Low-temperature flue gas waste heat utilization device and method

Abstract

The invention belongs to the technical field of heat recovery, and discloses a low-temperature flue gas waste heat utilization device and method.The low-temperature flue gas waste heat utilization device comprises a smoke exhaust pipe and a heat exchanger, a heat absorption pipe is arranged on the outer edge of an inner cavity of the smoke exhaust pipe, an outlet of the heat absorption pipe is connected with a heat inlet of the heat exchanger, and an inlet of the heat absorption pipe is connected with a heat outlet of the heat exchanger; the control valve assembly can guide smoke entering the smoke exhaust pipe, so that a vortex is formed in an inner cavity of the smoke exhaust pipe, and the heat absorption pipe is opposite to the outer edge of the vortex. Vortex can be formed in the smoke exhaust pipe, the temperature of the outer edge of the vortex is high, and the temperature of the inner side of the vortex is low, so that heat of low-temperature smoke is enriched, the absorption efficiency of the heat absorption pipe on the heat in the smoke is improved, meanwhile, the opening and closing amplitude of the control valve assembly can be adjusted according to different components of a combustion working medium, and the combustion efficiency is improved. And therefore, the flowing speed of the smoke in the smoke exhaust pipe and the size of the vortex are controlled, optimal energy utilization is achieved, and the practicability of the equipment is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat recovery, and specifically relates to a low-temperature flue gas waste heat utilization device and method. Background Art

[0002] Against the backdrop of global warming, the "low-carbon economy" based on low energy consumption and low pollution has become a global hot topic. The essence of the low-carbon economy is the issue of efficient use of energy, development of clean energy, and pursuit of green GDP. The core is the innovation of energy technology and emission reduction technology, industrial structure and system innovation, and the fundamental change of human survival and development concepts. Therefore, energy conservation is a long-term strategic policy for economic and social development, and it is also an extremely urgent task at present.

[0003] At present, there are many types of flue gas waste heat recovery devices in thermal power plants. Generally, heat exchange devices are directly connected in series on the flue. However, the existing heat exchangers have low energy utilization and poor equipment flexibility. They cannot obtain optimal energy utilization when the components of the combustion medium change, causing a large amount of heat flue gas to be discharged from the chimney into the atmosphere without being fully utilized, resulting in a decrease in boiler thermal efficiency and an increase in coal consumption for power generation. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a low-temperature flue gas waste heat utilization device and method, which can achieve optimal energy utilization when the components of the combustion medium change.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A low-temperature flue gas waste heat utilization device includes a smoke exhaust pipe and a heat exchanger, a heat absorption pipe is provided at the outer edge of the inner cavity of the smoke exhaust pipe, the outlet of the heat absorption pipe is connected to the heat inlet of the heat exchanger, and the inlet of the heat absorption pipe is connected to the heat outlet of the heat exchanger, and a control valve assembly is provided in the smoke exhaust pipe upstream of the heat absorption pipe, and the control valve assembly can guide the smoke entering the smoke exhaust pipe, thereby forming a vortex in the inner cavity of the smoke exhaust pipe, and the heat absorption pipe is opposite to the outer edge of the vortex.

[0006] Preferably, the control valve assembly includes a plurality of valve plates and a driving assembly for driving all the valve plates to rotate synchronously. The valve plates are fan-shaped or fan-shaped, and all the valve plates cooperate with each other to form a ring or a circle. When the driving assembly drives the valve plates to rotate, the rotating axis is along the radial direction of the smoke exhaust pipe.

[0007] Preferably, the valve plate is in the shape of a fan ring, and all the valve plates cooperate with each other to form a circular ring. A connecting seat is fixedly provided at the inner circle of the circular ring, and the connecting seat is fixedly connected to the smoke exhaust pipe through a connecting frame. The inner circle of the valve plate is rotatably connected to the connecting seat, and the outer circle of the valve plate is connected to a driving shaft, which is connected to the driving assembly.

[0008] Preferably, the valve plate is in the shape of a fan ring, the inner circle of the valve plate extends to the connecting seat, and the outer circle of the valve plate extends to the inner wall of the smoke exhaust pipe.

