Boiler flue waste heat recovery device

Abstract

The boiler flue waste heat recovery device comprises a connecting flange, a first sealing plate, a desulfurization treatment structure, a fan structure and an external water tank, the surface of a peripheral external circular pipe is connected with a water pipe, the water pipe penetrates through the first sealing plate to be connected with the external water tank, a connecting pipe is arranged in each set of external circular pipe, and first spiral plates are distributed on the outer surface of each connecting pipe in an annular array mode; the outer end face of the first spiral plate is fixedly connected with the inner surface of the external circular pipe, second spiral plates are distributed on the surface of the internal circular pipe in an annular array mode, a perforated circular plate is installed on the upper end face of the internal circular pipe, a partition plate dividing the internal circular pipe into two cavities is vertically installed in the internal circular pipe, and a hole is formed in the bottom of the partition plate. The surface of the perforated circular plate is connected with the external water tank through a connecting structure, the internal circular pipe is inserted into the connecting pipe, and the perforated circular plate is connected with the surface of the first sealing plate through a bolt. The boiler flue waste heat recovery device solves the problem that an existing boiler flue waste heat recovery device cannot fully absorb smoke heat, and consequently the waste heat recovery efficiency is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of heat recovery devices, and in particular to a boiler flue waste heat recovery device. Background Art

[0002] Over the years, in order to achieve efficient utilization of resources and reduce energy consumption, in terms of boilers, especially gas boilers, oil boilers, and high-efficiency coal-fired boilers, the heat in the high-temperature flue gas in the flue gas is absorbed by flue waste heat recovery devices. However, today's recovery devices have the problem of not being able to absorb heat efficiently and quickly, resulting in a large amount of heat being directly discharged into the air, thereby reducing energy conversion.

[0003] In order to improve the heat exchange efficiency, the current waste heat recovery device is equipped with a large number of heat exchange tubes inside, and they are staggered. This method can indeed improve the efficiency of waste heat recovery to a certain extent, but it cannot be further improved. In order to further improve it, Chinese patent CN110469865B, a boiler waste heat recovery and utilization device points out that when the furnace body discharges exhaust gas, the exhaust gas enters the interior of the smoke exhaust pipe. The high heat carried by the exhaust gas can heat the water in the water pipe. The clean water enters the interior of the water pipe through the water inlet. Since the water pipe is a spiral structure, the contact area between the water pipe and the smoke exhaust pipe can be increased, thereby improving the heating effect of the clean water and making full use of the heat of the exhaust gas for heating treatment. The above patent can indeed further improve the heat absorption efficiency, but there are still certain problems. Although the water pipe is spirally arranged outside the smoke exhaust pipe, it can only absorb the heat of the smoke near the inside of the smoke exhaust pipe, and the smoke at high temperature in the center cannot be effectively absorbed by the water pipe, so there are defects.

[0004] Therefore, in order to solve the above technical problems, more effectively absorb the heat of the flue gas and improve the efficiency of waste heat recovery, a boiler flue waste heat recovery device is proposed, which can solve the technical problems in the above-mentioned prior art. Summary of the Invention

[0005] In response to the deficiencies of the prior art, the present invention provides a boiler flue waste heat recovery device, which solves the problem that the existing boiler flue waste heat recovery device cannot effectively and fully absorb the flue gas heat, resulting in reduced waste heat recovery efficiency.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a boiler flue waste heat recovery device, comprising a connecting flange, a first sealing plate, a desulfurization treatment structure, a fan structure, and an external water tank, an inner and outer double-layer heat absorption structure is installed between the connecting flange and the first sealing plate, the inner and outer double-layer heat absorption structure is connected to the external water tank through a connecting structure, the inner and outer double-layer heat absorption structure comprises an outer heat absorption structure and an inner heat absorption structure, the outer heat absorption structure comprises an outer shell, an external circular pipe, a water pipe, a connecting pipe, and an outer shell; the outer shell is installed between the connecting flange and the first sealing plate, wherein circular holes are opened on the surfaces of the connecting flange and the first sealing plate, wherein a plurality of groups of external circular pipes are further installed between the connecting flange and the first sealing plate, each group of external circular pipes is arranged corresponding to the circular hole, and the external circular pipes located on the periphery are connected to the external circular pipes in the middle through connecting pipes. The circular tubes are connected, and the surface of the outer circular tubes is connected to a water pipe, which passes through the first sealing plate and is connected to the external water tank. A connecting pipe is also provided in each group of external circular tubes. The outer surface of the connecting tube is distributed with a first spiral plate in an annular array, and the outer end face of the first spiral plate is fixedly connected to the inner surface of the external circular tube. The inner heat absorption structure includes a built-in circular tube, a partition, a second spiral plate, a connecting structure, and a perforated circular plate; the surface of the built-in circular tube is distributed with a second spiral plate in an annular array, and a perforated circular plate is installed on the upper end face of the built-in circular tube. A partition is vertically installed inside the built-in circular tube to divide the built-in circular tube into two cavities, and an opening is provided at the bottom of the partition. The surface of the perforated circular plate is connected to the external water tank through a connecting structure, and the built-in circular tube is inserted into the connecting pipe, and the perforated circular plate is connected to the surface of the first sealing plate by bolts.

