Electrolytic cell short stack test system
By adding an alkali heater and a flow regulating valve to the electrolytic cell short-reactor testing system, combined with flexible connection and automated BOP subsystem, the problems of long cold start time and inaccurate alkali flow control were solved, realizing efficient, accurate and safe automated operation of electrolytic cell short-reactor testing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CRRC ZHUZHOU ELECTRIC LOCOMOTIVE RESEARCH INSTITUTE CO LTD
- Filing Date
- 2025-08-12
- Publication Date
- 2026-07-21
AI Technical Summary
In alkaline water electrolysis for hydrogen production, long cold start-up time, inaccurate alkaline flow control, cumbersome and time-consuming auxiliary operations, and high safety risks affect the efficiency and safety of short-chain iteration testing of electrolyzers.
An electrolytic cell short stack testing system was designed, comprising an electrolytic cell and testing accessories subsystem, a separation subsystem, and a BOP subsystem. By adding an alkali heater and a flow regulating valve to the separation subsystem, combined with flexible connecting pipelines and an automated BOP subsystem, rapid heating, precise flow control, and automated operation are achieved, reducing safety risks.
It significantly shortens cold start time, enables fine adjustment of alkali flow rate, reduces manual operation, improves system stability and safety, and achieves efficient, accurate and automated testing.
Smart Images
Figure CN224531065U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water electrolysis for hydrogen production technology, specifically to a short-reactor testing system for an electrolyzer. Background Technology
[0002] In the research and development of alkaline water electrolysis for hydrogen production technology and the optimization of electrolyzer performance, especially in the selection of core components (such as electrodes and diaphragms) and the design of internal flow channel structures, a large number of short-cycle, high-frequency iterative tests of short stacks (small-scale stack modules) are required. These tests require the system to be able to quickly and accurately obtain the operating parameters (such as pressure, temperature, and voltage) of the electrolyzer itself and its key inlet and outlet locations under various operating conditions such as variable pressure, variable temperature, and variable flow rate.
[0003] The primary challenge lies in the excessively long cold start time. Alkaline electrolyzers have a large short-stack heat capacity, and especially when the ambient temperature is low, relying solely on the heat generated by the system's own operation for preheating greatly extends the single test cycle and slows down the overall iteration speed.
[0004] Secondly, the accuracy and flexibility of alkali flow control are insufficient. Existing systems rely on pump speed or simple valves to adjust the flow rate, making it difficult to achieve precise and rapid adjustment of the alkali flow rate under variable flow conditions, which affects the accuracy of performance testing and the coverage of operating conditions.
[0005] Third, the separation system presents both safety risks and operational complexity. In particular, the design and installation of the hydrogen / oxygen-water separator (scrubber), if improperly laid out (e.g., inappropriate height, poor reflux), not only increases equipment costs and process complexity but also easily creates safety hazards such as gas carryover and uncontrolled liquid levels, affecting system stability and data reliability. Finally, the testing auxiliary processes have low automation levels and are time-consuming and labor-intensive. Key operations such as nitrogen purging and airtightness testing before startup, alkali removal after shutdown (recovering alkali from the electrolyzer and pipelines), tank cleaning, and alkali replenishment and water distribution during operation are highly dependent on manual operation. These processes are cumbersome, time-consuming (often several hours), and subject to human error and safety risks, making it difficult to achieve the goal of "less human" or even "unmanned" testing. Utility Model Content
[0006] This invention provides a short-stack electrolytic cell testing system, which aims to solve the problems of long cold start time, imprecise alkali flow control, and cumbersome and time-consuming auxiliary operations (such as nitrogen filling, alkali removal, and alkali replenishment) in frequent iterative testing of short-stack alkaline electrolytic cells.
