Gas tightness detection equipment for liquid flow stack and method for determining leakage point

Abstract

The invention discloses airtight detection equipment for a liquid flow electric pile and a method for determining a leakage point, and relates to the technical field of airtight detection of liquid flow electric piles. The airtight detection equipment for the liquid flow electric pile comprises a sealing detection main control unit and a data acquisition unit, wherein the sealing detection main control unit is arranged between an anode side flow channel inlet end and a cathode side flow channel inlet end of the liquid flow electric pile; the sealing detection main control unit comprises an air pressure supply module, a pressure sensing assembly and a fluid switching valve group. The sealing detection main control unit highly integrates the functions of air pressure supply, fluid switching, pressure sensing, environment monitoring, data acquisition and the like into unified equipment, and is compact in structure and convenient to move and deploy on site; the fluid switching valve group realizes automatic switching of gas supply paths, and an intelligent control interface of the data acquisition terminal is matched, so that an operator can start a detection process by one key through an operation panel without manually switching pipelines, the operation complexity is greatly reduced, and the detection efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of liquid flow fuel cell gas tightness testing technology, and in particular relates to a liquid flow fuel cell gas tightness testing device and a method for determining leak points. Background Technology

[0002] A flow battery stack typically consists of multiple individual cells stacked together via bipolar plates. It has independent electrolyte channels on the anode and cathode sides, respectively for transporting the positive and negative electrolytes. To ensure that the stack does not leak electrolyte, cross-contaminate gases, or become contaminated with external substances during long-term operation, its sealing performance is crucial.

[0003] Currently, traditional airtightness testing methods mainly include the "soap bubble method," the "water immersion method," and the "simple pressure gauge monitoring method." The "soap bubble method" and the "water immersion method" rely on manual observation of bubble formation to determine the leak point, which is highly subjective, has low sensitivity, and is unsuitable for large fuel cell stacks or on-site testing. While the "simple pressure gauge monitoring method" can record pressure changes, it is mostly a single-point measurement, unable to distinguish between leaks on the anode and cathode sides, and lacks automatic data acquisition and analysis capabilities, making accurate location difficult. Furthermore, these methods generally do not consider the impact of environmental temperature and humidity changes on gas pressure, easily leading to misjudgments or missed detections. More importantly, most existing testing devices have loose structures, with gas sources, valves, pressure gauges, and other components scattered, complex connecting pipelines, cumbersome operation, and low testing efficiency. At the same time, they lack safety protection mechanisms, posing certain safety hazards during high-pressure testing. Although some automated testing systems have introduced data acquisition modules, they often only focus on the single parameter of pressure and do not integrate functions such as environmental compensation, automatic flow path switching, and emergency shutdown. The system integration and intelligence level are low, making it difficult to meet the needs of modern flow battery production lines for efficient, accurate, and traceable testing.

[0004] To address these issues, we provide a liquid flow fuel cell stack airtightness testing device and a method for determining leak points. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] This invention relates to a gas tightness testing device for a liquid flow fuel cell, comprising a main control unit for sealing detection disposed between the inlet end of the anode-side flow channel and the inlet end of the cathode-side flow channel of the liquid flow fuel cell, wherein the main control unit for sealing detection includes a gas pressure supply module, a pressure sensing component and a fluid switching valve group;

[0007] The air pressure supply module is connected to the input end of the fluid switching valve group via a first connecting pipe. The output end of the fluid switching valve group is connected to the anode side flow channel inlet and the cathode side flow channel inlet of the liquid flow stack via a second connecting pipe and a third connecting pipe, respectively. The pressure sensing component is installed on the main detection pipe downstream of the intersection of the second connecting pipe and the third connecting pipe. The main detection pipe extends to the outside of the liquid flow stack and is electrically connected to the data acquisition terminal.

[0008] The pressure sensing component includes a dual-channel pressure transmitter. The two detection ports of the dual-channel pressure transmitter are respectively connected to the second and third connecting pipelines. Its signal output terminal is connected to the analog input module of the data acquisition terminal through a shielded cable. The air pressure supply module includes a high-pressure air source cylinder, a pressure reducing valve, and a filter. The outlet of the high-pressure air source cylinder is connected to the filter and the pressure reducing valve in sequence and then connected to the first connecting pipeline.