[0007] Through the above technical solution, further, there is a cavity between the external circular tube and the outer shell, the upper end face of the external circular tube is spaced apart from the lower end face of the first sealing plate, a connecting pipe is provided on the outer shell surface, and an insulation layer is installed on the outer surface of the outer shell.

[0008] Furthermore, the pitch of the first spiral plate increases gradually from bottom to top, and the gap between two adjacent groups of second spiral plates is large.

[0009] As a preferred technical solution, a clamping plate is installed on the surface of the external circular tube.

[0010] Furthermore, the external water tank includes an outer box, a water inlet box, a water outlet box, and a circular plate; the lower end of the circular plate is connected to the upper end surface of the first sealing plate, the outer box is installed on the surface of the circular plate, and the water inlet box and the water outlet box are both installed on the surface of the circular plate, so that a cavity is formed inside, and the surfaces of the outer box, the water inlet box, and the water outlet box are all provided with connecting pipes, and a desulfurization treatment structure is installed on the upper end surface of the water outlet tank.

[0011] As a preferred technical solution, the surface of the circular plate is provided with circular openings in a ring array, and a built-in plate is installed on the inner side of the circular plate. The upper end surface of the built-in plate is lower than the upper end surface of the circular plate, and a gap is left between the outer side surface of the built-in plate and the inner side surface of the circular plate.

[0012] Furthermore, the connection structure includes a water outlet pipe and a water inlet pipe; the water outlet pipe and the water inlet pipe pass through the perforated circular plate and extend into the corresponding cavity, and the water outlet pipe and the water inlet pipe both pass through the circular plate, wherein the water outlet pipe is connected to the water outlet box, and the water inlet pipe is connected to the water inlet box.

[0013] As a preferred technical solution, the desulfurization treatment structure includes an outer shell, a second sealing plate, and an annular water pipe; the outer shell is installed on the upper end face of the water outlet tank and wraps the circular plate inside, and a gap is left between the outer shell and the circular plate, the second sealing plate is installed on the upper end face of the circular plate, and the annular water pipe is installed on the upper end face of the second sealing plate. The surface of the annular water pipe is installed with nozzles in an annular array, and the surface of the outer shell is connected to a connecting pipe.

[0014] Furthermore, an L-shaped circular plate is installed on the outer periphery of the second sealing plate, and a baffle is installed on the outer end face of the connecting surface between the outer shell and the circular plate. A gap is left between the L-shaped circular plate and the outer shell, and an opening is also provided on the surface of the second sealing plate. A U-shaped tube is installed on the lower end face of the annular water pipe, and the U-shaped tube extends to the inside of the circular plate through the opening, wherein an arc-shaped circular plate is also installed on the inner surface of the outer shell near the port, and a third sealing plate is installed on the upper end face of the arc-shaped circular plate, and an operating opening is opened on the surface of the third sealing plate, and an outer end cover is installed on the upper end face of the outer shell, and the fan structure is installed on the upper end face of the outer end cover, and the upper end face of the annular water pipe is also connected to a connecting pipe, which passes through the third sealing plate and the outer end cover.

[0015] As a preferred technical solution, the fan structure includes a connecting seat and a centrifugal fan; the connecting seat is installed on the end surface of the outer end cover, and the centrifugal fan is installed on the outer end surface of the connecting seat;

[0016] The connecting pipe at the upper end of the annular water pipe is located between the centrifugal fan and the outer shell.

