Special hydraulic cylinder for PEM hydrogen production electrolytic cell

Abstract

The utility model discloses a special hydraulic cylinder for a PEM hydrogen production electrolytic cell, which comprises a cylinder body, the cylinder body comprises an outer wall and an inner wall, the outer edge of the bottom of the inner wall extends towards the outer wall, a cylinder body end cover is arranged at the top between the outer wall and the inner wall, the cylinder body end cover is connected with the inner side of the outer wall, a pressure spring is arranged between the cylinder body end cover and the bottom of the inner wall, and a hollow plunger is arranged at the top of the inner wall. A hollow sleeve is arranged in the inner wall; and an oil port is formed in the outer wall of the cylinder body. According to the utility model, the bolt hydraulic stretching principle is adopted to replace the bolt torque fastening mode in the prior art, so that the precise controlled pressing of each part of the electrolytic cell is realized, the operation intensity is reduced, and the precision of the pressing force is improved.

Description

Technical Field

[0001] The utility model relates to a special hydraulic cylinder for a PEM hydrogen production electrolyzer, belonging to the technical field of 700bar hydraulic cylinders. Background Art

[0002] The PEM electrolyzer is the core component of the proton exchange membrane water electrolysis hydrogen production system, and its assembly quality is crucial. The components of the PEM electrolyzer from the outside to the inside are: screw, nut, disc spring, compression plate, insulation layer, bipolar plate, insulation rubber ring, titanium mesh, titanium felt, membrane electrode, titanium felt, titanium mesh, insulation rubber ring, electrode plate, insulation layer, compression plate, disc spring, nut. These components are compressed and stacked by screws and compression plates to form a complete electrolyzer.

[0003] At present, the commonly used compression and stacking process is the torque tightening method. On-site workers use manual or electric torque wrenches to tighten the nuts of the PEM electrolyzer in sequence according to the rated torque and specified order. During the tightening process, the torque is converted into axial preload to achieve effective compression of the electrolyzer components. The applied axial preload is also used to provide the preload required for the electrolyzer disc spring assembly.

[0004] The prior art has the following defects:

[0005] 1. The torque tightening method requires that the axial preload force not only meets the compression requirements of the various components of the electrolytic cell, but also provides the preload force required by the disc spring assembly of the electrolytic cell. Since dozens of sets of screws need to be operated one by one during the tightening process, the labor intensity of the operator is relatively high. Therefore, an axial force application process equipment that can provide the electrolytic cell compression force is required.

[0006] 2. The ratio of torque tightening method to axial preload is usually 10%, and is easily affected by thread friction, end face friction and lubrication factors. Since the electrolytic cell has high requirements for the accuracy of axial clamping force, it usually needs to be controlled within 1%. Therefore, a more accurate axial force application process equipment is needed.

[0007] 3. The size of the screw used to fasten the PEM electrolyzer varies according to the specifications of the electrolyzer. Therefore, there is an urgent need for an axial force application process equipment that is compatible with screws of various specifications.

[0008] 4. During the tightening process of the PEM electrolyzer, the upper and lower compression plates need to be kept parallel. Therefore, the synchronization of the force needs to be considered when applying the axial force at multiple points. Summary of the invention

[0009] The technical problem to be solved by the utility model is that the torque fastening method has a high labor intensity.

[0010] In order to solve the above problems, the utility model provides a hydraulic cylinder dedicated to a PEM hydrogen production electrolyzer, which includes a cylinder body, the cylinder body includes an outer wall and an inner wall, the bottom outer edge of the inner wall extends toward the outer wall, a cylinder end cover is provided at the top between the outer wall and the inner wall, the cylinder end cover is connected to the inner side of the outer wall, a compression spring is provided between the cylinder end cover and the bottom of the inner wall, a hollow plunger is provided at the top of the inner wall, and a hollow sleeve is provided in the inner wall; an oil port is provided on the outer wall of the cylinder body.

[0011] Preferably, a bridge frame is provided at the bottom of the cylinder body, and a shift ring is provided inside the bridge frame.

[0012] More preferably, the bridge is connected to the cylinder body via set screws.

[0013] Preferably, two oil ports are provided on the outer wall of the cylinder body.

[0014] More preferably, the two oil ports on the outer wall of the cylinder body are at an angle of 90° on the projection surface.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. The utility model adopts the principle of hydraulic tensioning of bolts, replacing the torque tightening method of bolts in the prior art, realizing the precise and controlled pressing of various components of the electrolytic cell, reducing the operating intensity and improving the accuracy of the pressing force.

[0017] 2. The utility model can be matched with a replaceable stretching head, which can meet the needs of various screw stretching in different electrolytic cells.

[0018] 3. The utility model adopts a double oil port design, which is convenient for serial use when multiple hydraulic cylinders are pressed simultaneously, thereby improving the parallelism of the two compression plates of the electrolytic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a special hydraulic cylinder for a PEM hydrogen production electrolyzer provided by the utility model. DETAILED DESCRIPTION

[0020] In order to make the present invention more obvious and easy to understand, preferred embodiments are described in detail as follows in conjunction with the accompanying drawings.

[0021] Example

[0022] like Figure 1As shown, a hydraulic cylinder dedicated to a PEM hydrogen production electrolyzer provided by the utility model comprises a cylinder body 2, the cylinder body 2 comprises an outer wall and an inner wall, the outer edge of the bottom of the inner wall extends toward the outer wall, a cylinder body end cover 1 is provided at the top between the outer wall and the inner wall, the cylinder body end cover 1 is connected to the inner side of the outer wall, a compression spring 7 is provided between the cylinder body end cover 1 and the bottom of the inner wall, a hollow plunger 9 is provided at the top of the inner wall, and a hollow sleeve 8 is provided in the inner wall; an oil port 3 is provided on the outer wall of the cylinder body 2. A bridge frame 4 is provided at the bottom of the cylinder body 2, and a dial ring 5 is provided in the bridge frame 4. The bridge frame 4 is connected to the cylinder body 2 by a set screw 6.

[0023] Two oil ports 3 are arranged on the outer wall of the cylinder body 2, and the angle between the two oil ports 3 on the projection surface is 90°.

[0024] In actual work, the electrolytic cell screw will pass through the central control plunger 9 and the hollow sleeve 8, and the stretching head is used to engage with the electrolytic cell screw. Under the action of hydraulic pressure, the electrolytic cell screw is stretched, and the reaction force generated by the stretching is used to meet the compression requirements of various components of the electrolytic cell.

[0025] In view of the high precision requirements of the axial clamping force of the electrolytic cell, the output force of the hydraulic cylinder of the utility model can be regarded as the axial preload force of the screw, so there is no need to convert the torque tightening into the axial force through the empirical formula. The axial preload force of the screw can be accurately obtained through the output force calculation formula: hydraulic cylinder output force = effective area × hydraulic pressure.

[0026] In view of the problem of various specifications of electrolytic cell screws in the prior art, the hydraulic cylinder of the utility model is equipped with a replaceable stretching head to adapt to screws of different specifications. The stretching head can be flexibly adjusted and is suitable for screws of specifications from M16 to M30, thereby meeting the use requirements of various screws.

[0027] In view of the problem of parallelism of the electrolytic cell compression plate in the prior art, the utility model adopts a hydraulic cylinder with two oil ports. This design facilitates the serial operation of multiple hydraulic cylinders when synchronously compressing the electrolytic cell compression plate. Specifically, two oil ports are provided at the lower part of the cylinder body 2, and the oil ports are spaced 90 degrees apart to ensure that there is no interference between the hydraulic hoses.

Claims

1. A hydraulic cylinder for a PEM hydrogen production electrolyzer, characterized in that: The invention comprises a cylinder body (2), wherein the cylinder body (2) comprises an outer wall and an inner wall, wherein the outer edge of the bottom of the inner wall extends toward the outer wall, a cylinder body end cover (1) is provided at the top between the outer wall and the inner wall, the cylinder body end cover (1) is connected to the inner side of the outer wall, a compression spring (7) is provided between the cylinder body end cover (1) and the bottom of the inner wall, a hollow plunger (9) is provided at the top of the inner wall, and a hollow sleeve (8) is provided in the inner wall; an oil port (3) is provided on the outer wall of the cylinder body (2).

2. The hydraulic cylinder for PEM hydrogen production electrolyzer according to claim 1, characterized in that: A bridge frame (4) is provided at the bottom of the cylinder body (2), and a shifting ring (5) is provided inside the bridge frame (4).

3. The hydraulic cylinder for PEM hydrogen production electrolyzer according to claim 2, characterized in that: The bridge frame (4) is connected to the cylinder body (2) via set screws (6).

4. The hydraulic cylinder for PEM hydrogen production electrolyzer according to claim 1, characterized in that: Two oil ports (3) are provided on the outer wall of the cylinder body (2).

5. The hydraulic cylinder for PEM hydrogen production electrolyzer according to claim 4, characterized in that: The two oil ports (3) on the outer wall of the cylinder body (2) are arranged at an angle of 90° on the projection plane.

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