High-temperature reheater of fluidized bed boiler

Abstract

The utility model discloses a high-temperature reheater of a fluidized bed boiler, which comprises a separator, a hearth, a high-temperature reheating screen inlet header, a high-temperature reheating screen outlet header and a high-temperature reheating screen component, and the high-temperature reheating screen component comprises a high-temperature reheating screen descending section and a high-temperature reheating screen ascending section. The high-temperature reheating screen descending section and the high-temperature reheating screen ascending section are arranged in the hearth side by side and communicate with each other, the high-temperature reheating screen descending section communicates with the high-temperature reheating screen inlet header and extends into the hearth from the top of the hearth, and one end of the high-temperature reheating screen ascending section extends out of the top of the hearth and communicates with the high-temperature reheating screen outlet header; and the high-temperature reheating screen inlet header is communicated with the separator through the low-temperature reheater inlet header, the low-temperature reheater, the low-temperature reheater outlet header and the micro water spraying desuperheater. The device is convenient and fast to process and design, can reduce the temperature rise of a single process, and provides favorable conditions for controlling the wall temperature deviation of the reheat shield.

Description

Technical Field

[0001] The utility model relates to a high-temperature reheater of a fluidized bed boiler, belonging to the technical field of fluidized bed boilers. Background Art

[0002] The reheater of the existing circulating fluidized bed boiler is usually only arranged in the tail flue of the circulating dual fluidized bed boiler, and sometimes part of the reheater is arranged in the furnace area to enhance the heat exchange effect. Compared with the 350MW-class supercritical circulating fluidized bed boiler, the temperature and pressure of the 600MW and above-capacity ultra-supercritical circulating fluidized bed boiler have increased, and the grade of the materials used in the boiler body has been improved. The highest-grade material of the heating surface has been upgraded from SA213-TP347 (peened) to SA213-SUPER304H (peened), and the highest-grade material of the header has been upgraded from SA335-P91 to SA335-P92.

[0003] The high-temperature reheater screen of the existing 350MW-class supercritical circulating fluidized bed boiler reheater system usually adopts a process in which the working medium rises once (such as Figure 1 ), and a lower inlet header and an upper outlet header are provided. To meet the demand for reheated steam with higher parameters, when the outlet temperature is further increased, it is necessary to splice a variety of heating surface materials, which is not conducive to the design and manufacturing of the high-temperature reheater screen, and it is very likely that tube screen deformation will occur due to an increase in wall temperature deviation during actual operation. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is that when the high-temperature reheater screen of the existing circulating fluidized bed boiler faces reheated steam with higher parameters, it is necessary to splice a variety of heating surface materials, the design and processing are cumbersome, and tube screen deformation is likely to occur due to wall temperature difference during operation.

[0005] To solve the above technical problems, the utility model provides a high-temperature reheater of a fluidized bed boiler, which is convenient and fast in processing and design, and can reduce the temperature rise of a single process, providing favorable conditions for controlling the wall temperature deviation of the reheater screen.

[0006] To achieve the above technical purpose and reach the above technical effect, the present application is realized through the following technical solutions:

[0007] A high-temperature reheater for a fluidized bed boiler, comprising a separator, a furnace, a high-temperature reheater screen inlet header and a high-temperature reheater screen outlet header, and further comprising a low-temperature reheater inlet header, a low-temperature reheater, a low-temperature reheater outlet header, a microspray desuperheater and a high-temperature reheater screen assembly; the low-temperature reheater inlet header is communicated with the separator, the low-temperature reheater outlet header and the low-temperature reheater inlet header are communicated through the low-temperature reheater, the low-temperature reheater is located in the rear flue gas duct, and the high-temperature reheater screen inlet header and the low-temperature reheater outlet header are communicated through the microspray desuperheater; the high-temperature reheater screen assembly comprises a high-temperature reheater screen descending section and a high-temperature reheater screen ascending section, the high-temperature reheater screen descending section and the high-temperature reheater screen ascending section are arranged side by side in the furnace and communicated with each other, the high-temperature reheater screen descending section is communicated with the high-temperature reheater screen inlet header and extends into the furnace from the top of the furnace, and one end of the high-temperature reheater screen ascending section extends out from the top of the furnace and is communicated with the high-temperature reheater screen outlet header.

