High-efficiency gradient utilization medium and low temperature flue gas waste heat recovery system and method thereof

Abstract

The invention discloses an efficient gradient utilization medium and low temperature flue gas waste heat recovery system and method, and relates to the technical field of waste heat recovery. When the contact time between the medium and low temperature flue gas and a heat medium is short and the heat conduction contact area is small, the heat transferred to the heat medium by the medium and low temperature flue gas is small, the waste heat recovery amount is small, and the recovery effect is affected. The arc-shaped recess in the center of the inner side of the heat medium bin is matched with the smoke exhaust mechanism, the contact area between the inner side of the heat medium bin and smoke is increased through the recess, the smoke exhaust mechanism limits smoke exhaust, the contact area between the smoke and the heat medium bin is increased, and meanwhile the contact time between the smoke and the heat medium bin is prolonged; the heat of medium and low temperature flue gas is more effectively transferred to the heat medium in the heat medium bin, and the situation that the flue gas and the heat medium bin are small in contact area and short in retention time, heat is not completely transferred and discharged, and the waste heat recycling rate is low is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat recovery, and particularly to an efficient cascade utilization system and method for recovering waste heat from medium and low temperature flue gas. Background Art

[0002] During the process of waste heat recovery, when the contact time between medium and low temperature flue gas and the heat medium is short and the heat conduction contact area is small, the heat transferred from the medium and low temperature flue gas to the heat medium is small, resulting in less waste heat recovery and affecting the recovery effect. Summary of the Invention

[0003] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0004] An efficient cascade utilization system for recovering waste heat from medium and low temperature flue gas, comprising:

[0005] A tank body, at the bottom of the outer side of the tank body, a smoke inlet pipe is installed, one end of the smoke inlet pipe extends into the interior of the tank body, and a trough pipe is fixedly installed on the outer side of the tank body;

[0006] A smoke filtering mechanism, which is installed at the bottom of the inner wall of the tank body, and the bottom of the smoke filtering mechanism is communicated with one end of the smoke inlet pipe;

[0007] A tubular heat exchanger, which is fixedly installed at one end of the trough pipe away from the tank body;

[0008] A smoke exhaust mechanism, which is installed at the top of the inner wall of the tank body;

[0009] A liquid pump is fixedly installed on the outer side of the trough pipe. At the liquid inlet of the liquid pump, a lead-out pipe is fixedly installed. The lead-out pipe is fixedly installed inside the trough pipe. One end of the lead-out pipe away from the liquid pump is connected to the heat medium outlet of the tubular heat exchanger. An inlet pipe is fixedly installed on the inner wall of the trough pipe. One end of the inlet pipe is connected to the heat medium inlet of the tubular heat exchanger. Three-way pipes are fixedly installed at the other ends of both the inlet pipe and the liquid outlet of the liquid pump. A heat medium bin is fixedly installed on the outer side of the three-way pipe. The heat medium bin is a hollow bin with an inward arc-shaped depression at the center of the inner side. Through the arc-shaped depression at the center of the inner side of the heat medium bin, it cooperates with the smoke exhaust mechanism. By using the depression to increase the contact area between the inner side of the heat medium bin and the flue gas, and cooperating with the restriction of the smoke exhaust mechanism on the flue gas discharge, while increasing the contact area between the flue gas and the heat medium bin, the contact time between the flue gas and the heat medium bin is increased, so that the heat of the medium and low temperature flue gas can be more effectively transferred to the heat medium inside the heat medium bin, avoiding the small contact area between the flue gas and the heat medium bin and the short residence time, resulting in incomplete heat transfer and then discharge, leading to a low waste heat recovery utilization rate. The other two ends of the three-way pipe are both fixedly installed with heat medium pipes. The other ends of the heat medium pipes are communicated with another three-way pipe, and the heat medium pipes are located inside the heat medium bin.

