A piston type liquid hydrogen pump and hydrogenation system

Abstract

The present application discloses a piston-type liquid hydrogen pump and a hydrogenation system. In the piston-type liquid hydrogen pump, a first piston is arranged in a driving chamber, a first driving liquid inlet and outlet are provided on the first driving chamber, and a second driving liquid inlet and outlet are provided on the second driving chamber; a liquid hole connecting the first driving chamber and the second driving chamber is provided on the first piston, and a mushroom valve assembly is movably arranged in the liquid hole and seals the liquid hole when it moves to the opening of the liquid hole; a second piston is arranged in the hydraulic chamber; a piston rod is sealed and connected between the first piston and the second piston, and a liquid hydrogen one-way inlet and a liquid hydrogen one-way outlet are provided on the second hydraulic chamber. The hydrogenation system includes a liquid hydrogen storage tank, a vaporizer, a buffer tank, a liquid hydrogen pipeline, a gas hydrogenation machine and a piston-type liquid hydrogen pump. The piston-type liquid hydrogen pump and the hydrogenation system provided in the present application mechanically control the start and stop of the piston through the mushroom valve assembly, have a low failure rate, are 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.

Description

Technical Field

[0001] 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

[0002] 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 high hydrogen storage density, low storage and transportation costs, low storage pressure, and is safer.

[0003] 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-exposed working conditions. Therefore, under current technology, the maximum pressure resistance of liquid hydrogen storage tanks is relatively low. Hydrogen refueling stations that store liquid hydrogen 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.

[0004] The hydrogen pumps in the prior art are generally piston-type liquid hydrogen pumps, which are generally divided into external and semi-submersible types. The external liquid hydrogen pump is installed outside the liquid hydrogen storage tank and connected to the liquid hydrogen storage tank through a pipeline to achieve the transportation of liquid hydrogen. The hydraulic end of the semi-submersible liquid hydrogen pump, which is responsible for the compression and transportation of liquid hydrogen, is installed inside the storage tank and immersed in liquid hydrogen, while the drive end is installed outside the liquid hydrogen storage tank.

[0005] The inventors discovered in the process of realizing the invention 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, and 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 only controlled by time, which has low reliability for controlling the start and stop of the piston; third, a shuttle valve is used, which has a large mass and volume, requires a large driving force of the hydraulic fluid when moving, and has a slow moving speed, resulting in a delayed control response of the start and stop of the piston, a long time required for control, and low control accuracy. Summary of the invention

[0006] The purpose of the present application is to provide a piston-type liquid hydrogen pump and a hydrogenation system to solve the problems existing in the prior art. The start and stop of the piston is mechanically controlled by a mushroom valve assembly, which has a low failure rate and is stable and reliable. In addition, the mushroom valve assembly has a small mass, which is conducive to improving the response speed and increasing the control accuracy.

[0007] The technical solution of the present application provides a piston-type liquid hydrogen pump, comprising: a pump body, the pump body comprising: a driving part, the driving part comprising a driving chamber, a first piston is arranged in the driving chamber, the first piston is slidably and sealedly arranged in the driving chamber, and the driving chamber is divided into a relatively independent driving chamber 1 and driving chamber 2, the driving chamber 1 is provided with a first driving liquid inlet and outlet, and the driving chamber 2 is provided with a second driving liquid inlet and outlet; a mushroom valve assembly, the first piston is provided with a liquid hole connecting the driving chamber 1 and the driving chamber 2, the mushroom valve assembly is movably arranged in the liquid hole and moves 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 the opposite direction; a hydraulic part, the hydraulic part includes a hydraulic chamber, a second piston is arranged in the hydraulic chamber, 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, the piston rod is sealingly 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.

[0008] Optionally, a first diameter reduction step and a second diameter reduction 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 reduction step, it seals one opening of the liquid hole, and when the second sealing surface contacts the second diameter reduction step, it seals the other opening of the liquid hole.

