An electric furnace waste heat recovery system based on plate heat exchanger

Abstract

The utility model provides a kind of electric furnace waste heat recovery system based on plate heat exchanger, it is related to heat exchange equipment technical field, including integrated platform, and platform is sequentially laid smoke collection flow guide, front smoke adsorption purification, plate heat exchange, multi-flow water supply, waste heat terminal distribution, rear exhaust and intelligent control unit.Soot purification is completed after smoke is into smoke adsorption tower after flow guide, pressure stabilizing, and then is sent into plate integrated heat exchanger to carry out heat exchange.Multiple water supply pipeline is matched with tee valve, and water flow and hot water output parameter can be flexibly adjusted;Tail gas is discharged after being regulated after heat exchange, and the system is integrated in integrated platform, and the structure is stable, heat exchange area is provided with protective structure to reduce heat loss, and intelligent control unit is divided into each module, to realize automatic operation, smoke collection purification effect is good, waste heat recovery efficiency is high, heating regulation is flexible, operation and maintenance are convenient, land area is small, adapt to electric furnace field use, with energy saving and environmental protection value.

Description

Technical Field

[0001] This invention relates to the field of heat exchange equipment technology, and more specifically to an electric furnace waste heat recovery system based on a plate heat exchanger. Background Technology

[0002] During the production process of industrial electric furnaces, the equipment continuously generates a large amount of high-temperature flue gas. This flue gas contains abundant waste heat. If the flue gas is directly discharged into the atmosphere, it will not only result in a significant waste of thermal energy but also pollute the factory environment along with dust and impurities. Currently, the industry has gradually promoted waste heat recovery equipment to recover and reuse the waste heat from electric furnace flue gas. However, existing similar equipment has revealed many shortcomings in practical applications.

[0003] First, the flue gas collection system generally uses a simple straight-pipe inlet structure, which has a limited collection range and causes serious flue gas leakage. Furthermore, the flue gas delivery pressure and velocity are not adjustable, making it difficult to guarantee delivery stability in the face of flue gas volume variations caused by different production loads of the electric furnace. Second, most equipment lacks a proper pre-purification structure, allowing dust particles in the high-temperature flue gas to directly enter the core heat exchange area, easily causing blockage and wear of heat exchange plates and pipes, thus shortening the equipment's service life.

[0004] In the core waste heat exchange stage, traditional plate heat exchangers have a simple flow channel design, a short flue gas flow path, insufficient contact area between flue gas and heat exchange components, resulting in incomplete heat exchange and low waste heat recovery efficiency. The supporting water supply system has a fixed structure and a single water flow pattern, making it impossible to flexibly adjust the temperature and flow rate of the output hot water, thus failing to meet the diverse heating needs of the workshop.

[0005] In terms of overall equipment layout, the existing equipment has various functional components scattered and installed on the ground without a unified support base. Vibration during operation easily causes component displacement and loosening of connections, resulting in poor operational stability. The heat exchange areas are mostly open-style designs, leading to secondary heat loss and allowing debris from the workshop to easily enter the equipment, interfering with the normal operation of the heat exchange components. The exhaust gas emission process lacks flow control mechanisms, resulting in disordered emission of low-temperature exhaust gas, making it difficult to meet current industrial environmental emission standards.

[0006] In terms of control and management, traditional equipment often adopts centralized overall control, with modules such as flue gas diversion, purification, heat exchange, water supply, and exhaust not being managed separately. The control logic is complex, resulting in low levels of automation, a large amount of manual operation, and high difficulty in troubleshooting after a fault occurs, as well as low efficiency in daily operation and maintenance. In addition, the layout of the entire set of equipment is scattered and occupies a lot of space, while the site of industrial electric furnace workshops is generally compact, which greatly restricts the installation, relocation, and on-site layout of equipment.

[0007] Based on the various shortcomings of the existing technologies, in order to improve the overall performance of electric furnace flue gas collection, purification, heat exchange, and emission, increase the waste heat recovery and utilization rate, reduce operation and maintenance costs, and enhance equipment operation stability, automation level, and site adaptability, there is an urgent need in this field to design an electric furnace waste heat recovery system that is structurally integrated, functionally complete, and easy to manage. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides an electric furnace waste heat recovery system based on a plate heat exchanger, which solves the problems of easy flue gas dispersion, poor purification and dust removal effect, low heat exchange efficiency, and inconvenient heating regulation in existing electric furnace waste heat recovery equipment; unstable equipment operation, significant heat loss, crude exhaust emission control, low degree of automation, and scattered layout, large footprint, and poor site adaptability.

[0009] To achieve the above objectives, the present invention provides the following technical solution: An electric furnace waste heat recovery system based on a plate heat exchanger includes an integrated platform, on which a flue gas collection and guiding unit, a pre-flue gas adsorption and purification unit, a plate heat exchange unit, a multi-flow water supply unit, a waste heat terminal distribution unit, a rear exhaust unit, and an intelligent control unit are arranged sequentially.

[0010] As an optimized solution, a central mounting base is fixed to the middle of the upper surface of the integrated platform. The plate heat exchange unit includes a plate integrated heat exchanger, which includes two transversely symmetrical limiting side plates. The lower ends of the limiting side plates are fixedly mounted on the central mounting base by bolts.

[0011] As an optimized solution, an upper support plate and a lower support plate, symmetrically arranged vertically, are fixed between the two limiting side plates. As an optimized solution, the lower surface of the upper support plate is fixed with three sets of horizontally equally spaced upper heat exchange mechanisms, each set of the upper heat exchange mechanisms including several vertically equally spaced upper heat exchange plates.

