Flue bifurcated fluid flow splitting device and use thereof

Abstract

The application discloses a flue bifurcation type fluid distribution device and application thereof, and belongs to the technical field of flue fluid distribution. The distribution device comprises an inlet cavity main pipe and a plurality of distribution branch pipes. The inlets of the distribution branch pipes are communicated with the inlet cavity main pipe. The distribution branch pipes are arc-shaped pipes, and the outlets of the ends of the distribution branch pipes all face the inner wall of the flue. The application is applied in a large flue and is used for distributing the hot flue gas, which is used for heating the flue gas to be heated in the flue, into two streams after the hot flue gas enters the inlet cavity main pipe. Under the action of the distribution branch pipes, the hot flue gas is distributed to the low-temperature heating areas at the left and right walls of the flue, so that the purpose of heating the flue gas to be heated is achieved. The uniformity of the temperature field at the outlet section of the flue is ensured.

Description

Technical Field

[0001] This invention relates to the field of flue fluid diversion technology, and in particular to a large flue bifurcation fluid diversion device. Background Technology

[0002] When the high-temperature hot flue gas generated by the external or internal flue gas heating device enters the flue, due to the short flue gas flow path, the high-temperature hot flue gas and the low-temperature flue gas to be heated are not mixed sufficiently. This can easily cause the high-temperature hot flue gas to be excessively concentrated near the central axis of the flue. This is not only not conducive to the uniform mixing of hot and cold flue gas, but can also cause damage to some parts of the flue structure due to thermal stress, affecting the normal operation and service life of the flue equipment.

[0003] Chinese patent application number 201380019461.7, published on December 17, 2014, discloses a fluid distributor. This fluid distributor is suitable for uniformly distributing multiphase fluids or slurries from an inlet pipe to multiple outlet pipes under the action of overcoming gravity, thereby avoiding the problem of multiphase fluid stratification caused by gravity, which would lead to uneven distribution of multiphase fluids at multiple outlet pipes to various processing units and reduce the working efficiency of the processing units. However, this fluid distributor is limited to fluid diversion at a single inlet in a small space and requires an external power source to provide the power for fluid flow. It shows serious deficiencies for fluid diversion in a large space without a power source. This fluid distributor cannot meet the requirement of accurately distributing fluids to the target area in a directional and quantitative manner in a large space without a power source, thus making it difficult to achieve the uniformity of fluid temperature and velocity in a large space.

[0004] Chinese patent application number 202110330563.7, published on June 22, 2021, discloses a fluid distributor and a distribution pipe assembly. This fluid distributor, used in a heat exchanger, has a distribution chamber within its main body. Liquid enters the front distribution chamber through the inlet pipe and is then evenly distributed into the rear chamber under the action of the distribution chamber. The liquid entering the rear chamber then flows out through multiple distribution branch pipes. While this fluid distributor features uniform and stable flow distribution, it cannot accurately and quantitatively distribute fluid to target areas in a large space without an external power source, thus making it difficult to achieve uniformity of fluid temperature and velocity in a large space.

[0005] In summary, all patents concerning fluid diversion require external power to drive the fluid to flow within the distributor for diversion. Therefore, it is particularly important to achieve multi-regional directional and quantitative fluid diversion in a large space without external power, enhance the uniform mixing of the fluid, reduce resistance loss, and achieve the goal of uniform temperature and velocity in the flow field of a large-space flue.

[0006] For example, Chinese patent application number 201811375629.9, published on April 5, 2019, discloses a flow-diverting and flow-blocking device for a tubular GGH flue system. This device is located at a bend in the original flue upstream of the heat exchanger inlet and consists of an arc-shaped thin-plate structure and a straight thin-plate structure. The convex surface of the arc-shaped thin-plate structure faces the direction of the incoming flue gas flow, thus intercepting the flow. The straight thin-plate structure is located behind the arc-shaped thin-plate structure, acting as a flow divider. The bottom end of the arc-shaped thin-plate structure is tightly connected to the front end of the straight thin-plate structure, causing the incoming flow to be diverted and intercepted by the flow-diverting and flow-blocking device. After passing around the flow, two parts of the fluid with similar radial velocities but opposite directions are obtained. After merging, their radial velocities largely cancel each other out, making the velocity direction of the main flow field parallel to the flue direction. However, this device is only suitable for diverting and guiding fluid flow in fluid fields with a uniform inlet temperature field. It cannot guarantee the uniformity of the outlet temperature field when diverting fluid flow in fluid fields with non-uniform inlet temperature fields. Achieving uniformity of the temperature field at the flue outlet is particularly important.

