KR102495268B1 - Apparatus and method for water electrolysis evaluation - Google Patents

Abstract

a supply and circulation unit supplying water or an aqueous solution to the water electrolysis device and circulating, purifying, and discharging the discharged water discharged from the water electrolysis device to the outside; a current and/or voltage efficiency evaluation unit connected to the water electrolysis device to evaluate current and/or voltage efficiency of the water electrolysis device; and a flow rate or characteristic evaluation unit for evaluating the flow rate or characteristics of oxygen gas or hydrogen gas in the discharged product; a water electrolysis evaluation device and a water electrolysis evaluation method using the same are disclosed. According to this, not only the voltage efficiency, which is a representative performance index of water electrolysis, but also the flow of hydrogen and oxygen generated during water electrolysis are measured in real time to measure the amount of generated gas compared to the amount of current applied in real time, resulting in more precise performance of water electrolysis. can measure In addition, it is possible to safely operate the water electrolysis device without causing an explosion or the like. In addition, it is possible to reliably evaluate the performance of the water electrolyzer even in load fluctuations that inevitably accompany green hydrogen production. In addition, since a unit measuring device for measuring various characteristics or indicators required for water electrolysis evaluation can be modularized and installed, the applicability is excellent in various use environments.

Description

Apparatus and method for water electrolysis evaluation}

The present specification relates to a water electrolysis evaluation apparatus and method, and more particularly, to a water electrolysis performance and safety evaluation apparatus and method capable of evaluating safety as well as performance of a water electrolysis apparatus.

The present invention was carried out under the support of the following research and development projects.

(1) 2021 National Innovation Cluster Fostering (Non-R&D) Project "Development of Highly Reliable Basic Type Electrolysis Evaluation System" Project

(2) "Development of porous hybrid separator for alkaline water electrolysis coated with fluorine resin for ion exchange" of Small and Medium Business Technology Innovation Development Project (market response type) [Task number: S2848983, task management (specialized) institution name: Small and Medium Business Technology Information Agency, task Executing organization name: Sukyung Chemical Co., Ltd., research period: July 16, 2020 ~ July 15, 2022]

Hydrogen generated using water electrolysis is produced through electrolysis of water, and high-purity hydrogen and oxygen can be obtained. Future growth is expected due to the shift from gray hydrogen (reformed hydrogen) to green hydrogen due to carbon neutral policies.

The core of water electrolysis technology for green hydrogen production is to enable stable hydrogen production even under load fluctuation conditions of renewable energy that rapidly changes according to changes in sunlight conditions, such as solar or wind power.

Therefore, cell material development and system control are required for this. Accurate data must be secured in the water electrolysis cell development stage to manufacture a reliable cell, and for this purpose, it is necessary to accurately and reliably evaluate the performance of the water electrolysis device.

Conventionally, equipment for evaluating the performance of a fuel cell is known, but a device for evaluating the performance of a water electrolysis device is still in need of development.

Patent Document 1: Korean Patent Registration No. 2168378

In exemplary embodiments of the present invention, in one aspect, the amount of generated gas compared to the amount of current applied by measuring the flow of “hydrogen and oxygen” generated during water electrolysis in real time as well as measuring voltage efficiency, which is a representative performance indicator of water electrolysis. It is intended to provide a water electrolysis evaluation apparatus and method capable of measuring the performance of water electrolysis more precisely by measuring in real time.

In exemplary embodiments of the present invention, in another aspect, water electrolysis evaluation, which can reliably evaluate the performance of the water electrolysis device even in load fluctuation situations and enable the safe operation of the water electrolysis device without occurrence of explosion or the like. It is intended to provide an apparatus and method.

In exemplary embodiments of the present invention, in another aspect, since a unit measuring device for measuring various characteristics or indicators required for water electrolysis evaluation can be modularized and installed, applicability is excellent in various use environments, It is intended to provide a water electrolysis evaluation device and method.

In exemplary embodiments of the present invention, in a water electrolysis evaluation device, water or an aqueous solution is supplied to the water electrolysis device, and discharged from the water electrolysis device is circulated to the water electrolysis device, purified, and discharged to the outside. supply and circulation; a current and/or voltage efficiency evaluation unit connected to the water electrolysis device to evaluate current and/or voltage efficiency of the water electrolysis device; and a flow rate or characteristic evaluation unit for evaluating the flow rate or characteristics of oxygen gas or hydrogen gas in the discharged product.

In exemplary embodiments of the present invention, there is also a water electrolysis evaluation method, comprising the steps of supplying water or an aqueous solution to a water electrolysis device, circulating, purifying, and discharging an effluent discharged from the water electrolysis device to the outside; Evaluating current and/or voltage efficiency of the water electrolysis device by being connected to the water electrolysis device; And evaluating the flow rate or characteristics of oxygen gas or hydrogen gas in the discharged product; it provides a water electrolysis evaluation method comprising a.