[0012] As an optimized solution, three sets of horizontally equidistant lower heat exchange mechanisms are fixed on the upper surface of the lower support plate. Each set of lower heat exchange mechanisms includes several vertically equidistant lower heat exchange plates.

[0013] As an optimized solution, the three sets of lower heat exchange mechanisms and the three sets of upper heat exchange mechanisms are alternately arranged and separated into a serpentine flow channel. A serpentine heat exchange tube is fixed in the serpentine flow channel, and the serpentine heat exchange tube is a flat square-mouth tube.

[0014] As an optimized solution, the multi-flow water supply unit also includes six cross-flow water pipes. The six cross-flow water pipes are divided into two longitudinally symmetrical groups, with three cross-flow water pipes in each group arranged at equal intervals from top to bottom and located on both sides of the longitudinal direction of the plate integrated heat exchanger.

[0015] As an optimized solution, a longitudinal water pipe is connected between two longitudinally opposite transverse water pipes, and the middle section of each longitudinal water pipe passes through a set of upper or lower heat exchange plates that are longitudinally opposite.

[0016] As an optimized solution, a three-way reversing valve is provided at the connection between the cross-flow water pipe and the longitudinal flow water pipe.

[0017] As an optimized solution, the integrated platform is a horizontally grounded square platform.

[0018] As an optimized solution, the flue gas collection and diversion unit includes multiple bent square-mouth air inlet pipes, with a side support frame fixed to the lower surface of the square-mouth air inlet pipes, and the lower end of the side support frame fixed to the ground.

[0019] As an optimized solution, a manifold is fixed at the lower end of the square-mouth air inlet pipe, and a first mounting base plate is provided below the manifold. The first mounting base plate is fixed to one longitudinal side of the upper surface of the integrated platform.

[0020] As an optimized solution, a flue gas transfer box is fixed in the middle of the upper surface of the first mounting base plate. The flue gas transfer box is a U-shaped cylinder with an opening at the top, and the lower end of the confluence hopper is fixedly connected to the upper opening of the flue gas transfer box.

[0021] As an optimized solution, a booster pump is fixed to one side of the upper surface of the first mounting base plate, and the booster pump is connected to one end face of the flue gas transfer box.

[0022] As an optimized solution, a guide cone seat is fixed on the other end face of the flue gas transfer box, and an air inlet guide pipe is fixed at the end of the guide cone seat. An air inlet flow regulating valve is provided on the air inlet guide pipe.

[0023] As an optimized solution, a second mounting base plate is fixed to one side of the upper surface of the integrated platform. The pre-mounted flue gas adsorption and purification unit includes a flue gas adsorption tower. Three sets of centrally symmetrical support legs are welded to the lower end of the flue gas adsorption tower. The lower ends of the support legs are fixed to the upper surface of the second mounting base plate.

[0024] As an optimized solution, the end of the air inlet guide pipe is fixedly connected to the outer peripheral wall of the flue gas adsorption tower, and a temperature sensor is fixed on the inner peripheral wall of the flue gas adsorption tower where it connects with the air inlet guide pipe.

[0025] As an optimized solution, an annular baffle is fixed on the inner peripheral wall of the flue gas adsorption tower near the upper end, and a vertically extending isolation column is fixed on the lower surface of the annular baffle. The outer diameter of the isolation column is smaller than the inner diameter of the flue gas adsorption tower.

[0026] As an optimized solution, a spiral drainage plate is fixed on the inner peripheral wall of the isolation column.

[0027] As an optimized solution, an induced draft fan is fixed to the top of the flue gas adsorption tower.

[0028] As an optimized solution, two symmetrically arranged adsorption and ash-blocking filter screens are fixed on the outer peripheral wall of the isolation column, and the ends of the adsorption and ash-blocking filter screens are fixed on the inner peripheral wall of the flue gas adsorption tower.

[0029] As an optimized solution, an impurity collection box is provided directly below the flue gas adsorption tower, a feed vertical pipe is fixed at the upper end of the impurity collection box, and a discharge horizontal pipe is fixed on the transverse side wall of the impurity collection box.

[0030] As an optimized solution, a transversely extending high-temperature gas conveying pipe is fixed to the outer peripheral wall of the middle part of the flue gas adsorption tower, and the end of the high-temperature gas conveying pipe is fixed to the transverse outer wall of one of the limiting side plates.

[0031] As an optimized solution, a transversely extending cryogenic gas delivery pipe is fixed on the transverse outer wall of another limiting side plate, and the cryogenic gas delivery pipe is at the same horizontal height as the high-temperature gas delivery pipe.

[0032] As an optimized solution, one end of the serpentine heat exchange tube is fixed to the inner wall of one of the limiting side plates and connected to the high-temperature gas conveying pipe, while the other end of the serpentine heat exchange tube is fixed to the inner wall of the other limiting side plate and connected to the low-temperature gas conveying pipe.

[0033] As an optimized solution, a third mounting base plate is fixed to one side of the upper surface of the integrated platform. The multi-flow water supply unit also includes a water supply pump. The water supply pump is fixedly installed on the longitudinal side of the upper surface of the third mounting base plate. A longitudinally extending water inlet pipe is fixed to one side of the water supply pump, and a transversely extending water outlet pipe is fixed to the end of the water supply pump.

[0034] As an optimized solution, a water supply tank is fixed on the outer wall of the limiting side plate near the third mounting base plate. The water supply tank is a U-shaped tank with the opening facing upwards, and the end of the water supply pipe is fixedly connected to the lower end face of the water supply tank.

