Integrated double-side coating infrared drying heat pump combined supply system and control method

Abstract

The invention provides an integrated double-side coating infrared drying heat pump combined supply system which comprises a drying oven system used for drying a lithium battery pole piece base material, a first air nozzle mechanism and a second air nozzle mechanism are arranged in the drying oven system, and a heat pump system matched with the first air nozzle mechanism and the second air nozzle mechanism is arranged in the drying oven system. And the infrared heating assembly is used for heating the waste gas. The drying oven system is provided with an exhaust port, waste gas exhausted by the exhaust port is exhausted by an exhaust fan after being cooled by the heat pump circulating system through an air pipe, and the lithium battery coating base material drying device has the advantages of being capable of effectively improving the energy utilization rate and protecting the lithium battery coating base material, low in energy consumption and the like, and has great economic value and social value.

Description

Technical Field

[0001] This invention relates to the field of NMP exhaust gas treatment equipment design technology for lithium battery coating machines, and particularly to an integrated double-sided coating infrared drying heat pump combined supply system and control method. Background Technology

[0002] In battery manufacturing, electrode substrate coating is one of the key processes. After coating, the electrodes need to be heated and dried to evaporate the solvent. In the drying process of lithium-ion batteries, hot air is mainly used as the drying medium for convection drying, causing the wet solvent to evaporate from the coating slurry. The heat source is a critical piece of equipment in the drying system, ensuring uniform and thorough drying inside the oven and minimizing battery damage caused by drying defects, which affects the performance of the finished battery. The drying process is also a major energy-consuming stage. A professor at a US university collected and analyzed energy consumption data from lithium battery production. The main energy consumption in the lithium-ion battery production process includes oven drying, environmental control, and manufacturing equipment (slurry homogenization, coating, rolling, slitting, stacking, electrolyte injection, battery assembly, and formation, etc.). The highest energy consumption is mainly in the electrode drying process and the operating costs of the drying units in the drying room during battery production, accounting for approximately 46% of the total energy consumption in the lithium-ion battery production process. How to reduce the energy consumption of the electrode drying process is a common problem faced by the industry.

[0003] A domestic university conducted a professional analysis of the energy consumption of lithium battery electrode drying systems, establishing an energy balance analysis model based on the first law of thermodynamics. This model describes the calculation methods for energy consumption related to the heating of the electrode substrate and coating, solvent evaporation and phase change, heating of the drying medium, and system ventilation, as well as their balance with the total system energy input. A practical analysis and calculation were performed using a typical drying process for a water-soluble negative electrode coating as an example. The results show that the main energy consumption is for heating the drying medium, accounting for 93.30% of the total system energy consumption. Of the energy in the drying medium, the portion used for heating the substrate and coating is negligible, accounting for 0.14% and 0.21% respectively, while 6.74% is used for solvent consumption. System ventilation energy consumption is mainly used to overcome the resistance of the drying system and transport the drying medium, and its proportion in the total energy consumption is not high, at 6.70%. Traditional hot air drying methods suffer from high heat loss and an energy utilization rate of <10%, necessitating the adoption of new drying technologies to improve energy efficiency and reduce energy consumption. Therefore, further improvements are required. Summary of the Invention

[0004] This invention addresses the shortcomings of the prior art by providing an integrated double-sided coating infrared drying heat pump system that effectively improves energy utilization, protects lithium battery coating substrates, and has low energy consumption.

[0005] The technical solution adopted by the present invention to solve the above problems is as follows: This invention provides an integrated double-sided coated infrared drying heat pump system. This includes an oven system for drying lithium battery electrode substrates, the oven system comprising a first air nozzle mechanism and a second air nozzle mechanism. The oven system is equipped with an infrared heating component that works in conjunction with the first and second air nozzle mechanisms to heat the exhaust gas.

[0006] The oven system is equipped with an exhaust port. The exhaust gas emitted from the exhaust port is cooled by a heat pump circulation system through a duct before being discharged by an exhaust fan. The oven system is also equipped with a circulating air outlet, which is connected to the first air nozzle mechanism and the second air nozzle mechanism through a circulating fan and an air duct. The exhaust gas from the circulating air outlet is heated by the circulating fan through the air duct and then delivered to the first air nozzle mechanism and the second air nozzle mechanism respectively.

