Suspension valve disc system of immersed liquid hydrogen pump

Abstract

The invention discloses a suspension valve disc system of an immersed liquid hydrogen pump. The suspension valve disc system comprises a pump body and a piston rod arranged in the pump body. The connecting piece is movably installed in the piston rod, one end of the inhaul cable is fixedly connected with the connecting piece, the valve disc is fixedly connected with the other end of the inhaul cable, and the inhaul cable is connected with a first spring. The limiting table is arranged in the piston rod; the positioning table is arranged on the connecting piece; the spring II is arranged between the limiting table and the positioning table; the inhaul cable, the second spring and the first spring are each provided with a coating used for resisting liquid hydrogen permeation and low temperature so as to prolong the service life and improve the use performance. The coatings are additionally arranged on the surfaces of the inhaul cable, the second spring and the first spring and used for enhancing the corrosion resistance and hydrogen permeation resistance of the inhaul cable, the second spring and the first spring, so that the inhaul cable has good hydrogen embrittlement resistance and corrosion resistance, and the service life of the inhaul cable, the second spring and the first spring can be effectively prolonged.

Description

Technical Field

[0001] The invention relates to a submersible liquid hydrogen pump, in particular to a suspended valve disc system of a submersible liquid hydrogen pump. Background Art

[0002] Liquid hydrogen is a high-energy, ultra-low temperature liquid clean fuel. Compared with gaseous hydrogen and metal hydrides, liquid hydrogen has incomparable advantages in energy storage density and transportation costs, and has a broad development space. China has also issued a number of relevant policies to support the hydrogen source industry. The liquid hydrogen pump used for liquid hydrogen transportation is one of the important equipment in the liquid hydrogen industry.

[0003] The existing general reciprocating ultra-low temperature pumps are all exposed to the outside, and the temperature of liquid hydrogen is -253℃. If the liquid hydrogen pump is directly exposed to the atmosphere, the evaporation rate of liquid hydrogen will be high due to the high temperature, the efficiency will be reduced, and the cavitation phenomenon will increase. Therefore, in order to avoid the temperature of the liquid hydrogen pump being too high, it is necessary to perform deep pre-cooling before starting the pump. The preparation work is cumbersome and time-consuming. The pre-cooling time takes at least half an hour. The pump head must be fully adapted to the temperature of the low temperature environment before it can be used. If the liquid hydrogen pump is still at room temperature, the liquid will enter the pump body and start running, which will produce a large amount of cavitation and cannot generate pressure. In addition, the pump itself is made of metal, and the cold and hot and cavitation will also produce low-temperature contraction, resulting in a difference.

[0004] Therefore, some existing liquid hydrogen pumps directly place the pump body in liquid hydrogen, and the liquid hydrogen enters the piston from the liquid hydrogen pool, pushing the valve disc placed at the end of the piston to open the flow path between the piston and the valve disc, and then the liquid hydrogen is transmitted between the piston and the pump body before the liquid hydrogen is pumped out through the liquid outlet through the piston. The valve disc is suspended and installed in the piston through a cable and a spring; however, since the spring is in direct contact with liquid hydrogen for a long time and the temperature of liquid hydrogen is very low, direct contact with the spring will affect the performance and service life of the spring, and even fail. Once the spring fails, it cannot drive the valve disc to fit tightly with the end of the piston through the reset force, resulting in the inability to cut off the flow path between the valve disc and the piston, and it is impossible to work normally or even leak. To this end, a suspended valve disc system for a submersible liquid hydrogen pump is proposed. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems and to provide a suspended valve disc system for a submersible liquid hydrogen pump.

[0006] In order to achieve the above-mentioned purpose, the present invention provides the following technical solution: a suspended valve disc system of a submersible liquid hydrogen pump, comprising a pump body and a piston rod disposed in the pump body; characterized in that it also includes a connecting piece movably installed in the piston rod, a cable fixedly connected to the connecting piece at one end, and a valve disc fixedly connected to the other end of the cable, wherein the cable is connected to a spring 1; it also includes a limit platform arranged in the piston rod, a positioning platform arranged on the connecting piece, and a spring 2 installed between the limit platform and the positioning platform; the cable, spring 2 and spring 1 are all provided with a coating for resisting liquid hydrogen penetration and low temperature to improve service life and performance.

