KR101335505B1 - Air fuel ratio control apparatus and method of burner in reformer for fuel cell - Google Patents

Abstract

The present invention relates to an apparatus and method for adjusting burner air-fuel ratio of a reformer for a fuel cell to appropriately adjust the amount of air introduced into the burner so that fuel gas and residual hydrogen are completely burned in the burner in the reformer. According to the present invention, the oxygen sensor is installed in the exhaust pipe for detecting the oxygen concentration in the exhaust gas discharged from the reformer; And a controller for adjusting the amount of air supplied to the reformer by comparing the oxygen concentration value detected by the oxygen sensor with a preset oxygen concentration value.

Description

FUEL RATIO CONTROL APPARATUS AND METHOD OF BURNER IN REFORMER FOR FUEL CELL}

The present invention relates to a fuel cell, and more particularly, to a burner air-fuel ratio adjustment apparatus and method for properly adjusting the amount of air input to the burner so that fuel gas and residual hydrogen can be completely burned in the burner in the reformer. It is about.

A fuel cell is a power generation system that directly converts chemical energy into electrical energy through a chemical reaction with oxygen using hydrogen contained in hydrocarbon-based materials such as methanol, ethanol, and natural gas.

Polymer electrolyte membrane fuel cell (PEMFC) system is a high efficiency next generation distributed power generation system that produces electricity and heat by electrochemical reaction of hydrogen and air. The fuel cell system includes a fuel cell stack and a fuel processor as a main part, and additionally includes a fuel tank, a fuel pump, and the like.

In this case, the fuel cell stack has a structure in which several to several tens of unit cells including a membrane electrode assembly (MEA) and a separator are stacked, and the fuel processing device reforms the fuel gas to reform the hydrogen-rich reformed gas. A reformer for converting to a gas, a shift reactor for modifying and removing CO contained in the reforming gas, and a prox reactor.

The reformed gas generated in the fuel processor is supplied to the anode electrode of the fuel cell stack, and the hydrogen contained in the reformed gas meets with the oxygen supplied to the cathode electrode to perform an electrochemical reaction. It produces electricity and heat.

At this time, since the reaction in the reformer, the shift reactor and the proxy reactor is performed at a high temperature, the fuel processing apparatus is provided with a burner as a means for supplying necessary heat.

The burner basically burns fuel gas to generate heat, and the fuel gas is generally made up of hydrocarbon gas such as city gas.

Meanwhile, the reformed gas supplied to the anode of the fuel cell stack is not used in all of the power generation reactions occurring while passing through the fuel cell stack, and thus, residual hydrogen is not included in the gas discharged from the anode, that is, the anode off-gas. Gas is included.

At this time, by inducing the anode off-gas to the burner of the reformer, the combustion efficiency of the burner can be improved, Figure 1 shows such an example, Korean Patent Publication No. 10-2011-0051054 "polymer electrolyte type Fuel cell system ".

Here, the reformed gas exiting the reformer 10 is introduced into the fuel cell stack 30 through the selective oxidation reactor 20, and the remaining hydrogen gas discharged from the fuel cell stack 30 is reformed 10 again. Inflow into the burner 40 of the).

However, as described above, when the residual hydrogen gas is led to the burner and combusted, the residual hydrogen gas and the burner gas are combusted together. At this time, if the air-fuel ratio is not correct, the reactive hydrogen gas is first combusted, and a part of the burner gas is exhausted. There is a problem that the efficiency of the burner is lowered by being discharged to the gas.

In other words, when the oxygen is supplied due to the improper air-fuel ratio, there is a risk of harmful gas emission due to incomplete combustion, and when oxygen is excessively supplied, there is a problem that the reforming reaction does not occur due to the temperature decrease of the reformer due to the air cooling effect. .

Accordingly, in order to solve the above problems, the present invention measures the amount of burner gas and residual hydrogen gas supplied to the burner, and adjusts the burner air-fuel ratio of the reformer for a fuel cell to control the amount of air input to the burner so that complete combustion can occur. It is an object to provide an apparatus and method.

