CN111336541B - System and method for improving hot air temperature by using molten salt heat carrier - Google Patents
System and method for improving hot air temperature by using molten salt heat carrier Download PDFInfo
- Publication number
- CN111336541B CN111336541B CN202010087599.2A CN202010087599A CN111336541B CN 111336541 B CN111336541 B CN 111336541B CN 202010087599 A CN202010087599 A CN 202010087599A CN 111336541 B CN111336541 B CN 111336541B
- Authority
- CN
- China
- Prior art keywords
- molten salt
- hot air
- flue gas
- heat exchanger
- pipeline
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 150000003839 salts Chemical class 0.000 title claims abstract description 93
- 238000000034 method Methods 0.000 title claims abstract description 18
- 239000003546 flue gas Substances 0.000 claims abstract description 98
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 63
- 239000003245 coal Substances 0.000 claims abstract description 39
- 239000002817 coal dust Substances 0.000 claims abstract description 18
- 238000001035 drying Methods 0.000 claims abstract description 16
- 239000000843 powder Substances 0.000 claims description 20
- 239000000203 mixture Substances 0.000 claims description 11
- 239000000428 dust Substances 0.000 claims description 5
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims description 4
- 229910002651 NO3 Inorganic materials 0.000 claims description 4
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims description 4
- 150000002823 nitrates Chemical class 0.000 claims description 4
- 238000000227 grinding Methods 0.000 claims description 3
- 238000010298 pulverizing process Methods 0.000 abstract description 6
- 239000003077 lignite Substances 0.000 description 7
- 238000002485 combustion reaction Methods 0.000 description 4
- 239000000969 carrier Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 239000000779 smoke Substances 0.000 description 3
- 239000006096 absorbing agent Substances 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- -1 steam Substances 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
- F23L15/04—Arrangements of recuperators
-
- 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
- F23C7/02—Disposition of air supply not passing through burner
- F23C7/06—Disposition of air supply not passing through burner for heating the incoming air
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23K—FEEDING FUEL TO COMBUSTION APPARATUS
- F23K1/00—Preparation of lump or pulverulent fuel in readiness for delivery to combustion apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D20/00—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00
- F28D20/02—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00 using latent heat
- F28D20/021—Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00 using latent heat the latent heat storage material and the heat-exchanging means being enclosed in one container
-
- 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
-
- 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
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/14—Thermal energy storage
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Air Supply (AREA)
- Chimneys And Flues (AREA)
- Treating Waste Gases (AREA)
Abstract
The invention discloses a system and a method for improving the temperature of hot air by using a molten salt heat carrier, wherein the system comprises a boiler, the boiler is communicated with a vertical steering chamber at the tail part of the boiler, the vertical steering chamber at the tail part of the boiler is respectively communicated with a molten salt-flue gas heat exchanger and an SCR denitration device, the molten salt-flue gas heat exchanger is also communicated with the SCR denitration device, and the SCR denitration device is communicated with an air preheater; the molten salt-flue gas heat exchanger is also communicated with a molten salt-hot air heat exchanger, and the molten salt-flue gas heat exchanger and the molten salt-hot air heat exchanger are respectively communicated with a molten salt tank. The method comprises the following steps: on the basis of the prior art, a part of high-temperature flue gas enters a fused salt-flue gas heat exchanger for heat exchange, a fused salt heat carrier is heated and is sent into a fused salt-hot air heat exchanger, hot air is further heated in the fused salt-hot air heat exchanger, and finally enters a coal mill to dry coal dust and finish conveying the coal dust. The invention effectively improves the temperature of hot air and solves the problem of insufficient drying output of the pulverizing system.
Description
Technical Field
The present invention relates to a system and method, and more particularly, to a system and method for increasing the temperature of hot air using a molten salt heat carrier.
Background
In a thermal power plant, tail flue gas of a coal-fired boiler normally sequentially passes through an economizer, an SCR denitration device and an air preheater and then enters a dust removal and desulfurization device, and finally is discharged through a chimney. For the direct-fired pulverizing system of the medium-speed coal mill, cold air is conveyed into the air preheater through the fan to exchange heat with high-temperature flue gas, and hot air heated by the air preheater enters the medium-speed coal mill to finish drying, grinding and conveying of raw coal.
