A waste heat recovery system for the final section of a converter outlet flue

Abstract

The utility model discloses a kind of waste heat recovery systems of converter outlet flue end section, comprising: waste heat recovery inlet section flue, its two ends are connected with the end section flue of converter outlet flue and cooling flue respectively, cooling flue is connected with first, second gas-solid coupling separator intercommunication, first gas-solid coupling separator is connected with first quenching fire tube heat exchanger by first link flue;Second gas-solid coupling separator is connected with second quenching fire tube heat exchanger by second link flue;First gas-solid coupling separator, second gas-solid coupling separator are respectively provided with first, second separator heat exchange tube cooling mechanism;The cylinder of cooling flue, first link flue, second link flue, first, second quenching fire tube heat exchanger, first, second separator heat exchange tube cooling mechanism are connected with waste heat drum by several riser pipes and several downcomers intercommunication.The utility model has the advantages that the heat energy of high-temperature coal gas in end section flue can be effectively recovered, so as to avoid heat energy loss.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, specifically to a converter waste heat recovery system. Background Technology

[0002] The LT process is a dry purification and recovery technology for converter gas. During steelmaking in steel mills, the heat and iron oxide dust generated from the gas, high-temperature flue gas, and flue gas are all treated using the LT process for heat recovery and dust removal. The LT process converter waste heat recovery and purification system includes a waste heat recovery system and a purification system. The waste heat recovery system is directly linked to the converter steelmaking process and participates directly in production as part of the steel mill's steelmaking process.

[0003] The converter's flue gas outlet is connected to an outlet flue, and the final section of the outlet flue is typically treated using the thermal cooling (LT) method. The current LT method involves installing spray guns in the final section of the outlet flue to cool the high-temperature flue gas. The outlet of this final section is connected to an evaporative cooler, which has spray holes to accommodate the spray guns. The high-temperature gas in the converter is approximately 1450°C. After cooling in the outlet flue, the temperature in the final section is still around 900°C. The LT method, which involves spraying water mist in the final section of the flue and within the evaporative cooler, rapidly cools the gas from approximately 900°C to approximately 200°C. However, this LT method results in the complete waste of the 900°C-200°C waste heat resource and generates sludge and wastewater that pollutes the environment. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a waste heat recovery system at the end of the converter outlet flue, which can fully recover and utilize the waste heat of the high-temperature gas at the end of the outlet flue, avoid heat energy waste, and thus reduce the cost of converter steelmaking.

[0005] To solve the above problems, the technical solution adopted by this utility model is: a waste heat recovery system for the end section of a converter outlet flue, comprising: a waste heat recovery inlet flue, one end of which is connected to the end section of the converter outlet flue, and the other end of which is connected to a cooling flue. An adiabatic transition flue tee is provided at the outlet end of the cooling flue, the adiabatic transition flue tee having three flue ports, one of which is connected to the outlet end of the cooling flue, and the other two flue ports are respectively connected to a first gas-solid coupling separator and a second gas-solid coupling separator. The top of the first gas-solid coupling separator is connected to the flue gas inlet end of a vertically arranged first quench fire tube heat exchanger via a first connecting flue; the top of the second gas-solid coupling separator is connected to the flue gas inlet end of a vertically arranged first quench fire tube heat exchanger via a second connecting flue. The second quench fire-tube heat exchanger is connected to the flue gas inlet end; the lower end of the first quench fire-tube heat exchanger is connected to the first flue gas outlet pipe and the first ash discharge pipe, and the lower end of the second quench fire-tube heat exchanger is connected to the second flue gas outlet pipe and the second ash discharge pipe; the cooling flue, the first connecting flue, and the second connecting flue all adopt a water-cooled wall vaporization flue structure; the outer wall of the first gas-solid coupling separator is equipped with a first separator heat exchange tube cooling mechanism, and the outer wall of the second gas-solid coupling separator is equipped with a second separator heat exchange tube cooling mechanism; the cooling flue, the first connecting flue, the second connecting flue, the cylinder of the first quench fire-tube heat exchanger, the cylinder of the second quench fire-tube heat exchanger, the first separator heat exchange tube cooling mechanism, and the second separator heat exchange tube cooling mechanism are all connected to the waste heat steam drum through several riser pipes and several downcomer pipes.

