Automatic Leak Testing Method for Electrolytic Cells

Abstract

This application discloses an automatic leak testing method for an electrolytic cell, comprising: in response to a first command, automatically opening a first control valve on the connection line from the cathode gas phase outlet of the electrolytic cell to the hydrogen venting main, a second control valve on the connection line from the anode gas phase outlet of the electrolytic cell to the chlorine absorption main, and overflow control valves at the anode and cathode ends of the electrolytic cell; sending a drive command to the drive mechanism of the hydraulic cylinder of the electrolytic cell, thereby driving the hydraulic cylinder of the electrolytic cell to maintain the compression pressure of the hydraulic cylinder at 6.5 MPa, and adjusting the locking nut of the electrolytic cell to a released state via the drive mechanism; in response to a second command, opening the cathode liquid inlet control valve of the electrolytic cell to first inject cathode liquid into the electrolytic cell, and then, when the pressure difference between the cathode and anode reaches a first range, opening the anolyte inlet control valve of the electrolytic cell to inject anolyte into the electrolytic cell. This application improves the leak detection efficiency.

Description

Technical Field

[0001] This application relates to electrolytic cell leak detection technology, specifically to an automatic leak detection method for electrolytic cells. Background Technology

[0002] With the continuous development of ion-exchange membrane electrolyzers, most process controls have achieved automated operation. However, start-up and shutdown have not yet been fully automated. This is mainly because the start-up and shutdown process involves a large number of instrumentation and electrical equipment and real-time monitoring of process parameters, making the control process quite complex. Therefore, the start-up and shutdown process has always been mainly operated manually. However, the start-up and shutdown process is a complex process involving multiple manual operations. The start-up time is long, there is a lot of sampling and analysis data, and environmental factors have a significant impact, making it impossible to guarantee the start-up needs and schedules of domestic and foreign projects. Summary of the Invention

[0003] In view of the above problems, this application provides an automatic leak testing method for electrolytic cells, which can solve the problems of inconsistent detection methods and high professional requirements in the leak testing process of electrolytic cells.

[0004] According to a first aspect of this application, this application provides a method for automatic leak testing of an electrolytic cell, comprising:

[0005] In response to the first command, the first control valve on the connection line from the cathode gas phase outlet of the electrolyzer to the hydrogen venting main pipe, the second control valve on the connection line from the anode gas phase outlet of the electrolyzer to the chlorine absorption main pipe, and the overflow control valves set at the anode and cathode ends of the electrolyzer are automatically opened.

[0006] A drive command is sent to the drive mechanism of the hydraulic cylinder of the electrolytic cell, and the hydraulic cylinder of the electrolytic cell is driven by the drive mechanism to maintain the extrusion pressure of the hydraulic cylinder at 6.2MPa to 6.8MPa. The locking nut of the electrolytic cell is adjusted to be in the released state by the drive mechanism.

[0007] In response to the second command, the cathode liquid inlet control valve of the electrolytic cell is opened to inject cathode liquid into the electrolytic cell. When the pressure difference between the cathode and the anode reaches a first range, the anolyte inlet control valve of the electrolytic cell is opened to inject anolyte into the electrolytic cell. The pressure difference between the cathode and the anode is maintained within the first range until the cathode liquid fills the electrolytic cell, at which point the cathode liquid inlet control valve of the electrolytic cell is closed. And, when the anolyte fills the electrolytic cell, the anolyte inlet control valve of the electrolytic cell is closed.

[0008] Based on the volume of the electrolytic cell, the liquid filling time of the anode and cathode of the electrolytic cell is calculated. After the first set liquid filling time, the flow rate of the anode and cathode is reduced, and the first liquid phase discharge valve and the second liquid phase discharge valve of the gas-liquid separator at the cathode side and anode side of the electrolytic cell are opened. An indication message is output indicating whether there is an overflow in the outlet pipe of the electrolytic cell.

[0009] After the electrolytic cell is filled with liquid for a second set period of time, if it is determined that there is no overflow in any of the outlet pipes of the electrolytic cell, a prompt message indicating that the overflow requirement is not met is output, and the first and second water filling valves of the anode and cathode of the electrolytic cell are automatically closed; if it is determined that there is overflow in all the outlet pipes of the electrolytic cell, a prompt message indicating that the overflow requirement is met is output, and the first and second liquid phase discharge valves of the gas-liquid separators at the anode and cathode of the electrolytic cell are automatically closed.

