System and method for upgrading of low and medium temperature waste gas in a ring cooler

Abstract

The application discloses a system and method for upgrading utilization of middle and low temperature waste gas in a circular cooler, wherein the middle and low temperature waste gas in the circular cooler of sintering is sequentially subjected to heat and oxygen supplement treatment, step-by-step heat exchange and selective shunt steam supplement treatment, so as to obtain oxygen-rich hot waste gas and oxygen-rich steam-rich hot waste gas which can be directly used for sintering, and intermediate products such as high-parameter steam and industrial hot water, thereby realizing low-cost and high-efficiency waste heat recovery of the middle and low temperature waste gas in the circular cooler of sintering, and significantly reducing the emission of waste gas; the oxygen-rich hot waste gas and the oxygen-rich steam-rich hot waste gas are returned to the front end material surface and the rear end material surface of sintering respectively to realize oxygen-rich hot air sintering and oxygen-rich steam injection sintering, and the quality indexes of sintered ore products are further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the treatment of sintering ring cooling waste gas, in particular to a system and method for upgrading utilization of medium and low temperature waste gas in ring cooling, and belongs to the technical field of sintering ring cooling waste gas treatment. BACKGROUND

[0002] In the sintering production process, the temperature of the sinter cake can reach 700-800℃ after being unloaded from the sintering machine, and the physical sensible heat resource carried by it is the most important part of the sintering waste heat resource. In the process of using air to cool the sinter, the temperature of the sinter is reduced to below 150℃, and a large amount of hot air is generated. Generally, the cooling waste gas temperature at different parts of the sintering ring cooling machine is different, and the temperature gradually decreases from the material receiving end to the discharge end, which is generally divided into three sections: high temperature zone with temperature higher than 250℃, medium temperature zone with temperature of 150-250℃, and low temperature zone with temperature lower than 150℃.

[0003] In actual production, many enterprises have built sintering waste heat recovery systems to utilize the high-temperature cooling waste gas from the ring cooling machine in the form of waste heat power generation. Due to the low temperature of the medium and low temperature section cooling waste gas, the boiler heat exchange can only produce low parameter steam, and the waste heat utilization efficiency is low and the utilization cost is high. Some enterprises even directly discharge, which not only wastes resources but also pollutes the environment. In addition, some enterprises use part of the flue gas in the ring cooling machine to return to the upper sealing cover of the sintering machine in the form of hot air sintering to improve the heat utilization rate of the ring cooling waste gas, hoping to reduce the sintering fuel consumption and improve the sinter quality while reducing the ring cooling flue gas emission. For example, patent CN108731486A proposes a medium and low temperature waste gas recycling system and method in the ring cooling machine, which sets a smoke hood above the sintering machine and connects it with the smoke hood above the ring cooling machine, and converts the medium and low temperature waste gas of 80-250℃ from the ring cooling machine from being directly discharged into the atmosphere to being directly reused in the bed layer of the sintering machine, thereby replacing the air originally sucked from the surrounding atmosphere for the sintering of raw and auxiliary fuels, to fully utilize the sensible heat in the medium and low temperature waste gas and eliminate the pollution of direct discharge of dust-containing waste gas to the atmosphere. Patent CN106931792B proposes a method and device for comprehensive utilization of ring cooling machine waste gas, which uses the medium temperature waste gas of 150-220℃ for ORC low temperature power generation through heat exchange, and uses the used waste gas for hot air sintering in the sintering process, or mixes it with the ring cooling low temperature cooling waste gas below 150℃ to form waste gas around 100℃, and returns it to the sintering machine trolley for hot air sintering.

[0004] In summary, in the prior art, directly using the medium and low temperature section cooling waste gas for boiler heat exchange can only produce low parameter steam, the waste heat preheating utilization efficiency is low, the utilization cost is high, and returning the medium and low temperature waste gas to the sintering instead of air can utilize the waste heat to some extent from the energy angle, but since the cooling waste gas temperature is much higher than air, the gas volume expansion leads to the oxygen concentration being much lower than air (about 310 mg / L), the oxygen amount drawn into the sintering material layer is reduced, which is not conducive to fuel combustion and affects the sinter production quality, and the waste gas must be cooled to about 100°C before being returned to the sintering, so the waste heat utilization efficiency in the sintering process is low. SUMMARY

[0005] In view of the problems in the prior art that the sintering ring cooling medium and low temperature waste heat recovery and utilization efficiency is low, the cost is high, the temperature must be reduced before being returned to the sintering, and the waste heat utilization efficiency is low, the present application provides a system and method for upgrading and utilizing ring cooling medium and low temperature waste gas, which obtains oxygen-rich hot waste gas and oxygen-rich and steam-rich hot waste gas that can be directly used for sintering, high parameter steam and industrial hot water and other intermediate products by sequentially treating the sintering ring cooling medium and low temperature waste gas through heat and oxygen supplementing, step-by-step heat exchange and selective shunt steam supplementing, thereby realizing low-cost and high-efficiency waste heat recovery of the sintering ring cooling medium and low temperature waste gas, significantly reducing the waste gas emission, and further improving the sinter production and quality indexes.

[0006] To achieve the above technical purposes, the technical solution adopted by the present application is as follows:

[0007] According to the first embodiment of the present application, a system for upgrading and utilizing ring cooling medium and low temperature waste gas is provided.

[0008] A system for upgrading and utilizing ring cooling medium and low temperature waste gas, which comprises a shell and an inner cavity. The shell bottom is provided with a waste gas inlet connected with the inner cavity. The inner cavity is divided into a heat and oxygen supplementing zone, a first heat exchange zone, a second heat exchange zone and a shunt steam supplementing zone in sequence from bottom to top. The ring cooling medium and low temperature waste gas is converted into oxygen-rich hot waste gas and oxygen-rich and steam-rich hot waste gas that can be directly used for sintering process after sequentially passing through the heat and oxygen supplementing zone, the first heat exchange zone, the second heat exchange zone and the shunt steam supplementing zone.

[0009] As a preferred, the system further comprises a sintering machine and a ring cooler. According to the sintering material direction: a front section hood and a rear section hood are sequentially arranged on the sintering machine, and a one section hood, a two section hood and a three section hood are sequentially arranged on the ring cooler. The air outlets of the two section hood and the three section hood are connected with the waste gas inlet through air inlet pipes. The oxygen-rich hot waste gas outlet of the shunt steam supplementing zone is connected with the air inlet of the front section hood through a first circulating gas pipe, and the oxygen-rich and steam-rich hot waste gas outlet of the shunt steam supplementing zone is connected with the air inlet of the rear section hood through a second circulating gas pipe. Preferably, an electric plug valve is arranged in the waste gas inlet.

[0010] As preferred, on the sintering machine: the area covered by the front section hood is the 1 / 10 to 4 / 10 section of the material surface between the sintering ignition point and the sintering end point. The area covered by the rear section hood is the 5 / 10 to 8 / 10 section of the material surface between the sintering ignition point and the sintering end point.

[0011] As preferred, on the circular cooler: the air outlet of the third section hood is connected to the bottom air inlet of the second section of the circular cooler through an air supply pipe, and the air outlet of the second section hood is connected to the exhaust gas inlet through an air inlet pipe.

[0012] As preferred, an oxygen-enriched burner is arranged in the heat and oxygen supplementing area, and a combustible gas pipeline and an oxygen-enriched gas pipeline are connected to the oxygen-enriched burner.

[0013] As preferred, a plurality of oxygen-enriched burners are arranged in the heat and oxygen supplementing area, and a combustible gas pipeline and an oxygen-enriched gas pipeline are independently connected to each oxygen-enriched burner.

