A heat exchanger device for flue gas waste heat recovery

Abstract

The utility model relates to heat exchanger technical field, concretely relates to a heat exchanger device for flue gas waste heat recovery, the utility model provides a heat exchanger device for flue gas waste heat recovery, including outer frame and at least one installation on the heat exchange tube group of outer frame, the heat exchange tube group includes a plurality of radiating straight pipes, a plurality of radiating elbow pipes and a plurality of radiating spiral fins, the radiating straight pipe with the radiating spiral fin one to one corresponds, any adjacent two radiating straight pipes are connected through radiating elbow pipe, and the detachable connection between radiating elbow pipe and radiating straight pipe, the inner wall of each radiating straight pipe is installed with spiral fin, and the width of spiral fin is less than the radius of radiating straight pipe. Spiral fin is directly welded or inlaid in the inner wall of radiating straight pipe, and under the premise that the pipe diameter of radiating straight pipe and the volume of heat exchanger are not significantly increased, the heat transfer area of radiating straight pipe inside and flue gas contact is expanded.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, specifically to a heat exchanger device for flue gas waste heat recovery. Background Technology

[0002] A heat exchanger is a device that transfers some of the heat from a hot fluid to a cold fluid; it is also called a heat exchanger. Heat exchangers are widely used in chemical, petroleum, power, food, and many other industrial production processes. With the increasing demands for thermal efficiency and durability in steel plant heating furnaces, optimizing heat exchange pipes has become a key factor in improving heat exchange efficiency. The heat exchange tubes of finned air-cooled heat exchangers used in steel plant heating furnaces typically consist of straight heat dissipation tubes and U-shaped heat dissipation bends, with spiral heat dissipation fins on the outer circumference of the straight heat dissipation tubes.

[0003] Since there is no additional heat transfer structure inside the heat dissipation straight pipe, the heat exchange area between the pipe wall and the fluid is insufficient, and the heat exchange efficiency needs to be improved. Utility Model Content

[0004] (I) The problem to be solved by this utility model is that there is no additional heat transfer structure inside the heat dissipation straight pipe, the heat exchange area between the heat dissipation straight pipe wall and the fluid is insufficient, and the heat exchange efficiency needs to be improved.

[0005] (II) Technical Solution

[0006] A heat exchanger device for flue gas waste heat recovery includes an outer frame and at least one heat exchange tube assembly mounted on the outer frame. The heat exchange tube assembly includes multiple straight heat dissipation tubes, multiple bent heat dissipation tubes, and multiple spiral heat dissipation fins. The straight heat dissipation tubes and the spiral heat dissipation fins correspond one-to-one. The multiple straight heat dissipation tubes are arranged and installed in the outer frame along a first direction. Any two adjacent straight heat dissipation tubes are connected by the bent heat dissipation tubes. The bent heat dissipation tubes and the straight heat dissipation tubes are detachably connected. The spiral heat dissipation fins are mounted on the outer circumferential surface of the corresponding straight heat dissipation tubes. The inner wall of each straight heat dissipation tube is equipped with spiral fins, and the width of the spiral fins is smaller than the radius of the straight heat dissipation tube.

[0007] According to one embodiment of the present invention, the ratio of the width of the spiral blade to the radius of the heat dissipation straight pipe is 1 / 3 to 1 / 2.

[0008] According to one embodiment of the present invention, the end of the heat dissipation bend and the end of the heat dissipation straight pipe are connected by a flange.

[0009] According to one embodiment of the present invention, it includes a flue gas inlet pipe, a flue gas outlet pipe, a first connecting pipe and a second connecting pipe, wherein at least one branch pipe is connected to the side wall of the flue gas inlet pipe and at least one branch pipe is connected to the side wall of the flue gas outlet pipe.

[0010] The first end of the first connecting pipe is connected to the air inlet of the heat exchange tube assembly via a flange, the second end of the first connecting pipe is connected to the branch pipe via a flange, the first end of the second connecting pipe is connected to the air outlet of the heat exchange tube assembly via a flange, and the second end of the second connecting pipe is connected to the branch pipe via a flange.

