Liquid nitrogen cooling capacity recycling system for lithium battery plant

Abstract

The utility model relates to a liquid nitrogen cooling capacity recycling system for a lithium battery plant. The liquid nitrogen cooling capacity recycling system comprises a liquid nitrogen vaporizer, a refrigerating machine, a rotary dehumidifier, a heat exchanger, a circulating part I and a circulating part II, a heat transfer medium of the liquid nitrogen vaporizer circulates between the liquid nitrogen vaporizer and the heat exchanger through a circulating piece I; chilled water of the refrigerating machine circulates among the refrigerating machine, the rotary dehumidifier and the heat exchanger through the circulating part II. A heat transfer medium which is cooled after absorbing the cooling capacity of liquid nitrogen in the liquid nitrogen vaporizer is introduced into the heat exchanger through the first circulating part, chilled water which is heated after absorbing the heat of air in the rotary dehumidifier is introduced into the heat exchanger through the second circulating part, and the chilled water is preliminarily cooled after exchanging heat with the heat transfer medium in the heat exchanger. And the primarily cooled chilled water returns into the refrigerating machine again to absorb the cooling capacity of the cooling water so as to be further cooled, and the further cooled chilled water is provided for the rotary dehumidifier, so that the operation energy consumption of the refrigerating unit is effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of energy recovery and utilization, in particular to a liquid nitrogen cold energy recovery and utilization system for a lithium battery workshop. Background Technique

[0002] With the continuous growth of the power battery market, the production demand for lithium batteries is also increasing continuously. As a key gas in the production process of lithium batteries, nitrogen is indispensable in its application. First of all, in the manufacturing process of lithium batteries, nitrogen can be used for atmosphere control to build an anaerobic or low-oxygen atmosphere environment to prevent unnecessary reactions between the highly reactive materials of lithium batteries and oxygen. Secondly, in the assembly process of lithium batteries, nitrogen can be used as a protective gas to prevent the electrolyte in the battery and other components from being polluted by air, thereby improving the yield of the battery and extending the service life of the battery.

[0003] Lithium battery manufacturers generally produce nitrogen through nitrogen generators or directly purchase liquid nitrogen to meet their daily usage needs. Among them, liquid nitrogen is generally stored in liquid nitrogen tanks. When nitrogen is needed, liquid nitrogen exchanges heat with the external environment or heat transfer medium through a liquid nitrogen vaporizer, and its temperature gradually rises and is converted into nitrogen. However, a large amount of cold energy is released during the vaporization process of liquid nitrogen and is not recovered and utilized, resulting in waste of cold energy. In addition, a lithium battery workshop needs to use a rotary dehumidifier to process the air temperature and humidity of the workshop, and at the same time, a refrigeration unit is set up to provide chilled water for the rotary dehumidifier, and the refrigeration unit has the problem of high operating energy consumption. Content of the Utility Model

[0004] Based on this, in view of the problem that a large amount of cold energy is released during the vaporization of liquid nitrogen at present and is not recovered and utilized, resulting in waste of cold energy, and the problem that the refrigeration unit has high operating energy consumption, the utility model provides a liquid nitrogen cold energy recovery and utilization system for a lithium battery workshop.

[0005] A liquid nitrogen cold energy recovery and utilization system for a lithium battery workshop proposed by the utility model includes a liquid nitrogen vaporizer, a refrigeration machine and a rotary dehumidifier, and further includes a heat exchanger, a first circulation component and a second circulation component; the heat transfer medium of the liquid nitrogen vaporizer realizes circulation between the liquid nitrogen vaporizer and the heat exchanger through the first circulation component; the chilled water of the refrigeration machine realizes circulation among the refrigeration machine, the rotary dehumidifier and the heat exchanger through the second circulation component.

