A circulating water cooling structure of a nitrogen production system
By installing a vaporizer and an overpressure discharge valve in the closed water tank, the problems of waste when the liquid nitrogen storage tank is full and the energy consumption of circulating water cooling are solved, realizing the reuse of liquid nitrogen resources and the saving of electricity and water energy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XINYI GLASS WUHU
- Filing Date
- 2025-04-10
- Publication Date
- 2026-06-05
AI Technical Summary
In existing technologies, liquid nitrogen storage tanks are kept full for extended periods, leading to waste due to liquid nitrogen being emptied. Furthermore, circulating water cooling requires heat exchange towers, which consume a significant amount of electricity and water.
A vaporizer is installed in a closed water tank. Liquid nitrogen from the liquid nitrogen storage tank is transported to the vaporizer through an overpressure discharge valve, where it exchanges heat with the circulating water to achieve the reuse of liquid nitrogen. The temperature of the circulating water is controlled by the overpressure discharge valve to avoid the use of a heat exchange tower.
It enables the reuse of liquid nitrogen resources, avoids the waste of liquid nitrogen and nitrogen gas, saves electricity and water energy consumption, and simplifies the circulating water cooling process.
Smart Images
Figure CN224327415U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of nitrogen generation systems, and more specifically, it relates to a circulating water cooling structure for a nitrogen generation system. Background Technology
[0002] In industrial nitrogen production systems, in addition to centrifuges, precoolers, purifiers, air separation towers, and liquid nitrogen storage tanks, circulating water is also required to continuously cool the centrifuges. The main products of the air separation nitrogen tower are nitrogen gas and liquid nitrogen. Nitrogen gas can be supplied directly without special treatment; however, liquid nitrogen, with its low temperature (-195.79°C at standard atmospheric pressure), must be heated and vaporized (20°C at standard atmospheric pressure) in an emergency before being supplied to the relevant equipment. Since the liquid nitrogen storage tank will fill up during the long-term operation of the nitrogen tower, the liquid nitrogen produced by the air separation nitrogen tower will then be vaporized in the vaporizer through the equipped overpressure valve and vented, resulting in energy waste. Meanwhile, when supplying cooling circulating water to equipment requiring cooling, such as centrifuges, cold water from the water tank is pumped to the equipment via a circulating water pump. In the equipment, the water circulates thoroughly, carrying away heat before entering a hot water circulation tank. The hot water in the hot water circulation tank is then pumped to a cooling tower, where it exchanges heat with the air through packing material, fans, and other equipment. The resulting hot water then returns to the water tank for further cooling and reuse. In some areas with high temperatures or during peak summer months, a large number of cooling towers are needed to dissipate heat from the circulating water, consuming significant amounts of electricity and causing water evaporation. Furthermore, the contact between the circulating water and air during cooling in the cooling tower also leads to a decline in water quality.
[0003] The prior art includes a technology entitled "Constant Pressure Water Supply Closed-Loop Water Circulation Cooling System" with publication (announcement) number "CN103115463 A". This technology relates to a constant pressure water supply closed-loop water circulation cooling system, which consists of two circulating water pump control valves (one for operation and one for standby) mounted on a base, a circulating water pump, a heat exchanger inlet control valve, a heat exchanger, a heat exchanger outlet control valve, a constant pressure expansion tank, and water pipes connecting the above components, as well as a control cabinet. The circulating water is circulated by the circulating water pump and cooled by the heat exchanger. The constant pressure expansion tank is connected to the water supply pipe. A water bladder is installed in the middle of the water tank and filled with water supply. Compressed nitrogen or argon gas is filled between the water bladder and the tank body. The expansion and contraction of the water bladder stabilizes the water supply pressure, making it consistent with the circulating water pressure, thereby providing constant pressure water supply and ensuring the normal operation of the circulating water. It has the advantages of good constant pressure water supply effect, low cost, convenient use, and reliable operation, and can be widely used in places requiring closed-loop water circulation cooling.
