Sewage discharge control system and control method for water electrolysis hydrogen production system
By introducing a sewage discharge control system into the water electrolysis hydrogen production system, and using sensors and control units to precisely control the sewage discharge valve and pressure reducing valve, the safety hazards and pipeline blockage caused by simultaneous sewage discharge from multiple separators have been solved, and a safe and stable sewage discharge process has been achieved.
Patent Information
- Application Number
- CN202511607046.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-05
- Publication Date
- 2026-01-27
AI Technical Summary
The existing wastewater discharge system of water electrolysis hydrogen production system is prone to mutual interference due to the simultaneous discharge of wastewater from multiple gas-liquid separators, which may lead to excessive pressure in the wastewater discharge pipeline and cause rupture. Furthermore, manual control of individual wastewater discharge can easily lead to the accumulation of waste and pipeline blockage, posing safety hazards.
A sewage discharge control system is adopted, including an oxygen separator, a hydrogen separator group, a cooler, a control valve, a sensing component, and a control unit. The system monitors the drop in liquid level through level and temperature sensors, calculates the sewage discharge duration and rate, and uses a PID controller and PWM module to precisely control the opening of the sewage discharge valve and pressure reducing valve to ensure that each separator discharges sewage independently, avoiding cross-contamination and system pressure fluctuations.
Separate control of hydrogen and oxygen side discharges was achieved, avoiding accidents, ensuring the safety and stability of the discharge process, preventing pipeline blockage, and improving the controllability and safety of the system.
Smart Images
Figure CN121407151A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of wastewater discharge technology for water electrolysis hydrogen production systems, specifically a wastewater discharge control system and control method for water electrolysis hydrogen production systems. Background Technology
[0002] The water electrolysis hydrogen production system consists of an electrolyzer, a hydrogen separator, an oxygen separator, an alkali circulation pump, a gas-liquid separator, a purification system, and a DC power supply. The hydrogen, oxygen, and KOH solution generated in the electrolyzer are separated in the hydrogen and oxygen separators. The separated hydrogen and oxygen are cooled and separated into gas and water, respectively, before being output. The wastewater from the separation is discharged through a sewage pipe.
[0003] The existing sewage system is prone to mutual interference when multiple gas-liquid separators discharge sewage at the same time. It can also cause excessive pressure in the sewage pipes, leading to pipe rupture. In addition, the sewage discharge process often causes system pressure fluctuations due to instantaneous liquid discharge, which in turn causes fluctuations in the liquid levels of the oxygen separator and hydrogen separator. All of these factors pose potential safety hazards to the water electrolysis hydrogen production system.
[0004] Manually controlling each gas-liquid separator to discharge wastewater individually can lead to excessively long waiting times due to untimely monitoring. This can cause the wastewater in each separator to exceed the discharge limit, resulting in wastewater accumulation in the pipeline. Long-term use can easily cause pipeline blockage and also pose certain safety hazards. Therefore, there is an urgent need to develop a wastewater discharge control system and method for water electrolysis hydrogen production systems to solve the above problems. Summary of the Invention
[0005] The purpose of this invention is to provide a sewage discharge control system for a water electrolysis hydrogen production system. This system solves the problems mentioned above, such as the safety hazards caused by the simultaneous discharge of sewage from multiple gas-liquid separators, which can easily lead to mutual interference in the water electrolysis hydrogen production system, and the safety hazards caused by manually discharging sewage from individual gas-liquid separators, which can result in the sewage in each separator exceeding the discharge limit, causing pipeline blockage with long-term use.
[0006] To address the aforementioned technical problems, this invention provides a wastewater control system for a water electrolysis hydrogen production system, comprising an oxygen separator, a hydrogen separator group, a first cooler, a second cooler, several control valves, sensing components, and a control unit. The hydrogen separator group includes a hydrogen separator, a first gas-liquid separator, a second gas-liquid separator, a first drying gas-liquid separator, and a second drying gas-liquid separator. The hydrogen separator is connected to the oxygen separator via a pipeline. The first cooler is connected to the oxygen separator via a first cooling pipeline. The first cooler is connected to a third gas-liquid separator via a pipeline. The outlet of the third gas-liquid separator is connected to a first wastewater discharge pipeline.
[0007] The second cooler is connected to the hydrogen separator via a second cooling pipe. The inlet of the first gas-liquid separator is connected to the second cooler via a first conveying pipe, and its outlet is connected to a second drain pipe.
[0008] The second gas-liquid separator is connected to the second sewage pipe via a third sewage pipe, the first drying gas-liquid separator is connected to the second sewage pipe via a fourth sewage pipe, and the second drying gas-liquid separator is connected to the second sewage pipe via a fifth sewage pipe.
[0009] Several control valves are respectively installed on the first, second, third, fourth, and fifth sewage pipes, and are all connected to the control unit. There are five sets of sensing components, which are respectively installed on the side walls of the third gas-liquid separator, the first gas-liquid separator, the second gas-liquid separator, the first dry gas-liquid separator, and the second dry gas-liquid separator. The five sets of sensing components are respectively connected to the control unit.