According to a preferred embodiment of the present invention, the oxygen sensor is installed in the exhaust pipe for detecting the oxygen concentration in the exhaust gas discharged from the reformer; And a controller for adjusting the amount of air supplied to the reformer by comparing the oxygen concentration value detected by the oxygen sensor with a preset oxygen concentration value.

Here, the reformer includes a reforming apparatus for reacting the fuel gas supplied with steam to reform the hydrogen gas into a reforming gas containing a main component, and a burner for supplying air and burner gas to supply the heat source required for the reforming process to the reforming apparatus. do.

The fuel cell stack may further include a fuel cell stack configured to receive the reformed gas and generate electricity by an electrochemical reaction, and a hydrogen recycling line configured to recycle unreacted hydrogen of the fuel cell stack to the burner.

Then, a flow meter is installed to measure the amount of fuel gas supplied to the reformer and the burner gas supplied to the burner, and the air amount measuring means is provided to measure the amount of air supplied to the burner.

In this case, a flow meter may be installed in the hydrogen recycle line to measure the amount of unreacted hydrogen recycled to the burner, and the air amount measuring means may be a flow meter or a pressure sensor.

On the other hand, according to an embodiment of the present invention, the step of measuring the amount of burner gas introduced into the burner of the reformer; Detecting an oxygen concentration value of the exhaust gas discharged from the burner by means of detection means; And adjusting the amount of air supplied to the burner by comparing the oxygen concentration value detected by the detection means with a preset oxygen concentration value.

At this time, in the hydrogen recycle line connected from the fuel cell stack to the burner, the amount of residual hydrogen introduced into the burner may be measured by a flow meter.

The method may further include determining a burner supply air amount according to a preset air-fuel ratio.

The amount of burner gas may be measured by a flow meter, the oxygen concentration of the exhaust gas may be detected by an oxygen sensor, and the amount of air supplied to the burner may be measured by a flow meter or a pressure sensor.

According to the burner air-fuel ratio control apparatus and method of the fuel cell reformer according to an embodiment of the present invention, by recycling the unreacted hydrogen gas of the fuel cell stack to the burner of the reformer, there is an effect that the efficiency of the fuel cell system is improved. .

In addition, since unreacted hydrogen gas, which is relatively preheated, is supplied to the burner of the reformer, compared to the fuel and water at room temperature supplied to the reformer, the amount of heat required for the reforming reaction is reduced, thereby improving the efficiency of the reformer and the fuel cell system. There is.

In addition, when the burner gas and the unreacted residual hydrogen gas are mixed and burned in the burner, by controlling the amount of air introduced into the burner so as to maintain an appropriate air-fuel ratio, it is possible to prevent the emission of harmful gas or the performance of the reformer.

1 is a schematic diagram showing an example of burning unreacted residual hydrogen by recirculation to a burner;
2 is a block diagram of a burner air-fuel ratio adjusting device for a reformer for a fuel cell according to a first embodiment of the present invention.
3 is a flow chart of a method for adjusting the burner air-fuel ratio of the reformer for a fuel cell according to the first embodiment of the present invention.
Figure 4 is a block diagram of a burner air-fuel ratio control device of the reformer for a fuel cell according to a second embodiment of the present invention.
5 is a configuration diagram of a burner air-fuel ratio adjusting apparatus of a reformer for a fuel cell according to a third embodiment of the present invention.
Figure 6 is a flow chart of the burner air-fuel ratio control method of the reformer for a fuel cell according to a third embodiment of the present invention.
7 is a flow chart of a method for adjusting the burner air-fuel ratio of the reformer for a fuel cell according to a fourth embodiment of the present invention.

Hereinafter, a burner air-fuel ratio adjusting apparatus and method of a reformer for a fuel cell according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

In addition, the following embodiments are not intended to limit the scope of the present invention, but merely as exemplifications of the constituent elements set forth in the claims of the present invention, and are included in technical ideas throughout the specification of the present invention, Embodiments that include components replaceable as equivalents in the elements may be included within the scope of the present invention.