[0014] As preferred, in the primary heat exchange area, from bottom to top, a high-parameter steam superheater, a high-parameter steam evaporator, a high-parameter economizer, a deoxygenated evaporator, and a low-parameter economizer are arranged in sequence. Outside the primary heat exchange area, a steam drum, a deoxygenator, a desalted water pipe network, and a steam power generation device are arranged. The front end of the high-parameter steam superheater is connected to the steam power generation device through a pipeline and a valve, and the rear end thereof is connected to the steam drum through a pipeline. The front end and the rear end of the high-parameter steam evaporator are both connected to the steam drum through a pipeline. The front end of the high-parameter economizer is connected to the deoxygenator through a pipeline, and the rear end thereof is connected to the steam drum through a pipeline. The front end and the rear end of the deoxygenated evaporator are both connected to the deoxygenator through a pipeline. The front end of the low-parameter economizer is connected to the desalted water pipe network through a pipeline and a valve, and the rear end thereof is connected to the deoxygenator through a pipeline.

[0015] As preferred, in the secondary heat exchange area, an industrial water heater is arranged, and outside the secondary heat exchange area, an industrial water pipe network and a hot water utilization pipeline are arranged. The front end of the industrial water heater is connected to the industrial water pipe network, and the rear end thereof is connected to the hot water utilization pipeline.

[0016] As preferred, in the shunt steam supplementing area, a water mist spray pipe and a shunt baffle are arranged. The top end of the shunt baffle is connected to the shell and separates the shunt steam supplementing area into two horizontally parallel shunt chambers. The water mist spray pipe is arranged in one of the shunt chambers and has an oxygen-enriched and steam-enriched hot exhaust gas outlet at the top of the shunt chamber, and an oxygen-enriched hot exhaust gas outlet is arranged at the top of the other shunt chamber. Preferably, the top end of the shunt baffle is hinged to the shell, so that the shunt baffle can swing in the horizontal direction to adjust the size of the two shunt chambers.

[0017] As preferred, according to the material flow direction, the ring cooler comprises a ring cooling front section, a ring cooling middle section and a ring cooling rear section, and the bottom air inlet of the ring cooling front section and the bottom air inlet of the ring cooling rear section are respectively independently connected with a cooling fan. The bottom air inlet of the ring cooling middle section is provided with a blower.

[0018] According to the second embodiment of the present application, a method for upgrading the middle and low temperature waste gas of a ring cooler is provided.

[0019] A method for upgrading the middle and low temperature waste gas of a ring cooler or a method for upgrading the middle and low temperature waste gas of a ring cooler by using the system according to the first embodiment, the method comprising:

[0020] 1) mixing and combusting the middle temperature waste gas of a ring cooler and the low temperature waste gas of a ring cooler after heat and oxygen supplement to obtain oxygen-rich high temperature hot flue gas.

[0021] 2) using hot water to perform high temperature heat exchange on the oxygen-rich high temperature reheat flue gas to obtain high parameter steam and oxygen-rich middle temperature hot flue gas.

[0022] 3) using cold water to perform low temperature heat exchange on the oxygen-rich middle temperature flue gas to obtain industrial hot water and oxygen-rich hot waste gas.

[0023] 4) using water mist to perform atomization temperature control and steam adding treatment on part of the oxygen-rich hot waste gas to obtain oxygen-rich steam-rich hot waste gas.

[0024] 5) sending the oxygen-rich hot waste gas and the oxygen-rich steam-rich hot waste gas to the front section and the rear section of a sintering machine respectively for sintering treatment.

[0025] As preferred, the low temperature waste gas of a ring cooler is first circulated as the cooling medium of the ring cooling middle section and is cooled and heat exchanged with the material to obtain the middle temperature waste gas of a ring cooler, and then the middle temperature waste gas of a ring cooler is combusted after heat and oxygen supplement to obtain oxygen-rich high temperature hot flue gas.

[0026] As preferred, in step 1), the temperature of the low temperature waste gas of a ring cooler is lower than 150℃, preferably 110-150℃, more preferably 120-145℃. The temperature of the middle temperature waste gas of a ring cooler is not lower than 150℃, preferably 160-250℃, more preferably 170-240℃. The temperature of the oxygen-rich high temperature hot flue gas is not lower than 400℃, preferably 450-600℃, more preferably 500-550℃. The oxygen concentration of the oxygen-rich high temperature hot flue gas is not lower than 140mg / L, preferably 160-300mg / L, more preferably 180-260mg / L.

[0027] As preferred, in step 2), the pressure of the high-parameter steam is not less than 1.5 MPa, preferably 1.8-3 MPa, more preferably 2-2.5 MPa. The temperature of the high-parameter steam is not less than 350℃, preferably 380-500℃, more preferably 400-480℃. The temperature of the oxygen-enriched medium-temperature hot flue gas is not higher than 200℃, preferably 160-190℃, more preferably 170-180℃.

[0028] As preferred, in step 3), the temperature of the oxygen-enriched hot exhaust gas is not higher than 160℃, preferably 130-155℃, more preferably 135-150℃. The oxygen concentration of the oxygen-enriched hot exhaust gas is not less than 310 mg / L, preferably 320-400 mg / L, more preferably 330-380 mg / L.

[0029] As preferred, in step 4), the temperature of the oxygen-enriched steam-rich hot exhaust gas is not higher than 150℃, preferably 120-145℃, more preferably 130-140℃. The oxygen concentration of the oxygen-enriched steam-rich hot exhaust gas is not less than 320 mg / L, preferably 330-420 mg / L, more preferably 340-400 mg / L. The water vapor concentration of the oxygen-enriched steam-rich hot exhaust gas is not less than 3 wt%, preferably 3.2-5 wt%, more preferably 3.5-4.5 wt%.

[0030] As preferred, in step 4), the oxygen-enriched hot exhaust gas subjected to the atomization temperature-controlling steam-adding treatment accounts for 30-55%, preferably 34-50%, more preferably 38-48% of the total oxygen-enriched hot exhaust gas.

[0031] As preferred, in step 4), the front section of the sintering refers to the section where the first 1 / 10 to the fourth 1 / 10 of the material surface between the sintering ignition point and the sintering end point is located. The rear section of the sintering refers to the section where the fifth 1 / 10 to the eighth 1 / 10 of the material surface between the sintering ignition point and the sintering end point is located.

[0032] In the present application, the height of the shell is 1-300 m, preferably 3-100 m, more preferably 5-50 m; the thickness of the shell is 1-100 cm, preferably 1.5-60 cm, more preferably 3-40 cm. The height of the heat-supplementing and oxygen-supplementing zone, the primary heat-exchanging zone, the secondary heat-exchanging zone, and the shunt steam-supplementing zone in the vertical direction is the same or different.

[0033] In the present application, in order to solve the problems that the sintering ring cooling medium and low temperature waste gas (the ring cooling medium temperature waste gas discharged from the ring cooling medium section and the ring cooling low temperature waste gas discharged from the ring cooling rear section) is difficult to be efficiently utilized in the prior art, the present application sets the waste gas upgrading conversion mechanism with the heat and oxygen supplementing area, the first heat exchange area, the second heat exchange area and the shunt steam supplementing area to supplement oxygen and heat for the ring cooling medium and low temperature waste gas, so as to obtain the oxygen-rich high temperature hot flue gas, which can be directly used for cascade heat exchange to obtain the high parameter hot steam for power generation, and then the shunt steam supplementing treatment is carried out to obtain the oxygen-rich hot waste gas and the oxygen-rich and steam-rich hot waste gas which can be directly used for sintering. That is to say, the present application realizes the efficient utilization of the sintering ring cooling medium and low temperature waste gas through the upgrading conversion mechanism, and also realizes the full quality consumption of the waste gas without excess waste gas emission.

