Piston liquid hydrogen pump and hydrogen fueling system

Abstract

The present application discloses a piston liquid hydrogen pump and a hydrogen fueling system. In the piston liquid hydrogen pump, a first piston is provided in a driving cavity, a first driving liquid inlet / outlet is formed in a first driving cavity, and a second driving liquid inlet / outlet is formed in a second driving cavity; a liquid passing hole making the first driving cavity and the second driving cavity communicated with each other is formed in the first piston, and a mushroom valve assembly is movably provided in the liquid passing hole and seals the liquid passing hole when moving to openings of the liquid passing hole; a second piston is provided in a hydraulic cavity; a piston rod is sealingly connected between the first piston and the second piston, and a liquid hydrogen one-way inlet and a liquid hydrogen one-way outlet are formed in a second hydraulic cavity. The hydrogen fueling system comprises a liquid hydrogen storage tank, a vaporizer, a buffer tank, a liquid hydrogen pipe, a gaseous hydrogen fueling machine, and the piston liquid hydrogen pump. According to the piston liquid hydrogen pump and the hydrogen fueling system provided by the present application, the start and stop of the pistons are mechanically controlled by means of the mushroom valve assembly, so that the failure rate is low, and the stability and the reliability are achieved; and the mushroom valve assembly has a low mass, so that the response speed can be increased, and the control precision can be improved.

Description

A piston type liquid hydrogen pump and hydrogenation system

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on August 30, 2023, with application number 202311109538.1 and invention name “A Piston Type Liquid Hydrogen Pump and Hydrogenation System”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of liquid hydrogen storage and transportation, and in particular to a piston-type liquid hydrogen pump and a hydrogenation system. Background Art

[0003] Liquid hydrogen is more suitable for large-scale, long-distance transportation than gaseous hydrogen, and is more suitable for storage in large hydrogen refueling stations. Liquid hydrogen has a high storage density, low storage and transportation costs, low storage pressure, and is also safer.

[0004] Liquid hydrogen is stored in containers at ultra-low temperatures (20K). At ultra-low temperatures, steel becomes brittle and its strength weakens. In addition, there is a risk of hydrogen corrosion and hydrogen embrittlement in hydrogen-prone working conditions. Therefore, under current technology, the maximum pressure resistance of liquid hydrogen storage tanks is relatively low. Hydrogen refueling stations for liquid hydrogen storage require high-pressure gaseous hydrogen to refuel vehicles loaded with compressed hydrogen. Therefore, a high-pressure liquid hydrogen pump is needed to compress the liquid hydrogen to high pressure, transport it to the downstream vaporizer through a pipeline, and then vaporize it into high-pressure gaseous hydrogen for use in the hydrogen refueling machine. The hydrogen pump is a key equipment in the liquid hydrogen energy system. Its design and manufacturing standards are very high.

[0005] Existing hydrogen pumps are generally piston-type liquid hydrogen pumps, which are generally divided into external and semi-submersible types. External liquid hydrogen pumps are installed outside the liquid hydrogen storage tank and connected to the liquid hydrogen storage tank via pipelines to achieve liquid hydrogen transportation. Semi-submersible liquid hydrogen pumps, which are responsible for compressing and transporting liquid hydrogen, are installed inside the storage tank, immersed in the liquid hydrogen, while the drive end is installed outside the liquid hydrogen storage tank.

[0006] In the process of realizing the invention, the inventors found that the current semi-submersible liquid hydrogen pump generally uses sensor control, time and space, or shuttle valve control to control the stop of the piston. The above three control methods have the following shortcomings: First, for sensor control, position sensors or pressure sensors are generally installed at both ends of the hydraulic drive cylinder. The position sensors and pressure sensors have a high failure rate and poor reliability; second, for time control, the movement of the piston is greatly affected by the hydraulic driving force, and the start and stop of the piston is controlled only by time, which has low reliability for controlling the start and stop of the piston; third, the shuttle valve is used. The mass and volume of the shuttle valve are large, and the driving force of the hydraulic fluid is large when moving, and the moving speed is slow, resulting in a delayed control response of the start and stop of the piston, a long time required for control, and low control accuracy.

[0007] Summary of the Invention

[0008] The purpose of the present application is to provide a piston-type liquid hydrogen pump and hydrogenation system to solve the problems existing in the prior art. The start and stop of the piston are mechanically controlled by a mushroom valve assembly, which has a low failure rate, is stable and reliable, and the mushroom valve assembly has a small mass, which is conducive to improving the response speed and increasing the control accuracy.

[0009] The technical solution of the present application provides a piston-type liquid hydrogen pump, comprising: a pump body, the pump body comprising: a drive portion, the drive portion comprising a drive chamber, a first piston being provided in the drive chamber, the first piston being slidably and sealingly provided in the drive chamber to separate the drive chamber into relatively independent first drive chamber and second drive chamber, the first drive chamber being provided with a first inlet and outlet for drive liquid, the second drive chamber being provided with a second inlet and outlet for drive liquid; a mushroom valve assembly, the first piston being provided with a liquid passage hole connecting the first drive chamber and the second drive chamber, the mushroom valve assembly being movably provided in the liquid passage hole and being moved to The opening of the liquid hole is sealed, and the mushroom valve assembly includes a first valve stem and a second valve stem which are arranged opposite to each other and can extend out of the liquid hole in reverse; a hydraulic part, which includes a hydraulic chamber, in which a second piston is arranged, and the second piston is slidably and sealedly arranged in the hydraulic chamber to separate the hydraulic chamber into a first hydraulic chamber and a second hydraulic chamber; a piston rod, which is sealingly connected between the first piston and the second piston, and the second hydraulic chamber is located on the side of the second piston facing away from the first piston, and a one-way liquid hydrogen inlet and a one-way liquid hydrogen outlet are provided on the second hydraulic chamber.

[0010] Optionally, a first diameter-reduced step and a second diameter-reduced step are respectively provided on the inner walls of the two openings of the liquid hole, and the mushroom valve assembly includes a first sealing surface and a second sealing surface; when the first sealing surface contacts the first diameter-reduced step, it seals one opening of the liquid hole, and when the second sealing surface contacts the second diameter-reduced step, it seals the other opening of the liquid hole.

