Self-pressurization liquid nitrogen filling system and control method thereof

Abstract

The invention discloses a self-pressurization liquid nitrogen filling system which comprises an external liquid nitrogen tank, an equipment liquid nitrogen tank and a sucking pump, and a first pipeline and a second pipeline are connected between the external liquid nitrogen tank and the equipment liquid nitrogen tank; the air extracting pump is arranged on the first pipeline and communicated with the outside, the air extracting pump comprises a first air extracting opening and a second air extracting opening, the first air extracting opening is formed in the position where the first pipeline is communicated with the equipment liquid nitrogen tank, and the second air extracting opening is formed in the position where the first pipeline is communicated with the outside. According to the liquid nitrogen filling device, the first pipeline provided with the sucking pump and the second pipeline used for filling the equipment liquid nitrogen tank are arranged, the sucking pump sucks air from the equipment liquid nitrogen tank and the outside to pressurize the external liquid nitrogen tank, and controllable pressure difference is formed in the external liquid nitrogen tank and the equipment liquid nitrogen tank, so that automatic control over liquid nitrogen filling is achieved, control is accurate, and manpower is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a self-pressurized liquid nitrogen perfusion system and a control method thereof. Background Art

[0002] The liquid nitrogen filling system is a device used to accurately deliver liquid nitrogen to a specific container or target object. It plays an extremely important role in the liquid nitrogen tank filling operation of liquid nitrogen cryotherapy equipment.

[0003] In actual application scenarios, the traditional manual pouring and filling method of liquid nitrogen has many disadvantages. For example, it is very easy to cause the risk of personal injury to operators. At the same time, unnecessary liquid nitrogen loss will inevitably occur in the manual operation process.

[0004] The liquid nitrogen filling systems in the prior art mainly include foot-operated, hand-pumped, and mechanical types. These liquid nitrogen filling systems still rely on manual operation to a certain extent, and the operation is complicated, the liquid nitrogen filling efficiency is low, and there is also the problem that the filling process cannot be accurately controlled and the operator is still at risk of injury.

[0005] There is an urgent need for a liquid nitrogen perfusion system to solve these problems, so as to improve the safety of operation and significantly reduce the loss of liquid nitrogen, providing a strong guarantee for the stable and efficient operation of liquid nitrogen cryotherapy equipment. Summary of the invention

[0006] In order to overcome the above problems, the present invention proposes a self-pressurized liquid nitrogen filling system and a control method thereof. By providing a first pipeline with an air extraction pump and a second pipeline for filling the equipment liquid nitrogen tank, the first pipeline extracts air from the equipment liquid nitrogen tank and the outside world, pressurizes the external liquid nitrogen tank, and forms a pressure difference between the external liquid nitrogen tank and the equipment liquid nitrogen tank, thereby realizing automatic control of the filling of liquid nitrogen, the control is safe, the control is accurate, the liquid nitrogen loss is reduced, and manpower is saved.

[0007] The present invention provides a self-pressurized liquid nitrogen filling system, comprising: an external liquid nitrogen tank, an equipment liquid nitrogen tank and an air pump, wherein a first pipeline and a second pipeline are connected between the external liquid nitrogen tank and the equipment liquid nitrogen tank; the air pump is arranged on the first pipeline and is connected to the outside world, the air pump comprises a first air pumping port and a second air pumping port, the first air pumping port is arranged at the place where the first pipeline is connected to the equipment liquid nitrogen tank, the second air pumping port is arranged at the place where the air pump is connected to the outside world, and the equipment liquid nitrogen tank is evacuated through the second air pumping port, so that the pressure difference between the external liquid nitrogen tank and the equipment liquid nitrogen tank is increased, and the rate of filling liquid nitrogen into the equipment liquid nitrogen tank is increased. At the same time, the nitrogen generated by vaporization in the equipment liquid nitrogen tank can be pumped into the external liquid nitrogen tank again, and liquefied into liquid nitrogen at the low temperature of the external liquid nitrogen tank, thereby reducing the loss of liquid nitrogen.

