Freezing system utilizing liquid nitrogen gasification to assist in cooling

Abstract

The utility model discloses a refrigeration system utilizing liquid nitrogen gasification to assist in cooling, which comprises a refrigerator, a refrigerant intermediate tank, a liquid nitrogen storage tank and a heat exchange device, and the liquid nitrogen storage tank is connected to a nitrogen inlet of a lithium hexafluorophosphate production workshop through a pipeline of the heat exchange device. A refrigerant outlet of the lithium hexafluorophosphate production workshop is connected to a refrigerant inlet of the lithium hexafluorophosphate production workshop through a hot end element of the refrigerant intermediate tank, the heat exchange device, the refrigerator and a cold end element pipeline of the refrigerant intermediate tank. According to the utility model, the cooling capacity generated in the liquid nitrogen gasification process is recovered and is used for cooling a refrigerant, so that the energy consumption is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical process equipment, in particular to a refrigeration system utilizing liquid nitrogen gasification to assist in cooling. Background Art

[0002] Growing demand for lithium hexafluorophosphate (LFP) in the lithium battery material market is driving the need for more efficient production processes. Traditional refrigeration units rely on electricity and must operate 24 / 7. This not only results in high energy consumption, but also reduces refrigeration efficiency during prolonged high-load operation, ultimately impacting LFP production.

[0003] Therefore, those skilled in the art are committed to developing a refrigeration system that utilizes liquid nitrogen gasification to assist in cooling, so as to overcome the problems existing in the prior art. Utility Model Content

[0004] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is how to absorb a large amount of heat by gasification of liquid nitrogen to pre-cool the refrigerant, thereby reducing the operating load of the refrigeration unit.

[0005] To achieve the above-mentioned purpose, the present invention provides a refrigeration system that utilizes liquid nitrogen vaporization to assist in cooling, comprising a refrigerator, a refrigerant intermediate tank, a liquid nitrogen storage tank, and a heat exchange device. The liquid nitrogen storage tank is connected to the nitrogen inlet of a lithium hexafluorophosphate production workshop through a pipeline of the heat exchange device, and the refrigerant outlet of the lithium hexafluorophosphate production workshop is connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop through a pipeline of the hot end element of the refrigerant intermediate tank, the heat exchange device, the refrigerator, and the cold end element of the refrigerant intermediate tank.

[0006] Furthermore, the liquid nitrogen storage tank pipeline is connected to the cold fluid inlet of the heat exchange device, and the cold fluid outlet pipeline of the heat exchange device is connected to the nitrogen inlet of the lithium hexafluorophosphate production workshop.

[0007] Furthermore, the refrigerant outlet pipe of the lithium hexafluorophosphate production workshop is connected to the hot end inlet of the refrigerant intermediate tank, the hot end outlet pipe of the refrigerant intermediate tank is connected to the hot fluid inlet of the heat exchange device, the hot fluid outlet pipe of the heat exchange device is connected to the inlet of the freezer, the outlet pipe of the freezer is connected to the cold end inlet of the refrigerant intermediate tank, and the cold end outlet pipe of the refrigerant intermediate tank is connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop.

[0008] Furthermore, the hot end outlet of the refrigerant intermediate tank is connected to the hot fluid inlet of the heat exchange device through a hot end discharge pump device pipeline.

[0009] Furthermore, the hot end discharge pump device includes a first hot end discharge pump, a first hot end discharge pump shut-off valve, and a second hot end discharge pump shut-off valve. The hot end outlet pipe of the refrigerant intermediate tank is connected to the inlet of the first hot end discharge pump shut-off valve, the outlet pipe of the first hot end discharge pump shut-off valve is connected to the inlet of the first hot end discharge pump, the outlet of the first hot end discharge pump is connected to the inlet of the second hot end discharge pump shut-off valve, and the outlet pipe of the second hot end discharge pump shut-off valve is connected to the hot fluid inlet of the heat exchange device.

