Reversing flue of boiler

Abstract

The utility model discloses a boiler reversing flue which comprises a reversing flue body, and the reversing flue body is composed of a rectifier box and a reversing connector. The reversing flue body can be arranged at any position in a boiler flue and used for reversing high-temperature flue gas flowing through a rectifier box in any area of the boiler flue in any direction and then leading out and / or leading in again. And meanwhile, the smoke bias flow phenomenon is relieved, and uneven heat exchange of heat exchange equipment located on the upstream and the downstream of the reversing flue body in the boiler flue due to smoke bias flow is avoided.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, specifically to a boiler reversing flue. Background Technology

[0002] In existing waste heat recovery systems, especially in old boiler renovation projects, in order to save energy and reduce emissions or add a certain process, high-temperature flue gas is usually drawn out at a certain location in the original boiler flue. After passing through some external process equipment, the drawn high-temperature flue gas needs to be returned to the original boiler flue for further heat exchange.

[0003] Currently, common practices in old boiler retrofit projects include external cyclone separator pre-dust removal and external SCR denitrification processes. Because the high-temperature flue gas in the original boiler flue needs to be diverted to one side at an angle close to 90°, flue gas deviation inevitably occurs during the diversion process. For example, multiple heat exchange devices are often arranged in the boiler flue, with space reserved between adjacent devices for installation, maintenance, measurement, and purging. Since the flue gas inlet and re-inlet can often only be located within this space, they will inevitably be close to the upstream and downstream heat exchange devices, causing severe flue gas deviation in the heat exchange device area, resulting in uneven heat exchange and reduced efficiency.

[0004] For example, in the prior art, Chinese patent document with publication number CN212481227U describes a flow equalization plate structure for the inlet flue of a waste heat boiler. This structure performs a first flow equalization treatment on the flue gas by setting a first flow equalization plate structure at the first flue opening, and a second flow equalization treatment on the flue gas by a flow plate structure in the second flue, to prevent flow deviation.

[0005] Existing technologies only consider improving flue gas flow deviation by setting up a flow equalization plate structure. However, this structure cannot actually redirect high-temperature flue gas in any direction and then lead it out and / or reintroduce it. Therefore, it is necessary to propose a boiler reversing flue that can structurally achieve flue gas reversal while also mitigating flue gas flow deviation. Utility Model Content

[0006] One of the purposes of this application is to provide a boiler reversing flue that can both reverse the flue gas direction and alleviate flue gas deviation.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a boiler reversing flue, comprising a reversing flue body, wherein the reversing flue body is composed of a rectifier box and a reversing interface. The reversing flue body can be disposed at any position in the boiler flue, used to reversing the high-temperature flue gas in any area of ​​the boiler flue; simultaneously, the reversing interface can also be disposed in any direction of the rectifier box, used to reversing the high-temperature flue gas flowing through the rectifier box in any direction and then leading it out and / or reintroducing it.

[0008] Furthermore, the specific location and reversing direction of the reversing flue body can be set according to process requirements; since the flue gas temperature varies in different areas, when setting the reversing flue body, insulation and anti-corrosion measures can be selected or high-quality materials can be chosen, including but not limited to refractory casting or the use of heat-resistant and corrosion-resistant materials.

[0009] Furthermore, during the flue gas reversal process, the rectifier box has a rectifying function that can reduce flue gas deviation and prevent uneven heat exchange in the heat exchange equipment located upstream and downstream of the reversing flue body in the boiler flue due to flue gas deviation.

[0010] Furthermore, the reversing interface can be set at any position in the rectifier box, but in order to achieve better rectification effect, the reversing interface usually needs to be set to the longest path of flue gas flow, so that the high temperature flue gas can stay in the rectifier box for a longer time and the rectification effect is better.

[0011] Furthermore, the rectifier box is composed of four steel plates, or of steel plates and structural steel. It has a number of rectifier baffles and rectifier cones evenly arranged inside. The rectifier baffles evenly divide the rectifier box into a number of cavities of the same size. By arranging the rectifier cones in staggered and opposite directions in the upper and lower directions of the cavities, the rectifier box can be evenly divided into multiple non-interconnected flow channels.

[0012] Furthermore, the reversing interface is composed of four steel plates, or a combination of steel plates and structural steel. It contains at least one reversing baffle and multiple rectifier cones. The reversing baffle can evenly divide the reversing interface into two identical cavities. On the side of the cavity close to the rectifier box, by staggering and aligning the rectifier cones in the upper and lower directions on the reversing baffle, the reversing interface can be evenly divided into at least two non-connected flow channels.

