CN113883525A

CN113883525A - Garbage treatment system and method coupled with coal-fired generator set

Info

Publication number: CN113883525A
Application number: CN202111122820.4A
Authority: CN
Inventors: 王学斌; 周澳; 戴高峰; 赵小军; 孙锦余; 薛东发; 林柯荣; 毕武林; 王鹏; 刘义
Original assignee: Xian Jiaotong University
Current assignee: Xian Jiaotong University
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2022-01-04

Abstract

The invention discloses a garbage disposal system and a method for coupling a coal-fired generator set, wherein the system comprises: a first sorting device; the drying kiln is used for inputting the organic matters output by the first sorting device and performing drying treatment; the cracking kiln is used for inputting organic matters output by the drying kiln and carrying out pyrolysis treatment; a second sorting device; the coal-fired boiler is used for introducing coke output by the second sorting device into the hearth along with primary air and pulverized coal, and introducing pyrolysis oil gas output by the cracking kiln into the hearth along with the primary air or secondary air to perform combustion power generation; when the drying kiln is used for drying, flue gas output by a medium-temperature flue gas pipeline of the coal-fired boiler is used for supplying heat; when the pyrolysis kiln carries out pyrolysis treatment, the flue gas output by a high-temperature flue gas pipeline of the coal-fired boiler is adopted for supplying heat. The system can realize the resource utilization of the domestic garbage and the improvement of the boiler efficiency.

Description

Garbage treatment system and method coupled with coal-fired generator set

Technical Field

The invention belongs to the technical field of energy utilization and solid waste treatment, and particularly relates to a garbage treatment system and method of a coupling coal-fired generator set.

Background

Along with the rapid development of social economy, the acceleration of urbanization process and the rapid improvement of the living standard of people, the yield of municipal solid waste is also increased year by year. If the domestic garbage can not be treated in time, not only can a large amount of land be occupied, but also the environment in which the human beings rely on to live can be continuously polluted, and the health threat can be brought to the residents nearby.

At present, the treatment and disposal modes of the domestic garbage mainly comprise methods such as landfill, composting, incineration and the like. The sanitary landfill is the main method for treating the domestic garbage at present, but the method occupies a large amount of land resources, and the leachate has higher treatment cost and large leakage risk and is easy to cause secondary pollution; the garbage compost is built on the basis of garbage classification collection, is not suitable for mixed garbage, has low fermentation efficiency in the composting process and is easy to generate odor; the volume of the garbage can be greatly reduced by adopting incineration treatment, the volume of the garbage after incineration can be reduced by about 90%, various pathogenic microorganisms in the garbage can be eliminated by incineration, the calorific value generated by incineration can be recycled, and the municipal solid waste treated by the incineration method has the advantages of harmlessness, reduction, recycling and the like, so that the municipal solid waste is rapidly developed and applied.

The method for treating the municipal solid waste by coupling the large coal-fired power plant unit is a good method for treating the waste, on one hand, the municipal solid waste can be treated in a harmless and reducing manner, the construction cost of a newly-built waste incineration plant is reduced, on the other hand, the fuel energy utilization rate of the large coal-fired power plant unit is high, and the utilization efficiency of the heat value of the municipal solid waste can be greatly improved. At present, a plurality of coal-fired power plants adopt a method of directly mixing domestic garbage and coal for incineration, and the existing method for incinerating and treating garbage has some defects, including: the domestic garbage often contains refractory matters, and the domestic garbage is easy to be incompletely combusted when being directly put into a boiler, so that resource waste is caused; the domestic waste water content is big, directly burns in the boiler and causes boiler water wall to corrode easily, reduces boiler water wall life, and too much vapor can influence the temperature field in the coal fired boiler simultaneously to influence boiler efficiency.