[0004] However, this technology does not address the technical issues and solutions of this application. Utility Model Content
[0005] The technical problem to be solved by this utility model is to provide a circulating water cooling structure for a nitrogen generation system that is simple in structure, avoids the waste of liquid nitrogen caused by the liquid nitrogen storage tank being full for a long time, realizes the cooling of circulating water during the liquid nitrogen overpressure discharge process, realizes the reuse of liquid nitrogen resources, and eliminates the need for heat exchange towers to dissipate heat from the circulating water, thus saving electricity and water energy.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:
[0007] This utility model relates to a circulating water cooling structure for a nitrogen generation system. A vaporizer is installed in a closed water tank, and a first overpressure discharge valve is installed on the closed water tank. The inlet of the vaporizer is connected to a liquid nitrogen storage tank through a conveying pipeline, and a second overpressure discharge valve is installed on the conveying pipeline. The outlet of the vaporizer is connected to a gas supply pipeline, and an overpressure discharge pipeline is installed on the vaporizer. A third overpressure discharge valve is installed on the overpressure discharge pipeline.
[0008] The liquid nitrogen storage tank is connected to one end of a liquid nitrogen delivery pipe, and the other end of the liquid nitrogen delivery pipe is connected to an air separation nitrogen tower.
[0009] The outlet of the closed water tank is connected to the cooling inlet of the cooling water user equipment via a pipeline, and the cooling outlet of the cooling water user equipment is connected to the inlet of the closed water tank via a pipeline.
[0010] The outlet of the overpressure discharge pipe extends to the bottom of the closed water tank.
[0011] The liquid nitrogen delivery pipe is connected to the delivery pipeline between the second overpressure discharge valve and the vaporizer via a delivery branch pipe, and a fourth overpressure discharge valve is installed on the delivery branch pipe.
[0012] The gasifier is installed on a fixed bracket inside a closed water tank.
[0013] The first overpressure relief valve is either an automatic overpressure relief valve or a manual overpressure relief valve.
[0014] The second overpressure discharge valve is an automatic overpressure discharge valve.
[0015] The third overpressure discharge valve is an automatic overpressure discharge valve.
[0016] The fourth overpressure discharge valve is a manual overpressure discharge valve.
[0017] The working principle and beneficial effects of this utility model are as follows:
[0018] The circulating water cooling structure of the nitrogen generation system described in this utility model includes a closed-loop water tank for storing and supplying circulating water for cooling. A vaporizer is installed within the closed-loop water tank, and its inlet is connected to a liquid nitrogen storage tank via a pipeline. The liquid nitrogen storage tank is connected to an air separation nitrogen tower. After continuous operation, the liquid nitrogen storage tank fills up, and the generated liquid nitrogen is continuously supplied to the storage tank under system pressure. At this point, a second overpressure discharge valve connected to the liquid nitrogen storage tank detects overpressure and opens, releasing the excess liquid nitrogen from the storage tank until the pressure reaches the normal set value, at which point the second overpressure discharge valve closes. The discharged liquid nitrogen enters the vaporizer within the closed-loop water tank. The low temperature of the liquid nitrogen allows for thorough heat exchange with the circulating water in the closed-loop water tank. The low temperature released by the liquid nitrogen cools the circulating water, making it cold water, while the heated liquid nitrogen vaporizes into nitrogen gas. In this way, on the one hand, the liquid nitrogen released from the liquid nitrogen storage tank due to overpressure can be reused for cooling the circulating water, avoiding the waste of low-temperature resources caused by direct discharge of liquid nitrogen. The nitrogen gas formed can also be recovered or directly supplied to the equipment, avoiding the waste of nitrogen resources. On the other hand, the cooling of the circulating water no longer requires a heat exchange tower, thus eliminating the need for electricity and preventing water evaporation, thereby avoiding the waste of electrical and water energy. The third overpressure relief valve opens when the pressure in the vaporizer is too high, releasing pressure from top to bottom into the closed water tank, agitating the tank and ensuring full circulation of the water, reducing the temperature difference between the upper and lower parts of the water. After the pressure in the closed water tank reaches its upper limit, the first overpressure relief valve (one-way valve) at the top of the closed water tank releases the nitrogen gas formed from the liquid nitrogen, which has undergone sufficient heat exchange, into the atmosphere. Attached Figure Description