[0013] Furthermore, the flow baffle, rectifier cone, and reversing baffle separate the rectifier box and reversing interface into a flue gas inlet, a flue gas outlet, a flue gas re-inlet, and a flue gas re-outlet.

[0014] Furthermore, on the side of the rectifier box where the commutation interface is installed, the protective plate is cut with connecting windows at intervals according to the rectifier cone arrangement in the commutation interface, so as to realize channel connection.

[0015] Furthermore, the reversing flue body can be directly welded to the boiler flue, or an expansion joint can be installed for sealing.

[0016] Furthermore, the length of the reversing interface along the flue gas flow direction should preferably exceed 1m.

[0017] Furthermore, the flue gas velocity within the reversing flue body should preferably be 3–15 m / s.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] In this invention, the boiler reversing flue can not only realize the reversal of flue gas, but also alleviate the flue gas deviation, and avoid uneven heat exchange of the heat exchange equipment located upstream and downstream of the reversing flue body due to the flue gas deviation. Attached Figure Description

[0020] Figure 1 This is a side view of a boiler reversing flue provided in an embodiment of this application.

[0021] Figure 2 This is a front view of a boiler reversing flue provided in an embodiment of this application.

[0022] Figure 3 This is a top view of a boiler reversing flue provided in an embodiment of this application.

[0023] Figure 4 This is a schematic diagram of flue gas reversing in a rectifier box of a boiler reversing flue provided in an embodiment of this application.

[0024] Figure 5 This is a schematic diagram of the flue gas outlet of the reversing interface of a boiler reversing flue provided in an embodiment of this application.

[0025] Figure 6 This is a schematic diagram of the flue gas re-inlet of the reversing interface of a boiler reversing flue provided in an embodiment of this application.

[0026] Illustration:

[0027] 1. Boiler flue; 2. Reversing flue body; 3. Rectifier box; 301. Rectifier baffle; 302. Rectifier cone; 4. Reversing interface; 401. Reversing baffle; 5. Flue gas inlet; 6. Flue gas outlet; 7. Flue gas re-inlet; 8. Flue gas re-outlet. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] To illustrate the technical solution described in this application, specific embodiments are provided below.

[0030] Please see Figures 1 to 6 As shown, this embodiment provides a boiler reversing flue, including a reversing flue body 2, which consists of a rectifier box 3 and a reversing interface 4. The reversing flue body 2 can be set at any position in the boiler flue 1 to reversing the high-temperature flue gas in any area of ​​the boiler flue 1; at the same time, the reversing interface 4 can also be set in any direction of the rectifier box 3 to lead out and / or reintroduce the high-temperature flue gas flowing through the rectifier box 3 after reversing it in any direction.

[0031] Boiler flue 1 is the high-temperature flue gas flow channel of various types of boilers in the existing boiler industry. It can be easily and accurately understood by ordinary technicians in this field, and will not be described in detail here.

[0032] Furthermore, the specific location and reversing direction of the reversing flue body 2 can be set according to process requirements. In some embodiments, when it is necessary to extract flue gas within a certain temperature range, it is often necessary to select an installation, maintenance, measurement, and purging space between two sets of adjacent heat exchange equipment to extract the high-temperature flue gas. For example, in the SCR retrofit of old boilers, since SCR requires a certain temperature range to achieve good results, the high-temperature flue gas is usually extracted between the superheater and the high-temperature economizer, or between the high-temperature economizer and the low-temperature economizer. Of course, the specific location for extracting the high-temperature flue gas varies depending on different temperature requirements and boiler structure.

[0033] In other embodiments, the temperature range of the exhaust gas is not a primary consideration. Instead, the focus is on separating more dust before the high-temperature flue gas enters the convection heat exchanger to alleviate ash accumulation in the tail-end heat exchanger. For example, the retrofitting of an external cyclone separator in an older boiler typically requires placing it before the tail-end convection heat exchanger to separate dust from the high-temperature flue gas. Because the flue gas temperature is often high, it is usually necessary to optimize the cyclone separator material or adopt an internal casting method to extend its service life.

[0034] For example, since the flue gas temperature varies in different areas, when setting up the reversing flue body 2, thermal insulation and corrosion protection measures or high-quality materials can be selected, including but not limited to refractory casting or the use of heat-resistant and corrosion-resistant materials. In this embodiment, heat-resistant and corrosion-resistant materials are preferred for the design.