[0035] As an optimized solution, one end of each of the six cross-flow water pipes passes through one of the limiting side plates and is fixedly connected to the water supply tank, while the other end passes through another limiting side plate and extends to its outer side.

[0036] As an optimized solution, each of the upper heat exchange plates has three vertically spaced pipe installation ports arranged sequentially from top to bottom, and each of the lower heat exchange plates also has three identical pipe installation ports. The longitudinal water pipe is fixedly installed in the pipe installation ports.

[0037] As an optimized solution, an I-shaped bracket is provided between the two limiting side plates. The two ends of the I-shaped bracket are respectively fixed to the transverse inner wall of the two limiting side plates near the upper end. Two transversely symmetrical side sealing plates are also oscillatingly installed between the two limiting side plates. The upper end of the side sealing plate is fixed in the side slot of the I-shaped bracket, and the lower end of the side sealing plate is rotatably installed on the inner side wall of the two limiting side plates.

[0038] As an optimized solution, the waste heat terminal distribution unit includes a diversion distribution box, which is a U-shaped box with the opening facing downward and hollow. The lower end of the diversion distribution box is fixed to the upper surface of the central mounting base.

[0039] As an optimized solution, the distribution box is equipped with six hot water output pipes, which are arranged one-to-one with the six cross-flow water pipes. The end of each hot water output pipe is fixedly connected to the end of the cross-flow water pipe, and each hot water output pipe is equipped with a water outlet regulating valve.

[0040] As an optimized solution, the rear exhaust unit includes an exhaust support frame, which is a U-shaped frame with the opening facing downwards. The exhaust support frame is located above the water supply pump, and the lower end of the exhaust support frame is fixed to the upper surface of the third mounting base plate.

[0041] As an optimized solution, a transfer exhaust pump is fixed on the upper surface of the exhaust support frame, the end of the cryogenic gas delivery pipe is fixedly connected to the transfer exhaust pump, the end of the transfer exhaust pump is fixedly connected to an exhaust pipe, and an exhaust flow regulating valve is provided on the exhaust pipe.

[0042] As an optimized solution, an exhaust tower is fixed to one longitudinal side of the upper surface of the third mounting base plate, and an exhaust fan is provided on the top of the exhaust tower.

[0043] As an optimized solution, a fourth mounting base plate is fixed to one longitudinal side of the upper surface of the integrated platform, and the intelligent control unit includes a main control box and a secondary control box, which are fixed to the upper surface of the fourth mounting base plate.

[0044] As an optimized solution, the upper surface of the integrated platform is provided with a power supply circuit for power supply and signal transmission between the units.

[0045] As an optimized solution, the main electrical control box can integrate the control of the plate heat exchange unit and the waste heat terminal distribution unit.

[0046] As an optimized solution, the auxiliary electrical control box can integrate and control the flue gas collection and diversion unit, the pre-flue gas adsorption and purification unit, the multi-flow water supply unit, and the post-exhaust unit.

[0047] Compared with the prior art, the beneficial effects of the present invention are: 1. Excellent flue gas collection and transportation effect The flue gas collection and diversion unit adopts a combination structure of multi-section bent square-mouth air inlet pipes, a manifold, and a flue gas transfer box, which can comprehensively collect high-temperature flue gas from the electric furnace and prevent flue gas from escaping. By using a booster pump in conjunction with an air inlet flow regulating valve, the flue gas delivery speed and pressure can be stably controlled to ensure continuous and smooth flue gas delivery and adapt to flue gas delivery needs under different operating conditions.

[0048] 2. Excellent flue gas purification and dust removal capabilities The pre-filter flue gas adsorption purification unit adopts an innovative flue gas adsorption tower design. The tower features annular baffles, isolation columns, spiral guide plates, and symmetrically arranged adsorption and dust-blocking filters, with a rationally planned airflow path. After high-temperature flue gas enters the tower, the dust-blocking filters intercept and adsorb dust and impurities, preventing them from clogging heat exchange equipment in subsequent stages. After waste heat recovery, external cold air is introduced into the tower via a fan through the spiral guide plates. This cold air then veers upwards at the bottom of the tower, impacting the dust-blocking filters for backflushing and cleaning, and rapidly cooling the tower. Impurities generated during filtration fall directly into the lower impurity collection box and are periodically cleaned via a discharge pipe, facilitating maintenance and maintaining long-term purification efficiency. Simultaneously, a temperature sensor monitors the flue gas temperature in real time, allowing staff to easily monitor the operating status.

[0049] 3. High waste heat exchange efficiency and flexible heat exchange adjustment The plate heat exchange unit adopts an innovative integrated plate heat exchanger design. Inside the integrated plate heat exchanger, upper and lower heat exchange plates are arranged in an alternating pattern, forming a serpentine flue gas flow path with serpentine heat exchange tubes. This significantly extends the flow path of high-temperature flue gas, increases the contact area between the flue gas and the heat exchange plates, resulting in more efficient heat transfer and a significant improvement in waste heat recovery. During heat exchange, the flue gas flows within the serpentine heat exchange tubes, while water flows within the longitudinal water pipes between the heat exchange plates. The two do not directly contact each other; heat exchange occurs through the plates. The multi-directional water supply unit, using cross-flow and longitudinal water pipes with a three-way reversing valve, can flexibly switch water flow paths, changing the water flow heat exchange time and contact range. Combined with the outlet regulating valve to control the hot water output flow rate, it can adjust the outlet water temperature and heat supply as needed to adapt to the needs of different waste heat utilization terminals.

