Industrial waste heat recovery gradient utilization device and method based on multiphase flow enhanced heat transfer

Abstract

The invention belongs to the technical field of heat exchange devices, and particularly relates to an industrial waste heat recovery gradient utilization device and method based on multiphase flow enhanced heat transfer, which comprises a feeding conveyor belt for conveying materials, a drying cylinder and a tail gas treatment assembly, and further comprises a waste heat collection assembly and a heat transfer assembly which are sequentially connected with the tail gas treatment assembly, the waste heat collecting assembly is provided with a plurality of heat absorption points, absorbs heat from the tail gas treatment assembly and conducts the heat to materials of the feeding conveying belt along the heat transfer assembly. The opening and closing type heat insulation assembly is arranged in the feeding conveying belt, the heat transfer assembly penetrates through the opening and closing type heat insulation assembly, and the opening and closing type heat insulation assembly has three states of closing, opening and impacting; and during closing, the opening and closing type heat insulation assembly reaches the preset sealing degree at the overlapping position of the feeding conveying belt and the heat transfer assembly. A plurality of heat absorption points are arranged, gradient utilization of waste heat is carried out, meanwhile, three states of closing, opening and impacting are set, heat loss is reduced, and by-products generated by waste heat recovery are discharged.

Description

Technical Field

[0001] This invention belongs to the technical field of heat exchange devices, specifically relating to an industrial waste heat recovery and cascade utilization device and method based on multiphase flow enhanced heat transfer. Background Technology

[0002] In shotcrete granulation production, the wet granules produced by the granulator are continuously fed into the drying drum by a belt or screw conveyor. High-temperature hot air generated by a hot air furnace is blown into the drying drum, causing the hot air to exchange heat with the wet granules in a counter-current or co-current flow. The exhaust gas discharged from the drying drum carries heat, which is generally recovered and utilized using a waste heat recovery device.

[0003] Existing waste heat recovery devices generally utilize heat-conducting media to transfer heat. For example, the retrieved Chinese invention patent application (publication number: CN120333195A) discloses a high-efficiency cascade utilization system and method for recovering waste heat from medium and low temperature flue gas. By cooperating with the exhaust mechanism through the arc-shaped depression at the center of the inner side of the heat medium chamber, the contact area between the inner side of the heat medium chamber and the flue gas is increased. Combined with the exhaust mechanism's restriction on the exhaust of flue gas, the contact area between the flue gas and the heat medium chamber is increased, while the contact time between the flue gas and the heat medium chamber is also increased, so that the heat of the medium and low temperature flue gas is more effectively transferred to the heat-conducting media inside the heat medium chamber.

[0004] In actual exhaust gas waste heat recovery processes, the waste heat utilization method of increasing the heat conduction contact area at fixed points is easily affected by the temperature differences in the exhaust gas treatment process, causing the temperature at the end point of waste heat conduction to fluctuate, making it difficult to improve the temperature uniformity of waste heat utilization. Summary of the Invention

[0005] The purpose of this invention is to provide an industrial waste heat recovery and cascade utilization device and method based on multiphase flow enhanced heat transfer. It can set up multiple heat absorption points to carry out cascade utilization of waste heat, and set up three states: closed, open and impact, to reduce heat loss and discharge the by-products generated by waste heat recovery.

[0006] The specific technical solution adopted by this invention is as follows: An industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer includes a feeding conveyor belt for conveying materials, a drying cylinder, and a tail gas treatment assembly, and further includes: The waste heat collection component and the heat transfer component are connected in sequence to the exhaust gas treatment component. The waste heat collection component has multiple heat absorption points, which absorb heat from the exhaust gas treatment component and conduct it along the heat transfer component to the material on the feeding conveyor belt. An openable heat insulation component is installed inside the feeding conveyor belt and is penetrated by the heat transfer component. The openable heat insulation component has three states: closed, open, and impact. When closed, the openable heat insulation component closes at the position where the feeding conveyor belt overlaps with the heat transfer component to reduce heat loss. When opened, the openable heat insulation component discharges the byproducts of waste heat recovery; Upon impact, the openable thermal insulation component generates an impact force that acts on the byproducts, causing them to detach.

[0007] As an optional embodiment, the retractable thermal insulation assembly includes components disposed inside the feeding conveyor belt: The base and two baffles located on both sides of the base; Temperature sensors are used to monitor the temperature at the overlap point between the feeding conveyor belt and the heat transfer component in real time. A vertically connected mounting base, linear electric cylinder, and support plate are arranged in sequence. The bottom of the linear electric cylinder is connected to the base via the mounting base, and the cylinder rod of the linear electric cylinder is connected to the adjacent baffle via the support plate. When the temperature exceeds the temperature threshold, the linear electric cylinder rod extends and lifts the support plate and two baffles until the two baffles stick to the base and reach the closed state. When the temperature value does not exceed the temperature threshold, the linear electric cylinder rod shortens and lowers the support plate and two baffles, thereby opening the gap between the two baffles and the base, achieving the open state.