[0007] Furthermore, both the first and second air nozzle mechanisms consist of multiple air outlet structures. The first nozzle mechanism and the second nozzle mechanism are respectively located on both sides of the lithium battery electrode substrate.

[0008] Furthermore, the multiple air outlet structures of the first or second air outlet mechanism are connected by air ducts.

[0009] Furthermore, the heat pump cycle system consists of a compressor, a heat exchanger, an expansion valve, and an evaporator. The compressor, heat exchanger, expansion valve, and evaporator are connected by refrigerant pipelines and form a refrigerant circulation loop.

[0010] Furthermore, the evaporator of the heat pump cycle system is used to cool the exhaust gas discharged from the exhaust port. The heat exchanger of the heat pump circulation system is used to heat the exhaust gas discharged from the circulation vent.

[0011] Furthermore, the exhaust fan is connected to an NMP condensation and precipitation system via a duct to precipitate NMP waste gas. The NMP condensation and precipitation system is connected to an NMP secondary recovery system via a duct. The NMP waste gas passes through the NMP secondary recovery system and is then discharged to high altitude through the exhaust duct.

[0012] An integrated double-sided coated infrared drying heat pump system and control method, comprising the following steps: S1: The exhaust gas from the oven system is cooled by a heat pump circulation system through air ducts. S2: The cooled exhaust gas is discharged through an exhaust fan. S3: The exhaust gas from the circulating air vent of the oven system is heated by the circulating fan through the air duct and then enters the oven after being heated by the heat pump circulation system. S4: The exhaust gas, after being heated, enters the first and second air nozzle mechanisms of the oven system and is heated by the infrared heating element.

[0013] Furthermore, S1: The exhaust gas emitted from the exhaust port of the oven system is cooled through the air duct and heat pump circulation system, specifically, the exhaust gas is cooled from about 40°C to below 15°C after the gas-to-gas heat exchanger.

[0014] Furthermore, S2: After the exhaust gas is cooled and discharged through the exhaust fan, it then passes through the NMP condensation and precipitation system and the NMP secondary recovery system before being discharged into the high atmosphere through the exhaust duct.

[0015] Furthermore, the heat pump cycle system consists of a compressor, a heat exchanger, an expansion valve, and an evaporator. The compressor, heat exchanger, expansion valve, and evaporator are connected by refrigerant pipelines to form a refrigerant circulation loop. The refrigerant is heated and absorbs heat to evaporate in the evaporator, cooling the passing exhaust gas. Then, the gaseous refrigerant is pressurized by the compressor of the heat pump system, increasing its temperature and pressure. The high-temperature and high-pressure refrigerant gas enters the condenser, where it heats the circulating return air to above 120°C, raising the temperature of the passing exhaust gas.

[0016] The beneficial effects of this invention are as follows: The integrated double-sided coating infrared drying heat pump system and control method provided by this invention have the advantages of effectively improving energy utilization, protecting lithium battery coating substrate, and low energy consumption. The specific advantages of this application are reflected in the following aspects: (1) This application uses infrared radiation (wavelength 0.75-1000nm), which is part of the electromagnetic spectrum. The working principle of infrared drying technology is mainly based on the thermal effect and molecular resonance of infrared radiation, which has a significant thermal effect. When infrared radiation irradiates the surface of an object, most of the energy is absorbed by the material and converted into internal energy, causing the object's temperature to rise rapidly. This direct energy conversion avoids heat loss in traditional heat conduction methods and improves energy utilization efficiency. Significant energy savings are achieved by improving energy utilization.

