A method and system for efficiently increasing enthalpy power generation using waste heat from sintered ore

Abstract

The present invention discloses a method for generating electricity by increasing enthalpy using waste heat of sintered ore, comprising the following steps: Step S1: After the sintered red ore is discharged from the sintering machine, it enters the reverse heat exchanger for heat exchange to generate low-temperature sintered ore; after the low-temperature sintered ore is discharged from the reverse heat exchanger, it enters the low-temperature section cooler; air enters the low-temperature section cooler and heat-exchanges and cools the low-temperature sintered ore in the low-temperature section cooler to obtain primary heat exchange air; the primary heat exchange air enters the reverse heat exchanger and contacts and exchanges heat with the sintered red ore layer in the reverse heat exchanger. A system for generating electricity by increasing enthalpy using waste heat of sintered ore comprises an enthalpy-increasing boiler, a vertical reverse heat exchanger, a combustion device and a low-temperature section cooler; after the sintered red ore is discharged from the sintering machine, it enters the reverse heat exchanger and moves approximately from top to bottom in the reverse heat exchanger. The method and system can efficiently utilize the sensible heat and waste heat of sintered ore and burn to increase enthalpy, thereby significantly improving the power generation efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of sintered ore waste heat power generation, and in particular to a sintered ore waste heat high-efficiency enthalpy-increasing power generation method and system. Background Art

[0002] The sintering machine is the main equipment in the exhaust sintering process. It is suitable for the sintering operation of large-scale ferrous metallurgical sintering plants. It can sinter concentrate powder and rich ore powder of different compositions and different particle sizes into blocks, and partially eliminate harmful impurities such as sulfur and phosphorus contained in the ore. The sintering process of the sintering machine will also be accompanied by the generation of a large amount of sintering flue gas and sintered red ore. The sintering flue gas contains a high concentration of CO and a certain amount of waste heat that can be used for special power generation. The temperature of the sintered red ore just discharged from the sintering machine can reach above 700℃, so the sintered red ore also contains a large amount of sensible heat. The existing technology usually uses an annular cooler to air-cool the sintered red ore. The annular cooler is usually divided into 5 cooling areas and gas extraction areas according to the hot air temperature. The sintered red ore is discharged from the sintering machine and enters the cooling areas of sections 1, 2, 3, 4 and 5 in turn. The cold air gradually cools the sintered red ore from sections 1 to 5 of the annular cooler until it is cooled to about 150℃. In this process, the temperature of the hot waste gas generated varies between 70-500℃, but the existing technology can only recover and utilize the hot waste gas above 250℃ for power generation, and the power generation efficiency is low. The waste heat power generation capacity per ton of sintered ore is only 15-20kwh, and a large amount of hot waste gas below 250℃ cannot be used for power generation to realize waste heat utilization. The applicant found that the fundamental reason for the low efficiency of existing sintered ore cooling waste heat power generation is that during the sintered ore cooling process, the cooling air and the sintered red ore belong to cross-flow heat exchange, which not only obtains a low overall hot air temperature level, but also a large amount of hot air waste heat below 250℃ cannot enter the waste heat boiler for waste heat recovery due to its low grade, resulting in low water vapor parameters generated by the hot air of the sintered ore cooler in the waste heat boiler, and the sintering ring cooling system can only realize low-temperature and low-pressure parameter power generation, which ultimately leads to low power generation efficiency of the sintering waste heat power generation unit. Therefore, it is urgent to improve the existing sintered ore cooling waste heat power generation technology in order to further improve the utilization rate of sintering waste heat, and ultimately improve the power generation efficiency of the sintering waste heat power generation unit and reduce carbon emission intensity. Summary of the invention

[0003] An object of the present invention is to provide a method for efficiently increasing enthalpy of power generation using waste heat from sintered ore, which can efficiently utilize the sensible waste heat of sintered ore and increase enthalpy through combustion, thereby significantly improving power generation efficiency and reducing carbon emission intensity.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for efficiently increasing enthalpy and generating electricity using waste heat from sintered ore comprises the following steps:

[0006] Step S1: the sintered red ore after sintering is discharged from the sintering machine and enters the reverse heat exchanger for heat exchange to generate low-temperature sintered ore. The low-temperature sintered ore enters the low-temperature section cooler after being discharged from the reverse heat exchanger. Normal temperature air enters the low-temperature section cooler and heat-exchanges and cools the low-temperature sintered ore in the low-temperature section cooler to obtain primary heat exchange air. The primary heat exchange air enters the reverse heat exchanger and contacts and exchanges heat with the sintered red ore material layer in the reverse heat exchanger. The sintered red ore moves roughly from top to bottom in the reverse heat exchanger, and the primary heat exchange air moves roughly from bottom to top in the reverse heat exchanger, so that the primary heat exchange air is heated by the sintered red ore material layer to form secondary heat exchange air, and the sintered red ore is cooled by the primary heat exchange air to form low-temperature sintered ore;

[0007] Step S2: taking the first part of the secondary heat exchange air discharged from the reverse heat exchanger as combustion-supporting air and mixing it with the gas for combustion to generate high-temperature flue gas; taking the second part of the secondary heat exchange air discharged from the reverse heat exchanger as preheating air to preheat the gas, and the preheating air preheats the gas to form tertiary heat exchange air;

[0008] Step S3: the tertiary heat exchange air is exhausted or mixed with the primary heat exchange air and enters the reverse heat exchanger for heat exchange to generate secondary heat exchange air;

[0009] Step S4: The high-temperature flue gas enters the enthalpy-increasing boiler, undergoes heat exchange in the enthalpy-increasing boiler, and is then discharged.

[0010] Preferably, in step S4, the high-temperature flue gas is heat exchanged in the enthalpy increasing boiler so that the enthalpy increasing boiler generates steam and is used for the steam turbine generator. After heat exchange in the enthalpy increasing boiler, the high-temperature flue gas is discharged into the condensate preheater and is discharged after heat exchange again in the condensate preheater.

