Liquid nitrogen multi-point liquid supply integrated supply system

Abstract

The utility model provides a liquid nitrogen multi-point liquid supply integrated supply system. The liquid nitrogen multi-point liquid supply integrated supply system comprises a liquid nitrogen storage tank system, a control valve box, a liquid nitrogen output end and a PLC (Programmable Logic Controller), the liquid nitrogen storage tank system comprises at least one main liquid nitrogen storage tank and at least one standby liquid nitrogen storage tank, and a first vacuum stop valve located between the main liquid nitrogen storage tank and the first double-safety discharging system is arranged on a main liquid nitrogen conveying pipeline. The control valve box comprises a plurality of control branch pipes and a safety control main pipe, the main liquid nitrogen conveying pipeline and the standby liquid nitrogen conveying pipeline are respectively connected with one control branch pipe, each control branch pipe is provided with a second vacuum stop valve and a third vacuum stop valve in series, and the safety control main pipe is sequentially connected with the control branch pipes; the liquid nitrogen output end comprises at least one main liquid nitrogen output pipeline and at least one standby liquid nitrogen output pipeline, and the main liquid nitrogen output pipeline and the standby liquid nitrogen output pipeline are respectively connected with a control branch pipe. According to the system, a multi-path switching mechanism is realized through redundancy design of the main and standby liquid nitrogen storage tanks, and the reliability of the system is remarkably improved.

Description

Technical Field

[0001] This utility model relates to liquid nitrogen pipeline systems, specifically to a liquid nitrogen multi-point integrated supply system. Background Technology

[0002] Integrated liquid nitrogen supply systems with multiple supply points and mutual backups are mainly used to ensure a continuous and reliable supply of liquid nitrogen to multiple points of use. They can automatically switch to a backup source when a single supply source fails, thereby ensuring an uninterrupted supply of liquid nitrogen. This is crucial for many industries that rely on liquid nitrogen for cooling or processing, such as biomedicine, food freezing, and semiconductor manufacturing.

[0003] Currently, most liquid nitrogen delivery systems are single-point supply systems, with relatively simple system structure and low installation and maintenance costs. For example... Figure 1 As shown, this single-point liquid nitrogen supply system includes a liquid nitrogen storage tank 1 and multiple liquid nitrogen output points 2. The system relies on a single liquid nitrogen source and delivery path. If the supply point fails, such as due to pump damage, pipeline blockage, or leakage, the entire downstream liquid nitrogen supply will be interrupted, affecting the continuous operation of the production line or experiment.

[0004] The problems or shortcomings of existing technologies are as follows:

[0005] 1. Low reliability: Single-point liquid nitrogen supply system relies on a single liquid nitrogen source and delivery path. Once the supply point fails, such as pump damage, pipeline blockage or leakage, the liquid nitrogen supply of the entire downstream will be interrupted, affecting the continuous operation of the production line or experiment.

[0006] 2. Insufficient flexibility: For scenarios with multiple nitrogen demand points, single-point liquid supply makes it difficult to dynamically adjust the liquid supply volume according to the different needs of each usage point, which limits the flexibility and efficiency of the system.

[0007] 3. Maintenance and downtime risks: When equipment maintenance is carried out or a fault occurs that requires repair, the entire liquid supply process must be suspended because there is no backup system. This may lead to production stoppage or research interruption, increasing economic losses or research delays.

[0008] 4. Concentrated safety risks: All liquid supply relies on the same set of equipment. If a major safety problem occurs in this equipment, such as overpressure or leakage, it may have a wider impact on personnel and the environment. Utility Model Content

[0009] This utility model provides a liquid nitrogen multi-point integrated supply system, which includes a liquid nitrogen storage tank system, a control valve box, a liquid nitrogen output terminal, and a PLC controller. The two ends of the control valve box are connected to the liquid nitrogen storage tank system and the liquid nitrogen output terminal.

