Automatic switching supply method for low temperature storage tank and automatic switching supply device for low temperature storage tank

Abstract

The invention discloses a low-temperature storage tank automatic switching supply method and a low-temperature storage tank automatic switching supply device. The low-temperature storage tank automatic switching supply method comprises the following steps: if the first storage tank is in a standby state and the second storage tank is not in a standby state, the first storage tank supplies gas first; if the first storage tank is not in a standby state and the second storage tank is in a standby state, the second storage tank supplies gas first; when the first storage tank supplies gas first, the second storage tank performs a liquid filling operation until the standby state is reached; when the liquid level of the first storage tank drops to a first set liquid level, the first storage tank and the second storage tank jointly supply gas; when the liquid level of the first storage tank drops to a second set liquid level, the second storage tank alone supplies gas, and the first storage tank performs a liquid filling operation until the standby state is reached; when the liquid level of the second storage tank drops to the first set liquid level, the first storage tank and the second storage tank jointly supply gas; when the liquid level of the second storage tank drops to the second set liquid level, the first storage tank alone supplies gas. The gas supply can be ensured to be continuous and stable.

Description

Technical Field

[0001] The present invention relates to the technical field of gas supply methods, and in particular to an automatic switching supply method for a cryogenic storage tank and an automatic switching supply device for a cryogenic storage tank. Background Art

[0002] A cryogenic liquid storage tank is a container for storing cryogenic liquefied gas, which is liquid oxygen, liquid nitrogen, liquid argon or liquid carbon dioxide, etc. At present, cryogenic liquid storage tanks have been widely used in industry and daily life. In order to ensure that the amount of cryogenic liquefied gas is sufficient in the application, a main supply cryogenic liquid storage tank and a spare cryogenic liquid storage tank are generally provided. The main supply cryogenic liquid storage tank is used to supply the user's needs. When the liquid level of the main supply cryogenic liquid storage tank is too low or there is no liquid level, the spare cryogenic liquid storage tank is switched to supply the user's needs. However, in the prior art, when the liquid level of the main supply cryogenic liquid storage tank is too low or there is no liquid level, the main supply cryogenic liquid storage tank is directly stopped and switched to the spare cryogenic liquid storage tank for gas supply, and manual switching is adopted. If the operator is not skilled or the operator does not have time to go to the site for operation when emergency switching is required, it may cause the gas supply pressure or flow to drop, and even cause gas supply interruption, affecting production efficiency. Summary of the invention

[0003] The object of the present invention is to provide a method for automatically switching and supplying a cryogenic tank and a device for automatically switching and supplying a cryogenic tank, so as to solve the problem in the prior art that when the liquid level of the main cryogenic liquid storage tank is too low or there is no liquid level, the gas supply of the main cryogenic liquid storage tank is directly stopped and switched to the backup cryogenic liquid storage tank for gas supply, and manual switching is used, which may cause gas supply interruption.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] A low-temperature storage tank automatic switching supply method is applied to a low-temperature storage tank automatic switching supply device, wherein the low-temperature storage tank automatic switching supply device comprises a first storage tank and a second storage tank;

[0006] The method for automatically switching supply of low-temperature storage tanks comprises:

[0007] S1: Determine whether the first storage tank and the second storage tank are in a standby state;

[0008] If the first storage tank is in a standby state and the second storage tank is not in a standby state, proceed to S2;

[0009] If the first storage tank is not in a standby state and the second storage tank is in a standby state, proceed to S6;

[0010] S2: the first storage tank supplies gas to the gas-consuming equipment alone, and the second storage tank performs liquid filling operation until the second storage tank reaches a standby state;

[0011] S3: Determine whether the liquid level of the first storage tank drops to a first set liquid level; if so, proceed to S4;

[0012] S4: the first storage tank and the second storage tank jointly supply gas to the gas-consuming equipment;

[0013] S5: Determine whether the liquid level of the first storage tank drops to a second set liquid level; if so, proceed to S6;

[0014] S6: the second storage tank supplies gas to the gas-consuming equipment alone, and the first storage tank performs a liquid filling operation until the first storage tank reaches a standby state;

[0015] S7: Determine whether the liquid level of the second storage tank drops to the first set liquid level; if so, proceed to S8;

[0016] S8: The first storage tank and the second storage tank jointly supply gas to the gas-consuming equipment;

[0017] S9: Determine whether the liquid level of the second storage tank drops to a second set liquid level; if so, proceed to S2;

[0018] Wherein, the second set liquid level is below the first set liquid level.

[0019] As a preferred solution of the above-mentioned method for automatically switching supply of low-temperature storage tanks, judging whether the first storage tank and the second storage tank are in a standby state includes:

[0020] Determining whether the liquid level of the first storage tank reaches a third set liquid level and whether the pressure in the first storage tank reaches a first set pressure;

[0021] If both are reached, the first storage tank is in a standby state;

[0022] Determining whether the liquid level of the second storage tank reaches the third set liquid level and whether the pressure in the second storage tank reaches the first set pressure;

[0023] If both are reached, the second storage tank is in a standby state;

[0024] Wherein, the third set liquid level is above the first set liquid level.

