Hydrogen cryogenic cooling device and control method

Abstract

The present invention discloses a hydrogen cryogenic cooling device and control method, comprising an outer cavity, an inner cavity arranged within the outer cavity, and a buffer tank arranged within the inner cavity; the outer cavity is connected to an external liquid inlet pipe and an external liquid outlet pipe; the top of the inner cavity is connected to a hydrogen inlet pipe, which is spirally arranged in the inner cavity and connected to the top of the buffer tank; the bottom of the buffer tank is connected to a hydrogen outlet pipe; a hydrogen branch and a residual gas branch are formed at the end of the hydrogen outlet pipe; the inner cavity is also connected to an inner liquid inlet pipe and an inner liquid outlet pipe. The present invention adopts dual cooling of liquid nitrogen in the inner and outer cavities, which can cool high-pressure and high-speed hydrogen within a temperature range of 77K-298K; and the cryogenic cooling device adopts a multi-layer vacuum structure and a high-vacuum multi-layer insulation method, which has high insulation performance and is resistant to low temperatures and high pressures.

Description

Technical Field

[0001] The present invention belongs to the technical field of cryogenic cooling, and in particular relates to a hydrogen cryogenic cooling device and a control method. Background Art

[0002] The characteristics of hydrogen jets caused by hydrogen leaks, as well as the probability of ignition at different locations within the jet, are core to hydrogen safety research. They are of great significance to the quantitative risk assessment of hydrogen energy infrastructure and serve as an important basis for the formulation of relevant technical standards and safety regulations. To study the jet characteristics of cryogenic, underexpanded hydrogen, stable and controllable pre-cooling of the experimental gas is required. Existing cryogenic cooling equipment is unable to cool and stably output high-pressure, high-speed hydrogen within the temperature range of 77K-298K and lacks a design to combat hydrogen embrittlement. This poses a risk of hydrogen leaks, fails to provide a stable supply of experimental gas, and does not comply with laboratory safety regulations.

[0003] Therefore, there is an urgent need for a low-temperature cooling device that can be used to cool hydrogen and is also suitable for other experimental gases. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydrogen cryogenic cooling device and control method to solve the above problems, achieve intelligent control of the temperature and pressure of the hydrogen outlet, and realize the stable output of low-temperature hydrogen.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A hydrogen cryogenic cooling device comprises an outer cavity, an inner cavity arranged in the outer cavity, and a buffer tank arranged in the inner cavity; the outer cavity is connected to an external liquid inlet pipe and an external liquid outlet pipe;

[0007] The top of the inner cavity is connected to a hydrogen inlet pipe, which is spirally arranged in the inner cavity and is connected to the top of the buffer tank; the bottom of the buffer tank is connected to a hydrogen outlet pipe; the end of the hydrogen outlet pipe is formed with a hydrogen branch and a residual gas branch;

[0008] The inner cavity is also connected with an inner liquid inlet pipe and an inner liquid outlet pipe.

[0009] The outer cavity is also equipped with an outer cavity temperature sensor and an outer cavity liquid level gauge; the outer cavity is also connected to a nitrogen connecting pipe; the outer cavity liquid inlet pneumatic valve is installed on the outer liquid inlet pipe, and the outer cavity liquid discharge valve is installed on the outer liquid outlet pipe.

[0010] The inner cavity is also equipped with an inner cavity liquid level gauge and an inner cavity temperature sensor; the inner liquid inlet pipe is equipped with an inner cavity liquid inlet pneumatic valve, and the inner liquid outlet pipe is equipped with inner and outer cavity drain valves; the hydrogen inlet pipe is equipped with a hydrogen inlet stop valve.

[0011] The buffer tank is also equipped with a buffer tank temperature sensor and a buffer tank pressure sensor; the hydrogen outlet pipeline is equipped with a hydrogen outlet temperature sensor; the hydrogen outlet pressure sensor and a hydrogen outlet solenoid valve are installed on the hydrogen branch; and the residual gas branch is equipped with a residual gas outlet solenoid valve.

