Low-position heat pipe air preheater of biomass circulating fluidized bed boiler with V-shaped structure

Abstract

The utility model belongs to the technical field of energy-saving and consumption-reducing equipment of a biomass power plant, and particularly relates to a low-position heat pipe air preheater of a biomass circulating fluidized bed boiler with a V-shaped structure. The flue gas channel, the primary air channel and the secondary air channel are reasonably arranged, and the primary air heat pipe heat transfer elements and the secondary air heat pipe heat transfer elements are staggered in the V-shaped structure in the air preheater tube box, so that the arrangement space of the air preheater can be obviously reduced, and the cost of consumables is saved; heat of high-temperature flue gas is transmitted to cold air through media in the heat pipe heat transfer elements, air preheating efficiency can be effectively improved, corrosion and ash deposition caused by low-position arrangement of the low-temperature air preheater can be prevented, the service life of the air preheater is prolonged, and economical efficiency of a biomass power plant is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy-saving and consumption-reducing equipment for biomass power plants, and particularly relates to a low-position heat pipe air preheater for a V-type biomass circulating fluidized bed boiler. Background Art

[0002] In recent years, in order to improve the thermal efficiency of the boiler, horizontal tubular air preheaters are usually arranged at the low-temperature stage of the flue gas duct at the tail of the biomass circulating fluidized bed boiler. However, since the moisture content of the biomass fuel fed into the furnace is generally relatively high, and at the same time, the low-temperature corrosion and ash accumulation of chlorine ions in the biomass fuel need to be considered, the flue gas temperature of the biomass circulating fluidized bed boiler is often relatively high, usually above 160°C, which affects the overall economy of the biomass power plant.

[0003] In order to improve the overall power generation efficiency of the biomass power plant, the low-temperature stage air preheater of the existing biomass circulating fluidized bed boiler has gradually been changed to a heat pipe type air preheater. However, according to relevant public literature, in the actually operating biomass circulating fluidized bed boiler, the primary and secondary air preheater tube boxes of the newly built heat pipe type air preheater are usually arranged in an upper and lower level. This structure will significantly increase the layout space of the air preheater, increase the overall height of the newly built boiler, thereby increasing the construction cost of the boiler and the difficulty of retrofit layout, and thus affecting the economy of the retrofit. Content of the Utility Model

[0004] The technical problem to be solved by the utility model is: aiming at the deficiencies of the prior art, to provide a low-position heat pipe air preheater for a V-type biomass circulating fluidized bed boiler, the overall structure of which is compact, saves layout space, can effectively improve the air preheating efficiency, and can extend the service life of the air preheater.

[0005] The technical solution adopted by the utility model to solve the above technical problem is:

[0006] A low-position heat pipe air preheater for a V-type biomass circulating fluidized bed boiler, comprising an air preheater tube box 2. A flue gas passage is arranged in the middle of the air preheater tube box 2, and a primary air passage and a secondary air passage are respectively arranged at both ends. A primary heat pipe heat transfer element 24 is arranged between the flue gas passage and the primary air passage, and a secondary heat pipe heat transfer element 27 is arranged between the flue gas passage and the secondary air passage. The primary heat pipe heat transfer element 24 and the secondary heat pipe heat transfer element 27 are arranged in a V-shaped staggered manner in the air preheater tube box 2;

[0007] The top and bottom of the flue gas passage are respectively provided with a flue gas inlet 1 and a flue gas outlet 3. The two sides of the primary air passage are respectively provided with a primary air inlet 4 and a primary air outlet 7. The two sides of the secondary air passage are respectively provided with a secondary air inlet 5 and a secondary air outlet 6. A header support frame 8 is provided at the bottom of the air preheater header 2.

[0008] Furthermore, the primary air heat pipe heat transfer element 24 includes a first heat transfer element base pipe, a first flue gas passage spiral fin, and a first air passage spiral fin. The first flue gas passage spiral fin is located in the flue gas passage, and the first air passage spiral fin is located in the primary air passage.

[0009] Furthermore, the secondary air heat pipe heat transfer element 27 includes a second heat transfer element base pipe, a second flue gas passage spiral fin, and a second air passage spiral fin. The second flue gas passage spiral fin is located in the flue gas passage, and the second air passage spiral fin is located in the secondary air passage.