[0010] Furthermore, the hot end discharge pump device includes a first hot end discharge pump, a second hot end discharge pump, a first hot end discharge pump shut-off valve, a second hot end discharge pump shut-off valve, a third hot end discharge pump shut-off valve, and a fourth hot end discharge pump shut-off valve. The hot end outlet pipe of the refrigerant intermediate tank is connected to the inlet of the first hot end discharge pump shut-off valve and the inlet of the third hot end discharge pump shut-off valve. The outlet pipe of the first hot end discharge pump shut-off valve is connected to the inlet of the first hot end discharge pump. The outlet of the first hot end discharge pump is connected to the inlet of the second hot end discharge pump shut-off valve. The outlet pipe of the third hot end discharge pump shut-off valve is connected to the inlet of the second hot end discharge pump. The outlet of the second hot end discharge pump is connected to the inlet of the fourth hot end discharge pump shut-off valve. The outlet of the second hot end discharge pump shut-off valve and the outlet of the fourth hot end discharge pump shut-off valve are connected to the hot fluid inlet of the heat exchange device in parallel via pipes.

[0011] Furthermore, the cold end outlet of the refrigerant intermediate tank is connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop through a cold end discharge pump device pipeline.

[0012] Furthermore, the cold end discharge pump device includes a first cold end discharge pump, a first cold end discharge pump shut-off valve, and a second cold end discharge pump shut-off valve. The cold end outlet pipe of the refrigerant intermediate tank is connected to the inlet of the first cold end discharge pump shut-off valve, the outlet pipe of the first cold end discharge pump shut-off valve is connected to the inlet of the first cold end discharge pump, the outlet of the first cold end discharge pump is connected to the inlet of the second cold end discharge pump shut-off valve, and the outlet pipe of the second cold end discharge pump shut-off valve is connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop.

[0013] Furthermore, the cold end discharge pump device includes a first cold end discharge pump, a second cold end discharge pump, a first cold end discharge pump cut-off valve, a second cold end discharge pump cut-off valve, a third cold end discharge pump cut-off valve, and a fourth cold end discharge pump cut-off valve. The cold end outlet pipe of the refrigerant intermediate tank is connected to the inlet of the first cold end discharge pump cut-off valve and the inlet of the third cold end discharge pump cut-off valve. The outlet pipe of the first cold end discharge pump cut-off valve is connected to the inlet of the first cold end discharge pump, the outlet of the first cold end discharge pump is connected to the inlet of the second cold end discharge pump cut-off valve, the outlet pipe of the third cold end discharge pump cut-off valve is connected to the inlet of the second cold end discharge pump, the outlet of the second cold end discharge pump is connected to the inlet of the fourth cold end discharge pump cut-off valve, and the outlet of the second cold end discharge pump cut-off valve and the outlet of the fourth cold end discharge pump cut-off valve are connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop in parallel.

[0014] Furthermore, the freezer includes a first freezer and a second freezer, the hot fluid outlet pipe of the heat exchange device is connected to the inlet of the first freezer and the inlet of the second freezer, and the outlet of the first freezer and the outlet of the second freezer are connected to the cold end inlet of the refrigerant intermediate tank by parallel pipes.

[0015] The advantages of the present invention are:

[0016] 1. The temperature of the refrigerant drops after being pre-cooled by liquid nitrogen vaporization, thereby reducing the load of the refrigeration unit, improving the refrigeration efficiency, and ensuring efficient and safe production.

[0017] 2. The refrigeration capacity of the freezer is relatively reduced, thus saving electricity consumption.

[0018] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural diagram of a preferred embodiment of the utility model;

[0020] Figure 2 It is a structural schematic diagram of another preferred embodiment of the present utility model.

[0021] Among them, 10-freezer, 11, first freezer, 12-second freezer, 20-refrigerant intermediate tank, 21-hot end element, 22-cold end element, 30-liquid nitrogen storage tank, 40-heat exchange device, 41-cold fluid inlet, 42-cold fluid outlet, 43-hot fluid inlet, 44-hot fluid outlet, 51-refrigerant outlet of lithium hexafluorophosphate production workshop, 52-refrigerant inlet of lithium hexafluorophosphate production workshop, 53-nitrogen inlet of lithium hexafluorophosphate production workshop Port, 61-first hot end discharge pump, 62-first hot end discharge pump cut-off valve, 63-second hot end discharge pump cut-off valve, 64-second hot end discharge pump, 65-third hot end discharge pump cut-off valve, 66-fourth hot end discharge pump cut-off valve, 71-first cold end discharge pump, 72-first cold end discharge pump cut-off valve, 73-second cold end discharge pump cut-off valve, 74-second cold end discharge pump, 75-third cold end discharge pump cut-off valve, 76-fourth cold end discharge pump cut-off valve. DETAILED DESCRIPTION

[0022] The following describes several preferred embodiments of the present invention with reference to the accompanying drawings to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0023] In the drawings, components with identical structures are denoted by the same reference numerals, and components with similar structures or functions are denoted by similar reference numerals. The dimensions and thicknesses of each component shown in the drawings are arbitrary and are not limited by the present invention. For clarity, the thicknesses of components in some places in the drawings are exaggerated.