[0012] A hydrogen cryogenic cooling control method comprises the following steps:

[0013] S1 Check the air tightness of the equipment, set the liquid nitrogen height in the outer cavity and the inner cavity, the hydrogen outlet pressure and temperature parameters; open the hydrogen inlet stop valve, the external liquid inlet pipe and the internal liquid inlet pipe;

[0014] S2 temperature regulation: the hydrogen temperature at the hydrogen outlet pipeline is monitored by the hydrogen outlet temperature sensor, and the liquid nitrogen level setting value is adjusted through the feedback mechanism;

[0015] S3 liquid nitrogen level adjustment: the liquid nitrogen levels in the outer and inner cavities are monitored in real time by the outer and inner cavity liquid level gauges, and the inlet and outlet valves are controlled through the feedback mechanism until the liquid level is adjusted to the set value;

[0016] S4 pressure regulation, monitors the pressure at the hydrogen branch through the hydrogen outlet pressure sensor, and controls the outlet solenoid valve through the feedback mechanism until the outlet pressure reaches the set value;

[0017] After S5 cooling is completed, open the external liquid pipeline and the internal liquid pipeline to discharge liquid nitrogen; at the same time, open the residual gas outlet solenoid valve to discharge the residual hydrogen in the pipeline and purge it with nitrogen.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects:

[0019] 1. The present invention adopts dual cooling of liquid nitrogen in the inner and outer cavities, which can cool high-pressure and high-speed hydrogen in the temperature range of 77K-298K.

[0020] 2. The present invention monitors the hydrogen outlet temperature in real time and uses a feedback mechanism to intelligently adjust the liquid nitrogen levels in the inner and outer cavities to achieve precise control of the hydrogen outlet temperature.

[0021] 3. The cryogenic cooling equipment designed in the present invention has a built-in buffer tank, and the outlet is provided with a solenoid valve feedback adjustment to ensure stable hydrogen outlet pressure under a large mass flow rate (≥20g / s).

[0022] 4. This low-temperature cooling equipment adopts a multi-layer vacuum structure and a high vacuum multi-layer insulation method, which has high insulation performance and is resistant to low temperature and high pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work.

[0024] Figure 1 Schematic diagram of the equipment structure;

[0025] Figure 2 It is a flow chart of the control method;

[0026] Among them, 1. outer cavity; 2. outer cavity liquid inlet pneumatic valve; 3. inner cavity liquid inlet pneumatic valve; 4. outer cavity temperature sensor; 5. hydrogen inlet stop valve; 6. outer cavity liquid level gauge; 7. inner cavity; 8. outer cavity drain valve; 9. inner cavity drain valve; 10. buffer tank temperature sensor; 11. buffer tank pressure sensor; 12. buffer tank; 13. residual gas outlet solenoid valve; 14. hydrogen outlet solenoid valve; 15. hydrogen outlet pressure sensor; 16. hydrogen outlet temperature sensor; 17. inner cavity liquid level gauge; 18. inner cavity temperature sensor; 19. nitrogen connecting pipe. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the 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 efforts are within the scope of protection of the present invention.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] A hydrogen cryogenic cooling device comprises an outer cavity 1, an inner cavity 7 disposed in the outer cavity 1, and a buffer tank 12 disposed in the inner cavity 7; the outer cavity 1 is connected to an external liquid inlet pipe and an external liquid outlet pipe;

[0030] The top of the inner cavity 7 is connected to the hydrogen inlet pipe, which is spirally arranged in the inner cavity 7 and is connected to the top of the buffer tank 12; the bottom of the buffer tank 12 is connected to the hydrogen outlet pipe; the end of the hydrogen outlet pipe is formed with a hydrogen branch and a residual gas branch;

[0031] The inner cavity 7 is also connected with an inner liquid inlet pipe and an inner liquid outlet pipe.

[0032] The outer cavity 1 is also equipped with an outer cavity temperature sensor 4 and an outer cavity liquid level gauge 6; the outer cavity 1 is also connected to a nitrogen connecting pipe 19; the outer cavity liquid inlet pneumatic valve 2 is installed on the outer liquid inlet pipe, and the outer cavity liquid discharge valve 8 is installed on the outer liquid outlet pipe.

[0033] The inner cavity 7 is also equipped with an inner cavity liquid level gauge 17 and an inner cavity temperature sensor 18; the inner cavity liquid inlet pneumatic valve 3 is installed on the inner liquid inlet pipe, and the inner and outer cavity drain valves 9 are installed on the inner liquid outlet pipe; the hydrogen inlet stop valve 5 is installed on the hydrogen inlet pipe.