[0017] Compared with the prior art, the present invention provides a boiler flue waste heat recovery device with the following beneficial effects:

[0018] 1. This device uses an external circular tube, a connecting tube, and a first spiral plate; multiple groups of connecting tubes divide the flue into multiple groups of through pipes, so that the flue gas is divided into multiple groups of channels for circulation. After the flue gas passes through the connecting tube, the heat in the flue gas is absorbed by the connecting tube and the first spiral plate. At this time, water passes through the outer box and then through the water pipe into the space between the connecting tube and the external circular tube. The first spiral plate can increase the contact area with water, thereby effectively improving the efficiency of absorbing the heat of the flue gas.

[0019] 2. In order to further improve the heat absorption efficiency, this device uses a built-in circular tube, a second spiral plate, a perforated circular plate, and a partition. Water enters the water inlet pipe through the water inlet tank and then enters the built-in circular tube. The second spiral plate contacts the inner wall of the connecting tube, thereby shortening the width of the flue gas channel, so that the flue gas can fully contact the second spiral plate, the connecting tube, and the built-in circular tube, thereby absorbing the heat in the flue gas again through the built-in circular tube, thereby further improving the absorption of heat in the flue gas through the inner and outer double layers of heat absorption.

[0020] 3. In order to further improve the waste heat recovery efficiency, the pitch of the first spiral plate in this device gradually increases from bottom to top, so that the spiral plate at the bottom has a faster heat absorption efficiency. As the flue gas rises, the temperature will drop accordingly. Therefore, the first spiral plate has a smaller pitch (inlet section (high temperature zone)) from the inlet section (high temperature zone), the middle section (medium temperature zone), and the outlet section (low temperature zone), to increase the heat exchange area and quickly absorb the heat of the high-temperature flue gas. The pitch is moderate (middle section (medium temperature zone)) to balance the heat exchange efficiency and reduce the flow resistance of water. The pitch is larger in the outlet section (low temperature zone) to reduce the pressure, improve the overall energy efficiency and accelerate the circulation of water. In this way, it can not only effectively absorb the heat in the flue gas, but also quickly extract the heat-carrying water from the external circular tube.

[0021] 4. In order to prevent heat loss and improve the stability of heat transfer, the external circular tube in the plate device does not contact the lower end of the first sealing plate. Therefore, when the water in the external circular tube overflows, it will enter between the outer shell and the internal circular tube, so that the water with heat will directly immerse the external circular tube. Secondly, an insulation layer is installed on the inner side of the outer shell to prevent temperature loss. The immersion method can absorb the heat on the lower end surface of the external circular tube again, thereby further improving the efficiency of absorbing flue gas heat.

[0022] 5. This recycling device, see Figure 2 and Figure 5 It can be seen that the desulfurization and waste heat devices are installed together, so that desulfurization can be carried out directly after waste heat recovery, and the U-shaped tube extends into the circular plate. At this time, the remaining heat in the flue can be absorbed again, and the heat in the device itself is used to improve the efficiency of desulfurization. This not only improves the heat absorption rate but also meets the improvement of desulfurization efficiency at the same time. There is no need to install desulfurization equipment, thereby reducing the overall cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the present invention;

[0024] Figure 2 For the present invention Figure 1 AA cross-sectional view of ;

[0025] Figure 3For the present invention Figure 1 3D schematic diagram of

[0026] Figure 4 For the present invention Figure 2 A local enlarged schematic diagram of point A;

[0027] Figure 5 For the present invention Figure 1 Explosion diagram of the (excluding centrifugal fan);

[0028] Figure 6 This is a schematic diagram of the internal structure of the housing of the present invention;

[0029] Figure 7 This is a schematic diagram of the interior of the housing of the present invention;

[0030] Figure 8 For the present invention Figure 7 3D schematic diagram of

[0031] Figure 9 For the present invention Figure 1 Schematic diagram from above;

[0032] Figure 10 This is a schematic diagram of the external circular tube of the present invention;

[0033] Figure 11 For the present invention Figure 10 BB cross-sectional diagram;

[0034] Figure 12 For the present invention Figure 10 3D schematic diagram of

[0035] Figure 13 This is a schematic diagram of the built-in circular tube of the present invention;

[0036] Figure 14 For the present invention Figure 13 Schematic diagram of CC cross-section;

[0037] Figure 15 For the present invention Figure 13 3D schematic diagram of .

