A flue gas waste heat cascade comprehensive utilization device based on a gas generator

Abstract

The application discloses a flue gas waste heat cascade comprehensive utilization device based on a gas generator, relates to the technical field of flue gas waste heat utilization, and can realize cascade recovery of flue gas waste heat, and the waste heat of high-temperature flue gas flowing through the front end section can be used for high-temperature heating in a boiler core, and the waste heat of subsequent medium and low-temperature flue gas can be used for step-by-step heat preservation and preheating of the boiler, thereby effectively avoiding the problem that high and low temperature heat is neutralized in traditional single-pipeline heat exchange, improving the concentrated utilization efficiency of high-grade waste heat to a certain extent, and facilitating the cascade matching and quality recovery of energy.

Description

Technical Field

[0001] This invention relates to the field of flue gas waste heat utilization technology, and in particular to a cascade comprehensive utilization device for flue gas waste heat from a gas generator. Background Technology

[0002] Gas generators produce a large amount of high-temperature flue gas during operation, with temperatures typically reaching 400–600°C. This flue gas contains considerable waste heat resources. Direct discharge of such gas not only results in a serious waste of energy but also increases the environmental heat load.

[0003] Currently, most technologies for recovering waste heat from gas generator flue gas employ a single heat exchange pipeline design. This involves allowing high-temperature flue gas to flow sequentially through heat exchange elements within the same pipeline. Heat is transferred to the circulating working fluid via conduction and convection to achieve waste heat recovery. However, as the flue gas flows along the pipeline, its temperature gradually decreases with the continuous release of heat, creating a temperature gradient distribution with a high temperature at the front and a low temperature at the back. This results in heat neutralization between the high-temperature waste heat at the front and the low-temperature waste heat at the back within the heat exchange system, making it difficult to centrally and efficiently recover and utilize the high-grade waste heat from the high-temperature section.

[0004] Therefore, a comprehensive utilization device for waste heat from gas generator flue gas is proposed to solve some of the problems existing in the above-mentioned prior art. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies in the recovery of waste heat from flue gas from gas generators, where the high-temperature waste heat at the front end of the flue gas and the low-temperature waste heat at the rear end will neutralize each other in the heat exchange system, making it difficult to centrally and efficiently recover and utilize the high-grade waste heat in the high-temperature section. Therefore, this invention proposes a cascade comprehensive utilization device for waste heat from flue gas from gas generators.

[0006] To address the problems existing in the prior art, the present invention adopts the following technical solution: A comprehensive utilization device for waste heat from flue gas generated by a gas generator includes a first flue and a boiler. A second flue is fixedly connected to the middle of the first flue, and symmetrically arranged inlet and outlet water boxes are fixedly installed on the outer side of the second flue. Multiple uniformly distributed first heat exchange tubes are installed through the second flue, connecting the symmetrically arranged inlet and outlet water boxes. Second heat exchange tubes are fixedly installed in the boiler. A water pump is fixedly installed on the first flue, connecting one end of the inlet and second heat exchange tubes. The other end of the second heat exchange tubes is connected to the outlet water box. Multiple inlet and outlet water boxes are provided. The multiple symmetrically arranged inlet and outlet water boxes are orderly distributed along the flue gas flow direction in the second flue. Multiple second heat exchange tubes are coaxially installed in the boiler from the inside to the outside. The innermost second heat exchange tube is connected to the inlet and outlet water boxes corresponding to the flue gas inlet end, and the outermost second heat exchange tube is connected to the inlet and outlet water boxes corresponding to the flue gas outlet end.

[0007] Preferably, multiple first heat exchange tubes are staggered from top to bottom and from left to right in the second flue, and the multiple first heat exchange tubes are parallel to each other.

[0008] Preferably, multiple water pumps are arranged in an orderly manner along the first flue, and the rotating shafts of the multiple water pumps are fixedly connected on the same straight line. A servo motor is fixedly installed on the first flue, and a first gear is fixedly installed on the rotating shaft of one of the water pumps. A second gear that meshes with the first gear is fixedly installed on the drive shaft of the servo motor.

