Flow-speed-controllable multi-stage heat exchange waste heat recovery device for high-temperature slag particles

Abstract

The invention discloses a flow-speed-controllable high-temperature slag particle multi-stage heat exchange waste heat recovery device. The device comprises a uniform material distribution unit, a first-stage enhanced heat conduction and heat exchange unit, a gas-solid isolation unit and a second-stage suspension convection heat exchange unit which are sequentially connected from top to bottom; the uniform material distribution unit comprises a surge bin, a variable-frequency speed-regulating feeder arranged below the surge bin, and a material guide disc assembly used for uniformly distributing slag flow; the first-stage enhanced heat conduction and heat exchange unit comprises a pressure-bearing water jacket shell, a flow guide inner cylinder coaxially arranged in the pressure-bearing water jacket shell and a plurality of inclined high-heat-conduction spiral guide rails fixed to the outer wall of the flow guide inner cylinder; the gas-solid isolation unit is a double-gate-plate air-locking discharge valve arranged between the first-stage enhanced heat conduction and heat exchange unit and the second-stage suspended convection heat exchange unit; and the secondary suspension convection heat exchange unit comprises a cavity tower body, and a plurality of layers of airflow ejectors with different ejection angles are arranged on the side wall of the cavity tower body.

Description

Technical Field

[0001] This invention relates to the field of industrial waste heat recovery technology, specifically a high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate. Background Technology

[0002] High-temperature slag is a large quantity of high-temperature solid waste generated during the production processes of metallurgy, chemical industry, and other industries. Its discharge temperature is usually between 1400℃ and 1000℃. After preliminary granulation or crushing, the solid slag particles still carry a large amount of sensible heat. Therefore, efficient recovery of the waste heat from high-temperature solid slag particles is a major requirement for industrial energy conservation and emission reduction, and for achieving the "dual carbon" target. However, existing waste heat recovery devices often have the following problems:

[0003] 1. To improve heat exchange efficiency, it is necessary to extend the residence time of slag particles in the device and increase the heat exchange area. However, this can easily lead to the adhesion and accumulation of high-temperature slag particles on the heat exchange surface, eventually forming stubborn blockages.

[0004] 2. The upstream production process (such as blast furnace slag discharge) is intermittent and fluctuating, which leads to unstable slag particle flow rate entering the waste heat recovery device. Most existing devices lack the ability to accurately control the mass flow rate of slag particles and cannot achieve uniform material distribution in three-dimensional space. The slag flow is sometimes large and sometimes small and unevenly distributed, which directly leads to drastic fluctuations in the heat load of the downstream heat exchange unit, local overheating or insufficient heat exchange, and extremely unstable thermal regime.

[0005] 3. During the cooling process of high-temperature slag particles, the sensible heat grade decreases as the temperature decreases. Most existing technologies only perform single-stage heat exchange, recovering energy in a single form, and have low overall efficiency (effective energy efficiency).

[0006] Therefore, it is necessary to provide a high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate to solve the problems mentioned in the background art. Summary of the Invention

[0007] To achieve the above objectives, the present invention provides the following technical solution: a high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate, comprising a uniform material distribution unit, a first-stage enhanced heat conduction heat exchange unit, a gas-solid isolation unit and a second-stage suspension convection heat exchange unit connected sequentially from top to bottom;

[0008] The uniform material distribution unit includes a buffer bin, a variable frequency speed control feeder disposed below the buffer bin, and a guide plate assembly for uniformly distributing the slag flow.

[0009] The first-level enhanced heat conduction and heat exchange unit includes a pressure-bearing water jacket shell, a flow guide inner cylinder coaxially arranged inside the pressure-bearing water jacket shell, and multiple inclined high thermal conductivity spiral guide rails fixed to the outer wall of the flow guide inner cylinder.

[0010] The gas-solid isolation unit is a double-gate airlock unloading valve located between the primary enhanced heat conduction and heat exchange unit and the secondary suspended convection heat exchange unit.

[0011] The secondary suspended convection heat exchange unit includes a hollow tower body, on which multiple layers of air jets with different injection angles are provided on the side wall;

[0012] It also includes an intelligent control system, which is signal-connected to the variable frequency speed control feeder, the heat exchange circulation system of the pressure-bearing water jacket shell, and the air volume adjustment mechanism of the air jet injector.