[0038] In the figure: 1. connecting flange; 2. outer shell; 3. first sealing plate; 4. outer box; 5. water inlet box; 6. water outlet box; 7. outer shell; 8. connecting seat; 9. centrifugal fan; 10. arc-shaped circular plate; 11. built-in plate; 12. L-shaped circular plate; 13. circular plate; 14. second sealing plate; 15. annular water pipe; 16. third sealing plate; 17. clamping plate; 18. external circular pipe; 19. water pipe; 20. first spiral plate; 21. built-in circular pipe; 22. partition; 23. second spiral plate; 24. water outlet pipe; 25. water inlet pipe; 26. perforated circular plate; 27. baffle; 28. U-shaped pipe; 29. connecting pipe; 30. outer end cover. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Example

[0041] See also Figure 1-15 The present invention provides the following technical solutions: a boiler flue waste heat recovery device, comprising a connecting flange 1, a first sealing plate 3, a desulfurization treatment structure, a fan structure, and an external water tank. An inner and outer double-layer heat absorption structure is installed between the connecting flange 1 and the first sealing plate 3. The inner and outer double-layer heat absorption structure is connected to the external water tank through a connecting structure. The inner and outer double-layer heat absorption structure includes an outer heat absorption structure and an inner heat absorption structure. The outer heat absorption structure includes an outer shell 2, an external circular tube 18, a water pipe 19, a connecting pipe 29, and an outer shell 2; the outer shell 2 is installed between the connecting flange 1 and the first sealing plate 3. When installing the shell 2, it is necessary to install the external circular tube 18 and the connecting flange 1 in place, and then the shell 2 is moved from top to bottom so that it wraps the external circular tube 18 inside, and after fixing it with the connecting flange 1, the first sealing plate 3 is fixed to the upper end of the shell 2, wherein the connecting flange 1 and the first sealing plate 3 have circular holes on their surfaces, and multiple groups of external circular tubes 18 are installed between the connecting flange 1 and the first sealing plate 3, each group of external circular tubes 18 is arranged corresponding to the circular hole, and the external circular tubes 18 located on the periphery are connected to the external circular tube 18 in the middle through the connecting pipe (see Figure Figure 9), and the surface of the outer external circular tube 18 is connected to a water pipe 19, and the water pipe 19 passes through the first sealing plate 3 and is connected to the external water tank. Each group of external circular tubes 18 is also provided with a connecting pipe 29, and the outer surface of the connecting pipe 29 is distributed in an annular array with a first spiral plate 20 that increases the contact area with water. The outer end face of the first spiral plate 20 is fixedly connected to the inner surface of the external circular tube 18. Another way is to open a spiral groove on the surface of the connecting pipe 29 so that the spiral state of the spiral groove corresponds to the spiral state of the first spiral plate 20, and then directly clamp the first spiral plate 20 in the spiral groove. At this time, the first spiral plate 20 is in a clamped state. Since the outer end face of the first spiral plate 20 is in contact with the inner side face of the external circular tube 18, the stability is increased, and the inner side face of the groove is not completely clamped to the first spiral plate 20, and there is a certain gap between them, so it can effectively adapt to the phenomenon of thermal expansion and contraction. The service life of the first spiral plate 20 is prolonged, and the overall height of the spiral groove is consistent with the overall height of the first spiral plate 20, so the groove can limit the first spiral plate 20 to prevent the first spiral plate 20 from moving due to the thrust of the water flow. The inner heat absorption structure includes a built-in circular tube 21, a partition 22, a second spiral plate 23, a connecting structure, and a perforated circular plate 26; the second spiral plate 23 is distributed in a ring array on the surface of the built-in circular tube 21, and a perforated circular plate 26 is installed on the upper end face of the built-in circular tube 21. A partition 22 is vertically installed inside the built-in circular tube 21 to divide the built-in circular tube 21 into two cavities, and an opening is provided at the bottom of the partition 22. The surface of the perforated circular plate 26 is connected to the external water tank through a connecting structure, and the built-in circular tube 21 is inserted into the connecting pipe 29, and the perforated circular plate 26 is connected to the surface of the first sealing plate 3 by bolts.