[0010] Furthermore, the primary air heat pipe heat transfer element 24 and the secondary air heat pipe heat transfer element 27 are symmetrically arranged at an angle of 5-8° with respect to the horizontal line, and the first air passage spiral fin and the second air passage spiral fin are arranged in a V-shaped staggered manner.

[0011] Furthermore, an outer cover plate 21 of the primary air passage, an upper baffle 23 of the primary air, and a lower baffle 213 of the primary air are respectively provided on the outside, top, and bottom of the primary air passage, and a support plate 22 of the primary air passage is provided in the middle of the primary air passage.

[0012] Furthermore, an outer cover plate 211 of the secondary air passage, an upper baffle 29 of the secondary air, and a lower baffle 212 of the secondary air are respectively provided on the outside, top, and bottom of the secondary air passage, and a support plate 210 of the secondary air passage is provided in the middle of the secondary air passage.

[0013] Furthermore, an intermediate support plate 26 of the flue gas passage is provided in the middle of the flue gas passage.

[0014] Furthermore, a first channel partition plate 25 is provided between the primary air passage and the flue gas passage, and a through hole one for the primary air heat pipe heat transfer element 24 to pass through is reserved on the first partition plate 25.

[0015] Furthermore, a second channel partition plate 28 is provided between the secondary air passage and the flue gas passage, and a through hole two for the secondary air heat pipe heat transfer element 27 to pass through is reserved on the second partition plate 28.

[0016] The present utility model has the following main advantages compared with the prior art:

[0017] 1. The utility model provides a low - position heat pipe air pre - heater for a V - type biomass circulating fluidized bed boiler. Through the reasonable arrangement of the flue gas channel, primary air channel, and secondary air channel, and the V - type staggered arrangement of the primary air heat pipe heat transfer elements and secondary air heat pipe heat transfer elements in the air pre - heater tube box, the layout space of the air pre - heater can be significantly reduced, and the cost of consumables can be saved;

[0018] 2. The utility model transforms the existing horizontal tube - type air pre - heater for primary and secondary air arranged vertically at the low - temperature stage of the biomass circulating fluidized bed boiler into a single tube - box structure with the primary air heat pipe heat transfer elements and secondary air heat pipe heat transfer elements staggered in a V - type structure. The heat of the high - temperature flue gas is transferred to the cold air through the medium in the heat pipe heat transfer elements, which can effectively improve the air pre - heating efficiency and prevent the corrosion and ash accumulation phenomena caused by the low - position arrangement of the low - temperature stage air pre - heater, thereby prolonging the service life of the air pre - heater and improving the economy of the biomass power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a front - end view schematic diagram of the air pre - heater in the embodiment of the utility model;

[0020] Figure 2 It is a top - view schematic diagram of the air pre - heater in the embodiment of the utility model;

[0021] Figure 3 It is a cross - sectional schematic diagram of the air pre - heater tube box in the embodiment of the utility model.

[0022] In the figure: 1. Flue gas inlet; 2. Air pre - heater tube box; 21. Outer cover plate of primary air channel; 22. Support plate of primary air channel; 23. Upper baffle of primary air; 24. Primary air heat pipe heat transfer element; 25. First channel partition plate; 26. Intermediate support plate of flue gas channel; 27. Secondary air heat pipe heat transfer element; 28. Second channel partition plate; 29. Upper baffle of secondary air; 210. Support plate of secondary air channel; 211. Outer cover plate of secondary air channel; 212. Lower baffle of secondary air; 213. Lower baffle of primary air; 3. Flue gas outlet; 4. Primary air inlet; 5. Secondary air inlet; 6. Secondary air outlet; 7. Primary air outlet; 8. Tube box support frame. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to make the purpose, technical solutions and advantages of the utility model more clear and understandable, the following further details the utility model in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model. In addition, the technical features involved in the various embodiments of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0024] It should be noted that according to the implementation requirements, each step / component described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present utility model.

[0025] Embodiment 1. This embodiment provides a low-temperature heat pipe air preheater for a V-type biomass circulating fluidized bed boiler. As Figures 1 to 3 shown, it includes an air preheater tube box 2. A flue gas passage is provided in the middle of the air preheater tube box 2, and a primary air passage and a secondary air passage are respectively provided at both ends. A primary heat pipe heat transfer element 24 is provided between the flue gas passage and the primary air passage, and a secondary heat pipe heat transfer element 27 is provided between the flue gas passage and the secondary air passage. The primary heat pipe heat transfer element 24 and the secondary heat pipe heat transfer element 27 are arranged in a V-shaped staggered manner in the air preheater tube box 2;

[0026] A flue gas inlet 1 and a flue gas outlet 3 are respectively provided at the top and bottom of the flue gas passage. A primary air inlet 4 and a primary air outlet 7 are respectively provided on both sides of the primary air passage. A secondary air inlet 5 and a secondary air outlet 6 are respectively provided on both sides of the secondary air passage. A tube box support frame 8 is provided at the bottom of the air preheater tube box 2.

