CN202253608U - Circulating fluidized bed boiler water wall air film wear proof device and boiler - Google Patents

Abstract

The utility model discloses a circulating fluidized bed boiler water wall air film wear proof device and use this wear proof device's boiler, make the trompil on the fin between circulating fluidized bed boiler furnace's water wall pipe, thereby introduce the wind in the furnace from the outside bellows of furnace through connecting tube and produce the air film, this air film can destroy the wainscot flow that the bed material granule formed that descends, the flow direction of wainscot flow has been changed, reduce the velocity of flow and the concentration of descending granule simultaneously, thereby alleviate the erosive wear to the water wall pipe. And moreover, the water wall air film anti-abrasion device can be adjusted under the condition that the normal operation of the boiler is not influenced. And the formed gas film enables the area in the hearth to be in an oxidizing atmosphere, so that the corrosion of the water wall tubes can be prevented, and meanwhile, oxygen required by boiler combustion is fed into the boiler through different parts, so that staged combustion is realized, and the pollutant emission can be effectively reduced.

Description

Air film anti-wear device and boiler for water wall of circulating fluidized bed boiler

technical field

The utility model relates to a circulating fluidized bed boiler, in particular to a circulating fluidized bed boiler water cooling wall air film anti-wear device and a boiler.

Background technique

Circulating fluidized bed combustion technology is a clean coal combustion technology with a relatively high degree of marketization. Circulating fluidized bed boilers have been recognized at home and abroad for their advantages such as high efficiency, low pollution, wide adaptability to coal types, and good load regulation performance. It has been widely developed and applied, among which how to prevent the wear of circulating fluidized bed boiler furnace water wall is the key to its long-term safe and stable operation. At present, the anti-wear of circulating fluidized bed boiler water wall mainly adopts technical measures such as high-temperature spraying, diameter reduction of water-cooled wall tube, water-cooled wall let-off tube, anti-wear guard plate and multi-step anti-wear, these measures can solve the wear problem of water-cooled wall tube achieved good results.

From the perspective of the fluid dynamic characteristics and fluidization theory in the furnace, the furnace of the circulating fluidized bed boiler is in a state of rapid fluidization, and the rapid decline of the high-concentration and large-flux bed material in the furnace has caused erosion of the water-cooled walls around the furnace. , Although the wall-adhesive flow formed by the falling bed material strengthens the heat transfer of the water-cooled wall, it also causes wear to the water-cooled wall. From the top to the bottom of the furnace, the flow velocity, particle concentration and flux of the wall-adhering flow gradually increase. The multi-step anti-wear used in the prior art is to destroy the flow velocity and flow direction of the wall-adhering flow particles and weaken their impact on water cooling. The wear of the wall, but this technology requires welding pins on the water-cooled wall tubes in the furnace, and then adding castables, which has high requirements for the installation process and will affect the air flow in the furnace. With the wear and tear in the furnace and the boiler Expansion, anti-wear steps are prone to fall off, resulting in local wear of the water wall, and the use of anti-wear step technology needs to re-calculate the heat transfer of the heating surface and the impact on the boiler efficiency.

At the same time, with conventional anti-wear technology, once installed, the anti-wear process cannot be controlled and adjusted. For multi-step anti-wear technology, if too many steps are designed, it will affect the load capacity of the boiler and the heat absorption of other heating surfaces. If the design is too small, the effective anti-wear effect cannot be achieved, and it cannot be adjusted and controlled during operation. The number and shape of steps can be designed according to experience. The anti-wear technology of high-temperature spraying needs to invest a lot of money, and the sprayed layer is easy to fall off and cause local wear.

Utility model content

The purpose of this utility model is to provide a gas film anti-wear device for circulating fluidized bed boiler water-cooled wall tubes and a boiler using the gas film anti-wear device, so as to solve the problem that the existing anti-wear technology and devices cannot be used during boiler operation. Control and adjustment, and the problem of expensive capital and low efficiency.