[0006] Furthermore, in the aforementioned waste heat recovery system for the terminal section of a converter outlet flue, the cooling flue includes a first cooling flue section and a second cooling flue section connected sequentially along the flue gas flow direction. The inlet of the first cooling flue section is connected to the waste heat recovery inlet section flue, and the outlet of the second cooling flue section is connected to the adiabatic transition flue tee. The first cooling flue section and the second cooling flue section are respectively equipped with an upper cooling flue header and a lower cooling flue header. The upper cooling flue header is connected to the waste heat steam drum through a riser pipe, and the lower cooling flue header is connected to the steam drum through a downcomer pipe.

[0007] Furthermore, in the aforementioned waste heat recovery system for the terminal section of a converter outlet flue, the first connecting flue includes a first connecting flue section one and a first connecting flue section two connected sequentially along the flue gas flow direction. The lower end of the first connecting flue section one is connected to the flue gas outlet of the first separator at the top of the first gas-solid coupling separator. The upward bend of the first connecting flue section one connects to the upper end of the first connecting flue section two. The first connecting flue section two bends downward, and the lower end of the first connecting flue section two connects to the first quench fire tube heat exchanger. The flue gas inlet of the fire-tube heat exchanger is connected; the two ends of the first connecting flue section are respectively provided with the first connecting flue section upper header and the first connecting flue section lower header, and the two ends of the first connecting flue section are respectively provided with the first connecting flue section upper header and the first connecting flue section lower header; the first connecting flue section upper header and the first connecting flue section upper header are respectively connected to the waste heat steam drum through riser pipes, and the first connecting flue section lower header and the first connecting flue section lower header are respectively connected to the waste heat steam drum through downcomer pipes; The second connecting flue includes a second connecting flue section 1 and a second connecting flue section 2 connected sequentially along the flue gas flow direction. The lower end of the second connecting flue section 1 is connected to the flue gas outlet of the second separator at the top of the second gas-solid coupling separator. The second connecting flue section 1 bends upward to connect with the upper end of the second connecting flue section 2. The second connecting flue section 2 bends downward, and the lower end of the second connecting flue section 2 is connected to the flue gas inlet of the second fire tube heat exchanger of the second quench fire tube heat exchanger. The two ends of the second connecting flue section 1 are respectively provided with an upper header and a lower header. The two ends of the second connecting flue section 2 are respectively provided with an upper header and a lower header. The upper headers of the second connecting flue section 1 and the upper headers of the second connecting flue section 2 are respectively connected to the waste heat steam drum through riser pipes. The lower headers of the second connecting flue section 1 and the lower headers of the second connecting flue section 2 are respectively connected to the waste heat steam drum through downcomer pipes.

[0008] Furthermore, in the aforementioned waste heat recovery system for the terminal section of a converter outlet flue, a first ash hopper is provided at the bottom of the first gas-solid coupling separator, the bottom of the first ash hopper is connected to a first ash cooler through a first ash hopper output pipe, and the first ash cooler is connected to a first ash silo; a second ash hopper is provided at the bottom of the second gas-solid coupling separator, the bottom of the second ash hopper is connected to a second ash cooler through a second ash hopper output pipe, and the second ash cooler is connected to a second ash silo.

