A sintering machine and a circular cooler full-heat recovery high-efficiency power generation system

Abstract

The application provides a sintering machine and ring cooler full-heat recovery high-efficiency power generation system, belonging to the technical field of sintering process energy saving in steel metallurgy, and comprising a sintering machine, a ring cooler, a waste heat boiler, a hot water heat exchanger, a medium-pressure drum, a deaerator and a steam turbine; from bottom to top in the waste heat boiler, a low-temperature economizer, a low-pressure evaporator, a low-pressure superheater, a medium-pressure evaporator and a medium-pressure superheater are sequentially arranged; a first-stage flue gas outlet of the ring cooler and a second-stage flue gas outlet of the ring cooler are connected with the medium-pressure superheater and the medium-pressure evaporator respectively, and the flue gas discharged from the first-stage flue gas outlet of the ring cooler and the second-stage flue gas outlet of the ring cooler is mixed in the waste heat boiler and then sent into a flue gas inlet of the ring cooler through a circulating fan; third-stage, fourth-stage and fifth-stage flue gases of the ring cooler are sequentially and gradually connected in series, mixed, heated through the hot water heat exchanger, and then sent into the sintering machine through a hot air fan; the power generation system can realize full-heat recovery of the sintering machine and the ring cooler, fully utilize flue gas heat, and improve power generation efficiency.

Description

Technical Field

[0001] This invention belongs to the field of energy-saving technology for sintering processes in iron and steel metallurgy, specifically relating to a high-efficiency power generation system that recovers all waste heat from sintering machines and annular coolers. Background Technology

[0002] Sintering is a crucial step in steel production. The sintering machine and annular cooler generate large amounts of high-temperature flue gas during operation. If the heat carried by this flue gas is not recovered and utilized, it will result in significant energy waste. With the increasing national emphasis on energy conservation and emission reduction, steel companies have an increasingly urgent need for sintering waste heat recovery technology.

[0003] Currently, sintering waste heat recovery technology mainly adopts waste heat boiler power generation systems, but existing technologies generally have the following problems: First, waste heat recovery is insufficient. The flue gas temperature varies greatly in different sections of the annular cooler, and existing systems often only recover part of the high-temperature flue gas, resulting in a low overall waste heat recovery rate. Second, power generation efficiency is low. Due to unreasonable steam parameter design, the turbine's working efficiency is limited, making it difficult to maximize power generation. Third, flue gas heat is not fully recycled. The heat from the low-temperature flue gas in the annular cooler and the sintering machine flue gas is not effectively integrated, resulting in energy waste. Fourth, energy cascade utilization is insufficient. Waste heat at different temperature levels is not utilized according to temperature grade, with high-grade heat energy being used for low-grade demand, reducing energy utilization efficiency.

[0004] These technical deficiencies limit the economic benefits and energy-saving effects of sintering waste heat power generation systems, failing to meet the actual needs of steel enterprises for high-efficiency energy conservation. Therefore, there is an urgent need to develop a high-efficiency power generation system that can achieve full waste heat recovery from sintering machines and annular coolers, improve power generation efficiency, and fully utilize flue gas heat. Summary of the Invention

[0005] Based on the above-mentioned technical problems, the purpose of this invention is to provide a high-efficiency power generation system for the full waste heat recovery of sintering machines and annular coolers. This power generation system can realize the full waste heat recovery of sintering machines and annular coolers, make full use of flue gas heat, and improve power generation efficiency.

