Waste gas waste heat recycling system for sintering circular cooler

Abstract

The invention belongs to the technical field of waste heat utilization of sintering circular coolers, and discloses a waste gas waste heat recycling system of a sintering circular cooler. Comprising a first circular cooler section with a first exhaust fume collecting hood, a second circular cooler section with a second exhaust fume collecting hood, a third circular cooler section with a third exhaust fume collecting hood, a fourth circular cooler section with a fourth exhaust fume collecting hood, a waste heat boiler, a circulating fan, a high-temperature fan and a fourth-section cooling fan, the third exhaust fume collecting hood is communicated with an inlet of a high-temperature fan, an outlet of the high-temperature fan is communicated with a first-section lower air box of the circular cooler, and the fourth exhaust fume collecting hood is communicated with the outdoor environment through a fourth chimney or a dust remover; the waste heat boiler is communicated with an inlet of a circulating fan, and the circulating fan is communicated with a second-section lower air bellow of the circular cooler and a third-section lower air bellow of the circular cooler. By recycling the waste gas subjected to heat exchange and cooling of the waste heat boiler and the waste gas generated by the three sections of the circular cooler, the generating capacity and the energy utilization efficiency can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste heat utilization of sintering annular cooler, and relates to a waste heat recovery and utilization system, specifically a waste heat recovery and utilization system for waste gas of sintering annular cooler. Background Art

[0002] The sintering annular cooler is a key equipment for cooling sintered ore in the metallurgical industry, mainly used to cool high-temperature sintered ore to a temperature suitable for subsequent process treatment through a circulating cooling method. During the cooling process of high-temperature sintered ore, the sintering annular cooler will generate a large amount of waste heat. Research shows that the cooling waste gas discharged from the upper part of the sintering annular cooler accounts for 40% - 45% of the waste heat resources of the entire sintering process, which is the main part for waste heat recovery and utilization.

[0003] The existing waste heat recovery and utilization technology for sintering annular cooler waste gas mainly conducts cascaded energy conversion and utilization according to the energy grade of the waste gas discharged at different temperature sections of the annular cooler. At present, the existing waste heat recovery and utilization technology for sintering annular cooler waste gas has carried out waste heat power generation utilization on the waste gas in the high-temperature sections of the first and second sections of the annular cooler, and the waste gas in the third and fourth sections of the annular cooler is usually directly discharged. To improve the utilization rate of the waste gas, there are also waste heat recovery and utilization measures for the waste gas in the third section of the annular cooler, but the waste heat recovery and utilization of the medium-temperature waste gas in the third section of the annular cooler is mainly used for hot air sintering, waste gas recycling, and hot water preparation.

[0004] The Chinese patent application with the publication number CN118999171A discloses a "high-efficiency waste heat utilization system and method for sintering annular cooler based on zero waste gas emission", including: the waste gas outlets of the first and second sections of the annular cooler are connected to the waste gas inlets of the waste heat boiler; the waste gas outlet of the waste heat boiler is connected to the air inlet of the first circulation fan and the first and second air boxes of the annular cooler; the air inlets of the first cooling fan and the second cooling fan are both connected to the outdoor environment; the air outlet of the first cooling fan is successively connected to the fifth air box of the annular cooler and the waste gas outlet of the third air box; the air outlet of the second cooling fan is successively connected to the fourth air box of the annular cooler, the second circulation fan, and the fourth air box of the annular cooler; the waste gas outlet of the third air box of the annular cooler is connected to the hot air hood of the sintering machine. This patent document sends the medium-temperature waste gas in the third section of the annular cooler above the sintering machine material surface for hot air sintering.

[0005] The Chinese utility model patent with the authorization number CN221724937 U discloses a "sintering ring cooler waste heat recovery and utilization system", including: a crusher, which is inclined between the tail of the sintering machine and the feed inlet of the ring cooler; a smoke hood, which is arranged above the crusher to collect the high-temperature waste gas generated by the materials on the crusher; a high-temperature section waste heat recovery device, which is arranged in the high-temperature section of the ring cooler; a medium-temperature section waste heat recovery device, which is arranged in the medium-temperature section of the ring cooler; an air guiding pipeline, one end of which is connected to the smoke hood, and the other end is connected to the intake pipeline of any one or more of the first waste heat recovery device, the high-temperature section waste heat recovery device, and the medium-temperature section waste heat recovery device. This patent document sends the medium-temperature waste gas in the three sections of the ring cooler to the flue gas circulation system.