In order to solve the above problems, the embodiment of the utility model provides a circulating fluidized bed boiler water wall air film anti-wear device, including: the openings on the fins 2 arranged between the water wall tubes 3 of the circulating fluidized bed boiler hole 5, the wind box 4 arranged outside the circulating fluidized bed boiler furnace 1, and the connecting conduit 6 connecting the wind box 4 and the opening 5; wherein, the connecting conduit 6 passes the wind from the wind box 4 through The openings 5 are introduced into the furnace 1 of the circulating fluidized bed boiler so as to form an anti-wear gas film on the surface of the water wall tube 3 .

Preferably, the air film anti-wear device for the water wall of the circulating fluidized bed boiler further includes a guide device 7, the guide device 7 is arranged inside the connecting conduit 6 and guided into the furnace 1 of the circulating fluidized bed boiler The air flow inside flows to the water-cooled wall tubes 3 on both sides respectively, thereby forming a layer of anti-wear air film on the surface of the corresponding water-cooled wall tubes 3 .

Preferably, the air box 4 is connected to the hot primary air duct or the hot secondary air duct of the boiler through an air duct, and the air volume and air pressure are adjusted through the regulating valve on the air duct.

Preferably, the bellows 4 are arranged as an integral bellows on the same layer.

Preferably, the wind boxes 4 are arranged as multiple independent wind boxes on the same floor, and the multiple independent wind boxes are connected together through air ducts.

Preferably, the guide device 7 is arranged inside the connecting conduit 6 near one end of the circulating fluidized bed boiler furnace 1 .

Preferably, the guide device 7 is in a streamline shape along the airflow direction, so as to reduce the flow resistance against abrasion.

Preferably, the openings 5 are uniformly and sequentially opened at the same level of the boiler wall to form the same layer of gas film.

Preferably, the connecting conduit 6 is welded on the opening 5 .

Preferably, the guide device 7 has a left-right symmetrical structure.

Preferably, the air volume used for the anti-wear air film accounts for 15%-25% of the total air volume of the furnace.

In order to solve the above problems, the utility model also provides a boiler, including a circulating fluidized bed boiler furnace 1, fins 2, and water-cooled wall tubes 3, the fins 2 are arranged between the water-cooled wall tubes 3, and the The boiler also includes an air box 4, an opening 5, and a connecting conduit 6; wherein, the opening 5 is set on the fins 2 between the water wall tubes 3 of the circulating fluidized bed boiler furnace 1; the air box 4 is set Outside the circulating fluidized bed boiler furnace 1, the wind box 4 is communicated with the opening 5 through the connecting conduit 6; the connecting conduit 6 passes the wind from the wind box 4 through the opening 5 is introduced into the furnace 1 of the circulating fluidized bed boiler so as to form an anti-wear gas film on the surface of the water wall tube 3 .

Preferably, the boiler also includes a guiding device 7, which is arranged inside the connecting duct 6, and guides the airflow entering the furnace 1 of the circulating fluidized bed boiler to the water-cooled wall tubes on both sides respectively. 3 flows, so that a layer of anti-wear air film is formed on the surface of the corresponding water wall tube 3.

Preferably, the air box 4 of the boiler is connected to the hot primary air duct or the hot secondary air duct of the boiler through an air duct, and the air volume and air pressure are adjusted through the regulating valve on the air duct.

Preferably, the wind box 4 of the boiler is arranged as an integral wind box on the same floor.

Preferably, the wind boxes 4 of the boiler are arranged as multiple independent wind boxes on the same floor, and the multiple independent wind boxes are connected together through air ducts.

Preferably, the guide device 7 of the boiler is arranged inside the connecting conduit 6 near one end of the furnace 1 of the circulating fluidized bed boiler.

Preferably, the guide device 7 of the boiler is in a streamline shape along the airflow direction, so as to reduce the flow resistance against abrasion wind.

Preferably, the openings 5 of the boiler are uniformly and sequentially opened at the same level of the boiler wall to form the same layer of gas film.

Preferably, the connecting conduit 6 of the boiler is welded on the opening 5 .

Preferably, the guiding device 7 of the boiler is a left-right symmetrical structure.

