A dual-valve linkage vacuum filling device for liquid hydrogen storage tank and its use method

Abstract

The present invention provides a dual-valve linkage vacuum filling device for a liquid hydrogen storage tank and a method of using the device, comprising: a filling container, which is arranged at the top of the liquid hydrogen storage tank and is connected to a filling pump at its upper part, and its bottom is connected to the vacuum layer of the liquid hydrogen storage tank; a dual-valve mechanism, comprising a filling valve arranged between the upper part of the filling container and the filling pump, and a connecting valve arranged between the lower part of the filling container and the liquid hydrogen storage tank; a vacuum pumping mechanism, comprising a vacuum pumping assembly connected to the filling container through an exhaust pipeline, and a pressure sensor arranged in the filling container; a controller, which is respectively connected to the filling pump, the filling valve, the connecting valve, the vacuum pumping assembly and the pressure sensor, and is used to first load the filling container with filling material, then draw a certain vacuum on the filling container, and finally allow the filling material to fall into the vacuum layer of the liquid hydrogen storage tank. The present invention solves the technical problems of the prior art, which are long and inefficient due to the method of first filling and then vacuuming, and are prone to uneven filling and substandard vacuum.

Description

Technical Field

[0001] The present invention relates to the technical field of filling liquid hydrogen storage tanks, and in particular to a double-valve linkage vacuum filling device for liquid hydrogen storage tanks and a method of using the same. Background Art

[0002] Liquid hydrogen storage tanks are widely used in aerospace, energy storage, hydrogen fuel supply, and other fields. Their low-temperature storage characteristics require liquid hydrogen tanks to possess efficient thermal insulation capabilities. Currently, large liquid hydrogen storage tanks primarily utilize a medium or low vacuum method combined with filling with insulating materials (such as hollow glass microspheres and perlite) to reduce heat conduction. However, existing large liquid hydrogen storage tanks typically employ a one-time filling process with insulating materials (such as glass microspheres) followed by vacuuming. The presence of a large number of glass microspheres hinders gas discharge, resulting in long construction cycles, low efficiency, and the potential for problems such as uneven filling and substandard vacuum levels.

[0003] In response to the above problems, the present invention provides an optimized design that combines a filling device with an exhaust device, which can improve the vacuuming efficiency, speed up the construction speed and ensure the uniform filling of the insulation material. Summary of the Invention

[0004] The purpose of the present invention is to provide a dual-valve linkage vacuum filling device for liquid hydrogen storage tanks and a method of using the same, which solves the above-mentioned technical problems of long construction period, low efficiency, uneven filling and substandard vacuum.

[0005] This embodiment provides a dual-valve linkage vacuum filling device for a liquid hydrogen storage tank, comprising:

[0006] A filling container is provided on the top of the liquid hydrogen storage tank, and a filling pump is connected to the upper portion thereof, and the bottom thereof is used to communicate with the vacuum layer of the liquid hydrogen storage tank;

[0007] a dual-valve mechanism comprising a filling valve disposed between the upper portion of the filling container and the filling pump, and a connecting valve disposed between the lower portion of the filling container and the liquid hydrogen storage tank;

[0008] A vacuum pumping mechanism, comprising a vacuum pumping assembly connected to the filling container via an air extraction pipeline, and a pressure sensor provided on the filling container;

[0009] The controller is respectively connected to the filling pump, the filling valve, the connecting valve, the vacuum pumping assembly and the pressure sensor, and is used to first load the filling container with filling materials, then draw a certain vacuum on the filling container, and finally allow the filling materials to fall into the vacuum layer of the liquid hydrogen storage tank.

[0010] Furthermore, the controller has the following built-in modules:

[0011] Control module;

[0012] A vacuum pump switching module is connected to the control module and is used to automatically control the start and stop of the vacuum pumping component according to the vacuum degree data fed back by the pressure sensor;

[0013] The valve linkage module is connected to the control module and is used to control the opening and closing of the filling valve and the connecting valve and the working state of the filling pump according to the process of first filling, then vacuuming and finally blanking.

