Method for automatically testing leakage of electrolytic cell

Abstract

The invention discloses an automatic leakage test method for an electrolytic cell, and the method comprises the steps: responding to a first instruction, automatically opening a first control valve from a cathode gas phase outlet of the electrolytic bath to a connecting line of a hydrogen emptying header pipe, a second control valve from an anode gas phase outlet of the electrolytic bath to a connecting line of a chlorine absorption header pipe, and overflow control valves arranged at the cathode and anode ends of the electrolytic bath; a driving instruction is sent to a driving mechanism of a hydraulic oil cylinder of the electrolytic cell, the hydraulic oil cylinder of the electrolytic cell is driven through the driving mechanism, the extrusion pressure of the hydraulic oil cylinder is kept at 6.5 MPa, and a locking nut of the electrolytic cell is adjusted to be in a release state through the driving mechanism; and responding to the second instruction, opening a catholyte inlet control valve of the electrolytic cell, injecting catholyte into the electrolytic cell firstly, and opening an anolyte inlet control valve of the electrolytic cell to inject anolyte into the electrolytic cell under the condition that the pressure difference between the cathode pressure and the anode pressure reaches a first range. According to the invention, the leakage test detection efficiency is improved.

Description

Technical Field

[0001] The present application relates to an electrolytic cell leak detection technology, and in particular to an electrolytic cell automatic leak detection method. Background Art

[0002] With the continuous development of ion membrane electrolyzers, most process controls have been automated, but start-up and shutdown have not been fully automated so far. This is mainly because the start-up and shutdown process involves a lot of instrumentation and electrical equipment and real-time monitoring of process parameters, and the control process is relatively complicated, so the start-up and shutdown process has always been mainly manual operation; however, the start-up and shutdown process is a complex process that requires multiple manual operations, with a long start-up time, a large amount of sampling and analysis data, and a large impact from environmental factors, which cannot guarantee the start-up needs and progress of domestic and foreign projects. Summary of the invention

[0003] In view of the above problems, the present application provides a method for automatic leak testing of an electrolytic cell, which can solve the problems of inconsistent detection means and high professional requirements during the leak testing of the electrolytic cell.

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

[0005] In response to the first instruction, a first control valve on a connection line between a cathode gas phase outlet of the electrolyzer and a hydrogen venting main pipe, a second control valve on a connection line between an anode gas phase outlet of the electrolyzer and a chlorine absorption main pipe, and an overflow control valve provided at anode and cathode ends of the electrolyzer are automatically opened;

[0006] Sending a driving instruction to a driving mechanism of the hydraulic cylinder of the electrolytic cell, driving the hydraulic cylinder of the electrolytic cell through the driving mechanism, maintaining the extrusion pressure of the hydraulic cylinder at 6.2MPa-6.8MPa, and adjusting the locking nut of the electrolytic cell to be in a released state through the driving mechanism;

[0007] In response to a second instruction, the cathode liquid inlet control valve of the electrolytic cell is opened to inject cathode liquid into the electrolytic cell, and when the pressure difference between the cathode and the anode reaches a first range, the anode liquid inlet control valve of the electrolytic cell is opened to inject anode liquid into the electrolytic cell; and the pressure difference between the cathode and the anode is maintained within the first range until the cathode liquid fills the electrolytic cell, and the cathode liquid inlet control valve of the electrolytic cell is closed; and when the anode liquid fills the electrolytic cell, the anode liquid inlet control valve of the electrolytic cell is closed;

[0008] Based on the volume of the electrolytic cell, the time for the anode and cathode of the electrolytic cell to fill with liquid is calculated, and after the first set filling time, the flow rate of the anode and cathode water filling 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 the anode side outlet of the electrolytic cell are opened, and a prompt message is outputted to indicate whether the outlet pipe of the electrolytic cell overflows;

[0009] After the second set time after the electrolytic cell is full of liquid, if it is determined that there is an outlet pipe without overflow among all the outlet pipes of the electrolytic cell, a prompt message that the overflow requirement is not met is output, and the first water filling valve and the second water filling valve 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 that the overflow requirement is met is output, and the first liquid phase discharge valve and the second liquid phase discharge valve of the outlet gas-liquid separator of the anode and cathode of the electrolytic cell are automatically closed;

