Waste heat recovery system and waste heat recovery method of coal-fired unit

Abstract

The present invention discloses a waste heat recovery system and a waste heat recovery method of a coal-fired unit, which mainly includes a heat exchange outer cylinder and a heat recovery inner cylinder, the former is outside and the latter is inside, and a space is left between the two to form a heat exchange chamber, both sides of the heat exchange chamber are closed, and the inner wall of the heat recovery inner cylinder is installed with a plurality of fixed tubes in a uniform array, which are all arc-shaped and are connected to each other through a circulation pipe, and a filter cartridge is placed in the middle of the heat recovery inner cylinder. The advantage of the present invention is that the whole set of devices is composed of a heat recovery inner cylinder and a heat exchange outer cylinder, and a space is left between the two to form a heat exchange chamber, and liquid, clean gas or polluted gas can be introduced into the interior of the heat recovery inner cylinder separately or simultaneously, and the gas and liquid are separated to avoid contact between the two. When in use, the heat exchange chamber is filled with liquid or gas to be heated, and the heat in the liquid, clean gas or polluted gas with heat can be transferred to the liquid or gas to be heated to heat it up, which is convenient for later use.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary utilization of resources, and in particular to a waste heat recovery system and a waste heat recovery method for a coal-fired unit. Background Art

[0002] Waste heat refers to the sensible heat and latent heat that have not been reasonably utilized in the original design of energy-consuming devices of industrial enterprises that have been put into operation due to the limitations of historical, technological, and conceptual factors. It includes waste heat from high-temperature exhaust gas, waste heat from cooling media, waste heat from waste steam and waste water, waste heat from high-temperature products and slag, waste heat from chemical reactions, and waste heat from combustible waste gas, waste liquid, and waste materials. According to surveys, the total waste heat resources of various industries account for about 17%-67% of their total fuel consumption, and recyclable waste heat resources account for about 60% of the total waste heat resources. Flue gas is a common product in industrial production. Direct emission will not only cause waste of energy, but also affect the surrounding air environment. Therefore, how to efficiently utilize the waste heat has become a concern.

[0003] Based on this, the present application proposes a waste heat recovery system and a waste heat recovery method for a coal-fired unit, which can simultaneously recycle the heat in the flue gas generated during the operation of the coal-fired unit, reduce energy loss, and thus solve the above-mentioned problem. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a waste heat recovery system and a waste heat recovery method for a coal-fired unit to solve the problems mentioned in the background technology and overcome the deficiencies in the prior art.

[0006] (II) Technical solution

[0007] In order to solve the above-mentioned related problems and achieve the desired purpose, the present invention provides the following technical solutions: a waste heat recovery system of a coal-fired unit, comprising a heat exchange outer cylinder and a heat recovery inner cylinder, the former is outside and the latter is inside, and a space is left between the two to form a heat exchange chamber, both sides of the heat exchange chamber are closed, the inner wall of the heat recovery inner cylinder is installed with a plurality of uniformly arrayed fixed pipes, which are all arc-shaped and are connected to each other through a circulation pipe, a filter cartridge is placed in the middle position inside the heat recovery inner cylinder, filter elements are installed on both sides of the interior, spiral heat conduction pipes are installed on both sides of the exterior, and a discharge pipe is installed in the middle position of the exterior, the discharge pipe runs through the heat exchange chamber, gear rings are rotatably installed on both sides of the exterior of the heat recovery inner cylinder, first electromagnets are installed on the inner sides of the outer surfaces of the two gear rings, ring frames are rotatably installed on both sides of the interior of the heat exchange chamber, second electromagnets are installed on one side of the exterior of the two ring frames, and a plurality of circular arrayed fixed rods are installed on the other side of the exterior, and the two second electromagnets are magnetically connected to the two first electromagnets respectively.

[0008] Preferably, both sides of the outside of the heat recovery inner cylinder are closed by sealing plates, and a first valve is installed on the outside of the two sealing plates. One circulation pipe passes through a sealing plate, and a first circulation valve is installed at its outer end. The two spiral heat-conducting pipes pass through two sealing plates respectively, and a second valve is installed at their outer ends. A third valve is installed at the outer end of the discharge pipe.

