A kind of electricity generation system and method for coal-fired coupling domestic garbage pyrolysis
Technical field
The invention belongs to solidification disposal of waste field, in particular to the electricity generation system of a kind of coal-fired coupling domestic garbage pyrolysis and side
Method.
Background technique
With the quickening of urbanization process, the problem of " garbage-surrounded city ", is increasingly prominent, how to realize the recycling of rubbish without
Evilization disposition becomes urgent problem to be solved.Current most widely used method of disposal is waste incineration and generating electricity, but at this stage its
Treating capacity is still unable to satisfy demand.Standard compliant garbage incinerating power plant is created to need to expend flood tide fund and be faced with
The problems such as " neighbour keeps away effect ", while the harmful substances such as dioxin of Refuse Incineration Process generation, environment is caused inevitably
Secondary pollution.
The pyrolytic gasification technology of rubbish is another heat treatment mode, and principle is unstable using the heat of organic matter in garbage
It is qualitative, it is heated under anaerobic or anoxia condition, is allowed to decompose under the high temperature conditions, form combustible gas, tar liquid, solid can
Fire coke.Pyrolysismethod is more conducive to the efficient recycling of the energy compared to incineration method, and to more environment-friendly.Pyrolytic process is to restore
Property atmosphere under carry out, smoke discharge amount is small, and dust entrainment is few, and the generation of SOx, NOx and HCl also can be by under reducing atmosphere
To certain restrictions, while lower air equivalent is than the generation of inhibition dioxin.
On the other hand, the more attention with government to environmental problem, coal-burning power plant are gradually eliminated, steam turbine
It mostly can not oepration at full load.Rubbish is disposed with wide using the boiler and its mature smoke processing system of coal-burning power plant
Application prospect.However garbage water is high, calorific value is low, and geometric dimension is big, and physical parameter and coal dust difference are excessive, can not
Effectively with coal dust direct blending combustion.And rubbish coke strength is smaller, by being crushed its physical parameter closer to coal, is easy to
With coal multifuel combustion.
Therefore, it is necessary to design a kind of system and method for coal-fired coupling refuse pyrolysis, convert garbage into for coke and with
Coal mixes burning, while generating combustible gas, and pressurization is passed through blended burning of coal fired boiler, obtains cogenerated products.
Summary of the invention
The purpose of the present invention is realizing the pyrolysis of the efficient stable of house refuse, and the thermal decomposition product of house refuse is sent into and is fired
Coal burning boiler and coal mix burning, and the coal-fired load of a part is substituted in the case where not influencing coal-burning boiler system, reaches garbage as resource
Secondary pollution is reduced simultaneously.
For this purpose, first technical solution of the invention is: a kind of electricity generation system of coal-fired coupling domestic garbage pyrolysis, packet
It includes:
For rubbish coke and coal dust to be mixed burning, steam is generated with the circulating fluidized bed combustion coal system of heat supply or power generation;
For converting the house refuse after drying to the fixed bed refuse pyrolysis system of coke and synthesis gas;
For isolating synthesis gas cooling and purifying tar and obtaining the synthesis gas processing system of combustible gas;
The circulating fluidized bed combustion coal system include fluid-bed combustion furnace, furnace exit cyclone separator, feed back leg and
Combustion furnace screw(-type) feeder, fluid-bed combustion furnace left side lower section are equipped with coal dust material inlet, are connected with combustion furnace screw(-type) feeder;Stream
The outlet in fluidized bed combustion furnace roof portion is connect with furnace exit cyclone separator to be communicated;It is set on the burner hearth of the fluid-bed combustion furnace
There are 4~8 groups of gas nozzles;The fluid-bed combustion furnace lower right-hand side is connected with feed back leg;Fluidized bed combustion furnace bottom is equipped with
Lower cinder notch;
The fixed bed refuse pyrolysis system includes fixed-bed pyrolysis furnace and pyrolysis outlet of still cyclone separator, fixed bed
Top is connect with furnace exit cyclone separator on the left of pyrolysis oven, connects fluid-bed combustion furnace by feed back leg below left side;
Fixed-bed pyrolysis furnace roof portion connect with pyrolysis outlet of still cyclone separator and communicates;
The synthesis gas processing system includes electronics oil expeller and pressuring machine, and pyrolysis outlet of still cyclone separator connects electronics
Oil expeller, electronics oil expeller top connect pressuring machine, and pressuring machine is connected with the gas nozzle of fluid-bed combustion furnace;Electronics oil expeller
Lower section is equipped with tar outlet, and tar outlet is connected to combustion furnace screw(-type) feeder.
