Liquid nitrogen vaporization cold energy utilization system

Abstract

The utility model discloses a liquid nitrogen vaporization cold energy utilization system which comprises a liquid nitrogen storage tank, a water bath type vaporizer, an air temperature type vaporizer, a cooling tower and a compressed air device, and a liquid nitrogen outlet pipeline of the liquid nitrogen storage tank is connected with a liquid nitrogen inlet of the water bath type vaporizer. A liquid nitrogen outlet pipeline of the water bath type vaporizer is connected with a liquid nitrogen inlet of the air temperature type vaporizer; a circulating water outlet of the water bath type vaporizer is connected with a circulating water inlet of the cooling tower through a circulating water main path and is connected with a circulating water outlet of the cooling tower through a circulating water bypass; a circulating water outlet of the cooling tower is connected with a circulating water inlet of the compressed air equipment through a circulating water feeding pipeline; and a circulating water outlet pipeline of the compressed air equipment is connected with a circulating water inlet of the water bath vaporizer. According to the utility model, waste of cooling capacity of liquid nitrogen can be avoided; the load of the air temperature type vaporizer is reduced, and the frosting phenomenon is prevented; loads of a circulating water pump and a cooling fan in a cooling tower are reduced, and electric energy is saved; and the water loss of the circulating water system is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium battery production, and in particular relates to a liquid nitrogen vaporization cold energy utilization system. Background Art

[0002] Nitrogen is widely used as a protective gas in the lithium battery industry. One of the conventional methods of producing nitrogen is that the liquid nitrogen in the liquid nitrogen storage tank flows into the air-temperature vaporizer, absorbs the heat of the air and vaporizes into nitrogen. The vaporization of liquid nitrogen is an endothermic process, and the cold contained in the liquid nitrogen is taken away by the air, resulting in a large amount of cold waste; and the surface of the air-temperature vaporizer is prone to frost, which affects the vaporization effect, and it is necessary to defrost regularly or switch to a standby vaporizer.

[0003] In the compressed air system, the air compressor, cold dryer, and adsorption dryer all need to supply circulating cooling water to cool down when they are in operation. The circulating water exchanges heat with the air flow in the cooling tower, and part of the water evaporates to take away the heat, which reduces the temperature of the circulating water. In the cooling tower, the circulating water loses water due to evaporation; at the same time, the operation of the cooling fan also consumes a certain amount of electricity. Utility Model Content

[0004] Technical problems solved: In view of the above technical problems, the utility model provides a liquid nitrogen vaporization cold energy utilization system, which can avoid the waste of liquid nitrogen cold energy, reduce the load of production equipment, save electricity, and also reduce the water loss of circulating water.

[0005] Technical solution: A liquid nitrogen vaporization cold energy utilization system comprises a liquid nitrogen storage tank, a water bath vaporizer, an air temperature vaporizer, a cooling tower and a compressed air device, wherein the liquid nitrogen outlet pipeline of the liquid nitrogen storage tank is connected to the liquid nitrogen inlet of the water bath vaporizer, and the liquid nitrogen outlet pipeline of the water bath vaporizer is connected to the liquid nitrogen inlet of the air temperature vaporizer; the circulating water outlet of the water bath vaporizer is connected to the circulating water inlet of the cooling tower through a circulating water main line, and is connected to the circulating water outlet of the cooling tower through a circulating water bypass; the circulating water outlet of the cooling tower is connected to the circulating water inlet of the compressed air device through a circulating water supply pipeline; the circulating water outlet pipeline of the compressed air device is connected to the circulating water inlet of the water bath vaporizer.

[0006] Preferably, the compressed air equipment includes an air compressor, a cold dryer and a desiccant dryer.

[0007] Preferably, a temperature sensor is provided at the circulating water outlet of the water bath vaporizer.

[0008] Preferably, electric valves are provided on both the circulating water main circuit and the circulating water bypass circuit.

[0009] Preferably, a cooling fan is provided in the cooling tower, and the cooling fan is a variable frequency fan.

[0010] Preferably, a circulating water pump is provided on the circulating water supply pipeline.

[0011] Furthermore, the circulating water pump is a variable frequency water pump.

[0012] Beneficial effects: The utility model utilizes the heat absorption required for liquid nitrogen vaporization to cool the circulating cooling water, thereby avoiding the waste of cold capacity of liquid nitrogen; reducing the load of the air-temperature vaporizer to prevent the occurrence of frosting; reducing the load of the circulating water pump and the cooling fan in the cooling tower to save electric energy; and reducing the water loss of the circulating water system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the utility model;

[0014] The meanings of the numbers in the figure are as follows: 1. Liquid nitrogen storage tank, 2. Water bath vaporizer, 3. Air temperature vaporizer, 4. Cooling tower, 4-1. Cooling fan, 5. Circulating water pump, 6. Air compressor, 7. Cold dryer, 8. Dryer, 9. Temperature sensor, 10. Electric valve. DETAILED DESCRIPTION

[0015] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments. Example 1

[0016] like Figure 1 As shown, a liquid nitrogen vaporization cold energy utilization system includes a liquid nitrogen storage tank 1, a water bath vaporizer 2, an air temperature vaporizer 3, a cooling tower 4 and compressed air equipment, and the compressed air equipment includes an air compressor 6, a cold dryer 7 and an adsorption dryer 8.