The high-moisture lignite has high requirements on the drying capacity of the pulverizing system so as to evaporate external moisture of raw coal falling into the front of the furnace. However, the hot air quantity at the inlet of the existing coal mill is limited by the maximum ventilation quantity of the coal mill, so that the high-moisture lignite needs to be used at a higher hot air temperature to meet the drying output requirement of the pulverizing system. The denitration catalyst in the SCR denitration device runs for a long time at a temperature exceeding 400 ℃, and the phenomenon of local activity reduction or complete failure occurs, so that the flue gas temperature is required to be 320-400 ℃ for ensuring the safe operation of the catalyst, namely the flue gas temperature entering the air preheater cannot be higher than 400 ℃. However, due to the limitation of heat exchange temperature difference, the outlet air temperature of the air preheater can only be heated to about 370 ℃, and the requirement of the drying output of the high-moisture lignite coal mill is not satisfied. The existing units for burning high-moisture lignite have the problem that the drying output of a pulverizing system is insufficient, and no effective solution exists at present.
Disclosure of Invention
In order to solve the defects of the technology, the invention provides a system and a method for improving the temperature of hot air by using a molten salt heat carrier.
In order to solve the technical problems, the invention adopts the following technical scheme: the system for improving the temperature of hot air by using the molten salt heat carrier comprises a boiler, an SCR denitration device, an air preheater, a coal mill, a molten salt-flue gas heat exchanger, a molten salt tank and a molten salt-hot air heat exchanger;
The boiler is communicated with a vertical steering chamber at the tail part of the boiler, and a flue gas heat exchanger is arranged in the vertical steering chamber at the tail part of the boiler; the vertical steering chamber at the tail part of the boiler is respectively communicated with a bypass flue and a first denitration flue, the bypass flue is communicated with the fused salt-flue gas heat exchanger, and the first denitration flue is communicated with the SCR denitration device;
The molten salt-flue gas heat exchanger is communicated with the SCR denitration device through a second denitration flue, and the second denitration flue is converged with the first denitration flue; the SCR denitration device is communicated with an air preheater, the air preheater is respectively communicated with a flue gas discharge pipe and a fan interface pipeline, the flue gas discharge pipe is externally connected with a dust removal device, and the fan interface pipeline is externally connected with a fan;
The molten salt-flue gas heat exchanger is communicated with the molten salt-hot air heat exchanger through a second molten salt pipeline, the molten salt-flue gas heat exchanger is also communicated with a first molten salt pipeline, the first molten salt pipeline is communicated with the molten salt tank, and a molten salt pump is arranged on the first molten salt pipeline; the molten salt tank is internally provided with a molten salt heat carrier and communicated with a third molten salt pipeline, and the third molten salt pipeline is communicated with a molten salt-hot air heat exchanger;
The molten salt-hot air heat exchanger is also respectively communicated with a first hot air pipeline and a second hot air pipeline; the second hot-air pipeline is communicated with the air preheater, the first hot-air pipeline is communicated with the coal mill, and the coal mill is communicated with the boiler through the air powder conveying pipeline.
Further, both the fused salt-flue gas heat exchanger and the fused salt-hot air heat exchanger adopt a fused salt heat carrier as a heat transfer medium.
Further, the molten salt heat carrier is one or more of nitrate, carbonate, fluoride, chloride and binary mixed nitrate salt.
A method for improving the temperature of hot air by using a molten salt heat carrier comprises the following steps:
Firstly, grinding coal blocks into coal dust by a coal mill, simultaneously, feeding hot air into the coal mill by a first hot air pipeline, taking the hot air as a drying heat source and a conveying medium, enabling the coal dust to be dried by heat separation and then form a wind-powder mixture with the hot air, conveying the wind-powder mixture into a boiler by a wind-powder conveying pipeline for combustion, and generating high-temperature flue gas after the coal dust is combusted in the boiler;
Then, high-temperature flue gas enters a tail shaft steering chamber of the boiler, the temperature of the flue gas is 680-720 ℃, part of the flue gas is extracted into a bypass flue, the flue gas enters a fused salt-flue gas heat exchanger to exchange heat with a fused salt heat carrier, the temperature of the flue gas is reduced to 380-400 ℃, the fused salt heat carrier is heated to 400-500 ℃, the flue gas enters an SCR denitration device through a second denitration flue to be subjected to denitration treatment, and meanwhile, the fused salt heat carrier is heated in the fused salt-flue gas heat exchanger and then is sent into a fused salt-hot air heat exchanger through a second fused salt pipeline; after the rest of the flue gas exchanges heat through a flue gas heat exchanger in a steering room of a vertical shaft at the tail part of the boiler, the flue gas enters an SCR denitration device through a first denitration flue to carry out denitration treatment;
After the denitration treatment is finished, the flue gas enters an air preheater to exchange heat with cold air sent by a fan interface pipeline, the flue gas is discharged from a flue gas discharge pipe after the heat exchange, and the cold air absorbs heat to be hot air; hot air enters the molten salt-hot air heat exchanger from a second hot air pipeline, exchanges heat with the heated molten salt heat carrier, and rises to 420-450 ℃, and then enters the coal mill from a first hot air pipeline to dry coal dust and finish conveying the coal dust.