[0006] The utility model introduces the heat transfer medium cooled after absorbing the cold of liquid nitrogen in the liquid nitrogen vaporizer into the heat exchanger through the first circulation part, and introduces the chilled water heated after absorbing the heat of air in the rotary dehumidifier into the heat exchanger through the second circulation part. The chilled water exchanges heat with the heat transfer medium in the heat exchanger and then cools down. The cooled chilled water returns to the chiller again to absorb the cold of the cooling water and further cools down, and the further cooled chilled water is provided to the rotary dehumidifier, effectively using the cold of liquid nitrogen vaporization to preliminarily cool the chilled water, thereby reducing the operating energy consumption of the refrigeration unit; and the heat transfer medium heated by exchanging heat with the chilled water returns to the liquid nitrogen vaporizer through the first circulation part again to absorb the cold of liquid nitrogen to vaporize the liquid nitrogen, timely taking away the cold of liquid nitrogen vaporization, effectively inhibiting the supercooling and icing on the surface of the liquid nitrogen vaporizer, and ensuring the liquid nitrogen vaporization effect.

[0007] As a further improvement of the above solution of the utility model, the first circulation part includes a first circulation pipe, a second circulation pipe and a first circulation pump; both ends of the first circulation pipe are respectively communicated with the heat transfer medium outlet of the liquid nitrogen vaporizer and the cold medium inlet of the heat exchanger; both ends of the second circulation pipe are respectively communicated with the heat transfer medium inlet of the liquid nitrogen vaporizer and the cold medium outlet of the heat exchanger; the inlet and outlet of the first circulation pump are communicated on the pipeline of the first circulation pipe. The first circulation pump is provided to provide power to introduce the heat transfer medium of the liquid nitrogen vaporizer into the heat exchanger, and the heat transfer medium after heat exchange in the heat exchanger returns to the liquid nitrogen vaporizer again through the second circulation pipe, realizing the circulation of the heat transfer medium between the liquid nitrogen vaporizer and the heat exchanger.

[0008] As a further improvement of the above solution of the utility model, a first throttle valve is also connected to the pipeline of the first circulation pipe at the upstream position of the first circulation pump, and a heat insulation layer is arranged outside the first circulation pipe. The first throttle valve is provided to adjust the speed and flow rate of the heat transfer medium in the first circulation pipe, thereby realizing the control of the flow rate and pressure of the heat transfer medium; by arranging the heat insulation layer outside the first circulation pipe, the loss of the cold of the heat transfer medium is avoided.

[0009] As a further improvement of the above solution of the utility model, the second circulation part includes a third circulation pipe, a fourth circulation pipe and a second circulation pump; both ends of the third circulation pipe are respectively communicated with the chilled water outlet of the chiller and the hot medium inlet of the heat exchanger; both ends of the fourth circulation pipe are respectively communicated with the hot medium outlet of the heat exchanger and the chilled water inlet of the chiller; the inlet and outlet of the second circulation pump are communicated on the pipeline of the third circulation pipe; the chilled water inlet and outlet of the rotary dehumidifier are communicated on the pipeline of the third circulation pipe, and the rotary dehumidifier is located upstream of the second circulation pump. The second circulation pump is provided to provide power to introduce the chilled water of the rotary dehumidifier into the heat exchanger, and the chilled water preliminarily cooled by heat exchange in the heat exchanger flows into the chiller through the fourth circulation pipe for further cooling, and the further cooled chilled water flows into the rotary dehumidifier, realizing the circulation of the chilled water between the chiller, the rotary dehumidifier and the heat exchanger.

[0010] As a further improvement to the above solution of the present utility model, heat insulation layers are provided outside both the third circulation pipe and the fourth circulation pipe to avoid the loss of the cooling capacity of the chilled water.

[0011] As a further improvement to the above solution of the present utility model, the second circulation member further includes a three-way reversing valve one and a three-way reversing valve two. Two of the three passages of the three-way reversing valve one are connected to the pipeline of the third circulation pipe and the three-way reversing valve one is located downstream of the second circulation pump. The other passage of the three-way reversing valve one is connected to one of the passages of the three-way reversing valve two, and the other two passages of the three-way reversing valve two are connected to the pipeline of the fourth circulation pipe.

