High-temperature liquid melt centrifugal granulation waste heat recovery system and method

Abstract

The invention discloses a high-temperature liquid melt centrifugal granulation waste heat recovery system and method. The system comprises a granulation device, the bottom of the granulation device is connected with a moving bed device, and the bottom of the moving bed device is connected with a discharging device; one end of the cooling device is connected with the granulating device and the moving bed device, the other end of the cooling device is connected with a cache gas storage tank, and the cache gas storage tank is connected with a coal economizer through cloth bag dust removal; the economizer is connected with the convection heat exchange surface through the waste heat boiler and the boiler drum, the end part of the convection heat exchange surface is connected with a hot air pipeline, and the hot air pipeline is connected with the granulating device; and the waste heat recovery device is connected with the granulating device, the moving bed device, the discharging device, the coal economizer, the waste heat boiler and the boiler drum and used for waste heat recovery of the granulated high-temperature slag particles. After the high-temperature liquid melt is centrifugally granulated, through the synergistic effect of the cooling device and the waste heat recovery device, waste heat carried by high-temperature slag particles can be efficiently transferred and recovered, and the energy utilization efficiency is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature melt processing, and in particular relates to a system and method for recovering waste heat from centrifugal granulation of a high-temperature liquid melt. Background Art

[0002] The steel industry is an important pillar industry of my country's national economy. It has played an irreplaceable role in my country's industrial modernization process and provided important raw materials for economic development. In the steel production process, liquid slag is a by-product with a temperature of usually above 1200℃, containing a large amount of sensible heat and waste heat. It has not been fully recovered and efficiently utilized so far, and has become a global key problem that the steel industry needs to solve urgently.

[0003] At present, the treatment of liquid slag at home and abroad mainly adopts wet process, which usually uses water flow of a certain pressure to impact the liquid slag at the end of the slag groove, breaking it into droplets and rapidly cooling it to form solid slag particles. However, the limitations of this process are becoming increasingly prominent: first, it is highly dependent on water resources, and 0.8 to 1.20~1.2 tons of water are consumed for each ton of slag treatment; second, a large amount of harmful gases will be released, causing pollution; third, the energy consumption is large, and the drying process of each ton of slag consumes 0.617 GJ of electricity; most importantly, the water quenching process wastes a lot of high-quality heat energy, and its recovery rate is less than 10%.

[0004] These defects make it difficult for the wet process to meet the energy conservation and emission reduction needs of the steel industry. Compared with the wet process, the dry process does not consume water, does not emit harmful gases, and can achieve high-grade waste heat recovery effects that take into account the glass content of liquid slag, which has significant advantages.

[0005] The dry centrifugal granulation waste heat recovery process has become the most promising method in the field of slag treatment due to its advantages such as low energy consumption, good granulation effect, simple and compact equipment, and controllable particle size and morphology. However, the centrifugal granulation and waste heat recovery processes still face some challenges. Traditional heat exchange methods, such as the use of air or cooling air as a heat exchange medium, have poor heat exchange effects and low waste heat recovery efficiency due to their small heat capacity. At the same time, the existing hot air and water systems have certain limitations in design and configuration, and fail to fully utilize the high-temperature waste heat contained in the slag, and cannot achieve the ideal waste heat recovery efficiency, and are in urgent need of further optimization and improvement. Summary of the invention

[0006] The purpose of the present invention is to provide a system and method for recovering waste heat from centrifugal granulation of a high-temperature liquid melt, so as to solve the problem that the heat exchange method in the prior art uses only air or cooling air as the heat exchange medium, which has a small heat capacity and results in a poor heat exchange effect and low waste heat recovery efficiency; at the same time, the existing hot air and water systems have certain limitations in design and configuration, and fail to fully utilize the high-temperature waste heat contained in the slag, and cannot achieve the technical defect of achieving an ideal waste heat recovery efficiency.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, a high-temperature liquid melt centrifugal granulation waste heat recovery system is provided, comprising: A granulating device, the bottom of which is connected to a moving bed device, and the bottom of the moving bed device is connected to a discharging device; A cooling device, one end of which is connected to the granulating device and the moving bed device, and the other end of which is connected to a buffer gas storage tank, wherein the buffer gas storage tank is connected to the economizer through a bag dust collector; The economizer is connected to the convection heat exchange surface through the waste heat boiler and the boiler drum, and the end of the convection heat exchange surface is connected to a hot air duct, and the hot air duct is connected to the granulation device; The waste heat recovery device is connected with the granulation device, the moving bed device, the discharge device, the economizer, the waste heat boiler, and the boiler drum, and is used for recovering waste heat from the high-temperature slag particles after granulation.