[0024] The synthesis of lithium hexafluorophosphate involves some highly exothermic chemical reactions, such as the reaction of hexafluorophosphate with lithium salts. These reactions need to be carried out under strictly controlled temperature conditions to ensure the safety and efficiency of the reaction. In the production process of lithium hexafluorophosphate, the main function of the refrigerant is to control the reaction temperature and the heat generated during the cooling and separation process. Nitrogen can be used as a protective inert gas to prevent reaction with oxygen and moisture in the air. Usually nitrogen is obtained from liquid nitrogen storage tanks. The utility model recovers the cold energy generated during the gasification of liquid nitrogen and uses it for cooling the refrigerant, thereby reducing energy consumption. Example 1

[0025] like Figure 1As shown, this embodiment provides a refrigeration system that uses liquid nitrogen vaporization to assist in cooling, including a refrigerator 10, a refrigerant intermediate tank 20, a liquid nitrogen storage tank 30 and a heat exchange device 40. The liquid nitrogen storage tank 30 is connected to the nitrogen inlet 53 of the lithium hexafluorophosphate production workshop through a pipeline of the heat exchange device 40, and the refrigerant outlet 51 of the lithium hexafluorophosphate production workshop is connected to the refrigerant inlet 52 of the lithium hexafluorophosphate production workshop through a pipeline of the hot end element 21 of the refrigerant intermediate tank 20, the heat exchange device 40, the refrigerator 10 and the cold end element 22 of the refrigerant intermediate tank 20.

[0026] A partition is provided between the hot end component 21 of the refrigerant intermediate tank 20 and the cold end component 22 of the refrigerant intermediate tank 20 to separate the refrigerant with a high temperature from the refrigerant with a low temperature.

[0027] The liquid nitrogen storage tank 30 is connected to the cold fluid inlet 41 of the heat exchange device 40 through a pipeline, and the cold fluid outlet 42 of the heat exchange device 40 is connected to the nitrogen inlet 53 of the lithium hexafluorophosphate production workshop through a pipeline.

[0028] Specifically, the refrigerant outlet 51 pipeline of the lithium hexafluorophosphate production workshop is connected to the hot end inlet of the refrigerant intermediate tank 20, the hot end outlet pipeline of the refrigerant intermediate tank 20 is connected to the hot fluid inlet 43 of the heat exchange device 40, the hot fluid outlet 44 pipeline of the heat exchange device 40 is connected to the inlet of the freezer 10, the outlet pipeline of the freezer 10 is connected to the cold end inlet of the refrigerant intermediate tank 20, and the cold end outlet pipeline of the refrigerant intermediate tank 20 is connected to the refrigerant inlet 52 of the lithium hexafluorophosphate production workshop.

[0029] In some embodiments, the hot end outlet of the refrigerant intermediate tank 20 is connected to the hot fluid inlet 43 of the heat exchange device 40 through a hot end discharge pump device pipeline.

[0030] In this embodiment, the hot end discharge pump device includes a first hot end discharge pump 61, a first hot end discharge pump shut-off valve 62, and a second hot end discharge pump shut-off valve 63. The hot end outlet pipe of the refrigerant intermediate tank 20 is connected to the inlet of the first hot end discharge pump shut-off valve 62, the outlet pipe of the first hot end discharge pump shut-off valve 62 is connected to the inlet of the first hot end discharge pump 61, the outlet of the first hot end discharge pump 61 is connected to the inlet of the second hot end discharge pump shut-off valve 63, and the outlet pipe of the second hot end discharge pump shut-off valve 63 is connected to the hot fluid inlet 43 of the heat exchange device 40.

[0031] In some embodiments, the cold end outlet of the refrigerant intermediate tank 20 is connected to the refrigerant inlet 52 of the lithium hexafluorophosphate production workshop through a cold end discharge pump device pipeline.