[0034] In the present application, for the high temperature waste gas (the waste gas discharged from the ring cooling front section) of the sintering ring cooling, since the temperature of the high temperature waste gas is relatively high (the air temperature is generally > 250℃), the waste heat utilization can be directly carried out, for example, the high parameter steam is produced by being sent to the preheating boiler and is used for power generation or other metallurgical processes.

[0035] In the present application, the ring cooling low temperature waste gas can be first sent to the air supply pipe as the cooling medium of the ring cooling medium section, and is used for cooling and heat exchange of the material upwards to obtain the ring cooling medium temperature waste gas, and then the ring cooling medium temperature waste gas is sent to the upgrading conversion mechanism for upgrading conversion treatment. That is to say, the low temperature waste gas (temperature < 150℃) discharged from the ring cooling rear section of the ring cooling machine is recycled to replace all or part of the cold air at the cooling air inlet of the ring cooling machine as the cooling air of the ring cooling medium section to cool the sintered material. Through the recycling of the low temperature waste gas, on the one hand, the direct emission of the low temperature waste gas can be completely avoided, and the temperature of the medium temperature waste gas discharged from the ring cooling medium section with the original temperature of 150℃~250℃ is increased to 200℃~300℃, the sensible heat of the material is enriched, and the efficient recovery of the subsequent heat is beneficial; on the other hand, by replacing all or part of the cold air entering the ring cooling medium section, the total amount of the cold air used for cooling of the ring cooling machine is significantly reduced, and then the heat waste gas production is significantly reduced, and finally the heat emitted with the waste gas is also significantly reduced.

[0036] In the present application, although the temperature of the medium-temperature waste gas discharged from the middle section of the ring cooler is increased relative to the waste gas temperature of the conventional process, direct utilization of the medium-temperature waste gas still has the disadvantage of relatively low wind temperature, which makes the waste heat utilization efficiency relatively low (i.e. it is difficult to obtain high-parameter steam by heat exchange with industrial hot water). Therefore, the medium-temperature waste gas is transported into a heat-supplying and oxygen-supplying area for oxygen-rich combustion to realize heat and oxygen supply. The heat-supplying and oxygen-supplying area generally uses low-value combustible gas (such as blast furnace gas, converter gas, etc., which are low-value fuel gas easily obtained in a steel plant area, can realize self-sufficiency, and at the same time make the part of low-value fuel gas also be fully recycled; if necessary, high-value fuel or fuel gas can also be used, but the relative cost will be higher) to be combusted with oxygen-rich gas to supply oxygen-rich gas (oxygen excess). On the one hand, it is beneficial to promote the full combustion of low-value combustible gas, thereby increasing the flue gas temperature, and on the other hand, it can increase the oxygen concentration in the flue gas, i.e. to realize the increase of the oxygen concentration while realizing the heat supply to the sintering ring cooler medium- and low-temperature waste gas. After oxygen-rich combustion, the medium- and low-temperature waste gas is converted into oxygen-rich high-temperature hot flue gas with a temperature of 400°C or higher and an oxygen concentration of 140 mg / L or higher. That is, by oxygen-rich reheating of the medium- and low-temperature waste gas, the medium- and low-temperature waste gas which is difficult to utilize directly is converted into oxygen-rich high-temperature hot flue gas which is easy to utilize directly, and at the same time, efficient recycling of low-value combustible gas in the plant area is realized.

[0037] In the present application, the oxygen-enriched high-temperature hot flue gas is recovered and utilized efficiently by adopting the way of cascade heat exchange (high-temperature heat exchange in the first heat exchange zone and low-temperature heat exchange in the second heat exchange zone), that is, the oxygen-enriched high-temperature hot flue gas is sequentially subjected to high-temperature indirect heat exchange in the first heat exchange zone, low-temperature indirect heat exchange in the second heat exchange zone and temperature control cooling and homogenization by flow splitting and steam injection in the flow splitting and steam injection zone, to produce high-quality steam, industrial hot water and oxygen-enriched hot waste gas and oxygen-enriched steam-rich hot waste gas which can be directly reused for sintering, respectively. Specifically, the oxygen-enriched high-temperature hot flue gas is first subjected to heat exchange with industrial hot water in the first heat exchange zone to produce high-parameter steam with a pressure of ≥1.5 MPa and a temperature of ≥350℃ for power generation, and the temperature of the flue gas at the outlet of the first heat exchange zone is reduced to 160℃-200℃ (oxygen-enriched medium-temperature hot flue gas); then the oxygen-enriched medium-temperature hot flue gas is subjected to heat exchange with normal-temperature water (industrial water) in the second heat exchange zone to produce industrial hot water with a temperature of ≥90℃, which can be reused in the first heat exchange zone for heat exchange with the oxygen-enriched high-temperature hot flue gas to produce high-quality steam or used in the sintering production process, and the temperature of the flue gas at the outlet of the second heat exchange zone is reduced to 130-160℃ (oxygen-enriched hot waste gas); finally, part (for example, 30%-55%) of the oxygen-enriched hot waste gas is subjected to heat exchange and cooling by water atomization and injection in the flow splitting and steam injection zone, to further reduce the temperature of the flue gas and at the same time absorb heat and vaporize the water into steam, so as to produce oxygen-enriched steam-rich hot waste gas with a temperature of 120℃-155℃, an oxygen concentration of 320 mg / L-420 mg / L and a steam concentration of 3%-5%, which can be directly reused for sintering. That is to say, the oxygen-enriched high-temperature hot flue gas is efficiently utilized step by step by the way of cascade heat exchange, and multiple products which can be directly internally circulated are obtained, the oxygen-enriched high-temperature hot flue gas is completely utilized without waste gas emission.

[0038] In the present application, the oxygen-enriched hot waste gas and the oxygen-enriched steam-rich hot waste gas are respectively sent to the front and rear sections of the sintering machine through the circulating gas pipes to replace the normal-temperature air and enter the sintering bed to promote the sintering reaction. The front section of the sintering machine refers to the section where the first 1 / 10 to the fourth 1 / 10 of the material surface between the sintering ignition point and the sintering end point is located, and the rear section of the sintering machine refers to the section where the fifth 1 / 10 to the eighth 1 / 10 of the material surface between the sintering ignition point and the sintering end point is located. The oxygen-enriched hot waste gas is directly returned to the material surface of the front section of the sintering machine for hot air sintering, to improve the upper limit of the hot air temperature and realize oxygen-enriched sintering, optimize the sintering reaction process of the front and middle sections of the sintering machine and improve the production quality index of the sinter; and the oxygen-enriched steam-rich hot waste gas is directly returned to the material surface of the rear section of the sintering machine for oxygen-enriched steam injection sintering, to optimize the sintering reaction process of the middle and rear sections of the sintering machine and improve the production quality of the sinter.

[0039] In the present application, an oxygen-enriched burner is arranged in the heat and oxygen supplementing zone to increase the temperature and oxygen concentration of the medium and low-temperature waste gas in the circular cooler, which can be an independent heat supplementing burner and oxygen supplementing nozzle or an oxygen-enriched combustion burner; the upper end of the heat and oxygen supplementing zone is in communication with the lower end of the first heat exchange zone.

[0040] In the application, in the primary heat exchange zone, from bottom to top, there are high parameter steam superheater, high parameter steam evaporator, high parameter economizer, deaerating evaporator and low parameter economizer, outside of which there are steam drum, deaerator, desalted water pipe network and steam power generation device, the oxygen-enriched high-temperature hot flue gas from the heat and oxygen supplement zone is indirectly exchanged with the industrial hot water sent into the primary heat exchange zone, the industrial hot water absorbs the heat carried by the oxygen-enriched high-temperature hot flue gas and is converted into high parameter steam to generate power; the oxygen-enriched high-temperature hot flue gas is converted into oxygen-enriched medium-temperature hot flue gas and enters the secondary heat exchange zone upward.