[0010] Check if the pressure of the anode and cathode main outlet of the electrolytic cell is higher than the first set value. If it is higher than the first set value, close the first and second water filling valves at the anode and cathode inlets of the electrolytic cell. After confirming that all water filling valves at the anode and cathode inlets of the electrolytic cell are closed, increase the oil pressure of the extruder to the first set pressure, close the second control valve from the cathode gas phase outlet to the hydrogen vent main, the first control valve from the anode gas phase outlet to the chlorine absorption main, and the first, second, and third overflow valves of the anode and cathode. Set the cathode-side water filling flow rate to the second set value. When the electrode-side pressure is higher than the anode-side pressure by a second set pressure, the anode-side water flow rate of the electrolytic cell is set to a third set value; during the water filling process, the pressure difference between the cathode and anode of the electrolytic cell is maintained within a first range; when the anode-side pressure of the electrolytic cell exceeds the third set pressure, the second water filling valve on the anode side of the electrolytic cell is closed; when the cathode-side pressure exceeds the fourth set pressure, the first water filling valve on the cathode side of the electrolytic cell is closed; the electrolytic cell is checked for leaks, and if a leak is detected, a leak warning message is output.

[0011] When there is no leakage point in the electrolytic cell, the second overflow valve at the anode outlet of the electrolytic cell is opened, the pressure difference between the cathode side and the anode side of the electrolytic cell is set to the fifth set pressure, and the fifth set pressure is maintained by adjusting the opening degree of the first overflow valve at the cathode outlet.

[0012] When the second overflow valve at the anode side outlet of the electrolytic cell is detected to be open, the first overflow valve at the cathode side outlet of the electrolytic cell is opened; the fifth valve for starting up and charging nitrogen of the electrolytic cell is opened, and the nitrogen flow rate is set to the fourth set value.

[0013] Open the first control valve of the chlorine absorption main pipe, and open the first and second liquid phase discharge valves at the anode and cathode outlets of the electrolytic cell. Specifically, the second liquid phase discharge valve on the anode side of the electrolytic cell is fully open, and the first liquid phase discharge valve on the cathode side of the electrolytic cell is open. Drain the liquid from the outlet main pipe for at least five hours. After drainage, open the eighth valve from the anode inlet main pipe to the flushing main pipe of the electrolytic cell, and then open the seventh valve from the cathode inlet main pipe to the flushing main pipe of the electrolytic cell. Set the liquid drainage time to six hours, and close all valves from the anode and cathode inlet main pipes to the flushing main pipe of the electrolytic cell. Adjust the nitrogen flow rate to the fifth set value.

[0014] In some embodiments, the method further includes:

[0015] The cathode solution of the electrolytic cell is an alkaline solution with a concentration of 2% to 5%. This 2% to 5% alkaline solution is injected into the cathode side of the electrolytic cell at a flow ratio of 32% finished alkali to water of 1:5 to 1:25. The flow rate of the 2% to 5% alkaline solution is controlled at a sixth preset value. After a seventh preset charging time, the alkaline solution inlet valve of the electrolytic cell is automatically closed, and the flow rate of pure water entering the cathode chamber of the electrolytic cell is increased to maintain the pressure difference between the anode and cathode chambers. An automatic interlock is installed between the anode and cathode chambers of the electrolytic cell. When the pressure difference between the anode and cathode chambers exceeds a first range, the cathode solution charging flow rate is increased or decreased.

[0016] In some embodiments, the method further includes:

[0017] The first control valve on the connection line from the cathode gas phase outlet of the electrolytic cell to the hydrogen venting main, the second control valve on the connection line from the anode gas phase outlet of the electrolytic cell to the chlorine absorption main, and the first control valve from the anode gas phase outlet of the electrolytic cell to the chlorine absorption main, as well as the first overflow valve, second overflow valve, and third overflow valve of the anode and cathode, are set as valves controlled by electrical signals.

[0018] In some embodiments, the electrolytic cell includes stacked bipolar frames; a diaphragm is disposed between the first electrode plate and the second electrode plate in adjacent bipolar frames.

