Efficient, energy-saving and environment-friendly nitrogen supply system

Abstract

The utility model relates to a nitrogen supply system, in particular to a high-efficiency, energy-saving and environment-friendly nitrogen supply system, which is widely applied to industries needing high-purity nitrogen, such as photovoltaic cell manufacturing, lithium battery manufacturing, synthetic amine production and the like. According to the specific scheme, low-temperature nitrogen of the liquid nitrogen storage tank and the air separation nitrogen making device is mixed and subjected to heat exchange with normal-temperature air of the purification system in the heat exchanger, the mixed nitrogen is transferred into the air through the heat exchanger, the treated air is introduced into the air separation nitrogen making device to be recycled, and the overall energy efficiency of the system is improved; and the treated low-temperature nitrogen is introduced into a gas supply pipeline system, so that the cold energy of the low-temperature nitrogen is recycled. Evaporated nitrogen can be wasted in a traditional method. According to the scheme, the nitrogen is recycled and reintroduced into a production system, so that the loss of the nitrogen is reduced, and the supply cost of the nitrogen is reduced. And the existing system does not need to be transformed on a large scale, only a recovery pipeline and a heat exchange device need to be additionally arranged at key positions, and high feasibility and economical efficiency are achieved.

Description

Technical Field

[0001] The utility model relates to a nitrogen supply system, in particular to a highly efficient, energy-saving and environmentally friendly nitrogen supply system, which is widely used in industries requiring high-purity nitrogen, such as photovoltaic cell manufacturing, lithium battery manufacturing and synthetic amine production. Background Art

[0002] In industries such as photovoltaic cell manufacturing, lithium battery manufacturing, and synthetic amine production, it is crucial to maintain a continuous supply of high-purity nitrogen, so cryogenic liquid nitrogen storage tanks are needed to ensure 24-hour backup reserves. However, cryogenic liquid nitrogen storage tanks will produce a certain evaporation rate during the evaporation process, resulting in a waste of resources.

[0003] At present, many companies adopt the method of reheating the low-temperature nitrogen (GN2) released from the storage tank through the vaporizer and then sending it into the gas supply pipeline system. Although this method can effectively utilize nitrogen, the cold capacity of the low-temperature nitrogen is not effectively utilized, resulting in a waste of cold capacity.

[0004] Another common treatment method is to directly discharge the cryogenic nitrogen, which not only wastes the cooling capacity but also causes the evaporation loss of nitrogen. Therefore, finding a more efficient solution to achieve the rational use of cryogenic nitrogen will be an urgent problem to be solved in the industry.

[0005] The above information disclosed in the above background technology section is only used to enhance the understanding of the background technology of the technology described in this article. Therefore, the background technology may contain certain information that does not form the prior art known in this country to those skilled in the art. Utility Model Content

[0006] In order to solve the defects of the above-mentioned prior art, the utility model proposes a nitrogen supply system that is efficient, energy-saving and environmentally friendly.

[0007] The technical solution adopted by the utility model is as follows:

[0008] A highly efficient, energy-saving and environmentally friendly nitrogen supply system comprises: at least one liquid nitrogen storage tank, at least one air separation nitrogen making device, a cryogenic nitrogen buffer tank, a main heat exchanger and pipelines connecting the components, wherein the liquid nitrogen storage tank and the air separation nitrogen making device are in a parallel relationship and are respectively connected to the air inlet end of the cryogenic nitrogen buffer tank through a cryogenic nitrogen pipeline, and the air outlet end of the cryogenic nitrogen buffer tank is connected to the main heat exchanger and the air supply pipeline system through a heat exchange tube I; the main heat exchanger is also provided with a heat exchange tube II, and both ends of the heat exchange tube II are respectively connected to a purification system and the air separation nitrogen making device.

[0009] There are two liquid nitrogen storage tanks, which are connected in parallel with the cryogenic nitrogen buffer tank through a cryogenic nitrogen pipeline I.

[0010] The connecting pipeline between the liquid nitrogen storage tank and the cryogenic nitrogen buffer tank comprises a main pipe and two sets of branch pipes arranged in parallel.

[0011] A check valve is arranged on the main pipe.

[0012] The branch pipe is provided with a liquid nitrogen storage tank safety valve.

[0013] There are two air separation nitrogen production devices, which are connected in parallel with the low-temperature nitrogen buffer tank through the low-temperature nitrogen pipeline II.

[0014] The heat exchange tube I is connected in sequence with a low-temperature nitrogen buffer tank, a main heat exchanger and a gas supply pipeline system, and low-temperature nitrogen is arranged in the heat exchange tube I.

