KR20060130957A - Condensation water fuzzing system inside stack of fuel cell car and fuzzing method thereof - Google Patents

Abstract

Provided are an apparatus and a method for fuzzing condensed water of fuel cell vehicles, which prevent an occlusion of a channel by condensation of water even after long-term neglect, and thus improve low-temperature starting of a fuel cell stack and enhance durability. The apparatus for fuzzing condensed water of fuel cell vehicles comprises: many pipelines that form passages through which an air flow system forming a fuel cell system together with a hydrogen flow system and a cooling water flow system supplies air to a fuel cell stack(4) or sucks air from the fuel cell stack(4); many control valves(a-g) configured to form air flow passages to respective devices(1,2,3,5,6) installed on the pipelines; and ECU that controls many sensors(8) for measuring outside temperature and the devices(1,2,3,5,6) and respective control valves(a-g) for supplying air to the fuel cell stack(4) to perform fuzzing while a vehicle(V) measures the operation state.

Description

Condensation water fuzzing system inside stack of fuel cell car and fuzzing method

1 is a block diagram of a condensate purging device of a fuel cell vehicle according to the present invention

2 (a), (b) is a condensed water purge state diagram of a fuel cell vehicle according to the present invention

3 is a state diagram of a pause mode of a fuel cell vehicle according to the present invention.

4 is a suction mode state diagram of a fuel cell vehicle according to the present invention.

5 is a flowchart illustrating a condensate purging method of a fuel cell vehicle according to the present invention.

6 is a state diagram of a driving mode of a fuel cell vehicle according to the present invention.

    <Description of the symbols for the main parts of the drawings>

1: filter 2: compressor

3: humidifier 4: fuel cell stack

5: gas-liquid separator 6: water tank

7: Humid temperature sensor 8: Outside temperature sensor

10: stack connection line 11: humidifier connection line

12: stack discharge line 13: condensate recovery line

14: compressor connection line 15: stack auxiliary connection line

a, b, c, d, e, f, g: control valve V: vehicle

The present invention relates to a fuel cell vehicle, and more particularly, to a condensate purging device and a purging method of a fuel cell vehicle to remove condensate inside a fuel cell stack by forming the inside of the stack lower than atmospheric pressure at an outside air temperature of 4 ° C. or lower when stopped. .

Recently, in order to solve the problems caused by the use of fossil fuels, a battery system that generates electricity by supplying fuel (hydrogen gas or hydrocarbon) to the cathode and oxygen to the anode, that is, an anode and a cathode with an electrolyte in between. A fuel cell system is being developed that arranges a pair of electrodes and obtains both electricity and heat through the electrochemical reaction of ionized fuel gas.

The fuel cell power generation method directly converts the energy difference before and after the reaction into electrical energy through the electrochemical reaction between hydrogen and oxygen without undergoing combustion (oxidation) reaction of the fuel. Like fossil fuels, NOx and SOx It does not occur, and there is no noise and vibration, but the thermal efficiency is an eco-friendly power generation system of more than 80% of the combined amount of electricity generation and heat recovery.

The BOP (Balancing of Plant) of the fuel cell vehicle is typically an air supply unit forcibly blowing air, a hydrogen / water supply unit, a fuel cell stack, and humidity, temperature, and pressure in the system during operation. And a controller for controlling the components by receiving signals from sensors that measure information such as flow rate.

At this time, air and hydrogen flow rate and pressure flowing into the fuel cell stack are detected by a plurality of sensors located at the front and rear of the fuel cell stack, and controlled by a pressure regulator or a control valve to meet the requirements of the fuel cell stack.

In addition, such a fuel cell system has high humidity because gas is generated due to electrochemical reactions during operation of the fuel cell stack, heat generation, and water generation, that is, water is generated in the electrochemical reaction of the fuel cell at the cathode. In the anode, since the hydrogen ions are combined with water molecules and move through the electrolyte membrane to the cathode, the anode is further dried.

Therefore, the water management control to maintain a constant humidity by recovering the water generated during the electrochemical reaction of the fuel cell stack and re-supplied to the fuel hydrogen and air gas, of course, especially when the fuel is stopped In order to remove water remaining in the battery stack, a control is performed to force discharge of pressurized air into the stack by using an air supply device.

However, even when pressurized air is blown into the fuel cell stack and forcedly discharged, water condensed inside the fuel cell electrode or the electrode of the fuel electrode (especially between the catalyst layer and the gas diffusion layer) cannot be effectively removed. If the remaining condensed water condenses when the fuel cell stack is cooled below freezing point, the volume expands and a physical stress is applied to the catalyst layer.

In addition, in the condensed water condensed in the fuel cell stack as described above, the condensed water prevents gas diffusion into the electrode, thereby making it difficult to start early.