[0041] In the application, in the secondary heat exchange zone, there is an industrial water heater, which is connected with the industrial water pipe network arranged outside. The industrial water pipe network sends industrial cold water (ambient temperature) into the industrial water heater to be indirectly exchanged with the oxygen-enriched medium-temperature hot flue gas from the primary heat exchange zone, the industrial cold water absorbs heat to generate industrial hot water and supply the primary heat exchange zone and the sintering production process; the oxygen-enriched medium-temperature hot flue gas is cooled by heat exchange and is converted into oxygen-enriched hot waste gas and enters the shunt steam supplement zone upward.

[0042] In the application, in the shunt steam supplement zone, there are water mist spray pipes and shunt baffles, the top end of the shunt baffle is connected with the shell and divides the shunt steam supplement zone into two shunt chambers parallel in the horizontal direction, the shunt baffle can swing between the two shunt chambers to adjust the amount of oxygen-enriched hot waste gas from the secondary heat exchange zone entering the two shunt chambers (for example, the ratio of the left shunt chamber to the right shunt chamber is 30-55%:45-70%). In one of the shunt chambers (for example, the left shunt chamber in the application), there are water mist spray pipes for spraying water mist into the oxygen-enriched hot waste gas entering the shunt chamber, which reduces the temperature of the waste gas and increases the concentration of water vapor in the waste gas, thereby obtaining oxygen-enriched and steam-rich hot waste gas that can be directly reused for sintering. Figure 1

[0043] ​In the present application, the system and method of the present application adopts technical means such as comprehensive sintering ring cooling low-temperature waste gas cascade utilization, medium-temperature waste gas synchronous heat and oxygen supplementing upgrading, and gradient heat exchange steam enrichment, eliminates direct discharge of low-temperature waste gas, and then adopts low-value coal gas combustion heat supplementing and oxygen supplementing or oxygen-rich combustion in a steel plant area to increase the temperature of medium-temperature and low-temperature waste gas to meet the production requirement of high-parameter steam and significantly increase the oxygen content in the waste gas. After heat exchange to produce high-quality steam and industrial hot water, the selective shunt water spray form is adopted to further control the flue gas temperature, and the purpose of containing a certain amount of water vapor in the waste gas is achieved. By adopting the above technical measures, first, the waste heat recovery of sintering ring cooling medium-temperature and low-temperature waste gas is changed from direct discharge or low-parameter steam recovery to high-parameter steam recovery, and the quality and efficiency of waste heat recovery are improved; second, oxygen and steam are supplemented to the medium-temperature and low-temperature waste gas while heat is supplemented, the oxygen concentration in the waste gas returned to the sintering finally is increased (≥oxygen concentration in air at room temperature 310 mg / L), the oxygen content of the waste gas entering the sintering when the temperature is >120℃ can still meet the sintering reaction requirement, the negative influence of oxygen dilution at high temperature on the sintering process is eliminated, and the utilization rate of waste heat of the sintering process to the waste gas is improved; third, the oxygen-rich hot waste gas and the oxygen-rich and steam-rich hot waste gas are selectively returned to the waste gas of the front and rear material surfaces of the sintering to realize oxygen-rich hot blast sintering and oxygen-rich steam injection sintering, compared with ordinary air, the oxygen-rich hot waste gas contains excess oxygen and part of steam, the improvement effects of the existing “oxygen-rich sintering technology” and “material surface steam injection technology” on the sintering are superimposed, and when the sintering is performed by using the waste gas to replace air, the sintered ore production quality index can be significantly improved, and the pollutant emission can be reduced.

[0044] Compared with the prior art, the beneficial technical effects of the present application are as follows:

[0045] 1: The system and method provided by the present application change the waste heat recovery of sintering ring cooling medium-temperature and low-temperature waste gas from direct discharge or low-parameter steam recovery to high-parameter steam recovery, realize waste gas zero discharge, and significantly improve the quality and efficiency of waste heat recovery; at the same time, oxygen is supplemented to the medium-temperature and low-temperature waste gas while heat is supplemented, the oxygen concentration in the waste gas returned to the sintering finally is increased, the oxygen content of the waste gas entering the sintering material layer when the temperature is >120℃ can still meet the reaction requirement, the negative influence of oxygen dilution at high temperature on the sintering process is eliminated, and the utilization rate of waste heat of the sintering process to the waste gas is improved; in addition, oxygen-rich hot waste gas and oxygen-rich and steam-rich hot waste gas can be respectively produced, and the oxygen-rich hot blast sintering and oxygen-rich steam injection sintering are respectively performed on the front material surface and the rear material surface of the sintering to improve the sintered ore production quality and reduce the pollutant emission.

[0046] 2: The system and method provided by the present application integrate heat supplementing, oxygen enrichment, temperature control, steam injection and other units, comprehensively adopt the positive effects of technical means such as sintering ring cooling low-temperature waste gas cascade utilization, medium-temperature waste gas synchronous heat and oxygen supplementing upgrading, and gradient heat exchange steam enrichment, greatly improve the waste heat utilization efficiency of the medium-temperature and low-temperature waste gas of the ring cooler, and reduce the waste gas emission. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 Structure diagram of the system for upgrading the medium and low temperature exhaust gas of the ring cooler according to the present application.

[0048] Figure 2 Structure diagram of the system having a sintering machine and a ring cooler according to the present application.

[0049] Figure 3 Flow diagram of the method for upgrading the medium and low temperature exhaust gas of the ring cooler according to the present application.

[0050] The figure legend: 1: exhaust gas inlet; 101: electric plug-in valve; 2: heat and oxygen supplement area; 201: oxygen-enriched burner; 202: combustible gas pipeline; 203: oxygen-enriched gas pipeline; 3: primary heat exchange area; 301: high-parameter steam superheater; 302: high-parameter steam evaporator; 303: high-parameter economizer; 304: deoxygenated evaporator; 305: low-parameter economizer; 306: steam drum; 307: deaerator; 308: desalted water pipeline network; 309: pipeline valve; 310: steam power generation device; 4: secondary heat exchange area; 401: industrial water heater; 402: industrial water pipeline network; 403: hot water utilization pipeline; 5: shunt steam supplement area; 501: water mist spray pipe; 502: shunt baffle; 503: first circulating gas pipeline; 504: second circulating gas pipeline; 6: sintering machine; 601: front section smoke hood; 602: rear section smoke hood; 7: ring cooler; 701: first section air hood; 702: second section air hood; 703: third section air hood. DETAILED DESCRIPTION

[0051] The technical solutions of the present application are illustrated below, and the scope of protection requested by the present application includes but is not limited to the following embodiments.

[0052] A system for upgrading the medium and low temperature exhaust gas of the ring cooler, which comprises a shell and an inner cavity. The shell is provided with an exhaust gas inlet 1 communicating with the inner cavity. The inner cavity is divided into a heat and oxygen supplement area 2, a primary heat exchange area 3, a secondary heat exchange area 4, and a shunt steam supplement area 5 in series from bottom to top. The medium and low temperature exhaust gas of the ring cooler is converted into oxygen-enriched hot exhaust gas and oxygen-enriched steam-rich hot exhaust gas which can be directly used in the sintering process after passing through the heat and oxygen supplement area 2, the primary heat exchange area 3, the secondary heat exchange area 4, and the shunt steam supplement area 5 in sequence.