[0010] Check whether the pressure of the cathode and cathode main pipes at the outlet of the electrolytic cell is higher than the first set value. If it is higher than the first set value, close the first water filling valve and the second water filling valve at the cathode and cathode inlets of the electrolytic cell; after determining that the water filling valves at the cathode and cathode inlets of the electrolytic cell are all closed, increase the extruder oil pressure to the first set pressure, close the second control valve from the cathode gas phase outlet to the hydrogen venting main pipe, the first control valve from the anode gas phase outlet to the chlorine absorption main pipe, and the first overflow valve, the second overflow valve, and the third overflow valve of the cathode, set the cathode side water filling flow rate to the second set value, and when the cathode When the pressure on the cathode side is higher than the pressure on the anode side, which is higher than the second set pressure, the water filling flow rate on the anode side of the electrolytic cell is set to a third set value; during the water filling process, the pressure difference between the cathode and the anode of the electrolytic cell is maintained within the first range; when the pressure on the anode side of the electrolytic cell exceeds the third set pressure, the second water filling valve on the anode side of the electrolytic cell is closed, and when the pressure on the cathode side exceeds the fourth set pressure, the first water filling valve on the cathode side of the electrolytic cell is closed; check whether the electrolytic cell has a leak, and if a leak is detected in the electrolytic cell, output a prompt message indicating the leak;

[0011] In the case where there is no leakage point in the electrolytic cell, controlling the second overflow valve at the anode side outlet of the electrolytic cell to open, setting the difference between the pressure on the cathode side and the pressure on the anode side of the electrolytic cell to a fifth set pressure, and maintaining the fifth set pressure by adjusting the opening of the first overflow valve at the cathode side outlet;

[0012] When it is detected that the second overflow valve at the anode side outlet of the electrolytic cell is opened, the first overflow valve at the cathode side outlet of the electrolytic cell is opened; the fifth valve for nitrogen filling at the start-up of the electrolytic cell is opened, and the nitrogen flow rate is set to a fourth set value;

[0013] Open the first control valve of the chlorine absorption main pipe, open 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 on the anode side of the electrolytic cell is fully opened, and the first liquid phase discharge valve on the cathode side of the electrolytic cell is opened; drain the liquid on the outlet main pipe side for at least the fifth time period, after draining, open the eighth valve from the anode inlet main pipe of the electrolytic cell to the flushing main pipe, and then open the seventh valve from the cathode inlet main pipe of the electrolytic cell to the flushing main pipe; set the liquid discharge time to the sixth time period, and close all the valves from the anode inlet main pipe of the electrolytic cell to the flushing main pipe; adjust the nitrogen filling flow rate to the fifth set value.

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

[0015] The cathode liquid of the electrolytic cell is an alkali liquid with a concentration of 2% to 5%, and the alkali liquid with a concentration of 2% to 5% is injected into the cathode side of the electrolytic cell in a flow ratio of 32% finished alkali to water of 1:5 to 1:25. The flow rate of the alkali liquid with a concentration of 2% to 5% is controlled at a sixth set value. After filling for a seventh set time, the alkali liquid inlet valve of the electrolytic cell is automatically closed, and the pure water flow rate entering the cathode chamber of the electrolytic cell is increased to maintain the pressure difference between the anode and cathode chambers of the electrolytic cell; wherein an automatic interlock is arranged between the anode and cathode chambers of the electrolytic cell, and when the pressure difference between the anode and cathode chambers of the electrolytic cell exceeds a first range, the filling flow rate of the cathode liquid is increased or decreased.

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

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

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

[0019] The technical solution of the embodiment of the present application, by setting the relevant control valves in the control pipeline in the electrolyzer to an automatic adjustment structure, can automatically adjust the opening and closing of the valves on the pipeline in the electrolyzer based on the liquid inlet situation of the overall condition of the entire electrolyzer, and realize the leak detection of the electrolyzer. The embodiment of the present application changes some manual valves to automatic valves, increases important monitoring points, and most operations are automatically judged by the system to complete, reducing the exposure rate of operators on the scene during the start-up process, avoiding the operator's climbing operations, thereby greatly improving the safety of the operator. The leak detection parameter setting of the embodiment of the present application is based on the years of experience accumulation of driving experts, after repeated comparative tests, comprehensive scientific calculations, and finally determined. The various operations of the equipment completely follow the setting of the program, avoiding the negative impact of different operating habits of different operators on the equipment, and avoiding the misoperation of personnel, improving the standardization of the start-up process and the safety of the equipment. The embodiment of the present application compiles a timing sequence for the action of the valve, and the operator does not need to run around the factory to adjust the valve opening, nor does it require multiple people to cooperate in the operation, saving the time of running and communication, and also shortening the valve switch time, greatly shortening the start-up time.