[0011] Optionally, the mushroom valve assembly also includes a connecting rod, the first mushroom valve includes a first valve head, and the second mushroom valve includes a second valve head; a first limiting countersunk hole is provided on the first valve head, and a second limiting countersunk hole is provided on the second valve head, and the two ends of the connecting rod can be slidably limited in the first limiting countersunk hole and the second limiting countersunk hole respectively.

[0012] Optionally, the first valve head and the second valve head are polygonal or circular, and the thickness of the first valve head and the second valve head gradually decreases from the center to the periphery of the polygon or circle. The first position-limiting countersunk hole is located at the center of the first valve head, and the second position-limiting countersunk hole is located at the center of the second valve head. Optionally, there is one liquid passage hole, and the first and second diameter-reducing steps are respectively located at two openings of the liquid passage hole. The mushroom valve assembly includes a first mushroom valve and a second mushroom valve that are fixedly or movably connected. The first valve stem and the first sealing surface are located on the first mushroom valve, and the second valve stem and the second mushroom valve are both located on the second mushroom valve.

[0013] Optionally, the number of the liquid holes is two, and the first diameter reduction step and the second diameter reduction step are respectively located in the two liquid holes; the mushroom valve assembly includes two relatively independent first mushroom valves and second mushroom valves, the first mushroom valve and the second mushroom valve are respectively arranged in the two liquid holes, the first valve stem is located on the first mushroom valve, the second valve stem is located on the second mushroom valve, and the first valve stem and the second valve stem extend in opposite directions from the two liquid holes respectively.

[0014] Optionally, a first shaft seal is provided on the driving part, and a second shaft seal is provided on the hydraulic part. The piston rod passes through the driving part from the first shaft seal, and the piston rod passes through the hydraulic part from the second shaft seal; the first shaft seal and the second shaft seal are separated by a distance along the axial direction of the piston rod, and the exposed portion of the piston rod between the first shaft seal and the second shaft seal defines an exposed section.

[0015] Optionally, the piston-type liquid hydrogen pump also includes a drive assembly, which includes: a controller, a reversing valve, a hydraulic pump, a hydraulic pipe 1, a hydraulic pipe 2, a hydraulic box, and a pressure sensor; the hydraulic pipe 1 is connected between the first inlet and outlet of the drive liquid and the hydraulic box, and the hydraulic pipe 2 is connected between the second inlet and outlet of the drive liquid and the hydraulic box; the reversing valve is located on both the hydraulic pipe 1 and the hydraulic pipe 2, the hydraulic pump and the pressure sensor are located on the hydraulic pipe 1, and the pressure sensor is located on the outlet side of the hydraulic pump for detecting the pressure of the hydraulic pipe 1; the output end of the pressure sensor is communicatively connected to the input end of the controller; the input end of the hydraulic pump and the reversing valve is communicatively connected to the output end of the controller.

[0016] The present application also provides a hydrogenation system, comprising: a liquid hydrogen storage tank, a vaporizer, a buffer tank, a liquid hydrogen pipeline, a gas hydrogen pipeline, a gas hydrogenation machine, and a piston-type liquid hydrogen pump as described in any one of the above; the piston-type liquid hydrogen pump is arranged in the liquid hydrogen storage tank; the liquid hydrogen pipeline is connected between the liquid hydrogen storage tank and the vaporizer, the gas hydrogen pipeline is connected between the vaporizer and the gas hydrogenation machine, and the buffer tank is located on the gas hydrogen pipeline.

[0017] Optionally, the hydrogenation system further includes a liquid hydrogen hydrogenator and an insulated liquid hydrogen pipeline; the insulated liquid hydrogen pipeline is connected between the liquid hydrogen storage tank and the liquid hydrogen hydrogenator.

[0018] Optionally, the hydrogenation system further includes a precooling unit, which includes a precooling pipe and / or a heat exchanger; the hot end of the precooling pipe is connected to the gas hydrogenation machine, and the hot end of the precooling pipe is connected to the liquid hydrogen storage tank, or is connected to the cold end of the vaporizer, or is connected to the pipeline between the liquid hydrogen storage tank and the vaporizer; the heat exchanger includes a hot flow pipe and a cold flow pipe for heat exchange, the hot flow pipe is connected to the gas hydrogenation machine, and the cold flow pipe is connected to the liquid hydrogen storage tank, or is connected to the cold end of the vaporizer, or is connected to the pipeline between the liquid hydrogen storage tank and the vaporizer. Optionally, a vent pipe is installed on the liquid hydrogen storage tank, and a safety valve is provided on the vent pipe; the hydrogenation system further includes a pressurization pipe, and the pressurization pipe is connected between the vaporizer and the liquid hydrogen storage tank through a control valve.

[0019] Optionally, the number of the piston-type liquid hydrogen pumps is at least two, and at least two of the piston-type liquid hydrogen pumps are arranged in the liquid hydrogen storage tank.

[0020] The above technical solution has the following beneficial effects:

[0021] The piston-type liquid hydrogen pump and hydrogenation system provided by the present application have a mushroom valve assembly in which the first valve stem and the second valve stem can both protrude from the first piston at their respective end positions to mechanically control the movement of the first piston, so that the first piston can be stopped by mechanical control whether in the compression stroke or the suction stroke, without generating large mechanical impact and without relying on other components with high failure rates such as position sensors. In addition, the mushroom valve assembly has a very small mass and generates very little vibration on the cylinder wall when contacting the cylinder wall, thereby having the effects of high reliability, low vibration, and fast response speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic structural diagram of a piston-type liquid hydrogen pump according to an embodiment of the present application;

[0023] FIG2 is a schematic structural diagram of a piston-type liquid hydrogen pump provided with an exposed section in one embodiment of the present application;

[0024] FIG3 is a schematic structural diagram of a first mushroom valve and a second mushroom valve fixedly connected and arranged in a liquid passage hole in one embodiment of the present application;