[0009] Preferably, a second circulation valve is installed on one side of the exterior of the heat recovery inner cylinder, which is communicated with the heat exchange chamber.

[0010] Preferably, rotating mounting cylinders are installed on both sides of the outer surface of the heat recovery inner cylinder, and the two gear rings are rotatably installed outside the rotating mounting cylinders respectively. Fixed plates are installed on both ends of the outer surface of the heat recovery inner cylinder, and motors are installed on one side outside the two fixed plates, and gears are installed at the output ends thereof, and the two gears are respectively meshed with the two gear rings.

[0011] Preferably, one side of the outer surface of the two gear rings is concave to form a groove, and one side of the two ring frames away from the outer surface of the fixed rod is concave to form an installation groove, and the two first electromagnets and the second electromagnets are respectively installed in the two grooves and the installation groove.

[0012] Preferably, a plurality of heat-conducting columns in a uniform array are installed inside the plurality of fixed tubes, one end of which is inserted into the heat exchange cavity, and heat-conducting plates are installed at intervals between the plurality of fixed tubes.

[0013] Preferably, both sides of the outside of the filter cartridge are closed by sealing plates, and one side of the outer surface of the two sealing plates is installed with a plurality of straight cylinders in a circular array, which respectively pass through the two filter elements, and springs are installed inside the plurality of straight cylinders, and a sliding seat is installed on one side thereof, and a shift lever is rotatably installed at one end of the plurality of sliding seats.

[0014] Preferably, a clamp assembly for fixing is installed on the outside of the exhaust pipe, and sockets are provided on both sides of the outer surface of the exhaust pipe. The clamp assembly is located outside the heat recovery inner cylinder. The clamp assembly consists of two clamps and bolts. Slots are provided on both sides of the outside of the two clamps. The two bolts are respectively installed between the two groups of slots. The middle position of one side of the outer surface of the two clamps is protruded outward to form a socket, which is respectively inserted into the two sockets.

[0015] The recovery method of the waste heat recovery system of a coal-fired unit comprises the following steps:

[0016] 1) Assemble the components according to the designed structure to form a heat exchange device, and check its sealing performance;

[0017] 2) The medium to be heated circulates in the heat exchange chamber through the second circulation valve;

[0018] 3) Filling the fixed pipe with hot liquid through the first circulation valve to make it flow in the multiple fixed pipes;

[0019] 4) The hot and polluted gas is filled into the filter cartridge from both sides through the second valve on the spiral heat-conducting tube, and the filter element filters it;

[0020] 5) Fill the heat recovery inner cylinder with hot, clean gas directly through the first valve, and the heat is conducted through the heat-conducting column and the heat-conducting plate to heat the medium to be heated;

[0021] 6) Through the rotation of the gear ring, the rotational force can be transmitted to the ring frame, and the fixed rod stirs the medium to be heated;

[0022] 7) When the heating medium reaches a suitable temperature, discharge it and collect it for later use;

[0023] 8) The hot liquid or gas is discharged and collected for subsequent treatment.

[0024] (III) Beneficial effects

[0025] Compared with the prior art, the present invention provides a waste heat recovery system and a waste heat recovery method for a coal-fired unit, which have the following beneficial effects:

[0026] 1. The waste heat recovery system of the coal-fired unit consists of a heat recovery inner cylinder and a heat exchange outer cylinder. A space is left between the two to form a heat exchange chamber. Liquid, clean gas or polluted gas can be introduced into the heat recovery inner cylinder separately or simultaneously. The gas and liquid are separated to avoid contact between the two. When in use, the heat exchange chamber is filled with the liquid or gas to be heated. The heat in the liquid, clean gas or polluted gas with heat can be transferred to the liquid or gas to be heated to heat it up, which is convenient for later use.