[0025] As a preferred solution of the above-mentioned method for automatically switching supply of low-temperature storage tanks, the second storage tank is filled with liquid until the second storage tank reaches a standby state, comprising:

[0026] Relieving the pressure of the second storage tank until the pressure of the second storage tank reaches a second set pressure;

[0027] Filling the second storage tank with liquid until the liquid level of the second storage tank reaches the third set liquid level;

[0028] The second storage tank is pressurized until the pressure in the second storage tank reaches the first set pressure.

[0029] As a preferred solution of the above-mentioned method for automatically switching supply of low-temperature storage tanks, the first storage tank is filled with liquid until the first storage tank reaches a standby state, which includes:

[0030] Relieving the pressure of the first storage tank until the pressure of the first storage tank reaches a second set pressure;

[0031] Filling the first storage tank with liquid until the liquid level of the first storage tank reaches the third set liquid level;

[0032] The first storage tank is pressurized until the pressure in the first storage tank reaches the first set pressure.

[0033] The present invention also provides a low-temperature storage tank automatic switching supply device, which adopts the above-mentioned low-temperature storage tank automatic switching supply method, and the low-temperature storage tank automatic switching supply device also includes:

[0034] A first liquid outlet valve, a second liquid outlet valve and an air supply pipeline, wherein the inlet and outlet of the first liquid outlet valve are respectively connected to the first storage tank and the air supply pipeline, the inlet and outlet of the second liquid outlet valve are respectively connected to the second storage tank and the air supply pipeline, and the air supply pipeline is connected to the gas-consuming equipment;

[0035] a first vaporizer, the first vaporizer being disposed in the gas supply pipeline;

[0036] A first filling valve and a second filling valve, wherein the inlet and outlet of the first filling valve are respectively connected to the liquid filling port and the first storage tank; the inlet and outlet of the second filling valve are respectively connected to the liquid filling port and the second storage tank.

[0037] As a preferred solution of the above-mentioned automatic switching supply device for low-temperature storage tanks, the automatic switching supply device for low-temperature storage tanks also includes a first pressure relief valve and a second pressure relief valve, and the two ends of the first pressure relief valve are respectively connected to the first storage tank and the atmosphere; the two ends of the second pressure relief valve are respectively connected to the second storage tank and the atmosphere.

[0038] As a preferred embodiment of the above-mentioned automatic switching supply device for low-temperature storage tanks, the automatic switching supply device for low-temperature storage tanks also includes a first boosting valve, a second vaporizer, a second boosting valve and a third vaporizer, the inlet and outlet of the second vaporizer are respectively connected to the first storage tank and the inlet of the first boosting valve, the outlet of the first boosting valve is connected to the first storage tank, the inlet and outlet of the third vaporizer are respectively connected to the second storage tank and the inlet of the second boosting valve, and the outlet of the second boosting valve is connected to the second storage tank.

[0039] As a preferred solution of the above-mentioned automatic switching supply device for low-temperature storage tanks, the automatic switching supply device for low-temperature storage tanks also includes a controller, and the first liquid outlet valve, the second liquid outlet valve, the first pressure relief valve, the second pressure relief valve, the first boosting valve and the second boosting valve are all connected to the controller.

[0040] As a preferred solution of the above-mentioned automatic switching supply device for low-temperature storage tanks, there are multiple first vaporizers, and the multiple first vaporizers are arranged in parallel.

[0041] As a preferred solution of the above-mentioned automatic switching supply device for low-temperature storage tanks, the automatic switching supply device for low-temperature storage tanks also includes a regulating valve, which is arranged on the gas supply pipeline, and the inlet and outlet of the regulating valve are respectively connected to the first vaporizer and the gas-using equipment.

[0042] Beneficial effects of the present invention:

[0043] The present invention provides a method for automatically switching and supplying low-temperature storage tanks and a device for automatically switching and supplying low-temperature storage tanks. In the method for automatically switching and supplying low-temperature storage tanks, firstly, it is determined whether the first storage tank and the second storage tank are in a standby state according to the liquid level and pressure of the first storage tank and the second storage tank. If the first storage tank is in a standby state and the second storage tank is not in a standby state, the first storage tank is first used as the main supply storage tank, and the first storage tank first supplies gas to the gas-using equipment alone; if the first storage tank is not in a standby state and the second storage tank is in a standby state, the second storage tank is first used as the main supply storage tank, and the second storage tank first supplies gas to the gas-using equipment alone. For example, when the first storage tank first supplies gas alone, the second storage tank is filled with liquid while the first storage tank is supplying gas, so that the liquid level of the second storage tank reaches the third set liquid level and the pressure in the tank reaches the first set pressure, so that the second storage tank reaches a standby state, that is, a state in which gas can be supplied at any time, and at this time, the second storage tank serves as a spare storage tank. When the liquid level of the first tank drops to the first set level, the first tank and the second tank supply gas together. At this time, the liquid levels of the first tank and the second tank both drop. When the liquid level of the first tank drops to the second set level, the first tank stops supplying gas, and the second tank is used to supply gas alone. While the second tank is supplying gas, the first tank is filled with liquid until the first tank reaches a standby state. At this time, the first tank serves as a backup tank, and the second tank serves as a main supply tank. When the liquid level of the second tank drops to the first set level, the first tank and the second tank supply gas together. When the liquid level of the second tank drops to the second set level, the second tank stops supplying gas, and the first tank supplies gas alone. The second tank is filled with liquid until the second tank reaches a standby state. At this time, the first tank serves as a main supply tank, and the second tank serves as a backup tank. This cycle is repeated. The method for automatically switching the supply of low-temperature tanks is capable of seamlessly switching the supply of the first tank and the second tank, which can reduce the workload of operators; and between the gas supply of one of the first tank and the second tank being switched to the gas supply of the other, the first tank and the second tank supply gas together, which can reduce the impact caused by operating errors and ensure continuous and stable gas supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a flow chart of a method for automatically switching supply of a low-temperature storage tank provided by a specific embodiment of the present invention;

[0045] Figure 2 It is a structural schematic diagram of an automatic switching supply device for a low-temperature storage tank provided in a specific embodiment of the present invention.

[0046] In the figure:

[0047] 1. First storage tank; 2. Second storage tank; 3. First filling valve; 4. Second filling valve; 5. Liquid filling port; 6. First liquid outlet valve; 7. Second liquid outlet valve; 8. Second vaporizer; 9. First boost valve; 10. Third vaporizer; 11. Second boost valve; 12. First pressure relief valve; 13. Second pressure relief valve; 14. Gas supply pipeline; 15. First vaporizer; 16. Regulating valve; 17. First stop valve; 18. First liquid pipeline; 19. Second liquid pipeline; 20. Third stop valve; 21. Second stop valve; 22. Third liquid pipeline; 23. Fourth liquid pipeline; 24. Fourth stop valve. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0049] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0051] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0052] The present invention provides a method for automatically switching and supplying a low-temperature storage tank and a device for automatically switching and supplying a low-temperature storage tank, such as Figure 2 As shown, the automatic switching supply device for low-temperature storage tanks includes a first storage tank 1, a second storage tank 2, a first liquid outlet valve 6, a second liquid outlet valve 7, an air supply pipeline 14, a first vaporizer 15, a first filling valve 3 and a second filling valve 4, the inlet and outlet of the first liquid outlet valve 6 are respectively connected to the first storage tank 1 and the air supply pipeline 14, the inlet and outlet of the second liquid outlet valve 7 are respectively connected to the second storage tank 2 and the air supply pipeline 14, the air supply pipeline 14 is connected to the gas-using equipment, the first vaporizer 15 is arranged on the air supply pipeline 14, the inlet and outlet of the first filling valve 3 are respectively connected to the liquid filling port 5 and the first storage tank 1; the inlet and outlet of the second filling valve 4 are respectively connected to the liquid filling port 5 and the second storage tank 2.

[0053] In the automatic switching supply device for low-temperature storage tanks, the first filling valve 3 is opened, and the low-temperature liquid enters the first storage tank 1 from the liquid filling port 5 through the first filling valve 3 to fill the first storage tank 1. The second filling valve 4 is opened, and the low-temperature liquid enters the second storage tank 2 from the liquid filling port 5 through the second filling valve 4 to fill the second storage tank 2. The first liquid outlet valve 6 is opened, and the low-temperature liquid in the first storage tank 1 enters the gas supply pipeline 14 through the first liquid outlet valve 6, and enters the gas-using equipment after being vaporized by the first vaporizer 15 on the gas supply pipeline 14. The second liquid outlet valve 7 is opened, and the low-temperature liquid in the second storage tank 2 enters the gas supply pipeline 14 through the second liquid outlet valve 7, and enters the gas-using equipment after being vaporized by the first vaporizer 15 on the gas supply pipeline 14. When supplying gas to gas-using equipment, the one in the standby state between the first storage tank 1 and the second storage tank 2 supplies gas alone first. For example, the first storage tank 1 is in the standby state, and the second storage tank 2 is not yet in the standby state. At this time, the first liquid outlet valve 6 is opened, and the first storage tank 1 supplies gas alone first. When the liquid level of the first storage tank 1 drops to the first set liquid level, the second liquid outlet valve 7 is opened, and the first storage tank 1 and the second storage tank 2 supply gas together. At this time, the liquid level of the first storage tank 1 continues to drop. When the liquid level of the first storage tank 1 drops to the second liquid level, the first liquid outlet valve 6 is closed, and the second liquid outlet valve 7 is kept in the open state. The first storage tank 1 stops supplying gas, and the second storage tank 2 supplies gas alone. The low-temperature storage tank automatic switching supply device can automatically switch the first storage tank 1 or the second storage tank 2 for gas supply through the first liquid outlet valve 6 and the second liquid outlet valve 7. Between the gas supply from the first storage tank 1 and the gas supply from the second storage tank 2, the first storage tank 1 and the second storage tank 2 are supplied with gas together, and the gas supply can be seamlessly connected, and the gas supply is guaranteed to be stable, thereby reducing the workload of operators and the impact of operating errors.