[0010] Preferably, the smoke filtering mechanism includes a sealing disc which is fixedly installed at the bottom of the inner wall of the tank, and the top of the sealing disc is closely attached to the bottom of the heat medium bin. A conical cover is fixedly installed at the bottom of the sealing disc. The conical cover is a cylindrical cover with gradually decreasing inner and outer diameters from top to bottom. The unfolding shape of the dust removal filter bag is restricted by the conical cover, so that the dust removal filter bag cooperates with the inclined surface cylinder. By using the gradually decreasing gap between the dust removal filter bag and the inclined surface cylinder from bottom to top, the rising speed of the flue gas in the gap is accelerated. While the flue gas is filtered, the rapidly rising flue gas drives the filtered dust to move upward, avoiding blockage caused by accumulation. A bottom pipe is fixedly installed at the bottom of the conical cover, and one end of the bottom pipe is fixedly connected to one end of the smoke inlet pipe.

[0011] Preferably, a conical frame is fixedly installed at the bottom of the sealing disc. The conical frame is located inside the conical cover, and the outer diameter of the conical frame gradually decreases from top to bottom. A dust removal filter bag is fixedly installed on the outer side of the conical frame. An inclined surface cylinder is fixedly installed on the inner wall of the conical cover. By the cooperation of the inclined surface cylinder and the conical cover, there is a storage space between the inclined surface cylinder and the conical cover, providing a storage position for the dust filtered by the dust removal filter bag. At the same time, the inclined surface cylinder protects and restricts the dust in the storage space, preventing the introduced flue gas from blowing the dust and causing the dust to block the dust removal filter bag. The top end of the inclined surface cylinder inclines inward and is located outside the dust removal filter bag. The gap between the inclined surface cylinder and the dust removal filter bag gradually decreases from bottom to top, and there is a gap between the outer side of the dust removal filter bag and the top end of the inclined surface cylinder.

[0012] Preferably, the smoke exhaust mechanism includes a heat insulation cylinder which is fixedly installed at the top of the inner wall of the tank, and a top disc is fixedly installed on the inner wall of the heat insulation cylinder. A smoke exhaust pipe is fixedly installed on the inner wall of the top disc. A pressure disc is fixedly installed at the bottom of the top disc. By the cooperation of the pressure disc and the sealing disc, the inside and outside of the heat medium bin are blocked and sealed, realizing a double - shell space. While ensuring that the flue gas is introduced into the inner space, a heat insulation layer appears, avoiding the direct outward conduction of the heat of the medium - low - temperature flue gas and resulting in heat loss. The bottom end of the pressure disc is closely attached to the top of the heat medium bin, and the bottom end of the smoke exhaust pipe extends into the inner side of the heat medium bin.

[0013] Preferably, a hole disc is fixedly installed on the inner wall of the smoke exhaust pipe. A smoke guiding pipe is fixedly installed at the bottom of the hole disc. Smoke holes are evenly opened at the bottom of the outer side of the smoke guiding pipe. Through holes are evenly opened at the top of the hole disc. A sliding disc is slidably installed on the outer side of the smoke guiding pipe. The outer side of the sliding disc is slidably adapted to the inner wall of the smoke exhaust pipe, and an outer cover cylinder is fixedly installed at the bottom of the sliding disc. By the cooperation of the sliding disc and the outer cover cylinder, the inner flue gas is restricted, increasing the residence time of the flue gas inside, enabling more heat in the flue gas to be transferred to the heat medium in the heat medium bin, and improving the waste heat utilization effect of the medium - low - temperature flue gas. The inner wall of the outer cover cylinder is slidably adapted to the outer side of the smoke guiding pipe.

[0014] A method for using an efficient cascade utilization system for recovering waste heat from medium- and low-temperature flue gas consists of the following steps:

[0015] S1. Flue gas filtration: Connect the inlet flue pipe to the flue gas pipeline, and introduce the medium- and low-temperature flue gas into the flue gas filtering mechanism through the inlet flue pipe. During the upward movement of the flue gas, the flue gas filtering mechanism filters the soot in the flue gas.

[0016] S2. Flue gas heat conduction: After being filtered by the flue gas filtering mechanism, the flue gas enters the inner side of the heat medium bin. Through the contact between the flue gas and the heat medium bin, the heat is transferred to the heat medium in the heat medium bin, and the heat medium in the heat medium bin transfers the heat to the heat medium in the heat medium pipe.

[0017] S3. Heat conduction: After the heat medium in the heat medium pipe absorbs heat, the heat medium is driven by a liquid pump to flow through the inlet pipe and the outlet pipe in the tubular heat exchanger and the heat medium pipe, and the heat absorbed from the flue gas is transferred to the outside through the tubular heat exchanger.