Preferably, the fixed bed refuse pyrolysis system further includes Coke crusher and pyrolysis oven screw(-type) feeder;It is fixed
Top is equipped with garbage feeding mouth on the right side of bed pyrolysis oven, is connected with pyrolysis oven screw(-type) feeder;Under on the left of the fixed-bed pyrolysis furnace
Side is equipped with coke discharge port, is connected with Coke crusher, Coke crusher is connected with feed back leg;Fixed-bed pyrolysis furnace bottom is set
There is gasification agent inlet.
Preferably, the pyrolysis outlet of still cyclone separator is divided into two-way by flow control valve, is connected and fixed all the way
The gasification agent inlet of bed pyrolysis furnace bottom, the electronics oil expeller of another way connection synthesis gas processing system.
Preferably, in the fixed bed refuse pyrolysis system, pass through coke from the rubbish coke of fixed-bed pyrolysis furnace discharge
After crusher, rubbish coke particle diameter is less than 30mm.
Second technical solution of the invention is: a kind of electricity-generating method of coal-fired coupling domestic garbage pyrolysis, including following
Step:
1) coal dust is fed by combustion furnace screw(-type) feeder from the coal dust material inlet of fluid-bed combustion furnace, in the oxygen of fluidized gas
Change effect is lower to occur combustion reaction, and the flue gas of generation of burning enters furnace exit cyclone separator entrainment of taking hott bed material,
Gas solid separation under the action of centrifugal force takes hott bed material by material returning device and falls into fixed-bed pyrolysis furnace, and flue gas then enters fume treatment
System;
2) dry broken house refuse top charging on the right side of fixed-bed pyrolysis furnace by pyrolysis oven screw(-type) feeder
Afterwards, with take hott bed material pyrolysis furnace bottom carry out contact heat transfer, occur devolatilization reaction and pyrolysis reduction reaction;Pyrolysis generates
Rubbish coke be discharged into crusher, enter fluid-bed combustion furnace by feed back leg after broken and coal dust mix burning;Pyrolysis generate with
CO2、CO、H2、H2O and CH4Based on crude synthesis gas then enter pyrolysis oven cyclone separator, isolate and enter synthesis gas after lime-ash
Processing system, the synthesis gas temperature for being pyrolyzed outlet of still is about 500 DEG C~700 DEG C;
3) entering the rubbish coke of fluid-bed combustion furnace from feed back leg and coal dust is sufficiently mixed burning, fixed carbon is converted,
The clinker that coke and coal generate is discharged from the lower cinder notch of fluid-bed combustion furnace;Burning generate heat be used to produce steam with for
Heat or power generation;
4) after from the crude synthesis gas that pyrolysis oven cyclone separator comes out by flow control valve distribution regulation, part is returned
Fixed-bed pyrolysis furnace promotes newly generated synthesis gas discharge fixed-bed pyrolysis furnace, another part for providing pyrolysis atmosphere
Tar removing is removed by electronics oil expeller, obtained combustible gas is passed through after pressuring machine compression pressurization and conveys pressurization to fixed-bed pyrolysis furnace
Combustion gas.
Preferably, the hott bed material temperature degree of taking that fixed-bed pyrolysis furnace is fallen into the step 1) reaches 850 DEG C.
Preferably, the house refuse in the step 2) is sent into fixed-bed pyrolysis furnace after the pretreatments such as broken drying
Garbage raw material moisture content less than 20%.
Preferably, the tar obtained in step 4) from electronics oil expeller is delivered to the coal dust feed inlet of fluid-bed combustion furnace,
Oxidizing fire is carried out into combustion furnace.
Compared with prior art, beneficial effects of the present invention are as follows:
(1) present invention takes full advantage of existing coal-fired plant boiler and its fume treatment auxiliary, only needs based on this
Common fixed-bed pyrolysis furnace is coupled, a large amount of capital investment is reduced.
(2) coal dust multifuel combustion rubbish coke delivers equipment at full capacity by the present invention, and makes boiler by mixing burning synthesis gas
The thermal efficiency improves, and efficiently disposes house refuse while reducing consumption coal.