[0042] In this embodiment, the specific working principle is: water enters between the connecting pipe 29 and the external circular pipe 18 through the water pipe 19 through the external water tank. At this time, the connecting flange 1 is installed together with the boiler flue, and the flue gas passes through the connecting pipe 29 and the fan structure in sequence through the double-layer heat absorption structure and the desulfurization treatment structure and is discharged. The flue gas enters the connecting pipe 29, passes through the first spiral plate 20, and contacts the first spiral plate 20 through the water. The first spiral plate 20 increases the contact area with the water, so that it can effectively absorb the heat in the flue gas. In order to further enhance the efficiency of recovering the heat of the flue gas, the built-in circular pipe 21 is inserted into the connecting pipe 29 and passes through the first spiral plate 20. The two spiral plates 23 make contact with the inner surface of the connecting pipe 29, shortening the distance between the flue gas channels and extending the time for the flue gas to circulate through the connecting pipe 29, thereby further improving the efficiency of recovering the waste heat of the flue gas. The built-in circular tube 21 is divided into two cavities by the partition 22, so that one cavity is a water inlet cavity and the other is a water outlet cavity, which is connected to the external water tank through a connecting structure. An opening is provided at the bottom of the partition 22, so that water can only be pumped out to the external water tank through the connecting structure after filling the built-in circular tube 21, thereby delaying the residence time of the water and further improving the heat absorption efficiency of the flue gas, especially for the flue gas in the central area of the connecting pipe 29, which has a higher heat absorption.

[0043] It should be noted that this device can be directly connected to the boiler exhaust port, but it needs to be used in situations with low dust and high heat exchange efficiency. If the dust content is large, the connecting flange 1 in this device needs to be connected to the cyclone separator, and then the dust in the flue gas is filtered through the cyclone separator before entering this device. In order to cope with high dust environments, a layer of high-temperature resistant insulation blanket (material: ceramic fiber) will be wrapped on the surface of the cyclone separator. This can effectively reduce heat dissipation. This device is mainly used in low-dust environments such as gas boilers, oil boilers, and high-efficiency coal-fired boilers.

[0044] According to the above, in order to further improve the absorption of heat in the flue gas, the device can be specifically referred to Figure 10 It can be seen that there is a cavity between the external circular tube 18 and the outer shell 2, and there is a distance between the upper end surface of the external circular tube 18 and the lower end surface of the first sealing plate 3. Therefore, when the water in the external circular tube 18 overflows, it will directly immerse the external circular tube 18, so that the heat on the lower end surface of the internal circular tube 18, that is, the heat at the entrance section of the flue gas, is absorbed again, thereby further improving the efficiency of absorbing the heat of the flue gas. At this time, the water is discharged through the connecting pipe provided on the surface of the outer shell 2. In order to prevent temperature dissipation, an insulation layer is installed on the outer surface of the outer shell 2, and the material of the insulation layer is ceramic fiber material.

[0045] In order to further improve the efficiency of heat absorption of flue gas, it is possible to increase the water flow rate and improve the heat absorption rate at the same time. Figure 8It can be seen that the pitch of the first spiral plate 20 increases gradually from bottom to top. Figure 13 and Figure 15 It can be seen that there is a large gap between two adjacent groups of second spiral plates 23. Here, the first spiral plate 20 is divided into three parts: the high-temperature zone at the flue gas inlet, the medium-temperature zone in the middle, and the low-temperature zone at the outlet. The high-temperature zone has a small pitch, which increases heat absorption. As the water flows to the outside, the temperature will also decrease. Therefore, in addition to absorbing the flue gas heat again, the medium-temperature zone and the low-temperature zone gradually increase their pitch, thereby accelerating the flow of water and enabling the water to be discharged faster.

[0046] In order to improve the stability of the connection of the external circular tube 18, please refer to Figure 8 、 Figure 9 、 Figure 12 It can be seen that a clamping plate 17 is installed on the surface of the external circular tube 18. Circular holes are opened on the surface, middle and outer edge of the clamping plate 17, and the diameter of the circular hole is 2 mm larger than the diameter of the external circular tube 18, which can effectively deal with the problem of thermal expansion and contraction.

[0047] For details about the external water tank, please refer to Figure 6 and Figure 8 It can be seen that the external water tank includes an outer box 4, a water inlet box 5, a water outlet box 6, and a circular plate 13; the lower end of the circular plate 13 is connected to the upper end surface of the first sealing plate 3, the outer box 4 is installed on the surface of the circular plate 13, and the water inlet box 5 and the water outlet box 6 are both installed on the surface of the circular plate 13, so that a cavity is formed inside thereof, and the outer box 4, the water inlet box 5, and the water outlet box 6 are all provided with connecting pipes on the surface, and the upper end surface of the water outlet box 6 is installed with a desulfurization treatment structure. No matter what waste heat recovery device is used, it is impossible to absorb 100% of the heat in the flue gas. Therefore, a cavity is formed by the circular plate 13, the water inlet box 5, the outer box 4, and the water outlet box 6, which can not only store water, but also further absorb the heat in the flue gas through the circular plate 13. The connecting pipe on the surface of the water inlet box 5 is connected to the water pipe, and the connecting pipe on the surface of the water outlet box 6 is connected to the water pump, so that the hot water absorbed in the built-in circular tube 21 can be extracted, and the connecting pipe on the surface of the outer box 4 is also connected to the water pipe and enters the external circular tube 18 through the water pipe 19.