[0007] To achieve the above objectives, this utility model provides a short-stacking electrolytic cell testing system, comprising: Electrolytic cell and testing accessories subsystem: including the electrolytic cell body, pressure transmitters and temperature transmitters installed at the ends of the alkaline solution inlet / outlet pipelines of the electrolytic cell; The separation subsystem includes an alkali circulation pump, a hydrogen separator, an oxygen separator, a hydrogen-water separator, and an oxygen-water separator. The inlets of the hydrogen separator and the oxygen separator are connected to the alkali outlet of the electrolytic cell. The inlet of the alkali circulation pump is connected to the alkali outlet of the hydrogen separator and the oxygen separator, and its outlet is connected to the alkali inlet of the electrolytic cell via a pipeline. An alkali flow regulating valve and an alkali heater are installed on the pipeline from the outlet of the alkali circulation pump to the alkali inlet of the electrolytic cell. The inlets of the hydrogen-water separator and the oxygen-water separator are respectively connected to downstream hydrogen-using equipment and downstream oxygen-using equipment, and their liquid outlets are respectively connected to the hydrogen separator and the oxygen separator via liquid guide pipes. The installation height of the hydrogen-water separator is higher than that of the hydrogen separator, and the installation height of the oxygen-water separator is higher than that of the oxygen separator. BOP subsystem: includes an alkali tank and a pure water tank. The pure water tank and the alkali tank are connected by a water distribution pipeline. The alkali tank is connected to the inlet of the alkali circulation pump by an alkali supply pipeline. The alkali heater is connected to the alkali tank by an alkali removal pipeline loop.
[0008] Furthermore, the BOP subsystem also includes a nitrogen pipeline connected to the separation subsystem and equipped with a flow control valve.
[0009] Furthermore, an alkali cooler is also installed on the pipeline from the outlet of the alkali circulation pump to the alkali inlet of the electrolytic cell, and the alkali cooler is located between the alkali circulation pump and the alkali heater.
[0010] Furthermore, the separation subsystem also includes a hydrogen scrubber, an oxygen scrubber, a hydrogen cooler, and an oxygen cooler. The gas outlet of the hydrogen separator is connected to the inlet of the hydrogen scrubber, the gas outlet of the oxygen separator is connected to the inlet of the oxygen scrubber, the outlet of the hydrogen scrubber is connected to the inlet of the hydrogen cooler, and the outlet of the oxygen scrubber is connected to the inlet of the oxygen cooler. The outlet of the hydrogen cooler is connected to the inlet of the hydrogen-liquid separator, and the outlet of the oxygen cooler is connected to the inlet of the oxygen-liquid separator.
[0011] Furthermore, the alkali inlet and / or alkali outlet pipelines of the electrolytic cell are flexible connection pipelines.
[0012] Furthermore, a drain valve is installed on the alkaline solution outlet pipe of the electrolytic cell.
[0013] Furthermore, the flexible connecting pipe is a metal flexible hose.
[0014] Furthermore, the pure water tank is connected to the hydrogen scrubber and the oxygen scrubber via a water pipe, and a water replenishment pump is installed on the water pipe between the pure water tank and the hydrogen scrubber and the oxygen scrubber.
[0015] Furthermore, the liquid guide pipe connected to the hydrogen-water separator is inserted below the liquid surface of the hydrogen separator; the liquid guide pipe connected to the oxygen-water separator is inserted below the liquid surface of the oxygen separator.
[0016] Furthermore, the hydrogen separator and the oxygen separator are connected by a pipeline.