[0018] S4. Heat absorption and smoke exhaust: Through the cooperation of the smoke exhaust mechanism and the heat medium bin, after the heat of the medium- and low-temperature flue gas is absorbed, it is exhausted through the smoke exhaust mechanism.

[0019] The present invention provides an efficient cascade utilization system for recovering waste heat from medium- and low-temperature flue gas, which has the following beneficial effects:

[0020] First, in this efficient cascade utilization system for recovering waste heat from medium- and low-temperature flue gas, the arc-shaped depression at the center position inside the heat medium bin cooperates with the smoke exhaust mechanism. By using the depression to increase the contact area between the inner side of the heat medium bin and the flue gas, and cooperating with the restriction of the smoke exhaust mechanism on the flue gas discharge, while increasing the contact area between the flue gas and the heat medium bin, the contact time between the flue gas and the heat medium bin is also increased, so that the heat of the medium- and low-temperature flue gas can be more effectively transferred to the heat medium inside the heat medium bin, avoiding the situation where the contact area between the flue gas and the heat medium bin is small and the residence time is short, resulting in incomplete heat transfer and then discharge, and thus reducing the waste heat recovery utilization rate.

[0021] Second, in this efficient cascade utilization system for recovering waste heat from medium- and low-temperature flue gas, the expansion shape of the dust removal filter bag is restricted by the conical cover, so that the dust removal filter bag cooperates with the inclined surface cylinder. By using the gradually decreasing gap from bottom to top between the dust removal filter bag and the inclined surface cylinder, the upward speed of the flue gas in the gap is accelerated. While filtering the flue gas, the rapidly rising flue gas drives the filtered soot to move upward, avoiding blockage caused by accumulation.

[0022] Third, in this efficient cascade utilization system for recovering waste heat from medium- and low-temperature flue gas, through the cooperation of the inclined surface cylinder and the conical cover, there is a storage space between the inclined surface cylinder and the conical cover, providing a storage position for the soot filtered by the dust removal filter bag. At the same time, the inclined surface cylinder protects and restricts the soot in the storage space, preventing the introduced flue gas from blowing the soot and causing the soot to block the dust removal filter bag.

[0023] IV. The high-efficiency cascade utilization medium- and low-temperature flue gas waste heat recovery system uses a pressure plate and a sealing plate in cooperation to block and seal the inner and outer sides of the heat medium bin, creating a double-shell space. While ensuring that the flue gas is introduced into the inner space, a heat insulation layer appears to prevent the direct outward conduction of the heat of the medium- and low-temperature flue gas, resulting in heat loss.

[0024] V. The high-efficiency cascade utilization medium- and low-temperature flue gas waste heat recovery system uses a sliding plate and an outer cover cylinder in cooperation to restrict the flue gas inside, increasing the residence time of the flue gas inside, enabling more heat in the flue gas to be transferred to the heat medium in the heat medium bin, and improving the waste heat utilization effect of the medium- and low-temperature flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of a high-efficiency cascade utilization medium- and low-temperature flue gas waste heat recovery system according to the present invention;

[0026] Figure 2 is a partial structural dissection diagram of a high-efficiency cascade utilization medium- and low-temperature flue gas waste heat recovery system according to the present invention;

[0027] Figure 3 is a partial structural schematic diagram of a high-efficiency cascade utilization medium- and low-temperature flue gas waste heat recovery system according to the present invention;

[0028] Figure 4 is a partial structural dissection side view of a high-efficiency cascade utilization medium- and low-temperature flue gas waste heat recovery system according to the present invention;

[0029] Figure 5 is a partial structural dissection diagram of the smoke exhaust mechanism and the tank body according to the present invention;

[0030] Figure 6 is a partial structural dissection diagram of the smoke exhaust mechanism and the heat medium bin according to the present invention;

[0031] Figure 7 is a partial structural dissection bottom view of the smoke exhaust mechanism and the heat medium bin according to the present invention;

[0032] Figure 8 is a schematic structural diagram of the smoke filtering mechanism according to the present invention;

[0033] Figure 9 is a partial structural dissection diagram of the smoke filtering mechanism according to the present invention;

[0034] Figure 10 is a schematic diagram of the usage method according to the present invention.