[0013] Preferably, the guide plate assembly is rotatably mounted on the top of the guide inner cylinder, and includes a conical pressure-bearing shell with built-in reinforcing ribs. The outer surface of the conical pressure-bearing shell is uniformly provided with multiple streamlined guide wing plates along the circumference. The interior of the conical pressure-bearing shell integrates a cooling cavity, and a cooling mechanism is rotatably arranged in the cooling cavity.

[0014] Preferably, the cooling mechanism includes a conical seat and guide vanes uniformly fixed on the conical seat along the circumference. The guide vanes extend from the bottom of the conical seat to the top of the conical seat, and their shape is adapted to the cooling cavity. A liquid inlet channel is formed between two adjacent guide vanes, the outer wall of the conical seat, and the inner wall of the cooling cavity. A liquid outlet channel is opened at the center of the conical seat, and the tops of the multiple liquid inlet channels are connected to the tops of the liquid outlet channels.

[0015] Preferably, an extension tube communicating with the liquid outlet channel is fixedly provided at the bottom of the conical seat, a sealing plate is fixedly provided at the end of the extension tube, an extension ring is fixedly provided at the bottom of the conical pressure-bearing shell, the sealing plate and the extension ring are rotatably connected in a sealed manner, an annular cavity communicating with the liquid inlet ends of multiple liquid inlet channels is formed between the extension tube and the extension ring, an outlet pipe communicating with the liquid outlet channel and an inlet pipe communicating with the annular cavity are fixedly provided on the sealing plate, and the outlet pipe and the inlet pipe are communicating with an external cooling circulation mechanism.

[0016] Preferably, the bearing surface of the spiral guide rail is inclined to the inner wall of the pressure-bearing water jacket shell, with an inclination angle of 5° to 20°, and the spiral guide rail is made of copper-steel composite material or a metal matrix embedded with a uniform heat pipe.

[0017] Preferably, the lateral airflow jet includes an upper-layer downward-sloping jet, a middle-layer horizontal jet, and a lower-layer upward-sloping jet arranged from top to bottom.

[0018] Preferably, the hot air outlet of the secondary suspended convection heat exchange unit is equipped with a built-in cyclone separator.

[0019] A method for recovering waste heat from high-temperature slag particles through multi-stage heat exchange with controllable flow rate includes the following steps:

[0020] S1. The high-temperature slag particles are received through the uniform material distribution unit, and the variable frequency speed control feeder and the guide plate assembly are used in coordination to achieve precise control of the slag particle flow rate and uniform material distribution in three-dimensional space.

[0021] S2. The slag particles after being evenly distributed enter the first-stage enhanced heat conduction and heat exchange unit, and slide down the inclined spiral guide rail against the inner wall of the pressure-bearing water jacket shell. The high-temperature sensible heat is transferred to the cooling working fluid through contact heat conduction and radiation.

[0022] S3. The slag particles that have completed the first-stage heat exchange are sent to the second-stage suspension convection heat exchange unit through the double gate airlock discharge valve in the gas-solid isolation unit under the condition of physically isolating airflow interference.

[0023] S4. In the secondary suspension convection heat exchange unit, the slag particles are fully dispersed by the rotating suspension flow field formed by the multi-layer lateral airflow injectors, and undergo intense convection heat exchange with the cold air to further recover the medium and low temperature sensible heat.

[0024] S5. Through the intelligent control system, the feeding speed, cooling medium parameters and secondary air distribution parameters are monitored and adjusted in real time to ensure that the entire process from steps S1 to S4 is in a state of coordinated optimization.

