Safety control method and control device of alkaline electrolysis hydrogen production system and hydrogen production system

Abstract

The invention relates to the technical field of water electrolysis hydrogen production, and provides a safety control method and control device of an alkaline electrolysis hydrogen production system and the hydrogen production system.The safety control method of the alkaline electrolysis hydrogen production system comprises the steps that the current-moment oxygen concentration and the current-moment hydrogen concentration of each alkaline electrolysis bath are obtained; and when the current oxygen concentration of at least one alkaline electrolytic cell is smaller than a first oxygen concentration threshold value or the current hydrogen concentration of at least one alkaline electrolytic cell is smaller than a first hydrogen concentration threshold value, the alkaline electrolytic hydrogen production system is controlled to stop running, and inert gas is injected into the hydrogen separator and the oxygen separator. By means of the arrangement, the gas concentration of the oxygen side outlet and the hydrogen side outlet of each alkaline electrolytic cell is monitored, the working condition of each alkaline electrolytic cell can be accurately known, and when the concentration exceeds the threshold value range, the hydrogen production system can be stopped, inert gas can be injected into the separator, and therefore the hydrogen production efficiency is improved. The hydrogen concentration in the oxygen separator and the oxygen concentration in the hydrogen separator are reduced, and explosion is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production by water electrolysis, and in particular to a safety control method, a control device and a hydrogen production system for an alkaline electrolysis hydrogen production system. Background Art

[0002] The alkaline electrolyzer hydrogen production system is a technology that uses electrical energy to electrolyze alkaline liquid to produce hydrogen and oxygen. The alkaline electrolyzer hydrogen production system includes a power supply device, an alkaline electrolyzer, a separation and collection device, etc. The hydrogen and oxygen produced in the alkaline electrolyzer are discharged together with the alkaline liquid. The gas-liquid mixture of hydrogen and alkaline liquid enters the hydrogen separator, and the hydrogen is separated from the alkaline liquid before the hydrogen is collected. Similarly, the gas-liquid mixture of oxygen and alkaline liquid enters the oxygen separator, and the oxygen is separated from the alkaline liquid before the oxygen is collected.

[0003] With the development of hydrogen production systems, multiple alkaline electrolyzers will be used in parallel, and multiple alkaline electrolyzers will share the same separation and collection device. During the operation of the alkaline electrolyzer hydrogen production system, it is necessary to monitor the operating status of the hydrogen production system to ensure the safe operation of the hydrogen production system. However, the safety monitoring technology for hydrogen production systems with multiple alkaline electrolyzers in the relevant technology is not yet mature. For example, for the monitoring of gas purity, only the hydrogen content in oxygen or the oxygen content in hydrogen in the shared separation and collection device is monitored, and only simple monitoring can be performed. In some cases, even if the hydrogen content in oxygen or the oxygen content in hydrogen in the shared separation and collection device is within the threshold range, it is impossible to ensure that the specific working conditions of each alkaline electrolyzer are safe, the monitoring accuracy is low, the safety factor is low, and there are safety hazards. Moreover, when encountering extreme working conditions, it is impossible to respond in time.

[0004] Therefore, how to meet the demand for safety monitoring of a hydrogen production system with multiple alkaline electrolyzers is an important issue that needs to be urgently addressed in the industry. Summary of the invention

[0005] The present invention provides a safety control method, a control device and a hydrogen production system for an alkaline electrolysis hydrogen production system, which are used to meet the demand for safety monitoring of a hydrogen production system having multiple alkaline electrolytic cells.

[0006] The present invention provides a safety control method for an alkaline electrolysis hydrogen production system, wherein the alkaline electrolysis hydrogen production system comprises at least two alkaline electrolyzers, a hydrogen separator and an oxygen separator, wherein the oxygen side outlet of each alkaline electrolyzer is connected to the oxygen separator, and the hydrogen side outlet of each alkaline electrolyzer is connected to the hydrogen separator. The safety control method for the alkaline electrolysis hydrogen production system comprises: Obtaining the oxygen concentration at the oxygen-side outlet of each alkaline electrolyzer at the current moment and the hydrogen concentration at the hydrogen-side outlet of each alkaline electrolyzer at the current moment; When the oxygen concentration of at least one alkaline electrolyzer at the current moment is less than a first oxygen concentration threshold or the hydrogen concentration at the current moment is less than a first hydrogen concentration threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating, and inert gas is filled into the hydrogen separator and the oxygen separator.

[0007] A safety control method for an alkaline electrolysis hydrogen production system provided by the present invention further includes: When the oxygen concentration at the current moment of any of the alkaline electrolyzers is greater than the second oxygen concentration threshold and the hydrogen concentration at the current moment is greater than the second hydrogen concentration threshold, determine the oxygen concentration difference at the current moment and the hydrogen concentration difference at the current moment, the oxygen concentration difference at the current moment is the difference between the oxygen concentration at the current moment of each of the alkaline electrolyzers and the second oxygen concentration threshold, the hydrogen concentration difference at the current moment is the difference between the hydrogen concentration at the current moment of each of the alkaline electrolyzers and the second hydrogen concentration threshold, the second oxygen concentration threshold is greater than the first oxygen concentration threshold, and the second hydrogen concentration threshold is greater than the first hydrogen concentration threshold; When the oxygen concentration difference at the current moment of at least one of the alkaline electrolyzers is less than the first difference threshold or the hydrogen concentration difference at the current moment is less than the second difference threshold, an alarm is issued.

[0008] A safety control method for an alkaline electrolysis hydrogen production system provided by the present invention further includes: When the oxygen concentration at the current moment of at least one of the alkaline electrolyzers is less than the second oxygen concentration threshold or the hydrogen concentration at the current moment is less than the second hydrogen concentration threshold, an alarm prompt is continuously issued; When the duration that the oxygen concentration at the current moment of at least one of the alkaline electrolyzers is less than the second oxygen concentration threshold or the duration that the hydrogen concentration at the current moment is less than the second hydrogen concentration threshold is greater than the first time threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating, and inert gas is filled into the hydrogen separator and the oxygen separator.