First Embodiment

2 is a block diagram of a burner air-fuel ratio control apparatus of a reformer for a fuel cell according to a first embodiment of the present invention.

As shown in FIG. 2, the burner air-fuel ratio adjusting apparatus 100 of the reformer for a fuel cell according to the first embodiment of the present invention includes an oxygen sensor 500 for detecting an oxygen concentration of exhaust gas discharged from the reformer 200. And a controller 600 for adjusting the air amount of the combustion air supplied to the burner 220 of the reformer 200.

In addition, the fuel cell stack 300 which receives the reformed gas from the reformer 200 to generate electricity, and hydrogen which recycles unreacted hydrogen remaining in the fuel cell stack 300 to the burner 220 of the reformer 200. The recycling line 400 may further include.

Here, the reformer 200 includes a reformer 210 and a burner 220. The reformer 210 reacts the fuel gas with water vapor to reform the hydrogen into a reformed gas (sorigas). The fuel gas is supplied by the first pump 211 as a hydrocarbon fuel such as LNG, LPG, kerosene or the like.

In addition, the burner 220 is to maintain an appropriate temperature to facilitate the endothermic reforming reaction in the reforming apparatus 210, the room temperature (10 ℃) inside or outside the fuel cell system through the second pump (221) ˜40 ° C.) air is supplied, and burner gas is supplied through the third pump 222 to burn. At this time, the burner gas is a hydrocarbon-based fuel of the same kind as the fuel gas, and of course, it is also possible to use a conventional fluid transfer mechanism such as a blower instead of the pump.

Typically, a reformer for producing hydrogen by reacting fuel gas with steam, a shift converter for removing carbon monoxide so that the generated hydrogen gas does not poison the catalyst of the fuel cell stack 300, and an optional converter. The reformer 200 may also be referred to as a reformer including a Prox reactor, and the reformer 200 referred to hereinafter may be referred to as a reformer 210, and a burner for supplying a heat source for the reforming reaction. Note that it is referred to as a reformer 200, including (220) in advance.

The fuel cell stack 300 includes an anode and a cathode in each cell, a reformed gas discharged from the reformer 200 is supplied to the anode, air is supplied from the outside to the cathode, and an electrolyte membrane is formed. An electrochemical reaction proceeds as a medium to generate a current.

At this time, while the reformed gas passes through the fuel cell stack 300, not all reformed gas is used for the reaction for generating electricity, and the remaining hydrogen gas used for the reaction is used to improve the overall efficiency of the fuel cell system. It is mixed with a trace amount of unreformed fuel gas and re-supplied to the burner 220 of the reformer 200 through the hydrogen recycle line 400 as an anode-off gas.

At this time, since the anode off-gas is preheated by the heat of the fuel cell stack 300 when it is discharged from the fuel cell stack 300, the amount of burner gas supplied to the burner 220 can be reduced, and thus the burner Fuel consumption of the 220 is reduced, resulting in an increase in the efficiency of the fuel cell system including the reformer 200.

When the anode off gas is supplied to the burner 220 through the hydrogen recirculation line 400, combustion is performed while the anode off gas and the burner gas are mixed, and when the air is not supplied at an appropriate air-fuel ratio, the reformer ( Hazardous exhaust gas is discharged from 200 or the performance of the reformer 200 is degraded.

That is, when a smaller amount of air is supplied than the appropriate air-fuel ratio, hydrogen with high reactivity is first combusted, and a part of the burner gas is discharged to the exhaust gas, thereby lowering the efficiency of the burner 220 or emitting harmful gas due to incomplete combustion. If the air is excessively supplied, the reformer 200 may be dropped in temperature, thereby preventing the reforming reaction from occurring.

Therefore, it is necessary to appropriately adjust the air-fuel ratio of the burner 220, for this purpose by installing an oxygen sensor 500 in the exhaust pipe 230 of the reformer 200 to determine the oxygen concentration in the exhaust gas discharged from the reformer 200. The amount of air supplied to the burner 220 is adjusted by controlling the operation of the second pump 221 through the controller 600 by detecting and comparing the detected oxygen concentration with a predetermined oxygen concentration value.