[0006] The specific technical solution is as follows: A high-efficiency power generation system for full waste heat recovery from a sintering machine and an annular cooler includes: a sintering machine, an annular cooler, a waste heat boiler, a hot water heat exchanger, a medium-pressure boiler drum, a deaerator, and a steam turbine; the waste heat boiler is equipped with, from bottom to top, a low-temperature economizer, a low-pressure evaporator, a low-pressure superheater, a medium-pressure evaporator, and a medium-pressure superheater; the flue gas outlets of the first and second stages of the annular cooler are connected to the medium-pressure superheater and the medium-pressure evaporator, respectively, and the flue gas discharged from the first and second stages of the annular cooler is mixed in the waste heat boiler and then sent to the flue gas inlet of the annular cooler by a circulating fan; the flue gas from the third, fourth, and fifth stages of the annular cooler is mixed in series and then sent into the sintering machine by a hot air fan after heat exchange in the hot water heat exchanger; The medium-pressure boiler drum is located on one side of the waste heat boiler. The medium-pressure saturated steam in the medium-pressure boiler drum enters the medium-pressure superheater through the first exhaust pipe. After superheating, the produced medium-pressure superheated steam is sent to the steam turbine to generate electricity. A first water outlet pipe and a first return gas pipe are provided between the medium-pressure boiler drum and the medium-pressure evaporator. The flue gas outlet of the sintering machine's main flue is connected to the first exhaust pipe. The deaerator is located on one side of the waste heat boiler. The low-pressure saturated steam discharged from the deaerator enters the low-pressure superheater through the second exhaust pipe. After superheating, the discharged low-pressure superheated steam is given priority to supply gas for production. The remaining low-pressure superheated steam is added to the steam inlet of the steam turbine to generate electricity. A second water outlet pipe and a second return gas pipe are provided between the deaerator and the low-pressure evaporator.

[0007] In addition, the high-efficiency power generation system for full waste heat recovery of sintering machine and annular cooler provided by the present invention may also have the following additional technical features: In the above technical solution, the exhaust port of the steam turbine is connected to the condenser, the condensate discharged from the condenser is pumped into the inlet of the low-temperature economizer, the outlet of the low-temperature economizer is connected to the inlet of the hot water heat exchanger, and the outlet of the hot water heat exchanger is connected to the inlet of the deaerator.

[0008] In the above technical solution, the output shaft of the steam turbine is connected to the input end of the speed-changing clutch, the output end of the speed-changing clutch is connected to one end of the dual-shaft output motor, and the other end of the dual-shaft output motor is connected to the sintering main exhaust fan.

[0009] The present invention provides a high-efficiency power generation system for the complete waste heat recovery of a sintering machine and annular cooler, which, compared with the prior art, has the following advantages: 1. Full waste heat recovery from the sintering machine and the annular cooler was achieved. By introducing the high-temperature flue gas from the first and second stages of the annular cooler into the medium-pressure superheater and the medium-pressure evaporator, respectively, and then mixing the flue gas from the third, fourth, and fifth stages in series before exchanging heat through a hot water heat exchanger, and simultaneously using the flue gas from the sintering machine's main flue to supplement the medium-pressure steam, comprehensive recovery of all waste heat sources was achieved, significantly improving the waste heat utilization rate.

[0010] 2. Adopting a dual-pressure system to improve power generation efficiency. The system is equipped with two steam systems: a medium-pressure system and a low-pressure system. The medium-pressure steam is used for the main power generation of the steam turbine, while the low-pressure steam is given priority for production gas supply, and the remaining part is supplemented to the steam turbine's steam injection port for collaborative power generation. This realizes the cascade utilization of steam, which can improve the power generation efficiency by more than 8% compared with a single-pressure system, while meeting the gas demand for production and improving the overall energy utilization efficiency of the system.

[0011] 3. High-efficiency recycling of flue gas is achieved. The high-temperature flue gas from the first and second stages of the annular cooler is mixed and heat-exchanged in the waste heat boiler, and then sent back to the inlet of the annular cooler by the circulating fan. The flue gas from the third, fourth, and fifth stages is mixed in series and then sent into the sintering machine after heat exchange in the hot water heat exchanger. This forms a complete internal flue gas circulation system, which reduces flue gas emissions and environmental pollution. At the same time, the recycling of flue gas improves the efficiency of thermal energy utilization.

[0012] 4. A comprehensive energy cascade utilization system has been established. The waste heat boiler is equipped with a low-temperature economizer, a low-pressure evaporator, a low-pressure superheater, a medium-pressure evaporator, and a medium-pressure superheater, arranged sequentially from bottom to top. This, combined with the condensate being heated stage by stage through the low-temperature economizer, hot water heat exchanger, and deaerator, achieves a rational matching and cascade utilization of waste heat at different temperature levels. High-grade heat energy is used for high-grade needs, and low-grade heat energy is used for low-grade needs, avoiding energy grade degradation and loss.