[0035] In the figure: 1, tank body; 2, smoke exhaust mechanism; 3, tubular heat exchanger; 4, trough pipe; 5, smoke inlet pipe; 6, smoke filtering mechanism; 7, liquid pump; 8, outlet pipe; 9, inlet pipe; 10, heat medium bin; 11, three-way pipe; 12, heat medium pipe; 21, heat insulation cylinder; 22, top plate; 23, smoke exhaust pipe; 24, hole plate; 25, smoke guiding pipe; 26, sliding plate; 27, outer cover cylinder; 28, pressing plate; 61, sealing plate; 62, dust removal filter bag; 63, conical frame; 64, bottom pipe; 65, inclined surface cylinder; 66, conical cover. Specific implementation mode

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0037] The first embodiment is as Figures 1 to 5 shown. The present invention provides a technical solution:

[0038] An efficient stepped utilization medium and low temperature flue gas waste heat recovery system, comprising:

[0039] A tank body 1, a smoke inlet pipe 5 is installed at the bottom outside the tank body 1, one end of the smoke inlet pipe 5 extends into the interior of the tank body 1, and a trough pipe 4 is fixedly installed outside the tank body 1;

[0040] A smoke filtering mechanism 6, the smoke filtering mechanism 6 is installed at the bottom of the inner wall of the tank body 1, and the bottom of the smoke filtering mechanism 6 is communicated with one end of the smoke inlet pipe 5;

[0041] A tubular heat exchanger 3, the tubular heat exchanger 3 is fixedly installed at one end of the trough pipe 4 away from the tank body 1;

[0042] A smoke exhaust mechanism 2, the smoke exhaust mechanism 2 is installed at the top of the inner wall of the tank body 1;

[0043] A liquid pump 7 is fixedly installed on the outer side of the groove pipe 4. A lead-out pipe 8 is fixedly installed at the liquid inlet of the liquid pump 7. The lead-out pipe 8 is fixedly installed inside the groove pipe 4. The filtered flue gas enters the inner side of the heat medium bin 10. Through the cooperation between the heat medium bin 10 and the smoke exhaust mechanism 2, the flue gas is restricted inside the heat medium bin 10. Through the contact between the heat medium bin 10 and the flue gas, the heat in the medium and low temperature flue gas is absorbed and transferred to the heat medium inside the heat medium bin 10, causing the temperature of the heat medium to rise. At the same time, by using the contact between the heat medium inside the heat medium bin 10 and the heat medium pipe 12, the heat is further transferred to the heat medium in the heat medium pipe 12. One end of the lead-out pipe 8 away from the liquid pump 7 is connected to the heat medium export of the tubular heat exchanger 3. An inlet pipe 9 is fixedly installed on the inner wall of the groove pipe 4. One end of the inlet pipe 9 is connected to the heat medium inlet of the tubular heat exchanger 3. Three-way pipes 11 are fixedly installed at the other ends of both the inlet pipe 9 and the outlet of the liquid pump 7. A heat medium bin 10 is fixedly installed on the outer side of the three-way pipe 11. The heat medium bin 10 is a hollow bin with an inward arc-shaped depression at the center of the inner side. During the heat conduction process, the heat medium in the tubular heat exchanger 3 is led out by the liquid pump 7 through the lead-out pipe 8, and through the liquid pump 7 and the three-way pipe 11, it is introduced into the heat medium pipe 12. The heat medium that has absorbed heat in the original heat medium pipe 12 is introduced into the inlet pipe 9 through the three-way pipe 11 on the other side, and the high-temperature heat medium after absorbing heat is introduced into the tubular heat exchanger 3 through the inlet pipe 9 to exchange heat with the outside world, realizing the recovery and utilization of the waste heat of the flue gas. At the same time, in the heat medium bin 10, by using the arc-shaped depression at the center of the inner side of the heat medium bin 10 and cooperating with the smoke exhaust mechanism 2, the smoke storage space inside the heat medium bin 10 is increased, and at the same time, the contact area with the flue gas is increased, enabling the heat in the flue gas to be quickly transferred to the internal heat medium through the heat medium bin 10. The other two ends of the three-way pipe 11 are both fixedly installed with heat medium pipes 12. The other ends of the heat medium pipes 12 are connected to another three-way pipe 11, and the heat medium pipes 12 are located inside the heat medium bin 10.