[0032] In this embodiment, the cold end discharge pump device includes a first cold end discharge pump 71, a first cold end discharge pump shut-off valve 72, and a second cold end discharge pump shut-off valve 73. The cold end outlet pipe of the refrigerant intermediate tank 20 is connected to the inlet of the first cold end discharge pump shut-off valve 72, the outlet pipe of the first cold end discharge pump shut-off valve 72 is connected to the inlet of the first cold end discharge pump 71, the outlet of the first cold end discharge pump 71 is connected to the inlet of the second cold end discharge pump shut-off valve 73, and the outlet pipe of the second cold end discharge pump shut-off valve 73 is connected to the refrigerant inlet 52 of the lithium hexafluorophosphate production workshop. Example 2

[0033] like Figure 2 As shown, this embodiment provides a refrigeration system that uses liquid nitrogen vaporization to assist in cooling, including a first refrigerator 11, a second refrigerator 12, a refrigerant intermediate tank 20, a liquid nitrogen storage tank 30 and a heat exchange device 40. The liquid nitrogen storage tank 30 is connected to the nitrogen inlet 53 of the lithium hexafluorophosphate production workshop through a pipeline of the heat exchange device 40, and the refrigerant outlet 51 of the lithium hexafluorophosphate production workshop is connected to the refrigerant inlet 52 of the lithium hexafluorophosphate production workshop through a pipeline of the hot end element 21 of the refrigerant intermediate tank 20, the heat exchange device 40, the first refrigerator 11, the second refrigerator 12, and the cold end element 22 of the refrigerant intermediate tank 20.

[0034] The first freezer 11 and the second freezer 12 have the same structure. When the first freezer 11 is in operation, the second freezer 12 is in standby mode. Alternatively, when the second freezer 12 is in operation, the first freezer 11 is in standby mode.

[0035] A partition is provided between the hot end component 21 and the cold end component 22 of the refrigerant intermediate tank 20 to separate the high-temperature refrigerant from the low-temperature refrigerant.

[0036] The liquid nitrogen storage tank 30 is connected to the cold fluid inlet 41 of the heat exchange device 40 through a pipeline, and the cold fluid outlet 42 of the heat exchange device 40 is connected to the nitrogen inlet 53 of the lithium hexafluorophosphate production workshop through a pipeline.

[0037] Specifically, the refrigerant outlet 51 pipeline of the lithium hexafluorophosphate production workshop is connected to the hot end inlet of the refrigerant intermediate tank 20, the hot end outlet pipeline of the refrigerant intermediate tank 20 is connected to the hot fluid inlet 43 of the heat exchange device 40, the hot fluid outlet 44 pipeline of the heat exchange device 40 is connected to the inlet of the first freezer and the inlet of the second freezer, the outlet of the first freezer and the outlet of the second freezer are connected to the cold end inlet of the refrigerant intermediate tank 20 in parallel with the pipeline, and the cold end outlet pipeline of the refrigerant intermediate tank 20 is connected to the refrigerant inlet 52 of the lithium hexafluorophosphate production workshop.

[0038] In some embodiments, the hot end outlet of the refrigerant intermediate tank 20 is connected to the hot fluid inlet 43 of the heat exchange device 40 through a hot end discharge pump device pipeline.

[0039] In this embodiment, the hot end discharge pump device includes a first hot end discharge pump 61, a second hot end discharge pump 64, a first hot end discharge pump cut-off valve 62, a second hot end discharge pump cut-off valve 63, a third hot end discharge pump cut-off valve 65, and a fourth hot end discharge pump cut-off valve 66. The hot end outlet pipe of the refrigerant intermediate tank 20 is connected to the inlet of the first hot end discharge pump cut-off valve 62 and the inlet of the third hot end discharge pump cut-off valve 65. The outlet pipe of the first hot end discharge pump cut-off valve 62 is connected to the inlet of the third hot end discharge pump cut-off valve 65. The inlet of a hot end discharge pump 61, the outlet of the first hot end discharge pump 61 is connected to the inlet of the second hot end discharge pump shut-off valve 63, the outlet pipe of the third hot end discharge pump shut-off valve 65 is connected to the inlet of the second hot end discharge pump 64, the outlet of the second hot end discharge pump 64 is connected to the inlet of the fourth hot end discharge pump shut-off valve 66, and the outlet of the second hot end discharge pump shut-off valve 63 and the outlet of the fourth hot end discharge pump shut-off valve 66 are connected to the hot fluid inlet 43 of the heat exchange device 40 in parallel through pipes.