[0015] The heat exchange tube II is connected in sequence with a purification system, a main heat exchanger and an air separation nitrogen production device, and normal temperature air is arranged in the heat exchange tube II.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0017] In general, compared with the prior art, the utility model provides a highly efficient, energy-saving and environmentally friendly nitrogen supply system. There is no need to carry out large-scale transformation of the existing system, and only recovery pipelines and heat exchange devices need to be added at key positions, which has high feasibility and economy. In the specific scheme, the low-temperature nitrogen from the liquid nitrogen storage tank and the air separation nitrogen production device is mixed and heat exchanged with the normal temperature air of the purification system in a heat exchanger, and then transferred to the air through the heat exchanger. The treated air is passed into the air separation nitrogen production device for reuse, thereby improving the overall energy efficiency of the system; the treated low-temperature nitrogen is passed into the air supply pipeline system, thereby realizing the recovery and reuse of the coldness of the low-temperature nitrogen. The evaporated nitrogen will be wasted in the traditional method. This scheme recovers it and reintroduces it into the production system, reducing the loss of nitrogen and reducing the supply cost of nitrogen.

[0018] In summary, the utility model provides an efficient, energy-saving and environmentally friendly nitrogen supply system by rationally configuring a liquid nitrogen storage tank and an air separation nitrogen production device, optimizing the recovery and utilization of low-temperature nitrogen, and significantly improving the energy efficiency of the overall system. The system is suitable for multiple industrial fields that require high-purity nitrogen and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be described by way of examples with reference to the accompanying drawings, in which:

[0020] Figure 1 It is a structural schematic diagram of the nitrogen supply system in the utility model;

[0021] Figure 2 It is a structural schematic diagram of a nitrogen supply system in the prior art. DETAILED DESCRIPTION

[0022] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the 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. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0023] In the photovoltaic cell manufacturing industry, lithium battery manufacturing, synthetic amine production and other industries, since it is necessary to maintain an uninterrupted supply of high-purity nitrogen during the production process, it is necessary to use the low-temperature liquid nitrogen storage tank 1 to keep a 24-hour backup reserve, because the low-temperature liquid nitrogen storage tank 1 has a certain evaporation rate. Figure 2 At present, most companies either release the cryogenic nitrogen from the cryogenic liquid nitrogen storage tank 1, reheat it through the vaporizer 13 and send it to the gas supply pipeline system 8. The cryogenic nitrogen (GN2) usually has a high cooling capacity. This treatment method will waste this part of cooling capacity. Another treatment method is to directly vent the cryogenic nitrogen, which not only wastes cooling capacity but also wastes nitrogen evaporation.

[0024] In view of the above technical problems, this embodiment provides a nitrogen supply system with high efficiency, energy saving and environmental protection. Figure 1 , including the following main components:

[0025] Liquid nitrogen storage tank 1: used to store cryogenic liquid nitrogen and provide cryogenic nitrogen gas when needed.

[0026] Air separation nitrogen production unit 2: Extract high-purity nitrogen through distillation to meet production needs.

[0027] Cryogenic nitrogen buffer tank 3: used to collect cryogenic nitrogen from liquid nitrogen storage tank 1 and air separation nitrogen production device 2.

[0028] Main heat exchanger 4: used to transfer the coldness of the cryogenic nitrogen to the air to improve the energy efficiency of the entire system.

[0029] Piping system: connects various components to ensure efficient flow and utilization of cryogenic nitrogen.

[0030] The liquid nitrogen storage tank 1 and the air separation nitrogen production device 2 are in a parallel relationship and are respectively connected to the air inlet end of the cryogenic nitrogen buffer tank 3 through a cryogenic nitrogen pipeline Ⅰ11. The cryogenic nitrogen released by the liquid nitrogen storage tank 1 during the evaporation process is about -194°C and the cryogenic nitrogen in the distillation tower system of the air separation nitrogen production device 2 are recovered to the cryogenic nitrogen buffer tank 3 through the cryogenic nitrogen pipeline, thereby realizing the effective aggregation of resources.

[0031] The outlet end of the cryogenic nitrogen buffer tank 3 is connected to the main heat exchanger 4 through the heat exchange pipe Ⅰ5. The main heat exchanger 4 is provided with a heat exchange pipe Ⅱ6, and the two ends of the heat exchange pipe Ⅱ6 are respectively connected to the purification system 7 and the air separation nitrogen production device 2. The air from the purification system 7 and the cryogenic nitrogen are heat exchanged in the main heat exchanger 4, and the coldness of the cryogenic nitrogen is transferred to the air through the main heat exchanger 4 to reduce the air temperature.

[0032] Furthermore, the heat exchange tube Ⅰ5 is sequentially connected to a low-temperature nitrogen buffer tank 3, a main heat exchanger 4 and a gas supply pipeline system 8, and low-temperature nitrogen is arranged in the heat exchange tube Ⅰ5.

[0033] Furthermore, the heat exchange tube II 6 is sequentially connected to a purification system 7 , a main heat exchanger 4 and an air separation nitrogen production device 2 , and normal temperature air is arranged in the heat exchange tube II 6 .

