Anti-blocking device for oxide skin at elbow of U-shaped pipe on high-temperature heating surface of boiler

Abstract

The utility model provides an anti-blocking device for oxide skin at the elbow of a U-shaped pipe on a high-temperature heating surface of a boiler, which belongs to the technical field of power station boiler experiments and comprises an inlet header and an outlet header, and a plurality of heat exchange pipes are connected between the inlet header and the outlet header. An oxide skin anti-blocking mechanism is mounted at an elbow of the heat exchange pipe and comprises an oxide skin anti-blocking device with a triangular outer contour, and a plurality of anti-blocking device inlet pipes and a plurality of anti-blocking gas outlet pipes which are mounted on the two sides of the oxide skin anti-blocking device respectively; and the plurality of anti-blocking device inlet pipes and the plurality of anti-blocking gas outlet pipes are connected with the heat exchange pipe. Theoretical simulation calculation shows that the oxide skin anti-blocking mechanism with the contour in the shape of an equilateral triangle is additionally arranged at the elbow of the U-shaped pipe, so that oxide skin particles are obviously and stably deposited at the lower right corner of the oxide skin collecting mechanism in the shape of the equilateral triangle, and the problem of oxide skin blocking at the elbow of the U-shaped pipe is effectively avoided; and the problem of blockage caused by falling of an oxide film in the pipe is well solved.

Description

Technical Field

[0001] The utility model mainly relates to the technical field of power station boiler experiments, and in particular to an oxide scale blocking prevention device at a U-shaped tube elbow on a high-temperature heating surface of a boiler. Background Art

[0002] The problem of overheating and even overheating tube bursting caused by the oxide scale peeling off the inner wall of the high-temperature heating surface of the power station boiler and depositing inside the tube is one of the main problems that plague its safe and economical operation. As the boiler runs, an oxide film is formed on the inner surface of the high-temperature heating surface pipe, and long-term operation causes the thickness of the oxide film to increase. In the early stage of boiler startup, the temperature gradient of the high-temperature heating surface is large, which may cause the oxide film to fall off. Under the action of steam flow, it will be deposited at the U-shaped pipe elbow of the high-temperature heating surface, which is not conducive to the safe operation of the power station.

[0003] To address this problem, it is usually necessary to add an oxide scale collection device at the elbow of the U-shaped pipe. However, the different shapes of the adding devices have a great impact on the oxide scale collection effect, especially the oxide scale deposition position cannot be reasonably estimated, resulting in unsatisfactory oxide scale collection effect. For example, the invention patent with application number CN201810369466.7 adds a "U-shaped" oxide scale collection device at the elbow of the U-shaped pipe. In actual operation, the oxide scale is easy to gather at the upper port of the "U-shaped" device, and the oxide scale collection outlet is at the lower port, resulting in poor final oxide scale collection effect. The domestic oxide scale purging experimental device for power station boilers described in the invention patent CN201310079674.0 requires the addition of devices such as steam booster pumps and high-precision electronic scales, and has a complex structure and high cost. Utility Model Content

[0004] The utility model mainly provides an oxide scale blocking prevention device at a U-shaped tube elbow of a high-temperature heating surface of a boiler to solve the technical problems raised in the above-mentioned background technology.

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

[0006] A device for preventing scale from blocking at a U-shaped tube elbow on a high-temperature heating surface of a boiler, comprising an inlet header and an outlet header, wherein a plurality of heat exchange tubes are connected between the inlet header and the outlet header;

[0007] An oxide scale anti-blocking mechanism is installed at the elbow of the heat exchange tube, and the oxide scale anti-blocking mechanism includes an oxide scale anti-blocking device with a triangular outer contour, and multiple anti-blocking device inlet pipes and multiple anti-blocking gas exhaust pipes are respectively installed on both sides of the oxide scale anti-blocking device, and the multiple anti-blocking device inlet pipes and multiple anti-blocking gas exhaust pipes are all connected to the heat exchange tube.

[0008] Furthermore, the triangular outer contour of the oxide scale anti-blocking device is an "equilateral triangle".

[0009] Furthermore, the oxide scale anti-blocking device is provided with an oxide scale removing port at a bottom corner on one side of the oxide scale anti-blocking gas exhaust pipe close to the anti-blocking gas exhaust pipe.

[0010] Furthermore, the heat exchange tube has a U-shaped tube structure, and a plurality of heat exchange tubes form a heat exchange tube bundle.

[0011] Furthermore, the end of the heat exchange tube connected to the anti-blocking device inlet pipe is the heat exchange tube inlet end, and the end of the heat exchange tube connected to the anti-blocking gas exhaust pipe is the heat exchange tube outlet end.

