A centrifugal hydrogen booster circulating pump for hydrogen lubrication of bearings and cooling of motors

Abstract

This invention belongs to the field of hydrogen energy transportation and circulation boosting technology, and discloses a centrifugal hydrogen booster circulating pump with hydrogen-lubricated bearings and a cooling motor. It includes gas bearings, etc. The pump shaft is fixed at both ends by first and second gas bearings at the front and rear ends of a high-speed motor, respectively. A first impeller is fixed to the front end of the pump shaft, and a second impeller is fixed to the rear end. The centrifugal hydrogen booster circulating pump has a first volute at the front end and a second volute at the rear end. The first impeller is installed in the first volute, and the second impeller is installed in the second volute. One end of a diversion pipe is connected to the side of the outlet pipe on the volute, and the other end of the diversion pipe is sequentially connected to the high-speed motor's heat dissipation air gap and the gas bearing housing's air supply hole. This invention uses gas bearings instead of ball bearings in traditional circulating pumps as support components and directly uses hydrogen as the coolant for the motor and the lubricating medium for the bearings, which helps to improve the pump's hydrogen transportation efficiency and service life.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen energy transportation and circulation boosting technology, and more specifically, relates to a centrifugal hydrogen boosting circulation pump that lubricates bearings and cools motors with hydrogen. Background Technology

[0002] As a key component for hydrogen transportation and pressurization, hydrogen circulation pumps have become a research and development hotspot. Among them, centrifugal hydrogen circulation pumps are one of the important application types of hydrogen circulation pumps.

[0003] Traditional centrifugal hydrogen circulation pumps typically use ball bearings as support components, with lubricating oil as the bearing lubrication medium. This type of hydrogen circulation pump has a complex structure, high cost, large size, high power consumption, and high noise. Lubricating oil leakage is prone to cause damage to the battery stack and motor. In addition, in hydrogen fuel cells, the hydrogen remaining after the stack reaction contains a large amount of water vapor or even liquid water. When it enters the circulation pump, it freezes at low temperatures, causing difficulties in starting the motor.

[0004] Gas bearings are a type of hydrodynamic bearing. Their working principle involves a pressure film formed by gas in a wedge-shaped space between the shaft and the inner surface of the bearing when the rotor rotates at high speed, thus supporting the load. Gas bearings do not require lubricating oil; their working medium is gas, which is clean and pollution-free, and there is no friction with the rotor during operation. They have a wide applicable speed range and good operational stability. Based on these characteristics, gas bearings are more suitable for use in centrifugal hydrogen circulation pumps compared to traditional ball bearings.

[0005] Therefore, this invention addresses the technical problems of traditional centrifugal hydrogen circulation pumps by analyzing the operating conditions of hydrogen circulation pumps and combining the performance characteristics of gas bearings, and proposes a centrifugal hydrogen booster circulation pump that uses hydrogen to lubricate the bearings and cool the motor. Summary of the Invention

[0006] In view of this, the present invention proposes a centrifugal hydrogen booster circulation pump for hydrogen lubrication of bearings and cooling of motors, which solves the shortcomings of traditional oil film or grease lubrication bearings supporting hydrogen circulation, such as easy oil leakage, poor heat dissipation and water vapor accumulation, and helps to improve the hydrogen delivery efficiency and service life of hydrogen circulation pumps.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A centrifugal hydrogen booster circulating pump with hydrogen-lubricated bearings and a cooling motor includes a gas bearing, a high-speed motor, an inlet pipe, an outlet pipe, a volute, an impeller, a diversion pipe, and a pump shaft. The pump shaft is coaxially mounted inside the high-speed motor, with both its front and rear ends extending beyond the high-speed motor and fixed in position by a first gas bearing at the front end of the high-speed motor and a second gas bearing at the rear end of the high-speed motor, respectively. A first impeller is fixedly connected to the front end of the pump shaft, and a second impeller is fixedly connected to the rear end. The centrifugal hydrogen booster circulating pump has a first volute at the front end and a second volute at the rear end. The first impeller is installed inside the first volute and corresponds to a first inlet pipe on the first volute. The impeller is installed inside the second volute and corresponds to the second air inlet pipe on the second volute; the first impeller and the first volute together constitute the first impeller diffuser, and the second impeller and the second volute together constitute the second impeller diffuser; the side of the first air outlet pipe on the first volute is connected to one end of the first diversion air guide pipe, and the other end of the first diversion air guide pipe is sequentially connected to the high-speed motor cooling air gap in the high-speed motor heat sink and the air supply hole of the first gas bearing housing; the side of the second air outlet pipe on the second volute is connected to one end of the second diversion air guide pipe, and the other end of the second diversion air guide pipe is sequentially connected to the high-speed motor cooling air gap in the high-speed motor heat sink and the air supply hole of the second gas bearing housing.