[0025] FIG4 is a schematic structural diagram of a first mushroom valve and a second mushroom valve movably connected and arranged in a liquid passage hole in one embodiment of the present application;

[0026] FIG5 is a schematic structural diagram of a first mushroom valve and a second mushroom valve respectively disposed in two liquid passage holes in one embodiment of the present application;

[0027] FIG6 a is a schematic structural diagram of a first sealing surface abutting against a first diameter-reduced step in one embodiment of the present application;

[0028] FIG6 b is a schematic structural diagram of a second sealing surface abutting against a second radially reduced step in one embodiment of the present application;

[0029] FIG7 a is a schematic structural diagram of a first mushroom valve and a second mushroom valve connected by a connecting rod without contacting each other in one embodiment of the present application;

[0030] FIG7 b is a schematic structural diagram of a first mushroom valve and a second mushroom valve connected by a connecting rod and not in contact with each other in one embodiment of the present application;

[0031] FIG7c is a schematic structural diagram of a first mushroom valve and a second mushroom valve respectively abutting against a first sealing surface and a second sealing surface when the first mushroom valve and the second mushroom valve are connected by a connecting rod and do not contact each other in one embodiment of the present application;

[0032] FIG7 d is a schematic structural diagram of a first mushroom valve and a second mushroom valve respectively abutting against a first sealing surface and a second sealing surface when the first mushroom valve and the second mushroom valve are connected by a connecting rod and do not contact each other in one embodiment of the present application;

[0033] FIG7e is a schematic structural diagram of the first mushroom valve and the second mushroom valve in contact with each other in one embodiment of the present application;

[0034] FIG7 f is a schematic structural diagram of the first mushroom valve and the second mushroom valve in contact with each other in one embodiment of the present application;

[0035] FIG8a is a schematic structural diagram of a first valve head in an embodiment of the present application, in which the first valve head is a hexagonal shape with an arc transition;

[0036] FIG8 b is a schematic structural diagram of a pentagonal structure in which the first valve head is an arc transition in one embodiment of the present application;

[0037] FIG8c is a schematic structural diagram of a quadrilateral with a first valve head having an arc transition in one embodiment of the present application;

[0038] FIG8 d is a schematic structural diagram of a hexagonal first valve head in one embodiment of the present application;

[0039] FIG8e is a schematic diagram of a structure in which the first valve head is pentagonal in one embodiment of the present application;

[0040] FIG8f is a schematic structural diagram of a first valve head in a quadrilateral according to an embodiment of the present application;

[0041] FIG9 is a flow chart showing the driving connection between a drive assembly and a piston-type liquid hydrogen pump provided with a liquid hole in one embodiment of the present application;

[0042] FIG10 is a flow chart showing the driving connection between a drive assembly and a piston-type liquid hydrogen pump having two liquid holes in one embodiment of the present application;

[0043] FIG11 is a flow chart of a hydrogenation system according to an embodiment of the present application;

[0044] FIG12 is a flow chart of a hydrogenation system provided with a liquid hydrogenation machine and an insulated liquid hydrogen pipeline in one embodiment of the present application;

[0045] FIG13 is a flow chart of a hydrogenation system provided with a safety valve and a pressurized pipeline in one embodiment of the present application;

[0046] FIG14 is a schematic structural diagram of two piston-type liquid hydrogen pumps provided in a liquid hydrogen storage tank in one embodiment of the present application.

[0047] Reference numeral 100 - pump body; 1 - drive unit, 10 - drive chamber, 11 - first piston, 12 - drive chamber 1, 13 - drive chamber 2, 14 - first drive liquid inlet and outlet, 15 - second drive liquid inlet and outlet, 16 - liquid hole, 17 - first radial reduction step, 18 - second radial reduction step, 19 - first shaft seal; 2 - mushroom valve assembly, 20 - first sealing surface, 21 - second sealing surface, 22 - first mushroom valve, 23 - second mushroom valve, 24 - first valve stem, 25 - second valve stem, 26 - connecting rod, 27 - first valve head, 28 - second valve head, 29 - flow channel; 3 - hydraulic unit, 30 - hydraulic chamber, 31 - second piston, 32 - hydraulic chamber 1, 33 - hydraulic chamber 2, 34 - liquid hydrogen one-way inlet, 35 - liquid hydrogen one-way outlet, 36 - second shaft seal, 37 - mounting flange; 4 - piston rod, 40 - exposed section; 5-Controller, 50-Reversing valve, 51-Hydraulic pump, 52-Hydraulic pipe 1, 53-Hydraulic pipe 2, 54-Hydraulic box, 55-Pressure sensor; 6-Hydrogenation system, 60-Liquid hydrogen storage tank, 61-Vaporizer, 62-Buffer tank, 63-Liquid hydrogen pipeline, 630-Gas hydrogen pipeline, 64-Gas hydrogenation machine, 65-Liquid hydrogenation machine, 66-Insulated liquid hydrogen pipeline, 67-First temperature sensor, 68-First pressure sensor, 69-Second pressure sensor; 7-Boosting pipeline, 70-Vent pipe, 71-Safety valve, 72-Control valve, 73-Check valve, 74-Flow limiting orifice; 8-Precooling pipe. DETAILED DESCRIPTION

[0048] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0049] It is easy to understand that according to the technical solution of the present invention, a variety of structural modes and implementation modes can be replaced with each other by those skilled in the art without changing the essential spirit of the present invention. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the present invention and should not be regarded as the entire invention or as a limitation or restriction of the technical solution of the invention.

[0050] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly mentioned in this specification are defined relative to the structure shown in the drawings. They are relative concepts and may vary depending on the location and usage of the device. Therefore, these or other directional terms should not be interpreted as restrictive.

[0051] The present application provides a piston-type liquid hydrogen pump, comprising a pump body 100 . The pump body 100 comprises a driving portion 1 , a mushroom valve assembly 2 , a hydraulic portion 3 and a piston rod 4 .