The invention discloses a system and a method for improving the temperature of hot air by utilizing a fused salt heat carrier. Especially for the high-moisture lignite unit for combustion, through the system, the temperature of hot air at the outlet of the air preheater can be increased by more than 50 ℃, the temperature of the air-powder mixture at the outlet of the corresponding coal mill can be further increased, the design specification requirement of the temperature of the air-powder mixture at the outlet of the coal mill is fully met, and the problem of insufficient drying output of the powder making system is solved. The method adopts the molten salt inorganic heat carrier as a heat transfer medium, and can further improve the temperature of hot air, thereby meeting the requirements of drying output of a coal mill.
Drawings
FIG. 1 is a schematic diagram of the system of the present invention.
Fig. 2 is a diagram of a conventional coal-fired boiler system.
In the figure: 1. a boiler; 2. a vertical steering chamber at the tail of the boiler; 3. a molten salt-flue gas heat exchanger; 4. a molten salt pump; 5. a salt melting tank; 6. an SCR denitration device; 7. an air preheater; 8. a molten salt-hot air heat exchanger; 9. a first hot air pipeline; 10. a coal mill; 11. a wind powder conveying pipeline; 12. a bypass flue; 13. a flue gas heat exchanger; 14. a first denitration flue; 15. a second denitration flue; 16. a second hot air pipeline; 17. a first molten salt pipeline; 18. a second molten salt pipeline; 19. a third molten salt pipeline; 20. a flue gas discharge pipe; 21. a fan interface pipeline.
Detailed Description
The invention will be described in further detail with reference to the drawings and the detailed description.
The system for improving the temperature of hot air by using the molten salt heat carrier comprises a boiler 1, an SCR denitration device 6, an air preheater 7, a coal mill 10, a molten salt-flue gas heat exchanger 3, a molten salt tank 5 and a molten salt-hot air heat exchanger 8, as shown in figure 1;
The boiler 1 is communicated with a vertical steering chamber 2 at the tail part of the boiler, a smoke heat exchanger 13 is arranged in the vertical steering chamber 2 at the tail part of the boiler, and the smoke heat exchanger 13 is used for exchanging heat of high-temperature smoke generated by combustion of the boiler 1.
The vertical steering chamber 2 at the tail of the boiler is respectively communicated with a bypass flue 12 and a first denitration flue 14. The bypass flue 12 is additionally arranged on the basis of the original system of the thermal power plant and is communicated with the molten salt-flue gas heat exchanger 3, the molten salt-flue gas heat exchanger 3 is communicated with the SCR denitration device 6 through a No. two denitration flue 15, and a flue taking port of the bypass flue 12 is arranged at the vertical turning room 2 at the tail part of the boiler, so that the bypass flue 12 directly extracts high-temperature flue gas at the tail part of the boiler, sends the high-temperature flue gas into the molten salt-flue gas heat exchanger 3 for heat exchange, the temperature of the high-temperature flue gas is between 680 and 720 ℃, and is usually about 700 ℃, and after heat exchange of the molten salt-flue gas heat exchanger 3, the temperature of the flue gas is reduced to 380 to 400 ℃, and then the flue gas returns to the SCR denitration device 6 through the No. two denitration flue 15.
The first denitration flue 14 is directly communicated with the SCR denitration device 6, so that the rest of flue gas enters the SCR denitration device 6 from the first denitration flue 14 after heat exchange of the flue gas heat exchanger 13 in the vertical steering chamber 2 at the tail part of the boiler. The second denitration flue 15 is converged with the first denitration flue 14, so that the speed of flue gas entering the SCR denitration device 6 can be increased.
