Liquid hydrogen conveying centrifugal pump

Abstract

The invention discloses a liquid hydrogen conveying centrifugal pump which comprises a rotor assembly, an inner shell assembly and an outer shell assembly. The rotor assembly is sleeved in the inner shell assembly to form a core; and the core is sleeved in the outer shell assembly. A multi-stage centrifugal pump structure is adopted for conveying a liquid hydrogen medium, and a three-stage centrifugal wheel with long blades, middle blades and short blades, a radial inlet annular inlet shell, a combined inter-stage overflowing structure with radial guide blades and reverse guide blades and a combined sealing structure with static sealing, end face sealing and blow-off isolation sealing are adopted. By adopting a mounting mode which is compact in structure and convenient to disassemble, the liquid hydrogen medium can be transferred from an offshore transport ship to a storage tank, from the storage tank to the storage tank, from the storage tank to a tank car and the like; the whole structure is simple, and disassembly, assembly, disassembly and replacement are convenient; and the technical blank is filled.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid hydrogen transportation, and in particular relates to a liquid hydrogen transportation centrifugal pump. Background Art

[0003] At present, all countries are focusing on developing renewable energy sources such as solar energy, wind energy, and hydrogen energy. Among them, hydrogen energy has significant advantages. Hydrogen has a wide range of sources, is environmentally friendly, has high mass energy density, and is easy to match with other renewable energy sources. It has the potential to replace fossil fuels in the future.

[0004] Due to the low density of gaseous hydrogen under normal temperature and pressure conditions, in order to improve utilization efficiency, it is mostly stored and transported in high-pressure or ultra-high-pressure gaseous hydrogen or ultra-low temperature liquid hydrogen. Compared with liquid hydrogen, the storage and transportation efficiency of both is higher. Therefore, hydrogen liquefaction, storage, transportation and other related technologies and equipment have become important research contents for hydrogen energy utilization. As the main equipment in the liquid hydrogen transportation process, the liquid hydrogen delivery centrifugal pump will face the performance degradation of hydrogen materials due to hydrogen embrittlement due to long-term operation in a liquid hydrogen environment and high working pressure. The main manifestations are reduced toughness and accelerated fatigue crack growth rate, which leads to the liquid hydrogen delivery centrifugal pump not having the initial efficient sealing to the outside, resulting in liquid hydrogen leakage. After the liquid hydrogen leaks, it will quickly absorb heat to produce high-concentration hydrogen within a period of time, thereby causing an explosion. Therefore, the design of the liquid hydrogen delivery centrifugal pump is a big problem. Summary of the invention

[0005] The technical problem solved by the present invention is to overcome the deficiencies of the prior art and provide a liquid hydrogen transport centrifugal pump, aiming to solve the liquid hydrogen transport problem in the existing hydrogen energy industry and transport technology.

[0006] In order to solve the above technical problems, the present invention discloses a liquid hydrogen transport centrifugal pump, comprising: a rotor assembly, an inner shell assembly and an outer shell assembly; wherein the rotor assembly is sleeved in the inner shell assembly to form a core; and the core is sleeved in the outer shell assembly.

[0007] In the above liquid hydrogen transport centrifugal pump, the rotor assembly includes: a shaft, a first-stage centrifugal wheel, a second-stage centrifugal wheel, a third-stage centrifugal wheel, a first bearing, a second bearing, an end face sealing dynamic ring, a left clamping nut, a third-stage impeller rear clamping nut, a right clamping nut, a first-stage impeller flat key, a second-stage impeller flat key and a third-stage impeller flat key; wherein the first-stage centrifugal wheel, the second-stage centrifugal wheel and the third-stage centrifugal wheel are arranged in sequence from left to right; the first-stage centrifugal wheel, the second-stage centrifugal wheel and the third-stage centrifugal wheel are respectively connected to the shaft through the first-stage impeller flat key, the second-stage impeller flat key and the third-stage impeller flat key, and the flat key transmits torque ... A bearing and a second bearing are arranged at both ends of the shaft for supporting the shaft; the left clamping nut, the clamping nut behind the three-stage impeller and the right clamping nut are threadedly connected to the shaft; the left clamping nut is used to clamp the first-stage centrifugal wheel and the parts on the left side of the shaft; the clamping nut behind the three-stage impeller is used to axially clamp the first-stage centrifugal wheel, the second-stage centrifugal wheel and the third-stage centrifugal wheel; the right clamping nut is used to clamp the first-stage centrifugal wheel and the parts on the right side of the shaft; the thread rotation direction of the left clamping nut, the clamping nut behind the three-stage impeller and the right clamping nut is opposite to the rotation direction of the liquid hydrogen transport centrifugal pump, which plays a locking role.