According to exemplary embodiments of the present invention, voltage efficiency, which is a representative performance indicator of water electrolysis, is measured as well as flow of hydrogen and oxygen generated during water electrolysis in real time, so that the amount of generated gas relative to the amount of applied current is measured in real time. It is possible to measure the performance of water electrolysis more precisely by measuring with In addition, it is possible to safely operate the water electrolysis device without causing an explosion or the like.

In addition, it is possible to reliably evaluate the performance of the water electrolyzer even in load fluctuations that inevitably accompany green hydrogen production.

In addition, since a unit measuring device for measuring various characteristics or indicators required for water electrolysis evaluation can be modularized and installed, the applicability is excellent in various use environments.

1 is a schematic diagram showing the configuration and method of a water electrolysis evaluation apparatus of exemplary embodiments of the present invention.
2A is a schematic diagram showing a water electrolysis evaluation apparatus in an exemplary embodiment of the present invention. 2B to 2E are schematic diagrams illustrating a water electrolysis device used in an exemplary embodiment of the present invention.
3 is a schematic diagram showing a sensor module that can be installed in a water electrolysis evaluation device in an exemplary embodiment of the present invention.
4A and 4B are example screens showing the configuration and operation of the water electrolysis evaluation device on the display screen displayed on the top of the water electrolysis evaluation device in an exemplary embodiment of the present invention.
5 is a flow chart showing a safety control algorithm in an exemplary implementation of the present invention.
6 is a graph showing current density (FIG. 6a) and voltage change over time (FIG. 6b) while applying current to a water electrolysis single cell (reaction area 25 cm ² ) in Experiment 1 of the present invention.
7 is a graph in which current is applied to a polymer electrolyte water electrolysis single cell (reaction area 25 cm ² ) and the reaction cell voltage is measured by simulating actual Jeju Island wind power generation data according to capacity in Experiment 2 of the present invention.
8 is a graph obtained by measuring in real time the hydrogen flow rate generated by applying current to a polymer electrolyte water electrolysis single cell (reaction area 25 cm ² ) by simulating wind power generation data according to capacity in Experiment 3 of the present invention.
9 is a graph of real-time measurement of the hydrogen flow rate and hydrogen concentration in oxygen generated while applying current to a polymer electrolyte water electrolysis single cell (reaction area 25 cm ² ) by simulating wind power generation data according to capacity in Experiment 4 of the present invention am.
10 is a graph of the results of cross-verification of the current-voltage performance curve of the same polyelectrolyte water electrolysis single cell (reaction area of 25 cm ² ) in Experiment 5 of the present invention with other cells in two institutions.

In this specification, emission refers to oxygen or hydrogen discharged from a water electrolyzer; Or it is meant to include unreacted water or aqueous solution that can be discharged together with oxygen or hydrogen.

In the present specification, oxygen-containing emissions include oxygen alone or oxygen and unreacted water or aqueous solution.

In the present specification, the oxygen gas may further include unreacted water or an aqueous solution in addition to oxygen alone.

In the present specification, emission containing hydrogen means hydrogen alone or hydrogen and unreacted water or aqueous solution.

In the present specification, hydrogen gas may further include unreacted water or an aqueous solution in addition to hydrogen alone.

In the present specification, unreacted water or aqueous solution means water or aqueous solution that is not electrolyzed and remains after electrolysis in a water electrolysis device.

In this specification, water may mean pure water.

An aqueous solution herein may refer to an aqueous alkali solution.

Measuring the flow rate of oxygen and/or hydrogen herein may include measuring the flow rate of an oxygen-containing effluent (or oxygen gas) and/or a hydrogen-containing effluent (or hydrogen gas).

Purification herein means removing hydrogen from an oxygen effluent or oxygen gas, or removing oxygen from a hydrogen effluent or hydrogen gas.

In the present specification, characteristics may mean including evaluation of the presence or content (concentration) of hydrogen in oxygen gas, or evaluation of the presence or content (concentration) of oxygen in hydrogen gas.

In the present specification, when a part "includes" a certain component, it means that it may further include other components, not excluding other components unless otherwise stated.

In this specification, 1 channel means a case of evaluating a single water electrolysis device.

In this specification, two-channel refers to a case of evaluating two water electrolyzers.

Hereinafter, exemplary implementations of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram showing the configuration and method of a water electrolysis evaluation apparatus of exemplary embodiments of the present invention.