[0007] Chinese patent application number 201410604208.4, published on May 13, 2015, discloses a flue gas diversion control system for an economizer's built-in flue gas duct. This control system includes an inlet header, an outlet header, and multiple serpentine pipe coils located between the inlet and outlet headers. The control system also includes at least one baffle and a flue gas temperature regulating baffle. One end of the baffle passes through the outlet header and enters the flue gas duct between the inlet and outlet headers, dividing the flue gas duct. The flue gas temperature regulating baffle is located on the baffle, blocking the divided portion of the flue gas duct. Although this patent allows for the control and adjustment of flue gas volume and temperature according to boiler load, it focuses on fluid diversion under conditions of uniform inlet temperature rather than large temperature differences. The fluid diversion control system employed in this patent has a complex structure and high construction cost.

[0008] Therefore, a large flue gas diverter is needed to divert the high-temperature hot flue gas near the central axis of the flue to the low-temperature heating areas on the left and right sides of the flue, thereby improving the uniformity of flue gas temperature at the flue outlet section. Summary of the Invention

[0009] 1. The problem to be solved

[0010] To address the aforementioned problems, this invention proposes a bifurcation fluid distributor with low flow resistance, good diversion effect, adjustable diversion flow rate, and directional diversion. Furthermore, it is suitable for diverting high-temperature flue gas in large flues and can achieve uniform diversion of hot flue gas in large spaces without external power drive.

[0011] 2. Technical Solution

[0012] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0013] A flue gas branching fluid diversion device includes an inlet cavity main pipe and several branch pipes. The inlets of each branch pipe are connected to the inlet cavity main pipe. Each branch pipe is an arc-shaped pipe with adjustable length and height, and its outlet faces the inner wall of the flue gas duct. The horizontal cross-section of the inlet cavity main pipe can be circular, rectangular, or other shapes. High-temperature hot flue gas used to heat the flue gas in the flue enters the inlet cavity main pipe of the diversion device and is divided into several streams that flow into the branch pipes. Under the diversion effect of the branch pipes, the high-temperature hot flue gas flows upward along the flue gas wall, compensating for the deficiency that the flue gas near the original flue gas wall is not heated.

[0014] Furthermore, the cross-section of the inlet cavity main pipe (11) in the pipe diameter direction is rectangular. The length a of the rectangular cross-section is 2000-10000 mm, preferably 3000 mm. The longer the length, the better the capture of hot flue gas, but the corresponding flow resistance in the flue will increase. The width b of the rectangular cross-section is 1000-3400 mm, preferably 2200 mm. Similarly, the wider the width, the better the collection of hot flue gas in the flue, but the corresponding flow resistance in the flue will increase.

[0015] Furthermore, the horizontal cross-section of the branch pipe is circular, elliptical, or rectangular, and its size and number are adjustable. Using circular or elliptical pipes can reduce the resistance to the flow of the flue gas to be heated. The diameter of the circular horizontal cross-section is 100-2200 mm, preferably 2000 mm. The larger the aperture, the lower the pressure in the main inlet cavity, which is more conducive to the collection of hot flue gas in the main inlet cavity. However, after the aperture reaches a certain level, further increasing the aperture will reduce the flow rate of hot flue gas in the branch pipe, which is not conducive to the diversion. The major axis of the elliptical horizontal cross-section is 1 / 2b, and the minor axis is 1 / 2a.

[0016] Furthermore, the relative height between the center point of the outlet of the diversion branch pipe and the connection surface of the main inlet cavity is 1000-10000 mm, preferably 2000 mm or 6000 mm, and the relative horizontal width is 1000-10000 mm, preferably 4000 mm. By changing the horizontal length and vertical height of the diversion branch pipe, hot flue gas can be distributed to a designated spatial location, and the higher the relative height of the outlet of the diversion branch pipe, the lower the flow resistance of the fluid in the flue. If the horizontal length of the diversion branch pipe is long, the flow resistance of the fluid in the low-temperature zone on both sides of the flue will increase, and the high-temperature flue gas diverted from the diversion branch pipe will generate high-temperature zones on the left and right walls of the main flue, reducing the life of the flue wall. If the horizontal length of the diversion branch pipe is short, the high-temperature flue gas flowing out from the diversion branch pipe cannot be distributed to the low-temperature heating zones on the left and right sides of the flue, failing to meet the goal of diversion and heating.