[0025] Compared with the prior art, the present invention provides a high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate, which has the following beneficial effects:

[0026] In this invention, the combination of a variable frequency feeder and a rotary guide plate enables precise and proactive digital control of the slag particle mass flow rate from the source, and allows for uniform three-dimensional distribution of the slag flow. This solves the industry problem of unstable system operation caused by fluctuations in upstream material flow, providing a stable and controllable heat source input for subsequent efficient heat exchange. In the primary enhanced heat exchange unit, an inclined high-thermal-conductivity spiral guide rail is installed. Its inclination angle forces the slag particles to slide tightly against the cold wall, transforming the heat transfer mode from traditional loose material layer heat transfer to efficient contact heat transfer. The high-thermal-conductivity material acts as a "thermal bridge" to accelerate heat transfer; the open spiral structure completely eliminates common clogging problems found in moving beds and tubular heat exchangers. In the secondary suspended convection heat exchange unit, a multi-layer swirling jet is used on the sidewall to achieve efficient gas-solid mixing and heat exchange using a strong swirling flow field. The jet is positioned on the side to prevent slag particles from clogging the jet's air inlet. The material guide plate assembly is equipped with a "rotating outer shell + stationary inner core" cooling structure. The equipment's own rotation drives the cooling, achieving high-intensity uniform cooling without internal dynamic seals or additional pump power consumption. This significantly reduces the operating temperature of rotating parts that are directly subjected to high-temperature impacts, resulting in strong resistance to thermal deformation and anti-adhesion capabilities, greatly extending their service life. Furthermore, the intelligent control system organically combines "slag control, water control, and air control" to achieve multi-parameter collaborative optimization and adaptive adjustment, reducing operational difficulty and ensuring that the system operates stably and efficiently at the optimal economic operating point for a long period of time. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of the primary enhanced flow-guiding heat exchange unit in this invention;

[0029] Figure 3 This is a schematic diagram of the flow-guiding inner cylinder in this invention;

[0030] Figure 4 This is a partial cross-sectional structural diagram of the pressure-bearing water jacket and the flow-guiding inner cylinder in this invention;

[0031] Figure 5 This is a schematic diagram of the guide tray assembly in this invention;

[0032] Figure 6 This is a schematic diagram of the conical pressure-bearing shell in this invention;

[0033] Figure 7 This is a schematic diagram of the cooling mechanism in the present invention. Figure 1 ;

[0034] Figure 8 This is a schematic diagram of the cooling mechanism in the present invention. Figure 2 ;

[0035] In the diagram: 1. Buffer chamber; 2. Feed guide plate assembly; 21. Conical pressure shell; 211. Cooling cavity; 212. Extension ring; 22. Feed guide wing plate; 23. Cooling mechanism; 231. Conical seat; 232. Flow guide plate; 233. Liquid outlet channel; 234. Extension pipe; 235. Sealing plate; 236. Liquid outlet pipe; 237. Liquid inlet pipe; 3. Pressure water jacket shell; 31. Water inlet; 32. Gas-water mixture outlet; 4. Flow guide inner cylinder; 5. Spiral guide rail; 6. Double gate airlock unloading valve; 7. Cavity tower body; 100. First-stage enhanced heat transfer unit; 200. Second-stage suspension convection heat transfer unit; 300. Gas-solid isolation unit. Detailed Implementation

[0036] Please see Figures 1 to 8 In this embodiment of the invention, a high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate is described in more detail below with reference to the accompanying drawings and embodiments to make the objectives, technical solutions and advantages of the invention clearer.

[0037] Example 1: Device Example

[0038] This embodiment provides a high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate. Its main body is a tall vertical tower, which integrates a uniform material distribution unit, a first-stage enhanced heat conduction heat exchange unit 100, a gas-solid isolation unit 300 and a second-stage suspension convection heat exchange unit 200 from top to bottom, and is uniformly controlled by an intelligent control system (not shown in the figure), usually a PLC or DCS cabinet.

[0039] The uniform material distribution unit is located at the top of the device. Its core function is to achieve precise control and uniform spatial distribution of slag particle mass flow rate. It includes: a buffer bin 1, lined with wear-resistant and refractory material, used to receive and temporarily store high-temperature slag particles from the upstream granulation system to smooth flow fluctuations; the bin is equipped with a radar level gauge to monitor the material level and send signals to the intelligent control system; a variable frequency speed control feeder, which adopts a high-temperature resistant star feeder, installed at the bottom outlet of the buffer bin 1, and its drive motor is a variable frequency motor, thereby precisely controlling the output flow rate of slag particles, so that the system achieves the effect of "controllable flow rate"; and a guide plate assembly 2, which is installed directly below the feeder and above the guide inner cylinder 3, used to transform a concentrated slag flow into a uniformly sprinkled slag curtain.