[0019] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings therein:
[0020] Figure 1 This is a schematic diagram of the circulating water cooling structure of the nitrogen generation system described in this utility model;
[0021] The labels in the attached diagram are as follows: 1. Liquid nitrogen delivery pipe; 2. Fourth overpressure discharge valve; 3. Second overpressure discharge valve; 4. Delivery pipeline; 5. Vaporizer; 6. First overpressure discharge valve; 7. Third overpressure discharge valve; 8. Liquid nitrogen storage tank; 9. Closed water tank; 10. Gas delivery pipeline; 11. Overpressure discharge pipeline; 12. Air separation nitrogen tower; 13. Delivery branch pipe; 14. Fixed support. Detailed Implementation
[0022] The following description, with reference to the accompanying drawings, provides a more detailed explanation of the specific embodiments of this utility model, including the shape and structure of each component, the relative positions and connections between the parts, the functions and working principles of each part:
[0023] As attached Figure 1 As shown, this utility model is a circulating water cooling structure for a nitrogen generation system. A vaporizer 5 is installed inside a closed water tank 9. A first overpressure discharge valve 6 is installed on the closed water tank 9. The inlet of the vaporizer 5 is connected to a liquid nitrogen storage tank 8 via a conveying pipe 4. A second overpressure discharge valve 3 is installed on the conveying pipe 4. The outlet of the vaporizer 5 is connected to a gas supply pipe 10. An overpressure discharge pipe 11 is installed on the vaporizer 5, and a third overpressure discharge valve 7 is installed on the overpressure discharge pipe 11. This structure addresses the shortcomings of existing technologies by proposing an improved technical solution. In the structural setup, a closed-loop water tank 9 is installed to store and supply circulating water for cooling. A vaporizer 5 is installed within the closed-loop water tank 9. The inlet of the vaporizer 5 is connected to a liquid nitrogen storage tank 8 via a delivery pipe 4. The liquid nitrogen storage tank 8 is connected to an air separation nitrogen tower 12. After continuous operation of the air separation nitrogen tower (nitrogen production air separation tower), the liquid nitrogen storage tank 8 is full. During this period, the generated liquid nitrogen is continuously delivered to the liquid nitrogen storage tank 8 under system pressure. At this time, the second overpressure discharge valve 3, connected to the liquid nitrogen storage tank 8, detects overpressure in the tank and then opens, discharging the overpressurized liquid nitrogen from the liquid nitrogen storage tank 8 until the pressure in the liquid nitrogen storage tank 8 reaches the normal set value, after which the second overpressure discharge valve 3 closes. The discharged liquid nitrogen enters the vaporizer 5 within the closed-loop water tank 9. The low temperature of the liquid nitrogen allows for sufficient heat exchange with the circulating water in the closed-loop water tank 9. The low temperature released by the liquid nitrogen cools the circulating water, making it cold water, while the heated liquid nitrogen vaporizes into nitrogen gas. In this way, on the one hand, the liquid nitrogen released from the liquid nitrogen storage tank 8 due to overpressure is reused for cooling the circulating water, avoiding the waste of low-temperature resources caused by direct discharge of liquid nitrogen. The nitrogen gas formed can also be recovered or directly supplied to the equipment, avoiding the waste of nitrogen resources. On the other hand, the cooling of the circulating water no longer requires the use of a heat exchange tower, thus eliminating the need for electricity and preventing water evaporation, thereby avoiding the waste of electrical and water energy. The third overpressure discharge valve 7 is set up so that when the pressure in the vaporizer 5 is too high, the third overpressure discharge valve 7 opens, releasing pressure from top to bottom into the closed water tank 9, agitating the closed water tank 9, allowing the water in the closed water tank 9 to circulate fully, and reducing the temperature difference between the upper and lower parts of the water. After the pressure in the closed water tank 9 reaches the upper limit, the first overpressure discharge valve 6 (one-way valve) at the top of the closed water tank 9 releases the nitrogen gas formed from the liquid nitrogen that has completed heat exchange into the atmosphere. The circulating water cooling structure of the nitrogen generation system described in this utility model is simple in structure, avoids the waste of liquid nitrogen caused by the liquid nitrogen storage tank being full for a long time, achieves circulating water cooling during the liquid nitrogen overpressure discharge process, realizes the reuse of liquid nitrogen resources, and eliminates the need for heat exchange towers to dissipate heat from the circulating water, saving electrical and water energy.
