High-pressure fluidization air system for circulating fluidized bed boiler

Abstract

The utility model relates to a high-pressure fluidization air system for a circulating fluidized bed boiler, which comprises a high-pressure fluidization air system body, the high-pressure fluidization air system body consists of at least one group of centrifugal high-pressure fluidization fans, an air outlet mother pipe and a bypass pipeline, one side of each centrifugal high-pressure fluidization fan is connected with an air suction pipeline, and the other side of each centrifugal high-pressure fluidization fan is connected with an air outlet mother pipe. An inlet silencer and an inlet adjusting door are respectively arranged on the air suction pipeline, the other side of the centrifugal high-pressure fluidization fan is connected with one end of an air outlet pipeline, a check door and a first shut-off door are respectively arranged on the air outlet pipeline, the air outlet pipeline is connected with an air outlet main pipe, the air outlet main pipe is communicated with a return feeder, and the return feeder is communicated with the return feeder. The air outlet main pipe is further connected with a bypass pipeline, and the bypass pipeline is connected to the cold primary air main pipe. One end of the return feeder is connected with the separator, and the other end of the return feeder is connected to the hearth. The system has the advantages of being simple and reasonable in structure, low in manufacturing cost, flexible and reliable in system operation, convenient to construct, remarkable in effect and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of thermal power plant design, and in particular relates to a high-pressure fluidized air system for a circulating fluidized bed boiler. Background Art

[0002] Circulating fluidized bed boilers use fluidized combustion, and their main structure includes two parts: the combustion chamber (including dense phase area and dilute phase area) and the circulating furnace (including high-temperature gas-solid separator and return system). Circulating fluidized bed boilers have well solved the basic problems of thermodynamics, mechanics, materials science, and engineering problems such as expansion, wear, and overheating, and have become an advanced technology for the energy utilization of difficult-to-burn solid fuels (such as coal gangue, oil shale, urban garbage, sludge and other wastes).

[0003] There are a large amount of materials in the circulating fluidized bed boiler. The materials are fluidized, boiled and burned in the furnace. Under the action of the rising airflow, they move to the upper part of the furnace and release heat to the water-cooled wall and other heating surfaces arranged in the furnace. After a large amount of materials are brought into the suspension zone by the rising airflow, they are continuously decelerated and deviate from the main airflow under the action of gravity and other external forces. The solid materials entrained out of the furnace by the airflow are collected in the gas-solid separation device and sent back to the furnace through the return device for circulation combustion until they are burned out.

[0004] High-pressure fluidizing fans play an important role in circulating fluidized bed boiler units, providing the necessary conveying medium for material circulation. High-pressure fluidizing air is connected to the return feeder to help the material return to the furnace smoothly, and ensure that the unburned large particles do not burn against the wall, preventing the return feeder from coking.

[0005] The centrifugal fan is used as the high-pressure fluidized bed fan, and its fan operation adjustment performance is good, but the fan cannot operate safely and stably under low load for a long time. The circulating fluidized bed boiler has strong fuel adaptability. After the unit is put into operation, it often burns non-fossil fuels such as biomass and sludge, resulting in large fluctuations in the return volume and deviation from the unit's design conditions. At the same time, with the annual increase in the installed capacity of new energy such as photovoltaics and wind power, the circulating fluidized bed unit is also facing the peak load regulation requirements of large increases and decreases. The above two points require that the high-pressure fluidized wind system needs to operate more flexibly and be more adaptable to meet the operating requirements of the generator set under the new situation and maintain the safety, stability and reliability of the fan itself.

[0006] Therefore, a high-pressure fluidizing air system for a circulating fluidized bed boiler is designed to overcome the above problems. Summary of the invention

[0007] The purpose of the utility model is to overcome the deficiencies of the prior art and to provide a high-pressure fluidizing air system for a circulating fluidized bed boiler which has a simple and reasonable structure, a low cost, flexible and reliable system operation, convenient construction and significant effects.