[0017] The beneficial effects of this utility model are: Compared with existing technologies, the electrolytic cell short-circuit testing system provided by this utility model addresses the issue of long cold start times by adding an alkali heater to the separation subsystem to directly heat the circulating alkali solution. This, combined with an alkali flow regulating valve, precisely controls the flow rate, significantly improving the electrolytic cell's heating efficiency and drastically shortening the cold start time. Furthermore, to address the issue of imprecise alkali flow control, the system utilizes a alkali flow regulating valve that works in conjunction with the alkali circulation pump to achieve precise and rapid adjustment of the alkali flow rate entering the electrolytic cell, meeting the testing requirements under variable flow conditions. Finally, to address the issue of cumbersome and time-consuming auxiliary operations, the BOP subsystem adopts a separate alkali tank and pure water tank design, achieving automatic water replenishment and alkali mixing via a water distribution pipeline. Simultaneously, the alkali removal pipeline loop connects the alkali heater and the alkali tank, and in conjunction with the reverse operation of the alkali circulation pump and the inlet and outlet drain valves of the electrolytic cell, automatic alkali removal and waste liquid collection are achieved, reducing manual operation. To improve safety and efficiency, the separation subsystem sets the installation height of the hydrogen-water separator to be higher than that of the hydrogen separator, and the oxygen-water separator to be higher than that of the oxygen separator, and inserts its liquid outlet below the liquid surface of the lower separator through a liquid guide pipe, using gravity to achieve automatic liquid reflux, which simplifies the equipment (eliminating the need for a reflux pump) and prevents gas from carrying liquid, improving system stability. The collaboration of each subsystem achieves high efficiency, accuracy, safety and automation in the testing process. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.
[0019] Figure 1 This is a process flow layout diagram of an electrolytic cell and its testing accessories subsystem disclosed in an embodiment of this utility model.
[0020] Figure 2 This is an overall process flow diagram of a testing system disclosed in an embodiment of this utility model.
[0021] Reference numerals: 10. Electrolytic cell body; 11. Pressure transmitter; 12. Temperature transmitter; 13. Drain valve; 20. Alkali circulation pump; 21. Alkali cooler; 22. Alkali heater; 23-1. Hydrogen separator; 24-1. Hydrogen scrubber; 25-1. Hydrogen cooler; 26-1. Hydrogen-water separator; 23-2. Oxygen separator; 24-2. Oxygen scrubber; 25-2. Oxygen cooler; 26-2. Oxygen-water separator; 27. Alkali flow regulating valve; 30. Pure water tank; 31. Alkali tank; 32. Make-up water pump; 33. Water distribution pipeline; 34. Alkali supply pipeline; 35. Alkali removal pipeline loop; 36. Nitrogen pipeline; 37. Flow control valve. Detailed Implementation
[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0023] This invention provides a testing system specifically designed for short-stacking alkaline electrolyzers, aiming to achieve convenient and rapid performance verification. The system consists of three core functional subsystems working together: an electrolyzer and its testing accessories subsystem, a separation subsystem, and a BOP (Balance of Plant) subsystem responsible for water distribution, alkali replenishment, and nitrogen purging.
[0024] Electrolytic cells and their testing accessory subsystems (such as...) Figure 1 As shown, the system includes an electrolytic cell body 10, a pressure transmitter 11 and a temperature transmitter 12 installed at the ends of the alkali inlet / outlet pipelines of the electrolytic cell. In order to accurately obtain the key parameters of the inlet and outlet of the electrolytic cell body 10, the pressure transmitter 11 and the temperature transmitter 12 are directly installed at the ends of the alkali inlet and outlet pipelines and arranged close to the electrolytic cell body 10 to ensure the real-time performance and accuracy of the monitoring data.
[0025] Separation subsystems (such as) Figure 2(As shown) This device is responsible for processing the gas-liquid mixture generated during electrolysis and precisely controlling the alkali circulation. Its core components include an alkali circulation pump 20, a hydrogen separator 23-1, an oxygen separator 23-2, a hydrogen-water separator 26-1, and an oxygen-water separator 26-2. The inlets of the hydrogen separator 23-1 and the oxygen separator 23-2 are connected to the alkali outlet of the electrolytic cell 10; the inlet of the alkali circulation pump 20 is connected to the alkali outlet of the hydrogen separator 23-1 and the oxygen separator 23-2, and its outlet is connected to the alkali inlet of the electrolytic cell 10 via a pipeline; an alkali flow regulating valve 27 and an alkali heater 22 are installed on the pipeline from the outlet of the alkali circulation pump 20 to the alkali inlet of the electrolytic cell 10; the inlets of the hydrogen-water separator 26-1 and the oxygen-water separator 26-2 are connected to the downstream hydrogen-using equipment and the downstream oxygen-using equipment, respectively, and their liquid outlets are connected to the hydrogen separator 23-1 and the oxygen separator 23-2, respectively, via liquid guide pipes.