Preferably, the air volume used for the anti-wear air film accounts for 15%-25% of the total air volume of the furnace.

The air film anti-wear device for the water wall of the circulating fluidized bed boiler and the boiler using the anti-wear device in the embodiment of the utility model can introduce the wind from the bellows outside the furnace into the furnace through the connecting conduit to generate the air film, and the air film can Destroying the wall-adhesive flow formed by the descending bed material particles changes the flow direction of the wall-adhering flow, and at the same time reduces the flow velocity and concentration of the descending particles, thereby reducing the erosion and wear of the water-cooled wall tubes. Moreover, by adjusting the pressure of the bellows, the thickness of the gas film can be adjusted during the operation of the boiler, so as to realize the adjustment of the gas film anti-wear device of the water wall without affecting the normal operation of the boiler. Moreover, the gas film formed by the device makes the area in the furnace an oxidizing atmosphere, which can prevent the corrosion of the water-cooled wall tubes. At the same time, the oxygen required for boiler combustion is sent into the boiler through different parts, realizing staged combustion, which can effectively Reduce pollutant emissions.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments of the present utility model. For those skilled in the art, other drawings can also be obtained according to these drawings on the premise of not paying creative efforts.

Fig. 1 is the schematic diagram of the boiler furnace with the air film anti-wear device of the circulating fluidized bed boiler water wall of the utility model embodiment;

Fig. 2 is a cross-sectional top view of the furnace of a boiler with a water-cooled wall air film anti-wear device for a circulating fluidized bed boiler according to an embodiment of the utility model and a schematic diagram of the wind box therein;

Fig. 3 is a schematic diagram of the side partial water wall pipes and openings of the boiler furnace with a circulating fluidized bed boiler water wall air film anti-wear device according to an embodiment of the present invention;

Fig. 4 is the A-A direction view of Fig. 3, shows the schematic diagram that bellows and connecting conduit are connected;

Fig. 5 is the B-B direction view of Fig. 4, shows the schematic diagram of the multi-layer bellows arranged along the furnace height direction;

Fig. 6 is a schematic diagram of the horizontal cross-sectional structure of a single connecting conduit and a guide device of the air film anti-wear device of the water wall of the circulating fluidized bed boiler according to the embodiment of the utility model;

Fig. 7 is a flow chart of the method of using the air film anti-wear device on the water wall of the circulating fluidized bed boiler according to the embodiment of the present utility model.

Figure number:

1. Circulating fluidized bed boiler furnace; 2. Fins; 3. Water wall tube; 4. Bellows; 5. Opening hole; 6. Connecting conduit; 7. Guiding device.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Fig. 1 is a schematic diagram of a boiler furnace with an air film anti-wear device on a water wall of a circulating fluidized bed boiler according to an embodiment of the present invention. Fig. 2 is a cross-sectional top view of the furnace of a boiler with a water wall anti-wear device for a circulating fluidized bed boiler according to an embodiment of the present invention and a schematic diagram of a wind box therein. Fig. 3 is a schematic diagram of the side partial water-cooled wall tubes and openings of the boiler furnace with a circulating fluidized bed boiler water-cooled wall gas film anti-wear device according to an embodiment of the present invention; Fig. 4 is a view from the direction A-A of Fig. 3, showing the bellows and Schematic diagram of connecting catheter connections. Fig. 5 is a view taken along the direction B-B of Fig. 4, showing a schematic view of multi-layer wind boxes arranged along the furnace height direction.

As shown in FIGS. 1 and 2 , the circulating fluidized bed boiler of this embodiment includes a circulating fluidized bed boiler furnace 1 , fins 2 , and water-cooled wall tubes 3 , and the water-cooled wall tubes 3 are connected by fins 2 .