[0009] Preferably, the drive assembly includes a bevel gear ring, a bevel gear plate and a motor. The bevel gear ring is sleeved on the outer wall of the smoke exhaust pipe and is rotatably connected to the smoke exhaust pipe. The drive shaft connected to each valve plate passes through the smoke exhaust pipe and is connected to the bevel gear plate. All the bevel gear plates are meshed with the bevel gear ring, and at least one bevel gear plate is connected to the motor.

[0010] Preferably, a fan blade is fixedly provided in the smoke exhaust pipe downstream of the heat absorption pipe, and a first motor is connected to the fan blade to drive the fan blade to rotate. The first motor is fixedly connected to the smoke exhaust pipe through a fixing frame, and the fan blade is used to suck and discharge the smoke in the smoke exhaust pipe.

[0011] Preferably, the inlets of all heat absorbing tubes are connected to the first transfer tube, the outlets of all heat absorbing tubes are connected to the second transfer tube, the heat inlet of the heat exchanger is connected to the second transfer tube, and the heat outlet of the heat exchanger is connected to the second transfer tube.

[0012] Preferably, the heat exchanger includes a heat absorption barrel, a compressor and a capillary tube, the inlet of the compressor is connected to the second transfer tube, the outlet of the compressor is connected to the heat inlet of the heat absorption barrel, the heat outlet of the heat absorption barrel is connected to the inlet of the capillary tube, and the outlet of the capillary tube is connected to the first transfer tube.

[0013] Preferably, heat exchange fins are provided on the outside of the heat absorption tube, and the heat exchange fins are spiral fins or straight fins. When the heat exchange fins are straight fins, the straight fins extend along the axial direction of the heat absorption tube, and a plurality of straight fins are distributed circumferentially of the heat absorption tube.

[0014] The present invention further provides a method for utilizing waste heat from low-temperature flue gas, which is performed using the low-temperature flue gas waste heat utilization device as described above. The method comprises: When the flue gas flows along the exhaust pipe, the control valve assembly is used to guide the flue gas entering the exhaust pipe, so that the flue gas forms a vortex in the exhaust pipe. The temperature of the outer edge of the vortex is relatively high, and the temperature of the inner side is relatively low. As the vortex-shaped flue gas flows, the heat absorption tube absorbs the heat in the flue gas and heats the heat exchange medium. The heat exchange medium heated by the heat absorption tube enters the hot inlet of the heat exchanger from the outlet of the heat absorption tube and exchanges heat, so that the heat exchange medium is cooled. The cooled heat exchange medium enters the inlet of the heat absorption tube through the hot outlet of the heat exchanger and circulates heat exchange, thereby realizing the utilization of waste heat of low-temperature flue gas.

[0015] The present invention has the following beneficial effects: In the low-temperature flue gas waste heat utilization device of the present invention, a heat absorption pipe is arranged in the smoke exhaust pipe to absorb the heat of the smoke in the smoke exhaust pipe, and the smoke entering the smoke exhaust pipe is guided by the control valve assembly, thereby forming a vortex in the smoke exhaust pipe, and the temperature of the outer edge of the vortex is high, while the temperature of the inner side of the vortex is low, thereby achieving the enrichment of the heat of the low-temperature flue gas, and then improving the absorption efficiency of the heat in the smoke by the heat absorption pipe, and at the same time, the opening and closing amplitude of the control valve assembly can be adjusted according to the different components of the combustion working medium, so as to control the flow velocity of the smoke in the smoke exhaust pipe and the size of the vortex, thereby achieving optimal energy utilization and improving the practicability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a structural schematic diagram of the low-temperature flue gas waste heat utilization device of the present invention.

[0018] Figure 2 It is a schematic structural diagram of the heat absorption barrel in the low-temperature flue gas waste heat utilization device of the present invention.

[0019] Figure 3 It is a cross-sectional view of the low-temperature flue gas waste heat utilization device of the present invention.

[0020] Figure 4 It is a schematic diagram of the internal structure of the smoke exhaust pipe in the low-temperature flue gas waste heat utilization device of the present invention.