[0014] Furthermore, the vacuum pumping assembly includes a low vacuum pump first used for rough pumping and then a high vacuum pump used for fine pumping.

[0015] Furthermore, the low vacuum pump adopts a pump group consisting of a Roots pump and a rotary vane pump connected in series, and the high vacuum pump adopts a molecular pump.

[0016] Furthermore, it also includes a heating mechanism, which includes a heating belt wrapped around the outer wall of the filling container, a temperature sensor embedded in the inner wall of the container, and a PID temperature control module connected to the heating belt and the temperature sensor;

[0017] The controller also has a built-in temperature control module connected to the control module, which is used to dynamically adjust the power of the heating belt according to the PID temperature control module data to maintain a constant temperature state.

[0018] Furthermore, the filling container is a funnel-shaped container with a cone angle of 40° to 50°, and the inner wall is nano-coated or mirror-polished.

[0019] Furthermore, a filter blanket is provided at the inlet of the filling container that is connected to the air extraction pipeline. The pore size of the filter blanket is smaller than that of the filling material and the filter blanket is detachable and replaceable.

[0020] Furthermore, a bellows compensator is provided at the connection between the exhaust pipeline and the filling container to absorb thermal expansion and contraction deformation.

[0021] This embodiment also provides a method for using a dual-valve linkage vacuum packing device for a liquid hydrogen storage tank. The method is used for the aforementioned dual-valve linkage vacuum packing device for a liquid hydrogen storage tank, and the method includes the following steps:

[0022] S1. First, evacuate the vacuum layer of the liquid hydrogen storage tank by using an external vacuum pump or the vacuum pumping mechanism to reach a target vacuum degree;

[0023] S2. Close the connecting valve and open the filling valve. The filling pump starts to inject a certain amount of filling into the filling container through the feeding pipe.

[0024] S3. Close the filling valve and start the vacuum mechanism to evacuate the filling container. First, use the low vacuum pump to roughly evacuate the filling container. When the pressure drops to a certain level, switch to the high vacuum pump to perform fine evacuation until the pressure reaches the target vacuum degree.

[0025] S4. After reaching the target vacuum degree, the controller controls the opening of the connecting valve to allow the filler in the filler container to fall into the vacuum layer of the liquid hydrogen storage tank under the action of gravity; the S2-S4 operations are cycled, and the "filling → vacuuming → blanking" process is repeated until the vacuum layer is filled with a certain amount of filler.

[0026] This embodiment also provides another method for using a dual-valve linkage vacuum packing device for a liquid hydrogen storage tank. The method is used for the aforementioned dual-valve linkage vacuum packing device for a liquid hydrogen storage tank, and the method includes the following steps:

[0027] S1. First, evacuate the vacuum layer of the liquid hydrogen storage tank by using an external vacuum pump or the vacuum pumping mechanism to reach a target vacuum degree;

[0028] S2, start the heating mechanism to heat the filling container through the heating belt, and the heating temperature is controlled by the PID temperature control module;

[0029] S3. Close the connecting valve and open the filling valve. The filling pump starts to inject a certain amount of filling into the filling container through the filling delivery pipe.

[0030] S4. Close the filling valve and start the vacuum mechanism to evacuate the filling container. First, use the low vacuum pump to roughly evacuate the filling container. When the pressure drops to a certain level, switch to the high vacuum pump to perform fine evacuation until the pressure reaches the target vacuum level.

[0031] S5. The controller controls the opening of the connecting valve to allow the filler in the filler container to fall into the vacuum layer of the liquid hydrogen storage tank under the action of gravity; the S3-S5 operations are cycled, and the "filling → vacuuming → blanking" process is repeated until the vacuum layer is filled with a certain amount of filler.