[0009] Preferably, the centrifugal hydrogen booster circulating pump for hydrogen lubrication of bearings and cooling of motors according to the present invention further includes a first drying device and a second drying device. The first drying device is installed on a first branching gas pipe between a first outlet pipe and a high-speed motor heat sink, and the second drying device is installed on a second branching gas pipe between a second outlet pipe and a high-speed motor heat sink.

[0010] Preferably, the centrifugal hydrogen booster circulation pump adopts a symmetrical distribution on both sides, with the first and second inlet pipes, the first and second outlet pipes, the first and second volutes, and the first and second impellers all symmetrically distributed on both sides of the high-speed motor.

[0011] Preferably, the first gas bearing and the second gas bearing are symmetrically installed on both sides of the pump shaft. Under the rotation of the high-speed motor, an air film is formed in the bearing gap. Under the action of the air film, the bearing is suspended around the pump shaft, supporting the entire circulating pump system.

[0012] Preferably, the first gas bearing and the second gas bearing are herringbone spiral groove gas bearings or corrugated foil gas bearings.

[0013] Preferably, the high-speed motor heat dissipation air gap and the corresponding first and second diversion air pipes are located outside the high-speed motor or are internal flow channels of the high-speed motor.

[0014] By adopting the above technical solution, the centrifugal hydrogen booster circulating pump provided by the present invention uses a gas bearing instead of the ball bearing in the traditional circulating pump as a support component, and directly uses hydrogen as the coolant of the motor and the lubricating medium of the bearing to realize the boosting and circulating transportation of hydrogen.

[0015] Hydrogen enters the pump body through the inlet pipe, is pressurized by the blade diffuser, and then flows into the outlet pipe. In the outlet pipe cavity, a portion of the hydrogen passes through the diversion pipe and is dehumidified by the drying device at the front end of the motor before flowing to the high-speed motor cooling air gap and the gas bearing supply hole for cooling the motor coils and rotor, as well as lubricating the gas bearing. The hydrogen flowing through both sides of the gas bearing flows back to the other side of the pump shaft through the gas bearing gap. This part is connected to the impeller pressurization inlet and is pressurized again by the impeller rotation.

[0016] Compared with existing conventional centrifugal hydrogen circulation pumps, the advantages of this invention are:

[0017] 1. This invention uses a gas bearing as the supporting component of the circulating pump and directly uses hydrogen instead of lubricating oil as the lubricating medium, which fundamentally solves the problem of oil leakage in the circulating pump and effectively prevents lubricating oil from entering the fuel cell stack and motor air gap and causing damage. At the same time, the gas bearing has a wide applicable speed range, low friction torque, low vibration and low noise, which enables the hydrogen circulating pump to be applied to a wider range of complex working conditions and helps to improve the working stability of the hydrogen circulating pump.

[0018] 2. This invention uses hydrogen instead of cold oil or air as a coolant for the motor, rotor, and bearings, which enables rapid cooling of the motor during high-speed operation, prevents the motor from stopping due to overheating, and avoids the problem of reduced clearance in gas bearings due to thermal expansion.

[0019] 3. The present invention has a drying device installed in the circulating pump to dry and dehumidify the hydrogen used for heat dissipation and lubrication. This can fully remove water vapor from the hydrogen and prevent it from freezing after entering the circulating pump, which would prevent the motor from starting.

[0020] 4. The centrifugal hydrogen booster circulation pump proposed in this invention uses only hydrogen as its working medium, achieving an oil-free operating environment. This helps improve the utilization rate of hydrogen in fuel cells and the working efficiency of the hydrogen circulation pump, helps protect the high-speed motor in the hydrogen circulation pump, and effectively reduces the operating cost of the hydrogen circulation pump.