[0021] In the figure: 1-smoke exhaust pipe, 2-heat absorption pipe, 3-heat conduction block, 4-smoke inlet, 5-first transfer pipe, 6-second transfer pipe, 7-heat absorption barrel, 8-compressor, 9-first conduit, 10-second conduit, 11-capillary tube, 12-partition, 13-heat dissipation pipe, 14-drainage port, 15-water injection port, 16-valve, 17-fixed frame, 18-first motor, 19-fan blade, 20-connecting frame, 21-connecting seat, 22-first rotating seat, 23-rotating connecting shaft, 24-second rotating seat, 25-driving shaft, 26-valve plate, 27-mounting seat, 28-rotating frame, 29-bevel gear ring, 30-bevel gear plate, 31-mounting frame, 32-second motor, 33-heating chamber, 34-tapping chamber. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] See also Figure 1-Figure 4 The low-temperature flue gas waste heat utilization device of this embodiment includes a flue gas exhaust pipe 1 and a heat exchanger, see Figure 3 and Figure 4 A heat absorption tube 2 is provided at the outer edge of the inner cavity of the smoke exhaust pipe 1, the outlet of the heat absorption tube 2 (i.e. the upper port of the heat absorption tube 2) is connected to the heat inlet of the heat exchanger, and the inlet of the heat absorption tube 2 (i.e. the lower port of the heat absorption tube 2) is connected to the heat outlet of the heat exchanger. A control valve assembly is provided upstream of the heat absorption tube 2 (i.e. below the heat absorption tube 2) in the smoke exhaust pipe 1, and the control valve assembly can guide the smoke entering the smoke exhaust pipe 1, so as to form a vortex rotating around the central axis of the smoke exhaust pipe 1 in the inner cavity of the smoke exhaust pipe 1, and the heat absorption tube 2 is opposite to the outer edge of the vortex, so that when the vortex rotates and rises, the outer side of the vortex can fully exchange heat with the heat absorption tube 2.

[0024] The working method of the low-temperature flue gas waste heat utilization device of the above embodiment of the present invention includes: when the flue gas flows along the exhaust pipe 1 (a Figure 4 Taking the orientation shown as an example, when the flue gas flows from bottom to top), the flue gas entering the smoke exhaust pipe 1 is guided by the control valve assembly, so that the smoke forms a vortex in the smoke exhaust pipe 1 (that is, the smoke will rotate and rise around the central axis of the smoke exhaust pipe 1). The temperature of the outer edge of the vortex is relatively high, and the temperature of the inner side is relatively low. As the vortex-shaped smoke flows upward, the heat absorption tube 2 absorbs the heat in the smoke and heats the heat exchange medium. At the same time, the smoke temperature is reduced. The heat exchange medium heated by the heat absorption tube 2 enters the hot inlet of the heat exchanger from the outlet of the heat absorption tube 2 and exchanges heat, so that the heat exchange medium is cooled. The cooled heat exchange medium enters the inlet of the heat absorption tube 2 through the hot outlet of the heat exchanger and circulates heat exchange, thereby realizing the utilization of waste heat of low-temperature flue gas.

[0025] As a preferred embodiment of the present invention, see Figure 4, the control valve assembly of this embodiment can be set as the following structure: Specifically, the control valve assembly includes a plurality of valve plates 26 and a driving assembly for driving all valve plates 26 to rotate synchronously. The shape of the valve plates 26 is fan-shaped or fan-shaped. All valve plates 26 cooperate with each other to form a ring (when the shape of the valve plates 26 is fan-shaped) or a circle (when the shape of the valve plates 26 is fan-shaped). When the driving assembly drives the valve plates 26 to rotate, the rotating axis is along the radial direction of the smoke exhaust pipe 1. In the control valve assembly of the above structure, when the driving assembly drives the valve plates 26 to rotate a certain angle, the valve plates 26 will have a certain inclination angle. When the smoke flows through the valve plates 26, the guiding effect of the valve plates 26 can make the smoke form a vortex that rotates around the central axis of the smoke exhaust pipe 1. The rising angle and flow rate of the vortex can be controlled by the rotation angle of the valve plates 26. When the valve plates 26 are perpendicular to the central axis of the smoke exhaust pipe 1, all valve plates 26 are in a state of being connected end to end. As a preferred embodiment of the present invention, see Figure 4 On the basis of the above embodiment, further, the shape of the valve plate 26 of this embodiment adopts a fan ring, all valve plates 26 cooperate with each other to form a ring, the inner circle of the ring is fixedly provided with a connecting seat 21, the connecting seat 21 is fixedly connected to the smoke exhaust pipe 1 through a connecting frame, the inner circle of the valve plate 26 is rotatably connected to the connecting seat 21, the outer circle of the valve plate 26 is connected to a driving shaft 25, and the driving shaft 25 is connected to the driving assembly. In the above structure, the driving shaft 25 is driven to rotate by the driving assembly, and the driving shaft 25 can drive the valve plate 26 to rotate after rotating. This structure is relatively simple and reliable.