[0024] The liquid nitrogen storage tank 8 is connected to one end of the liquid nitrogen delivery pipe 1, and the other end of the liquid nitrogen delivery pipe 1 is connected to the air separation nitrogen tower 12. In this structure, the air separation nitrogen tower 12 continuously generates nitrogen gas and liquid nitrogen during operation. The nitrogen gas is supplied to equipment that requires nitrogen, and the liquid nitrogen is collected through the liquid nitrogen storage tank 8.
[0025] The outlet of the closed water tank 9 is connected to the cooling inlet of the cooling water user equipment via a pipeline, and the cooling outlet of the cooling water user equipment is connected to the inlet of the closed water tank 9 via a pipeline. In this structure, the circulating water is cold water, which is used to supply the equipment that needs to be cooled. After cooling the relevant equipment, the temperature of the circulating water rises and returns to the closed water tank, where it exchanges heat with liquid nitrogen to achieve further cooling.
[0026] The outlet of the overpressure discharge pipe 11 extends to the bottom of the closed water tank 9. In this structure, when the pressure inside the vaporizer 5 is too high, the third overpressure discharge valve 7 opens, releasing pressure from top to bottom into the closed water tank 9, agitating the tank and ensuring thorough water circulation, thus reducing the temperature difference between the upper and lower parts of the water. When the pressure inside the vaporizer 5 drops to a set range, the third overpressure discharge valve 7 automatically closes, stopping nitrogen discharge.
[0027] The liquid nitrogen delivery pipe 1 is connected to the delivery pipe 4 between the second overpressure discharge valve 3 and the vaporizer 5 via a delivery branch pipe 13. A fourth overpressure discharge valve 2 is installed on the delivery branch pipe 13. With the above structure, in the event of high temperatures, the liquid nitrogen in the liquid nitrogen storage tank can be directly supplied to the vaporizer by opening the fourth overpressure discharge valve 2 to cool the circulating water in the water tank.
[0028] The vaporizer 5 is mounted on a fixed bracket 14 inside the closed water tank 9. In this structure, the vaporizer 5 is mounted on the fixed bracket 14, which is fixedly connected to the closed water tank, ensuring reliable installation of the vaporizer 5 within the closed water tank and preventing it from easily shaking or falling.
[0029] The first overpressure relief valve 6 is either an automatic or manual overpressure relief valve. In this structure, the first overpressure relief valve 6 is a one-way valve, capable of automatically relieving overpressure or being manually operated. The second overpressure relief valve 3 is an automatic overpressure relief valve. It automatically opens when overpressure occurs and automatically closes after the pressure decreases. The third overpressure relief valve 7 is also an automatic overpressure relief valve. It automatically opens when overpressure occurs and automatically closes after the pressure decreases. The fourth overpressure relief valve 2 is a manual overpressure relief valve. It is normally closed and requires manual operation to open and close when needed.