[0008] Furthermore, the granulation device comprises a granulation bin, the top of which is connected to a hot air duct, and the outer side of the hot air duct is provided with a water-cooled membrane wall; The granulation bin has a roof, a granulation unit is arranged in the granulation bin, a flat material assembly is arranged at the bottom of the granulation unit through an inspection channel, and a cooling channel is arranged in the flat material assembly; The moving bed device comprises a moving bed, the bottom of the moving bed is provided with a particle accumulation section, the particle accumulation section is provided with a heat exchange tube bundle, and an air distribution plate is provided below the particle accumulation section; The cooling device comprises a first cooling unit and a second cooling unit, wherein the first cooling unit and the second cooling unit are both used to transport a first cooling medium; One end of the first cooling unit is connected to the flat material assembly, one end of the second cooling unit is connected to the air distribution plate, and the other ends of the first cooling unit and the second cooling unit are connected to the buffer gas storage tank; The waste heat recovery device includes a water pump, one end of which is connected to an external water source, and the other end is connected to a discharge device, a granulation device, a moving bed device, an economizer, a waste heat boiler and a boiler drum. The other end of the water pump is used to transport a second cooling medium.

[0009] Furthermore, the first cooling medium is carbon dioxide, argon or nitrogen.

[0010] Furthermore, the first cooling unit and the second cooling unit are both fans, and the first cooling unit and the second cooling unit are connected to the buffer gas tank through a filter.

[0011] Furthermore, the second cooling medium is water, a high-temperature organic heat carrier or a nanofluid.

[0012] Furthermore, the granulation unit is a sawtooth rotating disk, a cone-top rotating cup or a sandwich rotating multi-pointed disk.

[0013] Furthermore, a heat exchange plate is provided at the bottom of the granulation bin, and the heat exchange plate is located on one side of the maintenance passage.

[0014] Furthermore, water-cooled walls are provided around the granulating bin and the moving bed.

[0015] Furthermore, the discharge device comprises a spiral discharge machine, one end of which is connected to a rotary sealing valve, and the rotary sealing valve is connected to the bottom of the moving bed; The other end of the spiral discharge machine is provided with a water cooling sleeve, and the water cooling sleeve is connected to a water pump.

[0016] In a second aspect, a method for recovering waste heat from centrifugal granulation of a high-temperature liquid melt is provided. The method is performed using the high-temperature liquid melt centrifugal granulation waste heat recovery system as described above, comprising: Granulating the high-temperature liquid melt to obtain high-temperature slag particles; conveying a first cooling medium and a second cooling medium into a recovery system so that the first cooling medium and the second cooling medium exchange heat with the high-temperature slag particles; Wherein, when the first cooling medium is transported into the recovery system, the first cooling medium in the buffer gas storage tank is respectively sent to the air distribution plate and the flat material assembly through the first cooling unit and the second cooling unit. After heat exchange, the high-temperature medium passes through the hot air duct, and successively passes through the boiler drum, the waste heat boiler, the economizer, and the bag filter before returning to the buffer gas storage tank; the buffer gas storage tank then passes through the first cooling unit and the second cooling unit to send the first cooling medium to the air distribution plate in the moving bed device and the flat material assembly in the granulation device, forming a hot air circulation system; When the second cooling medium is transported to the recovery system, the second cooling medium is divided into four paths. The first path flows to the water-cooling jacket of the screw conveyor to further cool the slag particles. The second path flows to the water-cooling membrane wall on the hot air pipe to reduce the temperature of the hot air pipe and improve the stability and heat transfer efficiency of the hot air system. The third route directly cools high-temperature areas such as the wall of the granulation bin, and the fourth route flows to the waste heat boiler to improve waste heat recovery efficiency and reduce the heat load in the waste heat boiler; After the four cooling media merge in the boiler drum, they flow into the heat exchange tube bundle, heat exchange plate and the heating surface of the ceiling in turn. After these heat exchanges, the heat is recovered and finally returned to the boiler drum.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. After the high-temperature liquid melt is centrifugally granulated, the waste heat carried by the high-temperature slag particles can be efficiently transferred and recovered through the synergistic effect of the cooling device and the waste heat recovery device; secondly, the recovered high-temperature gas is returned to the buffer gas tank after being treated by the waste heat boiler, economizer and bag dust removal, and is sent back to the system for recycling, thereby realizing efficient reuse of thermal energy; finally, the waste heat recovery device, through flexible flow path configuration with waste heat boilers, economizers and other equipment, enables the waste heat of the high-temperature slag particles to be recovered and fully utilized at multiple points, further improving energy utilization efficiency.