[0009] A safety control method for an alkaline electrolysis hydrogen production system provided by the present invention further includes: Determine the oxygen concentration reduction rate at the oxygen side outlet of each alkaline electrolyzer according to the oxygen concentration at the current moment and the oxygen concentration at the previous moment, and determine the hydrogen concentration reduction rate at the hydrogen side outlet of each alkaline electrolyzer according to the hydrogen concentration at the current moment and the hydrogen concentration at the previous moment; When the oxygen concentration reduction rate or the hydrogen concentration reduction rate of at least one of the alkaline electrolytic cells is greater than a first concentration change rate threshold, an alarm is issued; When the oxygen concentration reduction rate or the hydrogen concentration reduction rate of at least one of the alkaline electrolytic cells is greater than a second concentration change rate threshold, an alarm prompt is continuously issued, and the second concentration change rate threshold is greater than the first concentration change rate threshold; When the oxygen concentration reduction rate or the hydrogen concentration reduction rate of at least one of the alkaline electrolyzers is greater than the second concentration change rate threshold for a duration greater than a second time threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating, and inert gas is filled into the hydrogen separator and the oxygen separator.

[0010] A safety control method for an alkaline electrolysis hydrogen production system provided by the present invention further includes: Obtaining the current gas pressure in the hydrogen separator or the oxygen separator; When the gas pressure at the current moment is greater than the first pressure threshold, an alarm is issued; When the gas pressure at the current moment is greater than a second pressure threshold, the alkaline electrolysis hydrogen production system is controlled to stop running, and the second pressure threshold is greater than the first pressure threshold.

[0011] A safety control method for an alkaline electrolysis hydrogen production system provided by the present invention further includes: Determine a separator pressure difference according to the current gas pressure of the hydrogen separator and the current gas pressure of the oxygen separator, wherein the separator pressure difference is the difference between the current gas pressure in the hydrogen separator and the current gas pressure in the oxygen separator; When the separator pressure difference is greater than a third difference threshold, an alarm is issued; When the separator pressure difference is greater than a fourth difference threshold, the alkaline electrolysis hydrogen production system is controlled to stop running, and the fourth difference threshold corresponds to the third difference threshold.

[0012] A safety control method for an alkaline electrolysis hydrogen production system provided by the present invention further includes: Obtaining the current temperature of the electrolysis chamber of each alkaline electrolytic cell, the current temperature of the hydrogen separator, and the current temperature of the oxygen separator; When the current temperature of the electrolysis chamber of at least one of the alkaline electrolytic cells is greater than the current average temperature of the separator, and the difference between the current temperature of the electrolysis chamber of the alkaline electrolytic cell and the current average temperature of the separator is greater than the fifth difference threshold, and the duration is greater than the third time threshold, an alarm is issued, and the current average temperature of the separator is the average of the current temperature of the hydrogen separator and the current temperature of the oxygen separator; When the difference between the current temperature of the electrolysis chamber of the alkaline electrolytic cell and the current average temperature of the separator is greater than a sixth difference threshold, and the duration is greater than a fourth time threshold, an over-temperature risk prompt and / or a shutdown prompt is issued, and the sixth difference threshold is greater than the fifth difference threshold; When the difference between the current temperature of the electrolysis chamber of the alkaline electrolytic cell and the current average temperature of the separator is greater than a sixth difference threshold, and the duration is greater than a fifth time threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating, and the fifth time threshold is greater than the fourth time threshold.

[0013] A safety control method for an alkaline electrolysis hydrogen production system provided by the present invention further includes: Obtaining the current voltage of the electrolysis chamber of each alkaline electrolytic cell; Determining the average voltage of the electrolysis chamber of each alkaline electrolysis cell at the current moment according to the voltage of the electrolysis chamber of each alkaline electrolysis cell at the current moment; When the difference between the current voltage of the electrolysis chamber of at least one of the alkaline electrolytic cells and the current average voltage is greater than a seventh difference threshold, an alarm is issued; When the voltage of the electrolysis chamber of at least one of the alkaline electrolytic cells is zero at the current moment, the alkaline electrolysis hydrogen production system is controlled to stop operating.

[0014] The present invention also provides a safety control device for an alkaline electrolysis hydrogen production system, the alkaline electrolysis hydrogen production system comprising at least two alkaline electrolyzers, a hydrogen separator and an oxygen separator, the oxygen side outlets of each alkaline electrolyzer are connected to the oxygen separator, the hydrogen side outlets of each alkaline electrolyzer are connected to the hydrogen separator, and the safety control device for the alkaline electrolysis hydrogen production system comprises: An acquisition module, adapted to acquire the oxygen concentration at the oxygen-side outlet of each alkaline electrolyzer at the current moment and the hydrogen concentration at the hydrogen-side outlet of each alkaline electrolyzer at the current moment; The processing module is suitable for controlling the alkaline electrolysis hydrogen production system to stop operating and filling the hydrogen separator and the oxygen separator with inert gas when the oxygen concentration of at least one alkaline electrolyzer at the current moment is less than the first oxygen concentration threshold or the hydrogen concentration at the current moment is less than the first hydrogen concentration threshold.

[0015] The present invention also provides a hydrogen production system, comprising: At least two alkaline electrolyzers; A hydrogen separator and an oxygen separator, wherein the oxygen outlet of each alkaline electrolyzer is connected to the oxygen separator, and the hydrogen outlet of each alkaline electrolyzer is connected to the hydrogen separator; A concentration detection mechanism, adapted to detect the oxygen concentration at the oxygen-side outlet of each of the alkaline electrolytic cells and the hydrogen concentration at the hydrogen-side outlet of each of the alkaline electrolytic cells; a pressure detection mechanism, adapted to detect at least the pressure in the hydrogen separator and the gas pressure in the oxygen separator; A temperature detection mechanism, adapted to detect the temperature of the electrolysis chamber of each alkaline electrolytic cell; A voltage detection mechanism, adapted to detect the voltage of the electrolysis chamber of each alkaline electrolytic cell; An inert gas filling mechanism, adapted to fill the hydrogen separator and the oxygen separator with inert gas; An alarm mechanism, adapted to issue an alarm prompt; The alkaline electrolytic cell, the concentration detection mechanism, the pressure detection mechanism, the temperature detection mechanism, the voltage detection mechanism, the alarm mechanism and the inert gas filling mechanism are all electrically connected to the controller, and the controller is capable of executing the safety control method of the alkaline electrolysis hydrogen production system as described above.