[0008] As an alternative, a bent rod and an impact member are welded sequentially to the sides of the two baffles that are close to each other, and the bent rod and the impact member are offset from the support plate along the axial direction of the linear electric cylinder; When the open state is reached, the linear electric cylinder intermittently lowers the support plate until the bent rod and impact member impact the base at a preset frequency, generating an impact force that acts on the by-product, causing it to fall off.

[0009] As an alternative, the base is folded with a central protrusion, and a first extension and a second extension are provided at the interval between the base and the two baffles. A polyurethane layer is bonded to the top of both baffles. When the first extension and the second extension come into contact, the base and the two baffles are closed.

[0010] As an optional solution, the heat transfer assembly includes a hollow heat-conducting roller, a third heat-conducting pipe, and a second spiral section arranged vertically in sequence. Rotary joints are connected between the two ends of the hollow heat-conducting roller and the opening of the third heat-conducting pipe, and mounting flanges are provided on the outside of the rotary joints. During operation, the second spiral segment partially overlaps with the waste heat collection component in a spiral manner, so that the heat absorbed by the waste heat collection component is conducted to the material on the feeding conveyor belt along the second spiral segment, the third heat-conducting pipe and the hollow heat-conducting roller.

[0011] As an optional solution, the waste heat collection assembly includes heat-conducting fins, a first heat-conducting pipe, a second heat-conducting pipe, and a first spiral section connected in sequence; The number of heat-conducting fins is set to three sets, which are used to form heat absorption points at different locations of the exhaust gas treatment component.

[0012] As an alternative, the feeding conveyor belt includes a frame and a belt located inside the frame, with a motor for rotating the belt and a controller for controlling the motor installed outside the frame; The openable heat insulation component is located inside the belt and is used to partially surround the top of the heat transfer component.

[0013] As an alternative, the drying cylinder includes a feed hopper, a first cylinder body, a second cylinder body, and a third cylinder body that are connected in a transverse sequence. An air inlet pipe for providing high-temperature gas is connected to the outside of the first cylinder body, and the third cylinder body is connected to an exhaust gas treatment assembly. When the feeding conveyor belt transports materials, the feeding hopper opens and receives the materials.

[0014] As an optional solution, the exhaust gas treatment assembly includes a first exhaust gas treatment pipe, a waste liquid tank, a second exhaust gas treatment pipe, and a third exhaust gas treatment pipe that are sequentially connected to the drying cylinder. The heat absorption point is located in the first exhaust gas treatment pipe, the second exhaust gas treatment pipe, and the third exhaust gas treatment pipe.

[0015] A method for cascade utilization of industrial waste heat recovery based on multiphase flow enhanced heat transfer, using the aforementioned industrial waste heat recovery cascade utilization device based on multiphase flow enhanced heat transfer, includes the following steps: Feeding stage: The feeding conveyor belt starts and continuously feeds the material into the drying cylinder. At the same time, the hot air furnace generates high-temperature gas and blows it into the drying cylinder to dry the material. The drying cylinder rotates and turns the material to increase the air-receiving area. Exhaust gas treatment stage: The exhaust gas treatment component filters impurities in the exhaust gas and sprays a solution, providing negative pressure suction to release the filtered exhaust gas into the atmospheric environment. Waste heat collection stage: The waste heat collection component forms three absorption hotspots at different locations in the exhaust gas treatment component and forms a closed loop outside the exhaust gas treatment component for the flow of heat transfer medium and to cooperate with the three absorption hotspots for heat absorption. Heat transfer stage: The heat transfer component and the waste heat collection component are spirally overlapped, and the temperature difference between the two realizes heat transfer. The heat of the waste heat collection component is conducted along the heat transfer component to the material on the feeding conveyor belt to achieve preheating of the material. Heat utilization stage: When the temperature value of the heat transfer component is detected to exceed the temperature threshold, the opening and closing heat insulation component is controlled to enter the closed state, forming a preset seal on the outside of the heat transfer component to reduce heat loss; when the temperature value of the heat transfer component is detected not to exceed the temperature threshold, the opening and closing heat insulation component is controlled to enter the open and impact state, generating an impact force that acts on the by-products, causing them to fall off.

