CN113898965A - High-temperature air preheating system for improving lignite blending combustion ratio - Google Patents
High-temperature air preheating system for improving lignite blending combustion ratio Download PDFInfo
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- CN113898965A CN113898965A CN202111370426.2A CN202111370426A CN113898965A CN 113898965 A CN113898965 A CN 113898965A CN 202111370426 A CN202111370426 A CN 202111370426A CN 113898965 A CN113898965 A CN 113898965A
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- air
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- temperature air
- lignite
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- 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
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- 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
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- 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
- F23L9/00—Passages or apertures for delivering secondary air for completing combustion of fuel
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N3/00—Regulating air supply or draught
- F23N3/002—Regulating air supply or draught using electronic means
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- 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
- F28D9/00—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28G—CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS
- F28G1/00—Non-rotary, e.g. reciprocated, appliances
- F28G1/16—Non-rotary, e.g. reciprocated, appliances using jets of fluid for removing debris
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- 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 a high-temperature air preheating system for improving the proportion of lignite blended combustion, which comprises a high-temperature air preheater air side inlet shutoff door, a high-temperature air preheater air side outlet shutoff door, a hot primary air main path adjusting door, a hot primary air main path, a hot primary air bypass and a hot primary air main pipe. The invention can not only obviously improve the temperature of hot primary air and solve the problem of insufficient drying output of the pulverized coal making system of the blended combustion lignite, but also reduce the heat absorption capacity of the reheating system and relieve the problem of over-temperature of the wall temperature caused by the blended combustion lignite.
Description
Technical Field
The invention belongs to the technical field of bituminous coal boilers, and particularly relates to a high-temperature air preheating system for improving the blending combustion ratio of lignite.
Background
China is one of the largest energy consuming countries in the world, and coal is determined to be an important component of energy consumption in China at present and in a long time in the future based on the characteristics of rich coal, poor oil and less gas in China. The low-rank inferior coal accounts for more than 55% of the coal reserves in China, and plays a very important role in energy consumption in China. China has abundant coal resources, different power coals have obvious coal quality characteristic difference, a power station boiler is usually designed and manufactured according to specific design coal types and check coal types, however, the actual coal and the design coal types of a power plant have great difference due to unbalanced coal market supply and demand relations, and the operation safety and the economical efficiency of a unit are seriously influenced.
Along with the change of coal markets, the mixed coal blending combustion is an effective way for solving the coal quality difference, and the lignite resources are rich in regions such as Mongolia and northeast, and the blended combustion of lignite in a certain proportion is an effective way for cost reduction and efficiency improvement of a thermal power plant. However, the bituminous coal boiler (mostly a direct-fired pulverizing system) has a plurality of problems in mixing and burning the lignite.
1. Lignite is large in moisture and low in heat productivity, and an original pulverizing system is insufficient in drying output, so that the load capacity of a unit is influenced;
2. in order to prevent the coal mill from being blocked and meet the requirement on the temperature at the outlet of the coal mill, the requirement can be met only by improving the primary air rate, so that flame delay is caused, the smoke temperature at the outlet of a hearth is increased, slag bonding is serious, the radiation heat absorption capacity of the hearth is reduced, and the overheating of a reheating system taking a convection heating surface as a main part is serious;
3. the primary air rate is higher than the design value, so that the secondary air rate is lower, the staged combustion effect is poor, and the generation amount of nitrogen oxides is higher;
based on the above problems, in order to satisfy the requirements of power plants for safe, efficient, economical and environment-friendly blending combustion of lignite, a high-temperature air preheating system for improving the blending combustion proportion of lignite needs to be provided urgently, and the technical problems are solved.
Disclosure of Invention
The invention aims to provide a high-temperature air preheating system for improving the blending proportion of lignite, and a coal-fired boiler applying the system can realize 30 percent (by weight) of 100 percent of THA load with the maximum blending proportion of lignite, 50 percent (by weight) of 75 percent of THA load with the maximum blending proportion of lignite and 70 percent (by weight) of 50 percent of THA load with the maximum blending proportion of lignite, thereby widening the coal adaptation range of the boiler, improving the purchasing flexibility of coal-fired power plants and reducing the coal-fired cost.