[0006] The Chinese invention patent application with the publication number CN117989874A discloses a "combined cooling and heating supply system and method based on the low-temperature waste heat resources of a sintering ring cooler", including: a flue gas and air system, a combined cooling and heating supply system; the flue gas and air system at least includes a sintering waste heat power generation tail flue gas system, a three-stage air supply system of the sintering ring cooler, and a four-stage air supply system of the sintering ring cooler. The combined cooling and heating supply system includes a flue gas-water heat exchanger and an absorption refrigeration unit; the flue gas-water heat exchanger is divided into three levels. The first-level heat exchanger is connected to the four-stage air supply system of the sintering ring cooler, the second-level heat exchanger is connected to the sintering waste heat power generation tail flue gas system, and the third-level heat exchanger is connected to the three-stage air supply system of the sintering ring cooler. This patent document utilizes the waste heat of the medium-temperature waste gas in the three sections of the ring cooler to prepare hot water.

[0007] The technical solutions of the above three patent documents all recover and utilize the waste heat in the three sections of the ring cooler, but none of them transfer the waste heat of the waste gas in the three sections of the ring cooler to the waste heat boiler for waste heat power generation by the existing waste heat power generation system, and thus cannot directly increase the power generation. Summary of the Invention

[0008] To solve the above deficiencies in the prior art, the present invention aims to provide a sintering ring cooler waste gas waste heat recovery and utilization system to achieve the purpose of increasing power generation.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows: A waste heat recovery and utilization system for a sintering annular cooler, comprising an annular cooler, a waste heat boiler, a circulation fan, a high-temperature fan, and a four-stage cooling fan. The annular cooler includes a first-stage annular cooler with a first smoke collection hood, a second-stage annular cooler with a second smoke collection hood, a third-stage annular cooler with a third smoke collection hood, and a fourth-stage annular cooler with a fourth smoke collection hood. The first smoke collection hood is connected to the waste heat boiler through a first air intake pipe, the second smoke collection hood is connected to the waste heat boiler through a second air intake pipe, the third smoke collection hood is connected to the inlet of the high-temperature fan through a third air intake pipe, the outlet of the high-temperature fan is connected to the lower air box of the first-stage annular cooler through a first air inlet pipe, and the fourth smoke collection hood is connected to the outdoor environment through a fourth chimney or a dust collector. The waste heat boiler is connected to the inlet of the circulation fan through a waste heat boiler outlet pipe. At the outlet of the circulation fan, a second air inlet pipe and a third air inlet pipe are branched. The second air inlet pipe is connected to the lower air box of the second-stage annular cooler, the third air inlet pipe is connected to the lower air box of the third-stage annular cooler, the inlet of the four-stage cooling fan is connected to the outdoor environment, and the outlet of the four-stage cooling fan is connected to the lower air box of the fourth-stage annular cooler through a four-stage cooling fan outlet pipe.

[0010] As a limitation of the present invention, a first air intake electric control valve is provided on the first air intake pipe, a second air intake electric control valve is provided on the second air intake pipe, and a third air intake electric control valve is provided on the third air intake pipe.

[0011] As a further limitation of the present invention, a first air inlet electric valve is provided on the first air inlet pipe, a second air inlet electric valve is provided on the second air inlet pipe, a third air inlet electric valve is provided on the third air inlet pipe, and a fourth air inlet electric valve is provided on the four-stage cooling fan outlet pipe.

[0012] As a still further limitation of the present invention, a first chimney is connected to the first air intake pipe, a first chimney relief valve is provided on the first chimney, a second chimney is connected to the second air intake pipe, a second chimney relief valve is provided on the second chimney, a third chimney is connected to the third air intake pipe, a third chimney relief valve is provided on the third chimney, and a fourth chimney relief valve is provided on the fourth chimney.

[0013] As another limitation of the present invention, the circulation fan, the high-temperature fan, and the four-stage cooling fan all adopt variable-frequency fans.

[0014] As a further limitation of the present invention, the waste gas temperature at the outlet of the first smoke collecting hood is 470 ± 20 °C, the waste gas temperature at the outlet of the second smoke collecting hood is 350 ± 20 °C, the waste gas temperature at the outlet of the third smoke collecting hood is 230 ± 20 °C, the waste gas temperature at the inlet of the lower air box of the first stage of the annular cooler is 230 ± 20 °C, the waste gas temperature at the inlet of the lower air box of the second stage of the annular cooler is 140 ± 20 °C, the waste gas temperature at the inlet of the lower air box of the third stage of the annular cooler is 140 ± 20 °C, and the gas temperature at the inlet of the lower air box of the fourth stage of the annular cooler is 35 ± 20 °C.