[0027] Further, the primary heat pipe heat transfer element 24 includes a first heat transfer element base tube, a first flue gas passage spiral fin, and a first air passage spiral fin. The first flue gas passage spiral fin is located in the flue gas passage, and the first air passage spiral fin is located in the primary air passage.

[0028] Further, the secondary heat pipe heat transfer element 27 includes a second heat transfer element base tube, a second flue gas passage spiral fin, and a second air passage spiral fin. The second flue gas passage spiral fin is located in the flue gas passage, and the second air passage spiral fin is located in the secondary air passage.

[0029] Further, the primary heat pipe heat transfer element 24 and the secondary heat pipe heat transfer element 27 are symmetrically arranged at an angle of 5-8° with respect to the horizontal line, and the first air passage spiral fin and the second air passage spiral fin are arranged in a V-shaped staggered manner.

[0030] Further, an outer cover plate 21 of the primary air passage, an upper baffle 23 of the primary air, and a lower baffle 213 of the primary air are respectively provided on the outside, top, and bottom of the primary air passage. A support plate 22 of the primary air passage is provided in the middle of the primary air passage.

[0031] Further, an outer cover plate 211 of the secondary air passage, an upper baffle 29 of the secondary air, and a lower baffle 212 of the secondary air are respectively provided on the outside, top, and bottom of the secondary air passage. A support plate 210 of the secondary air passage is provided in the middle of the secondary air passage.

[0032] Further, a middle support plate 26 of the flue gas passage is provided in the middle of the flue gas passage.

[0033] Further, a first channel partition plate 25 is provided between the primary air passage and the flue gas passage, and a through hole one for the primary air heat pipe heat transfer element 24 to pass through is reserved on the first partition plate 25.

[0034] Further, a second channel partition plate 28 is provided between the secondary air passage and the flue gas passage, and a through hole two for the secondary air heat pipe heat transfer element 27 to pass through is reserved on the second partition plate 28.

[0035] Embodiment 2. A low-temperature heat pipe air preheater for a V-type biomass circulating fluidized bed boiler provided in this embodiment. In a newly built biomass circulating fluidized bed boiler, the primary air heat pipe heat transfer element and the secondary air heat pipe heat transfer element are arranged in a staggered V-type structure for the heat pipe air preheater. This structure will significantly reduce the layout space of the air preheater, and can reduce the overall height of a newly built biomass circulating fluidized bed boiler with an evaporation capacity of 130 tons per hour by 3 - 4 m, thereby reducing more than 100 tons of boiler metal;

[0036] At the same time, based on the existing biomass circulating fluidized bed boiler, by transforming the primary and secondary air horizontal tubular air preheaters arranged vertically and horizontally at the low-temperature stage into a single tube box with the primary air heat pipe heat transfer element and the secondary air heat pipe heat transfer element arranged in a staggered V-type structure, the flue gas temperature of the boiler can be reached, preventing low-temperature corrosion and ash accumulation of the low-temperature stage air preheater, thereby improving the service life of the boiler and the economy of the biomass power plant.

[0037] The main components of this embodiment include: a flue gas inlet, a heat pipe air preheater tube box, a flue gas outlet, a primary air inlet, a secondary air inlet, a secondary air outlet, a primary air outlet, and a tube box support frame, etc. The heat pipe air preheater tube box is provided with a primary air heat pipe heat transfer element and a secondary air heat pipe heat transfer element. The heat transfer elements are arranged at an angle of 5 - 8° with the horizontal line. The primary air heat pipe heat transfer element and the secondary air heat pipe heat transfer element are arranged in a staggered V-type structure; one ends of the primary and secondary air heat pipe heat transfer elements are arranged in the flue gas passage, and the other ends are arranged in the primary and secondary air passages, with a partition in the middle.