[0044] Second embodiment, on the basis of the first embodiment, please refer to Figures 8 to 9 As shown, the smoke filtering mechanism 6 includes a sealing disc 61. The sealing disc 61 is fixedly installed at the bottom of the inner wall of the tank body 1, and the top of the sealing disc 61 is in close contact with the bottom of the heat medium bin 10. Through the connection between the bottom pipe 64 and the smoke inlet pipe 5, the medium and low temperature flue gas is introduced from the smoke inlet pipe 5 into the bottom pipe 64, and the flue gas is introduced into the inside of the conical cover 66 through the bottom pipe 64. After the flue gas enters the inside of the conical cover 66, the flue gas rises in the space between the inclined surface cylinder 65 and the dust removal filter bag 62. A conical cover 66 is fixedly installed at the bottom of the sealing disc 61. The conical cover 66 is a cylindrical cover with gradually decreasing inner and outer diameters from top to bottom, and a bottom pipe 64 is fixedly installed at the bottom of the conical cover 66. The bottom end of the bottom pipe 64 is fixedly connected to one end of the smoke inlet pipe 5.

[0045] A conical frame 63 is fixedly installed at the bottom of the sealing disk 61, and the conical frame 63 is located on the inner side of the conical cover 66, and the outer diameter of the conical frame 63 gradually decreases from top to bottom. A dust filter bag 62 is fixedly installed on the outer side of the conical frame 63, and a beveled cylinder 65 is fixedly installed on the inner wall of the conical cover 66. The top of the beveled cylinder 65 is inclined inwardly and is located on the outer side of the dust filter bag 62. During the rising process, the dust in the flue gas is filtered by the dust filter bag 62. At the same time, during the filtering process, the gap between the beveled cylinder 65 and the dust filter bag 62 is gradually reduced from bottom to top, so as to accelerate the rising speed of the flue gas in the gap, and drive the dust that cannot pass through the dust filter bag 62 into the space between the beveled cylinder 65 and the conical cover 66 for storage, and the gap between the beveled cylinder 65 and the dust filter bag 62 is gradually reduced from bottom to top, and there is a gap between the outer side of the dust filter bag 62 and the top of the beveled cylinder 65.

[0046] The third embodiment is based on the first and second embodiments. Figures 6 to 7 and Figure 10 As shown, the smoke exhaust mechanism 2 includes an insulating tube 21, which is fixedly installed on the top of the inner wall of the tank body 1, and a top plate 22 is fixedly installed on the inner wall of the insulating tube 21, a smoke exhaust pipe 23 is fixedly installed on the inner wall of the top plate 22, and a pressure plate 28 is fixedly installed on the bottom of the top plate 22. Through the cooperation of the smoke exhaust pipe 23 and the smoke guide pipe 25, they penetrate into the inner side of the hot medium bin 10. Through the gravity of the sliding plate 26 itself, the outer cover tube 27 seals the smoke hole of the smoke guide pipe 25, so that the smoke accumulates on the inner side of the hot medium bin 10, increasing the residence time of the smoke on the inner side of the hot medium bin 10, and the bottom end of the pressure plate 28 is tightly fitted with the top of the hot medium bin 10, and the bottom end of the smoke exhaust pipe 23 penetrates into the inner side of the hot medium bin 10.

[0047] A perforated plate 24 is fixedly installed on the inner wall of the smoke exhaust pipe 23, and a smoke guide pipe 25 is fixedly installed on the bottom of the perforated plate 24. Smoke holes are evenly opened on the bottom of the outer side of the smoke guide pipe 25, and through holes are evenly opened on the top of the perforated plate 24. A sliding plate 26 is slidably installed on the outer side of the smoke guide pipe 25. The outer side of the sliding plate 26 is slidably matched with the inner wall of the smoke exhaust pipe 23, and an outer cover tube 27 is fixedly installed on the bottom of the sliding plate 26. When smoke accumulates, the air pressure increases, and the sliding plate 26 begins to be pushed to slide upward, so that the outer cover tube 27 slides on the outer side of the smoke guide pipe 25, opens the smoke holes, and allows the smoke to enter the interior of the smoke guide pipe 25, and then continues to rise and is led out from the top of the smoke exhaust pipe 23. At the same time, according to the size of the air pressure, the position of the sliding plate 26 is controlled to make the outer cover tube 27 open different numbers of smoke holes to exhaust smoke, and the inner wall of the outer cover tube 27 is slidably matched with the outer side of the smoke guide pipe 25.

