A method, system and medium for rapid cooling and waste heat power generation of a high-temperature furnace

Abstract

The application discloses a system, a method and a medium for rapid cooling and waste heat power generation of a high-temperature furnace, and the system comprises a rapid cooling device, a heat energy conversion and power generation device and an intelligent control system. The rapid cooling device adopts a full-enclosing combined heat pipe structure, and through the combined arrangement of long heat pipes and short heat pipes, the upper part and the side of a graphitization furnace are subjected to dead angle-free heat taking, so that high-temperature materials at 2800-3000 DEG C are rapidly cooled to below 350 DEG C, and the cooling time is shortened by more than 50% compared with natural cooling. The combined heat pipe transmits heat to a steam generator to generate steam, the steam is delivered to a skid-mounted organic Rankine cycle or a steam turbine power generation system to generate power, and the utilization efficiency of waste heat power generation reaches 12%-15%. The intelligent control system adjusts the heat pipe insertion depth and the power generation load in real time, realizes controllable cooling rate and optimal power generation efficiency. The application is suitable for the graphitization production of lithium battery negative materials and various intermittent high-temperature furnaces, and realizes the dual goals of rapid cooling and efficient utilization of waste heat.

Description

Technical Field

[0001] This invention belongs to the field of energy-saving and environmental protection technology for high-temperature industrial furnaces and kilns. Specifically, it relates to a rapid cooling and waste heat power generation system, method, and storage medium for high-temperature furnaces and kilns. Background Technology

[0002] Graphitization is a crucial step in the production of lithium-ion battery anode materials, requiring materials to be heated to 2800-3000℃ to complete the graphitization transformation. After graphitization, the finished product inside the furnace must be cooled from an ultra-high temperature to 150-350℃ before being removed from the furnace. Due to the extremely high temperatures inside the furnace, and the fact that graphite products begin to oxidize above 300℃ and burn above 500℃ in the presence of oxygen, the industry currently generally adopts methods such as overall natural cooling of the furnace body or external surface spray ventilation for cooling. The cooling time is as long as about 30 days, resulting in an intermittent production cycle of more than 40 days per graphitization furnace, which severely restricts the capacity increase of lithium battery anode materials.

[0003] Meanwhile, the high-temperature materials and the large amount of heat accumulated in the furnace body are directly lost into the environment, resulting in huge energy waste. Although there are some waste heat recovery devices in the existing technology, most of them are fixed installations, which are difficult to adapt to the process requirements of top filling of graphitization furnaces and intermittent production. Moreover, the recovered heat has low utilization efficiency due to large fluctuations in heat source grade and unstable temperature.

[0004] To address the aforementioned issues, the applicant has developed relevant heat extraction technologies, such as the "Large Temperature Difference Combined Heat Pipe for Cooling and Heat Extraction in a Graphitization Furnace" disclosed in patent CN219914097U, which achieves stable heat extraction under ultra-high temperature conditions through a combination of various working fluids. Building upon this, the present invention further provides a fully enclosed rapid cooling device that is organically integrated with a waste heat power generation system, achieving the dual objectives of rapid cooling and efficient utilization of waste heat.

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method, system and medium for rapid cooling of high-temperature furnaces and waste heat power generation, so as to achieve precise cooling of the upper and side parts of the graphitization furnace and efficiently convert the recovered heat energy into electrical energy. Summary of the Invention

[0006] This invention provides a system and process for rapid cooling of high-temperature furnaces and kilns and waste heat power generation. The system rapidly cools high-temperature materials in a graphitization furnace (temperature approximately 2800-3000℃) to below 350℃ using a fully enclosed combined heat pipe heat extraction device, thus achieving rapid cooling of the furnace. The combined heat pipe transfers the heat from the high-temperature materials to a steam generator to produce steam. The high-temperature steam is then transported to a skid-mounted organic Rankine cycle (ORC) or steam turbine power generation system to expand and perform work, thereby driving a generator to generate electricity, achieving efficient recovery and energy conversion of high-temperature waste heat.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] In a first aspect, the present invention provides a system for rapid cooling of high-temperature furnaces and kilns and for generating electricity from waste heat, comprising:

[0009] A rapid cooling device includes a steel frame, a lifting mechanism, a steam generator, and a heat exchange element. The heat exchange element includes a combined heat pipe, which is divided into an evaporation section, an insulation section, and a cooling section. The evaporation section is used to absorb heat, and the cooling section is used to release heat. The combined heat pipe transfers heat to the steam generator, causing water to boil and generate steam.