[0010] The liquid nitrogen storage tank system includes at least one main liquid nitrogen storage tank and at least one backup liquid nitrogen storage tank. Each main liquid nitrogen storage tank and each backup liquid nitrogen storage tank are connected to the control valve box through a main liquid nitrogen delivery pipeline and a backup liquid nitrogen delivery pipeline, respectively. Both the main liquid nitrogen delivery pipeline and the backup liquid nitrogen delivery pipeline are equipped with a first dual safety discharge system. A first vacuum shut-off valve is provided on the main liquid nitrogen delivery pipeline between the main liquid nitrogen storage tank and the first dual safety discharge system.

[0011] The control valve box includes several control branch pipes and a safety control main pipe. The main liquid nitrogen delivery pipeline and the backup liquid nitrogen delivery pipeline are respectively connected to a control branch pipe. A second vacuum shut-off valve and a third vacuum shut-off valve are connected in series on each control branch pipe. The safety control main pipe is connected to the control branch pipes in sequence. The connection node between the safety control main pipe and the control branch pipe is located between the second vacuum shut-off valve and the third vacuum shut-off valve. A second dual safety discharge system is provided at one end of the safety control main pipe.

[0012] The liquid nitrogen output terminal includes at least one main liquid nitrogen output pipeline and at least one backup liquid nitrogen output pipeline. The main liquid nitrogen output pipeline and the backup liquid nitrogen output pipeline are respectively connected to a control branch pipe. Both the main liquid nitrogen output pipeline and the backup liquid nitrogen output pipeline are equipped with a third dual safety discharge system.

[0013] The first dual safety emission system, the first vacuum shut-off valve, the second vacuum shut-off valve, the third vacuum shut-off valve, the second dual safety emission system, and the third dual safety emission system are all connected to the PLC controller.

[0014] Furthermore, the first dual safety emission system, the second dual safety emission system, and the third dual safety emission system all include emission pipelines, which are connected to pressure gauges and two relief valves.

[0015] Furthermore, the other end of the safety control main pipe is connected to a residual liquid discharge port, which is equipped with a fourth vacuum shut-off valve.

[0016] Furthermore, the first vacuum shut-off valve, the second vacuum shut-off valve, the third vacuum shut-off valve, and the fourth vacuum shut-off valve are cryogenic pneumatic vacuum shut-off valves;

[0017] The first vacuum shut-off valve, the second vacuum shut-off valve, the third vacuum shut-off valve, and the fourth vacuum shut-off valve are connected to the PLC controller via pneumatic actuators. The pneumatic actuators include a double-acting cylinder and a position sensor, which provide real-time feedback on the valve opening and closing status to the PLC controller.

[0018] Furthermore, both the main liquid nitrogen storage tank and the backup liquid nitrogen storage tank are equipped with weighing sensors connected to the PLC controller at their bottoms.

[0019] The advantages of this utility model are:

[0020] (1) The system reliability is significantly improved by using a redundant design of main and backup liquid nitrogen storage tanks and a multi-channel switching mechanism controlled by PLC. When the main storage tank supply is abnormal, the PLC can automatically switch to the backup storage tank based on the data from the pressure sensor and flow meter, so as to achieve seamless liquid supply and ensure the continuous operation needs of critical areas.

[0021] (2) The control valve box adopts a multi-branch parallel structure to support dynamic pressure balance between different output pipelines. The opening degree of the vacuum shut-off valve of each branch is adjusted in real time through PID algorithm, so that the liquid nitrogen flow rate at multiple usage points can be independently controlled with precision to meet the differentiated liquid supply requirements of scenarios such as wafer cooling in semiconductor manufacturing.

[0022] (3) A triple safety protection system enables risk-layered control. The dual safety discharge system automatically depressurizes when the pipeline pressure is abnormal, and in conjunction with the emergency shut-off function of the cryogenic pneumatic valve, the leakage can be controlled within 0.5% of the system capacity. The residual liquid directional discharge design of the main safety control pipe ensures that residual liquid nitrogen in the branch pipe can be completely drained during maintenance operations, reducing the risk of frostbite to maintenance personnel.