[0009] The present invention is further configured such that the data acquisition terminal is disposed on the operation panel on the front of the device housing, and the operation panel is also provided with an emergency stop button, which is located at the lower right of the data acquisition terminal and is connected to the power control circuit of the fluid switching valve group via a hard wire.

[0010] The present invention is further configured such that the data acquisition terminal includes a data acquisition unit and a data storage module, the data acquisition unit is embedded in the operation panel on the front of the device housing, and the data storage module is a solid-state drive, which is located in an independent compartment inside the device housing.

[0011] The present invention is further configured such that the sealing detection main control unit also includes an ambient temperature and humidity sensor, the ambient temperature and humidity sensor is disposed beside the main detection pipeline and its probe is exposed to the air around the liquid flow charge stack, and the ambient temperature and humidity sensor establishes a communication connection with the data acquisition terminal through a signal line.

[0012] The present invention is further configured such that the second connecting pipe and the third connecting pipe are made of stainless steel corrugated pipe with an outer diameter of 10 mm and a wall thickness of 1.5 mm. The two ends of the stainless steel corrugated pipe are respectively connected to the output end of the fluid switching valve group and the inlet port of the liquid flow stack through compression fittings. The compression fitting is embedded in the annular groove on the outer wall of the stainless steel corrugated pipe.

[0013] A method for determining leak points in a flow fuel cell stack using a flow fuel cell air tightness testing device includes the following steps:

[0014] S1. Start the air pressure supply module and introduce gas into the anode side flow channel and cathode side flow channel of the liquid flow stack through the fluid switching valve group. After the pressure sensing component detects that the pressure in the flow channel reaches the set value, shut down the air pressure supply module and keep the pressure stable. Record the pressure change curve over time through the data acquisition terminal. When the pressure drop rate exceeds the preset threshold, the operator visually checks whether there is liquid seepage or bubble generation in each observation window area. If seepage or bubbles are found, mark the location corresponding to the observation window as a suspected leak area.

[0015] S2. Subsequently, the removable sealing heads on the anode side and the cathode side are disassembled in sequence. An endoscope probe is inserted into the flow channel through the flow channel outlet and pushed along the flow channel extension direction to observe whether there are cracks or sealing defects on the inner wall of the flow channel, and the coordinates of the defect location are recorded.

[0016] S3. Finally, the environmental parameters and pressure change data collected by the ambient temperature and humidity sensor are analyzed synchronously, and the final leak point is located by combining the switching sequence of the fluid switching valve group.

[0017] The invention is further configured such that, during endoscopic inspection, the illumination source at the front end of the endoscope probe is turned on, and its video signal is transmitted to the video input interface of the data acquisition unit via a cable. The internal image of the flow channel is displayed in real time on the data acquisition terminal. The operator judges the degree of leakage based on the direction and size of the crack in the image. The maximum insertion depth of the endoscope probe does not exceed 95% of the total length of the liquid flow stack flow channel, the outer diameter of the probe is at least 2 mm smaller than the inner diameter of the flow channel, and the advancement speed is controlled between 5 cm and 10 cm per second.

[0018] The present invention has the following beneficial effects:

[0019] 1. This invention employs a dual-channel pressure transmitter, which can simultaneously and independently monitor pressure changes in the flow channels on both the anode and cathode sides in real time. By synchronously acquiring and analyzing the pressure data from both sides through a data acquisition terminal, it can accurately identify minute pressure drop differences, thereby effectively determining the specific side (anode or cathode) where the leak occurred and achieving rapid location of the leak point. Combined with time-series pressure curve analysis, it can distinguish between actual leaks and interference factors such as temperature drift, significantly improving the sensitivity and reliability of detection.

[0020] 2. The sealing detection main control unit of the present invention highly integrates functions such as air pressure supply, fluid switching, pressure sensing, environmental monitoring and data acquisition into a unified device. It has a compact structure and is easy to move and deploy on site. The fluid switching valve group realizes automatic switching of air supply path. With the intelligent control interface of the data acquisition terminal, the operator can start the detection process with one click through the operation panel without manually switching pipelines, which greatly reduces the complexity of operation and improves the detection efficiency.

[0021] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

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

[0023] Figure 1 This is a schematic diagram of the process for the gas tightness testing equipment for a liquid flow fuel cell stack provided by the present invention.