[0009] Furthermore, in the aforementioned waste heat recovery system for the terminal section of a converter outlet flue, the first gas-solid coupling separator includes a first main body cylindrical section and a first conical section cylindrical section. The first separator heat exchange tube cooling mechanism includes a first heat exchange coil assembly and a first straight section heat exchange tube assembly. The first heat exchange coil assembly includes a first heat exchange coil wound around the outer wall of the first conical section cylindrical section. The first straight section heat exchange tube assembly includes a plurality of first straight section heat exchange tubes spaced apart around the outer wall of the first main body cylindrical section. The upper ends of all the first straight section heat exchange tubes are connected to... The upper heat exchanger of the first straight section is connected, and the lower ends of all the heat exchanger tubes of the first straight section are connected to the lower heat exchanger of the first straight section. The upper and lower heat exchanger tubes of the first straight section are arranged around the upper and lower ends of the outer wall of the cylindrical body of the first body section. The inlet end of the first heat exchanger tube in the first heat exchanger coil assembly is connected to the waste heat steam drum through a downcomer, and the outlet end of the first heat exchanger tube in the first heat exchanger coil assembly is connected to the waste heat steam drum through a riser. The upper heat exchanger tube of the first straight section is connected to the waste heat steam drum through a riser, and the lower heat exchanger tube of the first straight section... The second gas-solid coupling separator is connected to the waste heat steam drum via a downcomer; the second separator includes a second main body cylindrical section and a second conical section cylindrical section. The second separator heat exchange tube cooling mechanism includes a second heat exchange coil assembly and a second straight section heat exchange tube assembly. The second heat exchange coil assembly includes a second heat exchange coil wound around the outer wall of the second conical section cylindrical section. The second straight section heat exchange tube assembly includes a plurality of second straight section heat exchange tubes spaced apart around the outer wall of the second main body cylindrical section. The upper ends of all the second straight section heat exchange tubes are connected to the upper header of the second straight section heat exchange tube. The lower ends of the second straight heat exchange tubes are all connected to the lower header of the second straight heat exchange tubes. The upper header of the second straight heat exchange tubes and the lower header of the second straight heat exchange tubes are arranged around the upper and lower ends of the outer wall of the cylindrical body section of the second body section. The inlet end of the second heat exchange coil in the second heat exchange coil assembly is connected to the waste heat steam drum through a downcomer. The outlet end of the second heat exchange coil in the second heat exchange coil assembly is connected to the waste heat steam drum through a riser. The upper header of the second straight heat exchange tubes is connected to the waste heat steam drum through a riser. The lower header of the second straight heat exchange tubes is connected to the waste heat steam drum through a downcomer.

[0010] Furthermore, in the aforementioned waste heat recovery system at the end of the converter outlet flue, both the first flue gas outlet pipe and the second flue gas outlet pipe are connected to the main flue gas outlet pipe.

[0011] Furthermore, in the aforementioned waste heat recovery system at the end of the converter outlet flue, both the first and second ash pipes are connected to the heat exchanger dust discharge main pipe.

[0012] The advantages of this utility model are: This application provides a waste heat recovery system for the terminal section of the converter outlet flue, which replaces the traditional LT method and achieves a completely dry treatment. It can not only effectively recover the heat energy of the high-temperature gas at 900°C in the terminal flue 2, thereby avoiding heat energy loss and reducing steelmaking costs, but also avoid the environmental pollution caused by a large amount of sludge due to the LT method. In addition, since no spraying treatment is performed, it can effectively increase the enthalpy value of the gas product, thereby improving the quality of the gas product. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the waste heat recovery system at the end of the converter outlet flue as described in this utility model.

[0014] Figure 2 This is a schematic diagram of the arrangement structure of the steam drum and its riser and downcomer in the waste heat recovery system at the end of the converter outlet flue as described in this utility model. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and preferred embodiments.

[0016] like Figure 1 , Figure 2 As shown, a waste heat recovery system for the final section of a converter outlet flue includes: a waste heat recovery inlet flue 1, one end of which is connected to the outlet of the final section flue 2 of the converter outlet flue, and the other end of which is connected to a cooling flue 3. An adiabatic transition flue tee 4 is provided at the outlet end of the cooling flue 3. The adiabatic transition flue tee 4 has three flue ports, one of which is connected to the outlet end of the cooling flue 3, and the other two flue ports are respectively connected to a first gas-solid coupling separator 5 and a second gas-solid coupling separator 6. The adiabatic transition flue tee 4 serves as a transition and insulation mechanism. The high-temperature gas in the cooling flue 3 is divided into two streams by the insulated transition flue tee 4 and then enters the first gas-solid coupling separator 5, the first quench fire tube heat exchanger 7, the second gas-solid coupling separator 6, and the second quench fire tube heat exchanger 8 respectively. The use of two sets of equipment to share the heat recovery of the high-temperature gas generated in the converter can effectively reduce the weight of the quench fire tube heat exchanger and the gas-solid coupling separator, and can ensure that the heat energy of the high-temperature gas is fully released.