[0016] In the safety control method of the alkaline electrolysis hydrogen production system provided by the present invention, the alkaline electrolysis hydrogen production system includes at least two alkaline electrolyzers, a hydrogen separator and an oxygen separator, the oxygen side outlet of each alkaline electrolyzer is connected to the oxygen separator, and the hydrogen side outlet of each alkaline electrolyzer is connected to the hydrogen separator. During the operation of the alkaline electrolysis hydrogen production system, the current oxygen concentration at the oxygen side outlet of each alkaline electrolyzer and the current hydrogen concentration at the hydrogen side outlet of each alkaline electrolyzer are obtained. If the current oxygen concentration of at least one alkaline electrolyzer is less than the first oxygen concentration threshold or the current hydrogen concentration is less than the first hydrogen concentration threshold, the alkaline electrolysis hydrogen production system is controlled to stop running, and the hydrogen separator and the oxygen separator are filled with inert gas. With this arrangement, the gas concentrations at the oxygen-side outlet and the hydrogen-side outlet of each alkaline electrolyzer are monitored separately, so that the working condition of each alkaline electrolyzer can be accurately understood. Moreover, when the concentration exceeds the threshold range, not only will the hydrogen production system be shut down, but inert gas will also be filled into the separator to reduce the hydrogen concentration in the oxygen separator and the oxygen concentration in the hydrogen separator, thereby effectively avoiding explosions and ensuring the safe operation of the alkaline electrolysis hydrogen production system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1It is a structural schematic diagram of the alkaline electrolysis hydrogen production system provided by the present invention.

[0019] Figure 2 It is a flow chart of the safety control method of the alkaline electrolysis hydrogen production system provided by the present invention.

[0020] Reference numerals: 1. Alkaline electrolytic cell; 2. Hydrogen separator; 3. Oxygen separator; 4. Concentration detection mechanism; 5. Temperature detection mechanism; 6. Voltage detection mechanism; 7. Inert gas filling mechanism; 8. Pressure sensor; 9. Differential pressure level gauge. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Combine the following Figure 1 to Figure 2 The safety control method of the alkaline electrolysis hydrogen production system of the present invention is described.

[0023] like Figure 1 and Figure 2 As shown, the safety control method for the alkaline electrolysis hydrogen production system provided in the embodiment of the present invention can be executed by the control system of the hydrogen production system or other independent control equipment.

[0024] The alkaline electrolysis hydrogen production system applicable to this embodiment includes at least two alkaline electrolyzers 1, a hydrogen separator 2 and an oxygen separator 3, and the oxygen side outlet of each alkaline electrolyzer 1 is connected to the oxygen separator 3, and the hydrogen side outlet of each alkaline electrolyzer 1 is connected to the hydrogen separator 2. During the operation of the alkaline electrolysis hydrogen production system, the hydrogen produced by each alkaline electrolyzer 1 is circulated to the hydrogen separator 2 together with the alkali solution, and the oxygen produced by each alkaline electrolyzer 1 is circulated to the oxygen separator 3 together with the alkali solution. After the hydrogen and the alkali solution enter the hydrogen separator 2, the hydrogen is separated from the alkali solution, and the hydrogen is located above the alkali solution. Similarly, after the oxygen and the alkali solution enter the oxygen separator 3, the oxygen is separated from the alkali solution, and the oxygen is located above the alkali solution. The alkali solution in the oxygen separator 3 and the alkali solution in the hydrogen separator 2 are used for circulation, and the oxygen in the oxygen separator 3 and the hydrogen in the hydrogen separator 2 are collected separately.

[0025] The safety control method of the alkaline electrolysis hydrogen production system in this embodiment mainly includes steps 110 to 120.

[0026] Step 110: Obtain the current oxygen concentration at the oxygen-side outlet of each alkaline electrolytic cell and the current hydrogen concentration at the hydrogen-side outlet of each alkaline electrolytic cell.

[0027] Step 120: When the current oxygen concentration of at least one alkaline electrolyzer is less than a first oxygen concentration threshold or the current hydrogen concentration is less than a first hydrogen concentration threshold, the alkaline electrolysis hydrogen production system is controlled to stop running, and an inert gas is filled into the hydrogen separator and the oxygen separator.

[0028] With such arrangement, the gas concentrations at the oxygen side outlet and the hydrogen side outlet of each alkaline electrolyzer 1 are monitored respectively, so that the working condition of each alkaline electrolyzer 1 can be accurately understood. Moreover, when the concentration exceeds the threshold range, not only will the hydrogen production system be shut down, but inert gas will also be filled into the separator to reduce the hydrogen concentration in the oxygen separator 3 and the oxygen concentration in the hydrogen separator 2. In addition, filling the separator with inert gas can also narrow the explosion limit range of hydrogen, reduce the upper limit value of the explosion limit range of hydrogen, increase the lower limit value of the explosion limit range of hydrogen, and even make the mixed gas in the separator non-flammable, thereby effectively avoiding explosion and ensuring the safe operation of the alkaline electrolytic hydrogen production system.

[0029] The inert gas may be, but is not limited to, nitrogen.

[0030] It should be noted that the hydrogen concentration and oxygen concentration detected in the embodiment of the present invention are the gas concentrations at the gas outlet of each alkaline electrolytic cell 1 , rather than the gas concentrations in the hydrogen separator 2 and the oxygen separator 3 .

