CN103234364B - Device with griddle and process for generating power by efficiently recycling sinter waste heat - Google Patents

Abstract

A device with a griddle and a process for generating power by recycling sinter waste heat relate to the technical field of waste heat power generation. The device comprises a sinter cooling system, a waste heat power generation system and a smoke system. The sinter cooling system and the waste heat circulation power generation system are connected through the smoke system to form a loop. The process includes 1) sinter cooling, 2) the smoke system and 3) waste heat power generation. The device and the technological process for waste heat power generation have the advantages of completely utilizing waste heat discharged in the sinter cooling process, obviously increasing power generation quantity, obviously reducing system self power utilization rate and being remarkable in energy-saving effect.

Description

A kind of sinter waste heat recovery power generation equipment and process with ore screen

technical field

The invention belongs to the technical field of waste heat power generation, and in particular relates to a sinter waste heat efficient recovery power generation equipment and process with a sieve.

Background technique

The iron and steel industry is an important basic industry of the national economy, and its energy consumption accounts for about 15% of the total industrial energy consumption in the country. It is a key industry for energy conservation and emission reduction. In the process of iron and steel production, the energy consumption of the sintering process is relatively high, generally accounting for 10-12% of the total energy consumption of iron and steel enterprises, second only to the ironmaking process, and has a huge potential for energy saving. In the sintering process, the hot sintered ore discharged from the sintering machine must be cooled to about 150°C before entering the next process. At present, the sinter is cooled by using the air medium through the belt cooler or the ring cooler. During the cooling process of the sinter, the heat energy becomes the sensible heat of the waste gas, and the temperature of the waste gas is between 100-400°C. In the total energy consumption of the sintering process, nearly 50% of the heat energy is discharged in the form of sensible heat of the flue gas of the sintering machine and exhaust gas of the cooling machine. If it is not utilized, a large amount of waste heat resources will be wasted in vain.

At present, there are mainly two kinds of treatment methods for waste heat of exhaust gas as mentioned above:

One is direct discharge. The flue gas of the sintering machine and the exhaust gas of the cooling machine are directly discharged into the atmosphere, and the waste heat is not utilized;

The second is to use waste heat to produce steam for utilization. Use the waste gas at 270-450°C produced by the belt cooler or ring cooler I and II sections to set up a waste heat boiler for heat exchange to generate low-parameter saturated steam or superheated steam, which is used for the production of domestic steam or power generation in steel mills.

The waste heat recovery mainly has the following disadvantages:

1. Insufficient heat exchange. Cross-flow heat exchange between sinter and cooling air on belt cooler or ring cooler, the heat transfer effect is poor; the accumulation height of sinter material layer is low, the heat exchange time between hot sinter and cooling air is short, and the heat exchange is insufficient.

2. Poor sealing and serious air leakage. The quality of the sealing effect directly determines the performance and power generation of the power generation system. Limited by the structure of the belt cooler or the ring cooler, the seal of the belt cooler or the ring cooler is poor, and the air leakage is serious.

3. The waste heat utilization efficiency is low. In the existing sintering machine waste heat power generation system, the air is generally taken from the higher temperature sections I and II of the belt cooler or ring cooler, and the heat exchange end difference between the sintering ore and the cooling air is large, the flue gas temperature is low, and the waste heat utilization efficiency is low , The project investment payback period is long.

4. High power consumption. The sintered ore and the cooling air cross-flow heat exchange, and the cooling air volume required per unit weight of the sintered ore is large. In addition, because the air leakage problem of the system is difficult to solve, it also increases the cooling power consumption.

5. The waste heat parameters fluctuate greatly, which affects the waste heat power generation capacity and the safety and stability of the waste heat power generation system. During the production process of the sintering machine, the short-time shutdown within 30 minutes often occurs, which leads to the frequent shutdown of the waste heat turbine generator set, which seriously affects the power generation and the safety and stability of the waste heat power generation system.