[0018] 2. The hot air duct on the top of the granulation bin is equipped with a water-cooled membrane wall, which effectively prevents the hot air from overheating the duct and utilizes the heat of the hot air to improve the thermal efficiency of the system. The heating surface design in the granulation bin further absorbs the heat released during the melt granulation process and enhances the heat exchange effect. A cooling channel is provided in the flat material assembly and connected to the first cooling unit to ensure stable temperature control during the granulation process and prevent overheating. The heat exchange tube bundle at the bottom of the moving bed is connected to the second cooling unit to effectively cool the particle accumulation section and improve the heat recovery efficiency.

[0019] 3. By using different types of first cooling media as heat exchange media, the heat exchange effect and waste heat recovery efficiency are improved.

[0020] 4. The setting of the filter can effectively remove impurities and particulate matter in the cooling medium, prevent these impurities from entering the fan or buffer gas tank, causing damage to the equipment, extend the service life of the equipment and reduce maintenance costs.

[0021] 5. By selecting different types of second cooling media, it can be applied to waste heat recovery operations under different working conditions, thereby improving the application scope of the waste heat recovery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A schematic diagram of a waste heat recovery system for centrifugal granulation of a high-temperature liquid melt provided by the present invention; Figure 2 A flow chart of the method for recovering waste heat from centrifugal granulation of high-temperature liquid melt provided by the present invention; Among them: 1. Granulation bin; 2. Heat conduction mechanism; 3. Ceiling; 4. Granulation unit; 5. Maintenance passage; 6. Heat exchange plate; 7. Flat material assembly; 8. Heat exchange tube bundle; 9. Moving bed; 10. Air distribution plate; 11. Rotary sealing valve; 12. Screw discharger; 13. First cooling unit; 14. Second cooling unit; 15. Filter; 16. Buffer storage tank; 17. External air source; 18. Bag dust collector; 19. Economizer; 20. Waste heat boiler; 21. Boiler drum; 22. Hot air duct; 23. External water source; 24. Water pump; 25. Water-cooled wall; 26. Convective heat exchange surface. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0027] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0028] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] The steel industry is an important pillar industry of my country's national economy. It has played an irreplaceable role in my country's industrial modernization process and provided important raw materials for economic development. In the steel production process, liquid slag is a by-product with a temperature of usually above 1200℃, containing a large amount of sensible heat and waste heat. It has not been fully recovered and efficiently utilized so far, and has become a global key problem that the steel industry needs to solve urgently.

[0030] At present, the treatment of liquid slag at home and abroad mainly adopts wet process, which usually uses water flow of a certain pressure to impact the liquid slag at the end of the slag groove, breaking it into droplets and rapidly cooling it to form solid slag particles. However, the limitations of this process are becoming increasingly prominent: first, it is highly dependent on water resources, and 0.8 to 1.20~1.2 tons of water are consumed for each ton of slag treatment; second, a large amount of harmful gases will be released, causing pollution; third, the energy consumption is large, and the drying process of each ton of slag consumes 0.617 GJ of electricity; most importantly, the water quenching process wastes a lot of high-quality heat energy, and its recovery rate is less than 10%.

[0031] These defects make it difficult for the wet process to meet the energy conservation and emission reduction needs of the steel industry. Compared with the wet process, the dry process does not consume water, does not emit harmful gases, and can achieve high-grade waste heat recovery effects that take into account the glass content of liquid slag, which has significant advantages.