[0012] As a further improvement to the above solution of the present utility model, the liquid nitrogen cooling capacity recovery and utilization system for the lithium battery workshop further includes a liquid nitrogen tank, a first pipeline, a second pipeline and a main nitrogen supply pipe; the two ends of the first pipeline are respectively connected to the liquid nitrogen outlet of the liquid nitrogen tank and the liquid nitrogen inlet of the liquid nitrogen vaporizer; the two ends of the second pipeline are respectively connected to the nitrogen outlet of the liquid nitrogen vaporizer and the main nitrogen supply pipe. The liquid nitrogen tank is used to store liquid nitrogen and supply liquid nitrogen to the liquid nitrogen vaporizer, and the main nitrogen supply pipe provides nitrogen for the lithium battery production process.

[0013] As a further improvement to the above solution of the present utility model, a second throttle valve is connected to the first pipeline and a heat insulation layer is provided outside the first pipeline. The speed and flow rate of the liquid nitrogen in the first pipeline are adjusted by the provided second throttle valve, so as to realize the control of the flow rate and pressure of the liquid nitrogen; by providing a heat insulation layer outside the first pipeline, the loss of the cooling capacity of the liquid nitrogen is avoided.

[0014] As a further improvement to the above solution of the present utility model, the liquid nitrogen cooling capacity recovery and utilization system for the lithium battery workshop further includes a fifth circulation pipe, a sixth circulation pipe, a third circulation pump and a cooling tower; the two ends of the fifth circulation pipe are respectively connected to the cooling water outlet of the refrigerator and the cooling water inlet of the cooling tower; the two ends of the sixth circulation pipe are respectively connected to the cooling water outlet of the cooling tower and the cooling water inlet of the refrigerator; the inlet and outlet of the third circulation pump are connected to the pipeline of the fifth circulation pipe. The provided third circulation pump realizes the circulation of the cooling water between the cooling tower and the refrigerator, so as to provide cooling water for the refrigerator.

[0015] As a further improvement to the above solution of the present utility model, a third throttle valve is connected to the fifth circulation pipe and the third throttle valve is located upstream of the third circulation pump, a fourth throttle valve is connected to the sixth circulation pipe, and heat insulation layers are provided outside both the fifth circulation pipe and the sixth circulation pipe. The speed and flow rate of the cooling water in the fifth circulation pipe are adjusted by the provided third throttle valve, and the speed and flow rate of the cooling water in the sixth circulation pipe are adjusted by the provided fourth throttle valve, so as to realize the control of the flow rate and pressure of the cooling water; by providing heat insulation layers outside the fifth circulation pipe and the sixth circulation pipe, the loss of the cooling capacity of the cooling water is avoided.

[0016] Compared with the prior art, the present utility model has the following beneficial effects:

[0017] The utility model introduces the heat transfer medium cooled after absorbing the cold quantity of liquid nitrogen in the liquid nitrogen vaporizer into the heat exchanger through the first circulation part, and introduces the chilled water heated after absorbing the heat of air in the rotary dehumidifier into the heat exchanger through the second circulation part. The chilled water exchanges heat with the heat transfer medium in the heat exchanger and is preliminarily cooled. The preliminarily cooled chilled water returns to the refrigerating machine again to absorb the cold quantity of the cooling water and is further cooled, and the further cooled chilled water is provided to the rotary dehumidifier, effectively utilizing the cold quantity of liquid nitrogen vaporization to preliminarily cool the chilled water, thereby reducing the operating energy consumption of the refrigeration unit; and the heat transfer medium heated by exchanging heat with the chilled water returns to the liquid nitrogen vaporizer through the first circulation part again to absorb the cold quantity of liquid nitrogen to vaporize the liquid nitrogen, timely taking away the cold quantity of liquid nitrogen vaporization, effectively inhibiting the surface supercooling and icing of the liquid nitrogen vaporizer, and ensuring the liquid nitrogen vaporization effect. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a liquid nitrogen cold quantity recovery and utilization system for a lithium battery plant provided by an embodiment of the utility model.