(3) double bed of circulating fluidized bed combustion of the present invention and fixed-bed pyrolysis process designs, using bed material as heat carrier, two
It is recycled between burner hearth, solves the problems, such as the benefit again of the heat source input of the fixed-bed pyrolysis gasification endothermic reaction and single pyrolysis coke
With problem, while by control bed material internal circulating load, achievees the purpose that accurately control pyrolysis in-furnace temperature, ensure that holding for system
Continuous stable operation.
(4) rubbish is carried out pyrolytic gasification by the present invention under reductive condition, and smoke discharge amount is small, and dust entrainment is few, and
The generation of SOx, NOx and HCl also will receive certain restrictions under reducing atmosphere, while lower air equivalent is than inhibiting dioxin
Generation, rubbish is greatly reduced and directly burns bring secondary environmental pollution.
Detailed description of the invention
It is described in further detail below in conjunction with attached drawing and embodiments of the present invention
Fig. 1 is system structure diagram of the invention.
In the figure, it is marked as 1. fluid-bed combustion furnaces, 2. fixed-bed pyrolysis furnaces, 3. furnace exit cyclone separators, 4. times
Dipleg, 5. Coke crushers, 6. pyrolysis outlet of still cyclone separators, 7. electronics oil expellers, 8. pressuring machines, 9. combustion furnace spirals are given
Material machine, 10. pyrolysis oven screw(-type) feeders, 11. flow control valves, 12. material returning devices, a. house refuse, b. coal dust, c. rubbish are burnt
Charcoal, d. combustible gas, e. tar, f. steam, g. flue gas, h. gasifying agent, i. fluidized bed clinker, j. lime-ash, k. fluidized gas.
Specific embodiment
Referring to attached drawing.The present embodiment includes at circulating fluidized bed combustion coal system, fixed bed refuse pyrolysis system and synthesis gas
Reason system.Wherein, coal burning system designs the HG-480/13.7L.MG31 type circulating fluidized bed boiler based on power 135MW, pyrolysis
System design is based on fixture bed experiment data.
The circulating fluidized bed combustion coal system includes: fluid-bed combustion furnace 1, furnace exit cyclone separator 3, feed back
Leg 4 and combustion furnace screw(-type) feeder 9;It is equipped with coal dust material inlet in the burner hearth left wall face lower part of fluid-bed combustion furnace 1, with combustion furnace
Screw(-type) feeder 9 connects, and burner hearth right wall lower part is connect with feed back leg 4;1 bottom of fluid-bed combustion furnace is equipped with lower cinder notch, fluidisation
Gas k is passed through burner hearth from bottom by the air distribution plate right above lower cinder notch;The outlet at 1 top of fluid-bed combustion furnace and furnace exit
The connection of cyclone separator 3 communicates.
The fixed bed refuse pyrolysis system includes: fixed-bed pyrolysis furnace 2, pyrolysis outlet of still cyclone separator 6, coke
Crusher 5 and pyrolysis oven screw(-type) feeder 10;It is equipped with garbage feeding mouth on the burner hearth right wall top of fixed-bed pyrolysis furnace, with heat
Furnace screw(-type) feeder 10 is solved to connect;Left wall face top is connect with furnace exit cyclone separator 3, and the coke of left wall face lower part goes out
Material mouth is connect with Coke crusher 5;It is pyrolyzed the entrance that furnace bottom is equipped with gasifying agent h, the outlet of roof of the furnace and pyrolysis outlet of still
The connection of cyclone separator 6 communicates.
The synthesis gas processing system includes: electronics oil expeller 7 and pressuring machine 8.Pyrolysis oven synthesis gas goes out through pyrolysis oven
Mouth cyclone separator gas 6 after separation, into electronics oil expeller 7, obtains tar, combustible gas blasts pressuring machine 8 admittedly.The circulation
Fluidized bed coal system installs 4~8 groups of gas nozzles on the burner hearth of fluid-bed combustion furnace 1, and sending out from pressuring machine 8 has one
The combustion gas of constant-pressure is sprayed to burner hearth.