[0011] Preferably, in step S2, the third part of the secondary heat exchange air discharged from the reverse heat exchanger is taken as external hot air and discharged into the external heating surface of the enthalpy increasing boiler; in step S4, the high-temperature flue gas is first heat exchanged through the heating surface of the enthalpy increasing boiler after heat exchange in the enthalpy increasing boiler and then discharged into the condensate preheater; the exhaust steam generated by the steam turbine power generation is condensed through the condenser to form condensate, the condensate is preliminarily preheated through the condensate preheater and then deoxygenated through the deaerator to generate deoxygenated water, the deoxygenated water is pressurized by the feed water pump and then enters the external heating surface of the enthalpy increasing boiler for heat exchange in the first path, and enters the heating surface of the enthalpy increasing boiler for heat exchange in the second path and is mixed with the deoxygenated water in the first path and enters the enthalpy increasing boiler.

[0012] Preferably, in step S2, the third part of the secondary heat exchange air discharged from the reverse heat exchanger is used as external hot air and is mixed with the primary heat exchange air after heat exchange at the external heating surface of the enthalpy increase boiler and enters the reverse heat exchanger for heat exchange to generate secondary heat exchange air.

[0013] Further preferably, in the step S2, the first part of the secondary heat exchange air discharged from the reverse heat exchanger first passes through the GGH heat exchanger and the GGH booster fan and then is mixed with the fuel gas as combustion-supporting air to burn and generate high-temperature flue gas; in the step S1, the primary heat exchange air enters the reverse heat exchanger from the lower part of the vertical reverse heat exchanger and is discharged from the upper part of the reverse heat exchanger, and the sintered red ore layer enters the reverse heat exchanger from the upper part of the reverse heat exchanger and is discharged from the lower part of the reverse heat exchanger to form low-temperature sintered ore; in the step S4, the high-temperature flue gas is discharged after heat exchange in the enthalpy increase boiler, heat exchange in the condensate preheater and purification in the flue gas purifier.

[0014] Another object of the present invention is to provide a power generation system for implementing the above method, which specifically adopts the following scheme:

[0015] A sintering waste heat high-efficiency enthalpy-increasing power generation system includes an enthalpy-increasing boiler, a vertical reverse heat exchanger, a combustion device and a low-temperature section cooler. The sintered red ore after sintering is discharged from the sintering machine and enters the reverse heat exchanger and moves roughly from top to bottom in the reverse heat exchanger. The sintered red ore forms low-temperature sintered ore after heat exchange in the reverse heat exchanger and enters the low-temperature section cooler. Air enters the low-temperature section cooler and heat-exchanges and cools the low-temperature sintered ore in the low-temperature section cooler to obtain primary heat exchange air. The primary heat exchange air is collected in the low-temperature section. After being collected by the hood, it enters the reverse heat exchanger through the main flue and contacts and exchanges heat with the sintered red ore layer in the reverse heat exchanger. The sintered red ore moves roughly from top to bottom in the reverse heat exchanger, and the primary heat exchange air moves roughly from bottom to top in the reverse heat exchanger. The primary heat exchange air exchanges heat with the sintered red ore layer to form secondary heat exchange air. The sintered red ore is cooled by the primary heat exchange air to generate low-temperature sintered ore. The combustion device includes a combustion pipeline and a burner. The first part of the secondary heat exchange air discharged from the reverse heat exchanger The fuel gas discharged from the combustion pipeline through the first branch pipe as combustion-supporting air is mixed in the furnace of the heat-increasing boiler and burned in the burner to generate high-temperature flue gas; the second part of the secondary heat exchange air discharged from the reverse heat exchanger is used as preheating air to enter the gas preheater through the second branch pipe to preheat the fuel gas, and the high-temperature flue gas is purified and discharged by the flue gas purifier after heat exchange in the heat-increasing boiler; the heat-increasing boiler is connected to the steam turbine, and the steam generated by the heat-increasing boiler is used for steam turbine power generation; the steam turbine is connected to the condenser, and the condenser is preheated by the condensate preheater It is connected to the deaerator, and the deaerator is connected to the enthalpy increasing boiler. The exhaust steam generated by the steam turbine power generation is condensed by the condenser to form condensed water. The condensed water is preheated by the condensate preheater and then deoxygenated by the deaerator to generate deoxygenated water. The deoxygenated water is pressurized by the feed water pump and then enters the enthalpy increasing boiler. The gas preheater is also connected to the main flue through the first return pipeline. After the preheated air preheats the gas, it flows into the main flue through the first return pipeline and is mixed with the primary heat exchange air in the main flue and then enters the reverse heat exchanger for heat exchange to generate secondary heat exchange air.

[0016] Preferably, it also includes an external heating surface of the enthalpy increasing boiler and a heating surface of the enthalpy increasing boiler. After the high-temperature flue gas is heat-exchanged in the enthalpy increasing boiler, it is first heat-exchanged through the heating surface of the enthalpy increasing boiler and then discharged into the condensate preheater. The external heating surface of the enthalpy increasing boiler is connected to the reverse heat exchanger through a third branch pipe. The third part of the secondary heat exchange air discharged from the reverse heat exchanger is discharged into the external heating surface of the enthalpy increasing boiler through the third branch pipe as the external hot air for heat exchange. The external heating surface of the enthalpy increasing boiler is connected to the main flue through a second return pipe. After the external hot air is heat-exchanged in the external heating surface of the enthalpy increasing boiler, it flows into the main flue through the second return pipe and mixes with the primary heat exchange air in the main flue. Then they enter the reverse heat exchanger for heat exchange to generate secondary heat exchange air; the deaerator is connected with the first branch pipe and the second branch pipe respectively, and the deoxygenated water generated by the deaerator enters the external heating surface of the enthalpy increasing boiler through the first branch pipe for heat exchange in the first way, and enters the heating surface of the enthalpy increasing boiler through the second branch pipe for heat exchange in the second way. The first branch pipe and the second branch pipe are also connected with the enthalpy increasing boiler, so that the deoxygenated water generated by the deaerator enters the external heating surface of the enthalpy increasing boiler through the first branch pipe for heat exchange in the other way through the second branch pipe for heat exchange in the heating surface of the enthalpy increasing boiler and then mixes with the water after passing through the external heating surface of the enthalpy increasing boiler in the first way and enters the front heating surface of the enthalpy increasing boiler.