[0027] Among them, the inner wall of the heat recovery inner cylinder is installed with multiple annular fixed tubes, and circulation pipes are installed between each other to realize the circulation of liquid or gas. When in use, liquid is filled into the fixed tubes, and multiple uniformly arrayed heat-conducting columns are installed inside the multiple fixed tubes, one end of which is inserted into the heat exchange cavity to improve the heat exchange effect.

[0028] Among them, a filter cartridge is installed in the middle position inside the heat recovery inner cylinder, spiral heat pipes are installed on both sides of its outside, and filter elements are installed on both sides of its inside. When in use, polluted gas is filled into the filter cartridge, which can be filtered by the filter element. While exchanging heat, impurities mixed in the gas can be filtered.

[0029] Among them, the clean gas can be directly introduced into the heat recovery inner cylinder, and its heat is conducted through internal components such as fixed pipes.

[0030] 2. The waste heat recovery system of the coal-fired unit has a group of gears installed on the outside of the heat recovery inner cylinder, a first electromagnet is installed on the outside of each gear, and ring frames are installed on both sides of the inside of the heat exchange chamber, a second electromagnet is installed on one side of the outside, and a plurality of fixed rods in a circumferential array are installed on the other side of the outside, wherein the first electromagnet is magnetically connected to the second electromagnet. When the gear rotates, the ring frame can rotate along with it, and the fixed rod stirs the medium in the heat exchange chamber to ensure that the medium can be heated evenly and improve the heat exchange efficiency. This structure makes the assembly between the components simpler and more compact, avoids motion interference between the components, and also improves the sealing of the device.

[0031] 3. The recovery method of the waste heat recovery system of the coal-fired unit is as follows: first, the heat exchange medium is charged into the heat exchange chamber through the second circulation valve, the ring frame rotates with the gear to stir the heat exchange medium, and the fixed pipe is charged with liquid with heat, and the heat is transferred to the medium in the heat exchange chamber through the heat conduction column and the heat conduction plate; the hot polluted gas is charged into the filter cartridge from the spiral heat conduction pipes on both sides of the filter cartridge, and the impurities in the polluted gas can be adsorbed and filtered by the filter element in the filter cartridge, and the gas discharged later is collected; the hot non-polluted gas is directly charged into the heat recovery inner cylinder through the valve, and the heat can be conducted to heat the medium to be heated, and after the medium is heated for a period of time, the medium circulates from the second circulation valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 For the present invention Figure 1 A schematic cross-sectional structure diagram of;

[0034] Figure 3 It is a schematic diagram of the overall structure of the heat exchange outer cylinder in the present invention;

[0035] Figure 4 It is a schematic diagram of the internal structure of the heat exchange outer cylinder in the present invention;

[0036] Figure 5 This is a schematic diagram of the overall structure of the heat recovery inner cylinder in the present invention;

[0037] Figure 6 This is a schematic diagram of the internal structure of the heat recovery inner cylinder in the present invention;

[0038] Figure 7 It is a schematic diagram of the overall structure of the filter cartridge and a spiral heat conducting pipe in the present invention in an assembled state;

[0039] Figure 8 For the present invention Figure 7 Schematic diagram of the internal structure;

[0040] Fig. 9 It is a schematic diagram of the overall structure of the ring frame in the present invention;

[0041] Fig.10 It is a schematic diagram of the overall structure of the combined state of the gear and the gear ring in the present invention;

[0042] Fig.11 It is a schematic diagram of the overall structure of the clamp assembly in the present invention.