[0021] 5. The centrifugal hydrogen booster circulating pump proposed in this invention adopts a symmetrical structure on both sides, which allows hydrogen to enter the pump body from both sides, balancing the axial force on the impellers on both sides. This helps to improve the hydrogen pumping efficiency and the speed of hydrogen recycling, while reducing the bearing load and reducing bearing fatigue loss. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 This is an overall structural diagram of a centrifugal hydrogen booster circulating pump for lubricating bearings and cooling motors according to the present invention.

[0024] Figure 2 This is a cross-sectional view of a centrifugal hydrogen booster circulating pump for lubricating bearings and cooling motors according to the present invention.

[0025] Figure 3 This is an overall structural diagram of the first impeller diffuser in a centrifugal hydrogen booster circulating pump for hydrogen-lubricated bearings and cooling motors according to the present invention.

[0026] In the diagram: 1-High-speed motor, 2-Pump shaft, 3-First gas bearing, 4-Second gas bearing, 5-First impeller, 6-Second impeller, 7-First volute, 8-Second volute, 9-First inlet pipe, 10-Second inlet pipe, 11-First outlet pipe, 12-Second outlet pipe, 13-First diversion pipe, 14-Second diversion pipe, 15-Air supply hole for first gas bearing housing, 16-First drying device, 17-Second drying device, 18-High-speed motor heat sink. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] Example:

[0031] like Figures 1-3 As shown, the present invention provides a centrifugal hydrogen booster circulating pump for hydrogen lubrication of bearings and cooling of motor, including a gas bearing, a high-speed motor 1, an inlet pipe, an outlet pipe, a volute, an impeller, a diversion guide pipe, and a pump shaft 2.

[0032] in,

[0033] The pump shaft 2 is coaxially mounted inside the high-speed motor 1, with both its front and rear ends extending out of the high-speed motor 1 and being fixed in position by the first gas bearing 3 at the front end of the high-speed motor 1 and the second gas bearing 4 at the rear end of the high-speed motor 1, respectively.

[0034] The front end of the pump shaft 2 is fixedly connected to the first impeller 5, and the rear end is fixedly connected to the second impeller 6; the centrifugal hydrogen booster circulation pump has a first volute 7 at the front end and a second volute 8 at the rear end. The first impeller 5 is installed inside the first volute 7 and corresponds to the first air inlet pipe 9 on the first volute 7. The second impeller 6 is installed inside the second volute 8 and corresponds to the second air inlet pipe 10 on the second volute 8. The first impeller 5 and the first volute 7 together constitute the first impeller diffuser, and the second impeller 6 and the second volute 8 together constitute the second impeller diffuser.

[0035] The first air outlet pipe 11 on the first volute 7 is connected to one end of the first diversion air pipe 13 on its side. The other end of the first diversion air pipe 13 is connected in sequence to the high-speed motor cooling gap in the high-speed motor heat sink 18 and the air supply hole 15 of the first gas bearing housing. The second air outlet pipe 12 on the second volute 8 is connected to one end of the second diversion air pipe 14 on its side. The other end of the second diversion air pipe 14 is connected in sequence to the high-speed motor cooling gap in the high-speed motor heat sink 18 and the air supply hole of the second gas bearing housing.

[0036] In this invention, part of the pressurized hydrogen is pumped out directly through the two gas outlet pipes, and part is diverted through the diversion pipe. The hydrogen on both sides is respectively directed to the corresponding high-speed motor heat dissipation air gap and gas bearing housing gas supply hole, so as to guide the hydrogen to achieve heat dissipation of the motor and rotor and lubrication of the gas bearing. Moreover, the hydrogen flows into the bearing gap through the gas bearing housing gas supply hole, and under the high-speed rotation of the motor, it will also form a wedge-shaped gas film in the bearing gap to support the bearing suspension. Then the hydrogen flows back to the other side of the pump shaft through the bearing gap, and the impeller rotates and pressurizes again.