[0034] In the above scheme, the low-temperature nitrogen gas of -194 degrees Celsius discharged from the evaporation of the liquid nitrogen storage tank 1 is recovered into the low-temperature nitrogen buffer tank 3 through the low-temperature nitrogen pipeline Ⅰ11, and the low-temperature nitrogen in the distillation tower system of the air separation nitrogen making device is recovered into the low-temperature nitrogen buffer tank 3 through the low-temperature nitrogen pipeline Ⅱ12. The low-temperature nitrogen of the liquid nitrogen storage tank 1 and the air separation nitrogen making device is collected in the nitrogen buffer tank, and then enters the heat exchanger to exchange heat with the air (GA) entering the heat exchanger from the purification system 7, and then its cold is transferred to the air through the heat exchanger. The treated air is passed into the air separation nitrogen making device 2 for reuse, thereby improving the overall energy efficiency of the system; the treated low-temperature nitrogen is passed into the gas supply pipeline system 8, thereby realizing the recovery and reuse of the cold of the low-temperature nitrogen. The nitrogen supply system in the present application not only improves the utilization efficiency of nitrogen by effectively recovering and utilizing the cold of low-temperature nitrogen, but also significantly reduces the waste of resources, and has good economic and environmental benefits.

[0035] In a specific embodiment, two liquid nitrogen storage tanks 1 are provided, which are connected in parallel with the cryogenic nitrogen buffer tank 3 through a cryogenic nitrogen pipeline.

[0036] In a specific embodiment, the number of the liquid nitrogen storage tanks 1 is set to two, and the two liquid nitrogen storage tanks 1 are connected in parallel to each other and connected to the cryogenic nitrogen buffer tank 3 through a cryogenic nitrogen pipeline. This design has the following advantages:

[0037] Redundancy and reliability: By setting up two liquid nitrogen storage tanks 1, when one storage tank fails or undergoes maintenance, it can ensure that the system can still operate stably, thereby improving the reliability of gas supply.

[0038] Load balancing: When two liquid nitrogen storage tanks 1 work in parallel, the supply of liquid nitrogen can be flexibly adjusted according to actual needs to avoid a reduction in efficiency due to overload of a single storage tank.

[0039] Increased cooling capacity: The two liquid nitrogen storage tanks 1 supply cryogenic nitrogen at the same time, which can increase the total flow of cryogenic nitrogen and improve the cooling capacity of the cryogenic nitrogen buffer tank 3, thereby performing heat exchange more effectively.

[0040] Flexible configuration: The parallel design can flexibly adjust the amount of liquid nitrogen used according to production needs, adapt to different production situations, and improve the overall adaptability of the system.

[0041] In this embodiment, each liquid nitrogen storage tank 1 is also equipped with a liquid nitrogen level monitoring system and a temperature sensor to monitor the inventory and temperature of liquid nitrogen in real time, and to intelligently adjust the supply of liquid nitrogen through the control system. In addition, the design of the cryogenic nitrogen pipeline should ensure the low temperature characteristics of the fluid, and use high insulation materials to reduce the loss of cold.

[0042] In a specific embodiment of the present invention, the connecting pipe between the liquid nitrogen storage tank 1 and the cryogenic nitrogen buffer tank 3 includes a main pipe and two sets of branch pipes arranged in parallel. This structural design can effectively improve the safety and stability of the system, which is described in detail as follows:

[0043] Main pipe: The main pipe connecting the liquid nitrogen storage tank 1 and the cryogenic nitrogen buffer tank 3 is responsible for the overall gas flow to ensure the effective transmission of cryogenic nitrogen.

[0044] Branch pipes: Two sets of branch pipes arranged in parallel are respectively connected to each liquid nitrogen storage tank 1 to ensure that low-temperature nitrogen can be evenly supplied from the two storage tanks to the buffer tank when the system is running.

[0045] In this embodiment, a check valve 9 is provided on the main pipe, the main function of which is to prevent the cryogenic nitrogen from flowing back when the gas supply stops or a failure occurs, thereby ensuring the safe and stable operation of the system. The check valve 9 can effectively prevent the liquid nitrogen in the liquid nitrogen storage tank 1 from flowing back due to pressure changes, thereby maintaining the pressure balance of the system.

[0046] A liquid nitrogen storage tank safety valve 10 is provided on each group of branch pipes, which is used to automatically open when the internal pressure of the liquid nitrogen storage tank 1 is too high to release excess pressure and prevent the liquid nitrogen storage tank 1 from being dangerous due to overpressure. The setting of the safety valve enhances the safety of the system and ensures the safety of operators and equipment.

