CN115095854B - Low low-temperature economizer mounting structure of dynamic adjustable of wall temperature in air preheater rear end - Google Patents

Low low-temperature economizer mounting structure of dynamic adjustable of wall temperature in air preheater rear end Download PDF

Info

Publication number
CN115095854B
CN115095854B CN202210717701.1A CN202210717701A CN115095854B CN 115095854 B CN115095854 B CN 115095854B CN 202210717701 A CN202210717701 A CN 202210717701A CN 115095854 B CN115095854 B CN 115095854B
Authority
CN
China
Prior art keywords
flue gas
low
temperature
shaped
special
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
Application number
CN202210717701.1A
Other languages
Chinese (zh)
Other versions
CN115095854A (en
Inventor
石伟伟
韦红旗
申先念
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang Xinghe Zhituo Technology Co ltd
Original Assignee
Zhejiang Xinghe Zhituo Technology Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Zhejiang Xinghe Zhituo Technology Co ltd filed Critical Zhejiang Xinghe Zhituo Technology Co ltd
Priority to CN202210717701.1A priority Critical patent/CN115095854B/en
Publication of CN115095854A publication Critical patent/CN115095854A/en
Application granted granted Critical
Publication of CN115095854B publication Critical patent/CN115095854B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22D—PREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER FOR STEAM GENERATION; FEED-WATER SUPPLY FOR STEAM GENERATION; CONTROLLING WATER LEVEL FOR STEAM GENERATION; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN STEAM BOILERS
    • F22D1/00—Feed-water heaters, i.e. economisers or like preheaters
    • F22D1/02—Feed-water heaters, i.e. economisers or like preheaters with water tubes arranged in the boiler furnace, fire tubes, or flue ways
    • F22D1/08—Feed-water heaters, i.e. economisers or like preheaters with water tubes arranged in the boiler furnace, fire tubes, or flue ways the tubes having fins, ribs, gills, corrugations, or the like on their outer surfaces, e.g. in vertical arrangement
    • F22D1/10—Feed-water heaters, i.e. economisers or like preheaters with water tubes arranged in the boiler furnace, fire tubes, or flue ways the tubes having fins, ribs, gills, corrugations, or the like on their outer surfaces, e.g. in vertical arrangement in horizontal arrangement
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22D—PREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER FOR STEAM GENERATION; FEED-WATER SUPPLY FOR STEAM GENERATION; CONTROLLING WATER LEVEL FOR STEAM GENERATION; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN STEAM BOILERS
    • F22D1/00—Feed-water heaters, i.e. economisers or like preheaters
    • F22D1/36—Water and air preheating systems
    • F22D1/38—Constructional features of water and air preheating systems
    • 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
    • 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
    • F23J15/06—Arrangements of devices for treating smoke or fumes of coolers
    • 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
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Air Supply (AREA)

Abstract

According to the low-temperature economizer mounting structure with the dynamically adjustable temperature of the rear end wall of the air preheater, the end face of the cold end of a rotor of the air preheater is divided into N concentric rings through circumferential partition plates, and N is more than or equal to 2; the air side of the cold end face of the air preheater rotor is provided with N special-shaped air pipelines which are respectively butted with the N concentric rings, and the flue gas side of the cold end face of the air preheater rotor is provided with N special-shaped flue gas pipelines which are respectively butted with the N concentric rings; the N special-shaped flue gas pipelines respectively extend to the inlets of the low-temperature economizers; the flow in a special-shaped air pipeline is reduced, the heat exchange quantity of the heat storage element in the corresponding concentric ring is reduced, the heat release quantity of the flue gas flowing through the concentric ring is reduced, the temperature of the flue gas in the special-shaped flue gas pipeline on the flue gas side of the concentric ring is increased, the flue gas flows into the low-temperature economizer to raise the wall temperature of the corresponding subarea, so that the adhered condensed or crystallized substances are gasified, the flue gas is discharged out of the low-temperature economizer, the flow in each special-shaped air pipeline is reduced in a round-robin manner, and the dynamic subarea temperature adjustment of the low-temperature economizer is realized.