At this time, the target oxygen concentration value is preferably set to an appropriate range of values (for example, 4% to 6%). If the oxygen concentration value is too low, there is a risk of generation of harmful gases, and if the oxygen concentration value is too high, the reformer ( This is because there is a possibility that the performance of 200) may be degraded.

In addition, a flowmeter 700 is installed in the fuel gas supply line 212 and the burner gas supply line 223, respectively, to measure the amount of fuel gas supplied to the reformer 210 and burner gas supplied to the burner 220. Will be measured.

Therefore, the operation of the second pump 221 may be controlled by determining the air supply amount corresponding to the preset air-fuel ratio according to the measured value of the burner gas supplied to the burner 220.

At this time, in order to measure the amount of air supplied to the burner 220, air amount measuring means is installed in the air supply line 224 of the burner 220, the air amount measuring means is a flow meter 700 or a flow meter ( 700 may be used by installing a lower-cost pressure sensor (not shown). At this time, since the value measured by the pressure sensor may change according to the humidity of the gas, it is also possible to obtain a more precise correction value by adding a humidity sensor (not shown).

3 is a flow chart of a method for adjusting the burner air-fuel ratio of the reformer for a fuel cell according to the first embodiment of the present invention. Hereinafter, a method of controlling an air fuel ratio of a burner for a fuel cell according to a first embodiment of the present invention will be described with reference to FIG. 3.

Base air fuel ratio setting step ( S10 ):

The theoretical air-fuel ratio for complete combustion is set as the reference air-fuel ratio. In this case, the reference air-fuel ratio may be previously stored in the controller 600 as a default value, or may be newly set by the user. If necessary, the reference air-fuel ratio may be set as a reference air-fuel ratio.

Burner gas volume measurement step ( S20 ):

The amount of burner gas supplied to the burner 220 along the burner gas supply line 223 by the third pump 222 is measured by the flowmeter 700, and the measured value is transmitted to the controller 600.

Air Supply Determination Step ( S30 ):

With respect to the burner gas amount measured, the air supply amount according to the reference air-fuel ratio is determined by the controller 600, and the air supply amount is adjusted by controlling the operation of the second pump 221 (S40). In this case, the air supply amount is measured by a flow meter 700 or a pressure sensor installed in the air supply line 224.

Exhaust gas oxygen Concentration  Detection step ( S50 ):

The oxygen concentration value of the exhaust gas discharged through the exhaust pipe 230 of the reformer 200 is detected by the oxygen sensor 500, and the detected value is transmitted to the controller 600.

At this time, the controller 600 determines whether the detected oxygen concentration value is within a preset range (S60), and if it is outside the range, controls the operation of the second pump 221 to adjust the air supply amount, and if it is within the range, proceeds to the next step. do.

Air-fuel ratio calculation and reset phase ( S70 ):

The current air-fuel ratio is calculated based on the measured burner gas amount and the air supply amount, and is reset to the reference air-fuel ratio, and the flow returns to the burner gas amount measuring step S20 and the above-described process is repeated.

Second Embodiment

4 is a flow chart of a method for adjusting the burner air-fuel ratio of the reformer for a fuel cell according to the second embodiment of the present invention.

The burner air-fuel ratio adjustment method of the reformer for a fuel cell according to the second embodiment of the present invention is similar to the first embodiment of FIG. 3 described above, except that the reformer 200 can maintain a temperature suitable for the reforming reaction. A temperature sensor (not shown) is installed in the 200, and the controller 600 controls the third pump 222 to adjust the amount of burner gas supplied through the burner gas supply line 223 according to the measured temperature value. In this case, there is a difference in that the second pump 221 is controlled to supply air according to an appropriate air-fuel ratio.