[0007] Further preferably, the coating is a combination of any one or more of a boron nitride coating, a galvanized coating, a high entropy alloy coating, and a polyetheretherketone coating.

[0008] Further preferably, the coating is made by mixing multiple materials selected from the group consisting of vermiculite powder, silicon nitride, antimony trioxide, zinc borate, and rutile titanium dioxide.

[0009] Further preferably, the ratio of the coating is 30%-40% vermiculite powder, 30%-40% silicon nitride, 5%-10% antimony trioxide, 5%-12% zinc borate, and 10%-18% rutile titanium dioxide.

[0010] Further preferably, it also includes a protection module for isolating liquid hydrogen, the protection module includes a hollow connecting piece, an inner tube slidably installed in the connecting piece for protection and isolation, and the other end of the inner tube is fixedly connected to the valve disc; the cable and the spring are located in the connecting piece and the inner tube; and it also includes a multi-stage sealing ring installed between the inner tube and the connecting piece.

[0011] Further preferably, a safety module is included to provide safety protection for the use of the entire liquid hydrogen pump, wherein the safety module comprises an air pipe installed on the connector and passing through the piston rod at one end, and an air bag placed in the valve disc and connected to the inner tube to provide safety protection to avoid leakage due to failure.

[0012] Further preferably, it also includes a detachable sealing plate installed at the bottom of the valve disc and an ultra-low temperature sealing member arranged between the sealing plate and the valve disc.

[0013] Further preferably, the valve disc is provided with an arc-shaped groove, and the sealing plate is provided with an arc-shaped protrusion adapted to the arc-shaped groove.

[0014] Further preferably, it also includes a plurality of expansion grooves arranged on the side wall of the blocking plate to facilitate the expansion of the side wall after being compressed.

[0015] Further preferably, it also includes a pull rod arranged on the valve disc and the connecting member for connecting the pull cable.

[0016] The beneficial effects of the present invention are as follows: by adding a coating on the surface of the cable, the second spring and the first spring, the corrosion resistance and hydrogen penetration resistance of the cable, the second spring and the first spring are enhanced, so that the cable, the second spring and the first spring have good hydrogen embrittlement resistance and corrosion resistance, and the service life of the cable, the second spring and the first spring can be effectively improved; The connection piece and the inner tube are arranged to avoid direct contact between liquid hydrogen and the cable and spring, thereby preventing the spring from being affected by the low temperature of liquid hydrogen and affecting its performance and service life or even causing failure. At the same time, an airbag is installed in the valve disc, and the airbag is connected to the air source through the inner tube, the connecting piece and the air pipe. When the spring fails, air is supplied to the airbag, and the airbag expands after being inflated, and the sealing plate is pushed away from the valve disc through the extrusion force, and then falls on the bottom of the pump body to cover the liquid outlet. At the same time, after the airbag expands, an upward thrust is formed on the valve disc, and a downward thrust is formed on the sealing plate, thereby blocking the piston rod and the liquid outlet on the pump body, waiting for the staff to carry out maintenance, thereby avoiding the problem of liquid hydrogen leakage caused by the failure of the spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 is a schematic diagram of the structure of Embodiment 2 of the present invention; Figure 3 It is a partial structural schematic diagram of embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the local structure of the connecting piece of Example 2 of the present invention; Figure 5 It is a schematic diagram of the local structure of the valve disc in Example 2 of the present invention; Figure 6 It is a schematic diagram of the local structure of the connection between the blocking plate and the valve disc in Example 2 of the present invention; Figure 7 It is a schematic structural diagram of the blocking plate in Example 2 of the present invention.

[0018] Legend: 1. Pump body; 2. Piston rod; 21. Limiting platform; 3. Connecting piece; 31. Positioning platform; 4. Inner tube; 41. Multi-stage sealing ring; 5. Pull cable; 6. Valve disc; 61. Sealing plate; 62. Ultra-low temperature sealing element; 63. Arc-shaped slot; 64. Arc-shaped protrusion; 65. Pull rod; 66. Expansion slot; 7. Spring 1; 8. Spring 2; 9. Trachea; 91. Air bag. DETAILED DESCRIPTION

[0019] Next, we will further explain the suspension valve disc system of a submersible liquid hydrogen pump described in the present invention with reference to the drawings.