[0019] The technical solution of this application embodiment, by setting the relevant control valves in the control pipeline of the electrolytic cell to an automatically adjusting structure, can automatically adjust the opening and closing of the valves in the pipeline of the electrolytic cell based on the overall liquid inflow situation of the entire electrolytic cell, thereby realizing leak detection of the electrolytic cell. This application embodiment replaces some manual valves with automatic valves, increases important monitoring points, and most operations are automatically judged and completed by the system, reducing the exposure rate of operators on-site during start-up, avoiding operators from working at heights, and thus greatly improving operator safety. The leak detection parameter settings of this application embodiment are based on years of experience accumulated by start-up experts, and were finally determined after repeated comparative tests and comprehensive scientific calculations. All operations of the equipment strictly follow the program settings, avoiding the negative impact of different operating habits of different operators on the equipment, and also avoiding human error, improving the standardization of the start-up process and the safety of the equipment. This application embodiment has programmed a timing sequence for valve actions, eliminating the need for operators to run around the plant to adjust valve openings or for multiple people to cooperate in operation, saving time spent on running and communication, shortening valve opening and closing times, and greatly reducing start-up time.

[0020] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0022] Figure 1 A schematic diagram of the pipeline and valve connection structure of an electrolytic cell provided in an embodiment of this application is shown. Detailed Implementation

[0023] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0025] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0028] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0029] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 the embodiments of this application and simplifying the description, and are not intended to 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 the embodiments of this application.

[0030] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0031] The automated control method for automatic leak testing of electrolytic cells according to embodiments of this application includes several aspects such as real-time detection of key parameters during the leak testing process, control methods for key points, and control procedures for key locations. Based on the leak testing control procedure for a single electrolytic cell, it replaces the currently prevalent manual leak testing control method. This system, based on automated analytical instruments and control valve positions, intelligently regulates valves through real-time online data analysis to achieve the intended purpose. Later-stage automated instruments can also protect the safe and stable operation of the electrolytic cell through real-time data analysis during operation.

[0032] Figure 1 This application shows a schematic diagram of the piping and valve connection structure of an electrolytic cell according to an embodiment of the present application, as follows: Figure 1 As shown in the embodiment of this application, in the pipeline and valve connection structure of the electrolytic cell, the electrolytic cell, as a large-scale electrolysis equipment, traditionally has a start-up and shutdown process divided into a preparation stage, a start-up and operation stage, and a shutdown stage. The preparation stage includes processes such as electrolytic cell leak testing, liquid filling and air replacement, grid connection, and circulating heating. The start-up and operation stage requires personnel to operate the extruder, monitor the gas phase pressure in real time, and adjust some start-up parameters in real time. Similarly, the shutdown process also requires a large number of cumbersome procedures. The start-up and shutdown requirements are extremely strict and cumbersome, requiring the cooperation of multiple personnel. The cost of starting up once is high, and the start-up skills are difficult to master.

[0033] In this embodiment, in response to a first command, the first control valve on the connection line from the cathode gas phase outlet of the electrolyzer to the hydrogen venting main, the second control valve on the connection line from the anode gas phase outlet of the electrolyzer to the chlorine absorption main, and the overflow control valves at the anode and cathode ends of the electrolyzer are automatically opened; the first command may include an opening command for the electric valves, and the first command may include identification information of the valves to be opened. Figure 1 As shown, as an example, the first control valve can be Figure 1 The cathode vent valve; the second control valve may include the anode to absorption pipeline valve; the overflow control valve may include the anode and cathode drain valves, etc.

[0034] A drive command is sent to the drive mechanism of the hydraulic cylinder of the electrolytic cell, which drives the hydraulic cylinder of the electrolytic cell to maintain the extrusion pressure of the hydraulic cylinder at 6.2MPa to 6.8MPa. The lock nut of the electrolytic cell is then adjusted to be in a released state by the drive mechanism. As an example, the extrusion pressure of the hydraulic cylinder can be maintained at 6.3MPa, 6.4MPa, 6.5MPa, 6.6MPa, etc.

[0035] In response to the second command, the cathode liquid inlet control valve of the electrolytic cell is opened to inject cathode liquid into the electrolytic cell. When the pressure difference between the cathode and anode reaches a first range, the anolyte inlet control valve of the electrolytic cell is opened to inject anolyte into the electrolytic cell. The pressure difference between the cathode and anode is maintained within the first range until the cathode liquid fills the electrolytic cell, at which point the cathode liquid inlet control valve of the electrolytic cell is closed. And, when the anolyte fills the electrolytic cell, the anolyte inlet control valve of the electrolytic cell is closed. Here, the first range may include a water pressure between 0.2 mH2O and 0.5 mH2O.

[0036] Based on the volume of the electrolytic cell, the liquid filling time of the anode and cathode of the electrolytic cell is calculated. After the first set liquid filling time, the flow rate of the anode and cathode is reduced, and the first liquid phase discharge valve and the second liquid phase discharge valve of the gas-liquid separator at the cathode side and anode side of the electrolytic cell are opened. A prompt message is output to check whether there is overflow in the outlet pipe of the electrolytic cell. The first set time can include 15 to 20 minutes. Of course, the specific value of the first set time can also be set according to the current flow rate and the current liquid filling situation at the anode and cathode sides.