[0019] Reference numerals: 1, liquid nitrogen vaporizer; 2, refrigerating machine; 3, heat exchanger; 4, first circulation pipe; 5, second circulation pipe; 6, first circulation pump; 7, first throttle valve; 8, third circulation pipe; 9, fourth circulation pipe; 10, second circulation pump; 11, rotary dehumidifier; 12, first three-way reversing valve; 13, second three-way reversing valve; 14, liquid nitrogen tank; 15, first pipe; 16, second pipe; 17, main nitrogen supply pipe; 18, second throttle valve; 19, fifth circulation pipe; 20, sixth circulation pipe; 21, third circulation pump; 22, cooling tower; 23, third throttle valve; 24, fourth throttle valve. Detailed Embodiments

[0020] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0021] In view of the problems that a large amount of cold quantity released by liquid nitrogen vaporization is not recovered and utilized at present, resulting in waste of cold quantity, and the problem that the refrigeration unit has relatively high operating energy consumption, this embodiment provides a liquid nitrogen cold quantity recovery and utilization system for a lithium battery plant. Refer to Figure 1, the liquid nitrogen cold energy recovery and utilization system of the lithium battery plant in this embodiment includes a liquid nitrogen vaporizer 1, a refrigerating machine 2, a rotary dehumidifier 11, a heat exchanger 3, a first circulation component, and a second circulation component. It may also include a liquid nitrogen tank 14, a first pipeline 15, a second pipeline 16, a main nitrogen supply pipe 17, a fifth circulation pipe 19, a sixth circulation pipe 20, a third circulation pump 21, and a cooling tower 22.

[0022] Liquid nitrogen is stored in the liquid nitrogen tank 14. In this embodiment, the liquid nitrogen tank 14 adopts the prior art, and its working principle is clear and will not be elaborated here. Its main function is to store and transport liquid nitrogen. The liquid nitrogen tank 14 adopts high-vacuum heat insulation technology, which effectively reduces heat transfer, thereby maintaining the low temperature state of the liquid nitrogen in the tank to ensure the safety, stability, and effectiveness of the liquid nitrogen during use.

[0023] The liquid nitrogen vaporizer 1 is used to convert liquid nitrogen into nitrogen. In this embodiment, the liquid nitrogen vaporizer 1 adopts the prior art. Using the principle of heat exchange, the liquid nitrogen exchanges heat with the heat transfer medium, causing the liquid nitrogen to absorb heat and vaporize into a gaseous state. The liquid nitrogen inlet of the liquid nitrogen vaporizer 1 is connected to the liquid nitrogen outlet of the liquid nitrogen tank 14 through the first pipeline 15. In order to adjust the speed and flow rate of the liquid nitrogen to control the flow rate and pressure of the liquid nitrogen, a throttle valve 2 18 is connected to the first pipeline 15. The nitrogen outlet of the liquid nitrogen vaporizer 1 is connected to the main nitrogen supply pipe 17 through the second pipeline 16.

[0024] Through the above structural settings, when the throttle valve 1 7 is opened, the liquid nitrogen in the liquid nitrogen tank 14 flows into the liquid nitrogen channel of the liquid nitrogen vaporizer 1 through the first pipeline 15. The liquid nitrogen exchanges heat with the heat transfer medium in the liquid nitrogen vaporizer 1 and vaporizes to form nitrogen. The nitrogen enters the main nitrogen supply pipe 17 through the second pipeline 16 to provide nitrogen for the lithium battery production process. To avoid the loss of liquid nitrogen cold energy, a heat insulation layer can be provided outside the first pipeline 15.

[0025] The function of the heat exchanger 3 is to realize the transfer of heat from the hot medium to the cold medium and improve the energy utilization rate. In this embodiment, the heat exchanger 3 adopts the heat exchanger 3 of the prior art, and its working principle is clear and will not be elaborated here. It has a hot medium inlet, a hot medium outlet, a cold medium inlet, and a cold medium outlet.