[0008] Furthermore, the external liquid nitrogen tank includes a first liquid storage part, and the equipment liquid nitrogen tank includes a second liquid storage part; the first end of the first pipeline is located at the upper end of the port of the first liquid storage part, and the second end of the first pipeline is located at the upper end of the port of the second liquid storage part; the first end of the second pipeline is located at the bottom end of the first liquid storage part, and the second end of the second pipeline is located at the upper end of the port of the second liquid storage part. With this arrangement, the liquid nitrogen in the external liquid nitrogen tank can be continuously pumped into the equipment liquid nitrogen tank, and can be completely pumped into the equipment liquid nitrogen tank.

[0009] Furthermore, the tank openings of the external liquid nitrogen tank and the equipment liquid nitrogen tank are provided with sealing devices, and the first pipeline and the second pipeline pass through and are fixedly connected to the sealing device, so that the liquid nitrogen tank has better sealing performance.

[0010] Furthermore, a liquid level meter is provided in the liquid nitrogen tank of the equipment to detect the liquid nitrogen level in the liquid nitrogen tank of the equipment.

[0011] Furthermore, the liquid nitrogen tank of the equipment is connected to a third conduit, the third conduit is connected to the outside world, and a first on-off device is provided on the third conduit, the first on-off device can connect or cut off the third conduit with the outside world, so as to adjust the pressure in the liquid nitrogen tank of the equipment and ensure the safe operation of the equipment.

[0012] Furthermore, a second on-off device is provided on the second pipeline, and the control over the process of pumping the external liquid nitrogen tank into the liquid nitrogen tank of the equipment can be strengthened by controlling the second on-off device.

[0013] Furthermore, a pressure sensor is provided on the second pipeline to monitor the pressure in the pipeline and ensure the safe operation of the equipment.

[0014] The present invention provides a control method for a self-pressurizing liquid nitrogen perfusion system, which is used to control the self-pressurizing liquid nitrogen perfusion system as described above, and comprises the following steps:

[0015] S11 detects the liquid nitrogen level in the liquid nitrogen tank of the equipment;

[0016] S12: if the detection result shows that there is residual liquid nitrogen in the liquid nitrogen tank of the equipment, the vacuum pump is turned on and the second on-off device is turned on; if the detection result shows that there is no residual liquid nitrogen in the liquid nitrogen tank of the equipment, the vacuum pump is turned on and the second on-off device is turned on, and the first on-off device is kept turned on before the liquid nitrogen level in the liquid nitrogen tank of the equipment reaches a first preset value;

[0017] S13 determines whether the liquid nitrogen level in the liquid nitrogen tank of the device reaches a second preset value;

[0018] S14: if the second preset value is reached, the air pump is turned off; if the second preset value is not reached, step S11 is repeated.

[0019] Furthermore, the control method of the self-pressurized liquid nitrogen perfusion system also includes: if the pressure signal received by the pressure sensor exceeds a threshold value, controlling the vacuum pump to stop and controlling the first on-off device to open.

[0020] Furthermore, the control method of the self-pressurized liquid nitrogen filling system also includes: real-time monitoring of the liquid level of the liquid nitrogen tank of the equipment, and adjusting the power of the vacuum pump according to the real-time liquid level information of the liquid nitrogen tank of the equipment.