[0009] Preferably, a reciprocating screw shaft parallel to the first heat exchange tube is rotatably installed in the second flue, and a reciprocating screw sleeve is threaded onto the reciprocating screw shaft. A scraper is movably installed in the second flue, and the scraper is fixedly connected to the reciprocating screw sleeve. The scraper is sleeved on the outside of multiple first heat exchange tubes.

[0010] Preferably, the outer dimensions of the scraper are adapted to the inner dimensions of the second flue, and the scraper is provided with through holes corresponding to the multiple first heat exchange tubes.

[0011] Preferably, a first bevel gear is fixedly installed on the rotating shaft of one of the water pumps, and a second bevel gear that meshes with the first bevel gear is rotatably installed on the outer side of the first flue, and the second bevel gear is connected to the reciprocating lead screw shaft for transmission.

[0012] Preferably, the first heat exchange tube is rotatably connected to the second flue, and a rib is fixedly installed on the outer side of the first heat exchange tube. The rib is set as a spiral structure, and the internal size of the through hole is adapted to the outer size of the first heat exchange tube and the rib. The first heat exchange tube forms a spiral connection with the scraper through the cooperation of the rib and the through hole.

[0013] Preferably, a fan blade is rotatably installed inside the first flue, and a drive shaft that is rotatably connected to the fan blade is rotatably installed outside the first flue.

[0014] Preferably, a ratchet assembly is installed between the drive shaft and the first gear.

[0015] Preferably, the first flue has a circular cross-section, the second flue has a square cross-section, and the fan blades are positioned near the exhaust end of the second flue.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, by dividing the second flue into multiple heat exchange sections along the flue gas flow direction, and forming an independent circulation loop in each section through an independent inlet water box, outlet water box, first heat exchange pipe, water pump, and second heat exchange pipe coaxially arranged in the boiler, the waste heat of the flue gas can be recovered in stages. The waste heat of the high-temperature flue gas flowing through the front section can be used for high-temperature heating in the core of the boiler, while the waste heat of the subsequent medium and low temperature flue gas can be used for the boiler's step-by-step heat preservation and preheating. This effectively avoids the problem of mutual neutralization of high and low temperature heat in traditional single-pipe heat exchange, and improves the efficiency of centralized utilization of high-grade waste heat to a certain extent, making it easier to realize quality-based energy recovery and stage matching. 2. In this invention, a servo motor drives a reciprocating lead screw shaft to rotate, which in turn drives a scraper to reciprocate linearly along the first heat exchange tube. This allows for scraping and cleaning of the inner wall of the second flue and the outer wall of the first heat exchange tube. Simultaneously, since the outer wall of the first heat exchange tube is provided with spiral ribs, the cooperation between the ribs and the through holes on the scraper forces the first heat exchange tube to reciprocate, which to a certain extent improves the effectiveness and frequency of the device in cleaning dust accumulation on the surface of the heat exchange tube, effectively ensuring the long-term cleanliness of the surface of the first heat exchange tube. 3. In this invention, by setting the fan blades at the flue gas discharge end, they rotate under the push of the flowing flue gas. Then, the rotational power can be transmitted unidirectionally to the water pump shaft through the transmission shaft and ratchet assembly to drive it, providing auxiliary power for the operation of the water pump and the reciprocating screw shaft. This effectively reduces the energy consumption of the servo motor and improves the overall energy utilization efficiency of the entire system to a certain extent. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a perspective view of the present invention; Figure 2 This is a perspective view of the internal structure of the second flue of the present invention; Figure 3 This is a perspective view of the first heat exchange tube, ribs, and scraper of the present invention; Figure 4 This is an exploded view of the boiler and the second heat exchange tube of the present invention; Figure 5 This is a perspective view of the water pump, servo motor, first gear, second gear, transmission shaft, and ratchet assembly of the present invention. Figure 6 This is a top view of the present invention; Figure 7 For the present invention Figure 6 Sectional view at point AA; Figure 8 For the present invention Figure 6 Sectional view at point BB; Figure 9 For the present invention Figure 6 Sectional view at point CC.