[0032] The dry centrifugal granulation waste heat recovery process has become the most promising method in the field of slag treatment due to its advantages such as low energy consumption, good granulation effect, simple and compact equipment, and controllable particle size and morphology. However, the centrifugal granulation and waste heat recovery processes still face some challenges. Traditional heat exchange methods, such as the use of air or cooling air as a heat exchange medium, have poor heat exchange effects and low waste heat recovery efficiency due to their small heat capacity. At the same time, the existing hot air and water systems have certain limitations in design and configuration, and fail to fully utilize the high-temperature waste heat contained in the slag, and cannot achieve the ideal waste heat recovery efficiency, and are in urgent need of further optimization and improvement.

[0033] In order to solve the above technical defects, the inventor provides a system and method for recovering waste heat from centrifugal granulation of high-temperature liquid melt.

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings: like Figure 1As shown, an embodiment of the present invention, in the first aspect, provides a waste heat recovery system for centrifugal granulation of a high-temperature liquid melt, comprising: a granulating device, a moving bed device is connected to the bottom, and a discharging device is connected to the bottom of the moving bed device; a cooling device, one end of which is connected to the granulating device and the moving bed device, and the other end is connected to a buffer gas storage tank 16, and the buffer gas storage tank 16 is connected to an economizer 19 through a bag dust collector 18; the economizer 19 is connected to a convection heat exchange surface 26 through a waste heat boiler 20 and a boiler drum 21, and a hot air duct 22 is connected to the end of the convection heat exchange surface 26, and the hot air duct 22 is connected to the granulating device; a waste heat recovery device is connected to the granulating device, the moving bed device, the discharging device, the economizer 19, the waste heat boiler 20, and the boiler drum 21, and is used for recovering waste heat from high-temperature slag particles after granulation. In this process, after the high-temperature liquid melt is centrifugally granulated, the waste heat carried by the high-temperature slag particles can be efficiently transferred and recovered through the synergistic effect of the cooling device and the waste heat recovery device; secondly, the recovered high-temperature gas is processed by the waste heat boiler 20, the economizer 19 and the bag filter 18, and then returned to the buffer storage tank 16, and sent back into the system for recycling, so as to achieve efficient reuse of thermal energy. The buffer storage tank 16 is connected to the external gas source 17; finally, the waste heat recovery device, through the flexible flow path configuration with the waste heat boiler 20, the economizer 19 and other equipment, enables the waste heat of the high-temperature slag particles to be recovered and fully utilized at multiple points, thereby further improving energy utilization efficiency. Figure 1As shown, the granulation device includes a granulation bin 1, the top of the granulation bin 1 is connected to the hot air duct 22, and the outer side of the hot air duct 22 is provided with a water-cooled membrane wall; the granulation bin 1 has a ceiling 3, and a granulation unit 4 is provided in the granulation bin 1, and a flat material assembly 7 is provided at the bottom of the granulation unit 4 through an inspection channel 5, and a cooling channel is provided in the flat material assembly 7; the moving bed device includes a moving bed 9, and the bottom of the moving bed 9 has a particle accumulation section, and a heat exchange tube bundle 8 is provided on the particle accumulation section, and an air distribution plate 10 is provided below the particle accumulation section; the cooling device includes a first cooling unit 13 and a second cooling unit 14, and the first cooling unit 13 is connected to the hot air duct 22, and the hot air duct 22 is connected to the hot air duct 22; the cooling device includes a first cooling unit 13 and a second cooling unit 14, and the first cooling unit 13 ... The cooling unit 13 and the second cooling unit 14 are both used to transport the first cooling medium; one end of the first cooling unit 13 is connected to the flat material assembly 7, one end of the second cooling unit 14 is connected to the air distribution plate 10, and the other ends of the first cooling unit 13 and the second cooling unit 14 are connected to the buffer gas storage tank 16; the waste heat recovery device includes a water pump 24, one end of the water pump 24 is connected to an external water source 23, and the other end is connected to a discharge device, a granulation device, a moving bed device, an economizer 19, a waste heat boiler 20 and a boiler drum 21, and the other end of the water pump 24 is used to transport the second cooling medium. The hot air duct 22 at the top of the granulation bin 1 is provided with a water-cooled membrane wall, which effectively prevents the hot air from overheating the hot air duct 22, and at the same time utilizes the heat of the hot air to improve the thermal efficiency of the system, and the heating surface of the ceiling 3 in the granulation bin 1 further absorbs the heat released during the melt granulation process, thereby enhancing the heat exchange effect. A cooling channel is provided in the flat material component 7, which is connected to the first cooling unit 13, ensuring stable temperature control during the granulation process and preventing overheating. The heat exchange tube bundle 8 at the bottom of the moving bed 9 is connected to the second cooling unit 14, which effectively cools the particle accumulation section and improves the heat recovery efficiency. Secondly, the water pump 24 is connected to the external water source 23 to provide a second cooling medium for the discharge device, the moving bed device, the economizer 19, the waste heat boiler 20 and the boiler drum 21, thereby realizing the recycling of energy in the system and reducing energy consumption. Finally, the setting of the air distribution plate 10 enables the cooling medium to be evenly distributed, enhancing the cooling effect, while preventing the accumulation and blockage of particles. The setting of the maintenance channel 5 facilitates the maintenance and inspection of the equipment and improves the reliability and service life of the equipment. Through components such as bag dust collectors 18 and economizers 19, pollutants emitted by the system are effectively reduced, meeting environmental protection standards.