That is, the temperature of the reformer 200 is measured through a temperature sensor installed in the reformer 200 (S80), and if the measured value is within the temperature range required for the reforming reaction, it is determined to be normal (S90) and the second pump 221. To control the operation of, and if the measured temperature value is outside the temperature range required for the reforming reaction to control the operation of the third pump 222 (S100) is to reduce or increase the amount of burner gas supplied to the burner 220 . Of course, thereafter, as described above with reference to FIG. 3, the air supply amount is adjusted to an appropriate air-fuel ratio.

Third Embodiment

5 is a configuration diagram of a burner air-fuel ratio adjusting apparatus for a fuel cell reformer according to a third embodiment of the present invention, and FIG. 6 is a flowchart of a method for adjusting burner air-fuel ratio of a reformer for fuel cells according to a third embodiment of the present invention.

The third embodiment of the present invention is generally similar to the first embodiment described above, except that the flow meter 700 is installed in the hydrogen recycle line 400, and burner of the hydrogen remaining unreacted in the fuel cell stack 300 ( 220) There is a difference in measuring inputs.

Hereinafter, a third embodiment of the present invention will be described in detail with reference to FIGS. 5 and 6.

As shown in FIG. 5, the burner air-fuel ratio adjusting apparatus 100 of the reformer for a fuel cell according to the third embodiment of the present invention includes an oxygen sensor 500 that detects an oxygen concentration of exhaust gas discharged from the reformer 200. And a controller 600 for adjusting the air amount of the combustion air supplied to the burner 220 of the reformer 200.

In addition, the fuel cell stack 300 which receives the reformed gas from the reformer 200 to generate electricity, and hydrogen which recycles unreacted hydrogen remaining in the fuel cell stack 300 to the burner 220 of the reformer 200. The recycling line 400 may further include.

Here, the reformer 200 includes a reformer 210 and a burner 220. The reformer 210 reacts the fuel gas with water vapor to reform the hydrogen into a reformed gas (sorigas). The fuel gas is supplied by the first pump 211 as a hydrocarbon fuel such as LNG, LPG, kerosene or the like.

In addition, the burner 220 is to maintain an appropriate temperature to facilitate the endothermic reforming reaction in the reforming apparatus 210, the room temperature (10 ℃) inside or outside the fuel cell system through the second pump (221) ˜40 ° C.) air is supplied, and burner gas is supplied through the third pump 222 to burn. At this time, the burner gas is a hydrocarbon-based fuel of the same kind as the fuel gas, and of course, it is also possible to use a conventional fluid transfer mechanism such as a blower instead of the pump.

Typically, a reformer for producing hydrogen by reacting fuel gas with steam, a shift converter for removing carbon monoxide so that the generated hydrogen gas does not poison the catalyst of the fuel cell stack 300, and an optional converter. The reformer 200 may also be referred to as a reformer including a Prox reactor, and the reformer 200 referred to hereinafter may be referred to as a reformer 210, and a burner for supplying a heat source for the reforming reaction. It is referred to as a reformer 200, including the (220) as described above.

The fuel cell stack 300 includes an anode and a cathode in each cell, a reformed gas discharged from the reformer 200 is supplied to the anode, air is supplied from the outside to the cathode, and an electrolyte membrane is formed. An electrochemical reaction proceeds as a medium to generate a current.

At this time, while the reformed gas passes through the fuel cell stack 300, not all reformed gas is used for the reaction for generating electricity, and the remaining hydrogen gas used for the reaction is used to improve the overall efficiency of the fuel cell system. It is mixed with a trace amount of unreformed fuel gas and re-supplied to the burner 220 of the reformer 200 through the hydrogen recycle line 400 as an anode-off gas.

At this time, since the anode off-gas is preheated by the heat of the fuel cell stack 300 when it is discharged from the fuel cell stack 300, the amount of burner gas supplied to the burner 220 can be reduced, and thus the burner Fuel consumption of the 220 is reduced, resulting in an increase in the efficiency of the fuel cell system including the reformer 200.

When the anode off gas is supplied to the burner 220 through the hydrogen recirculation line 400, combustion is performed while the anode off gas and the burner gas are mixed, and when the air is not supplied at an appropriate air-fuel ratio, the reformer ( Hazardous exhaust gas is discharged from 200 or the performance of the reformer 200 is degraded.