[0037] After the electrolytic cell is filled with liquid for a second set period of time, if it is determined that there is no overflow in any of the outlet pipes of the electrolytic cell, a prompt message indicating that the overflow requirement is not met is output, and the first and second water filling valves at the inlet of the anode and cathode of the electrolytic cell are automatically closed; if it is determined that there is overflow in all the outlet pipes of the electrolytic cell, a prompt message indicating that the overflow requirement is met is output, and the first and second liquid phase discharge valves at the outlet gas-liquid separators of the anode and cathode of the electrolytic cell are automatically closed; here, the second set period of time may include 50 to 60 minutes, specifically set according to the liquid filling situation in the electrolytic cell.

[0038] Check if the pressure of the anode and cathode main outlet of the electrolytic cell is higher than the first set value. If it is higher than the first set value, close the first and second water filling valves at the anode and cathode inlets of the electrolytic cell. The first set value can be 10 kPa, but can be set according to the application scenario, such as 9.5 kPa, 9.8 kPa, 10.2 kPa, 10.5 kPa, etc. After confirming that all water filling valves at the anode and cathode inlets of the electrolytic cell are closed, increase the oil pressure of the extruder to the first set pressure, close the second control valve from the cathode gas phase outlet to the hydrogen vent main, the first control valve from the anode gas phase outlet to the chlorine absorption main, and the first, second, and third overflow valves of the anode and cathode. Set the cathode-side water filling flow rate to the second set value. When the cathode-side pressure is higher than the anode-side pressure than the second set pressure, set the anode-side water filling flow rate of the electrolytic cell to the third set value. Here, the first set pressure can be 8.5 MPa, or it can be set to other pressure values ​​according to the specific application scenario. The second and third settings can be the same or different. As an example, both the second and third settings are set to 5m. 3 / h; or the second setting value is set to 5.1m. 3 / h, the third setting is set to 5.3m 3 / h, etc. The second pressure setting can be set to 2KPa, 1.9KPa, etc.

[0039] During the water filling process, the pressure difference between the cathode and anode of the electrolytic cell is maintained within a first range. When the pressure on the anode side of the electrolytic cell exceeds a third set pressure, the second water filling valve on the anode side of the electrolytic cell is closed. When the pressure on the cathode side exceeds a fourth set pressure, the first water filling valve on the cathode side of the electrolytic cell is closed. The electrolytic cell is checked for leaks. If a leak is detected, a leak warning message is output. Here, the third set pressure can be set to 50 kPa, 51 kPa, 48 kPa, etc. The fourth set pressure can be set to 54 kPa, 52 kPa, 55 kPa, etc.

[0040] When there is no leakage point in the electrolytic cell, the second overflow valve at the anode outlet of the electrolytic cell is opened, the pressure difference between the cathode side and the anode side of the electrolytic cell is set to a fifth set pressure, and the fifth set pressure is maintained by adjusting the opening degree of the first overflow valve at the cathode outlet; here, the fifth set pressure can be set to 4 kPa, 4.1 kPa, 4.3 kPa, etc.

[0041] If the second overflow valve at the anode outlet of the electrolytic cell is detected to be open, the pressure cascade control of the electrolytic cell is released and the first overflow valve at the cathode outlet of the electrolytic cell is opened; the fifth nitrogen charging valve for start-up of the electrolytic cell is opened, and the nitrogen flow rate is set to the fourth set value; the fourth set value can be set to 50 Nm. 3 / h、51Nm 3 / h、55Nm 3 / h etc.

[0042] Open the first control valve of the chlorine absorption main pipe, and open the first and second liquid phase discharge valves at the anode and cathode outlets of the electrolytic cell. Specifically, the second liquid phase discharge valve on the anode side of the electrolytic cell is fully open, and the first liquid phase discharge valve on the cathode side of the electrolytic cell is open. Drain the liquid from the outlet main pipe for at least five hours. After drainage, open the eighth valve from the anode inlet main pipe to the flushing main pipe of the electrolytic cell, and then open the seventh valve from the cathode inlet main pipe to the flushing main pipe of the electrolytic cell. Set the liquid drainage time to a sixth hour, and completely close all valves from the anode and cathode inlet main pipes to the flushing main pipe of the electrolytic cell. Adjust the nitrogen flow rate to the fifth set value. The sixth hour can be set to 50 minutes, 55 minutes, 58 minutes, etc. The fifth set value can be set to 0.9 Nm. 3 / h、1Nm 3 / h, 1.2Nm 3 / h etc.