[0053] As preferred, the system further comprises a sintering machine 6 and a circular cooler 7. According to the sintering material flow direction, a front-stage hood 601 and a rear-stage hood 602 are sequentially arranged on the sintering machine 6, and a first-stage air hood 701, a second-stage air hood 702 and a third-stage air hood 703 are sequentially arranged on the circular cooler 7. The air outlets of the second-stage air hood 702 and the third-stage air hood 703 are connected to the waste gas inlet 1 through air inlets. The oxygen-rich hot waste gas outlet of the shunt steam supplement area 5 is connected to the air inlet of the front-stage hood 601 through a first circulating air pipe 503, and the oxygen-rich and steam-rich hot waste gas outlet of the shunt steam supplement area 5 is connected to the air inlet of the rear-stage hood 602 through a second circulating air pipe 504. Preferably, an electric plug valve 101 is arranged in the waste gas inlet 1.

[0054] As preferred, on the sintering machine, the area covered by the front-stage hood 601 is the first 1 / 10 to the fourth 1 / 10 of the material surface between the sintering ignition point and the sintering end point. The area covered by the rear-stage hood 602 is the fifth 1 / 10 to the eighth 1 / 10 of the material surface between the sintering ignition point and the sintering end point.

[0055] As preferred, on the circular cooler, the air outlet of the third-stage air hood 703 is connected to the bottom air inlet of the second-stage circular cooler below the second-stage air hood 702 through an air supply pipe, and the air outlet of the second-stage air hood 702 is connected to the waste gas inlet 1 through an air inlet pipe.

[0056] As preferred, an oxygen-rich burner 201 is arranged in the heat and oxygen supplement area 2, and a combustible gas pipe 202 and an oxygen-rich gas pipe 203 are connected to the oxygen-rich burner 201.

[0057] As preferred, a plurality of oxygen-rich burners 201 are arranged in the heat and oxygen supplement area 2, and a combustible gas pipe 202 and an oxygen-rich gas pipe 203 are independently connected to each oxygen-rich burner 201.

[0058] As preferred, from bottom to top, a high-parameter steam superheater 301, a high-parameter steam evaporator 302, a high-parameter economizer 303, a deoxygenation evaporator 304 and a low-parameter economizer 305 are sequentially arranged in the primary heat exchange area 3. A steam drum 306, a deoxygenator 307, a desalted water pipe network 308 and a steam power generation device 310 are arranged outside the primary heat exchange area 3. The front end of the high-parameter steam superheater 301 is connected to the steam power generation device 310 through a pipe and a valve, and the rear end thereof is connected to the steam drum 306 through a pipe. The front end and the rear end of the high-parameter steam evaporator 302 are both connected to the steam drum 306 through pipes. The front end of the high-parameter economizer 303 is connected to the deoxygenator 307 through a pipe, and the rear end thereof is connected to the steam drum 306 through a pipe. The front end and the rear end of the deoxygenation evaporator 304 are both connected to the deoxygenator 307 through pipes. The front end of the low-parameter economizer 305 is connected to the desalted water pipe network 308 through a pipe valve 309, and the rear end thereof is connected to the deoxygenator 307 through a pipe.

[0059] Preferably, an industrial water heater 401 is installed in the secondary heat exchange zone 4, and an industrial water pipeline 402 and a hot water utilization pipeline 403 are installed outside the secondary heat exchange zone 4. The front end of the industrial water heater 401 is connected to the industrial water pipeline 402, and its rear end is connected to the hot water utilization pipeline 403.

[0060] Preferably, a water mist nozzle 501 and a flow divider baffle 502 are provided in the flow divider replenishment zone 5. The top end of the flow divider baffle 502 is connected to the housing and divides the flow divider replenishment zone 5 into two horizontally parallel flow divider chambers. The water mist nozzle 501 is disposed in one of the flow divider chambers and has an oxygen-enriched and steam-enriched hot exhaust gas outlet at the top of the other flow divider chamber. Preferably, the top end of the flow divider baffle 502 is hinged to the housing, allowing the flow divider baffle 502 to swing horizontally to adjust the size of the two flow divider chambers. Example 1

[0061] like Figures 1-2 As shown, a system for upgrading and utilizing intermediate and low-temperature waste gas from an annular cooling system is disclosed. The system includes a shell and an inner cavity. A waste gas inlet 1, connected to the inner cavity, is located at the bottom of the shell. The inner cavity is divided from bottom to top into a series of interconnected heating and oxygenation zones: a primary heat exchange zone 2, a primary heat exchange zone 3, a secondary heat exchange zone 4, and a diversion steam replenishment zone 5. The intermediate and low-temperature waste gas from the annular cooling system is converted into oxygen-enriched hot waste gas and oxygen-enriched steam-enriched hot waste gas, which can be directly used in the sintering process, after passing through the heating and oxygenation zone 2, the primary heat exchange zone 3, the secondary heat exchange zone 4, and the diversion steam replenishment zone 5. Example 2

[0062] The system repeats Example 1, except that it also includes a sintering machine 6 and an annular cooler 7. According to the direction of the sintering material: a front fume hood 601 and a rear fume hood 602 are sequentially installed on the sintering machine 6; a first-stage air hood 701, a second-stage air hood 702, and a third-stage air hood 703 are sequentially installed on the annular cooler 7. The outlets of the second-stage air hood 702 and the third-stage air hood 703 are connected to the exhaust gas inlet 1 via inlet pipes. The outlet of the oxygen-enriched hot exhaust gas in the diversion and steam replenishment zone 5 is connected to the inlet of the front fume hood 601 via a first circulating air pipe 503; and the outlet of the oxygen-enriched and steam-enriched hot exhaust gas in the diversion and steam replenishment zone 5 is connected to the inlet of the rear fume hood 602 via a second circulating air pipe 504. Example 3

[0063] The same method as Example 2 is used, except that an electric slide gate valve 101 is installed in the exhaust gas inlet 1. Example 4

[0064] Repeat example 3, only on the sintering machine: the front section hood 601 covers the area from the first 1 / 10 to the fourth 1 / 10 of the sintering material surface between the sintering ignition point and the sintering end point. The rear section hood 602 covers the area from the fifth 1 / 10 to the eighth 1 / 10 of the sintering material surface between the sintering ignition point and the sintering end point. Example 5

[0065] Repeat example 4, only on the circular cooler: the air outlet of the three-section hood 703 is connected to the bottom air inlet of the second section of the circular cooler below the second section hood 702 through an air supply pipe, and the air outlet of the second section hood 702 is connected to the waste gas inlet 1 through an air inlet pipe. Example 6

[0066] Repeat example 5, only in the heat and oxygen supplement area 2, an oxygen-enriched burner 201 is arranged, and a combustible gas pipeline 202 and an oxygen-enriched gas pipeline 203 are connected to the oxygen-enriched burner 201. Example 7

[0067] Repeat example 6, only in the heat and oxygen supplement area 2, a plurality of oxygen-enriched burners 201 are arranged, and a combustible gas pipeline 202 and an oxygen-enriched gas pipeline 203 are independently connected to each oxygen-enriched burner 201. Example 8

[0068] Repeat example 7, only in the primary heat exchange area 3, a high-parameter steam superheater 301, a high-parameter steam evaporator 302, a high-parameter economizer 303, a deoxygenated evaporator 304, and a low-parameter economizer 305 are arranged from bottom to top in sequence. A steam drum 306, a deoxygenator 307, a desalted water pipe network 308, and a steam power generation device 310 are arranged outside the primary heat exchange area 3. The front end of the high-parameter steam superheater 301 is connected to the steam power generation device 310 through a pipeline and a valve, and the rear end is connected to the steam drum 306 through a pipeline. The front end and the rear end of the high-parameter steam evaporator 302 are both connected to the steam drum 306 through a pipeline. The front end of the high-parameter economizer 303 is connected to the deoxygenator 307 through a pipeline, and the rear end is connected to the steam drum 306 through a pipeline. The front end and the rear end of the deoxygenated evaporator 304 are both connected to the deoxygenator 307 through a pipeline. The front end of the low-parameter economizer 305 is connected to the desalted water pipe network 308 through a pipeline valve 309, and the rear end is connected to the deoxygenator 307 through a pipeline. Example 9