[0010] A thermal energy conversion and power generation device is connected to the steam generator and is used to receive the steam and convert its thermal energy into electrical energy; the thermal energy conversion and power generation device is integrated on a skid-mounted base to form a skid-mounted integrated generator set.

[0011] The intelligent control system is communicatively connected to both the rapid cooling device and the heat energy conversion and power generation device, and is used to control the cooling rate and power generation load.

[0012] In one embodiment, the combined heat pipe includes two length specifications: a short heat pipe is configured such that the end of its evaporation section reaches 100 mm from the upper surface of the crucible or box plate on the furnace surface, and a long heat pipe is configured such that the end of its evaporation section reaches 100 mm from the lower surface of the crucible or box plate on the furnace surface.

[0013] In one embodiment, the rapid cooling device is a heat extraction unit configured to be installed across the width of the graphitization furnace. For a graphitization furnace with a length of 36-40 meters and a width of 6-8 meters, 9-10 heat extraction units are installed in a single graphitization furnace.

[0014] In one embodiment, the heat energy conversion and power generation device is an organic Rankine cycle power generation system or a small steam turbine power generation system, and the waste heat power generation utilization efficiency ranges from 12% to 15%.

[0015] In one embodiment, an intermediate heat exchange buffer unit is also included, connected between the steam generator and the heat conversion and power generation device, for smoothing out fluctuations in steam parameters.

[0016] In one embodiment, the intelligent control system includes:

[0017] The temperature detection module is used to collect temperature data inside the furnace and at the outlet of the steam generator;

[0018] The lifting control module is used to control the lifting insertion depth and speed of the heat exchange element;

[0019] The power generation load control module is used to adjust the operating load of the power generation unit according to the steam parameters;

[0020] The central controller is used to execute preset control strategies.

[0021] Secondly, the present invention provides a method for rapid cooling and waste heat power generation in high-temperature furnaces, implemented based on any of the above-mentioned systems, comprising the following steps:

[0022] S1 hoists the rapid cooling device to the furnace surface for positioning and installation;

[0023] S2 inserts the heat exchange element into the high-temperature material through the lifting mechanism, so that the heat exchange element enters the heat extraction mode after contacting the material, and the heat is transferred to the steam generator to make the water boil and generate steam.

[0024] S3 delivers the steam to the skid-mounted integrated generator set, converting thermal energy into electrical energy;

[0025] S4 monitors temperature and steam parameters in real time through an intelligent control system, and dynamically adjusts the insertion depth of the heat exchange element and the load of the power generation device.

[0026] S5 When the furnace core temperature drops to the preset temperature, the rapid cooling device is lifted out.

[0027] In one embodiment, in step S2, the material temperature in contact with the heat exchange element is ≥200℃ when the heat exchange element enters the heat extraction mode; in step S5, the preset temperature is ≤350℃.

[0028] In one embodiment, in step S3, thermal energy is converted into electrical energy through an organic Rankine cycle or a small steam turbine, and the waste heat power generation utilization efficiency is controlled between 12% and 15%.

[0029] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any of the above methods.

[0030] Compared with the prior art, this application has at least the following technical effects:

[0031] 1. Full-encirclement precise cooling: This invention uses heat exchange elements (combined heat pipes) to fully enclose the upper and side parts of the graphitization furnace for heat extraction, achieving full coverage of the upper and side parts of the furnace core, thus achieving precise cooling and significant heat extraction effect.