[0030] The circulating water cooling structure of the nitrogen generation system described in this utility model includes a closed water tank 9 for storing and supplying circulating water for cooling. A vaporizer 5 is installed inside the closed water tank 9. The inlet of the vaporizer 5 is connected to a liquid nitrogen storage tank 8 via a conveying pipe 4. The liquid nitrogen storage tank 8 is connected to an air separation nitrogen tower 12. After continuous operation of the air separation nitrogen tower (nitrogen generation air separation tower), the liquid nitrogen storage tank 8 is full. During this period, the generated liquid nitrogen is continuously transported to the liquid nitrogen storage tank 8 under system pressure. At this time, the second overpressure discharge valve 3, connected to the liquid nitrogen storage tank 8, detects overpressure in the tank. The second overpressure discharge valve 3 then opens, discharging the overpressured liquid nitrogen from the liquid nitrogen storage tank 8 until the pressure inside the liquid nitrogen storage tank 8 reaches the normal set value, after which the second overpressure discharge valve 3 closes. The discharged liquid nitrogen enters the vaporizer 5 within the closed-loop water tank 9. The low temperature of the liquid nitrogen allows for thorough heat exchange with the circulating water in the closed-loop water tank 9. The low temperature released by the liquid nitrogen cools the circulating water, making it cold water, while the heated liquid nitrogen vaporizes into nitrogen gas. This process serves two purposes: firstly, it reuses the liquid nitrogen released from the liquid nitrogen storage tank 8 due to overpressure, using it for cooling the circulating water and avoiding the waste of low-temperature resources caused by direct discharge of liquid nitrogen. The resulting nitrogen gas can also be recovered or directly supplied to the equipment, preventing nitrogen resource waste. Secondly, cooling the circulating water no longer requires a heat exchange tower, thus eliminating the need for electricity and preventing water evaporation, thereby avoiding the waste of both electrical and water energy. The third overpressure relief valve 7 opens when the pressure in the vaporizer 5 is too high, releasing pressure from top to bottom into the closed-loop water tank 9, agitating the water and ensuring thorough circulation, reducing the temperature difference between the upper and lower parts of the water. After the pressure inside the closed water tank 9 reaches its upper limit, the first overpressure discharge valve 6 (one-way valve) at the top of the closed water tank 9 discharges nitrogen gas, which has completed heat exchange and is formed from liquid nitrogen, into the atmosphere.
[0031] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.
Claims
1. A circulating water cooling structure for a nitrogen generation system, characterized in that: A vaporizer (5) is installed in a closed water tank (9). A first overpressure discharge valve (6) is installed on the closed water tank (9). The inlet of the vaporizer (5) is connected to the liquid nitrogen storage tank (8) through the conveying pipe (4). A second overpressure discharge valve (3) is installed on the conveying pipe (4). The outlet of the vaporizer (5) is connected to the gas supply pipe (10). An overpressure discharge pipe (11) is installed on the vaporizer (5). A third overpressure discharge valve (7) is installed on the overpressure discharge pipe (11).
2. The circulating water cooling structure of the nitrogen generation system according to claim 1, characterized in that: The liquid nitrogen storage tank (8) is connected to one end of the liquid nitrogen delivery pipe (1), and the other end of the liquid nitrogen delivery pipe (1) is connected to the air separation nitrogen tower (12).
3. The circulating water cooling structure of the nitrogen generation system according to claim 1 or 2, characterized in that: The outlet of the closed water tank (9) is connected to the cooling inlet of the cooling water user equipment through a pipeline, and the cooling outlet of the cooling water user equipment is connected to the inlet of the closed water tank (9) through a pipeline.
4. The circulating water cooling structure of the nitrogen generation system according to claim 1 or 2, characterized in that: The outlet of the overpressure discharge pipe (11) extends to the bottom of the closed water tank (9).
5. The circulating water cooling structure of the nitrogen generation system according to claim 2, characterized in that: The liquid nitrogen delivery pipe (1) is connected to the delivery pipe (4) between the second overpressure discharge valve (3) and the vaporizer (5) through the delivery branch pipe (13), and the fourth overpressure discharge valve (2) is installed on the delivery branch pipe (13).
6. The circulating water cooling structure of the nitrogen generation system according to claim 1 or 2, characterized in that: The gasifier (5) is installed on a fixed bracket (14) inside a closed water tank (9).
7. The circulating water cooling structure of the nitrogen generation system according to claim 1 or 2, characterized in that: The first overpressure discharge valve (6) is an automatic overpressure discharge valve or a manual overpressure discharge valve.
8. The circulating water cooling structure of the nitrogen generation system according to claim 1 or 2, characterized in that: The second overpressure discharge valve (3) is an automatic overpressure discharge valve.
9. The circulating water cooling structure of the nitrogen generation system according to claim 1 or 2, characterized in that: The third overpressure discharge valve (7) is an automatic overpressure discharge valve.
10. The circulating water cooling structure of the nitrogen generation system according to claim 5, characterized in that: The fourth overpressure discharge valve (2) is a manual overpressure discharge valve.