[0040] The guide plate assembly 2 includes: a conical pressure-bearing shell 21, which is precision cast from heat-resistant cast steel and has a large cone angle and thin wall structure. To improve rigidity and prevent thermal deformation, its inner wall is cast with a network of radial and circumferential reinforcing ribs. The conical pressure-bearing shell 21 is rotatably mounted on the top of the inner guide cylinder 3 and is driven by a variable frequency motor; multiple guide vanes 22, which are uniformly welded along the circumference of the outer wall of the conical pressure-bearing shell 21. Their function is to guide and throw the slag particles that slide down the conical surface, ensuring that the slag particles fall evenly into the annular cross section of the first-level enhanced heat conduction and heat exchange unit 100 below; a cooling cavity 211 and a cooling mechanism 23. The inside of the conical pressure-bearing shell 21 is a sealed cooling cavity 211 that matches the shape of the outer shell. The cooling mechanism 23 is rotatably mounted in this cavity.

[0041] It should be noted that the guide vane 22 is not installed vertically. Its root is tilted at a backward angle of 15° to 25° with the normal direction of the cone surface (i.e., the tilting direction is opposite to the rotation direction). The airfoil is a streamlined curved surface optimized by hydrodynamics. This allows the falling slag particles to be guided around the vane when they impact it. The tangential component of the impact force on the inclined surface can also effectively assist in driving the guide disk to rotate, thereby significantly reducing the load on the drive motor and achieving energy saving.

[0042] The cooling mechanism 23 includes: a conical seat 231, which is a conical casting with its axis coinciding with the axis of the conical pressure shell 21; multiple guide vanes 232, which are welded around the conical seat 231, and their shape is adapted to the inner wall of the cooling cavity 211 while maintaining a gap, the guide vanes 232 dividing the cooling cavity 211 into multiple independent liquid inlet channels; and a liquid circuit system, in which the conical seat 231 has a liquid outlet channel 233 at its center, and an extension pipe 234 and a sealing disc 235 are connected to the bottom, the bottom of the conical pressure shell 21 has an extension ring 212, the sealing disc 235 and the extension ring 212 are connected to each other by a high-temperature mechanical seal, an annular cavity is formed between the extension pipe 234 and the extension ring 212, and the sealing disc 235 is connected to an inlet pipe 237 and an outlet pipe 236, which are connected to an external closed cooling circulation system (including a circulating pump, a plate heat exchanger, and an expansion tank).

[0043] Working principle: When the conical pressure shell 21 rotates, the cooling water inside it flows closely against the inner wall of the cooling cavity 211 relative to the conical pressure shell 21. This allows the cooling water to uniformly cool the entire pressure-bearing surface of the conical pressure shell 21, making the surface temperature of the conical pressure shell 21 more uniform and preventing hot spots. Subsequently, the heated water flows to the top of the cavity, flows into the central liquid outlet channel 233, and is discharged to the external heat exchanger for cooling through the liquid outlet pipe 236. The cooled water is pumped into the annular cavity through the liquid inlet pipe 237 and evenly distributed to the bottom of multiple liquid inlet channels to complete the circulation. This effectively reduces and maintains the temperature of the working surface of the guide plate, solves the problems of high-temperature slag adhesion and deformation, and improves the service life of the guide plate.

[0044] The primary enhanced heat transfer unit 100 is located directly below the feed tray assembly 2. It includes: a pressure-bearing water jacket shell 3, which is a vertical cylinder with a water inlet 31 at the bottom and a steam-water mixture outlet 32 ​​at the top, connected to an external steam drum, which can generate saturated steam for power generation; a flow guide inner cylinder 4, which is coaxially installed inside the pressure-bearing water jacket and mainly serves as a flow guide and mounting base; and eight spiral guide rails 5, which are welded to the outer wall of the flow guide inner cylinder 4 with a spiral helix angle of 32°. The bearing surface of the spiral guide rails is inclined at 10° to the inner wall of the water jacket. This inclination angle forces the sliding slag particles to slide tightly against the cold inner wall of the water jacket, thereby completing efficient heat exchange.