[0054] Optionally, the automatic switching supply device for low-temperature storage tanks further includes a first pressure relief valve 12 and a second pressure relief valve 13, and both ends of the first pressure relief valve 12 are connected to the first storage tank 1 and the atmosphere; and both ends of the second pressure relief valve 13 are connected to the second storage tank 2 and the atmosphere. When the liquid level of one of the first storage tank 1 and the second storage tank 2 reaches the second set liquid level, the vaporization gas supply to the gas-using equipment is stopped, and the other is switched to vaporization gas supply, and the one of the first storage tank 1 and the second storage tank 2 whose liquid level reaches the second set liquid level needs to be filled with liquid. Pressure relief is required before filling, and the pressure in the tank is released to the second set pressure, which can prevent the pressure in the tank from being released completely and causing air to enter the tank to cause pollution, and can also prepare for filling the tank with liquid. Opening the first pressure relief valve 12 can relieve the pressure of the first storage tank 1, and opening the second pressure relief valve 13 can relieve the pressure of the second storage tank 2. After the first storage tank 1 or the second storage tank 2 is filled with liquid until the liquid level reaches the third set liquid level, the first pressure relief valve 12 or the second pressure relief valve 13 is closed.

[0055] Optionally, the automatic switching supply device for low-temperature storage tanks further includes a first boosting valve 9, a second vaporizer 8, a second boosting valve 11 and a third vaporizer 10, the inlet and outlet of the second vaporizer 8 are respectively connected to the inlet of the first storage tank 1 and the first boosting valve 9, the outlet of the first boosting valve 9 is connected to the first storage tank 1, the inlet and outlet of the third vaporizer 10 are respectively connected to the second storage tank 2 and the inlet of the second boosting valve 11, and the outlet of the second boosting valve 11 is connected to the second storage tank 2. After the first storage tank 1 or the second storage tank 2 is filled with liquid until the liquid level reaches the third set liquid level, it is necessary to increase the pressure in the tank to the first set pressure so that the first storage tank 1 or the second storage tank 2 reaches the standby state, and continue to increase the pressure during the liquid supply vaporization process to keep the pressure in the tank stable. The first boosting valve 9 is opened, and the cryogenic liquid enters the second vaporizer 8 from the first storage tank 1, and then enters the first storage tank 1 after being vaporized in the second vaporizer 8, and the first storage tank 1 is pressurized; when the liquid level of the first storage tank 1 drops to the second set liquid level, the first boosting valve 9 is closed. The second boosting valve 11 is opened, and the cryogenic liquid enters the third vaporizer 10 from the second storage tank 2, and then enters the second storage tank 2 after being vaporized in the third vaporizer 10, and the second storage tank 2 is pressurized; when the liquid level of the second storage tank 2 drops to the second set liquid level, the second boosting valve 11 is closed.

[0056] Optionally, the automatic switching supply device for low-temperature storage tanks also includes two first stop valves 17 and two second stop valves 21, the number of the first filling valve 3 and the second filling valve 4 are both two, the liquid filling port 5 is connected to the first liquid phase pipeline 18, the second liquid phase pipeline 19, the third liquid phase pipeline 22 and the fourth liquid phase pipeline 23, the first liquid phase pipeline 18 and the second liquid phase pipeline 19 are both connected to the first storage tank 1, the third liquid phase pipeline 22 and the fourth liquid phase pipeline 23 are both connected to the second storage tank 2, one of the first stop valves 17 and one of the first filling valves 3 are arranged on the first liquid phase pipeline 18, the other first stop valve 17 and the other first filling valve 3 are arranged on the second liquid phase pipeline 19, and the first stop valve 17 is closer to the first storage tank 1 than the first filling valve 3; one of the second stop valves 21 and one of the second filling valves 4 are arranged on the third liquid phase pipeline 22, and the other second stop valve 21 and the other second The filling valve 4 is arranged on the fourth liquid phase pipeline 23, and the second stop valve 21 is closer to the second storage tank 2 than the second filling valve 4; the inlet of the second vaporizer 8 is connected to the second liquid phase pipeline 19, and the connecting point is located between the first filling valve 3 and the first stop valve 17; the inlet of the third vaporizer 10 is connected to the fourth liquid phase pipeline 23, and the connecting point is located between the second filling valve 4 and the second stop valve 21; the automatic switching supply device for low-temperature storage tanks also includes a third stop valve 20 and a fourth stop valve 24, one end of the third stop valve 20 is connected to the inlet of the second vaporizer 8, and the other end of the third stop valve 20 is connected to the second liquid phase pipeline 19 between the first filling valve 3 and the first stop valve 17, one end of the fourth stop valve 24 is connected to the inlet of the third vaporizer 10, and the other end of the fourth stop valve 24 is connected to the fourth liquid phase pipeline 23 between the second filling valve 4 and the second stop valve 21.