[0026] The refrigerating machine 2 is used to achieve the transfer of heat, so as to provide the required cooling effect in various occasions. In this embodiment, the refrigerating machine 2 adopts the existing technology, and its working principle is clear, so it will not be elaborated here. It has a chilled water inlet, a chilled water outlet, a cooling water inlet and a cooling water outlet. The chilled water temperature of the refrigerating machine 2 is controlled at 7-12°C. The cooling water outlet of the refrigerating machine 2 is connected to the cooling water inlet of the cooling tower 22 through the fifth circulation pipe 19, and the cooling water inlet of the refrigerating machine 2 is connected to the cooling water outlet of the cooling tower 22 through the sixth circulation pipe 20. The inlet and outlet of the third circulation pump 21 are connected to the pipeline of the fifth circulation pipe 19. By setting the third circulation pump 21, the cooling water is circulated between the cooling tower 22 and the refrigerating machine 2, so as to provide cooling water for the refrigerating machine 2. In order to adjust the speed and flow rate of the cooling water to control the flow rate and pressure of the cooling water, a throttle valve three 23 is connected to the fifth circulation pipe 19 and the throttle valve three 23 is located upstream of the third circulation pump 21, and a throttle valve four 24 is connected to the sixth circulation pipe 20. Through the above structural settings, when the throttle valve three 23 and the throttle valve four 24 are opened and the third circulation pump 21 is started, the cooling water can circulate between the cooling tower 22 and the refrigerating machine 2. To avoid energy loss, a heat insulation layer can be provided outside the fifth circulation pipe 19 and the sixth circulation pipe 20.

[0027] The first circulating member is used to achieve the circulation of the heat transfer medium of the liquid nitrogen vaporizer 1 between the liquid nitrogen vaporizer 1 and the heat exchanger 3. In this embodiment, the first circulating member includes a first circulation pipe 4, a second circulation pipe 5 and a first circulation pump 6. The two ends of the first circulation pipe 4 are respectively connected to the heat transfer medium outlet of the liquid nitrogen vaporizer 1 and the cold medium inlet of the heat exchanger 3; the two ends of the second circulation pipe 5 are respectively connected to the heat transfer medium inlet of the liquid nitrogen vaporizer 1 and the cold medium outlet of the heat exchanger 3; the inlet and outlet of the first circulation pump 6 are connected to the pipeline of the first circulation pipe 4. Through the above structural settings, when the throttle valve one 7 is opened and the first circulation pump 6 is started, the heat transfer medium of the liquid nitrogen vaporizer 1 flows into the heat exchanger 3 through the first circulation pipe 4 and then flows back to the liquid nitrogen vaporizer 1 through the second circulation pipe 5. In order to adjust the speed and flow rate of the heat transfer medium to control the flow rate and pressure of the heat transfer medium, a throttle valve one 7 is also connected to the upstream position of the first circulation pump 6 on the circulation pipe. To avoid energy loss, a heat insulation layer can be provided outside the first circulation pipe 4 and the second circulation pipe 5.