[0048] In order to speed up the circulation, please refer to Figure 2 and Figure 4It can be seen that the surface of the circular plate 13 is provided with circular openings in a ring array, and a built-in plate 11 is also installed on the inner side of the circular plate 13. The upper end surface of the built-in plate 11 is lower than the upper end surface of the circular plate 13, and a gap is left between the outer side surface of the built-in plate 11 and the inner side surface of the circular plate 13. This reduces the circulation space of the flue gas and generates a negative pressure state in the outer shell 7 through the fan mechanism, thereby accelerating the circulation speed of the flue gas, so that the device can improve the efficiency of absorbing heat in the flue gas while also allowing the flue gas to circulate quickly.

[0049] The connection structure can be found in Figure 6 and Figure 8 It can be seen that the connection structure includes an outlet pipe 24 and an inlet pipe 25; the outlet pipe 24 and the inlet pipe 25 extend through the perforated circular plate 26 to the corresponding cavity, and the outlet pipe 24 and the inlet pipe 25 both pass through the circular plate 13, wherein the outlet pipe 24 is connected to the outlet box 6, and the inlet pipe 25 is connected to the inlet box 5. The inlet pipe 25 and the outlet pipe 24 are both installed on the perforated circular plate 26 and inserted into the cavity. Secondly, it should be noted that the inlet pipe 25 and the outlet pipe 24 are both stainless steel telescopic pipes, and one end of the inlet pipe 25 and the outlet pipe 24 are connected to the perforated circular plate 26 by a flange. 6 is connected and fixed, and the surface of the circular plate 13 is provided with openings in an annular array, and the openings are divided into two layers corresponding to the water inlet box 5 and the water outlet box 6 respectively. The water inlet pipe 25 and the water outlet pipe 24 are directly fixedly connected to the corresponding openings of the circular plate 13 by welding, so that it can better withstand high temperature and high pressure, and the connection strength is high. Secondly, when cleaning and replacing the built-in circular tube 21, it is necessary to cut the water inlet pipe 25 and the water outlet pipe 24 to separate them from the connection relationship with the circular plate 13, and then remove the bolts connecting the perforated circular plate 26 and the first sealing plate 3, which is also more convenient for subsequent cleaning.

[0050] Desulfurization treatment structure, please refer to Figure 2 、 Figure 5 、 Figure 6 It can be seen that the desulfurization treatment structure includes a shell 7, a second sealing plate 14, and an annular water pipe 15; the shell 7 is installed on the upper end surface of the water outlet box 6 and wraps the circular plate 13 therein, and a gap is left between the shell 7 and the circular plate 13. The upper end surface of the circular plate 13 is installed with a second sealing plate 14, and the upper end surface of the second sealing plate 14 is installed with an annular water pipe 15. The surface of the annular water pipe 15 is equipped with nozzles in an annular array. The surface of the shell 7 is connected to a connecting pipe. The water required for desulfurization passes through the connecting pipe on the surface of the annular water pipe 15 (for details, please refer to Figure 1As shown), it enters the annular water pipe 15, and due to the increase in pressure, it is sprayed through the nozzle, thereby chemically reacting with the sulfide in the flue gas. It should be noted that although the desulfurization liquid can flush the reactants of the desulfurization liquid and the sulfide in the flue gas when it is sprayed through the nozzle, when the device is subsequently stopped, the sediment on the inner wall surface needs to be flushed and cleaned with water to prevent the sediment from scaling.