[0043] In this embodiment, the cathode solution of the electrolytic cell is an alkaline solution with a concentration of 2% to 5%. This 2% to 5% alkaline solution is injected into the cathode side of the electrolytic cell at a flow ratio of 32% finished alkali to water of 1:5 to 1:25. The flow rate of the 2% to 5% alkaline solution is controlled at a sixth preset value. After a seventh preset charging time, the alkaline solution inlet valve of the electrolytic cell is automatically closed, and the flow rate of pure water entering the cathode chamber of the electrolytic cell is increased to maintain the pressure difference between the anode and cathode chambers. An automatic interlock is installed between the anode and cathode chambers of the electrolytic cell. When the pressure difference between the anode and cathode chambers exceeds a first range, the cathode solution charging flow rate is increased or decreased. The sixth preset value can be 4m³. 3 / h, 4.2m 3 / h, 4.5m 3 / h, etc. The seventh setting allows you to set the duration to 15 minutes, 18 minutes, or 20 minutes, etc.

[0044] In this embodiment, the first control valve on the connection line from the cathode gas phase outlet of the electrolytic cell to the hydrogen venting main, the second control valve on the connection line from the anode gas phase outlet of the electrolytic cell to the chlorine absorption main, the first control valve from the anode gas phase outlet of the electrolytic cell to the chlorine absorption main, and the first overflow valve, second overflow valve, and third overflow valve of the anode and cathode are set as valves controlled by electrical signals.

[0045] The following specific examples further illustrate the essence of the technical solutions in the embodiments of this application. In the embodiments of this application, it is necessary to... Figure 1 The valves shown are configured as electrically controllable valves, or at least some of them are configured as electrically controlled valves. The following description is for illustrative purposes only and should not be construed as limiting the technical solutions of the embodiments of this application.

[0046] During the leak test of the electrolytic cell, a certain amount of alkaline solution is first filled into the cathode chamber. In actual operation, this filling amount cannot be precisely set. Furthermore, when the cathode chamber is filled with alkaline solution first, the anode chamber is empty at this time. The concentration difference between the two ion exchange membranes is large, which can easily cause local shrinkage of the ion exchange membrane.

[0047] During the filling and draining of the anode and cathode, it is necessary to maintain the pressure difference between them. Operators must closely monitor this pressure difference during these processes to ensure accurate adjustments. This requires operators to be familiar with the valve opening characteristics and to avoid excessively rapid adjustments. Different operators, due to variations in ability and personality, may exhibit different operating patterns, making it difficult to achieve standardized and accurate operations. In case of abnormal situations, the entire process relies on the operator's experience and adaptability. Therefore, a highly experienced and responsible start-up engineer is essential throughout the entire start-up process.

[0048] In this embodiment, some of the original manual valves are replaced with automatic valves. The valve type and function are selected according to the different functions of each valve. In order to complete the relevant actions and detection, reliable accessories are provided. The valves can operate in the required sequence and issue an alarm in abnormal conditions to remind the operator to deal with it in time. The operator can monitor the status of the relevant valves in real time in the control system, making the entire start-up process safer and more reliable.

[0049] This embodiment adds an inlet flow meter and an automatic inlet / outlet control valve. The volume of the anode and cathode chambers of the unit tank can be calculated. The flow rate of the alkali solution and water entering the tank is selected so that the flow meter and valve are within a good measurement and adjustment range. According to the concentration requirements of the alkali solution entering the cathode chamber, alkali solution and pure water are simultaneously added in proportion. The simultaneous addition of alkali solution and water can reduce the concentration of alkali solution entering the cathode chamber. Pure water is added to the anode chamber. The concentration difference between the two sides is reduced to the maximum extent, thus slowing down the shrinkage of the ion membrane.

[0050] In this embodiment, some manual valves for entering and exiting the tank are replaced with automatic valves. Different inlet and outlet regulating valves are used to control pressure and differential pressure at different start-up and shutdown stages. Transmitters with high precision and valves with good regulating performance are selected to ensure the regulating performance. When an abnormal situation occurs, an interlock is set to maintain the operating condition in a safe state and issue an alarm. After confirming the operating condition, the operator can adjust the program to manual mode and remotely control the relevant valves for subsequent processing.