[0069] Repeat example 8, only in the secondary heat exchange area 4, an industrial water heater 401 is arranged, and an industrial water pipe network 402 and a hot water utilization pipeline 403 are arranged outside the secondary heat exchange area 4. The front end of the industrial water heater 401 is connected to the industrial water pipe network 402, and the rear end is connected to the hot water utilization pipeline 403. Example 10

[0070] Example 9 is repeated, except that a water mist spray pipe 501 and a flow splitting baffle 502 are arranged in the flow splitting and steam supplementing area 5. The top end of the flow splitting baffle 502 is connected to the shell and divides the flow splitting and steam supplementing area 5 into two horizontally parallel flow splitting chambers. The water mist spray pipe 501 is arranged in one of the flow splitting chambers and an oxygen-rich and steam-rich hot exhaust gas outlet is formed at the top of the flow splitting chamber, while an oxygen-rich hot exhaust gas outlet is formed at the top of the other flow splitting chamber. Example 11

[0071] Example 10 is repeated, except that the top end of the flow splitting baffle 502 is hingedly connected to the shell, so that the flow splitting baffle 502 can swing in the horizontal direction to adjust the size of the two flow splitting chambers. Example 12

[0072] The system described in Example 11 is used to upgrade and utilize the medium and low temperature exhaust gas of the sintering circular cooler:

[0073] The mixed exhaust gas (temperature about 175℃, oxygen concentration about 206mg / L) of the low temperature cooling section of the sintering circular cooler is introduced into the heat supplementing and oxygen supplementing area. Coal gas and oxygen are used for oxygen-rich combustion in the heat supplementing and oxygen supplementing area to increase the temperature of the exhaust gas to 486℃ (in the condition of only increasing the temperature, the oxygen concentration is about 122mg / L) and increase the oxygen concentration to about 199mg / L, to obtain oxygen-rich high-temperature hot flue gas. The oxygen-rich high-temperature hot flue gas is sequentially passed through the first heat exchange area and the second heat exchange area in turn, and is converted into oxygen-rich hot exhaust gas with a temperature of about 155℃ and an oxygen concentration of about 352mg / L. In this process, high-parameter steam with a flow rate of 49t / h, a pressure of about 1.8MPa and a temperature of about 392℃ is generated for power generation, and hot water with a flow rate of 50t / h and a temperature of about 90℃ is generated for return to the sintering process. Then the angle of the flow splitting baffle is adjusted, about 40% of the oxygen-rich hot exhaust gas enters the atomizing and steam supplementing area (left flow splitting chamber) to spray water mist and is converted into oxygen-rich steam-rich hot exhaust gas with a temperature of about 140℃, an oxygen concentration of about 365mg / L and a water vapor content of about 3.7%. The oxygen-rich steam-rich hot exhaust gas is returned to the 5 / 10-8 / 10 section of the sintering machine between the ignition point and the end point for oxygen-rich steam injection sintering, and the remaining 60% of the oxygen-rich hot exhaust gas is returned to the 1 / 10-4 / 10 section of the sintering machine between the ignition point and the end point for oxygen-rich hot air sintering. Compared with the conventional process, the medium and low temperature waste heat exhaust gas is utilized in the form of waste heat power generation after upgrading, and at the same time the hot air temperature of the return sintering front section is increased from about 100℃ to 140-155℃, the overall utilization rate of sintering circular cooler waste heat is increased by 28%, the sintering return rate is decreased by 1.2%, the sintering drum strength is increased by 2.1%, the sintering utilization coefficient is increased by 0.034t / m 2 ·h -1 , the solid fuel consumption is decreased by 1.51kg / t, and the CO concentration of the sintering flue gas is decreased by 1272ppm. Example 13

[0074] The system described in Example 11 is used to upgrade and utilize the medium and low temperature waste gas from the ring cooler:

[0075] First, the low-temperature waste gas (about 142°C) discharged from the post-stage of the ring cooler is circulated back to the air inlet of the middle stage of the ring cooler through a pipeline as a cooling medium to cool the medium-temperature material and produce medium-temperature waste gas with a temperature of about 251°C and an oxygen concentration of about 176 mg / L; then the medium-temperature waste gas is introduced into the heat-supplying and oxygen-supplying area, where coal gas and oxygen are used for oxygen-enriched combustion to increase the temperature of the waste gas to 522°C (under the condition of only increasing the temperature, the oxygen concentration is about 116 mg / L) and increase the oxygen concentration to 181 mg / L, obtaining oxygen-enriched high-temperature hot flue gas; the oxygen-enriched high-temperature hot flue gas is sequentially passed through the first-stage heat exchange area and the second-stage heat exchange area, and is converted into oxygen-enriched hot waste gas with a temperature of about 141°C and an oxygen concentration of about 368 mg / L; in this process, high-parameter steam with a flow rate of 50.5 t / h, a pressure of about 2.3 MPa, and a temperature of about 416°C is generated for power generation, and hot water with a flow rate of 50 t / h and a temperature of about 90°C is generated for return to the sintering process; then the angle of the shunt baffle is adjusted, so that about 45% of the oxygen-enriched hot waste gas enters the atomization and steam addition area (left shunt chamber) for water mist spraying and addition, and is converted into oxygen-enriched steam-rich hot waste gas with a temperature of about 133°C, an oxygen concentration of about 378 mg / L, and a water vapor content of about 4%; the oxygen-enriched steam-rich hot waste gas is returned to the 5 / 10-8 / 10 section of the sintering machine between the ignition point and the end point for oxygen-enriched steam injection sintering, and the remaining 55% of the oxygen-enriched hot waste gas is returned to the 1 / 10-3 / 10 section of the sintering machine between the ignition point and the end point for oxygen-enriched hot air sintering. Compared with the conventional process, the total amount of medium and low temperature waste heat is reduced by 40%, and after upgrading, it is utilized in the form of waste heat power generation, at the same time, the temperature of the hot air on the front section of the sintering machine is increased from about 100°C to 133-141°C, the overall utilization rate of the sintering ring cooling waste heat is increased by 30%, the sinter return rate is decreased by 1.3%, the sinter drum strength is increased by 2.0%, the sintering utilization coefficient is increased by 0.037 t / m 2 ·h -1 , the solid fuel consumption is decreased by 1.55 kg / t, and the CO concentration of the sintering flue gas is decreased by 1305 ppm.

[0076] Comparative Example 1

[0077] The sintering process uses the conventional process, the low-temperature cooling section waste gas (about 142°C) of the ring cooler is directly discharged, and the medium-temperature cooling section waste gas (about 219°C) of the ring cooler is exchanged with a waste heat boiler and industrial water, producing low-parameter steam with a flow rate of about 11.5 t / h, a pressure of about 0.4 MPa, and a temperature of about 180°C, and hot water with a flow rate of about 50 t / h and a temperature of about 90°C, which cannot be fully utilized in the low-pressure steam plant, and the heat utilization efficiency is low.

[0078] Comparative Example 2

[0079] The sinter cooling adopts a conventional process, the exhaust gas (about 142℃) of the low-temperature cooling section of the ring cooler is directly discharged, and the exhaust gas (about 219℃) of the medium-temperature cooling section is returned to the sinter ignition section and the sinter material surface. Due to the high temperature of the exhaust gas, the obvious volume expansion, and the dilute oxygen content (about 188 mg / L), the oxygen amount inhaled into the sinter material layer per unit time is low, and the yield and quality of the sinter are reduced. In order to ensure the sinter quality, a large amount of cold air must be mixed to reduce the temperature of the exhaust gas, resulting in that the cooling exhaust gas and its heat cannot be fully utilized.