Description

Low low temperature economizer mounting structure of air preheater rear end wall temperature developments adjustable
Technical Field
The invention relates to a low-temperature economizer mounting structure with dynamically adjustable rear end wall temperature of an air preheater, and belongs to the technical field of flue gas waste heat utilization.
Background
The low-temperature economizer is used as flue gas waste heat recovery equipment of a power plant boiler, and the flue gas waste heat is utilized to heat condensed water of a steam turbine or medium water of an air heater, so that the purposes of reducing the exhaust gas temperature and simultaneously increasing the condensed water temperature or the medium water temperature of the air heater are achieved. The low-temperature economizer is generally arranged in a flue from an outlet of an air preheater to an inlet section of a dust remover, and can adopt the arrangement modes of horizontal arrangement, vertical bottom-to-top arrangement and vertical top-to-bottom arrangement. The temperature of the flue gas flowing through the low-temperature economizer can be reduced to be below 90 ℃, energy is saved, consumption is reduced, specific resistance of the flue gas can be reduced, and dust removal efficiency is improved. The low-temperature economizers all use water as a medium, and the heat pipe type low-temperature economizer also has the similar effect.
The low-temperature economizer often faces the problems of dust accumulation on the heating surface, abrasion, leakage of a heat exchange pipe and the like in the actual operation for the following reasons: (1) SO in flue gas when sulfur content in coal is too high 3 The fly ash can be condensed and separated out in the working temperature range of the low-temperature and low-temperature economizer, so that the ash deposition caused by the viscosity of the fly ash is enhanced; (2) in order to reduce the emission of NOx of a unit, a denitration device is generally arranged on the upper stream of the low-temperature economizer, the denitration device generally reduces the concentration of NOx in flue gas by using the oxidation-reduction reaction of ammonia gas and NOx, however, the unit has variable operation conditions, SO that a large amount of ammonia in the denitration device escapes to a downstream air preheater and the low-temperature economizer, and when the temperature of the flue gas is lower, the ammonia gas and SO are mixed 3 By-product NH is generated 4 HSO 4 The smoke is in a viscous liquid state and is adsorbed on the side heated wall surface of the smoke to cause dust deposition and blockage; (3) the flow velocity of the inlet of the low-temperature economizer is not uniform, the inner flow field is disordered due to ash accumulation on the heating surface, the local flue gas flow velocity and the fly ash concentration are too high, and meanwhile, the fly ash particles in the low-temperature flue gas are hard and easily wear the heating surface continuously; (4) the tube wall of the heat exchange tube bundle becomes thin due to abrasion, and the temperature of the flue gas is lower than the acid dew point (generally 95-160 ℃ and SO) 3 Concentration related) can cause leakage from the heat exchanger bundle, further exacerbating plugging and corrosion within the low temperature economizer.
In summary, the conventional low-temperature economizer faces the problems of soot deposition on the heating surface, abrasion, leakage of a heat exchange tube and the like for a long time, and how to effectively treat and prevent soot deposition and blockage of the low-temperature economizer is a big problem in the industry.
Disclosure of Invention
In order to solve the problems of dust accumulation on a heating surface, abrasion, leakage of a heat exchange pipe and the like of a low-low temperature economizer in the prior art, the invention provides a low-low temperature economizer mounting structure with a dynamically adjustable rear end wall temperature of an air preheater.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
a low-temperature economizer mounting structure with dynamically adjustable temperature of the rear end wall of an air preheater is characterized in that the end face of the cold end of an air preheater rotor is divided into N concentric rings through circumferential partition plates, and N is more than or equal to 2; the air side of the cold end face of the air preheater rotor is provided with N special-shaped air pipelines which are respectively butted with the N concentric rings, and the flue gas side of the cold end face of the air preheater rotor is provided with N special-shaped flue gas pipelines which are respectively butted with the N concentric rings; the N special-shaped flue gas pipelines respectively extend to the inlets of the low-temperature economizers; the flow in a special-shaped air pipeline is reduced, the heat exchange quantity of the heat storage element corresponding to the concentric ring is reduced, the heat release quantity of the flue gas flowing through the concentric ring is reduced, the temperature of the flue gas in the special-shaped flue gas pipeline on the flue gas side of the concentric ring is increased, the flue gas flows into the low-temperature economizer to increase the wall temperature of the corresponding subarea, so that the adhered condensed or crystallized substances are gasified, the low-temperature economizer is discharged along with the flue gas, the flow in each special-shaped air pipeline is reduced in a round-robin manner, and the subarea dynamic adjustment of the wall temperature of the low-temperature economizer is realized.
The air preheater is a rotary air preheater and is at least divided into two sub-bins, and at least one smoke side sub-bin and one air side medium sub-bin are arranged.
Each concentric ring on the cold end face of the air preheater rotor is correspondingly provided with a special-shaped air pipeline (air side) and a special-shaped smoke pipeline (smoke side).
This application circumference is circumferencial direction, and radial for the radial direction of air preheater, the axial indicates the axial of air preheater.