[0016] The technical effects achieved by this invention are as follows: This invention incorporates multiple heat absorption points to absorb heat from the exhaust gas treatment process and transfer it to materials at different locations on the feeding conveyor belt, enabling tiered utilization of waste heat. The openable heat insulation component has three states: closed, open, and impact. When closed, the belt and the hollow heat-conducting roller overlap to reduce heat loss. When open, the openable heat insulation component discharges the byproducts of waste heat recovery. During impact, the openable heat insulation component generates an impact force that acts on the byproducts, causing them to detach.

[0017] This invention employs three heat absorption points, spaced apart in different temperature zones of the exhaust gas treatment system, and using different heat transfer media. The heat transfer paths of the three heat absorption points are relatively isolated to prevent mutual interference, reduce the degree of temperature fluctuation at the endpoint of waste heat conduction, and improve the temperature uniformity of waste heat utilization.

[0018] This invention uses only a linear electric cylinder to achieve three states of the opening and closing heat insulation component: closed, open, and impact. It has a simple structure, a high degree of automation, and is suitable for continuous production in spray granulation towers.

[0019] This invention utilizes ethylene glycol / propylene glycol aqueous solution, mineral oil or synthetic oil, high-temperature heat transfer oil, and pentafluoropropane as heat transfer media to achieve enhanced multiphase flow heat transfer. The pentafluoropropane undergoes gas-liquid phase changes for rapid heat transfer. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer in Embodiment 1 of the present invention. Figure 2 This is the invention Figure 1 Schematic diagram of the residual heat collection component; Figure 3 This is the invention Figure 1 Cross-sectional view of the first exhaust gas treatment pipe in the middle; Figure 4 This is the invention Figure 1 Cross-sectional view of the second and third exhaust gas treatment pipes; Figure 5 This is the invention Figure 3 Top view of the central heat-conducting fin; Figure 6 This is the invention Figure 2 Schematic diagram of the heat transfer component; Figure 7 This is the invention Figure 2 Cross-sectional view of the heat transfer component; Figure 8 This is the invention Figure 6 Cross-sectional view of a hinged thermal insulation component; Figure 9 This is the invention Figure 8 Cross-sectional view of the central base; Figure 10 This is the invention Figure 8 Cross-sectional view of the middle baffle; Figure 11 This is the invention Figure 1 System block diagram of the controller controlling the signal transmission status; Figure 12 This is a flowchart of a method for the cascade utilization of industrial waste heat recovery based on multiphase flow enhanced heat transfer, as described in Embodiment 2 of the present invention.

[0021] The attached diagram lists the components represented by each number as follows: 1. Feeding conveyor belt; 101. Frame; 102. Belt; 103. Motor; 104. Controller; 2. Drying cylinder; 201. Feed hopper; 202. First cylinder body; 203. Air inlet pipe; 204. Second cylinder body; 205. Third cylinder body; 3. Exhaust gas treatment assembly; 301. First exhaust gas treatment pipe; 302. Waste liquid tank; 303. Second exhaust gas treatment pipe; 304. Third exhaust gas treatment pipe; 4. Waste heat collection assembly; 401. First heat pipe; 402. Heat-conducting fins; 403. Second heat pipe; 404. First spiral section; 5. Heat transfer components; 501. Hollow heat-conducting roller; 502. Third heat-conducting pipe; 503. Second spiral section; 504. Rotary joint; 505. Mounting flange; 6. Openable thermal insulation component; 601. Base; 602. Baffle; 603. Temperature sensor; 604. Mounting base; 605. Linear electric cylinder; 606. Support plate; 607. First extension; 608. Second extension; 609. Polyurethane layer; 6010. Bending rod; 6011. Impact component. Detailed Implementation

[0022] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0023] Example 1: like Figures 1-11 As shown, an industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer includes a feeding conveyor belt 1 for conveying materials, a drying cylinder 2, a tail gas treatment component 3, a waste heat collection component 4 and a heat transfer component 5 connected in sequence to the tail gas treatment component 3. In the post-processing of the spray granulation tower, the wet granules after being granulated by the spray granulator are continuously fed into the drying cylinder 2 by the feeding conveyor belt 1. At the same time, the hot air furnace generates high-temperature gas and blows it into the drying cylinder 2 to form countercurrent or cocurrent heat exchange with the wet granules, thereby realizing the material drying function. The waste heat collection component 4 has multiple heat absorption points, which absorb heat from the tail gas treatment component 3 and conduct it along the heat transfer component 5 to the material on the feeding conveyor belt 1 for preheating. The feeding conveyor belt 1 is equipped with an openable heat insulation component 6 that is penetrated by the heat transfer component 5. The openable heat insulation component 6 is provided with three states: closed, open, and impact. When closed, the openable heat insulation component 6 closes at the overlapping position of the feeding conveyor belt 1 and the heat transfer component 5 to reduce heat loss and concentrate the heat of the heat transfer component 5 to the feeding conveyor belt 1 for material preheating. When opened, the openable insulation component 6 discharges byproducts of waste heat recovery, such as condensate and material residue. During impact, the openable heat insulation component 6 generates an impact force that acts on the by-products, causing them to detach and increasing the rate of by-product discharge.