[0017] The top of the first gas-solid coupling separator 5 is connected to the flue gas inlet of the vertically arranged first quench fire-tube heat exchanger 7 via a first connecting flue. The top of the second gas-solid coupling separator 6 is connected to the flue gas inlet of the vertically arranged second quench fire-tube heat exchanger 8 via a second connecting flue. The lower end of the first quench fire-tube heat exchanger 7 is connected to a first flue gas outlet pipe 71 and a first ash discharge pipe 72. The lower end of the second quench fire-tube heat exchanger 8 is connected to a second flue gas outlet pipe 81 and a second ash discharge pipe 82. The cooling flue 3, the first connecting flue duct, and the second connecting flue all adopt a water-cooled wall vaporization flue structure. The first flue gas outlet pipe 71 and the second flue gas outlet pipe 81 are both connected to the main flue gas outlet pipe 10. The first ash discharge pipe 72 and the second ash discharge pipe 82 are both connected to the main dust discharge pipe 20 of the heat exchanger.

[0018] The outer wall of the first gas-solid coupling separator 5 is equipped with a first separator heat exchange tube cooling mechanism, and the outer wall of the second gas-solid coupling separator 6 is equipped with a second separator heat exchange tube cooling mechanism. The cooling flue 3, the first connecting flue, the second connecting flue, the shell of the first quench fire tube heat exchanger 7, the shell of the second quench fire tube heat exchanger 8, the first separator heat exchange tube cooling mechanism, and the second separator heat exchange tube cooling mechanism are all connected to the waste heat steam drum 9 through riser pipes and downcomer pipes, respectively.

[0019] The cooling flue 3 includes a first cooling flue section 31 and a second cooling flue section 32 connected sequentially along the flue gas flow direction. The inlet of the first cooling flue section 31 is connected to the waste heat recovery inlet section flue 1, and the outlet of the second cooling flue section 32 is connected to one flue port of the insulated transition flue tee 4. The first cooling flue section 31 is provided with an upper cooling flue header 311 and a lower cooling flue header 312 at both ends, and the second cooling flue section 32 is provided with an upper cooling flue header 321 and a lower cooling flue header 322 at both ends. The upper header 311 of the first section of the cooling flue is connected to the waste heat steam drum 9 through the first riser pipe 3111. The upper header 321 of the second section of the cooling flue is connected to the waste heat steam drum 9 through the second riser pipe 3211. The waste heat steam drum 9 is equipped with a first downcomer pipe 91, which is connected to the lower header 312 of the first section of the cooling flue and the lower header 322 of the second section of the cooling flue through two water supply pipes.

[0020] In this embodiment, the first connecting flue includes a first connecting flue section 51 and a first connecting flue section 52 connected sequentially along the flue gas flow direction. The lower end of the first connecting flue section 51 is connected to the first separator flue gas outlet 501 at the top of the first gas-solid coupling separator 5. The first connecting flue section 51 bends upward to connect with the upper end of the first connecting flue section 52. The first connecting flue section 52 bends downward, and the lower end of the first connecting flue section 52 is connected to the first fire tube heat exchanger flue gas inlet 701 of the first quench fire tube heat exchanger 7. The two ends of the first connecting flue section 51 are respectively provided with an upper header 511 and a lower header 512. The two ends of the first connecting flue section 52 are respectively provided with an upper header 521 and a lower header 522. The first connecting flue section upper header 511 and the first connecting flue section upper header 512 are connected to the waste heat steam drum 9 through the third riser pipe 5111 and the fourth riser pipe 5121, respectively; the first connecting flue section lower header 512 and the first connecting flue section lower header 522 are connected to the waste heat steam drum 9 through the second downcomer pipe 92.