[0048] A method for using a high-efficiency cascade utilization medium and low temperature flue gas waste heat recovery system, comprising the following steps:

[0049] S1. Flue gas filtration: Connect the inlet flue gas pipe 5 to the flue gas pipeline, so that medium and low-temperature flue gas is introduced into the flue gas filtering mechanism 6 through the inlet flue gas pipe 5. During the upward movement of the flue gas, the flue gas filtering mechanism 6 filters the dust in the flue gas.

[0050] S2. Flue gas heat conduction: After being filtered by the flue gas filtering mechanism 6, the flue gas enters the inner side of the heat medium bin 10. Through the contact between the flue gas and the heat medium bin 10, the heat is transferred to the heat medium in the heat medium bin 10, and the heat medium in the heat medium bin 10 transfers the heat to the heat medium in the heat medium pipe 12.

[0051] S3. Heat conduction: After the heat medium in the heat medium pipe 12 absorbs heat, the liquid pump 7 drives the heat medium to flow through the inlet pipe 9 and the outlet pipe 8 in the tubular heat exchanger 3 and the heat medium pipe 12, and the heat absorbed from the flue gas is transferred to the outside through the tubular heat exchanger 3.

[0052] S4. Heat absorption and smoke exhaust: Through the cooperation of the smoke exhaust mechanism 2 and the heat medium bin 10, after the heat of the medium and low-temperature flue gas is absorbed, it is discharged through the smoke exhaust mechanism 2.

[0053] During use, connect the flue gas pipeline to the inlet flue gas pipe 5, so that the flue gas is introduced into the equipment through the inlet flue gas pipe 5, and connect the heat medium pipeline that needs heat to the tubular heat exchanger 3 to transfer the heat of the absorbed medium and low-temperature flue gas to the outside for recycling. After the flue gas is introduced into the equipment, first, the medium and low-temperature flue gas is filtered by the flue gas filtering mechanism 6 to remove the dust in the flue gas. Then, the flue gas enters the inner side of the heat medium bin 10, and the heat medium bin 10 and the smoke exhaust mechanism 2 cooperate to control the flue gas. Utilize the contact between the heat medium bin 10 and the flue gas to absorb the heat of the flue gas, so that the temperature of the heat medium in the heat medium bin 10 rises for waste heat recovery.

[0054] In the flue gas filtering mechanism 6, through the connection between the bottom pipe 64 and the inlet flue gas pipe 5, the medium and low-temperature flue gas is introduced into the bottom pipe 64 through the inlet flue gas pipe 5, and the flue gas is introduced into the inside of the conical cover 66 through the bottom pipe 64. After the flue gas enters the inside of the conical cover 66, the flue gas rises in the space between the inclined surface cylinder 65 and the dust removal filter bag 62. At the same time, during the upward movement, the dust removal filter bag 62 is used to filter the dust in the flue gas. At the same time, during the filtering process, the gradually decreasing gap from bottom to top between the inclined surface cylinder 65 and the dust removal filter bag 62 is utilized to accelerate the upward movement speed of the flue gas in the gap, driving the dust that cannot pass through the dust removal filter bag 62 into the space between the inclined surface cylinder 65 and the conical cover 66 for storage.

[0055] The filtered flue gas enters the inner side of the heat medium bin 10. Through the cooperation between the heat medium bin 10 and the smoke exhaust mechanism 2, the flue gas is restricted inside the heat medium bin 10. By contacting the heat medium bin 10 with the flue gas, the heat in the medium and low-temperature flue gas is absorbed and transferred to the heat medium inside the heat medium bin 10, causing the temperature of the heat medium to rise. At the same time, by utilizing the contact between the heat medium inside the heat medium bin 10 and the heat medium pipe 12, the heat is further transferred to the heat medium in the heat medium pipe 12. During the heat conduction process, the heat medium in the tubular heat exchanger 3 is driven by the liquid pump 7 to be led out through the outlet pipe 8, and through the liquid pump 7 and the three-way pipe 11, it is introduced into the heat medium pipe 12. The heat medium that has absorbed heat in the original heat medium pipe 12 is passed through the three-way pipe 11 on the other side into the inlet pipe 9, and the high-temperature heat medium after absorbing heat is introduced into the tubular heat exchanger 3 through the inlet pipe 9 to exchange heat with the outside, realizing the recovery and utilization of the waste heat of the flue gas. At the same time, in the heat medium bin 10, by utilizing the arc-shaped depression at the center position on the inner side of the heat medium bin 10 and cooperating with the smoke exhaust mechanism 2, the smoke storage space inside the heat medium bin 10 is increased, and at the same time, the contact area with the flue gas is increased, enabling the heat in the flue gas to be quickly transferred to the internal heat medium through the heat medium bin 10.