The sector-shaped structure comprises two arcs with the same bending direction and a graph formed by two radial edges connecting two ends of the two arcs in a surrounding mode.
The applicant finds that when the flow in a special-shaped air pipeline is adjusted and reduced, the temperature of the smoke in the special-shaped smoke pipeline corresponding to the smoke side of the concentric ring where the pipeline is located rises. The N special-shaped flue gas pipelines respectively extend to the inlet of the low-temperature economizer, so that the mixing of flue gas in the special-shaped flue gas pipelines with flue gas in other special-shaped flue gas pipelines is avoided, the wall temperature of the heat exchange tube of the low-temperature economizer is increased in a partitioning manner, viscous and acidic substances on the tube wall are gasified, dust is loosened, and the dust is discharged out of the low-temperature economizer along with the flue gas. The flow in the special-shaped air pipeline is reduced through the cyclic circulation adjustment, and the wall temperature of the heat exchange pipe of the low-low temperature economizer is improved through the synchronous cyclic circulation in the subareas. When the flow control in a special-shaped air pipeline is smaller, the temperature rise amplitude of the wall of the heat exchange pipe of the low-temperature economizer in the partition corresponding to the concentric ring is larger, the ash removal anticorrosion capacity is stronger, the temperature rise time is longer, and the ash removal anticorrosion effect is more obvious. Of course, the larger the temperature rise amplitude is, the longer the temperature rise time is, and the larger the energy consumption is, and in practical application, the temperature rise amplitude can be selected and the temperature rise time can be determined according to the situation, so that the wall temperature dynamic control of the low-temperature economizer can be realized.
The special-shaped flue gas pipelines can turn in the process of extending to the inlet of the low-temperature economizer, in order to further improve the dust deposition prevention capacity, ash discharge hoppers are arranged at the starting positions of the special-shaped flue gas pipelines after turning, the ash discharge hoppers are in hollow quadrangular frustum structures with large top and small bottom, the upper bottom surfaces and the lower bottom surfaces of the ash discharge hoppers are two rectangles with centers on a vertical line, ash inlets are formed in the upper bottom surfaces and the lower bottom surfaces of the ash discharge hoppers, N-level ash discharge hoppers are correspondingly arranged on the N special-shaped flue gas pipelines, and the ash falling in the ash discharge hopper at the upper level can fall into the ash inlets of the ash discharge hoppers at the lower level from top to bottom.
The ash outlet hopper is in a hollow quadrangular frustum pyramid structure with a big top and a small bottom, namely the area of the ash inlet is larger than that of the ash outlet.
By adopting the technical scheme, after the flue gas enters the different-shape flue gas pipelines from the cold end of the air preheater, when the flue gas turns, part of fly ash particles in the flue gas are separated from the turning flue gas under the action of inertia and gravity of movement, and are discharged out of the flue step by step along the ash discharge hoppers at all stages, so that the deposition of part of fly ash particles in the low-temperature and low-temperature economizer at the downstream is avoided.
In order to improve the ash removal effect, the area of the ash inlet of each level of ash outlet hopper is gradually increased from top to bottom so as to ensure that the ash outlet of the previous level is within the coverage range of the ash inlet of the next level; the falling ash in the ash outlet hopper at the upper stage is communicated to the ash inlet of the ash outlet hopper at the lower stage through a pipeline; the number of the ash discharging hoppers at each level is equal, and 3-6 ash discharging hoppers can be set according to the width of the separation flue.
The low-low temperature economizer pipe box comprises a water outlet header, a pipe assembly and a water inlet header which are sequentially arranged along the flow direction of flue gas; the periphery of the pipe assembly is provided with a pipe box, and the water outlet header and the water inlet header are arranged on the outer side of the pipe box; the pipe assembly comprises more than two rows of serpentine pipe rows which are arranged in parallel along the flow direction of the flue gas, and all the serpentine pipe rows are vertical to the flow direction of the flue gas; each row of serpentine tube bank is composed of more than two serpentine heat exchange tubes, one end of each serpentine heat exchange tube is a water inlet end, the other end of each serpentine heat exchange tube is a water outlet end, the water inlet ends of the serpentine heat exchange tubes penetrate through the tube bank and are communicated with the water inlet header, and the water outlet ends of the serpentine heat exchange tubes penetrate through the tube bank and are communicated with the water outlet header; in order to further improve the heat exchange capacity of the low-temperature economizer, the serpentine tube bank adopts a countercurrent arrangement mode, and the water flow in the serpentine tube is opposite to the smoke flow outside the serpentine tube.
As one of the realization schemes, the serpentine tube bank adopts an integral arrangement mode: several parallel serpentine tube rows are arranged in the tube assembly to fill the heat exchange space.