[0017] Furthermore, several diversion holes are formed on the surface of the branch pipe facing away from the main inlet cavity. A portion of the high-temperature flue gas entering the branch pipe will flow towards the flue outlet through the diversion holes, thereby compensating for the relatively low temperature in the middle area. The high-temperature hot flue gas used for heating is evenly distributed to various parts of the horizontal cross-section of the flue after passing through the diversion device, ultimately achieving a uniform distribution of flue gas temperature at the flue outlet cross-section.

[0018] Furthermore, the diversion hole can be a circular hole, an elliptical hole, or a rectangular hole, wherein the diameter of the circular hole is 100-2200 mm, preferably 800 mm.

[0019] The flow rate of hot flue gas entering the diversion device is controlled by changing the cross-sectional area of ​​the main inlet cavity, the size and number of the branch pipes, and the flow rate and distribution of hot flue gas in the middle area of ​​the flue are controlled by changing the size, position and number of the branch pipes. This achieves the purpose of directional and quantitative diversion, thereby improving the uniformity of temperature and velocity at the flue outlet cross-section.

[0020] In the aforementioned flue gas bifurcation fluid diversion device, the high-temperature hot flue gas generated by the heating device for heating the low-temperature flue gas to be heated in the flue enters the main inlet cavity and is divided into at least two streams by the diversion branch pipes. Under the action of at least two diversion branch pipes on the left and right sides, most of the high-temperature flue gas flows along the inner diameter of the diversion branch pipes and finally flows out from the outlet section of the diversion branch pipes, delivering the high-temperature hot flue gas to the low-temperature areas to be heated on the left and right sides of the main flue. A small portion of the high-temperature flue gas flows out from the diversion holes on the upper surface of the diversion branch pipes to compensate for the deficiency of less hot flue gas in the middle part of the flue caused by diversion. The high-temperature flue gas flowing out from the diversion branch pipes is fully mixed and heat exchanged with the low-temperature flue gas to be heated flowing upward along the flue wall on the left and right sides of the main flue, thereby heating the low-temperature flue gas to be heated to the target temperature and ensuring the uniformity of fluid temperature at the flue outlet section. Because the low-temperature flue gas to be heated is the desulfurized and dust-removed flue gas to be denitrified, and the high-temperature hot flue gas in the branch pipe of the branched fluid distributor has a high flow velocity, there will be no problems such as ash accumulation, blockage, or difficulty in cleaning within the distributor. The distributor can directionally and quantitatively divert the hot fluid to the area where the cold fluid is located according to the distribution position of the hot and cold fluids in the flue, thereby solving the problem of uneven fluid temperature at the flue outlet section caused by the local unheated fluid in the flue not being heated.

[0021] An application of a bifurcated fluid diversion device for a flue is described, in which the aforementioned bifurcated fluid diversion device is coaxially installed in the middle position within a vertical flue, with adjustable height, width, and length. It is fixed to the flue wall using angle steel, leaving a certain gap between it and the flue wall. The lower end of the vertical flue is connected to GGH; and the shape of the main inlet cavity pipe is consistent with the shape of the vertical flue, wherein:

[0022] When the vertical flue is a rectangular flue, the distance from the outlet of the branch pipe end to the inner wall of the flue is 1 / 10 to 1 / 4 of the flue length or width, preferably 1 / 5 of the flue length or width; a larger gap is not conducive to the collection of hot fluid, while a smaller gap will increase the resistance to fluid flow.

[0023] When the vertical flue is cylindrical, the distance from the outlet of the branch pipe to the inner wall of the flue is 1 / 10 to 4 / 5 of the radius of the cylindrical flue, preferably 3 / 10 of the radius of the cylindrical flue.

[0024] Furthermore, the flue located below the bifurcated fluid diversion device includes at least one section of bent flue. The bent flue comprises an arc-shaped flue, a first bent flue, and a second bent flue, arranged in any order and connected. The first and second bent flues are rectangular flues and their positions are offset from the vertical direction. The bent flues are tightly fitted together and connected by fixed welding.

[0025] Furthermore, the angle between the first bend in the flue and the vertical direction is 15-60°, preferably 30°; the angle between the second bend in the flue and the vertical direction is 30-90°, preferably 45°.

[0026] Furthermore, a circular arc-shaped flue is preferred over an arc-shaped flue.

[0027] 3. Beneficial effects

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) The diversion device of the present invention can achieve uniform diversion of hot flue gas in a large space without external power drive, thereby achieving uniform mixing of hot and cold flue gas in the flue. It can not only play the role of uniform flow field, but also divert the high temperature fluid in the middle part of the flue to the low temperature region, so that the high temperature fluid and the low temperature fluid can fully exchange heat, thereby satisfying the uniformity of temperature at the outlet. The present invention is suitable for fluid diversion and temperature equalization at large temperature difference inlet. After diversion, it meets the goal of uniform outlet temperature. Moreover, it is relatively simple to build and implement and has low cost.