[0020] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0022] Figure 1 A schematic diagram of the piping and valve connection structure of an electrolytic cell provided in one embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0025] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0026] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0027] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0028] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0029] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0030] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0031] The automated control method for automatic leak testing of the electrolytic cell of the embodiment of the present application includes several aspects such as real-time detection of key parameters during the electrolytic cell leak testing, control methods of key points, and control processes of key positions. Based on the leak testing control process of a single electrolytic cell, it replaces the currently common manual leak testing control method. The system is based on automated analysis instruments and control valve positions. Through real-time online analysis of data, the valves are intelligently controlled to achieve the intended purpose. The automated instruments that intervene later can also protect the safety and stable operation of the electrolytic cell through real-time analysis of data during operation.

[0032] Figure 1 FIG. 1 shows a schematic diagram of the piping and valve connection structure of an electrolytic cell provided in an embodiment of the present application. Figure 1 As shown, in the piping and valve connection structure of the electrolytic cell of the embodiment of the present application, the electrolytic cell is a large-scale electrolytic equipment, and the traditional start-up and shutdown process is 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 to replace air, grid connection, and cycle heating; the start-up and operation stage requires personnel to cooperate in the operation of the extruder, real-time monitoring of the gas phase pressure, and real-time adjustment of some start-up parameters; similarly, the shutdown process also requires a large number of cumbersome processes; the start-up and shutdown requirements are extremely strict and cumbersome, requiring the cooperation of multiple personnel, the cost of one start-up is high, and the driving skills are difficult to master.

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

[0034] A driving instruction is sent to the driving mechanism of the hydraulic cylinder of the electrolytic cell, and the hydraulic cylinder of the electrolytic cell is driven by the driving mechanism to maintain the extrusion pressure of the hydraulic cylinder at 6.2MPa~6.8MPa, and the locking nut of the electrolytic cell is adjusted to be in a released state by the driving 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 instruction, the cathode liquid inlet control valve of the electrolytic cell is opened, and the cathode liquid is first injected into the electrolytic cell; when the pressure difference between the cathode and the anode pressure reaches a first range, the anode liquid inlet control valve of the electrolytic cell is opened, and the anode liquid is injected into the electrolytic cell; and the pressure difference between the cathode and the anode is maintained within the first range until the cathode liquid fills the electrolytic cell, and the cathode liquid inlet control valve of the electrolytic cell is closed; and, when the anode liquid fills the electrolytic cell, the anode liquid inlet control valve of the electrolytic cell is closed; here, the first range may include a water pressure between 0.2m H2O and 0.5m H2O.

[0036] Based on the volume of the electrolytic cell, the time for the anode and cathode of the electrolytic cell to fill with liquid is calculated, and after the first set filling time, the flow rate of the anode and cathode water 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 the anode side of the electrolytic cell are opened, and a prompt message is output to check whether the outlet pipe of the electrolytic cell overflows; the first set time may include 15 to 20 minutes. Of course, the specific value of the first set time may also be specifically set according to the current flow rate and the current filling of the anode and cathode sides.

[0037] After the second set time after the electrolytic cell is full of liquid, when it is determined that there is an outlet pipe without overflow among all the outlet pipes of the electrolytic cell, a prompt message that the overflow requirement is not met is output, and the first water filling valve and the second water filling valve at the inlet of the anode and cathode of the electrolytic cell are automatically closed; when it is determined that there is overflow in all the outlet pipes of the electrolytic cell, a prompt message that the overflow requirement is met is output, and the first liquid phase discharge valve and the second liquid phase discharge valve of the outlet gas-liquid separator of the anode and cathode of the electrolytic cell are automatically closed; here, the second set time may include 50 to 60 minutes, which is specifically set according to the situation of the liquid filled in the electrolytic cell.