[0024] See attached document Figure 1 The feeding conveyor belt 1 includes a frame 101 and a belt 102 located inside the frame 101. The support roller inside the frame 101 is used to support the belt 102. The frame 101 is equipped with a motor 103 for rotating the belt 102 and a controller 104 for controlling the motor 103. The controller 104 is connected to the motor 103 through a signal line. When the motor 103 starts, it rotates the support roller at a uniform speed and drives the belt 102 to rotate. The belt 102 carries the material forward to realize continuous feeding. The openable heat insulation component 6 is installed inside the belt 102 and is used to partially surround the top of the heat transfer component 5. It can achieve a preset sealing degree, reduce the heat loss of the heat transfer component 5, and concentrate the heat of the heat transfer component 5 to the feeding conveyor belt 1.

[0025] See attached document Figure 1 , Figure 3 and Figure 4The drying cylinder 2 includes a feed hopper 201, a first cylinder 202, a second cylinder 204, and a third cylinder 205 connected in a horizontal sequence. The first cylinder 202 and the third cylinder 205 are both mounted on the ground by supports. The second cylinder 204 is connected to the first cylinder 202 and the third cylinder 205 by an annular slide rail. When the material enters the second cylinder 204, the second cylinder 204 is rotated by a drive wheel. The inclined guide plate inside the second cylinder 204 turns the material. The outside of the first cylinder 202 is connected to an air inlet pipe 203 for providing high-temperature gas. The high-temperature gas generated by the hot air furnace is blown into the first cylinder 202, the second cylinder 204, and the third cylinder 205 along the air inlet pipe 203, where it exchanges heat with the material to achieve drying. The exhaust gas generated in the third cylinder 205 due to heat exchange is discharged along the exhaust gas treatment component 3. When the feeding conveyor belt 1 conveys materials, the feeding hopper 201 opens and receives the materials until the materials slide down the first cylinder 202 and fall into the second cylinder 204. After the feeding is completed, the feeding hopper 201 closes, so that the materials exchange heat with the high-temperature gas in the relatively sealed second cylinder 204.

[0026] See attached document Figure 1 , Figure 3 and Figure 4 The exhaust gas treatment assembly 3 includes a first exhaust gas treatment pipe 301, a waste liquid tank 302, a second exhaust gas treatment pipe 303, and a third exhaust gas treatment pipe 304, which are sequentially connected to the drying cylinder 2. When treating the exhaust gas, the first exhaust gas treatment pipe 301 filters dust and other impurities in the exhaust gas through a dust collector bag or a cyclone dust collector, resulting in a first airflow with a temperature of approximately 200°C. (See [link]). Figure 4 The second exhaust gas treatment pipe 303 sprays ammonia water, urea solution or limestone slurry into the first gas flow to carry out denitrification and desulfurization treatment, and obtains a second gas flow with a temperature of about 60°C. The third exhaust gas treatment pipe 304 has a built-in induced draft fan with an operating temperature range of 30°C to 40°C, which provides negative pressure attraction for the first and second gas flows, and can discharge the second gas flow into the atmospheric environment. The heat absorption points are located in the first exhaust gas treatment pipe 301, the second exhaust gas treatment pipe 303, and the third exhaust gas treatment pipe 304, respectively, to recover waste heat from the first gas flow at a temperature of about 200°C, the second gas flow at a temperature of about 60°C, and the tail flow with a temperature range of 30°C to 40°C.

