a drain pump 19 is further included, and the inlet of the drain pump 19 is connected to the inner cavity of the tank body 1201 through a drain pipe. The drain generated after the biomass fuel secondary pellets are heated is recovered by the drain pump 19 to the unit drain system.

[0036] Preferably, it further comprises a pneumatic isolation device 17; the second pipeline comprises a first connecting pipe and a second connecting pipe which are connected to each other, the inlet end of the first connecting pipe is connected to the discharge port of the pneumatic conveying device 16, the outlet end of the first connecting pipe is connected to the inlet of the pneumatic isolation device 17, the inlet end of the second connecting pipe is connected to the outlet of the pneumatic isolation device 17, and the outlet end of the second connecting pipe is connected to the feed port of the biomass fuel combustion device 18. The pneumatic isolation device 17 can effectively control the on-off of the second pipeline, and the pneumatic isolation device 17 is a prior art.

[0037] As a further preferred embodiment, the pneumatic isolation device 17 is a pneumatic gate valve. The pneumatic gate valve is a prior art.

[0038] When the first connecting pipe includes an upwardly extending climbing section, a through hole is provided on the first connecting pipe at the climbing section, and compressed air is passed upward into the first connecting pipe through the through hole to provide auxiliary power for the transportation of biomass fuel powder. The compressed air is provided by the air compressor 20. Specifically, the compressed air outlet of the air compressor 20 is connected to the through hole through an air pipeline.

[0039] Preferably, it further comprises a metering device 13, which is arranged on the third conveying device 14. The metering device 13 is a prior art. By arranging the metering device 13, the amount of biomass fuel powder conveyed to the biomass fuel combustion device 18 can be clearly known.

[0040] The metering device 13 can be an electronic belt scale. As a further preferred embodiment, the metering device 13 is a four-roller high-precision electronic belt scale. The four-roller high-precision electronic belt scale is a prior art.

[0041] Specifically, the sorting material discharging and conveying mechanism 11, the silo material discharging and conveying mechanism 5, the secondary crushing material discharging and conveying mechanism 8 and the lifting and conveying mechanism 9 are all screw conveyors.

[0042] As a further preferred embodiment, an air compressor 20 is further included, and the compressed air outlet of the air compressor 20 is connected to the second pipeline through a blowing pipe, and the connection between the blowing pipe and the second pipeline is located between the discharge port of the pneumatic conveying device 16 and the pneumatic partition device 17.

[0043] The embodiments of this specific implementation are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation, characterized in that: It comprises a primary crushing device (1), a first conveying device, a secondary crushing device (7), a second conveying device, a sorting device (10), a sorting material feeding and conveying mechanism (11), a drying device (12), a third conveying device (14), a tertiary crushing device (15), a pneumatic conveying device (16) and a biomass fuel combustion device (18); The first conveying device is used to convey the primary biomass fuel granules from the discharge port of the primary crushing device (1) to the feed port of the secondary crushing device (7); the second conveying device is used to convey the secondary biomass fuel granules from the discharge port of the secondary crushing device (7) to the feed port of the sorting device (10); the feed end of the sorting discharge conveying mechanism (11) is adjacent to and corresponding to the discharge port of the sorting device (10), and the discharge end of the sorting discharge conveying mechanism (11) is adjacent to the drying device (10). The feed ports of the device (12) are adjacent and correspondingly arranged; the third conveying device (14) is used to convey the sorted and dried biomass fuel secondary granular material from the discharge port of the drying device (12) to the feed port of the third-stage crushing device (15); the discharge port of the third-stage crushing device (15) is connected to the feed port of the pneumatic conveying device (16) through a first pipeline, and the discharge port of the pneumatic conveying device (16) is connected to the feed port of the biomass fuel combustion device (18) through a second pipeline.

2. The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation according to claim 1, characterized in that: The first conveying device comprises a first belt conveying mechanism (2), a silo (4), a silo unloading conveying mechanism (5) and a second belt conveying mechanism (6); The feed end of the first belt conveyor mechanism (2) is adjacent to and corresponding to the discharge port of the primary crushing device (1), and the discharge end of the first belt conveyor mechanism (2) is adjacent to and corresponding to the feed port of the silo (4); The silo unloading conveying mechanism (5) and the second belt conveying mechanism (6) are arranged in sequence along the material conveying direction L; the feed end of the silo unloading conveying mechanism (5) is adjacent to and corresponding to the discharge port of the silo (4); the discharge end of the silo unloading conveying mechanism (5) is adjacent to and corresponding to the feed end of the second belt conveying mechanism (6); and the discharge end of the second belt conveying mechanism (6) is adjacent to and corresponding to the feed port of the secondary crushing device (7).

3. The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation according to claim 2, characterized in that: It also comprises a magnet device (3), wherein the magnet device (3) is arranged above the discharge end of the first belt conveying mechanism (2).

4. The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation according to claim 2, characterized in that: The second conveying device comprises a secondary crushing and unloading conveying mechanism (8) and a lifting and conveying mechanism (9); The feed end of the secondary crushing material discharging and conveying mechanism (8) is adjacent to and corresponding to the discharge port of the secondary crushing device (7), the discharge end of the secondary crushing material discharging and conveying mechanism (8) is adjacent to and corresponding to the lower feed port of the lifting and conveying mechanism (9), and the upper discharge port of the lifting and conveying mechanism (9) is adjacent to and corresponding to the feed port of the sorting device (10).

5. The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation according to claim 1, characterized in that: The drying device (12) comprises a tank body (1201) and a heating mechanism (1202) arranged on the side wall of the tank body (1201); The discharge end of the sorting and unloading conveying mechanism (11) is adjacent to and corresponding to the feed inlet of the tank body (1201).

6. The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation according to claim 5, characterized in that: The heating mechanism (1202) is a steam-type heating coil, and the steam-type heating coil is installed around the outer circumference of the tank body (1201).

7. The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation according to claim 5, characterized in that: It also includes a drain pump (19), the inlet of the drain pump (19) is connected to the inner cavity of the tank body (1201) through a drain pipe.

8. The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation according to claim 1, characterized in that: It also includes a pneumatic partition device (17); the second pipeline includes a first connecting pipe and a second connecting pipe that are connected to each other, the inlet end of the first connecting pipe is connected to the discharge port of the pneumatic conveying device (16), the outlet end of the first connecting pipe is connected to the inlet of the pneumatic partition device (17), the inlet end of the second connecting pipe is connected to the outlet of the pneumatic partition device (17), and the outlet end of the second connecting pipe is connected to the feed port of the biomass fuel combustion device (18).

9. The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation according to claim 1, characterized in that: It also comprises a metering device (13), wherein the metering device (13) is arranged on the third conveying device (14).

10. The biomass fuel pretreatment system for coal-fired coupled biomass fuel power generation according to claim 4, characterized in that: The sorting material discharging and conveying mechanism (11), the silo material discharging and conveying mechanism (5), the secondary crushing material discharging and conveying mechanism (8) and the lifting and conveying mechanism (9) are all screw conveyors.

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