Accordingly, the present invention has been made in view of the above, and when the air is stopped, the flow passage between the air compressor and the fuel cell stack is controlled at an ambient temperature of 4 ° C. or lower, thereby supplying air in a state in which the pressure inside the stack is lower than atmospheric pressure. The purpose of this is to completely remove the remaining moisture and to prevent the low temperature start-up deterioration caused by the condensation below the freezing point of water.

The present invention for achieving the above object, the hydrogen flow system for condensing the discharged hydrogen while supplying hydrogen to the fuel cell stack, the cooling water flow system to remove and supply the ions in the supplied cooling water and supply air from the outside In a fuel cell vehicle consisting of an air flow system,

The air flow system is a stack connection line for purifying the external air sucked through the compressor using an air cleaner and then heating it to an appropriate temperature to pass air through the humidifier to remove moisture in the air to form an air passage into the fuel cell stack. And a humidifier connection line connecting the humidifier and the water tank, the gas discharge separator separating water from the gas discharged from the fuel cell stack, and a stack discharge line installed with a humidity sensor for measuring humidity in the discharge gas. Condensate recovery line connecting between the gas-liquid separator and the water tank to recover the separated condensate to the water tank while passing through the gas-liquid separator, and connected to the stack connection line to be located in front of the compressor at the rear of the gas-liquid separator installed in the stack discharge line. Compressor connection line and air cleaner installed on the stack connection line A piping line consisting of a stack auxiliary connection line which bypasses the path of the stack connection line branched from the rear to the back of the humidifier and connected to the fuel cell stack;

A first control valve located between the air cleaner and the compressor on the stack connection line, a second control valve installed between the compressor and the humidifier, a third control valve installed between the humidifier and the fuel cell stack on the stack connection line, A control consisting of a fourth control valve located in the humidifier connection line, a fifth control valve located in the condensate return line, a sixth control valve located in the compressor connection line, and a seventh control valve located in the stack auxiliary connection line. valve;

An outside air temperature sensor measuring outside temperature of the vehicle;

 An ECU which performs purging while controlling the control valves to reduce low temperature startability due to freezing before receiving a signal from an outside temperature sensor and various sensors installed in the vehicle; Characterized in that consisting of.

In addition, the condensate purging method of the present invention comprises an initial condition determination step of determining that the external temperature measured by the outside air temperature sensor installed outside the vehicle is at a temperature low enough to achieve water freezing and the driving stop state;

Preliminary purging step of performing air blowing mode to remove water remaining in the front part of the fuel cell stack by circulating air only in front of the fuel cell stack when starting again after satisfying the initial condition determination step. ;

After the first purging step, the air blows through the fuel cell stack, and blows the air to remove the remaining water in the front and rear portions with the fuel cell stack as the center, and then executes the air blowing / suction mode to inhale again. Main purging step;

After the main purging step, a temporary stop mode step of supplying air to the fuel cell stack without driving the compressor in order to prevent damage to the compressor supplying the compressed air due to a sudden pressure fluctuation caused by the opening and closing operation of each control valve according to the driving of the vehicle. ;

An operation mode preparation step of removing water remaining in the outside air passing through the fuel cell stack while the fuel cell stack is formed at a low pressure by the suction force of the compressor driven to have a small load after the pause mode step;

A driving step of driving the vehicle by driving an electric motor with an electric energy load generated in the stack by supplying hydrogen, cooling water, and air to a fuel cell stack after the operation mode preparation step; Characterized in that performed.

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

1 is a block diagram of a condensate purging device of a fuel cell vehicle according to the present invention. The fuel cell system of the present invention includes a hydrogen flow system for condensing hydrogen discharged while supplying hydrogen to a fuel cell stack, and It is composed of a cooling water flow system for supplying air from the outside and the cooling water flow system to supply after removing the ions in the cooling water,

The air flow system is supplied through an air cleaner (1) for removing foreign matters of the supplied air, a compressor (2) for pressurizing the air supplied from the air cleaner (1) to a predetermined pressure, and the compressor (2) A humidifier (3) for heating the air to an appropriate temperature to remove moisture in the air, a fuel cell stack (4) for supplying hydrogen and cooling water together with air to supply electricity generated by a chemical reaction between air and hydrogen to the motor, A gas-liquid separator 5 for separating water from the gas discharged from the fuel cell stack 4, a water tank 6 for storing condensed water separated from the gas-liquid separator 5, and discharged from the fuel cell stack 4 Sensor to measure humidity in the gas to be measured and the outside temperature of the vehicle (V), Piping line connecting the devices (1, 2, 3, 5, 6) to supply air to the fuel cell stack (4) And installed in the pipe line Been dog, lungs through the ECU to control the is composed of a plurality of control valves for controlling the flow passage of the air and condensed water.