6. Pollution of the environment. A small part of flue gas with a higher temperature from the ring cooler or with cooler enters the dual-pressure waste heat boiler for utilization. Some of the utilized flue gas is recycled, and some are directly discharged, and most of the rest of the unused flue gas is directly discharged. cause environmental pollution.

Contents of the invention

In order to overcome the above-mentioned technical problems, the present invention provides a sinter waste heat recovery power generation equipment and process with an ore screen. The waste heat power generation equipment and process can make full use of the waste heat discharged during the sinter cooling process, and the power generation capacity is obvious. Improvement, the self-consumption rate of the system is significantly reduced, and the energy-saving effect is remarkable.

The technical solution adopted in the present invention is: a sinter waste heat recovery power generation equipment with a sieve, including a sinter cooling system, a waste heat power generation system and a flue gas system;

The sinter cooling system includes a crushing device, a hot ore screening device, a hot ore conveying device, a fine ore conveying device, a cooling furnace, a cold ore discharge device and a cold ore conveying device, and the crushing device is arranged at the hot ore outlet of the sintering machine , the outlet of the crushing device is provided with a hot ore screening device, and the lower part of the hot ore screening device is provided with a fine ore conveying device. It is installed on the upper part of the hot ore inlet of the cooling furnace, and the cold ore outlet of the cooling furnace is sequentially connected with a cold ore discharge device and a cold ore conveying device;

The flue gas system includes a blower, a cooling furnace, a primary dust collector, an emergency release valve, a dual-pressure waste heat boiler for waste heat power generation, a secondary dust collector, an induced draft fan, and a chimney. The flue gas outlet of the cooling furnace is connected to the primary dust collector, the dual-pressure waste heat boiler of the waste heat power generation system, the secondary dust collector, the induced draft fan and the chimney through pipelines; an emergency relief valve is installed on the pipeline between the primary dust collector and the dual-pressure waste heat boiler ; There is a connecting pipe between the outlet of the induced draft fan and the inlet of the blower;

The waste heat power generation system includes a dual-pressure waste heat boiler, a steam-enhancing condensing steam turbine, a turbo generator, a condenser, a condensate pump, a seal heater, a low-pressure feed water pump, a main feed water pump, a deaerator, and a cooling tower and circulating water pump, the main steam outlet of the dual-pressure waste heat boiler is connected to the main steam valve of the steam-admission condensing turbine, and the low-pressure steam outlet of the dual-pressure waste heat boiler is respectively connected to the deaerator and the steam-admission port of the steam-admission condensing The steam-type steam turbine is connected to the steam-turbine generator, and the exhaust steam outlet at the tail of the steam-admission condensing turbine is connected to the steam inlet of the condenser; the condenser, the cooling tower connected to it and the circulating water pump constitute a circulating water system for exhaust steam cooling, The condensate outlet of the boiler is connected to the inlet of the condensate pump, the outlet of the condensate pump is connected to the inlet of the steam seal heater, and the outlet of the steam seal heater is connected to the water inlet of the low-temperature economizer of the dual-pressure waste heat boiler through a pipeline, which saves coal at low temperature The outlet of the deaerator is connected to the inlet of the deaerator, the outlet of the deaerator is respectively connected to the inlet of the low-pressure feed water pump and the main feed water pump, the outlet of the low-pressure feed water pump is connected to the water inlet of the low-pressure economizer of the dual-pressure waste heat boiler, and the main feed The outlet of the water pump is connected to the water inlet of the medium-pressure economizer of the dual-pressure waste heat boiler through a pipeline.

The hot ore screening device screens out 0-5mm fine sintered ore.

The hot ore conveying device adopts the mode of continuous conveying of hot ore by means of conveyor heat preservation.

The cooling furnace adopts a closed furnace type to cool the sintered ore.

The dual-pressure waste heat boiler is arranged vertically, and is provided with a main steam device for power generation and a low-pressure steam device for power generation and oxygen removal. The main steam device is equipped with a high-pressure steam drum, and the low-pressure steam device is equipped with a low-pressure steam drum.