[0050] 4. The equipment has a stable structure and good protection. Each functional unit of the entire device is fixed to the integrated platform by independent mounting base plates, support brackets, and limiting side plates. The overall layout is neat and the stress is even, making it less prone to displacement or shaking during operation. The side sealing cover plate cooperates with the I-shaped bracket to form a closed protection for the heat exchange area, reducing heat loss and preventing external debris from entering the heat exchange structure, thus ensuring the stable operation of the heat exchange components.

[0051] 5. Exhaust emissions are controllable and compliant. The low-temperature flue gas passes sequentially through the intermediate exhaust pump, exhaust flow regulating valve, exhaust tower and top exhaust fan, which can accurately control the exhaust flow and exhaust rate, smoothly complete the tail gas transportation and venting, effectively avoid disorderly emission of flue gas and meet the on-site environmental protection emission requirements.

[0052] 6. High degree of automation and control, stable operation and easy management This system adopts a zoned management mode with main and auxiliary electrical control boxes, corresponding to modules such as heat exchange, waste heat distribution, flue gas diversion, purification, water supply, and exhaust, respectively. The functions are clearly divided and the control logic is well-defined. Relying on the power supply circuit deployed on the integrated platform, the signals and power supply of each component are linked, and the entire set of equipment can operate automatically and continuously, reducing the intensity of manual operation, while facilitating fault diagnosis and daily maintenance, and improving the operational reliability of the entire waste heat recovery system.

[0053] 7. High overall integration and strong site adaptability This system centrally arranges all functional units on an integrated platform, with a high degree of equipment integration, compact layout, and small space occupation, making it easy to complete installation, relocation and deployment on the electric furnace site, and suitable for the limited installation space in industrial workshops. Attached Figure Description

[0054] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0055] Figure 1 This is a schematic diagram of the overall external structure of the present invention in the main viewing direction; Figure 2 This is a schematic diagram of the overall external structure of the present invention from a top-down perspective; Figure 3 This is a schematic diagram of the overall external structure of the present invention from the right-side view direction; Figure 4 This is a schematic diagram of the overall external structure of the present invention from the left-side view direction; Figure 5 This is an isometric schematic diagram of the three-dimensional structure of the present invention; Figure 6 For the present invention along Figure 2 A schematic diagram of the internal structure cut along line AA. Figure 7 For the present invention along Figure 1 A schematic diagram of the internal structure cut along the middle BB line; Figure 8 For the present invention along Figure 1 A schematic diagram of the internal structure cut along the CC line; Figure 9 For the present invention along Figure 3 A schematic diagram of the internal structure cut along the DD line.

[0056] In the diagram: 1-Integrated platform, 2-Square inlet pipe, 3-Side support frame, 4-Combining hopper, 5-First mounting base plate, 6-Flue gas transfer box, 7-Booster pump, 8-Guide cone seat, 9-Inlet guide pipe, 10-Inlet flow regulating valve, 11-Second mounting base plate, 12-Flue gas adsorption tower, 13-Support legs, 14-Temperature sensor, 15-Annular baffle, 16-Isolation column, 17-Spiral guide plate, 18-Exhaust fan, 19-Adsorption and ash-blocking filter screen, 20-Impurity collection box, 21-Feed vertical pipe, 22-Discharge horizontal pipe, 23-Central mounting base, 24-Plate integrated heat exchanger, 25-Limiting side plate, 26-High-temperature gas conveying pipe, 27-Low-temperature gas conveying pipe 28-Upper support plate, 29-Lower support plate, 30-Upper heat exchange plate, 31-Lower heat exchange plate, 32-Serpentine heat exchange tube, 33-Third mounting base plate, 34-Water supply pump, 35-Inlet pipe, 36-Water supply pipe, 37-Water supply tank, 38-Crossflow pipe, 39-Vertical flow pipe, 40-Three-way reversing valve, 41-I-shaped bracket, 42-Side sealing cover plate, 43-Diversion distribution box, 44-Hot water output pipe, 45-Outlet regulating valve, 46-Exhaust support frame, 47-Transfer exhaust pump, 48-Exhaust pipe, 49-Exhaust flow regulating valve, 50-Exhaust tower, 51-Exhaust fan, 52-Fourth mounting base plate, 53-Main electrical control box, 54-Auxiliary electrical control box, 55-Power supply circuit. Detailed Implementation

[0057] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0058] like Figures 1 to 9 As shown, an electric furnace waste heat recovery system based on a plate heat exchanger includes an integrated platform 1, which is a horizontally grounded square platform. The integrated platform 1 is provided with a flue gas collection and guiding unit, a pre-flue gas adsorption and purification unit, a plate heat exchange unit, a multi-flow water supply unit, a waste heat terminal distribution unit, a rear exhaust unit, and an intelligent control unit in sequence.

[0059] The flue gas collection and diversion unit includes multiple bent square-mouth air inlet pipes 2. A side support frame 3 is fixed on the lower surface of the square-mouth air inlet pipe 2, and the lower end of the side support frame 3 is fixed on the ground.

[0060] The lower end of the square-mouth air inlet pipe 2 is fixed with a confluence hopper 4, and a first mounting base plate 5 is provided below the confluence hopper 4. The first mounting base plate 5 is fixed on the longitudinal side of the upper surface of the integrated platform 1.

[0061] A flue gas transfer box 6 is fixed in the middle of the upper surface of the first mounting base plate 5. The flue gas transfer box 6 is a U-shaped cylinder with an opening at the top. The lower end of the confluence hopper 4 is fixedly connected to the upper opening of the flue gas transfer box 6.