[0008] In the above-mentioned liquid hydrogen transport centrifugal pump, the inner casing assembly includes: a blow-off casing, a blow-off nozzle, a discharge nozzle, a labyrinth sealing structure, an end face sealing static ring assembly, an inner casing clamping cover, an inlet inner casing, a first-stage reverse guide vane, a second-stage interstage casing, a second-stage reverse guide vane, a third-stage interstage casing, an outlet guide vane, an outlet guide vane cover, a first-stage impeller front sealing ring, a second-stage impeller front sealing ring, a third-stage impeller front sealing ring, a third-stage impeller rear sealing ring, a bearing seat and an expanded graphite pad; wherein the blow-off nozzle, the discharge nozzle and the labyrinth sealing structure are respectively connected to the blow-off casing by threads; the blow-off casing and the inlet inner casing are statically sealed to the outside by an expanded graphite pad, and are connected and fastened by evenly distributed bolts; the end face sealing static ring assembly is connected to the inlet inner casing by evenly distributed screws; the inner casing clamping cover , is positioned with the inlet inner casing by two pins distributed 120° circumferentially; the first-stage impeller front sealing ring, the second-stage impeller front sealing ring and the third-stage impeller front sealing ring are respectively connected to the inlet inner casing, the second-stage interstage casing and the third-stage interstage casing by evenly distributed screws; the third-stage impeller rear sealing ring and the bearing seat are connected to the outlet guide vane by evenly distributed screws; the outlet guide vane cover and the outlet guide vane are connected by evenly distributed screws; the first-stage reverse guide vane is positioned with the inlet inner casing by two pins distributed 120° circumferentially, and is connected and fixed with evenly distributed screws; the second-stage reverse guide vane is positioned with the second-stage interstage casing by two pins distributed 120° circumferentially, and is connected and fixed with evenly distributed screws; the outlet guide vane is positioned with the third-stage interstage casing by two pins distributed 120° circumferentially, and is connected and fixed with evenly distributed screws.

[0009] In the above-mentioned liquid hydrogen transport centrifugal pump, the outer shell assembly includes: an outer shell, an inlet pipe and an outlet pipe; wherein the core is located in the outer shell; the inlet pipe and the outlet pipe are respectively connected to the outer shell; the inlet pipe is located in the radial position of the outer shell and is used to connect to the upstream pipeline; the outlet pipe is located in the axial position of the outer shell and is used to connect to the downstream pipeline.

[0010] In the above-mentioned liquid hydrogen transport centrifugal pump, the liquid hydrogen transport centrifugal pump adopts radial inflow and axial outflow: liquid hydrogen flows in from the inlet pipe, passes through the inlet inner casing, the first-stage centrifugal wheel, the first-stage reverse guide vane, the second-stage centrifugal wheel, the second-stage interstage casing, the second-stage reverse guide vane, the third-stage centrifugal wheel, the third-stage interstage casing, and the outlet guide vane in sequence, and then flows out from the outlet pipe, so as to transport liquid hydrogen from one storage tank to another.

[0011] In the above liquid hydrogen transport centrifugal pump,

[0012] A primary centrifugal wheel comprises: a front cover plate a, a rear cover plate a, a long blade a, a middle blade a, a short blade a and a back blade a; wherein the front cover plate a, the rear cover plate a, the long blade a, the middle blade a, the short blade a and the back blade a are manufactured in one piece; the long blade a, the middle blade a and the short blade a are located between the front cover plate a and the rear cover plate a, and the back blade a is located on the right end surface of the rear cover plate a;

[0013] The secondary centrifugal wheel comprises: a front cover plate b, a rear cover plate b, a long blade b, a middle blade b, a short blade b and a back blade b; wherein the front cover plate b, the rear cover plate b, the long blade b, the middle blade b, the short blade b and the back blade b are manufactured in one piece; the long blade b, the middle blade b and the short blade b are located between the front cover plate b and the rear cover plate b, and the back blade b is located on the right end surface of the rear cover plate b;

[0014] The three-stage centrifugal wheel comprises: a front cover plate c, a rear cover plate c, a long blade c, a middle blade c, a short blade c and a rear convex shoulder; wherein the front cover plate c, the rear cover plate c, the long blade c, the middle blade c, the short blade c and the rear convex shoulder are manufactured in one piece; the long blade c, the middle blade c and the short blade c are located between the front cover plate c and the rear cover plate c, and the rear convex shoulder is located on the right end surface of the rear cover plate c.