[0018] In the picture: 1. First flue; 2. Second flue; 21. Water inlet box; 22. Water outlet box; 23. First heat exchange tube; 24. Rib; 3. Boiler; 31. Second heat exchange tube; 4. Water pump; 5. Reciprocating lead screw shaft; 51. Reciprocating lead screw sleeve; 52. Scraper; 53. Through hole; 6. Servo motor; 61. First gear; 62. Second gear; 63. First bevel gear; 64. Second bevel gear; 65. Fan blade; 66. Drive shaft; 67. Ratchet assembly. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Example: This example provides a device for the cascaded comprehensive utilization of waste heat from gas generator flue gas. See [link / reference]. Figure 1 - Figure 9Specifically, the system includes a first flue 1 and a boiler 3. A second flue 2 is fixedly connected to the middle of the first flue 1, and symmetrically arranged inlet boxes 21 and outlet boxes 22 are fixedly installed on the outer side of the second flue 2. Multiple evenly distributed first heat exchange tubes 23 are installed through the second flue 2, connecting the symmetrically arranged inlet boxes 21 and outlet boxes 22. A second heat exchange tube 31 is fixedly installed inside the boiler 3. A water pump 4 is fixedly installed on the first flue 1, connecting one end of the inlet box 21 and the second heat exchange tube 31. The other end of the second heat exchange tube 31 is connected to the outlet box 22. Multiple inlet boxes 21, outlet boxes 22, second heat exchange tubes 31, and water pumps 4 are provided, arranged symmetrically. The inlet box 21 and outlet box 22 are arranged in an orderly manner along the flue gas flow direction in the second flue duct 2. Multiple second heat exchange tubes 31 are coaxially installed in the boiler 3 from the inside to the outside. The innermost second heat exchange tube 31 is connected to the inlet box 21 and outlet box 22 corresponding to the flue gas inlet end, and the outermost second heat exchange tube 31 is connected to the inlet box 21 and outlet box 22 corresponding to the flue gas outlet end. Multiple water pumps 4 are arranged in an orderly manner along the first flue duct 1. The rotating shafts of multiple water pumps 4 are fixedly connected on the same straight line. A servo motor 6 is fixedly installed on the first flue duct 1. A first gear 61 is fixedly installed on the rotating shaft of one of the water pumps 4, and a second gear 62 that meshes with the first gear 61 is fixedly installed on the drive shaft of the servo motor 6.

[0021] When the device is in use, the high-temperature flue gas generated by the gas generator first enters the first flue 1 and flows into the second flue 2 inside it. The flue gas flows unidirectionally in the second flue 2, and the temperature gradually decreases. Along the flue gas flow direction, multiple heat exchange units consisting of an inlet box 21, an outlet box 22 and a first heat exchange tube 23 connecting them are distributed in sequence, corresponding to the high-temperature section, medium-temperature section and low-temperature section of the flue gas, respectively.

[0022] Each heat exchange unit constitutes an independent circulation loop. During the circulation process, the water pump 4 sends the low-temperature water, which has released some heat and is discharged from the corresponding second heat exchange tube 31 in the boiler 3, into the water inlet box 21 and distributes it to all the first heat exchange tubes 23 in the unit. When the flue gas flows through these first heat exchange tubes 23, heat exchange occurs through the tube walls, heating the water flow in the first heat exchange tubes 23. The heated water is collected in the water outlet box 22 and then flows into the corresponding second heat exchange tube 31 in the boiler 3, releasing the heat it carries to the working medium in the boiler 3. The working medium can be water or steam. Multiple second heat exchange tubes 31 in the boiler 3 are arranged coaxially from the inside to the outside and are set in accordance with the temperature gradient of the flue gas. The loop that receives the heat from the highest temperature flue gas is connected to the innermost second heat exchange tube 31 to heat the core of the boiler 3 in a high intensity. The loop that receives the heat from the medium and low temperature flue gas is connected to the second heat exchange tubes 31 in the middle and outer layers, mainly used to maintain the temperature of the boiler 3 and preheat the water inlet, realizing the stepwise injection of heat in the boiler 3.

