A backwash system for high temperature superheater and high temperature reheater of supercritical boiler

Abstract

This utility model relates to the field of backflushing technology for supercritical boilers, and particularly to a backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler. The backflushing system for a high-temperature superheater and high-temperature reheater of this utility model includes a reheater desuperheating water header, a main flushing pipeline, a first branch pipe, a second branch pipe, a high-temperature reheater, and a high-temperature superheater. One end of the main flushing pipeline is connected to the reheater desuperheating water header. One end of the first branch pipe and the second branch pipe are respectively connected to the other end of the main flushing pipeline. The other end of the first branch pipe is connected to the main steam outlet header of the high-temperature superheater, and the other end of the second branch pipe is connected to the outlet header of the high-temperature reheater. A filter pipeline is connected in parallel to the inlet header drain line of the high-temperature reheater, and a filter is installed on the filter pipeline. Advantages: The structure is reasonably designed, which can efficiently remove oxide scale, shorten the downtime maintenance cycle, reduce operation and maintenance costs, extend equipment life, and the whole process is safe and environmentally friendly.

Description

Technical Field

[0001] This utility model relates to the field of backwashing technology for supercritical boilers, and in particular to a backwashing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler. Background Technology

[0002] Circulating fluidized bed supercritical boilers are widely used in the power industry due to their high efficiency and low pollution. However, their high-temperature superheaters and reheaters operate under high temperature and high pressure environments for extended periods. Under the influence of high-temperature oxidation and thermal stress, oxide scale (mainly Fe3O4 and Fe2O3) easily forms on the inner walls of the tubes. Continuous accumulation of oxide scale can lead to the following problems:

[0003] 1) Deterioration of heat transfer: The low thermal conductivity of oxide scale (only 1 / 10-1 / 5 of that of metal) leads to local overheating of the pipe wall, accelerates material creep failure, and causes the risk of pipe bursting;

[0004] 2) Increased flow resistance: After the oxide scale peels off, it is deposited at elbows and welds with the steam flow, resulting in a reduction in flow area, an increase in steam pressure loss, and a decrease in unit efficiency.

[0005] 3) High maintenance costs: Traditional mechanical cleaning or chemical cleaning after shutdown requires disassembling the heated surface, which is time-consuming, and chemical agents can easily corrode the pipes.

[0006] Therefore, it is necessary to develop a high-temperature superheater and high-temperature reheater backflushing system for a supercritical boiler to solve the above-mentioned technical problems. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler, which effectively overcomes the defects of the prior art.

[0008] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0009] A backflushing system for a high-temperature superheater and a high-temperature reheater in a supercritical boiler includes a reheater desuperheating water header, a main flushing pipeline, a first branch pipe, a second branch pipe, a high-temperature reheater, and a high-temperature superheater. One end of the main flushing pipeline is connected to the reheater desuperheating water header. One end of the first branch pipe and the second branch pipe are respectively connected to the other end of the main flushing pipeline. The other end of the first branch pipe is connected to the main steam outlet header of the high-temperature superheater. The other end of the second branch pipe is connected to the outlet header of the high-temperature reheater. A filter pipeline is connected in parallel to the inlet header drain line of the high-temperature reheater, and a filter is installed on the filter pipeline.

[0010] Based on the above technical solution, the present invention can be further improved as follows.

[0011] Furthermore, a manual control valve is installed on the aforementioned main flushing pipeline.

[0012] Furthermore, the aforementioned manual control valve is provided in multiple forms.

[0013] Furthermore, a main pipe control valve is installed upstream of the connection between the reheater desuperheating water main pipe and the flushing main pipe.

[0014] Furthermore, the first branch pipe is equipped with a first backwash control valve.

[0015] Furthermore, a second backwash control valve is provided on the aforementioned second branch pipe.

[0016] Furthermore, an exhaust pipe is connected downstream of the aforementioned second branch pipe, and an exhaust valve is provided on the aforementioned exhaust pipe.

[0017] Furthermore, a first filter control valve is provided on the filter pipeline at the position upstream of the filter.

[0018] Furthermore, a second filter control valve is provided on the filter pipeline at the downstream position corresponding to the filter.

[0019] Furthermore, a temporary drainage control valve is installed on a section of the inlet header drainage pipeline that is connected in parallel with the filter.