[0023] (4) The modular architecture supports online maintenance. When any tank or branch is under maintenance, the system automatically isolates the faulty unit and redistributes the liquid supply path to ensure that the overall liquid supply capacity is not lower than the design value. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a single-point liquid nitrogen supply system in the prior art;

[0026] Figure 2 A schematic diagram of a multi-point integrated liquid nitrogen supply system provided by this utility model;

[0027] Figure 3 This is a schematic diagram of the first dual safety emission system;

[0028] Figure 4 This is a schematic diagram of switching the main liquid nitrogen storage tank to the backup liquid nitrogen storage tank to supply liquid nitrogen in Embodiment 1 of this utility model;

[0029] Figure 5 This is a schematic diagram illustrating the increased supply of one of the main liquid nitrogen storage tanks in Embodiment 2 of this utility model. Detailed Implementation

[0030] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0031] To fully understand this utility model, detailed steps and structures will be presented in the following description to illustrate the technical solution of this utility model. Preferred embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0032] Reference Figure 2-3 As shown, this utility model provides a liquid nitrogen multi-point integrated supply system, which includes a liquid nitrogen storage tank system 100, a control valve box 200, a liquid nitrogen output terminal 300, and a PLC controller (not shown in the figure). The two ends of the control valve box 200 are connected to the liquid nitrogen storage tank system 100 and the liquid nitrogen output terminal 300.

[0033] Liquid nitrogen storage tank system 100

[0034] The liquid nitrogen storage tank system 100 includes at least one main liquid nitrogen storage tank 110 and a backup liquid nitrogen storage tank 120. Each main liquid nitrogen storage tank 110 and each backup liquid nitrogen storage tank 120 are connected to the control valve box 200 through a main liquid nitrogen delivery pipeline 111 and a backup liquid nitrogen delivery pipeline 121, respectively.

[0035] Both the main liquid nitrogen delivery pipeline 111 and the backup liquid nitrogen delivery pipeline 121 are equipped with a first dual safety discharge system 130. A first vacuum shut-off valve 112 is provided on the main liquid nitrogen delivery pipeline 111 between the main liquid nitrogen storage tank 110 and the first dual safety discharge system 130.

[0036] Control valve box 200

[0037] The control valve box 200 is an integrated valve box. Inside the box, there are several control branch pipes 210 and a safety control main pipe 220. The main liquid nitrogen delivery pipeline 111 and the backup liquid nitrogen delivery pipeline 121 are respectively connected to a control branch pipe 210. A second vacuum shut-off valve 211 and a third vacuum shut-off valve 212 are connected in series on each control branch pipe 210. The safety control main pipe 220 is connected to the control branch pipes 210 in sequence. The connection node between the safety control main pipe 220 and the control branch pipes 210 is located between the second vacuum shut-off valve 211 and the third vacuum shut-off valve 212.

[0038] One end of the safety control main pipe 220 is equipped with a second dual safety discharge system 221, and the other end of the safety control main pipe 220 is connected to a residual liquid discharge port 222. The residual liquid discharge port 222 is located at the lowest point of the liquid nitrogen system. The residual liquid discharge port 222 is equipped with a fourth vacuum shut-off valve 223. By opening the fourth vacuum shut-off valve 223, the residual liquid in the pipeline can be discharged from the residual liquid discharge port 222 during maintenance and management.

[0039] Liquid nitrogen output 300

[0040] The liquid nitrogen output terminal 300 includes at least one main liquid nitrogen output pipeline 310 and at least one backup liquid nitrogen output pipeline 320. The main liquid nitrogen output pipeline 310 and the backup liquid nitrogen output pipeline 320 are respectively connected to a control branch pipe 210. Both the main liquid nitrogen output pipeline 310 and the backup liquid nitrogen output pipeline 320 are equipped with a third dual safety discharge system 330.

[0041] It should be noted that the backup liquid nitrogen storage tank 120 and the backup liquid nitrogen output pipeline 320 are normally closed. When the main liquid nitrogen storage tank 110 experiences an abnormality or insufficient supply, the backup liquid nitrogen storage tank 120 and / or the backup liquid nitrogen output pipeline 320 will be opened.