[0017] Further preferably, it also includes a GGH heat exchanger, a GGH pressure fan, a first blower, a second blower, a chimney and a purifier, the primary heat exchange air enters the reverse heat exchanger from the lower part of the reverse heat exchanger and is discharged from the upper part of the reverse heat exchanger, and the sintered red ore enters the reverse heat exchanger from the upper part of the reverse heat exchanger and is discharged from the lower part of the reverse heat exchanger; the first part of the secondary heat exchange air discharged from the reverse heat exchanger first passes through the GGH heat exchanger and the GGH pressure fan and then is mixed with the fuel gas as combustion air to burn and generate high-temperature flue gas; the first blower accelerates the air from the atmosphere into the low-temperature section cooler, and the second blower accelerates the primary heat exchange air from the main flue into the reverse heat exchanger; the condensate preheater is connected to the chimney through the exhaust pipe and the flue gas purifier, and a smoke exhaust fan is provided on the exhaust pipe.

[0018] In the above technical scheme, the sintered red ore that has been sintered enters the vertical reverse heat exchanger after being unloaded from the sintering machine, moves from top to bottom in the reverse heat exchanger and exchanges heat until low-temperature sintered ore is generated. The low-temperature sintered ore enters the low-temperature section cooler after being unloaded from the reverse heat exchanger. The air enters the low-temperature section cooler and exchanges heat with the low-temperature sintered ore in the low-temperature section cooler to obtain primary heat exchange air, so that the low calorific value sensible heat in the low-temperature sintered ore is replaced into the primary heat exchange air. The primary heat exchange air with the sensible heat of the low-temperature sintered ore serves as the cooling medium for the sintered red ore and is passed into the lower part of the vertical reverse heat exchanger, so that the primary heat exchange air has a movement trend from bottom to top in the reverse heat exchanger, while the sintered red ore has a movement trend from top to bottom in the reverse heat exchanger, so that the convective heat transfer efficiency is higher, and the temperature of the primary heat exchange air gradually accumulates and increases during the movement from bottom to top in the reverse heat exchanger, while the temperature of the sintered red ore gradually decreases from top to bottom in the reverse heat exchanger, so that the primary heat exchange air can be raised to a higher temperature. Compared with the previous air-cooled ring cooler, the primary heat exchange air further utilizes the sensible heat of the low-temperature sintered ore, so its initial temperature is higher and it gradually flows upward from the low-temperature part of the sintered red ore to the high-temperature part. Therefore, the primary heat exchange air has a higher temperature when it moves to the upper part of the reverse heat exchanger, and can even be stabilized at above 550°C. Therefore, compared with the air-cooled method of the ring cooler, the heat utilization rate of the sintered red ore is higher. A part of the secondary heat exchange air with gradually accumulated temperature is mixed with the gas as combustion air and burned to increase enthalpy to generate higher temperature high-temperature flue gas, while further increasing and ensuring the temperature and flow of the high-temperature flue gas entering the enthalpy-increasing boiler, so that the enthalpy-increasing boiler can stably and continuously generate high-pressure steam, thereby realizing continuous, stable and efficient power generation of the steam turbine. The second part of the secondary heat exchange air discharged from the reverse heat exchanger is taken as preheating air to preheat the gas, which helps to increase the gas temperature, and then helps to increase the theoretical combustion temperature of the low calorific value gas. The preheated air preheats the gas to form tertiary heat exchange air, which is mixed with the primary heat exchange air and circulated again to enter the reverse heat exchanger for heat exchange to generate secondary heat exchange air, further ensuring the secondary heat exchange air volume, and then ensuring the combustion air volume and gas temperature, and then ensuring that the enthalpy-increasing boiler stably and continuously produces high-pressure steam, thereby improving power generation efficiency. The third part of the secondary heat exchange smoke discharged from the reverse heat exchanger is taken as external hot air and discharged into the external heating surface of the enthalpy-increasing boiler, so that the deoxygenated water is pressurized by the feed water pump and enters the external heating surface of the enthalpy-increasing boiler for heat exchange, and the other way enters the heating surface of the enthalpy-increasing boiler for heat exchange and then mixes with the deoxygenated water passing through the outer cover heating surface before entering the enthalpy-increasing boiler, further increasing the temperature of the deoxygenated water before entering the enthalpy-increasing boiler, thereby assisting in improving the power generation efficiency of the enthalpy-increasing boiler. The third part of secondary heat exchange air discharged from the reverse heat exchanger is used as external hot air, and after heat exchange in the external heating surface of the enthalpy increasing boiler, it is mixed with the primary heat exchange air and enters the reverse heat exchanger for heat exchange to generate secondary heat exchange air, thereby further increasing the amount of secondary heat exchange air, thereby ensuring the amount of combustion air and the temperature of the gas, thereby ensuring that the enthalpy increasing boiler stably and continuously produces high-pressure steam and improves the power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the first implementation method of the sinter waste heat high-efficiency enthalpy-increasing power generation system;

[0020] Figure 2 This is a schematic diagram of the second implementation method of the sintered ore waste heat high-efficiency enthalpy-increasing power generation system.