Disclosure of Invention

In order to solve the above problems, the present invention provides a garbage disposal system and method coupled to a coal-fired power generating set, so as to solve one or more of the above technical problems. In the system, the coal-fired generator set is coupled with the garbage pyrolysis system, the boiler flue gas generated by the coal-fired generator set is used for drying and pyrolyzing the household garbage, and coke and pyrolysis oil gas generated by drying and pyrolyzing the household garbage can be introduced into the coal-fired boiler for combustion and power generation, so that the resource utilization of the household garbage and the improvement of the boiler efficiency are realized.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention discloses a garbage disposal system coupled with a coal-fired generator set, which comprises:

the first sorting device is used for inputting and sorting the household garbage to be treated and outputting organic matters which can be combusted and pyrolyzed;

the drying kiln is used for inputting the organic matters output by the first sorting device, drying the organic matters and outputting the dried organic matters;

the cracking kiln is used for inputting the organic matters output by the drying kiln, carrying out pyrolysis treatment and outputting pyrolysis oil gas and solid substances;

the second sorting device is used for inputting the solid substances output by the cracking kiln, sorting the solid substances and outputting cokes and the solid residues after the cokes are sorted;

the coal-fired boiler is used for introducing coke output by the second sorting device into a hearth along with primary air and pulverized coal, and introducing pyrolysis oil gas output by the cracking kiln into the hearth along with the primary air or secondary air to perform combustion power generation;

when the drying kiln is used for drying, the flue gas output by a medium-temperature flue gas pipeline of the coal-fired boiler is used for supplying heat; when the pyrolysis kiln carries out pyrolysis treatment, the flue gas output by the high-temperature flue gas pipeline of the coal-fired boiler is adopted for supplying heat.

The invention further improves the method and also comprises the following steps: and the condenser is used for condensing the moisture carried in the flue gas output after the drying treatment of the drying kiln, and the moisture obtained by condensation is used as boiler circulating make-up water.

The invention further improves the method and also comprises the following steps: the flue gas output after the drying treatment of the drying kiln is condensed and used for being input to a preset position at the upper part in the hearth of the coal-fired boiler for heating and recycling;

and the flue gas output after the pyrolysis treatment of the cracking kiln is input into a preset position at the upper part in the hearth of the coal-fired boiler for heating and recycling.

The further improvement of the invention is that the drying treatment temperature of the drying kiln is 100-140 ℃.

The invention is further improved in that the inlet of the high-temperature flue gas pipeline is positioned at the outlet of an economizer of the coal-fired boiler; the direction of the high-temperature flue gas entering the cracking kiln is consistent with the direction of the organic matter entering the cracking kiln, and the pyrolysis treatment temperature of the cracking kiln is 400-600 ℃.

A further development of the invention is that,

the first sorting device is provided with an inlet and an outlet;

the drying kiln is provided with a solid substance inlet, a gaseous substance inlet, a solid substance outlet and a gaseous substance outlet; the solid material inlet of the drying kiln is communicated with the outlet of the first sorting device;

the cracking kiln is provided with a central annular chamber and an outer annular chamber; the central annular chamber is provided with a solid substance inlet and a solid substance outlet, and the outer annular chamber is provided with a gaseous substance inlet and a gaseous substance outlet; the solid matter inlet of the central annular chamber is communicated with the solid matter outlet of the drying kiln; the gaseous substance outlet of the outer annular cavity is communicated with a preset position at the upper part in the hearth of the coal-fired boiler;

the second sorting device is provided with an inlet, a first outlet and a second outlet; the inlet of the second sorting device is communicated with the solid substance outlet of the central annular chamber, the first outlet of the second sorting device is used for outputting coke, and the second outlet of the second sorting device is used for outputting solid residues after the coke is sorted;

the fuel inlet of the coal-fired boiler is communicated with the first outlet of the second sorting device, and the primary air inlet and the secondary air inlet of the coal-fired boiler are respectively used for introducing primary air and secondary air; the high-temperature flue gas pipeline of the coal-fired boiler is communicated with the gaseous substance inlet of the outer annular cavity; and the medium-temperature flue gas pipeline of the coal-fired boiler is communicated with the gaseous substance inlet of the drying kiln.

The invention further improves the method and also comprises the following steps:

a condenser provided with an inlet, a first outlet and a second outlet; an inlet of the condenser is communicated with a gaseous substance outlet of the drying kiln, and a first outlet of the condenser is used for outputting liquid water; and a second outlet of the condenser is communicated with a preset position at the upper part in the hearth of the coal-fired boiler.

and the flue gas treatment device is used for inputting the flue gas output by the coal-fired boiler, performing dust removal, denitration and desulfurization treatment, and sending the flue gas into a chimney through a draught fan to be discharged after reaching a preset emission standard.