[0023] In the specific implementation process, such as Figure 2 - Figure 3 and Figure 7 - Figure 9 As shown, multiple first heat exchange tubes 23 are staggered from top to bottom and from left to right in the second flue 2. The multiple first heat exchange tubes 23 are parallel to each other. When the device is in use, the first heat exchange tubes 23 are arranged in a staggered parallel manner, which can maximize the heat exchange area and disturb the flue gas flow field to enhance the turbulence effect, thereby effectively improving the convective heat transfer efficiency between the flue gas and the first heat exchange tubes 23.

[0024] In the specific implementation process, such as Figure 2 - Figure 3 and Figure 9 As shown, a reciprocating screw shaft 5, parallel to the first heat exchange tube 23, is rotatably installed inside the second flue 2, and a reciprocating screw sleeve 51 is threaded onto the reciprocating screw shaft 5. A scraper 52 is movably installed inside the second flue 2, and the scraper 52 is fixedly connected to the reciprocating screw sleeve 51. The scraper 52 is sleeved on the outside of multiple first heat exchange tubes 23. A first bevel tooth 63 is fixedly installed on the rotating shaft of one of the water pumps 4. A second bevel tooth 64, which meshes with the first bevel tooth 63, is rotatably installed on the outside of the first flue 1, and the second bevel tooth 64 is drively connected to the reciprocating screw shaft 5.

[0025] When the device is in use, the servo motor 6 drives all the water pumps 4 to rotate synchronously through the meshing of the second gear 62 and the first gear 61, providing power to each independently set circulation loop. At the same time, the first bevel gear 63 connected to the rotating shaft of one of the water pumps 4 is driven to rotate. Through the meshing of the first bevel gear 63 and the second bevel gear 64, the reciprocating screw shaft 5 is driven to rotate. The rotating reciprocating screw shaft 5 converts the rotational motion into the reciprocating linear motion of the scraper 52 along the axial direction of the first heat exchange tube 23 through the reciprocating screw sleeve 51 screwed to it.

[0026] In the specific implementation process, such as Figure 2 - Figure 3 and Figure 9 As shown, the outer dimensions of the scraper 52 are adapted to the inner dimensions of the second flue 2. The scraper 52 has through holes 53 corresponding to multiple first heat exchange tubes 23. The first heat exchange tubes 23 are rotatably connected to the second flue 2. Ribs 24 are fixedly installed on the outer side of the first heat exchange tubes 23, and the ribs 24 are set in a spiral structure. The inner dimensions of the through holes 53 are adapted to the outer dimensions of the first heat exchange tubes 23 and the ribs 24. The first heat exchange tubes 23 are spirally connected to the scraper 52 through the cooperation of the ribs 24 and the through holes 53.

[0027] When the device is in use, the scraper 52 moves back and forth, with its outer edge closely adhering to the square inner wall of the second flue 2, scraping away the accumulated ash on the inner wall of the second flue 2. The through hole 53 on the scraper 52 is fitted around the outside of the first heat exchange tube 23 and the corresponding rib 24. Since the rib 24 has a spiral structure and the size of the through hole 53 is closely matched with the rib 24, when the scraper 52 moves in a straight line, the spiral surface of the rib 24 will be pushed by the side wall of the through hole 53, forcing the first heat exchange tube 23 to reciprocate around its own axis. With the cooperation of the above structures, the straight scraping of the scraper 52 and the rotation of the first heat exchange tube 23 are combined, which can more efficiently achieve comprehensive dynamic cleaning of the outer wall of the first heat exchange tube 23, effectively improving the dust removal effect of the device on the outer wall of the first heat exchange tube 23.