[0021] Figure Number:

[0022] 1. Sintering machine, 2. Reverse heat exchanger, 3. Low temperature section cooler, 4. Enthalpy increase boiler, 5. Steam turbine, 6. Condensate preheater, 9. Condenser, 61. Deaerator, 62. Feedwater pump, 7. Enthalpy increase boiler external heating surface, 8. Enthalpy increase boiler heating surface, 31. First blower, 41. Combustion pipeline, 42. Burner, 21. First branch, 22. Second branch, 23. Third In charge, 34. Second blower, 43. Gas preheater, 44. Purifier, 45. First return pipeline, 32. Low-temperature section collection hood, 33. Main flue, 46. GGH heat exchanger, 47. GGH booster fan, 48. Second return pipeline, 611. First branch pipe, 612. Second branch pipe, 63. Smoke exhaust pipeline, 44. Purifier, 64. Chimney, 65. Smoke exhaust fan. DETAILED DESCRIPTION

[0023] The following is a specific implementation method, which is described from two aspects: a method for efficiently increasing enthalpy of sintered ore waste heat for power generation and a power generation system for implementing the method. Figure 1 , Figure 2 As shown, the sintering waste heat high-efficiency enthalpy-increasing power generation method comprises the following steps:

[0024] Step S1: The sintered red ore (about 700°C) is discharged from the sintering machine 1 and enters the vertical reverse heat exchanger 2 for heat exchange to generate low-temperature sintered ore (about 150°C). The low-temperature sintered ore is discharged from the reverse heat exchanger 2 and enters the low-temperature section cooler 3. The air enters the low-temperature section cooler 3 and heat-exchanges and cools the low-temperature sintered ore in the low-temperature section cooler 3 to obtain primary heat exchange air, so that the low-value sensible heat in the low-temperature sintered ore is transferred to the primary heat exchange air. The primary heat exchange air enters the reverse heat exchanger 2 and contacts and exchanges heat with the sintered red ore material layer in the reverse heat exchanger 2. The sintered red ore moves roughly from top to bottom in the reverse heat exchanger 2. The primary heat exchange air The gas in the reverse heat exchanger 2 generally tends to move from bottom to top. Specifically, the primary heat exchange air enters the reverse heat exchanger 2 from the lower part of the reverse heat exchanger 2 and is discharged from the upper part of the reverse heat exchanger, and the sintered red ore enters the reverse heat exchanger from the upper part of the reverse heat exchanger and is discharged from the lower part of the reverse heat exchanger. This reverse flow heat exchange efficiency is higher, and the temperature of the primary heat exchange air gradually accumulates and increases during the movement from bottom to top of the reverse heat exchanger, and the temperature of the sintered red ore gradually decreases from top to bottom in the reverse heat exchanger, so that the primary heat exchange air is heated by the sintered red ore layer to form secondary heat exchange air with a higher temperature, and the sintered red ore is cooled by the primary heat exchange air to form low-temperature sintered ore. Compared with the previous air-cooled ring cooler cooling cycle, the primary heat exchange air carries the sensible heat of the low-temperature sintered ore, so the initial temperature is higher and it gradually flows upward from the low-temperature part of the sintered red ore to the high-temperature part. Therefore, the primary heat exchange air has a higher temperature when it moves to the upper part of the reverse heat exchanger, and can even be stabilized at more than 550°C. Therefore, compared with the air-cooled ring cooler, the utilization rate of waste heat from sintered red ore is higher.

[0025] Step S2: taking the first part of the secondary heat exchange air discharged from the reverse heat exchanger 2 as combustion air to mix with the gas for combustion to increase enthalpy and generate high-temperature flue gas with a higher temperature, further improving and ensuring the temperature and flow of the high-temperature flue gas; taking the second part of the secondary heat exchange air discharged from the reverse heat exchanger as preheating air to preheat the gas, assisting in increasing the gas temperature, and then assisting in increasing the temperature of the high-temperature flue gas, and increasing the theoretical combustion temperature of the low calorific value gas; controlling the gas volume and thus controlling the flow and temperature of the high-temperature flue gas, and the preheating air preheats the gas to form tertiary heat exchange air; the first part of the secondary heat exchange air is preferably first converted into combustion air with a certain pressure and temperature by the GGH heat exchanger and the GGH booster fan, and then mixed with the gas for combustion to generate high-temperature flue gas, ensuring the combustion air flow and gas combustion effect;

[0026] Step S3: The tertiary heat exchange air is mixed with the primary heat exchange air and circulated again to enter the reverse heat exchanger 2 for heat exchange to generate secondary heat exchange air, further ensuring the secondary heat exchange air volume and temperature, and then ensuring the combustion air volume and gas temperature;

[0027] Step S4: The high-temperature flue gas enters the enthalpy-increasing boiler 4, and heat exchange is performed in the enthalpy-increasing boiler so that the enthalpy-increasing boiler generates steam and is used for the steam turbine 5 generator. Since the temperature and flow rate of the high-temperature flue gas entering the enthalpy-increasing boiler 4 are both increased and kept stable, the enthalpy-increasing boiler can stably and continuously generate high-pressure steam, thereby realizing continuous, stable and efficient power generation of the steam turbine. After heat exchange in the enthalpy-increasing boiler 4, the high-temperature flue gas is discharged into the condensate preheater 6, and is purified and discharged after heat exchange again in the condensate preheater 6. In this way, the exhaust steam generated by the steam turbine 5 for power generation is condensed by the condenser 9 to form condensed water, and the condensed water is preliminarily preheated by the condensate preheater 6 and then deoxygenated by the deaerator 61 to generate deoxygenated water. The deoxygenated water is pressurized by the feed water pump 62 and enters the enthalpy-increasing boiler 4, thereby stably and continuously generating high-pressure steam, realizing continuous, stable and efficient power generation of the steam turbine, and the hot exhaust gas from cooling the sintered red ore can be used for steam turbine power generation with greater efficiency, and the power generation capacity of waste heat per ton of sintered ore can be significantly improved.