[0028] The rotary dehumidifier 11 is used to process the air temperature and humidity in the lithium battery workshop. The chilled water flowing through the rotary dehumidifier 11 will absorb the heat of the air and increase in temperature. The second circulation component is used to realize the circulation of the chilled water of the chiller 2 among the chiller 2, the rotary dehumidifier 11, and the heat exchanger 3. In this embodiment, the second circulation component includes a third circulation pipe 8, a fourth circulation pipe 9, a second circulation pump 10, a first three-way reversing valve 12, and a second three-way reversing valve 13. The two ends of the third circulation pipe 8 are respectively connected to the chilled water outlet of the chiller 2 and the heat medium inlet of the heat exchanger 3. The two ends of the fourth circulation pipe 9 are respectively connected to the heat medium outlet of the heat exchanger 3 and the chilled water inlet of the chiller 2. The inlet and outlet of the second circulation pump 10 are connected to the pipeline of the second circulation pipe 5. The chilled water inlet and outlet of the rotary dehumidifier 11 are connected to the pipeline of the third circulation pipe 8 and the rotary dehumidifier 11 is located upstream of the second circulation pump 10. Two of the passages of the first three-way reversing valve 12 are connected to the pipeline of the third circulation pipe 8 and the first three-way reversing valve 12 is located downstream of the second circulation pump 10. The other passage of the first three-way reversing valve 12 is connected to one of the passages of the second three-way reversing valve 13, and the other two passages of the second three-way reversing valve 13 are connected to the pipeline of the fourth circulation pipe 9. Through the above structural settings, by reversing the first three-way reversing valve 12 and the second three-way reversing valve 13, the second circulation pump 10 is connected to the heat exchanger 3, and the reversing valve is connected to the chiller 2. When the second circulation pump 10 is started, the chilled water that has absorbed the heat of the air in the rotary dehumidifier 11 enters the heat exchanger 3, then flows back to the chiller 2 through the fourth circulation pipe 9, and then returns to the rotary dehumidifier 11 from the third circulation pipe, realizing the circulation of the chilled water among the chiller 2, the rotary dehumidifier 11, and the heat exchanger 3; when the first three-way reversing valve 12 and the second three-way reversing valve 13 are reversed to close the connection between the heat exchanger 3 and the second circulation pump 10, and the second three-way reversing valve 13 closes the connection between the heat exchanger 3 and the chiller 2 and connects the first three-way reversing valve 12 and the second three-way reversing valve 13, the chilled water of the chiller 2 flows back to the chiller 2 after passing through the rotary dehumidifier 11 and through the first three-way reversing valve 12 and the second three-way reversing valve 13. To avoid energy loss, a heat preservation layer can be provided outside the third circulation pipe 8 and the fourth circulation pipe 9.

[0029] Through the above structural settings, this embodiment adopts the following working mode:

[0030] When the liquid nitrogen vaporizer 1 starts to work, through the commutation of the first three-way reversing valve 12 and the second three-way reversing valve 13, the second circulation pump 10 is connected to the heat exchanger 3, and the heat exchanger 3 is connected to the refrigerator 2. Open the first throttle valve 7, the second throttle valve 18, the third throttle valve 23, and the fourth throttle valve 24, and start the first circulation pump 6, the heat exchanger 3, the second circulation pump 10, and the third circulation pump 21; The liquid nitrogen in the liquid nitrogen tank 14 flows into the liquid nitrogen vaporizer 1 and absorbs the heat of the heat transfer medium in the liquid nitrogen vaporizer 1 to vaporize into nitrogen, and the nitrogen flows into the nitrogen supply main pipe 17 through the second pipeline 16 for use at the end of the workshop; The heat transfer medium that has absorbed the cold of the liquid nitrogen flows into the heat exchanger 3 under the action of the first circulation pump 6. At the same time, the chilled water that has been heated by heat exchange with the air in the rotary dehumidifier 11 flows into the heat exchanger 3 under the action of the second circulation pump 10. The chilled water and the heat transfer medium exchange heat in the heat exchanger 3. After heat exchange, the chilled water is preliminarily cooled and the heat transfer medium is heated; The heated heat transfer medium flows back into the liquid nitrogen vaporizer 1 again to provide heat for liquid nitrogen vaporization, and the preliminarily cooled chilled water flows back into the refrigerator 2 again; The cooling water of the cooling tower 22 flows into the refrigerator 2 under the action of the third circulation pump 21. The cooling water indirectly exchanges heat with the chilled water through the refrigerant in the refrigerator 2. After indirect heat exchange, the chilled water is further cooled and the cooling water is heated; The further cooled chilled water continues to circulate to the rotary dehumidifier 11 to be heated by heat exchange with the air, and the heated cooling water flows into the cooling tower 22 to release heat, ensuring that the cooling water in the cooling tower 22 remains at a stable temperature for use by the refrigerator 2; Circulate in this way to realize the normal operation of the rotary dehumidifier 11;