[0032] Compared with the prior art, the beneficial effects achieved by the present invention include at least:

[0033] The vacuum filling device combines a filling container with a vacuum pumping mechanism to achieve synchronous operation of vacuum pumping and filling. Since the glass microspheres fall freely in a vacuum environment rather than being affected by airflow or external interference, they are less likely to form segregation or uneven accumulation during the filling process, which helps to improve the uniformity of the vacuum layer, filling efficiency and vacuum degree to meet standards. The controller realizes fully automated operation of vacuum pump switching, valve linkage and temperature control, reducing manual intervention, operational errors and risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 A schematic structural diagram of a dual-valve linkage vacuum packing device for a liquid hydrogen storage tank provided in this embodiment;

[0036] Figure 2 A flow chart of a method for using the dual-valve linkage vacuum filling device for a liquid hydrogen storage tank provided in this embodiment.

[0037] icon:

[0038] 10-filling container; 20-liquid hydrogen storage tank; 30-filling pump;

[0039] 40-Dual valve mechanism; 41-Masking valve; 42-Connecting valve;

[0040] 50-vacuum pumping mechanism; 51-vacuum pumping assembly; 52-pressure sensor;

[0041] 60-controller;

[0042] 70-heating mechanism; 71-heating belt; 72-temperature sensor; 73-PID temperature control module;

[0043] 80-Glass microspheres. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. 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 shall fall within the scope of protection of the present invention.

[0045] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0046] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0047] The present invention provides a double valve linkage vacuum packing device for liquid hydrogen storage tanks, please refer to Figure 1 As shown, it includes a filling container 10, a filling pump 30, a double valve mechanism 40, a vacuum mechanism 50, a controller 60 and a heating mechanism 70.

[0048] Among them, the filling container 10 adopts a funnel-shaped container, which is connected to the top of the liquid hydrogen storage tank 20 and is connected to the vacuum layer of the liquid hydrogen storage tank 20 through a connecting pipe, serving as a vacuum space; the volume of the funnel-shaped container can be 5% of the volume of the vacuum layer of the liquid hydrogen storage tank 20, the cone angle can be 40°~50°, the inner wall is nano-coated or mirror-polished, and the material is 304 stainless steel; the interface between the feeding pipe and the funnel-shaped container adopts a flange sealing structure and is fixed to the top of the storage tank by bolts; in addition, the funnel-shaped container is smaller in size and simpler in structure than the annular vacuum layer, and can directly contact the external environment. The open structure of the funnel can also reduce powder residue, and the cleaning process is convenient and quick, reducing maintenance time and improving production efficiency.

[0049] The dual-valve mechanism 40 includes a filling valve 41 provided at the top of the funnel-shaped container and a connecting valve 42 at the bottom, which are used to control the communication state between the filling container 10 and the vacuum layer of the liquid hydrogen storage tank 20. In the dual-valve mechanism 40, the filling valve 41 can be a pneumatic butterfly valve located at the feed port at the top of the funnel-shaped container; the connecting valve 42 can be an electric stop valve located between the bottom of the funnel-shaped container and the storage tank. Specifically, the feed valve on the storage tank can be used as the connecting valve 42. Both the filling valve 41 and the connecting valve 42 are connected to the controller 60 (mostly a PLC controller) via signal lines and are opened and closed according to a preset program.