[0038] Among them, the flue gas inlet is the flue gas inlet of the air preheater of the biomass circulating fluidized bed boiler, where the flue gas temperature is high;

[0039] Further, the upper part of the flue gas inlet can be connected to the outlet of the economizer of the circulating fluidized bed boiler or the outlet of the upper-stage air preheater, and the upper part can be connected to the heat pipe air preheater tube box;

[0040] Furthermore, the heat pipe type air preheater pipe box comprises: a primary air channel outer cover plate, a primary air channel support plate, a primary air upper baffle plate, a primary air heat pipe heat transfer element, a primary air channel and a smoke channel separator plate, a smoke channel middle support plate, a secondary air heat pipe heat transfer element, a secondary air channel and a smoke channel separator plate, a secondary air upper baffle plate, a secondary air channel support plate, a secondary air channel outer cover plate, a secondary air lower baffle plate, and a primary air lower baffle plate;

[0041] Furthermore, the primary air upper baffle, the secondary air upper baffle, the secondary air lower baffle, and the primary air lower baffle should be a plurality of heterogeneous baffles;

[0042] Furthermore, the heat transfer elements of the primary and secondary air heat pipes include a heat transfer element base pipe, spiral fins for smoke channels, spiral fins for air channels, and sealing accessories for the heat transfer element base pipe;

[0043] Furthermore, the primary and secondary air heat transfer elements are arranged at an angle of 5 to 8 degrees to the horizontal line and staggered to form a V-shaped structure, so that the smoke flows in a horizontal direction;

[0044] Furthermore, the lower ends of the heat transfer elements of the primary and secondary air heat pipes are arranged in the smoke channel, and the smoke flushes the heat transfer elements horizontally; the other ends are arranged in the primary and secondary air channels, and the air flushes the heat transfer elements horizontally, and a partition is separated in the middle;

[0045] Furthermore, the base tube of the heat transfer element is filled with an organic or inorganic heat transfer medium. After being heated in the smoke channel, the heat transfer medium flows upward to transfer the heat to the air in the air channel. After completing the heat transfer, the heat transfer medium flows downward back to the smoke channel side to form a heat circulation transfer.

[0046] Furthermore, one end of the side of the heat pipe air preheater tube box is connected to the primary air cold end inlet, and the corresponding end is connected to the primary air hot end outlet;

[0047] Furthermore, one end of the other side of the heat pipe air preheater tube box is connected to the secondary air cold end inlet, and the corresponding end is connected to the secondary air hot end outlet;

[0048] Furthermore, the heat pipe air preheater has a pipe box support frame at the bottom of the pipe box to support all the weight, and the total weight finally falls on the steel structure of the boiler;

[0049] Furthermore, the pipe box support frame supports and connects to the smoke outlet, where the smoke temperature is low.

[0050] When used specifically:

[0051] Flue gas at a relatively high temperature enters the flue passage composed of the heat absorption sections of the primary air heat transfer element 24 and the secondary air heat transfer element 27 simultaneously through the flue gas inlet 1, and transversely scours the heat transfer elements. The heat transfer medium in the heat transfer elements flows upward to transfer the heat in the flue gas to the primary and secondary cold air arranged in the air passage. After the temperature of the flue gas decreases, it enters the flue gas dust removal system at the tail of the boiler through the flue gas outlet 3; while the cold air enters the heat insulation sections of the primary air heat transfer element 24 and the heat release sections of the secondary air heat transfer element 27 in the air passage from the primary air inlet 4 and the secondary air inlet 5 respectively; after the air temperature rises, it enters the upper-stage air preheater of the boiler through the primary and secondary air outlets.

[0052] Furthermore, the parts not described in detail in this application are the same as the prior art or are implemented using the prior art.

[0053] To sum up:

[0054] 1. The present utility model provides a low-temperature heat pipe air preheater for a V-shaped biomass circulating fluidized bed boiler. Through the reasonable setting of the flue gas passage, the primary air passage, and the secondary air passage, and the V-shaped staggered arrangement of the primary air heat pipe heat transfer element and the secondary air heat pipe heat transfer element in the air preheater tube bank, the layout space of the air preheater can be significantly reduced, and the cost of consumables can be saved;

[0055] 2. The present utility model transforms the primary and secondary air horizontal tube air preheaters arranged vertically and horizontally at the low-temperature stage of the prior art biomass circulating fluidized bed boiler into a single tube bank structure with a V-shaped staggered arrangement of the primary air heat pipe heat transfer element and the secondary air heat pipe heat transfer element. The heat of the high-temperature flue gas is transferred to the cold air through the medium in the heat pipe heat transfer element, which can effectively improve the air preheating efficiency, and can prevent the corrosion and ash accumulation phenomena caused by the low-position arrangement of the low-temperature stage air preheater, thereby prolonging the service life of the air preheater and improving the economy of the biomass power plant.