[0026] As a preferred embodiment of the present invention, see Figure 4 On the basis of the above embodiment, further, the valve plate 26 is in the shape of a fan ring, the inner circle of the valve plate 26 extends to the connecting seat 21, and the outer circle of the valve plate 26 extends to the inner wall of the smoke exhaust pipe 1. In this structure, the smoke can be reduced from flowing through the gap between the valve plate 26 and the inner wall of the smoke exhaust pipe 1 and the gap between the valve plate 26 and the connecting seat 21, thereby increasing the rotation speed of the vortex.

[0027] As a preferred embodiment of the present invention, see Figure 1-Figure 4In this embodiment, the driving assembly can adopt the following structure: specifically including a bevel gear ring 29, a bevel gear plate 30 and a motor, the bevel gear ring 29 is sleeved on the outer wall of the smoke exhaust pipe 1 and is rotatably connected to the smoke exhaust pipe 1, the driving shaft 25 connected to each valve plate 26 passes through the smoke exhaust pipe 1 and is connected to the bevel gear plate 30, all the bevel gear plates 30 are meshed with the bevel gear ring 29, and at least one bevel gear plate 30 is connected to the motor (into the second motor 32). In the driving assembly of the present embodiment, the bevel gear disc 30 connected to the motor serves as the driving wheel, and the remaining bevel gear discs 30 serve as driven wheels. After the bevel gear disc 30 is driven by the motor to rotate, the bevel gear disc 30 can drive the bevel gear ring 29 to rotate around the center of the smoke exhaust pipe 1. When the bevel gear ring 29 rotates, it can synchronously drive the remaining bevel gear discs 30 serving as driven wheels. Then, each bevel gear disc 30 drives the driving shaft 25 connected to it to rotate, and then drives the valve plate 26 connected to the driving shaft 25 to rotate. The driving assembly of the present embodiment can drive all the valve plates 26 to rotate synchronously, and has a simple and reliable structure.

[0028] As a preferred embodiment of the present invention, see Figure 1 , Figure 2 and Figure 4 In this embodiment, a fan blade 19 is fixedly provided in the exhaust pipe 1 downstream of the heat absorbing pipe 2, and a first motor 18 is connected to the fan blade 19 to drive the fan blade 19 to rotate. The first motor 18 is fixedly connected to the exhaust pipe 1 through a fixing frame 17, and the fan blade 19 is used to suck and discharge the smoke in the exhaust pipe 1. The first motor 18 can drive the fan blade 19 to rotate and draw the smoke upstream of the heat absorbing pipe 2 to the downstream, which can strengthen the vortex formed by the control valve assembly, so that the smoke flows to the outer edge of the vortex as much as possible, thereby improving the efficiency of heat exchange between the heat absorbing pipe 2 and the smoke.

[0029] As a preferred embodiment of the present invention, see Figure 1 , Figure 2 and Figure 4 In this embodiment, the inlets of all the heat absorbing tubes 2 are connected to the first transfer tube 5, the outlets of all the heat absorbing tubes 2 are connected to the second transfer tube 6, the heat inlet of the heat exchanger is connected to the second transfer tube 6, and the heat outlet of the heat exchanger is connected to the second transfer tube 6. The first transfer tube 5 can distribute the heat exchange medium to each heat absorbing tube 2, and the second transfer tube 6 can collect the high-temperature heat exchange medium flowing out of each heat absorbing tube 2 and introduce it into the heat inlet of the heat exchanger.