[0027] See attached document Figure 2 , Figure 4 and Figure 5The waste heat collection assembly 4 includes heat-conducting fins 402, a first heat-conducting pipe 401, a second heat-conducting pipe 403, and a first spiral section 404 connected in sequence. The heat-conducting fins 402 are arranged in three groups to form three heat absorption points at different locations in the exhaust gas treatment assembly 3. The first heat-conducting pipe 401, the second heat-conducting pipe 403, and the first spiral section 404 form a closed loop for the flow of the heat-conducting medium. (See [reference]). Figure 5 Each group has fifteen heat-conducting fins 402 evenly spaced and penetrated by adjacent first heat-conducting pipes 401. Due to the temperature difference of the three absorption points, the three groups of heat-conducting fins 402 need to be filled with different heat-conducting media. For example, one closed loop is filled with an ethylene glycol / propylene glycol aqueous solution, which is suitable for waste heat recovery of the tail flow with a temperature range of 30℃~40℃. Another closed loop is filled with mineral oil such as L-QB300 and L-QC320 or synthetic oil such as poly-α-olefin and diester, which is suitable for waste heat recovery of the second air flow with a temperature of about 60℃. One closed loop is filled with high-temperature heat-conducting oil, which is suitable for waste heat recovery of the first air flow with a temperature of about 200℃.

[0028] As an optional embodiment, the heat-conducting fins 402 are milled from an alloy cylinder and coated with an anti-stick coating to prevent dust and other impurities from adhering to the surface. Both the first heat-conducting pipe 401 and the second heat-conducting pipe 403 are covered with a polyurethane insulation layer. The second heat-conducting pipe 403 is supported by a bracket. Two semi-circular insulation covers are bolted to the outside of the first spiral section 404. The interior of the semi-circular insulation covers is filled with a polyurethane insulation layer. An oil pump is installed on the second heat-conducting pipe 403 via a connector. (See [reference]). Figure 11 The oil pump is electrically connected to the controller 104. The pump is used to agitate the heat transfer medium to flow unidirectionally within the closed loop, thereby achieving continuous heat transfer.

[0029] See attached document Figure 1 , Figure 2 and Figure 6The heat transfer assembly 5 includes a hollow heat-conducting roller 501, a third heat-conducting pipe 502, and a second spiral section 503 arranged vertically in sequence. Rotary joints 504 connect the two ends of the hollow heat-conducting roller 501 to the openings of the third heat-conducting pipe 502. A mounting flange 505 is provided on the outside of the rotary joint 504. During installation, the mounting flange 505 is fixed to the inside of the frame 101 with bolts to provide support, ensuring the connection between the hollow heat-conducting roller 501, the third heat-conducting pipe 502, the second spiral section 503, and the rotary joint 504. The head 504 forms a suspended heat transfer loop, which is filled with sufficient pentafluoropropane. The boiling point of pentafluoropropane is 15.3℃. It can absorb the heat conducted by the three heat absorption points and vaporize, so that it carries heat and rises and enters the hollow heat-conducting roller 501. The hollow heat-conducting roller 501 contacts the lower surface of the top of the belt 102 and rotates relative to the rotary joint 504. At this time, the hollow heat-conducting roller 501 and the belt 102 generate a temperature difference to achieve heat transfer, which is used to preheat the material on the belt 102. During operation, the second spiral section 503 and the first spiral section 404 overlap in a spiral manner, and the temperature difference between them enables heat transfer. The heat from the first spiral section 404 is conducted along the second spiral section 503, the third heat-conducting pipe 502 and the hollow heat-conducting roller 501 to the material on the feeding conveyor belt 1, thereby preheating the material.

[0030] To accommodate the three heat absorption points, the number of hollow heat-conducting rollers 501, the third heat-conducting pipe 502, and the second spiral section 503 are all set to three. The three hollow heat-conducting rollers 501 are set to form three preheating zones for utilizing waste heat in a stepwise manner from low to high temperature, so as to realize the preheating of materials from a lower temperature to a higher temperature.

[0031] See attached document Figure 2 , Figure 6 and Figure 7 The openable heat insulation component 6 includes a base 601, two baffles 602, a temperature sensor 603, and a vertically connected mounting base 604, linear electric cylinder 605, and support plate 606, all located inside the feeding conveyor belt 1. During installation, the base 601 is fixed to the inside of the frame 101 with bolts. The PT100 temperature sensor 603 is embedded in the middle of the base 601 and electrically connected to the controller 104. The detection end of the temperature sensor 603 is close to the hollow heat-conducting roller 501 and is used to monitor the temperature value at the overlapping position of the hollow heat-conducting roller 501 and the belt 102 in real time. The two baffles 602 are located on both sides of the base 601. The mounting base 604 is fixed to the upper surface of the base 601 with screws. The two sets of linear electric cylinders 605 are fixed to the top of the mounting base 604 with screws. The support plate 606 is fixed between the output end of the linear electric cylinder 605 and the side of the adjacent support plate 606 with screws. When the controller 104 detects that the temperature value exceeds the temperature threshold, it controls the linear electric cylinder 605 to extend the cylinder rod and lift the support plate 606 and the two baffles 602 until the two baffles 602 are attached to the base 601. At the same time, the top of the two baffles 602 are close to the belt 102. The two baffles 602 are attached to the base 601 to reach the closed state, which can form a preset degree of sealing on the outside of the hollow heat-conducting roller 501 to reduce heat loss. When the controller 104 detects that the temperature value does not exceed the temperature threshold, the linear electric cylinder 605 shortens its rod and lowers the support plate 606 and the two baffles 602, so that the gap between the two baffles 602 and the base 601 is opened, reaching the open state. Water vapor outside the hollow heat-conducting roller 501 condenses to form condensate. At this time, the condensate is discharged along the gap between the two baffles 602 and the base 601.