[0032] 2. Shorten the cooling cycle: Compared with natural cooling, the cooling time can be shortened by 50%, requiring about 12-15 days, which significantly improves equipment turnover rate and capacity, and the single furnace capacity can be increased by about 20-25%.

[0033] 3. High-efficiency power generation from waste heat: Steam is generated by a steam generator and connected to a skid-mounted ORC or steam turbine power generation system to realize the utilization of waste heat resources, with power generation efficiency stabilizing at 12%-15%.

[0034] 4. Automated operation: Once the device is hoisted to the graphitization production furnace, it automatically enters the heat extraction operation without manual assistance, reducing the probability of workers being exposed to high-temperature furnace surfaces and improving the working environment.

[0035] 5. Protect product quality: Due to the greatly shortened cooling time, the crucible or box plate is effectively blocked from contact with air, protecting the product from oxidation, thereby reducing the specific surface area of ​​the graphitized product and improving product quality.

[0036] 6. One-time low-temperature tapping: By rapidly extracting heat through heat exchange elements until the temperature reaches ≤350℃, tapping can be achieved in one go, effectively improving the service life of graphitization furnace equipment and facilities (furnace walls, electrode walls, crucibles or boxes, suction cranes, etc.).

[0037] 7. Save on auxiliary materials and equipment investment: It can reduce the thickness of auxiliary materials on the upper part and sides of the furnace core, thereby increasing the furnace loading capacity of the graphitization furnace; reduce the burning loss of auxiliary materials, increase the frequency of auxiliary material use, and save on the corresponding auxiliary material investment; it can save on the investment in equipment and facilities such as grab buckets.

[0038] 8. High flexibility of skid-mounted design: The generator set adopts a skid-mounted integrated design, which occupies a small area, is easy to install and debug, and can be used in rotation between different furnaces according to the production plan, thereby improving equipment utilization. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the overall structure of the graphitization furnace rapid cooling and waste heat power generation system according to an embodiment of the present invention, including a rapid cooling device 100, a skid-mounted ORC generator set 200, and an intelligent control system 300; the skid-mounted ORC generator set 200 includes an evaporator 201, an expander 202, a generator 203, a condenser 204, a working fluid pump 205, an electrical control system 206, and a skid-mounted base 210;

[0040] Figure 2 This is a schematic diagram of a combined heat pipe structure, including a shell 101, an evaporation section 102, an insulation section 103, a cooling section 104, and heat exchange fins 105.

[0041] Figure 3 This is a schematic diagram of the arrangement of the heat extraction unit on the graphitization furnace, including the graphitization furnace body 400, the heat extraction unit 500, the long heat pipe 600, the short heat pipe 700, and the positioning plate 800. Detailed Implementation

[0042] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0043] Example 1

[0044] This embodiment provides a system for rapid cooling and waste heat power generation in a graphitization furnace, applicable to box-type graphitization furnaces.

[0045] like Figure 1 As shown, the system includes a rapid cooling device 100, a skid-mounted ORC generator set 200, and an intelligent control system 300.

[0046] The rapid cooling device 100 is a fully enclosed rapid cooling device for a graphitization furnace, which consists of a steel frame, a control box, a motor, a lifting mechanism, a steam generator, and heat exchange elements (i.e., combined heat pipes).

[0047] like Figure 2 As shown, the combined heat pipe includes a shell 101, within which a space is provided for filling a special working fluid. Each heat pipe is divided into an evaporation section 102, an insulation section 103, and a cooling section 104, which together form a single unit. The evaporation section 102 is used for heat absorption, the insulation section 103 for heat preservation, and the cooling section 104 for heat release. The cooling section 104 is equipped with heat exchange fins 105 to enhance the heat exchange efficiency with water in the steam generator.