[0009] 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 opened on the first valve head, and a second limiting countersunk hole is opened 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.

[0010] 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 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. Optionally, the number of the liquid hole is one, and the first diameter reduction step and the second diameter reduction step are respectively located at two openings of the liquid 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.

[0011] 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.

[0012] 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; a distance is left between the first shaft seal and the second shaft seal along the axial direction of the piston rod, and the partially exposed part of the piston rod between the first shaft seal and the second shaft seal defines an exposed section.

[0013] Optionally, 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 pipe 1 is connected between the first inlet and outlet of the driving liquid and the hydraulic box, and the hydraulic pipe 2 is connected between the second inlet and outlet of the driving 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.

[0014] 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 liquid hydrogen pump as described in any one of the above; the piston 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.

[0015] Optionally, the hydrogenation system further includes a liquid hydrogen hydrogenation machine and an insulated liquid hydrogen pipeline; the insulated liquid hydrogen pipeline is connected between the liquid hydrogen storage tank and the liquid hydrogen hydrogenation machine.

[0016] 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 cold end of the precooling pipe 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 connected to the cold end of the vaporizer, or 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 boost pipe, which is connected between the vaporizer and the liquid hydrogen storage tank through a control valve.

[0017] 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.

[0018] The above technical solution has the following beneficial effects:

[0019] In the piston-type liquid hydrogen pump and hydrogenation system provided by the present application, the first valve stem and the second valve stem in the mushroom valve assembly 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 a large mechanical impact, and without relying on other components with a high failure rate 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, small vibration, and fast response speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of a piston-type liquid hydrogen pump in one embodiment of the present application;

[0021] Figure 2 This is a structural schematic diagram of a piston-type liquid hydrogen pump provided with an exposed section in one embodiment of the present application;

[0022] Figure 3 This is a schematic diagram of a structure in which a first mushroom valve and a second mushroom valve that are fixedly connected are arranged in a liquid passage hole in one embodiment of the present application;

[0023] Figure 4 This is a schematic diagram of a structure in which a first mushroom valve and a second mushroom valve that are movably connected are arranged in a liquid passage hole in one embodiment of the present application;

[0024] Figure 5 This is a schematic diagram of a structure in which a first mushroom valve and a second mushroom valve are respectively arranged in two liquid passage holes in one embodiment of the present application;

[0025] Figure 6a This is a schematic diagram of a structure in which a first sealing surface abuts against a first diameter reduction step in an embodiment of the present application;

[0026] Figure 6b This is a schematic diagram of the structure in which the second sealing surface abuts against the second diameter reduction step in one embodiment of the present application;

[0027] Figure 7a This is a schematic diagram of the structure in which 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;

[0028] Figure 7b This is a schematic diagram of the structure in which 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;

[0029] Figure 7c It is a structural schematic diagram of an embodiment of the present application in which the first mushroom valve and the second mushroom valve are connected by a connecting rod and abut against the first sealing surface and the second sealing surface respectively when they are not in contact with each other;

[0030] Figure 7d It is a structural schematic diagram of an embodiment of the present application in which the first mushroom valve and the second mushroom valve are connected by a connecting rod and abut against the first sealing surface and the second sealing surface respectively when they are not in contact with each other;

[0031] Figure 7e This is a schematic structural diagram of a first mushroom valve and a second mushroom valve in contact with each other in an embodiment of the present application;

[0032] Figure 7f This is a schematic structural diagram of a first mushroom valve and a second mushroom valve in contact with each other in an embodiment of the present application;

[0033] Figure 8a This is a schematic diagram of the structure of a first valve head in an embodiment of the present application that is a hexagon with an arc transition;

[0034] Figure 8b This is a schematic structural diagram of a first valve head in an embodiment of the present application that is a pentagon with an arc transition;

[0035] Figure 8c This is a schematic structural diagram of a first valve head in an embodiment of the present application that is a quadrilateral with an arc transition;