[0015] In the above-mentioned liquid hydrogen transport centrifugal pump, the inlet inner shell adopts an annular cross-section structure, and a first baffle and a second baffle are arranged in the flow channel of the inlet inner shell to play a flow stabilizing role; a first-stage radial guide vane is arranged on the inlet inner shell, and the first-stage radial guide vane is manufactured integrally with the inlet inner shell.

[0016] In the above-mentioned liquid hydrogen transport centrifugal pump, radial guide vanes a and annular cavities a are arranged on the secondary interstage casing; radial guide vanes b and annular cavities b are arranged on the third interstage casing; annular guide vanes a are arranged on the first anti-guide vane; and annular guide vanes b are arranged on the second anti-guide vane; wherein, the anti-guide vane a and the anti-guide vane b have the same structure, and the radial guide vane a and the radial guide vane b have the same structure; the radial guide vane a, the annular cavity a, the anti-guide vane a, the radial guide vane b, the annular cavity b and the anti-guide vane b constitute the structure of the interstage flow component; after the liquid hydrogen flows out from the first centrifugal wheel, it is pressure-expanded by the radial guide vanes a of the secondary interstage casing, and then passes through the annular cavity a, and the liquid hydrogen is introduced into the inlet of the secondary centrifugal wheel through the first anti-guide vane; after the liquid hydrogen flows out from the second centrifugal wheel, it is pressure-expanded by the radial guide vanes b of the third interstage casing, and then passes through the annular cavity b, and the liquid hydrogen is introduced into the inlet of the third centrifugal wheel through the second anti-guide vane.

[0017] In the above liquid hydrogen transport centrifugal pump,

[0018] The isolation of liquid hydrogen inside and outside the pump is achieved through a static seal formed by an expanded graphite pad;

[0019] The left end face of the end face seal dynamic ring contacts the right end face of the end face seal static ring assembly to form a dynamic seal structure; wherein, the isolation of liquid hydrogen from air is achieved through a dynamic seal structure and a labyrinth seal structure with blow-off holes, and 8 discharge nozzles are arranged on the blow-off shell to ensure the safety and reliability of the liquid hydrogen transport centrifugal pump during operation.

[0020] In the above-mentioned liquid hydrogen transport centrifugal pump, the first-stage impeller front sealing ring, the second-stage impeller front sealing ring, the third-stage impeller front sealing ring and the third-stage impeller rear sealing ring all adopt a trapezoidal sealing tooth structure.

[0021] The present invention has the following advantages:

[0022] The invention discloses a liquid hydrogen transport centrifugal pump, which adopts a multi-stage centrifugal pump structure to transport liquid hydrogen medium, adopts a three-stage centrifugal wheel with "long blades + middle blades + short blades", a radially inlet annular inlet shell, a combined interstage flow structure of "radial guide vanes + reverse guide vanes", and a combined sealing structure of "static seal + end face seal" with a blow-off isolation seal. It adopts a compact and easy-to-disassemble installation method to realize the transportation of liquid hydrogen medium from an offshore transport ship to a storage tank, from a storage tank to a storage tank, from a storage tank to a tank truck, etc.; the overall structure is simple, easy to disassemble, decompose and replace, and fills the technical gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a liquid hydrogen delivery centrifugal pump in an embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of the reverse structure of a primary centrifugal wheel in an embodiment of the present invention;

[0025] Figure 3 is a side view of a primary centrifugal wheel in an embodiment of the present invention;

[0026] Figure 4 It is a front structural schematic diagram of a primary centrifugal wheel in an embodiment of the present invention;

[0027] Figure 5 It is a schematic diagram of the reverse structure of a secondary centrifugal wheel in an embodiment of the present invention;

[0028] Figure 6 is a side view of a secondary centrifugal wheel in an embodiment of the present invention;

[0029] Figure 7 It is a front structural schematic diagram of a secondary centrifugal wheel in an embodiment of the present invention;

[0030] Figure 8 is a side view of a three-stage centrifugal wheel in an embodiment of the present invention;

[0031] Fig. 9 It is a front structural schematic diagram of a three-stage centrifugal wheel in an embodiment of the present invention;

[0032] Fig.10 1 is a schematic diagram of the front structure of an inlet inner shell in an embodiment of the present invention;

[0033] Fig.11 is a side view of an inlet inner shell in an embodiment of the present invention;

[0034] Fig.12 1 is a schematic diagram of the front structure of a two-stage interstage casing in an embodiment of the present invention;