[0038] Check whether the pressure of the cathode and cathode main pipes at the outlet of the electrolyzer is higher than the first set value. If it is higher than the first set value, close the first water filling valve and the second water filling valve at the cathode and cathode inlets of the electrolyzer; the first set value can be 10Kpa, which can be set according to the application scenario, for example, it can also be 9.5Kpa, 9.8Kpa, 10.2Kpa, 10.5Kpa, etc. After determining that all the water filling valves at the cathode and cathode inlets of the electrolyzer are closed, increase the extruder oil pressure to the first set pressure, close the second control valve from the cathode gas phase outlet to the hydrogen venting main pipe of the electrolyzer, the first control valve from the anode gas phase outlet to the chlorine absorption main pipe, and the first overflow valve, the second overflow valve, and the third overflow valve of the cathode and cathode, and 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, the anode side water filling flow rate of the electrolyzer is set to the third set value; here, the first set pressure can be 8.5Mpa, and can also be set to other pressure values ​​according to the specific use scenario. The second setting value and the third setting value may be the same or different. As an example, the second setting value and the third setting value are both set to 5m 3 / h; or the second set value is set to 5.1m 3 / h, the third setting value is set to 5.3m 3 / h, etc. The second set pressure 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 the first range; when the pressure on the anode side of the electrolytic cell exceeds the third set pressure, the second water filling valve on the anode side of the electrolytic cell is closed, and when the pressure on the cathode side exceeds the fourth set pressure, the first water filling valve on the cathode side of the electrolytic cell is closed; check whether the electrolytic cell has a leak, and if a leak is detected in the electrolytic cell, output a prompt message indicating the leak; here, the third set pressure can be set to 50KPa, 51KPa, 48KPa, etc. The fourth set pressure can be set to 54KPa, 52KPa, 55KPa, etc.

[0040] When there is no leakage point in the electrolytic cell, the second overflow valve at the anode side outlet of the electrolytic cell is controlled to open, the difference between the pressure on the cathode side and the pressure on 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 of the first overflow valve at the cathode side outlet; here, the fifth set pressure can be set to 4KPa, 4.1KPa, 4.3KPa, etc.

[0041] When 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 valve of the electrolytic cell for nitrogen filling at start-up is opened, and the nitrogen flow rate is set to the fourth set value; the fourth set value can be set to 50Nm 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 liquid-phase discharge valve and the second liquid-phase discharge valve at the anode and cathode outlets of the electrolytic cell, wherein the second liquid-phase discharge valve on the anode side of the electrolytic cell is fully opened, and the first liquid-phase discharge valve on the cathode side of the electrolytic cell is opened; drain the liquid on the outlet main pipe side for at least the fifth time period, and after draining, open the eighth valve from the anode inlet main pipe of the electrolytic cell to the flushing main pipe, and then open the seventh valve from the cathode inlet main pipe of the electrolytic cell to the flushing main pipe; set the liquid discharge time to the sixth time period, and close all the valves from the anode inlet main pipe of the electrolytic cell to the flushing main pipe; adjust the nitrogen filling flow rate to the fifth set value. The sixth time period can be set to 50 minutes, 55 minutes, 58 minutes, etc. The fifth set value can be set to 0.9Nm 3 / h、1Nm 3 / h、1.2Nm 3 / h, etc.

[0043] In the embodiment of the present application, the cathode liquid of the electrolytic cell is an alkali liquid with a concentration of 2% to 5%. The alkali liquid with a concentration of 2% to 5% is injected into the cathode side of the electrolytic cell in a flow ratio of 32% finished alkali to water of 1:5 to 1:25. The flow rate of the alkali liquid with a concentration of 2% to 5% is controlled at a sixth set value. After the seventh set time is filled, the alkali liquid inlet valve of the electrolytic cell is automatically closed, and the pure water flow rate of the cathode chamber of the electrolytic cell is increased to maintain the pressure difference between the anode and cathode chambers of the electrolytic cell; wherein an automatic interlock is provided between the anode and cathode chambers of the electrolytic cell, and when the pressure difference between the anode and cathode chambers of the electrolytic cell exceeds the first range, the filling flow rate of the cathode liquid is increased or decreased. The sixth set value can be 4m 3 / h、4.2m 3 / h、4.5m 3 / h, etc. The seventh setting time can be set to 15 minutes, 18 minutes or 20 minutes, etc.

