A lightweight pressurization device and method for a liquid hydrogen storage tank

Abstract

The present invention discloses a lightweight pressurization device and method for a liquid hydrogen storage tank. In the self-pressurization process of a conventional liquid hydrogen storage and supply system, the high-pressure hydrogen gas after vaporizing the liquid hydrogen is usually decompressed to a set pressure through a regulating valve, and then introduced into the liquid hydrogen storage tank for pressurization, and the hydrogen gas outlet pressure of the regulating valve is changed according to the actual outlet flow rate of the liquid hydrogen storage tank. However, the components such as the regulating valve and flowmeter in the above structure are relatively heavy, and it is difficult to adapt to working conditions with high requirements for lightweight indicators such as aircraft carriers. The present invention uses an electronically controlled hydrogen gas cut-off valve with a simple structure to replace large-volume and heavy components such as the regulating valve and flowmeter in the conventional liquid hydrogen storage and supply system, and at the same time changes the opening frequency of the electronically controlled hydrogen gas cut-off valve to achieve the purpose of regulating different liquid hydrogen flow rates, ultimately improving the storage weight ratio of the liquid hydrogen storage and supply system and the regulation accuracy of the liquid hydrogen flow rate.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy, and particularly relates to a lightweight pressurization device and method for a liquid hydrogen storage tank. Background Art

[0002] Hydrogen fuel vehicles have the advantage of zero carbon emissions and are regarded as the optimal solution to replace traditional energy vehicles in the future. The hydrogen storage system is an important part of hydrogen fuel vehicles and can be divided into two methods: high-pressure gaseous hydrogen storage and cryogenic liquid hydrogen storage. Compared with high-pressure gaseous hydrogen storage, for the same hydrogen storage capacity, cryogenic liquid hydrogen storage has a larger hydrogen storage capacity, as well as the characteristics of good stability and high safety, and can realize the storage and transportation of a large amount of hydrogen in various environments. Therefore, cryogenic liquid hydrogen storage is an ideal hydrogen storage technology for hydrogen fuel vehicles. However, in cryogenic liquid hydrogen storage technology, the weight of components such as liquid hydrogen storage tanks and their supporting regulating valves and pressure reducing valves accounts for a large proportion, seriously affecting the storage-weight ratio parameter of the overall system. Therefore, the lightweight of the hydrogen storage system has become an important indicator, which can reduce the cost of the hydrogen storage system, improve the product competitiveness and the driving range of the vehicle. In addition, for a liquid hydrogen storage and supply system using the self-pressurization method, due to the need to significantly reduce the pressure of the pressurizing gas, it is very difficult to adjust in small-flow working conditions, that is, it is difficult to achieve precise adjustment of low-temperature small flow. Summary of the Invention

[0003] The purpose of the present invention is to provide a lightweight pressurization device and method for a liquid hydrogen storage tank. In the self-pressurization process of a conventional liquid hydrogen storage and supply system, the high-pressure hydrogen gas after vaporizing the liquid hydrogen is usually reduced to a set pressure through a regulating valve and then introduced into the liquid hydrogen storage tank for pressurization, and the hydrogen gas outlet pressure of the regulating valve is changed according to the actual outlet flow of the liquid hydrogen storage tank. However, the components such as the regulating valve and flowmeter in the above structure are relatively heavy and difficult to adapt to working conditions with high requirements for lightweight indicators such as aircraft. To solve the above technical problems, the present invention uses an electronically controlled hydrogen gas cut-off valve with a simple structure to replace large-volume and heavy components such as the regulating valve and flowmeter in the conventional liquid hydrogen storage and supply system, and at the same time changes the opening frequency of the electronically controlled hydrogen gas cut-off valve to achieve the purpose of regulating different liquid hydrogen flows, ultimately improving the storage-weight ratio of the liquid hydrogen storage and supply system and the regulation accuracy of the liquid hydrogen flow.

[0004] The specific technical solution adopted by the present invention is as follows:

[0005] In the first aspect, the present invention provides a lightweight pressurization device for a liquid hydrogen storage tank, which includes a liquid hydrogen storage tank, a pressurization pipeline, a liquid hydrogen outflow pipeline, a pressure connection pipeline and a controller;

[0006] The pressurization pipeline is sequentially connected to the liquid phase space at the bottom of the liquid hydrogen storage tank, a pressurization vaporizer, an electronically controlled hydrogen gas cut-off valve and the gas phase space at the top of the liquid hydrogen storage tank, and is used for vaporizing a part of the liquid hydrogen in the liquid hydrogen storage tank to pressurize itself;

[0007] The liquid hydrogen outflow pipeline is successively connected to the liquid hydrogen outlet in the liquid phase space at the bottom of the liquid hydrogen storage tank, the liquid hydrogen stop valve, and the liquid hydrogen vaporizer, and then connected to the external hydrogen-using equipment, so as to input the liquid hydrogen medium inside the liquid hydrogen storage tank into the external hydrogen-using equipment;