[0030] As a preferred embodiment of the present invention, see Figure 1-Figure 4In this embodiment, the heat exchanger includes a heat absorption barrel 7, a compressor 8 and a capillary tube 11. The inlet of the compressor 8 is connected to the second transfer tube 6, the outlet of the compressor 8 is connected to the heat inlet of the heat absorption barrel 7, the heat outlet of the heat absorption barrel 7 is connected to the inlet of the capillary tube 11, and the outlet of the capillary tube 11 is connected to the first transfer tube 5. In this embodiment, the heat exchange medium (i.e., refrigerant gas) is compressed by the compressor 8 to form a high-temperature refrigerant liquid. The high-temperature refrigerant liquid flows into the heat absorption barrel 7 to heat the heat absorption medium (such as water) in the heat absorption barrel 7, thereby transferring the heat of the flue gas in the smoke exhaust pipe 1 absorbed by the heat exchange medium to the heat absorption medium. The normal-temperature heat exchange medium (i.e., refrigerant liquid) after heat dissipation flows into the capillary tube 11. Since the diameter of the capillary tube 11 is small, the flow rate of the refrigerant liquid in the capillary tube 11 will increase, and then the pressure will increase. After that, when the normal-temperature refrigerant liquid enters the heat absorption tube 2 through the capillary tube 11, the normal-temperature refrigerant liquid enters the low flow rate from the high flow rate and produces a large pressure drop. The large pressure drop reduces the boiling point of the refrigerant and starts to evaporate and absorb heat, forming a low-temperature refrigerant vapor and flowing into the heat absorption tube 2, thereby realizing the circulation recovery of heat in the smoke exhaust pipe 1.

[0031] As a preferred embodiment of the present invention, see Figure 3-Figure 4 In this embodiment, heat exchange fins are provided on the outside of the heat absorption tube 2. The heat exchange fins are spiral fins or straight fins. When the heat exchange fins are straight fins, the straight fins extend along the axial direction of the heat absorption tube 2 (that is, the straight fins are arranged along the up and down direction), and a plurality of straight fins are distributed in the circumferential direction of the heat absorption tube 2. In this embodiment, the use of heat exchange fins can increase the heat exchange efficiency between the heat absorption tube 2 and the flue gas.

[0032] As a preferred embodiment of the present invention, see Figure 3-Figure 4 In this embodiment, a plurality of heat absorbing tubes 2 are arranged on the outer edge of the inner cavity of the smoke exhaust pipe 1, and the plurality of heat absorbing tubes 2 are evenly distributed around the smoke exhaust pipe 1. Example See also Figure 1-Figure 4In the embodiment of the present invention, the low-temperature flue gas waste heat utilization device of the present embodiment comprises a cylindrical smoke exhaust pipe 1 and a plurality of groups of evenly arranged heat absorption pipes 2 arranged in the smoke exhaust pipe 1, and a plurality of heat conduction blocks 3 as heat exchange fins are fixedly connected to the outer wall of the heat absorption pipe 2, and the plurality of heat conduction blocks 3 are straight fins and parallel to the central axis of the heat absorption pipe 2, and the plurality of heat conduction blocks 3 are evenly distributed in the circumferential direction of the heat absorption pipe 2; the air inlet end (i.e., the lower end) of the heat absorption pipe 2 is fixedly connected with a first transfer pipe 5, and the upper ends of all the heat absorption pipes 2 are connected to the first transfer pipe 5, and the outlet of the heat absorption pipe 2 A second transfer tube 6 is connected to the gas end (i.e., the upper end), and the lower ends of all the heat absorbing tubes 2 are connected to the second transfer tube 6; a heat absorbing barrel 7 is arranged outside the exhaust pipe 1, and a first conduit 9 is fixedly connected to the liquid outlet end of the heat absorbing barrel 7, and the other end of the first conduit 9 is connected to the liquid inlet end of the first transfer tube 5, and a capillary tube 11 is installed between the two ends of the first conduit 9, and a compressor 8 is installed on the gas inlet end of the heat absorbing barrel 7, and the liquid outlet end of the compressor 8 is connected to one end of the second conduit 10, and the other end of the second conduit 10 is connected to the gas outlet end of the second transfer tube 6 Two groups of partitions 12 are fixedly connected in the heat absorption barrel 7, and a heating chamber 33 is set between the partitions 12. A branch chamber 34 is set on the upper side of the upper partition 12 and the lower side of the lower partition 12 in the heat absorption barrel 7. A heat dissipation pipe 13 fixedly connected between the two groups of partitions 12 is set between the two partitions 12. The two ends of the heat dissipation pipe 13 are connected to the branch chambers 34 on the upper and lower sides. The inner cavity of the heat dissipation pipe 13 is used for the circulation of the above-mentioned heat exchange working medium; a water injection port 15 is set at the bottom of one side of the heat absorption barrel 7, and a drainage port 14 is set at the top of the other side of the heat absorption barrel 7. A valve 16 is installed in the water injection port 15 and the drain port 14. The water injection port 15 and the drain port 14 are both connected to the heating chamber 33. The water injection port 15 and the drain port 14 are as far away from each other as possible so that the water body (i.e., the heat-absorbing working medium) can fully absorb heat; the air inlet end (i.e., the lower end) of the smoke exhaust pipe 1 is installed with a control valve assembly for controlling the smoke intake speed of the smoke exhaust pipe 1; the air outlet end (i.e., the upper end) of the smoke exhaust pipe 1 is connected with a blower assembly for extracting the smoke in the smoke exhaust pipe 1; the blower assembly and the control valve assembly are respectively located on the upper and lower sides of the heat-absorbing pipe 2.