[0020] It should be noted that all directional indications in the embodiments of the present invention, such as up, down, left, right, front, back, etc., are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture as shown in the figure. If the specific posture changes, the directional indication will also change accordingly.

[0021] In the present invention, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. should be understood in a broad sense; for example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example 1

[0022] See also Figure 1 As shown in, a suspension valve disc system of a submersible liquid hydrogen pump comprises a pump body 1 and a piston rod 2 disposed in the pump body 1; it is characterized in that it also comprises a connecting member 3 movably mounted in the piston rod 2, a cable 5 fixedly connected to the connecting member 3 at one end, and a valve disc 6 fixedly connected to the other end of the cable 5, wherein the cable 5 is connected to a spring 7; it also comprises a limit platform 21 disposed in the piston rod 2, a positioning platform 31 disposed on the connecting member 3, and a spring 2 8 mounted between the limit platform 21 and the positioning platform 31; the cable 5, the spring 2 8 and the spring 1 7 are all provided with a coating for resisting liquid hydrogen penetration and low temperature to improve service life and performance; The limit platform 21 and the positioning platform 31 are provided to limit the movement of the connecting member 3. The spring 28 is provided to elastically connect the connecting member 3 and the limit platform 21, and the spring 28 cooperates with the pull cable 5 and the valve disc 6 to reset. The coating is any one or more of a boron nitride coating, a zinc coating, a high entropy alloy coating, and a polyetheretherketone coating; By adding a coating on the surface of the cable, spring two and spring one, the corrosion resistance and hydrogen penetration resistance of the cable, spring two and spring one are enhanced, so that they have good hydrogen embrittlement resistance and corrosion resistance, and can effectively improve the service life of the cable, spring two and spring one. Example 2

[0023] The difference between this embodiment and embodiment 1 is that the coating in this embodiment is made of a mixture of multiple types of vermiculite powder, silicon nitride, antimony trioxide, zinc borate, and rutile titanium dioxide; vermiculite powder is used because it has good frost resistance and can ensure that its performance does not change at low temperatures; silicon nitride is used because it has high hardness, high strength, good wear resistance and chemical corrosion resistance; antimony trioxide is used because it has good cold resistance, good dimensional stability and mechanical strength under low temperature conditions, and will not be deformed or cracked due to temperature changes; zinc borate is used to improve corrosion resistance; rutile titanium dioxide is used because it has good weather resistance and chemical stability; The coating material ratio in this embodiment is 30% vermiculite powder, 35% silicon nitride, 8% antimony trioxide, 10% zinc borate, and 17% rutile titanium dioxide. Example 3

[0024] The difference between this embodiment and embodiment 2 is that the ratio of the coating material in this embodiment is 35% of vermiculite powder, 37% of silicon nitride, 7% of antimony trioxide, 9% of zinc borate, and 12% of rutile titanium dioxide. Example 4

[0025] See also Figure 2-Figure 7 As shown in , the difference between this embodiment and embodiments 1-3 is that this embodiment further includes a protection module for isolating liquid hydrogen for the cable and the spring, the protection module includes a hollow connection member 3, an inner tube 4 slidably installed in the connection member 3 for protection and isolation, and the other end of the inner tube 4 is fixedly connected to the valve disc 6; the cable 5 and the spring 7 are in the connection member 3 and the inner tube 4; In this embodiment, the connecting piece is arranged to be hollow. Through the arrangement of the connecting piece 3 and the inner tube 4, direct contact between liquid hydrogen and the cable 5 and the spring 7 is avoided, thereby preventing the spring 7 from being directly affected by the low temperature of liquid hydrogen and affecting its performance and service life or even causing failure.