[0015] Due to the adoption of the above technical solution, compared with the prior art, the beneficial effects achieved by the present invention are as follows: In the present invention, after the waste heat boiler exchanges heat and cools down the high-temperature waste gas generated by the first stage and the second stage of the annular cooler, it is respectively transported into the lower air box of the second stage and the lower air box of the third stage of the annular cooler by the circulating fan. Compared with the prior art, in the present invention, the waste gas that enters the lower air box of the second stage and the lower air box of the third stage of the annular cooler after heat exchange and cooling is used to cool the sintered ore. The second stage and the third stage of the annular cooler can generate waste gas at a higher temperature. Among them, the waste gas at a higher temperature generated in the second stage of the annular cooler is directly transported to the waste heat boiler for waste heat power generation, which increases the amount of steam generated by the waste heat boiler, and thus can effectively increase the power generation amount and improve the energy utilization efficiency. In addition, the present invention also transports the waste gas generated by the third stage of the annular cooler into the lower air box of the first stage of the annular cooler. Compared with the prior art, the first stage of the annular cooler can generate waste gas at a higher temperature and this waste gas is directly transported to the waste heat boiler for waste heat power generation. The present invention recovers and utilizes the waste heat of the waste gas from the third stage of the annular cooler and transports it to the waste heat boiler for waste heat power generation, which increases the amount of steam generated by the waste heat boiler, and thus can effectively increase the power generation amount and improve the energy utilization efficiency, and can generate relatively high economic benefits and environmental benefits. Specifically, taking a 200 m 2 sintering annular cooler as an example, after using the present invention to recover and utilize the waste heat of the waste gas from the third stage of the annular cooler, compared with the prior art, the waste heat boiler generates 8.2 t / h more steam, the waste heat power generation system increases the power generation amount by 1218 KW, the net increase in power generation is 928 KW, and the power generation per ton of ore increases by 3.09 KW. The present invention is suitable for use when waste heat recovery and utilization of the sintering annular cooler waste gas is required. Description of the Drawings

[0016] The following further describes the present invention in more detail with reference to the drawings and specific embodiments.

[0017] Figure 1 It is a schematic structural diagram of an embodiment of the present invention; In the figure: 1. Ring cooler; 2. Waste heat boiler; 3. Circulation fan; 4. High-temperature fan; 5. Four-stage cooling fan; 6. First chimney relief valve; 7. First air intake electric control valve; 8. Second chimney relief valve; 9. Second air intake electric control valve; 10. Third chimney relief valve; 11. Third air intake electric control valve; 12. Fourth chimney relief valve; 13. First air inlet electric valve; 14. Second air inlet electric valve; 15. Third air inlet electric valve; 16. Fourth air inlet electric valve; 17. First air intake pipe; 18. Second air intake pipe; 19. Waste heat boiler outlet pipe; 20. Third air intake pipe; 21. First air inlet pipe; 22. Second air inlet pipe; 23. Third air inlet pipe; 24. Four-stage cooling fan outlet pipe; 25. First chimney; 26. Second chimney; 27. Third chimney; 28. Fourth chimney. Detailed implementation manners

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and understanding the present invention, and are not used to limit the present invention.

[0019] As Figure 1 shown, this embodiment includes a ring cooler 1, a waste heat boiler 2, a circulation fan 3, a high-temperature fan 4, and a four-stage cooling fan 5. The ring cooler 1 includes a first-stage ring cooler section with a first smoke collection hood, a second-stage ring cooler section with a second smoke collection hood, a third-stage ring cooler section with a third smoke collection hood, and a fourth-stage ring cooler section with a fourth smoke collection hood. It should be noted that the waste heat boiler 2 needs to be used in conjunction with an existing waste heat power generation system to realize waste heat power generation.