[0044] In the embodiment of the present application, the first control valve on the connection line between the cathode gas phase outlet of the electrolyzer and the hydrogen venting main pipe, the second control valve on the connection line between the anode gas phase outlet of the electrolyzer and the chlorine absorption main pipe, the first control valve between the anode gas phase outlet of the electrolyzer and the chlorine absorption main pipe, and the first overflow valve, the second overflow valve, and the 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 solution of the embodiment of the present application. Figure 1 The valves shown in the figure are set as valves controllable by electric signals, or at least some of the valves are set as electrically controlled valves. The following description is only for illustrative purposes and should not be construed as limiting the technical solutions of the embodiments of the present application.

[0046] During the leak test of the electrolytic cell, a certain amount of alkali solution is first filled into the cathode chamber. In actual operation, this filling amount cannot be accurately set, and when the cathode chamber is filled with alkali solution first, while the anode chamber is in a liquid-free state, the concentration difference between the two times of the ion membrane is large, which can easily cause local shrinkage of the ion membrane.

[0047] During the process of filling and draining the anode and cathode, the pressure difference between the anode and cathode needs to be maintained. The operator needs to pay close attention to the pressure difference during the filling and draining process to ensure the accuracy of the adjustment. This requires the operator to be familiar with the valve opening characteristics and the adjustment cannot be too fast. Different operators will have different operating modes due to their different abilities and personalities, and the standardization and accuracy of the operation cannot be achieved. When abnormal situations occur, it is completely dependent on the operator's experience and adaptability. Therefore, an experienced, conscientious and responsible driving engineer is required throughout the entire driving process.

[0048] In the embodiment of the present application, some of the original manual valves are replaced with automatic valves, and the valve form and type are selected according to the different functions of each valve. In order to complete the relevant actions and detections, reliable accessories are attached. The valves can act in the required sequence and issue alarms in abnormal conditions to remind the operator to deal with them in time. The operator can grasp the status of the relevant valves in real time in the control system, making the entire driving process safer and more reliable.

[0049] The embodiment of the present application adds an inlet flow meter and an inlet and outlet automatic control valve. The volumes of the anode and cathode chambers of the unit cell can be obtained by calculation. The flow meters and valves for selecting the flow rates of the alkali solution and water entering the cell are within a good measurement and adjustment range. The alkali solution and pure water are simultaneously filled in proportion to the concentration requirements of the alkali solution filled into the cathode chamber. The simultaneous filling of alkali solution and water can reduce the concentration of the alkali solution entering the cathode chamber. Pure water is filled into the anode chamber, and the concentration difference on both sides is minimized, thereby slowing down the shrinkage of the ion membrane.

[0050] The embodiment of the present application changes some of the manual valves at the inlet and outlet of the tank into automatic valves, uses different inlet and outlet regulating valves to control the pressure and pressure difference in different start-up and shutdown stages, selects transmitters with higher precision and valves with better adjustment performance to ensure the performance of the adjustment, and when an abnormal situation occurs, sets an interlock to maintain the working condition in a safe state and sounds an alarm. The operator can adjust the program to the manual state after confirming the working condition, remotely control the relevant valves, and perform subsequent processing.

[0051] like Figure 1 As shown, the valve from the cathode gas phase outlet of the electrolytic cell to the hydrogen venting main pipe, the valve from the anode gas phase outlet to the chlorine absorption main pipe, and the anode and cathode overflow valves are changed from manual valves to automatic valves. The above valves are automatically opened after the tank leak test program starts. When the above valves are fully opened, the cylinder extrusion pressure is adjusted to 6.5MPa, and the locking nut is adjusted to be in a release state of 20mm away. After the adjustment is completed, the cathode liquid is filled first and then the anode liquid is filled. The cathode liquid inlet valve and the anode liquid inlet valve are changed from the original manual valves to automatic valves. A flow meter is added to the finished alkali filling pipeline to detect and control the flow of the filling pipeline. The cathode side and the anode side water filling pipelines are respectively provided with flow meters to automatically control the filling flow of the cathode liquid and the anode liquid, and the specific flow of the cathode liquid and the anode liquid can be obtained in real time.