As shown in FIG. 1, the water electrolysis evaluation device of an exemplary embodiment supplies water or an aqueous solution (W) to a water electrolysis device 100 that electrolyzes water or an aqueous solution (W) such as pure water or an aqueous alkali solution, and a supply and circulation unit that circulates, purifies, and discharges oxygen emission or hydrogen emission from the water electrolysis device 100 to the outside; a current and/or voltage efficiency evaluation unit connected to the water electrolysis device 100 to evaluate current and/or voltage efficiency; and a flow rate or characteristic evaluation unit for evaluating the flow rate or characteristics of oxygen gas or hydrogen gas in the discharged product.

The supply and circulation unit includes a supply pipe 211 and a tank 200 for supplying water or an aqueous solution (W) to the water electrolysis device 100, and a discharge pipe for discharging discharged water discharged from the water electrolysis device 100 ( 230), a chiller or cooler 300, and a gas-liquid separator 400.

In the tank 200, the exhaust gas enters, oxygen gas or hydrogen gas is discharged upward, and unreacted water or aqueous solution may be circulated back to the water electrolysis device 100.

The flow rate and characteristic evaluation unit may include flow meters for evaluating the flow rate of oxygen gas and/or hydrogen gas in the discharged product, or a measuring device for measuring the dew point, or whether hydrogen is mixed in the oxygen discharged product or the oxygen gas side, or hydrogen It may include various sensors (S1, S2, ..., Sn) that evaluate whether oxygen is mixed in the emission or hydrogen gas side.

A pump or a filter may be connected to the piping in the above drawings, if necessary.

More specifically, the water or aqueous solution (W) is provided to the tank 200 through the pipe 210 by a pump (not shown), and from the tank 200 through the inlet pipe 211 It passes through the inlet 101 of the water electrolysis device 100 and flows into the water electrolysis device 100. After undergoing water electrolysis in the water electrolysis device 100 , oxygen gas or oxygen emission is discharged from the outlet 102 and flows back into the tank 200 through the discharge pipe 230 .

The tank 200 may include a heater such as a line heater therein. Since the oxygen emission may include unreacted water or an aqueous solution (W) in addition to pure oxygen, the oxygen emission is introduced back into the tank 200, and then the unreacted water or aqueous solution (W) is caught and passed through the lower side of the tank 200. Through this, it is circulated back to the water electrolysis device 100 and used, and oxygen gas comes out through the upper side of the tank 200.

Since moisture may still be included in the oxygen gas in this case, moisture is removed while being cooled by passing through a second chiller or cooler 300 for heat exchange. Thereafter, moisture is completely removed once again while passing through the gas-liquid separator 400 including a demister such as silica, and only pure oxygen can be discharged, and then flowmeters and various sensors (S1, S2, ..., Sn ) to measure the flow rate and characteristics of the oxygen gas discharged while passing through it.

At this time, in particular, whether or not hydrogen is included in the oxygen gas is measured together.

On the other hand, through the hydrogen outlet 103 of the water electrolysis device 100, the hydrogen-containing discharge passes through the pipe 230 and passes through the chiller or cooler 300 or the gas-liquid separator 400 like oxygen, and unreacted water or aqueous solution Measure the flow rate and characteristics of the hydrogen gas discharged while passing through the flow meter and various sensors (S1, S2, ..., Sn).

At this time, in particular, whether oxygen is included in hydrogen gas is measured.

As described above, by measuring whether hydrogen is contained in oxygen gas and/or the degree thereof, or whether oxygen is contained in hydrogen gas and/or the degree thereof is measured, it is possible to prevent explosion and control risk factors of driving in advance. there is.

Meanwhile, the water electrolysis device 100 may be in the form of a water electrolysis cell or an assembly consisting of a stack.

The water electrolysis device 100 may be a PEM water electrolysis device or an alkaline water electrolysis device. In the case of PEM, water (a concept including pure water) is provided, and in the case of an alkaline water electrolysis device, an alkaline aqueous solution such as KOH aqueous solution may be provided.

In exemplary embodiments of the present invention, a specific device configuration is different depending on whether the water electrolysis device 100 is a PEM water electrolysis device, an alkaline water electrolysis device, or a hybrid type of PEM and alkaline water electrolysis device. It is detailed below.

In the case of PEM water electrolysis

First, in the case of PEM water electrolysis, as described with reference to FIG. 1 , a method (one-channel method) of connecting one tank 200 to one water electrolysis device 100 may be used. Here, when the number of water electrolyzers 100 is two or more, the same one-channel configuration can be made into a plurality (ie, two or more channels) corresponding to the number of water electrolyzers 100 . In the case of PEM water electrolysis, the hydrogen gas generated through the water electrolysis reaction does not enter the tank 200 again, but is discharged through the chiller or cooler 300 and the gas-liquid separator 400 as described above.