In order to achieve the purpose, the invention adopts the technical scheme that:
a high-temperature air preheating system for improving the proportion of lignite blended combustion comprises a high-temperature air preheater, a high-temperature air preheater air side inlet shutoff door, a high-temperature air preheater air side outlet shutoff door, a hot primary air main path adjusting door, a hot primary air main path, a hot primary air bypass and a hot primary air main pipe;
the hot primary air pipeline at the outlet of the rotary air preheater is divided into a hot primary air main path and a hot primary air bypass, a hot primary air main path adjusting door is arranged on the hot primary air main path, the hot primary air bypass is connected with the high-temperature air preheater through a high-temperature air preheater air side inlet shutoff door, and the hot primary air main path is converged into a hot primary air main pipe through a high-temperature air preheater air side outlet shutoff door after being reheated by high-temperature flue gas in a rear vertical shaft, and is connected into the coal pulverizer after being converged into a cold primary air pipe.
The invention is further improved in that the hot primary air main pipe, the hot primary air main path and the hot primary air bypass have the same flow area.
The invention has the further improvement that the material of the hot primary air bypass is 12Cr1 MoV.
The invention is further improved in that the high-temperature air preheater air side inlet shutoff door and the high-temperature air preheater air side outlet shutoff door are in a plug board door type.
The invention has the further improvement that the high-temperature air preheater adopts a plate heat exchanger, the distance between the side plates of the flue gas is not less than 40mm, and the material is 12Cr1 MoV.
The invention is further improved in that the high-temperature air preheater is arranged in a smoke temperature range of 400-500 ℃.
The invention is further improved in that a heat primary air main pipe sensor is arranged on the heat primary air main pipe, and the opening of the adjusting valve of the heat primary air main path is adjusted according to the feedback of the heat primary air main pipe sensor.
The invention is further improved in that a pressure difference sensor is arranged on the flue gas side of the high-temperature air preheater, a rake type soot blower is arranged above the high-temperature air preheater, and the rake type soot blower is put into operation according to the feedback of the pressure difference sensor.
The invention has at least the following beneficial technical effects:
1. arrange the high temperature air preheating system in shaft position behind the boiler, can improve hot primary air temperature by a wide margin for the brown coal that adapts to multiple proportion under different loads is mixed and is burnt: 30 percent (by weight) of 100 percent THA load maximum blending proportion lignite, 50 percent (by weight) of 75 percent THA load maximum blending proportion lignite and 70 percent (by weight) of 50 percent THA load maximum blending proportion lignite can be realized;
2. the primary air temperature is improved, the primary air rate returns to the design value, the flame center height is reduced, the radiation heat absorption capacity of a hearth is increased, the smoke temperature of the hearth outlet is reduced, the heat absorption capacity of a low-temperature reheater is reduced, and the problem that the wall temperature of a reheater system is over-temperature is avoided;
3. the proportion of the primary air and the secondary air returns to normal, so that staged combustion is realized, and the generation amount of nitrogen oxides can be reduced;
3. the application range of boiler coal types is widened, the purchasing flexibility of power plant coal is improved, and the coal burning cost is reduced.
4. The blowing of the rake type soot blower is guided by the flue gas side pressure difference of the high-temperature air preheater, so that the high-temperature air preheater is prevented from being blocked;
5. the hot primary air main pipe is provided with the adjusting baffle door, the required primary air temperature can be determined according to the actual lignite blending combustion proportion, and then the air quantity entering the high-temperature air preheater is changed by adjusting the opening degree of the baffle door, so that the hot primary air temperature is changed.
Drawings
Fig. 1 is a schematic structural diagram of a high-temperature air preheating system for increasing the blending combustion ratio of lignite according to the present invention.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
According to the high-temperature air preheater system for improving the lignite co-combustion ratio, the temperature of the required high-temperature air can be adjusted according to the lignite co-combustion ratio by the high-temperature air preheater system arranged in the rear vertical shaft of the boiler, so that the high-temperature air preheater system is suitable for the boiler co-combustion of different lignite ratios under different loads.