[0033] The working process of this embodiment is as follows: first, the low-temperature refrigerant gas in the heat absorption pipe 2 is heated by the flue gas in the smoke exhaust pipe 1, and the heated refrigerant gas flows into the compressor 8 along the second transfer pipe 6, so that the refrigerant gas is compressed by the compressor 8 to form a high-temperature refrigerant liquid, and the high-temperature refrigerant liquid flows into the heat absorption barrel 7, and the high-temperature coolant is diverted through multiple groups of heat dissipation pipes 13, so that the water in the heating room is heated through the heat dissipation pipes 13, so that the heat absorbed in the smoke exhaust pipe 1 is transferred to the water body, and the water injection port 15 is set Cold water is injected into the heating chamber, and then hot water is discharged through the drain port 14. The normal temperature refrigerant liquid after heat dissipation flows into the capillary tube 11. Since the diameter of the capillary tube 11 is small, the flow rate of the refrigerant liquid in the capillary tube 11 increases, and the pressure increases. Then, when the normal temperature refrigerant liquid enters the heat absorption tube 2 through the capillary tube 11, the normal temperature refrigerant enters the low flow rate from the high flow rate, and a large pressure drop is generated. The large pressure drop reduces the boiling point of the refrigerant and starts to evaporate and absorb heat, generating low temperature refrigerant vapor and flowing into the heat absorption tube 2, thereby realizing the circulation recovery of heat in the smoke exhaust pipe 1; In this process, the present invention can also guide the smoke entering the smoke exhaust pipe 1 through the control valve assembly, thereby forming a vortex in the smoke exhaust pipe 1, and the temperature of the outer edge of the vortex is high, while the temperature of the inner side of the vortex is low, thereby achieving heat enrichment of the low-temperature smoke, and then improving the absorption efficiency of the heat absorption tube 2 for the heat in the smoke.