[0011] According to one embodiment of the present invention, multiple heat exchange tube groups are provided, and the branch pipes, the sub-pipes and the heat exchange tube groups correspond one-to-one.

[0012] According to one embodiment of the present invention, the heat dissipation tube assembly includes a first tube segment and a second tube segment connected to each other. The end of the first tube segment away from the second tube segment is the flue gas inlet end, and the end of the second tube segment away from the first tube segment is the flue gas outlet end. The length ratio of the first tube segment to the length of the second tube segment is 2:3.

[0013] The first pipe section is made of stainless steel, and the second pipe section is made of aluminized steel.

[0014] According to one embodiment of the present invention, the wall thickness of the first pipe section is 3 mm.

[0015] According to one embodiment of the present invention, the two ends of the heat dissipation straight pipe are respectively provided with a first connecting flange, and the two ends of the heat dissipation bent pipe are respectively provided with a second connecting flange.

[0016] The beneficial effects of this utility model are:

[0017] Compared with conventional heat exchange tubes, this heat exchange tube assembly has at least the following advantages:

[0018] First, the spiral blades are directly welded or embedded in the inner wall of the heat dissipation straight pipe, which expands the heat transfer area in the heat dissipation straight pipe that is in contact with the flue gas without significantly increasing the outer diameter of the heat dissipation straight pipe and the volume of the heat exchanger.

[0019] Secondly, the spiral channels formed by the spiral blades extend the residence time of some flue gas in the heat dissipation straight pipe, thereby improving the heat exchange efficiency.

[0020] In addition, since the inner edge of the spiral blades forms a cylindrical straight channel, some flue gas flows directly out of the heat dissipation straight pipe from the straight channel, and some flue gas is discharged through the spiral channel. This can effectively disturb the flue gas flow without causing excessive flow resistance. It achieves the best balance between improving heat exchange efficiency and controlling flow resistance within a reasonable range, ensuring the economical operation of the entire heat exchanger.

[0021] Finally, the heat exchanger bends and straight tubes are detachably connected. When a heat exchanger bend or straight tube is damaged or blocked due to extreme conditions, it can be disassembled and replaced individually without scrapping the entire heat exchanger assembly, which greatly saves maintenance time and costs. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 A perspective view provided for an embodiment of this utility model;

[0024] Figure 2 A front view provided for an embodiment of this utility model;

[0025] Figure 3 This is a structural diagram of the present invention after removing the outer frame;

[0026] Figure 4 This is a structural diagram of the heat exchange tube assembly provided in an embodiment of the present utility model;

[0027] Figure 5 A structural diagram of the heat exchange tube assembly provided in this embodiment of the utility model after removing the heat dissipation spiral fins;

[0028] Figure 6 A front view of the heat dissipation straight pipe, heat dissipation bolt fins, and spiral fins provided in an embodiment of this utility model;

[0029] Figure 7 A side view of the heat dissipation straight pipe, heat dissipation bolt fins, and spiral fins provided in an embodiment of this utility model;

[0030] Figure 8 A cross-sectional view of the heat dissipation straight pipe, heat dissipation bolt fins, and spiral fins provided for an embodiment of this utility model.

[0031] Icons: 1. Outer frame; 2. Straight heat dissipation pipe; 201. First connecting flange; 202. Spiral fin; 3. Heat dissipation spiral fin; 4. Heat dissipation bend; 5. First connecting pipe; 6. Flue gas inlet pipe; 601. Branch pipe; 7. Flue gas outlet pipe; 701. Branch pipe; 8. Second connecting pipe. Detailed Implementation

[0032] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0033] like Figures 1-8 As shown, one embodiment of this utility model provides a heat exchanger device for flue gas waste heat recovery, including an outer frame 1 and at least one heat exchange tube assembly installed on the outer frame 1. The heat exchange tube assembly includes multiple heat dissipation straight tubes 2, multiple heat dissipation bent tubes 4, and multiple heat dissipation spiral fins 3. The heat dissipation straight tubes 2 and the heat dissipation spiral fins 3 correspond one-to-one. The multiple heat dissipation straight tubes 2 are arranged and installed in the outer frame 1 along a first direction. Any two adjacent heat dissipation straight tubes 2 are connected by heat dissipation bent tubes 4. The heat dissipation bent tubes 4 and the heat dissipation straight tubes 2 are detachably connected. The heat dissipation spiral fins 3 are installed on the outer peripheral surface of the corresponding heat dissipation straight tubes 2. Each heat dissipation straight tube 2 has a spiral fin 202 installed on its inner wall. The width of the spiral fin 202 is smaller than the radius of the heat dissipation straight tube 2.