The specific implementation mode is as follows: the embodiment is described by combining fig. 1, and the high-temperature air preheating system for improving the lignite co-combustion ratio of the embodiment comprises a high-temperature air preheater 1, a high-temperature air preheater air side inlet shutoff door 2, a high-temperature air preheater air side outlet shutoff door 3, a primary hot air main path adjusting door 4, a primary hot air main path 11, a primary hot air bypass 12 and a primary hot air main pipe 10, wherein a primary hot air pipeline at the outlet of a rotary air preheater 8 is divided into two paths, the primary hot air main path 11 and the primary hot air bypass 12 are arranged, the primary hot air main path adjusting door 4 is arranged on the primary hot air main path 12, the primary hot air bypass 11 is connected with the high-temperature air preheater 1 through the high-temperature air preheater air side inlet shutoff door 2 and is reheated by high-temperature flue gas in a rear shaft, the hot primary air is converged into a hot primary air main pipe 13 through an air side outlet shutoff door 3 of the high-temperature air preheater, and is converged with a cold primary air pipe and then is connected into a coal mill 9.
The specific working process is as follows: the required hot air temperature is determined by the lignite blending ratio and the designed primary air rate, the opening degree of an adjusting door 4 of a primary hot air main path 11 is adjusted according to the feedback value of a temperature sensor 5 on a primary hot air main pipe 10, and the primary air flow passing through a primary hot air bypass 12 is changed so as to adjust the hot air temperature to meet the blending combustion requirement; the rake type soot blower 6 arranged above the high-temperature air preheater 1 is put into operation periodically or guided to be put into operation according to feedback of a pressure difference transmitter 7 at the smoke side of the high-temperature air preheater, and if the pressure difference at the smoke side is larger than 300Pa, the rake type soot blower 6 is put into operation to prevent the high-temperature air preheater from being blocked to influence the heat exchange effect; if the lignite is not burnt or the rotary air preheater meets the requirement of hot air temperature, the inlet shutoff door 2 of the high-temperature air preheater and the outlet shutoff door 3 of the high-temperature air preheater are closed to isolate the high-temperature air preheater.
Various changes and modifications can be made by one skilled in the art without departing from the scope of the invention, and all equivalent technical solutions should also fall within the scope of the invention, which is defined by the claims.
Claims (8)
1. A high-temperature air preheating system for improving the proportion of lignite blended combustion is characterized by comprising a high-temperature air preheater (1), a high-temperature air preheater air side inlet shutoff door (2), a high-temperature air preheater air side outlet shutoff door (3), a hot primary air main path adjusting door (4), a hot primary air main path (11), a hot primary air bypass (12) and a hot primary air main pipe (10);
the hot primary air pipeline at the outlet of the rotary air preheater (8) is divided into a hot primary air main path (11) and a hot primary air bypass (12), a hot primary air main path adjusting door (4) is arranged on the hot primary air main path (12), the hot primary air bypass (11) is connected with the high-temperature air preheater (1) through a high-temperature air preheater air side inlet shutoff door (2), and is heated by high-temperature flue gas in a rear vertical shaft, and then is converged into a hot primary air main pipe (13) through a high-temperature air preheater air side outlet shutoff door (3), and is converged with a cold primary air pipe and then is connected into the coal mill (9).
2. The high-temperature air preheating system for increasing the lignite co-combustion ratio as claimed in claim 1, wherein the hot primary air main pipe (10), the hot primary air main path (11) and the hot primary air bypass path (12) have the same flow area.
3. The high-temperature air preheating system for increasing the lignite co-combustion ratio as claimed in claim 1, wherein the material of the hot primary air bypass (12) is 12Cr1 MoV.
4. A high-temperature air preheating system for increasing the proportion of lignite addition combustion according to claim 1, characterized in that the high-temperature air preheater air side inlet shutoff door (2) and the high-temperature air preheater air side outlet shutoff door (3) are of a plug door type.