[0052] During the charging process, the pressure difference between the cathode and cathode is kept within the required range. In order to reduce the shrinkage reaction caused by the concentration difference between the cathode and cathode, an alkali solution with a concentration of about 2% to 5% is charged into the cathode side, that is, the flow ratio of 32% of the 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 is very low. The relevant parameters of the valve and flow meter are calculated, and the manual adjustment method is obviously unable to complete accurate measurement and adjustment. Shorten the charging time of the alkali solution appropriately, and control the alkali solution flow rate at 4m 3 / h, the valve is in a good opening range, and the alkali solution valve into the tank is automatically closed after about 15 to 20 minutes of filling according to different flow calculations. At the same time, the pure water flow into the cathode chamber is increased to maintain the pressure difference between the anode and cathode chambers. In the process of filling the anode and cathode liquids and adjusting the flow, an automatic interlocking structure is set to increase or reduce the cathode liquid filling flow when the pressure difference exceeds the limit.

[0053] By calculating the actual volume of the electrolyzer, the time for the cathode and anode to be filled with liquid can be calculated. After 50 to 60 minutes of filling, the flow rate of the cathode and anode water filling is reduced, and the liquid phase discharge valves of the gas-liquid separators at the cathode and anode outlets are opened. These two valves are changed from the original manual valves to automatic valves, and the flow switch automatically detects whether the outlet hose is overflowing. If all outlet hoses have not overflowed ten minutes after the electrolyzer is full of liquid, the program automatically closes the cathode and anode inlet water filling valves, the program is suspended, and the operator is required to make on-site judgment and processing. If all outlet hoses have overflowed, the program automatically closes the liquid phase discharge valves of the cathode and anode outlet gas-liquid separators. When the pressure of the cathode and anode main pipes at the electrolyzer outlet is higher than 10KPa, the cathode and anode inlet water filling valves are closed. After the full-close signal of the cathode and anode inlet water filling valves is fed back, the extruder oil pressure is increased to 8.5MPa, the valve from the cathode gas phase outlet of the electrolyzer to the hydrogen venting main pipe, the valve from the anode gas phase outlet to the chlorine absorption main pipe, and the cathode and anode overflow valves are closed, and the cathode side water filling flow rate is set to 3 to 10m 3 / h, when the pressure on the cathode side is 2KPa higher than that on the anode side, set the anode side water filling flow rate to 3-10m 3 / h, set an interlocking structure during the water filling process, and adjust the water filling flow on the cathode side when the pressure difference between the anode and cathode exceeds the limit. When the pressure on the anode side exceeds 50KPa, close the anode side water filling valve, and when the pressure on the cathode side exceeds 54KPa, close the cathode side water filling valve. Set a 1-2 hour standing time to determine whether the pressure changes. If the pressure decreases, it will prompt "there is a leak in the electrolytic cell". If the pressure does not change, the program will continue to run automatically.

[0054] The leak detection program of the embodiment of the present application controls the opening of the anode side outlet overflow valve of the electrolytic cell, sets the pressure difference between the cathode side and the anode side to be approximately 4KPa, and maintains the pressure difference by adjusting the opening of the cathode side outlet overflow valve. When receiving the feedback signal that the anode side outlet overflow valve is fully open, the program fully opens the cathode side outlet overflow valve. Change the electrolytic cell startup nitrogen filling valve from a manual valve to an automatic valve, and set the nitrogen flow rate to 50Nm 3 / h, and the control loop is regulated by the original nitrogen flowmeter and the changed automatic valve. Open all the valves of the chlorine absorption main pipe to prevent pressure build-up. After all the valves are opened, slowly open the anode and cathode outlet drain valves of the electrolytic cell. The outlet main pipe measures the liquid to be drained for about 5 minutes. After draining, slowly open the anode inlet main pipe of the electrolytic cell to the flushing main pipe valve. After all the valves are opened, open the cathode inlet main pipe of the electrolytic cell to the flushing main pipe valve. Change the original manual valve to an automatic valve. Set the liquid discharge time to 50 minutes. Close all the valves from the cathode to the flushing main pipe of the electrolytic cell. After all the valves are closed, adjust the nitrogen filling flow rate to 1Nm 3 / h, and the tank leak test procedure is now completed.