[0026] In one embodiment, a safety module is also included to play a safety protection role for the use of the entire liquid hydrogen pump, and the safety module includes an air pipe 9 installed on the connecting piece 3 and one end of which passes through the piston rod 2, and an air bag 91 placed in the valve disc 6 and connected to the inner tube 4 to play a safety protection role to avoid leakage due to failure; the port of the air bag 91 can be fixedly installed in the valve disc 6 through a pressure plate and connected to the inner tube 4; the air pipe 9 and the connecting piece 3 can be connected by a flange or a joint; It also includes a sealing plate 61 detachably mounted on the bottom of the valve disc 6 and an ultra-low temperature sealing member 62 disposed between the sealing plate 61 and the valve disc 6; By providing the ultra-low temperature seal 62, liquid hydrogen is prevented from entering the valve disc 6 during use; By installing an airbag 91 in the valve disc 6, the airbag 91 is connected to the air source through the inner tube 4, the connecting piece 3 and the air pipe 9. When the spring 7 fails, air is supplied to the airbag 91. After the airbag 91 is inflated, it expands and pushes the sealing plate 61 away from the valve disc 6 through the extrusion force, and then falls on the bottom of the pump body 1 to cover the liquid outlet. At the same time, after the airbag 91 expands, it exerts an upward thrust on the valve disc 6 and a downward thrust on the sealing plate 61, thereby blocking the piston rod 2 and the liquid outlet on the pump body 1, waiting for the staff to perform maintenance, thereby avoiding the problem of liquid hydrogen leakage caused by the failure of the spring 7.

[0027] In one embodiment, the valve disc 6 is provided with an arc-shaped groove 63, and the blocking plate 61 is provided with an arc-shaped protrusion 64 adapted to the arc-shaped groove 63, so that the blocking plate 61 is connected through the matching of the arc-shaped protrusion 64 and the arc-shaped groove 63. The arc-shaped setting is adopted to facilitate the disassembly and assembly between the blocking plate 61 and the valve disc 6. When the air bag 91 expands to form an extrusion pressure on the blocking plate 61, the blocking plate 61 can break through the connection between the arc-shaped protrusion 64 and the arc-shaped groove 63 and fall off from the valve disc 6. After the valve disc 6 falls to the bottom of the pump body 1 after falling off, it can also block the liquid outlet. In combination with the expansion of the air bag 91, the blocking plate 61 forms a thrust, so that the blocking plate 61 is close to the ground of the pump body 1 to cut off the liquid outlet; In order to facilitate the disassembly and assembly of the sealing plate 61 and the valve disc 6, a plurality of expansion grooves 66 are provided on the side wall of the sealing plate 61 to facilitate the expansion of the side wall after being compressed, so that the sealing plate 61 can expand outward after being compressed to disconnect the arc-shaped protrusion 64 from the arc-shaped slot 63.

[0028] In one embodiment, it also includes a pull rod 65 arranged on the valve disc 6 and the connecting member 3 for connecting the cable 5. The pull rod 65 can be fixed on the valve disc 6 or the connecting member 3 by welding or other means, and is used to connect the cable 5 while avoiding blocking the connecting member 3 and the valve disc 6 to cause air path blockage.

[0029] In one embodiment, a multi-stage sealing ring 41 is further included between the inner tube 4 and the connector 3. The multi-stage sealing ring 41 is arranged between the inner tube 4 and the connector 3 to increase the sealing between the inner tube 4 and the connector 3 and prevent liquid hydrogen from leaking from the gap between the inner tube 4 and the connector 3.

[0030] When this embodiment is in use: during operation, the pressure of the liquid hydrogen entering the piston rod 2 is greater than the reset force of the spring 1 7 and the spring 2 8, which pushes the valve disc 6 to move downward, opening the flow path between the valve disc 6 and the piston rod 2, and the liquid hydrogen enters between the piston rod 2 and the pump body 1 and is discharged through the liquid outlet. When the pressure of the liquid hydrogen in the piston rod 2 is less than the reset force of the spring 1 7 and the spring 2 8, the spring 1 7 and the spring 2 8 drive the cable 5 and the valve disc 6 to move upward and reset, until the valve disc 6 fits with the end of the piston rod 2 to cut off the flow path; When the spring fails during use, if flow sensors and other instruments are installed on the liquid hydrogen discharge pipeline to monitor abnormal flow and pressure, the staff will supply air to the air pipe 9 through the air source, and the air pipe 9 will transport the gas through the connecting piece 3 and the inner tube 4 to the airbag 91 in the valve disc 6. The airbag 91 will expand after inflation, and the squeezing force during expansion will push the sealing plate 61 to detach from the valve disc 6, and fall on the pump body 1 to cover the liquid outlet. At the same time, the airbag 91 will expand during the continuous inflation process, forming a downward squeezing force on the sealing plate 61, so that the sealing plate 61 is close to the bottom of the pump body 1, cutting off the liquid outlet, and the valve disc 6 moves upward under the action of the reaction force until the valve disc 6 is close to the bottom of the piston rod 2, cutting off the flow path between the piston rod 2 and the bottom of the pump body 1, and waiting for the staff to perform maintenance after cutting off.