[0048] The heat pipe's shell material utilizes a carbon-carbon composite material and a graphite composite structure. The internal working fluids are configured according to temperature ranges, referencing the technical solution in patent CN219914097U, ensuring efficient operation across a wide temperature range of 3000℃ to 350℃. Specifically, different working fluids are configured for different temperature ranges. For example, alkali metals such as sodium and potassium are used in the high-temperature range, low-melting-point metals such as gallium and indium are used in the medium-temperature range, and conventional working fluids such as water and ethanol are used in the low-temperature range. This combination of multiple working fluids achieves efficient heat transfer across the entire temperature range.

[0049] The arrangement of the heat extraction unit, such as Figure 3 As shown, the application scenario in this embodiment is a box-type graphitization furnace with dimensions of 40000mm (length) × 7500mm (width). Each heat extraction unit has a customized size of 8000mm (length) × 4000mm (width). The heat extraction units are positioned and installed across the width of the box-type furnace. This application scenario can accommodate 10 heat extraction units.

[0050] Positioning plates are pre-installed on the side wall of the graphitization furnace to ensure that the legs of each heat-extracting unit can accurately press against the positioning plates, with a positioning deviation of ≤5mm. The positioning plates are made of high-temperature resistant stainless steel and have guide slopes to facilitate the quick and accurate positioning of the heat-extracting units.

[0051] The combined heat pipe lengths are configured as follows: short heat pipes extend 100mm from the furnace surface to the upper surface of the box furnace, while long heat pipes extend 100mm from the furnace surface to the lower surface of the box furnace. Two rows of long heat pipes are evenly arranged on each side, and eight rows of short heat pipes are evenly arranged at the top, with a center-to-center distance of 350mm between each heat pipe. This arrangement ensures complete coverage of the high-temperature materials within the graphitization furnace, creating a fully enclosed heat extraction system. The short heat pipes primarily absorb heat from the upper part of the furnace, while the long heat pipes penetrate deep into the sides of the furnace, achieving omnidirectional heat extraction from the furnace core.

[0052] The heat conversion and power generation unit 200 is an Organic Rankine Cycle (ORC) power generation system, integrated on a skid-mounted base 210. The base 210 is fixedly mounted with an evaporator 201, an expander 202, a generator 203, a condenser 204, a working fluid pump 205, and an electrical control system 206. All connecting pipes, valves, and instruments between the equipment are prefabricated, installed, and commissioned in the factory; only the steam inlet pipe and cooling water pipe need to be connected on-site for operation.

[0053] The rapid cooling device 100 has a pre-installed steam valve on the upper surface of its steam generator, which is connected to the evaporator 201 of the ORC generator set 200 via a steam pipe. The steam pipe is made of stainless steel corrugated pipe and has an insulation layer to reduce heat loss. A safety valve, pressure gauge, and temperature sensor are also installed on the pipe for real-time monitoring of steam parameters.

[0054] The intelligent control system 300 includes a PLC controller, thermocouples installed inside the furnace, a steam generator water level sensor, a lifting mechanism encoder, regulating valves, and a frequency converter, etc. Specifically:

[0055] Temperature detection module: includes multiple K-type thermocouples, which are arranged at different depths of the furnace core and the steam outlet of the steam generator to collect real-time temperature data at a sampling frequency of 1 time / minute.

[0056] Water level control module: Includes a float-type liquid level sensor and an electromagnetic water supply valve installed in the steam generator. It automatically supplies water when the water level is below the set lower limit and stops supplying water when the water level reaches the upper limit, ensuring continuous and stable steam generation.

[0057] Lifting control module: Includes encoder and limit switch installed on the lifting mechanism, used to precisely control the lifting insertion depth and speed of the heat exchange element. The insertion speed is controlled at 50-100mm / min to avoid impact damage to the crucible or box plate.

[0058] Power generation load control module: including electric regulating valves and frequency converters installed on steam pipelines, used to adjust the operating load of ORC generator set according to steam parameters to achieve optimal power generation efficiency.

[0059] The central controller uses a Siemens S7-1200 series PLC to execute preset control strategies, including automatic lifting timing control, temperature threshold judgment, fault alarm and interlock protection functions.