[0010] Furthermore, the plurality of control valves are respectively a first pressure reducing valve, a first drain valve, a second pressure reducing valve, a second drain valve, a third pressure reducing valve, a third drain valve, a fourth pressure reducing valve, a fourth drain valve, a fifth pressure reducing valve, and a fifth drain valve connected to the control unit. The first pressure reducing valve and the first drain valve are both installed on the first drain pipe, the second pressure reducing valve and the second drain valve are both installed on the second drain pipe, the third pressure reducing valve and the third drain valve are both installed on the third drain pipe, the fourth pressure reducing valve and the fourth drain valve are both installed on the fourth drain pipe, and the fifth pressure reducing valve and the fifth drain valve are both installed on the fifth drain pipe.
[0011] Furthermore, each group of the sensing components includes a liquid level sensor and a temperature sensor connected to the control unit. The liquid level sensor and temperature sensor of the five groups of the sensing components are respectively disposed on the side walls of the first gas-liquid separator, the second gas-liquid separator, the first drying gas-liquid separator, and the second drying gas-liquid separator. The liquid level sensor includes an upper liquid level sensor and a lower liquid level sensor.
[0012] Furthermore, the oxygen separator is equipped with a pressure sensor.
[0013] A wastewater control method for a water electrolysis hydrogen production system employs a wastewater control system for the system. The specific steps of the control method are as follows:
[0014] S1. Calculate the liquid level drop height in the oxygen separator and hydrogen separator group, input the value into the control unit, and set the upper limit value of the sewage discharge in the oxygen separator and hydrogen separator group in the control unit. The control unit calculates the volume of gas separated by the oxygen separator and hydrogen separator group per unit time, the sewage discharge time and discharge rate of the oxygen separator and hydrogen separator group under the same working conditions based on the set upper limit value and the input liquid level drop height value. Then, the PID controller of the control unit maps the calculated data to the PWM module of the control unit.
[0015] Input the corresponding sewage discharge execution commands for the oxygen separator, the first gas-liquid separator, the second gas-liquid separator, the first drying gas-liquid separator, and the second drying gas-liquid separator into the control unit, assign the corresponding address number to the corresponding sewage discharge execution command, overlay and edit the corresponding address number into a single sewage discharge execution command, and then store the single sewage discharge execution command in the instruction register with variable function in the control unit;
[0016] S2. During sewage discharge, the control unit sends a command signal to the command register. Upon receiving the signal, the command register checks its current variable value. If the current variable value is 1, the command register sends a signal to the control unit. Upon receiving the signal, the control unit activates a query device to look up the address number corresponding to the variable value 1. The control unit then controls the actuator to execute the sewage discharge command corresponding to that address number. First, it queries the liquid level sensors on the oxygen separator, the first gas-liquid separator, the second gas-liquid separator, the first drying gas-liquid separator, or the second drying gas-liquid separator. When the liquid level values of the oxygen separator and hydrogen separator group exceed the set sewage discharge upper limit, the control unit's actuator queries the segment of a single sewage discharge command containing that address number, and the control unit's actuator executes the command for that segment.
[0017] The instructions for this section are as follows: The control unit adjusts the corresponding sewage discharge time according to the monitored current. The sewage discharge time adjustment delay buffer time is increased by 1 minute, and the sewage discharge time is automatically adjusted to t + 1min. After the adjustment is completed, the control unit will periodically monitor the liquid level values detected by the oxygen separator and hydrogen separator group, calculate the discharge rate corresponding to the sewage discharge valve based on the liquid level, and compare the monitored discharge rate with the set discharge rate. The control unit adjusts the opening degree of the corresponding sewage discharge valve and pressure reducing valve based on the comparison data, and controls the opening of the corresponding sewage discharge valve and pressure reducing valve so that the sewage in the corresponding oxygen separator and hydrogen separator group can be discharged through the corresponding sewage discharge pipe within the specified sewage discharge time. After the sewage discharge is completed, the control unit closes the corresponding sewage discharge valve and pressure reducing valve to end the sewage discharge, realizing single sewage discharge of a single separator in the oxygen separator and hydrogen separator group.
[0018] If the sewage discharge time exceeds the set sewage discharge limit during the sewage discharge process, the control unit will send a signal to the alarm device to issue an alarm prompt, and then manually determine whether there is an abnormality in the signal transmission of the corresponding liquid level sensor.
[0019] After the sewage discharge is completed, the variable value in the instruction register will automatically increment by 1, that is, the variable value in the instruction register will be 2 at this time; if the liquid level value does not exceed the set liquid level drop height value, that is, a single sewage discharge execution instruction will not be executed, and after the query is completed, the variable value in the instruction register will also automatically increment by 1, that is, the variable value in the instruction register will be 1+1, that is, the variable value in the instruction register will be 2 at this time.
[0020] According to the above control process, the query unit of the control unit queries the liquid level values on the liquid level sensors on the oxygen separator, the second gas-liquid separator, the first drying gas-liquid separator, and the second drying gas-liquid separator in sequence and decides whether to discharge sewage. If sewage discharge is required, sewage discharge is carried out according to the above-mentioned single sewage discharge execution command.
[0021] When the queryer of the control unit finds that the variable value in the instruction register is equal to the total amount of oxygen separator and hydrogen separator group, the control unit will initialize the variable value in the instruction register after executing the single discharge execution instruction, and the initial value of the variable value is 1, so that the control system continues to query and / or execute the single discharge execution instruction. Each time the control system is powered on again, the control unit will also initialize the variable value in the instruction register.