[0024] The attached diagram lists the components represented by each number as follows:

[0025] 100. Sealing detection main control unit; 101. Air pressure supply module; 101a. High-pressure air source cylinder; 101b. Pressure reducing valve; 101c. Filter; 102. Pressure sensing assembly; 102a. Dual-channel pressure transmitter; 103. Fluid switching valve group; 104. First connecting pipeline; 105. Second connecting pipeline; 106. Third connecting pipeline; 107. Main detection pipeline; 108. Data acquisition terminal; 108a. Emergency stop button; 108b. Data acquisition unit; 108c. Data storage module; 109. Ambient temperature and humidity sensor. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Example

[0028] Please see Figure 1 The present invention is a gas tightness testing device for a liquid flow fuel cell, including a sealing detection main control unit 100 disposed between the inlet end of the anode side flow channel and the inlet end of the cathode side flow channel of the liquid flow fuel cell. The sealing detection main control unit 100 includes a gas pressure supply module 101, a pressure sensing component 102 and a fluid switching valve group 103.

[0029] The air pressure supply module 101 is connected to the input end of the fluid switching valve group 103 via the first connecting pipe 104. The output end of the fluid switching valve group 103 is connected to the anode side flow channel inlet and the cathode side flow channel inlet of the liquid flow stack via the second connecting pipe 105 and the third connecting pipe 106, respectively. The pressure sensing component 102 is installed on the main detection pipe 107 downstream of the intersection of the second connecting pipe 105 and the third connecting pipe 106. The main detection pipe 107 extends to the outside of the liquid flow stack and is electrically connected to the data acquisition terminal 108.

[0030] The pressure sensing component 102 includes a dual-channel pressure transmitter 102a. The two detection ports of the dual-channel pressure transmitter 102a are respectively connected to the second connecting pipe 105 and the third connecting pipe 106. Its signal output terminal is connected to the analog input module of the data acquisition terminal 108 through a shielded cable. The air pressure supply module 101 includes a high-pressure air source cylinder 101a, a pressure reducing valve 101b and a filter 101c. The outlet of the high-pressure air source cylinder 101a is connected to the filter 101c and the pressure reducing valve 101b in sequence and then connected to the first connecting pipe 104.

[0031] Specifically, the data acquisition terminal 108 is located on the operation panel on the front of the device housing. The operation panel is also equipped with an emergency stop button 108a, which is located at the lower right of the data acquisition terminal 108 and is connected to the power control circuit of the fluid switching valve group 103 via a hard wire. The data acquisition terminal 108 includes a data acquisition unit 108b and a data storage module 108c. The data acquisition unit 108b is embedded in the operation panel on the front of the device housing, and the data storage module 108c is a solid-state drive, which is located in an independent compartment inside the device housing.

[0032] The sealing detection main control unit 100 also includes an ambient temperature and humidity sensor 109. The ambient temperature and humidity sensor 109 is located beside the main detection pipeline 107 and its probe is exposed to the air around the liquid flow stack. The ambient temperature and humidity sensor 109 establishes a communication connection with the data acquisition terminal 108 through a signal line.

[0033] Furthermore, the second connecting pipe 105 and the third connecting pipe 106 are made of stainless steel corrugated pipe with an outer diameter of 10 mm and a wall thickness of 1.5 mm. The two ends of the stainless steel corrugated pipe are connected to the output end of the fluid switching valve group 103 and the inlet port of the liquid flow fuel cell stack respectively through compression fittings. The compression fitting is embedded in the annular groove on the outer wall of the stainless steel corrugated pipe. Using stainless steel corrugated pipe as the second and third connecting pipes 106 provides good flexibility, pressure resistance and vibration resistance. Combined with compression fittings, it enables fast, reliable and leak-free connection and adapts to the interface position changes of different models of liquid flow fuel cells.