[0031] The protection scope of the present invention is not limited to the above embodiments and their variations. Conventional modifications and replacements made by those skilled in the art based on the contents of this embodiment all fall within the protection scope of the present invention.

Claims

1. A suspended valve disc system for a submersible liquid hydrogen pump, comprising a pump body and a piston rod disposed in the pump body; wherein: It also includes a connecting piece movably installed in the piston rod, a cable with one end fixedly connected to the connecting piece, and a valve disc fixedly connected to the other end of the cable, and the cable is connected to a spring 1; it also includes a limit platform arranged in the piston rod, a positioning platform arranged on the connecting piece, and a spring 2 installed between the limit platform and the positioning platform; the cable, spring 2 and spring 1 are all provided with a coating for resisting liquid hydrogen penetration and low temperature to improve service life and performance.

2. The suspension valve disc system of a submersible liquid hydrogen pump according to claim 1, characterized in that: The coating is any one or more combinations of a boron nitride coating, a zinc-plated coating, a high-entropy alloy coating, and a polyetheretherketone coating.

3. The suspended valve disc system of a submersible liquid hydrogen pump according to claim 1, characterized in that: The coating is prepared by mixing multiple materials selected from vermiculite powder, silicon nitride, antimony trioxide, zinc borate and rutile titanium dioxide.

4. The suspended valve disc system of a submersible liquid hydrogen pump according to claim 3, characterized in that: The coating comprises 30%-40% of vermiculite powder, 30%-40% of silicon nitride, 5%-10% of antimony trioxide, 5%-12% of zinc borate and 10%-18% of rutile titanium dioxide.

5. The suspended valve disc system of a submersible liquid hydrogen pump according to claim 1, characterized in that: It also includes a protection module for isolating liquid hydrogen, the protection module includes a hollow connecting piece, an inner tube slidably installed in the connecting piece for protection and isolation, and the other end of the inner tube is fixedly connected to the valve disc; the cable and the spring are located in the connecting piece and the inner tube; and it also includes a multi-stage sealing ring installed between the inner tube and the connecting piece.

6. A suspension valve disc system for a submersible liquid hydrogen pump according to claim 5, characterized in that: It also includes a safety module that serves as a safety protection for the use of the entire liquid hydrogen pump. The safety module includes an air pipe installed on the connecting piece and with one end passing through the piston rod, and an air bag placed in the valve disc and connected to the inner tube to serve as a safety protection to avoid leakage due to failure.

7. A suspension valve disc system for a submersible liquid hydrogen pump according to claim 6, characterized in that: The utility model also comprises a detachable blocking plate installed at the bottom of the valve disc and an ultra-low temperature sealing member arranged between the blocking plate and the valve disc.

8. The suspended valve disc system of a submersible liquid hydrogen pump according to claim 7, characterized in that: The valve disc is provided with an arc-shaped groove, and the blocking plate is provided with an arc-shaped protrusion matched with the arc-shaped groove.

9. A suspension valve disc system for a submersible liquid hydrogen pump according to claim 8, characterized in that: It also includes a plurality of expansion grooves arranged on the side wall of the blocking plate to facilitate the expansion of the side wall after being compressed.

10. The suspended valve disc system of a submersible liquid hydrogen pump according to claim 6, characterized in that: It also includes a pull rod which is arranged on the valve disc and the connecting piece and is used to connect the pull cable.

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