[0052] The driving portion 1 includes a driving chamber 10, in which a first piston 11 is disposed. The first piston 11 is slidably and sealedly disposed in the driving chamber 10, dividing the driving chamber 10 into a relatively independent first driving chamber 12 and a second driving chamber 13. The first driving chamber 12 is provided with a first driving liquid inlet and outlet 14, and the second driving chamber 13 is provided with a second driving liquid inlet and outlet 15.

[0053] As shown in Figures 1 to 5, a liquid passage hole connecting the first drive chamber 12 and the second drive chamber 13 is provided on the first piston 11. The mushroom valve assembly 2 is movably arranged in the liquid passage hole 16 and seals the liquid passage hole 16 when it moves to the opening of the liquid passage hole 16. The mushroom valve assembly 2 includes a first valve stem 24 and a second valve stem 25 that are arranged in opposite directions and can extend out of the liquid passage hole 16 in reverse.

[0054] The hydraulic part 3 includes a hydraulic chamber 30 , in which a second piston 31 is disposed. The second piston 31 is slidably and sealedly disposed in the hydraulic chamber 30 , dividing the hydraulic chamber 30 into a first hydraulic chamber 32 and a second hydraulic chamber 33 .

[0055] As shown in Figures 1 and 2, the piston rod 4 is sealed between the first piston 11 and the second piston 31. The second hydraulic chamber 33 is located on the side of the second piston 31 facing away from the first piston 11. The second hydraulic chamber 33 is provided with a liquid hydrogen one-way inlet 34 and a liquid hydrogen one-way outlet 35. The piston rod 4 connects the first piston 11 and the second piston 31, forming an integrated linkage mechanism that can move under the action of hydraulic pressure (hydraulic oil) to compress and absorb liquid hydrogen, realizing the fundamental function of the piston-type liquid hydrogen pump. The liquid hydrogen one-way inlet 34 and the liquid hydrogen one-way outlet 35 are both provided with a one-way valve 73.

[0056] In the piston-type liquid hydrogen pump provided in the embodiment of the present application, during the compression stroke, hydraulic oil is input into the first drive chamber 12 of the drive unit 1 through the first drive liquid inlet and outlet 14. The hydraulic oil pushes the first piston 11 downward within the first drive chamber 12. The first piston 11 is connected to the second piston 31 via the piston rod 4, driving the second piston 31 to move downward simultaneously, squeezing liquid hydrogen within the second hydraulic chamber 33. The pressurized liquid hydrogen is then output through the liquid hydrogen one-way outlet 35 and the discharge pipeline.

[0057] During the suction stroke, the hydraulic oil is connected to the second driving chamber 13 of the driving part 1 through the second driving liquid inlet and outlet 15. The hydraulic oil pushes the second piston 31 upward in the second driving chamber 13, and the second piston 31 is also driven upward by the piston rod 4. Liquid hydrogen is sucked into the second hydraulic chamber 33 through the liquid hydrogen one-way inlet 34 so that the liquid hydrogen can be compressed in the next compression stroke.

[0058] At the end of the compression stroke and the suction stroke, the mushroom valve assembly 2 is used to stop the movement of the first piston 11. The first valve stem 24 and the second valve stem 25 will protrude a certain distance from the first piston 11 when in the closed position. When the piston moves to the end point, the protruding first valve stem 24 or second valve stem 25 first contacts the cavity wall of the drive cavity 10, and the mushroom valve assembly 2 is supported by the cylinder wall and stops moving. At this time, the first piston 11 continues to move under the push of the hydraulic oil, causing the relative position of the mushroom valve assembly 2 and the first piston 11 to change. The mushroom valve assembly 2 detaches from the opening of the liquid hole 16, and the liquid passage of the liquid hole 16 is opened. The hydraulic oil flows to the other side of the first piston 11 through the opened passage, causing the hydraulic oil pressure on the other side to rise rapidly. The pressure difference on both sides of the first piston 11 decreases rapidly, and the first piston 11 loses the thrust to continue moving and stops.

[0059] The first valve stem 24 and the second valve stem 25 can both mechanically control the movement of the first piston 11 at the end positions of their respective strokes, so that the first piston 11 can be reliably stopped regardless of whether it is in the compression stroke or the suction stroke. This stopping control relies on the balance of hydraulic oil pressure on both sides of the first piston 11, does not produce large mechanical impact, and does not rely on other components with high failure rates such as position sensors.

[0060] In the embodiment of the present application, the first valve stem 24 and the second valve stem 25 in the mushroom valve assembly 2 can both protrude from the first piston 11 at their respective end positions to mechanically control the movement of the first piston 11, so that the first piston 11 can be mechanically controlled to stop whether in the compression stroke or the suction stroke, without generating a large mechanical impact and without relying on other components with a high failure rate such as position sensors. Moreover, the mass of the mushroom valve assembly 2 is very small, and the vibration generated on the cylinder wall when contacting the cylinder wall is very small, which has the effects of high reliability, small vibration, and fast response speed.

[0061] As an optional embodiment, a first and a second tapered step 17 and 18 are respectively provided on the inner walls of the two openings of the fluid hole 16. The mushroom valve assembly 2 includes a first sealing surface 20 and a second sealing surface 21. When the first sealing surface 20 contacts the first tapered step 17, it can seal one opening of the fluid hole 16 under hydraulic oil pressure. When the second sealing surface 21 contacts the second tapered step 18, it can seal the other opening of the fluid hole 16 under hydraulic oil pressure. As shown in Figures 6a and 6b, the first and second tapered steps 17 and 18 in the embodiments of the present application can be defined by a cylindrical structure provided on the inner wall of the fluid hole 16 opening. The cylindrical structure is fixed to the inner wall of the fluid hole 16 by means of threaded connection, welding, interference fit, etc., so that the opening of the fluid hole 16 is in a tapered state, defining the first and second tapered steps 17 and 18. The cylindrical structure can be a nut.