[0022] Furthermore, the calculation method for the emission rate in S1 is as follows: first, based on the ideal gas law... Where p is the gas pressure in Pa, V is the gas volume in m³, n is the gas molecular weight in mol, T is the gas temperature in K, and R is the molar gas constant with a value of 8.314. The ideal hydrogen gas equation under standard operating conditions can then be derived as follows: ①, and in the equation, P0 is the absolute pressure of the gas under standard operating conditions, and the pressure is 101325 Pa, T0 is the temperature of the gas under standard operating conditions, and the temperature is 273.15 K, and Q is the volume of hydrogen produced per unit time under standard operating conditions.
[0023] Then, according to the ideal gas law The ideal hydrogen gas equation under production conditions is derived as follows: ②, where P1—absolute gas pressure under production conditions, T1—gas temperature under production conditions, and V1—volume of hydrogen produced per unit time under production conditions.
[0024] Finally, based on ① and ②, the formula for calculating the volume of gas separated by the hydrogen separator group (2) per unit time under the same production conditions is: Where, V1—the volume of gas separated per unit time under the same operating conditions, I—the DC working current of electrons passing through the circuit during water electrolysis, n—the number of electrolysis cells corresponding to the electrolytic cell during water electrolysis, η—the utilization efficiency of the current, P0—the absolute pressure value of the gas under standard operating conditions, and this pressure value is 101325Pa, T0—the gas temperature under standard operating conditions, and this gas temperature is 273.15K, P1—the absolute pressure of the gas detected by the pressure sensor under the current production operating conditions, and T1—the gas temperature detected by the temperature sensor under the current production operating conditions.
[0025] The formula for the volume of oxygen produced by an oxygen separator under operating conditions: .
[0026] Furthermore, the formula for calculating the gas production volume per unit time under the standard operating conditions is as follows: The formula for calculating the hydrogen production volume per unit time under the standard operating conditions is: Where Q is the volume of hydrogen produced per unit time under standard operating conditions, I is the DC working current of electrons passing through the circuit during water electrolysis, n is the number of electrolysis cells corresponding to the electrolytic cell during water electrolysis, η is the current utilization efficiency, and 2390 is the theoretical amount of electricity required to produce 1 cubic meter of hydrogen.
[0027] Under standard operating conditions, the volume of oxygen produced per unit time by the oxygen separator is equal to Q / 2.
[0028] Furthermore, the calculation method for the liquid level drop height in the oxygen separator and hydrogen separator group in S1 is as follows: Where H is the height of the liquid level drop in the oxygen separator and hydrogen separator group per unit time, which is the rate of drop in the sewage level; V1 is the volume of oxygen or hydrogen produced per unit time under production conditions; and S1 is the bottom area of the oxygen separator and hydrogen separator group.
[0029] Furthermore, the formula for calculating the sewage discharge time of the oxygen separator and hydrogen separator group in S1 is as follows: t—drainage time, LT1—set upper drain level, LT2—set lower drain level, H—the height of liquid level drop in the oxygen separator and hydrogen separator group per unit time, which is the drain level drop rate.
[0030] The beneficial effects of the present invention are: the control system of the present invention can separate the hydrogen side and oxygen side sewage discharge, avoiding the problem of accidents caused by cross-contamination;
[0031] The interlocking settings and control methods of the control unit ensure that multiple separators sharing the same sewage outlet can only discharge sewage to one separator at a time. This ensures that each separator in the oxygen separator and hydrogen separator group can calculate the volume of gas produced by separation based on the set liquid level drop height. The sewage discharge duration and discharge rate of the sewage pipeline can be precisely controlled by calculating the liquid level drop height and the volume of gas produced by separation. This stabilizes the outlet pressure within a suitable range, avoiding the situation where multiple separators sharing the same sewage outlet apply for sewage discharge repeatedly, and preventing the problem of unstable system pressure caused by simultaneous sewage discharge impact. Attached Figure Description
[0032] To more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 This is an overall structural diagram of the sewage control system for the water electrolysis hydrogen production system of this invention;
[0034] Figure 2 This is a flowchart of a single discharge execution instruction for the hydrogen separator group in the discharge control system of the water electrolysis hydrogen production system of the present invention;
[0035] In the diagram, 1-Oxygen separator, 2-Hydrogen separator assembly, 3-First cooler, 4-Second cooler, 5-Control valve, 6-Sensing component, 7-First cooling pipe, 8-Second cooling pipe, 9-First conveying pipe, 10-First drain pipe, 12-Second drain pipe, 13-Third drain pipe, 14-Fourth drain pipe, 15-Fifth drain pipe, 16-Pressure sensor, 21-Hydrogen separator, 22-First gas-liquid separator. 23-Second gas-liquid separator, 24-First drying gas-liquid separator, 25-Second drying gas-liquid separator, 26-Third gas-liquid separator, 51-First pressure reducing valve, 52-First drain valve, 53-Second pressure reducing valve, 54-Second drain valve, 55-Third pressure reducing valve, 56-Third drain valve, 57-Fourth pressure reducing valve, 58-Fourth drain valve, 59-Fifth pressure reducing valve, 60-Fifth drain valve, 61-Level sensor, 62-Temperature sensor. Detailed Implementation
[0036] The technical solutions in the embodiments of the invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0037] The following will describe specific embodiments of the present invention and accompanying drawings. Figure 1-2 The present invention provides a detailed description of a wastewater discharge control system for a water electrolysis hydrogen production system, comprising an oxygen separator 1, a hydrogen separator group 2, a first cooler 3, a second cooler 4, several control valves 5, a sensing component 6, and a control unit. The oxygen separator 1 is equipped with a pressure sensor 16. The hydrogen separator group 2 consists of a hydrogen separator 21, a first gas-liquid separator 22, a second gas-liquid separator 23, a first drying gas-liquid separator 24, and a second drying gas-liquid separator 25. The hydrogen separator 21 is connected to the oxygen separator 1 via a pipeline. The control system separates the wastewater discharge from the hydrogen side and the oxygen side to avoid cross-contamination and potential accidents.