[0008] The pressure supply pipeline is successively connected to the pressure supply pipeline between the booster vaporizer and the electronically controlled hydrogen stop valve, the pressure supply valve, and the liquid hydrogen outflow pipeline at the rear end of the hydrogen vaporizer, and is used to realize the control of the start and stop of the gas supply through the opening and closing of the pressure supply valve;

[0009] The controller is respectively connected to the electronically controlled hydrogen stop valve and the pressure sensor through signal power lines. The pressure sensor is used to detect the pressure in the gas phase space at the top of the liquid hydrogen storage tank. The electronically controlled hydrogen stop valve realizes pulsed gas supply through alternate start and stop. The controller is used to feedback and adjust the opening frequency of the electronically controlled hydrogen stop valve according to the pressure signal measured by the pressure sensor to realize the adjustment of the liquid hydrogen flow rate.

[0010] As a preference of the first aspect above, the gas phase space at the top of the liquid hydrogen storage tank is connected to an external booster gas source, and the booster gas source applies an additional pressure to the gas phase space at the top of the liquid hydrogen storage tank in addition to the self-boosting of liquid hydrogen vaporization.

[0011] As a preference of the first aspect above, the function relationship P = f(m) between the pressure P in the gas phase space at the top of the liquid hydrogen storage tank and the liquid hydrogen outlet flow rate m of the liquid hydrogen storage tank is pre-stored in the controller; when supplying hydrogen to the external hydrogen-using equipment, according to the liquid hydrogen supply flow rate target value, the corresponding gas phase space pressure target value is converted through this function relationship, and then the opening frequency of the electronically controlled hydrogen stop valve is adjusted so that the pressure value measured by the pressure sensor is maintained at this gas phase space pressure target value.

[0012] As a preference of the first aspect above, the function relationship P = f(m) is obtained by fitting the calibration test data of the liquid hydrogen storage tank lightweight pressurization device.

[0013] As a preference of the first aspect above, the function relationship P = f(m) is obtained by fitting with a unary nonlinear regression method.

[0014] As a preference of the first aspect above, the liquid hydrogen storage tank, the booster vaporizer, the liquid hydrogen outflow pipeline, the liquid hydrogen stop valve, and the liquid hydrogen vaporizer are all wrapped with heat insulation materials.

[0015] In the second aspect, the present invention provides a method for pressurizing a liquid hydrogen storage tank using the liquid hydrogen storage tank lightweight pressurization device according to any one of the schemes in the first aspect, which includes the following steps:

[0016] S1. Perform a separate calibration test on the liquid hydrogen storage tank in the liquid hydrogen storage tank lightweight booster device in advance, apply different pressures P to the internal gas phase space of the liquid hydrogen storage tank, and measure the liquid hydrogen outlet flow m of the liquid hydrogen storage tank by a flow meter respectively, and obtain the functional relationship P=f(m) between P and m by performing a univariate nonlinear regression fitting on the test data, and store it in the controller for calling;

[0017] S2. Use the lightweight booster device of the liquid hydrogen storage tank to self-pressurize and supply hydrogen to the external hydrogen-using equipment. The liquid hydrogen medium from the liquid hydrogen storage tank first enters the booster pipeline, and then enters the booster vaporizer to absorb external heat and then quickly vaporize and boost the pressure to convert into hydrogen. The electronically controlled hydrogen stop valve is continuously and alternately started and stopped at the initial frequency. During the start and stop process, part of the hydrogen enters the gas phase space at the top of the liquid hydrogen storage tank through the electronically controlled hydrogen stop valve for boosting, so that the liquid hydrogen medium at the bottom of the liquid hydrogen storage tank enters the liquid hydrogen outflow pipeline, enters the liquid hydrogen vaporizer through the liquid hydrogen stop valve, absorbs external heat and then vaporizes into hydrogen and is input into the hydrogen-using equipment;

[0018] In this process, the pressure sensor measures the pressure of the gas phase space at the top of the liquid hydrogen storage tank in real time and feeds it back to the controller. The controller calculates the real-time liquid hydrogen flow value m at the current moment according to the preset function relationship P = f(m). i , and the real-time liquid hydrogen flow value m i Compared with the target value m0 of liquid hydrogen supply flow required by hydrogen equipment, if m i If it is lower than m0, the start and stop frequency of the electronically controlled hydrogen shut-off valve will be increased. i If it is higher than m0, the start and stop frequency of the electronically controlled hydrogen shut-off valve is reduced, thereby i Maintain consistency with m0;

[0019] If the external hydrogen-using equipment stops using hydrogen and its hydrogen inlet valve is closed, the pressure-releasing valve is opened to connect the hydrogen from the booster vaporizer to the liquid hydrogen outflow pipeline at the outlet of the liquid hydrogen vaporizer through the pressure-releasing pipeline, and a pressure balanced with the top gas phase space is applied to the liquid hydrogen outlet of the liquid hydrogen storage tank to control the liquid hydrogen medium inside the liquid hydrogen storage tank to stop flowing out; if the external hydrogen-using equipment needs hydrogen again, the pressure-releasing valve is closed, and the controller is used to control the start and stop frequency of the electronically controlled hydrogen shut-off valve to adjust the liquid hydrogen flow output from the liquid hydrogen storage tank.