[0062] A booster pump 7 is fixed horizontally on one side of the upper surface of the first mounting base plate 5. The booster pump 7 is connected to one end face of the flue gas transfer box 6.

[0063] A guide cone seat 8 is fixed on the other end face of the flue gas transfer box 6. An air inlet guide pipe 9 is fixed at the end of the guide cone seat 8. An air inlet flow regulating valve 10 is provided on the air inlet guide pipe 9.

[0064] A second mounting base plate 11 is fixed to one side of the upper surface of the integrated platform 1. The pre-mounted flue gas adsorption and purification unit includes a flue gas adsorption tower 12. Three sets of centrally symmetrical support legs 13 are welded to the lower end of the flue gas adsorption tower 12. The lower end of the support legs 13 is fixed to the upper surface of the second mounting base plate 11.

[0065] The end of the air inlet guide pipe 9 is fixedly connected to the outer peripheral wall of the flue gas adsorption tower 12, and a temperature sensor 14 is fixed on the inner peripheral wall of the flue gas adsorption tower 12 where it connects with the air inlet guide pipe 9.

[0066] An annular baffle 15 is fixed on the inner peripheral wall near the upper end of the flue gas adsorption tower 12. A vertically extending isolation column 16 is fixed on the lower surface of the annular baffle 15. The outer diameter of the isolation column 16 is smaller than the inner diameter of the flue gas adsorption tower 12.

[0067] A spiral drainage plate 17 is fixed on the inner peripheral wall of the isolation column 16.

[0068] An induced draft fan 18 is fixed to the top of the flue gas adsorption tower 12.

[0069] Two symmetrically arranged adsorption and ash-blocking filter screens 19 are fixed on the outer peripheral wall of the isolation column 16, and the ends of the adsorption and ash-blocking filter screens 19 are fixed on the inner peripheral wall of the flue gas adsorption tower 12.

[0070] An impurity collection box 20 is provided directly below the flue gas adsorption tower 12. A feed vertical pipe 21 is fixed at the upper end of the impurity collection box 20, and a discharge horizontal pipe 22 is fixed on the transverse side wall of the impurity collection box 20.

[0071] A central mounting base 23 is fixed in the middle of the upper surface of the integrated platform 1. The plate heat exchange unit includes a plate integrated heat exchanger 24, which is fixed on one side of the upper surface of the central mounting base 23.

[0072] The plate integrated heat exchanger 24 includes two transversely symmetrical limiting side plates 25, the lower ends of which are fixedly mounted on the central mounting base 23 by bolts.

[0073] A transversely extending high-temperature gas conveying pipe 26 is fixed to the outer peripheral wall of the middle part of the flue gas adsorption tower 12, and the end of the high-temperature gas conveying pipe 26 is fixed to the transverse outer wall of one of the limiting side plates 25.

[0074] Another limiting side plate 25 has a transversely extending low-temperature gas conveying pipe 27 fixed on its transverse outer wall. The low-temperature gas conveying pipe 27 and the high-temperature gas conveying pipe 26 are at the same horizontal height.

[0075] An upper support plate 28 and a lower support plate 29 are symmetrically provided between the two limiting side plates 25. The two ends of the upper support plate 28 and the lower support plate 29 are respectively fixed to the inner sidewalls of the two limiting side plates 25.

[0076] Three sets of horizontally equidistant upper heat exchange mechanisms are fixed on the lower surface of the upper support plate 28. Each set of upper heat exchange mechanisms includes several vertically equidistant upper heat exchange plates 30.

[0077] Three sets of horizontally equally spaced lower heat exchange mechanisms are fixed on the upper surface of the lower support plate 29. The three sets of lower heat exchange mechanisms are alternately arranged with the three sets of upper heat exchange mechanisms and separated into a serpentine flow channel. Each set of lower heat exchange mechanisms includes several lower heat exchange plates 31 arranged longitudinally at equal intervals.

[0078] Each upper heat exchange plate 30 has three vertically spaced pipe installation ports arranged from top to bottom, and each lower heat exchange plate 31 also has three identical pipe installation ports.

[0079] A serpentine heat exchange tube 32 is fixed in the serpentine flow channel between the upper heat exchange mechanism and the lower heat exchange mechanism. The serpentine heat exchange tube 32 is a flat square tube and is clamped between the upper support plate 28 and the lower support plate 29.

[0080] One end of the serpentine heat exchange tube 32 is fixed to the inner wall of one of the limiting side plates 25 and connected to the high-temperature gas conveying pipe 26. The other end of the serpentine heat exchange tube 32 is fixed to the inner wall of another limiting side plate 25 and connected to the low-temperature gas conveying pipe 27.

[0081] A third mounting base plate 33 is fixed to one side of the upper surface of the integrated platform 1. The third mounting base plate 33 is located on the opposite side of the second mounting base plate 11. The multi-flow water supply unit includes a water supply pump 34. The water supply pump 34 is fixedly installed on one side of the upper surface of the third mounting base plate 33. A longitudinally extending water inlet pipe 35 is fixed to one side of the water supply pump 34. A transversely extending water supply pipe 36 is fixed to the end of the water supply pump.

[0082] A water supply tank 37 is fixed on the outer wall of the limiting side plate 25 near the third mounting base plate 33. The water supply tank 37 is a U-shaped box with the opening facing upwards, and the end of the water supply pipe 36 is fixedly connected to the lower end face of the water supply tank 37.