In the present embodiment, coal dust b enters fluid-bed combustion furnace 1 from the feed of combustion furnace screw(-type) feeder 9, the life after drying
Rubbish a enters fixed-bed pyrolysis furnace 2 from the feed of pyrolysis oven screw(-type) feeder 10;From the rubbish coke c of furnace discharge is pyrolyzed through overfocus
After charcoal crusher 5, partial size becomes smaller, and mechanical strength reduces, and is easy to mix burning with coal dust;It is sent into the rubbish of fluid-bed combustion furnace after crushing
Rubbish coke particle diameter is less than 30mm.
Concrete operations the following steps are included:
Step 1): the qualified coal dust b of primary screening reaches 7mm hereinafter, by combustion furnace spiral using broken rear partial size
Batcher 10 is fed from the coal dust material inlet on 1 left wall face top of fluid-bed combustion furnace, while partial size≤1mm bed is covered in burner hearth
Expect sand.
Step 2): the air that temperature is about 200 DEG C is passed through fluidized bed combustion by the air distribution plate of 1 bottom of fluid-bed combustion furnace
Furnace.Under the oxidation of fluidized gas k combustion reaction occurs for coal dust b after combustion-supporting oil drop fire, the flue gas g of generation of burning entrainment of
It takes hott bed material and enters furnace exit cyclone separator 3, under the influence of centrifugal force gas solid separation, take hott bed material particle by returning
Glassware 12 falls into fixed-bed pyrolysis furnace 2, and flue gas g then enters smoke processing system.
Step 3): furnace design bed temperature is 890 DEG C, and actual motion bed temperature maintains 800 DEG C~920 DEG C or so, burner hearth
Exit gas temperature design temperature reaches 890 DEG C;Furnace exit cyclone separator 3 uses heat preservation, fire resisting and wear-resisting material,
To reduce heat waste, the hott bed material particle temperature of taking for falling into fixed-bed pyrolysis furnace 2 is made to reach 850 DEG C or so.Increase bed material amount, improves
The internal circulating load of material can reduce bed temperature.Increase bed drain purge, bed drops, inventory is reduced, and bed temperature can be made to increase.
Step 4): the house refuse a of (crude waste is crushed after sieving magnetic separation) passes through pyrolysis oven screw feeder after pretreatment
Machine 10 enters fixed-bed pyrolysis furnace 2 from the material inlet above pyrolysis oven right wall.House refuse a and take hott bed material fixed bed heat
Contact heat transfer in furnace 2 is solved, and devolatilization reaction and pyrolysis reduction reaction occurs.It is sent into the house refuse a of fixed-bed pyrolysis furnace 2
Moisture content is less than 20%.
Step 5): the rubbish coke c for being pyrolyzed generation is discharged into Coke crusher 5, enters fluidized bed by feed back leg 4 after being crushed
Combustion furnace 1 and coal dust b mix burning.The rubbish coke c partial size for being sent into fluid-bed combustion furnace after crushing is less than 30mm.What pyrolysis generated
With CO2、CO、H2、H2O and CH4Based on crude synthesis gas then enter pyrolysis oven cyclone separator 6, isolate to enter after lime-ash j and close
At gas processing system.
Step 6): after the crude synthesis gas come out from pyrolysis oven cyclone separator 6 is by the distribution regulation of flow control valve 11,
Part returns to fixed-bed pyrolysis furnace 2 as gasifying agent h for providing pyrolysis atmosphere, while promoting newly generated synthesis gas discharge solid
Fixed bed pyrolysis oven 2, another part remove tar removing e by electronics oil expeller 7, and obtained combustible gas d is passed through the compression pressurization of pressuring machine 8
The backward conveying of fluid-bed combustion furnace 1 pressurization combustion gas.The feed inlet that obtained tar e is delivered to fluid-bed combustion furnace enters burning
Furnace, coal dust b mixes burning together with rubbish coke c, combustible gas d and tar e and generates steam, to heat supply or power generation.
Step 7): regulated and controled by controlling the bed material amount for falling into fixed-bed pyrolysis furnace 2 and the feeding coal ratio of house refuse a
The temperature of fixed-bed pyrolysis furnace 2 controls 2 bed temperature of fixed-bed pyrolysis furnace and outlet syngas temperatures at 500 DEG C~700 DEG C.Table 1
Based on experimental data, the product property to gasify to refuse pyrolysis under different temperatures is analyzed, and can be mentioned for the control of pyrolysis oven bed temperature
For reference.
Product distribution and characteristic under the conditions of the different pyrolysis temperatures of table 1.