[0057] The two first stop valves 17 and the third stop valve 20 are both in a normally open state, and the first filling valve 3 arranged on the second liquid phase pipeline 19 is in a normally closed state. When the first storage tank 1 is filled with liquid, the first filling valve 3 arranged on the first liquid phase pipeline 18 is opened, and the first storage tank 1 is filled with liquid through the first liquid phase pipeline 18; when the first storage tank 1 is pressurized, the first boosting valve 9 is opened, and the low-temperature liquid in the first storage tank 1 passes through the first stop valve 17 on the second liquid phase pipeline 19 and then passes through the third stop valve 20 to enter the second vaporizer 8, and after being vaporized in the second vaporizer 8, passes through the first boosting valve 9 to enter the first storage tank 1. When the first filling valve 3 on the first liquid phase pipeline 18 fails, the first stop valve 17 on the first liquid phase pipeline 18 is closed to facilitate the maintenance of the failed first filling valve 3. At this time, the first filling valve 3 on the second liquid phase pipeline 19 can be opened, and the third stop valve 20 can be closed to fill the first storage tank 1 through the second liquid phase pipeline 19. After the liquid level of the first storage tank 1 reaches the third set liquid level, the first filling valve 3 on the second liquid phase pipeline 19 is closed and the third stop valve 20 is opened, which will not affect the filling of the first storage tank 1, thereby preventing gas supply interruption.

[0058] Similarly, the two second stop valves 21 and the fourth stop valve 24 are both in a normally open state, and the second filling valve 4 provided on the fourth liquid phase pipeline 23 is in a normally closed state. When filling the second storage tank 2, the second filling valve 4 on the third liquid phase pipeline 22 is opened, and the second storage tank 2 is filled with liquid through the third liquid phase pipeline 22. When pressurizing the second storage tank 2, the second boosting valve 11 is opened, and the low-temperature liquid in the second storage tank 2 passes through the second stop valve 21 on the fourth liquid phase pipeline 23 and then passes through the fourth stop valve 24 to enter the third vaporizer 10, and after being vaporized in the third vaporizer 10, passes through the second boosting valve 11 to enter the second storage tank 2. When the second filling valve 4 on the third liquid phase pipeline 22 fails, the second stop valve 21 on the third liquid phase pipeline 22 is closed to facilitate the maintenance of the faulty second filling valve 4. At this time, the second filling valve 4 on the fourth liquid phase pipeline 23 can be opened, and the fourth stop valve 24 can be closed. The second storage tank 2 is filled with liquid through the fourth liquid phase pipeline 23. After the liquid level of the second storage tank 2 reaches the third set liquid level, the second filling valve 4 on the fourth liquid phase pipeline 23 is closed and the fourth stop valve 24 is opened. It will not affect the filling of the second storage tank 2, thereby preventing gas supply interruption. Optionally, the automatic switching supply device for low-temperature storage tanks also includes a controller, and the first liquid outlet valve 6, the second liquid outlet valve 7, the first pressure relief valve 12, the second pressure relief valve 13, the first boost valve 9 and the second boost valve 11 are all connected to the controller. Optionally, the controller is a PLC controller. The opening and closing of the first liquid outlet valve 6, the second liquid outlet valve 7, the first pressure relief valve 12, the second pressure relief valve 13, the first boosting valve 9 and the second boosting valve 11 are controlled by the controller without manual operation by the operator. The opening and closing of the valves can be controlled more accurately and timely, and the workload of the staff can be reduced.

[0059] Optionally, there are multiple first vaporizers 15, and multiple first vaporizers 15 are arranged in parallel. After the cryogenic liquid gas enters the gas supply pipeline 14 from the first storage tank 1 or the second storage tank 2, it enters the multiple parallel first vaporizers 15 for vaporization at the same time. The gas vaporized by the multiple first vaporizers 15 is gathered again and supplied to the gas-using equipment, which can quickly increase the vaporization speed of the cryogenic liquid gas.