[0036] Figure 8d This is a schematic diagram of a structure in which the first valve head is hexagonal in one embodiment of the present application;

[0037] Figure 8e This is a schematic diagram of a structure in which the first valve head is a pentagon in one embodiment of the present application;

[0038] Figure 8fThis is a schematic structural diagram of a first valve head in a quadrilateral shape in one embodiment of the present application;

[0039] Fig. 9 This is a flow chart of a driving connection between a driving assembly and a piston-type liquid hydrogen pump having a liquid through hole in one embodiment of the present application;

[0040] Fig.10 This is a flow chart of a driving connection between a driving assembly and a piston-type liquid hydrogen pump provided with two liquid holes in one embodiment of the present application;

[0041] Fig.11 This is a flow chart of a hydrogenation system in one embodiment of the present application;

[0042] Fig.12 This 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;

[0043] Fig.13 This is a flow chart of a hydrogenation system provided with a safety valve and a pressurized pipeline in one embodiment of the present application;

[0044] Fig.14 This is a schematic diagram of the structure of two piston-type liquid hydrogen pumps provided in a liquid hydrogen storage tank in one embodiment of the present application.

[0045] Reference Numbers

[0046] 100- pump body;

[0047] 1-driving part, 10-driving chamber, 11-first piston, 12-driving chamber 1, 13-driving chamber 2, 14-driving liquid first inlet and outlet, 15-driving liquid second inlet and outlet, 16-liquid hole, 17-first diameter reduction step, 18-second diameter reduction step, 19-first shaft seal;

[0048] 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;

[0049] 3-hydraulic part, 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;

[0050] 4-piston rod, 40-exposed hollow section;

[0051] 5-controller, 50-reversing valve, 51-hydraulic pump, 52-hydraulic pipe 1, 53-hydraulic pipe 2, 54-hydraulic box, 55-pressure sensor;

[0052] 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;

[0053] 7-boosting pipeline, 70-vent pipe, 71-safety valve, 72-control valve, 73-check valve, 74-flow limiting orifice plate;

[0054] 8- Pre-cool the tubes. DETAILED DESCRIPTION

[0055] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0056] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a variety of structural modes and implementation modes that can be replaced by those skilled in the art can be replaced with each other. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the invention.

[0057] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. They are relative concepts and may change accordingly according to different positions and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0058] The present application provides a piston type liquid hydrogen pump, comprising: a pump body 100. The pump body 100 comprises: a driving part 1, a mushroom valve assembly 2, a hydraulic part 3 and a piston rod 4.

[0059] The driving part 1 includes a driving chamber 10, in which a first piston 11 is arranged. The first piston 11 is slidably and sealedly arranged in the driving chamber 10 to separate 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 inlet and outlet 14 for driving liquid, and the second driving chamber 13 is provided with a second inlet and outlet 15 for driving liquid.

[0060] like Figures 1 to 5 As shown, the first piston 11 is provided with a liquid passage hole connecting the first driving chamber 12 and the second driving chamber 13, the mushroom valve assembly 2 is movably arranged in the liquid passage hole 16 and seals the liquid passage hole 16 when moving to the opening of the liquid passage hole 16, and the mushroom valve assembly 2 includes a first valve stem 24 and a second valve stem 25 which are arranged back to back and can extend out of the liquid passage hole 16 in the opposite direction.

[0061] 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 .

[0062] like Figure 1 to Figure 2 As shown, the piston rod 4 is sealed and connected between the first piston 11 and the second piston 31, and 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 with the first piston 11 and the second piston 31, which can move under the action of hydraulic pressure (hydraulic oil) to compress liquid hydrogen and inhale liquid hydrogen, realizing the basic 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.

[0063] 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 driving chamber 12 of the driving part 1 through the first driving liquid inlet and outlet 14, and the hydraulic oil pushes the first piston 11 to move downward in the first driving chamber 12. The first piston 11 is connected to the second piston 31 through the piston rod 4, driving the second piston 31 to move downward at the same time, squeezing liquid hydrogen in the second hydraulic chamber 33, and the pressurized liquid hydrogen is output through the liquid hydrogen one-way outlet 35 and the discharge pipeline.