The SCR denitration device 6 is communicated with the air preheater 7, so that the flue gas treated by the SCR denitration device 6 can enter the air preheater 7 for heat exchange.
The air preheater 7 is respectively communicated with a flue gas discharge pipe 20 and a fan interface pipeline 21. Wherein, the flue gas discharge pipe 20 is externally connected with a dust removing device, and the flue gas can be discharged through a chimney after being safely treated by the dust removing system; the fan interface pipeline 21 is externally connected with a fan, cold air is fed by the fan, and the cold air and the flue gas entering the air preheater 7 are subjected to heat exchange to form hot air.
As shown in fig. 2, the original system of the thermal power plant is that at this time, the hot air formed after heat exchange of the air preheater 7 directly enters the coal mill 10 through the hot air pipeline, and in general, the air temperature at the outlet of the air preheater 7 can only reach about 370 ℃, which is insufficient to meet the requirement of drying output of the high-moisture lignite coal mill. Therefore, the molten salt-hot air heat exchanger 8 is additionally arranged on the hot air pipeline in the system for improving the temperature of hot air by utilizing the molten salt heat carrier, and the concrete setting mode is as follows: as shown in fig. 1, the molten salt-hot air heat exchanger 8 is communicated with the molten salt-flue gas heat exchanger 3 through a second molten salt pipeline 18, and the molten salt-hot air heat exchanger 8 is also respectively communicated with a first hot air pipeline 9 and a second hot air pipeline 16; the second heat separation pipeline 16 is communicated with the air preheater 7, the first hot air pipeline 9 is communicated with the coal mill 10, and the coal mill 10 is communicated with the boiler 1 through the air powder conveying pipeline 11.
Therefore, the molten salt-flue gas heat exchanger 3 sends the heated molten salt heat carrier into the molten salt-hot air heat exchanger 8 through the second molten salt pipe 18, so that hot air entering the molten salt-hot air heat exchanger 8 can exchange heat with the heated molten salt heat carrier, the temperature of the heated molten salt heat carrier is 400-500 ℃ and does not generate phase change, the hot air absorbs the heat of the molten salt heat carrier, the air temperature is further raised to be more than 420 ℃ from about 370 ℃, the heated hot air enters the coal mill 10 through the first hot air pipeline 9 to dry coal dust entering the boiler 1, the temperature of an air-powder mixture at the outlet of the coal mill 10 is also raised to be more than 60 ℃ from 55 ℃, and the problem of insufficient drying output of a pulverizing system is effectively solved.
Meanwhile, the system for improving the temperature of hot air by using the molten salt heat carrier disclosed by the invention is additionally provided with the molten salt tank 5, and the molten salt tank 5 is used for containing the molten salt heat carrier. The molten salt tank 5 is communicated with the molten salt-flue gas heat exchanger 3 through a first molten salt pipeline 17, and a molten salt pump 4 is arranged on the first molten salt pipeline 17 so as to pump a molten salt heat carrier into the molten salt-flue gas heat exchanger 3; the molten salt tank 5 is also communicated with the molten salt-hot air heat exchanger 8 through a third molten salt pipeline 19, after the molten salt heat carrier in the molten salt-hot air heat exchanger 8 exchanges heat with hot air, the temperature is reduced, and the molten salt heat carrier is recycled into the molten salt tank 5 through the third molten salt pipeline 19, so that the molten salt heat carrier is repeatedly used, and the production cost is saved.
The fused salt heat carrier is used as a heat transfer medium for both the fused salt-flue gas heat exchanger 3 and the fused salt-hot air heat exchanger 8. Heat carriers are intermediate media for transferring and transporting heat, and are classified industrially into two major categories, organic heat carriers and inorganic heat carriers. Wherein, the inorganic heat carrier comprises water, steam, air, flue gas, molten salt, etc. Molten salt is inorganic salt in molten state, and has good heat transfer performance, high use temperature, capacity of meeting various use temperatures and low price.
The molten salt heat carrier can adopt one or more of nitrate, carbonate, fluoride, chloride and binary mixed nitrate salt. The nitrate, carbonate, fluoride, chloride and the like have good heat transfer and storage performance, higher working temperature, wider working temperature range, low vapor pressure and low viscosity. Binary mixed molten nitrate salt and the like, has good heat resistance stability, is nonflammable, and has no phase change in the whole heat absorption and heat transfer cycle when the use temperature is below 600 ℃, and the molten salt has large heat capacity, so that the heat absorber can bear higher heat flux density, thereby enabling the heat absorber to be more compact, reducing the manufacturing cost and reducing the heat loss.