[0031] When the liquid nitrogen vaporizer 1 stops working, to ensure the normal supply of cooling water, through the commutation of the first three-way reversing valve 12 and the second three-way reversing valve 13, the first three-way reversing valve 12 closes the connection between the heat exchanger 3 and the second circulation pump 10, and the second three-way reversing valve 13 closes the connection between the heat exchanger 3 and the refrigerator 2 and connects the first three-way reversing valve 12 and the second three-way reversing valve 13; The heat exchanger 3 and the first circulation pump 6 stop working, start the second circulation pump 10 and open the third throttle valve 23 and the fourth throttle valve 24; The cooling water of the cooling tower 22 flows into the refrigerator 2 under the action of the third circulation pump 21. The cooling water exchanges heat with the chilled water in the refrigerator 2. After heat exchange, the chilled water is cooled and the cooling water is heated; The cooled chilled water continues to circulate to the rotary dehumidifier 11 to be heated by heat exchange with the air, and the heated cooling water flows into the cooling tower 22 to mix with the cooling water in the cooling tower 22 to release heat, ensuring that the cooling water in the cooling tower 22 remains at a stable temperature for use by the refrigerator 2; The chilled water that has been heated by heat exchange with the air in the rotary dehumidifier 11 flows back to the refrigerator 2 through the first three-way reversing valve 12 and the second three-way reversing valve 13 under the action of the second circulation pump 10 to continue cooling; Circulate in this way to realize the normal operation of the rotary dehumidifier 11.

[0032] In this embodiment, the temperature of liquid nitrogen is below -196°C, while the temperature of chilled water in the lithium battery workshop is generally controlled between 7°C and 12°C. The heat transfer medium of the liquid nitrogen vaporizer 1 is used to recover the cold energy of liquid nitrogen vaporization, and then the heat exchanger 3 is used for the heat exchange between the heat transfer medium and the chilled water, which can avoid the problem that the chilled water and liquid nitrogen directly exchange heat and easily cause the pipeline to freeze, and ensure the stable operation of the system.

[0033] It should be noted that when a component is referred to as being "installed on" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "set on" another component, it can be directly set on the other component or there may be an intermediate component at the same time. When a component is considered to be "fixed to" another component, it can be directly fixed to the other component or there may be an intermediate component at the same time.

[0034] 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 this utility model belongs. The terms used in the description of this utility model in this specification are only for the purpose of describing specific embodiments and are not intended to limit this utility model. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0035] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0036] The above-described embodiments only represent several implementation manners of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of this utility model, several modifications and improvements can still be made, and these all belong to the protection scope of this utility model. Therefore, the protection scope of the utility model patent should be subject to the appended claims.

Claims

1. A liquid nitrogen cooling capacity recovery and utilization system for a lithium battery plant, comprising a liquid nitrogen vaporizer (1), a refrigerator (2) and a rotary dehumidifier (11), characterized in that: It also includes a heat exchanger (3), a circulation component 1, and a circulation component 2; the heat transfer medium of the liquid nitrogen vaporizer (1) is circulated between the liquid nitrogen vaporizer (1) and the heat exchanger (3) through the circulation component 1; the chilled water of the refrigerator (2) is circulated between the refrigerator (2), the rotary dehumidifier (11), and the heat exchanger (3) through the circulation component 2; The circulation component 1 comprises a circulation pipe 1 (4), a circulation pipe 2 (5) and a circulation pump 1 (6); the two ends of the circulation pipe 1 (4) are respectively connected to the heat transfer medium outlet of the liquid nitrogen vaporizer (1) and the cold medium inlet of the heat exchanger (3); the two ends of the circulation pipe 2 (5) are respectively connected to the heat transfer medium inlet of the liquid nitrogen vaporizer (1) and the cold medium outlet of the heat exchanger (3); the inlet and outlet of the circulation pump 1 (6) are connected to the pipeline of the circulation pipe 1 (4); The circulation component 2 comprises a circulation pipe 3 (8), a circulation pipe 4 (9) and a circulation pump 2 (10); the two ends of the circulation pipe 3 (8) are respectively connected to the chilled water outlet of the refrigerator (2) and the heat medium inlet of the heat exchanger (3); the two ends of the circulation pipe 4 (9) are respectively connected to the heat medium outlet of the heat exchanger (3) and the chilled water inlet of the refrigerator (2); the inlet and outlet of the circulation pump 2 (10) are connected to the pipeline of the circulation pipe 3 (8); the chilled water inlet and the chilled water outlet of the rotary dehumidifier (11) are connected to the pipeline of the circulation pipe 3 (8), and the rotary dehumidifier (11) is located upstream of the circulation pump 2 (10).