[0021] Technical Effects

[0022] Due to the adoption of the above technology, the present invention has the following positive effects compared with the prior art:

[0023] (1) The present invention provides a first pipeline with an air extraction pump and a second pipeline for filling the equipment liquid nitrogen tank. The first pipeline is used to extract air from the equipment liquid nitrogen tank and the outside to pressurize the external liquid nitrogen tank, thereby increasing the pressure difference between the external liquid nitrogen tank and the equipment liquid nitrogen tank. The automatic control of liquid nitrogen filling is achieved by controlling the speed of the air extraction pump. The control is accurate, the operation is safe, and manpower is saved. At the same time, the nitrogen generated by vaporization in the equipment liquid nitrogen tank can be pumped into the external liquid nitrogen tank again, liquefied under the low temperature of the liquid nitrogen in the external liquid nitrogen tank, and then the liquid nitrogen is replenished, thereby reducing the loss of liquid nitrogen during the pumping process.

[0024] (2) The present invention provides a control method for a self-pressurized liquid nitrogen filling system. By controlling the on-off device and the vacuum pump, the pressure difference between the external liquid nitrogen tank and the equipment liquid nitrogen tank is maximized during filling. While self-pressurizing, the power of the vacuum pump is adjusted according to the liquid nitrogen level of the equipment liquid nitrogen tank, making the self-pressurized liquid nitrogen filling system more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0026] Figure 1 The figure shows a schematic diagram of the connection structure of a self-pressurized liquid nitrogen perfusion system according to an embodiment of the present invention.

[0027] Figure 2 Shown is a flow chart of a control method for a self-pressurized liquid nitrogen perfusion system according to an embodiment of the present invention.

[0028] Figure numerals: external liquid nitrogen tank 11, equipment liquid nitrogen tank 12, vacuum pump 13, first pipeline 14, second pipeline 15, first vacuum port 16, second vacuum port 17, first liquid storage part 18, second liquid storage part 19, first end A of first pipeline, second end B of first pipeline, first end C of second pipeline, second end D of second pipeline, port E of first liquid storage part, bottom end F of first liquid storage part, port G of second liquid storage part, sealing device 20, liquid level meter 21, third conduit 22, first on-off device 23, second on-off device 24, pressure sensor 25. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions of various embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that in order to clearly and intuitively present the technical solution of the present invention, some components are omitted in the drawings, which is only used as a schematic and does not constitute a specific limitation of the present invention. In addition, the arrows in the drawings of the present invention represent the direction of fluid flow.

[0031] The present invention provides a self-pressurized liquid nitrogen filling system, comprising: an external liquid nitrogen tank 11, an equipment liquid nitrogen tank 12 and an air pump 13, wherein a first pipeline 14 and a second pipeline 15 are connected between the external liquid nitrogen tank 11 and the equipment liquid nitrogen tank 12; the air pump 13 is arranged on the first pipeline 14 and communicated with the outside world, and the air pump 13 comprises a first air pumping port 16 and a second air pumping port 17, wherein the first air pumping port 16 is arranged at a place where the first pipeline 14 and the equipment liquid nitrogen tank 12 are connected, and the second air pumping port 17 is arranged at a place where the air pump 13 is connected with the outside world. The first pipeline 14 is used to extract gas from the outside and the equipment liquid nitrogen tank 12 and pump gas into the external liquid nitrogen tank 11, so as to realize the self-pressurization of the external liquid nitrogen tank 11 and increase the pressure difference between the external liquid nitrogen tank 11 and the equipment liquid nitrogen tank 12, so as to ensure that the external liquid nitrogen tank 11 can continuously provide liquid nitrogen to the equipment liquid nitrogen tank 12 to maintain the liquid nitrogen supply of the equipment; the first gas extraction port 16 of the liquid nitrogen pump is arranged at the connection point between the first pipeline 14 and the liquid nitrogen pump, so that the equipment liquid nitrogen tank 12 is always in a negative pressure state after being evacuated, which further increases the speed at which the liquid nitrogen in the external liquid nitrogen tank 11 enters the equipment liquid nitrogen tank 12. The second pipeline 15 is used to transport liquid nitrogen from the external liquid nitrogen tank 11 to the equipment liquid nitrogen tank 12. At the same time, there will be a certain amount of vaporized liquid nitrogen, that is, nitrogen, in the equipment liquid nitrogen tank 12. The nitrogen in the equipment liquid nitrogen tank 12 enters the external liquid nitrogen tank 11 under the action of the vacuum pump 13. The nitrogen is liquefied under the low temperature in the external liquid nitrogen tank 11 to become liquid nitrogen, which reduces the manual dumping that causes the nitrogen to escape into the air, effectively recovers and replenishes the liquid nitrogen in the external liquid nitrogen tank 11, and reduces the loss of liquid nitrogen.