[0035] Fig.13 is a side view of a two-stage interstage casing in an embodiment of the present invention;

[0036] Fig.14 1 is a schematic diagram of the front structure of a three-stage interstage casing in an embodiment of the present invention;

[0037] Fig.15 is a side view of a three-stage interstage casing in an embodiment of the present invention;

[0038] Fig.16 1 is a schematic diagram of the front structure of a first-stage reverse guide vane in an embodiment of the present invention;

[0039] Fig.17 is a side view of a first-stage reverse guide vane in an embodiment of the present invention;

[0040] Fig.18 1 is a schematic diagram of the front structure of a secondary reverse guide vane in an embodiment of the present invention;

[0041] Fig.19 is a side view of a secondary reverse guide vane in an embodiment of the present invention;

[0042] Fig. 20 It is a structural schematic diagram of a trapezoidal sealing tooth structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0044] Reference Figure 1 In this embodiment, the liquid hydrogen delivery centrifugal pump includes: a rotor assembly, an inner shell assembly and an outer shell assembly. The rotor assembly is sleeved in the inner shell assembly to form a core; the core is sleeved in the outer shell assembly. The liquid hydrogen delivery centrifugal pump can be externally connected to a normal temperature explosion-proof motor, has a simple structure, simplifies the liquid hydrogen delivery pump system, is economical, and has strong feasibility.

[0045] In this embodiment, the rotor assembly may specifically include: a shaft 1, a first-stage centrifugal wheel 2, a second-stage centrifugal wheel 3, a third-stage centrifugal wheel 4, a first bearing 5, a second bearing 6, an end face sealing dynamic ring 7, a left clamping nut 8, a third-stage impeller rear clamping nut 9, a right clamping nut 10, a first-stage impeller flat key 11, a second-stage impeller flat key 12, and a third-stage impeller flat key 13. Among them, the first-stage centrifugal wheel 2, the second-stage centrifugal wheel 3, and the third-stage centrifugal wheel 4 are arranged in sequence from left to right; the first-stage centrifugal wheel 2, the second-stage centrifugal wheel 3, and the third-stage centrifugal wheel 4 are connected to the shaft 1 through the first-stage impeller flat key 11, the second-stage impeller flat key 12, and the third-stage impeller flat key 13, respectively, and the flat keys transmit torque. The first bearing 5 and the second bearing 6 are arranged at both ends of the shaft 1 for supporting the shaft 1. The left clamping nut 8, the clamping nut 9 behind the three-stage impeller and the right clamping nut 10 are threadedly connected with the shaft 1; the left clamping nut 8 is used to clamp the first-stage centrifugal wheel 2 and the parts on the left shaft system thereof; the clamping nut 9 behind the three-stage impeller is used to axially clamp the first-stage centrifugal wheel 2, the second-stage centrifugal wheel 3 and the third-stage centrifugal wheel 4; the right clamping nut 10 is used to clamp the first-stage centrifugal wheel 2 and the parts on the right shaft system thereof; the thread rotation direction of the left clamping nut 8, the clamping nut 9 behind the three-stage impeller and the right clamping nut 10 is opposite to the rotation direction of the liquid hydrogen transport centrifugal pump, which plays a locking role.

[0046] In this embodiment, the inner casing assembly may specifically include: a blow-off casing 14, a blow-off nozzle 15, a discharge nozzle 16, a labyrinth seal structure 17, an end face sealing static ring assembly 18, an inner casing clamping cover 19, an inlet inner casing 20, a first-stage reverse guide vane 21, a second-stage interstage casing 22, a second-stage reverse guide vane 23, a third-stage interstage casing 24, an outlet guide vane 25, an outlet guide vane cover 26, a first-stage impeller front sealing ring 27, a second-stage impeller front sealing ring 28, a third-stage impeller front sealing ring 29, a third-stage impeller rear sealing ring 30, a bearing seat 31 and an expanded graphite pad 32. Among them, the blow-off nozzle 15, the discharge nozzle 16 and the labyrinth seal structure 17 are respectively connected to the blow-off shell 14 through threads; the blow-off shell 14 and the inlet inner shell 20 are statically sealed to the outside through the expanded graphite pad 32, and are fastened by evenly distributed bolts; the end face sealing static ring assembly 18 is connected to the inlet inner shell 20 through evenly distributed screws; the inner shell pressing cover 19 is positioned with the inlet inner shell 20 through two pins distributed 120° circumferentially; the first-stage impeller front sealing ring 27, the second-stage impeller front sealing ring 28 and the third-stage impeller front sealing ring 29 are respectively connected to the inlet inner shell 20, the second-stage intermediate shell 20 and the second-stage intermediate shell 20 through evenly distributed screws. The third-stage impeller rear sealing ring 30 and the bearing seat 31 are connected to the outlet guide vane 25 by evenly spaced screws; the outlet guide vane cover 26 and the outlet guide vane 25 are connected by evenly spaced screws; the first-stage reverse guide vane 21 is positioned with the inlet inner casing 20 by two pins distributed 120° circumferentially, and is fixed with evenly spaced screws; the second-stage reverse guide vane 23 is positioned with the second-stage interstage casing 22 by two pins distributed 120° circumferentially, and is fixed with evenly spaced screws; the outlet guide vane 25 is positioned with the third-stage interstage casing 24 by two pins distributed 120° circumferentially, and is fixed with evenly spaced screws.

