KR20220011833A - Electrolysis device preventing accident through power control - Google Patents

Abstract

The present invention relates to an accident prevention-type electrolysis device through power control, which includes a power storage part between a power generation part and an electrolysis part to adjust the voltage and current transmitted from the power storage part so that it is possible to prevent the explosion of the electrolysis part or a gas-liquid separation part due to a change in the power load of the power generation part, thereby maximising stability. The electrolysis device comprises: a power generation part that produces electrical energy; a power storage part that converts the electrical energy produced by the power generation part into DC power, stores and transmits the same; an electrolysis part that produces oxygen and hydrogen using the DC power transmitted from the power storage part; a gas-liquid separation part that separates oxygen and hydrogen produced from the electrolysis part; and a control part that limits the oxygen concentration in the gas-liquid separation part to a lower explosive limit by measuring and controlling the current and voltage of the DC power transmitted from the power storage part to the electrolysis part.

Description

Accident prevention type electrolysis device through power control {ELECTROLYSIS DEVICE PREVENTING ACCIDENT THROUGH POWER CONTROL}

The content disclosed in the present specification relates to an electrolysis device for driving the electrolysis unit and the like by storing the electricity produced by the power generation unit in the power storage unit.

Unless otherwise indicated herein, the material described in this section is not prior art to the claims of this application, and inclusion in this section is not an admission that it is prior art.

The 21st century energy environment problems such as climate change, energy shortage, resource depletion, and energy poverty have arrived due to the reckless development of industries based on fossil fuels. To this end, countries around the world are actively responding by promoting the climate change agreement, Tokyo Protocol, and negotiations on a new climate change regime. As part of this, research is being conducted on a system to increase energy utilization by linking various renewable energy such as solar power and wind power and energy storage devices with water electrolysis.

Although interest in hydrogen at home and abroad has increased, the supply of hydrogen is not active due to the problem that electricity generation and power supply are not smoothly provided to the water electrolysis system due to weather fluctuations.

As a method for improving this problem, Patent Document 1 discloses a solar cell, a wind generator, a battery, an inverter, and an electrolysis device for generating, supplying, and storing energy for a short period of time, converting the remaining electricity into hydrogen and storing it for a long period of time and then converting it back into electricity , storage tank, fuel cell, compressor, burner using stored hydrogen, industrial power distribution network that exchanges with industrial electricity, reformer that receives city gas supply, a controller and computer that controls and checks all the above conditions. In Patent Document 2, a solar power generation unit including a solar panel made of solar cells, a wind power generation unit including a wind turbine, the solar panel and power generated from the wind turbine are distributed A control unit including a controller for controlling distribution to consumers, storage batteries or electrolyzers, an inverter for converting DC power into AC power, and a constant voltage circuit according to Disclosed is a renewable energy generation system including an electrolyzer for producing hydrogen and oxygen with electric power supplied from the electrolyzer, and a fuel cell for generating electric power using the hydrogen produced in the electrolyzer.

Although Patent Document 1 and Patent Document 2 are provided and stored with a solar cell, a wind power generator, a battery and a capacitor, the waste of the storage battery may cause pollution, and it is still difficult to secure the stability of the water electrolysis system according to the load fluctuation There is this.

Republic of Korea Registered Utility Model No. 20-0245895 (July 29, 2001) Republic of Korea Patent Publication No. 10-2009-0059389 (June 11, 2009)

It is intended to provide an accident prevention type electrolysis device through power control that maximizes the stability of the electrolysis unit and gas-liquid separation unit connected to the power generation unit while harmless to the environment.

In addition, it is not limited to the technical problems as described above, and it is obvious that another technical problem may be derived from the following description.

According to an embodiment of the disclosure, an accident prevention type electrolysis device through power control is a power generation unit that produces electrical energy, and a power storage unit that converts the electrical energy produced by the power generation unit into DC power, stores it, and transmits it , an electrolysis unit for producing oxygen and hydrogen by using the DC power transmitted from the power storage unit, a gas-liquid separation unit for separating oxygen and hydrogen produced from the electrolysis unit, and transmission from the power storage unit to the electrolysis unit and a control unit for limiting the oxygen concentration in the gas-liquid separation unit to the lower explosive limit by measuring and controlling the current and voltage of the DC power source.

In addition, the power generation unit may generate electricity through any one of natural energy of solar power, hydraulic power, and wind power.

In addition, the power storage unit may include a DC/AC converter and a vanadium redox flow battery.