[0032] During the feeding process, there are gaps on the belt 102, which cause the debris blown off during the material drying process to fall along the gaps and adhere to the base 601 to form byproducts with the condensate. Once they accumulate, they may cause blockages or even block the temperature sensor 603.

[0033] See attached document Figure 7 , Figure 8 and Figure 11 On the side of the two baffles 602 that are close to each other, a bent rod 6010 and an impact member 6011 are welded in sequence. The bent rod 6010 and the impact member 6011 are offset from the support plate 606 along the axial direction of the linear electric cylinder 605 to avoid interference between the impact member 6011 and the support plate 606. When the linear electric cylinder 605 is started, it can drive the bent rod 6010 and the impact member 6011 to rise and fall. When the open state is reached, the controller 104 controls the linear electric cylinder 605 to intermittently lower the support plate 606 until the bending rod 6010 and the impact member 6011 impact the base 601 at a frequency of twenty times per minute, generating an impact force that acts on the by-products, causing them to fall off, promoting the by-products to detach from the base 601, and reducing by-product residue.

[0034] As an optional embodiment, the bending rod 6010 may be made of shape memory alloy, and the impact member 6011 may be made of high temperature resistant rubber. When the impact member 6011 contacts the base 601, it deforms itself to prevent the base 601 from bending, so as to maintain the shape of the base 601.

[0035] See attached document Figure 8 , Figure 9 and Figure 10The base 601 is a folded shape with a convex center. A first extension 607 and a second extension 608 are provided at the interval between the base 601 and the two baffles 602. During installation, the base 601 and the two first extensions 607 are integrally milled, and the baffles 602 and the second extensions 608 are integrally milled. A polyurethane layer 609 is bonded to the top of the two baffles 602 to reduce heat loss. When the two baffles 602 are raised, the first extension 607 and the second extension 608 come into contact, and the contact gap is filled by a silicone pad to improve the sealing. The base 601 and the two baffles 602 are then closed.

[0036] It should be noted that the first heat pipe 401, the second heat pipe 403, the first spiral section 404, the hollow heat-conducting roller 501, the third heat pipe 502, and the second spiral section 503 are all made of copper to ensure good thermal conductivity. The base 601 and the baffle 602 are both made of calcium silicate board or inorganic fiber board, which achieves heat insulation while providing good support performance.