The adjacent special-shaped flue gas pipelines are separated by a partition plate. In order to further improve the anti-blocking effect, as another implementation scheme, the serpentine tube rows adopt a grouping arrangement mode: a partition plate between adjacent special-shaped flue gas pipelines extends into the pipe box and divides the inside of the pipe box into N sub heat exchange spaces, a group of snake-shaped heat exchange tube rows are arranged in each sub heat exchange space, and each group of snake-shaped heat exchange tube rows comprises more than two rows of snake-shaped tube rows which are arranged in parallel; the water inlet ends of all the snakelike heat exchange tubes penetrate out of the tube box and are communicated with the water inlet header, and the water outlet ends of all the snakelike heat exchange tubes penetrate out of the tube box and are communicated with the water outlet header. Therefore, mixing of high-temperature flue gas and low-temperature flue gas in the pipe box can be avoided, and the anti-blocking effect is better ensured.
In order to further improve the ash removal and corrosion prevention effects, the outer surface of the coiled pipe is provided with H-shaped fins as an expanded heating surface, the height of the fins is preferably 50-100mm, and the distance between the fins is 1/3 of the height of the fins. The technical scheme can effectively reduce the side resistance of the flue gas of the low-temperature economizer, reduce the deposition of fly ash, enhance the ash removal and corrosion prevention effects of the partition cycle temperature rise, and increase the heat exchange area to ensure the heat exchange capability of the low-temperature economizer.
In order to further reduce the continuous abrasion of the fly ash particles in the flue gas to the heat exchange tubes in the low-temperature economizer, a flow equalizing and guiding device can be arranged at the tail end of the separation flue, so that the flow field in the low-temperature economizer is uniform, and the abrasion of local high-speed areas to the heat exchange tubes is avoided.
As a preferred implementation scheme, the special-shaped air pipeline and the special-shaped flue gas pipeline are respectively provided with one end being a fan-shaped opening, the other end is gradually transited to the rectangular opening, the two radial sides of the fan-shaped opening are connected to the side edge of the cold end sector plate in the corresponding concentric ring, and the plane where the fan-shaped opening is located is flush with the sealing surface of the cold end sector plate.
In the technical scheme, when the flow in a certain corresponding special-shaped air pipeline is reduced, the flow of other special-shaped air pipelines is correspondingly increased, the flow in each special-shaped air pipeline is reduced through the circulation of the automatic control system, and the total flow is kept basically unchanged.
In order to improve the sealing performance of the joint of the sector opening and the concentric ring, a T-shaped sealing surface is arranged at the sector opening connected with the arc edge of the concentric ring, a circumferential seal is arranged on the circumferential partition plate, and the circumferential seal is clamped at the end part of the circumferential partition plate through bolts.
The prior art is referred to in the art for techniques not mentioned in the present invention.
The low-temperature economizer mounting structure with the dynamically adjustable rear end wall temperature of the air preheater can well solve the problems of dust accumulation, abrasion, heat exchange tube leakage and the like on the heating surface of the traditional low-temperature economizer, and has the advantages of reasonable arrangement, high heat exchange efficiency and the like, and the engineering economic value is obvious.
Drawings
Fig. 1 is a schematic sectional view of an elevation of a low-temperature economizer mounting structure with dynamically adjustable rear end wall temperature of an air preheater in embodiment 4 of the invention (a heat exchange tube bank is integrally arranged).
Fig. 2 is a schematic sectional view of an elevation of a low-temperature economizer mounting structure with dynamically adjustable rear end wall temperature of an air preheater in embodiment 5 of the invention (heat exchange tube rows are arranged in groups).
Fig. 3 is a view from direction a in fig. 1 (illustrating structural features of a cold end face of a rotor of the rotary air preheater).
Fig. 4 is a structural feature of the end faces of the cold ends of the flue gas side and the air side of the rotor of the rotary air preheater.
Fig. 5 is a schematic view of a T-shaped sealing structure.
FIG. 6 is a view along the direction B in FIG. 1, and shows the structural features of the ash discharge hopper at each stage of the divided flue.
In the figure, 0 is a rotary air preheater rotor, 1 is a circumferential partition plate, 2 is an air side fan-shaped port, 3 is a flue gas side fan-shaped port, 4 is a circumferential seal, 5 is a T-shaped seal surface, 6 is a special-shaped flue gas pipeline, 7 is an ash discharge hopper, 8 is a flow guide device, 9 is a low-low temperature economizer pipe box, 10 is a water inlet header, 11 is a serpentine pipe row, 12 is an H-shaped fin, 13 is a water outlet header, 14 is a flue gas flow direction, and 15 is an air flow direction.
Detailed Description
Example 1
As shown in fig. 1, a low-temperature economizer mounting structure with dynamically adjustable temperature at the rear end wall of an air preheater takes a horizontal arrangement mode of a low-temperature economizer from an outlet of the air preheater to an inlet pipe section of a dust remover as an example, as shown in fig. 3, the end face of a cold end of a rotor of the air preheater is divided into 3 concentric rings (proved by practice, 5 or the number of the concentric rings can be adopted); as shown in fig. 1, 3 special-shaped air pipelines respectively butted with 3 concentric rings are arranged on the air side of the cold end surface of the air preheater rotor, and 3 special-shaped flue gas pipelines respectively butted with 3 concentric rings are arranged on the flue gas side of the cold end surface of the air preheater rotor; 3 special-shaped flue gas pipelines respectively extend to the inlets of the low-temperature economizers; the flow in a special-shaped air pipeline is reduced, the heat exchange quantity of the heat storage element in the corresponding concentric ring is reduced, the heat release quantity of the flue gas flowing through the concentric ring is reduced, the temperature of the flue gas in the special-shaped flue gas pipeline on the flue gas side of the concentric ring is increased, the flue gas flows into the low-temperature economizer to raise the wall temperature of the corresponding subarea, so that the adhered condensed or crystallized substances are gasified, the flue gas is discharged out of the low-temperature economizer, the flow in each special-shaped air pipeline is reduced in a round-robin manner, and the dynamic subarea temperature adjustment of the low-temperature economizer is realized.