[0008] Preferably, the high-temperature reheater screen assembly further comprises a high-temperature reheater screen intermediate mixing header, the high-temperature reheater screen descending section and the high-temperature reheater screen ascending section are communicated through the high-temperature reheater screen intermediate mixing header, and the high-temperature reheater screen intermediate mixing header is located outside the furnace.

[0009] Furthermore, multiple groups of the high-temperature reheater screen assemblies are provided and are concentrated or separately collected into the high-temperature reheater screen intermediate mixing header.

[0010] The high-temperature reheater for a fluidized bed boiler provided by the present utility model has the following advantages:

[0011] 1. For the high-temperature reheater of the fluidized bed boiler used in the present utility model, the tube screens are arranged in the furnace, and the tube screens of each high-temperature reheater screen adopt a process in which the working medium first descends and then ascends, that is, each tube screen includes a high-temperature reheater screen descending section and a high-temperature reheater screen ascending section, which can reduce the temperature rise of a single process and provide favorable conditions for controlling the wall temperature deviation of the reheater screen; in addition, the types of the heating surface and fin materials of a single process are controllable, and the design does not require more material transition sections, which is beneficial to processing and welding forming.

[0012] 2. For the high-temperature reheater of the fluidized bed boiler of the present utility model, a high-temperature reheater screen intermediate mixing header for the working medium is arranged in the middle of the process where the high-temperature reheater tube screen descends and then ascends. After the working medium in the descending section is mixed in the middle, it then enters the tubes in the ascending section, and the working medium flow is more uniform and the temperature deviation is smaller. Description of the Drawings

[0013] Figure 1 It is a schematic diagram of a prior art circulating fluidized bed boiler;

[0014] Figure 2 It is a schematic structural diagram of a high-temperature reheater for a fluidized bed boiler of the present utility model;

[0015] In the figure:

[0016] 1 - Separator; 2 - Furnace; 3 - High - temperature reheater screen inlet header; 4 - High - temperature reheater screen outlet header; 5 - Low - temperature reheater inlet header; 6 - Low - temperature reheater; 7 - Low - temperature reheater outlet header; 8 - Micro spray desuperheater; 9 - High - temperature reheater screen assembly; 91 - High - temperature reheater screen downcomer; 92 - High - temperature reheater screen riser; 93 - High - temperature reheater screen intermediate mixing header; 10 - Reheater inlet. Specific embodiments

[0017] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present utility model. Specific Embodiment 1:

[0019] Refer to Figure 2 , the present utility model provides a high - temperature reheater for a fluidized - bed boiler, including a separator 1, a furnace 2, a high - temperature reheater screen inlet header 3 and a high - temperature reheater screen outlet header 4; further including a low - temperature reheater inlet header 5, a low - temperature reheater 6, a low - temperature reheater outlet header 7, a micro spray desuperheater 8 and a high - temperature reheater screen assembly 9; the low - temperature reheater inlet header 5 is connected to the reheater inlet 10 through a pipeline, the low - temperature reheater outlet header 7 is connected to the low - temperature reheater inlet header 5 through the low - temperature reheater 6, the low - temperature reheater 6 is located in the rear gas duct, and the high - temperature reheater screen inlet header 3 is connected to the low - temperature reheater outlet header 7 through the micro spray desuperheater 8;