Claims

1. A system for upgrading of medium and low temperature exhaust gas of ring cooling, characterized in that: The system comprises a shell and an inner cavity; the bottom of the shell is provided with a waste gas inlet (1) communicating with the inner cavity; the inner cavity is divided into a heat and oxygen supplementing zone (2), a first heat exchanging zone (3), a second heat exchanging zone (4) and a shunt steam supplementing zone (5) in sequence from bottom to top; the medium and low temperature waste gas of the ring cooler passes through the heat and oxygen supplementing zone (2), the first heat exchanging zone (3), the second heat exchanging zone (4) and the shunt steam supplementing zone (5) in sequence and is converted into oxygen-rich hot waste gas and oxygen-rich steam-rich hot waste gas which can be directly used in the sintering process.

2. The system of claim 1, wherein: The system further comprises a sintering machine (6) and a ring cooler (7); according to the movement direction of the sintering material: the front section hood (601) and the rear section hood (602) are sequentially arranged on the sintering machine (6), and the one section hood (701), the two section hood (702) and the three section hood (703) are sequentially arranged on the ring cooler (7); the air outlets of the two section hood (702) and the three section hood (703) are connected to the waste gas inlet (1) through air inlet pipes; the oxygen-rich hot waste gas outlet of the shunt steam supplementing zone (5) is connected to the air inlet of the front section hood (601) through a first circulating gas pipe (503), and the oxygen-rich steam-rich hot waste gas outlet of the shunt steam supplementing zone (5) is connected to the air inlet of the rear section hood (602) through a second circulating gas pipe (504).

3. The system of claim 2, wherein: An electric plug valve (101) is arranged in the waste gas inlet (1).

4. The system of claim 2, wherein: On the sintering machine: the front section hood (601) covers the first 1 / 10 to the fourth 1 / 10 of the material surface between the sintering ignition point and the sintering end point; the rear section hood (602) covers the fifth 1 / 10 to the eighth 1 / 10 of the material surface between the sintering ignition point and the sintering end point; and / or On the ring cooler: the air outlet of the three section hood (703) is connected to the bottom air inlet of the second section of the ring cooler below the two section hood (702) through an air supply pipe, and the air outlet of the two section hood (702) is connected to the waste gas inlet (1) through an air inlet pipe.

5. The system of any one of claims 1-4, wherein: An oxygen-enriched burner (201) is arranged in the heat and oxygen supplementing zone (2), and a combustible gas pipeline (202) and an oxygen-enriched gas pipeline (203) are connected to the oxygen-enriched burner (201).

6. The system of claim 5, wherein: A plurality of oxygen-enriched burners (201) are arranged in the heat and oxygen supplementing zone (2), and a combustible gas pipeline (202) and an oxygen-enriched gas pipeline (203) are independently connected to each oxygen-enriched burner (201).

7. The system of any of claims 1-4, 6, wherein: The high-parameter steam superheater (301), the high-parameter steam evaporator (302), the high-parameter economizer (303), the deoxygenation evaporator (304) and the low-parameter economizer (305) are sequentially arranged in the primary heat exchange zone (3) from bottom to top; the steam drum (306), the deaerator (307), the desalted water pipe network (308) and the steam power generation device (310) are arranged outside the primary heat exchange zone (3); the front end of the high-parameter steam superheater (301) is connected with the steam power generation device (310) through a pipeline and a valve, and the rear end thereof is connected with the steam drum (306) through a pipeline; the front end and the rear end of the high-parameter steam evaporator (302) are both connected with the steam drum (306) through a pipeline; the front end of the high-parameter economizer (303) is connected with the deaerator (307) through a pipeline, and the rear end thereof is connected with the steam drum (306) through a pipeline; the front end and the rear end of the deoxygenation evaporator (304) are both connected with the deaerator (307) through a pipeline; the front end of the low-parameter economizer (305) is connected with the desalted water pipe network (308) through a pipeline valve (309), and the rear end thereof is connected with the deaerator (307) through a pipeline.

8. The system of claim 5, wherein: The high-parameter steam superheater (301), the high-parameter steam evaporator (302), the high-parameter economizer (303), the deoxygenation evaporator (304) and the low-parameter economizer (305) are sequentially arranged in the primary heat exchange zone (3) from bottom to top; the steam drum (306), the deaerator (307), the desalted water pipe network (308) and the steam power generation device (310) are arranged outside the primary heat exchange zone (3); the front end of the high-parameter steam superheater (301) is connected with the steam power generation device (310) through a pipeline and a valve, and the rear end thereof is connected with the steam drum (306) through a pipeline; the front end and the rear end of the high-parameter steam evaporator (302) are both connected with the steam drum (306) through a pipeline; the front end of the high-parameter economizer (303) is connected with the deaerator (307) through a pipeline, and the rear end thereof is connected with the steam drum (306) through a pipeline; the front end and the rear end of the deoxygenation evaporator (304) are both connected with the deaerator (307) through a pipeline; the front end of the low-parameter economizer (305) is connected with the desalted water pipe network (308) through a pipeline valve (309), and the rear end thereof is connected with the deaerator (307) through a pipeline.

9. The system of any of claims 1-4, 6, 8, wherein: The industrial water heater (401) is arranged in the secondary heat exchange zone (4), and the industrial water pipe network (402) and the hot water utilization pipeline (403) are arranged outside the secondary heat exchange zone (4); the front end of the industrial water heater (401) is connected with the industrial water pipe network (402), and the rear end thereof is connected with the hot water utilization pipeline (403).

10. The system of claim 5, wherein: The industrial water heater (401) is arranged in the secondary heat exchange zone (4), and the industrial water pipe network (402) and the hot water utilization pipeline (403) are arranged outside the secondary heat exchange zone (4); the front end of the industrial water heater (401) is connected with the industrial water pipe network (402), and the rear end thereof is connected with the hot water utilization pipeline (403).

11. The system of claim 7, wherein: An industrial water heater (401) is arranged in the secondary heat exchange zone (4), and an industrial water pipe network (402) and a hot water utilization pipeline (403) are arranged outside the secondary heat exchange zone (4); the front end of the industrial water heater (401) is connected with the industrial water pipe network (402), and the rear end thereof is connected with the hot water utilization pipeline (403).

12. The system of any one of claims 1-4, 6, 8, 10-11, wherein: A water mist spray pipe (501) and a shunt baffle (502) are arranged in the shunt steam supplementing zone (5); the top end of the shunt baffle (502) is connected with the shell and divides the shunt steam supplementing zone (5) into two shunt chambers arranged side by side in the horizontal direction, the water mist spray pipe (501) is arranged in one of the shunt chambers, and an oxygen-rich and steam-rich hot waste gas outlet is formed in the top of the shunt chamber, while an oxygen-rich hot waste gas outlet is formed in the top of the other shunt chamber.

13. The system of claim 5, wherein: A water mist spray pipe (501) and a shunt baffle (502) are arranged in the shunt steam supplementing zone (5); the top end of the shunt baffle (502) is connected with the shell and divides the shunt steam supplementing zone (5) into two shunt chambers arranged side by side in the horizontal direction, the water mist spray pipe (501) is arranged in one of the shunt chambers, and an oxygen-rich and steam-rich hot waste gas outlet is formed in the top of the shunt chamber, while an oxygen-rich hot waste gas outlet is formed in the top of the other shunt chamber.

14. The system of claim 7, wherein: A water mist spray pipe (501) and a shunt baffle (502) are arranged in the shunt steam supplementing zone (5); the top end of the shunt baffle (502) is connected with the shell and divides the shunt steam supplementing zone (5) into two shunt chambers arranged side by side in the horizontal direction, the water mist spray pipe (501) is arranged in one of the shunt chambers, and an oxygen-rich and steam-rich hot waste gas outlet is formed in the top of the shunt chamber, while an oxygen-rich hot waste gas outlet is formed in the top of the other shunt chamber.

