Cold balance system for NMP coating recovery device

Abstract

The utility model belongs to the technical field of recovery, and particularly relates to a cold balance system for an NMP coating recovery device, which comprises an NMP recovery module, a cold balance module, a heat pump module and a coating drying module, the NMP recovery module, the cold balance module, the heat pump module and the coating drying module are sequentially connected, the NMP recovery module, the cold balance module and the heat pump module are sequentially connected to form a refrigerant water balance loop. The NMP recovery module, the cold balance module, the heat pump module and the coating drying module are sequentially connected, so that comprehensive utilization of energy in the coating drying process, the NMP recovery process and the working process of the heat pump module is achieved, the energy-saving effect is improved, and control over cold balance can be achieved through the arrangement of the refrigerant water balance loop; the system can better manage temperature and cold balance.

Description

Technical Field

[0001] The utility model relates to the technical field of recycling, in particular to a cold balance system for an NMP coating recycling device. Background Art

[0002] During the production and manufacturing process of lithium batteries, the coating machine will generate a large amount of high-temperature NMP waste gas, which needs to be recovered and treated using an NMP recovery system. The drying of the coating and the recovery of NMP consume a lot of energy.

[0003] In the traditional process, the temperature of NMP waste gas drops to about 15°C after condensation treatment before entering the next process. Some NMP waste gas needs to be heated to about 110°C before returning to the coater. However, the operating energy consumption of this process is often relatively high because the condensation and heating treatments of the waste gas are carried out separately, and the cold and heat cannot be used efficiently. When the cold and heat are used in a comprehensive manner, it is easy to have a cold and heat imbalance due to the inability to regulate the heat and cold separately, resulting in the inability to accurately control the temperature during electrode drying and NMP waste gas treatment.

[0004] Based on this, it is urgent to invent a cold balance system for a coating recovery device. Utility Model Content

[0005] The utility model aims to provide a cold balance system for an NMP coating recovery device in view of the deficiencies in the prior art, which not only has good energy-saving effect, but also has good cold balance effect of various parts of the system, is easy to accurately control the temperature, and ensures the excellence of the electrode coating process.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] Provided is a cold balance system for an NMP coating recovery device, comprising an NMP recovery module, a cold balance module, a heat pump module and a coating drying module connected in sequence,

[0008] The NMP recovery module, the cold balance module and the heat pump module are connected in sequence to form a refrigerant water balance loop. The NMP recovery module is used to convert the high-temperature NMP waste gas produced by the coating and drying module into low-temperature liquid NMP. The cold balance module is used to control the NMP recovery temperature in the NMP recovery module.

[0009] Specifically, the cold balance module includes a chiller and a cold water pump connected to the chiller, the heat pump module includes a low-temperature refrigerant heat exchanger, a high-temperature refrigerant heat exchanger and a heat pump unit, the NMP recovery module includes an air-to-air heat exchanger, a low-temperature heat exchanger and an exhaust fan, and the low-temperature refrigerant heat exchanger, the chiller, the cold water pump and the low-temperature heat exchanger form the refrigerant water balance circuit.

[0010] Specifically, the chiller includes a chilled water tank, and a four-way valve is provided at the chiller. The four-way valve is respectively connected to the inlet and outlet of the chilled water tank and the refrigerant water pipeline.

[0011] Specifically, the heat pump module is connected to the coating drying module to form a heating medium water circuit, and the coating drying module is connected to the NMP recovery module to form a gas circulation circuit.

[0012] Specifically, the coating drying module is composed of a coating oven, a circulation fan, and a high-temperature heat exchanger. The gas circulation circuit starts from the coating oven, passes through the exhaust fan, the gas-gas heat exchanger, the low-temperature heat exchanger, the gas-gas heat exchanger, the circulation fan, and the high-temperature heat exchanger in sequence, and finally returns to the coating oven; the heating medium water circuit starts from the high-temperature refrigerant heat exchanger, passes through the heating medium water pump and the high-temperature heat exchanger in sequence, and then returns to the heat pump unit.

[0013] Specifically, an auxiliary heater is also connected to the gas circulation circuit.