[0028] In a preferred embodiment, in step S2, the third part of the secondary heat exchange air discharged from the reverse heat exchanger 2 is taken as the external hot air and discharged into the external heating surface 7 of the enthalpy increasing boiler; in step S4, the high-temperature flue gas is firstly heat-exchanged through the heating surface 8 of the enthalpy increasing boiler after heat exchange in the enthalpy increasing boiler and then discharged into the condensate preheater 6; in this way, the exhaust steam generated by the steam turbine 5 for power generation is condensed by the condenser 9 to form condensate, and the condensate is preliminarily preheated by the condensate preheater 6 and then deoxygenated by the deaerator 61 to generate Deoxygenated water, after being pressurized by the feed water pump 62, enters the external heating surface 7 of the enthalpy increasing boiler for heat exchange in the first route, and enters the heating surface 8 of the enthalpy increasing boiler for heat exchange in the second route, and then mixes with the deoxygenated water that passes through the external heating surface 7 of the enthalpy increasing boiler in the first route and enters the enthalpy increasing boiler. This can effectively increase the temperature of the deoxygenated water before entering the enthalpy increasing boiler, thereby ensuring more stable and continuous production of high-pressure steam, thereby assisting in improving the power generation efficiency of the enthalpy increasing boiler, and achieving continuous, stable and efficient power generation of the steam turbine. The third part of the secondary heat exchange air discharged from the reverse heat exchanger 2 is used as external hot air, and after heat exchange in the external heating surface 7 of the enthalpy increasing boiler, it is mixed with the primary heat exchange air and circulated again into the reverse heat exchanger 2 for heat exchange to generate secondary heat exchange air, further increasing the amount of secondary heat exchange air, thereby ensuring the amount of combustion-supporting air and the temperature of the gas, thereby ensuring that the enthalpy increasing boiler stably and continuously produces high-pressure steam and improves the power generation efficiency.

[0029] The sintered ore waste heat high-efficiency enthalpy-increasing power generation system comprises an enthalpy-increasing boiler 4, a vertical reverse heat exchanger 2, a combustion device and a low-temperature section cooler 3. The sintered red ore that has been sintered enters the reverse heat exchanger 2 after being discharged from the sintering machine 1 and moves roughly from top to bottom in the reverse heat exchanger 2. After heat exchange in the reverse heat exchanger 2, the sintered red ore forms a low-temperature sintered ore (about 150°C) and enters the low-temperature section cooler 3 for further cooling to obtain cooled sintered ore. The air is accelerated by the first blower 31 from the atmosphere into the low-temperature section cooler 3 and heat-exchanges and cools the low-temperature sintered ore in the low-temperature section cooler 3 to obtain primary heat-exchange air, so that the low-value sensible heat in the low-temperature sintered ore is transferred to the primary heat-exchange air. The primary heat-exchange air is collected by the low-temperature section collecting hood 32 and then enters the reverse heat exchanger 2 through the main flue 33 and contacts and exchanges heat with the sintered red ore material layer in the reverse heat exchanger 2. The sintered red ore moves roughly from top to bottom in the reverse heat exchanger 2, and the primary heat-exchange air moves roughly from bottom to top in the reverse heat exchanger 2. The primary heat exchange air enters the reverse heat exchanger 2 from the lower part of the reverse heat exchanger 2 and is discharged from the upper part of the reverse heat exchanger, and the sintered red ore enters the reverse heat exchanger from the upper part of the reverse heat exchanger and is discharged from the lower part of the reverse heat exchanger. This reverse flow heat exchange efficiency is higher, and the temperature of the primary heat exchange air gradually accumulates and increases during the movement from bottom to top of the reverse heat exchanger. The temperature of the sintered red ore gradually decreases from top to bottom in the reverse heat exchanger, so that the primary heat exchange air is gradually heated by the sintered red ore layer to form secondary heat exchange air with higher temperature, and the sintered red ore is cooled by the primary heat exchange air to form low-temperature sintered ore. Compared with the previous air-cooled annular cooler cooling cycle, the primary heat exchange air carries the sensible heat of the low-temperature sintered ore, so the initial temperature is higher and it gradually flows upward from the low-temperature part of the sintered red ore to the high-temperature part. Therefore, the primary heat exchange air has a higher temperature when it moves to the upper part of the reverse heat exchanger, and can even be stabilized at above 550°C. Therefore, compared with the annular cooler air cooling method, the secondary heat exchange air temperature obtained in this application is higher. The combustion device includes a combustion pipeline 41 and a burner 42. The first part of the secondary heat exchange air discharged from the reverse heat exchanger 2 is mixed with the gas discharged from the combustion pipeline 41 in the furnace of the enthalpy-increasing boiler through the first branch pipe 21 and burned in the burner 42 to increase the enthalpy and generate a higher temperature high-temperature flue gas, further improving and ensuring the temperature and flow of the high-temperature flue gas; the second part of the secondary heat exchange air discharged from the reverse heat exchanger is used as preheated air through the second branch pipe 22 to enter the gas preheater 43 to preheat the gas, assist in increasing the gas temperature, and then assist in increasing the temperature of the high-temperature flue gas; the gas volume is controlled to control the flow and temperature of the high-temperature flue gas.The high-temperature flue gas enters the enthalpy increasing boiler 4, and is purified by the flue gas purifier 44 and discharged after heat exchange in the enthalpy increasing boiler 4; the enthalpy increasing boiler 4 is connected to the steam turbine 5, and the steam generated by the enthalpy increasing boiler 4 is used for power generation by the steam turbine 5; the steam turbine 5 is connected to the condenser 9, and the condenser 9 is connected to the deaerator 61 through the condensate preheater 6, and the deaerator 61 is connected to the enthalpy increasing boiler 4, so that the exhaust steam generated by the steam turbine 5 for power generation is condensed by the condenser 9 to form condensed water, and the condensed water is preheated by the condensate preheater 6 and deoxygenated by the deaerator 61 to generate deoxygenated water, and the deoxygenated water is pressurized by the feed water pump 62 and enters the enthalpy increasing boiler 4. Since the temperature and flow rate of the high-temperature flue gas entering the enthalpy-increasing boiler 4 are both increased and kept stable, the enthalpy-increasing boiler can stably and continuously generate high-pressure steam, thereby realizing continuous, stable and efficient power generation of the steam turbine. At the same time, the hot exhaust gas from cooling the sintered red ore can be used for steam turbine power generation with greater efficiency, and the waste heat power generation per ton of sintered ore can be significantly improved. The above-mentioned gas preheater 43 is also connected to the main flue 33 via the first return pipe 45, so that the preheated air preheats the gas and then flows into the main flue 33 through the first return pipe 45 and mixes with the primary heat exchange air in the main flue 33 and then circulates into the reverse heat exchanger for heat exchange to generate secondary heat exchange air, further ensuring the secondary heat exchange air volume and temperature, thereby ensuring the combustion air volume and gas temperature, thereby ensuring the stable and continuous generation of high-pressure steam by the enthalpy-increasing boiler. The first part of the secondary heat exchange air discharged from the reverse heat exchanger can be first transformed into combustion air with a certain pressure and temperature by the GGH heat exchanger 46 and the GGH pressure fan 47, and then used as combustion air to mix with the gas for combustion to generate high-temperature flue gas, thereby ensuring the combustion air flow rate and the gas combustion effect. A second blower 34 is provided on the main flue 33, so that the primary heat exchange air can be accelerated from the main flue 33 into the reverse heat exchanger 2.