[0055] Those skilled in the art should understand that, although the control pipeline in the electrolyzer and the control valves at the anode and cathode inlets are named after the control functions, the pipeline connection method, the setting position of the control valve and the control braking method are all clear. Based on the above records of the embodiments of the present application, the start and stop of the ion membrane electrolyzer are automatically controlled, and the start and stop of the ion membrane electrolyzer can be realized through the automatic control process without relying on professionals.

[0056] The technical solution of the embodiment of the present application, by setting the relevant control valves in the control pipeline in the electrolyzer to an automatic adjustment structure, can automatically adjust the opening and closing of the valves on the pipeline in the electrolyzer based on the liquid inlet situation of the overall condition of the entire electrolyzer, and realize the leak detection of the electrolyzer. The embodiment of the present application changes some manual valves to automatic valves, increases important monitoring points, and most operations are automatically judged by the system to complete, reducing the exposure rate of operators on the scene during the start-up process, avoiding the operator's climbing operations, thereby greatly improving the safety of the operator. The leak detection parameter setting of the embodiment of the present application is based on the years of experience accumulation of driving experts, after repeated comparative tests, comprehensive scientific calculations, and finally determined. The various operations of the equipment completely follow the setting of the program, avoiding the negative impact of different operating habits of different operators on the equipment, and avoiding the misoperation of personnel, improving the standardization of the start-up process and the safety of the equipment. The embodiment of the present application compiles a timing sequence for the action of the valve, and the operator does not need to run around the factory to adjust the valve opening, nor does it require multiple people to cooperate in the operation, saving the time of running and communication, and also shortening the valve switch time, greatly shortening the start-up time.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for automatic leak testing of an electrolytic cell, characterized in that: The method comprises: In response to the first instruction, a first control valve on a connection line between a cathode gas phase outlet of the electrolyzer and a hydrogen venting main pipe, a second control valve on a connection line between an anode gas phase outlet of the electrolyzer and a chlorine absorption main pipe, and an overflow control valve provided at anode and cathode ends of the electrolyzer are automatically opened; Sending a driving instruction to a driving mechanism of the hydraulic cylinder of the electrolytic cell, driving the hydraulic cylinder of the electrolytic cell through the driving mechanism, maintaining the extrusion pressure of the hydraulic cylinder at 6.2MPa-6.8MPa, and adjusting the locking nut of the electrolytic cell to be in a released state through the driving mechanism; In response to a second instruction, the cathode liquid inlet control valve of the electrolytic cell is opened to inject cathode liquid into the electrolytic cell, and when the pressure difference between the cathode and the anode reaches a first range, the anode liquid inlet control valve of the electrolytic cell is opened to inject anode liquid into the electrolytic cell; and the pressure difference between the cathode and the anode is maintained within the first range until the cathode liquid fills the electrolytic cell, and the cathode liquid inlet control valve of the electrolytic cell is closed; and when the anode liquid fills the electrolytic cell, the anode liquid inlet control valve of the electrolytic cell is closed; Based on the volume of the electrolytic cell, the time for the anode and cathode of the electrolytic cell to fill with liquid is calculated, and after the first set filling time, the flow rate of the anode and cathode water filling 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 the anode side outlet of the electrolytic cell are opened, and a prompt message for checking whether the outlet pipe of the electrolytic cell overflows is output; After the second set time after the electrolytic cell is full of liquid, if it is determined that there is an outlet pipe without overflow among all the outlet pipes of the electrolytic cell, a prompt message that the overflow requirement is not met is output, and the first water filling valve and the second water filling valve 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 that the overflow requirement is met is output, and the first liquid phase discharge valve and the second liquid phase discharge valve of the outlet gas-liquid separator of the anode and cathode of the electrolytic cell are automatically closed; Check whether the pressure of the cathode and cathode main pipes at the outlet of the electrolytic cell is higher than the first set value. If it is higher than the first set value, close the first water filling valve and the second water filling valve at the cathode and cathode inlets of the electrolytic cell; after determining that the water filling valves at the cathode and cathode inlets of the electrolytic cell are all closed, increase the extruder oil pressure to the first set pressure, close the second control valve from the cathode gas phase outlet to the hydrogen venting main pipe, the first control valve from the anode gas phase outlet to the chlorine absorption main pipe, and the first overflow valve, the second overflow valve, and the third overflow valve of the cathode, set the cathode side water filling flow rate to the second set value, and when the cathode When the pressure on the cathode side is higher than the pressure on the anode side, which is higher than the second set pressure, the water filling flow rate on the anode side of the electrolytic cell is set to a third set value; during the water filling process, the pressure difference between the cathode and the anode of the electrolytic cell is maintained within the first range; when the pressure on the anode side of the electrolytic cell exceeds the third set pressure, the second water filling valve on the anode side of the electrolytic cell is closed, and when the pressure on the cathode side exceeds the fourth set pressure, the first water filling valve on the cathode side of the electrolytic cell is closed; check whether the electrolytic cell has a leak, and if a leak is detected in the electrolytic cell, output a prompt message indicating the leak; In the case where there is no leakage point in the electrolytic cell, controlling the second overflow valve at the anode side outlet of the electrolytic cell to open for a third set time, setting the difference between the pressure on the cathode side and the pressure on the anode side of the electrolytic cell to a fifth set pressure, and maintaining the fifth set pressure by adjusting the opening of the first overflow valve at the cathode side outlet; When it is detected that the second relief valve at the anode side outlet of the electrolytic cell is opened for a fourth set time, the pressure cascade control of the electrolytic cell is released and the first relief valve at the cathode side outlet of the electrolytic cell is opened; the fifth valve for nitrogen filling at the start-up of the electrolytic cell is opened, and the nitrogen flow rate is set to a fourth set value; Open the first control valve of the chlorine absorption main pipe, open 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 on the anode side of the electrolytic cell is fully opened, and the first liquid phase discharge valve on the cathode side of the electrolytic cell is opened; drain the liquid on the outlet main pipe side for at least the fifth time period, after draining, open the eighth valve from the anode inlet main pipe of the electrolytic cell to the flushing main pipe, and then open the seventh valve from the cathode inlet main pipe of the electrolytic cell to the flushing main pipe; set the liquid discharge time to the sixth time period, and close all the valves from the anode inlet main pipe of the electrolytic cell to the flushing main pipe; adjust the nitrogen filling flow rate to the fifth set value.