The invention is further improved in that the fuel inlet of the coal-fired boiler is also communicated with the solid matter outlet of the cracking kiln.

The invention discloses an operation method of a garbage disposal system coupled with a coal-fired generator set, which comprises the following steps:

the first sorting device inputs the household garbage to be processed, sorts the household garbage and outputs organic matters capable of being combusted and pyrolyzed;

the drying kiln inputs the organic matters output by the first sorting device, carries out drying treatment and outputs the dried organic matters;

the cracking kiln inputs the organic matters output by the drying kiln, carries out pyrolysis treatment and outputs pyrolysis oil gas and solid substances;

the second sorting device inputs the solid substances output by the cracking kiln, sorts the solid substances and outputs cokes and solid residues after the cokes are sorted;

the coal-fired boiler feeds the coke output by the second sorting device into a hearth along with primary air and pulverized coal, and feeds pyrolysis oil gas output by the cracking kiln into the hearth along with the primary air or secondary air to perform combustion power generation;

Compared with the prior art, the invention has the following beneficial effects:

the garbage treatment system provided by the invention is mutually coupled with the coal burner unit system while ensuring the high-efficiency and clean treatment of the garbage, so that the garbage can be effectively utilized, the energy utilization rate of the garbage is improved, the pollutant discharge of the garbage treatment is reduced, and the remarkable economic benefit is brought. Specifically, (1) a garbage cracking system is coupled outside the coal-fired generator set, the household garbage can be sorted, dried and pyrolyzed in advance, coke and pyrolysis oil gas entering the coal-fired boiler are high-quality fuels and can be completely combusted, and therefore the clean resource utilization of the household garbage is realized. (2) After the domestic garbage is treated by the drying kiln and the cracking kiln, the moisture content is greatly reduced, impurities in the garbage are removed, the combustion heat value of the fuel is greatly improved, and the boiler efficiency is improved. (3) The coke and pyrolysis oil gas generated by pyrolysis of the household garbage can partially replace fire coal, so that the consumption of the fire coal is reduced, the problem of treatment of the municipal household garbage is solved, and the household garbage is used as renewable energy, so that carbon emission reduction of a thermal power plant can be realized. (4) The flue gas that utilizes coal fired boiler to produce comes to carry out drying and pyrolysis to domestic waste, need not the external world and builds relevant heating system, has saved the investment construction cost of system.

In the invention, the condenser is added in the garbage treatment system, so that the water in the garbage can be effectively utilized and recycled as boiler make-up water, and the water treatment cost of the coal-fired power plant can be further reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below; it is obvious that the drawings in the following description are some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic structural diagram according to a second embodiment of the present invention;

FIG. 2 is a schematic structural view according to a third embodiment of the present invention;

FIG. 3 is a schematic structural view of a fourth embodiment according to the present invention;

FIG. 4 is a schematic flow chart of a method according to a second embodiment of the present invention;

in the figure, 1, domestic garbage; 2. a first sorting device; 3. drying the kiln; 4. a cracking kiln; 5. a condenser; 6. a second sorting device; 7. coke; 8. a coal-fired boiler; 9. a flue gas treatment device; 10. a chimney; 11. an induced draft fan; 12. a centrifugal pump; 13. a valve; 14. primary air; 15. secondary air; 16. solid residue; 17. a high temperature flue gas duct; 18. a medium temperature flue gas pipeline; 19. liquid water.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The invention is described in further detail below with reference to the accompanying drawings:

example 1

The garbage disposal system of the embodiment of the invention coupled with a coal-fired generator set comprises:

the first sorting device 2 is used for inputting and sorting the household garbage 1 to be processed and outputting organic matters which can be combusted and pyrolyzed;

the drying kiln 3 is used for inputting the organic matters output by the first sorting device 2, performing drying treatment and outputting the dried organic matters;

the cracking kiln 4 is used for inputting the organic matters output by the drying kiln 3, carrying out pyrolysis treatment and outputting pyrolysis oil gas and solid substances;