[0035] In this embodiment, the first cooling medium is carbon dioxide, argon or nitrogen.

[0036] In this embodiment, the first cooling unit 13 and the second cooling unit 14 are both fans, and the first cooling unit 13 and the second cooling unit 14 are connected to the buffer gas storage tank 16 through the filter 15 .

[0037] In this embodiment, the second cooling medium is water, a high-temperature organic heat carrier or a nanofluid; among them, water is suitable for scenes with relatively low temperatures. Water has a high specific heat capacity and good thermal conductivity, and can efficiently transfer heat within the conventional temperature range; the high-temperature organic heat carrier is suitable for scenes with relatively high system operating temperatures (usually exceeding 150°C). Compared with water, high-temperature organic heat carriers have lower evaporation pressures and higher thermal stability, and can provide stable heat transfer at higher temperatures while avoiding the problem of water vaporization at high temperatures. Common high-temperature organic heat carriers include silicone oil, aromatic heat carrier oils, etc.; nanofluids are suitable for systems that require extremely high heat transfer efficiency, especially under high heat loads and compact space requirements. By dispersing nanoscale metal or metal oxide particles (such as aluminum oxide, copper oxide, etc.) in water or organic heat carriers, the thermal conductivity of nanofluids has been significantly improved, and can provide higher cooling than conventional fluids.

[0038] In this embodiment, the granulation unit 4 is a sawtooth rotating disk, a cone-top rotating cup or a sandwich rotating multi-pointed disk.

[0039] like Figure 1 As shown, a heat exchange plate 6 is provided at the bottom of the granulation bin 1, and the heat exchange plate 6 is located on one side of the maintenance passage 5. Water-cooled walls 25 are provided around the granulation bin 1 and the moving bed 9. Specifically, the heat exchange plate 6 is located at the bottom of the granulation bin 1, and can directly contact and absorb the heat of the high-temperature slag particles falling from the granulation bin 1. This direct contact heat exchange method usually has a high heat exchange efficiency and helps to quickly reduce the temperature of the slag particles. The heat exchange plate 6 is located on one side of the maintenance passage 5, so that when maintenance and overhaul are required, the staff can easily approach the heat exchange plate 6, reducing the maintenance difficulty and time cost. In addition, the water-cooled wall 25 can absorb the radiant heat of the high-temperature slag and flame in the furnace, and generate steam or hot water in the pipe, thereby reducing the temperature of the furnace wall and protecting the furnace wall from high temperature damage. The water-cooled wall 25 helps to reduce the temperature of the furnace wall and reduce the risks of furnace wall deformation and cracking caused by high temperature, thereby improving the safety of the entire system. The water-cooled wall 25 is arranged around the granulation bin 1 and the moving bed 9, which can further enhance the heat exchange effect of the entire system and improve energy utilization efficiency. Figure 1 As shown, the discharge device includes a spiral discharge machine 12, one end of which is connected to a rotary sealing valve 11, which is connected to the bottom of the moving bed 9; the other end of the spiral discharge machine 12 is provided with a water cooling jacket, which is connected to a water pump 24.