[0020] As a preferred embodiment of the second aspect, the target value m0 of the liquid hydrogen supply flow rate has an allowable fluctuation range centered on itself, m i If it is within this range, it is considered as m i Maintain consistency with m0, and there is no need to adjust the current start and stop frequency of the electronically controlled hydrogen shut-off valve.

[0021] It should be pointed out that the various technical features in the above preferred embodiments can be combined without conflicting with each other and do not constitute a limitation.

[0022] The prominent and beneficial technical effects of the present invention compared with the prior art are as follows: The liquid hydrogen is pressurized by using an electric globe valve with high-speed start and stop, replacing large-volume and heavy components such as regulating valves and liquid hydrogen flow meters in the conventional liquid hydrogen storage and supply system, and greatly improving the storage weight ratio of the liquid hydrogen storage and supply system. By continuously supplying gas to the liquid hydrogen storage tank in a pulsed manner through the electric globe valve with high-speed start and stop, the pressure in the gas phase space is increased orderly from low to high, realizing precise regulation of the low-temperature liquid hydrogen flow rate and effectively solving the problem of small-flow regulation in the system. By setting up a bypass pipeline, the supply of liquid hydrogen can be stopped briefly, and the overall system fluctuation caused by the conventional method of stopping liquid supply by exhausting gas in the gas phase space is effectively avoided. The overall system control strategy is simple, safe and reliable, has multiple operation modes, and is convenient for application and promotion.

[0023] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the drawings to fully understand the purpose, features and effects of the present invention. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of a lightweight pressurization device for a liquid hydrogen storage tank of the present invention.

[0025] In the figure: liquid hydrogen storage tank 1, pressurization pipeline 2, pressurization vaporizer 3, electric hydrogen globe valve 4, signal power line 5, controller 6, pressure sensor 7, liquid hydrogen outflow pipeline 8, liquid hydrogen globe valve 9, liquid hydrogen vaporizer 10, pressure connection pipeline 11, pressure connection valve 12. Detailed Embodiments

[0026] To make the above objects, features and advantages of the present invention more obvious and understandable, the detailed embodiments of the present invention will be described below in conjunction with the drawings. Many specific details are set forth in the following description to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below. The technical features in the various embodiments of the present invention can be combined correspondingly without conflict.

[0027] In the description of the present invention, it should be understood that when an element is considered to be "connected" to another element, it can be directly connected to the other element or indirectly connected, that is, there is an intermediate element. On the contrary, when an element is referred to as being "directly" connected to another element, there is no intermediate element.

[0028] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0029] See Figure 1 , in a preferred embodiment of the present invention, a lightweight pressurization device for a liquid hydrogen storage tank is provided, which mainly includes components such as a liquid hydrogen storage tank 1, a pressurization pipeline 2, a pressurization vaporizer 3, an electric control hydrogen cut-off valve 4, a signal power line 5, a controller 6, a pressure sensor 7, a liquid hydrogen outflow pipeline 8, a liquid hydrogen cut-off valve 9, a liquid hydrogen vaporizer 10, a pressure conduction pipeline 11, a pressure conduction valve 12, etc. The assembly and actuation relationships between the components will be described in detail below.

[0030] The liquid hydrogen storage tank 1 is used to store liquid hydrogen. When liquid hydrogen is injected, the inner cavity of the entire liquid hydrogen storage tank 1 will be divided into a liquid phase space at the bottom and a gas phase space at the top. The liquid hydrogen outlet of the liquid hydrogen storage tank 1 is located at the bottom of the tank. When the liquid hydrogen outlet is opened, the outflow rate is directly affected by the pressure in the gas phase space of the tank. In the self-pressurization process of a conventional liquid hydrogen storage and supply system, usually, the high-pressure hydrogen gas after vaporizing a part of the liquid hydrogen in the liquid hydrogen storage tank 1 is reduced to a set pressure through a regulating valve, and then introduced into the gas phase space at the top of the liquid hydrogen storage tank 1 for pressurization, and the hydrogen outlet pressure of the regulating valve is changed according to the actual outlet flow rate of the liquid hydrogen storage tank. In the present invention, a simple-structured and lightweight electric control hydrogen cut-off valve is used to replace large-volume and heavy components such as the regulating valve and flowmeter in the conventional liquid hydrogen storage and supply system. However, since the regulating valve is cancelled, it is impossible to directly control the pressure in the gas phase space at the top of the liquid hydrogen storage tank 1 through a valve. Therefore, in the present invention, the purpose of regulating different liquid hydrogen flow rates is achieved by changing the opening frequency of the electric control hydrogen cut-off valve 4. The electric control hydrogen cut-off valve 4 enables high-pressure hydrogen gas to enter the top of the liquid hydrogen storage tank 1 in the form of pulsed gas supply through high-frequency start and stop, and the start and stop frequency directly affects the gas supply flow rate, thereby changing the pressure in the gas phase space at the top of the liquid hydrogen storage tank 1, and finally improving the storage weight ratio and the regulation accuracy of the liquid hydrogen flow rate of the liquid hydrogen storage and supply system. The following will describe in detail how to achieve specific pressure and flow control based on the electric control hydrogen cut-off valve 4 through the cooperation of various components and pipelines.