[0037] Furthermore, in this invention, the high-speed motor heat dissipation air gap and the corresponding first diversion air guide pipe 13 and second diversion air guide pipe 14 can be located outside the high-speed motor 1 or can be internal flow channels of the high-speed motor 1. In other words, the hydrogen delivery channel for motor heat dissipation and bearing lubrication can be located outside the motor, but is not limited to this layout and can also be located inside the motor.

[0038] In addition, the centrifugal hydrogen booster circulating pump for hydrogen lubrication of bearings and cooling of motors of the present invention also includes a first drying device 16 and a second drying device 17. The first drying device 16 is installed on the first diversion guide pipe 13 between the first outlet pipe 11 and the high-speed motor heat sink 18, and the second drying device 17 is installed on the second diversion guide pipe 14 between the second outlet pipe 12 and the high-speed motor heat sink 18.

[0039] This invention installs a drying device at the front end of the high-speed motor radiator of the circulating pump to filter water vapor in the hydrogen. It dries and dehumidifies the hydrogen used for cooling and lubrication after pressurization, preventing humid hydrogen from flowing into the heat dissipation gap and bearing gap of the high-speed motor, causing icing and making it difficult to start the motor at low temperatures.

[0040] The centrifugal hydrogen booster circulation pump of the present invention adopts a symmetrical distribution on both sides. The first inlet pipe 9 and the second inlet pipe 10, the first outlet pipe 11 and the second outlet pipe 12, the first volute 7 and the second volute 8, and the first impeller 5 and the second impeller 6 are all symmetrically distributed on both sides of the high-speed motor 1.

[0041] This invention symmetrically mounts impeller diffusers on both sides of a high-speed motor. Hydrogen from the fuel cell reactor can be drawn into the pump body through the inlet pipes on both sides, where it is simultaneously pressurized by the impellers. After diffusion, it is pumped out through the outlet pipes on both sides to the fuel cell anode. By employing a symmetrical structure on both sides, this invention allows hydrogen to enter the pump body from both sides, balancing the axial forces on the impellers on both sides. This helps improve the hydrogen extraction efficiency of the circulating pump and the speed of hydrogen recycling, while reducing the bearing load and minimizing bearing fatigue losses.

[0042] The present invention uses gas bearings to support the load. More specifically, the first gas bearing 3 and the second gas bearing 4 are symmetrically installed on both sides of the pump shaft 2 to bear the pump body load. Under the rotation of the high-speed motor 1, an air film is formed in the bearing gap. Under the action of the air film, the bearing is suspended around the pump shaft 2, supporting the entire circulating pump system.

[0043] Furthermore, the first gas bearing 3 and the second gas bearing 4 in this invention can be herringbone spiral groove gas bearings, corrugated foil gas bearings, or other types of dynamic pressure gas bearings.

[0044] In addition, in this embodiment, the dry hydrogen used for motor cooling and bearing lubrication can also be directly introduced into the hydrogen in the high-pressure hydrogen cylinder of the fuel cell.

[0045] This invention is based on a symmetrical hydrogen circulation pump structure. It uses hydrogen-lubricated dynamic pressure gas bearings to support the load. The high-pressure hydrogen, after being compressed by the rotating blades, is dehumidified by a drying device and then split. Part of the hydrogen flows through a splitting pipe to the motor coil and rotor for cooling and heat dissipation, and then flows back to the lower-pressure booster inlet of the circulation pump impeller through the outlet. The other part flows as a lubricating medium through the gas bearings on both sides of the rotor (i.e., the pump shaft) and then flows back to the booster inlet of the circulation pump blades through the gap between the hydrogen bearings, thus achieving circulation boosting.

[0046] The centrifugal hydrogen booster circulating pump proposed in this invention uses a gas bearing as the motor rotor support component, and the working medium contains only hydrogen. In addition to boosting and transporting hydrogen, it also directly uses hydrogen for bearing lubrication and high-speed motor cooling. By using hydrogen instead of cold oil or air as the coolant for the motor, rotor, and bearings, it can achieve rapid cooling of the motor during high-speed operation, preventing the motor from stopping due to overheating and avoiding the problem of reduced clearance in the gas bearing due to thermal expansion. At the same time, by using hydrogen instead of traditional oil film grease to lubricate the bearings, there is no need to provide additional oil or air as a motor cooling medium, fundamentally solving the problem of oil pollution caused by oil leakage. This effectively improves the utilization rate of hydrogen and the working efficiency of the hydrogen circulating pump, helps protect the high-speed motor in the hydrogen circulating pump, reduces the risk of corrosion damage to the circulating pump, and reduces the operating cost of the hydrogen circulating pump. In addition, the advantages of low friction, low resistance, and low vibration of the gas bearing help ensure the high-speed and stable operation of the hydrogen circulating pump, enabling the hydrogen circulating pump to be applied to a wider range of complex working conditions.

[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0048] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A centrifugal hydrogen booster circulating pump for hydrogen lubrication of bearings and cooling of motors, characterized in that, The pump includes a gas bearing, a high-speed motor, an inlet pipe, an outlet pipe, a volute, an impeller, a diversion pipe, and a pump shaft. The pump shaft is coaxially mounted inside the high-speed motor, with both its front and rear ends extending beyond the motor and fixed in position by a first gas bearing at the front end of the high-speed motor and a second gas bearing at the rear end, respectively. A first impeller is fixedly connected to the front end of the pump shaft, and a second impeller is fixedly connected to the rear end. The centrifugal hydrogen booster pump has a first volute at the front end and a second volute at the rear end. The first impeller is installed inside the first volute and corresponds to the first inlet pipe on the first volute. The second impeller is installed inside the second volute and corresponds to... The second air inlet pipe is on the second volute; the first impeller and the first volute together constitute the first impeller diffuser, and the second impeller and the second volute together constitute the second impeller diffuser; the side of the first air outlet pipe on the first volute is connected to one end of the first diversion air guide pipe, and the other end of the first diversion air guide pipe is sequentially connected to the high-speed motor cooling air gap in the high-speed motor cooling box and the air supply hole of the first gas bearing housing; the side of the second air outlet pipe on the second volute is connected to one end of the second diversion air guide pipe, and the other end of the second diversion air guide pipe is sequentially connected to the high-speed motor cooling air gap in the high-speed motor cooling box and the air supply hole of the second gas bearing housing. It also includes a first drying device and a second drying device. The first drying device is installed on the first diversion air pipe between the first air outlet pipe and the high-speed motor heat sink, and the second drying device is installed on the second diversion air pipe between the second air outlet pipe and the high-speed motor heat sink. Hydrogen enters the pump body through the inlet pipe, is pressurized by the blade diffuser, and then flows into the outlet pipe. In the outlet pipe cavity, a portion of the hydrogen passes through the diversion pipe and is dehumidified by the drying device at the front end of the motor before flowing to the high-speed motor cooling air gap and the gas bearing supply hole for cooling the motor coils and rotor, as well as lubricating the gas bearing. The hydrogen flowing through both sides of the gas bearing flows back to the other side of the pump shaft through the gas bearing gap. This part is connected to the impeller pressurization inlet and is pressurized again by the impeller rotation.

2. The centrifugal hydrogen booster circulating pump for hydrogen lubrication of bearings and cooling of motors according to claim 1, characterized in that, The centrifugal hydrogen booster circulation pump adopts a symmetrical distribution on both sides, with the first and second inlet pipes, the first and second outlet pipes, the first and second volutes, and the first and second impellers all symmetrically distributed on both sides of the high-speed motor.

3. A centrifugal hydrogen booster circulating pump for hydrogen lubrication of bearings and cooling of motors according to claim 2, characterized in that, The first and second gas bearings are symmetrically installed on both sides of the pump shaft. Under the rotation of the high-speed motor, an air film is formed in the bearing gap. Under the action of the air film, the bearings are suspended around the pump shaft, supporting the entire circulating pump system.

4. A centrifugal hydrogen booster circulating pump for hydrogen lubrication of bearings and cooling of motors according to any one of claims 1-3, characterized in that, The first gas bearing and the second gas bearing are either herringbone spiral groove gas bearings or corrugated foil gas bearings.

5. A centrifugal hydrogen booster circulating pump for hydrogen lubrication of bearings and cooling of motors according to claim 1, characterized in that, The heat dissipation air gap of the high-speed motor and the corresponding first and second diversion air pipes are located outside the high-speed motor or are internal flow channels of the high-speed motor.

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