[0051] like Figure 1 As shown, the valves from the cathode gas phase outlet to the hydrogen venting main, the valve from the anode gas phase outlet to the chlorine absorption main, and the anode and cathode overflow valves of the electrolytic cell were changed from manual to automatic. After the cell leak test procedure begins, the above valves will automatically open. When all the above valves are fully open, the hydraulic cylinder extrusion pressure is adjusted to 6.5 MPa, and the locking nut is adjusted to the 20 mm release position. After the adjustment is completed, the cathode liquid is filled first, followed by the anode liquid. The cathode liquid inlet valve and the anode liquid inlet valve were changed from manual to automatic. A flow meter was added to the finished alkali filling pipeline to detect and control the flow rate of the filling pipeline. Flow meters were installed on the cathode side and anode side water filling pipelines respectively to automatically control the filling flow rate of the cathode liquid and anode liquid and to obtain the specific flow rate of the cathode liquid and anode liquid in real time.

[0052] During the charging process, the pressure difference between the anode and cathode should be maintained within the required range. To reduce the contraction reaction caused by the concentration difference between the anode and cathode, an alkaline solution with a concentration of approximately 2% to 5% is charged to the cathode side, i.e., the flow ratio of 32% finished alkali to water is 1:5 to 1:25. If the charging time of the alkali solution and water is the same, the flow rate of the alkali solution will be very low. Accurate measurement and adjustment cannot be achieved by calculating the relevant parameters of the valve and flow meter, as manual adjustment is clearly insufficient. Therefore, the charging time of the alkali solution should be appropriately shortened, and the flow rate of the alkali solution should be controlled at 4m³ / min. 3 With the valve operating at a suitable opening range (approximately [number] h), the alkaline solution inlet valve automatically closes after approximately 15-20 minutes of charging, based on different flow rates. Simultaneously, the pure water flow rate into the cathode chamber is increased to maintain the pressure difference between the anode and cathode chambers. An automatic interlocking mechanism is implemented during the charging of anode and cathode liquids and flow rate adjustments. If the pressure difference exceeds the limit, the charging flow rate of the cathode liquid is increased or decreased accordingly.

[0053] By calculating the actual volume of the electrolytic cell, the liquid filling time for the anode and cathode can be estimated. After 50-60 minutes of filling, reduce the water flow rate to the anode and cathode, and open the liquid phase discharge valves of the gas-liquid separators at the cathode and anode outlets. These two valves, previously manual, are now automatic, and a flow switch automatically detects whether there is overflow in the outlet hoses. If, after ten minutes of filling the electrolytic cell, all outlet hoses have not overflowed, the program automatically closes the anode and cathode inlet water filling valves, pauses the program, and requires the operator to make on-site judgment and handling. If all outlet hoses overflow, the program automatically closes the liquid phase discharge valves of the gas-liquid separators at the cathode and anode outlets. When the pressure of the anode and cathode main outlet pipes exceeds 10 kPa, close the anode and cathode inlet water filling valves. After receiving the feedback that the anode and cathode inlet water filling valves are fully closed, increase the press oil pressure to 8.5 MPa, close the valves from the anode gas phase outlet to the hydrogen vent main pipe, the valve from the anode gas phase outlet to the chlorine absorption main pipe, and the anode and cathode overflow valves, and set the cathode-side water filling flow rate to 3-10 m³ / h. 3 When the cathode-side pressure is 2 kPa higher than the anode-side pressure, the anode-side water flow rate is set to 3–10 m³ / h. 3 The water filling process is equipped with an interlocking structure. When the pressure difference between the anode and cathode exceeds the limit, the water filling flow rate on the cathode side is adjusted. When the pressure on the anode side exceeds 50 kPa, the water filling valve on the anode side is closed; when the pressure on the cathode side exceeds 54 kPa, the water filling valve on the cathode side is closed. A set set time of 1 to 2 hours is used to check for pressure changes. If the pressure decreases, a message "Leakage point in the electrolytic cell" is displayed; if the pressure does not change, the program continues to run automatically.