[0028] In the specific implementation process, such as Figure 1 , Figure 5 and Figure 9 As shown, a fan blade 65 is rotatably installed inside the first flue 1, and a drive shaft 66 connected to the fan blade 65 is rotatably installed on the outside of the first flue 1. A ratchet assembly 67 is installed between the drive shaft 66 and the first gear 61. When the device is in use, the flue gas discharged from the second flue 2 flows through the fan blade 65 at the end of the first flue 1, which can drive it to rotate. The rotation of the fan blade 65 is transmitted to the ratchet assembly 67 through the drive shaft 66. When the servo motor 6 is not working or has insufficient power, the kinetic energy generated by the flue gas flow can assist in driving the first gear 61 to rotate through the one-way transmission function of the ratchet assembly 67, thereby sharing the driving load of the water pump 4 and the reciprocating screw shaft 5. When the servo motor 6 provides the main power, the ratchet assembly 67 prevents the power from being transmitted back to the fan blade 65, which can avoid interference and effectively ensure the stability of the device during operation.

[0029] In the specific implementation process, such as Figure 1 , Figure 2 and Figure 6 - Figure 9 As shown, the first flue 1 has a circular cross-section, and the second flue 2 has a square cross-section. The fan blade 65 is positioned near the flue gas discharge end of the second flue 2. When the device is in use, the circular cross-section of the first flue 1 facilitates flue gas flow and the installation of the fan blade 65, while the square cross-section of the second flue 2 facilitates the arrangement of regular and parallel first heat exchange tubes 23 and the installation of linear motion components such as scraper 52. By positioning the fan blade 65 near the flue gas discharge end, negative pressure induction and flow field regularization can be achieved at the outlet of the second flue 2 to a certain extent, so that the heat of the flue gas is concentrated in the second flue 2 for heat exchange.

[0030] Specifically, the working principle of this invention is as follows: After the device is started, the high-temperature flue gas flows sequentially through the independent heat exchange units of each temperature section in the second flue 2. The circulating water in each unit, driven by the corresponding water pump 4, independently absorbs the specific grade of heat of the flue gas in that section and delivers it to the second heat exchange tubes 31 at different radial positions in the boiler 3 for release. This achieves a stepped, targeted, and efficient recovery of flue gas heat from high to low. At the same time, the servo motor 6 drives the reciprocating screw shaft 5 to rotate, which drives the scraper 52 to perform axial reciprocating motion to remove ash from the inner wall of the second flue 2 and the outer wall of the first heat exchange tube 23. During this process, the cooperation between the through hole 53 and the spiral rib 24 can drive the first heat exchange tube 23 to rotate back and forth, improving the ash removal effect. During the flue gas emission process, the residual kinetic energy of the flue gas can drive the fan blade 65 to rotate. Through the one-way transmission connection of the ratchet assembly 67, it provides auxiliary power for the water pump 4 and the cleaning mechanism, reduces active energy consumption, and achieves dual comprehensive utilization of flue gas thermal energy and residual kinetic energy.

[0031] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for the cascaded comprehensive utilization of waste heat from gas generator flue gas, comprising a first flue (1) and a boiler (3), characterized in that: A second flue (2) is fixedly connected to the middle of the first flue (1), and a symmetrically arranged water inlet box (21) and water outlet box (22) are fixedly installed on the outside of the second flue (2). Multiple evenly distributed first heat exchange tubes (23) are installed through the second flue (2), connecting the symmetrically arranged water inlet box (21) and water outlet box (22). A second heat exchange tube (31) is fixedly installed inside the boiler (3). A water pump (4) is fixedly installed on the first flue (1), connecting one end of the water inlet box (21) and the second heat exchange tube (31). The other end is connected to the water outlet box (22). There are multiple water inlet boxes (21), water outlet boxes (22), second heat exchange tubes (31) and water pumps (4). Multiple symmetrically arranged water inlet boxes (21) and water outlet boxes (22) are distributed in an orderly manner along the flue gas flow direction in the second flue (2). Multiple second heat exchange tubes (31) are coaxially installed in the boiler (3) from the inside to the outside. The second heat exchange tube (31) located on the innermost side is connected to the water inlet box (21) and water outlet box (22) corresponding to the flue gas inlet end. The second heat exchange tube (31) located on the outermost side is connected to the water inlet box (21) and water outlet box (22) corresponding to the flue gas outlet end.