According to practice, when the flow in a special-shaped air pipeline is adjusted and reduced, the temperature of the smoke in the special-shaped smoke pipeline corresponding to the smoke side of the concentric ring where the pipeline is located rises. The N special-shaped flue gas pipelines respectively extend to the inlet of the low-temperature economizer, so that the mixing of flue gas in the special-shaped flue gas pipelines with flue gas in other special-shaped flue gas pipelines is avoided, the wall temperature of the heat exchange tube of the low-temperature economizer is increased in a partitioning manner, viscous and acidic substances on the tube wall are gasified, dust is loosened, and the dust is discharged out of the low-temperature economizer along with the flue gas. The flow in the special-shaped air pipeline is reduced through the cyclic circulation adjustment, and the wall temperature of the heat exchange pipe of the low-low temperature economizer is improved through the synchronous cyclic circulation in the subareas. When the flow control in a special-shaped air pipeline is smaller, the temperature rise amplitude of the wall of the heat exchange pipe of the low-temperature economizer in the partition corresponding to the concentric ring is larger, the ash removal anticorrosion capacity is stronger, the temperature rise time is longer, and the ash removal anticorrosion effect is more obvious. Of course, the larger the temperature rise amplitude is, the longer the temperature rise time is, and the larger the energy consumption is, and in practical application, the temperature rise amplitude can be selected and the temperature rise time can be determined according to the situation, so that the wall temperature dynamic control of the low-temperature economizer can be realized.
Example 2
On the basis of the embodiment 1, the following improvements are further made: the special-shaped flue gas pipeline can turn in the process of extending to the inlet of the low-temperature economizer, as shown in figure 1, after turning, the special-shaped flue gas pipeline horizontally extends to the inlet of the low-temperature economizer so as to further improve the dust deposition prevention capability, as shown in figures 1 and 6, the ash discharge hopper is in a hollow quadrangular frustum pyramid structure with a large upper part and a small lower part, the upper bottom surface and the lower bottom surface of the ash discharge hopper are two rectangles with centers on a vertical line, the upper bottom surface is an ash inlet, the lower bottom surface is an ash outlet, 3 special-shaped flue gas pipelines are correspondingly provided with 3 stages of ash discharge hoppers, and from top to bottom, the ash falling in the ash discharge hopper at the upper stage can fall into the ash inlet of the ash discharge hopper at the lower stage.
By adopting the technical scheme, after the flue gas enters the different-shape flue gas pipelines from the cold end of the air preheater, when the flue gas turns, partial fly ash particles in the flue gas are separated from the turning flue gas under the action of inertia and gravity of movement, and are discharged out of the flue step by step along the ash discharge hoppers at all stages, so that the deposition of partial fly ash particles in the low-temperature economizer at the downstream is avoided.
Example 3
On the basis of the embodiment 2, the following improvements are further made: in order to improve the ash removal effect, as shown in fig. 1 and 6, the areas of the ash inlets of the ash hoppers at all levels are gradually increased from top to bottom so as to ensure that the ash outlet at the previous level is within the coverage range of the ash inlet at the next level; the falling ash in the ash outlet hopper at the upper stage is communicated to the ash inlet of the ash outlet hopper at the lower stage through a pipeline; the number of the ash discharging hoppers at each stage is equal to 3 (proved by practice, 4 or 6 ash discharging hoppers can be used, and the like, so that the ash falling energy can be basically and completely output).
Example 4
On the basis of the embodiment 2 or 3, the following improvements are further made: as shown in fig. 1, the low-temperature economizer header comprises a water outlet header, a pipe assembly and a water inlet header which are sequentially arranged along the flow direction of flue gas; the periphery of the pipe assembly is provided with a pipe box, and the water outlet header and the water inlet header are arranged on the outer side of the pipe box; the pipe assembly comprises more than two rows of serpentine pipe rows which are arranged in parallel along the flow direction of the flue gas, and all the serpentine pipe rows are vertical to the flow direction of the flue gas; each row of serpentine tube bank is composed of more than two serpentine heat exchange tubes, one end of each serpentine heat exchange tube is a water inlet end, the other end of each serpentine heat exchange tube is a water outlet end, the water inlet ends of the serpentine heat exchange tubes penetrate through the tube bank and are communicated with the water inlet header, and the water outlet ends of the serpentine heat exchange tubes penetrate through the tube bank and are communicated with the water outlet header; in order to further improve the heat exchange capacity of the low-temperature and low-temperature economizer, the coiled tube bank adopts a countercurrent arrangement mode, and the flow direction of water in the coiled tube is opposite to the flow direction of smoke outside the coiled tube. As shown in fig. 1, the serpentine tube rows are integrally arranged: several parallel serpentine tube rows are arranged in the tube assembly to fill the heat exchange space.