[0012] Furthermore, the anti-blocking device inlet pipe and the heat exchange tube inlet end of the heat exchange tube, and the anti-blocking gas exhaust pipe and the heat exchange tube outlet end of the heat exchange tube are vertically connected through flanges.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] The utility model discloses an oxide scale anti-blocking mechanism at the U-shaped tube elbow of the high-temperature heating surface of the boiler with an outline of an "equilateral triangle". Theoretical simulation calculations show that the addition of an oxide scale anti-blocking mechanism with an outline of an "equilateral triangle" at the U-shaped tube elbow significantly makes the oxide scale particles stably deposited at the lower right corner of the "equilateral triangle" oxide scale collecting mechanism, effectively avoiding the oxide scale blockage problem at the U-shaped tube elbow, and better solving the blockage problem of the oxide film falling off the tube. Compared with oxide scale anti-blocking devices of other shapes, the utility model has a simple structure, is easy to operate, has obvious effects, and has low use and maintenance costs.

[0015] The design result of the utility model has the advantages of convenient process realization, broad application prospects, low cost, etc., can provide guidance for the selection of boiler blowing parameters, and can be applied to the field of power station boiler experimental technology.

[0016] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0018] Figure 2 This is a schematic diagram of the structure of the oxide skin anti-blocking mechanism of the utility model;

[0019] Figure 3 It is a geometrical schematic diagram of different shapes of oxide scale anti-blocking devices at the U-shaped tube elbow of the high-temperature heating surface of the boiler;

[0020] Figure 4 This is the distribution diagram of oxide scale particle concentration in oxide scale collection devices of different shapes at the U-shaped tube elbows of the high-temperature heating surface of the boiler.

[0021] In the figure: 1. Inlet header; 2. Outlet header; 3. Inlet end of heat exchange tube; 4. Outlet end of heat exchange tube; 5. Heat exchange tube; 6. Oxide scale anti-blocking mechanism; 61. Oxide scale anti-blocking device; 62. Anti-blocking device inlet pipe; 63. Anti-blocking gas exhaust pipe; 7. Oxide scale removal port. DETAILED DESCRIPTION

[0022] In order to facilitate the understanding of the present invention, the present invention will be described in more detail below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings, but the present invention can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the content disclosed in the present invention more thorough and comprehensive.

[0023] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0025] For examples, please refer to the attached Figure 1-4 , a device for preventing scale from blocking at a U-shaped tube elbow of a high-temperature heating surface of a boiler, comprising an inlet header 1 and an outlet header 2, wherein a plurality of heat exchange tubes 5 are connected between the inlet header 1 and the outlet header 2;

[0026] An oxide scale anti-blocking mechanism 6 is installed at the elbow of the heat exchange tube 5, and the oxide scale anti-blocking mechanism 6 includes an oxide scale anti-blocking device 61 with a triangular outer contour, and multiple anti-blocking device inlet pipes 62 and multiple anti-blocking gas exhaust pipes 63 respectively installed on both sides of the oxide scale anti-blocking device 61. The multiple anti-blocking device inlet pipes 62 and the multiple anti-blocking gas exhaust pipes 63 are all connected to the heat exchange tube 5.

[0027] For details, please refer to the attached Figure 2 , the triangular outer contour of the oxide scale anti-blocking device 61 is an "equilateral triangle";

[0028] In this embodiment, it should be noted that, compared with other conventional oxide scale blocking devices in the shape of a "U-shaped" and a "circular" shape, the oxide scale is obviously deposited in large quantities at the corners of the triangular device, which facilitates the cleaning of the oxide scale.

[0029] For details, please refer to the attached Figure 1 and attached Figure 2 The oxide scale anti-blocking device 61 is provided with an oxide scale removal port 7 at the bottom corner of one side close to the anti-blocking gas exhaust pipe 63;

[0030] In this embodiment, it should be noted that when the unit is operating normally, the scale removal port 7 is in a closed state. When the unit is stopped for maintenance, the scale removal port 7 can be opened to clear the deposited scale particles.

[0031] For details, please refer to the attached Figure 1 The heat exchange tube 5 is a U-shaped tube structure, and a plurality of heat exchange tubes 5 form a heat exchange tube bundle.

[0032] Furthermore, one end of the heat exchange tube 5 connected to the anti-blocking device inlet tube 62 is the heat exchange tube inlet end 3, and one end of the heat exchange tube 5 connected to the anti-blocking gas outlet tube 63 is the heat exchange tube outlet end 4;

[0033] In this embodiment, it should be noted that the steam passes through the inlet header 1, the heat exchange tube inlet end 3, the oxide scale anti-blocking device 61, the heat exchange tube outlet end 4 in sequence, and reaches the outlet header 2; during operation, the oxide scale shed from the inner wall of the pipeline is carried by the steam and moves in the heat exchange tube 5, which endangers the safe operation of the pipeline. An "equilateral triangle" anti-blocking mechanism is added. When the unit is running, the oxide scale particles carried in the steam are deposited in the lower right corner of the device in large quantities. When the unit is shut down, the oxide scale removal port 7 is opened to remove the oxide scale deposited in the lower right corner.