[0040] During specific operation, the granulation device is used to granulate the high-temperature melt and perform preliminary heat exchange. The top of the granulation bin 1 is connected to the convection heat exchange surface 26 through the hot air duct 22. The convection heat exchange surface 26 can be a natural circulation boiler tube bundle including a steam drum, or a forced circulation boiler tube bundle without a steam drum. The natural circulation boiler tube bundle including a steam drum is suitable for occasions with lower loads, and utilizes the temperature difference and density difference of the hot fluid to naturally drive the fluid circulation; the forced circulation boiler tube bundle without a steam drum is suitable for occasions with larger heat loads. By externally pumping the fluid, a higher flow rate can be provided to quickly improve the heat exchange efficiency.

[0041] A water-cooled wall 25 is provided outside the hot air duct 22 and connected to the waste heat recovery device to improve the heat exchange efficiency of the hot air duct 22; an inspection channel 5 is provided in the granulation bin 1 to provide a convenient operating space for maintenance and repair of the equipment, and a flattening assembly 7 is provided at the lower part of the inspection channel 5 to flatten the material layer to prevent slagging caused by particle accumulation; a cooling channel is provided in the flattening assembly 7, and the cooling channel is connected to the first cooling unit 13 to ensure that the particle temperature during the flattening process is appropriate and to prevent slagging caused by local overheating; the granulation unit 4 is arranged at the upper part of the inspection channel 5, and the outlet end of the heat conduction mechanism 2 is opposite to the granulation unit 4, and the high-temperature melt enters the granulation unit 4 from the inlet of the heat conduction mechanism 2; a heat exchange plate 6 is provided at the bottom of the granulation bin 1 to exchange heat with it during the falling process of the particles, and a water-cooled wall 25 is arranged circumferentially around the granulation bin 1, and a moving bed 9 is provided below the granulation bin 1. The moving bed device is used to heat exchange and cool the melt particles and recover waste heat; the particle accumulation section at the bottom of the moving bed 9 is provided with a heat exchange tube bundle 8, and an air distribution plate 10 is provided below the particle accumulation section. The air distribution plate 10 is connected to the second cooling unit 14 and is used to send cooling air into the moving bed 9 to exchange heat with the particles and promote the cooling of the slag particles. The moving bed 9 is circumferentially arranged with a water-cooled wall 25. The discharge device includes a spiral discharger 12, one end of which is connected to a rotary sealing valve 11, which is connected to the bottom of the moving bed 9; the other end of the spiral discharger 12 is provided with a water cooling sleeve, which is connected to a water pump 24. The water cooling sleeve is installed on the outer shell or blade of the spiral discharger 12, surrounding the key parts of the spiral shaft or the conveying pipeline to ensure that the cooling water can effectively take away the heat generated by the discharge of high-temperature slag, further cool the slag particles, and ensure the long-term operation of the spiral discharger 12 and the entire system to avoid failure or efficiency reduction due to overheating.

[0042] In the waste heat recovery device, the water pump 24 delivers the second cooling medium into the system. The second cooling medium exchanges heat with the high-temperature slag particles by flowing through the water-cooled sleeve of the spiral discharge machine 12, the water-cooled wall 25 on the hot air duct 22, the economizer 19, the waste heat boiler 20, the boiler drum 21, the heat exchange tube bundle 8, the water-cooled wall 25, the heat exchange plate 6 and the heating surface of the ceiling 3, thereby realizing waste heat recovery. The cooling device is connected to the cooling channel of the flat material assembly 7 through a pipeline. Specifically, the other end of the first cooling unit 13 and the second cooling unit 14 are both connected to the buffer storage tank 16, and a filter 15 is provided between them to remove impurities in the cooling air and protect the normal operation of the fan. The bag filter 18 is respectively connected to the buffer storage tank 16 and the economizer 19, and the economizer 19 is connected to the waste heat boiler 20. The waste heat boiler 20 is connected to the hot air duct 22 through the convection heat exchange surface 26.