[0062] As an optional embodiment, the mushroom valve assembly 2 further includes a connecting rod 26. The first mushroom valve 22 includes a first valve head 27, and the second mushroom valve 23 includes a second valve head 28. The first valve head 27 defines a first position-limiting countersunk hole, and the second valve head 28 defines a second position-limiting countersunk hole. The ends of the connecting rod 26 are slidably positioned within the first and second position-limiting countersunk holes, respectively. A first sealing surface 20 is located on the first valve head 27, and a first position-limiting countersunk hole is defined on the side of the first valve head 27 facing away from the first sealing surface 20. A second sealing surface 21 is located on the second valve head 28, and a second position-limiting countersunk hole is defined on the side of the second valve head 28 facing away from the second sealing surface 21.

[0063] The connecting rod 26 is a pin-shaped straight rod. Limiting projections are provided at each end of the connecting rod 26. These limiting projections are retained within the first and second limiting counterbores, respectively, provided in the constricted opening. This allows the connecting rod 26 to slide freely without slipping out. The connecting rod 26 guides and positions the first and second mushroom valves 22, 23, maintaining their relative positions. This ensures that the first and second mushroom valves 22, 23 can only move in the direction of the first piston 11, preventing angular deflection of the first and second mushroom valves 22, 23.

[0064] The connecting rod 26 is subject to minimal forces, primarily the weight of the mushroom valve assembly 2, minor impact forces during startup and shutdown, and unbalanced forces from fluid scouring. The strength of the connecting rod 26 is designed based on these forces. To reduce the size and stress of the connecting rod 26, the combined depths of the first and second stop counterbores can be designed to be greater than the length of the connecting rod 26. This allows the first and second valve heads 27, 28 to contact each other during normal operation, rather than through the connecting rod 26. This transfers the impact forces acting on the mushroom valve assembly 2 to the mushroom valve assembly itself, shielding the connecting rod 26 from impact forces and subjecting it only to unbalanced forces. The connecting rod 26 can be made thinner, and reducing its size facilitates reducing the size of the first and second stop counterbores. This reduces the strength of the first and second valve heads 27, 28 without increasing their thickness. The umbrella-shaped first and second valve heads 27, 28 can be made as thin as possible to achieve high-pressure sealing and rapid response with minimal weight.

[0065] As an optional embodiment, the first valve head 27 and the second valve head 28 are polygonal or circular, and the thickness of the first valve head 27 and the second valve head 28 gradually decreases from the center of the polygon or circle to the periphery. The first position-limiting countersunk hole is located at the center of the first valve head 27, and the second position-limiting countersunk hole is located at the center of the second valve head 28. As shown in Figures 8a to 8e, when the first valve head 27 and the second valve stem 25 are polygonal, such as a square, pentagon, or hexagon, the gap between the polygon and the circular fluid hole 16 on the first piston 11 naturally forms a flow channel 29 for the hydraulic oil. When the first valve head 27 and the second valve head 28 are circular, several guide grooves need to be opened on the circumference to form a gap with the fluid hole 16, which serves as the flow channel 29 for the hydraulic oil fluid.

[0066] As shown in Figures 7a to 7e, the first valve head 27 and the second valve head 28 are designed to be thick in the middle and thin at the edges. The middle portion of the first and second valve heads 27, 28 bears pressure and is the area of ​​greatest stress. The edges, in conjunction with the first and second sealing surfaces 20, 21, provide a seal, and the edges have a weight-to-area ratio that is smaller than that of the center portion. This structure minimizes weight while maintaining its load-bearing area and compressive strength. This results in a faster response time for the mushroom valve assembly 2 when switching between its open and closed positions.

[0067] At the moment of starting, the hydraulic oil is reversed, and the pressure of the hydraulic oil continues to increase. The hydraulic oil pressure pushes the mushroom valve assembly 2 to move inside the first piston 11 and move to the other end to close. Only after the mushroom valve assembly 2 quickly moves to the other side and closes, the hydraulic oil pressure on both sides of the first piston 11 will establish a pressure difference, and the first piston 11 will generate thrust and move. Under the same cross-sectional area, the smaller the mass of the valve core, the earlier it moves and the earlier it closes; the larger the mass of the valve core, the later it moves and the later it closes. Therefore, the response speed of the valve core with a small mass is fast and the response effect is good. In this application, the mushroom-shaped first valve head 27 and the second valve head 28 are the preferred shapes for achieving response.

[0068] As an optional embodiment, the number of the liquid passage hole 16 is one, and the first and second radially reduced steps 17 and 18 are respectively located at the two openings of the liquid passage hole 16. The mushroom valve assembly 2 includes a first mushroom valve 22 and a second mushroom valve 23 that are fixedly or movably connected. The first valve stem 24 and the first sealing surface 20 are located on the first mushroom valve 22, and the second valve stem 25 and the second mushroom valve 23 are both located on the second mushroom valve 23. The first valve stem 24 is mounted on the side of the first mushroom valve 22 where the first sealing surface 20 is provided, and the second valve stem 25 is mounted on the side of the second mushroom valve 23 where the second sealing surface 21 is provided.

[0069] As shown in Figure 3, when the first mushroom valve 22 and the second mushroom valve 23 are fixedly connected, they form a mushroom valve chain. The fixedly connected mushroom valve chain is machined from a single piece of material into a mushroom valve chain shape, simplifying the design and improving reliability.

[0070] As an alternative embodiment, there are two liquid passage holes 16, with the first and second radially reduced steps 17 and 18 respectively located in the two liquid passage holes 16. The mushroom valve assembly 2 includes two relatively independent first and second mushroom valves 22 and 23, respectively disposed in the two liquid passage holes 16. The first valve stem 24 is located on the first mushroom valve 22, and the second valve stem 25 is located on the second mushroom valve 23. The first and second valve stems 24 and 25 extend in opposite directions from the two liquid passage holes 16. As shown in FIG5 , this embodiment of the present application is another alternative embodiment of the mushroom valve assembly 2 and liquid passage hole 16. The first and second mushroom valves 22 and 23 are respectively disposed in opposite directions in the two liquid passage holes 16. Compared to arranging both the first and second mushroom valves 22 and 23 in a single liquid passage hole 16, this reduces the weight of the mushroom valves in the liquid passage hole 16, reduces the driving force required to move the mushroom valves, shortens the time it takes for the valves to close due to fluid force, and improves the responsiveness and closing speed of the mushroom valve assembly 2.