[0030] In a preferred embodiment, the sintering waste heat high-efficiency enthalpy-increasing power generation system further includes an enthalpy-increasing boiler external heating surface 7 and an enthalpy-increasing boiler heating surface 8. After the high-temperature flue gas is heat-exchanged in the enthalpy-increasing boiler 4, it is first heat-exchanged again on the enthalpy-increasing boiler heating surface 8 and then discharged into the condensate preheater 6. The enthalpy-increasing boiler external heating surface 7 is connected to the reverse heat exchanger 2 via the third branch pipe 23. The third part of the secondary heat exchange air discharged from the reverse heat exchanger 2 is discharged as external hot air via the third branch pipe 23 into the enthalpy-increasing boiler external heating surface 7 for heat exchange. The external heating surface 7 of the enthalpy increasing boiler is connected to the main flue 33 via the second return pipe 48, so that the external hot air flows into the main flue 33 again through the second return pipe 48 after heat exchange at the external heating surface 7 of the enthalpy increasing boiler, and is mixed with the primary heat exchange air in the main flue 33 and then circulated into the reverse heat exchanger 2 for heat exchange to generate secondary heat exchange air, thereby further increasing the amount of secondary heat exchange air, thereby ensuring the amount of combustion air and the temperature of the fuel gas, thereby ensuring that the enthalpy increasing boiler stably and continuously produces high-pressure steam, thereby improving the power generation efficiency. The deaerator 61 is connected to the first branch pipe 611 and the second branch pipe 612 respectively. The deoxygenated water generated by the deaerator 61 enters the enthalpy increasing boiler in two ways. The first way enters the external heating surface 7 of the enthalpy increasing boiler through the first branch pipe 611 for heat exchange, and the second way enters the heating surface 8 of the enthalpy increasing boiler through the second branch pipe 612 for heat exchange. The first branch pipe 611 and the second branch pipe 612 are connected to the enthalpy increasing boiler, so that the deoxygenated water generated by the deaerator 61 enters the external heating surface of the enthalpy increasing boiler through the first branch pipe 611 for heat exchange, and the other way enters the heating surface of the enthalpy increasing boiler through the second branch pipe 612 for heat exchange and then merges into the enthalpy increasing boiler. In this way, the temperature of the deoxygenated water before entering the enthalpy increasing boiler 4 can be effectively improved, thereby ensuring a more stable and continuous generation of higher pressure steam, thereby assisting in improving the power generation efficiency of the enthalpy increasing boiler 4 and realizing continuous, stable and efficient power generation of the steam turbine 5. The condensate preheater 6 is connected to the chimney 64 via the smoke exhaust pipe 63 and the purifier 44. A smoke exhaust fan 65 is provided on the smoke exhaust pipe 63. After the high-temperature flue gas is heat exchanged in the enthalpy increasing boiler 4, it is first heat exchanged on the heating surface 8 of the enthalpy increasing boiler and then discharged into the condensate preheater 6, and then discharged to the atmosphere via the smoke exhaust pipe 63, the purifier 44 and the chimney 64.

[0031] In the above technical scheme, the sintered red ore is discharged from the sintering machine 1 and enters the reverse heat exchanger 2. It moves from top to bottom in the reverse heat exchanger 2. After heat exchange in the reverse heat exchanger 2, the sintered red ore forms low-temperature sintered ore and enters the low-temperature section cooler 3. The air is accelerated by the first blower 31 from the atmosphere to enter the low-temperature section cooler 3 and heat-exchanges and cools the low-temperature sintered ore in the low-temperature section cooler 3 to obtain primary heat exchange air, so that the low-value latent heat in the low-temperature sintered ore is transferred to the primary heat exchange air. The primary heat exchange air is collected by the low-temperature section collecting hood 32 and then passes through the main flue 3. 3 enters the reverse heat exchanger 2 and contacts and exchanges heat with the sintered red ore layer in the reverse heat exchanger 2. The sintered red ore moves roughly from top to bottom in the reverse heat exchanger 2, and the primary heat exchange air moves from bottom to top in the reverse heat exchanger 2, so that the temperature of the primary heat exchange air gradually accumulates and increases during the movement from bottom to top in the reverse heat exchanger, and the temperature of the sintered red ore gradually decreases from top to bottom in the reverse heat exchanger, so that the primary heat exchange air is gradually heated by the sintered red ore layer to form secondary heat exchange air with higher temperature, and the sintered red ore is cooled by the primary heat exchange air to form low-temperature sintered ore. The first part of the secondary heat exchange air discharged from the reverse heat exchanger 2 is used as combustion air to merge with the gas discharged from the combustion pipeline 41 through the first branch pipe 21 and burn in the burner 42 to increase enthalpy and generate high-temperature flue gas with a higher temperature, further increasing and ensuring the temperature and flow of the high-temperature flue gas; the second part of the secondary heat exchange air discharged from the reverse heat exchanger is used as preheating air to enter the gas preheater 43 through the second branch pipe 22 to preheat the gas, assist in increasing the gas temperature, and then assist in increasing the temperature of the high-temperature flue gas. After preheating the gas, the preheated air flows into the main flue 33 through the first return pipe 45 and mixes with the primary heat exchange air in the main flue 33, and then circulates into the reverse heat exchanger for heat exchange to generate secondary heat exchange air, further ensuring the amount and temperature of the secondary heat exchange air.