[0034] In this embodiment, since a spiral fin 202 is provided on the inner wall of each heat dissipation straight pipe 2, and since the width of the spiral fin 202 is smaller than the radius of the heat dissipation straight pipe 2, such as Figure 7 As shown, a cylindrical straight channel 203 is formed around the inner edge of the spiral blade 202, and a spiral channel is formed between the blades of the spiral blade 202. Compared with conventional heat exchange tubes, this heat exchange tube assembly has at least the following advantages:

[0035] First, the spiral blades 202 are directly welded or embedded in the inner wall of the heat dissipation straight pipe 2, which expands the heat transfer area in the heat dissipation straight pipe 2 that is in contact with the flue gas without significantly increasing the outer diameter of the heat dissipation straight pipe 2 and the volume of the heat exchanger.

[0036] Secondly, the spiral channel formed by the spiral blades 202 extends the residence time of some flue gas in the heat dissipation straight pipe 2, thereby improving the heat exchange efficiency;

[0037] In addition, since the inner edge of the spiral blades 202 forms a cylindrical straight channel 203, some flue gas flows directly out of the heat dissipation straight pipe 2 through the straight channel 203, and some flue gas is discharged through the spiral channel. This can effectively disturb the flue gas flow without causing excessive flow resistance. It achieves the best balance between improving heat exchange efficiency and controlling flow resistance within a reasonable range, ensuring the economical operation of the entire heat exchanger.

[0038] Finally, the heat dissipation bend 4 and the heat dissipation straight tube 2 are detachably connected. When the heat dissipation bend 4 or the heat dissipation straight tube 2 is damaged or blocked due to extreme conditions, it can be disassembled and replaced separately without scrapping the entire heat exchange tube assembly, which greatly saves maintenance time and costs.

[0039] In some embodiments, the ratio of the width of the spiral blade 202 to the radius of the heat dissipation straight pipe 2 is 1 / 3 to 1 / 2. Preferably, the ratio of the width of the spiral blade 202 to the radius of the heat dissipation straight pipe 2 is 1:2.

[0040] In some embodiments, the spiral blade 202 and the heat dissipation straight pipe 2 are made of the same material.

[0041] In this embodiment, as Figure 3 and Figure 4 As shown, the two ends of the heat exchange straight tube 2 are respectively provided with first connecting flanges 201, and the two ends of the U-shaped heat exchange elbow 4 are respectively provided with second connecting flanges. The first connecting flange 201 at one end of the heat exchange straight tube 2 and the second connecting flange at one end of the heat exchange elbow 4 are fixedly connected by bolts. Since both the heat exchange straight tube 2 and the heat exchange elbow 4 can be disassembled and replaced individually, there is no need to scrap the entire heat exchange tube assembly, which greatly saves maintenance time and costs.

[0042] Optionally, a sealing ring is provided between the first connecting flange 201 and the second connecting flange to improve sealing performance.

[0043] In this embodiment, as Figure 1 and Figure 3 As shown, there are multiple heat exchanger tube assemblies, which are evenly arranged and installed inside the outer frame 1 along the width direction of the outer frame 1.

[0044] This heat exchanger device also includes a flue gas inlet pipe 6, a flue gas outlet pipe 7, a first connecting pipe 5, and a second connecting pipe 8, such as... Figure 4 As shown, the inlet of the heat exchange tube group's heat dissipation straight pipe 2 at the inlet end is connected to a first connecting pipe 5, the outlet of the heat exchange tube group's heat dissipation straight pipe 2 at the outlet end is connected to a second connecting pipe 8, multiple branch pipes 601 corresponding to the first connecting pipe 5 are connected to the side wall of the flue gas inlet pipe 6, and multiple branch pipes 701 corresponding to the second connecting pipe 8 are connected to the side wall of the flue gas outlet pipe 7.