[0071] As an optional embodiment, the drive unit 1 is provided with a first shaft seal 19, and the hydraulic unit 3 is provided with a second shaft seal 36. The piston rod 4 is sealed and extends out of the drive unit 1 through the first shaft seal 19, and the piston rod 4 is sealed and extends out of the hydraulic unit 3 through the second shaft seal 36. The first shaft seal 19 and the second shaft seal 36 are spaced apart along the axial direction of the piston rod 4, and the exposed portion of the piston rod 4 between the first shaft seal 19 and the second shaft seal 36 defines an exposed section 40. The exposed section 40 on the piston rod 4 is completely exposed to the ambient air. The design of the exposed section 40 completely isolates the drive unit 1 from the hydraulic unit 3. If the first shaft seal 19 fails, the hydraulic oil will only leak into the ambient air. If hydrogen leaks, the hydrogen can fully flow and diffuse in the exposed section 40, avoiding pressure buildup. If the second shaft seal 36 fails, the hydrogen in the storage tank will also only leak into the ambient air. In the event of a failure in either the first shaft seal 19 or the second shaft seal 36, hydraulic oil is prevented from entering the liquid hydrogen storage tank 60 through the gap between the shaft and the shaft sleeve, potentially contaminating the liquid hydrogen. This also prevents hydrogen gas within the liquid hydrogen storage tank 60 from entering the hydraulic oil system and posing an explosion hazard, resulting in an inherently safer design. Specifically, hydraulic oil and hydrogen gas are prevented from mixing in the event of a shaft seal failure. Furthermore, both the first shaft seal 19 and the second bearing 36 are equipped with O-rings that mate with the piston rod 4, ensuring water, dust, and weather resistance.

[0072] Specifically, a mounting flange 37 is provided above the hydraulic section 3, and the second shaft seal 36 is located on the mounting flange 37. An exposed section 40 is located above the mounting flange 37. As shown in Figure 2, after the piston-type liquid hydrogen pump is installed upright on top of the liquid hydrogen storage tank 60, the exposed section 40 is exposed to the ambient air. The lower portion of the mounting flange 37 is connected to the liquid hydrogen storage tank 60. During operational inspections, the first shaft seal 19 on the piston rod 4 is checked for oil (hydraulic oil) leaks, and the second shaft seal 36 is checked for gas (hydrogen) leaks at the exposed section 40. This facilitates the timely inspection of the sealing performance of the first and second shaft seals 19 and 36, allowing for timely detection and repair of any anomalies. Because the piston rod 4 is completely exposed in the exposed section 40, it can also be used for equipment operational status diagnosis and integrity checks. For example, this can be used to monitor piston rod 4 vibration, stroke length, operational stability, displacement accuracy, and more. Online monitoring sensors can be installed in the exposed section 40 for online monitoring, forming an intelligent liquid hydrogen pump with fault detection capabilities.

[0073] As an optional embodiment, the piston-type liquid hydrogen pump further includes a drive assembly, comprising: a controller 5, a reversing valve 50, a hydraulic pump 51, a hydraulic pipe 1 52, a hydraulic pipe 2 53, a hydraulic tank 54, and a pressure sensor 55. The hydraulic pipe 1 52 communicates between the first drive liquid inlet and outlet 14 and the hydraulic tank 54, while the hydraulic pipe 2 53 communicates between the second drive liquid inlet and outlet 15 and the hydraulic tank 54. The reversing valve 50 is located on both the hydraulic pipe 1 52 and the hydraulic pipe 2 53. The hydraulic pump 51 and the pressure sensor 55 are located on the hydraulic pipe 1 52. The pressure sensor 55 is located on the outlet side of the hydraulic pump 51 and is used to detect the pressure in the hydraulic pipe 1 52. The output end of the pressure sensor 55 is communicatively connected to the input end of the controller 5. The input ends of the hydraulic pump 51 and the reversing valve 50 are communicatively connected to the output end of the controller 5. The hydraulic tank 54 in this embodiment of the present application stores hydraulic oil.

[0074] As shown in Figures 9 and 10, the mushroom valve assembly 2 mechanically controls the stroke to stop at the end point. During the compression stroke, the controller 5 controls the valve position of the reversing valve 50 to connect the hydraulic oil to the driving chamber 12 of the driving unit 1. The hydraulic oil pushes the first piston 11 downward in the driving chamber 12. The controller 5 determines whether the first piston 11 has reached the end point of the compression stroke by monitoring the pressure change through the pressure sensor 55. After the first piston 11 stops at the end point, the controller controls the reversing valve 50 to reverse and perform the suction stroke. The hydraulic oil is connected to the driving chamber 2 13 of the driving unit 1. The hydraulic oil pushes the second piston 31 upward in the driving chamber 2 13. Then, it is mechanically controlled to stop by the mushroom valve assembly 2 at the end point of the suction stroke. After being detected by the controller 5, it reverses again and starts the next stroke. This control cycle is repeated until the controller 5 issues a stop instruction.

[0075] The present application also provides a hydrogenation system 6, comprising: a liquid hydrogen storage tank 60, a vaporizer 61, a buffer tank 62, a liquid hydrogen pipeline 63, a gas hydrogen pipeline 630, a gas hydrogen hydrogenator 64 and the piston-type liquid hydrogen pump described in any one of the above embodiments; the piston-type liquid hydrogen pump is arranged in the liquid hydrogen storage tank 60; the liquid hydrogen pipeline 63 is connected between the liquid hydrogen storage tank 60 and the vaporizer 61, the gas hydrogen pipeline 630 is connected between the vaporizer 61 and the gas hydrogenator 64, and the buffer tank 62 is located on the gas hydrogen pipeline 630.

[0076] As shown in Figure 11, this application controls the operation of the liquid hydrogen pump to transport liquid hydrogen downstream. The vaporizer 61 vaporizes the high-pressure liquid hydrogen and raises the temperature to produce room-temperature, high-pressure hydrogen gas. This gas is then stored in the buffer tank 62 and supplied to the hydrogenator. Hydrogenation precooling utilizes the liquid hydrogen's inherent cooling capacity, meeting the T40-level rapid hydrogenation requirements of the J2601 protocol.