[0040] Among them, the first hot end discharge pump 61 and the second hot end discharge pump 64 have the same structure. When the first hot end discharge pump 61 is in working state, the second hot end discharge pump 64 is in standby state, or when the second hot end discharge pump 64 is in working state, the first hot end discharge pump 61 is in standby state.

[0041] In some embodiments, the cold end outlet of the refrigerant intermediate tank 20 is connected to the refrigerant inlet 52 of the lithium hexafluorophosphate production workshop through a cold end discharge pump device pipeline.

[0042] In this embodiment, the cold end discharge pump device includes a first cold end discharge pump 71, a second cold end discharge pump 74, a first cold end discharge pump cut-off valve 72, a second cold end discharge pump cut-off valve 73, a third cold end discharge pump cut-off valve 75, and a fourth cold end discharge pump cut-off valve 76. The cold end outlet pipe of the refrigerant intermediate tank 20 is connected to the inlet of the first cold end discharge pump cut-off valve 72 and the inlet of the third cold end discharge pump cut-off valve 75. The outlet pipe of the first cold end discharge pump cut-off valve 72 is connected to the first The inlet of the cold end discharge pump 71, the outlet of the first cold end discharge pump 71 is connected to the inlet of the second cold end discharge pump cut-off valve 73, the outlet pipe of the third cold end discharge pump cut-off valve 75 is connected to the inlet of the second cold end discharge pump 74, the outlet of the second cold end discharge pump 74 is connected to the inlet of the fourth cold end discharge pump cut-off valve 76, and the outlet of the second cold end discharge pump cut-off valve 73 and the outlet of the fourth cold end discharge pump cut-off valve 76 are connected to the refrigerant inlet 52 of the lithium hexafluorophosphate production workshop through parallel pipes.

[0043] Among them, the first cold end discharge pump 71 and the second cold end discharge pump 74 have the same structure. When the first cold end discharge pump 71 is in working state, the second cold end discharge pump 74 is in standby state, or when the second cold end discharge pump 74 is in working state, the first cold end discharge pump 71 is in standby state.

[0044] The above describes in detail the preferred embodiments of the present invention. It should be understood that numerous modifications and variations based on the concepts of the present invention can be made by those skilled in the art without inventive effort. Therefore, any technical solution that can be derived by a person skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology shall be within the scope of protection defined by the claims.

Claims

1. A refrigeration system using liquid nitrogen gasification to assist cooling, characterized in that: It includes a refrigerator, a refrigerant intermediate tank, a liquid nitrogen storage tank and a heat exchange device. The liquid nitrogen storage tank is connected to the nitrogen inlet of the lithium hexafluorophosphate production workshop through the pipeline of the heat exchange device. The refrigerant outlet of the lithium hexafluorophosphate production workshop is connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop through the hot end element of the refrigerant intermediate tank, the heat exchange device, the refrigerator and the cold end element pipeline of the refrigerant intermediate tank.

2. The refrigeration system utilizing liquid nitrogen gasification to assist in cooling as claimed in claim 1, characterized in that: The liquid nitrogen storage tank pipeline is connected to the cold fluid inlet of the heat exchange device, and the cold fluid outlet pipeline of the heat exchange device is connected to the nitrogen inlet of the lithium hexafluorophosphate production workshop.

3. The refrigeration system utilizing liquid nitrogen gasification to assist in cooling as claimed in claim 1, characterized in that: The refrigerant outlet pipe of the lithium hexafluorophosphate production workshop is connected to the hot end inlet of the refrigerant intermediate tank, the hot end outlet pipe of the refrigerant intermediate tank is connected to the hot fluid inlet of the heat exchange device, the hot fluid outlet pipe of the heat exchange device is connected to the inlet of the freezer, the outlet pipe of the freezer is connected to the cold end inlet of the refrigerant intermediate tank, and the cold end outlet pipe of the refrigerant intermediate tank is connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop.

4. The refrigeration system utilizing liquid nitrogen gasification to assist in cooling as claimed in claim 3, characterized in that: The hot end outlet of the refrigerant intermediate tank is connected to the hot fluid inlet of the heat exchange device through a hot end discharge pump device pipeline.