[0013] 5. Full utilization of waste heat from the sintering machine's main flue gas. The flue gas outlet of the sintering machine's main flue gas is connected to the medium-pressure steam pipeline, using the heat carried by the sintering machine's flue gas to supplement and superheat the medium-pressure steam, further increasing the output and parameters of the medium-pressure steam, and increasing the turbine's work capacity. Compared with systems that do not utilize the sintering machine's flue gas, this can increase power generation by more than 10%, achieving comprehensive recovery and efficient utilization of waste heat from the sintering machine and annular cooler, significantly improving the overall waste heat utilization rate and power generation efficiency of the system. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a high-efficiency power generation system for full waste heat recovery from a sintering machine and an annular cooler according to the present invention. in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows: 10 Sintering machine, 11 Circulating cooler, 12 Waste heat boiler, 13 Hot water heat exchanger, 14 Medium-pressure boiler drum, 15 Deaerator, 16 Steam turbine, 17 First exhaust pipe, 18 First water outlet pipe, 19 First return gas pipe, 20 Second exhaust pipe, 21 Second water outlet pipe, 22 Second return gas pipe, 23 Condenser, 24 Water pump, 25 Variable speed clutch, 26 Dual-shaft output motor, 27 Sintering main exhaust fan, 28 Circulating fan, 29 Hot air fan. Detailed Implementation

[0015] The following are specific implementation cases and appendices. Figure 1 The present invention will be further described, but the present invention is not limited to these embodiments.

[0016] A high-efficiency power generation system for full waste heat recovery of sintering machine 10 and annular cooler 11, such as Figure 1 As shown, the system includes: a sintering machine 10, an annular cooler 11, a waste heat boiler 12, a hot water heat exchanger 13, a medium-pressure boiler drum 14, a deaerator 15, and a steam turbine 16. The waste heat boiler 12, from bottom to top, is equipped with a low-temperature economizer, a low-pressure evaporator, a low-pressure superheater, a medium-pressure evaporator, and a medium-pressure superheater. The first and second stage flue gas outlets of the annular cooler 11 are connected to the medium-pressure superheater and the medium-pressure evaporator, respectively. The flue gas discharged from the first and second stage flue gas outlets of the annular cooler 11 is mixed in the waste heat boiler 12 and then sent to the flue gas inlet of the annular cooler 11 by a circulating fan 28. The flue gas from the third, fourth, and fifth stages of the annular cooler 11 is mixed in series and then sent to the sintering machine 10 by a hot air fan 29 after heat exchange in the hot water heat exchanger 13. The medium-pressure boiler drum 14 is equipped with... On one side of the waste heat boiler 12, the medium-pressure saturated steam in the medium-pressure boiler drum 14 enters the medium-pressure superheater through the first exhaust pipe 17. After superheating, the produced medium-pressure superheated steam is sent to the steam turbine 16 to generate electricity. A first water outlet pipe 18 and a first return gas pipe 19 are provided between the medium-pressure boiler drum 14 and the medium-pressure evaporator. The flue gas outlet of the main flue of the sintering machine 10 is connected to the first exhaust pipe 17. The deaerator 15 is located on one side of the waste heat boiler 12. The low-pressure saturated steam discharged from the deaerator 15 enters the low-pressure superheater through the second exhaust pipe 20. After superheating, the discharged low-pressure superheated steam is given priority to supply gas for production. The remaining low-pressure superheated steam is added to the steam inlet of the steam turbine 16 to generate electricity. A second water outlet pipe 21 and a second return gas pipe 22 are provided between the deaerator 15 and the low-pressure evaporator.