[0017] The liquid nitrogen outlet pipeline of the liquid nitrogen storage tank 1 is connected to the liquid nitrogen inlet of the water bath vaporizer 2, and the liquid nitrogen outlet pipeline of the water bath vaporizer 2 is connected to the liquid nitrogen inlet of the air temperature vaporizer 3. The liquid nitrogen in the liquid nitrogen storage tank 1 flows through the water bath vaporizer 2 and the air temperature vaporizer 3 in sequence, and supplies nitrogen to the outside after being completely vaporized. In the water bath vaporizer 2, the liquid nitrogen absorbs the heat of the circulating return water and partially or completely vaporizes. When partially vaporized, the liquid nitrogen can continue to vaporize in the air temperature vaporizer 3 until it is completely vaporized; when completely vaporized, the air temperature vaporizer 3 only serves as a section of the pipeline.

[0018] The circulating water outlet of the water bath evaporator 2 is connected to the circulating water inlet of the cooling tower 4 through the circulating water main circuit, and is connected to the circulating water outlet of the cooling tower 4 through the circulating bypass. Both the circulating water main circuit and the circulating water bypass are provided with an electric valve 10. The opening and closing of the electric valve 10 can control the flow path of the circulating water.

[0019] The circulating water outlet of the cooling tower 4 is connected to the circulating water inlet of the compressed air equipment through the circulating water supply pipeline. The circulating water supply pipeline is provided with a circulating water pump 5, which is a variable frequency water pump. The circulating water outlet pipeline of the compressed air equipment is connected to the circulating water inlet of the water bath vaporizer 2. The cold circulating water flows from the cooling tower 4 to the circulating water pump 5, and after being pressurized, it is sent to the air compressor 6, the cold dryer 7, and the adsorption dryer 8 to absorb the heat generated by the operation of the equipment. The above pipeline is the circulating water supply pipeline; the hot circulating water flows out of the air compressor 6, the cold dryer 7, and the adsorption dryer 8 and first flows to the water bath vaporizer 2 to be cooled by liquid nitrogen, and then flows to the cooling tower 4. The above pipeline is the circulating return water pipeline. The circulating water supply / return water pipeline constitutes a complete circulating water loop. The temperature of the circulating water supply / return water pipeline can generally be set to 32℃ / 42℃.

[0020] A temperature sensor 9 is provided at the circulating water outlet of the water bath vaporizer 2. A cooling fan 4-1 is provided in the cooling tower 4, and the cooling fan 4-1 is a variable frequency fan. The temperature sensor 9 can monitor the temperature of the circulating water after being cooled by liquid nitrogen to control the opening and closing of the electric valve 10 in the downstream pipeline. When the circulating water temperature monitored by the temperature sensor 9 is greater than 32°C, the electric valve 10 of the circulating water main circuit is opened and the electric valve 10 of the circulating water bypass is closed, and all the circulating water flows to the cooling tower 4 to further cool down to 32°C. At this time, the circulating water loop is a conventional open circulating water system, and there is water loss in the circulating water; on the other hand, the temperature of the circulating water has been reduced after being cooled in the water bath vaporizer 2. After flowing to the cooling tower 4, the cooling fan 4-1 can reduce the frequency and reduce power consumption compared with normal times. When the circulating water temperature monitored by the temperature sensor 9 is ≤32°C, the electric valve 10 of the circulating water bypass is opened and the electric valve 10 of the circulating water main circuit is closed. All the circulating water flows through the circulating water bypass and avoids the cooling tower 4. At this time, the circulating water loop is a closed circulating water system. Compared with the open circulating water system, the water loss is greatly reduced. On the other hand, when the circulating water temperature is lower than 32°C, the circulating water supply / return water temperature difference increases, which can appropriately reduce the frequency of the circulating water pump 5 and save electric energy.

Claims

1. A liquid nitrogen vaporization cold energy utilization system, characterized in that: The invention comprises a liquid nitrogen storage tank (1), a water bath vaporizer (2), an air temperature vaporizer (3), a cooling tower (4) and compressed air equipment, wherein the liquid nitrogen outlet pipeline of the liquid nitrogen storage tank (1) is connected to the liquid nitrogen inlet of the water bath vaporizer (2), and the liquid nitrogen outlet pipeline of the water bath vaporizer (2) is connected to the liquid nitrogen inlet of the air temperature vaporizer (3); the circulating water outlet of the water bath vaporizer (2) is connected to the circulating water inlet of the cooling tower (4) through a circulating water main line, and is connected to the circulating water outlet of the cooling tower (4) through a circulating water bypass; the circulating water outlet of the cooling tower (4) is connected to the circulating water inlet of the compressed air equipment through a circulating water supply pipeline; and the circulating water outlet pipeline of the compressed air equipment is connected to the circulating water inlet of the water bath vaporizer (2).

2. A liquid nitrogen vaporization cold energy utilization system according to claim 1, characterized in that: The compressed air equipment comprises an air compressor (6), a cold dryer (7) and a desiccant dryer (8).

3. The liquid nitrogen vaporization cold energy utilization system according to claim 1, characterized in that: A temperature sensor (9) is provided at the circulating water outlet of the water bath vaporizer (2).

4. The liquid nitrogen vaporization cold energy utilization system according to claim 1, characterized in that: Electric valves (10) are provided on both the circulating water main circuit and the circulating water bypass circuit.

5. The liquid nitrogen vaporization cold energy utilization system according to claim 1, characterized in that: A cooling fan (4-1) is provided in the cooling tower (4), and the cooling fan (4-1) is a variable frequency fan.

6. The liquid nitrogen vaporization cold energy utilization system according to claim 1, characterized in that: A circulating water pump (5) is provided on the circulating water supply pipeline.

7. The liquid nitrogen vaporization cold energy utilization system according to claim 6, characterized in that: The circulating water pump (5) is a variable frequency water pump.

Images