[0047] In this embodiment, the outer shell assembly may specifically include: an outer shell 34, an inlet pipe and an outlet pipe. The core is located in the outer shell 34; the inlet pipe and the outlet pipe are connected to the outer shell 34 respectively; the inlet pipe is located in the radial position of the outer shell 34, and is used to connect to the upstream pipeline; the outlet pipe is located in the axial position of the outer shell 34, and is used to connect to the downstream pipeline.

[0048] In this embodiment, the liquid hydrogen transport centrifugal pump adopts radial inflow and axial outflow: liquid hydrogen flows in from the inlet pipe, passes through the inlet inner casing 20, the first-stage centrifugal wheel 2, the first-stage reverse guide vane 21, the second-stage centrifugal wheel 3, the second-stage interstage casing 22, the second-stage reverse guide vane 23, the third-stage centrifugal wheel 4, the third-stage interstage casing 24, and the outlet guide vane 25 in sequence, and then flows out from the outlet pipe, so as to transport the liquid hydrogen from one tank to another.

[0049] In this embodiment, the first-stage centrifugal wheel 2 and the second-stage centrifugal wheel 3 have the same structure.

[0050] like Figures 2 to 4As shown, the primary centrifugal wheel 2 comprises: a front cover plate a351, a rear cover plate a361, a long blade a371, a middle blade a381, a short blade a391 and a back blade a401. The front cover plate a351, the rear cover plate a361, the long blade a371, the middle blade a381, the short blade a391 and the back blade a401 are manufactured in one piece; the long blade a371, the middle blade a381 and the short blade a391 are located between the front cover plate a351 and the rear cover plate a361, and the back blade a401 is located on the right end surface of the rear cover plate a361.

[0051] like Figures 5 to 7 As shown, the secondary centrifugal wheel 3 includes: a front cover plate b352, a rear cover plate b362, a long blade b372, a middle blade b382, a short blade b392 and a back blade b402. The front cover plate b352, the rear cover plate b362, the long blade b372, the middle blade b382, the short blade b392 and the back blade b402 are manufactured in one piece; the long blade b372, the middle blade b382 and the short blade b392 are located between the front cover plate b352 and the rear cover plate b362, and the back blade b402 is located on the right end surface of the rear cover plate b362.

[0052] like Figures 8-9 As shown, the three-stage centrifugal wheel 4 includes: a front cover plate c353, a rear cover plate c363, a long blade c373, a middle blade c383, a short blade c393 and a rear convex shoulder 41. The front cover plate c353, the rear cover plate c363, the long blade c373, the middle blade c383, the short blade c393 and the rear convex shoulder 41 are manufactured in one piece; the long blade c373, the middle blade c383 and the short blade c393 are located between the front cover plate c353 and the rear cover plate c363, and the rear convex shoulder 41 is located on the right end surface of the rear cover plate c363.

[0053] The front cover plate, the rear cover plate, the long blades, the middle blades, the short blades, the back blades and the rear convex shoulder constitute a three-stage closed centrifugal pump structure. Since the density of the liquid hydrogen medium is small and the dynamic viscosity is similar to that of the gas, it is easy to generate eddy currents in the flow channel of the impeller, causing uneven distribution of relative velocity. In severe cases, it will cause flow separation and cause "stall". Therefore, the present invention adopts the structural form of "long blades + middle blades + short blades" to improve the constraint of the blades on the liquid hydrogen in the impeller flow channel. Furthermore, the long blades, the middle blades and the short blades adopt the twisted blade design method to improve the efficiency of the impeller. Furthermore, in order to balance the axial force of the liquid hydrogen transport centrifugal pump, back blades are added to the back of the first-stage centrifugal wheel and the second-stage centrifugal wheel, and a rear convex shoulder is added to the back of the third-stage centrifugal wheel. The rear convex shoulder adopts a toothed labyrinth seal structure, and a reflux hole is provided on the third-stage centrifugal wheel, which is a component of the axial force balancing system.