[0020] The high - temperature reheater screen assembly 9 includes a high - temperature reheater screen downcomer 91 and a high - temperature reheater screen riser 92. The high - temperature reheater screen downcomer 91 and the high - temperature reheater screen riser 92 are installed side by side in the furnace 2 and are interconnected. The high - temperature reheater screen downcomer 91 is connected to the high - temperature reheater screen inlet header 3 and extends into the furnace 2 from the top of the furnace 2, and one end of the high - temperature reheater screen riser 92 extends out from the top of the furnace 2 and is connected to the high - temperature reheater screen outlet header 4. Specific Embodiment 2:

[0022] Refer to Figure 2, in this embodiment, the high-temperature reheater screen assembly 9 further includes a high-temperature reheater screen intermediate mixing header 93. The high-temperature reheater screen downcomer 91 and the high-temperature reheater screen riser 92 are connected through the high-temperature reheater screen intermediate mixing header 93. The high-temperature reheater screen intermediate mixing header 93 is located outside the furnace 2. After the working medium in the high-temperature reheater screen downcomer 91 is mixed, it then enters the tubes of the high-temperature reheater screen riser 92, and the working medium flow is more uniform and the temperature deviation is smaller. The other components and connection relationships are the same as those in the first specific embodiment. Specific Embodiment Three:

[0024] In this embodiment, multiple groups of high-temperature reheater screen assemblies 9 can be installed, and multiple groups of high-temperature reheater screen assemblies 9 are all connected between the high-temperature reheater screen inlet header 3 and the high-temperature reheater screen outlet header 4. The other components and connection relationships are the same as those in the first specific embodiment.

[0025] As mentioned above, the above are only the preferred embodiments of the present invention, and do not impose any formal or substantial limitations on the present invention. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the premise of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any equivalent changes, such as minor modifications, decorations, and evolutions made by those skilled in the art who are familiar with this specialty without departing from the spirit and scope of the present invention by using the technical content disclosed above, are equivalent embodiments of the present invention; at the same time, any equivalent changes, such as modifications, decorations, and evolutions made to the above embodiments based on the essential technology of the present invention, still fall within the scope of the technical solutions of the present invention.

Claims

1. A high temperature reheater for a fluidized bed boiler, comprising a separator (1), a furnace (2), a high temperature reheat panel inlet header (3) and a high temperature reheat panel outlet header (4), characterized in that: The utility model also comprises a low-temperature reheater inlet header (5), a low-temperature reheater (6), a low-temperature reheater outlet header (7), a micro-spray water desuperheater (8) and a high-temperature reheat screen assembly (9); the low-temperature reheater inlet header (5) is connected to the separator (1); the low-temperature reheater outlet header (7) is connected to the low-temperature reheater inlet header (5) through the low-temperature reheater (6); the low-temperature reheater (6) is located in the rear smoke shaft; the high-temperature reheat screen inlet header (3) is connected to the low-temperature reheater outlet header (7) through the micro-spray water desuperheater ( 8) connected; the high-temperature reheat screen assembly (9) comprises a high-temperature reheat screen descending section (91) and a high-temperature reheat screen ascending section (92), the high-temperature reheat screen descending section (91) and the high-temperature reheat screen ascending section (92) are arranged side by side in the furnace (2) and are connected to each other, the high-temperature reheat screen descending section (91) is connected to the high-temperature reheat screen inlet header (3) and extends from the top of the furnace (2) into the furnace (2), and one end of the high-temperature reheat screen ascending section (92) extends from the top of the furnace (2) and is connected to the high-temperature reheat screen outlet header (4).

2. A high temperature reheater for a fluidized bed boiler according to claim 1, characterized in that: The high-temperature reheat screen assembly (9) further comprises a high-temperature reheat screen intermediate mixing header (93), the high-temperature reheat screen descending section (91) and the high-temperature reheat screen ascending section (92) are connected via the high-temperature reheat screen intermediate mixing header (93), and the high-temperature reheat screen intermediate mixing header (93) is located outside the furnace (2).

3. A high temperature reheater for a fluidized bed boiler as claimed in claim 2, characterized in that: The high-temperature reheat shield components (9) are provided in multiple groups.

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