[0014] Specifically, the coating oven has multiple sections, and each section of the coating oven is connected to the gas circulation circuit and the heating medium water circuit.

[0015] Specifically, temperature detectors are provided in the refrigerant water balance circuit, the heating medium water circuit, and the gas circulation circuit.

[0016] Specifically, controllers are provided for both the circulation fan and the exhaust fan.

[0017] Specifically, a tail gas treatment system is further included.

[0018] The beneficial effects of the present utility model are as follows: By connecting the NMP recovery module, the cold balance module, the heat pump module, and the coating drying module in sequence, the comprehensive utilization of energy in the coating drying process, the NMP recovery process, and the operation process of the heat pump module is realized, improving the energy-saving effect. And through the setting of the refrigerant water balance circuit, the control of cold balance can be achieved, and the system can better manage temperature and cold balance. Description of the Drawings

[0019] The drawings described herein are used to provide a further understanding of the present utility model, and constitute a part of the present utility model. The schematic embodiments and descriptions thereof are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0020] Figure 1 is a schematic structural diagram of Embodiment 1 in the present utility model;

[0021] Figure 2It is an enlarged view of the cold balance module in Embodiment 1 of the present utility model;

[0022] Among them: 1 - NMP recovery module; 11 - gas-gas heat exchanger; 12 - low-temperature heat exchanger; 13 - exhaust fan; 14 - tail gas treatment system; 2 - cold balance module; 21 - chiller; 211 - cold water tank; 212 - four-way valve; 22 - cold water pump; 3 - heat pump module; 31 - low-temperature refrigerant heat exchanger; 32 - high-temperature refrigerant heat exchanger; 33 - heat pump unit; 34 - heat medium water pump; 4 - coating and drying module; 41 - coating oven; 42 - circulation fan; 43 - high-temperature heat exchanger; 44 - auxiliary heater; 5 - refrigerant water balance circuit; 6 - heat medium water circuit; 7 - gas circulation circuit. Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs. The terms used in the specification of the present application herein are only for the purpose of describing specific embodiments, and are not intended to limit the present application.

[0024] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0025] Although the present application is disclosed above in a preferred embodiment, it is not used to limit the claims. Any person skilled in the art can make several possible changes and modifications without departing from the concept of the present application. Therefore, the protection scope of the present application should be determined by the scope defined by the claims of the present application.

[0026] Such as Figure 1As shown, the inventor found that in the existing technology, the coating drying process and the NMP recovery process are set as two separate processes. When providing heat for coating drying, the heat pump directly discharges the cold energy into nature, and when providing cold energy for NMP recovery through the heat pump, the heat is directly discharged into nature, resulting in a double waste of heat and cold energy. Moreover, the discharged heat and cold energy will also have an impact on the environment. Therefore, in order to complement the energy of the NMP recovery module 1, the heat pump module 3, and the coating drying module 4, the inventor connected the NMP recovery module 1, the heat pump module 3, and the coating drying module 4 together to achieve efficient recycling of energy. Since the NMP recovery module 1, the heat pump module 3, and the coating drying module 4 are all connected together, the heat pump cannot separately adjust the temperature of the NMP recovery module 1 or the coating drying module 4. Therefore, the inventor set up a refrigerant water balance circuit 5 to adjust the cold balance in the circulation circuit, thereby improving the stability of the temperature and the heat and cold balance in the system.

[0027] Embodiment 1

[0028] As Figure 1 shown, a cold balance system for an NMP coating recovery device includes an NMP recovery module 1, a cold balance module 2, a heat pump module 3, and a coating drying module 4.

[0029] The NMP recovery module 1 is used to recover the NMP evaporated during the drying process of the electrode sheet for reuse of the NMP. Since the NMP is reused without emission, it can prevent NMP from polluting the environment.

[0030] The coating drying module 4 is used to dry the coated electrode sheet.

[0031] The heat pump module 3 is used to generate cold energy and heat energy to supply the NMP recovery module 1 and the coating drying module 4 respectively.

[0032] The cold balance module 2 is used to regulate the cold balance of the coating recovery device.