[0032] Among them, the external liquid nitrogen tank 11 includes a first liquid storage part 18, and the equipment liquid nitrogen tank 12 includes a second liquid storage part 19; the first liquid storage part 18 and the second liquid storage part 19 are cavity parts for accommodating liquid nitrogen, the first end A of the first pipeline is located at the upper end of the port E of the first liquid storage part, and the second end B of the first pipeline is located at the upper end of the port G of the second liquid storage part; the first end C of the second pipeline is located at the bottom end F of the first liquid storage part, and the second end D of the second pipeline is located at the upper end of the port G of the second liquid storage part. The first end A of the first pipeline is used to pump the gas extracted from the outside or the equipment liquid nitrogen tank 12 into the external liquid nitrogen tank 11 to achieve pressurization, so it is set at a position far away from the liquid nitrogen level in the first liquid storage part 18, so as to utilize the increase in gas pressure to pump the liquid nitrogen in the first liquid storage part 18 from the first end C of the second pipeline into the second pipeline 15, and transport it along the second pipeline 15 to the equipment liquid nitrogen tank 12. The second end B of the first pipeline is used to extract gas from the equipment liquid nitrogen tank 12 , and therefore needs to be set at a position far away from the liquid level in the equipment liquid nitrogen tank 12 to prevent the liquid nitrogen from being drawn back into the external liquid nitrogen tank 11 .

[0033] The tank openings of the external liquid nitrogen tank 11 and the equipment liquid nitrogen tank 12 are provided with a sealing device 20, and the first pipeline 14 and the second pipeline 15 pass through and are fixedly connected to the sealing device 20, so as to enhance the sealing performance of the equipment. The sealing device 20 can be a sealing cover or a sealing plug.

[0034] In some embodiments, a liquid level meter 21 is provided in the equipment liquid nitrogen tank 12, and the liquid level meter 21 can be used to determine whether there is liquid nitrogen remaining in the equipment liquid nitrogen tank 12 or whether the liquid level in the equipment liquid nitrogen tank 12 meets a preset value.

[0035] In some embodiments, a pressure sensor 25 is provided on the second pipeline 15 to detect the pressure value in the second pipeline 15 and adjust the power of the vacuum pump 13 according to the pressure value to ensure continuous supply of nitrogen to the liquid nitrogen tank 12 of the equipment.

[0036] In some embodiments, the equipment liquid nitrogen tank 12 is connected to a third conduit 22, the third conduit 22 is connected to the outside world, and a first on-off device 23 is provided on the third conduit 22, the first on-off device 23 can connect or cut off the third conduit 22 with the outside world. When it is detected that the pressure in the equipment is too high, the first on-off device 23 is opened to relieve the pressure on the equipment liquid nitrogen tank 12 to ensure the safe operation of the equipment.

[0037] In some embodiments, a second on-off device 24 is provided on the second pipeline 15 to control the start and stop of liquid nitrogen perfusion.