In addition, the vanadium redox flow battery is provided between the stack portion, the electrolyte storage tank for supplying the electrolyte to the stack portion, the stack portion and the electrolyte storage tank to supply the electrolyte from the electrolyte storage tank to the stack portion. and a recovery passage provided between the stack unit and the electrolyte storage tank to recover the electrolyte from the stack unit to the electrolyte storage tank.

In addition, the stack unit may include at least one battery cell, and the battery cell may include a positive electrode, a negative electrode facing the positive electrode, and an ion exchange membrane interposed between the positive electrode and the negative electrode.

In addition, the electrolysis unit may use any one of alkaline water electrolysis, proton exchange membrane water electrolysis, and high-temperature steam decomposition water electrolysis.

According to an embodiment disclosed in the present specification, an accident prevention type electrolysis device through power control is provided with a power storage unit between the power generation unit and the electrolysis unit, so that the voltage and current transmitted from the power storage unit can be adjusted, so that the power generation unit As the explosion of the electrolysis unit or gas-liquid separation unit due to the change in the power load of the unit is prevented, stability can be maximized.

In addition, even when the power supply from the power generation unit is not smooth, the power stored in the power storage unit can be supplied, so there is an effect that a smooth power supply is always possible.

1 is a schematic diagram showing an electrolysis device according to an embodiment of the content disclosed in the present specification.
2 is a block diagram of an electrolysis apparatus according to an embodiment.
3 is a cross-sectional view showing an example of a vanadium redox flow battery.
4 and 5 are graphs showing experimental results according to Experimental Example 1.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

In describing the embodiments of the present invention, if it is determined that a detailed description of a well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

Figure 1 is a schematic diagram showing an electrolysis device according to an embodiment of the content disclosed herein, Figure 2 is a block diagram of the electrolysis device according to an embodiment.

1 and 2 , the electrolysis device 1 includes a power generation unit 100 , a power storage unit 200 , an electrolysis unit 300 , a gas-liquid separation unit 400 and a control unit 500 . .

The power generation unit 100 may generate electric energy through any one of natural energy of solar power, hydraulic power, and wind power. For example, in the case of generating electric energy using sunlight, the power generation unit may be configured with a plurality of solar cell arrays and may produce electric energy by condensing sunlight incident from the outside.

On the other hand, since the electric energy produced from the power generation unit 100 has high volatility, when it is directly supplied to the electrolysis unit 300 , the life of the electrolysis unit 300 is reduced as well as in the stack of the electrolysis unit 300 . Oxygen in hydrogen or hydrogen in oxygen may cause problems leading to accidents such as fire or explosion. Such high variability power may adversely affect the electrolysis unit 300 as well as reduce overall system efficiency.

Accordingly, in order to match the rated power transmitted to the electrolysis unit 300 , the power storage unit 200 may be connected and installed between the power generation unit 100 and the electrolysis unit 300 .

The power storage unit 200 may include a DC/AC converter 210 and a chargeable vanadium redox flow battery 250 . The power storage unit 200 converts the electrical energy produced by the power generation unit 100 into DC power through the DC/AC converter 210, sends it to the vanadium redox flow battery 250, and stores it, and electrolyzes it. It can be transmitted to the unit 300 .

The DC/AC converter 210 may be connected to the power generation unit 100 to invert the electric energy produced by the power generation unit 100 to DC/AC and output it to the power system. In more detail, the DC/AC converter 210 may convert the electrical energy produced by the power generation unit 100 into DC power for supplying the power system.

The vanadium redox flow battery 250 stores and transmits the DC power converted by the DC/AC converter 210 , and the transmitted current and voltage may be controlled by the controller 500 .

3 is a cross-sectional view showing an example of a vanadium redox flow battery.

Referring to FIG. 3 , the vanadium redox flow battery 250 includes a stack portion 10 , an electrolyte storage tank 20 for supplying electrolyte to the stack portion 10 , the stack portion 10 , and the electrolyte storage tank (20) is provided between the supply passage 30 for supplying the electrolyte from the electrolyte storage tank 20 to the stack portion 10, and the stack portion 10 and the electrolyte storage tank 20 provided between the stack A recovery passage 40 for recovering the electrolyte from the unit 10 to the electrolyte storage tank 20 may be included.