5. A high-temperature air preheating system for increasing the lignite co-combustion ratio as claimed in claim 1, wherein the high-temperature air preheater (1) is a plate heat exchanger, the distance between the flue gas side plates is not less than 40mm, and the material is 12Cr1 MoV.
6. A high-temperature air preheating system for increasing the lignite co-combustion ratio as claimed in claim 1, wherein the high-temperature air preheater (1) is arranged in a smoke temperature range of 400-500 ℃.
7. The high-temperature air preheating system for increasing the lignite blending combustion ratio as claimed in claim 1, wherein a primary hot air main pipe sensor (5) is arranged on the primary hot air main pipe (10), and the opening degree of the primary hot air main path adjusting door (4) is adjusted according to the feedback of the primary hot air main pipe sensor (5).
8. A high-temperature air preheating system for increasing the lignite co-combustion ratio as claimed in claim 1, wherein a pressure difference sensor (7) is arranged on the flue gas side of the high-temperature air preheater (1), a rake type soot blower (6) is arranged above the high-temperature air preheater (1), and the rake type soot blower (6) is put into operation according to the feedback of the pressure difference sensor (7).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111370426.2A CN113898965A (en) | 2021-11-18 | 2021-11-18 | High-temperature air preheating system for improving lignite blending combustion ratio |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111370426.2A CN113898965A (en) | 2021-11-18 | 2021-11-18 | High-temperature air preheating system for improving lignite blending combustion ratio |
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| CN113898965A true CN113898965A (en) | 2022-01-07 |
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| CN202111370426.2A Pending CN113898965A (en) | 2021-11-18 | 2021-11-18 | High-temperature air preheating system for improving lignite blending combustion ratio |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07208701A (en) * | 1994-01-17 | 1995-08-11 | Ishikawajima Harima Heavy Ind Co Ltd | Temperature controller for inlet gas of denitrating device for boiler |
| CN103041703A (en) * | 2012-12-27 | 2013-04-17 | 浙江信耳科技有限公司 | SCR (Selective Catalytic Reduction) flue gas denitration system for burning lignite |
| CN206786748U (en) * | 2017-04-10 | 2017-12-22 | 武汉燃控科技热能工程有限公司 | The soot blower of tube-type air preheater |
| CN110500601A (en) * | 2019-08-22 | 2019-11-26 | 华能国际电力股份有限公司 | The method that processing SCR denitration the escaping of ammonia is excessive, air preheater blocks |
| CN113028446A (en) * | 2021-05-08 | 2021-06-25 | 珠海市华远自动化科技有限公司 | Automatic temperature regulating system for isolating heat exchange by utilizing flue gas bypass |
| CN113294799A (en) * | 2021-05-27 | 2021-08-24 | 东方电气集团东方锅炉股份有限公司 | Hot primary air and air-powder mixture heat exchange system |
-
2021
- 2021-11-18 CN CN202111370426.2A patent/CN113898965A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07208701A (en) * | 1994-01-17 | 1995-08-11 | Ishikawajima Harima Heavy Ind Co Ltd | Temperature controller for inlet gas of denitrating device for boiler |
| CN103041703A (en) * | 2012-12-27 | 2013-04-17 | 浙江信耳科技有限公司 | SCR (Selective Catalytic Reduction) flue gas denitration system for burning lignite |
| CN206786748U (en) * | 2017-04-10 | 2017-12-22 | 武汉燃控科技热能工程有限公司 | The soot blower of tube-type air preheater |
| CN110500601A (en) * | 2019-08-22 | 2019-11-26 | 华能国际电力股份有限公司 | The method that processing SCR denitration the escaping of ammonia is excessive, air preheater blocks |
| CN113028446A (en) * | 2021-05-08 | 2021-06-25 | 珠海市华远自动化科技有限公司 | Automatic temperature regulating system for isolating heat exchange by utilizing flue gas bypass |
| CN113294799A (en) * | 2021-05-27 | 2021-08-24 | 东方电气集团东方锅炉股份有限公司 | Hot primary air and air-powder mixture heat exchange system |
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