[0017] (2) Heat pump technology is a green and energy-saving technology. The heat pump system uses the work of the compressor to "pump" the heat in the low-temperature heat source (such as air, water, soil or industrial waste heat) to the high-temperature end. Its energy efficiency ratio (COP) can reach 3-5, which is far superior to traditional electric heating equipment. During the hot air drying process of the coating machine electrode, a large amount of waste heat gas of 40~105 degrees needs to be discharged. The heat pump system can be fully utilized to absorb the waste heat and convert it into usable high-temperature hot air for drying the coated wet electrode in the oven. The cold energy generated by the heat pump low-temperature evaporator can be used to condense and recover NMP solvent, which achieves two goals at once and saves more energy.

[0018] (3) By integrating double-sided coating, infrared drying, and heat pump combined cooling and heating technologies, this system achieves comprehensive breakthroughs in energy efficiency, environmental friendliness, and process adaptability, becoming a core solution for high-end coating equipment in fields such as lithium batteries and flexible electronics. In conclusion, this application has significant economic and social value. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the principle structure of an embodiment 1 of the integrated double-sided coated infrared drying heat pump system of the present invention; Figure 2 This is a flowchart of the working process of Embodiment 1 of the integrated double-sided coated infrared drying heat pump combined supply system of the present invention; Figure 3 This is a schematic diagram of the principle structure of an embodiment 2 of the integrated double-sided coated infrared drying heat pump combined supply system of the present invention. Detailed Implementation

[0020] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The drawings are for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention. Example 1

[0021] like Figure 1-2 As shown, this invention provides an integrated double-sided coated infrared drying heat pump combined supply system. The system includes an oven system 1 for drying lithium battery electrode substrate 100, wherein the oven system 1 is provided with a first air nozzle mechanism 101 and a second air nozzle mechanism 102. The oven system 1 is equipped with an infrared heating component 2 that cooperates with the first air nozzle mechanism 101 and the second air nozzle mechanism 102 to heat the exhaust gas.

[0022] The oven system 1 is equipped with an exhaust port 103. The exhaust gas emitted from the exhaust port 103 is cooled by the heat pump circulation system 4 through the air duct 3 and then discharged by the exhaust fan 5. The oven system 1 is also provided with a circulating air outlet 104. The circulating air outlet 104 is connected to the first air nozzle mechanism 101 and the second air nozzle mechanism 102 through the circulating fan 6 and the air duct 3. The exhaust gas from the circulating air outlet 104 is heated by the circulating fan 6 through the air duct 3 and then delivered to the first air nozzle mechanism 101 and the second air nozzle mechanism 102 respectively.

[0023] In this embodiment, the first air nozzle mechanism 101 and the second air nozzle mechanism 102 are composed of multiple air outlet structures 105. The first nozzle mechanism 101 and the second nozzle mechanism 102 are respectively disposed on both sides of the lithium battery electrode substrate.

[0024] In this embodiment, multiple air outlet structures 105 of the first air outlet mechanism 101 or the second air outlet mechanism 102 are connected by air duct 3.

[0025] In this embodiment, the heat pump circulation system 4 consists of a compressor 7, a heat exchanger 8, an expansion valve 9, and an evaporator 10. The compressor 7, heat exchanger 8, expansion valve 9, and evaporator 10 are connected by a refrigerant pipeline 11 and form a refrigerant circulation loop.

[0026] In this embodiment, the evaporator 10 of the heat pump cycle system 4 is used to cool the exhaust gas discharged from the exhaust port 103. The heat exchanger 8 of the heat pump circulation system 4 is used to heat the exhaust gas discharged from the circulation vent 104.

[0027] In this embodiment, the exhaust fan 5 is connected to an NMP condensation and precipitation system 200 via a duct 3 for precipitating NMP waste gas. The NMP condensation and precipitation system 200 is connected to an NMP secondary recovery system 300 via a duct 3. The NMP waste gas passes through the NMP secondary recovery system 300 and is then discharged to the upper atmosphere via the exhaust duct 400.

[0028] An integrated double-sided coated infrared drying heat pump system and control method, comprising the following steps: S1: The exhaust gas emitted from the exhaust port 103 of the oven system 1 is cooled by the heat pump circulation system 4 through the air duct 3. S2: The cooled exhaust gas is discharged through exhaust fan 5. S3: The exhaust gas emitted from the circulating air outlet 104 of the oven system 1 is heated by the circulating fan 6 through the air duct 3 and then enters the oven through the heat pump circulation system 4. S4: The exhaust gas after being heated enters the first air nozzle mechanism 101 and the second air nozzle mechanism 102 of the oven system 1, and is heated by the infrared heating component 2.