[0021] The second connecting flue includes a first connecting flue section 61 and a second connecting flue section 62 connected sequentially along the flue gas flow direction. The lower end of the first connecting flue section 61 is connected to the flue gas outlet 601 of the second separator at the top of the second gas-solid coupling separator 6. The first connecting flue section 61 bends upward to connect with the upper end of the second connecting flue section 62. The second connecting flue section 62 bends downward, and its lower end is connected to the flue gas inlet 801 of the second fire tube heat exchanger of the second quench fire tube heat exchanger 8. The two ends of the first connecting flue section 61 are respectively provided with an upper header 611 and a lower header 612. The two ends of the second connecting flue section 62 are respectively provided with an upper header 621 and a lower header 622. The upper header 611 of the first section of the second connecting flue and the upper header 621 of the second connecting flue are connected to the waste heat steam drum 9 through the fifth riser pipe 6111 and the sixth riser pipe 6211, respectively; the lower header 612 of the first section of the second connecting flue and the lower header 622 of the second connecting flue are connected to the waste heat steam drum 9 through the third downcomer pipe 93.

[0022] The first gas-solid coupling separator 5 includes a first main body cylindrical body 53 and a first conical section cylindrical body 54. The first separator heat exchange tube cooling mechanism includes a first heat exchange coil assembly and a first straight section heat exchange tube assembly. The first heat exchange coil assembly includes a first heat exchange coil 541 wound around the outer wall of the first conical section cylindrical body 54. The first straight section heat exchange tube assembly includes a plurality of straight section heat exchange tubes spaced apart around the outer wall of the first main body cylindrical body 53. The upper ends of all the first straight section heat exchange tubes are connected to the first straight section upper heat exchange header 531, and the lower ends of all the first straight section heat exchange tubes are connected to the first straight section lower heat exchange header 532. The first straight section upper heat exchange header 531 and the first straight section lower heat exchange header 532 are arranged around the upper and lower ends of the outer wall of the first main body cylindrical body 53. The second gas-solid coupling separator 6 includes a second main body cylindrical body 63 and a second conical section cylindrical body 64. The second separator heat exchange tube cooling mechanism includes a second heat exchange coil assembly and a second straight section heat exchange tube assembly. The second heat exchange coil assembly includes a second heat exchange coil 641 wound around the outer wall of the second conical section cylindrical body 64. The second straight section heat exchange tube assembly includes a plurality of second straight section heat exchange tubes spaced apart around the outer wall of the second main body cylindrical body 63. The upper ends of all the second straight section heat exchange tubes are connected to the upper header 631 of the second straight section heat exchange tubes, and the lower ends of all the second straight section heat exchange tubes are connected to the lower header 632 of the second straight section heat exchange tubes. The upper header 631 and the lower header 632 of the second straight section heat exchange tubes are arranged around the upper and lower ends of the outer wall of the second main body cylindrical body 63. For simplified view, Figure 2 The document does not specify the first straight heat exchange tube and the second straight heat exchange tube.

[0023] In this embodiment, the inlet end of the first heat exchange coil 541 in the first heat exchange coil assembly and the inlet end of the second heat exchange coil 641 in the second heat exchange coil assembly are connected to the waste heat drum 9 through the fourth downcomer 94. The outlet end of the first heat exchange coil 541 in the first heat exchange coil assembly and the outlet end of the heat exchange coil 641 in the second heat exchange coil assembly are connected to the waste heat drum 9 through the seventh riser 90.

[0024] The first straight-section heat exchanger upper header 531 is connected to the waste heat drum 9 via the eighth riser pipe 5311, and the second straight-section heat exchanger upper header 631 is connected to the waste heat drum 9 via the ninth riser pipe 6311. The first straight-section heat exchanger lower header 533 and the second straight-section heat exchanger lower header 633 are connected to the waste heat drum 9 via the fifth downcomer pipe 95.