[0034] In one case of this embodiment, see Figure 1 to Figure 4The control valve assembly comprises a connecting frame 20 fixedly connected to the air inlet end of the smoke exhaust pipe 1, a connecting seat 21 is fixedly connected to the connecting frame 20, a plurality of groups of first rotating seats 22 distributed in a circumference are evenly fixedly connected to the outer edge of the connecting seat 21, a rotating connecting shaft 23 is rotatably connected in the first rotating seat 22, a plurality of groups of second rotating seats 24 distributed in a circumference are fixedly connected to the outer wall of the smoke exhaust pipe 1, a driving shaft 25 is rotatably connected in the second rotating seat 24, a valve plate 26 is fixedly connected between the driving shaft 25 and the rotating connecting shaft 23, thereby realizing the rotational connection between the valve plate 26 and the connecting seat 21 and the rotational connection between the valve plate 26 and the smoke exhaust pipe 1; the valve plate 26 is arranged in a fan shape, and a plurality of groups of valve plates 26 cooperate with each other to form a ring, and a bevel gear plate 30 is fixedly connected to the driving shaft 25 connected to each valve plate 26, so the bevel gear plate 30, the driving shaft 25 and the valve plate 26 are one by one Correspondingly, all bevel gear discs 30 are located outside the smoke exhaust pipe 1, and a mounting seat 27 is fixedly connected to the outer wall of the smoke exhaust pipe 1, and a rotating frame 28 is rotatably connected to the mounting seat 27, so that the rotating frame 28 can rotate around the central axis of the smoke exhaust pipe 1, and a bevel gear ring 29 is fixedly connected to the rotating frame 28, so that the bevel gear ring 29 can rotate around the central axis of the smoke exhaust pipe 1, and the bevel gear ring 29 is synchronously meshed with multiple groups of bevel gear discs 30, and a mounting frame 31 is fixedly connected to the outer wall of the smoke exhaust pipe 1, and a second motor 32 is fixedly connected to the mounting frame 31, and the output shaft of the second motor 32 is fixedly connected to one of the bevel gear discs 30 for driving the bevel gear disc 30 to rotate, and the bevel gear disc 30 also serves as an active bevel gear disc, and the other bevel gear discs 30 all serve as driven bevel gear discs; the inner end of each valve plate 26 extends to the connecting seat 21, and the outer end extends to the inner wall of the smoke exhaust pipe 1; The control valve assembly drives the active bevel gear plate to rotate through the second motor 32, and the active bevel gear plate meshes with the bevel gear ring 29, thereby driving the bevel gear ring 29 to rotate. The bevel gear ring 29 meshes with multiple groups of driven bevel gear plates synchronously, driving multiple groups of driven bevel gear plates to rotate synchronously. All bevel gear plates 30 drive their respective connected drive shafts 25 to rotate, and each drive shaft 25 is connected to drive the valve plate 26 to rotate. At this time, multiple groups of valve plates 26 can rotate synchronously. When the valve plates 2 When the valve plate 26 rotates to the horizontal position, the multiple valve plates 26 are connected to form a ring, thereby completely closing the smoke exhaust pipe 1 together with the connecting seat 21. When the valve plate 26 rotates to open, the multiple valve plates 26 rotate and tilt synchronously. At this time, the smoke is blown into the smoke exhaust pipe 1 in an oblique direction under the drive of the inclined valve plate 26. At this time, the multiple obliquely blown airflows form vortices in the smoke exhaust pipe 1, and the temperature of the outer edge of the vortex is high, while the temperature of the inner side of the vortex is low, thereby achieving the enrichment of the heat of the low-temperature smoke, thereby improving the absorption efficiency of the heat absorbing tube 2 for the heat in the smoke.

[0035] In one case of this embodiment, see Figure 1 to Figure 4The above-mentioned air blowing assembly includes a fixing frame 17 fixedly connected to the air outlet end of the smoke exhaust pipe 1, a first motor 18 is fixedly connected to the fixing frame 17, and a fan blade 19 is connected to the output shaft of the first motor 18. The air blowing assembly drives the fan blade 19 to rotate through the first motor 18, so that the smoke in the smoke exhaust pipe 1 is sucked and discharged through the rotating fan blade 19, and at the same time, the flow velocity of the smoke when it flows through the valve plate 26 can be accelerated, and the speed of the smoke forming a vortex and the radial distribution of the smoke in the smoke exhaust pipe 1 are promoted.

[0036] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any reference numerals in the claims should not be regarded as limiting the claims involved.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-temperature flue gas waste heat utilization device, characterized in that: The invention comprises a smoke exhaust pipe (1) and a heat exchanger, wherein a heat absorbing pipe (2) is provided at the outer edge of the inner cavity of the smoke exhaust pipe (1), the outlet of the heat absorbing pipe (2) is connected to the heat inlet of the heat exchanger, and the inlet of the heat absorbing pipe (2) is connected to the heat outlet of the heat exchanger, and a control valve assembly is provided in the smoke exhaust pipe (1) upstream of the heat absorbing pipe (2), wherein the control valve assembly can guide smoke entering the smoke exhaust pipe (1), thereby forming a vortex in the inner cavity of the smoke exhaust pipe (1), and the heat absorbing pipe (2) is opposite to the outer edge of the vortex.

2. A low-temperature flue gas waste heat utilization device according to claim 1, characterized in that: The control valve assembly comprises a plurality of valve plates (26) and a driving assembly for driving all the valve plates (26) to rotate synchronously, the valve plates (26) being in the shape of a fan or a fan ring, all the valve plates (26) cooperate with each other to form a ring or a circle, and the rotation axis of the valve plates (26) when the driving assembly drives the valve plates (26) to rotate is along the radial direction of the smoke exhaust pipe (1).