[0077] When the piston-type liquid hydrogen pump includes a drive assembly, the controller 5 in the drive assembly can also be used in the hydrogenation system 6. A first pressure sensor 68 is provided on the liquid hydrogen pipeline 63, a first temperature sensor 67 is provided on the gas hydrogen pipeline 630, and a second pressure sensor 69 is provided on the buffer tank 62. These sensors are used to measure the temperature and pressure at various locations. The detection signals are transmitted to the controller 5, and the controller 5 controls the hydrogenation system as a whole according to the temperature and pressure signals.

[0078] As an optional embodiment, the hydrogenation system 6 also includes a liquid hydrogen hydrogenator 65 and an insulated liquid hydrogen pipeline 66; the insulated liquid hydrogen pipeline 66 is connected between the liquid hydrogen storage tank 60 and the liquid hydrogen hydrogenator 65. As shown in Figure 12, in the embodiment of the present application, the output pressure and output flow of the piston-type liquid hydrogen pump are adjustable, and can be controlled by the controller 5 at any time as needed, which is very convenient to meet various process needs. Through the pump output pressure regulation and valve switching, the system can hydrogenate both gas hydrogen-carrying vehicles and liquid hydrogen-carrying vehicles. Double-layer insulated pipelines are used for the transportation of low-temperature liquid hydrogen and low-temperature gas hydrogen. The controller 5 collects the pressure and temperature signals of each detection point, and intelligently controls the transportation of each device and process medium (the control valve is not fully represented).

[0079] As an optional embodiment, the hydrogenation system 6 further includes a precooling unit, which includes a precooling pipe 8 and / or a heat exchanger. The hot end of the precooling pipe 8 is connected to the gas-hydrogen hydrogenation machine 65, and the hot end of the precooling pipe 8 is connected to the liquid hydrogen storage tank 60, or is connected to the cold end of the vaporizer 61, or is connected to the pipeline between the liquid hydrogen storage tank 60 and the vaporizer 61. The heat exchanger includes a hot flow pipe and a cold flow pipe for phase heat exchange, the hot flow pipe is connected to the gas-hydrogen hydrogenation machine 65, and the cold flow pipe is connected to the liquid hydrogen storage tank 60, or is connected to the cold end of the vaporizer 61, or is connected to the pipeline between the liquid hydrogen storage tank 60 and the vaporizer 61. The embodiment of the present application includes at least one of the pre-cooling pipe 8 and the heat exchanger, through which the gas hydrogen hydrogenator 65 and the liquid hydrogen storage tank 60, or the cold end of the vaporizer 61, or the pipeline between the liquid hydrogen storage tank 60 and the vaporizer 61 are controllably connected for heat exchange. And / or a heat exchanger is used to realize heat exchange between the gas hydrogen hydrogenator 65 and the liquid hydrogen storage tank 60, or the cold end of the vaporizer 61, or the pipeline between the liquid hydrogen storage tank 60 and the vaporizer 61, so as to use the cold capacity of the liquid hydrogen itself for pre-cooling during the gas hydrogenation process, and have the ability of rapid hydrogenation. The liquid hydrogen storage tank 60 in the embodiment of the present application can be a storage tank with zero boil-off (ZBO) capability.

[0080] As an optional embodiment, a vent pipe 70 is installed on the liquid hydrogen storage tank 60, and a safety valve 71 is provided on the vent pipe 70; the hydrogenation system 6 also includes a boost pipe 7, and the boost pipe 7 is connected between the vaporizer 61 and the liquid hydrogen storage tank 60 through a control valve 72. As shown in Figure 13, in the embodiment of the present application, the cold capacity of liquid hydrogen itself is used for pre-cooling during the hydrogenation of gaseous hydrogen, and the system has the ability to quickly hydrogenate. The low-temperature hydrogen at the saturation temperature of the vaporization section of the vaporizer 61 is used to control the pressurization of the liquid hydrogen storage tank 60. The system also has various accessories and technical measures required by engineering specifications, such as a control valve 72, a flow limiting orifice 74, a one-way valve 73, a vent pipe 70, and a safety valve 71 located on the vent pipe 70.

[0081] As an optional embodiment, the number of the piston-type liquid hydrogen pumps is at least two, and the at least two piston-type liquid hydrogen pumps are arranged in the liquid hydrogen storage tank 60. As shown in Figure 14, installing at least two piston-type liquid hydrogen pumps on a liquid hydrogen storage tank 60 is conducive to realizing multiple pumps for mutual backup or multiple pumps working in parallel, increasing the total delivery capacity, and providing selection for various processes with different requirements.

[0082] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0083] The above are only the principles and preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several other variations can be made based on the principles of the present invention, which should also be considered as the scope of protection of the present invention.

Claims

1. A piston type liquid hydrogen pump, characterized in that: include: A pump body, comprising: A driving part, wherein the driving part comprises a driving chamber, wherein a first piston is disposed in the driving chamber, wherein the first piston is slidably and sealedly disposed in the driving chamber, and the driving chamber is divided into a relatively independent first driving chamber and a second driving chamber, wherein a first driving liquid inlet and outlet are provided in the first driving chamber, and a second driving liquid inlet and outlet are provided in the second driving chamber; A mushroom valve assembly, wherein the first piston is provided with a liquid passage hole communicating with the first driving chamber and the second driving chamber, the mushroom valve assembly is movably arranged in the liquid passage hole and seals the liquid passage hole when moving to the opening of the liquid passage hole, and the mushroom valve assembly comprises a first valve stem and a second valve stem which are arranged in opposite directions and can extend out of the liquid passage hole in opposite directions; A hydraulic part, wherein the hydraulic part comprises a hydraulic chamber, wherein a second piston is disposed in the hydraulic chamber, and wherein the second piston is slidably and sealedly disposed in the hydraulic chamber to separate the hydraulic chamber into a first hydraulic chamber and a second hydraulic chamber; A piston rod, wherein the piston rod is sealed and connected between the first piston and the second piston, the second hydraulic chamber is located on the side of the second piston facing away from the first piston, and a liquid hydrogen one-way inlet and a liquid hydrogen one-way outlet are provided on the second hydraulic chamber.