[0037] Example 2: like Figure 11 As shown, a method for cascade utilization of industrial waste heat recovery based on multiphase flow enhanced heat transfer, using the industrial waste heat recovery cascade utilization device based on multiphase flow enhanced heat transfer as provided in Example 1, includes the following steps: Feeding stage: The feeding conveyor belt 1 starts and continuously feeds the wet granular material into the drying cylinder 2. At the same time, the hot air furnace generates high-temperature gas and blows it into the drying cylinder 2 to form countercurrent or cocurrent heat exchange with the material to achieve the material drying function. The second cylinder body 204 rotates and drives the inclined guide plate to turn the material over, increasing the air receiving area. Exhaust gas treatment stage: The first exhaust gas treatment pipe 301 filters dust and other impurities in the exhaust gas through a dust collector bag or cyclone dust collector to obtain a first airflow with a temperature of about 200℃. The second exhaust gas treatment pipe 303 sprays ammonia water, urea solution or limestone slurry into the first airflow for denitrification and desulfurization treatment to obtain a second airflow with a temperature of about 60℃. The third exhaust gas treatment pipe 304 has a built-in induced draft fan with an operating temperature range of 30℃~40℃, which provides negative pressure attraction for the first and second airflows and can discharge the second airflow into the atmosphere. Waste heat collection stage: The number of heat-conducting fins 402 is set to three sets, which are used to form three absorption hot spots at different positions of the exhaust gas treatment component 3. The first heat-conducting pipe 401, the second heat-conducting pipe 403 and the first spiral section 404 form a closed loop for the flow of heat-conducting medium. Since the three heat absorption points have different temperatures, the three sets of heat-conducting fins 402 need to be filled with different heat-conducting media. For example, one closed loop is filled with an ethylene glycol / propylene glycol aqueous solution, which is suitable for waste heat recovery of the tail flow with a temperature range of 30℃~40℃. Another closed loop is filled with mineral oil such as L-QB300 and L-QC320 or synthetic oil such as polyα-olefin and diester, which is suitable for waste heat recovery of the second air flow with a temperature of about 60℃. Yet another closed loop is filled with high-temperature heat-conducting oil, which is suitable for waste heat recovery of the first air flow with a temperature of about 200℃. Heat transfer stage: The second spiral section 503 and the first spiral section 404 overlap in a spiral manner, and the temperature difference between them realizes heat transfer. The heat of the first spiral section 404 is conducted to the material on the feeding conveyor belt 1 along the second spiral section 503, the third heat conduction pipe 502 and the hollow heat conduction roller 501, thereby preheating the material. Heat utilization stage: When the controller 104 detects that the temperature value exceeds the temperature threshold, it controls the linear electric cylinder 605 to extend the cylinder rod and lift the support plate 606 and the two baffles 602 until the two baffles 602 are attached to the base 601. At the same time, the top of the two baffles 602 are close to the belt 102. The two baffles 602 are attached to the base 601 to reach the closed state, which can form a preset degree of sealing on the outside of the hollow heat-conducting roller 501 to reduce heat loss. When the controller 104 detects that the temperature value does not exceed the temperature threshold, the cylinder rod of the linear electric cylinder 605 shortens and lowers the support plate 606 and the two baffles 602, so that the gap between the two baffles 602 and the base 601 is opened, reaching the open state. Water vapor outside the hollow heat-conducting roller 501 condenses to form condensate. At this time, the condensate is discharged along the gap between the two baffles 602 and the base 601. When the open state is reached, the controller 104 controls the linear electric cylinder 605 to intermittently lower the support plate 606 until the bending rod 6010 and the impact member 6011 impact the base 601 at a frequency of twenty times per minute, generating an impact force that acts on the by-products, causing them to fall off, promoting the by-products to detach from the base 601, and reducing by-product residue.

[0038] The above description is merely an optional embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. An industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer, comprising a feeding conveyor belt (1) for conveying materials, a drying cylinder (2), and a tail gas treatment assembly (3), characterized in that, Also includes: Waste heat collection component (4) and heat transfer component (5) are connected in sequence to the exhaust gas treatment component (3). The waste heat collection component (4) has multiple heat absorption points, which absorb heat from the exhaust gas treatment component (3) and conduct it along the heat transfer component (5) to the material on the feeding conveyor belt (1). The openable heat insulation component (6) is installed inside the feeding conveyor belt (1) and is penetrated by the heat transfer component (5). The openable heat insulation component (6) has three states: closed, open and impact. When closed, the openable heat insulation component (6) closes at the position where the feeding conveyor belt (1) overlaps with the heat transfer component (5) to reduce heat loss; When opened, the openable heat insulation component (6) discharges the byproducts of waste heat recovery; Upon impact, the openable heat insulation component (6) generates an impact force that acts on the byproduct, causing it to fall off.

2. The industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer according to claim 1, characterized in that, The openable heat insulation component (6) includes a component disposed inside the feeding conveyor belt (1): The base (601) and two baffles (602) located on both sides of the base (601); Temperature sensor (603) is used to monitor the temperature value at the overlapping position of the feeding conveyor belt (1) and the heat transfer component (5) in real time; A mounting base (604), a linear electric cylinder (605), and a support plate (606) are connected vertically in sequence. The bottom of the linear electric cylinder (605) is connected to the base (601) through the mounting base (604), and the cylinder rod of the linear electric cylinder (605) is connected to the adjacent baffle (602) through the support plate (606). When the temperature exceeds the temperature threshold, the rod of the linear electric cylinder (605) extends and lifts the support plate (606) and the two baffles (602) until the two baffles (602) stick to the base (601) and reach the closed state; When the temperature value does not exceed the temperature threshold, the cylinder rod of the linear electric cylinder (605) shortens and lowers the support plate (606) and the two baffles (602), so that the gap between the two baffles (602) and the base (601) is opened, and the open state is achieved.

3. The industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer according to claim 2, characterized in that: On the side of each of the two baffles (602) that are close to each other, a bent rod (6010) and an impact member (6011) are welded in sequence. The bent rod (6010) and the impact member (6011) are offset from the support plate (606) along the axial direction of the linear electric cylinder (605). When the open state is reached, the linear electric cylinder (605) intermittently lowers the support plate (606) until the bent rod (6010) and the impact member (6011) impact the base (601) at a preset frequency, generating an impact force that acts on the by-product, causing it to fall off.