In the case of alkaline water electrolysis

In the case of alkaline water electrolysis, unlike FIG. 1, two tanks 200 are connected to one water electrolysis device 100, and an aqueous alkaline solution is supplied from the two tanks 200 to one water electrolysis device 100. (1 channel method).

Even here, when the number of water electrolytic devices 100 is two or more, the above-described one-channel configuration can be made plural (ie, two or more channels) to correspond to the number of water electrolyzers 100 .

In addition, the oxygen discharge or oxygen gas discharge portion is the same as in FIG. 1, but in the case of hydrogen discharge or hydrogen gas discharge, unlike FIG. Hydrogen gas entering 200 and primarily removing the unreacted aqueous alkaline solution is discharged through the aforementioned chiller or cooler 300 and the gas-liquid separator 400.

For PEM and Alkaline Hybrid Water Electrolysis

In the apparatus of exemplary embodiments of the present invention, it can be configured to allow evaluation of alkaline and polymer electrolyte water electrolysis cells, and each of the two channels can be assigned to a desired type of water electrolysis cell and operated simultaneously.

That is, as described above, in addition to evaluating PEM water electrolysis with 1 channel (or 2 channels) and evaluating alkaline water electrolysis with 1 channel (or 2 channels) (or simultaneous evaluation), 2 channels are evaluated as PEM and alkaline. It can be configured as a hybrid.

In particular, in the case of a hybrid configuration, an auxiliary tank of a smaller size, for example, an auxiliary tank of about 1/2 volume, separate from a tank designed to supply electrolyte (or water) in the evaluation device and separate generated oxygen and hydrogen from the electrolyte. Connect more auxiliary tanks in series. In this way, the same pair can be connected in parallel so that two channels can be used without distinguishing between alkaline and PEM.

More specifically, in the general 1-channel or 2-channel water electrolysis evaluation device, water supply of the water electrolysis device (ie, two cells) and hydrogen/oxygen pipelines generated during the water electrolysis reaction are connected together. Therefore, even with two channels, it is possible to evaluate the water electrolysis performance of two water electrolyzers (two cells) during simultaneous water electrolysis operation, but it is impossible to quantitatively analyze the gas generated from each water electrolysis device (each cell). There is a downside to that.

In addition, since the aqueous solutions used in PEM (Proton Exchange Membrane) type water electrolysis and alkaline water electrolysis are pure/alkaline aqueous solutions, they cannot be used simultaneously.

Therefore, by constructing a hybrid two-channel type including an auxiliary tank as described above (see FIG. 4B to be described later), the above problem can be solved, and the water electrolysis of several water electrolysis devices (water electrolysis cells) in one evaluation device. It can effectively analyze the entire cycle and simultaneously analyze PEM and alkaline water electrolysis.

2A is a schematic diagram showing a water electrolysis evaluation apparatus in an exemplary embodiment of the present invention. For clarity, in FIG. 2a , the water electrolysis evaluation device is shown except for the pipe line.

As shown in FIG. 2A , the exemplary water electrolysis evaluation apparatus 1000 has an upper and lower structure. The upper part consists of a first box containing a display (D) and a control device and a table part in front of it. A cell assembly, which is the water electrolysis device 100, is placed on the table, and a pipe is connected thereto to perform water electrolysis evaluation.

2B to 2E are schematic diagrams illustrating a water electrolysis device used in an exemplary embodiment of the present invention.

As shown in FIGS. 2B to 2E, the water electrolysis cell constitutes a bipolar plate (FIGS. 2D and 2E) together with a current collector (FIG. 2C), and the bipolar plate is mounted on a rod assembly. As described above, it is placed in front of the display of the water electrolysis evaluation apparatus 1000 of FIG. 2A, and a flow meter is connected thereto.

Referring again to FIG. 2A , the lower portion includes a supply and circulation unit, and includes a tank 200, a gas-liquid separator 400, a chiller and a cooler 300, and the like. In addition, a supply pump (P) for supplying water or an aqueous solution and a cooling unit (C) for cooling the entire circulation unit may be further included. In addition, various flow meters for evaluating the flow rate of oxygen gas or hydrogen gas may be further included, and various sensors (Sn) for detecting dew point of oxygen gas or hydrogen gas or detection of hydrogen in oxygen gas or oxygen in hydrogen gas may be further included. can include

In the water electrolysis evaluation device 1000, an alarm notifying the device of danger may be further installed when there is a risk of explosion, and an emergency stop device E for stopping operation in an emergency state may be attached.