[0031] The pressurization pipeline 2 is successively connected to the liquid phase space at the bottom of the liquid hydrogen storage tank 1, the pressurization vaporizer 3, the electronically controlled hydrogen cut-off valve 4, and the gas phase space at the top of the liquid hydrogen storage tank 1. The pressurization vaporizer 3 is used to vaporize a part of the liquid hydrogen flowing out of the liquid hydrogen storage tank 1 to form high-pressure hydrogen. The heat source for vaporization can come from air, external working medium, or by means of electric heating, etc. The electronically controlled hydrogen cut-off valve 4 can achieve high-speed start and stop under the control of an external power supply in the controller. When it is opened, a small amount of hydrogen will pass through, gradually increasing the pressure value inside the gas phase space of the liquid hydrogen storage tank, so that the high-pressure hydrogen can enter the top of the liquid hydrogen storage tank 1 in the form of pulsed gas supply, thereby pressurizing the liquid hydrogen storage tank itself.

[0032] The liquid hydrogen outflow pipeline 8 is successively connected to the liquid hydrogen outlet at the bottom liquid phase space of the liquid hydrogen storage tank 1, the liquid hydrogen cut-off valve 9, and the liquid hydrogen vaporizer 10, and then connected to an external hydrogen-using device, inputting the liquid hydrogen medium inside the liquid hydrogen storage tank 1 into the external hydrogen-using device. The liquid hydrogen cut-off valve 9 can control the on-off of the liquid hydrogen outflow pipeline 8. The liquid hydrogen vaporizer 10 can vaporize the liquid hydrogen transported from the liquid hydrogen storage tank 1 according to the hydrogen demand of the external hydrogen-using device, and then input it into the external hydrogen-using device. The specific form of the hydrogen-using device is not limited, and it can be a power system such as a hydrogen engine or a hydrogen fuel cell.

[0033] The pressure connection pipeline 11 is successively connected to the pressurization pipeline 2 between the pressurization vaporizer 3 and the electronically controlled hydrogen cut-off valve 4, the pressure connection valve 12, and the liquid hydrogen outflow pipeline 8 at the rear end of the liquid hydrogen vaporizer 10, and is used to realize the control of the start and stop of gas supply of the liquid hydrogen storage and supply system through the opening and closing of the pressure connection valve 12. The principle of realizing the control of the start and stop of gas supply of the liquid hydrogen storage and supply system by the opening and closing of the pressure connection valve 12 is to utilize the pressure balance between the gas phase space and the liquid hydrogen outlet of the liquid hydrogen storage tank 1. When the pressure connection valve 12 is closed, the high-pressure hydrogen generated by the pressurization vaporizer 3 only enters the gas phase space at the top of the liquid hydrogen storage tank 1. Therefore, the pressure of the gas phase space at the top of the liquid hydrogen storage tank 1 is higher than the pressure of the liquid hydrogen outlet, and the internal liquid hydrogen will be pressed out of the liquid hydrogen storage tank 1 under the pressure difference, and the greater the pressure difference, the greater the outflow rate. However, when the pressure connection valve 12 is opened, the high-pressure hydrogen generated by the pressurization vaporizer 3 will not only enter the gas phase space at the top of the liquid hydrogen storage tank 1, but also be connected between the hydrogen vaporizer 10 and the external hydrogen-using device along the pressure connection pipeline 11. Since the intake valve at the front end of the external hydrogen-using device is closed when it is not using hydrogen, the hydrogen pressure in the pressure connection pipeline 11 will be transmitted to the liquid hydrogen outlet of the liquid hydrogen storage tank 1 through the liquid hydrogen outflow pipeline 8, so that the pressure of the gas phase space at the top of the liquid hydrogen storage tank 1 is no longer higher than the pressure of the liquid hydrogen outlet, the pressure difference is balanced, and the flow rate at the liquid hydrogen outlet quickly drops to 0. Thus, the pressure connection valve 12 can be used to quickly stop the gas supply and quickly resume the gas supply of the liquid hydrogen storage and supply system.