[0020] The beneficial effects of this utility model are: reasonable structural design, efficient removal of oxide scale, shortening of downtime maintenance cycle, reduction of operation and maintenance costs, extension of equipment life, and safety and environmental protection throughout the process. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the backwashing system of the high-temperature superheater and high-temperature reheater of the supercritical boiler of this utility model.

[0022] The attached diagram lists the components represented by each number as follows:

[0023] 1. Reheater desuperheating water main pipe; 2. Flushing main pipe; 3. First branch pipe; 4. Second branch pipe; 5. High-temperature reheater; 6. High-temperature superheater; 7. Filter; 11. Main pipe control valve; 21. Manual control valve; 31. First backflushing control valve; 41. Second backflushing control valve; 42. Exhaust pipe; 51. Outlet main pipe; 52. Inlet header drain line; 53. Filter line; 61. Main steam outlet main pipe; 71. Drainage temporary control valve; 421. Exhaust valve; 531. First filter control valve; 532. Second filter control valve. Detailed Implementation

[0024] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0025] Example

[0026] like Figure 1 As shown, the backflushing system of the high-temperature superheater and high-temperature reheater of the supercritical boiler in this embodiment includes a reheater desuperheating water header 1, a flushing main pipeline 2, a first branch pipe 3, a second branch pipe 4, a high-temperature reheater 5, and a high-temperature superheater 6. One end of the flushing main pipeline 2 is connected to the reheater desuperheating water header 1. One end of the first branch pipe 3 and the second branch pipe 4 are respectively connected to the other end of the flushing main pipeline 2. The other end of the first branch pipe 3 is connected to the main steam outlet header 61 of the high-temperature superheater 6. The other end of the second branch pipe 4 is connected to the outlet header 51 of the high-temperature reheater 5. The inlet header drain line 52 of the high-temperature reheater 5 is connected in parallel with a filter line 53, and a filter 7 is provided on the filter line 53.

[0027] In this embodiment, the backwashing system for the high-temperature superheater and high-temperature reheater of the supercritical boiler uses reheater desuperheating water as the backwashing water source. Through pipeline control and switching, the backwash water is introduced into the outlet header 51 of the high-temperature reheater 5 and the main steam outlet header 61 of the high-temperature superheater 6, forming a reverse flow path: the backwashing medium flows through the outlet headers of the high-temperature reheater 5 and the high-temperature superheater 6, as well as each parallel branch pipe. Utilizing the system's inherent pressure and directional flow design, the oxide scale on the pipe walls is peeled off. Finally, the wastewater carrying the detached impurities is centrally discharged through the inlet header drain lines 52 of the high-temperature superheater 6 and the high-temperature reheater 5. This process achieves reverse high-pressure backwashing without dismantling the heated surfaces, and the backwash water source and drain path reuse the unit's original piping system. Simultaneously, a filter 7 is added to the inlet header drain line 52 of the high-temperature reheater 5 to intercept detached oxide scale particles, ensuring the safety of the drain system. Overall, through reverse high-pressure backwashing and system integration design, the following significant advantages are achieved:

[0028] 1) Highly efficient removal of oxide scale: The inherent pressure of the reheater desuperheating water drives the reverse flushing, which directly impacts and peels off the dense oxide layer on the pipe wall, resulting in high removal efficiency;

[0029] 2) Shorten downtime maintenance cycle: No need to disassemble the heated surface, the flushing process can be carried out after shutdown;

[0030] 3) Reduce operation and maintenance costs: reuse the original piping and drainage system of the unit to avoid adding complex equipment;

[0031] 4) Extend equipment life: Periodic backflushing effectively inhibits oxide scale thickening, reduces the risk of pipe wall overheating, and effectively extends the service life of the heated surface;

[0032] 5) Safety and environmental protection: The flushing wastewater is discharged to the unit's wastewater treatment system through the inlet header drainage to avoid pollution from chemical cleaning agents, and the flushing parameters are dynamically adjusted to prevent damage to the pipes.

[0033] In this embodiment, a manual control valve 21 is provided on the aforementioned main flushing pipeline 2. The flow of backflushing water in the pipeline is controlled by this manual control valve 21.

[0034] In this embodiment, multiple manual control valves 21 are provided. Specifically, three manual control valves 21 are provided, two of which are respectively designated as primary manual control valves and secondary manual control valves, and the remaining one is designated as a master manual control valve.

[0035] In this embodiment, a main pipe control valve 11 is provided upstream of the connection between the reheater desuperheating water main pipe 1 and the flushing main pipe 2. The main pipe control valve 11 can control the normal flow and flow rate of desuperheating water to the flushing main pipe 2.