[0038] The first cooler 3 is connected to the oxygen separator 1 via the first cooling pipe 7. The first cooler 3 is also connected to the third gas-liquid separator 26 via a pipe. The outlet of the third gas-liquid separator 26 is connected to the first drain pipe 10. The second cooler 4 is connected to the hydrogen separator 21 via the second cooling pipe 8. The inlet of the first gas-liquid separator 22 is connected to the second cooler 4 via the first conveying pipe 9, and its outlet is connected to the second drain pipe 12.
[0039] The second gas-liquid separator 23 is connected to the second sewage pipe 12 via the third sewage pipe 13; the first drying gas-liquid separator 24 is connected to the second sewage pipe 12 via the fourth sewage pipe 14; and the second drying gas-liquid separator 25 is connected to the second sewage pipe 12 via the fifth sewage pipe 15.
[0040] Several control valves 5 are respectively installed on the first sewage pipe 10, the second sewage pipe 12, the third sewage pipe 13, the fourth sewage pipe 14 and the fifth sewage pipe 15, and are all connected to the control unit. There are five sets of sensing components 6, which are respectively installed on the side walls of the third gas-liquid separator 26, the first gas-liquid separator 22, the second gas-liquid separator 23, the first dry gas-liquid separator 24 and the second dry gas-liquid separator 25. The five sets of sensing components 6 are respectively connected to the control unit.
[0041] Several control valves 5 are respectively connected to the control unit: a first pressure reducing valve 51, a first drain valve 52, a second pressure reducing valve 53, a second drain valve 54, a third pressure reducing valve 55, a third drain valve 56, a fourth pressure reducing valve 57, a fourth drain valve 58, a fifth pressure reducing valve 59, and a fifth drain valve 60. The first pressure reducing valve 51 and the first drain valve 52 are both installed on the first drain pipe 10, the second pressure reducing valve 53 and the second drain valve 54 are both installed on the second drain pipe 12, the third pressure reducing valve 55 and the third drain valve 56 are both installed on the third drain pipe 13, the fourth pressure reducing valve 57 and the fourth drain valve 58 are both installed on the fourth drain pipe 14, and the fifth pressure reducing valve 59 and the fifth drain valve 60 are both installed on the fifth drain pipe 15.
[0042] The first pressure reducing valve 51, the second pressure reducing valve 53, the third pressure reducing valve 55, the fourth pressure reducing valve 57, and the fifth pressure reducing valve 59 are non-reversible valves, which can effectively prevent interference to other pipes that are not in a state of discharge when discharging sewage into a single sewage pipe, thereby improving the controllability of single sewage discharge.
[0043] Each set of sensing components 6 includes a liquid level sensor 61 and a temperature sensor 62 connected to the control unit. The liquid level sensor 61 includes an upper liquid level sensor and a lower liquid level sensor, which are respectively installed on the upper and lower parts of the first gas-liquid separator 22, the second gas-liquid separator 23, the first drying gas-liquid separator 24, and the second drying gas-liquid separator 25. The liquid level sensors 61 and temperature sensors 62 of the five sets of sensing components 6 are respectively set on the side walls of the first gas-liquid separator 22, the second gas-liquid separator 23, the first drying gas-liquid separator 24, and the second drying gas-liquid separator 25.
[0044] A wastewater control method for a water electrolysis hydrogen production system employs a wastewater control system for the system. The specific steps of the control method are as follows:
[0045] The liquid level drop height in oxygen separator 1 and hydrogen separator group 2 is calculated and input into the control unit. The upper limit value of sewage discharge in oxygen separator 1 and hydrogen separator group 2 is set in the control unit. The control unit calculates the volume of gas separated by oxygen separator 1 and hydrogen separator group 2 per unit time, sewage discharge time and discharge rate of oxygen separator 1 and hydrogen separator group 2 under the same working conditions based on the set upper limit value and the input liquid level drop height value. The calculated data is then mapped to the PWM module of the control unit through the PID controller of the control unit.
[0046] The emission rate is calculated using the ideal gas law. Where p is the gas pressure in Pa, V is the gas volume in m³, n is the gas molecular weight in mol, T is the gas temperature in K, and R is the molar gas constant with a value of 8.314. The ideal hydrogen gas equation under standard operating conditions can then be derived as follows: ①, and in the equation, P0 is the absolute pressure of the gas under standard operating conditions, and the pressure is 101325 Pa, T0 is the temperature of the gas under standard operating conditions, and the temperature is 273.15 K, and Q is the volume of hydrogen produced per unit time under standard operating conditions.