[0054] The leak detection program in this embodiment controls the opening of the anode-side outlet overflow valve of the electrolytic cell. The pressure difference between the cathode and anode sides is set to approximately 4 kPa, and this pressure difference is maintained by adjusting the opening of the cathode-side outlet overflow valve. When a feedback signal indicating that the anode-side outlet overflow valve is fully open is received, the program fully opens the cathode-side outlet overflow valve. The nitrogen charging valve for electrolytic cell startup is changed from a manual valve to an automatic valve, and the nitrogen flow rate is set to 50 Nm³. 3 The flow rate is adjusted by a control loop consisting of the existing nitrogen flow meter and the modified automatic valves. Fully open the chlorine absorption main valve to prevent pressure buildup. After all valves are open, slowly open the drain valves at the anode and cathode outlets of the electrolytic cell. Allow approximately 5 minutes for the liquid to drain completely from the outlet main. After draining, slowly open all valves from the anode inlet main to the flushing main. Then, open all valves from the cathode inlet main to the flushing main, changing from manual to automatic valves. Set the liquid draining time to 50 minutes. Finally, completely close all valves from the cathode to the flushing main. After all valves are closed, adjust the nitrogen flow rate to 1 Nm³. 3 / h, the tank leak test procedure is now complete.

[0055] Those skilled in the art should understand that although the control pipelines and control valves at the anode and cathode inlets and outlets of the electrolyzer are named according to their control functions, their pipeline connection methods, valve locations, and control braking methods are all clear. Based on the foregoing description of the embodiments of this application, the start-up and shutdown of the ion-exchange membrane electrolyzer are automated. Through the automated control process, the start-up and shutdown of the ion-exchange membrane electrolyzer can be achieved without relying on professional personnel.

[0056] The technical solution of this application embodiment, by setting the relevant control valves in the control pipeline of the electrolytic cell to an automatically adjusting structure, can automatically adjust the opening and closing of the valves in the pipeline of the electrolytic cell based on the overall liquid inflow situation of the entire electrolytic cell, thereby realizing leak detection of the electrolytic cell. This application embodiment replaces some manual valves with automatic valves, increases important monitoring points, and most operations are automatically judged and completed by the system, reducing the exposure rate of operators on-site during start-up, avoiding operators from working at heights, and thus greatly improving operator safety. The leak detection parameter settings of this application embodiment are based on years of experience accumulated by start-up experts, and were finally determined after repeated comparative tests and comprehensive scientific calculations. All operations of the equipment strictly follow the program settings, avoiding the negative impact of different operating habits of different operators on the equipment, and also avoiding human error, improving the standardization of the start-up process and the safety of the equipment. This application embodiment has programmed a timing sequence for valve actions, eliminating the need for operators to run around the plant to adjust valve openings or for multiple people to cooperate in operation, saving time spent on running and communication, shortening valve opening and closing times, and greatly reducing start-up time.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for automatically testing a cell for leaks, comprising the steps of: The method comprises: in response to the first instruction, automatically opening a first control valve on a hydrogen venting main connecting line of a cathode gas phase outlet of an electrolytic cell, a second control valve on a chlorine absorption main connecting line of an anode gas phase outlet of the electrolytic cell, and an overflow control valve arranged at a cathode and anode end of the electrolytic cell; sending a driving instruction to a driving mechanism of a hydraulic cylinder of the electrolytic cell, driving the hydraulic cylinder of the electrolytic cell through the driving mechanism, maintaining a pressing pressure of the hydraulic cylinder at 6.2 MPa-6.8 MPa, and adjusting the driving mechanism to release a locking nut of the electrolytic cell; in response to the second instruction, opening a cathode liquid inlet control valve of the electrolytic cell, injecting a cathode liquid into the electrolytic cell, opening an anode liquid inlet control valve of the electrolytic cell to inject an anode liquid into the electrolytic cell when a pressure difference between the cathode and the anode reaches a first range, maintaining the pressure difference between the cathode and the anode at the first range until the cathode liquid fills the electrolytic cell, and closing the cathode liquid inlet control valve of the electrolytic cell, and when the anode liquid fills the electrolytic cell, closing the anode liquid inlet control valve of the electrolytic cell; based on a volume of the electrolytic cell, calculating a time for liquid injection into the cathode and the anode of the electrolytic cell, reducing a liquid injection flow rate of the cathode and the anode after a first set time length, opening a first liquid phase discharge valve and a second liquid phase discharge valve of a cathode side and an anode side outlet gas-liquid separator of the electrolytic cell, and outputting prompt information for checking whether overflow occurs at an outlet pipe of the electrolytic cell; after a second set time length after the electrolytic cell is filled with liquid, when it is determined that there is an outlet pipe without overflow among all outlet pipes of the electrolytic cell, outputting prompt information that does not meet the overflow requirement, and automatically closing an inlet first liquid injection valve and a second liquid injection valve of the cathode and the anode of the electrolytic cell, and when it is determined that there is overflow among all outlet pipes of the electrolytic cell, outputting prompt information that meets the overflow requirement, and automatically closing a first liquid phase discharge valve and a second liquid phase discharge valve of an outlet gas-liquid separator of the cathode and the anode of the electrolytic cell. checking whether the pressure of the electrolytic cell outlet anode and cathode manifold is higher than the first set value, in the case of higher than the first set value, closing the first water filling valve and the second water filling valve of the electrolytic cell anode and cathode inlet; after determining that the water filling valve of the electrolytic cell anode and cathode inlet is closed, increasing the extruder oil pressure to the first set pressure, closing the second control valve of the electrolytic cell cathode gas phase outlet to the hydrogen gas venting manifold, the first control valve of the electrolytic cell anode gas phase outlet to the chlorine gas absorption manifold, and the first overflow valve, the second overflow valve and the third overflow valve of the electrolytic cell anode and cathode, setting the cathode side water filling flow rate as the second set value, and setting the anode side water filling flow rate of the electrolytic cell as the third set value in the case of the cathode side pressure being higher than the anode side pressure by the second set pressure; maintaining the pressure difference between the electrolytic cell cathode and anode within the first range during the water filling process; closing the anode side second water filling valve of the electrolytic cell in the case of the anode side pressure exceeding the third set pressure, and closing the cathode side first water filling valve of the electrolytic cell in the case of the cathode side pressure exceeding the fourth set pressure; setting a predetermined length of time for the standing time, judging whether the pressure changes, and prompting the electrolytic cell to have a leakage point in the case of the pressure decreasing, and outputting the prompt information of the leakage point; in the case of the electrolytic cell not having a leakage point, controlling the second overflow valve of the anode side outlet of the electrolytic cell to open for the third set length of time, setting the pressure difference between the cathode side and the anode side of the electrolytic cell as the fifth set pressure, and adjusting the fifth set pressure through the opening degree of the first overflow valve of the cathode side outlet; in the case of detecting that the anode side outlet second overflow valve of the electrolytic cell opens for the fourth set length of time, releasing the pressure cascade control of the electrolytic cell and opening the first overflow valve of the cathode side outlet of the electrolytic cell; opening the fifth valve of the electrolytic cell for starting nitrogen filling, and setting the nitrogen flow rate as the fourth set value; opening the first control valve of the chlorine gas absorption manifold, opening the first liquid phase discharge valve and the second liquid phase discharge valve of the anode and cathode outlets of the electrolytic cell, wherein the second liquid phase discharge valve of the anode side of the electrolytic cell is fully opened, and the first liquid phase discharge valve of the cathode side of the electrolytic cell is opened; draining the liquid on the outlet manifold side for at least the fifth length of time, opening the eighth valve of the electrolytic cell anode inlet manifold to the flushing manifold after the liquid is drained, and opening the seventh valve of the electrolytic cell cathode inlet manifold to the flushing manifold; setting the liquid discharge time as the sixth length of time, and fully closing the valve of the electrolytic cell anode and cathode inlet manifold to the flushing manifold; and adjusting the nitrogen filling flow rate as the fifth set value.