2. The piston type liquid hydrogen pump according to claim 1, characterized in that: The inner walls of the two openings of the liquid passage hole are respectively provided with a first diameter reduction step and a second diameter reduction step, and the mushroom valve assembly includes a first sealing surface and a second sealing surface; When the first sealing surface contacts the first diameter-shrinking step, one opening of the liquid passage hole is sealed. When the second sealing surface contacts the second diameter-shrinking step, the other opening of the liquid passage hole is sealed.

3. The piston type liquid hydrogen pump according to any one of claims 1 to 2, characterized in that: The mushroom valve assembly further includes a connecting rod, the first mushroom valve includes a first valve head, and the second mushroom valve includes a second valve head; The first valve head is provided with a first limiting countersunk hole, the second valve head is provided with a second limiting countersunk hole, and both ends of the connecting rod are slidably limited in the first limiting countersunk hole and the second limiting countersunk hole, respectively.

4. The piston type liquid hydrogen pump according to claim 3, characterized in that: The first valve head and the second valve head are polygonal or circular, and the thickness of the first valve head and the second valve head gradually decreases from the center of the polygon or the circle to the periphery. The first limit countersunk hole is located at the center of the first valve head, and the second limit countersunk hole is located at the center of the second valve head.

5. The piston type liquid hydrogen pump according to claim 2, characterized in that: The number of the liquid-passing hole is one, and the first diameter-shrinking step and the second diameter-shrinking step are respectively located at two openings of the liquid-passing hole; The mushroom valve assembly includes a first mushroom valve and a second mushroom valve that are fixedly or movably connected, the first valve stem and the first sealing surface are located on the first mushroom valve, and the second valve stem and the second mushroom valve are both located on the second mushroom valve.

6. The piston type liquid hydrogen pump according to claim 3, characterized in that: The number of the liquid-passing holes is two, and the first diameter-shrinking step and the second diameter-shrinking step are respectively located in the two liquid-passing holes; The mushroom valve assembly includes two relatively independent first mushroom valves and second mushroom valves, the first mushroom valve and the second mushroom valve are respectively arranged in the two liquid holes, the first valve stem is located on the first mushroom valve, the second valve stem is located on the second mushroom valve, and the first valve stem and the second valve stem extend in opposite directions from the two liquid holes respectively.

7. The piston type liquid hydrogen pump according to claim 1, characterized in that: The driving part is provided with a first shaft seal, the hydraulic part is provided with a second shaft seal, the piston rod passes through the driving part from the first shaft seal, and the piston rod passes through the hydraulic part from the second shaft seal; The first shaft seal and the second shaft seal are spaced apart in the axial direction of the piston rod, and a partially exposed portion of the piston rod between the first shaft seal and the second shaft seal defines an exposed empty section.

8. The piston type liquid hydrogen pump according to claim 1, characterized in that: The piston type liquid hydrogen pump also includes a driving assembly, which includes: a controller, a reversing valve, a hydraulic pump, a hydraulic pipe 1, a hydraulic pipe 2, a hydraulic box, and a pressure sensor; The hydraulic first pipe is connected between the first inlet and outlet of the driving fluid and the hydraulic box. The second hydraulic pipe is connected between the second inlet and outlet of the driving fluid and the hydraulic box; The reversing valve is located on both the hydraulic pipe 1 and the hydraulic pipe 2, the hydraulic pump and the pressure sensor are located on the hydraulic pipe 1, and the pressure sensor is located on the outlet side of the hydraulic pump and is used to detect the pressure of the hydraulic pipe 1; The output end of the pressure sensor is communicatively connected to the input end of the controller; The input ends of the hydraulic pump and the reversing valve are communicatively connected with the output end of the controller.

9. A hydrogenation system, characterized in that: include: A liquid hydrogen storage tank, a vaporizer, a buffer tank, a liquid hydrogen pipeline, a gas hydrogen pipeline, a gas hydrogenation machine, and a piston liquid hydrogen pump according to any one of claims 1 to 8; The piston type liquid hydrogen pump is arranged in the liquid hydrogen storage tank; The liquid hydrogen pipeline is connected between the liquid hydrogen storage tank and the vaporizer, the gas hydrogen pipeline is connected between the vaporizer and the gas hydrogenation machine, and the buffer tank is located on the gas hydrogen pipeline.

10. The hydrogenation system according to claim 9, characterized in that: The hydrogenation system also includes a liquid hydrogenation machine and an insulated liquid hydrogen pipeline; The insulated liquid hydrogen pipeline is connected between the liquid hydrogen storage tank and the liquid hydrogenator.

11. The hydrogenation system according to claim 9, characterized in that: The hydrogenation system further comprises a precooling unit, which comprises a precooling pipe and / or a heat exchanger; The hot end of the precooling tube is connected to the gas hydrogenation machine, and the hot end of the precooling tube is connected to the liquid hydrogen storage tank, or connected to the cold end of the vaporizer, or connected to the pipeline between the liquid hydrogen storage tank and the vaporizer; The heat exchanger includes a hot flow pipe and a cold flow pipe for heat exchange, the hot flow pipe is connected to the gas hydrogenation machine, and the cold flow pipe is connected to the liquid hydrogen storage tank, or is connected to the cold end of the vaporizer, or is connected to the pipe between the liquid hydrogen storage tank and the vaporizer.

12. The hydrogenation system according to claim 9, characterized in that: The liquid hydrogen storage tank is provided with a vent pipe, and the vent pipe is provided with a safety valve; The hydrogenation system further comprises a pressurizing pipeline, which is connected between the vaporizer and the liquid hydrogen storage tank via a control valve.

13. The hydrogenation system according to claim 9, characterized in that: The number of the piston-type liquid hydrogen pumps is at least two, and at least two of the piston-type liquid hydrogen pumps are arranged in the liquid hydrogen storage tank.

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