[0054] In this embodiment, if Figures 10-11As shown, the inlet inner shell 20 adopts an annular cross-section structure, and a first baffle 43 and a second baffle 44 are arranged in the flow channel of the inlet inner shell 20 to stabilize the flow. A first-stage radial guide vane 45 is arranged on the inlet inner shell 20, and the first-stage radial guide vane 45 is manufactured integrally with the inlet inner shell 20, which reduces the number of parts and simplifies the structure of the liquid hydrogen delivery centrifugal pump.

[0055] In this embodiment, if Figures 12-13 As shown, radial guide vanes a461 and an annular cavity a471 are provided on the secondary interstage casing 22. Figures 14-15 As shown, radial guide vanes b462 and annular cavities b472 are provided on the third-stage interstage casing 24. Figures 16-17 As shown, the first-stage reverse guide vane 21 is provided with a reverse guide vane a481. Figures 18-19 As shown, the secondary reverse guide vane 23 is provided with a reverse guide vane b482. Among them, the reverse guide vane a481 and the reverse guide vane b482 have the same structure, and the radial guide vane a461 and the radial guide vane b462 have the same structure. The radial guide vane a461, the annular cavity a471, the reverse guide vane a481, the radial guide vane b462, the annular cavity b472 and the reverse guide vane b482 constitute the structure of the interstage flow component. After the liquid hydrogen flows out from the primary centrifugal wheel 2, it is expanded by the radial guide vane a461 of the secondary interstage casing 22, and then passes through the annular cavity a471, and the liquid hydrogen is introduced into the inlet of the secondary centrifugal wheel 3 through the primary reverse guide vane 21; after the liquid hydrogen flows out from the secondary centrifugal wheel 3, it is expanded by the radial guide vane b462 of the tertiary interstage casing 24, and then passes through the annular cavity b472, and the liquid hydrogen is introduced into the inlet of the tertiary centrifugal wheel 4 through the secondary reverse guide vane 23. The functions of the radial guide vanes, the annular cavity and the reverse guide vanes are to reduce the flow velocity and eliminate the liquid rotation component while guiding the liquid hydrogen.

[0056] In this embodiment, the isolation of liquid hydrogen inside and outside the pump is achieved by a static seal formed by an expanded graphite pad 32. The left end face of the end face seal dynamic ring 7 is in contact with the right end face of the end face seal static ring assembly 18 to form a dynamic seal structure; the isolation of liquid hydrogen from air is achieved by a dynamic seal structure and a labyrinth seal structure 17 with a blow-off hole, and 8 discharge nozzles 16 are provided on the blow-off housing 14 to ensure the safety and reliability of the liquid hydrogen delivery centrifugal pump during operation.

[0057] In this embodiment, the first-stage impeller front sealing ring 27, the second-stage impeller front sealing ring 28, the third-stage impeller front sealing ring 29 and the third-stage impeller rear sealing ring 30 all adopt a trapezoidal sealing tooth structure, such as Fig. 20 Compared with the rectangular tooth structure, the trapezoidal seal tooth structure has a shorter axial length and stronger tooth root strength under the same number of teeth.

[0058] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0059] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A liquid hydrogen delivery centrifugal pump, characterized in that: include: A rotor assembly, an inner housing assembly and an outer housing assembly; wherein the rotor assembly is sleeved in the inner housing assembly to form a core; The core is sleeved in the outer shell assembly.

2. The liquid hydrogen delivery centrifugal pump according to claim 1, characterized in that: The rotor assembly comprises: a shaft (1), a first-stage centrifugal wheel (2), a second-stage centrifugal wheel (3), a third-stage centrifugal wheel (4), a first bearing (5), a second bearing (6), an end face sealing dynamic ring (7), a left clamping nut (8), a third-stage impeller rear clamping nut (9), a right clamping nut (10), a first-stage impeller flat key (11), a second-stage impeller flat key (12) and a third-stage impeller flat key (13); wherein the first-stage centrifugal wheel (2), the second-stage centrifugal wheel (3) and the third-stage centrifugal wheel (4) are arranged in sequence from left to right; the first-stage centrifugal wheel (2), the second-stage centrifugal wheel (3) and the third-stage centrifugal wheel (4) are connected to the shaft (1) via the first-stage impeller flat key (11), the second-stage impeller flat key (12) and the third-stage impeller flat key (13) respectively, and the flat keys transmit torque. The first bearing (5) and the second bearing (6) are arranged at both ends of the shaft (1) for supporting the shaft (1); the left clamping nut (8), the clamping nut (9) behind the third-stage impeller and the right clamping nut (10) are threadedly connected to the shaft (1); the left clamping nut (8) is used to clamp the first-stage centrifugal wheel (2) and the parts on the left side of the shaft system; the clamping nut (9) behind the third-stage impeller is used to axially clamp the first-stage centrifugal wheel (2), the second-stage centrifugal wheel (3) and the third-stage centrifugal wheel (4); the right clamping nut (10) is used to clamp the first-stage centrifugal wheel (2) and the parts on the right side of the shaft system; the thread rotation direction of the left clamping nut (8), the clamping nut (9) behind the third-stage impeller and the right clamping nut (10) is opposite to the rotation direction of the liquid hydrogen transport centrifugal pump, so as to play a locking role.