[0035] As one of the preferred solutions in this embodiment, during the flue gas reversal process, the flue gas deviation is reduced by the rectification effect of the rectifier box 3. Under the rectification effect of the rectifier box 3, uneven heat exchange of the heat exchange equipment located upstream and downstream of the reversing flue body 2 in the boiler flue 1 due to flue gas deviation can be avoided.

[0036] It should be noted that the heat exchange equipment is the heating surface installed in the boiler flue 1. The heating surface is mainly a convective heating surface, including but not limited to evaporators, superheaters, economizers and various preheaters, etc. Those skilled in the art can easily and accurately understand this, so it will not be described in detail here.

[0037] Furthermore, the reversing interface 4 can be set at any position in the rectifier box 3, and its direction can also be adjusted as needed. However, in order to achieve better rectification effect, the reversing interface 4 is usually set to the longest path of the flue gas flow, so that the high-temperature flue gas can stay in the rectifier box 3 for a longer time and achieve better rectification effect.

[0038] For example, such as Figure 1 As shown, in this embodiment, the flue gas outlet 6 is located at the lower right of the reversing flue body 2, while the corresponding flue gas re-inlet 7 is located at the upper right of the reversing flue body 2. The advantage of this arrangement is:

[0039] 1. When the high-temperature flue gas in boiler flue 1 enters the reversing flue body 2 through flue gas inlet 5, it can only be drawn out through flue gas outlet 6 due to the restriction of rectifier box 3. The high-temperature flue gas needs to flow to the bottom of rectifier box 3 before it can be drawn out. In other words, the path for the high-temperature flue gas to be drawn out is longer than that for drawing out from the upper right, so the flue gas can stay in rectifier box 3 for a longer time, and the rectification effect is better.

[0040] 2. When the returning high-temperature flue gas enters the reversing flue body 2 through the flue gas re-inlet 7, it can only return to the boiler flue 1 through the flue gas re-outlet 8 due to the constraint of the rectifier box 3. The high-temperature flue gas needs to enter from the top of the rectifier box 3 before it can return to the boiler flue 1 downwards. Similarly, the return path of the high-temperature flue gas is longer than that of returning directly from the lower right, so the flue gas can stay in the rectifier box 3 for a longer time, resulting in a better rectification effect.

[0041] Please see Figures 1 to 6As shown, the rectifier box 3 achieves rectification through the following means: the rectifier box 3 is composed of four steel plates, or of steel plates and structural steel. It has a number of rectifier baffles 301 and rectifier cones 302 uniformly arranged inside. The rectifier baffles 301 uniformly divide the rectifier box 3 into a number of cavities with the same flow cross-section. By arranging the rectifier cones 302 in staggered and opposite directions in the upper, lower and / or front and rear directions of these cavities, the rectifier box 3 can be uniformly divided into multiple non-interconnected flow channels.

[0042] Please see Figures 1 to 6 As shown, the reversing interface 4 is composed of four steel plates, or a combination of steel plates and structural steel. It contains at least one reversing baffle 401 and multiple rectifier cones 302. The reversing baffle 401 can evenly divide the reversing interface 4 into two cavities with the same flow cross-section. On the side of the cavity close to the rectifier box 3, by staggering and aligning the rectifier cones 302 in the upper, lower and / or left and right directions of the reversing baffle 401, the reversing interface 4 can be evenly divided into at least two non-connected flow channels.

[0043] refer to Figures 4-6 As can be seen, when the flue gas flows into the rectifying cone 302, the rectifying cone 302 can evenly divide the flue gas into several regions of the same cross-sectional size to achieve uniform flow. Within the narrow space of the rectifying baffle 301, the high-temperature flue gas can be rectified. When the flue gas flows out of the rectifying cone 302, the rectifying cone 302 can guide the flue gas to diffuse evenly in order to stabilize the flow.

[0044] Furthermore, the rectifier baffle 301, rectifier cone 302, and reversing baffle 401 divide the rectifier box 3 and reversing interface 4 into a flue gas inlet 5, a flue gas outlet 6, a flue gas re-inlet 7, and a flue gas re-outlet 8. Each inlet and outlet consists of several evenly distributed gaps of the same size.