the second sorting device 6 is used for inputting the solid substances output by the cracking kiln 4, sorting the solid substances, and outputting cokes 7 and solid residues 16 after the cokes are sorted;

the coal-fired boiler 8 is used for introducing the coke 7 output by the second sorting device 6 into the hearth along with primary air 14 and pulverized coal, and introducing pyrolysis oil gas output by the pyrolysis kiln 4 into the hearth along with the primary air 14 or secondary air 15 for combustion and power generation;

when the drying kiln 3 is used for drying, the flue gas output by the medium-temperature flue gas pipeline 18 of the coal-fired boiler 8 is used for supplying heat; when the pyrolysis kiln 4 is used for pyrolysis treatment, the flue gas output by the high-temperature flue gas pipeline 17 of the coal-fired boiler 8 is used for heat supply.

In the system provided by the embodiment of the invention, the coal-fired generator set is coupled with the garbage pyrolysis system, the boiler flue gas generated by the coal-fired generator set is used for drying and pyrolyzing the household garbage, and the coke and pyrolysis oil gas generated by drying and pyrolyzing the household garbage can be introduced into the coal-fired boiler for combustion and power generation, so that the resource utilization of the household garbage and the improvement of the boiler efficiency are realized.

Example 2

An exemplary embodiment of the present invention, as shown in fig. 1, specifically provides a system for coupling a coal-fired power generating unit to process household garbage, comprising: a garbage cracking system and a coal-fired power generation system; wherein the garbage cracking system comprises a first sorting device 2, a drying kiln 3, a cracking kiln 4, a condenser 5 and a second sorting device 6; the coal-fired power generation system comprises a coal-fired boiler 8 (illustratively, a power plant coal-fired boiler), a flue gas treatment device 9, a chimney 10 and an induced draft fan 11.

The inlet of the first sorting device 2 is used for inputting the household garbage 1, and the outlet of the first sorting device is connected with the solid material inlet of the drying kiln 3; the drying kiln 3 is provided with two inlets of a solid substance inlet and a gaseous substance inlet, and two outlets of a solid substance outlet and a gaseous substance outlet, and the gaseous substance inlet of the drying kiln 3 is connected with the medium-temperature flue gas outlet of the coal-fired boiler 8 through a medium-temperature flue gas pipeline 18; a solid substance outlet of the drying kiln 3 is connected with a solid substance inlet of the cracking kiln 4, and a gaseous substance outlet of the drying kiln 3 is connected with an inlet of the condenser 5; the cracking kiln 4 also comprises a solid substance inlet and a gaseous substance inlet, and a solid substance outlet and a gaseous substance outlet, wherein the solid substance inlet enters the central annular chamber, the gaseous substance inlet enters the outer annular chamber, the gaseous substance inlet is connected with the high-temperature flue gas outlet of the coal-fired boiler 8 through the high-temperature flue gas pipeline 17, the solid substance outlet of the cracking kiln 4 is connected with the inlet of the second sorting device 6, and the gaseous substance outlet of the cracking kiln 4 is connected with the primary air 14 inlet of the coal-fired boiler 8.

In the embodiment of the present invention, the outlet of the second sorting device 6 is the coke 7 and the solid residue 16 after the coke is sorted.

Specifically, the inlet of the condenser 5 is flue gas output from the drying kiln 3, and the outlet is liquid water 19 and flue gas after condensation treatment; the inlet of the centrifugal pump 12 is connected with the flue gas outlet of the condenser 5 and the gaseous substance outlet of the cracking kiln 4, the communicating pipelines are respectively provided with a valve 13, and the outlet of the centrifugal pump 12 is connected with the upper part of the hearth of the coal-fired boiler 8.

In the embodiment of the invention, a fuel inlet of a coal-fired boiler 8 is connected with a coke outlet of a second sorting device 6, a gaseous substance outlet of a cracking kiln 4 and externally introduced primary air 14, a secondary air inlet is introduced with secondary air 15 from the outside, a flue gas pipeline is respectively connected with a gaseous substance inlet of a drying kiln 3 and the cracking kiln 4 through a medium-temperature flue gas pipeline 18 and a high-temperature flue gas pipeline 17, a flue gas outlet of the coal-fired boiler 8 is connected with an inlet of a flue gas treatment device 9, and the flue gas treatment device 9 is connected with an inlet of a chimney 10 through an induced draft fan 11.