[0030] (2) The cross-section of the branch pipe of the diversion device of the present invention is circular, elliptical, rectangular or other geometric shapes. It is preferred to use circular or elliptical shapes, which can greatly reduce the resistance loss of fluid flow in the flue, thereby reducing the workload of the induced draft fan and helping to save energy and reduce consumption.

[0031] (3) By changing the cross-sectional area of ​​the main inlet cavity of the diversion device and the number and size of the diversion branches, the present invention can control the flow rate of hot flue gas entering the diversion device. At the same time, the position of the outlet of the branch pipe end can be adjusted by the horizontal length and vertical height of the branch pipe, so that the hot flue gas can be accurately delivered to the low temperature flue area to be heated. The uniformity of the temperature of the flue gas to be heated in the flue can be greatly improved by quantitative and directional diversion of hot flue gas.

[0032] (4) By opening a certain number and size of holes on the upper surface of the branch pipe, the present invention can help to compensate for the low temperature in a small local area in the middle of the flue. At the same time, since the temperature of the heated flue gas is not very high, there is no need to use expensive high-temperature resistant materials, which can greatly reduce material costs. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the flue bifurcation fluid diversion device in Example 1;

[0034] Figure 2 This is a diagram showing the usage status of the flue bifurcation fluid diversion device in Example 1;

[0035] Figure 3 This is a schematic diagram of the structure of Example 1, where a curved flue is connected to the bottom of a rectangular flue;

[0036] Figure 4 This is a schematic diagram of the flue bifurcation fluid diversion device in Example 2;

[0037] Figure 5 This is a diagram showing the usage status of the flue bifurcation fluid diversion device in Example 2;

[0038] Figure 6 This is a schematic diagram of the flue bifurcation fluid diversion device in Example 3;

[0039] Figure 7 This is a top view of the flue bifurcation fluid diversion device in Example 3;

[0040] Figure 8 This is a diagram showing the usage status of the flue bifurcation fluid diversion device in Example 3;

[0041] Figure 9 This is a diagram showing the usage status of the guide vane diverter in the comparative example;

[0042] Figure 10 This is a comparison of the vertical cross-sectional temperature cloud map of the flue obtained from numerical simulation of the flue bifurcation fluid diversion device in Example 2 and the conventional flue guide plate diversion in the comparative example.

[0043] Figure 11This is a comparison chart of the flue outlet temperature cloud map obtained from numerical simulation of the flue bifurcation fluid diversion device in Example 2 and the conventional flue guide plate diversion in the comparative example;

[0044] In the picture:

[0045] 1. Diversion device; 11. Main inlet cavity pipe; 12. Diversion branch pipe; 121. Diversion hole; 2. Rectangular flue; 3. Cylindrical flue; 4. Bent flue; 41. Arc flue; 42. First bent flue; 43. Second bent flue. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0047] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0048] Example 1

[0049] like Figure 1 The illustrated flue bifurcation fluid diversion device includes: a cubic inlet cavity main pipe 11 and two diversion branch pipes 12 connected above the inlet cavity main pipe 11.

[0050] Specifically, the diversion device 1 includes a cubic inlet cavity main pipe 11 and two diversion branch pipes 12. The cross-section of the inlet cavity main pipe 11 in the diameter direction is rectangular, and the length of the rectangular cross-section is represented by a. The range of a is 2000 to 10000 mm, and the preferred length in this embodiment is 3000 mm. The longer the length, the more beneficial it is for capturing hot flue gas, but the flow resistance in the flue will increase accordingly. The rectangular cross-section of the inlet cavity main pipe 11 is represented by b, and the range of b is 1000 to 3400 mm, and the preferred length in this embodiment is 2200 mm. Similarly, the wider the width, the more beneficial it is for collecting hot flue gas in the flue, but the flow resistance in the flue will increase accordingly. The size and number of the two branch pipes 12 are adjustable, and the shape of the pipe cross-section can be circular, elliptical, or other shapes. In this embodiment, a circular or elliptical shape is preferred. If it is a circular hole, the diameter of the hole is 100-2200 mm, and in this embodiment, 2000 mm is preferred. If it is an elliptical hole, the major axis of the hole is 1 / 2b, and the minor axis is 1 / 2a. The height of the branch pipe 12 is adjustable, with a maximum relative height range of 1000-4000 mm. In this embodiment, 2000 mm is preferred. The higher the height, the lower the flow resistance of the fluid in the flue. The relative horizontal width of the branch pipe 12 is 1000-10000 mm, and 4000 mm is preferred. If the horizontal length of the branch pipe 12 is long, the flow resistance of the fluid in the low-temperature zone on both sides of the flue will be reduced. This will increase the high-temperature flue gas exiting from the branch pipe 12, creating high-temperature zones on the left and right walls of the main flue and reducing the flue wall life. If the horizontal length of the branch pipe 12 is too short, the high-temperature flue gas flowing out from the branch pipe 12 cannot be distributed to the low-temperature areas to be heated on the left and right sides of the flue, failing to meet the goal of diversion and heating. By adjusting the vertical height and horizontal length of the branch pipe 12, the high-temperature flue gas can be diverted directionally to the low-temperature areas to be heated in the flue. By adjusting the cross-sectional area of ​​the main inlet cavity 11 and the diameter of the branch pipe 12, the flow rate of the high-temperature flue gas entering the diversion device 1 can be adjusted, thereby quantitatively diverting the high-temperature flue gas to the low-temperature areas to be heated in the flue, effectively raising the flue gas temperature in the low-temperature areas to be heated.