[0064] 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 to move upward in the second driving chamber 13, and the second piston 31 is also driven to move upward through the piston rod 4. Liquid hydrogen is sucked into the second hydraulic chamber 33 through the liquid hydrogen one-way inlet 34 so as to compress the liquid hydrogen in the next compression stroke.

[0065] 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, the protruding first valve stem 24 or the 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 driven by the hydraulic oil continues to move, causing the relative position of the mushroom valve assembly 2 and the first piston 11 to change. The mushroom valve assembly 2 is separated 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, resulting in a rapid increase in the hydraulic oil pressure on the other side. The pressure difference on both sides of the first piston 11 is rapidly reduced, and the first piston 11 loses the thrust to continue moving and stops.

[0066] 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 stop control relies on the balance of the hydraulic oil pressure on both sides of the first piston 11, does not produce a large mechanical impact, and does not rely on other components with a high failure rate such as position sensors.

[0067] 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 stopped by mechanical control 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. In addition, 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.

[0068] As an optional embodiment, the inner walls of the two openings of the liquid hole 16 are respectively provided with a first diameter reduction step 17 and a second diameter reduction step 18, and 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 diameter reduction step 17, one opening of the liquid hole 16 can be sealed under the hydraulic oil pressure, and when the second sealing surface 21 contacts the second diameter reduction step 18, the other opening of the liquid hole 16 can be sealed under the hydraulic oil pressure. Figure 6a to Figure 6b As shown, the first and second diameter-shrinking steps 17 and 18 in the embodiment of the present application can be defined by a cylindrical structure disposed on the inner wall of the opening of the liquid hole 16. The cylindrical structure is fixed to the inner wall of the liquid hole 16 by threaded connection, welding, interference fit, etc., so that the opening of the liquid hole 16 is in a state of diameter shrinkage, defining the first and second diameter-shrinking steps 17 and 18. The cylindrical structure can be a nut.

[0069] 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 is provided with a first limiting countersunk hole, and the second valve head 28 is provided with a second limiting countersunk hole, and the two ends of the connecting rod 26 are respectively slidably limited in the first limiting countersunk hole and the second limiting countersunk hole. The first sealing surface 20 is located on the first valve head 27, and the first valve head 27 is provided with a first limiting countersunk hole on the side facing away from the first sealing surface 20. The second sealing surface 21 is located on the second valve head 28, and the second valve head 28 is provided with a second limiting countersunk hole on the side facing away from the second sealing surface 21.

[0070] The connecting rod 26 is a pin-shaped straight rod, and both ends of the connecting rod 26 can be provided with limiting protrusions, and the limiting protrusions are respectively limited in the first limiting counterbore and the second limiting counterbore provided in the constriction, so that the connecting rod 26 can slide freely but will not slide out. The connecting rod 26 guides and positions the first mushroom valve 22 and the second mushroom valve 23, and maintains the relative position between the first mushroom valve 22 and the second mushroom valve 23. The first mushroom valve 22 and the second mushroom valve 23 can only move in the direction of movement of the first piston 11, and the angle of the first mushroom valve 22 and the second mushroom valve 23 is prevented from being deflected.