[0042] PLC control system

[0043] The first dual safety emission system 130, the first vacuum shut-off valve 112, the second vacuum shut-off valve 211, the third vacuum shut-off valve 212, the second dual safety emission system 221, and the third dual safety emission system 330 are all connected to the PLC controller. Each dual safety emission system and vacuum shut-off valve is adjusted by the PLC controller according to production needs. The specific adjustment is based on settings made by engineers according to the situation. The relevant setting steps are conventional techniques used by those skilled in the art and will not be elaborated here.

[0044] The PLC controller has a built-in multi-channel digital / analog input / output module, which can acquire standard signals from pressure gauge 132, position sensor, and load cell in real time. The system integrates a PID control algorithm module to dynamically calculate the nitrogen consumption rate at each point of use based on the tank weighing data, and interacts with the host computer monitoring system via the MODBUS TCP protocol. For cryogenic operating conditions, the control program adopts a triple redundancy architecture design, with the main processor and two hot-standby processors synchronizing data at millisecond levels via a fiber optic synchronization bus to ensure seamless system switching in the event of a single point of failure.

[0045] The pneumatic actuator is equipped with dual independent air supply circuits, allowing the backup gas cylinder group to maintain emergency operation for 72 hours in case of main air source failure. The position sensor uses a magnetostrictive linear encoder, with a valve opening feedback resolution of 0.1°, which, combined with the PLC's fuzzy control algorithm, enables precise flow regulation. The safety interlock module includes a 16-level event priority judgment matrix. When a pipeline pressure fluctuation exceeding ±15% of the set value is detected for 300ms, a three-level emergency response is immediately triggered: the primary response starts the backup pump group, the secondary response shuts down the faulty branch, and the ultimate response activates full-area emergency discharge.

[0046] In an optional embodiment, the first dual safety emission system 130, the second dual safety emission system 221, and the third dual safety emission system 330 have the same structure. Taking the first dual safety emission system 130 as an example, the first dual safety emission system 130 includes an emission pipeline 131, which is connected to a pressure gauge 132 and two relief valves 133. When the pressure gauge 132 detects that the pipeline pressure exceeds 1.5 times the working pressure, the PLC controller opens the relief valves 133 to release pressure. By setting two relief valves 133, a safety redundancy is provided to ensure the overall safety of the system.

[0047] In an optional embodiment, the first vacuum shut-off valve 112, the second vacuum shut-off valve 211, the third vacuum shut-off valve 212, and the fourth vacuum shut-off valve 223 are cryogenic pneumatic vacuum shut-off valves. The first vacuum shut-off valve 112, the second vacuum shut-off valve 211, the third vacuum shut-off valve 212, and the fourth vacuum shut-off valve 223 are connected to the PLC controller via pneumatic actuators. The pneumatic actuators include a double-acting cylinder and a position sensor, which provide real-time feedback of the valve's opening and closing status to the PLC controller.

[0048] In an optional embodiment, both the main liquid nitrogen storage tank 110 and the backup liquid nitrogen storage tank 120 are equipped with weighing sensors connected to a PLC controller at their bottoms. These weighing sensors monitor the weight of the liquid nitrogen within the tanks in real time, thereby precisely controlling the liquid nitrogen supply and providing timely warnings of insufficient liquid nitrogen. Based on the data from the weighing sensors, the PLC controller can intelligently adjust the liquid nitrogen delivery rate to ensure a stable and adequate supply of liquid nitrogen at each point of use.

[0049] Example 1

[0050] The entire system can operate in a main-supplement tank mode. Under normal operating conditions, the main liquid nitrogen storage tank 110 supplies liquid nitrogen. In case of system failure or problems, the supply end is switched to the backup liquid nitrogen storage tank 120. Figure 4 As shown, this ensures a stable supply of liquid nitrogen throughout the downstream process, without affecting the continuous operation of the production line or experiment.