[0060] Optionally, the low temperature storage tank automatic switching supply device further includes a regulating valve 16, which is disposed on the gas supply pipeline 14, and the inlet and outlet of the regulating valve 16 are respectively connected to the first vaporizer 15 and the gas-consuming device. The controller is connected to the regulating valve 16, and the regulating valve 16 adjusts its opening according to the pressure set in the controller to maintain a stable gas supply to the gas-consuming device.

[0061] The method for automatically switching supply of low-temperature storage tanks is applied to an automatic switching supply device of low-temperature storage tanks, such as Figure 1 As shown, the automatic switching supply method of the cryogenic storage tank includes:

[0062] S1: Determine whether the first storage tank 1 and the second storage tank 2 are in a standby state; if the first storage tank 1 is in a standby state and the second storage tank 2 is not in a standby state, proceed to S2; if the first storage tank 1 is not in a standby state and the second storage tank 2 is in a standby state, proceed to S6.

[0063] Specifically, determining whether the first storage tank 1 and the second storage tank 2 are in a standby state includes:

[0064] It is determined whether the liquid level of the first storage tank 1 reaches the third set liquid level and whether the pressure in the first storage tank 1 reaches the first set pressure; if both are reached, the first storage tank 1 is in a standby state.

[0065] It is determined whether the liquid level of the second storage tank 2 reaches the third set liquid level and whether the pressure in the second storage tank 2 reaches the first set pressure; if both are reached, the second storage tank 2 is in a standby state.

[0066] The liquid level reaching the third set liquid level proves that the liquid level of the first storage tank 1 or the second storage tank 2 meets the standby requirement, and the pressure reaching the first set pressure proves that the pressure inside the first storage tank 1 or the second storage tank 2 meets the standby requirement. When the first storage tank 1 or the second storage tank 2 is in the standby state, it has met the gas supply requirement and can supply gas to the gas-using equipment at any time.

[0067] S2: The first storage tank 1 supplies gas to the gas-using equipment alone, and the second storage tank 2 performs a liquid filling operation until the second storage tank 2 reaches a standby state. When the first storage tank 1 is in a standby state, and the second storage tank 2 is not in a standby state, the first liquid outlet valve 6 is opened, and the first storage tank 1 is used to supply gas to the gas-using equipment alone. While the first storage tank 1 is supplying gas, the second storage tank 2 can be filled with liquid until the liquid level of the second storage tank 2 reaches the third set liquid level and the pressure in the tank reaches the first set pressure, so that the second storage tank 2 is in a standby state as a backup.

[0068] Specifically, the second storage tank 2 is filled with liquid until the second storage tank 2 reaches a standby state, including: depressurizing the second storage tank 2 until the pressure of the second storage tank 2 reaches a second set pressure; filling the second storage tank 2 until the liquid level of the second storage tank 2 reaches a third set liquid level; and pressurizing the second storage tank 2 until the pressure in the second storage tank 2 reaches the first set pressure.

[0069] Open the second pressure relief valve 13 to relieve the pressure of the second storage tank 2 until the pressure in the second storage tank 2 is relieved to the second set pressure. At this time, the second pressure relief valve 13 is not closed. The pressure relief in the second storage tank 2 to the second set pressure can facilitate the filling of the second storage tank 2, and can prevent air from entering the second storage tank 2 and causing pollution. After the pressure in the second storage tank 2 is relieved to the second set pressure, open the second filling valve 4 to fill the second storage tank 2, and stop filling when the liquid level of the second storage tank 2 reaches the third set level, and close the second filling valve 4 and the second pressure relief valve 13. When the liquid level of the second storage tank 2 reaches the third set level, and the second filling valve 4 and the second pressure relief valve 13 are closed, open the second boosting valve 11 to boost the pressure in the second storage tank 2 until the pressure in the second storage tank 2 reaches the first set pressure, and close the second boosting valve 11.

[0070] S3: Determine whether the liquid level of the first storage tank 1 drops to the first set liquid level; if so, proceed to S4. S4: The first storage tank 1 and the second storage tank 2 jointly supply gas to the gas-consuming equipment. When the liquid level of the first storage tank 1 drops to the first set liquid level, keep the first liquid outlet valve 6 open, and then open the second liquid outlet valve 7. The first storage tank 1 and the second storage tank 2 jointly supply gas to the gas-consuming equipment, which can ensure that the gas supply remains stable when switching from the first storage tank 1 to the second storage tank 2, and there will be no unstable gas supply or gas interruption due to failure to open the second liquid outlet valve 7 in time.

[0071] S5: Determine whether the liquid level of the first storage tank 1 drops to the second set liquid level; if so, proceed to S6, wherein the second set liquid level is below the first set liquid level, and the third set liquid level is above the first set liquid level.