[0071] The force on the connecting rod 26 is very small, and the force is mainly the gravity of the mushroom valve assembly 2, the small impact force during start-stop, and the unbalanced force of fluid flushing. The strength of the connecting rod 26 is designed according to its force conditions. In order to reduce the size of the connecting rod 26 and reduce the force on the connecting rod 26, the sum of the depths of the first limit countersunk hole and the second limit countersunk hole can be designed to be greater than the length of the connecting rod 26, so that the first valve head 27 and the second valve head 28 can contact each other in normal conditions without contacting through the connecting rod 26, so that the impact force on the mushroom valve assembly 2 is transferred to the mushroom valve assembly 2 itself, and the connecting rod 26 is not subject to the impact force, but only to the unbalanced force. The connecting rod 26 can be made small, and reducing the size of the connecting rod 26 is conducive to reducing the size of the first limit countersunk hole and the second limit countersunk hole. Reducing the first limit countersunk hole and the second limit countersunk hole can ensure the strength of the first valve head 27 and the second valve head 28 without adding additional thickness. The umbrella-shaped first valve head 27 and the second valve head 28 can be made as thin as possible to achieve high-pressure sealing and rapid response at the lightest weight.

[0072] 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 limit countersunk hole is located at the center of the first valve head 27, and the second limit countersunk hole is located at the center of the second valve head 28. Figures 8a to 8e As shown, when the first valve head 27 and the second valve stem 25 are polygonal shapes such as square, pentagon, hexagon, etc., the gap between the polygon and the circular liquid 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, it is necessary to open a plurality of guide grooves on the circumference to form a gap with the liquid hole 16 as a flow channel 29 for the hydraulic oil fluid.

[0073] like Figures 7a to 7eAs shown, 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 part of the first valve head 27 and the second valve head 28 bears pressure and is the area with the greatest stress. The edges cooperate with the first sealing surface 20 and the second sealing surface 21 to seal, and the weight-to-area ratio of the edges is smaller than that of the center part. This structure can reduce the weight as much as possible while keeping its force-bearing area and pressure resistance unchanged. As a result, the mushroom valve assembly 2 has a faster response time when switching between its open position and closed position.

[0074] At the moment of starting, the hydraulic oil is switched, 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 valve core with a small mass has a fast response speed and a good response effect. In the present application, the mushroom-shaped first valve head 27 and the second valve head 28 are the preferred shapes for achieving response.

[0075] As an optional embodiment, the number of the liquid passage hole 16 is one, and the first diameter-shrinking step 17 and the second diameter-shrinking step 18 are respectively located at 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 installed on a side of the first mushroom valve 22 where the first sealing surface 20 is provided, and the second valve stem 25 is installed on a side of the second mushroom valve 23 where the second sealing surface 21 is provided.

[0076] like Figure 3 As shown, when the first mushroom valve 22 and the second mushroom valve 23 are fixedly connected, the first mushroom valve 22 and the second mushroom valve 23 are fixedly connected together to form a mushroom string valve. The fixedly connected mushroom string valve is processed using a whole piece of material and mechanically processed into a mushroom string valve shape, which simplifies the design and improves reliability.

[0077] As an optional embodiment, the number of the liquid passage holes 16 is two, and the first diameter reduction step 17 and the second diameter reduction step 18 are respectively located in the two liquid passage holes 16; the mushroom valve assembly 2 includes two relatively independent first mushroom valves 22 and second mushroom valves 23, the first mushroom valve 22 and the second mushroom valve 23 are respectively arranged in the two liquid passage holes 16, the first valve stem 24 is located on the first mushroom valve 22, the second valve stem 25 is located on the second mushroom valve 23, and the first valve stem 24 and the second valve stem 25 respectively extend in opposite directions from the two liquid passage holes 16. Figure 5 As shown, the embodiment of the present application is another optional embodiment of the mushroom valve assembly 2 and the liquid hole 16. The first mushroom valve 22 and the second mushroom valve 23 are respectively arranged in opposite directions in the two liquid holes 16. Compared with arranging the first mushroom valve 22 and the second mushroom valve 23 in one liquid hole 16 at the same time, it is beneficial to reduce the weight of the mushroom valve in the liquid hole 16, so that the driving force required to move the mushroom valve is smaller, and the time for closing by fluid force is also short, thereby improving the response closing speed of the mushroom valve assembly 2.