[0056] In the smoke exhaust mechanism 2, through the cooperation of the smoke exhaust pipe 23 and the smoke guiding pipe 25, it penetrates deep into the inner side of the heat medium bin 10. Due to the gravity of the sliding disk 26 itself, the outer cover cylinder 27 closes the smoke holes of the smoke guiding pipe 25, causing the flue gas to accumulate inside the heat medium bin 10, increasing the residence time of the flue gas inside the heat medium bin 10. When the flue gas accumulates, the air pressure increases, starting to push the sliding disk 26 to slide upward, causing the outer cover cylinder 27 to slide upward on the outside of the smoke guiding pipe 25, opening the smoke holes, enabling the flue gas to enter the inside of the smoke guiding pipe 25, and then continuing to rise and being led out from the top of the smoke exhaust pipe 23. At the same time, according to the magnitude of the air pressure, the position of the sliding disk 26 is controlled to enable the outer cover cylinder 27 to open different numbers of smoke holes for smoke exhaust.

[0057] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0058] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An efficient cascade utilization system for recovering waste heat from medium- and low-temperature flue gas, characterized in that, Comprising: A tank body (1), at the bottom of the outer side of the tank body (1), a smoke inlet pipe (5) is installed, one end of the smoke inlet pipe (5) extends into the interior of the tank body (1), and a groove pipe (4) is fixedly installed on the outer side of the tank body (1); A smoke filtering mechanism (6), the smoke filtering mechanism (6) is installed at the bottom of the inner wall of the tank body (1), and the bottom of the smoke filtering mechanism (6) is communicated with one end of the smoke inlet pipe (5); A tube heat exchanger (3), the tube heat exchanger (3) is fixedly installed at one end of the groove pipe (4) away from the tank body (1); A smoke exhaust mechanism (2), the smoke exhaust mechanism (2) is installed at the top of the inner wall of the tank body (1); A liquid pump (7) is fixedly installed on the outer side of the groove pipe (4), a liquid outlet pipe (8) is fixedly installed at the liquid inlet of the liquid pump (7), the liquid outlet pipe (8) is fixedly installed inside the groove pipe (4), one end of the liquid outlet pipe (8) away from the liquid pump (7) is connected to the heat medium outlet of the tube heat exchanger (3), an inlet pipe (9) is fixedly installed on the inner wall of the groove pipe (4), one end of the inlet pipe (9) is connected to the heat medium inlet of the tube heat exchanger (3), and three-way pipes (11) are fixedly installed at the other ends of the inlet pipe (9) and the liquid outlet of the liquid pump (7), a heat medium bin (10) is fixedly installed on the outer side of the three-way pipe (11), the heat medium bin (10) is a hollow bin with an inward arc-shaped depression at the center of the inner side, the other two ends of the three-way pipe (11) are fixedly installed with heat medium pipes (12), the other ends of the heat medium pipes (12) are communicated with another three-way pipe (11), and the heat medium pipes (12) are located inside the heat medium bin (10).

2. The high-efficiency cascade utilization medium- and low-temperature flue gas waste heat recovery system according to claim 1, wherein: The smoke filtering mechanism (6) includes a sealing disc (61), the sealing disc (61) is fixedly installed at the bottom of the inner wall of the tank body (1), and the top of the sealing disc (61) is in close contact with the bottom of the heat medium bin (10), and a conical cover (66) is fixedly installed at the bottom of the sealing disc (61).

3. An efficient cascade utilization medium and low temperature flue gas waste heat recovery system according to claim 2, characterized in that: The conical cover (66) is a cylindrical cover with gradually decreasing inner and outer diameters from top to bottom, and a bottom pipe (64) is fixedly installed at the bottom of the conical cover (66), and the bottom end of the bottom pipe (64) is fixedly connected to one end of the smoke inlet pipe (5).