[0034] Since the above-mentioned liquid hydrogen flow rate is controlled by changing the pressure in the gas phase space of the liquid hydrogen storage tank 1, a controller 6 is provided in the present invention for feedback control. The controller 6 is respectively connected to the electronically controlled hydrogen cut-off valve 4 and the pressure sensor 7 through signal power lines 5, and the three constitute a feedback control system. The sensing end of the pressure sensor 7 extends into the gas phase space at the top of the liquid hydrogen storage tank 1 for detecting the pressure in the gas phase space at the top of the liquid hydrogen storage tank 1. The electronically controlled hydrogen cut-off valve 4 realizes pulsed gas supply by alternately starting and stopping. The controller 6 is used to feedback and adjust the opening frequency of the electronically controlled hydrogen cut-off valve 4 according to the pressure signal measured by the pressure sensor 7 to achieve liquid hydrogen flow rate adjustment.

[0035] In an embodiment of the present invention, the function relationship P = f(m) between the pressure P in the gas phase space at the top of the liquid hydrogen storage tank 1 and the liquid hydrogen outlet flow rate m of the liquid hydrogen storage tank 1 can be pre-stored in the controller 6. When supplying hydrogen to an external hydrogen-using device, according to the target value m0 of the liquid hydrogen supply flow rate, the corresponding target value P0 of the pressure in the gas phase space at the top is converted through the function relationship P = f(m), and then the opening frequency of the electronically controlled hydrogen cut-off valve 4 is adjusted so that the pressure value measured by the pressure sensor 7 is maintained at the target value of the pressure in the gas phase space at the top.

[0036] In addition, the above function relationship P = f(m) is obtained by fitting the calibration test data of the lightweight pressurization device of the liquid hydrogen storage tank. The function form and fitting method of the function relationship P = f(m) can be realized according to the prior art. Nonlinear fitting methods such as regression equation fitting and neural network can be used to construct this function relationship. In an embodiment of the present invention, the above function relationship P = f(m) is preferably obtained by fitting with a unary nonlinear regression method.

[0037] In addition, it should be noted that the above function relationship P = f(m) is a function relationship between P and m, and in the present invention, m is used to solve for P. In practical applications, it can also be set in the form of an inverse function, that is, taking m as the dependent variable and P as the independent variable, to form a corresponding function relationship m = f -1 (P). The essence of the two function forms is the same and both can be used in the present invention.

[0038] Of course, although the liquid hydrogen storage tank 1 in the present invention mainly relies on its own liquid hydrogen vaporization to achieve self-pressurization, if necessary, the gas phase space at the top of the liquid hydrogen storage tank 1 is connected to an external pressurized gas source, and the pressurized gas source applies an additional pressure to the gas phase space at the top of the liquid hydrogen storage tank 1 in addition to the self-pressurization by its own liquid hydrogen vaporization.

[0039] In addition, in the present invention, heat insulation materials are preferably wrapped outside the main components such as the liquid hydrogen storage tank 1, the pressurizing vaporizer 3, the liquid hydrogen outflow pipeline 8, the liquid hydrogen cut-off valve 9, and the liquid hydrogen vaporizer 10 to reduce heat leakage of the system.

[0040] Based on the aboveFigure 1 The lightweight pressurizing device for a liquid hydrogen storage tank shown in the figure, in another embodiment of the present invention, also provides a liquid hydrogen storage tank pressurizing method, which comprises the following steps:

[0041] S1. Perform a separate calibration test on the liquid hydrogen storage tank 1 in the liquid hydrogen storage tank lightweight booster device in advance. Apply different pressures P to the internal gas phase space of the liquid hydrogen storage tank 1, and measure the liquid hydrogen outlet flow m of the liquid hydrogen storage tank 1 through a flow meter. Perform a univariate nonlinear regression fitting on the test data to obtain the functional relationship P=f(m) between P and m, and store it in the controller 6 for calling.

[0042] S2. Use the lightweight booster device of the liquid hydrogen storage tank to self-boost hydrogen supply to the external hydrogen-using equipment. The liquid hydrogen medium from the liquid hydrogen storage tank 1 first enters the booster pipeline 2, and then enters the booster vaporizer 3 to absorb external heat and quickly vaporize and boost to convert into hydrogen. The electronically controlled hydrogen stop valve 4 continuously starts and stops at the initial frequency. During the start and stop process, part of the hydrogen enters the gas phase space at the top of the liquid hydrogen storage tank 1 through the electronically controlled hydrogen stop valve 4 for boosting, so that the liquid hydrogen medium at the bottom of the liquid hydrogen storage tank 1 enters the liquid hydrogen outflow pipeline 8, enters the liquid hydrogen vaporizer 10 through the liquid hydrogen stop valve 9, absorbs external heat and vaporizes to hydrogen and inputs into the hydrogen-using equipment. In this process, the pressure sensor 7 measures the pressure of the gas phase space at the top of the liquid hydrogen storage tank 1 in real time and feeds it back to the controller 6. The controller 6 calculates the real-time liquid hydrogen flow value m at the current moment according to the preset function relationship P=f(m). i , and the real-time liquid hydrogen flow value m i Compared with the target value m0 of liquid hydrogen supply flow required by hydrogen equipment, if m i If it is lower than m0, the start and stop frequency of the electronically controlled hydrogen shut-off valve 4 is increased. i If it is higher than m0, the start and stop frequency of the electronically controlled hydrogen shut-off valve 4 is reduced, thereby reducing m i Maintain the consistency with m0. If the external hydrogen-using equipment stops using hydrogen and its hydrogen inlet valve is closed, the pressure-through valve 12 is opened to connect the hydrogen from the booster vaporizer 3 to the liquid hydrogen outflow pipeline 8 at the outlet of the liquid hydrogen vaporizer 10 through the pressure-through pipeline 11, and a pressure balanced with the top gas phase space is applied to the liquid hydrogen outlet of the liquid hydrogen storage tank 1 to control the liquid hydrogen medium inside the liquid hydrogen storage tank 1 to stop flowing out; if the external hydrogen-using equipment needs hydrogen again, the pressure-through valve 12 is closed, and the start-stop frequency of the electronically controlled hydrogen stop valve 4 is continued to be adjusted by the controller 6 to adjust the liquid hydrogen flow output from the liquid hydrogen storage tank 1.