[0047] Then, according to the ideal gas law The ideal hydrogen gas equation under production conditions is derived as follows: ②, where P1—absolute gas pressure under production conditions, T1—gas temperature under production conditions, and V1—volume of hydrogen produced per unit time under production conditions.
[0048] Finally, based on ① and ②, the formula for calculating the volume of gas separated by hydrogen separator group 2 per unit time under the same production conditions is: Wherein, V1—the volume of gas separated per unit time under the same operating conditions, I—the DC working current of electrons passing through the circuit during water electrolysis, n—the number of electrolysis cells corresponding to the electrolytic cell during water electrolysis, η—the utilization efficiency of the current, P0—the absolute pressure value of the gas under standard operating conditions, and this pressure value is 101325Pa, T0—the gas temperature under standard operating conditions, and this gas temperature is 273.15K, P1—the absolute pressure of the gas detected by the pressure sensor under the current production operating conditions, and T1—the gas temperature detected by the temperature sensor 62 under the current production operating conditions;
[0049] Formula for the volume of oxygen produced by oxygen separator 1 under production conditions: .
[0050] The formula for calculating the gas production volume per unit time under standard operating conditions is as follows:
[0051] The formula for calculating the hydrogen production volume per unit time under standard operating conditions for hydrogen separator group 2 is as follows: Where Q is the volume of hydrogen produced per unit time under standard operating conditions, I is the DC working current of electrons passing through the circuit during water electrolysis, n is the number of electrolysis cells corresponding to the electrolytic cell during water electrolysis, η is the current utilization efficiency, and 2390 is the theoretical amount of electricity required to produce 1 cubic meter of hydrogen.
[0052] Under standard operating conditions, the volume of oxygen produced per unit time by oxygen separator 1 is equal to Q / 2.
[0053] The calculation method for the liquid level drop height in oxygen separator 1 and hydrogen separator group 2: Where H is the height of the liquid level drop in oxygen separator 1 and hydrogen separator group 2 per unit time, which is the rate of drop in the sewage level; V1 is the volume of oxygen or hydrogen produced per unit time under production conditions; and S1 is the bottom area of oxygen separator 1 and hydrogen separator group 2.
[0054] The formula for calculating the sewage discharge time of oxygen separator 1 and hydrogen separator group 2 in S1 is as follows: t—drainage time, LT1—set upper drain level, LT2—set lower drain level, H—the height of liquid level drop in oxygen separator 1 and hydrogen separator group 2 per unit time, which is the drain level drop rate.
[0055] Next, the corresponding sewage discharge execution commands for oxygen separator 1, first gas-liquid separator 22, second gas-liquid separator 23, first dry gas-liquid separator 24 and second dry gas-liquid separator 25 are input into the control unit, and the corresponding sewage discharge execution commands are assigned corresponding address numbers. The corresponding address numbers are superimposed and edited into a single sewage discharge execution command, and then the single sewage discharge execution command is stored in the instruction register with variable function in the control unit.
[0056] During sewage discharge, the control unit sends a command signal to the command register. Upon receiving the signal, the command register checks its current variable value. If the current variable value is 1, the command register sends a signal to the control unit. The control unit, upon receiving the signal, activates a query device to look up the address number corresponding to the variable value 1. The control unit then controls the actuator to execute the sewage discharge command corresponding to that address number. First, it queries the values detected by the level sensor 61 on oxygen separator 1, the first gas-liquid separator 22, the second gas-liquid separator 23, the first drying gas-liquid separator 24, or the second drying gas-liquid separator 25. When the queried level values of oxygen separator 1 and hydrogen separator group 2 exceed the set sewage discharge upper limit, the control unit's actuator queries the segment of a single sewage discharge execution command containing that address number, and executes the command for that segment.
[0057] The instructions for this section are as follows: The control unit adjusts the corresponding sewage discharge time according to the monitored current. The sewage discharge time adjustment delay buffer time is increased by 1 minute, and the sewage discharge time is automatically adjusted to t + 1min. After the adjustment is completed, the control unit will periodically monitor the liquid level values detected by oxygen separator 1 and hydrogen separator group 2, and calculate the discharge rate corresponding to the sewage discharge valve based on the liquid level. The control unit compares the monitored discharge rate with the set discharge rate. Based on the comparison data, the control unit adjusts the opening degree of the corresponding sewage discharge valve and pressure reducing valve, and controls the opening of the corresponding sewage discharge valve and pressure reducing valve, so that the sewage in the corresponding oxygen separator 1 and hydrogen separator group 2 can be discharged through the corresponding sewage discharge pipe within the specified sewage discharge time. After the sewage discharge is completed, the control unit closes the corresponding sewage discharge valve and pressure reducing valve to end the sewage discharge, realizing single sewage discharge of a single separator in oxygen separator 1 and hydrogen separator group 2.
[0058] If the sewage discharge time exceeds the set sewage discharge limit during the sewage discharge process, the control unit will send a signal to the alarm device to issue an alarm prompt, and then manually determine whether there is an abnormality in the signal transmission of the corresponding liquid level sensor 61.
[0059] The setting of a sewage discharge duration monitoring system prevents one separator from taking too long to discharge sewage, which could affect the sewage discharge of other separators and seriously impact the overall hydrogen production efficiency of the hydrogen production system. The system also uses an alarm issued by the control unit to remind personnel to take action, thereby improving the monitorability and safety of the hydrogen production system.