Meanwhile, the above-described sensor Sn may be mounted and used in a module form. That is, since the characteristics of the oxygen gas or hydrogen gas measured by the water electrolysis evaluation device may differ depending on the overall use environment, the sensor (Sn) or other flowmeters required for measurement can be attached to and detached from the water electrolysis evaluation device in the form of a module. provided in the form of
In an exemplary embodiment, one or more modular sensors are detachably mounted to the water electrolysis device, and the modular sensors include: a fluid inlet; fluid outlet; and a control and communication unit for controlling sensors and communicating with external devices.

3 is a schematic diagram showing a sensor module that can be installed in a water electrolysis evaluation device in an exemplary embodiment of the present invention.

As shown in FIG. 3, various sensors (S1, S2, ..., Sn) may be supplied to the water electrolysis evaluation device in the form of modules to be installed and detached. The corresponding sensor (S1, S2,...,Sn) module has an inlet (In) through which fluid, that is, a gas such as oxygen gas or hydrogen gas, or a liquid such as water or aqueous solution, can be supplied and an outlet (outlet) discharged after measurement. Out) and may include a control and communication unit (S1-10, ..., Sn-10) that controls the corresponding module and communicates with external devices. Here, the control and communication unit may include a processor and a communication module for controlling and communicating.

4A and 4B are example screens showing the configuration and operation of the water electrolysis evaluation device on the display screen (D) displayed on the top of the water electrolysis evaluation device 1000 according to an exemplary embodiment of the present invention.

Figure 4a illustrates the case of a general 2-channel supplying two water electrolyzers (two cells) of the same type, and Figure 4b illustrates a hybrid type 2-channel of a PEM and an alkaline water electrolyzer including an auxiliary tank. .

To explain the operation method, first open the breaker behind the water electrolysis evaluation device to activate the system, and activate the control mode of the Electrolyzer Test System program on the screen. Subsequently, a circulation pump (eg, P-100 or P101 in FIG. 4A) is operated to supply water or an aqueous solution as a raw material for water electrolysis to a tank (eg, D-100 or D-101 in FIG. 4A) and circulate it. Microgear pump (Max2700cc/min) can be used as the circulation pump, which enables precise control of pure circulation flow rate. Oxygen emission or hydrogen emission discharged from the water electrolysis cell passes through a chiller or cooler without passing through the tank 100 as described above, passes through a gas-liquid separator including a demister (eg, LS-200 in FIG. 4), and then passes through a flowmeter (eg, the MFM-100 in FIGS. 4a and 4b) and passes through a hydrogen or oxygen detection sensor (eg, the detector in FIGS. 4a and 4b). Additionally, various filters may be used as needed.

On the other hand, it is possible to control the temperature for experiments for various conditions of the performance of the water electrolysis cell. That is, a line heater is installed in the tank (eg, E-100 and E-102 in FIGS. 4A and 4B ), and a heater or cooler is installed in the circulation line to precisely control the temperature. A temperature and pressure display device (eg, TI-109, TI-104, TI-105, TI-110, PI-100, etc. of FIGS. 4A and 4B) may be installed in the circulation line.

For the water electrolysis evaluation test, after matching the desired experimental conditions, the power of the rectifier is turned on, the set current amount and limit voltage are input, and the power is turned on (Power On) and activated to proceed with the test (e.g., the right side of the display screen in FIG. 2a). see top section).

According to exemplary embodiments of the present invention, it is possible to accurately measure the flow rate of oxygen gas and hydrogen gas generated by water electrolysis reaction. In particular, purification (chiller or cooler specification - 20 ° C) is performed to increase the ratio of oxygen or hydrogen in the generated gas by removing moisture by cooling the hydrogen gas and oxygen gas. Accordingly, it is possible to more accurately evaluate the degree of oxygen and/or hydrogen generation.

In addition, the apparatus of exemplary embodiments of the present invention, real-time monitoring (eg H ₂ , O ₂ Detector in FIG. 4) capable of preventing mixing of oxygen and hydrogen is possible. In addition, with this real-time monitoring system (H ₂ , O ₂ Detector), immediate response is possible when a dangerous situation is detected. In a non-limiting example, for example, a mixing level of hydrogen and oxygen (eg, Low Explosion Level, LEL 4%) may be set, and operation may be stopped when the corresponding level is exceeded. In addition, with the introduction of an automation system, it is possible to maintain the system below the explosion limit level by installing a nitrogen gas purge system, which is an inert gas, in case of a dangerous situation.