[0043] In another embodiment of the present invention, a calibration and control process of the above-mentioned liquid hydrogen storage tank lightweight pressurizing device in actual use is provided, and the specific steps are as follows:

[0044] Step 1, before the lightweight pressurization device of the liquid hydrogen storage tank is installed on corresponding vehicles such as aircraft and spacecraft, first install the liquid hydrogen storage tank 1 therein on a conventional liquid hydrogen storage and supply system with a regulating valve and a flowmeter for calibration testing. After the liquid hydrogen output from the bottom of the liquid hydrogen storage tank 1 vaporizes to form high-pressure hydrogen, it is decompressed to a set pressure through the regulating valve and then introduced into the gas phase space at the top of the liquid hydrogen storage tank 1 for pressurization, and the liquid hydrogen outlet flow rate of the liquid hydrogen storage tank 1 is detected through the flowmeter. Continuously change the pressure in the gas phase space at the top of the liquid hydrogen storage tank 1 through the regulating valve, and then test the liquid hydrogen outlet flow rate under the corresponding pressure. Then, obtain the functional relationship P = f(m) between the pressure P in the gas phase space inside the liquid hydrogen storage tank 1 and the liquid hydrogen outlet flow rate m through fitting by the unary nonlinear regression method.

[0045] Step 2, transform the conventional liquid hydrogen storage and supply system, remove components such as the regulating valve and the liquid hydrogen flowmeter, use the electric control hydrogen cut-off valve 4 to replace the regulating valve, input the functional relationship P = f(m) into the controller 6, form the lightweight pressurization device of the liquid hydrogen storage tank as shown in Figure 1 the figure, and install it in a vehicle with high requirements for lightweight.

[0046] Step 3, the lightweight pressurization device of the liquid hydrogen storage tank starts self-pressurizing to supply liquid hydrogen. The liquid hydrogen medium from the liquid hydrogen storage tank 1 first enters the pressurization pipeline 2, and then enters the pressurization vaporizer 3 to quickly vaporize after absorbing external heat, changing from liquid hydrogen to high-pressure hydrogen. The electric control hydrogen cut-off valve 4 continuously starts and stops at a specific frequency at high speed. During the start-stop process, a small amount of hydrogen enters the gas phase space at the top of the liquid hydrogen storage tank 1 through the electric control hydrogen cut-off valve 4. After the corresponding pressure rises, the liquid hydrogen medium at the bottom of the liquid hydrogen storage tank 1 enters the liquid hydrogen outflow pipeline 8, enters the liquid hydrogen vaporizer 10 through the liquid hydrogen cut-off valve 9, quickly vaporizes into hydrogen after absorbing external heat, and finally is transported to a power system such as a hydrogen engine or a fuel cell through the pipeline. The pressure sensor 7 measures the pressure in the gas phase space at the top of the liquid hydrogen storage tank 1, and transmits the pressure data to the controller 6 through the signal power line 5. The controller 6 obtains the liquid hydrogen flow rate value m at the current moment according to the preset functional relationship P = f(m) i . Assuming that the set flow rate is m0, the flow rate adjustment modes of the liquid hydrogen storage and supply system include the following five types:

[0047] Mode 1, increase the liquid hydrogen flow rate: If m i is less than the set liquid hydrogen flow rate set value m0, the controller 6 increases the high-speed start-stop frequency of the electric control hydrogen cut-off valve 4 through the signal power line 5. The pulsed hydrogen entering the gas phase space at the top of the liquid hydrogen storage tank 1 increases, the corresponding pressure rises, and the liquid hydrogen outlet flow rate increases;

[0048] Mode 2, decrease the liquid hydrogen flow rate: If m iIf it is greater than the set liquid hydrogen flow rate value m0, the controller 6 reduces the high-speed start-stop frequency of the electronically controlled hydrogen cut-off valve 4 through the signal power line 5. As the volume of the gas phase space at the top of the liquid hydrogen storage tank 1 decreases, the corresponding pressure drops, and the liquid hydrogen outlet flow rate decreases;