[0008] The utility model is implemented through the following technical scheme: a high-pressure fluidized air system for a circulating fluidized bed boiler, comprising a high-pressure fluidized air system body, the high-pressure fluidized air system body consisting of at least one group of centrifugal high-pressure fluidized blowers, an air outlet main pipe and a bypass duct, one side of the centrifugal high-pressure fluidized blower is connected to an air suction duct, an inlet muffler and an inlet regulating door are respectively arranged on the air suction duct, the other side of the centrifugal high-pressure fluidized blower is connected to one end of the air outlet duct, a check door and a first shut-off door are respectively arranged on the air outlet duct, the air outlet duct is connected to the air outlet main pipe, the air outlet main pipe is connected to a return feeder, the air outlet main pipe is also connected to a bypass duct, and the bypass duct is connected to a cold primary air main pipe; one end of the return feeder is connected to a separator, and the other end thereof is connected to a furnace.

[0009] Preferably, the centrifugal high-pressure fluidizing blower is connected to an exhaust pipe on its outlet pipe, and an outlet silencer and an outlet regulating door are provided on the exhaust pipe respectively, so as to prevent the operation from deviating from the design working condition, the pressure difference of the return device from decreasing, and the bypass pipe valve from malfunctioning and being unable to open.

[0010] Preferably, a bypass regulating door and a second shut-off door are respectively provided on the bypass duct, and the second shut-off door is close to one side of the bypass duct, and the bypass regulating door and the second shut-off door are used to regulate the high-pressure fluidizing air volume of the bypass duct entering the cold primary air main pipe.

[0011] Preferably, the bypass duct, the air suction duct, the air outlet duct and the exhaust duct are all made of Q235-B material.

[0012] The beneficial effects of the utility model are as follows:

[0013] The utility model discloses a high-pressure fluidized air system for a circulating fluidized bed boiler. The system is flexible and reliable in operation, can meet the operation requirements of the unit under different loads and different fuels, and can be applied not only to coal-fired units, but also to units burning garbage, sludge, biomass and other fuels. The whole system has a simple structure and a low cost, can ensure the safe and stable operation of the fan, improve the operating efficiency of the fan, reduce the waste of electric energy, and has the advantages of convenient construction, significant effect, and no need for new equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the utility model. DETAILED DESCRIPTION

[0015] In order to enable those skilled in the art to more clearly understand the objectives, technical solutions and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0016] In the description of the present invention, it is necessary to understand that the orientation or position relationship indicated by the terms such as "up", "down", "left", "right", "inside", "outside", "horizontal" and "vertical" is based on the orientation or position relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or original referred to must have a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0017] The present invention will be described in detail below with reference to the accompanying drawings: Figure 1 As shown, a high-pressure fluidized air system for a circulating fluidized bed boiler includes a high-pressure fluidized air system body 1, wherein the high-pressure fluidized air system body 1 is composed of at least one group of centrifugal high-pressure fluidized air fans 2, an air outlet main pipe 3 and a bypass pipe 4, one side of the centrifugal high-pressure fluidized air fan 2 is connected to an air suction pipe 5, on which an inlet muffler 6 and an inlet regulating door 7 are respectively arranged, and the other side of the centrifugal high-pressure fluidized air fan 2 is connected to one end of an air outlet pipe 8, on which a check door 9 and a first shut-off door 10 are respectively arranged, the air outlet pipe 8 is connected to the air outlet main pipe 3, and the air outlet main pipe 3 is connected to a return device 12, and the air outlet main pipe 3 is also connected to a bypass pipe 4, and the bypass pipe 4 is connected to a cold primary air main pipe 14; one end of the return device 12 is connected to a separator 15, and the other end thereof is connected to a furnace 16.

[0018] The outlet duct 8 of the centrifugal high-pressure fluidizing fan 2 is connected to an exhaust duct 17, and an outlet muffler 18 and an outlet regulating door 19 are respectively provided on the exhaust duct 17 to prevent the operation from deviating from the design conditions, the pressure difference of the return device from decreasing, and the bypass duct valve malfunctioning and unable to open.

[0019] The bypass duct 4 is respectively provided with a bypass regulating door 13 and a second shut-off door 11, and the second shut-off door 11 is close to one side of the bypass duct 4. The bypass regulating door 13 and the second shut-off door 11 are used to adjust the high-pressure fluidizing air volume of the bypass duct 4 entering the cold primary air main pipe.