[0034] Furthermore, the anti-blocking device inlet pipe 62 and the heat exchange tube inlet end 3 of the heat exchange tube 5, and the anti-blocking gas outlet pipe 63 and the heat exchange tube outlet end 4 of the heat exchange tube 5 are vertically connected through flanges;

[0035] In this embodiment, it should be noted that the flange connection can facilitate assembly.

[0036] In addition, in this embodiment, the length of each side cross section of the "equilateral triangle" oxide scale blocker 61 (device thickness) is the pipe diameter, the width is half of the pipe diameter, and the side length is n times the pipe diameter, where n is an integer greater than or equal to 5 times the pipe diameter;

[0037] The particle deposition conditions of oxide scale collection devices of different shapes at the U-shaped tube elbows on the high-temperature heating surface of the boiler were simulated by Ansys-fluent.

[0038] As shown in the attached figure, Figure 1 The geometrical schematic diagrams of different shapes of oxide scale collection devices at the U-shaped tube elbow of the high-temperature heating surface of the boiler: (a) without any device, (b) adding a "triangular" oxide scale anti-blocking device, (c) adding a "U-shaped" oxide scale anti-blocking device, (d) adding a "circular" oxide scale anti-blocking device;

[0039] Figure 2 This is the distribution of oxide scale particle concentration in oxide scale collection devices of different shapes at the U-shaped pipe elbow of the high-temperature heating surface of the boiler. It can be seen from the figure that both the "U-shaped" and "circular" oxide scale anti-blocking devices cannot cause a large number of oxide scale particles to be deposited in a specific position; adding an "equilateral triangle" oxide scale anti-blocking device has a more obvious effect, and the oxide scale particles that fall off the pipe can be deposited in a large number in the lower right corner of the device.

[0040] The above description of the utility model in combination with the accompanying drawings is an exemplary description. Obviously, the specific implementation of the utility model is not limited to the above-mentioned method. As long as the non-substantial improvements are made by adopting the method concept and technical solution of the utility model, or the concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A device for preventing scale from blocking at a U-shaped tube elbow on a high-temperature heating surface of a boiler, comprising an inlet header (1) and an outlet header (2), characterized in that: A plurality of heat exchange tubes (5) are connected between the inlet header (1) and the outlet header (2); An oxide scale anti-blocking mechanism (6) is installed at the elbow of the heat exchange tube (5), and the oxide scale anti-blocking mechanism (6) comprises an oxide scale anti-blocking device (61) with a triangular outer contour, and a plurality of anti-blocking device inlet pipes (62) and a plurality of anti-blocking gas outlet pipes (63) respectively installed on both sides of the oxide scale anti-blocking device (61), and the plurality of anti-blocking device inlet pipes (62) and the plurality of anti-blocking gas outlet pipes (63) are all connected to the heat exchange tube (5).

2. The device for preventing oxide scale from blocking at the U-shaped tube elbow of the high-temperature heating surface of a boiler according to claim 1 is characterized in that: The triangular outer contour of the oxide scale anti-blocking device (61) is an "equilateral triangle".

3. The device for preventing oxide scale from blocking at the U-shaped tube elbow of the high-temperature heating surface of a boiler according to claim 1, characterized in that: The oxide scale anti-blocking device (61) is provided with an oxide scale removal port (7) at a bottom corner of one side close to the anti-blocking gas exhaust pipe (63).

4. The device for preventing oxide scale from blocking at the U-shaped tube elbow of the high-temperature heating surface of a boiler according to claim 1, characterized in that: The heat exchange tube (5) is of a U-shaped tube structure, and a plurality of heat exchange tubes (5) form a heat exchange tube bundle.

5. The device for preventing oxide scale from blocking at the U-shaped tube elbow of the high-temperature heating surface of a boiler according to claim 4, characterized in that: One end of the heat exchange tube (5) connected to the anti-blocking device inlet tube (62) is the heat exchange tube inlet end (3), and one end of the heat exchange tube (5) connected to the anti-blocking gas exhaust pipe (63) is the heat exchange tube outlet end (4).

6. The device for preventing oxide scale from blocking at the U-shaped tube elbow of the high-temperature heating surface of a boiler according to claim 5, characterized in that: The anti-blocking device inlet pipe (62) and the heat exchange tube inlet end (3) of the heat exchange tube (5), as well as the anti-blocking gas outlet pipe (63) and the heat exchange tube outlet end (4) of the heat exchange tube (5) are vertically connected via flanges.

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