[0072] S6: The second storage tank 2 supplies gas to the gas-using equipment alone, and the first storage tank 1 performs a liquid filling operation until the first storage tank 1 reaches a standby state. When the liquid level of the first storage tank 1 drops to the second set liquid level, the first liquid outlet valve 6 is closed, the first storage tank 1 stops supplying gas to the gas-using equipment, and the second liquid outlet valve 7 continues to be opened, the second storage tank 2 is used to supply gas to the gas-using equipment alone, and the first storage tank 1 is filled with liquid until the liquid level of the first storage tank 1 reaches the third set liquid level and the pressure in the tank reaches the first set pressure, so that the first storage tank 1 is in a standby state as a backup.

[0073] If the first storage tank 1 is not in the standby state when the gas supply just starts, but the second storage tank 2 is in the standby state, the second storage tank 2 is first used to supply gas to the gas-consuming equipment alone, and the first storage tank 1 is filled with liquid until the first storage tank 1 reaches the standby state. After the first storage tank 1 reaches the standby state, it can supply gas to the gas-consuming equipment at any time. At this time, the first storage tank 1 is used as a backup.

[0074] Specifically, the first storage tank 1 is filled with liquid until the first storage tank 1 reaches a standby state, including: depressurizing the first storage tank 1 until the pressure of the first storage tank 1 reaches a second set pressure; filling the first storage tank 1 until the liquid level of the first storage tank 1 reaches a third set liquid level; and pressurizing the first storage tank 1 until the pressure in the first storage tank 1 reaches the first set pressure.

[0075] The first pressure relief valve 12 is opened to relieve the pressure of the first storage tank 1 until the pressure in the first storage tank 1 is relieved to the second set pressure, and the first pressure relief valve 12 is not closed at this time. Then, the first filling valve 3 is opened to fill the first storage tank 1 with liquid. When the liquid level of the first storage tank 1 reaches the third set liquid level, the filling is stopped, and the first filling valve 3 and the first pressure relief valve 12 are closed. Finally, the first boosting valve 9 is opened to boost the pressure of the second storage tank 2 until the pressure of the first storage tank 1 reaches the first set pressure, and the first boosting valve 9 is closed.

[0076] S7: Determine whether the liquid level of the second storage tank 2 drops to the first set liquid level; if so, proceed to S8; S8: The first storage tank 1 and the second storage tank 2 jointly supply gas to the gas-using equipment. When the liquid level of the second storage tank 2 drops to the first set liquid level, keep the second liquid outlet valve 7 open, and then open the first liquid outlet valve 6, the first storage tank 1 and the second storage tank 2 jointly supply gas to the gas-using equipment, which can ensure that the gas supply is stable when switching from the second storage tank 2 to the first storage tank 1, and there will be no unstable gas supply or gas interruption due to failure to open the first liquid outlet valve 6 in time.

[0077] S9: Determine whether the liquid level of the second storage tank 2 drops to the second set liquid level; if so, proceed to S2.

[0078] When the liquid level in the second storage tank 2 drops to the second set liquid level, the second liquid outlet valve 7 is closed, the second storage tank 2 stops supplying gas, and the first liquid outlet valve 6 continues to be opened. The first storage tank 1 supplies gas to the gas-consuming equipment alone. While the first storage tank 1 is supplying gas, the second storage tank 2 is filled with liquid until the second storage tank 2 is in a standby state as a backup.

[0079] It can be understood that when the gas supply is just started, if the first storage tank 1 is in a standby state and the second storage tank 2 is not in a standby state, the cycle is S2-S3-S4-S5-S6-S7-S8-S9; if the first storage tank 1 is not in a standby state and the second storage tank 2 is in a standby state, the cycle is S6-S7-S8-S9-S2-S3-S4-S5.

[0080] It is understandable that if the first storage tank 1 and the second storage tank 2 are both in standby state when the gas supply is just started, the first storage tank 1 will supply gas first, and the second storage tank 2 will be used as a backup, and then the gas will be recycled to perform S3-S4-S5-S6-S7-S8-S9-S2.

