RU2757533C1 - Device for studying structure and principle of operation of solid oxide fuel cell - Google Patents

Abstract

FIELD: power industry; educational equipment.

SUBSTANCE: invention relates to educational equipment in the field of power industry, namely to a device that is a visual and methodological tutorial; it can be used to conduct laboratory and practical classes in educational institutions, when studying an alternative energy course. The proposed device is a kind of simulator for working with a solid oxide fuel cell (hereinafter – SOFC). The device for studying the structure and principle of operation of the fuel cell includes a cell for the studied SOFC equipped with a heater, a flow meter, at least one regulator of fuel gas flow, at least one nozzle for supplying fuel gas to the device, a means for displaying information and entering data, a control board, a system of pipes and wired connections, wherein the control board is connected by means of wired connections to the heater and the means for displaying information and entering data, and the flow meter is installed directly on the board or connected to it by a wired connection, in addition, the control board contains wired connections for electrical contact with the studied SOFC. The device can additionally be equipped with an exhaust gas afterburner located at an outlet of the cell, as well as a reformer located on a line for supplying fuel gas to the cell for the studied SOFC. In addition, the device can be equipped with a means of forcibly feeding an oxidizer into the cell for the studied SOFC and/or into the reformer and afterburner.

EFFECT: invention is aimed at expanding the functionality of educational and methodological equipment, namely a device (stand) for studying the structure and principle of operation of a fuel cell; the proposed technical solution is also aimed at providing visual control of the process of optimizing operating parameters of the device, in particular, the proposed invention makes it possible to get more effectively acquainted with the operation of the SOFC due to the direct visual regulation of processes taking place in it by selecting optimal parameters.

5 cl, 7 dwg

Description

The invention relates to training equipment in the field of energy, namely to a device that is a visual and methodological aid and can be used for laboratory and practical exercises in educational institutions when studying the course of alternative energy. The proposed device is a kind of simulator for working with a solid oxide fuel cell (SOFC).

One of the predominant trends in the development of modern energy is the so-called "green energy". In the process of operation of the corresponding power plants, there is no pollution of the environment.

Clean energy, of course, includes energy based on the use of hydrogen, or natural, associated, as well as synthesis gas as a carrier for the accumulation, transportation and subsequent generation of electricity.

Currently, a number of fuel cells (FCs) have been developed related to the field of chemical current sources with direct conversion of chemical energy of fuel (hydrogen, synthesis gas, etc.) into electrical and thermal energy, for example, (RU 160133 U1, 03/10/2016) , as well as, for example, (RU 2625460 C2, 2015).

However, the operation of electrochemical generators based on such FCs requires special knowledge and skills, which are currently poorly developed among consumers. In this regard, additional consecration in educational programs or visual aids of the principle of operation of fuel cells and other electrochemical devices is necessary.

This is especially important for beginners, in particular students.

Currently, there are a large number of visual aids, for example, training stands, in various fields of technology. But in the field of hydrogen energy, there are not enough teaching aids in the form of training stands for studying the structure and principle of operation of fuel cells. So, for example, a device is known (RU 2678902). However, it is intended to study the structure and principle of operation of only a hydrogen fuel cell with a proton-exchange membrane and cannot be used to study the structure and principle of operation of a solid oxide fuel cell (SOFC).

From the prior art, no devices (stands) have been identified for studying the structure and operating principle of solid oxide fuel cells.

The technical result, which the claimed invention is aimed at, is to expand the functionality of educational and methodological equipment, namely, a device (stand) for studying the structure and principle of operation of a fuel cell.

The proposed technical solution is aimed at providing visual control of the process of optimizing the operating parameters of the device. In particular, the proposed invention makes it possible to more effectively familiarize oneself with the operation of the SOFC due to the direct visual control of the processes occurring in it by selecting the optimal parameters.

The specified technical result is achieved due to the fact that the device for studying the structure and the principle of operation of the fuel cell includes a cell for the investigated SOFC, equipped with a heater (if necessary with a temperature meter), a flow meter (flow meter of consumed gases), at least one fuel flow regulator. gas, at least one branch pipe for supplying fuel gas to the device, means for displaying information and inputting data, a control board, a system of pipes and wire connections, the control board being connected via wire connections to a heater and means for displaying information and inputting data, and the flowmeter is installed directly on the board or is connected to it by a wire connection; in addition, the board contains wire connections for contact with the SOFC under investigation.

The means for displaying information and entering data, depending on the equipment used, in particular, can be either a touch screen or a monitor with a keyboard.

When using fossil fuel, the device is equipped with a reformer (fuel preparation unit) located on the fuel gas supply line to the cell for the investigated SOFC.