Example 3

In a second embodiment of the present invention, as shown in fig. 2, a system for coupling and treating domestic garbage by a coal-fired power generation unit is provided, wherein the system for coupling and treating domestic garbage by a coal-fired power generation unit is arranged on the system shown in fig. 1, and a gaseous substance outlet of a cracking kiln 4 is changed from being connected with a primary air inlet of a coal-fired boiler 8 to being connected with a secondary air inlet of the coal-fired boiler 8. Wherein, the coke generated by pyrolysis and the externally introduced primary air 14 enter the coal-fired boiler 8 from the primary air inlet of the coal-fired boiler 8 for combustion power generation, and the pyrolysis oil gas enters the upper part of the combustor through the secondary air inlet together with the externally introduced secondary air 15 for combustion supporting, so that the average flue gas temperature in the hearth is increased.

Example 4

In a third embodiment of the present invention, as shown in fig. 3, a system for coupling and treating domestic garbage by a coal-fired power generating set is provided, wherein the system for coupling and treating domestic garbage by a coal-fired power generating set is arranged on the system shown in fig. 1, and a high-temperature flue gas pipeline 17 and a medium-temperature flue gas pipeline 18 are connected through a control valve; the control valve between the medium temperature flue gas pipeline 18 and the high temperature flue gas pipeline 17 can flexibly adjust the amount and temperature of flue gas entering the drying kiln 3 and the cracking kiln 4 according to the requirements of the drying kiln 3 and the cracking kiln 4, a large valve is opened, high temperature flue gas in the high temperature flue gas pipeline 17 enters the medium temperature flue gas pipeline 18 through the valve to increase, the temperature of the drying kiln 3 rises, the temperature of the cracking kiln 4 falls, otherwise, the valve is closed, the high temperature flue gas in the high temperature flue gas pipeline 17 enters the medium temperature flue gas pipeline 18 through the valve to decrease, the temperature of the drying kiln 3 falls, and the temperature of the cracking kiln 4 rises.

Example 5

The operation method of the garbage disposal system coupled with the coal-fired generator set comprises the following steps:

the first sorting device 2 inputs the household garbage 1 to be treated, sorts the household garbage and outputs organic matters which can be combusted and pyrolyzed;

the drying kiln 3 inputs the organic matters output by the first sorting device 2, performs drying treatment and outputs the dried organic matters;

the cracking kiln 4 inputs the organic matters output by the drying kiln 3 and carries out pyrolysis treatment, and pyrolysis oil gas and solid substances are output;

the second sorting device 6 inputs the solid substances output by the cracking kiln 4 and sorts the solid substances, and outputs coke 7 and solid residues 16 after the coke is sorted;

the coal-fired boiler 8 leads the coke 7 output by the second sorting device 6 into a hearth along with primary air 14 and pulverized coal, and leads pyrolysis oil gas output by the pyrolysis kiln 4 into the hearth along with the primary air 14 or secondary air 15 for combustion and power generation;

Example 6

The method for coupling treatment of household garbage by a coal-fired generator set provided by the embodiment of the invention is shown in FIG. 4 and comprises the following steps:

delivering the household garbage to a first sorting device for sorting, and removing non-organic matters such as metal, glass, slag and the like in the household garbage through manual work, magnetic separation and screening to obtain organic matters capable of being combusted and pyrolyzed;

sending the sorted organic matters into a drying kiln for drying to remove most of water in the organic matters, wherein the drying kiln is supplied with heat by smoke from a medium-temperature smoke pipeline, an inlet of the medium-temperature smoke pipeline is positioned at an outlet of an air preheater of the coal-fired boiler, and the temperature of the drying kiln is between 100 ℃ and 140 ℃;

feeding the dried organic matters into a cracking kiln for pyrolysis to obtain pyrolysis oil gas and solid matters, wherein the cracking kiln is supplied with heat by flue gas from a high-temperature flue gas pipeline, an inlet of the high-temperature flue gas pipeline is positioned at an outlet of a coal-fired boiler economizer, the direction of the flue gas entering the cracking kiln is consistent with the direction of the organic matters entering the cracking kiln, and the pyrolysis is carried out smoothly, and the temperature of the cracking kiln is between 400 ℃ and 600 ℃;