[0034] The flow fuel cell stack airtightness testing equipment provided in this embodiment constructs an integrated, closed-loop controlled sealing detection main control unit 100 to achieve independent gas supply and synchronous pressure monitoring of the flow channels on the anode and cathode sides of the flow fuel cell stack. This allows for efficient and accurate airtightness testing and leak location. A stable and clean test gas source is provided by the gas pressure supply module 101, regulated to a safe operating pressure by the pressure reducing valve 101b, and impurities and moisture are removed by the filter 101c, ensuring the purity of the gas entering the system and preventing contamination of the stack interior or impact on testing accuracy. This gas source is delivered to the fluid switching valve group 103 via the first connecting pipeline 104. This valve group automatically switches the airflow path according to testing requirements, respectively... Test gas is introduced into the second connecting pipe 105 or the third connecting pipe 106, and then into the inlet of the anode or cathode side flow channel of the liquid flow stack, enabling time-sharing independent pressure testing. The pressure sensing component 102, installed on the main detection pipe 107, uses a dual-channel pressure transmitter 102a, capable of simultaneously acquiring pressure signals from both the anode and cathode sides in real time. The data is transmitted to the data acquisition terminal 108 via a shielded cable, effectively avoiding electromagnetic interference and ensuring signal accuracy. The data acquisition terminal 108 not only displays and records pressure change curves in real time but also incorporates ambient environmental parameters collected by the ambient temperature and humidity sensor 109 to perform temperature and humidity compensation corrections on the pressure data, improving the reliability of the test results. The entire system is safety-interlocked via the emergency stop button 108a on the operation panel. In case of an abnormality, the power supply to the fluid switching valve group 103 can be immediately cut off, stopping the gas supply and ensuring the safety of equipment and personnel. The data storage module 108c uses a solid-state drive to ensure long-term stable storage of test data, facilitating traceability and analysis. In summary, this invention achieves automation, intelligence, and high precision in liquid flow stack gas tightness detection through comprehensive design including gas path layout optimization, high-precision sensing and monitoring, environmental parameter compensation, and safety interlocking mechanisms. It is particularly suitable for the identification and location of minute leaks under complex operating conditions.

[0035] A method for determining leak points in a flow fuel cell stack using a flow fuel cell air tightness testing device includes the following steps:

[0036] S1. Start the air pressure supply module 101 and introduce gas into the anode side flow channel and cathode side flow channel of the liquid flow stack through the fluid switching valve group 103. After the pressure sensing component 102 detects that the pressure in the flow channel reaches the set value, shut down the air pressure supply module 101 and keep the pressure stable. Record the pressure change curve over time through the data acquisition terminal 108. When the pressure drop rate exceeds the preset threshold, the operator visually checks whether there is liquid seepage or bubble generation in each observation window area. If seepage or bubbles are found, mark the location corresponding to the observation window as a suspected leak area.

[0037] S2. Subsequently, the removable sealing heads on the anode side and the cathode side are disassembled in sequence. An endoscope probe is inserted into the flow channel through the flow channel outlet and pushed along the flow channel extension direction to observe whether there are cracks or sealing defects on the inner wall of the flow channel, and the coordinates of the defect location are recorded.

[0038] S3. Finally, the environmental parameters and pressure change data collected by the ambient temperature and humidity sensor 109 are analyzed synchronously, and the final leak point is located by combining the switching sequence of the fluid switching valve group 103.

[0039] During endoscopic testing, the illumination source at the front end of the endoscope probe is turned on, and its video signal is transmitted to the video input interface of the data acquisition terminal 108 via a cable. The internal image of the flow channel is displayed in real time on the data acquisition unit 108b. The operator judges the degree of leakage based on the direction and size of the cracks in the image. The maximum insertion depth of the endoscope probe does not exceed 95% of the total length of the liquid flow stack flow channel, the outer diameter of the probe is at least 2 mm smaller than the inner diameter of the flow channel, and the advancement speed is controlled between 5 cm and 10 cm per second.