The dual-pressure waste heat boiler is equipped with a secondary superheater, a desuperheater, a primary superheater, a medium-pressure evaporator, a low-pressure superheater, a medium-pressure economizer II, a low-pressure evaporator, a medium-pressure Pressure economizer Ⅰ, low pressure economizer and low temperature economizer.

The deaerator is an atmospheric thermal deaerator, and the steam source comes from low-pressure steam produced by a double-pressure waste heat boiler. the

A sinter waste heat recovery power generation process with a sieve, comprising the following steps:

1) Sinter cooling: The hot sinter discharged from the sintering machine enters the cooling furnace through the crushing device, the hot ore screening device, and the hot ore conveying device, and is discharged and transported through the cold ore discharging device and the cold ore conveying device after being cooled in the cooling furnace. Walk;

2) Flue gas system: the cooling furnace is cooled by air. After the air is pressurized by the blower, it enters the cooling furnace to cool the sintered ore. After the second dust removal, the low-temperature flue gas enters the induced draft fan to be pressurized, and then is discharged through the chimney; an emergency relief valve is installed on the pipeline between the primary dust collector and the dual-pressure waste heat boiler, and a connection is provided between the induced draft fan and the blower. Pipeline and regulating valve to realize flue gas circulation;

3) Waste heat power generation: the main steam generated by the dual-pressure waste heat boiler enters the steam-enhancing condensing turbine through the main steam valve, and the low-pressure steam generated by the dual-pressure waste heat boiler enters the steam-enhancing condensing turbine through the steam-enhancing valve, and the two steams jointly promote The steam turbine works, and the steam turbine drives the steam turbine generator to generate electricity. The exhaust steam at the tail of the steam supplement condensing steam turbine is cooled in the condenser by the circulating water system composed of the cooling tower and the circulating water pump, and then becomes condensed water. The condensed water is then passed through the condensed water pump, After being heated by the vapor seal heater, it enters the low-temperature economizer of the dual-pressure waste heat boiler, and then enters the deaerator after heating. After removing the oxygen in the water, a part of the water is pressurized by the main feedwater pump and enters the medium-pressure economizer I to be heated into saturated hot water. Then it enters the medium-pressure steam drum. The saturated water in the steam drum is circulated and heated in the medium-pressure evaporator to become saturated steam. The saturated steam passes through the primary superheater, desuperheater, and secondary superheater to become main steam. The main steam enters the main steam valve of the steam turbine through the pipeline, forming a closed circuit for main steam waste heat power generation; the other part of water is pressurized by the low-pressure feed water pump and enters the low-pressure economizer of the dual-pressure waste heat boiler, and enters the low-pressure steam drum after being heated. The saturated water is heated in the low-pressure evaporator through natural circulation to become saturated steam, and the saturated steam passes through the low-temperature superheater to become low-pressure superheated steam, and then divided into two parts, one part enters the deaerator to heat the feed water for deaeration, and the other part enters the supplementary steam Condensing steam turbines generate power.

Beneficial effects of the present invention:

1. Improve the quality of sinter ore and increase the amount of finished ore. The cooling time of the hot sinter is long, and the heat exchange is more sufficient; the temperature difference of the heat exchange is balanced, avoiding the fragmentation of the hot sinter due to rapid cooling, improving the strength of the sinter, reducing the amount of returned ore, and increasing the amount of finished ore.

2. Increase the flue gas temperature, improve the steam parameters, and improve the efficiency of waste heat power generation. The sinter is continuously conveyed through the conveyor for heat preservation, the temperature of the cooling furnace is increased, the heat exchange between the sinter and the cooling air is countercurrent, the heat exchange is sufficient, the flue gas temperature is increased, and the steam parameters of waste heat power generation are correspondingly increased. Medium temperature and medium pressure steam parameters can be used to improve Power generation efficiency, greater power generation.

3. Reduce the power consumption of the cooling system. The cooling air volume required for furnace cooling is small, which completely solves the problem of air leakage, so the self-consumption of cooling system is greatly reduced.