That is, when a smaller amount of air is supplied than the appropriate air-fuel ratio, hydrogen with high reactivity is first combusted, and a part of the burner gas is discharged to the exhaust gas, thereby lowering the efficiency of the burner 220 or emitting harmful gas due to incomplete combustion. If the air is excessively supplied, the reformer 200 may be dropped in temperature, thereby preventing the reforming reaction from occurring.

Therefore, it is necessary to appropriately adjust the air-fuel ratio of the burner 220, for this purpose by installing an oxygen sensor 500 in the exhaust pipe 230 of the reformer 200 to determine the oxygen concentration in the exhaust gas discharged from the reformer 200. The amount of air supplied to the burner 220 is adjusted by controlling the operation of the second pump 221 through the controller 600 by detecting and comparing the detected oxygen concentration with a predetermined oxygen concentration value.

At this time, the target oxygen concentration value is preferably set to an appropriate range of values (for example, 4% to 6%). If the oxygen concentration value is too low, there is a risk of generation of harmful gases, and if the oxygen concentration value is too high, the reformer ( This is because there is a possibility that the performance of 200) may be degraded.

In addition, a flowmeter 700 is installed in the fuel gas supply line 212, the burner gas supply line 223, and the hydrogen recirculation line 400, respectively, to the fuel gas and the burner 220 supplied to the reformer 210. The amount of burner gas supplied and the amount of unreacted hydrogen gas recycled to the burner 220 are measured.

Therefore, the operation of the second pump 221 may be controlled by determining the air supply amount corresponding to the preset air-fuel ratio according to the measured values of the burner gas and the unreacted hydrogen gas supplied to the burner 220.

At this time, in order to measure the amount of air supplied to the burner 220, air amount measuring means is installed in the air supply line 224 of the burner 220, the air amount measuring means is a flow meter 700 or a flow meter ( 700 may be used by installing a lower-cost pressure sensor (not shown). At this time, since the value measured by the pressure sensor may change according to the humidity of the gas, it is also possible to obtain a more precise correction value by adding a humidity sensor (not shown).

Hereinafter, a method of controlling an air fuel ratio of a burner for a fuel cell according to a third embodiment of the present invention will be described with reference to FIG. 6.

Base air fuel ratio setting step ( S10 ):

The theoretical air-fuel ratio for complete combustion is set as the reference air-fuel ratio. In this case, the reference air-fuel ratio may be previously stored in the controller 600 as a default value, or may be newly set by the user. If necessary, the reference air-fuel ratio may be set as a reference air-fuel ratio.

Burner gas volume measurement step ( S20 ):

The amount of burner gas supplied to the burner 220 along the burner gas supply line 223 by the third pump 222 is measured by the flowmeter 700, and the measured value is transmitted to the controller 600.

Residual hydrogen measurement step ( S25 ):

The amount of residual hydrogen supplied to the burner 220 along the hydrogen recycle line 400 from the anode of the fuel cell stack 300 is measured by the flowmeter 700, and the measured value is transmitted to the controller 600.

Air supply judging step ( S30 ):

With respect to the burner gas amount and the residual hydrogen amount, the air supply amount according to the reference air-fuel ratio is determined by the controller 600, and the air supply amount is adjusted by controlling the operation of the second pump 221 (S40). In this case, the air supply amount is measured by a flow meter 700 or a pressure sensor installed in the air supply line 224.

Exhaust gas oxygen Concentration  Detection step ( S50 ):

The oxygen concentration value of the exhaust gas discharged through the exhaust pipe 230 of the reformer 200 is detected by the oxygen sensor 500, and the detected value is transmitted to the controller 600.

At this time, the controller 600 determines whether the detected oxygen concentration value is within a preset range (S60), and if it is outside the range, controls the operation of the second pump 221 to adjust the air supply amount, and if it is within the range, proceeds to the next step. do.

Air-fuel ratio calculation and reset phase ( S70 ):

The current air-fuel ratio is calculated based on the measured burner gas amount, the residual hydrogen amount, and the air supply amount, and is reset to the reference air-fuel ratio, and the flow returns to the burner gas amount measuring step S20 and the above-described process is repeated.