2. The method according to claim 1, characterized in that The method further comprises: The cathode liquid of the electrolytic cell is an alkali liquid with a concentration of 2% to 5%, and the alkali liquid with a concentration of 2% to 5% is injected into the cathode side of the electrolytic cell in a manner of a flow ratio of 32% finished alkali to water of 1:5 to 1:

25. The flow rate of the alkali liquid with a concentration of 2% to 5% is controlled at a sixth set value. After filling for a seventh set time, the alkali liquid inlet valve of the electrolytic cell is automatically closed, and the pure water flow rate of the cathode chamber of the electrolytic cell is increased to maintain the pressure difference between the anode and cathode chambers of the electrolytic cell; wherein an automatic interlock is arranged between the anode and cathode chambers of the electrolytic cell, and when the pressure difference between the anode and cathode chambers of the electrolytic cell exceeds a first range, the filling flow rate of the cathode liquid is increased or decreased.

3. The method according to claim 1, characterized in that The method further comprises: The first control valve on the connection line between the cathode gas phase outlet of the electrolyzer and the hydrogen venting main pipe, the second control valve on the connection line between the anode gas phase outlet of the electrolyzer and the chlorine absorption main pipe, the first control valve between the anode gas phase outlet of the electrolyzer and the chlorine absorption main pipe, and the first overflow valve, the second overflow valve, and the third overflow valve of the anode and cathode are set as valves controlled by electrical signals.

4. The method according to any one of claims 1 to 3, characterized in that The electrolytic cell comprises mutually stacked bipolar frames; a diaphragm is arranged between the first electrode plates and the second electrode plates in which the frames in adjacent bipolar frames are stacked.

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