[0043] In the figure: 1-heat exchange outer cylinder, 2-sealing plate, 3-motor, 4-gear, 5-gear ring, 6-first circulation valve, 7-second valve, 8-clamp assembly, 8a-clamping plate, 8b-bolt, 8c-insertion table, 9-third valve, 10-first electromagnet, 11-second electromagnet, 12-ring frame, 13-sealed plate, 14-filter element, 15-heat conduction column, 16-spiral heat conduction pipe, 17-discharge pipe, 18-spring, 19-sliding seat, 20-shift lever, 21-heat recovery inner cylinder, 22-rotating installation cylinder, 23-fixed plate, 24-fixed pipe, 25-circulation pipe, 26-jack, 27-filter cylinder, 28-straight cylinder, 29-installation groove, 30-fixed rod, 31-slotted mouth, 32-heat conduction plate, 33-second circulation valve, 34-first valve. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0045] See also Figure 1-11 The waste heat recovery system of the coal-fired unit includes a heat exchange outer cylinder 1 and a heat recovery inner cylinder 21, the former is outside and the latter is inside, and a space is left between the two to form a heat exchange cavity, both sides of the heat exchange cavity are closed, and the inner wall of the heat recovery inner cylinder 21 is installed with a plurality of fixed pipes 24 in a uniform array, which are all arc-shaped and are connected to each other through a circulation pipe 25, and a filter cartridge 27 is placed in the middle of the heat recovery inner cylinder 21, and filter elements 14 are installed on both sides of the inner side, and spiral heat conduction pipes 1 are installed on both sides of the outer side. 6, a discharge pipe 17 is installed at the middle position of the outside, and the discharge pipe 17 runs through the heat exchange chamber. Gear rings 5 ​​are rotatably installed on both sides of the outside of the heat recovery inner cylinder 21, and the first electromagnets 10 are installed on the inner sides of the outer surfaces of the two gear rings 5. Ring frames 12 are rotatably installed on both sides of the inside of the heat exchange chamber, and second electromagnets 11 are installed on one side of the outside of the two ring frames 12. A plurality of fixed rods 30 in a circumferential array are installed on the other side of the outside, and the two second electromagnets 11 are magnetically connected to the two first electromagnets 10 respectively.

[0046] As an optional technical solution of the present invention:

[0047] The two sides of the outside of the heat recovery inner cylinder 21 are closed by sealing plates 2, and the first valve 34 is installed on the outside of the two sealing plates 2. A circulation pipe 25 passes through a sealing plate 2, and a first circulation valve 6 is installed at its outer end. Two spiral heat-conducting pipes 16 pass through the two sealing plates 2 respectively, and second valves 7 are installed at their outer ends. A third valve 9 is installed at the outer end of the discharge pipe 17. The valve controls the inflow and outflow or circulation of the liquid. When installing it, it is necessary to ensure that it has good sealing with the installation position.

[0048] As an optional technical solution of the present invention:

[0049] A second circulation valve 33 is installed on one side of the exterior of the heat recovery inner cylinder 21 and communicates with the heat exchange chamber so that the medium to be heated can circulate in the heat exchange chamber to ensure uniform heating.

[0050] As an optional technical solution of the present invention:

[0051] Rotating mounting cylinders 22 are installed on both sides of the outer surface of the heat recovery inner cylinder 21, and two gear rings 5 ​​are rotatably installed outside the rotating mounting cylinder 22 respectively. Fixed plates 23 are installed on both ends of the outer surface of the heat recovery inner cylinder 21, and motors 3 are installed on one side of the outside of the two fixed plates 23, and gears 4 are installed on the output ends thereof. The two gears 4 are respectively meshed with the two gear rings 5. When installing the gears 4 and the gear rings 5, it is necessary to ensure that there is a good lubrication effect between them and the installation position to ensure their smooth rotation.

[0052] As an optional technical solution of the present invention:

[0053] One side of the outer surface of the two gear rings 5 ​​is concave to form a groove, and one side of the outer surface of the two ring frames 12 away from the fixing rod 30 is concave to form a mounting groove 29. The two first electromagnets 10 and the second electromagnet 11 are respectively installed in the two grooves and the mounting groove 29. The electromagnet can be multiple or a whole, as long as it can be ensured that the ring frame 12 can rotate with the gear ring 5. In order to avoid the electromagnet from being attracted to other components, other components can be made of non-magnetic materials.

[0054] As an optional technical solution of the present invention:

[0055] A plurality of uniformly arrayed heat-conducting columns 15 are installed inside the plurality of fixed tubes 24, one end of which is inserted into the heat exchange cavity, and heat-conducting plates 32 are installed at intervals between the plurality of fixed tubes 24. The heat-conducting plates 32 and the heat-conducting columns 15 are made of materials with strong thermal conductivity to ensure rapid heat conduction.