[0031] The above-mentioned first oxygen concentration threshold and first hydrogen concentration threshold are the lower concentration limit values ​​of the alkaline electrolysis hydrogen production system. When the current oxygen concentration of any alkaline electrolyzer 1 is greater than the first oxygen concentration threshold, and the current hydrogen concentration of any alkaline electrolyzer 1 is greater than the first hydrogen concentration threshold, the alkaline electrolysis hydrogen production system can operate. When the current oxygen concentration of any alkaline electrolyzer 1 is close to the first oxygen concentration threshold or the current hydrogen concentration of any alkaline electrolyzer 1 is close to the first hydrogen concentration threshold, the alkaline electrolysis hydrogen production system can operate, but it is an extreme operating condition, and the operating condition of each alkaline electrolyzer 1 is poor.

[0032] In this embodiment, a second oxygen concentration threshold and a second hydrogen concentration threshold are set for the alkaline electrolysis hydrogen production system, the second oxygen concentration threshold is greater than the first oxygen concentration threshold, and the second hydrogen concentration threshold is greater than the first hydrogen concentration threshold. When the detected hydrogen concentration at the current moment is greater than the second hydrogen concentration threshold and the oxygen concentration at the current moment is greater than the second oxygen concentration threshold, it indicates that the operating condition of the alkaline electrolyzer 1 is good, and the second oxygen concentration threshold and the second hydrogen concentration threshold are the lower limits of the gas concentration when the alkaline electrolyzer 1 is in good operating condition.

[0033] At this time, the oxygen concentration difference at the current moment and the hydrogen concentration difference at the current moment can be determined, wherein the oxygen concentration difference at the current moment is the difference between the oxygen concentration of each alkaline electrolyzer 1 at the current moment and the second oxygen concentration threshold, and the hydrogen concentration difference at the current moment is the difference between the hydrogen concentration of each alkaline electrolyzer 1 at the current moment and the second hydrogen concentration threshold.

[0034] The oxygen concentration difference at the current moment and the hydrogen concentration difference at the current moment represent the degree of proximity between the gas concentration generated by the alkaline electrolytic cell 1 and the lower limit of the gas concentration corresponding to a good working condition.

[0035] If the oxygen concentration difference of at least one alkaline electrolytic cell 1 at the current moment is less than the first difference threshold, or the hydrogen concentration difference at the current moment is less than the second difference threshold, an alarm is issued to remind the staff that the alkaline electrolytic cell 1 is about to deviate from a good operating condition and needs attention and investigation of the cause.

[0036] If the current oxygen concentration of at least one alkaline electrolyzer 1 is less than the second oxygen concentration threshold or the current hydrogen concentration is less than the second hydrogen concentration threshold, an alarm will continue to be issued to warn the staff that the alkaline electrolyzer 1 has deviated from the good operating condition and is extremely close to the limit condition, and the alkaline electrolysis hydrogen production system is about to shut down and cannot operate.

[0037] If the oxygen concentration of at least one alkaline electrolyzer 1 at the current moment is less than the duration of the second oxygen concentration threshold or the hydrogen concentration at the current moment is less than the second hydrogen concentration threshold for a duration greater than the first time threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating and inert gas is filled into the hydrogen separator 2 and the oxygen separator 3.

[0038] Specifically, the first hydrogen concentration threshold may be 99.7%, the first oxygen concentration threshold may be 98.3%, the second hydrogen concentration threshold may be 99.8%, the second oxygen concentration threshold may be 98.5%, the first difference threshold may be 0.02%, the second difference threshold may be 0.05%, and the first time threshold may be 3 minutes.

[0039] In the embodiment of the present invention, in the process of controlling the alkaline electrolytic hydrogen production system according to the hydrogen concentration value at the hydrogen side outlet of each alkaline electrolyzer 1 and the oxygen concentration value at the oxygen side outlet of each alkaline electrolyzer 1, the hydrogen concentration reduction rate at the hydrogen side outlet of each alkaline electrolyzer 1 and the oxygen concentration reduction rate at the oxygen side outlet of each alkaline electrolyzer 1 are also monitored, and the alkaline electrolytic hydrogen production system is controlled according to the hydrogen concentration reduction rate and the oxygen concentration reduction rate.

[0040] Specifically, after obtaining the hydrogen concentration at the current moment and the oxygen concentration at the current moment, the oxygen concentration reduction rate at the oxygen side outlet of each alkaline electrolytic cell 1 is determined according to the oxygen concentration at the current moment and the oxygen concentration at the previous moment, and the hydrogen concentration reduction rate at the hydrogen side outlet of each alkaline electrolytic cell 1 is determined according to the hydrogen concentration at the current moment and the hydrogen concentration at the previous moment.

[0041] If the oxygen concentration reduction rate or the hydrogen concentration reduction rate of at least one alkaline electrolytic cell 1 is greater than the first concentration change rate threshold, an alarm is issued to remind the staff that there is an emergency in the operating condition of the alkaline electrolytic cell 1, the operating condition is deteriorating rapidly, and special attention is required.

[0042] If the oxygen concentration reduction rate or the hydrogen concentration reduction rate of at least one alkaline electrolytic cell 1 is greater than the second concentration change rate threshold, and the second concentration change rate threshold is greater than the first concentration change rate threshold, an alarm will continue to be issued.

[0043] If the oxygen concentration reduction rate or hydrogen concentration reduction rate of at least one alkaline electrolyzer 1 is greater than the second concentration change rate threshold for a duration greater than the second time threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating and inert gas is filled into the hydrogen separator 2 and the oxygen separator 3.

[0044] The first concentration change rate threshold is 0.02% per second, the second concentration change rate threshold is 0.05% per second, and the second time threshold may be 20 seconds.

[0045] In the embodiment of the present invention, during the operation of the alkaline electrolysis hydrogen production system, the gas pressure in the hydrogen separator 2 and the gas pressure in the oxygen separator 3 are also monitored.

[0046] The alkaline electrolysis hydrogen production system also includes a pressure control system for controlling the gas pressures in the hydrogen separator 2 and the oxygen separator 3 so that the gas pressures in the hydrogen separator 2 and the gas pressures in the oxygen separator 3 are maintained within a certain range.