[0049] Mode 3. Maintain the liquid hydrogen flow rate: If m i is equal to the set liquid hydrogen flow rate value m0, the controller 6 maintains the high-speed start-stop frequency of the electronically controlled hydrogen cut-off valve 4 through the signal power line 5, and the liquid hydrogen outlet flow rate remains stable;

[0050] Mode 4. Resume after the liquid hydrogen supply process flow rate becomes 0: During the liquid hydrogen storage and supply process of the liquid hydrogen storage and supply system, the demand for liquid hydrogen by hydrogen-consuming equipment such as the power system under certain specific working conditions will change to 0 for a short time, and the inlet valve of the hydrogen-consuming equipment such as the power system is closed. At this time, the pressure relief valve 12 can be opened, and the high-pressure hydrogen from the booster vaporizer 3 enters the liquid hydrogen outflow pipeline 8 through the pressure relief pipeline 11, so that the pressure value at the outlet of the liquid hydrogen vaporizer 10 is equal to the pressure value of the gas phase space at the top of the liquid hydrogen storage tank 1. At this time, the liquid hydrogen medium inside the liquid hydrogen storage tank 1 no longer flows out, and the liquid hydrogen flow rate value m0 instantaneously changes to 0; when the demand for liquid hydrogen by hydrogen-consuming equipment such as the power system changes to m0 again, the pressure relief valve 12 is closed, and then the high-speed start-stop frequency of the electronically controlled hydrogen cut-off valve 4 is adjusted through the controller 6 to achieve the set liquid hydrogen flow rate value m0.

[0051] However, it should be noted that limited by the control accuracy and the pressure detection accuracy, if a specific numerical point of m0 is set, m i and m0 itself cannot be maintained in a completely consistent state for a long time. Therefore, in actual industrial applications, the target value m0 of the liquid hydrogen supply flow rate can be set to have a permitted fluctuation range centered on itself. If m i is within this range, it is considered that m i maintains consistency with m0, and there is no need to adjust the current start-stop frequency of the electronically controlled hydrogen cut-off valve 4.

[0052] In addition, it should be noted that the above-mentioned liquid hydrogen storage tank lightweight pressurization device and method in the present invention can be used not only for the liquid hydrogen storage and supply system, but also for the lightweight storage and supply of media such as liquid oxygen, liquid helium, and liquid methane.

[0053] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A lightweight pressurization device for a liquid hydrogen storage tank, characterized in that, It includes a liquid hydrogen storage tank (1), a pressurizing pipeline (2), a liquid hydrogen outflow pipeline (8), a pressure - passing pipeline (11), and a controller (6); The pressurizing pipeline (2) is successively connected to the liquid - phase space at the bottom of the liquid hydrogen storage tank (1), a pressurizing vaporizer (3), an electronically - controlled hydrogen stop valve (4), and the gas - phase space at the top of the liquid hydrogen storage tank (1), and is used to vaporize part of the liquid hydrogen in the liquid hydrogen storage tank (1) to pressurize itself; The liquid hydrogen outflow pipeline (8) is successively connected to the liquid hydrogen outlet of the liquid - phase space at the bottom of the liquid hydrogen storage tank (1), a liquid hydrogen stop valve (9), a liquid hydrogen vaporizer (10), and then connected to an external hydrogen - using device, and inputs the liquid hydrogen medium inside the liquid hydrogen storage tank (1) into the external hydrogen - using device; The pressure - passing pipeline (11) is successively connected to the pressurizing pipeline (2) between the pressurizing vaporizer (3) and the electronically - controlled hydrogen stop valve (4), a pressure - passing valve (12), and the liquid hydrogen outflow pipeline (8) at the rear end of the hydrogen vaporizer (10), and is used to realize the control of gas supply start - stop through the opening and closing of the pressure - passing valve (12); The controller (6) is respectively connected to the electronically - controlled hydrogen stop valve (4) and a pressure sensor (7) through a signal power line (5). The pressure sensor (7) is used to detect the pressure in the gas - phase space at the top of the liquid hydrogen storage tank (1). The electronically - controlled hydrogen stop valve (4) realizes pulsed gas supply through alternate start - stop. The controller (6) is used to feedback - regulate the opening frequency of the electronically - controlled hydrogen stop valve (4) according to the pressure signal measured by the pressure sensor (7) to realize the regulation of liquid hydrogen flow rate.

2. The lightweight pressurization device for a liquid hydrogen storage tank according to claim 1, wherein The gas - phase space at the top of the liquid hydrogen storage tank (1) is connected to an external pressurizing gas source, and an additional pressure other than the self - vaporization pressurization of the liquid hydrogen is applied to the gas - phase space at the top of the liquid hydrogen storage tank (1) by the pressurizing gas source.