[0056] As an optional technical solution of the present invention:

[0057] Both sides of the outside of the filter cartridge 27 are closed by a sealing plate 13. One side of the outer surface of the two sealing plates 13 is installed with a plurality of straight cylinders 28 in a circumferential array, which respectively penetrate the two filter elements 14. Springs 18 are installed inside the plurality of straight cylinders 28, and a sliding seat 19 is installed on one side. A blocking lever 20 is rotatably installed at one end of the plurality of sliding seats 19. By placing it vertically, the filter element 14 can be blocked to prevent it from slipping. After placing the blocking lever 20 horizontally, it can be retracted into the straight cylinder 28, making it convenient to remove the filter element 14.

[0058] As an optional technical solution of the present invention:

[0059] A clamp assembly 8 for fixing is installed on the outside of the discharge pipe 17. Plug holes 26 are provided on both sides of the outer surface of the discharge pipe 17. The clamp assembly 8 is located outside the heat recovery inner cylinder 21. The clamp assembly 8 consists of two clamping plates 8a and bolts 8b. Slots 31 are provided on both sides of the outside of the two clamping plates 8a. Two bolts 8b are respectively installed between the two groups of slots 31. The middle position of one side of the outer surface of the two clamping plates 8a is convex to form a plug platform 8c, which is respectively inserted into the two plug holes 26. Placing the clamp assembly 8 outside the heat exchange outer cylinder 1 can fix the position of the discharge pipe 17 to prevent it from falling or shaking, so as to ensure the structural and firmness of the entire device.

[0060] The recovery method of the waste heat recovery system of a coal-fired unit comprises the following steps:

[0061] 1) Assemble the components according to the designed structure to form a heat exchange device, and check its sealing performance;

[0062] 2) The medium to be heated circulates in the heat exchange chamber through the second circulation valve 33;

[0063] 3) Filling the fixed pipes 24 with hot liquid through the first circulation valve 6, so that the hot liquid flows in the multiple fixed pipes 24;

[0064] 4) The hot and polluted gas is charged into the filter cartridge 27 from both sides through the second valve 7 on the spiral heat conducting tube 16, and the filter element 14 filters it;

[0065] 5) The hot, clean gas is directly charged into the heat recovery inner cylinder 21 through the first valve 34, and the heat is conducted through the heat-conducting column 15 and the heat-conducting plate 32 to increase the temperature of the medium to be heated;

[0066] 6) The rotation of the gear ring 5 can transmit the rotational force to the ring frame 12, and the fixed rod 30 stirs the medium to be heated;

[0067] 7) When the heating medium reaches a suitable temperature, discharge it and collect it for later use;

[0068] 8) The hot liquid or gas is discharged and collected for subsequent treatment.

[0069] The electrical components mentioned in this article are all connected to an external main controller and 220V mains electricity, and the main controller can be a conventional known device for controlling a computer or the like.