[0047] Specifically, the current gas pressure in the hydrogen separator 2 and the oxygen separator 3 is obtained respectively. If the current gas pressure is greater than the first pressure threshold, an alarm is issued to remind the staff that the gas pressure in the hydrogen separator 2 and the oxygen separator 3 has increased and the pressure control system may fail.

[0048] If the gas pressure at the current moment is greater than the second pressure threshold, and the second pressure threshold is greater than the first pressure threshold, the alkaline electrolysis hydrogen production system is controlled to stop running.

[0049] In this embodiment, a connecting pipeline is provided between the bottom of the hydrogen separator 2 and the bottom of the oxygen separator 3, and the connecting pipeline is connected to the alkali liquid circulation system for the circulation of the alkali liquid. A control valve is provided on the connecting pipeline, and the on-off state of the connecting pipeline can be controlled by the control valve. When the control valve is in an open state, the hydrogen separator 2, the oxygen separator 3 and the connecting pipeline form a communicating vessel, so, generally, the gas pressure in the hydrogen separator 2 is equal to the gas pressure in the oxygen separator 3.

[0050] In this embodiment, during the operation of the alkaline electrolysis hydrogen production system, the separator pressure difference is determined based on the current gas pressure of the hydrogen separator 2 and the current gas pressure of the oxygen separator 3. The separator pressure difference is the difference between the current gas pressure in the hydrogen separator 2 and the current gas pressure in the oxygen separator 3.

[0051] If the separator pressure difference is greater than the third difference threshold, an alarm is issued to remind the staff that the control valve on the connecting pipeline may not be opened as required.

[0052] If the separator pressure difference is greater than a fourth difference threshold, and the fourth difference threshold is equal to the third difference threshold, the alkaline electrolysis hydrogen production system is controlled to stop running.

[0053] Specifically, the first pressure threshold may be 105% of the system design pressure, and the second pressure threshold may be 110% of the system design pressure.

[0054] When determining the separator pressure difference, the gas pressure in the hydrogen separator 2 and the gas pressure in the oxygen separator 3 may be detected respectively, and then the difference may be calculated.

[0055] A differential pressure level gauge 9 may also be provided between the bottom of the hydrogen separator 2 and the bottom of the oxygen separator 3, and the differential pressure level gauge 9 may be used to monitor the liquid level difference between the hydrogen separator 2 and the oxygen separator 3, and the liquid level difference between the hydrogen separator 2 and the oxygen separator 3 corresponds to the separator pressure difference. At this time, the third difference threshold may be a liquid level difference of 60 mm, and the fourth difference threshold may be a liquid level difference of 120 mm.

[0056] In the embodiment of the present invention, during the operation of the alkaline electrolysis hydrogen production system, the temperature of the electrolysis chamber of the alkaline electrolysis cell 1 is also monitored.

[0057] Specifically, during the operation of the alkaline electrolysis hydrogen production system, the current temperature of the electrolysis chamber of each alkaline electrolytic cell 1, the current temperature of the hydrogen separator 2, and the current temperature of the oxygen separator 3 are obtained. According to the current temperature of the hydrogen separator 2 and the current temperature of the oxygen separator 3, the current average temperature of the separator is determined, and the current average temperature of the separator is the average value of the current temperature of the hydrogen separator 2 and the current temperature of the oxygen separator 3.

[0058] If the current temperature of the electrolysis chamber of at least one alkaline electrolysis cell 1 is greater than the current average temperature of the separator, the alkaline electrolysis hydrogen production system is controlled according to the difference between the current temperature of the electrolysis chamber of the alkaline electrolysis cell 1 and the current average temperature of the separator.

[0059] If the difference between the current temperature of the electrolysis chamber of the alkaline electrolytic cell 1 and the current average temperature of the separator is greater than the fifth difference threshold, and the duration is greater than the third time threshold, an alarm is issued.

[0060] If the difference between the current temperature of the electrolysis chamber of the alkaline electrolytic cell 1 and the current average temperature of the separator is greater than the sixth difference threshold, the sixth difference threshold is greater than the fifth difference threshold, and the duration is greater than the fourth time threshold, an over-temperature risk warning and / or shutdown warning is issued.

[0061] If the difference between the current temperature of the electrolysis chamber of the alkaline electrolysis cell 1 and the current average temperature of the separator is greater than the sixth difference threshold, and the duration is greater than the fifth time threshold, and the fifth time threshold is greater than the fourth time threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating.

[0062] When obtaining the temperature of the electrolysis chamber, the temperature of the bipolar plate can be directly detected. The fifth difference threshold can be 5 degrees Celsius, the sixth difference threshold can be 10 degrees Celsius, the third time threshold can be 5 minutes, the fourth time threshold can be 5 minutes, and the fifth time threshold can be 20 minutes.

[0063] In the embodiment of the present invention, during the operation of the alkaline electrolysis hydrogen production system, the voltage of the electrolysis chamber of the alkaline electrolysis cell 1 is also monitored.

[0064] Specifically, during the operation of the alkaline electrolysis hydrogen production system, the current voltage of the electrolysis chamber of each alkaline electrolysis cell 1 is obtained. According to the current voltage of the electrolysis chamber of each alkaline electrolysis cell 1, the current average voltage of the electrolysis chamber of each alkaline electrolysis cell 1 is determined.

[0065] If the difference between the current voltage of the electrolysis chamber of at least one alkaline electrolysis cell 1 and the current average voltage is greater than the seventh difference threshold, an alarm is issued.

[0066] If the current voltage of the electrolysis chamber of at least one alkaline electrolysis cell 1 is zero, it is determined that the system is short-circuited, and the alkaline electrolysis hydrogen production system is controlled to stop running.

[0067] The seventh difference threshold may be 10% of the difference between the average voltages at the current moment.