[0025] The bottom of the first gas-solid coupling separator 5 is provided with a first ash hopper 502. The bottom of the first ash hopper 502 is connected to the first ash cooler 504 through the first ash hopper output pipe 503. The first ash cooler 504 is connected to the first ash bin 505. The bottom of the second gas-solid coupling separator 6 is provided with a second ash hopper 602. The bottom of the second ash hopper 602 is connected to the second ash cooler 604 through the second ash hopper output pipe 603. The second ash cooler 604 is connected to the second ash bin 605.

[0026] In traditional converters, high-temperature gas at around 1450°C enters the converter's outlet flue gas duct from the converter's flue gas outlet. In the final section of the outlet flue gas duct (flue gas duct 2), the temperature of the high-temperature flue gas drops to around 900°C. This high-temperature gas in the final section of flue gas duct 2 is typically cooled by water spraying using the LT method. Specifically, the LT method involves spraying the high-temperature flue gas into the final section of the outlet flue gas duct (flue gas duct 2) for cooling, and then further spraying it into an evaporative cooler, thus rapidly reducing the flue gas temperature from around 900°C to around 200°C. This process obviously wastes the thermal energy required to cool the gas from 900°C to 200°C, and the spray cooling process also generates a large amount of sludge and wastewater, leading to environmental pollution.

[0027] In this application, the high-temperature gas generated in the converter at approximately 1450°C enters the converter's outlet flue gas duct from the converter's flue gas outlet until it enters the final section of the outlet flue gas duct, where the temperature drops to approximately 900°C. In this application, the high-temperature gas in the final section of the outlet flue gas duct 2 is not sprayed and directly passes through the waste heat recovery inlet flue gas duct 1, sequentially through the first cooling flue gas duct 31 and the second cooling flue gas duct 32. The high-temperature gas releases heat in the first and second cooling flue gas ducts 31 and 32, thus achieving heat recovery. Then, it is split into two paths through the insulated transition flue gas tee 4: one path enters the first gas-solid coupling separator 5, and the other path enters the second gas-solid coupling separator 6.

[0028] The high-temperature coal gas undergoes preliminary dust removal in the first gas-solid coupling separator 5 and the second gas-solid coupling separator 6. The high-temperature coal gas transfers heat to the heat exchange tube cooling mechanisms of both the first and second separators. Dust within the first gas-solid coupling separator 5 is collected in the first ash hopper 502. The dust in the first ash hopper 502 is cooled through the first ash hopper outlet pipe 503 and then enters the first ash cooler 504 before entering the first ash silo 505. Similarly, dust within the second gas-solid coupling separator 6 is collected in the second ash hopper 602. The dust in the second ash hopper 602 is cooled through the second ash hopper outlet pipe 603 and then enters the second ash cooler 604 before entering the second ash silo 605.

[0029] The high-temperature coal gas in the first gas-solid coupling separator 5, after preliminary dust removal, enters the flue gas inlet of the first quench fire-tube heat exchanger 7 through the first connecting flue, and then enters the heat exchange tube bundle in the first quench fire-tube heat exchanger 7 for rapid cooling. The high-temperature coal gas in the second gas-solid coupling separator 6, after preliminary dust removal, enters the flue gas inlet of the second quench fire-tube heat exchanger 8 through the second connecting flue, and then enters the heat exchange tube bundle in the second quench fire-tube heat exchanger 8 for rapid cooling. The high-temperature coal gas is further cooled to 200°C while undergoing further dust removal in the first quench fire-tube heat exchanger 7 and the second quench fire-tube heat exchanger 8. The cooled coal gas converges from the first flue gas outlet pipe 71 of the first quench fire-tube heat exchanger 7 and the second flue gas outlet pipe 81 of the second quench fire-tube heat exchanger 8 into the flue gas outlet main pipe 10 and is then discharged for further dust removal. Dust in the first quench fire-tube heat exchanger 7 and the second quench fire-tube heat exchanger 8 is discharged into the main dust discharge pipe 20 of the heat exchanger through the first ash pipe 72 and the second ash pipe 82, respectively, and then discharged outwards.