[0020] The bypass duct 4, the air suction duct 5, the air outlet duct 8 and the exhaust duct 17 are all made of Q235-B material. Specific embodiments

[0021] Reference Figure 1As shown, the air in the utility model enters the centrifugal high-pressure fluidizing fan 2 through the inlet silencer 6, the inlet regulating door 7 and the suction duct 5, and after being pressurized by the fan, it is led upward from the outlet duct 8. An exhaust duct 17 is led out from each outlet duct 8, and connected to the outlet regulating door 19 and the outlet silencer 18 upward. The two outlet ducts 8 are connected to the outlet main pipe 3 after merging, and connected to the return feeder 12 upward. The bypass duct 4 is horizontally led out from the outlet main pipe 3 in front of the return feeder 12, and connected to the cold primary air main pipe 14 through the bypass regulating door 13.

[0022] When the circulating fluidized bed boiler and the high-pressure flow fan are operated under the design conditions, the exhaust pipe valve and the bypass pipe valve remain closed, and the fan exhaust enters the circulating fluidized bed boiler return feeder through the outlet pipe; when the operation deviates from the design conditions and the return feeder pressure difference decreases, the exhaust pipe valve remains closed, the bypass pipe valve opens, and the fan exhaust partly enters the cold primary air main pipe through the bypass pipe, and partly enters the return feeder through the outlet pipe; when the operation deviates from the design conditions, the return feeder pressure difference decreases, and the bypass pipe valve fails and cannot be opened, the exhaust pipe valve opens, and the fan exhaust partly enters the atmosphere through the exhaust pipe, and partly enters the return feeder through the outlet pipe. The air ducts are all made of Q235-B material.

[0023] This system is suitable for circulating fluidized bed boilers and has the potential for application to units burning garbage, sludge, biomass and other fuels. The entire system has a simple structure and low cost, can ensure the safe and stable operation of the fan, improve the flexibility and applicability of the fan operation, improve the fan operation efficiency, reduce the waste of electricity, and has the advantages of convenient construction, significant effect, and no new equipment. At the same time, it can meet the needs of large-scale load increase and decrease and peak-shaving operation of circulating fluidized bed units, and can adapt to the boiler's mixed combustion of biomass, sludge and other non-fossil fuels, and improve the flexibility of unit operation and fuel adaptability.

[0024] The specific embodiments described herein are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A high-pressure fluidizing air system for a circulating fluidized bed boiler, comprising a high-pressure fluidizing air system body (1), characterized in that: The high-pressure fluidized air system body (1) is composed of at least one group of centrifugal high-pressure fluidized air fans (2), an air outlet main pipe (3) and a bypass pipe (4); one side of the centrifugal high-pressure fluidized air fan (2) is connected to an air suction pipe (5), an inlet silencer (6) and an inlet regulating door (7) are respectively arranged on the air suction pipe (5); the other side of the centrifugal high-pressure fluidized air fan (2) is connected to one end of an air outlet pipe (8), a check door (9) and a first shut-off door (10) are respectively arranged on the air outlet pipe (8); the air outlet pipe (8) is connected to an air outlet main pipe (3), the air outlet main pipe (3) is connected to a return device (12), the air outlet main pipe (3) is also connected to a bypass pipe (4), and the bypass pipe (4) is connected to a cold primary air main pipe (14); one end of the return device (12) is connected to a separator (15), and the other end is connected to a furnace (16).

2. The high-pressure fluidizing air system for a circulating fluidized bed boiler according to claim 1, characterized in that: The outlet duct (8) of the centrifugal high-pressure fluidizing fan (2) is connected to an exhaust duct (17), and the exhaust duct (17) is provided with an outlet muffler (18) and an outlet regulating door (19) respectively, for preventing the operation from deviating from the design working conditions, the pressure difference of the return device from decreasing, and the bypass duct valve malfunctioning and unable to open.

3. The high-pressure fluidizing air system for a circulating fluidized bed boiler according to claim 2, characterized in that: The bypass duct (4) is provided with a bypass regulating door (13) and a second shutoff door (11), respectively, and the second shutoff door (11) is close to one side of the bypass duct (4). The bypass regulating door (13) and the second shutoff door (11) are used to regulate the volume of high-pressure fluidizing air entering the cold primary air main pipe from the bypass duct (4).

4. The high-pressure fluidizing air system for a circulating fluidized bed boiler according to claim 3, characterized in that: The bypass duct (4), the air suction duct (5), the air outlet duct (8) and the exhaust duct (17) are all made of Q235-B material.

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