[0056] The above embodiments are only used to illustrate the design concept and characteristics of the present utility model, and the purpose is to enable those skilled in the art to understand the content of the present utility model and implement it accordingly. The protection scope of the present utility model is not limited to the above embodiments. Therefore, all equivalent changes or modifications made according to the principles and design ideas disclosed by the present utility model are within the protection scope of the present utility model.

Claims

1. A low-level heat pipe air preheater for a biomass circulating fluidized bed boiler with a V-shaped structure, characterized in that: The air preheater comprises an air preheater pipe box (2), wherein a smoke channel is provided in the middle of the air preheater pipe box (2) and primary air channels and secondary air channels are provided at both ends respectively, a primary air heat pipe heat transfer element (24) is provided between the smoke channel and the primary air channel, a secondary air heat pipe heat transfer element (27) is provided between the smoke channel and the secondary air channel, and the primary air heat pipe heat transfer element (24) and the secondary air heat pipe heat transfer element (27) are arranged in a V-shaped staggered manner in the air preheater pipe box (2); The top and bottom of the smoke channel are respectively provided with a smoke inlet (1) and a smoke outlet (3); the two sides of the primary air channel are respectively provided with a primary air inlet (4) and a primary air outlet (7); the two sides of the secondary air channel are respectively provided with a secondary air inlet (5) and a secondary air outlet (6); and the bottom of the air preheater pipe box (2) is provided with a pipe box support frame (8).

2. The V-shaped biomass circulating fluidized bed boiler low-level heat pipe air preheater according to claim 1, characterized in that: The primary air heat pipe heat transfer element (24) comprises a heat transfer element base tube 1, a smoke channel spiral fin 1 and an air channel spiral fin 1, wherein the smoke channel spiral fin 1 is located in the smoke channel, and the air channel spiral fin 1 is located in the primary air channel.

3. The V-shaped biomass circulating fluidized bed boiler low-level heat pipe air preheater according to claim 2, characterized in that: The secondary air heat pipe heat transfer element (27) comprises a second heat transfer element base tube, a second smoke channel spiral fin and a second air channel spiral fin. The second smoke channel spiral fin is located in the smoke channel, and the second air channel spiral fin is located in the secondary air channel.

4. The V-shaped biomass circulating fluidized bed boiler low-level heat pipe air preheater according to claim 3, characterized in that: The primary air heat pipe heat transfer element (24) and the secondary air heat pipe heat transfer element (27) are symmetrically arranged at an angle of 5 to 8 degrees with the horizontal line, and the air channel spiral fins 1 and 2 are arranged in a V-shaped staggered manner.

5. The V-shaped biomass circulating fluidized bed boiler low-level heat pipe air preheater according to claim 1, characterized in that: A primary air channel outer cover plate (21), a primary air upper baffle plate (23), and a primary air lower baffle plate (213) are respectively provided on the outside, top, and bottom of the primary air channel, and a primary air channel support plate (22) is provided in the middle of the primary air channel.

6. The V-shaped biomass circulating fluidized bed boiler low-level heat pipe air preheater according to claim 1, characterized in that: The outer side, top and bottom of the secondary air channel are respectively provided with a secondary air channel outer cover plate (211), a secondary air upper baffle plate (29) and a secondary air lower baffle plate (212), and the middle part of the secondary air channel is provided with a secondary air channel support plate (210).

7. The V-shaped biomass circulating fluidized bed boiler low-level heat pipe air preheater according to claim 1, characterized in that: A smoke channel middle support plate (26) is provided in the middle of the smoke channel.

8. The V-shaped biomass circulating fluidized bed boiler low-level heat pipe air preheater according to claim 1, characterized in that: A channel partition plate (25) is provided between the primary air channel and the smoke channel, and a through hole (24) is reserved on the partition plate (25) for the primary air heat pipe heat transfer element (24) to pass through.

9. The V-shaped biomass circulating fluidized bed boiler low-level heat pipe air preheater according to claim 1, characterized in that: A second channel partition plate (28) is provided between the secondary air channel and the smoke channel, and a second through hole (28) is reserved on the second partition plate (28) for the secondary air heat pipe heat transfer element (27) to pass through.

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