[0038] The present invention also provides a control method for a self-pressurized liquid nitrogen perfusion system, comprising:

[0039] S11 detects the liquid level in the liquid nitrogen tank 12 of the equipment;

[0040] S12 If the detection result shows that there is liquid nitrogen remaining in the equipment liquid nitrogen tank 12, the vacuum pump 13 is turned on and the second on-off device 24 is turned on; if there is liquid nitrogen remaining in the equipment liquid nitrogen tank 12, the temperature in the equipment liquid nitrogen tank 12 is not higher than the boiling point of liquid nitrogen, and the liquid nitrogen pumped into the external liquid nitrogen tank 11 will not be quickly vaporized into nitrogen in the equipment liquid nitrogen tank 12. At this time, the second on-off device 24 is turned on, and the vacuum pump 13 pumps gas into the external liquid nitrogen tank 11 through the first vacuum port 16 and the second vacuum port 17 of the first pipeline 14. The liquid nitrogen in the external liquid nitrogen tank 11 is vaporized under the action of gas pressure. The liquid nitrogen in the equipment is pressed into the equipment liquid nitrogen tank 12 through the second pipeline 15. At the same time, since the vacuum pump 13 continuously extracts the equipment air and the nitrogen formed after the liquid nitrogen is vaporized, the equipment liquid nitrogen tank 12 is in a negative pressure state, which increases the pressure difference between the external liquid nitrogen tank 11 and the equipment liquid nitrogen tank 12, and speeds up the rate at which the liquid nitrogen in the external liquid nitrogen tank 11 is pumped into the equipment liquid nitrogen tank 12. In addition, when the vaporized nitrogen in the equipment liquid nitrogen tank 12 is pumped into the external liquid nitrogen tank 11, part of the nitrogen will be liquefied into liquid nitrogen in the external liquid nitrogen tank 11, which replenishes the liquid nitrogen in the external liquid nitrogen tank 11 and reduces the loss of liquid nitrogen.

[0041] If the detection result shows that there is no liquid nitrogen remaining in the equipment liquid nitrogen tank 12, the vacuum pump 13 is turned on and the second on-off device 24 is turned on, and the first on-off device 23 is kept open before the liquid nitrogen level in the equipment liquid nitrogen tank 12 reaches the first preset value; since there is no liquid nitrogen remaining in the equipment liquid nitrogen tank 12, the temperature in the equipment liquid nitrogen tank 12 will be higher than the boiling point of liquid nitrogen, and the liquid nitrogen in the external liquid nitrogen tank 11 will be vaporized to form a large amount of nitrogen when it is pumped into the equipment liquid nitrogen tank 12, causing the gas pressure of the liquid nitrogen tank to rise sharply. Turning on the first on-off device 23 can keep the vaporized nitrogen in the equipment liquid nitrogen tank 12 from being discharged, which is conducive to increasing the pressure difference between the external liquid nitrogen tank 11 and the equipment liquid nitrogen tank 12, and facilitating the filling of liquid nitrogen. When the liquid level of the equipment liquid nitrogen tank 12 reaches the first preset value, it is determined that the temperature in the equipment liquid nitrogen tank 12 is not higher than the boiling point of liquid nitrogen, and the liquid nitrogen pumped into the equipment liquid nitrogen tank 12 rarely vaporizes, and the first on-off device 23 can be closed to continue to add liquid nitrogen.

[0042] S13 determines whether the liquid nitrogen level in the equipment liquid nitrogen tank 12 reaches a second preset value, where the second preset value is a preset value of the liquid nitrogen level for filling the equipment liquid nitrogen tank 12 according to the needs of equipment operation.

[0043] S14: if the second preset value is reached, the air pump 13 is turned off; if the second preset value is not reached, step S11 is repeated.

[0044] In some embodiments, if the pressure signal received by the pressure sensor 25 exceeds a threshold value, the vacuum pump 13 is controlled to stop, and the first on-off device 23 is controlled to open, and the gas in the equipment liquid nitrogen tank 12 is discharged to the atmosphere through the third conduit 22, so as to relieve the pressure, stabilize the air pressure in the equipment liquid nitrogen tank 12, and ensure the safe operation of the equipment.