The boiler of this embodiment includes a circulating fluidized bed boiler water-cooled wall anti-wear device, wherein, as shown in Figure 2, the gas-film anti-wear device of the boiler includes the water-cooled wall tubes 3 between the circulating fluidized bed boiler furnace The opening 5 provided on the fin 2. Wherein, holes are opened on the fins 2, and the holes may be square holes or small oval holes, and the number and positions of the holes are determined according to the technological parameters of the boiler. The openings 5 are arranged at different elevations of the boiler, and by spraying anti-wear wind, a multi-layer gas film along the height direction of the boiler is formed, which destroys the medium flow direction of the wall-attached downward flow, and prevents the water-cooled wall tube 3 from being scoured and worn; and The openings 5 are arranged at the same level of the boiler, and the holes are evenly and sequentially opened along the four walls of the boiler at the same level, so that the same layer of anti-wear gas film can be formed.

In this embodiment, the gas film anti-wear device in the boiler also includes a wind box 4 provided outside the furnace 1 of the circulating fluidized bed boiler, and the opening 5 communicates with the wind box 4 through a connecting conduit 6 . The bellows 4 is arranged outside the furnace. According to the process requirements, one integral bellows can be installed on the same floor, and multiple independent bellows can also be installed. As shown in Figure 4, it is a schematic diagram of an integral bellows installed on the same floor of the boiler. It is also possible to set multi-layer openings 5 and corresponding bellows 4 at different elevations of the furnace according to the wear-resistant requirements to increase the wear-resistant strength. As shown in Figure 5, it shows the multi-layer bellows arranged along the furnace height schematic diagram. And the bellows of different layers are connected through air ducts, and adjusting valves are respectively installed on the air ducts to control the air volume and air pressure entering each bellows. The air box 4 is connected with the hot primary air duct or hot secondary air duct of the boiler through the air duct, and directly uses the hot primary air or hot secondary air as the anti-wear wind, which not only reduces the emission of pollutants, but also improves the utilization efficiency of the boiler .

The air volume of the anti-grinding wind is adjusted according to the working conditions of the circulating fluidized bed boiler, such as starting, stopping, and load lifting, and is controlled between 15% and 25% of the total air volume during normal operation of the boiler.

Fig. 6 is a schematic diagram of a horizontal cross-sectional structure of a single connecting conduit and a guide device of the air film anti-wear device for the water wall of a circulating fluidized bed boiler according to an embodiment of the utility model.

In this embodiment, the connecting conduits 6 can be welded to the openings 5 on the fins 2 of the water wall 3 , and the other end is connected to the wind box 4 , and the anti-wear air is passed into the furnace 1 through each connecting conduit 6 . The guiding device 7 is arranged inside the connecting conduit 6, close to the end of the furnace 1, and its function is to change the direction of the anti-wear wind sprayed into the furnace, and flow to the water-cooled wall tubes on both sides at a certain angle, forming a gap on the surface of the water-cooled wall tubes. Air film. The guiding device is in a streamline shape along the airflow direction, thereby reducing the flow resistance of the anti-abrasive wind.

In this embodiment, the guide device 7 can be arranged as a left-right symmetrical structure, and its inlet part divides the connecting duct 6 into three channels, the flow area of the middle channel is smaller than that of the two sides, and the flow of the middle channel along the airflow direction The area gradually increases, and the flow area of the channels on both sides is smaller than that of the middle channel, thereby guiding the anti-wear wind to accelerate and flow forward along the channels on both sides under the action of the guide device 7 .

The multi-layer air boxes are connected to the hot primary air duct or the hot secondary air duct of the boiler through the air duct, and the air volume and air pressure are adjusted by adjusting the regulating valve on the air duct, so as to adjust the thickness and stiffness of the air film of each layer. The anti-friction gas film formed in the furnace 1 of the circulating fluidized bed boiler destroys the direction and flow velocity of the wall-attached flow and the descending particle flow, thereby reducing the erosion and wear of the water-cooled wall tubes.