[0070] In summary, the characteristics, assembly methods, use processes and functions of each component in the waste heat recovery system and waste heat recovery method of the coal-fired unit are as follows: the whole device consists of a heat recovery inner cylinder 21 and a heat exchange outer cylinder 1, with a space between the two to form a heat exchange cavity. Liquid, clean gas or contaminated gas can be introduced into the heat recovery inner cylinder 21 separately or simultaneously. The gas and liquid are separated to avoid contact between the two. When in use, the heat exchange cavity is filled with the liquid or gas to be heated, and the liquid, clean gas or contaminated gas with heat is introduced into the heat exchange cavity. The heat in the polluted gas can be transferred to the liquid or gas to be heated, so that it can be heated up and convenient for later use. The inner wall of the heat recovery inner cylinder 21 is installed with multiple annular fixed pipes 24, and the circulation pipes 25 are installed between the two to realize the circulation of liquid or gas. When in use, the fixed pipes 24 are filled with liquid, and the interior of the multiple fixed pipes 24 is installed with multiple uniform arrays of heat-conducting columns 15, one end of which is inserted into the heat exchange cavity, which can improve the heat exchange effect. A filter cartridge 27 is installed in the middle of the heat recovery inner cylinder 21, and the two outer ends thereof are connected to the filter cartridge 27. The spiral heat conducting pipe 16 is installed on both sides of the inner tube 27, and the filter element 14 is installed on both sides of the inner tube 27. When in use, the dirty gas is filled into the filter cartridge 27, and the filter element 14 can filter it. While exchanging heat, the impurities mixed with the gas can be filtered. The clean gas can be directly passed into the heat recovery inner tube 21, and its heat is conducted through the internal components such as the fixed tube 24. A group of gears are installed on the outside of the heat recovery inner tube 21, and the first electromagnet 10 is installed on the outside of each gear. Rings are installed on both sides of the heat exchange cavity. The frame 12 has a second electromagnet 11 installed on one side of its exterior, and a plurality of fixed rods 30 in a circumferential array installed on the other side of its exterior, wherein the first electromagnet 10 is magnetically connected to the second electromagnet 11. When the gear rotates, the ring frame 12 can rotate along with it, and the fixed rods 30 can stir the medium in the heat exchange chamber to ensure that the medium can be heated evenly and improve the heat exchange efficiency. This structure makes the assembly between the components simpler and more compact, avoids motion interference between the components, and also improves the sealing of the device.

[0071] First, the heat exchange medium is charged into the heat exchange chamber through the second circulation valve 33, and the ring frame 12 rotates with the gear to stir the heat exchange medium, and the liquid with heat is charged into the fixed pipe 24, and the heat is transferred to the medium in the heat exchange chamber through the heat conduction column 15 and the heat conduction plate 32; the hot polluted gas is charged into it from the spiral heat conduction pipes 16 on both sides of the filter cartridge 27, and the impurities in the polluted gas can be adsorbed and filtered by the filter element 14 in the filter cartridge 27, and the gas discharged later is collected; the hot non-polluted gas is directly charged into the heat recovery inner cylinder 21 through the valve, and the heat can be conducted to heat the medium to be heated. After the medium is heated for a period of time, the medium circulates from the second circulation valve 33

[0072] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0073] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Waste heat recovery system of coal-fired units, characterized by: The heat exchanger comprises a heat exchange outer cylinder (1) and a heat recovery inner cylinder (21), the former being outside and the latter being inside, with a space left between the two to form a heat exchange chamber, both sides of the heat exchange chamber being closed, the inner wall of the heat recovery inner cylinder (21) being provided with a plurality of fixed pipes (24) arranged in a uniform array, all of which are arc-shaped and are connected to each other through a circulation pipe (25), a filter cartridge (27) being placed in the middle of the heat recovery inner cylinder (21), filter elements (14) being installed on both sides of the inner cylinder, spiral heat conduction pipes (16) being installed on both sides of the outer cylinder, and a discharge pipe being installed in the middle of the outer cylinder. (17), the discharge pipe (17) passes through the heat exchange chamber, gear rings (5) are rotatably mounted on both sides of the exterior of the heat recovery inner cylinder (21), first electromagnets (10) are mounted on the inner sides of the outer surfaces of the two gear rings (5), ring frames (12) are rotatably mounted on both sides of the interior of the heat exchange chamber, second electromagnets (11) are mounted on one side of the exterior of the two ring frames (12), and multiple fixed rods (30) in a circumferential array are mounted on the other side of the exterior, and the two second electromagnets (11) are magnetically connected to the two first electromagnets (10) respectively.

2. The waste heat recovery system of a coal-fired unit according to claim 1, characterized in that: The two sides of the outside of the heat recovery inner cylinder (21) are closed by sealing plates (2), and the outsides of the two sealing plates (2) are both equipped with a first valve (34). One of the circulation pipes (25) passes through one of the sealing plates (2), and a first circulation valve (6) is installed at its outer end. The two spiral heat conduction pipes (16) respectively pass through the two sealing plates (2), and a second valve (7) is installed at their outer ends. The outer end of the discharge pipe (17) is equipped with a third valve (9).