[0060] Specific work process:

[0061] Preliminary preparation and hoisting: After the graphitization furnace is powered off, it should be left to stand for 2-3 days to allow the temperature field inside the furnace to become more uniform, while eliminating thermal stress and preventing the furnace body from cracking due to sudden cooling. During the standing period, a hoisting plan for the device of this invention should be prepared in advance, including the hoisting sequence, personnel division of labor, and safety measures.

[0062] After the static heat preservation period, each unit of the device of this invention is installed and positioned. A workshop overhead crane is used to hoist the heat extraction units one by one to the furnace surface, and positioning is achieved quickly using positioning plates. The installation time for each unit is approximately 15 minutes. During installation, operators do not need to enter the high-temperature furnace area; the hoisting operation is controlled via remote control, ensuring personnel safety.

[0063] Heat extraction process: After the device is hoisted to the graphitization production furnace, the lifting mechanism is activated through the intelligent control system to slowly insert the heat exchange elements (combined heat pipes) into the high-temperature material. The lifting mechanism uses a double lead screw synchronous drive to ensure that the heat pipes are inserted vertically and avoid deflection.

[0064] When the heat exchange element comes into contact with materials at ≥200℃, the working fluid inside the heat pipe rapidly vaporizes, quickly entering the heat extraction mode. Heat is transferred from the evaporation section through the adiabatic section to the cooling section. The cooling section is equipped with heat exchange fins that promptly and intensely exchange heat with the water in the steam generator, causing the water to boil and generate steam. The heat transfer process of the heat pipe is phase change heat transfer, with extremely high heat transfer efficiency; the heat transfer capacity of a single heat pipe can reach 10-20kW.

[0065] During the heat extraction process, the water temperature inside the steam generator is maintained at around 100℃, and the steam pressure generated by water boiling is approximately 0.1-0.3 MPa (gauge pressure). The steam generator is equipped with a level valve to replenish water in a timely manner, ensuring a continuous and stable steam production. The steam output fluctuates with changes in furnace temperature, with a higher output initially and a gradual decrease later.

[0066] Power generation process: Steam generated by the steam generator is transported to the skid-mounted ORC generator set 200 through steam pipelines, and then enters the evaporator 201 to exchange heat with the organic working fluid. The organic working fluid used in this embodiment is R245fa, which has a boiling point of approximately 15°C, making it suitable for low-temperature waste heat power generation.

[0067] The organic working fluid absorbs heat and evaporates in the evaporator, becoming a high-temperature, high-pressure gas that drives the expander 202 to rotate and perform work, thereby generating electricity through the generator 203. The exhaust gas after performing work enters the condenser 204, where it exchanges heat with cooling water and condenses into a liquid state. After being pressurized by the working fluid pump 205, it is sent back to the evaporator 201, completing a closed-loop cycle.

[0068] In this embodiment, through optimized design, the waste heat power generation efficiency of the ORC system can reach approximately 14%. Based on the steam output of a single furnace, each furnace can recover steam to generate approximately 40,000 kWh of electricity. At an electricity price of 0.6 yuan / kWh, each furnace can generate economic benefits of approximately 24,000 yuan.

[0069] Cooling Completion and Unit Transfer: On days 12-15 of heat extraction, temperature is measured using thermocouples (range ≤1000℃). If the furnace core temperature is ≤350℃, rapid cooling is complete. The intelligent control system issues a prompt signal, and operators use an overhead crane to hoist the unit to the next production furnace for heat extraction.

[0070] After the equipment is hoisted out, the temperature of the material inside the furnace has dropped to below 350℃, far below the oxidation initiation temperature of graphite (approximately 500℃), thus eliminating the need for additional cooling time. Using a suction crane to remove the low-temperature auxiliary materials from the furnace in one go significantly improves production efficiency.

[0071] This embodiment was compared with the natural cooling method, and the results are as follows:

[0072] Cooldown time comparison:

[0073] Natural cooling method: After the graphitization furnace is powered on, the entire furnace body is naturally cooled, which takes 25-30 days. This is mainly due to the limited heat dissipation area of ​​the furnace body and the low thermal conductivity of the material.