[0043] In a second aspect, a method for recovering waste heat from centrifugal granulation of a high-temperature liquid melt is provided, wherein the method is carried out using the waste heat recovery system for centrifugal granulation of a high-temperature liquid melt as described above, such as Figure 2 As shown, including: S101, granulating the high-temperature liquid melt to obtain high-temperature slag particles; illustratively, the high-temperature liquid melt enters the granulation unit 4 through the heat conduction mechanism 2 for processing, and obtains high-temperature slag particles.

[0044] S102. Convey a first cooling medium and a second cooling medium into a recovery system so that the first cooling medium and the second cooling medium exchange heat with the high-temperature slag particles. Exemplarily, the working process of the first cooling medium is as follows: when conveying the first cooling medium, the first cooling medium in the buffer gas storage tank 16 is respectively conveyed into the air distribution plate 10 and the flat material assembly 7 through the first cooling unit 13 and the second cooling unit 14. After heat exchange, the high-temperature medium passes through the hot air duct 22, and successively passes through the boiler drum 21, the waste heat boiler 20, the economizer 19, and the bag filter 18 before returning to the buffer gas storage tank 16. The buffer gas storage tank 16 then passes through the first cooling unit 13 and the second cooling unit 14 to convey the first cooling medium into the air distribution plate 10 in the moving bed device and the flat material assembly 7 in the granulation device to form a hot air circulation system.

[0045] The second cooling medium waste heat recovery is specifically as follows: when the second cooling medium is transported to the recovery system, the second cooling medium is divided into four paths, the first path flows to the water-cooling jacket of the screw discharger 12 to further cool the slag particles, prevent the screw discharger 12 from overheating, and ensure the long-term operation of the equipment; the second path flows to the water-cooled wall 25 on the hot air duct 22 to reduce the temperature of the hot air duct 22, prevent heat loss, and improve the stability and heat transfer efficiency of the hot air system; the third path flows to the water-cooled wall 25 to directly cool the high-temperature areas such as the wall of the granulating bin 1 to avoid slagging; the fourth path flows to the waste heat boiler 20 to improve the waste heat recovery efficiency and reduce the heat load in the waste heat boiler 20; after the four cooling media converge in the boiler drum 21, they flow into the heat exchange tube bundle 8, the heat exchange plate 6 and the heating surface of the ceiling 3 in turn, and after these heat exchanges, the heat is recovered and finally returned to the boiler drum 21, and heat exchange is fully performed through four cooling paths, which significantly improves the overall waste heat recovery efficiency and ensures the stable operation and high efficiency of the equipment.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the pending claims of the invention.

Claims

1. A high-temperature liquid melt centrifugal granulation waste heat recovery system, characterized in that: include: A granulating device, the bottom of which is connected to a moving bed device, and the bottom of the moving bed device is connected to a discharging device; A cooling device, one end of which is connected to the granulating device and the moving bed device, and the other end of which is connected to a buffer gas storage tank (16), wherein the buffer gas storage tank (16) is connected to an economizer (19) via a bag dust collector (18); The economizer (19) is connected to a convection heat exchange surface (26) via a waste heat boiler (20) and a boiler drum (21); an end of the convection heat exchange surface (26) is connected to a hot air duct (22); and the hot air duct (22) is connected to a granulating device; A waste heat recovery device is connected to the granulation device, the moving bed device, the discharge device, the economizer (19), the waste heat boiler (20) and the boiler drum (21), and is used to recover waste heat from the high-temperature slag particles after granulation.

2. The high-temperature liquid melt centrifugal granulation waste heat recovery system according to claim 1 is characterized in that: The granulation device comprises a granulation bin (1), the top of the granulation bin (1) is connected to a hot air duct (22), and a water-cooled wall (25) is provided on the outside of the hot air duct (22); The granulation bin (1) has a ceiling (3), a granulation unit (4) is provided in the granulation bin (1), a flat material assembly (7) is provided at the bottom of the granulation unit (4) through an inspection passage (5), and a cooling passage is provided in the flat material assembly (7); The moving bed device comprises a moving bed (9), the bottom of the moving bed (9) having a particle accumulation section, the particle accumulation section being provided with a heat exchange tube bundle (8), and an air distribution plate (10) being provided below the particle accumulation section; The cooling device comprises a first cooling unit (13) and a second cooling unit (14), wherein the first cooling unit (13) and the second cooling unit (14) are both used to transport a first cooling medium; One end of the first cooling unit (13) is connected to the flat material assembly (7), one end of the second cooling unit (14) is connected to the air distribution plate (10), and the other ends of the first cooling unit (13) and the second cooling unit (14) are connected to a buffer gas storage tank (16); The waste heat recovery device comprises a water pump (24); one end of the water pump (24) is connected to an external water source (23); the other end of the water pump (24) is connected to a discharge device, a granulation device, a moving bed device, an economizer (19), a waste heat boiler (20) and a boiler drum (21); the other end of the water pump (24) is used to transport a second cooling medium.