3. The liquid hydrogen delivery centrifugal pump according to claim 2, characterized in that: The inner casing assembly comprises: a blow-off casing (14), a blow-off nozzle (15), a discharge nozzle (16), a labyrinth seal structure (17), an end face seal static ring assembly (18), an inner casing clamping cover (19), an inlet inner casing (20), a first-stage reverse guide vane (21), a second-stage interstage casing (22), a second-stage reverse guide vane (23), a third-stage interstage casing (24), an outlet guide vane (25), an outlet guide vane cover (26), a first-stage impeller front seal ring (27), a second-stage impeller front seal ring (28), The third-stage impeller front sealing ring (29), the third-stage impeller rear sealing ring (30), the bearing seat (31) and the expanded graphite pad (32); wherein the blow-off nozzle (15), the discharge nozzle (16) and the labyrinth seal structure (17) are respectively connected to the blow-off shell (14) through threads; the blow-off shell (14) and the inlet inner shell (20) are externally statically sealed through the expanded graphite pad (32) and are fastened by evenly distributed bolts; the end face sealing static ring assembly (18) and the inlet inner shell (20) are evenly connected. The inner casing is connected by evenly spaced screws; the inner casing pressing cover (19) is positioned with the inlet inner casing (20) by two pins distributed 120° in the circumferential direction; the first-stage impeller front sealing ring (27), the second-stage impeller front sealing ring (28) and the third-stage impeller front sealing ring (29) are respectively connected to the inlet inner casing (20), the second-stage interstage casing (22) and the third-stage interstage casing (24) by evenly spaced screws; the third-stage impeller rear sealing ring (30) and the bearing seat (31) are connected to the outlet guide vane (25) by evenly spaced screws; the outlet guide vane The cover (26) and the outlet guide vane (25) are connected by evenly spaced screws; the first-stage reverse guide vane (21) is positioned with the inlet inner casing (20) by two pins distributed at 120° in the circumferential direction, and is connected and fixed by evenly spaced screws; the second-stage reverse guide vane (23) is positioned with the second-stage interstage casing (22) by two pins distributed at 120° in the circumferential direction, and is connected and fixed by evenly spaced screws; the outlet guide vane (25) is positioned with the third-stage interstage casing (24) by two pins distributed at 120° in the circumferential direction, and is connected and fixed by evenly spaced screws.

4. The liquid hydrogen delivery centrifugal pump according to claim 3, characterized in that: An outer shell assembly comprises: an outer shell (34), an inlet pipe and an outlet pipe; wherein the core is located in the outer shell (34); the inlet pipe and the outlet pipe are respectively connected to the outer shell (34); the inlet pipe is located in a radial position of the outer shell (34) and is used to connect to an upstream pipeline; the outlet pipe is located in an axial position of the outer shell (34) and is used to connect to a downstream pipeline.

5. The liquid hydrogen delivery centrifugal pump according to claim 4, characterized in that: The liquid hydrogen transport centrifugal pump adopts radial inflow and axial outflow: liquid hydrogen flows in from an inlet pipe, passes through an inlet inner casing (20), a first-stage centrifugal wheel (2), a first-stage reverse guide vane (21), a second-stage centrifugal wheel (3), a second-stage interstage casing (22), a second-stage reverse guide vane (23), a third-stage centrifugal wheel (4), a third-stage interstage casing (24), and an outlet guide vane (25) in sequence, and then flows out from an outlet pipe, so as to transport liquid hydrogen from one storage tank to another storage tank.