[0026] Understandably, the gaseous alkaline solution produced by the electrolytic cell 10 first enters the hydrogen separator 23-1 and oxygen separator 23-2 for preliminary gas-liquid separation. The separated alkaline solution is collected and driven by the alkaline solution circulation pump 20, flowing through the alkaline solution flow regulating valve 27 and the alkaline solution heater 22 before being sent back to the alkaline solution inlet of the electrolytic cell 10. The separated hydrogen and oxygen are then further purified by a series of treatments, entering the downstream hydrogen-water separator 26-1 and oxygen-water separator 26-2 respectively.
[0027] In traditional technical solutions, the water separated by the gas-water separator is generally discharged through a drain valve and a drain pipe. Unstable drainage can lead to unstable gas pressure and large fluctuations in hydrogen flow during operation. This invention eliminates the drain valve by elevating the gas-water separator, creating free flow. Specifically, in this separation subsystem, the installation positions of the hydrogen-water separator 26-1 and the oxygen-water separator 26-2 are both higher than those of the corresponding hydrogen separator 23-1 and oxygen separator 23-2. Furthermore, their liquid outlets are inserted below the liquid surface of the lower hydrogen separator 23-1 and oxygen separator 23-2 through liquid guide pipes, allowing for automatic liquid return by gravity.
[0028] BOP subsystem (such as BOP subsystem) Figure 2 (As shown) It provides the raw materials, concentration adjustment, and safety assurance required for operation. It includes independently arranged alkali tank 31 and pure water tank 30. The volume of alkali tank 31 is larger than the amount of alkali required for system operation, which can realize automatic water replenishment and alkali preparation during short-circuit operation, reducing manual operation and lowering operational safety hazards. Specifically, the pure water tank 30 supplies water to the alkali tank 31 through the water distribution pipeline 33 to realize automatic water replenishment and alkali preparation. The alkali tank 31 supplies alkali to the inlet of the alkali circulation pump 20 through the alkali supply pipeline 34. In addition, an alkali return pipeline loop 35 is designed to connect the alkali heater 22 and the alkali tank 31 for alkali recovery when the system is shut down or the tank is replaced.
[0029] Preferably, the BOP subsystem also includes a nitrogen line 36 connected to the separation subsystem and equipped with a flow control valve 37, wherein the flow control valve 37 can be a needle valve, used to control nitrogen charging protection and airtightness testing during start-up and shutdown processes.
[0030] Preferably, an alkali cooler 21 is also installed between the alkali circulation pump 20 and the alkali heater 22 on the pipeline from the outlet of the alkali circulation pump 20 to the alkali inlet of the electrolytic cell 10. The function of the alkali cooler 21 is to remove the heat generated during electrolysis, precisely control the temperature of the alkali returning to the electrolytic cell 10, and ensure that it operates within the set optimal operating range, thereby maintaining stable electrolysis efficiency and protecting the electrolytic cell.
[0031] Preferably, the separation subsystem further includes a hydrogen scrubber 24-1, an oxygen scrubber 24-2, a hydrogen cooler 25-1, and an oxygen cooler 25-2. The gas outlet of the hydrogen separator 23-1 is connected to the hydrogen scrubber inlet 24-1, the gas outlet of the oxygen separator 23-2 is connected to the oxygen scrubber inlet 24-2, the hydrogen scrubber outlet 24-1 is connected to the hydrogen cooler inlet 25-1, and the oxygen scrubber outlet 24-2 is connected to the oxygen cooler inlet 25-2. The hydrogen cooler outlet 25-1 is connected to the hydrogen-liquid separator inlet 26-1, and the oxygen cooler outlet 25-2 is connected to the oxygen-liquid separator inlet 26-2.