[0051] like Figure 2 As shown, in this embodiment, the above-mentioned diversion device is applied to the rectangular flue 2. That is, the diversion device 1 and the rectangular flue 2 are arranged coaxially along the longitudinal centerline and fixed to the inner wall of the rectangular flue 2 using angle steel. A certain gap is left between the diversion device 1 and the inner wall of the rectangular flue 2. The distance from the outlet of the diversion branch pipe 12 to the inner wall of the flue is 1 / 10 to 1 / 4 of the flue length. In this embodiment, it is selected as 1 / 5 of the flue length or width. If the gap width is too large, it will affect the flow rate of the high-temperature hot flue gas entering the main pipe of the inlet cavity of the bifurcated fluid diverter. If the gap width is too small, it will increase the resistance loss of the fluid in the flue. Therefore, the gap width should be selected appropriately.

[0052] It is worth noting that, such as Figure 3 As shown, a bent flue 4 is connected below the rectangular flue 2. Located below the bifurcated fluid diversion device, the bent flue 4 includes an arc-shaped flue 41, a first bent flue 42, and a second bent flue 43, which are connected in any order. The angle between the first bent flue 42 and the vertical direction is 15-60°, preferably 30°; the angle between the second bent flue 43 and the vertical direction is 30-90°, preferably 45°. The bent flue shape increases the flow path of the fluid within the flue, improving the mixing time of the hot and cold fluids. Simultaneously, turbulence occurs when the fluid passes through the bent section, which is beneficial for the mixing and heat exchange of the hot and cold fluids.

[0053] Example 2

[0054] This embodiment of the flue gas branching fluid diversion device has a structure that is basically the same as that of Embodiment 1, such as... Figure 4 and Figure 5 As shown, furthermore: a certain number and size of diversion holes 121 are opened on the upper surface of the diversion branch pipe 12.

[0055] In this embodiment, a certain number and size of diversion holes 121 are opened on the diversion branch pipe 12 of the diversion device 1. The diversion holes 121 can be round holes, elliptical holes, rectangular holes, etc., preferably round holes. The size, position and number of holes are adjustable. The diameter of the holes is 100 to 2200 mm. In this embodiment, 800 mm is preferred. The larger the hole diameter, the lower the pressure in the main inlet cavity, which is more conducive to the collection of hot flue gas in the main inlet cavity. However, after the hole diameter reaches a certain level, further increasing the hole diameter will reduce the flow rate of hot flue gas in the branch pipe, which is not conducive to diversion. When the high-temperature flue gas passes through the diversion device 1, it is divided into two streams, left and right, by the diversion branch pipe 12. During this process, the temperature on the left and right sides of the flue cross-section tends to be relatively high, while the temperature in the middle area is relatively low. By opening a certain number and size of diversion holes 121 on the diversion branch pipe 12 of the diversion device 1, a portion of the high-temperature flue gas flowing along the diversion branch pipe 12 can flow through the diversion holes 121 towards the flue outlet, thus compensating for the relatively low temperature in the middle part of the flue cross-section. This achieves the target requirement of a temperature difference of ±10℃ at the flue outlet cross-section.

[0056] Example 3

[0057] like Figure 6 and 7 As shown, the flue bifurcation fluid diversion device described in this embodiment consists of a cylindrical inlet cavity main pipe 11 and four diversion branch pipes 12.