4. The industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer according to claim 2, characterized in that: The base (601) is a folded shape with a central protrusion. A first extension (607) and a second extension (608) are provided at the interval between the base (601) and the two baffles (602). A polyurethane layer (609) is bonded to the top of the two baffles (602). When the first extension (607) and the second extension (608) come into contact, the base (601) closes with the two baffles (602).

5. The industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer according to claim 1, characterized in that: The heat transfer assembly (5) includes a hollow heat-conducting roller (501), a third heat-conducting pipe (502), and a second spiral section (503) arranged vertically in sequence. Rotary joints (504) are connected between the two ends of the hollow heat-conducting roller (501) and the opening of the third heat-conducting pipe (502). An installation flange (505) is provided on the outside of the rotary joint (504). During operation, the second spiral segment (503) partially overlaps with the waste heat collection component (4) in a spiral manner, so that the heat absorbed by the waste heat collection component (4) is conducted to the material on the feeding conveyor belt (1) along the second spiral segment (503), the third heat conduction pipe (502) and the hollow heat conduction roller (501).

6. The industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer according to claim 1, characterized in that: The waste heat collection assembly (4) includes heat-conducting fins (402), a first heat-conducting pipe (401), a second heat-conducting pipe (403), and a first spiral section (404) connected in sequence. The number of heat-conducting fins (402) is set to three groups, which are used to form hot spots at different positions of the exhaust gas treatment component (3).

7. The industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer according to claim 1, characterized in that: The feeding conveyor belt (1) includes a frame (101) and a belt (102) located inside the frame (101). A motor (103) for rotating the belt (102) and a controller (104) for controlling the motor (103) are installed outside the frame (101). The openable heat insulation component (6) is disposed inside the belt (102) and is used to partially surround the top of the heat transfer component (5).

8. The industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer according to claim 1, characterized in that: The drying cylinder (2) includes a feed hopper (201), a first cylinder (202), a second cylinder (204) and a third cylinder (205) connected in a transverse sequence. The first cylinder (202) is connected to an air inlet pipe (203) for providing high-temperature gas, and the third cylinder (205) is connected to an exhaust gas treatment assembly (3). When the feeding conveyor belt (1) transports materials, the feeding hopper (201) opens and receives the materials.

9. The industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer according to claim 1, characterized in that: The exhaust gas treatment assembly (3) includes a first exhaust gas treatment pipe (301), a waste liquid tank (302), a second exhaust gas treatment pipe (303), and a third exhaust gas treatment pipe (304) that are sequentially connected to the drying cylinder (2). The heat absorption points are located in the first exhaust gas treatment pipe (301), the second exhaust gas treatment pipe (303), and the third exhaust gas treatment pipe (304).

10. A method for cascade utilization of industrial waste heat based on multiphase flow enhanced heat transfer, using the industrial waste heat recovery and cascade utilization device based on multiphase flow enhanced heat transfer as described in any one of claims 1-9, characterized in that, Includes the following steps: Feeding stage: The feeding conveyor belt (1) is started to continuously feed the material into the drying cylinder (2). At the same time, the hot air furnace generates high temperature gas and blows it into the drying cylinder (2) to dry the material. The drying cylinder (2) rotates and turns the material to increase the air-receiving area. Exhaust gas treatment stage: The exhaust gas treatment component (3) filters impurities in the exhaust gas and sprays a solution to provide negative pressure attraction and discharge the filtered exhaust gas into the atmospheric environment. Waste heat collection stage: The waste heat collection component (4) forms three heat absorption points at different positions of the exhaust gas treatment component (3) and forms a closed loop outside the exhaust gas treatment component (3) for the flow of heat-conducting medium and to cooperate with the three heat absorption points for heat absorption; Heat transfer stage: The heat transfer component (5) and the waste heat collection component (4) are spirally overlapped, and the two generate a temperature difference to achieve heat transfer, so that the heat of the waste heat collection component (4) is conducted along the heat transfer component (5) to the material on the feeding conveyor belt (1) to achieve preheating of the material. Heat utilization stage: When the temperature value of the heat transfer component (5) is detected to exceed the temperature threshold, the openable heat insulation component (6) is controlled to enter the closed state, forming a preset sealing degree outside the heat transfer component (5) to reduce heat loss; when the temperature value of the heat transfer component (5) is detected not to exceed the temperature threshold, the openable heat insulation component (6) is controlled to enter the open and impact state, generating impact force, acting on the by-products, causing them to fall off.

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