[0017] With the above structure, the high-temperature flue gas discharged from the first and second stage flue gas outlets of the annular cooler 11 enters the medium-pressure superheater and the medium-pressure evaporator respectively, and after being mixed in the waste heat boiler 12, it enters the annular cooler 11 for recycling under the action of the circulating fan 28. Water in the medium-pressure boiler drum 14 evaporates in the medium-pressure evaporator, and the resulting steam enters the medium-pressure boiler drum 14 to generate medium-pressure saturated steam. This medium-pressure saturated steam enters the medium-pressure superheater, is superheated, and then discharged as medium-pressure superheated steam. It is then sent to the steam turbine 16 to generate electricity. At the same time, the medium-pressure saturated steam discharged from the main flue of the sintering machine 10 mixes with the medium-pressure saturated steam from the first exhaust pipe and enters the medium-pressure superheater together.

[0018] Water in the deaerator 15 evaporates in the low-pressure evaporator, and the resulting steam enters the deaerator 15 to generate low-pressure saturated steam. This low-pressure saturated steam enters the low-pressure superheater, is superheated, and the discharged low-pressure superheated steam is preferentially supplied to the production gas. The remaining low-pressure superheated steam is added to the steam inlet of the turbine 16 to generate electricity.

[0019] After the flue gas from the third, fourth, and fifth stages of the annular cooler 11 is mixed, it enters the hot water heat exchanger 13 for heat exchange, and then enters the sintering machine 10 for combustion under the action of the hot air fan 29.

[0020] This system achieves full waste heat recovery from the sintering machine 10 and the annular cooler 11. By introducing the high-temperature flue gas from the first and second stages of the annular cooler 11 into the medium-pressure superheater and the medium-pressure evaporator respectively, and then mixing the flue gas from the third, fourth, and fifth stages in series, the system exchanges heat through the hot water heat exchanger 13. At the same time, the system utilizes the flue gas from the main flue of the sintering machine 10 to supplement the medium-pressure steam, thus achieving comprehensive recovery of all waste heat sources and significantly improving the waste heat utilization rate.

[0021] This system employs a dual-pressure system to improve power generation efficiency. The system consists of two steam systems: a medium-pressure system and a low-pressure system. The medium-pressure steam is used for the main power generation of turbine 16, while the low-pressure steam is prioritized for production use, with the remainder supplementing the turbine 16's steam inlet for collaborative power generation. This achieves cascaded utilization of steam, increasing power generation efficiency by more than 8% compared to a single-pressure system, while simultaneously meeting production gas requirements and improving the system's overall energy utilization efficiency.

[0022] This system achieves efficient recycling of flue gas. The high-temperature flue gas from the first and second stages of the annular cooler 11 is mixed and heat-exchanged in the waste heat boiler 12, and then sent back to the inlet of the annular cooler 11 by the circulating fan 28. The flue gas from the third, fourth, and fifth stages is mixed in series and then sent into the sintering machine 10 after heat exchange in the hot water heat exchanger 13, forming a complete internal flue gas circulation system. This reduces flue gas emissions and environmental pollution, while the recycling of flue gas improves the efficiency of thermal energy utilization.

[0023] This system establishes a comprehensive energy cascade utilization system. The waste heat boiler 12 is equipped with a low-temperature economizer, a low-pressure evaporator, a low-pressure superheater, a medium-pressure evaporator, and a medium-pressure superheater, arranged sequentially from bottom to top. This, combined with the condensate being heated stage by stage through the low-temperature economizer, hot water heat exchanger 13, and deaerator 15, achieves a rational matching and cascade utilization of waste heat at different temperatures and grades. High-grade heat energy is used for high-grade needs, and low-grade heat energy is used for low-grade needs, avoiding energy grade degradation and loss.

[0024] This system makes full use of the waste heat from the flue gas in the sintering machine's No. 10 flue. The flue gas outlet of the sintering machine's No. 10 flue is connected to the medium-pressure steam pipeline, using the heat carried by the flue gas to supplement and superheat the medium-pressure steam, further increasing the output and parameters of the medium-pressure steam, and increasing the work capacity of the steam turbine No. 16. Compared with systems that do not utilize the flue gas from the sintering machine No. 10, this system can increase power generation by more than 10%, achieving comprehensive recovery and efficient utilization of the waste heat from the sintering machine No. 10 and the annular cooler No. 11, significantly improving the overall waste heat utilization rate and power generation efficiency of the system.