3. The waste heat recovery system of a coal-fired unit according to claim 1, characterized in that: A second circulation valve (33) is installed on one side of the exterior of the heat recovery inner cylinder (21) and is in communication with the heat exchange chamber.

4. The waste heat recovery system of a coal-fired unit according to claim 1, characterized in that: Rotating mounting cylinders (22) are mounted on both sides of the outer surface of the heat recovery inner cylinder (21); the two gear rings (5) are rotatably mounted outside the rotating mounting cylinders (22), respectively; fixing plates (23) are mounted on both ends of the outer surface of the heat recovery inner cylinder (21); motors (3) are mounted on one side of the exterior of the two fixing plates (23); gears (4) are mounted on the output ends of the motors (3); and the two gears (4) are meshed with the two gear rings (5) respectively.

5. The waste heat recovery system of a coal-fired unit according to claim 1, characterized in that: One side of the outer surface of the two gear rings (5) is concave to form a groove, one side of the outer surface of the two ring frames (12) away from the fixing rod (30) is concave to form a mounting groove (29), and the two first electromagnets (10) and the second electromagnets (11) are respectively installed in the two grooves and the mounting groove (29).

6. The waste heat recovery system of a coal-fired unit according to claim 1, characterized in that: A plurality of uniformly arrayed heat-conducting columns (15) are installed inside the plurality of fixed tubes (24), one end of which is inserted into the heat exchange cavity, and a heat-conducting plate (32) is installed at intervals between each of the plurality of fixed tubes (24).

7. The waste heat recovery system of a coal-fired unit according to claim 1, characterized in that: Both sides of the outside of the filter cartridge (27) are sealed by a sealing plate (13), and one side of the outer surface of the two sealing plates (13) is equipped with a plurality of straight cylinders (28) in a circumferential array, which respectively penetrate the two filter elements (14), and a spring (18) is installed inside the plurality of straight cylinders (28), and a sliding seat (19) is installed on one side thereof, and a shift lever (20) is rotatably installed on one end of the plurality of sliding seats (19).

8. The waste heat recovery system of a coal-fired unit according to claim 1, characterized in that: A clamp assembly (8) for fixing is installed on the outer side of the discharge pipe (17), and insertion holes (26) are provided on both sides of the outer surface of the discharge pipe (17). The clamp assembly (8) is located outside the heat recovery inner cylinder (21), and the clamp assembly (8) is composed of two clamping plates (8a) and bolts (8b). Slots (31) are provided on both sides of the outer sides of the two clamping plates (8a), and the two bolts (8b) are respectively installed between the two groups of slots (31). The middle position of one side of the outer surface of the two clamping plates (8a) is protruded to form an insertion platform (8c), which is respectively inserted into the two insertion holes (26).

9. A recovery method for a waste heat recovery system of a coal-fired unit, characterized in that: The following steps are included: 1) Assemble the components according to the designed structure to form a heat exchange device, and check its sealing performance; 2) The medium to be heated circulates in the heat exchange chamber through the second circulation valve (33); 3) Filling the fixed pipe (24) with hot liquid through the first circulation valve (6) so that the hot liquid flows in the plurality of fixed pipes (24); 4) The hot and polluted gas is charged into the filter cartridge (27) from both sides through the second valve (7) on the spiral heat conducting pipe (16), and the filter element (14) filters the hot and polluted gas; 5) directly charging hot, clean gas into the heat recovery inner cylinder (21) through the first valve (34), and the heat is conducted through the heat conducting column (15) and the heat conducting plate (32) to increase the temperature of the medium to be heated; 6) The rotation of the gear ring (5) can transmit the rotational force to the ring frame (12), and the fixed rod (30) stirs the medium to be heated; 7) When the heating medium reaches a suitable temperature, discharge it and collect it for later use; 8) The hot liquid or gas is discharged and collected for subsequent treatment.

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