Fig. 7 is a flow chart of the method of using the air film anti-wear device on the water wall of the circulating fluidized bed boiler according to the embodiment of the present utility model. As shown in the figure, the anti-wear method of the gas film on the water wall of the circulating fluidized bed boiler according to the embodiment of the present invention includes:

Step S101, making holes on the fins between the water wall tubes of the furnace of the circulating fluidized bed boiler. Holes are made on the fins, and the holes can be square holes or small oval holes, and the number and positions of the holes are determined according to the process parameters of the boiler. The openings are arranged at different elevations of the boiler, and by spraying anti-abrasive wind, a multi-layer gas film along the height direction of the boiler is formed, which destroys the medium flow direction of the wall-attached downflow and prevents the water-cooled wall tube from scouring and wear; while in the boiler Holes are set at the same elevation, and holes are evenly opened along the four walls of the boiler at the same elevation, so that the same layer of anti-wear gas film can be formed.

Step S102, sending the hot primary air or the hot secondary air of the boiler into the furnace of the circulating fluidized bed boiler through the opening through the wind box. According to process requirements and anti-wear needs, one integral bellows can be set on the same floor, or several separate bellows can be set. The bellows of different layers are connected through air ducts, and adjusting valves are installed on the air ducts to control the air volume and air pressure entering each bellows. The air box is connected with the hot primary air duct or the hot secondary air duct of the boiler through the air duct, and directly uses the hot primary air or hot secondary air as the anti-wear air, which not only reduces the emission of pollutants, but also improves the utilization efficiency of the boiler.

Step S103, the hot primary air or the hot secondary air forms an anti-friction air film on the surface of the water wall tube. The wind is introduced into the furnace from the air box outside the furnace through the connecting duct to generate an anti-wear air film, which can destroy the wall-adhesive flow formed by the falling bed material particles, change the flow direction of the wall-adhering flow, and reduce the friction of the falling particles Flow rate and concentration, thereby reducing the erosion and wear of the water-cooled wall tubes.

The air film anti-wear device for the water wall of the circulating fluidized bed boiler and the boiler using the anti-wear device in the embodiment of the utility model can introduce the wind from the bellows outside the furnace into the furnace through the connecting conduit to generate the air film, and the air film can Destroying the wall-adhesive flow formed by the descending bed material particles changes the flow direction of the wall-adhering flow, and at the same time reduces the flow velocity and concentration of the descending particles, thereby reducing the erosion and wear of the water-cooled wall tubes. Moreover, by adjusting the pressure of the bellows, the thickness of the gas film can be adjusted during the operation of the boiler, so as to realize the adjustment of the gas film anti-wear device of the water wall without affecting the normal operation of the boiler. Moreover, the gas film formed by the device makes the area in the furnace an oxidizing atmosphere, which can prevent the corrosion of the water-cooled wall tubes. At the same time, the oxygen required for boiler combustion is sent into the boiler through different parts, realizing staged combustion, which can effectively Reduce pollutant emissions.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present utility model in detail. Within the protection scope of the utility model, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model shall be included in the protection scope of the utility model.

Claims (22)