4. Improve the adaptability and safety of waste heat power generation system. The cooling furnace is designed with a hot sinter storage section, which avoids the fluctuation of waste heat parameters and the shutdown of the steam turbine generator set due to the short-term shutdown of the sintering machine, and improves the adaptability and safety of the waste heat power generation system.

5. Improve the heat exchange efficiency between sinter and cooling air to ensure the cooling effect of sinter. Before the sinter enters the cooling furnace, it first passes through the hot ore screen to remove the sinter below 5mm, so as to ensure the porosity of the sinter in the cooling furnace, reduce the ventilation resistance, and ensure the cooling effect of the sinter.

6. Reduce the discharge of pollutants such as smoke and dust, and improve the environmental quality. The whole system can basically achieve zero leakage, and the gas smoke can be discharged after dust removal by dust removal equipment, so it can greatly reduce pollutant emissions and improve the working environment.

7. Design the emptying system to reduce the impact of waste heat turbine generator set failure on sinter cooling. Since the valves are installed on the exhaust gas pipeline at the inlet and outlet of the dual-pressure waste heat boiler and the exhaust gas pipeline at the outlet of the primary dust removal, the cooling furnace system can operate continuously and stably after emergency decommissioning of the waste heat power generation system to ensure the normal cooling of the sinter.

8. The temperature of the cooling air is easy to adjust to ensure the cooling effect of the sinter. A connecting pipe is set between the induced draft fan and the blower, and by adjusting the air volume from the induced draft fan to the blower, the temperature of the cooling air can be adjusted to ensure the temperature of the cold mine.

9. The steam-enhancing and condensing type steam turbine-turbine-generator unit is adopted, and the parameters can be optimized according to the flue gas temperature, and the steam parameters of the dual-pressure waste heat boiler and the steam turbine can be reasonably determined, so as to select the steam-turbine-turbine-generator unit with matching parameters and improve the efficiency. system efficiency.

10. The boiler feed water adopts thermal deoxygenation, and the water at about 104 ℃ after deoxygenation is directly supplied to the dual-pressure waste heat boiler, which not only ensures that the exhaust gas temperature of the dual-pressure waste heat boiler is about 120 ℃, but also ensures the oxygen index of the boiler feed water.

11. The control system adopts DCS distributed control system to ensure the safe and stable operation of the system.

12. Due to the above-mentioned multiple technologies, a large amount of waste heat released during the sinter cooling process is used to generate electricity, which improves the utilization efficiency of waste heat and has a remarkable energy-saving effect.

13. Utilizing sinter waste heat to generate electricity reduces thermal pollution and production costs of enterprises. Taking the 265M ² sintering machine supporting the construction of waste heat power generation project as an example, it is equivalent to reducing the burning of more than 30,000 tons of standard coal per year and reducing the emission of 100,000 tons of coal into the atmosphere. More than tons of carbon dioxide and other gases are beneficial to environmental protection, and at the same time improve energy utilization efficiency, thereby improving the competitiveness of enterprises;

14. The waste heat power generation device all adopts domestic equipment, and the equipment investment is low. It has good promotion value and good market prospect.

Description of drawings

Fig. 1 is the equipment schematic diagram of the present invention;

Fig. 2 is a partially enlarged view of the dual-pressure waste heat boiler of the present invention.

Marked in the figure: 1. Sintering machine, 2. Crushing device, 3. Hot ore screening device, 4. Hot ore conveying device, 5. Fine ore conveying device, 6. Cooling furnace, 7. Primary dust collector, 8. Emergency relief valve, 9. Dual-pressure waste heat boiler, 10. Steam supplement condensing steam turbine, 11. Steam turbine generator, 12. Cooling tower, 13. Circulating water pump, 4. Condenser, 15. Condensate water pump, 16. Steam seal heater, 17. Low-pressure feed water pump, 18. Main feed water pump, 19. Deaerator, 20. Secondary dust collector, 21. Induced fan, 22. Chimney, 23. Blower, 24. Cold ore discharge Device, 25, cold ore conveying device, 26, medium pressure steam drum, 27, low pressure steam drum.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. As shown in the figure, a sinter waste heat recovery power generation equipment and process with a sieve includes a sinter cooling system, a waste heat power generation system and a flue gas system. The sinter cooling system and waste heat power generation system are connected by the flue gas system to form a circuit;