[0051] In order to prevent the desulfurization water from entering the housing 7, please refer to Figure 2 、 Figure 4 、 Figure 5 、 Figure 6 It can be seen that an L-shaped circular plate 12 is also installed on the periphery of the second sealing plate 14, and a baffle 27 is installed on the outer end surface of the connection surface between the outer shell 7 and the circular plate 13. A gap is left between the L-shaped circular plate 12 and the outer shell 7, and an opening is also provided on the surface of the second sealing plate 14. A U-shaped tube 28 is installed on the lower end surface of the annular water pipe 15, and the U-shaped tube 28 extends through the opening to the inside of the circular plate 13, wherein an arc-shaped circular plate 10 is also installed on the inner surface of the outer shell 7 near the port, and a third sealing plate 16 is installed on the upper end surface of the arc-shaped circular plate 10. A running opening is opened on the surface of the third sealing plate 16, and an outer end cover 30 is installed on the upper end surface of the outer end cover 30. The fan structure is installed on the upper end surface of the outer end cover 30. The upper end surface of the annular water pipe 15 is also connected to a connecting pipe, which passes through the third sealing plate 16 and the outer end cover 30. When the nozzle sprays When spraying, in order to increase the contact area with the flue gas, the flue gas emitted from the opening on the surface of the circular plate 13 is passed through the L-shaped circular plate 12 through the gap between the L-shaped circular plate 12 and the inner surface of the shell 7. Since the annular water pipe 15 is installed on the second sealing plate 14, the contact area between the desulfurization water and the flue gas can be effectively increased. At this time, the water expands in the spraying direction due to the spraying, so the water will enter the gap between the L-shaped circular plate 12 and the shell 7. In order to prevent the water from being unable to concentrate in a specific area and being inconvenient to discharge, the desulfurization water is always kept between the arc-shaped circular plate 10 and the L-shaped circular plate 12 through the arc-shaped circular plate 10, and then discharged through the connecting pipe on the surface of the shell 7. With the continuous flushing of the desulfurization water, the sediment can be effectively flushed away to prevent the deposition of sediment.

[0052] According to the above, the desulfurization treatment structure and the further waste heat recovery structure are both installed in the circular plate 13, thereby simplifying the existing equipment structure and realizing the integration of waste heat reabsorption and desulfurization treatment.

[0053] The fan structure is detailed in Figure 1 and Figure 5 It can be seen that the fan structure includes a connecting seat 8 and a centrifugal fan 9; the connecting seat 8 is installed on the end surface of the outer end cover 30, and the centrifugal fan 9 is installed on the outer end surface of the connecting seat 8;

[0054] See Figure 1 It can be seen that the connecting pipe at the upper end of the annular water pipe 15 is located between the centrifugal fan 9 and the housing 7 .

[0055] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A boiler flue waste heat recovery device, comprising a connecting flange (1), a first sealing plate (3), a desulfurization treatment structure, a fan structure, and an external water tank, characterized in that: An inner and outer double-layer heat absorbing structure is installed between the connecting flange (1) and the first sealing plate (3), and the inner and outer double-layer heat absorbing structure is connected to the external water tank through the connecting structure, and the inner and outer double-layer heat absorbing structure includes an outer heat absorbing structure and an inner heat absorbing structure; the outer heat absorbing structure includes an outer shell (2), an external circular tube (18), a water pipe (19), a connecting pipe (29), and an outer shell (2); the outer shell (2) is installed between the connecting flange (1) and the first sealing plate (3), wherein the connecting flange (1) and the first sealing plate (3) are provided with circular holes on their surfaces, wherein a plurality of groups of external circular tubes (18) are further installed between the connecting flange (1) and the first sealing plate (3), each group of external circular tubes (18) is arranged corresponding to the circular holes, the external circular tubes (18) located at the periphery are communicated with the external circular tubes (18) at the middle through the connecting pipe, and the surface of the outer circular tubes (18) is connected with a water pipe (19), which passes through the first sealing plate (3) and is connected to the external water tank, and each group A connecting pipe (29) is further provided in the external circular tube (18); the outer surface of the connecting pipe (29) is provided with a first spiral plate (20) distributed in an annular array; the outer end surface of the first spiral plate (20) is fixedly connected to the inner surface of the external circular tube (18); the inner heat absorption structure comprises an internal circular tube (21), a partition (22), a second spiral plate (23), a connecting structure, and an open hole circular plate (26); the surface of the internal circular tube (21) is provided with a second spiral plate (23) distributed in an annular array. A perforated circular plate (26) is installed on the upper end surface of the built-in circular tube (21), and a partition (22) is vertically installed inside the built-in circular tube (21) to divide the built-in circular tube (21) into two cavities. An opening is provided at the bottom of the partition (22), and the surface of the perforated circular plate (26) is connected to the external water tank through a connecting structure. The built-in circular tube (21) is inserted into the connecting pipe (29), and the perforated circular plate (26) is connected to the surface of the first sealing plate (3) through bolts.