[0036] In this embodiment, a first backwash control valve 31 is provided on the first branch pipe 3. The first backwash control valve 31 can control the backwash water to flow in reverse through the first branch pipe 3 into the high-temperature superheater 6 to achieve backwashing.

[0037] In this embodiment, a second backwash control valve 41 is provided on the second branch pipe 4. The second backwash control valve 41 can control the backwash water to flow in reverse through the second branch pipe 4 into the high-temperature reheater 5 to achieve backwashing.

[0038] In this embodiment, an exhaust pipe 42 is connected downstream of the second branch pipe 4, and an exhaust valve 421 is provided on the exhaust pipe 42. The design of the exhaust pipe 42 and the exhaust valve 421 enables the effective removal of gas entering the second branch pipe 4 after the exhaust valve 421 is opened.

[0039] In a preferred embodiment, a first filter control valve 531 is provided on the filter line 53 at the position upstream of the filter 7.

[0040] In the above implementation scheme, the first filter control valve 531 can control the normal flow state of the fluid in the filter pipeline 53, thereby switching between filtration and normal discharge.

[0041] Preferably, a second filter control valve 532 is provided on the filter pipeline 53 at the downstream position corresponding to the filter 7. By using the second filter control valve 532 in conjunction with the first filter control valve 531, the filter 7 can be kept away from fluid, and the dual valve control makes the fluid control of the pipeline more stable.

[0042] As a preferred embodiment, a temporary drainage control valve 71 is provided on a section of the inlet header drainage pipeline 52 connected in parallel with the filter 7.

[0043] In the above implementation scheme, one of the temporary condensate control valve 71, the first filter control valve 531, and the second filter control valve 532 can be opened or closed. During backwashing, the first filter control valve 531 and the second filter control valve 532 are opened, and the temporary condensate control valve 71 is closed. This is used to intercept detached oxide scale particles and ensure the safety of the condensate drainage system. During normal boiler operation, the first filter control valve 531 and the second filter control valve 532 are closed, and the temporary condensate control valve 71 is opened for normal condensate drainage.

[0044] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0046] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0047] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0049] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A backflushing system for a high-temperature superheater and high-temperature reheater in a supercritical boiler, characterized in that: The system includes a reheater desuperheating water header (1), a flushing main pipeline (2), a first branch pipe (3), a second branch pipe (4), a high-temperature reheater (5), and a high-temperature superheater (6). One end of the flushing main pipeline (2) is connected to the reheater desuperheating water header (1). One end of the first branch pipe (3) and the second branch pipe (4) are respectively connected to the other end of the flushing main pipeline (2). The other end of the first branch pipe (3) is connected to the main steam outlet header (61) of the high-temperature superheater (6). The other end of the second branch pipe (4) is connected to the outlet header (51) of the high-temperature reheater (5). The inlet header drain line (52) of the high-temperature reheater (5) is connected in parallel with a filter line (53), and a filter (7) is provided on the filter line (53).

2. The backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler according to claim 1, characterized in that: The main flushing pipeline (2) is equipped with a manual control valve (21).

3. The backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler according to claim 2, characterized in that: The manual control valve (21) is provided in multiple forms.

4. The backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler according to claim 1, characterized in that: A main pipe control valve (11) is provided upstream of the connection between the reheater desuperheating water main pipe (1) and the flushing main pipe (2).

5. The backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler according to claim 1, characterized in that: The first branch pipe (3) is equipped with a first backwash control valve (31).

6. The backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler according to claim 1, characterized in that: The second branch pipe (4) is equipped with a second backwash control valve (41).

7. The backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler according to claim 1, characterized in that: The second branch pipe (4) is connected to an exhaust pipe (42) downstream, and an exhaust valve (421) is provided on the exhaust pipe (42).

8. A backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler according to any one of claims 1 to 7, characterized in that: A first filter control valve (531) is provided on the filter pipeline (53) at the position upstream of the filter (7).

9. The backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler according to claim 8, characterized in that: A second filter control valve (532) is provided on the filter pipeline (53) at the downstream part of the filter (7).

10. The backflushing system for a high-temperature superheater and high-temperature reheater of a supercritical boiler according to claim 8, characterized in that: A temporary drainage control valve (71) is provided on a section of the inlet header drainage pipeline (52) that is connected in parallel with the filter (7).

Images