Fourth Embodiment

7 is a flowchart of a method for adjusting the burner air-fuel ratio of the reformer for a fuel cell according to the fourth embodiment of the present invention.

The burner air-fuel ratio adjustment method of the reformer for a fuel cell according to the fourth embodiment of the present invention is similar to the above-described third embodiment, except that the reformer 200 maintains a temperature suitable for the reforming reaction. A temperature sensor (not shown) is installed in the controller, and the controller 600 controls the amount of burner gas supplied through the burner gas supply line 223 by controlling the third pump 222 according to the measured temperature value. The two pumps 221 are different in that they are controlled to supply air according to an appropriate air-fuel ratio.

That is, the temperature of the reformer 200 is measured through a temperature sensor installed in the reformer 200 (S90), and if the measured value is within the temperature range required for the reforming reaction, it is determined as normal (S100) and the second pump 221. To control the operation of, and if the measured temperature value is outside the temperature range required for the reforming reaction to control the operation of the third pump 222 (S110) is to reduce or increase the amount of burner gas supplied to the burner 220 . Of course, thereafter, as described above in the third embodiment, the air supply amount is adjusted at an appropriate air-fuel ratio.

100: burner air-fuel ratio control device of the fuel cell reformer
200: reformer
210: reformer
220: Burner
230: exhaust pipe
300: fuel cell stack
400: hydrogen recycle line
500: oxygen sensor
600: controller
700: Flow Meter

Claims (11)

A reformer including a reformer for reacting the supplied fuel gas with steam to reform the hydrogen into a reforming gas mainly composed of hydrogen, and a burner for receiving air and burner gas and supplying a heat source for reforming to the reformer;
An oxygen sensor installed in the exhaust pipe to detect the oxygen concentration in the exhaust gas discharged from the reformer;
A hydrogen recycling line for recycling unreacted hydrogen of the fuel cell stack receiving the reformed gas from the reformer to generate electricity by an electrochemical reaction, to the burner;
According to the measured value of the amount of burner gas supplied to the burner and the amount of unreacted hydrogen recycled to the burner, the amount of air supplied to the burner is adjusted to match a preset air-fuel ratio, And a controller for adjusting the amount of air supplied to the burner by comparing the oxygen concentration value detected by the oxygen sensor with a preset oxygen concentration value.
delete delete The method according to claim 1,
Flow meters are respectively installed to measure the amount of fuel gas supplied to the reformer and burner gas supplied to the burner, and air amount measuring means is provided to measure the amount of air supplied to the burner. Burner air-fuel ratio control device for fuel cell reformer.
The method according to claim 1,
Burner air-fuel ratio control apparatus of the reformer for a fuel cell, characterized in that the flow meter is installed in the hydrogen recycle line to measure the amount of unreacted hydrogen recycled to the burner.
The method according to claim 4, The air amount measuring means,
Burner air-fuel ratio regulating device of a reformer for a fuel cell, characterized in that the flow meter or pressure sensor.
Measuring the amount of burner gas introduced into the burner of the reformer;
In the hydrogen recycle line from the fuel cell stack to the burner, the amount of residual hydrogen introduced into the burner is measured by a flow meter;
Adjusting an amount of air supplied to the burner according to a predetermined air-fuel ratio with respect to the measured amount of burner gas and the remaining amount of hydrogen;
Detecting an oxygen concentration value of the exhaust gas discharged from the burner by means of detection means; And
And adjusting the amount of air supplied to the burner by comparing the oxygen concentration value detected by the detecting means with a preset oxygen concentration value.
delete delete The method of claim 7,
The amount of burner gas is measured by a flow meter, and the oxygen concentration value of the exhaust gas is detected by an oxygen sensor.
The method of claim 7,
Method of adjusting the burner air-fuel ratio of the reformer for a fuel cell, characterized in that the amount of air supplied to the burner is measured by a flow meter or a pressure sensor.

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