[0045] In some embodiments, the liquid level of the liquid nitrogen tank 12 of the device is monitored in real time, and the power of the vacuum pump 13 is adjusted according to the real-time liquid level information of the liquid nitrogen tank 12 of the device. The delivery speed of the liquid nitrogen is adjusted by adjusting the power of the vacuum pump 13, thereby ensuring the continuity and stability of the liquid nitrogen supply.

[0046] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary technical means in the art that are not disclosed by the present invention.

Claims

1. A self-pressurized liquid nitrogen perfusion system, comprising: An external liquid nitrogen tank, an equipment liquid nitrogen tank and an air pump, wherein a first pipeline and a second pipeline are connected between the external liquid nitrogen tank and the equipment liquid nitrogen tank; The vacuum pump is arranged on the first pipeline and connected with the outside world. The vacuum pump includes a first vacuum port and a second vacuum port. The first vacuum port is arranged at the connection point between the first pipeline and the equipment liquid nitrogen tank, and the second vacuum port is arranged at the connection point between the vacuum pump and the outside world.

2. The self-pressurized liquid nitrogen perfusion system according to claim 1, characterized in that: The external liquid nitrogen tank includes a first liquid storage part, and the equipment liquid nitrogen tank includes a second liquid storage part; The first end of the first pipeline is located at the upper end of the port of the first liquid storage part, and the second end of the first pipeline is located at the upper end of the port of the second liquid storage part; The first end of the second pipeline is located at the bottom end of the first liquid storage part, and the second end of the second pipeline is located at the upper end of the port of the second liquid storage part.

3. The self-pressurized liquid nitrogen perfusion system according to claim 2, characterized in that: The tank openings of the external liquid nitrogen tank and the equipment liquid nitrogen tank are provided with sealing devices, and the first pipeline and the second pipeline penetrate through and are fixedly connected to the sealing devices.

4. The self-pressurized liquid nitrogen perfusion system according to claim 3, characterized in that: A liquid level gauge is arranged in the liquid nitrogen tank of the equipment.

5. The self-pressurized liquid nitrogen perfusion system according to claim 4, characterized in that: The liquid nitrogen tank of the equipment is connected with a third conduit, the third conduit is communicated with the outside world, and a first on-off device is arranged on the third conduit, the first on-off device can connect or cut off the third conduit with the outside world.

6. The self-pressurized liquid nitrogen perfusion system according to claim 5, characterized in that: The second pipeline is provided with a second on-off device.

7. The self-pressurized liquid nitrogen perfusion system according to claim 6, characterized in that: The second pipeline is provided with a pressure sensor.

8. A method for controlling a self-pressurizing liquid nitrogen perfusion system, for controlling the self-pressurizing liquid nitrogen perfusion system as claimed in claim 7, characterized in that: The following steps are involved: S11 detects the liquid nitrogen level in the liquid nitrogen tank of the equipment; S12 If the detection result shows that there is residual liquid nitrogen in the liquid nitrogen tank of the equipment, the vacuum pump is turned on and the second on-off device is turned on; if the detection result shows that there is no residual liquid nitrogen in the liquid nitrogen tank of the equipment, the vacuum pump is turned on and the second on-off device is turned on, and the first on-off device is kept turned on before the liquid nitrogen level in the liquid nitrogen tank of the equipment reaches a first preset value; S13: Determine whether the liquid nitrogen level in the liquid nitrogen tank of the device reaches a second preset value; S14: if the second preset value is reached, the air pump is turned off; if the second preset value is not reached, step S11 is repeated.

9. The control method of the self-pressurized liquid nitrogen perfusion system according to claim 8, characterized in that: If the pressure signal received by the pressure sensor exceeds a threshold value, the vacuum pump is controlled to stop, and the first on-off device is controlled to open.

10. The control method of the self-pressurized liquid nitrogen perfusion system according to claim 8, characterized in that: Also includes: The liquid level of the liquid nitrogen tank of the equipment is monitored in real time, and the power of the vacuum pump is adjusted according to the real-time liquid level information of the liquid nitrogen tank of the equipment.

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