[0025] In an embodiment of the present invention, the exhaust port of the steam turbine 16 is connected to the condenser 23, and the condensate discharged from the condenser 23 is sent to the inlet of the low-temperature economizer by the water pump 24. The outlet of the low-temperature economizer is connected to the inlet of the hot water heat exchanger 13, and the outlet of the hot water heat exchanger 13 is connected to the inlet of the deaerator 15.

[0026] By connecting the steam turbine 16 to the condenser 23, the condensate discharged from the condenser 23 is sent to the low-temperature economizer by the water pump 24 for heating and then enters the heat exchanger for heat exchange. The water after heat exchange enters the deaerator 15.

[0027] In an embodiment of the present invention, the output shaft of the steam turbine 16 is connected to the input end of the speed change clutch 25, the output end of the speed change clutch 25 is connected to one end of the dual-shaft output motor 26, and the other end of the dual-shaft output motor 26 is connected to the sintering main exhaust fan 27.

[0028] The output shaft of the steam turbine 16 is connected to the dual-shaft output motor 26 via the speed change clutch 25. The other end of the dual-shaft output motor 26 drives the sintering main exhaust fan 27, so that the steam turbine 16 can directly drive the sintering main exhaust fan 27 while generating electricity, thereby reducing the power consumption of the motor and lowering the plant power consumption rate.

[0029] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-efficiency power generation system for full waste heat recovery from a sintering machine and an annular cooler, characterized in that, include: Sintering machine, annular cooler, waste heat boiler, hot water heat exchanger, medium-pressure boiler drum, deaerator and steam turbine; The waste heat boiler is equipped with a low-temperature economizer, a low-pressure evaporator, a low-pressure superheater, a medium-pressure evaporator, and a medium-pressure superheater, arranged from bottom to top. The flue gas outlets of the first and second stages of the annular cooler are connected to the medium-pressure superheater and the medium-pressure evaporator, respectively. The flue gas discharged from the first and second stages of the annular cooler is mixed in the waste heat boiler and then sent to the flue gas inlet of the annular cooler by the circulating fan. The flue gas from the third, fourth and fifth stages of the annular cooler is mixed in series and then heat-exchanged by a hot water heat exchanger before being sent into the sintering machine by a hot air blower. The medium-pressure boiler drum is located on one side of the waste heat boiler. The medium-pressure saturated steam in the medium-pressure boiler drum enters the medium-pressure superheater through the first exhaust pipe. The superheated medium-pressure steam produced is sent to the steam turbine to generate electricity. A first water outlet pipe and a first gas return pipe are provided between the medium-pressure boiler drum and the medium-pressure evaporator. The flue gas outlet of the sintering machine's main flue is connected to the first exhaust pipe; The deaerator is located on one side of the waste heat boiler. The low-pressure saturated steam discharged from the deaerator enters the low-pressure superheater through the second exhaust pipe, is superheated, and then discharged as low-pressure superheated steam. It is preferentially supplied to the production gas, and the remaining low-pressure superheated steam is added to the steam inlet of the steam turbine to generate electricity. A second water outlet pipe and a second return gas pipe are provided between the deaerator and the low-pressure evaporator.

2. The high-efficiency power generation system for full waste heat recovery of a sintering machine and annular cooler according to claim 1, characterized in that, The turbine's exhaust port is connected to the condenser. The condensate discharged from the condenser is pumped into the inlet of the low-temperature economizer. The outlet of the low-temperature economizer is connected to the inlet of the hot water heat exchanger, and the outlet of the hot water heat exchanger is connected to the inlet of the deaerator.

3. The high-efficiency power generation system for full waste heat recovery of a sintering machine and annular cooler according to claim 1, characterized in that, The output shaft of the steam turbine is connected to the input end of the speed-changing clutch, the output end of the speed-changing clutch is connected to one end of the dual-shaft output motor, and the other end of the dual-shaft output motor is connected to the sintering main exhaust fan.

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