In an exemplary embodiment, when the hydrogen concentration in the oxygen gas is less than a set reference value, the existing operating conditions are maintained, and when the hydrogen concentration is greater than the set reference value, an emergency stop operation procedure is performed. The emergency stop operation procedure is based on one or more set operating current values. The applied current value can be reduced.
In an exemplary embodiment, the emergency stop operation procedure reduces the applied current value until it is below the first set operating current value, when it is below the first set operating current value, turns off the applied voltage and performs nitrogen purging, oxygen gas and hydrogen The gas is discharged, and nitrogen purging is terminated and emergency stop occurs when the operating current setting value is equal to or less than the second operating current setting value, the hydrogen concentration in the oxygen gas is less than the set reference value, and the temperature of the water electrolyzer is less than the preset temperature. It may be to stop driving.
5 is a flow chart showing a safety control algorithm in an exemplary implementation of the present invention.

As shown in FIG. 5, for example, the control algorithm is divided into two steps.

In general, the operating range is limited to more than 20% load of normal operation based on current density to prevent recombination of oxygen and hydrogen, and the hydrogen gas concentration in oxygen is 4% or more as the explosive limit point, for example, in a non-limiting embodiment, 3.5% is the reference point to be set to

That is, if the concentration of hydrogen in oxygen is less than 3.5%, the existing operating conditions are maintained, and if it is greater than 3.5%, an emergency battery operation procedure is started. Accordingly, an emergency alarm sounds, the factor current value is reduced, and the line heater in the tank is stopped. In addition, the applied current value is continuously decreased so that the operating current value of the water electrolysis device is equal to or less than the preset operating current value (S1), and when the value is lower than the first operating current value (S1), the applied voltage is turned off and nitrogen purging is performed. and releases oxygen and hydrogen.

Subsequently, the above process is continued so that the operating current set value of the water electrolysis device is equal to or less than the second operating current set value (S2) set in advance, and the second operating current set value (S2) or less, the hydrogen concentration in oxygen is less than 3.5%, water electrolysis When the temperature of the device falls below the preset temperature, nitrogen purging is terminated, the water supply pump is turned off, the oxygen and hydrogen valves are closed, the emergency alarm is terminated, and the emergency stop operation is terminated.

As described above, according to the water electrolysis standard evaluation apparatus and method of exemplary embodiments of the present invention, voltage efficiency, which is a representative performance index of water electrolysis, is measured, as well as the flow of "hydrogen and oxygen" generated during water electrolysis in real time. It is possible to measure the performance of water electrolysis more precisely by measuring the amount of generated gas compared to the amount of applied current in real time. In addition, step by step removal of water or aqueous solution from hydrogen-containing emissions or oxygen-containing emissions generated from the electrolyzer, and precise monitoring of whether hydrogen is contained in hydrogen emissions or oxygen emissions are included to prepare for accidents and increase safety. can

In addition, by configuring various internal sensor devices to be modularized, the configuration of the water electrolysis evaluation device can be easily changed according to the use environment.

In addition, water electrolysis performance can be evaluated while maintaining high reliability even during load fluctuations. Therefore, it is possible to verify the reliability of water electrolysis performance when hydrogen is linked with renewable energy such as sunlight and wind power, which show large changes in electricity production depending on the weather.

In addition, the manufacturing cost of the device is low, so it is thought that it can greatly contribute to the domestic and overseas dissemination of domestic equipment.

Exemplary embodiments of the present invention are described in more detail through the following examples. Embodiments disclosed herein are illustrated for purposes of explanation only, and embodiments of the present invention may be implemented in various forms and should not be construed as being limited to the embodiments described herein.

[Experiment 1]

FIG. 6 of Experiment 1 is a graph showing current density (FIG. 6a) and voltage change over time (FIG. 6b) while applying current to a water electrolysis single cell (reaction area: 25 cm ² ). The measured temperature of the water electrolysis cell was 47.9 ± 1.56 ℃, the pressure was 1 atm, and DI water was flowed at 300 ccm to the anode of the water electrolysis cell.

In detail, FIG. 6a shows that the same experiment was performed by increasing the current density applied to the cell from 0.25 A/cm ² to 1.50 A/cm ² by 0.25 A units, repeating the cell group and device ON/OFF 10 times. It is a kind of reliability test result to see how much difference there is while proceeding on different days (D1 to D10). D1 to D10 are almost identical, indicating reliability.

In addition, FIG. 6B is a test result of a long-term test evaluation when the current density is set to 1.5A/cm2 while the cell is hung on the device and turned ON/OFF every day. Here, the change in the graph is thought to be that IV changes when there is a change in pressure while continuously supplying distilled water for the reaction, and it is thought to indicate that the performance of the cell decreases little by little, although it is not a big difference.

[Experiment 2]

FIG. 7 of Experiment 2 is a graph in which current is applied to a polymer electrolyte water electrolysis single cell (reaction area 25 cm 2 ) and the reaction cell voltage is measured by simulating actual Jeju Island wind power generation data according to capacity. The measured temperature of the water electrolysis cell was 47.9 ± 1.56 ℃, the pressure was 1 atm, and DI water was flowed at 300 ccm to the anode of the water electrolysis cell. It can be seen that the voltage reacts in real time to the changing current without time delay.

