CN113048470A - Ultralow-emission experimental process for pulverized coal combustion - Google Patents
Ultralow-emission experimental process for pulverized coal combustion Download PDFInfo
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- CN113048470A CN113048470A CN202110348239.8A CN202110348239A CN113048470A CN 113048470 A CN113048470 A CN 113048470A CN 202110348239 A CN202110348239 A CN 202110348239A CN 113048470 A CN113048470 A CN 113048470A
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Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C5/00—Disposition of burners with respect to the combustion chamber or to one another; Mounting of burners in combustion apparatus
- F23C5/08—Disposition of burners
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C7/00—Combustion apparatus characterised by arrangements for air supply
- F23C7/002—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion
- F23C7/004—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion using vanes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C9/00—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber
- F23C9/06—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber for completing combustion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D17/00—Burners for combustion conjointly or alternatively of gaseous or liquid or pulverulent fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J15/00—Arrangements of devices for treating smoke or fumes
- F23J15/003—Arrangements of devices for treating smoke or fumes for supplying chemicals to fumes, e.g. using injection devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J15/00—Arrangements of devices for treating smoke or fumes
- F23J15/006—Layout of treatment plant
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J15/00—Arrangements of devices for treating smoke or fumes
- F23J15/02—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material
- F23J15/022—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material for removing solid particulate material from the gasflow
- F23J15/025—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material for removing solid particulate material from the gasflow using filters
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23L—SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
- F23L15/00—Heating of air supplied for combustion
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/12—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using combustion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J2215/00—Preventing emissions
- F23J2215/10—Nitrogen; Compounds thereof
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J2215/00—Preventing emissions
- F23J2215/10—Nitrogen; Compounds thereof
- F23J2215/101—Nitrous oxide (N2O)
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J2215/00—Preventing emissions
- F23J2215/20—Sulfur; Compounds thereof
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery
Abstract
The invention discloses an ultralow emission experiment process for pulverized coal combustion, and belongs to the technical field of pulverized coal combustion emission. The combustion unit of the invention adopts pulverized coal as a combustion raw material, air required by combustion is introduced into the furnace body through the primary air pipe, the secondary air pipe and the burnout air pipe, and meanwhile, partial flue gas generated by combustion of the combustion unit is sent into the furnace body through the flue gas circulation unit, so that the combustion environment of the pulverized coal is improved, the self-stable combustion of the pulverized coal is realized, and the pulverized coal can be fully burnt out; the flue gas that the burning unit produced carries out the dust removal denitration through dust removal denitration unit, later gets into desulfurization unit and carries out the desulfurization, the pollutant content in the effectual reduction flue gas.
Description
Technical Field
The invention relates to the technical field of pulverized coal combustion and emission experiments, in particular to an ultralow emission experiment process for pulverized coal combustion.
Background
In order to protect the environment and promote sustainable development, the emission of enterprises in the production process of the enterprises needs to reach certain standards, and the pulverized coal is used as a combustion raw material, the combustion of the pulverized coal can generate a large amount of heat, and simultaneously, the pulverized coal also generates NO containingX、SO2Pollutants such as dust, thereby it needs to control the pollutants that its burning formed to need to be demanded, in order to reduce the pollutant content that pulverized coal burning produced, adopt modes such as ammonia Selective Catalytic Reduction (SCR), bag collector, lime or limestone wet desulfurization to handle the flue gas among the prior art, but in order to further reduce the pollutant content in the flue gas, need to study pulverized coal burning test, but often prepare relevant flue gas among the prior art, this flue gas itself is not the product after pulverized coal burning, because the product after pulverized coal burning is more complicated, therefore probably not the same with the research result in the experiment, therefore, need further improvement.
Disclosure of Invention
1. Technical problem to be solved by the invention
In order to solve the technical problems, the invention aims to provide an experimental process for coal powder combustion ultralow emission, which can realize a coal powder self-stabilization combustion experiment, ensure that coal powder is fully combusted, test the dust removal efficiency, denitration efficiency and desulfurization efficiency of combustion flue gas in high-temperature dust removal, SCR denitration and wet desulfurization, realize full-flow test of combustion, dust removal, denitration and desulfurization in a laboratory and realize ultralow emission of solid fuel combustion flue gas in the laboratory. The system simultaneously carries out experimental research on the influence factors of combustion, dust removal, denitration and desulfurization, and further obtains the optimal parameters of the system corresponding to the combustion, the dust removal, the denitration and the desulfurization respectively.
2. Technical scheme
In order to achieve the purpose, the technical scheme provided by the invention is as follows:
the invention relates to an ultra-low emission experimental process for pulverized coal combustion, which comprises the following steps of,
step one, the combustion unit works
The powder feeder conveys pulverized coal into a cyclone burner of the furnace body, and meanwhile, a pipeline of the powder feeder is communicated with a primary air pipe, the primary air pipe is used for conveying air required by combustion, and the temperature of the air in the primary air pipe is 300-400 ℃;
the secondary air pipe conveys air with the temperature of 300-400 ℃ to the cyclone burner;
the liquefied petroleum gas is conveyed into the cyclone burner by the liquefied petroleum tank;
igniting at the outlet of the cyclone burner;
step two, dedusting and denitration are performed by a dedusting and denitration unit;
step three, desulfurizing by a desulfurization unit;
and step four, the flue gas circulating unit is used for conveying part of the flue gas generated by the combustion of the combustion unit into the furnace body, and the content of the flue gas conveyed to the combustion unit through the flue gas circulating unit accounts for 5% -35% of the total amount of the flue gas.
As a further improvement of the invention, the flue gas content sent to the combustion unit by the flue gas circulation unit in the fourth step accounts for 27 percent of the total flue gas content.