3. The high-temperature liquid melt centrifugal granulation waste heat recovery system according to claim 2 is characterized in that: The first cooling medium is carbon dioxide, argon or nitrogen.

4. The high-temperature liquid melt centrifugal granulation waste heat recovery system according to claim 2 is characterized in that: The first cooling unit (13) and the second cooling unit (14) are both fans, and the first cooling unit (13) and the second cooling unit (14) are connected to a buffer gas storage tank (16) via a filter (15).

5. The high-temperature liquid melt centrifugal granulation waste heat recovery system according to claim 2 is characterized in that: The second cooling medium is water, a high-temperature organic heat carrier or a nanofluid.

6. The high-temperature liquid melt centrifugal granulation waste heat recovery system according to claim 2, characterized in that: The granulation unit (4) is a sawtooth rotating disk, a cone-top rotating cup or a sandwich rotating multi-pointed disk.

7. The high-temperature liquid melt centrifugal granulation waste heat recovery system according to claim 2, characterized in that: A heat exchange plate (6) is provided at the bottom of the granulation bin (1), and the heat exchange plate (6) is located on one side of the maintenance passage (5).

8. The high-temperature liquid melt centrifugal granulation waste heat recovery system according to claim 2, characterized in that: Water-cooled walls (25) are provided around the granulation bin (1) and the moving bed (9).

9. The high-temperature liquid melt centrifugal granulation waste heat recovery system according to claim 2, characterized in that: The discharge device comprises a spiral discharge machine (12), one end of the spiral discharge machine (12) is connected to a rotary sealing valve (11), and the rotary sealing valve (11) is connected to the bottom of the moving bed (9); The other end of the spiral discharge machine (12) is provided with a water cooling jacket, and the water cooling jacket is connected to a water pump (24).

10. A method for recovering waste heat from centrifugal granulation of high-temperature liquid melt, characterized in that: The method is carried out by using the high-temperature liquid melt centrifugal granulation waste heat recovery system according to any one of claims 1 to 9, comprising: Granulating the high-temperature liquid melt to obtain high-temperature slag particles; conveying a first cooling medium and a second cooling medium into a recovery system so that the first cooling medium and the second cooling medium exchange heat with the high-temperature slag particles; Wherein, when the first cooling medium is transported into the recovery system, the first cooling medium in the buffer gas storage tank is respectively sent to the air distribution plate and the flat material assembly through the first cooling unit and the second cooling unit. After heat exchange, the high-temperature medium passes through the hot air duct, and successively passes through the boiler drum, the waste heat boiler, the economizer, and the bag filter before returning to the buffer gas storage tank; the buffer gas storage tank then passes through the first cooling unit and the second cooling unit to send the first cooling medium to the air distribution plate in the moving bed device and the flat material assembly in the granulation device, forming a hot air circulation system; When the second cooling medium is transported to the recovery system, the second cooling medium is divided into four paths. The first path flows to the water-cooling jacket of the spiral discharger to further cool the slag particles. The second path flows to the water-cooling wall on the hot air pipe to reduce the temperature of the hot air pipe and improve the stability and heat transfer efficiency of the hot air system. The third route directly cools high-temperature areas such as the wall of the granulation bin, and the fourth route flows to the waste heat boiler to improve waste heat recovery efficiency and reduce the heat load in the waste heat boiler; After the four cooling media merge in the boiler drum, they flow into the heat exchange tube bundle, heat exchange plate and convection heat exchange surface of the ceiling in turn. After these heat exchanges, the heat is recovered and finally returned to the boiler drum.

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