[Experiment 3]

This Experiment 3 and FIG. 8 are graphs of real-time measurement of the hydrogen flow rate generated by applying current to a polymer electrolyte water electrolysis single cell (reaction area 25 cm ² ) by simulating wind power generation data according to capacity. The measured temperature of the water electrolysis cell was 47.9 ± 1.56 ℃, the pressure was 1 atm, and DI water was flowed at 300 ccm to the anode of the water electrolysis cell.

The current efficiency can be calculated from the amount of hydrogen generation measured against each applied current value. It can be seen that the change in hydrogen flow rate is measured in real time without time delay for the changing current.

[Experiment 4]

9 of Experiment 4 is a graph obtained by measuring the hydrogen flow rate and hydrogen concentration in oxygen in real time while applying current to a polymer electrolyte water electrolysis single cell (reaction area 25 cm ² ) by simulating wind power generation data according to capacity. The measured temperature of the water electrolysis cell was 47.9 ± 1.56 ℃, the pressure was 1 atm, and DI water was flowed at 300 ccm to the anode of the water electrolysis cell.

Under fluctuating current input conditions, the oxygen concentration in hydrogen gas can be measured in real time from the amount of oxygen and hydrogen generated at both electrodes of the water electrolysis cell that cross over through the separator. For reference, in order to accurately evaluate the voltage/current efficiency, it is necessary to be able to analyze the flow rate of generated hydrogen gas and the crossover amount of hydrogen gas through the separator inside the single cell of water electrolysis in real time, and there should be no time delay. .

On the other hand, it can be seen that the oxygen concentration in hydrogen reaches 2%, which is the operating limit, under specific operating conditions (current change). Through this function, it was possible to evaluate the safety of the water electrolysis cell within the risk standard of 4%.

[Experiment 5]

10 of Experiment 5 is a graph of the results of cross-verification of the current-voltage performance curve of the same polymer electrolyte water electrolysis single cell (reaction area of 25 cm ² ) with other cells in two institutions. The measured temperature of the water electrolysis cell was 47.9 ± 1.56 ℃, the pressure was 1 atm, and DI water was flowed at 50 ccm to the anode of the water electrolysis cell. After changing the current density and maintaining each section for 5 minutes, the stabilized voltage value was obtained and the IV performance curve was shown. Reproducibility was secured when cross-validation was performed at institutions 1 and 2 for samples A and B. For reference, the sample anode was iridium black (2.0 mg/cm ² ), the cathode was Pt/C (0.5 mg/cm ² ), Nafion 115, and Mott's powder sintered titanium porous body were used as a diffuser.

Although non-limiting and exemplary implementations of the present invention have been described above, the technical idea of the present invention is not limited to the accompanying drawings or the above description. It is obvious to those skilled in the art that various types of modifications are possible within the scope of the technical spirit of the present invention, and also, these types of modifications will fall within the scope of the claims of the present invention.

Claims (21)