[0068] In summary, the safety control method of the alkaline electrolysis hydrogen production system provided in the embodiment of the present invention realizes the safety control of the hydrogen production system having multiple alkaline electrolytic cells 1 arranged in parallel, and the working condition of each alkaline electrolytic cell 1 can be accurately understood during the control process. During the control process, the alkaline electrolysis hydrogen production system is comprehensively controlled with gas concentration, gas pressure, temperature of the electrolysis chamber and voltage of the electrolysis chamber as measurement indicators, and alarm prompts are given in different levels to remind staff to pay attention, warn staff, and make a safe emergency stop.

[0069] On the other hand, based on the same general inventive concept, an embodiment of the present invention further provides a safety control device for an alkaline electrolysis hydrogen production system. The safety control device for an alkaline electrolysis hydrogen production system described below and the safety control method for an alkaline electrolysis hydrogen production system described above can be referenced to each other.

[0070] The alkaline electrolysis hydrogen production system includes at least two alkaline electrolyzers 1, a hydrogen separator 2 and an oxygen separator 3. The oxygen side outlet of each alkaline electrolyzer 1 is connected to the oxygen separator 3, and the hydrogen side outlet of each alkaline electrolyzer 1 is connected to the hydrogen separator 2.

[0071] An embodiment of the present invention provides a safety control device for an alkaline electrolysis hydrogen production system, comprising an acquisition module and a processing module.

[0072] The acquisition module is suitable for acquiring the oxygen concentration at the oxygen-side outlet of each alkaline electrolyzer at the current moment and the hydrogen concentration at the hydrogen-side outlet of each alkaline electrolyzer at the current moment.

[0073] The processing module is suitable for controlling the alkaline electrolysis hydrogen production system to stop operating and filling the hydrogen separator and the oxygen separator with inert gas when the current oxygen concentration of at least one alkaline electrolyzer is less than the first oxygen concentration threshold or the current hydrogen concentration is less than the first hydrogen concentration threshold.

[0074] On the other hand, based on the same general inventive concept, an embodiment of the present invention further provides a hydrogen production system, and the hydrogen production system described below and the safety control method of the alkaline electrolysis hydrogen production system described above can be referenced to each other.

[0075] The hydrogen production system provided in this embodiment includes at least two alkaline electrolyzers 1, a hydrogen separator 2, an oxygen separator 3, a concentration detection mechanism 4, a pressure detection mechanism, a temperature detection mechanism 5, a voltage detection mechanism 6, an inert gas filling mechanism 7, an alarm mechanism and a controller.

[0076] The oxygen side outlet of each alkaline electrolyzer 1 is connected to the oxygen separator 3, and the hydrogen side outlet of each alkaline electrolyzer 1 is connected to the hydrogen separator 2. During the operation of the alkaline electrolysis hydrogen production system, the hydrogen produced by each alkaline electrolyzer 1 flows to the hydrogen separator 2 together with the alkali liquid, and the oxygen produced by each alkaline electrolyzer 1 flows to the oxygen separator 3 together with the alkali liquid. After the hydrogen and the alkali liquid enter the hydrogen separator 2, the hydrogen is separated from the alkali liquid, and the hydrogen is located above the alkali liquid. Similarly, after the oxygen and the alkali liquid enter the oxygen separator 3, the oxygen is separated from the alkali liquid, and the oxygen is located above the alkali liquid.

[0077] The alkaline solution in the oxygen separator 3 and the alkaline solution in the hydrogen separator 2 are used for circulation, and the oxygen in the oxygen separator 3 and the hydrogen in the hydrogen separator 2 are collected separately.

[0078] A connecting pipeline is provided between the bottom of the hydrogen separator 2 and the bottom of the oxygen separator 3, and the connecting pipeline is connected to the alkali liquid circulation system for the circulation of the alkali liquid. A control valve is provided on the connecting pipeline, and the on-off state of the connecting pipeline can be controlled by the control valve. When the control valve is in an open state, the hydrogen separator 2, the oxygen separator 3 and the connecting pipeline form a communicating vessel.

[0079] A concentration detection mechanism 4 is provided at the oxygen outlet of each alkaline electrolytic cell 1 to detect the oxygen concentration at the oxygen outlet of each alkaline electrolytic cell 1. A concentration detection mechanism 4 is provided at the hydrogen outlet of each alkaline electrolytic cell 1 to detect the hydrogen concentration at the hydrogen outlet of each alkaline electrolytic cell 1.

[0080] The pressure detection mechanism is used to detect at least the pressure in the hydrogen separator 2 and the gas pressure in the oxygen separator 3 .

[0081] Each alkaline electrolytic cell 1 is correspondingly provided with a temperature detection mechanism 5 and a voltage detection mechanism 6 . The temperature detection mechanism 5 is used to detect the temperature of the electrolysis chamber of each alkaline electrolytic cell 1 , and the voltage detection mechanism 6 is used to detect the voltage of the electrolysis chamber of each alkaline electrolytic cell 1 .

[0082] The inert gas filling mechanism 7 is used to fill the hydrogen separator 2 and the oxygen separator 3 with inert gas as required. The alarm mechanism is used to issue an alarm prompt as required.

[0083] The above-mentioned alkaline electrolytic cell 1, concentration detection mechanism 4, pressure detection mechanism, temperature detection mechanism 5, voltage detection mechanism 6, inert gas filling mechanism 7 and alarm mechanism are all electrically connected to the controller, and the controller can execute the safety control method of the alkaline electrolysis hydrogen production system provided in any of the above-mentioned embodiments.

[0084] With such arrangement, during the operation of the alkaline electrolysis hydrogen production system, the controller controls the operation of the alkaline electrolytic cell 1, the concentration detection mechanism 4, the pressure detection mechanism, the temperature detection mechanism 5, the voltage detection mechanism 6, the inert gas filling mechanism 7 and the alarm mechanism, so that the gas concentrations at the oxygen side outlet and the hydrogen side outlet of each alkaline electrolytic cell 1 can be monitored separately, and the working condition of each alkaline electrolytic cell 1 can be accurately understood. Moreover, when the concentration exceeds the threshold range, not only will the hydrogen production system be shut down, but the separator will also be filled with inert gas to reduce the hydrogen concentration in the oxygen separator 3 and the oxygen concentration in the hydrogen separator 2, thereby effectively avoiding explosion.