[0032] The workflow is as follows: The crude hydrogen gas discharged from the top of hydrogen separator 23-1 first enters hydrogen scrubber 24-1, where trace amounts of alkaline mist and impurities entrained in the gas are removed. The scrubbed and purified hydrogen then enters hydrogen cooler 25-1 for cooling. The cooled hydrogen (which may contain condensate at this point) then flows into hydrogen-water separator 26-1 for further separation and removal of the condensate, ultimately yielding dry, pure hydrogen. The oxygen treatment process is similar and will not be repeated here.
[0033] Preferably, the pure water tank 30 is divided into two lines: one line is connected to the alkali tank 31, and the other line is connected to the hydrogen scrubber 24-1 and the oxygen scrubber 24-2 through a water pipe. A water replenishment pump 32 is installed on the water pipe between the pure water tank 30 and the hydrogen scrubber 24-1 and the oxygen scrubber 24-2. The hydrogen scrubber 24-1 and the oxygen scrubber 24-2 clean the gas by spraying pure water.
[0034] Preferably, the mechanical and electrical interfaces of the electrolytic cell within the electrolytic cell and testing accessory subsystem are all flexible connections. Specifically, the alkali inlet and / or alkali outlet pipelines of the electrolytic cell body 10 are all made of flexible metal hoses (flexible connection pipelines). This design allows for a certain displacement margin during installation and disassembly. The copper busbar supplying DC power to the electrolytic cell is also connected to the power busbar of the electrolytic cell via flexible connections (such as flexible cables or soft copper braided strips). This flexible connection design greatly simplifies the installation, disassembly, and replacement process of electrolytic cell bodies 10 of different sizes, providing convenience for frequent iterative testing.
[0035] For ease of maintenance, a dedicated drain valve 13 is installed at the lowest point of the alkaline solution outlet pipe of the electrolytic cell 10 (or other locations prone to liquid accumulation) to remove waste liquid when necessary.
[0036] In order to obtain the operating data of the electrolytic cell 10 in real time and accurately, all monitoring equipment (including the cell inspection instrument for monitoring the voltage and temperature of each cell, pressure transmitter 11, temperature transmitter 12, etc.) are installed close to the electrolytic cell 10 to minimize measurement delay and signal interference.
[0037] Preferably, in the alkaline electrolyzer hydrogen production system, the hydrogen separator 23-1 and the oxygen separator 23-2 are connected by a pipeline to maintain the gas phase pressure balance inside the two separators.
[0038] Before startup: Nitrogen is introduced into the system to replace the air; the alkali solution starts from the alkali solution tank 31, is pressurized by the alkali solution circulation pump 20, enters the alkali solution cooler 21, flows through the alkali solution heater 22, and the heated alkali solution is divided into two paths to enter the cathode alkali solution inlet and the anode alkali solution inlet of the electrolytic cell 10. The alkali solution is electrolyzed within the electrolytic cell 10 to generate hydrogen and oxygen. The resulting mixed fluid is discharged from the four alkali solution outlets of the electrolytic cell 10, divided into two paths: Cathode side: Alkaline solution mixture containing hydrogen → enters hydrogen separator 23-1; Anode side: Oxygen-containing alkaline solution mixture → enters oxygen separator 23-2.
[0039] The degassed alkaline solutions flowing from the bottom of hydrogen separator 23-1 and oxygen separator 23-2 merge and return to alkaline solution tank 31, forming a closed-loop cycle. The hydrogen treatment path is as follows: the hydrogen mixture exits from the top of hydrogen separator 23-1 and enters hydrogen scrubber 24-1 (spraying to remove alkaline mist). After scrubbing, the wet hydrogen enters hydrogen cooler 25-1 for cooling, causing condensate to form. The cooled hydrogen then enters hydrogen-water separator 26-1. Hydrogen-water separator 26-1 is installed at a raised position, with its bottom liquid guide pipe inserted below the liquid surface of hydrogen separator 23-1. The condensate automatically flows back to hydrogen separator 23-1 by gravity (eliminating the need for a transfer pump and reducing the risk of leakage). The gas then enters hydrogen-water separator 26-1 to remove residual droplets before outputting pure hydrogen. The oxygen treatment process is similar and will not be repeated here.