[0020] The first smoke collection hood is connected to the waste heat boiler 2 through a first air intake pipe 17, the second smoke collection hood is connected to the waste heat boiler 2 through a second air intake pipe 18, the third smoke collection hood is connected to the inlet of the high-temperature fan 4 through a third air intake pipe 20, the outlet of the high-temperature fan 4 is connected to the lower air box of the first-stage ring cooler section through a first air inlet pipe 21, and the fourth smoke collection hood is connected to the outdoor environment through the fourth chimney 28 or a dust collector. The waste heat boiler 2 is connected to the inlet of the circulation fan 3 through a waste heat boiler outlet pipe 19. At the outlet of the circulation fan 3, a second air inlet pipe 22 and a third air inlet pipe 23 are branched. The second air inlet pipe 22 is connected to the lower air box of the second-stage ring cooler section, and the third air inlet pipe 23 is connected to the lower air box of the third-stage ring cooler section. The inlet of the four-stage cooling fan 5 is connected to the outdoor environment, and the outlet of the four-stage cooling fan 5 is connected to the lower air box of the fourth-stage ring cooler section through a four-stage cooling fan outlet pipe 24. In this embodiment, the fourth smoke collection hood is connected to the outdoor environment through the fourth chimney 28.

[0021] Further, a first air intake electric regulating valve 7 is provided on the first air intake duct 17, a second air intake electric regulating valve 9 is provided on the second air intake duct 18, and a third air intake electric regulating valve 11 is provided on the third air intake duct 20. A first air inlet electric valve 13 is provided on the first air inlet duct 21, a second air inlet electric valve 14 is provided on the second air inlet duct 22, and a third air inlet electric valve 15 is provided on the third air inlet duct 23. A fourth air inlet electric valve 16 is provided on the air outlet duct of the four-stage cooling fan 24. A first chimney 25 is connected to the first air intake duct 17, and a first chimney relief valve 6 is provided on the first chimney 25. A second chimney 26 is connected to the second air intake duct 18, and a second chimney relief valve 8 is provided on the second chimney 26. A third chimney 27 is connected to the third air intake duct 20, and a third chimney relief valve 10 is provided on the third chimney 27. A fourth chimney relief valve 12 is provided on the fourth chimney 28. It should be noted that when the fourth smoke collecting hood is connected to the outdoor environment through a dust collector, a dust collector outlet duct relief valve needs to be provided on the dust collector outlet duct.

[0022] The circulating fan 3, the high-temperature fan 4, and the four-stage cooling fan 5 are all variable-frequency fans. When using this embodiment, by adjusting the frequencies of the circulating fan 3, the high-temperature fan 4, and the four-stage cooling fan 5, the air volume of each fan can be adjusted, and thus the exhaust gas temperatures at the outlets of the first smoke collecting hood, the second smoke collecting hood, the third smoke collecting hood, the inlet of the lower air box of the first stage of the annular cooler, the inlet of the lower air box of the second stage of the annular cooler, the inlet of the lower air box of the third stage of the annular cooler, and the inlet of the lower air box of the fourth stage of the annular cooler can be controlled to be at reasonable values to ensure that the temperature of the sintered ore at the outlet of the sintering annular cooler meets the process requirements. Specifically, the exhaust gas temperature at the outlet of the first smoke collecting hood should be 470 ± 20 °C, the exhaust gas temperature at the outlet of the second smoke collecting hood should be 350 ± 20 °C, the exhaust gas temperature at the outlet of the third smoke collecting hood should be 230 ± 20 °C, the exhaust gas temperature at the inlet of the lower air box of the first stage of the annular cooler should be 230 ± 20 °C, the exhaust gas temperature at the inlet of the lower air box of the second stage of the annular cooler should be 140 ± 20 °C, the exhaust gas temperature at the inlet of the lower air box of the third stage of the annular cooler should be 140 ± 20 °C, and the gas temperature at the inlet of the lower air box of the fourth stage of the annular cooler should be 35 ± 20 °C. Thereby, the temperature of the sintered ore at the outlet of the sintering annular cooler can be made lower than the upper limit of the process requirements by 120 °C.

[0023] When using this embodiment, the first air intake electric regulating valve 7, the second air intake electric regulating valve 9, the third air intake electric regulating valve 11, the first air inlet electric valve 13, the second air inlet electric valve 14, the third air inlet electric valve 15, the fourth air inlet electric valve 16, and the fourth chimney relief valve 12 should all be in the open state, while the first chimney relief valve 6, the second chimney relief valve 8, and the third chimney relief valve 10 should all be in the closed state. Specifically, when this embodiment operates normally, the waste gas in the first stage of the annular cooler is collected by the first smoke collecting hood and then transported to the waste heat boiler 2 through the first air intake pipeline 17. The waste gas in the second stage of the annular cooler is collected by the second smoke collecting hood and then transported to the waste heat boiler 2 through the second air intake pipeline 18. After the waste gas is cooled by heat exchange in the waste heat boiler 2, it enters the waste heat boiler outlet pipeline 19 and is respectively transported to the lower air box of the second stage of the annular cooler and the lower air box of the third stage of the annular cooler under the action of the circulating fan 3, to conduct circulating cooling on the sintered ore on the sintering annular cooler. The waste gas in the third stage of the annular cooler is collected by the third smoke collecting hood and then transported to the inlet of the high-temperature fan 4 through the third air intake pipeline 20, and then transported to the lower air box of the first stage of the annular cooler through the first air inlet pipeline 21, and finally enters the waste heat boiler 2, thus realizing the recovery and utilization of the waste heat of the waste gas in the third stage of the annular cooler. The outdoor ambient air enters the lower air box of the fourth stage of the annular cooler under the action of the fourth stage cooling fan 5 to further cool the sintered ore, and the waste gas generated in the fourth stage of the annular cooler is directly discharged into the air.