[0045] Furthermore, the branch pipe 601 on the flue gas outlet pipe 7 is connected to the first connecting pipe 5 at the inlet end of the heat exchange tube group via a flange, and the branch pipe 701 on the flue gas outlet pipe 7 is connected to the second connecting pipe 8 at the outlet end of the heat exchange tube group via a flange.

[0046] In this way, flue gas can be simultaneously delivered to multiple heat exchange tube groups through the flue gas inlet pipe 6. After heat exchange in the heat exchange tube groups, the flue gas is finally discharged from the flue gas outlet pipe 7.

[0047] In some embodiments, the first connecting pipe 5 and the air inlet of the heat dissipation straight pipe 2 at the air inlet end of the heat exchange tube group are connected by a flange, and the second connecting pipe 8 and the air outlet of the heat dissipation straight pipe 2 at the air outlet end of the heat exchange tube group are connected by a flange.

[0048] It is important to note that the first half of the heat exchange tube is the high-temperature zone (flue gas temperature ≤1200°C), while the second half is the low-temperature zone (flue gas temperature ≤1200°C). This means that the flue gas temperature drops rapidly after passing through the first half of the heat exchange tube, but decreases significantly by the time it reaches the second half. Previously, the heat exchange tubes of air-cooled heat exchangers used in steel plant heating furnaces were made entirely of 3.5mm thick 2520 stainless steel, offering good high-temperature corrosion resistance, but at a higher cost.

[0049] To address the aforementioned issues, in this embodiment, the heat dissipation tube assembly includes a first tube segment and a second tube segment connected to each other. The end of the first tube segment furthest from the second tube segment is the flue gas inlet end, and the end of the second tube segment furthest from the first tube segment is the flue gas outlet end. The length ratio of the first tube segment to the second tube segment is 2:3. In other words, the first tube segment is the high-temperature section of the heat exchange tube, and the second tube segment is the low-temperature section of the heat exchange tube.

[0050] The first section of the tubes (roughly 35%-45% of the total heat exchange tubes) is made of 2848 or 2520 stainless steel, while the second section is made of 20G aluminized steel. 20G aluminized steel is widely used in applications requiring simultaneous resistance to medium and high temperatures and corrosive media. Its high-temperature corrosion resistance is slightly inferior to that of 2848 or 2520 stainless steel, but 20G aluminized steel is cheaper.

[0051] Preferably, the first tube section accounts for 40% of the total heat exchange tube group.

[0052] As can be seen, in this embodiment, because the high-temperature corrosion resistance requirements for the pipes in the front section (high-temperature section) of the heat exchange tube are high, while the requirements for the high-temperature corrosion resistance requirements for the pipes in the rear section (low-temperature section) are low, the heat exchange tube is divided into a first pipe section (high-temperature section) and a second pipe section (low-temperature section). The first pipe section is made of 2848 stainless steel or 2520 stainless steel, which have high high-temperature corrosion resistance and are relatively expensive, while the second pipe section is made of 20G aluminized steel, which has poor high-temperature corrosion resistance but is less expensive. This satisfies the functional requirements of the heat exchanger while saving costs.

[0053] As a specific embodiment, such as Figure 4 and Figure 5As shown, the heat exchange tube assembly includes 10 straight heat dissipation tubes 2. From the air inlet end to the air outlet end of the heat exchange tube assembly, the 10 straight heat dissipation tubes 2 are sequentially labeled as: a, b, c, d, e, f, g, h, i, j. Adjacent straight heat dissipation tubes 2 are connected by heat dissipation bends 4, totaling 9 heat dissipation bends 4. From the air inlet end to the air outlet end of the heat exchange tube assembly, the 9 heat dissipation bends 4 are sequentially labeled as: A, B, C, D, E, F, G, H, I.

[0054] Among them, the four straight heat dissipation pipes 2, a, b, c, and d, are made of 2848 stainless steel, while the remaining six straight heat dissipation pipes 2, e, f, g, h, i, and j, are made of 20G aluminized steel; the three bent heat dissipation pipes 4, A, B, and C, are made of 2848 stainless steel, while the remaining five bent heat dissipation pipes 4, D, E, F, G, H, and I, are made of 20G aluminized steel.