[0033] The NMP recovery module 1, the cold balance module 2, the heat pump module 3, and the coating drying module 4 are connected in sequence. Among them, the NMP recovery module 1, the cold balance module 2, and the heat pump module 3 are connected in sequence to form a refrigerant water balance circuit 5.

[0034] By connecting the NMP recovery module 1, the cold balance module 2, the heat pump module 3, and the coating and drying module 4 in sequence, the entire system forms a closed energy cycle, reducing waste, increasing efficiency, and being conducive to energy conservation, emission reduction, and environmental protection. This approach is a progress in industrial applications such as battery production, aiming to enhance the continuous production capacity and the economy of sustainable development. The refrigerant water balance circuit 5 controls the cold balance of the entire system by controlling the cold balance of the refrigerant water, stabilizing the temperature of the refrigerant water, and thus improving the stability of the entire system.

[0035] Specifically, the NMP recovery module 1 includes an air-air heat exchanger 11, a low-temperature heat exchanger 12, and an exhaust fan 13. The NMP recovery module 1 can be placed above or on the side of the coating oven 41, etc., which can adapt to the space layout and save floor space. Especially in some industrial production environments with limited space, it can improve the space utilization rate of the factory. The cold balance module 2 includes a chiller 21 and a chilled water pump 22. The cold balance module 2 uses the chiller 21 and the chilled water pump 22 to maintain the stability of the hot and cold states in the system. By controlling the power of the chiller 21 and the water pressure of the chilled water pump 22, the heat exchange power of the exhaust gas at the low-temperature heat exchanger 12 can be adjusted arbitrarily, maintaining the optimal heat absorption power for the exhaust gas. The heat pump module 3 includes a low-temperature refrigerant heat exchanger 31, a high-temperature refrigerant heat exchanger 32, and a heat pump unit 33. Through these two heat exchangers, the heat pump system can control the temperature of the heat medium or refrigerant water entering, thereby achieving free adjustment of the water supply temperature.

[0036] Specifically, the refrigerant water balance circuit 5 starts from the low-temperature refrigerant heat exchanger 31, passes through the chiller 21, the chilled water pump 22, and the low-temperature heat exchanger 12 in sequence, and then flows back to the low-temperature refrigerant heat exchanger 31.

[0037] More specifically, the refrigerant water balance circuit 5 is as follows: The heat pump unit 33 recovers the low-grade heat of the low-temperature heat exchanger 12 of the NMP recovery module 1 and converts it into high-grade heat after the actions of a low-temperature compressor and a high-temperature compressor, etc. At the heat pump unit 33, the low-temperature refrigerant heat exchanger 31 serves as the evaporator of the heat pump unit 33. The refrigerant water absorbs low-grade heat to produce refrigerant water at about 7°C. When the temperature of the refrigerant water cannot reach about 7°C after passing through the heat pump unit 33, the refrigerant water continues to pass through the chiller 21 to further lower the refrigeration temperature to reach refrigerant water at about 7°C. The refrigerant water is pressurized by the chilled water pump 22 and then passes through the low-temperature heat exchanger 12, causing the temperature of the low-temperature heat exchanger 12 to drop, which is used for cooling and condensing the exhaust gas of the NMP recovery module 1.

[0038] Such as Figure 2As shown, in some embodiments, the chiller 21 includes a chilled water tank, and a four-way valve is provided at the chiller 21. The four-way valve is respectively connected to the inlet and outlet of the chilled water tank and the refrigerant water pipeline. The four-way valve can flexibly adjust the inlet and outlet of the chilled water tank to meet the cooling requirements due to the change of ambient temperature at different times of the day. The chilled water stored in the chilled water tank is used for the cooling process. If the temperature drops, it can absorb the heat released by the refrigerant water to maintain the temperature stability of the chilled water. Conversely, if the temperature rises, the four-way valve can increase the flow rate of the chilled water tank. This design can achieve dynamic regulation of the refrigeration capacity of the chiller 21, avoiding the state where the refrigeration equipment is always operating at full load when the temperature changes greatly, resulting in energy waste, and can quickly carry out refrigeration.