[0078] As an optional embodiment, the driving part 1 is provided with a first shaft seal 19, and the hydraulic part 3 is provided with a second shaft seal 36. The piston rod 4 is sealed and passes through the driving part 1 from the first shaft seal 19, and the piston rod 4 is sealed and passes through the hydraulic part 3 from 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 part 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 driving part 1 from the hydraulic part 3. When the first shaft seal 19 fails, the hydraulic oil will only leak into the ambient air. When hydrogen leaks, the hydrogen can fully flow and diffuse in the exposed section 40 to avoid pressure build-up. When the second shaft seal 36 fails, the hydrogen in the storage tank will also only leak into the ambient air. When the first shaft seal 19 or the second shaft seal 36 fails, it prevents the hydraulic oil from entering the liquid hydrogen storage tank 60 through the gap between the shaft and the shaft sleeve to contaminate the liquid hydrogen, and also prevents the hydrogen in the liquid hydrogen storage tank 60 from entering the hydraulic oil system to form an explosion hazard, which is an inherently safer design. That is, when the shaft seal fails, the hydraulic oil and hydrogen will not mix. In addition, the first shaft seal 19 and the second bearing 36 are both provided with O-rings that match the piston rod 4 to achieve waterproof, dustproof and weatherproof.

[0079] Specifically, a mounting flange 37 is provided above the hydraulic part 3, and the second shaft seal 36 is located on the mounting flange 37. The exposed section 40 is located at the upper part of the mounting flange 37. Figure 2As shown, after the piston-type liquid hydrogen pump is installed upright on the top of the liquid hydrogen storage tank 60, the exposed section 40 is exposed to the ambient air. The lower part of the mounting flange 37 is connected to the liquid hydrogen storage tank 60. During the operation status inspection, check whether the first shaft seal 19 on the piston rod 4 is leaking oil (hydraulic oil) at the exposed section 40, and check whether the second shaft seal 36 is leaking gas (hydrogen), so as to facilitate the inspection of the sealing performance of the first shaft seal 19 and the second shaft seal 36 at any time, and timely discover and repair any abnormalities. Since the piston rod 4 in the exposed section 40 is completely exposed, it can also be used for equipment operation status diagnosis and integrity inspection. For example, vibration monitoring, stroke length monitoring, operation stability detection, displacement accuracy detection, etc. of the piston rod 4. An online monitoring sensor can be installed at the exposed section 40 for online monitoring, which can form an intelligent liquid hydrogen pump with fault detection function.

[0080] As an optional embodiment, the piston type liquid hydrogen pump further includes a driving assembly, which includes: a controller 5, a reversing valve 50, a hydraulic pump 51, a hydraulic pipe 1 52, a hydraulic pipe 2 53, a hydraulic box 54, and a pressure sensor 55. The hydraulic pipe 1 52 is connected between the first inlet and outlet 14 of the driving liquid and the hydraulic box 54, and the hydraulic pipe 2 53 is connected between the second inlet and outlet 15 of the driving liquid and the hydraulic box 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, and the pressure sensor 55 is located on the outlet side of the hydraulic pump 51 for detecting the pressure of the hydraulic pipe 1 52; the output end of the pressure sensor 55 is connected to the input end of the controller 5 in communication; the input end of the hydraulic pump 51 and the reversing valve 50 are connected to the output end of the controller 5 in communication. The hydraulic box 54 in the embodiment of the present application stores hydraulic oil.

[0081] like Fig. 9 and Fig.10 As shown, 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, and 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 the pressure change monitored by the pressure sensor 55, and after the first piston 11 stops at the end point, 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, and the hydraulic oil pushes the second piston 31 upward in the driving chamber 13, and then 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 is reversed again to start the next stroke. The control is repeated in this cycle until the controller 5 issues an instruction to stop the operation.

[0082] 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 hydrogenation machine 64 and a piston-type liquid hydrogen pump as 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 hydrogenation machine 64, and the buffer tank 62 is located on the gas hydrogen pipeline 630.