[0032] The high-temperature flue gas enters the enthalpy increasing boiler 4 and performs heat exchange in the enthalpy increasing boiler 4; the exhaust steam generated by the steam turbine 5 is condensed by the condenser 9 to form condensed water, which is preheated by the condensed water preheater 6 and deoxygenated by the deaerator 61 to generate deoxygenated water, and the deoxygenated water is pressurized by the feed water pump 62 and enters the enthalpy increasing boiler 4. Alternatively, the third part of the secondary heat exchange air discharged from the reverse heat exchanger 2 is discharged as external hot air through the third branch pipe 23 into the external heating surface 7 of the enthalpy increasing boiler for heat exchange, and the external hot air flows into the main flue 33 again through the second return pipe 48 after heat exchange in the external heating surface 7 of the enthalpy increasing boiler, and is mixed with the primary heat exchange air in the main flue 33 and then circulated into the reverse heat exchanger 2 for heat exchange to generate secondary heat exchange air, further increasing the amount of secondary heat exchange air, thereby ensuring the amount of combustion-supporting air and the temperature of the gas, thereby ensuring that the enthalpy increasing boiler stably and continuously generates high-pressure steam, and improving the power generation efficiency. The deoxygenated water generated by the deaerator 61 enters the enthalpy increasing boiler in two ways. The first way enters the external heating surface 7 of the enthalpy increasing boiler through the first branch pipe 611 for heat exchange, and the second way enters the heating surface 8 of the enthalpy increasing boiler through the second branch pipe 612 for heat exchange and then merges into the enthalpy increasing boiler, effectively increasing the temperature of the deoxygenated water before entering the enthalpy increasing boiler 4, thereby ensuring more stable and continuous production of higher pressure steam, thereby assisting in improving the power generation efficiency of the enthalpy increasing boiler 4 and achieving continuous, stable and efficient power generation of the steam turbine 5. After heat exchange in the enthalpy increasing boiler 4, the high-temperature flue gas first exchanges heat on the heating surface 8 of the enthalpy increasing boiler and then is discharged into the condensate preheater 6, and then discharged to the atmosphere through the exhaust pipe 63, the flue gas purifier 43, and the chimney 64. Since the low calorific value latent heat and high calorific value sensible heat in the sintered ore are accumulated in the high-temperature flue gas, and the low-value sensible heat after the preheated air and the external hot air heat exchange is also recycled for calorific value accumulation and combustion enthalpy increase, the temperature and flow rate of the high-temperature flue gas entering the enthalpy increase boiler 4 are greatly improved and can be kept stable. Therefore, the enthalpy increase boiler can stably and continuously generate high-pressure steam and then realize the continuous, stable and efficient power generation of the steam turbine, thereby reducing the carbon emission intensity. This sintered ore waste heat high-efficiency enthalpy increase power generation system can increase the power generation efficiency to 14%-19%, and the waste heat power generation per ton of sintered ore is increased to 19-26kwh.

[0033] This embodiment is only an illustration of the concept and implementation of the present invention, and does not limit it. Under the concept of the present invention, technical solutions that have not been substantially changed are still within the scope of protection.

Claims

1. A method for efficiently increasing enthalpy and generating electricity using waste heat from sintered ore, characterized in that The steps include: Step S1: the sintered red ore enters the reverse heat exchanger for heat exchange to generate low-temperature sintered ore. The low-temperature sintered ore is discharged from the reverse heat exchanger and enters the low-temperature section cooler. The air enters the low-temperature section cooler and heat-exchanges and cools the low-temperature sintered ore in the low-temperature section cooler to obtain primary heat exchange air. The primary heat exchange air enters the reverse heat exchanger and contacts and exchanges heat with the sintered red ore material layer in the reverse heat exchanger, so that the primary heat exchange air is heated by the sintered red ore material layer to form secondary heat exchange air. Step S2: taking the first part of the secondary heat exchange air discharged from the reverse heat exchanger as combustion-supporting air and mixing it with the gas for combustion to generate high-temperature flue gas; taking the second part of the secondary heat exchange air discharged from the reverse heat exchanger as preheating air to preheat the gas, and the preheating air preheats the gas to form tertiary heat exchange air; Step S3: the tertiary heat exchange air is exhausted or mixed with the primary heat exchange air and enters the reverse heat exchanger for heat exchange to generate secondary heat exchange air; Step S4: the high-temperature flue gas enters the enthalpy-increasing boiler, and is discharged after heat exchange in the enthalpy-increasing boiler; In step S4, the high-temperature flue gas is heat exchanged in the enthalpy increasing boiler so that the enthalpy increasing boiler generates steam and is used for the steam turbine generator. The high-temperature flue gas is discharged into the condensate preheater after heat exchange in the enthalpy increasing boiler, and is discharged after heat exchange again in the condensate preheater; In the step S2, the third part of the secondary heat exchange air discharged from the reverse heat exchanger is taken as the external hot air and discharged into the external heating surface of the enthalpy increasing boiler; in the step S4, the high-temperature flue gas is firstly heat exchanged through the heating surface of the enthalpy increasing boiler after heat exchange in the enthalpy increasing boiler and then discharged into the condensate preheater; the exhaust steam generated by the steam turbine power generation is condensed by the condenser to form condensate, the condensate is preliminarily preheated by the condensate preheater and then deoxygenated by the deaerator to generate deoxygenated water, the deoxygenated water is pressurized by the feed water pump and enters the external heating surface of the enthalpy increasing boiler for heat exchange in the first path, and enters the heating surface of the enthalpy increasing boiler for heat exchange in the second path and is mixed with the deoxygenated water in the first path and enters the enthalpy increasing boiler.

2. The sintering waste heat high-efficiency enthalpy-increasing power generation method according to claim 1, characterized in that: In step S2, the third part of the secondary heat exchange air discharged from the reverse heat exchanger is used as external hot air and is mixed with the primary heat exchange air after heat exchange at the external heating surface of the enthalpy increase boiler and enters the reverse heat exchanger for heat exchange to generate secondary heat exchange air.