[0085] The derivation process of the beneficial effects of the hydrogen production system in the embodiment of the present invention is generally similar to the derivation process of the beneficial effects of the safety control method of the alkaline electrolysis hydrogen production system described above, so it will not be repeated here.

[0086] For the concentration detection mechanism 4, a sub-separator and a purity meter can be respectively set on the pipeline at the hydrogen side outlet and the pipeline at the oxygen side outlet of each alkaline electrolyzer 1. The hydrogen and alkali liquid output by each alkaline electrolyzer 1 will first enter the sub-separator before entering the hydrogen separator 2. After the alkali liquid and hydrogen are separated in the sub-separator, the purity meter can be used to detect the hydrogen concentration in the sub-separator. Similarly, the oxygen and alkali liquid output by each alkaline electrolyzer 1 will first enter the sub-separator before entering the oxygen separator 3. After the alkali liquid and oxygen are separated in the sub-separator, the purity meter can be used to detect the oxygen concentration in the sub-separator.

[0087] As for the pressure detection mechanism, a pressure sensor 8 may be provided in the hydrogen separator 2 and the oxygen separator 3, respectively, and the pressure sensor 8 may be used to detect the gas pressure in the hydrogen separator 2 and the gas pressure in the oxygen separator 3. The separator pressure difference may be calculated and determined according to the gas pressure in the hydrogen separator 2 and the gas pressure in the oxygen separator 3 detected by the pressure sensor 8. A differential pressure level gauge 9 may also be provided between the bottom of the hydrogen separator 2 and the bottom of the oxygen separator 3, and the differential pressure level gauge 9 may be used to monitor the liquid level difference between the hydrogen separator 2 and the oxygen separator 3, and the liquid level difference between the hydrogen separator 2 and the oxygen separator 3 corresponds to the separator pressure difference.

[0088] As for the temperature detection mechanism 5 , a temperature sensor capable of detecting the temperature of the bipolar plates may be provided on the alkaline electrolytic cell 1 , and the details are not described in detail.

[0089] For the inert gas filling mechanism 7, connecting pipelines can be respectively arranged at the top of the hydrogen separator 2 and the top of the oxygen separator 3, and the connecting pipelines are connected to the nitrogen cylinder group. A valve is arranged on the connecting pipeline to control the on-off state of the connecting pipeline. When the valve is opened, the nitrogen in the nitrogen cylinder group spontaneously flows into the hydrogen separator 2 and the oxygen separator 3 under the action of its own pressure. At this time, the valve can be electrically connected to the controller.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention 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 make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A safety control method for an alkaline electrolysis hydrogen production system, characterized in that: The alkaline electrolysis hydrogen production system comprises at least two alkaline electrolyzers, a hydrogen separator and an oxygen separator, wherein the oxygen side outlet of each alkaline electrolyzer is connected to the oxygen separator, and the hydrogen side outlet of each alkaline electrolyzer is connected to the hydrogen separator. The safety control method of the alkaline electrolysis hydrogen production system comprises: Obtaining the oxygen concentration at the oxygen-side outlet of each alkaline electrolyzer at the current moment and the hydrogen concentration at the hydrogen-side outlet of each alkaline electrolyzer at the current moment; When the oxygen concentration of at least one alkaline electrolyzer at the current moment is less than a first oxygen concentration threshold or the hydrogen concentration at the current moment is less than a first hydrogen concentration threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating, and inert gas is filled into the hydrogen separator and the oxygen separator.

2. The safety control method for an alkaline electrolysis hydrogen production system according to claim 1, characterized in that: Also includes: When the oxygen concentration at the current moment of any of the alkaline electrolyzers is greater than the second oxygen concentration threshold and the hydrogen concentration at the current moment is greater than the second hydrogen concentration threshold, determine the oxygen concentration difference at the current moment and the hydrogen concentration difference at the current moment, the oxygen concentration difference at the current moment is the difference between the oxygen concentration at the current moment of each of the alkaline electrolyzers and the second oxygen concentration threshold, the hydrogen concentration difference at the current moment is the difference between the hydrogen concentration at the current moment of each of the alkaline electrolyzers and the second hydrogen concentration threshold, the second oxygen concentration threshold is greater than the first oxygen concentration threshold, and the second hydrogen concentration threshold is greater than the first hydrogen concentration threshold; When the oxygen concentration difference at the current moment of at least one of the alkaline electrolyzers is less than the first difference threshold or the hydrogen concentration difference at the current moment is less than the second difference threshold, an alarm is issued.

3. The safety control method for an alkaline electrolysis hydrogen production system according to claim 2, characterized in that: Also includes: When the oxygen concentration at the current moment of at least one of the alkaline electrolyzers is less than the second oxygen concentration threshold or the hydrogen concentration at the current moment is less than the second hydrogen concentration threshold, an alarm prompt is continuously issued; When the duration that the oxygen concentration at the current moment of at least one of the alkaline electrolyzers is less than the second oxygen concentration threshold or the duration that the hydrogen concentration at the current moment is less than the second hydrogen concentration threshold is greater than the first time threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating, and inert gas is filled into the hydrogen separator and the oxygen separator.

4. The safety control method for an alkaline electrolysis hydrogen production system according to claim 3, characterized in that: Also includes: Determine the oxygen concentration reduction rate at the oxygen side outlet of each alkaline electrolyzer according to the oxygen concentration at the current moment and the oxygen concentration at the previous moment, and determine the hydrogen concentration reduction rate at the hydrogen side outlet of each alkaline electrolyzer according to the hydrogen concentration at the current moment and the hydrogen concentration at the previous moment; When the oxygen concentration reduction rate or the hydrogen concentration reduction rate of at least one of the alkaline electrolytic cells is greater than a first concentration change rate threshold, an alarm is issued; When the oxygen concentration reduction rate or the hydrogen concentration reduction rate of at least one of the alkaline electrolytic cells is greater than a second concentration change rate threshold, an alarm prompt is continuously issued, and the second concentration change rate threshold is greater than the first concentration change rate threshold; When the oxygen concentration reduction rate or the hydrogen concentration reduction rate of at least one of the alkaline electrolyzers is greater than the second concentration change rate threshold for a duration greater than a second time threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating, and inert gas is filled into the hydrogen separator and the oxygen separator.