If complete oxidation of excess gases is required, a flue gas afterburner is installed at the outlet of the cell. The need to install an afterburner can arise both when using hydrogen fuel and organic.

The device can be equipped with a means of forced supply of the oxidant (oxidant supply unit) to the cell for the investigated SOFC and / or to the reformer and afterburner.

The device is additionally equipped with a protective heat-resistant shield.

A cell is understood as a structure in which the SOFC under study is located and connected to wire connections and branch pipes to the fuel preparation unit and to the oxidizer supply unit. The cell can be additionally equipped with a SOFC temperature meter, for example, a thermocouple.

The nozzles are understood as the elements connecting the microtubular solid oxide fuel cell (MT SOFC) with the fuel supply pipes (hoses). The drawings show a particular case of a branch pipe.

The proposed invention is illustrated by graphic materials.

FIG. 1 shows a general view of the claimed device;

FIG. 2 - the same in perspective view;

FIG. 3 - rear view (with the rear cover of the case (base) removed;

FIG. 4 is a longitudinal section of the device (rear view);

FIG. 5 - cell with a heater and with the investigated SOFC placed in it;

FIG. 6 - General view of a microtubular SOFC with collector wires fixed on the electrodes;

FIG. 7 - output of the anode current collection.

A device for studying the structure and principle of operation of a solid oxide fuel cell includes a cell 1 for accommodating the investigated SOFC 2, equipped with a fuel cell heater 3 and, if necessary, a temperature meter (not shown in the drawing). In addition, the claimed device includes at least one flow meter 4, means 5 for displaying information and inputting data (touch screen or monitor with keyboard), and a control board (not shown). The control board can be with or without an electronic load module, while the load can be external.

When using fossil fuel, the device is additionally equipped with reformer 6 (fuel preparation unit), which is necessary for converting fossil fuel into synthesis gas, afterburner 8 for complete oxidation of residual fuel gas components, as well as air blowers (fans 9 and 10) installed in front of reformer 6 and afterburner 8, respectively. A shut-off solenoid valve (not shown in the drawings) can be installed between the branch pipe 7 for connecting the fuel source (cylinder) and the reformer 6. As a rule, a shut-off valve is present on gas (fuel) cylinders. The reformer 6 or the afterburner 8 can be additionally equipped with heaters (not shown in the drawings) to heat the reformer and the afterburner to operating temperatures and with their temperature meters (not shown in the drawings).

The flow meter 4 is located between the pipe for connecting the fuel cylinder and the inlet pipe 11 for supplying the fuel gas to the SOFC. The flow meter is connected by means of pipes and / or flexible hoses. A solid oxide fuel cell 2, a heater 3 of a cell 1 and a means of displaying information and data input 5, as well as, if any, fans 9, 10 and 12 are connected to the control board and the electronic load module are wired (not shown in the drawings), and not indicated in the drawings, cell temperature meter, reformer and afterburner heaters, reformer and afterburner temperature meters. Flowmeter 4 can be connected to the board with wired connections, or it can be fixed directly on the board itself.

The supply of the oxidant for the chemical reaction in the solid oxide fuel cell is carried out by convective transfer of oxygen in the air. A scheme with forced supply of the oxidizer by pumping it with a pump or fan 12 can be applied.

The device can be additionally equipped with means for blowing (cooling) the control board and the electronic load module, for example, a fan (not shown).

Also, the device may additionally contain a connector for connecting an external load, which is connected to the fuel cell by a power line. This port is required for connecting external devices or voltage and current converters.

The data entry tool can be made in different variations. So, for example, it can be implemented as a separate unit, for example, a keyboard, or the function of pointing and entering on a touch screen, or a mouse connected via a USB port, or it can contain a quadrature encoder.

The device can be additionally equipped with sensors for carbon monoxide, carbon dioxide, hydrogen, hydrocarbons. Such sensors allow emergency shutdown of the device by closing the solenoid valve if the sensor detects fuel leakage into the external environment, or in case of exceeding the threshold values in the exhaust gases.

The following is used as a fuel source:

- a balloon with a metal hydride, in which hydrogen is stored in a bound state in the form of a hydride and is released in the range of room temperatures;

- a cylinder with compressed hydrogen;

- a bottle with liquefied organic fuel;

- a cylinder with compressed hydrocarbon fuel.

All elements of the device can be located on the base. A table, stand, etc. can be used as a base.

The base can accommodate seats for a fuel bottle and for spare fuel bottles, as well as a connector for connecting to an external fuel source. On the base can be located controls of the parameters of the device.

Structural elements such as flow meter, electronic control board, electronic load and fans are located in the device housing.

The claimed device for studying the structure and principle of operation of a solid oxide fuel cell (SOFC) is a kind of simulator and can be used by novice specialists to acquire skills in working with SOFC.