[0039] Preferably, the heat pump module 3 is connected to the coating and drying module 4 to form a heat medium water circuit 6, and the coating and drying module 4 is connected to the NMP recovery module 1 to form a gas circulation circuit 7.

[0040] Specifically, the coating and drying module 4 is composed of a coating oven 41, a circulation fan 42, and a high-temperature heat exchanger 43. The coating oven 41 plays an important role in the coating process. Through precise temperature control, it ensures the coating quality and effect, enabling the coating to be evenly coated and cured. And the coating oven 41 can meet the synthesis and drying requirements of different types of coatings by designing adjustable temperature, humidity, and wind speed. The exhaust fan 13 is a key part in the coating and drying module 4 for removing and treating waste gas. It ensures the safe discharge of unnecessary gases generated during the process in the oven, such as volatiles, steam, or excess heat, etc., to prevent impacts on the environment and the health of operators, and is also a link to maintain the stability of the environment in the oven. The circulation fan 42 cooperates with the exhaust fan 13 to form a gas flow system. It is mainly used to maintain the air flow in the oven to ensure uniform drying of the coating, and at the same time can promote the treated air to return to the oven for the next cycle.

[0041] The gas circulation circuit starts from the coating oven 41, passes through the exhaust fan 13, the gas-gas heat exchanger 11, the low-temperature heat exchanger 12, the gas-gas heat exchanger 11, the circulation fan 42, and the high-temperature heat exchanger 43 in sequence, and finally returns to the coating oven 41; the heat medium water circuit 6 starts from the high-temperature refrigerant heat exchanger 32, passes through the high-temperature heat exchanger 43 and the heat medium water pump 34 in sequence, and then returns to the heat pump unit 33.

[0042] More specifically, the gas circulation loop is as follows: The NMP waste gas at about 110°C discharged from the exhaust fan 13 of the coating and drying module 4 is initially cooled to 30 - 40°C after heat exchange with the circulating return air in the air-air heat exchanger 11, and further cooled to 15 - 18°C after heat exchange with chilled water in the low-temperature heat exchanger 12. After the NMP condensate droplets are intercepted and collected by the demister, 5 - 10% of the exhaust gas is discharged to the atmosphere after environmental protection treatment in the exhaust gas treatment system 14, while 90 - 95% is used as circulating return air. After heat exchange in the air-air heat exchanger 11, it returns to the coating and drying module 4 through the circulation fan 42. In the coating and drying module 4, the circulating return air exits the air-air heat exchanger 11, passes through the circulation fan 42, and after being heated and raised in temperature by the high-temperature heat exchanger 43, returns to the coating oven 41. The hot and dry gas returning to the oven absorbs a large amount of NMP after purging the electrode sheet, and then returns to the NMP recovery module 1 under the action of the exhaust fan 13, and the electrode sheet becomes dry after passing through the coating oven 41.

[0043] The hot medium water loop 6 is as follows: The high-temperature refrigerant heat exchanger 32 serves as the condenser of the heat pump unit 33, and produces high-temperature hot medium water at about 130°C by absorbing high-grade heat. The high-temperature hot medium water enters the high-temperature heat exchanger 43, and the heat is transferred from the high-temperature hot medium water to the high-temperature heat exchanger 43 and then to the circulating return air blown out by the circulation fan 42, realizing the heating of the circulating return air. After the heat is transferred to the high-temperature heat exchanger 43, the temperature of the high-temperature hot medium water drops, and then it is heat-exchanged with the heat pump unit 33 again under the action of the hot medium water pump 34.

[0044] In this application, through the settings of the gas circulation loop 7, the refrigerant water balance loop 5, and the hot medium water loop 6, the efficient utilization of the heat and cold of the heat pump can be realized, improving the efficiency of the entire system, reducing energy waste, and also conforming to the environmental protection concept.

[0045] In the refrigerant water balance loop 5 of this application, a chiller 21 is provided to control the cold balance of the refrigerant water.

[0046] During the operation of the coating and recycling integrated cold balance system, there are many situations that require cold balance adjustment, such as:

[0047] One is during normal operation. The heat pump unit 33 has high-temperature and / or high-pressure protection and unloading mechanisms. In the case of two or more heat pump units 33 operating in parallel, a program can be set to make them operate and unload alternately, that is, when one heat pump unit 33 is in unloading protection, the other heat pump unit 33 operates normally.