Example 5
The difference from example 4 is: in order to further improve the anti-blocking effect, as shown in fig. 2, the serpentine tube rows are arranged in groups: a partition plate between adjacent special-shaped flue gas pipelines extends into the pipe box and divides the inside of the pipe box into 3 sub-heat exchange spaces, each sub-heat exchange space is internally provided with a group of snakelike heat exchange pipe rows, and each group of snakelike heat exchange pipe rows comprises more than two snakelike pipe rows which are arranged in parallel; the water inlet ends of all the snakelike heat exchange tubes penetrate out of the tube box and are communicated with the water inlet header, and the water outlet ends of all the snakelike heat exchange tubes penetrate out of the tube box and are communicated with the water outlet header. Therefore, the mixing of high-temperature flue gas and low-temperature flue gas in the pipe box can be avoided, and the anti-blocking effect is better ensured.
Example 6
On the basis of the embodiments 4 and 5, the following improvements are further made: in order to further improve the ash removal and corrosion prevention effects, H-shaped fins are arranged on the outer surface of the coiled pipe and used as an expanded heating surface, the height of each fin is 60mm, and the distance between every two fins is 1/3 of the height of each fin. According to the technical scheme, the smoke side resistance of the low-temperature economizer can be effectively reduced, the fly ash deposition is reduced, the ash removal and corrosion prevention effects of partition circulating temperature rise are enhanced, and meanwhile, the heat exchange area is increased to ensure the heat exchange capability of the low-temperature economizer.
Example 7
On the basis of the embodiment 6, the following improvements are further made: in order to further reduce the continuous abrasion of the fly ash particles in the flue gas to the heat exchange tubes in the low-temperature economizer, a flow equalizing and guiding device can be arranged at the tail end of the separation flue, so that the flow field in the low-temperature economizer is uniform, and the abrasion of local high-speed areas to the heat exchange tubes is avoided.
Example 8
On the basis of the embodiment 7, the following improvements are further made: the special-shaped air pipeline and the special-shaped flue gas pipeline are respectively provided with a fan-shaped opening at one end and a rectangular opening at the other end, the two radial sides of the fan-shaped openings are connected to the side edges of the cold end sector plates in the corresponding concentric rings, and the plane where the fan-shaped openings are located is flush with the sealing surface of the cold end sector plate. In the technical scheme, when the flow in a certain corresponding special-shaped air pipeline is reduced, the flow of other special-shaped air pipelines is correspondingly increased, the flow in each special-shaped air pipeline is reduced through the circulation of the automatic control system, and the total flow is kept basically unchanged. In order to improve the sealing performance of the joint of the sector-shaped opening and the concentric ring, as shown in fig. 4-5, a T-shaped sealing surface is arranged at the sector-shaped opening connected with the arc-shaped edge of the concentric ring, a circumferential seal is arranged on the circumferential partition plate, and the circumferential seal is clamped at the end part of the circumferential partition plate through bolts.
The above-described mounting structure produces the following effects by practice: (1) the air flow in the air preheater is adjusted through the circulation in different zones, the wall temperature of the corresponding heat exchange tube in the low-temperature and low-temperature coal-saving process is increased through the circulation in different zones synchronously, so that the viscosity and the acidic deposited ash adsorbed on the wall temperature are gasified and loosened, the cleaning is easy, and the deposited ash and the low-temperature corrosion are avoided; (2) the special-shaped flue gas pipelines respectively extend to the inlets of the low-temperature and low-temperature economizers, so that the mixing of high-temperature flue gas and low-temperature flue gas in a ring division manner can be avoided, and the effect of improving the wall temperature of the heat exchange tubes of the low-temperature and low-temperature economizers in a partitioning manner is ensured; (3) the special-shaped flue gas pipeline is provided with ash outlets in a grading manner at the turning position, so that fly ash particles can be smoothly discharged out of a flue under the action of inertia and gravity, and the deposition of part of fly ash in a low-low temperature economizer is avoided; (4) the special-shaped flue gas pipeline divides flue gas into a plurality of smaller streams of fluid, and the tail end of the special-shaped flue gas pipeline is provided with the flow guide device, so that better flow field uniformity is obtained, and the abrasion to the heat exchange pipe caused by the non-uniform flow field of the flue gas side is avoided; (5) in the partitioned circulating temperature rise process of the low-low temperature economizer, although the temperature of the condensed water in the corresponding coil pipe rows of the partitions is raised, the condensed water in the pipe rows of the partitions is mixed in the water outlet header, so that the overall water temperature rise amplitude is limited, the overall water temperature fluctuation amplitude is small, and the normal operation of downstream equipment cannot be influenced.