[0040] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A device for testing the airtightness of a liquid flow fuel cell stack, characterized in that, It includes a sealing detection main control unit (100) disposed between the inlet end of the anode side flow channel and the inlet end of the cathode side flow channel of the liquid flow stack. The sealing detection main control unit (100) includes a gas pressure supply module (101), a pressure sensing component (102), and a fluid switching valve group (103). The air pressure supply module (101) is connected to the input end of the fluid switching valve group (103) through the first connecting pipe (104). The output end of the fluid switching valve group (103) is connected to the anode side flow channel inlet and the cathode side flow channel inlet of the liquid flow stack through the second connecting pipe (105) and the third connecting pipe (106), respectively. The pressure sensing component (102) is installed on the main detection pipe (107) downstream of the intersection of the second connecting pipe (105) and the third connecting pipe (106). The main detection pipe (107) extends to the outside of the liquid flow stack and is electrically connected to the data acquisition terminal (108). The pressure sensing component (102) includes a dual-channel pressure transmitter (102a). The two detection ports of the dual-channel pressure transmitter (102a) are respectively connected to the second connecting pipe (105) and the third connecting pipe (106). Its signal output terminal is connected to the analog input module of the data acquisition terminal (108) through a shielded cable. The air pressure supply module (101) includes a high-pressure air source cylinder (101a), a pressure reducing valve (101b) and a filter (101c). The outlet of the high-pressure air source cylinder (101a) is connected to the filter (101c) and the pressure reducing valve (101b) in sequence and then connected to the first connecting pipe (104).

2. The gas tightness testing device for a liquid flow fuel cell stack according to claim 1, characterized in that, The data acquisition terminal (108) is located on the operation panel on the front of the device housing. The operation panel is also equipped with an emergency stop button (108a). The emergency stop button (108a) is located at the lower right of the data acquisition terminal (108) and is connected to the power control circuit of the fluid switching valve group (103) via a hard wire.

3. The airtightness testing device for a liquid flow fuel cell stack according to claim 1, characterized in that, The data acquisition terminal (108) includes a data acquisition unit (108b) and a data storage module (108c). The data acquisition unit (108b) is embedded in the operation panel on the front of the device housing, and the data storage module (108c) is a solid-state drive, which is located in an independent compartment inside the device housing.

4. The airtightness testing device for a liquid flow fuel cell stack according to claim 1, characterized in that, The sealing detection main control unit (100) also includes an ambient temperature and humidity sensor (109). The ambient temperature and humidity sensor (109) is located next to the main detection pipeline (107) and its probe is exposed to the air around the liquid flow stack. The ambient temperature and humidity sensor (109) establishes a communication connection with the data acquisition terminal (108) through a signal line.

5. The gas tightness testing device for a liquid flow fuel cell stack according to claim 1, characterized in that, The second connecting pipe (105) and the third connecting pipe (106) are made of stainless steel corrugated pipe with an outer diameter of 10 mm and a wall thickness of 1.5 mm. The two ends of the stainless steel corrugated pipe are connected to the output end of the fluid switching valve group (103) and the inlet port of the liquid flow stack respectively through compression fittings. The compression fitting is embedded in the annular groove on the outer wall of the stainless steel corrugated pipe.

6. The method for determining the leak point of a liquid flow fuel cell using a liquid flow fuel cell air tightness testing device according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Start the air pressure supply module (101), and introduce gas into the anode side flow channel and cathode side flow channel of the liquid flow stack through the fluid switching valve group (103). After the pressure sensing component (102) detects that the pressure in the flow channel reaches the set value, shut down the air pressure supply module (101) and keep the pressure stable. Record the pressure change curve over time through the data acquisition terminal (108). When the pressure drop rate exceeds the preset threshold, the operator visually checks whether there is liquid seepage or bubble generation in each observation window area. If seepage or bubbles are found, mark the location corresponding to the observation window as a suspected leak area. S2. Subsequently, the removable plugs on the anode and cathode sides are disassembled in sequence. An endoscope probe is inserted into the flow channel through the outlet and pushed along the flow channel extension direction to observe whether there are cracks or sealing defects on the inner wall of the flow channel, and the coordinates of the defect location are recorded. S3. Finally, the environmental parameters and pressure change data collected by the ambient temperature and humidity sensor (109) are analyzed synchronously, and the final leak point is located by combining the switching sequence of the fluid switching valve group (103).

7. The method for determining the leak point of a liquid flow fuel cell according to claim 6, characterized in that, During endoscopic testing, the illumination source at the front end of the endoscope probe is turned on, and its video signal is transmitted to the video input interface of the data acquisition terminal (108) via cable. The image inside the flow channel is displayed in real time on the data acquisition unit (108b). The operator judges the degree of leakage based on the direction and size of the crack in the image. The maximum insertion depth of the endoscope probe does not exceed 95% of the total length of the liquid flow stack flow channel. The outer diameter of the probe is at least 2 mm smaller than the inner diameter of the flow channel. The advancement speed is controlled between 5 cm and 10 cm per second.

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