[0083] like Fig.11 As shown, the present application controls the operation of the liquid hydrogen pump to transport the liquid hydrogen downstream. The vaporizer 61 vaporizes the high-pressure liquid hydrogen and raises the temperature to high-pressure gas hydrogen at room temperature, which is stored in the buffer tank 62 and supplied to the hydrogenator. The hydrogenation precooling can use the cooling capacity of the liquid hydrogen itself to meet the T40-level rapid hydrogenation requirements of the J2601 protocol.

[0084] When the piston-type liquid hydrogen pump includes a driving assembly, the controller 5 in the driving 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, which are used to measure the temperature and pressure at various locations. The detection signal is transmitted to the controller 5, and the controller 5 controls the hydrogenation system as a whole according to the temperature and pressure signals.

[0085] As an optional embodiment, the hydrogenation system 6 further includes a liquid hydrogenation machine 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 hydrogenation machine 65. Fig.12 As shown, in the embodiment of the present application, the output pressure and output flow of the piston 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 adjustment and valve switching, the system can hydrogenate both gas hydrogen-carrying vehicles and liquid hydrogen-carrying vehicles. Low-temperature liquid hydrogen and low-temperature gas hydrogen are transported using double-layer insulated pipes. 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).

[0086] 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 hydrogenation machine 65, and the cold 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 pipeline and a cold flow pipeline for heat exchange, the hot flow pipeline is connected to the gas hydrogenation machine 65, and the cold flow pipeline 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 precooling 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 for precooling 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.

[0087] As an optional embodiment, the liquid hydrogen storage tank 60 is equipped with a vent pipe 70, and the vent pipe 70 is provided with a safety valve 71; the hydrogenation system 6 also includes a booster pipe 7, and the booster pipe 7 is connected between the vaporizer 61 and the liquid hydrogen storage tank 60 through a control valve 72. Fig.13 As shown, in the embodiment of the present application, the cold capacity of liquid hydrogen itself is used for precooling during the hydrogenation process of gaseous hydrogen, and the system has the ability of rapid hydrogenation. 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.

[0088] As an optional embodiment, 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 60. Fig.14 As shown, installing at least two piston-type liquid hydrogen pumps on a liquid hydrogen storage tank 60 is conducive to realizing the mutual backup of multiple pumps, or multiple pumps working in parallel, increasing the total delivery capacity, and providing selection for various processes with different requirements.

[0089] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0090] 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 modifications can be made based on the principles of the present invention, which should also be considered as the protection scope 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; The mushroom valve assembly comprises a first mushroom valve and a second mushroom valve which are fixedly or movably connected, and the mushroom valve assembly further comprises a connecting rod, wherein the first mushroom valve comprises a first valve head, and the second mushroom valve comprises a second valve head; a first limiting counterbore is provided on the first valve head, and a second limiting counterbore is provided on the second valve head, and both ends of the connecting rod are slidably limited in the first limiting counterbore and the second limiting counterbore respectively; The first valve stem is located on the first valve head, the second valve stem is located on the second valve head, the first position limiting countersunk hole is located at the center of the first valve head, the second position limiting countersunk hole is located at the center of the second valve head, and the sum of the depths of the first position limiting countersunk hole and the second position limiting countersunk hole is greater than the length of the connecting rod; 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, the first valve head has a first sealing surface, and the second valve head has 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 claim 2, characterized in that: The first valve head and the second valve head are polygonal or circular, and thicknesses of the first valve head and the second valve head gradually decrease from the center to the periphery of the polygon or the circle.

4. 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.

5. 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.

6. 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 first hydraulic pipe is connected between the first inlet and outlet of the driving fluid and the hydraulic box, and 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.

7. 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 6; 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.

8. The hydrogenation system according to claim 7, 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.

9. The hydrogenation system according to claim 7, 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 cold 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.

10. The hydrogenation system according to claim 7, 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.

11. The hydrogenation system according to claim 7, 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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