the pyrolyzed solid substances are sorted by a second sorting device to obtain coke and other solid residues, and the coke and pyrolysis oil gas are introduced into the coal-fired boiler along with primary air and pulverized coal of the coal-fired boiler to be combusted and generate power;

the flue gas at the outlet of the drying kiln is sent into a condenser to condense the moisture carried in the flue gas, and the moisture obtained by condensation can be used as boiler circulating make-up water;

the flue gas passing through the drying kiln and the cracking kiln is re-fed into the flue gas above the coal-fired boiler through a centrifugal pump for heating and recycling;

and the flue gas from the flue gas outlet of the coal-fired boiler is sent into a flue gas treatment device for dedusting, denitration and desulfurization, and then is sent into a chimney through a draught fan to be discharged after meeting the required emission standard.

In summary, the waste treatment system provided by the invention is mutually coupled with the coal burner set system while ensuring the high-efficiency and clean treatment of the waste, so that the waste can be effectively utilized, the energy utilization rate of the waste is improved, and the pollutant discharge of the waste treatment is reduced, thereby bringing remarkable economic benefit. Specifically, (1) a garbage cracking system is coupled outside the coal-fired generator set, the household garbage can be sorted, dried and pyrolyzed in advance, coke and pyrolysis oil gas entering the coal-fired boiler are high-quality fuels and can be completely combusted, and therefore the clean resource utilization of the household garbage is realized. (2) After the domestic garbage is treated by the drying kiln and the cracking kiln, the moisture content is greatly reduced, impurities in the garbage are removed, the combustion heat value of the fuel is greatly improved, and the boiler efficiency is improved. (3) The coke and pyrolysis oil gas generated by pyrolysis of the household garbage can partially replace fire coal, so that the consumption of the fire coal is reduced, the problem of treatment of the municipal household garbage is solved, and the household garbage is used as renewable energy, so that carbon emission reduction of a thermal power plant can be realized. (4) The flue gas that utilizes coal fired boiler to produce comes to carry out drying and pyrolysis to domestic waste, need not the external world and builds relevant heating system, has saved the investment construction cost of system.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims

1. A refuse treatment system coupled with a coal-fired power generating unit is characterized by comprising:

the first sorting device (2) is used for inputting and sorting the household garbage (1) to be treated and outputting organic matters which can be combusted and pyrolyzed;

the drying kiln (3) is used for inputting the organic matters output by the first sorting device (2), drying the organic matters and outputting the dried organic matters;

the cracking kiln (4) is used for inputting the organic matters output by the drying kiln (3) and carrying out pyrolysis treatment, and outputting pyrolysis oil gas and solid substances;

the second sorting device (6) is used for inputting the solid substances output by the cracking kiln (4), sorting the solid substances, and outputting the coke (7) and the solid residues (16) after the coke is sorted;

the coal-fired boiler (8) is used for introducing coke (7) output by the second sorting device (6) into the hearth along with primary air (14) and pulverized coal, and introducing pyrolysis oil gas output by the cracking kiln (4) into the hearth along with the primary air (14) or secondary air (15) for combustion and power generation;

when the drying kiln (3) is used for drying, the flue gas output by a medium-temperature flue gas pipeline (18) of the coal-fired boiler (8) is used for supplying heat; when the pyrolysis kiln (4) is used for pyrolysis treatment, the flue gas output by the high-temperature flue gas pipeline (17) of the coal-fired boiler (8) is used for heat supply.

2. The system of claim 1, further comprising:

and the condenser (5) is used for condensing moisture carried in the flue gas output after the drying treatment of the drying kiln (3), and the moisture obtained by condensation is used as boiler circulating make-up water.

3. The system of claim 2, further comprising:

the flue gas output after the drying treatment of the drying kiln (3) is condensed and is input to a preset position at the upper part in the hearth of the coal-fired boiler (8) for heating and recycling;

and the flue gas output after the pyrolysis treatment of the pyrolysis kiln (4) is input into a preset position at the upper part in the hearth of the coal-fired boiler (8) for heating and recycling.