[0030] As described above, this application provides a waste heat recovery system for the final section of the converter outlet flue, which replaces the traditional LT method and achieves a completely dry treatment. It can not only effectively recover the heat energy of the high-temperature gas at 900°C in the final flue 2, thereby avoiding heat loss and reducing steelmaking costs, but also avoid the environmental pollution caused by the large amount of sludge generated by the LT method. In addition, since no spraying treatment is performed, it can effectively increase the enthalpy value of the gas product, thereby improving the quality of the gas product.

Claims

1. A waste heat recovery system for the terminal section of a converter outlet flue, comprising: The waste heat recovery inlet flue is connected at one end to the end of the converter outlet flue. Its distinguishing feature is that the other end of the waste heat recovery inlet flue is connected to a cooling flue. An adiabatic transition flue tee is provided at the outlet end of the cooling flue. This tee has three flue ports, one of which is connected to the outlet end of the cooling flue, and the other two ports are respectively connected to a first gas-solid coupling separator and a second gas-solid coupling separator. The top of the first gas-solid coupling separator is connected to the flue gas inlet end of a vertically arranged first quench fire-tube heat exchanger via a first connecting flue. The top of the second gas-solid coupling separator is connected to the flue gas inlet end of a vertically arranged second quench fire-tube heat exchanger via a second connecting flue. The lower end of the first quench fire-tube heat exchanger is connected to the first flue gas outlet pipe and the first ash discharge pipe, and the lower end of the second quench fire-tube heat exchanger is connected to the second flue gas outlet pipe and the second ash discharge pipe. The cooling flue, the first connecting flue, and the second connecting flue all adopt a water-cooled wall vaporization flue structure. The outer wall of the first gas-solid coupling separator is equipped with a first separator heat exchange tube cooling mechanism, and the outer wall of the second gas-solid coupling separator is equipped with a second separator heat exchange tube cooling mechanism. The cooling flue, the first connecting flue, the second connecting flue, the cylinder of the first quench fire-tube heat exchanger, the cylinder of the second quench fire-tube heat exchanger, the first separator heat exchange tube cooling mechanism, and the second separator heat exchange tube cooling mechanism are all connected to the waste heat steam drum through several riser pipes and several downcomer pipes.

2. The waste heat recovery system at the end of the converter outlet flue according to claim 1, characterized in that: The cooling flue includes a first cooling flue section and a second cooling flue section connected sequentially along the flue gas flow direction. The inlet of the first cooling flue section is connected to the waste heat recovery inlet section flue, and the outlet of the second cooling flue section is connected to the insulated transition flue tee. The first and second cooling flue sections are respectively equipped with an upper cooling flue header and a lower cooling flue header. The upper cooling flue header is connected to the waste heat steam drum through a riser pipe, and the lower cooling flue header is connected to the steam drum through a downcomer pipe.

3. The waste heat recovery system at the end of the converter outlet flue as described in claim 1, characterized in that: The first connecting flue includes a first connecting flue section 1 and a first connecting flue section 2 connected sequentially along the flue gas flow direction. The lower end of the first connecting flue section 1 is connected to the flue gas outlet of the first separator at the top of the first gas-solid coupling separator. The upward bend of the first connecting flue section 1 connects to the upper end of the first connecting flue section 2. The first connecting flue section 2 bends downward, and the lower end of the first connecting flue section 2 is connected to the flue gas inlet of the first fire tube heat exchanger of the first quench fire tube heat exchanger. The two ends of the first connecting flue section 1 are respectively provided with an upper header and a lower header. The two ends of the first connecting flue section 2 are respectively provided with an upper header and a lower header. The upper header of the first connecting flue section 1 and the upper header of the first connecting flue section 2 are respectively connected to the waste heat steam drum through riser pipes. The lower header of the first connecting flue section 1 and the lower header of the first connecting flue section 2 are respectively connected to the waste heat steam drum through downcomer pipes. The second connecting flue includes a second connecting flue section 1 and a second connecting flue section 2 connected sequentially along the flue gas flow direction. The lower end of the second connecting flue section 1 is connected to the flue gas outlet of the second separator at the top of the second gas-solid coupling separator. The second connecting flue section 1 bends upward to connect with the upper end of the second connecting flue section 2. The second connecting flue section 2 bends downward, and the lower end of the second connecting flue section 2 is connected to the flue gas inlet of the second fire tube heat exchanger of the second quench fire tube heat exchanger. The two ends of the second connecting flue section 1 are respectively provided with an upper header and a lower header. The two ends of the second connecting flue section 2 are respectively provided with an upper header and a lower header. The upper headers of the second connecting flue section 1 and the upper headers of the second connecting flue section 2 are respectively connected to the waste heat steam drum through riser pipes. The lower headers of the second connecting flue section 1 and the lower headers of the second connecting flue section 2 are respectively connected to the waste heat steam drum through downcomer pipes.