15. The system of claim 9, wherein: A water mist spray pipe (501) and a shunt baffle (502) are arranged in the shunt steam supplementing zone (5); the top end of the shunt baffle (502) is connected with the shell and divides the shunt steam supplementing zone (5) into two shunt chambers arranged side by side in the horizontal direction, the water mist spray pipe (501) is arranged in one of the shunt chambers, and an oxygen-rich and steam-rich hot waste gas outlet is formed in the top of the shunt chamber, while an oxygen-rich hot waste gas outlet is formed in the top of the other shunt chamber.

16. The system of claim 12, wherein: The top end of the shunt baffle (502) is hinged with the shell, so that the shunt baffle (502) can swing in the horizontal direction to adjust the size of the two shunt chambers.

17. The system of any of claims 13-15, wherein: The top end of the shunt baffle (502) is hinged with the shell, so that the shunt baffle (502) can swing in the horizontal direction to adjust the size of the two shunt chambers.

18. A method for upgrading and utilizing the medium and low temperature waste heat of a ring cooling system according to any one of claims 1-17, characterized in that: The method comprises: 1) mixing and supplementing heat and oxygen to the ring cooling medium-temperature waste gas and the ring cooling low-temperature waste gas to obtain oxygen-rich high-temperature hot flue gas; 2) using hot water to perform high-temperature heat exchange on the oxygen-rich high-temperature reheat flue gas to obtain high-parameter steam and oxygen-rich medium-temperature hot flue gas; 3) using cold water to perform low-temperature heat exchange on the oxygen-rich medium-temperature flue gas to obtain industrial hot water and oxygen-rich hot waste gas; 4) using water mist to perform atomization temperature control and steam supplementing treatment on part of the oxygen-rich hot waste gas to obtain oxygen-rich steam-rich hot waste gas; 5) sending the oxygen-rich hot waste gas and the oxygen-rich steam-rich hot waste gas to the front and rear sections of the sintering machine for sintering treatment.

19. The system of claim 18, wherein: The ring cooling low-temperature waste gas is first circulated as a cooling medium of the middle section of the ring cooler, and the material is cooled and exchanged heat to obtain ring cooling medium-temperature waste gas, and then the ring cooling medium-temperature waste gas is heated and oxygen-supplied to be combusted to obtain oxygen-rich high-temperature hot flue gas.

20. The method of claim 19, wherein: In step 1), the temperature of the ring cooling low-temperature waste gas is lower than 150 DEG C; the temperature of the ring cooling medium-temperature waste gas is not lower than 150 DEG C; the temperature of the oxygen-rich high-temperature hot flue gas is not lower than 400 DEG C; the oxygen concentration of the oxygen-rich high-temperature hot flue gas is not lower than 140 mg / L; and / or In step 2), the pressure of the high-parameter steam is not lower than 1.5 MPa; the temperature of the high-parameter steam is not lower than 350 DEG C; the temperature of the oxygen-rich medium-temperature hot flue gas is not higher than 200 DEG C; and / or In step 3), the temperature of the oxygen-rich hot waste gas is not higher than 160 DEG C; the oxygen concentration of the oxygen-rich hot waste gas is not lower than 310 mg / L.

21. The method of claim 20, wherein: In step 1), the temperature of the ring cooling low-temperature waste gas is 110-150 DEG C; the temperature of the ring cooling medium-temperature waste gas is 160-250 DEG C; the temperature of the oxygen-rich high-temperature hot flue gas is 450-600 DEG C; the oxygen concentration of the oxygen-rich high-temperature hot flue gas is 160-300 mg / L; and / or In step 2), the pressure of the high-parameter steam is 1.8-3 MPa; the temperature of the high-parameter steam is 380-500 DEG C; the temperature of the oxygen-rich medium-temperature hot flue gas is 160-190 DEG C; and / or In step 3), the temperature of the oxygen-rich hot waste gas is 130-155 DEG C; the oxygen concentration of the oxygen-rich hot waste gas is 320-400 mg / L.

22. The method of claim 21, wherein: In step 1), the temperature of the ring cooling low-temperature waste gas is 120-145 DEG C; the temperature of the ring cooling medium-temperature waste gas is 170-240 DEG C; the temperature of the oxygen-rich high-temperature hot flue gas is 500-550 DEG C; the oxygen concentration of the oxygen-rich high-temperature hot flue gas is 180-260 mg / L; and / or In step 2), the pressure of the high-parameter steam is 2-2.5 MPa; the temperature of the high-parameter steam is 400-480 DEG C; the temperature of the oxygen-rich medium-temperature hot flue gas is 170-180 DEG C; and / or In step 3), the temperature of the oxygen-rich hot waste gas is 135-150 DEG C; the oxygen concentration of the oxygen-rich hot waste gas is 330-380 mg / L.

23. The method of any one of claims 18-22, wherein: In step 4), the temperature of the oxygen-rich and steam-rich hot waste gas is not higher than 150 DEG C; the oxygen concentration of the oxygen-rich and steam-rich hot waste gas is not lower than 320 mg / L; the water vapor concentration of the oxygen-rich and steam-rich hot waste gas is not lower than 3 wt%.

24. The method of claim 23, wherein: In step 4), the temperature of the oxygen-rich and steam-rich hot waste gas is 120-145 DEG C; the oxygen concentration of the oxygen-rich and steam-rich hot waste gas is 330-420 mg / L; the water vapor concentration of the oxygen-rich and steam-rich hot waste gas is 3.2-5 wt%.

25. The method of claim 24, wherein: In step 4), the temperature of the oxygen-rich and steam-rich hot waste gas is 130-140 DEG C; the oxygen concentration of the oxygen-rich and steam-rich hot waste gas is 340-400 mg / L; the water vapor concentration of the oxygen-rich and steam-rich hot waste gas is 3.5-4.5 wt%.

26. The method of claim 23, wherein: In step 4), the oxygen-enriched hot waste gas subjected to the atomization temperature control and steam addition treatment accounts for 30-55% of the total oxygen-enriched hot waste gas; and / or In step 4), the front section of sintering refers to the section where the first 1 / 10 to 4 / 10 of the material surface is located between the sintering ignition point and the sintering endpoint; and the rear section of sintering refers to the section where the last 5 / 10 to 8 / 10 of the material surface is located between the sintering ignition point and the sintering endpoint.

27. The method of claim 24, wherein: In step 4), the oxygen-enriched hot waste gas subjected to the atomization temperature control and steam addition treatment accounts for 30-55% of the total oxygen-enriched hot waste gas; and / or In step 4), the front section of sintering refers to the section where the first 1 / 10 to 4 / 10 of the material surface is located between the sintering ignition point and the sintering endpoint; and the rear section of sintering refers to the section where the last 5 / 10 to 8 / 10 of the material surface is located between the sintering ignition point and the sintering endpoint.

28. The method of claim 25, wherein: In step 4), the oxygen-enriched hot waste gas subjected to the atomization temperature control and steam addition treatment accounts for 30-55% of the total oxygen-enriched hot waste gas; and / or In step 4), the front section of sintering refers to the section where the first 1 / 10 to 4 / 10 of the material surface is located between the sintering ignition point and the sintering endpoint; and the rear section of sintering refers to the section where the last 5 / 10 to 8 / 10 of the material surface is located between the sintering ignition point and the sintering endpoint.

29. The method of any one of claims 26-28, wherein: In step 4), the oxygen-enriched hot waste gas subjected to the atomization temperature control and steam addition treatment accounts for 34-50% of the total oxygen-enriched hot waste gas.

30. The method of claim 29, wherein: In step 4), the oxygen-enriched hot waste gas subjected to the atomization temperature control and steam addition treatment accounts for 38-48% of the total oxygen-enriched hot waste gas.

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