[0074] In this embodiment, the cooling time is shortened to 12-15 days by using a fully enclosed heat extraction device, a reduction of more than 50%. The initial cooling rate can reach 10-15℃ / h, and the cooling rate gradually decreases in the later stage, but overall it is far superior to natural cooling.

[0075] Single furnace capacity increase:

[0076] Due to the shortened cooling cycle, equipment turnover rate has significantly improved. The original production cycle per furnace was approximately 40-45 days, which has now been reduced to 27-30 days, increasing production by 1-2 furnaces per year. Simultaneously, because the cooling device reduces the thickness of auxiliary materials on the upper and sides of the furnace core, the furnace loading capacity has increased by approximately 5-8%. Overall, the single-furnace capacity has increased by approximately 20-25%.

[0077] In this embodiment, the electricity generated by the recovered steam per furnace is approximately 40,000 kWh. Based on an annual production of 10 furnaces, the annual power generation is approximately 400,000 kWh, which can meet the electricity needs of part of the plant area and reduce the cost of purchased electricity. Due to the significantly shortened cooling time, the contact time between the crucible or tank plate and air is effectively blocked, resulting in a significant reduction in the degree of product oxidation. Testing showed that the specific surface area of ​​the graphitized product decreased by approximately 5%, the initial coulombic efficiency increased by approximately 0.5%, and the antioxidant performance was significantly improved. Traditional cooling methods require a thicker layer of auxiliary materials to protect the product. This embodiment achieves effective protection of the product through rapid cooling, reducing the thickness of the auxiliary materials in the upper and sides of the furnace core by approximately 10-15%, correspondingly reducing the amount of auxiliary materials burned off. At the same time, the frequency of auxiliary material use increases from 3-5 times to 6-8 times, saving approximately 10% in auxiliary material input. Under traditional cooling methods, the furnace body is in a high-temperature state for a long time, resulting in significant thermal stress damage. This embodiment shortens the duration of high temperature by rapidly cooling down, effectively improving the service life of equipment and facilities such as furnace walls, electrode walls, crucibles or box plates, and suction cranes in the graphitization furnace, which is expected to extend the service life by about 15-20%.

[0078] Example 2

[0079] The difference between this embodiment and Embodiment 1 lies in the structure of the heat energy conversion and power generation device and the setting of the intermediate heat exchange buffer unit.

[0080] The thermal energy conversion and power generation unit adopts a small steam turbine power generation system to replace the ORC generator set. The steam turbine power generation system includes waste heat boiler, steam turbine, generator, condenser and feedwater pump, etc., which are also integrated on a skid-mounted base.

[0081] During the cooling process of the high-temperature furnace, the initial furnace temperature reaches as high as 3000℃, resulting in high-temperature and high-pressure steam generated by the steam generator. Later, as the furnace temperature drops to several hundred degrees Celsius, the steam parameters decrease accordingly. This fluctuation in parameters poses a challenge to the stable operation of the power generation unit.

[0082] To address this issue, this embodiment adds a molten salt regenerative buffer tank as an intermediate heat exchange buffer unit between the steam generator and the steam turbine. The molten salt regenerative buffer tank is filled with molten salt (using a binary salt, i.e., 60% NaNO3 + 40% KNO3), and its operating temperature range is 220℃-550℃.

[0083] Work process:

[0084] The steam generated by the steam generator first enters the molten salt regenerator buffer tank, where it exchanges heat with the molten salt. When the steam temperature is high, the molten salt absorbs and stores the heat; when the steam temperature decreases, the molten salt releases heat to heat the steam, thus stabilizing the steam parameters entering the turbine.

[0085] Through the "peak shaving and valley filling" effect of the molten salt regenerative buffer tank, the steam temperature fluctuation range was reduced from the original 150℃-300℃ to 200℃-250℃, and pressure fluctuations were also effectively suppressed. Stable steam parameters ensured that the steam turbine always operated in the high-efficiency range, with the power generation efficiency remaining stable at over 13% and the fluctuation range not exceeding ±1%.