As a further improvement of the invention, a primary heat exchanger is arranged between the combustion unit and the dedusting and denitration unit, and a secondary heat exchanger is arranged between the dedusting and denitration unit and the desulfurization unit; the flue gas sent to the combustion unit by the flue gas circulation unit comprises flue gas in a pipeline between the primary heat exchanger and the dust removal and denitration unit, flue gas in a pipeline between the dust removal and denitration unit and the secondary heat exchanger, and flue gas exhausted by the pipeline after being desulfurized by the desulfurization unit.
As a further improvement of the invention, the cyclone burner comprises a gas pipe, a premixing pipe and a cyclone pipe, wherein the gas pipe is sleeved inside the premixing pipe, the length of the gas pipe is less than that of the premixing pipe, the gas pipe is communicated with the liquefaction tank, a primary air port is formed in the side wall of the premixing pipe, and the primary air port is communicated with a primary air pipe; the cyclone tube is sleeved outside the premixing tube, a cyclone blade is arranged between the cyclone tube and the premixing tube, and a secondary air port is formed in the side wall of the cyclone tube and communicated with a secondary air pipe.
As a further improvement of the invention, a primary air preheater and a secondary air preheater are arranged on a pipeline between the combustion unit and the primary heat exchanger, the primary air preheater is used for heating air in the primary air pipe, and the secondary air preheater is used for heating air in the secondary air pipe.
As a further improvement of the invention, the air in the primary air pipe is divided into two branches, one branch flows through the primary air preheater, the other branch does not pass through the primary air preheater, and the air of the two branches is mixed after the primary air preheater; similarly, the air in the secondary air pipe is divided into two branches, one branch flows through the secondary air preheater, the other branch does not pass through the secondary air preheater, and the air of the two branches is mixed after the secondary air preheater.
As a further improvement of the invention, in the first step, additives are injected into the pulverized coal combustion area in the furnace body, and the additives comprise anti-slagging and anti-coking additivesOne or more of an agent, a NOx removal agent, a sulfur fixing agent or a coal-fired catalyst; wherein, the anti-slagging and anti-coking additive is titanium isopropoxide or silicon-aluminum type additive, and the silicon-aluminum type additive can be kaolin, vermiculite and SiO2Or one or more of fly ash; the NOx removal agent is ammonia gas or urea; the sulfur-fixing agent is one or more of limestone, CaO, hydrated lime or MgO; the fire coal catalyst is one or more of oxides or hydroxides of alkali metals, alkaline earth metals and transition elements and salts thereof.
As a further improvement of the invention, in the first step, ammonia gas is sprayed in the area of 850-950 ℃ in the furnace body, and the ammonia gas and NO in the flue gasXThe concentration ratio is controlled to be 0.9-1.05.
As a further improvement of the invention, the dust removal and denitration unit in the second step comprises a denitration tower, a high-temperature dust removal mechanism and a low-dust SCR denitration mechanism are arranged in the denitration tower from bottom to top, the high-temperature dust removal mechanism comprises a plurality of high-temperature dust removal pipes, and the high-temperature dust removal pipes adopt ceramic pipe dust removal filter elements or Fe-Cr metal dust removal filter elements; the low-dust SCR denitration mechanism comprises a spray gun and an SCR denitration catalyst, and the spray gun is used for spraying liquid ammonia in the reducing agent storage tank into flue gas.
As a further improvement of the invention, the desulfurization unit in the third step comprises a desulfurization tower and a slurry pool, the desulfurization tower is arranged above the slurry pool, a plurality of spray headers and a demister are sequentially arranged inside the desulfurization tower from bottom to top, and the slurry pool is connected with the spray headers through a slurry pump and a pipeline; and an oxidation fan is arranged on one side of the slurry pool.
3. Advantageous effects
Compared with the prior art, the technical scheme provided by the invention has the following remarkable effects:
(1) according to the ultralow-emission experiment process for pulverized coal combustion, the combustion environment of pulverized coal in the furnace body is adjusted by controlling the temperature of air entering different pipelines in the furnace body, so that the pulverized coal can be fully combusted while the pulverized coal is self-stabilized; further, byThe smoke circulating unit sends part of smoke generated in the pulverized coal combustion process into the furnace body, so that the combustion environment of the pulverized coal is regulated and controlled, and NO generated by combustion in the furnace body is effectively reducedX(ii) a In addition, the flue gas generated by combustion is subjected to dust removal and denitration through the dust removal and denitration unit, and then enters the desulfurization unit for desulfurization, so that the content of pollutants in the flue gas is effectively reduced;
(2) according to the ultralow-emission experimental process for pulverized coal combustion, research shows that NO generated by pulverized coal combustion when the content of flue gas sent to the combustion unit by the flue gas circulation unit accounts for 27% of the total amount of the flue gasXThe content is lowest; the flue gas conveyed to the interior of the furnace body through the circulating unit comprises flue gas in a pipeline between the primary heat exchanger and the dedusting and denitration unit, flue gas in a pipeline between the dedusting and denitration unit and the secondary heat exchanger, and flue gas discharged by the pipeline after being desulfurized by the desulfurization unit;
(3) according to the ultralow-emission experimental process for pulverized coal combustion, the structure of the cyclone burner is designed, so that air required in the combustion process is mixed with pulverized coal and natural gas in the burner in different ways, and in addition, the temperature of air in different pipelines is controlled, so that the combustion environment is further improved, and the self-stable combustion and burnout of the pulverized coal are facilitated;