In the water electrolysis evaluation device,
A supply and circulation unit for supplying water or an aqueous solution to the water electrolysis unit and circulating, purifying, and discharging discharged water discharged from the water electrolysis unit to the outside, wherein the supply and circulation unit supplies water to the water electrolysis unit. Alternatively, a supply comprising a tank for supplying an aqueous solution and into which oxygen discharge or hydrogen discharge is introduced, a chiller or cooler for supplying oxygen gas or hydrogen gas discharged from the tank, and a gas-liquid separator for supplying the discharge discharged from the chiller or cooler. and circulation;
a current and voltage efficiency evaluation unit connected to the water electrolysis device to evaluate current and voltage efficiencies of the water electrolysis device; and
A flow rate and characteristic evaluation unit for evaluating the flow rate and characteristics of oxygen gas or hydrogen gas from the discharged product that has passed through the gas-liquid separator;
It is to measure the amount of generated gas compared to the amount of applied current in real time,
Water electrolysis evaluation apparatus, characterized in that for controlling the operation of the water electrolysis evaluation apparatus by evaluating the content of hydrogen in the oxygen gas or the content of oxygen in the hydrogen gas. delete delete According to claim 1,
After oxygen discharge from the water electrolysis device is supplied to the tank, unreacted water or aqueous solution is removed from the tank, and then oxygen gas is supplied to the chiller or cooler,
The water electrolysis device is a PEM or alkaline water electrolysis device, characterized in that. According to claim 1,
After hydrogen discharge from the water electrolysis device is supplied to the tank, unreacted water or aqueous solution is removed from the tank, and then hydrogen gas is supplied to the chiller or cooler,
The water electrolysis apparatus is an alkaline water electrolysis apparatus. According to claim 1,
The water electrolysis device may be a one-channel type having one water electrolysis device; or a water electrolysis evaluation device characterized in that it is a two-channel method having two water electrolysis devices. According to claim 6,
The two-channel method is a water electrolysis evaluation device, characterized in that a hybrid form of a PEM water electrolysis device and an alkaline water electrolysis device. According to claim 7,
The water electrolysis evaluation device of the hybrid type comprises a first tank for supplying water or an aqueous solution connected to each water electrolysis device and a second auxiliary tank having a smaller size than the first tank. According to claim 1,
The water electrolysis device has an upper and lower structure,
The upper portion includes a first box including a display and a current and/or voltage efficiency evaluation unit and a table unit on which the water electrolysis device is placed,
The lower part includes a tank, a chiller or cooler, a gas-liquid separator, and a flow rate and characteristic evaluation unit. According to claim 9,
The flow rate and characteristic evaluation unit includes at least one of a flow meter for evaluating the flow rate of oxygen gas or hydrogen gas in the discharged product, a measuring device for measuring a dew point, and a detector for detecting hydrogen in oxygen gas or oxygen in hydrogen gas. A water electrolysis evaluation device comprising: According to claim 9,
One or more modularized sensors are detachably mounted in the water electrolysis device.
The modularized sensor includes a fluid inlet; fluid outlet; and a control and communication unit for controlling sensors and communicating with external devices. According to claim 1,
If the hydrogen concentration in the oxygen gas is less than the set reference value, the existing operating conditions are maintained, and if it is more than the set reference value, the emergency stop operation procedure is performed.
The water electrolysis evaluation device, characterized in that the emergency stop operation procedure reduces the applied current value based on one or more operating current set values. According to claim 12,
The emergency stop operation procedure reduces the applied current value until it is less than the first operating current set value, and when it is less than the first operating current set value, the applied voltage is turned off, nitrogen purging is performed, and oxygen gas and hydrogen gas are discharged,
When the operating current set value is equal to or less than the preset second operating current value, the hydrogen concentration in the oxygen gas is less than the set reference value, and the temperature of the water electrolyzer is less than the preset temperature, nitrogen purging is terminated and the emergency stop operation is terminated. A water electrolysis evaluation device characterized by In the water electrolysis evaluation method using the water electrolysis evaluation apparatus of claim 1,
A step of supplying water or an aqueous solution to a water electrolysis device and circulating, purifying, and discharging the discharged product discharged from the water electrolysis device to the outside, wherein the step is to convert the discharged product discharged from the water electrolysis device to the water electrolysis device. circulating it to a supply tank and supplying it to the water electrolysis device again, cooling the exhaust gas discharged from the tank, and passing the cooled gas through a gas-liquid separator;
Evaluating current and voltage efficiency of the water electrolysis device by being connected to the water electrolysis device; and
Evaluating the flow rate and characteristics of oxygen gas or hydrogen gas in the discharged product that has passed through the gas-liquid separator;
It is to measure the amount of generated gas compared to the amount of applied current in real time,
The water electrolysis evaluation method further comprising the step of controlling the operation of the water electrolysis evaluation device by evaluating the content of hydrogen in the oxygen gas or the content of oxygen in the hydrogen gas. delete delete According to claim 14,
The water electrolysis device may be a one-channel type having one water electrolysis device; or a water electrolysis evaluation method characterized in that it is a two-channel method having two water electrolysis devices. According to claim 17,
The water electrolysis evaluation method, characterized in that the two-channel method is a hybrid method of a PEM water electrolysis device and an alkaline water electrolysis device. According to claim 18,
The hybrid method comprises a first tank for supplying water or an aqueous solution connected to each water electrolysis device and a second auxiliary tank having a smaller size than the first tank. According to claim 14,
If the hydrogen concentration in the oxygen gas is less than the set reference value, the existing operating conditions are maintained, and if it is more than the set reference value, the emergency stop operation procedure is performed.
The water electrolysis evaluation method, characterized in that the emergency stop operation procedure reduces the applied current value based on one or more operating current set values. According to claim 20,
The emergency stop operation procedure reduces the applied current value until it is less than the first operating current set value, and when it is less than the first operating current set value, the applied voltage is turned off, nitrogen purging is performed, and oxygen gas and hydrogen gas are discharged,
When the operating current set value is equal to or less than the preset second operating current value, the hydrogen concentration in the oxygen gas is less than the set reference value, and the temperature of the water electrolyzer is less than the preset temperature, nitrogen purging is terminated and the emergency stop operation is terminated. Water electrolysis evaluation method characterized.

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