5. The refrigeration system utilizing liquid nitrogen gasification to assist in cooling as claimed in claim 4, characterized in that: The hot end discharge pump device includes a first hot end discharge pump, a first hot end discharge pump shut-off valve, and a second hot end discharge pump shut-off valve. The hot end outlet pipe of the refrigerant intermediate tank is connected to the inlet of the first hot end discharge pump shut-off valve, the outlet pipe of the first hot end discharge pump shut-off valve is connected to the inlet of the first hot end discharge pump, the outlet of the first hot end discharge pump is connected to the inlet of the second hot end discharge pump shut-off valve, and the outlet pipe of the second hot end discharge pump shut-off valve is connected to the hot fluid inlet of the heat exchange device.

6. The refrigeration system utilizing liquid nitrogen gasification to assist in cooling as claimed in claim 4, characterized in that: The hot end discharge pump device includes a first hot end discharge pump, a second hot end discharge pump, a first hot end discharge pump shut-off valve, a second hot end discharge pump shut-off valve, a third hot end discharge pump shut-off valve, and a fourth hot end discharge pump shut-off valve. The hot end outlet pipe of the refrigerant intermediate tank is connected to the inlet of the first hot end discharge pump shut-off valve and the inlet of the third hot end discharge pump shut-off valve. The outlet pipe of the first hot end discharge pump shut-off valve is connected to the inlet of the first hot end discharge pump, the outlet of the first hot end discharge pump is connected to the inlet of the second hot end discharge pump shut-off valve, the outlet pipe of the third hot end discharge pump shut-off valve is connected to the inlet of the second hot end discharge pump, the outlet of the second hot end discharge pump is connected to the inlet of the fourth hot end discharge pump shut-off valve, and the outlet of the second hot end discharge pump shut-off valve and the outlet of the fourth hot end discharge pump shut-off valve are connected to the hot fluid inlet of the heat exchange device in parallel via pipes.

7. The refrigeration system utilizing liquid nitrogen gasification to assist in cooling as claimed in claim 3, characterized in that: The cold end outlet of the refrigerant intermediate tank is connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop through a cold end discharge pump device pipeline.

8. The refrigeration system utilizing liquid nitrogen gasification to assist in cooling as claimed in claim 7, characterized in that: The cold end discharge pump device includes a first cold end discharge pump, a first cold end discharge pump shut-off valve, and a second cold end discharge pump shut-off valve. The cold end outlet pipe of the refrigerant intermediate tank is connected to the inlet of the first cold end discharge pump shut-off valve, the outlet pipe of the first cold end discharge pump shut-off valve is connected to the inlet of the first cold end discharge pump, the outlet of the first cold end discharge pump is connected to the inlet of the second cold end discharge pump shut-off valve, and the outlet pipe of the second cold end discharge pump shut-off valve is connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop.

9. The refrigeration system utilizing liquid nitrogen gasification to assist in cooling as claimed in claim 7, characterized in that: The cold end discharge pump device includes a first cold end discharge pump, a second cold end discharge pump, a first cold end discharge pump cut-off valve, a second cold end discharge pump cut-off valve, a third cold end discharge pump cut-off valve, and a fourth cold end discharge pump cut-off valve. The cold end outlet pipe of the refrigerant intermediate tank is connected to the inlet of the first cold end discharge pump cut-off valve and the inlet of the third cold end discharge pump cut-off valve. The outlet pipe of the first cold end discharge pump cut-off valve is connected to the inlet of the first cold end discharge pump, the outlet of the first cold end discharge pump is connected to the inlet of the second cold end discharge pump cut-off valve, the outlet pipe of the third cold end discharge pump cut-off valve is connected to the inlet of the second cold end discharge pump, the outlet of the second cold end discharge pump is connected to the inlet of the fourth cold end discharge pump cut-off valve, and the outlet of the second cold end discharge pump cut-off valve and the outlet of the fourth cold end discharge pump cut-off valve are connected to the refrigerant inlet of the lithium hexafluorophosphate production workshop in parallel through pipes.

10. The refrigeration system utilizing liquid nitrogen gasification to assist in cooling as claimed in claim 3, characterized in that: The freezer includes a first freezer and a second freezer, the hot fluid outlet pipe of the heat exchange device is connected to the inlet of the first freezer and the inlet of the second freezer, and the outlet of the first freezer and the outlet of the second freezer are connected to the cold end inlet of the refrigerant intermediate tank by parallel pipes.

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