[0045] The gas-solid isolation unit 300 adopts a double-gate airlock unloading valve 6, whose valve plate is water-cooled and driven by a hydraulic system. During operation, the two valve plates open and close alternately, and nitrogen is introduced into the intermediate chamber to form an air curtain seal, thereby physically isolating the airflow of the first-stage and second-stage suspended convection heat exchange units 200, ensuring that the two-stage heat exchange conditions are independent and do not interfere with each other.

[0046] The secondary suspension convection heat exchange unit 200 is used for deep recovery of slag particles at medium and low temperature sensible heat. It includes: a hollow tower body 7, which is cylindrical in shape and lined with a refractory insulation layer; and airflow injectors, which are arranged in three layers along the height direction of the hollow tower body 7, with multiple injectors evenly distributed in each layer.

[0047] The lower ejector is installed at the bottom of the tower body at an angle of 35° upwards to disperse and lift the falling slag particles, forming an initial fluidized state. The middle ejector is installed in the middle of the tower body at an angle of 0° horizontally to maintain a strong horizontal vortex in the center of the tower body, so that the slag particles are in a "rotating suspended bed" state, which greatly prolongs the gas-solid contact time. The upper ejector is installed at the top of the tower body at an angle of 15° downwards to form a suppressive air curtain, which promotes the settling of slag particles and prevents fine powder from being directly carried away.

[0048] The top of the hollow tower body 7 is also equipped with a built-in cyclone separator, which is used to perform primary purification of the outlet hot air, capture most of the particles, and export the hot air, which can be used for raw material drying.

[0049] The intelligent control system employs a PLC-based distributed control system. The system collects signals in real time from pressure sensors in the steam drum, temperature sensors at various levels, feeder speed feedback, and fan frequency. Through built-in PID control algorithms and collaborative logic, it achieves the following:

[0050] 1) The feeder speed is automatically adjusted according to the steam drum pressure to stabilize the steam production load;

[0051] 2) Fine-tune the cooling water circulation rate based on the temperature in the middle of the primary enhanced heat transfer unit 100;

[0052] 3) Dynamically adjust the total air volume and ratio of the three-layer ejector according to the secondary slag discharge temperature.

[0053] Furthermore, all operations can be completed in the central control room, achieving efficient, unmanned operation around the clock.

[0054] Example 2: Method Example

[0055] This embodiment describes in detail the process method for waste heat recovery using the above-mentioned device, which includes the following steps:

[0056] S1. Precise Flow Control and Uniform Material Distribution: Slag particles from the granulation system enter the buffer bin 1. The intelligent control system adjusts the speed of the variable frequency feeder based on upstream signals and the setpoint of the local steam drum pressure, thereby stabilizing the slag flow. Simultaneously, it drives the guide plate assembly 2 to rotate, causing the slag particles to be evenly distributed and enter the first-stage enhanced heat transfer unit 100. During this process, the rotating guide plate achieves self-uniform cooling through its unique internal cooling structure, ensuring stable plate surface temperature and guaranteeing material distribution accuracy and component lifespan from the source.

[0057] S2, First-level enhanced heat conduction and heat exchange: The slag particles fall onto the spiral guide rail 5 of the first-level enhanced heat conduction and heat exchange unit 100. Under the guidance of gravity and a 10° inclination angle, the slag particles spiral down close to the inner wall of the cold pressure-bearing water jacket shell 3. The heat is efficiently transferred to the water in the water jacket through direct contact conduction and the "thermal bridge" effect of the high thermal conductivity copper-steel composite spiral guide rail 5. At the same time, the slag particles are cooled. At this time, a large amount of saturated steam is generated in the water jacket, thereby transforming the inefficient radiation and convection into efficient contact conduction.

[0058] S3. Gas-solid physical isolation conveying: The slag particles that have completed the first-stage heat exchange fall into the double-gate airlock discharge valve 6. The programmed alternating opening and closing of the valve and the nitrogen sealing ensure that the slag particles are sent into the second-stage tower under the condition of complete isolation from airflow. This is the key to preventing the thermal characteristics of the high and low temperature sections from interfering with each other and ensuring the efficient operation of each stage.