The sinter cooling system includes crushing device 2, hot ore screening device 3, hot ore conveying device 4, fine ore conveying device 5, cooling furnace 6, cold ore discharge device 24 and cold ore conveying device 25, crushing device 2 Set at the hot ore outlet of the sintering machine 1, the outlet of the crushing device 2 is connected to the inlet of the hot ore screening device 3, the fine ore outlet of the hot ore screening device 3 is connected to the inlet of the fine ore conveying device 5, and the outlet of the hot ore screening device 3 It is connected with the inlet of the hot ore conveying device 4, the outlet of the hot ore conveying device 4 is arranged on the upper part of the hot ore inlet of the cooling furnace 6, and the cold ore outlet of the cooling furnace 6 is sequentially connected with a cold ore discharging device 24 and a cold ore conveying device 25;

The flue gas system includes a blower 23, a cooling furnace 6, a primary dust collector 7, a dual-pressure waste heat boiler 9 of a waste heat power generation system, an emergency relief valve 8, a dual-pressure waste heat boiler 9, a secondary dust collector 20, an induced draft fan 21 and Chimney 22, air outlet of blower 23 communicate with the flue gas inlet of the lower part of cooling furnace 6, and the flue gas outlet of cooling furnace 6 is connected to primary dust collector 7, dual-pressure waste heat boiler 9 of waste heat power generation system, secondary dust collector 20, An emergency release valve 8 is installed on the pipeline between the induced draft fan 21 and the chimney 22, the primary dust collector 7 and the dual-pressure waste heat boiler 9, and a connecting pipeline is installed between the outlet of the induced draft fan 21 and the inlet of the blower 23;

The waste heat power generation system includes a dual-pressure waste heat boiler 9, a steam-enhancing condensing steam turbine 10, a steam turbine generator 11, a cooling tower 12, a circulating water pump 13, a condenser 14, a condensed water pump 15, a seal heater 16, Low-pressure feed water pump 17, main feed water pump 18 and deaerator 19, the main steam outlet of dual-pressure waste heat boiler 9 is connected to steam supplement condensing turbine 10, steam supplement condensing turbine 10 is connected to turbine generator 11, steam supplement condensing The exhaust steam outlet at the tail of the steam turbine 10 is connected to the steam inlet of the condenser 14, and the condenser 14, the cooling tower 12 connected thereto and the circulating water pump 13 constitute a cooling circulating water system for exhaust steam, and the condensed water outlet of the condenser 14 Connect the inlet of the condensate pump 15, the outlet of the condensate pump 15 is connected to the inlet of the seal heater 16, the outlet of the seal heater 16 is connected to the water inlet of the low-temperature economizer of the dual-pressure waste heat boiler 9 through a pipeline, and the outlet of the low-temperature economizer The water outlet is connected to the inlet of the deaerator 19, the outlet of the deaerator 19 is respectively connected to the low-pressure feed water pump 17 and the main feed water pump 18, and the outlet of the low-pressure feed water pump 17 is connected to the water inlet of the low-pressure economizer of the dual-pressure waste heat boiler 9 , the outlet of the main feedwater pump 18 is connected to the water inlet of the medium-pressure economizer of the dual-pressure waste heat boiler 9 through a pipeline.

The hot ore conveying device 4 is conveyed by means of continuous conveying in the hot state of the conveyor.

The hot ore screening device 3 screens out 0-5mm fine sintered ore.

The dual-pressure waste heat boiler 9 is a double-pressure waste heat boiler and is vertically arranged. It is provided with a main steam device for power generation and a low-pressure steam device for deoxidation and power generation. The main steam device is provided with a medium-pressure steam drum 26 and a low-pressure steam The device is provided with a low-pressure steam drum 27.