[0058] like Figure 8As shown, in this embodiment, the diversion device 1 is applied inside the cylindrical flue 3. The diversion device 1 and the circular flue 1 are arranged along the same central axis, and angle steel is used to connect and fix the diversion device 1 to the flue wall. Let the cross-sectional radius of the cylindrical flue 3 be r, then the radius of the inlet cavity main pipe 11 of the diversion device 1 is 0.1~0.9r, and in this embodiment, it is preferably 0.5r. If the radius of the inlet cavity main pipe 11 of the diversion device 1 is too large, the cross-sectional area of ​​the inlet cavity main pipe 11 will increase, which will reduce the gap between the inlet cavity main pipe 11 of the diversion device 1 and the circular flue wall, resulting in increased flow resistance of flue gas in the flue, and thus increasing the working load of the fan. If the radius of the inlet cavity main pipe 11 of the diversion device is too small, the cross-sectional area of ​​the inlet cavity main pipe 11 will decrease, which is not conducive to the collection of hot flue gas. Therefore, the radius of the inlet cavity main pipe 11 of the diversion device is preferably 0.5r. Four branch pipes 12 are evenly distributed on the upper surface of the main inlet cavity 11. Several branch holes 121 are opened on the upper plane of the main inlet cavity 11, and at least one branch hole 121 is opened in each branch pipe 12. The radius of the branch hole 121 is 0.05 to 0.45r, and in this embodiment, it is preferably 0.25r. The branch pipe 12 is an arc-shaped pipe with a radius of 1000–10000 mm, preferably 6000 mm. The distance between the end of the branch pipe 12 and the flue wall 201 is 0.1–0.8r, preferably 0.3r. A larger distance between the end of the branch pipe 12 and the flue is not conducive to the diversion of hot fluid, while a smaller distance increases the fluid flow resistance in the flue and causes excessive local temperature on the flue wall due to the hot flue gas being too concentrated, shortening the service life of the flue. The height between the end of the branch pipe 12 and the plane 202 is 1000–10000 mm, preferably 6000 mm. The radius of the diversion hole 121 is 0.01–0.05r, preferably 0.03r. If the hole diameter is too small, it is not conducive to the heating of the intermediate low-temperature region. If the hole diameter is too large, most of the hot flue gas will flow upward through the small hole, affecting the flow rate of hot flue gas in the branch pipe, and thus affecting the diversion effect of the branched fluid diverter.

[0059] It is worth noting that a bent flue 4 is connected below the rectangular flue 2. Located below the bifurcated fluid diversion device, the bent flue 4 includes an arc-shaped flue 41, a first bent flue 42, and a second bent flue 43, arranged in any order and connected. The first bent flue 42 has an angle of 15–60° with the vertical direction, preferably 30°; the second bent flue 43 has an angle of 30–90° with the vertical direction, preferably 45°. The bent flue shape increases the flow path of the fluid within the flue, improving the mixing time of the hot and cold fluids. Simultaneously, turbulence occurs when the fluid passes through the bent section, which is beneficial for the mixing and heat exchange of the hot and cold fluids.

[0060] Comparative Example

[0061] like Figure 9 The diagram shows a conventional guide plate diversion device, which consists of a flue 1 and guide plates 2 and 3. The guide plates 201 and 202 are symmetrically arranged along the vertical central axis of the flue. Angle steel is used to fix the guide plates to the flue wall. The guide plates 201 and 202 are rectangular plates with a length of 1000-4000mm, preferably 2000mm, and a width of 500-3000mm, preferably 1500mm. The angle between the guide plates 201 and 202 and the horizontal direction is 45°. If the angle is too large, the high-temperature flue gas cannot be effectively diverted to both sides of the flue. If the angle is too small, the flow resistance of the flue gas in the flue will increase. The distance between the bottom edge of the guide plates 201 and 202 and the vertical center axis of the flue is 100-2000mm, preferably 1000mm. If the distance is too large, it will not be conducive to the diversion of high-temperature hot flue gas near the center axis of the flue. If the distance is too small, the hot flue gas will not achieve the diversion effect. The guide plates 301 and 302 are located above the guide plates 201 and 202, and are also symmetrically arranged along the vertical central axis of the flue. The guide plates 301 and 302 are rectangular plates with a length of 1000-4000mm, preferably 2000mm, and a width of 500-3000mm, preferably 1500mm. The angle between the guide plates 301 and 302 and the horizontal direction is 45°. The distance between the bottom edge of the guide plates 301 and 302 and the vertical central axis of the flue is 500-4000mm, preferably 2000mm. If the distance is too large, the flow resistance of the flue gas on the left and right sides of the flue will increase. If the distance is too small, the hot flue gas passing through the guide plates 201 and 202 cannot be well diverted.