4. The refuse treatment system coupled with a coal-fired power generation unit according to claim 1, wherein the drying temperature of the drying kiln (3) is 100-140 ℃.

5. The waste disposal system coupled with a coal-fired power generation unit according to claim 1, wherein the inlet of the high temperature flue gas pipeline (17) is positioned at the outlet of the economizer of the coal-fired boiler (8); the direction of the high-temperature flue gas entering the cracking kiln (4) is consistent with the direction of the organic matter entering the cracking kiln, and the pyrolysis treatment temperature of the cracking kiln (4) is 400-600 ℃.

6. The waste disposal system of claim 1, wherein the waste disposal system comprises a waste disposal unit,

the first sorting device (2) is provided with an inlet and an outlet;

the drying kiln (3) is provided with a solid substance inlet, a gaseous substance inlet, a solid substance outlet and a gaseous substance outlet; the solid substance inlet of the drying kiln (3) is communicated with the outlet of the first sorting device (2);

the cracking kiln (4) is provided with a central annular chamber and an outer annular chamber; the central annular chamber is provided with a solid substance inlet and a solid substance outlet, and the outer annular chamber is provided with a gaseous substance inlet and a gaseous substance outlet; the solid matter inlet of the central annular chamber is communicated with the solid matter outlet of the drying kiln (3); the gaseous substance outlet of the outer annular cavity is communicated with a preset position at the upper part in the hearth of the coal-fired boiler (8);

the second sorting device (6) is provided with an inlet, a first outlet and a second outlet; the inlet of the second sorting device (6) is communicated with the solid substance outlet of the central annular chamber, the first outlet of the second sorting device (6) is used for outputting coke (7), and the second outlet of the second sorting device (6) is used for outputting solid residue (16) after the coke is sorted;

the fuel inlet of the coal-fired boiler (8) is communicated with the first outlet of the second sorting device (6), and the primary air (14) inlet and the secondary air (15) inlet of the coal-fired boiler (8) are respectively used for introducing primary air (14) and secondary air (15); a high-temperature flue gas pipeline (17) of the coal-fired boiler (8) is communicated with a gaseous substance inlet of the outer annular cavity; and a medium-temperature flue gas pipeline (18) of the coal-fired boiler (8) is communicated with a gaseous substance inlet of the drying kiln (3).

7. The system of claim 6, further comprising:

a condenser (5), the condenser (5) being provided with an inlet, a first outlet and a second outlet; an inlet of the condenser (5) is communicated with a gaseous substance outlet of the drying kiln (3), and a first outlet of the condenser (5) is used for outputting liquid water (19); and a second outlet of the condenser (5) is communicated with a preset position at the upper part in the hearth of the coal-fired boiler (8).

8. The system of claim 6, further comprising:

and the flue gas treatment device (9) is used for inputting the flue gas output by the coal-fired boiler (8), performing dust removal, denitration and desulfurization treatment, and sending the flue gas into a chimney through a draught fan to be discharged after reaching a preset discharge standard.

9. A coal-fired power plant coupled waste disposal system as defined in claim 6, wherein the fuel inlet of said coal-fired boiler (8) is further communicated with the solid matter outlet of said cracking furnace (4).

10. A method of operating a waste management system coupled to a coal-fired power generation unit of claim 1, comprising the steps of:

the first sorting device (2) inputs the household garbage (1) to be treated, sorts the household garbage and outputs organic matters which can be combusted and pyrolyzed;

the drying kiln (3) inputs the organic matters output by the first sorting device (2) and carries out drying treatment, and outputs the dried organic matters;

the cracking kiln (4) inputs the organic matters output by the drying kiln (3) for pyrolysis treatment, and outputs pyrolysis oil gas and solid substances;

the second sorting device (6) inputs the solid substances output by the cracking kiln (4) and sorts the solid substances, and outputs the coke (7) and the solid residues (16) after the coke (7) is sorted;

the coal-fired boiler (8) leads the coke (7) output by the second sorting device (6) into a hearth along with primary air (14) and pulverized coal, and leads pyrolysis oil gas output by the cracking kiln (4) into the hearth along with the primary air (14) or secondary air (15) for combustion and power generation;