[0050] The vacuum mechanism 50 includes a vacuum assembly 51 connected to the filling container 10 and a pressure sensor 52 provided on the filling container 10; the vacuum assembly 51 is connected to the funnel-shaped container through an exhaust pipe to vacuum the funnel-shaped container; the vacuum assembly 51 includes a low vacuum pump group and a high vacuum pump, the low vacuum pump group is composed of a roots pump and a rotary vane pump in series, and is used to initially vacuum the funnel-shaped container to 100 Pa; the high vacuum pump is a molecular pump, which increases the vacuum degree in the funnel-shaped container to 6.67Pa by further vacuuming; the low vacuum pump group and the high vacuum pump work together to significantly shorten the construction time and improve the construction efficiency; the optimized design of the vacuum pump group reduces energy consumption, and the device uses a molecular pump as a high vacuum pump. Compared with the diffusion pump, the molecular pump has many advantages such as energy saving, environmental protection, and cost saving; in addition, the inlet of the exhaust pipe is covered with a filter blanket to prevent the glass microspheres 80 from entering the pipe while allowing gas to pass through; the filter blanket can be fixed to the inner wall of the pipe by a clamp, which is convenient for disassembly and cleaning; in addition, the pressure sensor 52 is embedded in the funnel-shaped container for real-time monitoring of the vacuum degree in the funnel and feedback to the controller 60; in addition, a bellows compensator is provided at the connection between the exhaust pipe and the funnel-shaped container to absorb thermal expansion and contraction deformation.

[0051] The controller 60 is connected to the dual valve mechanism 40, heating mechanism 70, vacuum mechanism 50, temperature sensor 72, stuffing pump 30, and pressure sensor 52 via signal lines to achieve fully automated operation. The controller 60 has the following built-in functional modules: a control module; a vacuum pump switching module, connected to the control module, for automatically controlling the start and stop of the low vacuum pump group and the high vacuum pump according to the vacuum degree data fed back by the pressure sensor 52; a valve linkage module, connected to the control module, for controlling the opening and closing of the stuffing valve 41 and the connecting valve 42 and the working state of the stuffing pump 30 according to the "stuffing → vacuum → blanking" process; and a temperature control module, connected to the control module, for dynamically adjusting the power of the heating belt 71 according to the data of the PID temperature control module 73 to maintain a constant temperature.

[0052] The heating mechanism 70 includes a heating belt 71 wound around the outer wall of the funnel-shaped container, a temperature sensor 72 embedded in the inner wall of the container, a PID temperature control module 73 connecting the heating belt 71 and the temperature sensor 72, and a heat-insulating material outside the heating belt. The heating belt 71 can be evenly wound around the outer wall of the funnel-shaped container in a spiral manner, and the heating temperature can be 40-80°C, and the specific heating temperature is adjusted according to the vacuum pumping rate. The outer covering of the heat-insulating material can reduce heat loss and make heating more uniform. The temperature sensor 72 is embedded in the inner wall of the funnel-shaped container and is connected to the PID temperature control module 73 via a signal line, and the temperature data is fed back to the controller 60 in real time.

[0053] This embodiment also provides a method for using a dual-valve linkage vacuum packing device for a liquid hydrogen storage tank. The method is used for the vacuum packing device, wherein the vacuum packing device includes a heating mechanism 70, and the vacuum assembly 51 includes a low vacuum pump group and a high vacuum pump; please refer to Figure 2 As shown, the method includes the following steps:

[0054] Step 1: Before the device is officially put into operation, the annular vacuum layer of the storage tank is first evacuated using an external vacuum pump or the vacuum pumping mechanism 50. When an external vacuum pump is used, it can be directly connected to the vacuum port of the storage tank for evacuation. Similarly, in addition to evacuating the storage tank through the filling container, the vacuum pumping mechanism 50 can also be connected to the vacuum port of the storage tank for evacuation through another vacuum pipe. When pre-evacuating the storage tank, since there are no glass microspheres 80 to obstruct the airflow, the evacuation time is short and the target vacuum degree can be quickly reached. In this way, in the subsequent filling process, only a short vacuum is required on the funnel-shaped container, thereby improving overall efficiency.

[0055] Step 2: Before filling, the funnel-shaped container is pre-treated. Heating mechanism 70 is activated, and heating belt 71 spirally wraps around the outer wall of the funnel-shaped container to uniformly heat it. The temperature is controlled by PID temperature control module 73 within a range of 40-80°C, determined by the vacuum pumping rate. During the heating process, temperature sensor 72 monitors the container's inner wall temperature in real time to ensure sufficient desorption of adsorbed moisture and volatile substances, thereby reducing resistance during the subsequent vacuum pumping phase.