[0081] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for automatically switching supply of low temperature storage tanks, characterized in that: Applicable to an automatic switching supply device for a low-temperature storage tank, the automatic switching supply device for a low-temperature storage tank comprising a first storage tank (1) and a second storage tank (2); The low-temperature storage tank automatic switching supply device also includes: A first liquid outlet valve (6), a second liquid outlet valve (7) and an air supply pipeline (14), wherein the inlet and outlet of the first liquid outlet valve (6) are respectively connected to the first storage tank (1) and the air supply pipeline (14), and the inlet and outlet of the second liquid outlet valve (7) are respectively connected to the second storage tank (2) and the air supply pipeline (14), and the air supply pipeline (14) is connected to a gas-consuming device; a first vaporizer (15), the first vaporizer (15) being arranged on the gas supply pipeline (14); a first filling valve (3) and a second filling valve (4), wherein the inlet and outlet of the first filling valve (3) are respectively connected to the liquid filling port (5) and the first storage tank (1); and the inlet and outlet of the second filling valve (4) are respectively connected to the liquid filling port (5) and the second storage tank (2); The low-temperature storage tank automatic switching supply device further comprises a first pressure relief valve (12) and a second pressure relief valve (13), wherein two ends of the first pressure relief valve (12) are respectively connected to the first storage tank (1) and the atmosphere; and two ends of the second pressure relief valve (13) are respectively connected to the second storage tank (2) and the atmosphere. The low-temperature storage tank automatic switching supply device further comprises a first boosting valve (9), a second vaporizer (8), a second boosting valve (11) and a third vaporizer (10), wherein the inlet and outlet of the second vaporizer (8) are respectively connected to the first storage tank (1) and the inlet of the first boosting valve (9), the outlet of the first boosting valve (9) is connected to the first storage tank (1), the inlet and outlet of the third vaporizer (10) are respectively connected to the second storage tank (2) and the inlet of the second boosting valve (11), and the outlet of the second boosting valve (11) is connected to the second storage tank (2); The method for automatically switching supply of low-temperature storage tanks comprises: S1: determining whether the first storage tank (1) and the second storage tank (2) are in a standby state; If the first storage tank (1) is in a standby state and the second storage tank (2) is not in a standby state, proceed to S2; If the first storage tank (1) is not in a standby state and the second storage tank (2) is in a standby state, proceed to S6; S2: the first storage tank (1) supplies gas to the gas-consuming equipment alone, and the second storage tank (2) performs a liquid filling operation until the second storage tank (2) reaches a standby state; S3: Determine whether the liquid level of the first storage tank (1) drops to a first set liquid level; if so, proceed to S4; S4: the first storage tank (1) and the second storage tank (2) jointly supply gas to the gas-consuming equipment; S5: determining whether the liquid level of the first storage tank (1) has dropped to a second set liquid level; if so, proceeding to S6; S6: the second storage tank (2) supplies gas to the gas-consuming equipment alone, and the first storage tank (1) performs a liquid filling operation until the first storage tank (1) reaches a standby state; S7: Determine whether the liquid level of the second storage tank (2) drops to the first set liquid level; if so, proceed to S8; S8: the first storage tank (1) and the second storage tank (2) jointly supply gas to the gas-consuming equipment; S9: Determine whether the liquid level of the second storage tank (2) drops to a second set liquid level; if so, proceed to S2; wherein the second set liquid level is below the first set liquid level; Determining whether the first storage tank (1) and the second storage tank (2) are in a standby state includes: Determining whether the liquid level of the first storage tank (1) reaches a third set liquid level and whether the pressure in the first storage tank (1) reaches a first set pressure; If both are reached, the first storage tank (1) is in a standby state; Determining whether the liquid level of the second storage tank (2) reaches the third set liquid level and whether the pressure in the second storage tank (2) reaches the first set pressure; If both are reached, the second storage tank (2) is in a standby state; Wherein, the third set liquid level is above the first set liquid level; The second storage tank (2) is filled with liquid until the second storage tank (2) reaches a standby state, comprising: Relieving the pressure of the second storage tank (2) until the pressure of the second storage tank (2) reaches a second set pressure; Filling the second storage tank (2) with liquid until the liquid level in the second storage tank (2) reaches the third set liquid level; Pressurizing the second storage tank (2) until the pressure in the second storage tank (2) reaches the first set pressure; The first storage tank (1) is filled with liquid until the first storage tank (1) reaches a standby state, comprising: Relieving the pressure of the first storage tank (1) until the pressure of the first storage tank (1) reaches a second set pressure; Filling the first storage tank (1) with liquid until the liquid level in the first storage tank (1) reaches the third set liquid level; The first storage tank (1) is pressurized until the pressure in the first storage tank (1) reaches the first set pressure.

2. The method for automatically switching and supplying low-temperature storage tanks according to claim 1, characterized in that: The low-temperature storage tank automatic switching supply device also includes a controller, and the first liquid outlet valve (6), the second liquid outlet valve (7), the first pressure relief valve (12), the second pressure relief valve (13), the first boosting valve (9) and the second boosting valve (11) are all connected to the controller.

3. The method for automatically switching and supplying low-temperature storage tanks according to claim 1, characterized in that: There are a plurality of the first vaporizers (15), and the plurality of the first vaporizers (15) are arranged in parallel.

4. The method for automatically switching and supplying low-temperature storage tanks according to claim 1, characterized in that: The low-temperature storage tank automatic switching supply device further comprises a regulating valve (16), wherein the regulating valve (16) is arranged on the gas supply pipeline (14), and an inlet and an outlet of the regulating valve (16) are respectively connected to the first vaporizer (15) and the gas-using equipment.

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