[0034] The buffer tank 12 is also equipped with a buffer tank temperature sensor 10 and a buffer tank pressure sensor 11; a hydrogen outlet temperature sensor 16 is installed on the hydrogen outlet pipeline; a hydrogen outlet pressure sensor 15 and a hydrogen outlet solenoid valve 14 are installed on the hydrogen branch; and a residual gas outlet solenoid valve 13 is installed on the residual gas branch.

[0035] A hydrogen cryogenic cooling control method comprises the following steps:

[0036] S1, system initialization,

[0037] S11. Check the air tightness of the equipment to avoid gas leakage. Ensure that the environment is well ventilated to prevent the accumulation of leaked gas and potential safety hazards.

[0038] S12. Activate the safety monitoring system to monitor the cooling system's operating status in real time. If overpressure or overtemperature occurs inside the cooling equipment, an audible and visual alarm will be triggered, the cooling process will be suspended, and the relief valve will be opened to release gas. If a gas leak occurs in the system, an audible and visual alarm will be triggered, the cooling process will be suspended, ventilation will be activated, and personnel will be evacuated.

[0039] S13. Set parameters such as the liquid nitrogen height of the internal and external liquid nitrogen cavities, and the pressure and temperature at the hydrogen outlet.

[0040] S14. Open the hydrogen inlet stop valve and allow hydrogen to enter the pipeline.

[0041] S15. Open the pneumatic valves for liquid inlet into the inner and outer cavities to allow liquid nitrogen to enter the inner and outer cavities, and replenish the liquid nitrogen in the cavities to a preset height.

[0042] S2, temperature regulation,

[0043] The temperature sensor at the hydrogen outlet monitors the temperature at the hydrogen outlet in real time.

[0044] S21. If the temperature at the hydrogen outlet meets the set value, keep the liquid nitrogen levels in the inner and outer cavities unchanged.

[0045] S22. If the temperature at the hydrogen outlet is lower than the set value, the liquid nitrogen level set values ​​of the inner and outer cavities are increased through the feedback mechanism until the hydrogen outlet temperature meets the set value.

[0046] S23. If the temperature at the hydrogen outlet is higher than the set value, the liquid nitrogen level set values ​​of the inner and outer cavities are reduced through the feedback mechanism until the hydrogen outlet temperature meets the set value.

[0047] S3, liquid nitrogen level adjustment,

[0048] The internal and external cavity liquid level gauges monitor the liquid nitrogen levels in the internal and external cavities in real time.

[0049] S31. If the liquid level height of the inner and outer cavities is higher than the set value, the drain solenoid valve opens and the liquid nitrogen in the cavity is discharged. When the set liquid level is reached, the drain solenoid valve closes and stops draining.

[0050] S32. If the liquid level heights of the inner and outer cavities are lower than the set value, the liquid inlet pneumatic valve opens and liquid nitrogen is input into the cavity until the set liquid level is reached.

[0051] S4, pressure regulation,

[0052] The hydrogen outlet pressure sensor monitors the pressure at the hydrogen outlet in real time.

[0053] S41. When the pressure at the hydrogen outlet reaches the set value, the low-temperature solenoid valve at the hydrogen outlet opens and the hydrogen is discharged.

[0054] S42. If the pressure at the hydrogen outlet is higher than the set value, open the solenoid valve at the residual gas outlet and adjust the opening until the hydrogen outlet pressure meets the set value.

[0055] S43. If the pressure at the hydrogen outlet is lower than the set value, the solenoid valve at the hydrogen outlet is closed until the pressure reaches the set value and the solenoid valve at the hydrogen outlet is opened again.

[0056] S5, cooling is completed,

[0057] S51. Export and save the work data.

[0058] S52, opening the two residual liquid discharge pneumatic valves to discharge the heat exchange medium inside the cavity.

[0059] S53. Open the residual hydrogen gas discharge valve to discharge the residual hydrogen in the system pipeline and purge it with nitrogen.

[0060] S54. Confirm that the readings of each sensor meet the shutdown conditions, close all valves and control systems, and turn off the power.

[0061] In one embodiment of the present invention, the external cavity liquid level setting value is 500mm, the external cavity liquid level upper limit is 550mm, and the external cavity liquid control range is 10mm; the internal cavity liquid level upper limit is 800mm, the internal cavity liquid level setting value is 700mm, and the internal cabinet liquid control range is 10mm; the exhaust temperature range is 1°C, the exhaust temperature setting value is -170°C; the pressure upper limit is 10MPa.