[0056] Step 3: Filling operation: close the connecting valve 42 and open the filling valve 41, and the filling pump 30 starts to work, and the hollow glass microspheres 80 are injected into the funnel-shaped container through the glass microsphere 80 delivery pipeline.

[0057] Step 4: After the funnel-shaped container is filled to a certain extent, such as when it is full, the filling valve 41 is closed and the vacuum mechanism 50 is started to vacuum the funnel-shaped container. This process is divided into two stages, including a low vacuum stage, in which the funnel-shaped container is first roughly evacuated by the low vacuum pump group, and the pressure sensor 52 monitors the pressure change in real time; when the pressure drops to 100 Pa or ≤100 Pa, the controller 60 triggers a switching instruction to enter the high vacuum stage; in this stage, the low vacuum pump group is turned off and the molecular pump is started for fine vacuuming, and the vacuuming is continued until the pressure reaches 6.67 Pa (corresponding to 5×10⁻² Torr). This vacuum degree can effectively eliminate the influence of residual gas in the gaps between microspheres on the thermal insulation performance.

[0058] Step 5: Controller 60 controls the opening of connecting valve 42. Under the influence of gravity, hollow glass microspheres 80 slide evenly along the conical surface of the funnel into the vacuum layer of the storage tank. The "filling → vacuuming → dropping" process repeats until the vacuum layer is filled to a certain level, such as completely. Furthermore, the filling volume of filling container 10 can be controlled by the pumping volume per unit time and the pumping time. The filling volume of the vacuum layer of the storage tank can be controlled based on the pre-filled volume of filling container 10, the ratio of the filling volume to the vacuum layer filling volume, and the number of filling cycles.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A double-valve linkage vacuum filling device for liquid hydrogen storage tanks, characterized in that: include: A filling container (10) is arranged on the top of the liquid hydrogen storage tank (20), and the upper portion thereof is connected to a filling pump (30), and the bottom portion thereof is used to communicate with the vacuum layer of the liquid hydrogen storage tank (20); A dual valve mechanism (40) comprising a filling valve (41) disposed between an upper portion of the filling container (10) and the filling pump (30), and a connecting valve (42) disposed between a lower portion of the filling container (10) and the liquid hydrogen storage tank (20); A vacuum pumping mechanism (50) comprising a vacuum pumping assembly (51) connected to the filling container (10) via an air extraction pipeline, and a pressure sensor (52) provided on the filling container (10); The controller (60) is respectively connected to the filling pump (30), the filling valve (41), the connecting valve (42), the vacuum pumping assembly (51) and the pressure sensor (52), and is used to first load the filling container (10), then evacuate the filling container (10) to a certain vacuum, and finally allow the filling to fall into the vacuum layer of the liquid hydrogen storage tank (20).

2. The double-valve linkage vacuum filling device for liquid hydrogen storage tanks according to claim 1, characterized in that: The controller (60) has the following built-in modules: Control module; A vacuum pump switching module is connected to the control module and is used to automatically control the start and stop of the vacuum pumping component (51) according to the vacuum degree data fed back by the pressure sensor (52); The valve linkage module is connected to the control module and is used to control the opening and closing of the filling valve (41) and the connecting valve (42) and the working state of the filling pump (30) according to the process of first filling, then vacuuming and finally blanking.

3. The double-valve linkage vacuum filling device for liquid hydrogen storage tanks according to claim 2, characterized in that: The vacuum pumping assembly (51) comprises a low vacuum pump for rough pumping first and a high vacuum pump for fine pumping later.

4. The double-valve linkage vacuum filling device for liquid hydrogen storage tanks according to claim 3, characterized in that: The low vacuum pump adopts a pump group consisting of a Roots pump and a rotary vane pump connected in series, and the high vacuum pump adopts a molecular pump.