[0048] During the unloading process of the heat pump unit 33, i.e., neither cooling nor heating, the temperature of the low-temperature refrigerant in the heat pump unit 33 increases, which may lead to insufficient cooling capacity of the low-temperature refrigerant for cold water in the low-temperature refrigerant heat exchanger 31. This further causes insufficient cooling capacity of the cold water for the NMP waste gas in the low-temperature heat exchanger 12, that is, it causes the outlet temperature of the NMP waste gas to rise, and may not meet the NMP concentration emission standard. At this time, the refrigeration of the chiller 21 needs to be supplemented to meet the cooling capacity of the cold water in the low-temperature heat exchanger 12.

[0049] One is due to the influence of the ambient temperature. When the ambient temperature is high, the heat required by the oven decreases, while the cooling capacity required at the low-temperature heat exchanger 12 increases, resulting in sufficient heat at the high-temperature refrigerant heat exchanger 32 and insufficient cooling capacity at the low-temperature refrigerant heat exchanger 31. The chiller 21 can be turned on to assist in supplementing the cooling capacity. When the coater stops, the chiller 21 can also be turned on to assist the coater oven in quickly cooling down.

[0050] The chiller 21 provided in this application can meet the supplementary cooling capacity in various situations, achieve the heat and cold balance of the system, and ensure the tail gas temperature and concentration of the NMP waste gas.

[0051] Embodiment 2

[0052] Different from Embodiment 1: The gas circulation loop 7 is further connected with an auxiliary heater 44. When the circulating return air passes through the high-temperature heat exchanger 43 and then through the auxiliary heater 44, the temperature of the circulating return air after passing through the high-temperature heat exchanger 43 can be adjusted again. The coating oven 41 has multiple sections, and each section of the coating oven 41 is connected to the gas circulation loop 7 and the heat medium water loop 6, and the temperature of each oven can be controlled separately to accurately control the temperature of different areas to meet the coating treatment requirements at different stages, such as maintaining the best drying or curing conditions, improving production efficiency and product quality. Each oven can be adjusted through its respective control system to ensure the accurate execution of the process.

[0053] The inlet and outlet of the high-temperature heat exchanger 43 are respectively connected to the outlet and inlet of the high-temperature refrigerant heat exchanger 32 of the heat pump module 3 through high-temperature heat medium water pipes. Each oven can control the temperature of the circulating return air of the oven by setting a separate high-temperature refrigerant heat exchanger 32 and respectively controlling the flow rate of the heat medium water flowing through the high-temperature refrigerant heat exchanger 32. Since the return air temperature requirements of each coating oven 41 are different, only controlling the flow rate of the heat medium water cannot meet the temperature requirements of all ovens. At this time, the auxiliary heater 44 is connected to the auxiliary heating system (such as heat-conducting oil or steam) to assist in heating the return air, so as to achieve the purpose of heating and temperature control, and achieve a wider range of temperature adjustment. When affected by the ambient temperature, when the ambient temperature is relatively low, the heat required by the oven increases, while the cooling capacity required at the low-temperature heat exchanger 12 decreases, resulting in insufficient heat at the high-temperature refrigerant heat exchanger 32 and sufficient cooling capacity at the low-temperature refrigerant heat exchanger 31. The auxiliary heater 44 can be turned on to generate additional heat for supplementation to meet the temperature and heat requirements of the oven, and the heat balance of the coating recovery device can be adjusted. By setting the auxiliary heater 44 and the chiller 21, the heat balance of the refrigerant water balance circuit 5 and the gas circulation circuit 7 can be controlled, making the heat and cold balance of the coating recovery device better.

[0054] Preferably, temperature detectors are provided in the refrigerant water balance circuit 5, the heat medium water circuit 6, and the gas circulation circuit 7. The temperature detectors ensure an automated adjustment process and can maintain the heat balance between the circuits. This not only helps to save energy, but also improves the energy utilization efficiency of the coating recovery device, reduces operating costs, enables the coating recovery device to adapt to external temperature changes, and ensures the stable progress of the process.