3. A low-temperature flue gas waste heat utilization device according to claim 2, characterized in that: The valve plate (26) is in the shape of a fan ring. All the valve plates (26) cooperate with each other to form a circular ring. A connecting seat (21) is fixedly provided at the inner circle of the circular ring. The connecting seat (21) is fixedly connected to the smoke exhaust pipe (1) via a connecting frame. The inner circle of the valve plate (26) is rotatably connected to the connecting seat (21). The outer circle of the valve plate (26) is connected to a driving shaft (25), and the driving shaft (25) is connected to the driving assembly.

4. A low-temperature flue gas waste heat utilization device according to claim 3, characterized in that: The valve plate (26) is in the shape of a fan ring, the inner circle of the valve plate (26) extends to the connecting seat (21), and the outer circle of the valve plate (26) extends to the inner wall of the smoke exhaust pipe (1).

5. The low-temperature flue gas waste heat utilization device according to claim 3, characterized in that: The driving assembly comprises a bevel gear ring (29), a bevel gear plate (30) and a motor; the bevel gear ring (29) is sleeved on the outer wall of the smoke exhaust pipe (1) and is rotatably connected to the smoke exhaust pipe (1); a driving shaft (25) connected to each valve plate (26) passes through the smoke exhaust pipe (1) and is connected to the bevel gear plate (30); all the bevel gear plates (30) are meshed with the bevel gear ring (29); and at least one bevel gear plate (30) is connected to the motor.

6. The low-temperature flue gas waste heat utilization device according to claim 1, characterized in that: A fan blade (19) is fixedly provided in the smoke exhaust pipe (1) downstream of the heat absorption pipe (2); a first motor (18) is connected to the fan blade (19) for driving the fan blade (19) to rotate; the first motor (18) is fixedly connected to the smoke exhaust pipe (1) via a fixing frame (17); and the fan blade (19) is used to suck and discharge smoke in the smoke exhaust pipe (1).

7. The low-temperature flue gas waste heat utilization device according to claim 1, characterized in that: The inlets of all the heat absorbing tubes (2) are connected to the first transfer tube (5), the outlets of all the heat absorbing tubes (2) are connected to the second transfer tube (6), the heat inlet of the heat exchanger is connected to the second transfer tube (6), and the heat outlet of the heat exchanger is connected to the second transfer tube (6).

8. The low-temperature flue gas waste heat utilization device according to claim 7, characterized in that: The heat exchanger comprises a heat absorption barrel (7), a compressor (8) and a capillary tube (11); the inlet of the compressor (8) is connected to the second transfer tube (6); the outlet of the compressor (8) is connected to the heat inlet of the heat absorption barrel (7); the heat outlet of the heat absorption barrel (7) is connected to the inlet of the capillary tube (11); and the outlet of the capillary tube (11) is connected to the first transfer tube (5).

9. The low-temperature flue gas waste heat utilization device according to claim 1, characterized in that: Heat exchange fins are provided on the outside of the heat absorption tube (2), and the heat exchange fins are spiral fins or straight fins. When the heat exchange fins are straight fins, the straight fins extend along the axial direction of the heat absorption tube (2), and a plurality of straight fins are distributed in the circumferential direction of the heat absorption tube (2).

10. A method for utilizing waste heat from low-temperature flue gas, characterized in that: The method is carried out using the low-temperature flue gas waste heat utilization device according to any one of claims 1 to 9, and the method comprises: When the smoke flows along the smoke exhaust pipe (1), the smoke entering the smoke exhaust pipe (1) is guided by the control valve assembly, so that the smoke forms a vortex in the smoke exhaust pipe (1), the temperature of the outer edge of the vortex is relatively high, and the temperature of the inner side is relatively low. As the vortex-shaped smoke flows, the heat absorption pipe (2) absorbs heat in the smoke and heats the heat exchange medium. The heat exchange medium heated by the heat absorption pipe (2) enters the heat inlet of the heat exchanger from the outlet of the heat absorption pipe (2) and performs heat exchange, so that the heat exchange medium is cooled. The cooled heat exchange medium enters the inlet of the heat absorption pipe (2) through the hot outlet of the heat exchanger and performs cyclic heat exchange, thereby realizing the utilization of the waste heat of the low-temperature smoke.

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