The invention also discloses a method for improving the temperature of hot air by using the molten salt heat carrier, which comprises the following steps:
Firstly, a coal mill 10 grinds coal blocks into coal dust, meanwhile, a first hot air pipeline 9 feeds hot air into the coal mill 10, the hot air serves as a drying heat source and a conveying medium, the coal dust is subjected to heat separation drying and then forms a wind-powder mixture with the hot air, the wind-powder mixture is conveyed into a boiler 1 by a wind-powder conveying pipeline 11 to be combusted, and high-temperature flue gas is generated after the coal dust is combusted in the boiler 1;
Then, high-temperature flue gas enters a vertical shaft steering chamber 2 at the tail part of the boiler, the temperature of the flue gas is 680-720 ℃, part of the flue gas is extracted into a bypass flue 12, enters a molten salt-flue gas heat exchanger 3 to exchange heat with a molten salt heat carrier, the temperature of the flue gas is reduced to 380-400 ℃, the molten salt heat carrier is heated to 400-500 ℃, the flue gas enters an SCR denitration device 6 through a second denitration flue 15 to carry out denitration treatment, and meanwhile, the molten salt heat carrier is heated in the molten salt-flue gas heat exchanger 3 and then is sent into a molten salt-hot air heat exchanger 8 through a second molten salt pipeline 18; the rest of the flue gas enters the SCR denitration device 6 through a first denitration flue 14 for denitration treatment after heat exchange of a flue gas heat exchanger 13 in the tail shaft steering chamber 2 of the boiler;
After the denitration treatment is finished, the flue gas enters an air preheater 7 to exchange heat with cold air sent by a fan interface pipeline 21, the flue gas is discharged from a flue gas discharge pipe 20 after the heat exchange, and the cold air absorbs heat to be hot air; hot air enters the molten salt-hot air heat exchanger 8 from the second hot air pipeline 16, exchanges heat with the heated molten salt heat carrier, rises to 420-450 ℃, and then enters the coal mill 10 from the first hot air pipeline 9 so as to dry coal dust and finish conveying the coal dust.
The system and the method for improving the hot air temperature by utilizing the molten salt heat carrier effectively improve the hot air temperature by additionally arranging the bypass flue, the molten salt-flue gas heat exchanger, the molten salt-hot air heat exchanger and other related molten salt systems on the basis of the original process system of the coal-fired boiler of the thermal power plant. Especially for the high-moisture lignite unit for combustion, through the system, the temperature of hot air at the outlet of the air preheater can be increased by more than 50 ℃, the temperature of the air-powder mixture at the outlet of the corresponding coal mill can be further increased, the design specification requirement of the temperature of the air-powder mixture at the outlet of the coal mill is fully met, and the problem of insufficient drying output of the powder making system is solved.
The above embodiments are not intended to limit the present invention, and the present invention is not limited to the above examples, but is also intended to be limited to the following claims.