Claims (9)

1. The utility model provides a low temperature economizer mounting structure of air preheater rear end wall temperature developments adjustable which characterized in that: the end face of the cold end of the air preheater rotor is divided into N concentric rings by a circumferential partition plate, wherein N is more than or equal to 2; the air side of the cold end face of the air preheater rotor is provided with N special-shaped air pipelines which are respectively butted with the N concentric rings, and the flue gas side of the cold end face of the air preheater rotor is provided with N special-shaped flue gas pipelines which are respectively butted with the N concentric rings; n special-shaped flue gas pipelines respectively extend to the inlet of the low-temperature economizer; reducing the flow in a special-shaped air pipeline, reducing the heat exchange quantity of a heat storage element in a corresponding concentric ring, reducing the heat release quantity of flue gas flowing through the concentric ring, increasing the temperature of the flue gas in the special-shaped flue gas pipeline at the flue gas side of the concentric ring, flowing into a low-temperature economizer to increase the wall temperature of a corresponding subarea, gradually gasifying the adhered condensed or crystallized substances, discharging the low-temperature economizer along with the flue gas, reducing the flow in each special-shaped air pipeline in turn, and realizing the dynamic subarea temperature adjustment of the low-temperature economizer;
the special-shaped flue gas pipelines extend to the inlet of the low-temperature economizer to turn, ash discharge hoppers are arranged at the starting positions of the special-shaped flue gas pipelines after the special-shaped flue gas pipelines turn, the ash discharge hoppers are in hollow quadrangular frustum pyramid structures with large top and small bottom, the upper bottom surfaces and the lower bottom surfaces of the ash discharge hoppers are two rectangles with centers on a vertical line, the upper bottom surfaces are ash inlets, the lower bottom surfaces are ash outlets, N special-shaped flue gas pipelines are correspondingly provided with N-level ash discharge hoppers, and from top to bottom, ash falling in the ash discharge hoppers at the upper level are communicated with the ash inlets of the ash discharge hoppers at the lower level through pipelines.
2. The air preheater low-temperature and low-temperature economizer mounting structure with dynamically adjustable rear end wall temperature according to claim 1, is characterized in that: from top to bottom, the area of the ash inlet of each level of ash outlet hopper is gradually increased; the number of the ash discharging hoppers at each level is equal and is 3-6.
3. The low-temperature economizer mounting structure with dynamically adjustable wall temperature at the rear end of an air preheater as recited in claim 1 or 2, wherein: the low-low temperature economizer pipe box comprises a water outlet header, a pipe assembly and a water inlet header which are sequentially arranged along the flow direction of flue gas; the periphery of the pipe assembly is provided with a pipe box, and the water outlet header and the water inlet header are arranged on the outer side of the pipe box; the pipe assembly comprises more than two serpentine pipe rows which are arranged in parallel along the flow direction of the flue gas, and all the serpentine pipe rows are vertical to the flow direction of the flue gas; each row of the serpentine heat exchange tubes is composed of more than two serpentine heat exchange tubes, one end of each serpentine heat exchange tube is a water inlet end, the other end of each serpentine heat exchange tube is a water outlet end, the water inlet ends of the serpentine heat exchange tubes penetrate through the tube box to be communicated with the water inlet header, and the water outlet ends of the serpentine heat exchange tubes penetrate through the tube box to be communicated with the water outlet header; the snakelike bank of tubes adopts the mode of arranging against current, and the water flow is to the flue gas flow direction opposite outside the pipe in the snakelike intraductal with.
4. The air preheater low-temperature and low-temperature economizer mounting structure with dynamically adjustable rear end wall temperature according to claim 3, wherein: the serpentine tube bank adopts an integral arrangement mode: several parallel serpentine tube rows are arranged in the tube assembly to fill the heat exchange space.
5. The air preheater low-temperature and low-temperature economizer mounting structure with dynamically adjustable rear end wall temperature according to claim 3, wherein: the serpentine tube rows are arranged in groups: the adjacent special-shaped flue gas pipelines are separated by partition plates, the partition plates between the adjacent special-shaped flue gas pipelines extend into the pipe box and divide the inside of the pipe box into N sub-heat exchange spaces, each sub-heat exchange space is internally provided with a group of snakelike heat exchange pipe rows, and each group of snakelike heat exchange pipe rows comprises more than two snakelike pipe rows which are arranged in parallel; the water inlet ends of all the snakelike heat exchange tubes penetrate out of the tube box and are communicated with the water inlet header, and the water outlet ends of all the snakelike heat exchange tubes penetrate out of the tube box and are communicated with the water outlet header.
6. The air preheater low-temperature and low-temperature economizer mounting structure with dynamically adjustable rear end wall temperature according to claim 3, wherein: the outer surface of the coiled pipe is provided with H-shaped fins, the height of the fins is 50-100mm, and the distance between the fins is 1/3 of the height of the fins.
7. The low-low temperature economizer mounting structure with dynamically adjustable air preheater rear end wall temperature according to claim 1 or 2, characterized in that: the tail end of the separation flue is provided with a flow equalizing and guiding device.
8. The low-temperature economizer mounting structure with dynamically adjustable wall temperature at the rear end of an air preheater as recited in claim 1 or 2, wherein: the equal one end of dysmorphism air conduit and dysmorphism flue gas pipeline is fan-shaped mouthful, and the other end passes through gradually to the rectangle mouth, and the radial limit in both sides of fan-shaped mouthful is connected at the cold junction sector plate side that corresponds the concentric ring intra-annular, and the plane that the fan-shaped mouthful is located flushes with the sealed face of cold junction sector plate.
9. The low-low temperature economizer mounting structure of air preheater rear end wall temperature developments adjustable of claim 8, characterized in that: keeping the total flow of air unchanged, and reducing the flow in each different air pipeline in a round inspection mode; the sector department that meets with the arc limit of concentric ring is provided with the sealed face of T type to set up the circumference seal on the just right circumference baffle of the sealed face of T type, the circumference seal passes through the bolt clamping at circumference baffle tip.
CN202210717701.1A 2022-06-20 2022-06-20 Low low-temperature economizer mounting structure of dynamic adjustable of wall temperature in air preheater rear end Active CN115095854B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210717701.1A CN115095854B (en) 2022-06-20 2022-06-20 Low low-temperature economizer mounting structure of dynamic adjustable of wall temperature in air preheater rear end