[0083] The multi-flow water supply unit also includes six cross-flow water pipes 38. The six cross-flow water pipes 38 are divided into two longitudinally symmetrical groups. Each group has three cross-flow water pipes 38 arranged at equal intervals from top to bottom and located on both sides of the longitudinal direction of the plate integrated heat exchanger 24. One end of each of the six cross-flow water pipes 38 passes through one of the limiting side plates 25 and is fixedly connected to the water supply tank 37. The other end passes through the other limiting side plate 25 and extends to its outer side.

[0084] A longitudinal water pipe 39 is connected between two longitudinally opposite transverse water pipes 38. Each longitudinal water pipe 39 passes through several upper heat exchange plates 30 or lower heat exchange plates 31 and is fixedly clamped in the pipe installation port.

[0085] A three-way reversing valve 40 is provided at the connection between the cross-flow water pipe 38 and the longitudinal flow water pipe 39.

[0086] An I-shaped bracket 41 is provided between the two limiting side plates 25. The two ends of the I-shaped bracket 41 are respectively fixed on the transverse inner wall of the two limiting side plates 25 near the upper end. Two transversely symmetrical side sealing covers 42 are also oscillatingly installed between the two limiting side plates 25. The upper end of the side sealing cover 42 is fixed in the side slot of the I-shaped bracket 41, and the lower end of the side sealing cover 42 is rotatably installed on the inner side wall of the two limiting side plates 25.

[0087] The waste heat terminal distribution unit includes a diversion distribution box 43, which is a U-shaped box with the opening facing downward and hollow. The lower end of the diversion distribution box 43 is fixed on the upper surface of the central mounting base 23.

[0088] The distribution box 43 is equipped with six hot water output pipes 44, which correspond one-to-one with six cross-flow water pipes 38. The end of the hot water output pipe 44 is fixedly connected to the end of the cross-flow water pipe 38. Each hot water output pipe 44 is equipped with a water outlet regulating valve 45.

[0089] The rear exhaust unit includes an exhaust support frame 46, which is a U-shaped frame with the opening facing downwards. The exhaust support frame 46 is located above the water supply pump 34, and the lower end of the exhaust support frame 46 is fixed to the upper surface of the third mounting base plate 33.

[0090] An intermediate exhaust pump 47 is fixed on the upper surface of the exhaust support frame 46. The end of the cryogenic gas delivery pipe 27 is fixedly connected to the intermediate exhaust pump 47. An exhaust pipe 48 is fixedly connected to the end of the intermediate exhaust pump 47. An exhaust flow regulating valve 49 is provided on the exhaust pipe 48.

[0091] An exhaust tower 50 is fixed on one longitudinal side of the upper surface of the third mounting base plate 33, and an exhaust fan 51 is provided on the top of the exhaust tower 50.

[0092] A fourth mounting base plate 52 is fixed on one longitudinal side of the upper surface of the integrated platform 1. The fourth mounting base plate 52 is located on the opposite side of the first mounting base plate 5. The intelligent control unit includes a main control box 53 and a secondary control box 54, which are fixed on the upper surface of the fourth mounting base plate 52.

[0093] The upper surface of the integrated platform 1 is provided with a power supply circuit 55 for power supply and signal transmission between units.

[0094] The main electrical control box 53 can integrate the control of the plate heat exchange unit and the waste heat terminal distribution unit.

[0095] The auxiliary electrical control box 54 can integrate and control the flue gas collection and diversion unit, the pre-flue gas adsorption and purification unit, the multi-flow water supply unit, and the post-exhaust unit.

[0096] When using this invention: The high-temperature flue gas generated by the electric furnace first enters the flue gas collection and guiding unit, then flows into the collection hopper 4 through the multi-section bend square inlet pipe 2, and then flows into the flue gas transfer box 6. The booster pump 7 pressurizes and pushes the flue gas, opens the intake flow regulating valve 10, and regulates the intake flow. The flue gas is transported to the pre-flue gas adsorption and purification unit through the intake guide pipe 9, and the purification and adsorption are completed in the flue gas adsorption tower 12.

[0097] After the flue gas enters the flue gas adsorption tower 12, the temperature sensor 14 monitors the flue gas temperature in real time. The airflow flows along the outer peripheral wall of the isolation column 16 and passes through two sets of symmetrically arranged adsorption and dust blocking filters 19 to complete the adsorption of impurities and the interception of dust. The filtered impurities fall into the impurity collection box 20 below, are collected through the feed vertical pipe 21, and are periodically discharged by the discharge horizontal pipe 22. After the high-temperature flue gas completely passes through the adsorption and ash-blocking filter screen 19, it enters the high-temperature gas conveying pipe 26. Then, the flue gas is sent into the plate heat exchange unit through the high-temperature gas conveying pipe 26. The high-temperature flue gas entering the plate integrated heat exchanger 24 flows along the internal flow channel of the serpentine heat exchange tube 32 and exchanges heat with the upper heat exchange plate 30 and the lower heat exchange plate 31. After releasing heat, the flue gas becomes low-temperature flue gas and flows out from the low-temperature gas conveying pipe 27. At the same time, the multi-flow water supply unit is started. The water supply pump 34 sends cold water into the water supply tank 37 through the inlet pipe 35 and the upper water pipe 36. The cold water is then diverted from the water supply tank 37 to six cross-flow water pipes 38. The flow direction is switched with the three-way reversing valve 40 to form multiple heat exchange circuits. The heat exchange time is changed by switching the water flow path, and the water temperature is adjusted. Water flows in the longitudinal water pipe 39 and indirectly contacts the upper heat exchange plate 30 and the lower heat exchange plate 31 to complete heat exchange. The hot water after heat exchange and heating is connected to the distribution box 43 of the waste heat terminal distribution unit through the cross water pipe 38. The flow rate is adjusted by the outlet regulating valve 45 on each hot water output pipe 44, and the high-temperature hot water is delivered to each waste heat use terminal as needed.