(4) according to the ultralow-emission experimental process for pulverized coal combustion, disclosed by the invention, in order to further reduce the content of pollutants generated by pulverized coal combustion, the additive is sprayed into a pulverized coal combustion area, and SO in flue gas can be effectively reduced through the additiveXThe content is increased, and meanwhile, the ash melting point is increased, so that the slag bonding is avoided, and the service life of the whole experiment system is effectively prolonged; in addition, ammonia gas is sprayed into the furnace body in the 850-950 ℃ area and is reduced by the ammonia gas, so that NO in the flue gas is further reducedXGenerating;
(5) according to the ultralow-emission experimental process for pulverized coal combustion, flue gas generated by pulverized coal combustion and flue gas conveyed into a furnace body through the circulating unit can effectively improve the combustion environment, but the total flow of the flue gas in the furnace and in a flue becomes large, so that the flow velocity of the flue gas in a tail flue is high, the high-temperature dust removal and the SCR denitration are integrally designed to avoid the excessive washing of dust in the flue gas on an SCR denitration catalyst in the dust removal and denitration unit, so that the high-temperature dust removal is carried out on the flue gas before denitration, the dust concentration in the flue gas is effectively reduced, the service life of the SCR denitration catalyst is prolonged, and the denitration and dust removal efficiency of the dust removal and denitration unit is also improved;
(6) the invention relates to an ultralow-emission experimental process for pulverized coal combustion, wherein a desulfurization unit sprays lime slurry in a slurry pool into a desulfurization tower through a plurality of spray headers SO as to ensure that SO in lime and flue gas2Reacting under the action of oxygen to remove SO in the flue gas2。
Drawings
FIG. 1 is a schematic structural diagram of an apparatus for an ultra-low emission experimental process for pulverized coal combustion according to the present invention;
FIG. 2 is a schematic view of a cyclone burner according to the present invention;
FIG. 3 shows the different flue gas circulation amounts and NO when the air excess coefficient is 0.9 according to the present inventionXA concentration distribution line graph;
FIG. 4 shows the different flue gas circulation amounts and NO when the air excess factor is 0.8 in the present inventionXA concentration distribution line graph;
FIG. 5 shows the different flue gas circulation amounts and NO when the air excess factor is 0.7 according to the present inventionXConcentration profile line graph.
The reference numerals in the schematic drawings illustrate:
110. a furnace body; 120. a liquefaction tank; 130. a powder feeder; 141. a blower; 142. a main pipe; 143. a primary air duct; 144. a secondary air duct; 145. a burnout air duct; 151. a primary air preheater; 152. a secondary air preheater; 160. a cyclone burner; 161. a burner tube; 162. a primary tuyere; 163. a secondary tuyere; 164. a swirl tube; 165. a swirl vane;
210. a primary heat exchanger;
310. a high temperature dust removal pipe; 320. a reducing agent storage tank; 330. an SCR denitration catalyst;
410. a secondary heat exchanger;
510. an oxidation fan; 520. a slurry tank; 530. a slurry pump; 540. a shower head; 550. a demister;
610. an induced draft fan;
710. a first circulation pipe; 720. a second circulation pipe; 730. a third circulation pipe; 740. circulating the induced draft fan; 750. and (4) a gas mixing pipe.
Detailed Description
For a further understanding of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings and examples.
Example 1
With reference to fig. 1 and fig. 2, the device of the ultra-low emission experimental process for pulverized coal combustion of the present embodiment includes a combustion unit, a dust removal and denitration unit, a desulfurization unit, and a flue gas circulation unit, wherein the combustion unit includes a furnace body 110, a powder feeder 130, and a cyclone burner 160, the cyclone burner 160 is disposed inside the upper end of the furnace body 110, the powder feeder 130 is communicated with the cyclone burner 160 through a pipeline, pulverized coal is loaded in the powder feeder 130, the pulverized coal is conveyed to the cyclone burner 160 along the pipeline so as to enter the furnace body 110 for subsequent combustion, in addition, a liquefaction tank 120 is disposed on one side of the furnace body 110, liquefied petroleum gas is loaded in the liquefaction tank 120, and the liquefaction tank 120 is communicated with the cyclone burner 160 through a pipeline so as to provide fuel for pulverized coal combustion; in addition, air required for combustion in the combustion unit is blown into the furnace body 110 by the blower 141, thereby facilitating combustion of the pulverized coal.
Although this test system adopts buggy as the required raw materials of burning, in the combustion process, can simulate the produced flue gas of actual pulverized coal burning, because test system and actual factory device are different, lead to the combustion degree of buggy also different, therefore pollutant content in the flue gas is also different, in order to carry out the abundant research to the flue gas that the pulverized coal burning produced, the combustion environment of buggy is controlled to this embodiment, make the buggy realize in furnace body 110 inside when steady burning, guarantee that the buggy can fully burn out.
Researches find that the air blown into the furnace body 110 by the blower 141 is divided into multiple paths, and the temperature of the air in each path is controlled, so that the combustion environment of pulverized coal is effectively improved; specifically, air required by combustion of the combustion unit of the embodiment is introduced into the furnace body 110 through the primary air pipe 143, the secondary air pipe 144 and the burnout air pipe 145, that is, the air is divided into three branches after entering the blower 141, wherein one branch enters the primary air pipe 143, the primary air pipe 143 flows through the pipeline of the powder feeder 130 and enters the cyclone burner 160, and the air temperature in the primary air pipe 143 is controlled to be 300-400 ℃; the other branch enters a secondary air pipe 144, the secondary air pipe 144 is directly communicated with the cyclone burner 160, and the temperature of air in the secondary air pipe 144 is controlled to be 300-400 ℃; the last branch enters the over-fire air duct 145, the over-fire air duct 145 is communicated with the inside of the furnace body 110, and the air in the over-fire air duct 145 has a normal room temperature. Inside this embodiment sends the air to furnace body 110 through different pipelines, the temperature of air in the while control each pipeline to adjust the environment in the furnace body 110, make follow-up buggy in combustion-process, can realize from steady burning and abundant burn-off.