[0024] It should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the above embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A waste heat recovery and utilization system for sintering annular cooler, characterized in that: It includes a circular cooler, a waste heat boiler, a circulation fan, a high-temperature fan, and four-stage cooling fans. The circular cooler includes the first stage of the circular cooler with a first smoke collection hood, the second stage of the circular cooler with a second smoke collection hood, the third stage of the circular cooler with a third smoke collection hood, and the fourth stage of the circular cooler with a fourth smoke collection hood; The first smoke collection hood is connected to the waste heat boiler through a first air intake pipeline, the second smoke collection hood is connected to the waste heat boiler through a second air intake pipeline, the third smoke collection hood is connected to the inlet of the high-temperature fan through a third air intake pipeline, the outlet of the high-temperature fan is connected to the lower air box of the first stage of the circular cooler through a first air inlet pipeline, and the fourth smoke collection hood is connected to the outdoor environment through a fourth chimney or a dust collector; The waste heat boiler is connected to the inlet of the circulation fan through a waste heat boiler outlet pipeline. At the outlet of the circulation fan, a second air inlet pipeline and a third air inlet pipeline are branched. The second air inlet pipeline is connected to the lower air box of the second stage of the circular cooler, the third air inlet pipeline is connected to the lower air box of the third stage of the circular cooler, the inlet of the four-stage cooling fan is connected to the outdoor environment, and the outlet of the four-stage cooling fan is connected to the lower air box of the fourth stage of the circular cooler through a four-stage cooling fan outlet pipeline.

2. The waste heat recovery and utilization system for sintering annular cooler exhaust gas according to claim 1, wherein: A first air intake electric control valve is provided on the first air intake pipeline, a second air intake electric control valve is provided on the second air intake pipeline, and a third air intake electric control valve is provided on the third air intake pipeline.

3. The waste heat recovery and utilization system for sintering annular cooler exhaust gas according to claim 2, wherein: A first air inlet electric valve is provided on the first air inlet pipeline, a second air inlet electric valve is provided on the second air inlet pipeline, a third air inlet electric valve is provided on the third air inlet pipeline, and a fourth air inlet electric valve is provided on the four-stage cooling fan outlet pipeline.

4. A waste heat recovery and utilization system for sintering annular cooler exhaust gas according to claim 3, characterized in that: A first chimney is connected to the first air intake pipeline, a first chimney relief valve is provided on the first chimney, a second chimney is connected to the second air intake pipeline, a second chimney relief valve is provided on the second chimney, a third chimney is connected to the third air intake pipeline, a third chimney relief valve is provided on the third chimney, and a fourth chimney relief valve is provided on the fourth chimney.

5. A waste heat recovery and utilization system for sintering annular cooler exhaust gas according to any one of claims 1-4, characterized in that: The circulation fan, the high-temperature fan, and the four-stage cooling fans all adopt variable-frequency fans.

6. The waste heat recovery and utilization system for sintering annular cooler exhaust gas according to claim 5, wherein: The waste gas temperature at the outlet of the first smoke collection hood is 470±20°C, the waste gas temperature at the outlet of the second smoke collection hood is 350±20°C, the waste gas temperature at the outlet of the third smoke collection hood is 230±20°C, the waste gas temperature at the inlet of the lower air box of the first stage of the circular cooler is 230±20°C, the waste gas temperature at the inlet of the lower air box of the second stage of the circular cooler is 140±20°C, the waste gas temperature at the inlet of the lower air box of the third stage of the circular cooler is 140±20°C, and the gas temperature at the inlet of the lower air box of the fourth stage of the circular cooler is 35±20°C.

Images