[0055] It should be noted that the spiral blades 202 inside the four straight heat dissipation pipes 2 (a, b, c, d) are made of 2848 stainless steel, while the spiral blades 202 inside the six straight heat dissipation pipes 2 (e, f, g, h, i, j) are made of 20G aluminized steel.

[0056] Optionally, in this embodiment, since 2848 stainless steel has strong high temperature resistance and oxidation resistance, the wall thickness of the first pipe section can be reduced to 3mm, which can reduce thermal resistance and enhance heat transfer efficiency.

[0057] In the description of this utility model, it should be noted that the terms "upper" and "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0058] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0059] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A heat exchanger device for flue gas waste heat recovery, characterized in that, The device includes an outer frame (1) and at least one heat exchange tube assembly mounted on the outer frame (1). The heat exchange tube assembly includes multiple heat dissipation straight tubes (2), multiple heat dissipation bends (4), and multiple heat dissipation spiral fins (3). The heat dissipation straight tubes (2) and the heat dissipation spiral fins (3) correspond one-to-one. The multiple heat dissipation straight tubes (2) are arranged and installed in the outer frame (1) along a first direction. Any two adjacent heat dissipation straight tubes (2) are connected by the heat dissipation bends (4). The heat dissipation bends (4) and the heat dissipation straight tubes (2) are detachably connected. The heat dissipation spiral fins (3) are installed on the outer circumferential surface of the corresponding heat dissipation straight tubes (2). Each heat dissipation straight tube (2) has a spiral fin (202) installed on its inner wall. The width of the spiral fin (202) is smaller than the radius of the heat dissipation straight tube (2).

2. The heat exchanger device for flue gas waste heat recovery according to claim 1, characterized in that, The ratio of the width of the spiral blade (202) to the radius of the heat dissipation straight pipe (2) is 1 / 3 to 1 / 2.

3. A heat exchanger device for flue gas waste heat recovery according to claim 1, characterized in that, The ends of the heat dissipation bend (4) and the heat dissipation straight pipe (2) are connected by a flange.

4. A heat exchanger device for flue gas waste heat recovery according to claim 3, characterized in that, It includes a flue gas inlet pipe (6), a flue gas outlet pipe (7), a first connecting pipe (5) and a second connecting pipe (8). At least one branch pipe (601) is connected to the side wall of the flue gas inlet pipe (6), and at least one branch pipe (701) is connected to the side wall of the flue gas outlet pipe (7). The first end of the first connecting pipe (5) is connected to the air inlet of the heat exchange tube assembly through a flange, the second end of the first connecting pipe (5) is connected to the branch pipe (601) through a flange, the first end of the second connecting pipe (8) is connected to the air outlet of the heat exchange tube assembly through a flange, and the second end of the second connecting pipe (8) is connected to the branch pipe (701) through a flange.

5. A heat exchanger device for flue gas waste heat recovery according to claim 4, characterized in that, The heat exchange tube group is provided in multiple ways, and the branch pipe (601), the branch pipe (701) and the heat exchange tube group correspond one to one.

6. A heat exchanger device for flue gas waste heat recovery according to claim 1, characterized in that, The heat dissipation tube assembly includes a first tube segment and a second tube segment connected to each other. The end of the first tube segment away from the second tube segment is the flue gas inlet end, and the end of the second tube segment away from the first tube segment is the flue gas outlet end. The length ratio of the first tube segment to the second tube segment is 2:

3. The first pipe section is made of stainless steel, and the second pipe section is made of aluminized steel.

7. A heat exchanger device for flue gas waste heat recovery according to claim 6, characterized in that, The wall thickness of the first pipe section is 3mm.

8. A heat exchanger device for flue gas waste heat recovery according to claim 1, characterized in that, The two ends of the heat dissipation straight pipe (2) are respectively provided with a first connecting flange (201), and the two ends of the heat dissipation bent pipe (4) are respectively provided with a second connecting flange.

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