4. The waste heat recovery system at the end of the converter outlet flue as described in claim 1, characterized in that: The bottom of the first gas-solid coupling separator is provided with a first ash hopper. The bottom of the first ash hopper is connected to the first ash cooler through the first ash hopper output pipe. The first ash cooler is connected to the first ash silo. The bottom of the second gas-solid coupling separator is equipped with a second ash hopper. The bottom of the second ash hopper is connected to the second ash cooler through the second ash hopper output pipe. The second ash cooler is connected to the second ash silo.

5. The waste heat recovery system at the end of the converter outlet flue according to claim 1, characterized in that: The first gas-solid coupling separator includes a first main body cylindrical section and a first conical section cylindrical section. The first separator heat exchange tube cooling mechanism includes a first heat exchange coil assembly and a first straight section heat exchange tube assembly. The first heat exchange coil assembly includes a first heat exchange coil wound around the outer wall of the first conical section cylindrical section. The first straight section heat exchange tube assembly includes a plurality of first straight section heat exchange tubes spaced apart around the outer wall of the first main body cylindrical section. The upper ends of all the first straight section heat exchange tubes are connected to the upper header of the first straight section heat exchange tubes. The lower ends are all connected to the lower header of the first straight section heat exchanger. The upper header and the lower header of the first straight section heat exchanger are arranged around the upper and lower ends of the outer wall of the columnar cylinder of the first body section. The inlet end of the first heat exchange coil in the first heat exchange coil assembly is connected to the waste heat steam drum through a downcomer, and the outlet end of the first heat exchange coil in the first heat exchange coil assembly is connected to the waste heat steam drum through a riser. The upper header of the first straight section heat exchanger is connected to the waste heat steam drum through a riser, and the lower header of the first straight section heat exchanger is connected to the waste heat steam drum through a downcomer. The two-gas-solid coupling separator includes a second main body cylindrical section and a second conical section cylindrical section. The heat exchange tube cooling mechanism of the second separator includes a second heat exchange coil assembly and a second straight section heat exchange tube assembly. The second heat exchange coil assembly includes a second heat exchange coil wound around the outer wall of the second conical section cylindrical section. The second straight section heat exchange tube assembly includes a plurality of second straight section heat exchange tubes spaced apart around the outer wall of the second main body cylindrical section. The upper ends of all the second straight section heat exchange tubes are connected to the upper header of the second straight section heat exchange tubes. The lower ends of both are connected to the lower header of the second straight section heat exchanger. The upper header of the second straight section heat exchanger and the lower header of the second straight section heat exchanger are arranged around the upper and lower ends of the outer wall of the columnar cylinder of the second body section. The inlet end of the second heat exchange coil in the second heat exchange coil assembly is connected to the waste heat steam drum through a downcomer. The outlet end of the second heat exchange coil in the second heat exchange coil assembly is connected to the waste heat steam drum through a riser. The upper header of the second straight section heat exchanger is connected to the waste heat steam drum through a riser. The lower header of the second straight section heat exchanger is connected to the waste heat steam drum through a downcomer.

6. The waste heat recovery system at the end of the converter outlet flue according to claim 1, characterized in that: Both the first and second flue gas outlet pipes are connected to the main flue gas outlet pipe.

7. The waste heat recovery system at the end of the converter outlet flue according to claim 1, characterized in that: Both the first and second rows of ash pipes are connected to the main dust discharge pipe of the heat exchanger.

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