6. The liquid hydrogen delivery centrifugal pump according to claim 2, characterized in that: A first-stage centrifugal wheel (2) comprises: a front cover plate a (351), a rear cover plate a (361), a long blade a (371), a middle blade a (381), a short blade a (391) and a back blade a (401); wherein the front cover plate a (351), the rear cover plate a (361), the long blade a (371), the middle blade a (381), the short blade a (391) and the back blade a (401) are manufactured in one piece; the long blade a (371), the middle blade a (381) and the short blade a (391) are located between the front cover plate a (351) and the rear cover plate a (361), and the back blade a (401) is located on the right end surface of the rear cover plate a (361); A secondary centrifugal wheel (3) comprises: a front cover plate b (352), a rear cover plate b (362), a long blade b (372), a middle blade b (382), a short blade b (392) and a back blade b (402); wherein the front cover plate b (352), the rear cover plate b (362), the long blade b (372), the middle blade b (382), the short blade b (392) and the back blade b (402) are manufactured in one piece; the long blade b (372), the middle blade b (382) and the short blade b (392) are located between the front cover plate b (352) and the rear cover plate b (362), and the back blade b (402) is located on the right end surface of the rear cover plate b (362); A three-stage centrifugal wheel (4) comprises: a front cover plate c (353), a rear cover plate c (363), a long blade c (373), a middle blade c (383), a short blade c (393) and a rear convex shoulder (41); wherein the front cover plate c (353), the rear cover plate c (363), the long blade c (373), the middle blade c (383), the short blade c (393) and the rear convex shoulder (41) are manufactured in one piece; the long blade c (373), the middle blade c (383) and the short blade c (393) are located between the front cover plate c (353) and the rear cover plate c (363), and the rear convex shoulder (41) is located on the right end surface of the rear cover plate c (363).

7. The liquid hydrogen delivery centrifugal pump according to claim 3, characterized in that: The inlet inner casing (20) adopts an annular cross-section structure, and a first baffle (43) and a second baffle (44) are arranged in the flow channel of the inlet inner casing (20) to play a flow stabilizing role; a first-stage radial guide vane (45) is arranged on the inlet inner casing (20), and the first-stage radial guide vane (45) and the inlet inner casing (20) are manufactured in one piece.

8. The liquid hydrogen delivery centrifugal pump according to claim 3, characterized in that: A radial guide vane a (461) and an annular cavity a (471) are provided on the second-stage interstage casing (22); a radial guide vane b (462) and an annular cavity b (472) are provided on the third-stage interstage casing (24); a reverse guide vane a (481) is provided on the first-stage reverse guide vane (21); and a reverse guide vane b (482) is provided on the second-stage reverse guide vane (23); wherein the reverse guide vane a (481) and the reverse guide vane b (482) have the same structure, and the radial guide vane a (461) and the radial guide vane b (462) have the same structure; the radial guide vane a (461), the annular cavity a (471), the reverse guide vane a (481) and the annular cavity a (471) are provided on the third-stage interstage casing (24); ), radial guide vanes b (462), annular cavity b (472) and reverse guide vanes b (482) constitute the structure of the interstage flow component; after the liquid hydrogen flows out from the first-stage centrifugal wheel (2), it is expanded by the radial guide vanes a (461) of the second-stage interstage casing (22), and then passes through the annular cavity a (471), and the liquid hydrogen is introduced into the inlet of the second-stage centrifugal wheel (3) through the first-stage reverse guide vanes (21); after the liquid hydrogen flows out from the second-stage centrifugal wheel (3), it is expanded by the radial guide vanes b (462) of the third-stage interstage casing (24), and then passes through the annular cavity b (472), and the liquid hydrogen is introduced into the inlet of the third-stage centrifugal wheel (4) through the second-stage reverse guide vanes (23).

9. The liquid hydrogen delivery centrifugal pump according to claim 3, characterized in that: The isolation of liquid hydrogen inside and outside the pump is achieved by a static seal formed by an expanded graphite gasket (32); The left end face of the end face seal dynamic ring (7) contacts the right end face of the end face seal static ring assembly (18) to form a dynamic seal structure; wherein the isolation of liquid hydrogen from air is achieved through the dynamic seal structure and the labyrinth seal structure (17) with blow-off holes, and 8 discharge nozzles (16) are arranged on the blow-off housing (14) to ensure the safety and reliability of the liquid hydrogen transport centrifugal pump during operation.

10. The liquid hydrogen delivery centrifugal pump according to claim 3, characterized in that: The first-stage impeller front sealing ring (27), the second-stage impeller front sealing ring (28), the third-stage impeller front sealing ring (29) and the third-stage impeller rear sealing ring (30) all adopt a trapezoidal sealing tooth structure.

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