[0086] Compared to Example 1, this example increases the equipment investment in the molten salt thermal storage buffer tank, but it offers more stable power generation efficiency, making it particularly suitable for applications requiring high power output stability. Furthermore, steam turbine power generation systems have higher requirements for steam parameters; this example expands the system's applicability by incorporating a buffer unit.

[0087] Example 3

[0088] The difference between this embodiment and Embodiment 1 lies in the expansion of the application scenario, applying the system of the present invention to a crucible-type graphitization furnace.

[0089] The structure of crucible-type graphitization furnaces differs from that of box-plate-type graphitization furnaces. In a crucible-type furnace, the material is arranged in cylindrical crucibles. To accommodate this characteristic, the arrangement of the heat extraction unit has been adjusted accordingly.

[0090] Combined heat pipe length settings: short heat pipes extend from the furnace surface to 100mm from the top surface of the crucible, and long heat pipes extend from the furnace surface to 100mm from the bottom surface of the crucible. Since the crucible is cylindrical, the heat pipes are arranged in a staggered pattern with a center-to-center distance of 300mm to ensure that each crucible is surrounded by a heat pipe.

[0091] Number of heat extraction units: For a crucible-type graphitization furnace with dimensions of 30000mm (length) × 6000mm (width), each heat extraction unit is 6000mm × 4000mm in size, and a total of 8 heat extraction units are installed.

[0092] The working process is basically the same as in Example 1. Actual testing showed that the cooling time of the crucible-type graphitization furnace was reduced from 28 days to 14 days, a reduction of 50%. Each furnace recovers approximately 30,000 kWh of electricity from the recovered steam, with a waste heat power generation efficiency of approximately 13.5%. Product quality was also improved, with reduced oxidation levels and a decrease in specific surface area of ​​approximately 4.5% within the crucible.

[0093] Example 4

[0094] The difference between this embodiment and Embodiment 1 lies in the optimization of the control strategy of the intelligent control system.

[0095] In this embodiment, the intelligent control system adopts an adaptive lifting control strategy. Based on real-time data of the furnace temperature distribution, the insertion depth of the heat pipe is dynamically adjusted. When the furnace core temperature is high, the heat pipe insertion depth is shallow to avoid damage due to excessive temperature; as the furnace core temperature decreases, the insertion depth is gradually increased to ensure effective heat extraction.

[0096] The specific control logic is as follows: Set the furnace core temperature thresholds T1=2000℃, T2=1000℃, and T3=500℃. When T>T1, the insertion depth is 60% of the designed depth; when T1≥T>T2, the insertion depth is 80%; when T2≥T>T3, the insertion depth is 100%; when T≤T3, the heat pipe removal procedure is started.

[0097] This embodiment also achieves coordinated control of power generation load and cooling rate. When there is a large difference between peak and off-peak electricity prices, the system can dynamically adjust the power generation load according to the electricity price signal: prioritize power generation during peak electricity price periods and appropriately reduce the cooling rate; increase the cooling rate during off-peak electricity price periods, quickly converting heat into steam but temporarily not generating electricity or generating electricity at a low load.

[0098] Through the aforementioned coordinated control, this embodiment maximizes the economic benefits of power generation while ensuring the cooling effect. Calculations show that by leveraging peak-valley electricity price arbitrage, the economic benefits per boiler can be increased by approximately 15%.

[0099] The system and method described in this invention are applicable not only to box-type graphitization furnaces and crucible-type graphitization furnaces, but also to various high-temperature furnaces and kilns that operate intermittently, such as carbon roasting furnaces, ceramic shuttle kilns, and metallurgical furnaces. Its fully enclosed rapid cooling design combined with a skid-mounted generator set is particularly suitable for industrial scenarios requiring rapid cooling and waste heat recovery, demonstrating significant industrial application value and economic benefits.