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210717701.1A CN115095854B (en) 2022-06-20 2022-06-20 Low low-temperature economizer mounting structure of dynamic adjustable of wall temperature in air preheater rear end

Publications (2)

Publication Number Publication Date
CN115095854A CN115095854A (en) 2022-09-23
CN115095854B true CN115095854B (en) 2023-04-14

Family

ID=83293757

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210717701.1A Active CN115095854B (en) 2022-06-20 2022-06-20 Low low-temperature economizer mounting structure of dynamic adjustable of wall temperature in air preheater rear end

Country Status (1)

Country Link
CN (1) CN115095854B (en)

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009079840A (en) * 2007-09-26 2009-04-16 Babcock Hitachi Kk Boiler device
CN203598607U (en) * 2013-10-25 2014-05-21 福建鑫泽环保设备工程有限公司 Flue-gas denitrifying and pre-dedusting device
CN205079216U (en) * 2015-10-28 2016-03-09 江苏中科重工股份有限公司 Fin economizer
CN108224459A (en) * 2017-11-30 2018-06-29 江苏理文造纸有限公司 A kind of boiler smoke heat energy recovering method
CN113819775A (en) * 2021-08-30 2021-12-21 浙江兴核智拓科技有限公司 Rotary heat exchanger anti-blocking system and anti-blocking method based on circulating temperature rise of circulating wheel
CN113958964B (en) * 2021-11-10 2022-12-20 浙江兴核智拓科技有限公司 Low-temperature economizer with dynamically adjustable downstream wall temperature of rotary air preheater

Also Published As

Publication number Publication date
CN115095854A (en) 2022-09-23

Similar Documents

Publication Publication Date Title
CN113958964B (en) Low-temperature economizer with dynamically adjustable downstream wall temperature of rotary air preheater
CN111306567A (en) Hot air positive pressure blowing system for inhibiting blockage of air preheater and working method thereof
CN105737182A (en) Smoke in-depth cooler
CN115095854B (en) Low low-temperature economizer mounting structure of dynamic adjustable of wall temperature in air preheater rear end
CN210740368U (en) Economizer with water conservancy diversion structure
CN216081103U (en) Heat pipe type heat exchanger
CN203432434U (en) Band fin cast plate-type air pre-heater
CN213930895U (en) Re-flow economizer device
CN213778733U (en) Heat pipe low-temperature economizer
CN201402078Y (en) Flue gas-flue gas heat exchanging device for flue gas desulfurization during heat power generation
CN212456948U (en) Hot air positive pressure purging system for inhibiting blockage of air preheater
CN212456949U (en) Separation type air preheating system for preventing ABS (anti-lock brake System) of air preheater from being blocked
CN109813143B (en) Heat exchanger for flue gas waste heat utilization
CN206974246U (en) A kind of tubular heat exchange device
CN217356853U (en) Low-resistance high-efficiency coal economizer
CN212456918U (en) Low-temperature economizer flue device
CN112611232B (en) Multi-channel structure for preventing dust deposition of tail flue of industrial pulverized coal furnace
CN219318411U (en) Radial heat pipe low-temperature economizer system
CN214949072U (en) Waste incineration exhaust-heat boiler
CN110285401B (en) Pure combustion furfural residue CFB boiler
CN110715557A (en) Furnace flue gas waste heat recovery heat exchanger
CN113566618B (en) Energy-saving type axial space-changing flue gas condenser
CN212408617U (en) Low-low-temperature economizer capable of dredging deposited ash
CN218380528U (en) Cement manufacture line kiln hood waste heat system of recycling
CN218443486U (en) Magnesium slag waste heat utilization device

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