The stack unit 10 is a minimum unit in which charging and discharging occurs through an electrolyte, and includes at least one battery cell, and a separator may be provided between the battery cell and adjacent battery cells. The battery cell may include a positive electrode 11 , a negative electrode 12 facing the positive electrode 11 , and an ion exchange membrane 13 interposed between the positive electrode 11 and the negative electrode 12 . The ion exchange membrane 13 may be formed of a fluorine-based resin or a porous polymer resin.

The electrolyte storage tank 20 may include an electrolyte storage tank for an anode for supplying an electrolyte to the anode 11 and an electrolyte storage tank for a cathode for supplying an electrolyte to the anode 12 .

The supply passage 30 may connect the electrolyte storage tank 20 and the stack portion 10 so that the electrolyte can be supplied from the electrolyte storage tank 20 to the stack portion 10 .

The recovery passage 40 may connect the stack portion 10 and the electrolyte storage tank 20 so that the electrolyte can be recovered from the stack portion 10 to the electrolyte storage tank 20 .

The supply passage 30 and the recovery passage 40 are on the anode 11 side and the cathode 12 side to supply and recover the electrolyte to the anode 11 and the cathode 12 of the stack unit 10 . Each may be provided.

For example, in the vanadium redox flow battery 250 , when charging occurs, V ⁴⁺ ions may be oxidized to V ⁵⁺ ions at the positive electrode, and V ³⁺ ions may be reduced to V ²⁺ ions at the negative electrode. The electrolyte storage tank for positive electrode accommodates positive electrolyte rich in V ⁴⁺ ions and V ⁵⁺ ions, and the electrolyte storage tank for negative electrode can accommodate negative electrolyte rich in V ²⁺ ions and V ³⁺ ions. In this state, an anode electrolyte rich in V ⁴⁺ ions and V ⁵⁺ ions and a cathode electrolyte rich in V ²⁺ ions and V ³⁺ ions may move to the stack unit 10 by the operation of the pump 30a. When the charging process occurs in the stack unit 10 , the positive electrolyte and the negative electrolyte may be changed to a state rich in V ⁵⁺ ions and V ²⁺ ions, respectively.

The electrolysis unit 300 may be classified according to the type of electrolyte used, for example, alkaline electrolysis, proton exchange membrane electrolysis, and high temperature steam decomposition water electrolysis (THE). , High Temperature Electrolysis) using any one method, preferably alkaline electrolysis method or proton exchange membrane water electrolysis (Proton Exchange Membrane Electrolysis), it is possible to produce high-purity hydrogen. For example, in alkaline water electrolysis, electrolytes such as 20-30 wt% potassium hydroxide (KOH) and sodium hydroxide (NaOH) are supplied to the stack, and hydrogen at the cathode and oxygen at the anode are produced in a molar ratio of 2 to 1 through an electrochemical reaction can do.

The gas-liquid separation unit 400 may allow oxygen and hydrogen introduced from the electrolysis unit 300 to be separated more effectively without a reverse flow. The gas-liquid separator 400 may separate the leachate from the gas, suck the condensed condensed water, and discharge it again as the leachate.

For example, the gas-liquid separation unit 400 includes a storage space for separating and transporting the mixed effluent introduced into the body, an inlet for inducing the inflow of the mixed effluent, a separator for preventing the reverse flow of the mixed effluent therein, and the inflow. It may be composed of a gas outlet for discharging gas by separating the mixed effluent, a condensate inlet for sucking condensed water generated in the vacuum device, and a leachate outlet for discharging the separated leachate.

The control unit 500 can measure and control the current and voltage transmitted from the electrolysis unit 300 so that the rated power required by the electrolysis unit 300 can be constantly supplied. In addition, the oxygen concentration in the gas-liquid separation unit 400 may be limited to the lower explosive limit, in detail may be limited to 4%. Specifically, the explosive range of hydrogen in air is 4 to 75%, the explosive range of oxygen is 4 to 74%, and the explosive range of hydrogen in oxygen may be limited not to exceed 4 to 94%.

For example, when the high variability output power from the power generation unit 100 is directly transferred to the electrolysis unit 300 , the electric power exceeding the rated power is transmitted to the electrolysis unit 300 and hydrogen in the electrolysis unit 300 . A fire may occur due to inflow of oxygen or hydrogen in oxygen, or the oxygen concentration in hydrogen in the gas-liquid separation unit 400 may exceed the lower explosive limit of 4%. In addition, when power exceeding the rated power is transmitted, the life of the electrolysis unit 300 may be reduced. Therefore, it is preferable to constantly control the voltage and current transmitted from the electrolysis unit 300 .