[0100] Taking a graphitization workshop with an annual production capacity of 100,000 tons of lithium battery anode materials as an example, after adopting the system of this invention, the annual production capacity can be increased by about 25,000 tons, creating direct economic benefits of about 200 million yuan; at the same time, waste heat is recovered to generate about 4 million kWh of electricity, saving about 2.4 million yuan in electricity costs; and the consumption of auxiliary materials is reduced by about 10%, saving about 5 million yuan in costs; the comprehensive economic benefits are very significant.

[0101] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A system for rapid cooling and waste heat power generation in high-temperature furnaces, characterized in that, include: A rapid cooling device includes a steel frame, a lifting mechanism, a steam generator, and a heat exchange element. The heat exchange element includes a combined heat pipe, which is divided into an evaporation section, an insulation section, and a cooling section. The evaporation section is used to absorb heat, and the cooling section is used to release heat. The combined heat pipe transfers heat to the steam generator, causing water to boil and generate steam. A thermal energy conversion and power generation device is connected to the steam generator and is used to receive the steam and convert its thermal energy into electrical energy; the thermal energy conversion and power generation device is integrated on a skid-mounted base to form a skid-mounted integrated generator set. The intelligent control system is communicatively connected to both the rapid cooling device and the heat energy conversion and power generation device, and is used to control the cooling rate and power generation load.

2. The system according to claim 1, characterized in that, The combined heat pipes include two length specifications: the short heat pipe is configured such that the end of its evaporation section reaches 100mm from the upper surface of the crucible or box plate on the furnace surface, and the long heat pipe is configured such that the end of its evaporation section reaches 100mm from the lower surface of the crucible or box plate on the furnace surface.

3. The system according to claim 1, characterized in that, The rapid cooling device is a heat extraction unit, which is configured to be installed across the width of the graphitization furnace. For a graphitization furnace with a length of 36-40 meters and a width of 6-8 meters, 9-10 heat extraction units are installed in a single graphitization furnace.

4. The system according to claim 1, characterized in that, The heat energy conversion and power generation device is an organic Rankine cycle power generation system or a small steam turbine power generation system, with a waste heat power generation utilization efficiency ranging from 12% to 15%.

5. The system according to claim 1, characterized in that, It also includes an intermediate heat exchange buffer unit, which is connected between the steam generator and the heat energy conversion and power generation device to smooth out fluctuations in steam parameters.

6. The system according to claim 1, characterized in that, The intelligent control system includes: A temperature detection module is used to collect temperature data inside the furnace and at the outlet of the steam generator. The lifting control module is used to control the lifting insertion depth and speed of the heat exchange element; The power generation load control module is used to adjust the operating load of the power generation unit according to the steam parameters; The central controller is used to execute preset control strategies.

7. A method for rapid cooling and waste heat power generation in high-temperature furnaces, implemented based on the system described in any one of claims 1-6, characterized in that, Includes the following steps: S1 hoists the rapid cooling device to the furnace surface for positioning and installation; S2 inserts the heat exchange element into the high-temperature material through the lifting mechanism, so that the heat exchange element enters the heat extraction mode after contacting the material, and the heat is transferred to the steam generator to make the water boil and generate steam. S3 delivers the steam to the skid-mounted integrated generator set, converting thermal energy into electrical energy; S4 monitors temperature and steam parameters in real time through an intelligent control system, and dynamically adjusts the insertion depth of the heat exchange element and the load of the power generation device. S5 When the furnace core temperature drops to the preset temperature, the rapid cooling device is lifted out.

8. The method according to claim 7, characterized in that, In step S2, the material temperature in contact with the heat exchange element is ≥200℃, and the heat extraction mode is entered; in step S5, the preset temperature is ≤350℃.

9. The method according to claim 7, characterized in that, In step S3, thermal energy is converted into electrical energy through an organic Rankine cycle or a small steam turbine, and the waste heat power generation utilization efficiency is controlled between 12% and 15%.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 7 to 9.

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