[0055] Preferably, controllers are provided for both the circulation fan 42 and the exhaust fan 13, which can control the wind speed in real time and are connected to temperature sensors. They can control the wind speed passing through the low-temperature heat exchanger 12 and the high-temperature heat exchanger 43 according to the controlled temperature, thereby adjusting the heat transfer and regulating the energy balance of the entire coating recovery device.

[0056] Preferably, an exhaust gas treatment system 14 is also provided. Through the exhaust gas treatment system 14, the exhaust gas can be discharged. Since the exhaust gas continuously flows out, the negative pressure of the oven can be maintained to prevent NMP from flowing out and polluting the environment.

[0057] Others are the same as those in Embodiment 1 and will not be elaborated here.

[0058] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A cold balance system for an NMP coating recovery device, characterized in that: It includes an NMP recovery module (1), a cold balance module (2), a heat pump module (3), and a coating drying module (4) connected in sequence. The NMP recovery module (1), the cold balance module (2), and the heat pump module (3) are connected in sequence to form a refrigerant water balance circuit (5). The NMP recovery module (1) is used to convert the high-temperature NMP waste gas produced by the coating drying module (4) into low-temperature liquid NMP, and the cold balance module (2) is used to control the NMP recovery temperature in the NMP recovery module (1).

2. The cold balance system for the NMP coating recovery device according to claim 1, wherein: The cold balance module (2) includes a chiller (21) and a chilled water pump (22) connected to the chiller (21). The heat pump module (3) includes a low-temperature refrigerant heat exchanger (31), a high-temperature refrigerant heat exchanger (32), and a heat pump unit (33). The NMP recovery module (1) includes an air-air heat exchanger (11), a low-temperature heat exchanger (12), and an exhaust fan (13). The low-temperature refrigerant heat exchanger (31), the chiller (21), the chilled water pump (22), and the low-temperature heat exchanger (12) form the refrigerant water balance circuit (5).

3. The cold balance system for the NMP coating recovery device according to claim 2, wherein: The chiller (21) includes a chilled water tank (211), and a four-way valve (212) is provided at the chiller. The four-way valve (212) is respectively connected to the inlet and outlet of the chilled water tank (211) and the refrigerant water pipeline.

4. The cold balance system for the NMP coating recovery device according to claim 2, wherein: The heat pump module (3) is connected to the coating drying module (4) to form a heat medium water circuit (6), and the coating drying module (4) is connected to the NMP recovery module (1) to form a gas circulation circuit (7).

5. The cold balance system for the NMP coating recovery device according to claim 4, wherein: The coating drying module (4) is composed of a coating oven (41), a circulation fan (42), and a high-temperature heat exchanger (43). The gas circulation circuit (7) starts from the coating oven (41), passes through the exhaust fan (13), the air-air heat exchanger (11), the low-temperature heat exchanger (12), the air-air heat exchanger (11), the circulation fan (42), and the high-temperature heat exchanger (43) in sequence, and finally returns to the coating oven (41). The heat medium water circuit (6) starts from the high-temperature refrigerant heat exchanger (32), passes through a heat medium water pump (34) and the high-temperature heat exchanger (43) in sequence, and then returns to the high-temperature refrigerant heat exchanger (32).

6. The cold balance system for the NMP coating recovery device according to claim 5, characterized in that: An auxiliary heater (44) is also connected to the gas circulation circuit (7).

7. The cold balance system for the NMP coating recovery device according to claim 5, characterized in that: The coating oven (41) has multiple sections, and each section of the coating oven (41) is connected to the gas circulation circuit (7) and the heat medium water circuit (6).

8. The cold balance system for the NMP coating recovery device according to claim 5, wherein: Temperature detectors are provided in the refrigerant water balance circuit (5), the heat medium water circuit (6), and the gas circulation circuit (7).

9. The cold balance system for the NMP coating recovery device according to claim 5, characterized in that: Controllers are provided for the circulation fan (42) and the exhaust fan (13).

10. The cold balance system for the NMP coating recovery device according to claim 1, characterized in that: It also includes a tail gas treatment system (14).

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