[0059] S4. Secondary Suspension Convection Deep Heat Exchange: After the slag particles enter the secondary tower 7, they are dispersed and lifted by the impact of the high-speed airflow in the lower layer, and then drawn into the "suspension rotating bed" by the strong vortex in the middle layer. Here, the slag particles undergo intense and sufficient countercurrent convection heat exchange with the ambient temperature air. The heat-exchanged slag particles are then discharged through the bottom slag discharge valve. During this process, the air is heated and becomes a high-quality hot air product after being dusted by the top cyclone separator. The core of this stage is to create a "suspension vortex" flow pattern, which achieves extremely high gas-solid heat exchange intensity and waste heat recovery depth in a compact space.

[0060] S5. Intelligent Collaborative Optimization Throughout the Entire Process: The intelligent control system acts as the "brain" throughout the entire process. It fine-tunes the feeding speed of S1 in real time based on the target pressure value of the steam drum in S2; adjusts the cooling water flow rate based on the temperature monitoring point in the middle of the S2 unit; and dynamically optimizes the air volume ratio of the three-layer injectors in S4 based on the temperature feedback of the target slag particles from the temperature sensor at the slag discharge port. The entire process constitutes multiple closed-loop control loops, ensuring that the device always operates adaptively at the optimal efficiency point.

[0061] In summary, this invention, through the combination of a "variable frequency feeder + rotary guide plate," achieves precise and proactive digital control of the slag particle mass flow rate from the source, and can uniformly distribute the slag flow in three dimensions. This solves the industry problem of unstable system operation caused by fluctuations in upstream material flow, providing a stable and controllable heat source input for subsequent efficient heat exchange. In the first-stage enhanced heat exchange unit 100, an inclined high-thermal-conductivity spiral guide rail is installed. Its inclination angle forces the slag particles to slide tightly against the cold wall, transforming the heat transfer mode from traditional loose material layer heat transfer to efficient contact heat transfer. High-thermal-conductivity materials act as "thermal bridges" to accelerate heat transfer. The open spiral structure completely eliminates common clogging problems found in moving beds and tubular heat exchangers. In the second-stage suspended convection heat exchange unit 2… The system employs a multi-layered swirling jet spray on the side wall, utilizing a strong swirling flow field to achieve efficient gas-solid mixing and heat exchange. The ejector is positioned on the side to prevent slag particles from clogging the ejector's air inlet. Furthermore, the "rotating outer shell + stationary inner core" cooling structure of the guide plate assembly 2 utilizes the equipment's own rotational drive for cooling, achieving high-intensity, uniform cooling without internal dynamic seals or additional pump power consumption. This significantly reduces the operating temperature of rotating components directly subjected to high-temperature impacts, resulting in strong resistance to thermal deformation and anti-adhesion capabilities, greatly extending its service life. The intelligent control system organically combines "slag control, water control, and air control," achieving multi-parameter collaborative optimization and adaptive adjustment, reducing operational difficulty and ensuring long-term, stable, and efficient operation of the system at the optimal economic operating point.

[0062] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate, characterized in that, It includes a uniform material distribution unit, a primary enhanced heat conduction and heat exchange unit, a gas-solid isolation unit, and a secondary suspended convection heat exchange unit connected sequentially from top to bottom; The uniform material distribution unit includes a buffer chamber (1), a variable frequency speed control feeder disposed below the buffer chamber (1), and a guide plate assembly (2) for uniformly distributing the slag flow. The first-level enhanced heat conduction and heat exchange unit includes a pressure-bearing water jacket shell (3), a flow guide inner cylinder (2) coaxially arranged inside the pressure-bearing water jacket shell (3), and multiple inclined high thermal conductivity spiral guide rails (5) fixed to the outer wall of the flow guide inner cylinder (2); The gas-solid isolation unit is a double-gate airlock unloading valve (6) located between the primary enhanced heat conduction and heat exchange unit and the secondary suspension convection heat exchange unit; The secondary suspended convection heat exchange unit includes a cavity tower (7), and its sidewall is provided with multiple layers of air jets with different injection angles; It also includes an intelligent control system, which is signal-connected to the variable frequency speed control feeder, the heat exchange circulation system of the pressure water jacket shell (3), and the air volume adjustment mechanism of the air jet.