4. An efficient cascade utilization medium and low temperature flue gas waste heat recovery system according to claim 3, characterized in that: A conical frame (63) is fixedly installed at the bottom of the sealing disc (61), the conical frame (63) is located inside the conical cover (66), and the outer diameter of the conical frame (63) gradually decreases from top to bottom, and a dust removal filter bag (62) is fixedly installed on the outer side of the conical frame (63).

5. An efficient cascaded utilization medium and low temperature flue gas waste heat recovery system according to claim 4, characterized in that: An inclined surface cylinder (65) is fixedly installed on the inner wall of the conical cover (66), the top end of the inclined surface cylinder (65) inclines inwards and is located outside the dust removal filter bag (62), the gap between the inclined surface cylinder (65) and the dust removal filter bag (62) gradually decreases from bottom to top, and there is a gap between the outer side of the dust removal filter bag (62) and the top end of the inclined surface cylinder (65).

6. An efficient cascade utilization medium and low temperature flue gas waste heat recovery system according to claim 5, characterized in that: The smoke exhaust mechanism (2) includes a heat insulation cylinder (21), the heat insulation cylinder (21) is fixedly installed at the top of the inner wall of the tank body (1), and a top disc (22) is fixedly installed on the inner wall of the heat insulation cylinder (21), and a smoke exhaust pipe (23) is fixedly installed on the inner wall of the top disc (22).

7. An efficient cascade utilization medium and low temperature flue gas waste heat recovery system according to claim 6, characterized in that: A pressure plate (28) is fixedly installed at the bottom of the top plate (22). The bottom end of the pressure plate (28) is in close contact with the top of the heat medium bin (10). The bottom end of the smoke exhaust pipe (23) extends into the inside of the heat medium bin (10).

8. An efficient cascade utilization medium and low temperature flue gas waste heat recovery system according to claim 7, characterized in that: A hole plate (24) is fixedly installed on the inner wall of the smoke exhaust pipe (23). A smoke guide pipe (25) is fixedly installed at the bottom of the hole plate (24). Smoke holes are evenly formed in the bottom of the outer side of the smoke guide pipe (25). Through holes are evenly formed in the top of the hole plate (24).

9. An efficient cascade utilization medium and low temperature flue gas waste heat recovery system according to claim 8, characterized in that: A sliding plate (26) is slidably installed on the outer side of the smoke guide pipe (25). The outer side of the sliding plate (26) is slidably adapted to the inner wall of the smoke exhaust pipe (23). The bottom of the sliding plate (26) is fixedly installed with an outer cover cylinder (27). The inner wall of the outer cover cylinder (27) is slidably adapted to the outer side of the smoke guide pipe (25).

10. A method for using an efficient cascade utilization medium and low temperature flue gas waste heat recovery system according to any one of claims 1-9, characterized in that, It consists of the following steps: S1. Flue gas filtration: Connect the inlet smoke pipe (5) to the flue gas pipeline, so that medium and low temperature flue gas is introduced into the smoke filtration mechanism (6) through the inlet smoke pipe (5). During the upward movement of the flue gas, the smoke filtration mechanism (6) filters the soot in the flue gas; S2. Flue gas heat conduction: After being filtered by the smoke filtration mechanism (6), the flue gas enters the inside of the heat medium bin (10). Through the contact between the flue gas and the heat medium bin (10), heat is transferred to the heat medium in the heat medium bin (10), and the heat medium in the heat medium bin (10) transfers the heat to the heat medium in the heat medium pipe (12); S3. Heat conduction: After the heat medium in the heat medium pipe (12) absorbs heat, the heat medium is driven by the liquid pump (7) to flow through the inlet pipe (9) and the outlet pipe (8) between the tubular heat exchanger (3) and the heat medium pipe (12), and the absorbed flue gas heat is transferred to the outside through the tubular heat exchanger (3); S4. Heat absorption and smoke exhaust: Through the cooperation of the smoke exhaust mechanism (2) and the heat medium bin (10), after the heat of the medium and low temperature flue gas is absorbed, it is discharged through the smoke exhaust mechanism (2).

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