5. The safety control method for an alkaline electrolysis hydrogen production system according to any one of claims 1 to 4, characterized in that: Also includes: Obtaining the current gas pressure in the hydrogen separator or the oxygen separator; When the gas pressure at the current moment is greater than the first pressure threshold, an alarm is issued; When the gas pressure at the current moment is greater than a second pressure threshold, the alkaline electrolysis hydrogen production system is controlled to stop running, and the second pressure threshold is greater than the first pressure threshold.

6. The safety control method for an alkaline electrolysis hydrogen production system according to claim 5, characterized in that: Also includes: Determine a separator pressure difference according to the current gas pressure of the hydrogen separator and the current gas pressure of the oxygen separator, wherein the separator pressure difference is the difference between the current gas pressure in the hydrogen separator and the current gas pressure in the oxygen separator; When the separator pressure difference is greater than a third difference threshold, an alarm is issued; When the separator pressure difference is greater than a fourth difference threshold, the alkaline electrolysis hydrogen production system is controlled to stop running, and the fourth difference threshold corresponds to the third difference threshold.

7. The safety control method for an alkaline electrolysis hydrogen production system according to any one of claims 1 to 4, characterized in that: Also includes: Obtaining the current temperature of the electrolysis chamber of each alkaline electrolytic cell, the current temperature of the hydrogen separator, and the current temperature of the oxygen separator; When the current temperature of the electrolysis chamber of at least one of the alkaline electrolytic cells is greater than the current average temperature of the separator, and the difference between the current temperature of the electrolysis chamber of the alkaline electrolytic cell and the current average temperature of the separator is greater than the fifth difference threshold, and the duration is greater than the third time threshold, an alarm is issued, and the current average temperature of the separator is the average of the current temperature of the hydrogen separator and the current temperature of the oxygen separator; When the difference between the current temperature of the electrolysis chamber of the alkaline electrolytic cell and the current average temperature of the separator is greater than a sixth difference threshold, and the duration is greater than a fourth time threshold, an over-temperature risk prompt and / or a shutdown prompt is issued, and the sixth difference threshold is greater than the fifth difference threshold; When the difference between the current temperature of the electrolysis chamber of the alkaline electrolytic cell and the current average temperature of the separator is greater than a sixth difference threshold, and the duration is greater than a fifth time threshold, the alkaline electrolysis hydrogen production system is controlled to stop operating, and the fifth time threshold is greater than the fourth time threshold.

8. The safety control method for an alkaline electrolysis hydrogen production system according to any one of claims 1 to 4, characterized in that: Also includes: Obtaining the current voltage of the electrolysis chamber of each alkaline electrolytic cell; Determining the average voltage of the electrolysis chamber of each alkaline electrolysis cell at the current moment according to the voltage of the electrolysis chamber of each alkaline electrolysis cell at the current moment; When the difference between the current voltage of the electrolysis chamber of at least one of the alkaline electrolytic cells and the current average voltage is greater than a seventh difference threshold, an alarm is issued; When the voltage of the electrolysis chamber of at least one of the alkaline electrolytic cells is zero at the current moment, the alkaline electrolysis hydrogen production system is controlled to stop operating.

9. A safety control device for an alkaline electrolysis hydrogen production system, characterized in that: The alkaline electrolysis hydrogen production system comprises at least two alkaline electrolyzers, a hydrogen separator and an oxygen separator, wherein the oxygen side outlet of each alkaline electrolyzer is connected to the oxygen separator, and the hydrogen side outlet of each alkaline electrolyzer is connected to the hydrogen separator. The safety control device of the alkaline electrolysis hydrogen production system comprises: An acquisition module, adapted to acquire the oxygen concentration at the oxygen side outlet of each alkaline electrolyzer at the current moment and the hydrogen concentration at the hydrogen side outlet of each alkaline electrolyzer at the current moment; The processing module is suitable for controlling the alkaline electrolysis hydrogen production system to stop operating and filling the hydrogen separator and the oxygen separator with inert gas when the oxygen concentration of at least one alkaline electrolyzer at the current moment is less than the first oxygen concentration threshold or the hydrogen concentration at the current moment is less than the first hydrogen concentration threshold.

10. A hydrogen production system, characterized in that: include: at least two alkaline electrolyzers (1); A hydrogen separator (2) and an oxygen separator (3), wherein the oxygen-side outlet of each alkaline electrolytic cell (1) is connected to the oxygen separator (3), and the hydrogen-side outlet of each alkaline electrolytic cell (1) is connected to the hydrogen separator (2); A concentration detection mechanism (4) adapted to detect the oxygen concentration at the oxygen side outlet of each alkaline electrolytic cell (1) and the hydrogen concentration at the hydrogen side outlet of each alkaline electrolytic cell (1); A pressure detection mechanism, adapted to detect at least the pressure in the hydrogen separator (2) and the gas pressure in the oxygen separator (3); A temperature detection mechanism (5) adapted to detect the temperature of an electrolysis chamber of each alkaline electrolysis cell (1); A voltage detection mechanism (6) adapted to detect the voltage of the electrolysis chamber of each alkaline electrolytic cell (1); An inert gas filling mechanism (7) adapted to fill the hydrogen separator (2) and the oxygen separator (3) with inert gas; An alarm mechanism, adapted to issue an alarm prompt; A controller, wherein the alkaline electrolytic cell (1), the concentration detection mechanism (4), the pressure detection mechanism, the temperature detection mechanism (5), the voltage detection mechanism (6), the alarm mechanism and the inert gas filling mechanism (7) are all electrically connected to the controller, and the controller is capable of executing the safety control method for the alkaline electrolysis hydrogen production system according to any one of claims 1 to 8.

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