Example 1. Electrolysis device

An electrolysis device was prepared in which a power storage unit equipped with a 50KW stack unit was connected between the power generation unit and the electrolysis unit, and the control unit was connected between the power storage unit, the electrolysis unit and the gas-liquid separation unit. As the electrolysis device, a 10Nm ³ /h class alkaline water electrolysis system was used.

Comparative Example 1. Electrolysis device

An electrolysis device having the same structure as in Example 1 was prepared except that the power storage unit and the control unit were not installed.

Experimental Example 1. Evaluation of safety performance

In order to confirm the safety of the electrolysis device prepared in Example 1 and Comparative Example 1, an experiment was conducted as follows.

Electric energy of 200KWH from sunlight was stored in the power storage unit and applied to the electrolysis unit while maintaining the power at 110kw. The electrolysis unit was maintained at 10 bar and 80 °C. And the amount of hydrogen generated from the hydrogen discharge part of the electrolysis part was measured, and the oxygen concentration in hydrogen was measured using a portable oxygen meter.

4 and 5 are graphs showing experimental results according to Experimental Example 1.

Referring to FIG. 4 , it was confirmed that the output power value was constant and hydrogen and oxygen without cross-contamination were stably produced. In addition, it was found that the oxygen concentration in hydrogen was 0.5%, which did not reach the lower oxygen explosion limit of 4%. On the other hand, referring to FIG. 5 , it was confirmed that the power load of sunlight fluctuates greatly, and the liquid levels of hydrogen and oxygen cross and move. Therefore, it could be inferred that there is a possibility of contamination through mixing of hydrogen and oxygen as the pressures of hydrogen and oxygen cross, and that if oxygen is excessively introduced into hydrogen in the form of bubbles, the lower explosive limit of 4% may be exceeded.

Although preferred embodiments of the present invention have been described with reference to the accompanying drawings, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and represent all of the technical spirit of the present invention. Therefore, it should be understood that there may be various equivalents and modifications that can be substituted for them at the time of filing the present application. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the following claims rather than the detailed description, and the meaning and scope of the claims and their All changes or modifications derived from the concept of equivalents should be construed as being included in the scope of the present invention.

1: electrolysis device 10: stack unit
11: positive 12: negative
13: ion exchange membrane 20: electrolyte storage tank
30: supply flow path 30a: pump
40: recovery path 100: power generation department
200: power storage unit 210: DC/AC converter
250: vanadium redox flow battery 300: electrolysis unit
400: gas-liquid separation unit 500: control unit

Claims (6)

a power generation unit that produces electrical energy;
a power storage unit for converting, storing, and transmitting the electric energy produced by the power generation unit into DC power;
an electrolysis unit for producing oxygen and hydrogen by using the DC power transmitted from the power storage unit;
a gas-liquid separation unit for separating oxygen and hydrogen produced from the electrolysis unit; and
Accident prevention type electricity through power control including; a control unit that limits the oxygen concentration in the gas-liquid separation unit to an explosion lower limit by measuring and controlling the current and voltage of the DC power transmitted from the power storage unit to the electrolysis unit decomposition device.
According to claim 1,
The power generation unit is an accident prevention type electrolysis device through power control that produces electricity through any one of natural energy of solar power, hydraulic power, and wind power.
According to claim 1,
The power storage unit is an accident prevention type electrolysis device through power control including a DC / AC converter and a vanadium redox flow battery.
4. The method of claim 3,
The vanadium redox flow battery is
stack unit;
an electrolyte storage tank for supplying an electrolyte to the stack;
a supply passage provided between the stack portion and the electrolyte storage tank to supply an electrolyte from the electrolyte storage tank to the stack portion; and
Accident prevention type electrolysis device through power control comprising a; a recovery passage provided between the stack portion and the electrolyte storage tank to recover the electrolyte from the stack portion to the electrolyte storage tank.
5. The method of claim 4,
The stack unit includes at least one battery cell,
The battery cell is
anode;
a negative electrode facing the positive electrode; and
Accident prevention type electrolysis device through power control including an ion exchange membrane interposed between the positive electrode and the negative electrode.
According to claim 1,
The electrolysis unit uses any one of Alkaline Electrolysis, Proton Exchange Membrane Electrolysis, and High Temperature Electrolysis (THE) Accident through power control Anti-electrolysis device.

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