The dual-pressure waste heat boiler 9 is equipped with a secondary superheater, a desuperheater, a primary superheater, a medium-pressure evaporator, a low-pressure superheater, a medium-pressure economizer II, a low-pressure evaporator, and a medium-pressure economizer Ⅰ. Low pressure economizer and low temperature economizer.

The deaerator 19 is an atmospheric thermal deaerator, and the steam source comes from the low-pressure steam produced by the double-pressure waste heat boiler.

An emergency relief valve 8 is installed on the exhaust gas pipeline at the outlet of the cooling furnace 6, and a control valve is installed on the exhaust gas pipeline at the inlet and outlet of the dual-pressure waste heat boiler 9. Even if the dual-pressure waste heat boiler or power generation system fails, the sinter can still be cooled normally.

A connecting pipeline is arranged between the air blower 23 and the induced draft fan 21 . Part or all of the flue gas can enter the cooling furnace through the connecting pipe to realize the adjustment of the temperature of the cooling air and ensure the cooling effect of the sinter.

A sinter waste heat recovery power generation process with a sieve, comprising the following steps:

1) Sinter cooling: the sinter discharged from the sintering machine 1 at about 700°C passes through the crushing device 2, the hot ore screening device 3, the hot ore conveying device 4, enters the cooling furnace 6, and is cooled by flue gas in the cooling furnace , the cold sintered ore at about 150°C is discharged and transported away through the cold ore discharge device 24 and the cold ore conveying device 25;

2) Flue gas system: the cooling furnace 6 uses flue gas for cooling. After being pressurized by the blower 23, the flue gas enters the cooling furnace 6 to cool the sintered ore. After the cooled flue gas passes through the primary dust collector 7, it enters the double-pressure waste heat boiler 9. Perform heat exchange. After the heat exchange, the low-temperature flue gas at about 120°C passes through the secondary dust collector 20, enters the induced draft fan 21 for pressurization, and then discharges it through the chimney 22. There is a connecting pipe between the induced draft fan 21 and the blower 23 , adjust the flue gas temperature at the inlet of the blower 23;

3) Waste heat power generation: the main steam generated after heat exchange by the dual-pressure waste heat boiler 9 enters the main steam valve of the supplementary steam condensing turbine 10 through the main steam valve, and the low-pressure steam generated by the dual-pressure waste heat boiler 9 enters the supplementary steam condensing valve through the supplementary steam valve. Steam-type steam turbine 10 steam intake valve, the main steam and low-pressure steam jointly drive the steam-enrichment condensing steam turbine 10 to do work, the steam-enrichment condensing turbine 10 drives the turbine generator 11 to generate electricity, and the tail of the steam-enhancement condensing turbine 10 exhausts steam In the condenser 14, after being cooled by the circulating water system composed of the cooling tower 12 and the circulating water pump 13, it becomes condensed water, and the condensed water is heated by the condensed water pump 15 and the steam seal heater 16, and then enters the low-temperature economizer of the dual-pressure waste heat boiler 9 After being heated, it enters the deaerator 19. After removing the oxygen in the water, a part of the water is pressurized by the main feed water pump 18 and enters the medium-pressure economizer. After being heated to saturated hot water, it enters the medium-pressure steam drum 26. The saturated hot water of the steam drum After being circulated and heated in the evaporator, it becomes saturated steam. The saturated steam passes through the primary superheater, desuperheater, and secondary superheater to become main steam. , forming a main steam power generation closed loop; the other part of water is pressurized by the low-pressure feed water pump 17 and enters the low-pressure economizer of the dual-pressure waste heat boiler 9, is heated into saturated hot water and enters the low-pressure steam drum 27, and the saturated water of the steam drum passes through Natural circulation becomes saturated steam after being heated in the evaporator, and the saturated steam passes through the low-pressure superheater to become low-pressure steam, and then is divided into two parts, one part enters the deaerator 19 to heat the feed water for deaeration, and the other part enters the supplementary steam condensing steam turbine 10 works to generate electricity.