[0040] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. A short-stacking test system for an electrolytic cell, characterized in that, include: Electrolytic cell and testing accessories subsystem: including the electrolytic cell body, pressure transmitters and temperature transmitters installed at the ends of the alkaline solution inlet / outlet pipelines of the electrolytic cell; The separation subsystem includes an alkali circulation pump, a hydrogen separator, an oxygen separator, a hydrogen-water separator, and an oxygen-water separator. The inlets of the hydrogen separator and the oxygen separator are connected to the alkali outlet of the electrolytic cell. The inlet of the alkali circulation pump is connected to the alkali outlet of the hydrogen separator and the oxygen separator, and its outlet is connected to the alkali inlet of the electrolytic cell via a pipeline. An alkali flow regulating valve and an alkali heater are installed on the pipeline from the outlet of the alkali circulation pump to the alkali inlet of the electrolytic cell. The inlets of the hydrogen-water separator and the oxygen-water separator are respectively connected to downstream hydrogen-using equipment and downstream oxygen-using equipment, and their liquid outlets are respectively connected to the hydrogen separator and the oxygen separator via liquid guide pipes. The installation height of the hydrogen-water separator is higher than that of the hydrogen separator, and the installation height of the oxygen-water separator is higher than that of the oxygen separator. BOP subsystem: includes an alkali tank and a pure water tank. The pure water tank and the alkali tank are connected by a water distribution pipeline. The alkali tank is connected to the inlet of the alkali circulation pump by an alkali supply pipeline. The alkali heater is connected to the alkali tank by an alkali removal pipeline loop.
2. The electrolytic cell short stack testing system as described in claim 1, characterized in that, The BOP subsystem also includes a nitrogen pipeline connected to the separation subsystem and equipped with a flow control valve.
3. The electrolytic cell short stack testing system as described in claim 1, characterized in that, An alkali cooler is also installed on the pipeline from the outlet of the alkali circulation pump to the alkali inlet of the electrolytic cell. The alkali cooler is located between the alkali circulation pump and the alkali heater.
4. The electrolytic cell short stack testing system as described in claim 1, characterized in that, The separation subsystem further includes a hydrogen scrubber, an oxygen scrubber, a hydrogen cooler, and an oxygen cooler. The gas outlet of the hydrogen separator is connected to the inlet of the hydrogen scrubber, the gas outlet of the oxygen separator is connected to the inlet of the oxygen scrubber, the outlet of the hydrogen scrubber is connected to the inlet of the hydrogen cooler, and the outlet of the oxygen scrubber is connected to the inlet of the oxygen cooler. The outlet of the hydrogen cooler is connected to the inlet of the hydrogen-liquid separator, and the outlet of the oxygen cooler is connected to the inlet of the oxygen-liquid separator.
5. The electrolytic cell short stack testing system as described in claim 1, characterized in that, The alkaline solution inlet and / or alkaline solution outlet pipelines of the electrolytic cell are flexible connection pipelines.
6. The electrolytic cell short-pile testing system as described in claim 5, characterized in that, A drain valve is installed on the alkaline solution outlet pipe of the electrolytic cell.
7. The electrolytic cell short stack testing system as described in claim 6, characterized in that, The flexible connection pipe is a metal flexible hose.
8. The electrolytic cell short stack testing system as described in claim 4, characterized in that, The pure water tank is connected to the hydrogen scrubber and the oxygen scrubber via a water pipe, and a water replenishment pump is installed on the water pipe between the pure water tank and the hydrogen scrubber and the oxygen scrubber.
9. The electrolytic cell short stack testing system as described in claim 1, characterized in that, The liquid guide pipe connected to the hydrogen-water separator is inserted below the liquid surface of the hydrogen separator; the liquid guide pipe connected to the oxygen-water separator is inserted below the liquid surface of the oxygen separator.
10. The electrolytic cell short stack testing system as described in claim 1, characterized in that, The hydrogen separator and the oxygen separator are connected by a pipeline.