3. The lightweight pressurization device for a liquid hydrogen storage tank according to claim 1, characterized in that, The function relationship P = f(m) between the pressure P in the gas - phase space at the top of the liquid hydrogen storage tank (1) and the liquid hydrogen outlet flow rate m of the liquid hydrogen storage tank (1) is pre - stored in the controller (6); when supplying hydrogen to an external hydrogen - using device, according to the target value of the liquid hydrogen supply flow rate, the corresponding target value of the pressure in the gas - phase space at the top is converted through this function relationship, and then the opening frequency of the electronically - controlled hydrogen stop valve (4) is adjusted to make the pressure value measured by the pressure sensor (7) maintain at this target value of the pressure in the gas - phase space at the top.

4. The lightweight pressurization device for a liquid hydrogen storage tank according to claim 3, wherein The function relationship P = f(m) is obtained by fitting the calibration test data of the lightweight pressurization device of the liquid hydrogen storage tank in advance.

5. The lightweight pressurization device for a liquid hydrogen storage tank according to claim 4, characterized in that, The function relationship P = f(m) is obtained by fitting with a unary non - linear regression method.

6. The lightweight pressurization device for a liquid hydrogen storage tank according to claim 1, wherein The liquid hydrogen storage tank (1), the pressurizing vaporizer (3), the liquid hydrogen outflow pipeline (8), the liquid hydrogen stop valve (9), and the liquid hydrogen vaporizer (10) are all wrapped with heat - insulating materials on the outside.

7. A method for pressurizing a liquid hydrogen storage tank using the liquid hydrogen storage tank lightweight pressurization device according to any one of claims 1 to 6, characterized in that, It includes the following steps: S1. Conduct a separate calibration test on the liquid hydrogen storage tank (1) in the lightweight pressurization device of the liquid hydrogen storage tank in advance. By applying different pressures P to the internal gas - phase space of the liquid hydrogen storage tank (1) and respectively measuring the liquid hydrogen outlet flow rate m of the liquid hydrogen storage tank (1) through a flowmeter, the function relationship P = f(m) between P and m is obtained through unary non - linear regression fitting of the test data, and is stored in the controller (6) for calling; S2. A lightweight pressurizing device for a liquid hydrogen storage tank is used to self-pressurize and supply hydrogen to an external hydrogen-using device. The liquid hydrogen medium from the liquid hydrogen storage tank (1) first enters the pressurizing pipeline (2), and then enters the pressurizing vaporizer (3) to absorb external heat and then rapidly vaporize and pressurize to be converted into hydrogen. The electronically controlled hydrogen stop valve (4) is continuously and alternately started and stopped at an initial frequency. During the start and stop process, part of the hydrogen enters the gas phase space at the top of the liquid hydrogen storage tank (1) through the electronically controlled hydrogen stop valve (4) to be pressurized, so that the liquid hydrogen medium at the bottom of the liquid hydrogen storage tank (1) enters the liquid hydrogen outflow pipeline (8), enters the liquid hydrogen vaporizer (10) through the liquid hydrogen stop valve (9), absorbs external heat and then vaporizes into hydrogen and is input into the hydrogen-using device. During this process, the pressure sensor (7) measures the pressure in the gas phase space at the top of the liquid hydrogen storage tank (1) in real time and feeds it back to the controller (6). The controller (6) calculates the real-time liquid hydrogen flow rate value m at the current moment according to the preset functional relationship P = f(m). i , and compares the real-time liquid hydrogen flow rate value m i with the target value m0 of the liquid hydrogen supply flow rate required by the hydrogen-consuming equipment. If m i is lower than m0, the start-stop frequency of the electronically controlled hydrogen cut-off valve (4) is increased. If m i is higher than m0, the start-stop frequency of the electronically controlled hydrogen cut-off valve (4) is decreased, so as to keep m i consistent with m0; If the external hydrogen-using equipment stops using hydrogen and its hydrogen inlet valve is closed, the pressure-releasing valve (12) is opened to connect the hydrogen from the booster vaporizer (3) to the liquid hydrogen outflow pipeline (8) at the outlet of the liquid hydrogen vaporizer (10) through the pressure-releasing pipeline (11), and a pressure balanced with the top gas phase space is applied to the liquid hydrogen outlet of the liquid hydrogen storage tank (1), so that the liquid hydrogen medium inside the liquid hydrogen storage tank (1) stops flowing out; if the external hydrogen-using equipment needs hydrogen again, the pressure-releasing valve (12) is closed, and the start-stop frequency of the electronically controlled hydrogen stop valve (4) is continued to be adjusted through the controller (6) to adjust the liquid hydrogen flow output from the liquid hydrogen storage tank (1).

8. The method for pressurizing a liquid hydrogen storage tank according to claim 7, wherein The target value m0 of the liquid hydrogen supply flow rate has a permissible fluctuation range centered on itself, m i If it is within this range, it is regarded as m i maintaining consistency with m0 and no adjustment is required for the current start-stop frequency of the electronically controlled hydrogen cut-off valve (4).

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