3. The sintering waste heat high-efficiency enthalpy-increasing power generation method according to claim 2, characterized in that: In the step S2, the first part of the secondary heat exchange air discharged from the reverse heat exchanger first passes through the GGH heat exchanger and the GGH booster fan and then is mixed with the fuel gas as combustion air to burn and generate high-temperature flue gas; in the step S1, the primary heat exchange air enters the reverse heat exchanger from the lower part of the vertical reverse heat exchanger and is discharged from the upper part of the reverse heat exchanger, and the sintered red ore layer enters the reverse heat exchanger from the upper part of the reverse heat exchanger and is discharged from the lower part of the reverse heat exchanger to form low-temperature sintered ore; in the step S4, the high-temperature flue gas is discharged after heat exchange in the enthalpy increase boiler, heat exchange in the condensate preheater and purification in the flue gas purifier.

4. A sintered ore waste heat high-efficiency enthalpy-increasing power generation system, comprising an enthalpy-increasing boiler, characterized in that: It also includes a vertical reverse heat exchanger, a combustion device and a low-temperature section cooler. The sintered red ore is discharged from the sintering machine and enters the reverse heat exchanger and moves roughly from top to bottom in the reverse heat exchanger. The sintered red ore forms low-temperature sintered ore after heat exchange in the reverse heat exchanger and enters the low-temperature section cooler. Air enters the low-temperature section cooler and heat-exchanges and cools the low-temperature sintered ore in the low-temperature section cooler to obtain primary heat exchange air. The primary heat exchange air is collected by the low-temperature section collection hood and then enters the reverse heat exchanger through the main flue and is The primary heat exchange air contacts and exchanges heat with the sintered red ore layer in the reverse heat exchanger. The sintered red ore moves roughly from top to bottom in the reverse heat exchanger. The primary heat exchange air exchanges heat with the sintered red ore layer to form secondary heat exchange air. The sintered red ore is cooled by the primary heat exchange air to generate low-temperature sintered ore. The combustion device includes a combustion pipeline and a burner. The first part of the secondary heat exchange air discharged from the reverse heat exchanger is used as combustion air through the first The gas discharged from the branch pipe and the combustion pipeline is mixed in the furnace of the enthalpy increasing boiler and burned in the burner to generate high-temperature flue gas; the second part of the secondary heat exchange air discharged from the reverse heat exchanger is used as preheated air to enter the gas preheater through the second branch pipe to preheat the gas, and the high-temperature flue gas is purified and discharged by the flue gas purifier after heat exchange in the enthalpy increasing boiler; the enthalpy increasing boiler is connected to the steam turbine, and the steam generated by the enthalpy increasing boiler is used for steam turbine power generation; the steam turbine is connected to the condenser, and the condenser is connected to the degassing device through the condensate preheater and the degassing device. The deaerator is connected to the enthalpy increasing boiler, the exhaust steam generated by the steam turbine power generation is condensed by the condenser to form condensed water, the condensed water is preheated by the condensate preheater and then deoxygenated by the deaerator to generate deoxygenated water, the deoxygenated water is pressurized by the feed water pump and then enters the enthalpy increasing boiler; the gas preheater is also connected to the main flue through the first return pipeline, the preheated air preheats the gas and then flows into the main flue through the first return pipeline and mixes with the primary heat exchange air in the main flue and then enters the reverse heat exchanger for heat exchange to generate secondary heat exchange air; The enthalpy increasing boiler also includes an external heating surface and an enthalpy increasing boiler heating surface. After the high-temperature flue gas exchanges heat in the enthalpy increasing boiler, it first exchanges heat through the enthalpy increasing boiler heating surface and then is discharged into the condensate preheater. The external heating surface of the enthalpy increasing boiler is connected to the reverse heat exchanger via a third branch pipe. The third part of the secondary heat exchanged air discharged from the reverse heat exchanger is discharged into the external heating surface of the enthalpy increasing boiler via the third branch pipe as external hot air for heat exchange. The external heating surface of the enthalpy increasing boiler is connected to the main flue via a second return pipe. After the external hot air exchanges heat in the external heating surface of the enthalpy increasing boiler, it flows into the main flue through the second return pipe and is mixed with the primary heat exchanged air in the main flue and then returns to the main flue. And enters the reverse heat exchanger for heat exchange to generate secondary heat exchange air; the deaerator is connected with the first branch pipe and the second branch pipe respectively, and the deoxygenated water generated by the deaerator enters the external heating surface of the enthalpy increasing boiler through the first branch pipe for heat exchange in the first path, and enters the heating surface of the enthalpy increasing boiler through the second branch pipe for heat exchange in the second path. The first branch pipe and the second branch pipe are also connected with the enthalpy increasing boiler, so that the deoxygenated water generated by the deaerator enters the external heating surface of the enthalpy increasing boiler through the first branch pipe for heat exchange in the other path through the second branch pipe for heat exchange in the heating surface of the enthalpy increasing boiler and then mixes with the water in the first path after passing through the external heating surface of the enthalpy increasing boiler and enters the front heating surface of the enthalpy increasing boiler.

5. The sintered ore waste heat high-efficiency enthalpy-increasing power generation system according to claim 4, characterized in that: It also includes a GGH heat exchanger, a GGH booster fan, a first blower, a second blower, a chimney and a purifier. The primary heat exchange air enters the reverse heat exchanger from the lower part of the reverse heat exchanger and is discharged from the upper part of the reverse heat exchanger, and the sintered red ore enters the reverse heat exchanger from the upper part of the reverse heat exchanger and is discharged from the lower part of the reverse heat exchanger; the first part of the secondary heat exchange air discharged from the reverse heat exchanger first passes through the GGH heat exchanger and the GGH booster fan and then is mixed with the fuel gas as combustion air to burn and generate high-temperature flue gas; the first blower accelerates the air from the atmosphere into the low-temperature section cooler, and the second blower accelerates the primary heat exchange air from the main flue into the reverse heat exchanger; the condensate preheater is connected to the chimney through the exhaust pipe and the flue gas purifier, and a smoke exhaust fan is provided on the exhaust pipe.

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