[0029] In this embodiment, S1: The exhaust gas emitted from the exhaust port 103 of the oven system is cooled by the heat pump circulation system 4 through the air duct 3. Specifically, the exhaust gas is cooled from about 40°C to below 15°C after the gas-to-gas heat exchanger.

[0030] In this embodiment, S2: After the exhaust gas is cooled and discharged through the exhaust fan 5, it passes through the NMP condensation and precipitation system 12 and the NMP secondary recovery system 13, and then is discharged to the high altitude through the exhaust duct 3.

[0031] In this embodiment, the heat pump circulation system 4 consists of a compressor 7, a heat exchanger 8, an expansion valve 9, and an evaporator 10. The compressor 7, heat exchanger 8, expansion valve 9, and evaporator 10 are connected by a refrigerant pipeline 11 to form a refrigerant circulation loop. The refrigerant is heated and absorbs heat to evaporate in the evaporator 10, which cools the passing exhaust gas. Then, the gaseous refrigerant is pressurized by the compressor 7 of the heat pump system, and its temperature and pressure increase. The high-temperature and high-pressure refrigerant gas enters the condenser, where the circulating return air is heated to above 120°C, which heats the passing exhaust gas. Example 2

[0032] The difference between this embodiment and the previous embodiment is that: like Figure 3 As shown, this embodiment can also use a water-soluble agent to replace NMP exhaust gas. With a water-based solvent, water will not pollute the environment, and no exhaust gas treatment device is required. Infrared heating integrated with a heat pump achieves combined heating and drying, greatly reducing the energy consumption of the device.

[0033] The integrated double-sided coating infrared drying heat pump system and control method provided by this invention have the advantages of effectively improving energy utilization, protecting lithium battery coating substrate, and low energy consumption. The specific advantages of this application are reflected in the following aspects: (1) This application uses infrared radiation (wavelength 0.75-1000nm), which is part of the electromagnetic spectrum. The working principle of infrared drying technology is mainly based on the thermal effect and molecular resonance of infrared radiation, which has a significant thermal effect. When infrared radiation irradiates the surface of an object, most of the energy is absorbed by the material and converted into internal energy, causing the object's temperature to rise rapidly. This direct energy conversion avoids heat loss in traditional heat conduction methods and improves energy utilization efficiency. Significant energy savings are achieved by improving energy utilization.

[0034] (2) Heat pump technology is a green and energy-saving technology. The heat pump system uses the compressor 7 to pump the heat from a low-temperature heat source (such as air, water, soil or industrial waste heat) to a high-temperature end. Its energy efficiency ratio (COP) can reach 3-5, which is far superior to traditional electric heating equipment. During the hot air drying process of the coating machine electrode, a large amount of waste heat gas at 40-105 degrees Celsius needs to be discharged. The heat pump system can be fully utilized to absorb the waste heat and convert it into usable high-temperature hot air for drying the coated wet electrode in the oven. The cold energy generated by the heat pump low-temperature evaporator 10 can be used to condense and recover NMP solvent, achieving two goals at once and saving energy.

[0035] (3) By integrating double-sided coating, infrared drying, and heat pump combined cooling and heating technologies, this system achieves comprehensive breakthroughs in energy efficiency, environmental friendliness, and process adaptability, becoming a core solution for high-end coating equipment in fields such as lithium batteries and flexible electronics. This application replaces traditional electric heating and chiller units with a heat pump system, reducing overall energy consumption by 0%-70% and improving the energy efficiency of the infrared drying module by 30%. The infrared drying temperature can be controlled between 80-120℃, avoiding high-temperature damage to the flexible substrate. The use of a double-sided coating module combined with high-precision slot extrusion technology significantly improves electrode production efficiency. In summary, this application has significant economic and social value.