SOFC requires fuel and an oxidizer to operate. Hydrogen or organic gaseous fuel is used as a fuel, and oxygen from the ambient air is used as an oxidizing agent.

The fuel tank, which is replaceable (not shown in the drawing), is connected to the nozzle 7 located on the body 13 of the device. Hydrogen from a hydrogen cylinder through a reduction gas reducer, a shut-off solenoid valve (not shown in the drawing) and a flow meter 4 flows through pipes and hoses into a solid oxide fuel cell (SOFC). In the case of using organic fuel (synthesis gas, etc.), the fuel from the cylinder enters the reformer 6 through a reduction gas reducer, a shut-off solenoid valve (not shown in the drawing) and a flow meter 4 through pipes. Oxygen from the air, necessary for the fuel conversion reaction in reformer 6, is supplied by pumping it with a fan 9. Oxygen from the air, necessary for the oxidation reaction of residual fuel components in the afterburner 8, is supplied by pumping it with a fan 10, a membrane pump or another type of blower. The inlet air temperature is equal to the ambient temperature. In solid oxide fuel cell 2, the chemical energy of the fuel (synthesis gas, hydrogen, CO, hydrocarbons) is directly converted into electrical and thermal energy. Due to the oxidation reaction of the fuel on the electrodes 14, 15 (cathode and anode, respectively) of the fuel cell 2, a potential difference is created. Changes in the electrochemical parameters of the fuel cell (depending on external conditions) can be recorded by connecting the load to the electrodes 14, 15 by current leads 16.

The indication of the measured and set values is carried out on the means 5. The flow meter 4 registers and monitors the consumption of fuel supplied to the fuel cell 2 or to the reformer 6 (depending on the type of fuel used).

Means 5 are necessary to ensure the visibility of the ongoing processes in the operation of the fuel cell while simultaneously selecting the optimal parameters (modes) of the device.

The device is equipped with a fuel gas flow regulator, the handles 17 of which are located on the front panel of the device.

Since the operation of SOFCs is carried out at very high temperatures, the design of the claimed device presupposes the presence of a thermal shield, which ensures the safety of work on the study of the structure and principle of operation of a solid oxide fuel cell. The thermal shield can be transparent, for example, made of quartz or other heat-resistant glass, and provides visibility of the SOFC heating and cooling processes, as well as additional visual control of the integrity of the investigated SOFC.

The data entry tool allows you to set the required operating modes. The monitor (display) displays the set operating parameters of the device and measured values, such as the electric current of the investigated SOFC, the voltage of the investigated SOFC, the power of the investigated SOFC, fuel consumption, air flows, the temperature of the investigated SOFC, the temperature in the reformer chamber, and the temperature in the afterburner.

The electronic load allows you to simulate the consumer. All electrical energy transmitted to the electronic load is converted into thermal energy, which is dissipated in the air, which can be facilitated by an additionally installed fan.

Sometimes it is advisable to supplement the device with connectors or terminals for connecting an external load. Connectors or terminals allow you to connect an external consumer and measure the voltage with third-party devices, and can be located on the control board of the device.

An example of a specific implementation of the claimed device.

First, a sample of a microtubular solid oxide fuel cell (MT-SOFC) is prepared for measurements.

For this, a wire 18 of a silver-based alloy is wound on the surface of the cathode. Winding step ~ 10-15 mm. To improve the contact of the wire with the cathode surface, a conductive paste based on silver or platinum can be used.

Then, inside the MT-SOFC, a thin nickel wire 19 is placed, folded three times (anode current collection), so that the ends of the wire protrude 15-25 mm from both sides of the fuel cell.

After that, silicone hoses 20 with plastic adapters 21 are put on the ends of the MT-SOFC, fixing the anode current collector from both ends of the solid oxide fuel cell. Nickel wire 19, clamped by the hoses, is led out.

The thermal protective screen is removed from the device during the MT-SOFC installation into the cell.

The measured MT-SOFC sample is placed inside the cylindrical heating element 3 of the cell. The fuel cell is fixed by branch pipes 11 (for example, in the form of silicone hoses) connecting the pipes for supplying and removing fuel gases with plastic adapters 21 mounted on the fuel cell 2.

Scheme of further connection of the device elements:

Option 1. When using hydrogen.

The hydrogen cylinder is connected through the inlet pipe and the reduction gear according to the following scheme: hydrogen cylinder - reduction gear - solenoid valve - fuel gas flow regulator - flow meter - MT SOFC (through the 11 cell nozzles) - outlet 22.

If it is necessary to oxidize excess hydrogen gases, an afterburner 8 is installed in front of the branch pipe 22.

Option 2. When using organic, for example, hydrocarbon fuel.