[0045] As one of the preferred embodiments, in this embodiment, the commutation interface 4 is installed on the right side of the rectifier box 3. Correspondingly, on the side where the commutation interface 4 is installed, the rectifier box 3 has its protective plate cut with connecting windows at intervals according to the arrangement of the rectifier cones 302 in the commutation interface 4. Figure 5 and Figure 6 (The cutting window in the middle) is used to achieve the connection between the flue gas re-inlet 7 and the flue gas re-outlet 8 of the rectifier box 3, and between the flue gas inlet 5 and the flue gas outlet 6.

[0046] Preferably, the reversing flue body 2 can be directly welded to the boiler flue 1, or an expansion joint can be installed for sealing.

[0047] Preferably, the length of the reversing interface 4 along the flue gas flow direction should exceed 1m.

[0048] Preferably, the flue gas velocity inside the reversing flue body 2 is 3 to 15 m / s.

[0049] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents. The terms "upper," "lower," "left," "right," "front," "rear," "inlet," "outlet" or other terms expressing positional relationships used in the invention are only for better describing the relative positional relationships of various structures or processes in the invention, and do not mean that any component of the invention is located in an absolute position before or after.

Claims

1. A boiler reversing flue, characterized in that, The system includes a reversing flue body (2), which consists of a rectifier box (3) and a reversing interface (4). The reversing flue body (2) is located at any position in the boiler flue (1) and is used to reversing the high-temperature flue gas in any area of ​​the boiler flue (1). The reversing interface (4) is located in any direction of the rectifier box (3) and is used to reversing the high-temperature flue gas flowing through the rectifier box (3) in any direction and then leading it out and / or re-introducing it.

2. The boiler reversing flue according to claim 1, characterized in that: The specific location and reversing direction of the reversing flue body (2) can be set according to the process requirements. Since the flue gas temperature varies in different areas, heat preservation and anti-corrosion measures are adopted, or refractory materials are cast or heat-resistant and corrosion-resistant materials are used to set the reversing flue body (2).

3. A boiler reversing flue according to claim 1, characterized in that: During the flue gas reversal process, the rectifier box (3) is used to reduce the flue gas deviation and avoid uneven heat exchange of the heat exchange equipment located upstream and downstream of the reversal flue body (2) in the boiler flue (1) due to the flue gas deviation.

4. A boiler reversing flue according to any one of claims 1 to 3, characterized in that: The reversing interface (4) is set at any position in the rectifier box (3); in order to achieve better rectification effect, the reversing interface (4) is set to the longest path of flue gas flow.

5. A boiler reversing flue according to any one of claims 1 to 3, characterized in that: The rectifier box (3) is composed of four steel plates or steel plates and structural steel. It is equipped with several rectifier baffles (301) and rectifier cones (302) evenly arranged inside. The rectifier baffles (301) evenly divide the rectifier box (3) into several cavities of the same size. By arranging the rectifier cones (302) in a staggered and opposite manner in the upper and lower directions of the cavity, the rectifier box (3) can be evenly divided into multiple non-interconnected flow channels.

6. A boiler reversing flue according to claim 5, characterized in that: The reversing interface (4) is composed of four steel plates or steel plates and structural steel. It has at least one reversing baffle (401) and multiple rectifier cones (302) inside. The reversing baffle (401) can evenly divide the reversing interface (4) into two identical cavities. On the side of the cavity close to the rectifier box (3), by staggering and aligning the rectifier cones (302) on the upper and lower sides of the reversing baffle (401), the reversing interface (4) can be evenly divided into at least two non-connected flow channels.

7. A boiler reversing flue according to claim 6, characterized in that: The rectifier baffle (301), rectifier cone (302) and reversing baffle (401) divide the rectifier box (3) and reversing interface (4) into a flue gas inlet (5), a flue gas outlet (6), a flue gas re-inlet (7) and a flue gas re-outlet (8).

8. A boiler reversing flue according to claim 6, characterized in that: On the side where the rectifier box (3) is installed, its protective plate is cut with connecting windows at intervals according to the rectifier cone (302) in the rectifier box (4) to achieve channel connection.

9. A boiler reversing flue according to any one of claims 1 to 3, characterized in that: The reversing flue body (2) is directly welded to the boiler flue (1), or an expansion joint is installed for sealing.

10. A boiler reversing flue according to any one of claims 1 to 3, characterized in that: The length of the reversing interface (4) along the flue gas flow direction exceeds 1m, and the flue gas flow velocity in the reversing flue body (2) is 3 to 15m / s.

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