1. A circulating fluidized bed boiler water wall air film antiwear device, characterized in that, the circulating fluidized bed boiler water wall air film antiwear device comprises: The openings (5) arranged on the fins (2) between the water-cooled wall tubes (3) of the circulating fluidized bed boiler, and the air box (4) arranged outside the furnace (1) of the circulating fluidized bed boiler And the connecting conduit (6) connecting the bellows (4) and the opening (5); wherein, The connecting duct (6) introduces the wind from the wind box (4) into the circulating fluidized bed boiler furnace (1) through the opening (5), so that the wind in the water wall tube (3) A wear-resistant air film is formed on the surface. 2. The air film anti-wear device for the water wall of the circulating fluidized bed boiler according to claim 1, characterized in that, the air film anti-wear device for the water wall of the circulating fluidized bed boiler also includes a guiding device (7), the The guiding device (7) is arranged inside the connecting conduit (6), and guides the airflow entering the furnace (1) of the circulating fluidized bed boiler to flow respectively to the water-cooled wall tubes (3) on both sides, so that the corresponding A layer of anti-wear air film is formed on the surface of the water wall tube (3). 3. The air film anti-wear device of the circulating fluidized bed boiler water wall according to claim 1, characterized in that, the bellows (4) is connected with the hot primary air duct or the hot secondary air duct of the boiler through an air duct, The regulating valve on the air duct regulates the air volume and air pressure. 4. The air film anti-wear device for the water wall of the circulating fluidized bed boiler according to claim 3, characterized in that the air box (4) is arranged as an integral air box on the same floor. 5. The air film anti-wear device for circulating fluidized bed boiler water wall according to claim 3, characterized in that, the bellows (4) are arranged as multiple independent bellows on the same floor, and the multiple independent bellows pass through the air Roads are connected together. 6. The air film anti-wear device of the circulating fluidized bed boiler water wall according to claim 2, characterized in that, the guide device (7) is arranged inside the connecting conduit (6) close to the circulating fluidized bed One end of the bed boiler furnace (1). 7. The air film anti-wear device for circulating fluidized bed boiler water wall according to claim 6, characterized in that, the guide device (7) is in a streamline shape along the airflow direction, thereby reducing the wear resistance of the anti-wear wind flow resistance. 8. The air film anti-wear device for the water wall of a circulating fluidized bed boiler according to claim 1, characterized in that the openings (5) are uniformly and sequentially opened at the same elevation of the boiler wall to form the same layer air film. 9. The air film anti-wear device for the water wall of the circulating fluidized bed boiler according to claim 1, characterized in that the connecting conduit (6) is welded on the opening (5). 10. The air film anti-wear device for the water wall of the circulating fluidized bed boiler according to claim 2, characterized in that the guide device (7) has a left-right symmetrical structure. 11. The air film anti-wear device for the water wall of a circulating fluidized bed boiler according to claim 1, characterized in that the air volume used for the anti-wear air film accounts for 15% to 25% of the total air volume of the furnace. 12. A boiler comprising a circulating fluidized bed boiler furnace (1), fins (2), and water-cooled wall tubes (3), the fins (2) being arranged between the water-cooled wall tubes (3), It is characterized in that the boiler also includes a wind box (4), an opening (5), and a connecting conduit (6); wherein, The opening (5) is arranged on the fins (2) between the water wall tubes (3) of the circulating fluidized bed boiler furnace (1); the wind box (4) is arranged on the circulating fluidized bed The outside of the bed boiler furnace (1), the air box (4) is communicated with the opening (5) through the connecting conduit (6); The connecting duct (6) introduces the wind from the wind box (4) into the circulating fluidized bed boiler furnace (1) through the opening (5), so that the wind in the water wall tube (3) A wear-resistant air film is formed on the surface. 13. The boiler according to claim 12, characterized in that, the boiler further comprises a guide device (7), the guide device (7) is arranged inside the connecting conduit (6), and guides the The airflow in the furnace (1) of the circulating fluidized bed boiler respectively flows to the water-cooled wall tubes (3) on both sides, thereby forming a layer of anti-wear gas film on the surface of the corresponding water-cooled wall tubes (3). 14. The boiler according to claim 12, characterized in that the air box (4) is connected to the hot primary air duct or the hot secondary air duct of the boiler through an air duct, and the air volume and air pressure are adjusted through the regulating valve on the air duct . 15. The boiler according to claim 14, characterized in that, the wind boxes (4) are arranged as an integral wind box on the same floor. 16. The boiler according to claim 14, characterized in that, the wind boxes (4) are arranged as multiple independent wind boxes on the same floor, and the multiple independent wind boxes are connected together through air ducts. 17. The boiler according to claim 13, characterized in that the guide device (7) is arranged inside the connecting conduit (6) close to one end of the circulating fluidized bed boiler furnace (1). 18. The boiler according to claim 17, characterized in that, the guide device (7) is in a streamline shape along the airflow direction, thereby reducing the flow resistance against abrasion wind. 19. The boiler according to claim 12, characterized in that the openings (5) are uniformly and sequentially opened at the same elevation of the boiler wall to form the same layer of gas film. 20. The boiler according to claim 12, characterized in that the connecting conduit (6) is welded on the opening (5). 21. The boiler according to claim 13, characterized in that, the guide device (7) is a left-right symmetrical structure. 22. The boiler according to claim 12, characterized in that the air volume used for the anti-wear gas film accounts for 15%-25% of the total air volume of the furnace.

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