[0060] After the sewage discharge is completed, the variable value in the instruction register will automatically increment by 1, that is, the variable value in the instruction register will be 2 at this time; if the liquid level value does not exceed the set sewage discharge upper limit, that is, a single sewage discharge execution instruction will not be executed, and the variable value in the instruction register will also automatically increment by 1 after the query is completed, that is, the variable value in the instruction register will be 1+1, that is, the variable value in the instruction register will be 2 at this time.
[0061] According to the above control process, the query unit of the control unit queries the liquid level values on the liquid level sensor 61 on the oxygen separator 1, the second gas-liquid separator 23, the first dry gas-liquid separator 24 and the second dry gas-liquid separator 25 in sequence and decides whether to discharge sewage. If sewage discharge is required, sewage discharge is carried out according to the above single sewage discharge execution command.
[0062] When the query function of the control unit finds that the variable value in the instruction register is equal to the total amount of oxygen separator 1 and hydrogen separator group 2, the control unit will initialize the variable value in the instruction register after executing the single discharge execution instruction. The initial value of the variable value is 1, so that the control system continues to query and / or execute the single discharge execution instruction. The control unit will also initialize the variable value in the instruction register each time the control system is powered on again.
[0063] In this embodiment, the control unit controls the oxygen separator 1 and the hydrogen separator group 2 separately, separating the oxygen and hydrogen effluent discharges. This effectively avoids the problem of gas cross-contamination that could lead to accidents.
[0064] When the oxygen separator 1 is drained, the control unit will determine whether to adjust the opening of the first pressure reducing valve 51 and the first drain valve 52 on the first drain pipe 10 based on the signal fed back by the liquid level sensor 61 on the oxygen separator 1, and at the same time determine whether to open or close.
[0065] When the hydrogen separator group 2 is drained, the actuator of the control unit executes a single drain execution command, thereby sequentially querying the corresponding liquid level sensors 61 on the hydrogen separator 21, the first gas-liquid separator 22, the second gas-liquid separator 23, the first dry gas-liquid separator 24, and the second dry gas-liquid separator 25, and determining whether to drain based on the query results. During the sequential query, the separator whose liquid level value fed back by the liquid level sensor 61 exceeds the set drain upper limit value is drained. The control unit then controls the corresponding drain pipe to drain. If the hydrogen separator 21 and / or the first gas-liquid separator 22 is drained, the control unit adjusts the opening of the second pressure reducing valve 53 and the second drain valve 54 on the second drain pipe 12 according to the calculated discharge rate, so that the dirt of the hydrogen separator 21 and / or the first gas-liquid separator 22 is discharged from the second drain pipe 12.
[0066] If the second gas-liquid separator 23 is to be discharged, the control unit adjusts the opening of the third pressure reducing valve 55 and the third discharge valve 56 on the third discharge pipe 13 according to the calculated discharge rate, and discharges the sewage from the third discharge pipe 13 to the second discharge pipe 12 and then discharges it.
[0067] If the first dry gas-liquid separator 24 is drained, the control unit adjusts the opening of the fourth pressure reducing valve 57 and the fourth drain valve 58 on the fourth drain pipe 14 according to the calculated discharge rate, and discharges the waste from the fourth drain pipe 14 to the second drain pipe 12 and then discharges it.
[0068] If the second dry gas-liquid separator 25 is to be drained, the control unit adjusts the opening of the fifth pressure reducing valve 59 and the fifth drain valve 60 on the fifth drain pipe 15 according to the calculated discharge rate, and discharges the waste from the fifth drain pipe 15 to the second drain pipe 12 and then discharges it.
[0069] The interlocking settings and control methods of the control unit ensure that multiple separators sharing the same sewage outlet can only discharge sewage to one separator at a time. This ensures that each separator in oxygen separator 1 and hydrogen separator group 2 can calculate the volume of gas produced based on the set liquid level drop height. The sewage discharge duration and discharge rate of the sewage pipeline can be precisely controlled by calculating the liquid level drop height and the volume of gas produced, thus stabilizing the drain outlet pressure within a suitable range. This avoids the situation where multiple separators sharing the same sewage outlet repeatedly apply for sewage discharge, and prevents the problem of unstable system pressure caused by simultaneous sewage discharge impact.
[0070] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.