[0036] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. An integrated double-sided coated infrared drying heat pump system, characterized in that: This includes an oven system for drying lithium battery electrode substrates, the oven system comprising a first air nozzle mechanism and a second air nozzle mechanism. The oven system is equipped with an infrared heating element that works in conjunction with the first and second air nozzle mechanisms to heat the exhaust gas. The oven system is equipped with an exhaust port. The exhaust gas emitted from the exhaust port is cooled by a heat pump circulation system through a duct before being discharged by an exhaust fan. The oven system is also equipped with a circulating air outlet, which is connected to the first air nozzle mechanism and the second air nozzle mechanism through a circulating fan and an air duct. The exhaust gas from the circulating air outlet is heated by the circulating fan through the air duct and then delivered to the first air nozzle mechanism and the second air nozzle mechanism respectively.

2. The integrated double-sided coated infrared drying heat pump system according to claim 1, characterized in that: The first and second air nozzle mechanisms are composed of multiple air outlet structures. The first nozzle mechanism and the second nozzle mechanism are respectively located on both sides of the lithium battery electrode substrate.

3. The integrated double-sided coated infrared drying heat pump system according to claim 1, characterized in that: The multiple air outlet structures of the first or second air outlet mechanism are connected by air ducts.

4. The integrated double-sided coated infrared drying heat pump system according to claim 1, characterized in that: The heat pump cycle system consists of a compressor, a heat exchanger, an expansion valve, and an evaporator. The compressor, heat exchanger, expansion valve, and evaporator are connected by refrigerant pipelines and form a refrigerant circulation loop.

5. The integrated double-sided coated infrared drying heat pump system according to claim 1, characterized in that: The evaporator of the heat pump cycle system is used to cool the exhaust gas discharged from the exhaust port. The heat exchanger of the heat pump circulation system is used to heat the exhaust gas discharged from the circulation vent.

6. The integrated double-sided coated infrared drying heat pump system according to claim 1, characterized in that: The exhaust fan is connected to an NMP condensation and precipitation system via a duct to precipitate NMP waste gas. The NMP condensation and precipitation system is connected to an NMP secondary recovery system via a duct. The NMP waste gas passes through the NMP secondary recovery system and is then discharged into the upper atmosphere via the exhaust duct.

7. An integrated two-sided coating infrared drying heat pump cogeneration system and control method, characterized by, Includes the following steps: S1: The exhaust gas from the oven system is cooled by a heat pump circulation system through air ducts. S2: The cooled exhaust gas is discharged through an exhaust fan. S3: The exhaust gas from the circulating air vent of the oven system is heated by the circulating fan through the air duct and then enters the oven after being heated by the heat pump circulation system. S4: The exhaust gas, after being heated, enters the first and second air nozzle mechanisms of the oven system and is heated by the infrared heating element.

8. The integrated double-sided coated infrared drying heat pump combined supply system and control method according to claim 7, characterized in that: S1: The exhaust gas emitted from the oven system is cooled by the heat pump circulation system through the air duct. Specifically, the exhaust gas is cooled from about 40°C to below 15°C after the gas-to-gas heat exchanger.

9. The integrated double-sided coated infrared drying heat pump combined supply system and control method according to claim 7, characterized in that: S2: After being cooled, the exhaust gas is discharged through the exhaust fan, then passes through the NMP condensation and precipitation system and the NMP secondary recovery system, and finally is discharged into the high atmosphere through the exhaust duct.

10. The integrated double-sided coated infrared drying heat pump system and control method according to claim 7, characterized in that: The heat pump circulation system consists of a compressor, a heat exchanger, an expansion valve, and an evaporator. The compressor, heat exchanger, expansion valve, and evaporator are connected by refrigerant pipelines to form a refrigerant circulation loop. The refrigerant is heated and absorbs heat to evaporate in the evaporator, cooling the passing exhaust gas. Then, the gaseous refrigerant is pressurized by the compressor of the heat pump system, increasing its temperature and pressure. The high-temperature and high-pressure refrigerant gas enters the condenser, where it heats the circulating return air to above 120°C, raising the temperature of the passing exhaust gas.

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