[0062] Figure 10This is a comparison of vertical cross-sectional temperature cloud maps of a flue obtained through numerical simulation of a bifurcated fluid diverter proposed in this invention and a conventional flue gas diversion device with a guide vane. The simulation conditions were that high-temperature hot flue gas at 1120°C mixed with 170°C flue gas to be heated in the flue. Figure b) on the right shows the vertical cross-sectional temperature cloud map of the flue obtained using the bifurcated fluid diverter proposed in Example 2, while Figure a) on the left shows the vertical cross-sectional temperature cloud map of the flue obtained using a conventional guide vane in the comparative example. It is clear from the figures that after using the bifurcated fluid diverter proposed in this invention, the high-temperature flue gas in the flue is better distributed to the low-temperature heating areas on both sides of the flue. In contrast, using a conventional guide vane diversion device easily leads to the heating areas on both sides of the flue not receiving high-temperature flue gas, resulting in lower temperatures in these areas. This results in uneven mixing of the heated flue gas and the flue gas to be heated in the flue, failing to meet the target requirement of temperature uniformity at the flue outlet section. Therefore, by using the flue bifurcation fluid diversion device proposed in this invention, the heated flue gas can be directionally and quantitatively distributed to the low-temperature region in the flue according to the position of the flue gas to be heated in the flue, so as to meet the target requirement of uniform temperature at the flue outlet section.

[0063] Figure 11 This is a comparison of flue outlet temperature cloud maps obtained from numerical simulations of the bifurcation fluid diverter proposed in this invention and the conventional flue baffle diverter. The simulation conditions were the mixing of high-temperature hot flue gas at 1120℃ and the flue gas to be heated in the flue at 170℃. Figure b) on the right shows the flue outlet temperature cloud map obtained using the bifurcation fluid diverter proposed in Example 2, while Figure a) on the left shows the flue outlet temperature cloud map obtained using the conventional flue baffle diverter as a comparative example. It is clear from the figures that after using the bifurcation fluid diverter proposed in this invention, the temperature of the flue gas to be heated in the flue tends to be more uniform, and the temperature difference at the flue outlet cross-section is 11℃, meeting the target requirement of ±10℃. In contrast, the temperature difference at the outlet cross-section of the device using the conventional flue baffle diverter is 40℃, failing to meet the target requirement of ±10℃. The present invention proposes a bifurcated fluid distributor that can directionally and quantitatively distribute high-temperature flue gas to various regions within the flue, thereby effectively solving the problem that the high-temperature flue gas ejected from the burner outlet is excessively concentrated in the area near the central axis of the flue, resulting in insufficient heating of the flue gas near the left and right side walls of the flue and causing excessively low temperatures. This is beneficial for the uniform mixing and heat exchange of the heating flue gas and the flue gas to be heated within the large flue, improving the temperature uniformity at the flue outlet cross-section and meeting the target requirement of ±10℃ temperature difference at the outlet cross-section.

[0064] Tables 1 and 2 are parameter tables for the bifurcation fluid diversion device in Example 2 and the conventional guide vane diversion device in the comparative example, respectively.

[0065] Table 1. Parameters of the bifurcation fluid diversion device in Example 2

[0066] Serial Number Project Name parameter 1 Maximum temperature at flue outlet 199℃ 2 Minimum temperature at flue outlet 188℃ 3 Average temperature at flue outlet 194℃ 4 Temperature difference at flue outlet 11℃ 5 Flue inlet and outlet resistance loss 154Pa

[0067] Table 2. Parameters of Conventional Guide Plate Diverter Devices in Comparative Examples

[0068] Serial Number Project Name parameter 1 Maximum temperature at flue outlet 213℃ 2 Minimum temperature at flue outlet 173℃ 3 Average temperature at flue outlet 194℃ 4 Temperature difference at flue outlet 40℃ 5 Flue inlet and outlet resistance loss 169Pa

[0069] Furthermore, as shown in Table 1, after adopting the bifurcation fluid diversion device described in this invention, the average temperature at the flue outlet is 194℃, the highest temperature is 199℃, and the lowest temperature is 188℃, with a cross-sectional temperature difference of 11℃, meeting the target of an outlet cross-sectional temperature difference of less than ±10℃. As shown in Table 2, when using a conventional guide plate diversion device, the average temperature at the flue outlet is 194℃, the highest temperature is 213℃, and the lowest temperature is 173℃, with a cross-sectional temperature difference of 40℃, failing to meet the target of an outlet cross-sectional temperature difference of less than ±10℃. Comparing Tables 1 and 2, it can be found that after adopting the bifurcation fluid diversion device described in this invention, the resistance loss at the flue inlet and outlet is reduced by 15Pa, thus demonstrating that the fluid bifurcation fluid diversion device described in this invention has the characteristics of low flow resistance and good diversion effect.