2. The method of claim 1, wherein, The method further comprises: The cathode liquid of the electrolytic cell is 2%-5% concentration of lye, the 2%-5% concentration of lye is injected into the cathode side of the electrolytic cell in the way of 32% finished product alkali and water flow ratio of 1:5-1:25, the flow of the 2%-5% concentration of lye is controlled at the sixth set value, after the seventh set time length, the inlet lye valve of the electrolytic cell is automatically closed, the inlet pure water flow of the cathode chamber of the electrolytic cell is increased, so as to maintain the pressure difference of the cathode chamber and the anode chamber of the electrolytic cell; wherein, an automatic interlock is arranged between the cathode chamber and the anode chamber of the electrolytic cell, when the pressure difference of the cathode chamber and the anode chamber of the electrolytic cell exceeds the first range, the inlet flow of the cathode liquid is increased or decreased.

3. The method of claim 1, wherein, The method further comprises: The first control valve on the connection line of the cathode gas phase outlet of the electrolytic cell to the hydrogen gas venting main pipe, the second control valve on the connection line of the anode gas phase outlet of the electrolytic cell to the chlorine gas absorption main pipe, and the first control valve and the first overflow valve, the second overflow valve, the third overflow valve of the anode gas phase outlet of the electrolytic cell to the chlorine gas absorption main pipe and the anode and cathode are set as the valves controlled by electric signal.

4. The method according to any one of claims 1 to 3, characterized in that, The electrolytic cell comprises a plurality of bipolar frames stacked with each other; a diaphragm is arranged between the first electrode plate and the second electrode plate of the frame body in the adjacent bipolar frames.

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