2. The high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate according to claim 1, characterized in that, The guide plate assembly (2) is rotatably mounted on the top of the guide inner cylinder (3). It includes a conical pressure-bearing shell (21) with built-in reinforcing ribs. Multiple streamlined guide wing plates (22) are uniformly arranged on the outer surface of the conical pressure-bearing shell (21) along the circumference. A cooling cavity (211) is integrated inside the conical pressure-bearing shell (211). A cooling mechanism (23) is rotatably arranged in the cooling cavity (211).

3. The high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate according to claim 2, characterized in that, The cooling mechanism (23) includes a conical seat (231) and guide vanes (232) uniformly fixed on the conical seat (231) along the circumference. The guide vanes (232) extend from the bottom of the conical seat (231) to the top of the conical seat (231), and their shape is adapted to the cooling cavity (211). A liquid inlet channel is formed between two adjacent guide vanes (232), the outer wall of the conical seat (231), and the inner wall of the cooling cavity (211). A liquid outlet channel (233) is opened at the center of the conical seat (231), and the top of the multiple liquid inlet channels is connected to the top of the liquid outlet channel (233).

4. The high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate according to claim 3, characterized in that, The bottom of the conical seat (231) is fixedly provided with an extension tube (234) communicating with the liquid outlet channel (233). The end of the extension tube (234) is fixedly provided with a sealing plate (235). The bottom of the conical pressure shell (21) is fixedly provided with an extension ring (212). The sealing plate (235) and the extension ring (212) are sealed and rotatably connected. An annular cavity communicating with the liquid inlet end of multiple liquid inlet channels is formed between the extension tube (234) and the extension ring (212). The sealing plate (235) is fixedly provided with a liquid outlet pipe (236) communicating with the liquid outlet channel (233) and an inlet pipe (237) communicating with the annular cavity. The liquid outlet pipe (236) and the inlet pipe (237) are connected to an external cooling circulation mechanism.

5. The high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate according to claim 1, characterized in that, The bearing surface of the spiral guide rail (5) is inclined to the inner wall of the pressure-bearing water jacket shell (3) at an angle of 5° to 10°, and the spiral guide rail (5) is made of copper-steel composite material or metal matrix embedded with heat pipes.

6. The high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate according to claim 1, characterized in that, The lateral airflow jet includes an upper-layer downward-sloping jet, a middle-layer horizontal jet, and a lower-layer upward-sloping jet arranged from top to bottom.

7. The high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate according to claim 1, characterized in that, The hot air outlet of the secondary suspended convection heat exchange unit is equipped with a built-in cyclone separator.

8. A method for recovering waste heat from high-temperature slag particles through multi-stage heat exchange with controllable flow rate, comprising using a high-temperature slag particle multi-stage heat exchange waste heat recovery device with controllable flow rate as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. High-temperature slag particles are received through the uniform material distribution unit, and the variable frequency speed control feeder and the guide plate assembly (2) are used to control the slag particle flow rate and uniform material distribution in three-dimensional space. S2. After being uniformly distributed, the slag particles enter the first-level enhanced heat conduction and heat exchange unit and slide down the inclined spiral guide rail (5) against the inner wall of the pressure-bearing water jacket shell (3). The high-temperature sensible heat is transferred to the cooling working fluid through contact heat conduction and radiation. S3. The slag particles that have completed the first-stage heat exchange are sent to the second-stage suspension convection heat exchange unit through the double gate airlock discharge valve (6) in the gas-solid isolation unit under the condition of physically isolating airflow interference. S4. In the secondary suspension convection heat exchange unit, the slag particles are fully dispersed by the rotating suspension flow field formed by the multi-layer lateral airflow injectors, and undergo intense convection heat exchange with the cold air to further recover the medium and low temperature sensible heat. S5. Through the intelligent control system, the feeding speed, cooling medium parameters and secondary air distribution parameters are monitored and adjusted in real time to ensure that the entire process from steps S1 to S4 is in a state of coordinated optimization.

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