Further, referring to fig. 2, the swirling burner 160 of the present embodiment includes a gas pipe 161, a premixing pipe, and a swirling pipe 164, wherein the gas pipe 161 is sleeved inside the premixing pipe, and the length of the gas pipe 161 is smaller than that of the premixing pipe, and the gas pipe 161 is communicated with the liquefied tank 120 through a pipeline, so that liquefied petroleum gas enters the gas pipe 161 along the pipeline, thereby facilitating subsequent mixing of natural gas with pulverized coal and air, and controlling combustion of pulverized coal; the side wall of the premixing tube is provided with a primary air port 162, the primary air port 162 is communicated with a primary air pipe 143, and the primary air pipe 143 flows through the pipeline of the powder feeder 130 and enters the cyclone burner 160, so that the air in the primary air pipe 143 drives the pulverized coal to move and sends the pulverized coal to the cyclone burner 160, and meanwhile, in the moving process, the air in the primary air pipe 143 heats the pulverized coal, so that the pulverized coal is preheated before entering the cyclone burner 160, and the subsequent combustion of the pulverized coal is facilitated; in addition, the swirl tube 164 is sleeved outside the premix tube, swirl blades 165 are arranged between the swirl tube 164 and the premix tube, a secondary air port 163 is formed in the side wall of the swirl tube 164, and the secondary air port 163 is communicated with the secondary air pipe 144.
When the combustion unit is used for a combustion test, natural gas enters the cyclone burner 160 from the gas pipe 161, air in the primary air pipe 143 carries pulverized coal to enter the premix pipe through the primary air port 162, the gas pipe 161 is sleeved inside the premix pipe, the natural gas in the gas pipe 161 is preheated while the air carries the pulverized coal to move downwards along the premix pipe, when the natural gas flows out from the gas pipe 161, the natural gas is primarily mixed with the air carrying the pulverized coal, the primarily mixed mixture continues to move along the premix pipe, meanwhile, air in the secondary air pipe 144 enters the cyclone pipe 164 from the secondary air port 163 along the pipeline and moves downwards along the cyclone pipe 164, the air is sent out of the cyclone burner 160 through the cyclone blades 165, the air sent out through the cyclone blades 165 is further mixed with the primarily mixed mixture, and then the ignition process is completed through the ignition rod, the pulverized coal is fully combusted while the self-stable combustion of the pulverized coal is realized; in addition, NO in flue gas generated by pulverized coal combustion is effectively reducedXThe content of (a).
It should be noted that in this embodiment, the overfire air duct 145 may move along the outer wall of the furnace body 110 to adjust the conveying position of the overfire air, so that the working condition experiments of different overfire air positions may be performed.
In addition, the swirl vanes 165 in this embodiment are machined by a cyclone mill, and the swirl angle is fixed. The swirl vanes 165 can be replaced according to actual conditions, thereby adjusting the swirl angle. The outlet of the premixing pipe is provided with a stable combustion tooth, which is convenient for the combustion of the pulverized coal.
The flue gas that the combustion unit burning of this embodiment produced is discharged to dust removal denitration unit from furnace body 110 bottom, carries out the dust removal denitration to the flue gas through dust removal denitration unit, later, the flue gas gets into desulfurization unit and carries out the desulfurization, discharges afterwards, and the desorption condition of pollutant in the produced flue gas of pulverized coal burning can be studied to whole process, and the content of pollutant is low in the discharged flue gas, realizes the ultralow emission of pulverized coal burning flue gas.
Furthermore, the flue gas circulation unit is used for sending part of the flue gas generated by the combustion of the combustion unit into the furnace body 110, and the content of the flue gas sent to the combustion unit through the flue gas circulation unit accounts for 5% -35% of the total amount of the flue gas, and can be 5%, 7%, 10%, 15%, … … 25%, … … 35%.
As shown in fig. 1, in the present embodiment, a primary heat exchanger 210 is disposed between the combustion unit and the dust removal and denitration unit, and a secondary heat exchanger 410 is disposed between the dust removal and denitration unit and the desulfurization unit; the primary heat exchanger 210 and the secondary heat exchanger 410 are both vertical tubular heat exchangers, flue gas generated by combustion of the primary heat exchanger and the secondary heat exchanger flows through an inner pipeline of the heat exchanger, cooling water flows along an outer pipeline of the heat exchanger, and the flue gas is cooled through the cooling water, wherein the outlet flue gas temperature of the primary heat exchanger 210 is adjusted within the range of 200-400 ℃, and the outlet flue gas temperature of the secondary heat exchanger 410 is adjusted within the range of 80-150 ℃. Through adjusting the flue gas temperature, on the one hand, be convenient for control whole test system's steady operation, on the other hand, be convenient for the desorption pollutant in the flue gas.
Research shows that when the content of the flue gas sent to the combustion unit by the flue gas circulation unit accounts for 27 percent of the total amount of the flue gas, NO generated by the combustion of pulverized coal of the flue gas circulation unitXThe content is the lowest. Specifically, in this embodiment, the flue gas sent to the combustion unit by the flue gas circulation unit includes flue gas in a pipeline between the primary heat exchanger 210 and the dust removal and denitration unit, flue gas in a pipeline between the dust removal and denitration unit and the secondary heat exchanger 410, and flue gas exhausted from the pipeline after being desulfurized by the desulfurization unit; as shown in fig. 1, dotted lines in the figure indicate the respective pipelines, a first circulation pipe 710 is used for conveying flue gas in the pipeline between the primary heat exchanger 210 and the dust-removing and denitration unit, a second circulation pipe 720 is used for conveying flue gas in the pipeline between the dust-removing and denitration unit and the secondary heat exchanger 410, a third circulation pipe 730 is used for conveying flue gas discharged from the pipeline after being desulfurized by the desulfurization unit, in order to facilitate conveying flue gas into the furnace body 110, the first circulation pipe 710, the second circulation pipe 720 and the third circulation pipe 730 are communicated with a gas mixing pipe 750, the gas mixing pipe 750 is communicated with the interior of the furnace body 110, and a circulating induced draft fan 740 is arranged on the gas mixing pipe 750.