Claims
1. A wastewater control system for a water electrolysis hydrogen production system, characterized in that, The system includes an oxygen separator (1), a hydrogen separator group (2), a first cooler (3), a second cooler (4), several control valves (5), a sensing component (6), and a control unit. The hydrogen separator group (2) consists of a hydrogen separator (21), a first gas-liquid separator (22), a second gas-liquid separator (23), a first drying gas-liquid separator (24), and a second drying gas-liquid separator (25). The hydrogen separator (21) is connected to the oxygen separator (1) via a pipe. The first cooler (3) is connected to the oxygen separator (1) via a first cooling pipe (7). The first cooler (3) is connected to a third gas-liquid separator (26) via a pipe. The outlet of the third gas-liquid separator (26) is connected to a first sewage pipe (10). The second cooler (4) is connected to the hydrogen separator (21) via a second cooling pipe (8). The inlet of the first gas-liquid separator (22) is connected to the second cooler (4) via a first conveying pipe (9), and the outlet is connected to a second drain pipe (12). The second gas-liquid separator (23) is connected to the second sewage pipe (12) via the third sewage pipe (13), the first drying gas-liquid separator (24) is connected to the second sewage pipe (12) via the fourth sewage pipe (14), and the second drying gas-liquid separator (25) is connected to the second sewage pipe (12) via the fifth sewage pipe (15). Several control valves (5) are respectively installed on the first sewage pipe (10), the second sewage pipe (12), the third sewage pipe (13), the fourth sewage pipe (14) and the fifth sewage pipe (15), and are all connected to the control unit. There are five sets of sensing components (6) respectively installed on the side walls of the third gas-liquid separator (26), the first gas-liquid separator (22), the second gas-liquid separator (23), the first dry gas-liquid separator (24) and the second dry gas-liquid separator (25). The five sets of sensing components (6) are respectively connected to the control unit.
2. The wastewater control system for a water electrolysis hydrogen production system according to claim 1, characterized in that, The control valves (5) are respectively a first pressure reducing valve (51), a first drain valve (52), a second pressure reducing valve (53), a second drain valve (54), a third pressure reducing valve (55), a third drain valve (56), a fourth pressure reducing valve (57), a fourth drain valve (58), a fifth pressure reducing valve (59), and a fifth drain valve (60) connected to the control unit. The first pressure reducing valve (51) and the first drain valve (52) are both installed on the first drain pipe (10), the second pressure reducing valve (53) and the second drain valve (54) are both installed on the second drain pipe (12), the third pressure reducing valve (55) and the third drain valve (56) are both installed on the third drain pipe (13), the fourth pressure reducing valve (57) and the fourth drain valve (58) are both installed on the fourth drain pipe (14), and the fifth pressure reducing valve (59) and the fifth drain valve (60) are both installed on the fifth drain pipe (15).
3. The wastewater control system for a water electrolysis hydrogen production system according to claim 1, characterized in that, Each of the sensing components (6) includes a liquid level sensor (61) and a temperature sensor (62) connected to the control unit. The liquid level sensor (61) and temperature sensor (62) of the five sets of sensing components (6) are respectively disposed on the side walls of the first gas-liquid separator (22), the second gas-liquid separator (23), the first drying gas-liquid separator (24), and the second drying gas-liquid separator (25). The liquid level sensor (61) includes an upper liquid level sensor and a lower liquid level sensor.
4. The wastewater control system for a water electrolysis hydrogen production system according to claim 1, characterized in that, The oxygen separator (1) is equipped with a pressure sensor (16).
5. A method for controlling wastewater discharge in a water electrolysis hydrogen production system, characterized by employing the wastewater discharge control system for a water electrolysis hydrogen production system according to any one of claims 1-4, wherein... The specific steps of the control method are as follows: S1. Calculate the liquid level drop height of the liquid phase in the oxygen separator (1) and the hydrogen separator group (2), and input the value into the control unit. Set the upper limit value of the sewage discharge in the oxygen separator (1) and the hydrogen separator group (2) in the control unit. The control unit calculates the volume of gas separated by the oxygen separator (1) and the hydrogen separator group (2) under the same working condition, the sewage discharge time and the discharge rate of the oxygen separator (1) and the hydrogen separator group (2) under the same working condition based on the set upper limit value and the input liquid level drop height value. Then, the calculated data is mapped to the PWM module of the control unit through the PID controller of the control unit. Input the corresponding sewage discharge execution instructions for oxygen separator (1), first gas-liquid separator (22), second gas-liquid separator (23), first dry gas-liquid separator (24) and second dry gas-liquid separator (25) into the control unit, assign the corresponding address number to the corresponding sewage discharge execution instruction, overlay and edit the corresponding address number into a single sewage discharge execution instruction, and then store the single sewage discharge execution instruction in the instruction register with variable function in the control unit; S2. During sewage discharge, the control unit sends an instruction signal to the instruction register. After receiving the signal, the instruction register checks the current variable value. If the current variable value is 1, the instruction register sends a signal to the control unit. After receiving the signal, the control unit starts the query device to query the address number corresponding to the variable value 1. The control unit controls the actuator to execute the sewage discharge execution command corresponding to the address number. First, the execution command queries the values detected by the liquid level sensor (61) on the oxygen separator (1), the first gas-liquid separator (22), the second gas-liquid separator (23), the first drying gas-liquid separator (24), or the second drying gas-liquid separator (25). When the liquid level values of the oxygen separator (1) and the hydrogen separator group (2) exceed the set sewage discharge upper limit, the actuator of the control unit queries the segment of the single sewage discharge execution command where the address number is located, and the actuator of the control unit executes the command of that segment. The instructions in this section are as follows: The control unit adjusts the corresponding sewage discharge time according to the monitored current. The sewage discharge time adjustment delay buffer time is increased by 1 minute, and the sewage discharge time is automatically adjusted to t + 1min. After the adjustment