5. The double-valve linkage vacuum filling device for liquid hydrogen storage tanks according to claim 3, characterized in that: The device further comprises a heating mechanism (70), wherein the heating mechanism (70) comprises a heating belt (71) wound around the outer wall of the filling container (10), a temperature sensor (72) embedded in the inner wall of the container, and a PID temperature control module (73) connected to the heating belt (71) and the temperature sensor (72); The controller (60) also has a built-in temperature control module connected to the control module, which is used to dynamically adjust the power of the heating belt (71) according to data from the PID temperature control module (73) to maintain a constant temperature state.

6. The double-valve linkage vacuum filling device for liquid hydrogen storage tanks according to claim 1, characterized in that: The filling container (10) is a funnel-shaped container with a cone angle of 40° to 50°, and its inner wall is subjected to nano-coating or mirror polishing.

7. The double-valve linkage vacuum filling device for liquid hydrogen storage tanks according to claim 1, characterized in that: A filter blanket is provided at the inlet of the filling container (10) that is in communication with the air extraction pipeline. The filter blanket has a pore size smaller than that of the filling material and is detachable and replaceable.

8. The double-valve linkage vacuum filling device for liquid hydrogen storage tanks according to claim 1, characterized in that: A bellows compensator is provided at the connection between the exhaust pipeline and the filler container (10) for absorbing thermal expansion and contraction deformation.

9. A method for using a double-valve linkage vacuum packing device for a liquid hydrogen storage tank, characterized in that: The method of use is used for the double-valve linkage vacuum filling device for a liquid hydrogen storage tank according to claim 3, and the method of use comprises the following steps: S1, first evacuating the vacuum layer of the liquid hydrogen storage tank (20) by an external vacuum pump or the vacuum pumping mechanism (50) to achieve a target vacuum degree; S2, closing the connecting valve (42) and opening the filling valve (41), the filling pump (30) works, and injects a certain amount of filling into the filling container (10) through the feeding pipe; S3, closing the filling valve (41), starting the vacuum pumping mechanism (50) to vacuum the filling container (10); firstly, roughly pumping the filling container (10) by using a low vacuum pump, and when the pressure drops to a certain level, switching to a high vacuum pump to perform fine pumping until the pressure reaches the target vacuum degree; S4, the controller (60) controls the opening of the connecting valve (42), so that the filler in the filler container (10) falls into the vacuum layer of the liquid hydrogen storage tank (20) under the action of gravity; the S2-S4 operations are circulated, and the "filling → vacuuming → dropping" process is repeated until a certain amount of filler is filled in the vacuum layer.

10. A method for using a double-valve linkage vacuum filling device for a liquid hydrogen storage tank, characterized in that: The method of use is used for the double-valve linkage vacuum filling device for a liquid hydrogen storage tank according to claim 5, and the method of use comprises the following steps: S1, first evacuating the vacuum layer of the liquid hydrogen storage tank (20) by an external vacuum pump or the vacuum pumping mechanism (50) to achieve a target vacuum degree; S2, starting the heating mechanism (70) to heat the filling container (10) via the heating belt (71), and the heating temperature is controlled by the PID temperature control module (73); S3, closing the connecting valve (42) and opening the filling valve (41), the filling pump (30) operates, and injects a certain amount of filling into the filling container (10) through the filling delivery pipe; S4, closing the filling valve (41), starting the vacuum pumping mechanism (50) to vacuum the filling container (10); firstly, roughly pumping the filling container (10) by using a low vacuum pump, and when the pressure drops to a certain level, switching to a high vacuum pump to perform fine pumping until the pressure reaches the target vacuum degree; S5. The controller (60) controls the opening of the connecting valve (42) so that the filler in the filler container (10) falls into the vacuum layer of the liquid hydrogen storage tank (20) under the action of gravity; the operations S3-S5 are circulated, and the "filling → vacuuming → dropping" process is repeated until a certain amount of filler is filled in the vacuum layer.

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