Claims (8)

1. A sinter waste heat recovery power generation equipment with a sieve, characterized in that it includes a sinter cooling system, a waste heat power generation system and a flue gas system; The sinter cooling system includes crushing device (2), hot ore screening device (3), hot ore conveying device (4), fine ore conveying device (5), cooling furnace (6), cold ore discharge device ( 24) and cold ore conveying device (25), the crushing device (2) is installed at the hot ore outlet of the sintering machine, the outlet of the crushing device (2) is equipped with a hot ore screening device (3), and the hot ore screening device (3 ) is provided with a fine ore conveying device (5), the outlet of the hot ore screening device (3) is connected to the inlet of the hot ore conveying device (4), and the outlet of the hot ore conveying device (4) is set in the cooling furnace ( 6) On the upper part of the hot ore inlet, the cold ore outlet of the cooling furnace (6) is sequentially connected with a cold ore discharge device (24) and a cold ore conveying device (25); The flue gas system includes a blower (23), a cooling furnace (6), a primary dust collector (7), an emergency relief valve (8), a dual-pressure waste heat boiler (9) for waste heat power generation, and a secondary dust collector (20) , induced draft fan (21), chimney (22), air outlet of blower fan (23) is connected with flue gas pipeline at the inlet of cooling furnace (6), and the flue gas outlet of cooling furnace (6) is connected to primary dust collector (7), Dual-pressure waste heat boiler (9), secondary dust collector (20), induced draft fan (21) and chimney (22); emergency relief valve is installed on the pipeline between primary dust collector (7) and dual-pressure waste heat boiler (9) (8); There is a connecting pipe between the outlet of the induced draft fan (21) and the inlet of the blower (23); The waste heat power generation system includes a dual-pressure waste heat boiler (9), a steam-enhancing condensing steam turbine (10), a steam turbine generator (11), a condenser (14), a condensate pump (15), and a seal heater (16), low-pressure feed water pump (17), main feed water pump (18), deaerator (19), cooling tower (12) and circulating water pump (13), the main steam outlet of the dual-pressure waste heat boiler (9) is connected to make up The main steam valve of the condensing steam turbine (10), and the low-pressure steam outlet of the dual-pressure waste heat boiler (9) are respectively connected to the deaerator (19) and the steam inlet of the condensing steam turbine (10). The steam turbine (10) is connected to the steam turbine generator (11), and the tail exhaust steam outlet of the steam-admission condensing steam turbine (10) is connected to the steam inlet of the condenser (14); the condenser (14) and the cooling tower connected thereto (12) and the circulating water pump (13) constitute the circulating water system for exhaust steam cooling, the condensate outlet of the condenser (14) is connected to the inlet of the condensate pump (15), the outlet of the condensate pump (15) and the seal heater ( 16), the outlet of the steam seal heater (16) is connected to the water inlet of the low-temperature economizer of the dual-pressure waste heat boiler (9) through pipes, and the water outlet of the low-temperature economizer is connected to the inlet of the deaerator (19) connection, the outlet of the deaerator (19) is respectively connected to the inlet of the low-pressure feedwater pump (17) and the main feedwater pump (18), and the outlet of the low-pressure feedwater pump (17) is connected to the inlet of the low-pressure economizer of the dual-pressure waste heat boiler (9). The water port is connected, and the outlet of the main feed water pump (18) is connected to the water inlet of the medium-pressure economizer of the dual-pressure waste heat boiler (9) through a pipeline. 2. The sinter waste heat recovery power generation equipment with sieve according to claim 1, characterized in that: the hot ore screening device (3) screens out 0-5mm fine sinter. 3. The sinter waste heat recovery power generation equipment with sieve according to claim 1, characterized in that: the hot ore conveying device (4) adopts the mode of continuous conveying of hot ore with heat preservation by the conveyor. 4. The sinter waste heat recovery power generation equipment with sieve according to claim 1, characterized in that: the cooling furnace (6) adopts a closed furnace type to cool the sinter. 