[0070] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. An application of a flue gas branching fluid diversion device, characterized in that: The bifurcated fluid diversion device is coaxially installed in the middle of the vertical flue, and the lower end of the vertical flue is connected to GGH; The bifurcated fluid diversion device includes an inlet cavity main pipe (11) and several diversion branches (12). The inlets of the diversion branches (12) are all connected to the inlet cavity main pipe (11). The diversion branches (12) are arc-shaped pipes, and the outlets of the diversion branches (12) are all facing the inner wall of the flue. The shape of the main inlet cavity (11) is consistent with the shape of the vertical flue, wherein: When the vertical flue is a rectangular flue (2), the distance from the end outlet of the branch pipe (12) to the inner wall of the flue is 1 / 10 to 1 / 4 of the flue width; When the vertical flue is a cylindrical flue (3), the distance from the end outlet of the branch pipe (12) to the inner wall of the flue is 1 / 10 to 4 / 5 of the radius of the cylindrical flue (3).

2. The application of the flue gas branching fluid diversion device according to claim 1, characterized in that: When the vertical flue is a rectangular flue (2), the distance from the end outlet of the branch pipe (12) to the inner wall of the flue is 1 / 5 of the flue width; When the vertical flue is a cylindrical flue (3), the distance from the end outlet of the branch pipe (12) to the inner wall of the flue is 3 / 10 of the radius of the cylindrical flue (3).

3. The application of the flue gas branching fluid diversion device according to claim 1, characterized in that: The cross-section of the main inlet cavity pipe (11) in the pipe diameter direction is rectangular, with a length a of 2000~10000 mm and a width b of 1000~3400 mm.

4. The application of the flue gas branching fluid diversion device according to claim 3, characterized in that: a is 3000 mm, and b is 2200 mm.

5. The application of the flue gas branching fluid diversion device according to claim 3, characterized in that: The horizontal cross-section of the branch pipe (12) is circular, elliptical or rectangular, wherein the diameter of the circular horizontal cross-section is 100~2200 mm; the major axis of the elliptical horizontal cross-section is 1 / 2b and the minor axis is 1 / 2a.

6. The application of the flue gas branching fluid diversion device according to claim 5, characterized in that: The diameter of the circular horizontal cross-section is 2000 mm.

7. The application of the flue gas branching fluid diversion device according to claim 3, characterized in that: The distance between the center point of the outlet of the branch pipe (12) and the connection surface of the main inlet cavity pipe (11) is 1000~10000mm, and the relative horizontal width is 1000~10000mm.

8. The application of the flue gas branching fluid diversion device according to claim 7, characterized in that: The relative height is 2000 mm or 6000 mm, and the relative horizontal width is 4000 mm.

9. The application of a flue bifurcation fluid diversion device according to any one of claims 1 to 8, characterized in that: The branch pipe (12) has several branch holes (121) on its surface facing away from the main inlet cavity pipe (11).

10. The application of the flue gas branching fluid diversion device according to claim 9, characterized in that: The diversion hole (121) is a round hole, an elliptical hole, or a rectangular hole, wherein the diameter of the round hole is 100~2200mm.

11. The application of the flue gas branching fluid diversion device according to claim 10, characterized in that: The diameter of the round hole is 800 mm.

12. The application of the flue gas branching fluid diversion device according to claim 1, characterized in that: The flue located below the bifurcated fluid diversion device includes at least one section of bent flue (4), the bent flue (4) includes an arc-shaped flue (41) in any order and connected, a first bent flue (42) and a second bent flue (43), wherein the first bent flue (42) and the second bent flue (43) are rectangular flues and their positions are deviated from the vertical direction.

13. The application of the flue gas branching fluid diversion device according to claim 12, characterized in that: The angle between the first bend in the flue (42) and the vertical direction is 15~60°; the angle between the second bend in the flue (43) and the vertical direction is 30~90°.

14. The application of the flue gas branching fluid diversion device according to claim 13, characterized in that: The first bend in the flue (42) has an angle of 30° with the vertical direction; the second bend in the flue (43) has an angle of 45° with the vertical direction.

15. The application of the flue gas branching fluid diversion device according to claim 12, characterized in that: The arc-shaped flue (41) is a circular arc-shaped flue.

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