is completed, the control unit will monitor the liquid level values detected by the oxygen separator (1) and the hydrogen separator group (2) at intervals, calculate the discharge rate corresponding to the sewage discharge valve according to the liquid level, and compare the monitored discharge rate with the set discharge rate. The control unit adjusts the opening degree of the corresponding sewage discharge valve and pressure reducing valve according to the comparison data, and controls the opening of the corresponding sewage discharge valve and pressure reducing valve so that the sewage in the corresponding oxygen separator (1) and hydrogen separator group (2) can be discharged through the corresponding sewage discharge pipe within the specified sewage discharge time. After the sewage discharge is completed, the control unit closes the corresponding sewage discharge valve and pressure reducing valve to end the sewage discharge, so as to realize the single sewage discharge of a single separator in the oxygen separator (1) and hydrogen separator group (2). If the sewage discharge time exceeds the set sewage discharge limit during the sewage discharge process, the control unit will send a signal to the alarm device to issue an alarm prompt, and then manually determine whether there is an abnormality in the signal transmission of the corresponding liquid level sensor (61). After the sewage discharge is completed, the variable value in the instruction register will automatically increment by 1, that is, the variable value in the instruction register will be 2 at this time; if the liquid level value does not exceed the set sewage discharge upper limit, that is, a single sewage discharge execution instruction will not be executed, and the variable value in the instruction register will also automatically increment by 1 after the query is completed, that is, the variable value in the instruction register will be 1+1, that is, the variable value in the instruction register will be 2 at this time. According to the above control process, the query unit of the control unit queries the liquid level values on the liquid level sensor (61) on the oxygen separator (1), the second gas-liquid separator (23), the first dry gas-liquid separator (24), and the second dry gas-liquid separator (25) in sequence and decides whether to discharge sewage. If sewage discharge is required, sewage discharge is carried out according to the above single sewage discharge execution command. When the query function of the control unit finds that the variable value of the instruction register is equal to the total amount of the oxygen separator (1) and the hydrogen separator group (2), the control unit will initialize the variable value of the instruction register after executing the single discharge execution instruction, and the initial value of the variable value is 1, so that the control system continues to query and / or execute the single discharge execution instruction. Each time the control system is powered on again, the control unit will also initialize the variable value of the instruction register.
6. The wastewater control method for a water electrolysis hydrogen production system according to claim 5, characterized in that, The method for calculating the emission rate in S1 is as follows: first, based on the ideal gas law... Where p is the gas pressure in Pa, V is the gas volume in m³, n is the gas molecular weight in mol, T is the gas temperature in K, and R is the molar gas constant with a value of 8.
314. The ideal hydrogen gas equation under standard operating conditions can then be derived as follows: ①, and in the equation, P0 is the absolute pressure of the gas under standard operating conditions, and the pressure is 101325 Pa, T0 is the temperature of the gas under standard operating conditions, and the temperature is 273.15 K, and Q is the volume of hydrogen produced per unit time under standard operating conditions. Then, according to the ideal gas law The ideal hydrogen gas equation under production conditions is derived as follows: ②, where P1—absolute gas pressure under production conditions, T1—gas temperature under production conditions, and V1—volume of hydrogen produced per unit time under production conditions. Finally, based on ① and ②, the formula for calculating the volume of gas separated by the hydrogen separator group (2) per unit time under the same production conditions is: , where V1—the volume of gas separated per unit time under the same working conditions, I—the DC working current of electrons passing through the circuit during water electrolysis, n—the number of electrolysis cells corresponding to the electrolytic cell during water electrolysis, η—the utilization efficiency of the current, P0—the absolute pressure value of the gas under standard working conditions, and the pressure value is 101325Pa, T0—the gas temperature under standard working conditions, and the gas temperature is 273.15K, P1—the absolute pressure of the gas detected by the pressure sensor under the current production working conditions, T1—the gas temperature detected by the temperature sensor (62) under the current production working conditions; Formula for the volume of oxygen produced by the oxygen separator (1) under production conditions: .
7. The wastewater control method for a water electrolysis hydrogen production system according to claim 6, characterized in that, The formula for calculating the gas production volume per unit time under the standard operating conditions is as follows: The formula for calculating the hydrogen production volume per unit time under standard operating conditions for the hydrogen separator group (2) is as follows: Where Q is the volume of hydrogen produced per unit time under standard operating conditions, I is the DC working current of electrons passing through the circuit during water electrolysis, n is the number of electrolysis cells corresponding to the electrolytic cell during water electrolysis, η is the current utilization efficiency, and 2390 is the theoretical amount of electricity required to produce 1 cubic meter of hydrogen. The oxygen separator (1) produces a volume of oxygen per unit time under standard operating conditions equal to Q / 2.
8. The wastewater control method for a water electrolysis hydrogen production system according to claim 5, characterized in that, The calculation method for the liquid level drop height in the oxygen separator (1) and hydrogen separator group (2) in S1 is as follows: H is the height of the liquid level drop in the oxygen separator (1) and hydrogen separator group (2) per unit time, which is the rate of drop in the sewage level. V1 is the volume of oxygen or hydrogen produced per unit time under production conditions. S1 is the bottom area of the oxygen separator (1) and hydrogen separator group (2).
9. A wastewater control method for a water electrolysis hydrogen production system according to claim 8, characterized in that, The formula for calculating the sewage discharge time of the oxygen separator (1) and hydrogen separator group (2) in S1 is as follows: t—drainage time, LT1—set upper drain level, LT2—set lower drain level, H—the height of the liquid level drop in the oxygen separator (1) and hydrogen separator group (2) per unit time, which is the drain level drop rate.