2. The liquid nitrogen cooling capacity recovery and utilization system for lithium battery plant according to claim 1 is characterized in that: A throttle valve 1 (7) is also connected to the circulation pipe 1 (4) at a position upstream of the circulation pump 1 (6), and a heat-insulating layer is arranged outside the circulation pipe 1 (4).

3. The liquid nitrogen cooling capacity recovery and utilization system for lithium battery plant according to claim 1 is characterized in that: The circulation pipe 3 (8) and the circulation pipe 4 (9) are both provided with a heat-insulating layer outside.

4. The lithium battery plant liquid nitrogen cooling recovery and utilization system according to claim 3 is characterized in that: The circulation component 2 further comprises a three-way reversing valve 1 (12) and a three-way reversing valve 2 (13), two of the three-way reversing valve 1 (12) being connected to the pipeline of the circulation pipe 3 (8) and the three-way reversing valve 1 (12) being located downstream of the circulation pump 2 (10), the other of the three-way reversing valve 1 (12) being connected to one of the three-way reversing valve 2 (13), and the other two of the three-way reversing valve 2 (13) being connected to the pipeline of the circulation pipe 4 (9).

5. The liquid nitrogen cooling capacity recovery and utilization system for lithium battery plant according to claim 1 is characterized in that: The lithium battery plant liquid nitrogen cold recovery and utilization system further comprises a liquid nitrogen tank (14), a first pipeline (15), a second pipeline (16) and a nitrogen supply main pipe (17); the two ends of the first pipeline (15) are respectively connected to the liquid nitrogen outlet of the liquid nitrogen tank (14) and the liquid nitrogen inlet of the liquid nitrogen vaporizer (1); the two ends of the second pipeline (16) are respectively connected to the nitrogen outlet of the liquid nitrogen vaporizer (1) and the nitrogen supply main pipe (17).

6. The liquid nitrogen cooling capacity recovery and utilization system for lithium battery plant according to claim 5 is characterized in that: The pipe one (15) is connected to the throttle valve two (18) and a heat-insulating layer is arranged outside the pipe one (15).

7. The liquid nitrogen cooling capacity recovery and utilization system for lithium battery plant according to claim 1 is characterized in that: The lithium battery plant liquid nitrogen cold recovery and utilization system further comprises a circulation pipe five (19), a circulation pipe six (20), a circulation pump three (21) and a cooling tower (22); the two ends of the circulation pipe five (19) are respectively connected to the cooling water outlet of the refrigerator (2) and the cooling water inlet of the cooling tower (22); the two ends of the circulation pipe six (20) are respectively connected to the cooling water outlet of the cooling tower (22) and the cooling water inlet of the refrigerator (2); the inlet and outlet of the circulation pump three (21) are connected to the circulation pipe five (19).

8. The liquid nitrogen cooling capacity recovery and utilization system for lithium battery plant according to claim 1 is characterized in that: The circulation pipe five (19) is connected to a throttle valve three (23) and the throttle valve three (23) is located upstream of the circulation pump three (21), the circulation pipe six (20) is connected to a throttle valve four (24), and the circulation pipe five (19) and the circulation pipe six (20) are both provided with insulation layers.

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