2. The boiler flue waste heat recovery device according to claim 1, characterized in that: A cavity is provided between the external circular tube (18) and the outer shell (2), a distance is left between the upper end surface of the external circular tube (18) and the lower end surface of the first sealing plate (3), a connecting pipe is provided on the surface of the outer shell (2), and an insulation layer is installed on the outer surface of the outer shell (2).

3. The boiler flue waste heat recovery device according to claim 1, characterized in that: The pitch of the first spiral plate (20) increases gradually from bottom to top, and the gap between two adjacent groups of second spiral plates (23) is large.

4. The boiler flue waste heat recovery device according to claim 2, characterized in that: A clamping plate (17) is installed on the surface of the external circular tube (18).

5. The boiler flue waste heat recovery device according to claim 1, characterized in that: The external water tank comprises an outer box (4), a water inlet box (5), a water outlet box (6), and a circular plate (13); the lower end of the circular plate (13) is connected to the upper end surface of the first sealing plate (3); the outer box (4) is mounted on the surface of the circular plate (13); and the water inlet box (5) and the water outlet box (6) are both mounted on the surface of the circular plate (13) to form a cavity therein; and the surfaces of the outer box (4), the water inlet box (5), and the water outlet box (6) are all provided with connecting pipes, and the upper end surface of the water outlet box (6) is provided with a desulfurization treatment structure.

6. The boiler flue waste heat recovery device according to claim 5, characterized in that: The circular plate (13) has circular openings formed in an annular array on its surface. A built-in plate (11) is installed on the inner side of the circular plate (13). The upper end surface of the built-in plate (11) is lower than the upper end surface of the circular plate (13). A gap is left between the outer side surface of the built-in plate (11) and the inner side surface of the circular plate (13).

7. The boiler flue waste heat recovery device according to claim 1, characterized in that: The connection structure comprises a water outlet pipe (24) and a water inlet pipe (25); the water outlet pipe (24) and the water inlet pipe (25) penetrate the perforated circular plate (26) and extend into the corresponding cavity, wherein the water outlet pipe (24) and the water inlet pipe (25) both pass through the circular plate (13), wherein the water outlet pipe (24) is connected to the water outlet box (6), and the water inlet pipe (25) is connected to the water inlet box (5).

8. The boiler flue waste heat recovery device according to claim 1, characterized in that: The desulfurization treatment structure comprises an outer shell (7), a second sealing plate (14), and an annular water pipe (15); the outer shell (7) is installed on the upper end surface of the water outlet box (6) and wraps the circular plate (13) therein, with a gap left between the outer shell (7) and the circular plate (13); the second sealing plate (14) is installed on the upper end surface of the circular plate (13); the annular water pipe (15) is installed on the upper end surface of the second sealing plate (14); nozzles are installed in an annular array on the surface of the annular water pipe (15); and a connecting pipe is connected to the surface of the outer shell (7).

9. The boiler flue waste heat recovery device according to claim 8, characterized in that: An L-shaped circular plate (12) is also installed on the periphery of the second sealing plate (14), a baffle (27) is installed on the outer end surface of the connection surface between the outer shell (7) and the circular plate (13), a gap is left between the L-shaped circular plate (12) and the outer shell (7), and an opening is also provided on the surface of the second sealing plate (14), a U-shaped tube (28) is installed on the lower end surface of the annular water pipe (15), and the U-shaped tube (28) extends through the opening to the inside of the circular plate (13), wherein an arc-shaped circular plate (10) is also installed on the inner surface of the outer shell (7) near the port, and a third sealing plate (16) is installed on the upper end surface of the arc-shaped circular plate (10), and an operation opening is opened on the surface of the third sealing plate (16), and an outer end cover (30) is installed on the upper end surface of the outer shell (7), and the fan structure is installed on the upper end surface of the outer end cover (30), and the upper end surface of the annular water pipe (15) is also connected to a connecting pipe, which passes through the third sealing plate (16) and the outer end cover (30).

10. The boiler flue waste heat recovery device according to claim 9, characterized in that: The fan structure comprises a connecting seat (8) and a centrifugal fan (9); the connecting seat (8) is mounted on the end surface of the outer end cover (30), and the centrifugal fan (9) is mounted on the outer end surface of the connecting seat (8); The connecting pipe at the upper end of the annular water pipe (15) is located between the centrifugal fan (9) and the housing (7).

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