[0051] Example 2

[0052] This system can also adopt a multi-tank liquid supply mode, using vacuum shut-off valves to regulate the flow rate of different tanks. If one main liquid nitrogen tank 110 malfunctions, the supply volume of another main liquid nitrogen tank 110 can be increased. Figure 5 As shown, this addresses the issue of ensuring liquid supply. Because the supply pipelines in the distribution device are interconnected, if a problem occurs in a single supply pipeline, the liquid supply mode can be quickly switched by adjusting the shut-off valve. Furthermore, subsequent inspections can easily pinpoint the problem location.

[0053] The preferred embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above. Devices and structures not described in detail herein should be understood as being implemented in a conventional manner within the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this utility model using the disclosed methods and techniques, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of this utility model. This does not affect the essential content of this utility model. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model, without departing from the content of the technical solution of this utility model, still fall within the protection scope of the technical solution of this utility model.

Claims

1. A liquid nitrogen multi-point supply integration system, characterized in that, The integrated liquid nitrogen multi-point supply system includes a liquid nitrogen storage tank system, a control valve box, a liquid nitrogen output terminal, and a PLC controller. The liquid nitrogen storage tank system includes at least one main liquid nitrogen storage tank and at least one backup liquid nitrogen storage tank. Each main liquid nitrogen storage tank and each backup liquid nitrogen storage tank are connected to a control valve box through a main liquid nitrogen delivery pipeline and a backup liquid nitrogen delivery pipeline, respectively. Both the main liquid nitrogen delivery pipeline and the backup liquid nitrogen delivery pipeline are equipped with a first dual safety discharge system. A first vacuum shut-off valve is provided on the main liquid nitrogen delivery pipeline between the main liquid nitrogen storage tank and the first dual safety discharge system. The control valve box includes several control branch pipes and a safety control main pipe. The main liquid nitrogen delivery pipeline and the backup liquid nitrogen delivery pipeline are each connected to a control branch pipe. A second vacuum shut-off valve and a third vacuum shut-off valve are connected in series on each control branch pipe. The safety control main pipe is connected to the control branch pipes in sequence. The connection node between the safety control main pipe and the control branch pipe is located between the second vacuum shut-off valve and the third vacuum shut-off valve. A second dual safety discharge system is provided at one end of the safety control main pipe. The liquid nitrogen output terminal includes at least one main liquid nitrogen output pipeline and at least one backup liquid nitrogen output pipeline. The main liquid nitrogen output pipeline and the backup liquid nitrogen output pipeline are each connected to a control branch pipe. Both the main liquid nitrogen output pipeline and the backup liquid nitrogen output pipeline are equipped with a third dual safety discharge system. The first dual safety emission system, the first vacuum shut-off valve, the second vacuum shut-off valve, the third vacuum shut-off valve, the second dual safety emission system, and the third dual safety emission system are all connected to the PLC controller.

2. The integrated liquid nitrogen multi-point supply system of claim 1, wherein, The first dual safety emission system, the second dual safety emission system, and the third dual safety emission system all include emission pipelines, which are connected to pressure gauges and two relief valves.

3. The integrated liquid nitrogen multi-point supply system of claim 1, wherein, The other end of the safety control main pipe is connected to a residual liquid discharge port, which is equipped with a fourth vacuum shut-off valve.

4. The integrated liquid nitrogen multi-point supply system of claim 3, wherein, The first vacuum shut-off valve, the second vacuum shut-off valve, the third vacuum shut-off valve, and the fourth vacuum shut-off valve are cryogenic pneumatic vacuum shut-off valves. The first vacuum shut-off valve, the second vacuum shut-off valve, the third vacuum shut-off valve, and the fourth vacuum shut-off valve are connected to the PLC controller via pneumatic actuators. The pneumatic actuators include a double-acting cylinder and a position sensor.

5. The integrated liquid nitrogen multi-point supply system of claim 1, wherein, Both the main liquid nitrogen storage tank and the backup liquid nitrogen storage tank are equipped with weighing sensors at the bottom that are connected to the PLC controller.

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