[0062] In one embodiment of the present invention, the device adopts a multi-layer vacuum structure, in which the inner cavity 7 is made of 316L stainless steel and the outer cavity 1 is made of 304 stainless steel with a thickness of 3 mm. In order to improve the thermal insulation performance of the low-temperature cooling equipment, a high vacuum multi-layer insulation method is adopted, and palladium oxide and molecular sieve are used for moisture and oxygen absorption treatment to ensure the long-lasting vacuum degree of the interlayer.

[0063] In one embodiment of the present invention, the pipelines in the device are all made of 1 / 2BA grade or above hydrogen-resistant stainless steel pipes, and are connected by airtight interfaces to avoid gas leakage.

[0064] In one embodiment of the present invention, the device is also equipped with a safety detection system to reduce the risk of accidents caused by overpressure, overtemperature and gas leakage in the system.

[0065] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0066] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A hydrogen cryogenic cooling device, characterized in that: include: An outer cavity (1), an inner cavity (7) disposed within the outer cavity (1), and a buffer tank (12) disposed within the inner cavity (7); the outer cavity (1) is connected to an external liquid inlet pipe and an external liquid outlet pipe; The top of the inner cavity (7) is connected to a hydrogen inlet pipeline, the hydrogen inlet pipeline is spirally arranged in the inner cavity (7), and the hydrogen inlet pipeline is connected to the top of the buffer tank (12); the bottom of the buffer tank (12) is connected to a hydrogen outlet pipeline; the end of the hydrogen outlet pipeline is formed with a hydrogen branch and a residual gas branch; The inner cavity (7) is also connected to an inner liquid inlet pipe and an inner liquid outlet pipe; The outer cavity (1) is also equipped with an outer cavity temperature sensor (4) and an outer cavity liquid level gauge (6); the outer cavity (1) is also connected to a nitrogen connection pipe (19); the outer cavity liquid inlet pneumatic valve (2) is installed on the outer liquid inlet pipe, and the outer cavity liquid discharge valve (8) is installed on the outer liquid outlet pipe; The inner cavity (7) is also equipped with an inner cavity liquid level gauge (17) and an inner cavity temperature sensor (18); the inner liquid inlet pipe is equipped with an inner cavity liquid inlet pneumatic valve (3), and the inner liquid outlet pipe is equipped with inner and outer cavity liquid discharge valves (9); the hydrogen inlet pipe is equipped with a hydrogen inlet stop valve (5); The buffer tank (12) is also equipped with a buffer tank temperature sensor (10) and a buffer tank pressure sensor (11); the hydrogen outlet pipeline is equipped with a hydrogen outlet temperature sensor (16); the hydrogen outlet pressure sensor (15) and a hydrogen outlet solenoid valve (14) are equipped on the hydrogen branch line; and the residual gas branch line is equipped with a residual gas outlet solenoid valve (13); The device adopts a multi-layer vacuum structure, wherein the inner cavity (7) is made of 316L stainless steel, and the outer cavity (1) is made of 304 stainless steel.

2. A hydrogen cryogenic cooling control method, comprising the hydrogen cryogenic cooling device according to claim 1, characterized in that: The following steps are involved: S1. Check the air tightness of the equipment, set the liquid nitrogen height in the outer cavity and the inner cavity, the hydrogen outlet pressure and temperature parameters; open the hydrogen inlet stop valve, the outer liquid inlet pipe and the inner liquid inlet pipe; S2, temperature regulation, monitors the hydrogen temperature at the hydrogen outlet pipeline through the hydrogen outlet temperature sensor, and adjusts the liquid nitrogen level set value through the feedback mechanism; S3, liquid nitrogen level adjustment, using the external cavity liquid level gauge and the internal cavity liquid level gauge to monitor the liquid nitrogen levels in the external cavity and the internal cavity in real time, and controlling the liquid inlet valve and the liquid discharge valve through the feedback mechanism until the liquid level is adjusted to the set value; S4, pressure regulation, monitors the pressure at the hydrogen branch through the hydrogen outlet pressure sensor, and controls the outlet solenoid valve through the feedback mechanism until the outlet pressure reaches the set value; S5. After cooling is completed, open the external liquid pipeline and the internal liquid pipeline to discharge liquid nitrogen; at the same time, open the residual gas outlet solenoid valve to discharge the residual hydrogen in the pipeline and purge it with nitrogen.

Images