5. The sinter waste heat recovery power generation equipment with sieve according to claim 1, characterized in that: the dual-pressure waste heat boiler (9) is vertically arranged, and is provided with a main steam device for power generation and A low-pressure steam device used for power generation and oxygen removal. The main steam device is equipped with a high-pressure steam drum, and the low-pressure steam device is equipped with a low-pressure steam drum. 6. The sinter waste heat recovery power generation equipment with sieve according to claim 1, characterized in that: the dual-pressure waste heat boiler (9) is provided with two-stage superheater, reducer Thermostat, primary superheater, medium pressure evaporator, low pressure superheater, medium pressure economizer II, low pressure evaporator, medium pressure economizer I, low pressure economizer and low temperature economizer. 7. The sinter waste heat recovery power generation equipment with sieve according to claim 1, characterized in that: the deaerator (19) is an atmospheric thermal deaerator (19), and the steam source comes from two The low-pressure steam produced by the waste heat boiler (9). 8. The power generation process of a sinter waste heat recovery power generation equipment with a sieve according to claim 1, characterized in that it comprises the following steps: 1) Sinter cooling: the hot sinter discharged from the sintering machine passes through the crushing device (2), the hot ore screening device (3), and the hot ore conveying device (4) into the cooling furnace (6), and in the cooling furnace (6) After internal cooling, it is discharged and transported away through the cold ore discharge device (24) and the cold ore conveying device (25); 2) Flue gas system: the cooling furnace (6) is cooled by air. After being pressurized by the blower (23), the air enters the cooling furnace (6) to cool the sintered ore. The waste heat boiler (9) is used for heat exchange. After the heat exchange, the low-temperature flue gas enters the induced draft fan (21) to be pressurized, and then is discharged through the chimney (22); the primary dust collector (7) and the dual-pressure An emergency relief valve (8) is installed on the pipeline between the waste heat boiler (9), and a connecting pipeline and a regulating valve are installed between the induced draft fan (21) and the blower (23) to realize the flue gas circulation; 3) Waste heat power generation: the main steam generated by the dual-pressure waste heat boiler (9) enters the steam-enhancing condensing turbine (10) through the main steam valve, and the low-pressure steam generated by the dual-pressure waste heat boiler (9) enters the steam-enhancing condensing turbine through the steam-enhancing valve. Steam turbine (10), two streams of steam jointly drive the steam turbine to do work, the steam turbine drives the steam turbine generator (11) to generate electricity, and the exhaust steam at the tail of the supplementary steam condensing steam turbine (10) passes through the cooling tower ( 12) The circulating water system composed of the circulating water pump (13) becomes condensed water after being cooled, and the condensed water enters the low-temperature province of the dual-pressure waste heat boiler (9) after being heated by the condensed water pump (15) and the steam seal heater (16). After being heated, it enters the deaerator (19). After removing the oxygen in the water, part of the water is pressurized by the main feed water pump (18) and enters the medium-pressure economizer I. After being heated to saturated hot water, it enters the medium-pressure steam drum. The saturated water in the steam drum is circulated and heated in the medium-pressure evaporator to become saturated steam, and the saturated steam passes through the primary superheater, desuperheater, and secondary superheater to become main steam, and the main steam enters the main steam of the steam turbine through the pipeline. door, forming a closed circuit for main steam waste heat power generation; the other part of water is pressurized by the low-pressure feed water pump (17) and enters the dual-pressure waste heat boiler (9) low-pressure economizer, and enters the low-pressure steam drum after being heated. After being heated in the low-pressure evaporator through natural circulation, the saturated steam becomes saturated steam, and then the saturated steam passes through the low-temperature superheater to become low-pressure superheated steam, and then it is divided into two parts, one part enters the deaerator (19) to heat the feed water for deaeration, and the other part enters The steam-enhancing condensing steam turbine (10) acts to generate power.