The flue gas that each part circulates in this embodiment can freely adjust according to operating condition, because three pipelines are the flue gas of taking out from different positions, its flue gas composition, pollutant concentration and temperature allDifferent. The flue gas in the pipeline between the primary heat exchanger (210) and the dedusting and denitration unit has the highest temperature and pollutant concentration; the flue gas in the pipeline between the dust removal and denitration unit and the secondary heat exchanger (410) is subjected to dust removal and denitration treatment, the temperature is reduced, and fly ash and NO are reducedXThe concentration is greatly reduced; the flue gas of the desulfurized pipeline has the lowest temperature and pollutants, and the flue gas humidity is greatly increased due to the limestone-gypsum method desulfurization. In addition, the temperature inside the furnace body 110 may change during the actual combustion process.
Therefore, the smoke extracted from three different positions is sent into the furnace again to be adjusted according to the actual situation. For example, the extraction of flue gases from three locations may reduce the temperature within the furnace, thereby reducing the risk of slagging and reducing NOXAnd (4) generating. However, if less attrition of the SCR catalyst is desired, more of the desulfurized flue gas is extracted. If the load is not high and the furnace temperature is not high enough, the requirement of stable combustion needs to be considered, more smoke is extracted from the front two positions.
This embodiment sends the produced part flue gas of pulverized coal combustion process to furnace body 110 in through flue gas circulation unit, and the air of different temperatures is sent to furnace body 110 in through different pipelines simultaneously, under the combined action of cyclone 160, regulates and control the combustion environment of buggy, under the circumstances of guaranteeing buggy from steady burning and abundant burn-out, effectively reduces the NO in the produced flue gas of burningXNamely, the NO in the flue gas generated by the combustion of the pulverized coal is reduced from the sourceXThe content of (b) is favorable for environmental protection.
In addition, as shown in fig. 1, the present embodiment is provided with a primary air preheater 151 and a secondary air preheater 152 on the pipeline between the combustion unit and the primary heat exchanger 210, the primary air preheater 151 is used for heating the air in the primary air duct 143, and the secondary air preheater 152 is used for heating the air in the secondary air duct 144.
It should be noted that, in the present embodiment, the primary air preheater 151 and the secondary air preheater 152 are both tube heat exchangers, and the tube heat exchangers both use flue gas generated by burning pulverized coal as a heat source, the flue gas flows in an inner pipeline of the tube heat exchanger, and air in the primary air duct 143 flows through an outer pipeline of the primary air preheater 151; similarly, in the secondary air preheater 152, the flue gas flows through the inner duct, and the air in the secondary air duct 144 flows through the outer duct of the secondary air preheater 152. The embodiment heats the air in the corresponding air pipe through the burning smoke, thereby realizing the effective utilization of resources.
Preferably, in this embodiment, the air in the primary air duct 143 is divided into two branches, one branch flows through the primary air preheater 151, the other branch does not pass through the primary air preheater 151, the air of the two branches is mixed after the primary air preheater 151, and the temperature of the mixed air is 300-400 ℃; similarly, the air in the secondary air duct 144 is also divided into two branches, one branch flows through the secondary air preheater 152, the other branch does not pass through the secondary air preheater 152, the air in the two branches is mixed after passing through the secondary air preheater 152, and the temperature of the mixed air is 300-400 ℃.
The furnace body 110 of the embodiment is sequentially provided with a corundum-mullite inner container with the thickness of 40mm and the temperature resistance of 1550 ℃, an alumina silicate fiber blanket with the thickness of 40mm and the temperature resistance of 1430 ℃ containing zirconium and the thickness of 317.5mm and the temperature resistance of 1260 ℃ from inside to outside, and the corundum-mullite resistance wire is arranged between the inner container and the alumina silicate fiber blanket to relieve the harm caused by local over-temperature of a water-cooled wall. The outer steel shell of the furnace body 110 is made of 201 materials, and the gasket is made of polytetrafluoroethylene materials through flange connection, so that the air tightness of the furnace body 110 is guaranteed, and the normal operation of a test system is facilitated.
Example 2
The experimental process for the pulverized coal combustion ultra-low emission test of the present example is substantially the same as that of example 1, and further,
in the embodiment, additives are injected into the pulverized coal combustion zone in the furnace body 110, and the additives comprise one or more of slag-preventing and coking-preventing additives, NOx-removing agents, sulfur-fixing agents or coal-fired catalysts; wherein the anti-slagging and anti-coking additive is titanium isopropoxide or silicon-aluminum additive, and the silicon-aluminum additive can be kaolin, vermiculite or SiO2Or one or more of fly ash. When titanium isopropoxide is added, the adding proportion of the titanium isopropoxide accounts for 3% -5% of the amount of the coal fed into the furnace; when addingWhen the silicon-aluminum type additive is added, the mass of the silicon-aluminum type additive accounts for 2-10% of the total mass of the coal powder, and the ash melting point can be improved by the silicon-aluminum type additive or the titanium isopropoxide, so that coking is avoided or relieved; the NOx removing agent is ammonia gas or urea, and the adding amount of the NOx removing agent and NO in the smoke gasXThe ratio is controlled to be 0.9-1.05; the sulfur-fixing agent is one or more of limestone, CaO, hydrated lime or MgO, and the addition amount of the sulfur-fixing agent is related to the sulfur content in the coal, so that the Ca/S ratio and the MgO ratio are controlled to be 1-2.5; the coal-fired catalyst is one or more of oxides or hydroxides of alkali metals, alkaline earth metals and transition elements and salts thereof, the combustion performance of coal can be changed through the coal-fired catalyst, the combustion of coal dust is promoted, the burnout rate of the coal dust is improved, and the control quality generally accounts for 0.1-2% of the total mass of the coal dust.