2. The device for the cascade comprehensive utilization of waste heat from gas generator flue gas according to claim 1, characterized in that: Multiple first heat exchange tubes (23) are staggered from top to bottom and from left to right in the second flue (2), and the multiple first heat exchange tubes (23) are parallel to each other.

3. The device for the cascade comprehensive utilization of waste heat from gas generator flue gas according to claim 1, characterized in that: Multiple water pumps (4) are arranged in an orderly manner along the first flue (1). The rotating shafts of the multiple water pumps (4) are fixedly connected on the same straight line. A servo motor (6) is fixedly installed on the first flue (1). A first gear (61) is fixedly installed on the rotating shaft of one of the water pumps (4). A second gear (62) that meshes with the first gear (61) is fixedly installed on the drive shaft of the servo motor (6).

4. The device for the cascade comprehensive utilization of waste heat from gas generator flue gas according to claim 3, characterized in that: A reciprocating screw shaft (5) parallel to the first heat exchange tube (23) is rotatably installed inside the second flue (2), and a reciprocating screw sleeve (51) is threaded onto the reciprocating screw shaft (5). A scraper (52) is movably installed inside the second flue (2), and the scraper (52) is fixedly connected to the reciprocating screw sleeve (51). The scraper (52) is sleeved on the outside of multiple first heat exchange tubes (23).

5. A device for the cascaded comprehensive utilization of waste heat from gas generator flue gas according to claim 4, characterized in that: The outer dimensions of the scraper (52) are adapted to the inner dimensions of the second flue (2), and the scraper (52) is provided with through holes (53) corresponding to a plurality of first heat exchange tubes (23).

6. A device for the cascaded comprehensive utilization of waste heat from gas generator flue gas according to claim 4, characterized in that: A first bevel gear (63) is fixedly installed on the shaft of one of the water pumps (4), and a second bevel gear (64) that meshes with the first bevel gear (63) is rotatably installed on the outer side of the first flue (1), and the second bevel gear (64) is connected to the reciprocating screw shaft (5) for transmission.

7. A device for the cascaded comprehensive utilization of waste heat from gas generator flue gas according to claim 5, characterized in that: The first heat exchange tube (23) is rotatably connected to the second flue (2). A rib (24) is fixedly installed on the outside of the first heat exchange tube (23), and the rib (24) is set as a spiral structure. The internal size of the through hole (53) is adapted to the external size of the first heat exchange tube (23) and the rib (24). The first heat exchange tube (23) forms a spiral connection with the scraper (52) through the cooperation of the rib (24) and the through hole (53).

8. A device for the cascaded comprehensive utilization of waste heat from gas generator flue gas according to claim 1, characterized in that: A fan blade (65) is rotatably installed inside the first flue (1), and a drive shaft (66) that is rotatably connected to the fan blade (65) is rotatably installed on the outside of the first flue (1).

9. A device for the cascaded comprehensive utilization of waste heat from gas generator flue gas according to claim 8, characterized in that: A ratchet assembly (67) is installed between the drive shaft (66) and the first gear (61).

10. A device for the cascaded comprehensive utilization of waste heat from gas generator flue gas according to claim 8, characterized in that: The first flue (1) has a circular cross-section, the second flue (2) has a square cross-section, and the fan blade (65) is located near the exhaust end of the second flue (2).

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