The hydrocarbon fuel cylinder through the inlet pipe and the reduction gearbox is connected according to the following scheme: fuel cylinder - reduction gearbox - solenoid valve - fuel gas flow regulator - flow meter - reformer - MT SOFC (through nozzles 11 of the cell) - afterburner 8 - outlet 22.

Option 3. It is possible to combine two circuits (option 1 and option 2) in one device.

Below are some examples of measurements.

Measurements on a propane-butane fuel mixture.

A cylinder with a liquefied propane-butane mixture is connected to the quick-disconnect connector on the side surface of the device.

The device is powered on by a switch located, for example, on the rear panel of the device (stand).

To carry out measurements on a propane-butane mixture, it is necessary to select the required type of fuel - "propane-butane" on the display.

The target temperature of the fuel cell heater is manually set on the display and provided automatically by the control board using a thermocouple temperature control. Temperature range 500-750 ° C.

The afterburner is automatically heated to a temperature of at least 350 ° C. The air supply to the afterburner is automatically switched on by a centrifugal fan.

After the afterburner heats up to the target temperature, the display shows a message that the reformer heating is on.

The reformer is heated automatically until it reaches a temperature of 650 ° C and air is supplied to the reformer by a membrane pump.

Once the reformer has heated to the target temperature, a warning is displayed to warn that fuel must be supplied before heating the fuel cell.

After confirming the readiness to turn on the heating of the cell, it is necessary to manually open the valve on the gas cylinder and, according to the readings of the flow meter on the screen, set the required flow with the needle valve (fuel flow regulator) using the knob 17.

After the heater of the cell with the fuel cell reaches the set temperature, a message is displayed about the readiness to take measurements.

By clicking on the menu item “Take I – V characteristic” (volt-ampere characteristic), the I – V characteristic of the investigated MT-SOFC is automatically plotted by automatically changing its own internal resistance of the electronic load built into the control board.

Carrying out measurements on hydrogen.

The device is powered on by a switch located, for example, on the rear panel of the device (stand).

To carry out measurements on hydrogen, the display must select the required type of fuel - "hydrogen".

The target fuel cell heater temperature is manually set on the display. Temperature range 500-750 ° C.

The display shows a warning that fuel must be supplied before heating the fuel cell.

After confirming the readiness to turn on the heating of the cell, it is necessary to connect the metal hydride cylinder with hydrogen to the quick-disconnect connection on the side surface of the device, according to the readings of the flow meter on the screen, set the required flow with the needle fuel flow regulator using the knob 17.

After the heater of the cell with the fuel cell reaches the set temperature, a message is displayed about the readiness to take measurements.

By clicking on the "Take I - V characteristic" menu item, the I - V characteristic of the fuel cell is automatically plotted.

Conducting laboratory and practical exercises on the proposed device allows you to study:

structure, design and principle of operation of a solid oxide fuel cell;

fuel cell thermodynamics;

the characteristic curve and the curve of the change in the power of the fuel cell;

efficiency;

necessary components for the formation of power supplies based on solid oxide fuel cells for autonomous power supply of devices;

power electronics and voltage conversion.

Modes and parameters that can be set on the proposed device:

- Shutdown temperature: the maximum temperature of any of the device blocks (if there are appropriate temperature meters) at which the fuel supply to the reformer or fuel cell is shut off by closing the shut-off solenoid valve.

- Rotation speed of the fan for supplying oxidant to the fuel cell.

- Setting the electronic load mode: constant current (voltage change), constant voltage (current change) and constant power modes.

The developed visual-methodological device can be used both to demonstrate the operation of alternative energy sources, and as training and education of personnel working in the field of energy.

Claims (5)

1. A device for studying the structure and principle of operation of a solid oxide fuel cell (SOFC), including a cell for the investigated SOFC equipped with a heater, a flow meter, at least one fuel gas flow regulator, at least one branch pipe for supplying fuel gas to the device, means for displaying information and data input, a control board, a system of pipes and wire connections, where the control board is connected via wired connections to the heater and means for displaying information and data input, and the flow meter is installed directly on the board or is connected to it by a wired connection, in addition the control board contains wire connections for electrical contact with the SOFC under study. 2. The device according to claim 1, characterized in that it is equipped with an exhaust gas afterburner located at the outlet of the cell. 3. The device according to claim 1, characterized in that it is equipped with a reformer located on the fuel gas supply line to the cell for the investigated SOFC. 4. Device according to any one of paragraphs. 1-3, characterized in that it is equipped with a means of forced supply of the oxidant to the cell for the investigated SOFC and / or to the reformer and afterburner. 5. The device according to claim 1, characterized in that it is equipped with a protective heat-resistant screen.

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