Claims (3)
1. A method for increasing the temperature of hot air by using a molten salt heat carrier, which is characterized in that: the method for improving the temperature of the hot air is realized based on a hot air system, and the hot air system comprises a boiler (1), an SCR denitration device (6), an air preheater (7), a coal mill (10), a fused salt-flue gas heat exchanger (3), a fused salt tank (5) and a fused salt-hot air heat exchanger (8);
The boiler (1) is communicated with a vertical steering chamber (2) at the tail part of the boiler, and a flue gas heat exchanger (13) is arranged in the vertical steering chamber (2) at the tail part of the boiler; the vertical steering chamber (2) at the tail of the boiler is respectively communicated with a bypass flue (12) and a first denitration flue (14), the bypass flue (12) is communicated with the fused salt-flue gas heat exchanger (3), and the first denitration flue (14) is communicated with the SCR denitration device (6);
The molten salt-flue gas heat exchanger (3) is communicated with the SCR denitration device (6) through a second denitration flue (15), and the second denitration flue (15) is converged with a first denitration flue (14); the SCR denitration device (6) is communicated with the air preheater (7), the air preheater (7) is respectively communicated with a flue gas discharge pipe (20) and a fan interface pipeline (21), the flue gas discharge pipe (20) is externally connected with a dust removing device, and the fan interface pipeline (21) is externally connected with a fan;
the molten salt-flue gas heat exchanger (3) is communicated with the molten salt-hot air heat exchanger (8) through a second molten salt pipeline (18), the molten salt-flue gas heat exchanger (3) is also communicated with a first molten salt pipeline (17), the first molten salt pipeline (17) is communicated with the molten salt tank (5), and a molten salt pump (4) is arranged on the first molten salt pipeline (17); the molten salt tank (5) is internally provided with a molten salt heat carrier and is communicated with a third molten salt pipeline (19), and the third molten salt pipeline (19) is communicated with the molten salt-hot air heat exchanger (8);
The molten salt-hot air heat exchanger (8) is also respectively communicated with a first hot air pipeline (9) and a second hot air pipeline (16); the second hot air pipeline (16) is communicated with the air preheater (7), the first hot air pipeline (9) is communicated with the coal mill (10), and the coal mill (10) is communicated with the boiler (1) through the air powder conveying pipeline (11);
the method for improving the temperature of the hot air comprises the following steps:
Firstly, grinding coal blocks into coal dust by a coal mill (10), simultaneously, feeding hot air into the coal mill (10) by a first hot air pipeline (9), taking the hot air as a drying heat source and a conveying medium, drying the coal dust by the hot air, forming a wind-powder mixture with the hot air, conveying the wind-powder mixture into a boiler (1) by a wind-powder conveying pipeline (11), and burning the coal dust in the boiler (1) to generate high-temperature flue gas;
Then, high-temperature flue gas enters a vertical steering chamber (2) at the tail part of the boiler, the temperature of the flue gas is 680-720 ℃, part of the flue gas is extracted into a bypass flue (12), enters a molten salt-flue gas heat exchanger (3) to exchange heat with a molten salt heat carrier, the temperature of the flue gas is reduced to 380-400 ℃, the molten salt heat carrier is heated to 400-500 ℃, the flue gas enters an SCR denitration device (6) through a second denitration flue (15) to carry out denitration treatment, and meanwhile, the molten salt heat carrier is sent into a molten salt-hot air heat exchanger (8) through a second molten salt pipeline (18) after being heated by the flue gas in the molten salt-flue gas heat exchanger (3); the rest of the flue gas enters an SCR denitration device (6) through a first denitration flue (14) for denitration treatment after heat exchange of a flue gas heat exchanger (13) in a vertical steering chamber (2) at the tail part of the boiler;
After the denitration treatment is finished, the flue gas enters an air preheater (7) to exchange heat with cold air sent by a fan interface pipeline (21), the flue gas is discharged from a flue gas discharge pipe (20) after the heat exchange, and the cold air absorbs heat to be changed into hot air; hot air enters a molten salt-hot air heat exchanger (8) from a second hot air pipeline (16), exchanges heat with a heated molten salt heat carrier, and rises to 420-450 ℃, and then enters a coal mill (10) from a first hot air pipeline (9) so as to dry coal dust and finish conveying the coal dust.
2. The method for increasing the temperature of hot air using a molten salt heat carrier according to claim 1, wherein: the fused salt-flue gas heat exchanger (3) and the fused salt-hot air heat exchanger (8) both adopt a fused salt heat carrier as a heat transfer medium.