[0098] After heat exchange, the low-temperature flue gas enters the rear exhaust unit, is drawn by the intermediate exhaust pump 47, and is discharged from the exhaust pipe 48 after the exhaust flow regulating valve 49 controls the exhaust volume. Finally, the exhaust gas is vented with the assistance of the exhaust fan 51 at the top of the exhaust tower 50.

[0099] After the flue gas heat exchange is completed and the machine is shut down, the induced draft fan 18 at the top of the flue gas adsorption tower 12 is started to introduce cold outside air into the flue gas adsorption tower 12 from above. After passing through the spiral guide plate 17 on the inner wall of the isolation column cylinder 16, it forms a swirling flow and continues to flow downward. It then turns back upward at the bottom of the flue gas adsorption tower 12 to impact the dust and impurities attached to the adsorption and dust-blocking filter screen 19, causing them to fall off. Backflushing prevents the adsorption and dust-blocking filter screen 19 from becoming clogged, and enables rapid cooling of the tower body when the flue gas adsorption tower 12 needs to be inspected and maintained.

[0100] During the operation of the entire equipment, the intelligent control unit provides full control: the main electrical control box 53 is responsible for the parameter and operation control of the plate heat exchange and waste heat distribution links, and the auxiliary electrical control box 54 uniformly controls the flue gas diversion, purification, water supply and exhaust units. The power supply and signal linkage of each component of the equipment are realized by relying on the power supply circuit 55 on the integrated platform 1 to ensure the stable and continuous operation of the system.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A plate heat exchanger based electric furnace waste heat recovery system characterized by: It includes an integrated platform, on which are sequentially arranged a flue gas collection and diversion unit, a pre-flue gas adsorption and purification unit, a plate heat exchange unit, a multi-flow water supply unit, a waste heat terminal distribution unit, a rear exhaust unit and an intelligent control unit. A central mounting base is fixed to the middle of the upper surface of the integrated platform. The plate heat exchange unit includes a plate integrated heat exchanger. The plate integrated heat exchanger includes two transversely symmetrical limiting side plates. The lower end of the limiting side plates is fixedly mounted on the central mounting base by bolts. A symmetrical upper support plate and a lower support plate are fixed between the two limiting side plates. The lower surface of the upper support plate is fixed with three sets of horizontally equally spaced upper heat exchange mechanisms. Each set of the upper heat exchange mechanisms includes several vertically equally spaced upper heat exchange plates. The upper surface of the lower support plate is fixed with three sets of horizontally equally spaced lower heat exchange mechanisms. Each set of the lower heat exchange mechanisms includes several vertically equally spaced lower heat exchange plates. The three sets of lower heat exchange mechanisms and the three sets of upper heat exchange mechanisms are alternately arranged and separated into a serpentine flow channel. A serpentine heat exchange tube is fixed in the serpentine flow channel. The serpentine heat exchange tube is a flat square tube. The multi-flow water supply unit also includes six cross-flow water pipes. The six cross-flow water pipes are divided into two longitudinally symmetrical groups. Each group has three cross-flow water pipes arranged at equal intervals from top to bottom and located on both sides of the longitudinal direction of the plate integrated heat exchanger. A longitudinal water pipe is connected between two longitudinally opposite transverse water pipes, and the middle section of each longitudinal water pipe passes through a set of longitudinally opposite upper or lower heat exchange plates. A three-way reversing valve is provided at the connection between the cross-flow water pipe and the longitudinal flow water pipe.

2. The electric furnace waste heat recovery system based on plate heat exchanger according to claim 1, characterized in that: The integrated platform is a square platform that is horizontally grounded; The flue gas collection and diversion unit includes multiple bent square-mouth air inlet pipes, and a side support frame is fixed on the lower surface of the square-mouth air inlet pipes. The lower end of the side support frame is fixed to the ground. The lower end of the square-mouth air inlet pipe is fixed with a manifold, and a first mounting base plate is provided below the manifold. The first mounting base plate is fixed to one longitudinal side of the upper surface of the integrated platform. A flue gas transfer box is fixed in the middle of the upper surface of the first mounting base plate. The flue gas transfer box is a U-shaped cylinder with an opening at the top. The lower end of the confluence hopper is fixedly connected to the upper opening of the flue gas transfer box. A booster pump is fixed to one side of the upper surface of the first mounting base plate, and the booster pump is connected to one end face of the flue gas transfer box. A guide cone seat is fixed on the other end face of the flue gas transfer box, and an air inlet guide pipe is fixed at the end of the guide cone seat. An air inlet flow regulating valve is provided on the air inlet guide pipe.