The additive can be selected according to the flue gas generated by actual pulverized coal combustion, and can be a slagging-preventing and coking-preventing additive, a slagging-preventing and coking-preventing additive and a sulfur-fixing agent, and a sulfur-fixing agent and a coal-fired catalyst. The additives of this example are silica-alumina type additives and sulfur-fixing agents as well as coal-fired catalysts.
It should be noted that the additive of the embodiment may be delivered to the interior of the furnace body 110 through a pipeline on the furnace body 110, or may be partially controlled to be delivered to the interior of the furnace body 110 through the circulating flue gas; all the additives can be conveyed to the interior of the furnace body 110 through the circulating flue gas.
Preferably, all the additives in the embodiment are conveyed into the furnace body 110 through the circulating flue gas, SO that the additives can be fully contacted with the flue gas generated by burning the pulverized coal, and the additives can effectively reduce SO in the flue gasXThe content is increased, and meanwhile, the ash melting point is increased, so that the slagging is avoided, the service life of the whole experiment system is effectively prolonged, and the maximum effect of the additive is further exerted.
In addition, ammonia gas is sprayed into the furnace body 110 at 850-950 ℃, and the concentration of the ammonia gas and NO in the flue gas are controlledXThe concentration ratio is controlled to be 0.9-1.05, and can be 0.9, 0.95 … … 0.1.1, 0.105. Reducing by ammonia gas to further reduce NO in flue gasXThereby further reducing the generation of coal dustThe pollutant content generated by combustion is beneficial to the ultralow emission of pollutants in the whole test system after subsequent treatment.
In this example, the ammonia concentration and NO in the flue gasXThe concentration ratio was controlled to 0.9.
It is worth noting that although the flue gas sent from the flue gas recirculation unit to the combustion unit contains flue gas which has not been denitrified or desulfurized, it contains a certain content of NOXHowever, the circulation amount of the flue gas is relatively small, so that NO is generatedXHas increased total concentration of NOXStay time in the furnace body 110, NO is prolongedXContact time with the reducing component, thereby increasing the likelihood that NOx will be reduced; secondly, the flue gas recirculation can also reduce the oxygen concentration and the combustion temperature of a main combustion area of the pulverized coal, thereby reducing and inhibiting thermal NOXFurther reduce NO in the flue gasXThe content of (A); finally, the flue gas is recycled to circulating NOXProvides the opportunity of contacting with the components at the initial and middle stages of the coal powder combustion to form the reburning effect, so that the reduction efficiency is greatly improved, and the NO in the flue gas is reduced againXIncluding hydrocarbons, NOx precursors, carbon black, minerals and highly reactive char.
As shown in fig. 1, the dust removal and denitration unit of the embodiment includes a denitration tower, a high temperature dust removal mechanism and a low-dust SCR denitration mechanism are arranged in the denitration tower from bottom to top, the high temperature dust removal mechanism includes a plurality of high temperature dust removal pipes 310, and the high temperature dust removal pipes 310 are made of ceramic pipe dust removal filter core materials (SiO pipe dust removal filter core materials)2/Al2O3The filter core material of two dust removing pipes makes the dust removing system have strong wear resistance and high temperature resistance, and the operation temperature is as follows: the normal temperature is 800 ℃, the ash is removed by pulse, and the pressure loss is less than 1500 Pa.
The low-dust SCR denitration mechanism comprises a spray gun and an SCR denitration catalyst 330, the spray gun is used for spraying liquid ammonia in the reducing agent storage tank 320 into flue gas, the sprayed liquid ammonia is fully mixed with the flue gas through the spray gun, and NO in the flue gas is reducedXContent (c); the flue gas then passes through SCR denitration catalyst 330, through SCThe R denitration catalyst 330 catalyzes to increase the denitration efficiency, so that the denitration efficiency reaches 95% or more.
It is worth noting that the flue gas enters the high temperature dust removal pipe 310 from the bottom, thereby reducing the concentration of fly ash in the flue gas and reducing the particle size of dust. The SCR denitration catalyst 330 can reduce the loss of the SCR denitration catalyst 330 and avoid inactivation and poisoning in a low-dust environment, thereby increasing the service life of the SCR denitration catalyst 330, reducing flue blockage and erosion wear, and ensuring the normal operation of subsequent treatment.
The liquid ammonia injection amount in the embodiment can be self-adaptive and real-time controlled according to various parameters detected by a CEMS flue gas online monitoring system and a flue gas temperature sensor which are installed on a denitration tower, the flow of the liquid ammonia is accurately controlled through an MFC mass flow controller, and the whole process is controlled through a PLC control system.
In addition, as shown in fig. 1, the desulfurization unit of the present embodiment includes a desulfurization tower and a slurry tank 520, the desulfurization tower is installed above the slurry tank 520, a plurality of spray headers 540 and a demister 550 are sequentially arranged inside the desulfurization tower from bottom to top, and the slurry tank 520 is connected to the spray headers 540 through a slurry pump 530 and a pipeline; an oxidation fan 510 is arranged on one side of the slurry tank 520.
Preferably, there are 3 showerheads 540 in this embodiment.
Air is blown into the slurry tank 520 through the oxidation fan 510, SO that the air and lime slurry are mixed with each other, the lime slurry in the slurry tank 520 is sent to the spray header 540 through the slurry pump 530, the lime slurry is sprayed into the desulfurization tower through the spray header 540, and the lime and SO in the flue gas are enabled to be separated2Reacting under the action of oxygen to remove SO in the flue gas2。
In the ultra-low emission experiment process for pulverized coal combustion of the embodiment, the combustion unit works, the powder feeder 130 conveys pulverized coal into the cyclone burner 160 of the furnace body 110, meanwhile, the pipeline of the powder feeder 130 is communicated with the primary air pipe 143, the primary air pipe 143 is used for conveying air required by combustion, and the air temperature in the primary air pipe 143 is 300-400 ℃; the secondary air pipe 144 conveys air with the temperature of 300-400 ℃ into the cyclone burner 160; the liquefaction tank 120 delivers liquefied gas into the cyclone burner 160; igniting at the outlet of the cyclone burner 160 to burn the pulverized coal, wherein the actual flue gas temperature generated in an ignition chamber in the furnace body 110 is about 1300 ℃; the temperature of the flue gas reaching the tail part of the hearth after radiation and convection heat exchange is about 1000 ℃, and then the flue gas enters the primary air preheater 151 and heats the air in the primary air pipe 143, and the outlet flue gas temperature of the primary air preheater 151 is 800-1000 ℃. Then, the flue gas enters a secondary air preheater 152 and heats the air in a secondary air pipe 144, the temperature of the flue gas at the outlet of the secondary air preheater 152 is 700-800 ℃, then the flue gas enters a primary heat exchanger 210, the temperature of the flue gas is adjusted to 200-400 ℃ after the heat exchange between the flue gas and water, and then the flue gas enters a dedusting and denitration unit for dedusting and denitration; then, the flue gas enters a secondary heat exchanger 410, the temperature of the flue gas is adjusted to 100-150 ℃ after heat exchange, and then the flue gas enters a desulfurization unit for desulfurization; the actual flue gas after desulfurization is discharged to the outside atmosphere by the induced draft fan 610.
In the process, part of the flue gas generated by combustion is sent to the gas mixing pipe 750 through the first circulating pipe 710, the second circulating pipe 720 and the third circulating pipe 730 by the circulating induced draft fan 740, and is finally sent to the inside of the furnace body 110, so that the combustion environment of the pulverized coal is adjusted.
The test for the ultra-low emission test process for pulverized coal combustion according to the embodiment is carried out, and partial data results are shown in fig. 3-5.
For FIGS. 3, 4 and 5, the abscissa indicates the distance from the furnace inlet, i.e., the distance from the cyclone burner 160 inside the furnace body 110, and the ordinate indicates the NO in the flue gasXConcentration; in the figure, r refers to the content of flue gas fed to the combustion unit by the flue gas recirculation unit in the total amount of flue gas, and is exemplified by r being 0%, r being 10%, r being 15%, r being 20%, and r being 27%. Specifically, fig. 3 is data measured at an air excess coefficient of 0.9, fig. 4 is data measured at an air excess coefficient of 0.8, and fig. 5 is data measured at an air excess coefficient of 0.7.
As can be derived from FIGS. 3, 4 and 5, the farther from the furnace inlet the NO in the flue gas isXThe concentration is lower and lower, and the content of NO in the smoke is higher and higher along with the content of the circulating smokeXThe concentration also has a decreasing trend, and as can be seen from the broken line graph, when r is 27%, NO in the flue gas generated by the combustion of the pulverized coalXThe content is the lowest.
The present invention and its embodiments have been described above schematically, without limitation, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if the person skilled in the art receives the teaching, without departing from the spirit of the invention, the person skilled in the art shall not inventively design the similar structural modes and embodiments to the technical solution, but shall fall within the scope of the invention.
Claims (10)
1. An ultralow emission experiment process for pulverized coal combustion is characterized in that: the process is that the raw materials are mixed,
step one, the combustion unit works
The powder feeder (130) conveys pulverized coal into a cyclone burner (160) of the furnace body (110), meanwhile, a pipeline of the powder feeder (130) is communicated with a primary air pipe (143), the primary air pipe (143) is used for conveying air required by combustion, and the temperature of the air in the primary air pipe (143) is 300-400 ℃;
the secondary air pipe (144) conveys air with the temperature of 300-400 ℃ to the cyclone burner (160);
the liquefied petroleum gas is conveyed into the cyclone burner (160) by the liquefied tank (120);
igniting at the outlet of the cyclone burner (160);
step two, dedusting and denitration are performed by a dedusting and denitration unit;
step three, desulfurizing by a desulfurization unit;
and step four, the flue gas circulating unit is used for conveying part of the flue gas generated by the combustion of the combustion unit into the furnace body (110), and the content of the flue gas conveyed to the combustion unit through the flue gas circulating unit accounts for 5% -35% of the total amount of the flue gas.
2. The ultra-low emission experimental process for pulverized coal combustion as claimed in claim 1, wherein: in the fourth step, the content of the flue gas sent to the combustion unit by the flue gas circulation unit accounts for 25-30% of the total amount of the flue gas.
3. The ultra-low emission experimental process for pulverized coal combustion as claimed in claim 2, characterized in that: a primary heat exchanger (210) is arranged between the combustion unit and the dedusting and denitration unit, and a secondary heat exchanger (410) is arranged between the dedusting and denitration unit and the desulfurization unit; the flue gas sent to the combustion unit by the flue gas circulation unit comprises flue gas in a pipeline between the primary heat exchanger (210) and the dedusting and denitration unit, flue gas in a pipeline between the dedusting and denitration unit and the secondary heat exchanger (410), and flue gas exhausted from the pipeline after being desulfurized by the desulfurization unit.
4. The ultra-low emission experimental process for pulverized coal combustion as claimed in claim 3, characterized in that: the cyclone burner (160) comprises a gas pipe (161), a premixing pipe and a cyclone pipe (164), wherein the gas pipe (161) is sleeved inside the premixing pipe, the length of the gas pipe (161) is smaller than that of the premixing pipe, the gas pipe (161) is communicated with the liquefaction tank (120), a primary air port (162) is formed in the side wall of the premixing pipe, and the primary air port (162) is communicated with a primary air pipe (143); the cyclone tube (164) is sleeved outside the premixing tube, a cyclone blade (165) is arranged between the cyclone tube (164) and the premixing tube, a secondary air port (163) is formed in the side wall of the cyclone tube (164), and the secondary air port (163) is communicated with the secondary air pipe (144).
5. The ultra-low emission experimental process for pulverized coal combustion as claimed in claim 4, wherein: and a primary air preheater (151) and a secondary air preheater (152) are arranged on a pipeline between the combustion unit and the primary heat exchanger (210), the primary air preheater (151) is used for heating air in the primary air pipe (143), and the secondary air preheater (152) is used for heating air in the secondary air pipe (144).
6. The ultra-low emission experimental process for pulverized coal combustion as claimed in claim 5, characterized in that: the air in the primary air pipe (143) is divided into two branches, one branch flows through the primary air preheater (151), the other branch does not pass through the primary air preheater (151), and the air in the two branches is mixed after passing through the primary air preheater (151); similarly, the air in the secondary air duct (144) is divided into two branches, one branch flows through the secondary air preheater (152), the other branch does not pass through the secondary air preheater (152), and the air in the two branches is mixed after the secondary air preheater (152).
7. The ultra-low emission experimental process for pulverized coal combustion as claimed in claim 1 or 6, wherein: in the first step, additives are sprayed into a coal powder combustion area in the furnace body (110), wherein the additives comprise one or more of slag-preventing and coking-preventing additives, NOx-removing agents, sulfur-fixing agents or coal-fired catalysts.
8. The ultra-low emission experimental process for pulverized coal combustion as claimed in claim 7, wherein: in the first step, ammonia gas is sprayed into the furnace body (110) at the temperature of 850-950 ℃, and the ammonia gas and NO in the flue gasXThe concentration ratio is controlled to be 0.9-1.05.
9. The ultra-low emission experimental process for pulverized coal combustion as claimed in claim 1, wherein: the dust removal and denitration unit in the second step comprises a denitration tower, a high-temperature dust removal mechanism and a low-dust SCR denitration mechanism are arranged in the denitration tower from bottom to top, the high-temperature dust removal mechanism comprises a plurality of high-temperature dust removal pipes (310), and the high-temperature dust removal pipes (310) adopt ceramic pipe dust removal filter elements or Fe-Cr metal dust removal filter elements; the low-dust SCR denitration mechanism comprises a spray gun and an SCR denitration catalyst (330), and the spray gun is used for spraying liquid ammonia in a reducing agent storage tank (320) into flue gas.
10. The ultra-low emission experimental process for pulverized coal combustion as claimed in claim 1, wherein: the desulfurization unit in the third step comprises a desulfurization tower and a slurry pool (520), the desulfurization tower is arranged above the slurry pool (520), a plurality of spray headers (540) and a demister (550) are sequentially arranged in the desulfurization tower from bottom to top, and the slurry pool (520) is connected with the spray headers (540) through a slurry pump (530) and a pipeline; and an oxidation fan (510) is arranged on one side of the slurry pool (520).
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011106789A (en) * | 2009-11-20 | 2011-06-02 | Mitsubishi Heavy Ind Ltd | Pulverized coal burning boiler system |
| CN102425789A (en) * | 2011-11-03 | 2012-04-25 | 华北电力大学（保定） | Coal-fired fluidized bed micro oxygen rich combustion CO2 emission reduction method and system |
| CN105066113A (en) * | 2015-07-27 | 2015-11-18 | 四川川锅锅炉有限责任公司 | Coal-powder boiler oxygen-enriched combustion smoke near-zero emission and power generation system |
| CN111425866A (en) * | 2020-03-27 | 2020-07-17 | 西安交通大学 | Power station boiler low NO for coupling semicoke and sludge mixed burningxMixed combustion system |
| CN111450681A (en) * | 2020-04-14 | 2020-07-28 | 安徽工业大学 | Denitration, desulfurization and dust removal integrated system for supercritical carbon dioxide coal-fired boiler |
| CN112066403A (en) * | 2020-09-16 | 2020-12-11 | 安徽工业大学 | Ultra-low emission integrated system of supercritical carbon dioxide coal-fired boiler |
-
2021
- 2021-03-31 CN CN202110348239.8A patent/CN113048470A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011106789A (en) * | 2009-11-20 | 2011-06-02 | Mitsubishi Heavy Ind Ltd | Pulverized coal burning boiler system |
| CN102425789A (en) * | 2011-11-03 | 2012-04-25 | 华北电力大学（保定） | Coal-fired fluidized bed micro oxygen rich combustion CO2 emission reduction method and system |
| CN105066113A (en) * | 2015-07-27 | 2015-11-18 | 四川川锅锅炉有限责任公司 | Coal-powder boiler oxygen-enriched combustion smoke near-zero emission and power generation system |
| CN111425866A (en) * | 2020-03-27 | 2020-07-17 | 西安交通大学 | Power station boiler low NO for coupling semicoke and sludge mixed burningxMixed combustion system |
| CN111450681A (en) * | 2020-04-14 | 2020-07-28 | 安徽工业大学 | Denitration, desulfurization and dust removal integrated system for supercritical carbon dioxide coal-fired boiler |
| CN112066403A (en) * | 2020-09-16 | 2020-12-11 | 安徽工业大学 | Ultra-low emission integrated system of supercritical carbon dioxide coal-fired boiler |
Non-Patent Citations (4)
| Title |
|---|
| 刘雁主编: "《系统建模与仿真》", 31 January 2021 * |
| 周宜树主编: "《锅炉运行500问》", 31 January 1983 * |
| 徐进良: "《超临界二氧化碳动力循环研究进展及展望》", 《热力发电》 * |
| 电力工业部电力机械局主编: "《火力发电厂设备手册 第8册 仪表及自动控制系统设备》", 华中科技大学出版社 * |
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