3. The method for increasing the temperature of hot air using a molten salt heat carrier according to claim 2, wherein: the molten salt heat carrier is one or more of nitrate, carbonate, fluoride, chloride and binary mixed nitrate salt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010087599.2A CN111336541B (en) | 2020-02-12 | 2020-02-12 | System and method for improving hot air temperature by using molten salt heat carrier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010087599.2A CN111336541B (en) | 2020-02-12 | 2020-02-12 | System and method for improving hot air temperature by using molten salt heat carrier |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111336541A CN111336541A (en) | 2020-06-26 |
| CN111336541B true CN111336541B (en) | 2024-07-19 |
Family
ID=71182165
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010087599.2A Active CN111336541B (en) | 2020-02-12 | 2020-02-12 | System and method for improving hot air temperature by using molten salt heat carrier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111336541B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112944385A (en) * | 2021-04-09 | 2021-06-11 | 西安热工研究院有限公司 | Hot primary air heating system |
| CN113217979A (en) * | 2021-05-08 | 2021-08-06 | 中煤科工集团重庆研究院有限公司 | Multi-state coupling peak regulation intelligent control system for gas heat accumulation oxidation, electric auxiliary heat and molten salt heat accumulation |
| CN113175686B (en) * | 2021-05-08 | 2022-12-27 | 中煤科工集团重庆研究院有限公司 | Preheating method of molten salt heat storage system based on gas heat storage oxidation |
| CN113188360A (en) * | 2021-05-25 | 2021-07-30 | 中煤科工集团重庆研究院有限公司 | Multifunctional molten salt heat storage and supply method and system based on gas heat storage oxidation, power generation waste heat and valley electricity |
| CN114288852A (en) * | 2022-02-16 | 2022-04-08 | 西安西热锅炉环保工程有限公司 | Wide-load coal-fired boiler denitration system and working method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN211976924U (en) * | 2020-02-12 | 2020-11-20 | 江苏慧峰仁和环保科技有限公司 | System for utilize fused salt heat carrier to improve hot-blast temperature |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5707546B2 (en) * | 2011-04-11 | 2015-04-30 | 三菱日立パワーシステムズ株式会社 | Solar thermal boiler system |
| CN207797100U (en) * | 2017-11-08 | 2018-08-31 | 昆山市三维换热器有限公司 | Flue gas denitrification system |
| CN209706109U (en) * | 2019-01-22 | 2019-11-29 | 上海电力学院 | Phase transformation heat pipe-type power plant's First air heats thermoregulating system |
| CN109966915A (en) * | 2019-03-29 | 2019-07-05 | 北京国电龙源环保工程有限公司 | A kind of gasification of biomass coupling coal-burning boiler full load SCR denitration system and process |
-
2020
- 2020-02-12 CN CN202010087599.2A patent/CN111336541B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN211976924U (en) * | 2020-02-12 | 2020-11-20 | 江苏慧峰仁和环保科技有限公司 | System for utilize fused salt heat carrier to improve hot-blast temperature |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111336541A (en) | 2020-06-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111336541B (en) | System and method for improving hot air temperature by using molten salt heat carrier | |
| CN100358800C (en) | Electric furnace method yellow phosphorus tail gas residual heat comprehensive balance utilizing system | |
| CN104654815A (en) | Mosaic ceramic kiln waste heat power generation comprehensive utilization system | |
| CN110986031B (en) | System for avoiding water vapor condensation in gas boiler flue gas recirculation pipeline | |
| CN211976924U (en) | System for utilize fused salt heat carrier to improve hot-blast temperature | |
| CN207936049U (en) | A kind of smoke heat energy utilizes system | |
| CN104990396A (en) | System for carrying out lignite drying and water recovery by using waste heat of power plant | |
| CN108658417A (en) | A kind of coal unit collaboration desiccation municipal sludge system | |
| CN211040991U (en) | Coal-fired coupling sludge drying and incinerating system considering waste heat utilization | |
| CN103983088A (en) | System and method for predrying lignite and recycling water by using waste heat of power station | |
| CN205592967U (en) | A waste heat power generation system for dangerous waste disposal trade of industry | |
| CN110145754A (en) | It can prevent the boiler flue gas treatment system and method for back-end surfaces low-temperature corrosion | |
| CN202947153U (en) | Gas-fired boiler flue gas heat energy recovery system with water spraying chamber | |
| CN103822439B (en) | One utilizes surplus heat of power plant to carry out pre-dried system and method to brown coal | |
| CN202947152U (en) | Gas boiler flue gas heat energy recovery system with a preheater | |
| CN110894954A (en) | High-temperature tail gas purification and waste heat recovery system | |
| CN203384961U (en) | Boiler tail gas waste heat reclaimer | |
| CN103234206B (en) | Recycling method and recycling device of fire coal high temperature flue gas | |
| CN107166358B (en) | Boiler system for producing double heat carriers | |
| CN203857749U (en) | System used for preheating lignite by power plant waste heat and recycling water | |
| CN201385389Y (en) | Natural rubber steam drying oven | |
| CN204917977U (en) | A flue gas heat energy comprehensive utilization system for producing sodium tripolyphosphate | |
| CN103657406A (en) | Low-temperature flue denitration system | |
| CN211902938U (en) | Smoke waste heat recycling smoke cooler system | |
| CN103160639B (en) | Converter smoke waste heat utilizing system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |