CN218918967U

CN218918967U - Device for judging weak drainage area of bipolar plate

Info

Publication number: CN218918967U
Application number: CN202222969812.XU
Authority: CN
Inventors: 吕平; 孙昕; 徐源泉; 韩猛; 邢丹敏
Original assignee: Sunrise Power Co Ltd
Current assignee: Sunrise Power Co Ltd
Priority date: 2022-11-08
Filing date: 2022-11-08
Publication date: 2023-04-25
Anticipated expiration: 2032-11-08

Abstract

The utility model provides a device for judging a drainage weak area of a bipolar plate, which comprises a visual battery, a water circulation system and a gas supply system, wherein the visual battery comprises a first transparent end plate, an air cavity inlet is formed in the left side of the first transparent end plate, a hydrogen cavity inlet is formed in the right side of the first transparent end plate, the water circulation system comprises a solenoid valve V, a water tank, a solenoid valve II, a water pump and a solenoid valve IV which are sequentially connected, the solenoid valve IV is connected with the hydrogen cavity inlet, a pressure gauge II is arranged on a pipeline between the solenoid valve IV and the hydrogen cavity inlet, the water tank inlet is connected with a solenoid valve V outlet, the gas supply system comprises a gas source, a solenoid valve I and a solenoid valve III which are sequentially connected, and the pressure gauge I is arranged on a pipeline between the solenoid valve III and the air cavity inlet. The technical scheme of the utility model solves the problem that the drainage condition of the bipolar plate cannot be truly, intuitively and comprehensively reflected in the prior art.

Description

Device for judging weak drainage area of bipolar plate

Technical Field

The utility model relates to the technical field of proton exchange membrane fuel cells, in particular to a device for judging a weak drainage area of a bipolar plate.

Background

The proton exchange membrane fuel cell is a clean and efficient energy conversion device, has the advantages of green pollution-free, high efficiency, low noise and the like, and has been widely paid attention to the market in recent years. The bipolar plate in the fuel cell is used as a key part, has the functions of conducting electrons, providing a three-cavity flow field and the like, and the design of the bipolar plate is critical to the performance of a galvanic pile.

The normal operation of the fuel cell needs to continuously supply fuel and oxidant to the catalytic layer through the flow channel, water is needed to be used as a medium for proton transmission in the reaction process, but water generated by the reaction also needs to be discharged out of the cell through the flow channel in time, if liquid water generated by the reaction in the flow channel cannot be discharged in time, gas transmission can be blocked, and the performance and the service life of a galvanic pile are affected, so that the drainage performance of the bipolar plate needs to be considered at the beginning of the design of the bipolar plate.

At present, although an online observation device for drainage of the bipolar plate appears, because of the limitation of the structure of the bipolar plate or the device structure, only the drainage condition of a local bipolar plate can be observed, and the drainage condition in a bipolar plate flow channel can not be truly, intuitively and comprehensively reflected, so that the optimization design work of the bipolar plate is affected, and the development efficiency is not improved.

Disclosure of Invention

According to the technical problem that the drainage condition of the bipolar plate cannot be truly, intuitively and comprehensively reflected, the device for judging the drainage weak area of the bipolar plate is provided. The utility model mainly utilizes the water circulation system and the gas supply system to carry out water injection purging on the inner cavity of the bipolar plate in the visual battery, and the drainage condition in the bipolar plate flow channel is observed through the transparent end plate of the visual battery to judge the weak drainage area of the bipolar plate.

The utility model adopts the following technical means:

an apparatus for determining a region of weakness in drainage of a bipolar plate comprising: a visual battery, a water circulation system and a gas supply system;

the visual battery comprises a first transparent end plate, wherein an air cavity inlet is formed in the left side of the first transparent end plate, and a hydrogen cavity inlet is formed in the right side of the first transparent end plate;

the water circulation system comprises an electromagnetic valve V, a water tank, an electromagnetic valve II, a water pump and an electromagnetic valve IV which are sequentially connected, wherein the electromagnetic valve IV is connected with an inlet of the hydrogen cavity, a pressure gauge II is arranged on a pipeline between the electromagnetic valve IV and the inlet of the hydrogen cavity, and an inlet of the water tank is connected with an outlet of the electromagnetic valve V;

the air supply system comprises an air source, an electromagnetic valve I and an electromagnetic valve III which are sequentially connected, the electromagnetic valve III is connected with the air cavity inlet, and a pressure gauge I is arranged on a pipeline between the electromagnetic valve III and the air cavity inlet;

the visual battery further comprises a second transparent end plate, a bipolar plate, a fastening device, a sealing gasket I and a sealing gasket II, wherein the first transparent end plate is fixedly connected with the second transparent end plate through the fastening device, and the sealing gasket I, the bipolar plate and the sealing gasket II are sequentially placed between the first transparent end plate and the second transparent end plate.

Further, the water circulation system further comprises a solenoid valve VI and a storage tank, wherein a hydrogen cavity outlet is formed in the first transparent end plate and located below the air cavity inlet, an air cavity outlet is formed in the first transparent end plate and located below the hydrogen cavity inlet, the hydrogen cavity outlet and the air cavity outlet are respectively communicated to a common pipeline I, the common pipeline I is provided with two branches, one branch is connected to the inlet of the solenoid valve V, the other branch is connected to the inlet of the solenoid valve VI, and the storage tank is connected with the outlet of the solenoid valve VI.

Further, the outlet of the electromagnetic valve I and the outlet of the water pump are respectively communicated to a common pipeline II, the common pipeline II is provided with two branches, one branch is connected to the air cavity inlet, the electromagnetic valve III and the pressure gauge I are arranged, the other branch is connected to the hydrogen cavity inlet, and the electromagnetic valve IV and the pressure gauge II are arranged.

Further, glue lines are arranged on the bipolar plates, and a piece of transparent polyester PEN is respectively arranged on the anode side and the cathode side of the bipolar plates.

Further, the first transparent end plate and the second transparent end plate are acrylic plates with the thickness of 5 cm.

Compared with the prior art, the utility model has the following advantages:

the device for judging the weak area of the bipolar plate drainage can be used for off-line testing, the visual battery is connected with the water circulation system and the gas supply system, the discharging process of liquid water on the surface of the bipolar plate can be visually, truly, effectively and comprehensively observed by controlling the supply of cooling liquid and gas, the weak area of the bipolar plate drainage can be accurately judged, the optimal design and research and development of the bipolar plate are positively influenced, the research and development efficiency is improved, and the device provided by the utility model is simple in structure and convenient to use and maintain.

In conclusion, the visual battery is connected with the water circulation system and the gas supply system by the technical scheme, and the process of removing liquid water on the surface of the bipolar plate can be intuitively, truly, effectively and comprehensively observed by controlling the supply of cooling liquid and gas. Therefore, the technical scheme of the utility model solves the problem that the drainage condition of the bipolar plate cannot be truly, intuitively and comprehensively reflected in the prior art.

For the reasons, the utility model can be widely popularized in the fields of proton exchange membrane fuel cells and the like.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present utility model, and other drawings may be obtained according to the drawings without inventive effort to a person skilled in the art.

Fig. 1 is a schematic view of an apparatus for determining a weak drainage area of a bipolar plate according to the present utility model.

Fig. 2 is a schematic structural view of a first transparent end plate according to the present utility model.

Fig. 3 is a schematic structural view of a second transparent end plate according to the present utility model.

In the figure: 1. a visual battery; 3. a gas source; 4. a water tank; 5. a storage tank; 6. a water pump; 7. a pressure gauge I; 8. a pressure gauge II; 10. an air chamber inlet; 12. a hydrogen chamber outlet; 13. a hydrogen chamber inlet; 15. an air chamber outlet; s1, an electromagnetic valve I; s2, an electromagnetic valve II; s3, an electromagnetic valve III; s4, an electromagnetic valve IV; s5, an electromagnetic valve V; s6, an electromagnetic valve VI.

Detailed Description

It should be noted that, without conflict, the embodiments of the present utility model and features of the embodiments may be combined with each other. The utility model will be described in detail below with reference to the drawings in connection with embodiments.

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the utility model, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present utility model. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present utility model unless it is specifically stated otherwise. Meanwhile, it should be clear that the dimensions of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In the description of the present utility model, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present utility model and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present utility model: the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present utility model.

Example 1

As shown in fig. 1 to 3, the present utility model provides a device for judging a weak drainage area of a bipolar plate, comprising: the visual battery 1 is connected with the water circulation system and the gas supply system through pipelines;

the visual battery 1 includes: the sealing device comprises a first transparent end plate, a second transparent end plate, a bipolar plate, a fastening device, a sealing gasket I and a sealing gasket II, wherein the first transparent end plate is fixedly connected with the second transparent end plate through the fastening device, and the sealing gasket I, the bipolar plate and the sealing gasket II are sequentially arranged between the first transparent end plate and the second transparent end plate;

the left surface of the first transparent end plate is provided with an air cavity inlet 10 and a hydrogen cavity outlet 12 in sequence from top to bottom, and the right surface of the first transparent end plate is provided with a hydrogen cavity inlet 13 and an air cavity outlet 15 in sequence from top to bottom;

the water circulation system includes: the device comprises a water tank 4, a solenoid valve II S2, a solenoid valve IV S4, a solenoid valve V S5, a solenoid valve VI S6, a storage tank 5, a water pump 6 and a pressure gauge II 8, wherein an outlet of the water tank 4, the solenoid valve II S2, the water pump 6, the solenoid valve IV S4 and a hydrogen cavity inlet 13 are sequentially connected, the pressure gauge II 8 is arranged on a pipeline between the solenoid valve IV S4 and the hydrogen cavity inlet 13, an inlet of the water tank 4 is connected with an outlet of the solenoid valve V S, and the storage tank 5 is connected with an outlet of the solenoid valve VI S6;

the gas supply system includes: air supply 3, solenoid valve I S1, solenoid valve III S3 and manometer I7, air supply 3 solenoid valve II S2 solenoid valve III S3 with air chamber entry 10 connects gradually, manometer I7 sets up solenoid valve III S3 with on the pipeline between the air chamber entry 10.

Further, the hydrogen chamber outlet 12 and the air chamber outlet 15 are respectively connected to a common line I, and the common line I is provided with two branches, one of which is connected to the inlet of the solenoid valve V S5, the other is connected to the inlet of the solenoid valve VI S6, and the storage tank 5 is connected to the outlet of the solenoid valve VI S6.

Further, the outlet of the electromagnetic valve I S and the outlet of the water pump 6 are respectively communicated to a common pipeline II, and the common pipeline II is provided with two branches, wherein one branch is connected to the air cavity inlet 10 and is provided with the electromagnetic valve III S3, and the other branch is connected to the hydrogen cavity inlet 13 and is provided with the electromagnetic valve IV S4.

Still further, the water circulation system and the gas supply system may not be operated simultaneously.

Further, the electromagnetic valves I-VI are used for controlling the flow and the flow route of the cooling liquid and the gas.

Further, the pressure gauge I and the pressure gauge II are used for monitoring the pressure of the air chamber inlet 10 and the hydrogen chamber inlet 13.

Further, the storage tank 5 is mainly used for storing the cooling liquid and gas discharged from the visual cell 1.

Further, glue lines are arranged on the bipolar plates and used for fastening and sealing.

Further, a sheet of transparent polyester PEN is placed on each of the anode and cathode sides of the bipolar plate to ensure adequate contact between the bipolar plate and the first and second transparent end plates.

Further, the first transparent end plate and the second transparent end plate are acrylic plates with the thickness of 5cm, and the thickness of 5cm is selected to ensure that the first transparent end plate and the second transparent end plate can maintain higher flatness in the fastening process.

Further, the fastening means consists of 18 screws.

The utility model can be used for off-line test, and is connected with a water circulation system and a gas supply system by utilizing a visual battery, and the discharge process of liquid water on the surface of the bipolar plate can be intuitively, truly, effectively and comprehensively observed by controlling the supply of cooling liquid and gas, thereby being beneficial to accurately judging the weak area of the drainage of the bipolar plate, having positive influence on the optimal design and research and development of the bipolar plate and improving the research and development efficiency.

The device for judging the drainage weak area of the bipolar plate provided by the utility model is used for judging the drainage weak area of the bipolar plate, and comprises the following specific steps:

s1, after the visual battery 1, the water circulation system and the gas supply system are connected, the air tightness of the device is detected, and the air tightness of the device is ensured to be good;

s2, starting a water circulation system, starting an electromagnetic valve II S2, an electromagnetic valve IV S4, an electromagnetic valve V S and a water pump 6, closing an electromagnetic valve I S, an electromagnetic valve III S3 and an electromagnetic valve VI S6, pumping cooling liquid from cooling liquid in a water tank 4 by pressure provided by the water pump 6, sequentially passing through the electromagnetic valve II S2, the water pump 6, the electromagnetic valve IV S4, a pressure gauge II 8 and a hydrogen cavity inlet 13, monitoring the pressure of the hydrogen cavity inlet 13 by the pressure gauge II 8, controlling the pressure within a range of 10-100 kPa, and fully circulating the cooling liquid in the hydrogen cavity until the cooling liquid is full;

s3, closing a water circulation system, closing a water pump, closing a solenoid valve II S2, closing a solenoid valve III S3 and a solenoid valve V S, opening a gas supply system, opening a solenoid valve I S, a solenoid valve IV S4 and a solenoid valve VI S6 to enable gas to gradually enter a hydrogen cavity, monitoring the gas pressure of an inlet 13 of the hydrogen cavity through a pressure gauge II 8, adjusting the gas pressure to be 50kPa, enabling gas to flow out from a gas source 3, sequentially passing through the solenoid valve I S and the solenoid valve IV S4, entering the hydrogen cavity, circulating to an outlet 12 of the hydrogen cavity in the hydrogen cavity, discharging the hydrogen cavity into a storage tank 5 through the solenoid valve VI S6, and discharging cooling liquid together with the gas into the storage tank 5;

s4, observing the removing process of the liquid water on the surface of the bipolar plate in the hydrogen cavity through the first transparent end plate, and judging and recording a weak area of side drainage of the hydrogen cavity of the bipolar plate;

s5, closing the gas supply system, and closing the solenoid valve I S, the solenoid valve III S3 and the solenoid valve VI S6;

s6, starting a water circulation system, starting an electromagnetic valve II S2, an electromagnetic valve III S3, an electromagnetic valve V S and a water pump, closing an electromagnetic valve I S, an electromagnetic valve IV S4 and an electromagnetic valve VI S6, monitoring the pressure of an air cavity inlet 10 through a pressure gauge I7, controlling the pressure within the range of 10-100 kPa, and fully circulating cooling liquid in the air cavity until the cooling liquid is full;

s7, closing a water circulation system, closing a water pump, a solenoid valve II S2, a solenoid valve IV S4 and a solenoid valve V S5, opening a gas supply system, opening a solenoid valve I S, a solenoid valve III S3 and a solenoid valve VI S6 to enable gas to gradually enter the air cavity through a pipeline, monitoring the gas pressure of an air cavity inlet 10 through a pressure gauge I7, adjusting the gas pressure to be 50kPa, enabling gas to flow out of a gas source 3, sequentially passing through the solenoid valve I S1 and the solenoid valve III S3 and then entering the air cavity, circulating to an air cavity outlet 15 in the air cavity and discharging the gas into a storage tank 5 through the solenoid valve VI S6, and discharging cooling liquid together with the gas into the storage tank 5;

s8, the removing process of the liquid water on the surface of the bipolar plate in the air cavity can be observed through the second transparent end plate, and the weak area of the side drainage of the air cavity of the bipolar plate is judged and recorded.

The utility model can be used for observing and judging the drainage process and the weak area of the bipolar plate, and can also be used for testing the influence of different gases on the drainage process and the weak area of the bipolar plate, and the specific implementation scheme is as follows:

s2, starting a water circulation system, starting an electromagnetic valve II S2, an electromagnetic valve IV S4, an electromagnetic valve V S and a water pump, closing an electromagnetic valve I S, an electromagnetic valve III S3 and an electromagnetic valve VI S6, monitoring the pressure of an inlet 13 of a hydrogen cavity through a pressure gauge II 8, controlling the pressure within a range of 10-100 kPa, and fully circulating cooling liquid in the hydrogen cavity until the cooling liquid is full;

s3, closing a water circulation system, closing a water pump, a solenoid valve II S2, a solenoid valve III S3 and a solenoid valve V S, opening a gas supply system, opening a solenoid valve I S, a solenoid valve IV S4 and a solenoid valve VI S6 to enable gas I to gradually enter a hydrogen cavity, monitoring the gas pressure of an inlet 13 of the hydrogen cavity through a pressure gauge II 8, adjusting the gas pressure to 50kPa, enabling the gas I to flow out of a gas source 3, sequentially passing through the solenoid valve I S1 and the solenoid valve IV S4 and then entering the hydrogen cavity, circulating the hydrogen cavity to an outlet 12 of the hydrogen cavity and discharging the hydrogen cavity into a storage tank 5 through the solenoid valve VI S6, and discharging cooling liquid along with the gas I into the storage tank 5;

s4, observing and recording the removal process of the liquid water on the surface of the bipolar plate in the hydrogen cavity through the first transparent end plate;

s5, closing the gas supply system, closing the solenoid valve I S1, the solenoid valve IV S4 and the solenoid valve VI S6, and stopping supplying the gas I to the visual battery;

s6, starting the water circulation system again, starting the electromagnetic valve II S2, the electromagnetic valve IV S4, the electromagnetic valve V S5 and the water pump, closing the electromagnetic valve I S, the electromagnetic valve III S3 and the electromagnetic valve VI S6, monitoring the pressure of the inlet 13 of the hydrogen cavity through the pressure gauge II 8, controlling the pressure within the range of 10-100 kPa, and fully circulating the cooling liquid in the hydrogen cavity until the cooling liquid is full;

s7, closing a water circulation system, closing a water pump, a solenoid valve II S2, a solenoid valve III S3 and a solenoid valve V S5, opening the gas supply system again, opening a solenoid valve I S, a solenoid valve IV S4 and a solenoid valve VI S6 to enable gas II to gradually enter a hydrogen cavity, monitoring the gas pressure of an inlet 13 of the hydrogen cavity through a pressure gauge II 8, adjusting the gas pressure to 50kPa, enabling the gas II to flow out of a gas source 3, sequentially passing through the solenoid valve I S1 and the solenoid valve IV S4 and then entering the hydrogen cavity, circulating the hydrogen cavity to an outlet 12 of the hydrogen cavity and discharging the hydrogen cavity into a storage tank 5 through the solenoid valve VI S6, and discharging cooling liquid along with the gas II into the storage tank 5;

s8, observing and recording the removal process of the liquid water on the surface of the bipolar plate in the hydrogen cavity through the first transparent end plate;

s9, comparing the difference of liquid water removal on the side surface of the hydrogen cavity of the bipolar plate by respectively introducing two different gases, and analyzing the influence of the different gases on the liquid water removal on the side surface of the hydrogen cavity of the bipolar plate.

The test of the influence of different gases on the drainage process and the weak area of the bipolar plate can flexibly select the test air cavity according to actual detection requirements, and the embodiment only takes the hydrogen air cavity side as an example to perform the influence detection of different gases on the drainage process and the weak area of the hydrogen air cavity side of the bipolar plate.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced with equivalents; such modifications and substitutions do not depart from the spirit of the technical solutions according to the embodiments of the present utility model.

Claims

1. An apparatus for determining a region of weakness in drainage of a bipolar plate, comprising: a visual battery, a water circulation system and a gas supply system;

the gas supply system comprises a gas source, a solenoid valve I and a solenoid valve III which are sequentially connected, wherein the solenoid valve III is connected with an air cavity inlet, and a pressure gauge I is arranged on a pipeline between the solenoid valve III and the air cavity inlet.

2. The device for judging a drainage weak area of a bipolar plate according to claim 1, wherein the visual battery further comprises a second transparent end plate, a bipolar plate, a fastening device, a sealing gasket I and a sealing gasket II, wherein the first transparent end plate is fixedly connected with the second transparent end plate through the fastening device, and the sealing gasket I, the bipolar plate and the sealing gasket II are sequentially arranged between the first transparent end plate and the second transparent end plate.

3. The device for judging a weak drainage area of a bipolar plate according to claim 2, wherein the water circulation system further comprises a solenoid valve VI and a storage tank, a hydrogen cavity outlet is arranged on the first transparent end plate and is positioned below the air cavity inlet, an air cavity outlet is arranged on the first transparent end plate and is positioned below the hydrogen cavity inlet, the hydrogen cavity outlet and the air cavity outlet are respectively communicated to a common pipeline I, the common pipeline I is provided with two branches, one branch is connected to the inlet of the solenoid valve V, the other branch is connected to the inlet of the solenoid valve VI, and the storage tank is connected with the outlet of the solenoid valve VI.

4. A device for judging a weak drainage area of a bipolar plate according to claim 3, wherein the outlet of the electromagnetic valve I and the outlet of the water pump are respectively communicated to a common pipeline II, and the common pipeline II is provided with two branches, one branch is connected to the air cavity inlet and provided with the electromagnetic valve III and the pressure gauge I, and the other branch is connected to the hydrogen cavity inlet and provided with the electromagnetic valve IV and the pressure gauge II.

5. The apparatus for determining a weak drainage area of a bipolar plate according to claim 4, wherein a glue line is provided on the bipolar plate, and a piece of transparent polyester PEN is placed on each of the anode side and the cathode side of the bipolar plate.

6. The apparatus for determining a weak drainage area of a bipolar plate according to claim 5, wherein the first transparent end plate and the second transparent end plate are acrylic plates each having a thickness of 5 cm.