3. The electric furnace waste heat recovery system based on a plate heat exchanger according to claim 2, characterized in that: A second mounting base plate is fixed to one side of the upper surface of the integrated platform. The pre-mounted flue gas adsorption and purification unit includes a flue gas adsorption tower. Three sets of centrally symmetrical support legs are welded to the lower end of the flue gas adsorption tower. The lower end of the support legs is fixed to the upper surface of the second mounting base plate. The end of the air inlet guide pipe is fixedly connected to the outer peripheral wall of the flue gas adsorption tower, and a temperature sensor is fixed on the inner peripheral wall of the flue gas adsorption tower where it connects with the air inlet guide pipe. An annular baffle is fixed on the inner peripheral wall near the upper end of the flue gas adsorption tower, and a vertically extending isolation column is fixed on the lower surface of the annular baffle. The outer diameter of the isolation column is smaller than the inner diameter of the flue gas adsorption tower. A spiral guide plate is fixed on the inner circumferential wall of the isolation column; An induced draft fan is fixed at the top of the flue gas adsorption tower; Two symmetrically arranged adsorption and ash-blocking filter screens are fixed on the outer peripheral wall of the isolation column, and the ends of the adsorption and ash-blocking filter screens are fixed on the inner peripheral wall of the flue gas adsorption tower.

4. The electric furnace waste heat recovery system based on a plate heat exchanger according to claim 3, characterized in that: An impurity collection box is provided directly below the flue gas adsorption tower. A feed vertical pipe is fixed to the upper end of the impurity collection box, and a discharge horizontal pipe is fixed to the transverse side wall of the impurity collection box. A transversely extending high-temperature gas conveying pipe is fixed to the outer peripheral wall of the middle part of the flue gas adsorption tower, and the end of the high-temperature gas conveying pipe is fixed to the transverse outer wall of one of the limiting side plates. A transversely extending low-temperature gas delivery pipe is fixed on the transverse outer wall of another limiting side plate, and the low-temperature gas delivery pipe is at the same horizontal height as the high-temperature gas delivery pipe. One end of the serpentine heat exchange tube is fixed to the inner wall of one of the limiting side plates and connected to the high-temperature gas conveying pipe, while the other end of the serpentine heat exchange tube is fixed to the inner wall of the other limiting side plate and connected to the low-temperature gas conveying pipe.

5. The electric furnace waste heat recovery system based on a plate heat exchanger according to claim 4, characterized in that: The upper surface of the integrated platform is fixed with a third mounting base plate on one side in the horizontal direction. The multi-flow water supply unit also includes a water supply pump. The water supply pump is fixedly installed on the upper surface of the third mounting base plate on one side in the vertical direction. A longitudinally extending water inlet pipe is fixed on one side of the water supply pump, and a horizontally extending water outlet pipe is fixed at the end of the water supply pump. A water supply tank is fixed on the outer wall of the limiting side plate near the third mounting base plate. The water supply tank is a U-shaped tank with the opening facing upwards. The end of the water supply pipe is fixedly connected to the lower end face of the water supply tank. One end of each of the six cross-flow water pipes passes through one of the limiting side plates and is fixedly connected to the water supply tank, while the other end passes through the other limiting side plate and extends to its outer side. Each of the upper heat exchange plates has three vertically spaced pipe installation ports arranged from top to bottom, and each of the lower heat exchange plates also has three identical pipe installation ports. The longitudinal water pipe is fixedly installed in the pipe installation ports.

6. The electric furnace waste heat recovery system based on a plate heat exchanger according to claim 1, characterized in that: An I-shaped bracket is provided between the two limiting side plates. The two ends of the I-shaped bracket are respectively fixed to the transverse inner wall of the two limiting side plates near the upper end. Two transversely symmetrical side sealing plates are also oscillatingly installed between the two limiting side plates. The upper end of the side sealing plate is fixed in the side slot of the I-shaped bracket, and the lower end of the side sealing plate is rotatably installed on the inner side wall of the two limiting side plates.

7. The electric furnace waste heat recovery system based on a plate heat exchanger according to claim 1, characterized in that: The waste heat terminal distribution unit includes a diversion distribution box, which is a U-shaped box with the opening facing downward and hollow. The lower end of the diversion distribution box is fixed to the upper surface of the central mounting base. The distribution box is equipped with six hot water output pipes, which are arranged in a one-to-one correspondence with the six cross-flow water pipes. The end of each hot water output pipe is fixedly connected to the end of the cross-flow water pipe, and each hot water output pipe is equipped with a water outlet regulating valve.

8. The electric furnace waste heat recovery system based on a plate heat exchanger according to claim 5, characterized in that: The rear exhaust unit includes an exhaust support frame, which is a U-shaped frame with the opening facing downwards. The exhaust support frame is located above the water supply pump, and the lower end of the exhaust support frame is fixed to the upper surface of the third mounting base plate. An intermediate exhaust pump is fixed on the upper surface of the exhaust support frame, the end of the cryogenic gas delivery pipe is fixedly connected to the intermediate exhaust pump, the end of the intermediate exhaust pump is fixedly connected to an exhaust pipe, and an exhaust flow regulating valve is provided on the exhaust pipe. An exhaust tower is fixed to one longitudinal side of the upper surface of the third mounting base plate, and an exhaust fan is provided on the top of the exhaust tower.

9. The electric furnace waste heat recovery system based on a plate heat exchanger according to claim 1, characterized in that: A fourth mounting base plate is fixed to one longitudinal side of the upper surface of the integrated platform. The intelligent control unit includes a main control box and a secondary control box, which are fixed to the upper surface of the fourth mounting base plate. The upper surface of the integrated platform is provided with a power supply circuit for power supply and signal transmission between the units.

10. The electric furnace waste heat recovery system based on a plate heat exchanger according to claim 9, characterized in that: The main electrical control box can integrate and control the plate heat exchange unit and the waste heat terminal distribution unit; The auxiliary electrical control box can integrate and control the flue gas collection and diversion unit, the pre-flue gas adsorption and purification unit, the multi-flow water supply unit, and the post-exhaust unit.

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