[0047] In the above implementation, not only the safety and reliability of the liquid nitrogen supply system are improved, but also it is ensured that the pressure change can be quickly responded to during operation to avoid system failure or accidents caused by pressure problems. Through the cooperation of the check valve 9 and the safety valve, the entire system has a good self-protection ability, which helps to achieve a long-term stable supply of low-temperature nitrogen, effectively improves the safety, stability and operational flexibility of the system, and provides a more reliable guarantee for the use of liquid nitrogen, which meets the requirements of modern industry for safety, efficiency and environmental protection.

[0048] In a specific embodiment, the number of the air separation nitrogen generators 2 is set to two, and the two air separation nitrogen generators 2 are connected in parallel with each other and connected to the cryogenic nitrogen buffer tank 3 through the cryogenic nitrogen pipeline II12. This design has the following advantages and characteristics:

[0049] The parallel configuration of two air separation nitrogen generators 2 enables the system to provide a stable nitrogen supply under high demand conditions. When one unit is under maintenance or fails, the other unit can work independently to ensure a continuous supply of nitrogen, greatly improving the reliability of the system.

[0050] By working in parallel, the two air separation nitrogen production devices 2 can jointly undertake the gas production task, optimize load distribution, improve overall efficiency, and avoid performance degradation caused by overload of a single device.

[0051] The system can flexibly adjust the nitrogen production according to actual needs. Users can choose to enable one or two devices according to changes in production needs, thereby achieving efficient and economical nitrogen production.

[0052] The parallel setting provides safety redundancy. When a problem occurs in one device, the other device can still ensure the normal operation of the system, reducing the risk of production stoppage due to equipment failure.

[0053] Connection method: The cryogenic nitrogen pipeline II12 is responsible for gathering the output gases of the two air separation nitrogen production devices 2 to the cryogenic nitrogen buffer tank 3. In the design, the cryogenic nitrogen pipeline II12 uses high insulation materials to ensure that the cold loss of cryogenic nitrogen during the transportation process is minimized and the overall energy efficiency of the system is improved.

[0054] The design of this implementation not only enhances the flexibility and reliability of the nitrogen production system, but also improves the efficiency and safety of the nitrogen supply, and is very suitable for the diversity and variability of modern industrial demand for nitrogen. As mentioned above, the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it; although the utility model is described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that it is still possible to modify the technical solutions recorded in the aforementioned embodiments, or to make equivalent replacements for some of the technical features therein; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A highly efficient, energy-saving and environmentally friendly nitrogen supply system, characterized in that: include: At least one liquid nitrogen storage tank, at least one air separation nitrogen making device, a cryogenic nitrogen buffer tank, a main heat exchanger and pipelines connecting the various components. The liquid nitrogen storage tank and the air separation nitrogen making device are in parallel and are respectively connected to the air inlet end of the cryogenic nitrogen buffer tank through a cryogenic nitrogen pipeline. The air outlet end of the cryogenic nitrogen buffer tank is connected to the main heat exchanger and the air supply pipeline system through a heat exchange tube I. The main heat exchanger is also provided with a heat exchange tube II, and both ends of the heat exchange tube II are respectively connected to a purification system and an air separation nitrogen making device.

2. The high-efficiency, energy-saving and environmentally friendly nitrogen supply system according to claim 1 is characterized in that: There are two liquid nitrogen storage tanks, which are connected in parallel with the cryogenic nitrogen buffer tank through a cryogenic nitrogen pipeline I.

3. The high-efficiency, energy-saving and environmentally friendly nitrogen supply system according to claim 2 is characterized in that: The connecting pipeline between the liquid nitrogen storage tank and the cryogenic nitrogen buffer tank comprises a main pipe and two sets of branch pipes arranged in parallel.

4. The high-efficiency, energy-saving and environmentally friendly nitrogen supply system according to claim 3 is characterized in that: A check valve is arranged on the main pipe.

5. The high-efficiency, energy-saving and environmentally friendly nitrogen supply system according to claim 3 is characterized in that: The branch pipe is provided with a liquid nitrogen storage tank safety valve.

6. The high-efficiency, energy-saving and environmentally friendly nitrogen supply system according to claim 4, characterized in that: There are two air separation nitrogen production devices, which are connected in parallel with the low-temperature nitrogen buffer tank through the low-temperature nitrogen pipeline II.

7. The high-efficiency, energy-saving and environmentally friendly nitrogen supply system according to claim 1, characterized in that: The heat exchange tube I is connected in sequence with a low-temperature nitrogen buffer tank, a main heat exchanger and a gas supply pipeline system, and low-temperature nitrogen is arranged in the heat exchange tube I.

8. The high-efficiency, energy-saving and environmentally friendly nitrogen supply system according to claim 1, characterized in that: The heat exchange tube II is connected in sequence with a purification system, a main heat exchanger and an air separation nitrogen production device, and normal temperature air is arranged in the heat exchange tube II.

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