Here, the sensor is composed of a wet temperature sensor (7) for sensing the moisture in the gas discharged to the rear end of the gas-liquid separator (5), an outside temperature sensor (8) for measuring the outside temperature of the vehicle (V), Although not shown, the flow rate and pressure of the incoming air and hydrogen are located at the front and rear of the fuel cell stack, and the ECU controls the entire flow rate and pressure to meet the requirements of the fuel cell stack.

The pipe line includes a stack connection line 10 connected to external air introduced from the air cleaner 1 to the fuel cell stack 4 through the compressor 2 and the humidifier 3, and the fuel cell. Humidifier connection line 11 connecting the humidifier 3 and the water tank 6 to heat the air supplied to the stack 4 to remove moisture, and the gas discharged from the fuel cell stack 4 to the outside. Stack discharge line 12 passing through the gas-liquid separator 5 to discharge, the gas-liquid separator 5 and the water tank 6 to recover the condensed water separated through the gas-liquid separator 5 toward the water tank 6. A condensate recovery line 13 connecting between the compressor connection line 14 and the stack connection line 10 connected to the front of the compressor 2 at the rear of the gas-liquid separator 5 installed in the stack discharge line 12. Branch behind the air cleaner (1) to the rear of the humidifier (3) It comprises a fuel cell stack (4) in the stack secondary connection line 15 for supplying a small amount of air customs (small diameter pipes).

Here, the stack auxiliary connection line 15 is introduced into the compressor 2 through the compressor connection line 14 after a small amount of air passes through the fuel cell stack 4 to reduce the load of the compressor 2. Along with the zoom, the decompression of the stack 4 is accompanied by a secondary function of evaporating condensate in the stack 4.

In addition, the control valves (a, b, c) provided on the stack connection line (10) of the control valve opening and closing control by the ECU is the compressor connection line (14) between the air cleaner (1) and the compressor (2) Is installed between the first control valve (a) and the second control valve (b) installed between the compressor (2) and the humidifier (3) and between the humidifier (3) and the fuel cell stack (4). And a third control valve (c).

The control valve of the humidifier connection line 11 is installed between the humidifier 3 and the water tank 6 as a fourth control valve d.

In addition, the control valve of the condensate recovery line 13 is installed between the gas-liquid separator 5 and the water tank 6 as the fifth control valve (e).

In addition, the control valve of the compressor connection line 14 is the sixth control valve (f), on the stack connection line 10 leading to the stack discharge line 12 and the compressor 2 at the rear of the gas-liquid separator 5. It is connected to the stack connection line 10 from the rear of the first control valve (a) installed in.

In addition, the control valve of the stack auxiliary connection line 15 is the seventh control valve (g), the rear of the third control valve (c) in front of the first control valve (a) installed in the stack connection line (10). In the stack connection line 10 is connected.

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

The present invention blows compressed air into the fuel cell stack 4 at ambient temperature of 4 ° C. or lower when the vehicle is stopped and condensed water and water remaining in the humidifier 3 and the fuel cell stack 4. This prevents the lowering of low temperature startability due to condensation below freezing point of water.

That is, when the ECU determines that the external temperature measured by the outside temperature sensor 8 installed outside the vehicle V is 4 ° C. or lower as shown in FIG. 5, the fuel cell stack 4 is stopped. Humidifier blowing mode for removing the moisture or condensate in the humidifier (3) provided in the stack connection line 10, which is a passage for supplying external air to the air.

This blowing mode removes moisture or condensate in the humidifier 3 by blowing air between the stack connection line 10 and the humidifier connection line 11, as shown in FIG. 2 (a). While opening the first and second control valves (a, b) provided in the stack connection line (10) and the fourth control valve (d) provided in the humidifier connection line (11) to secure an air supply passage, The 6 · 7 control valves (c, f, g) are closed.

Subsequently, the ECU drives the compressor 2 so that compressed air flows into the humidifier 3 through the stack connection line 10, and then discharges moisture or condensed water in the humidifier 3 as air pressure to connect the humidifier to the humidifier. (11) is introduced into the water tank (6), wherein the remaining water in the humidifier connecting line 11 is returned to the water tank (6) while the compressed air supplied passes through the compressed air is a water tank ( It is discharged to outside through 6).

At this time, the fifth control valve (e) provided in the condensate recovery line 13 is also opened to discharge moisture or condensate in the gas-liquid separator 5 to the water tank 6 through the condensate recovery line 13. As the internal pressure in the fuel cell stack 4 decreases due to the closing of the third control valve c, a low pressure is generated in the stack discharge line 12. As a result, the moisture or condensed water in the gas-liquid separator 5 becomes a water tank. Discharged to (6).

As such, after moisture or condensate in the humidifier 3 is removed, as shown in FIG. 5, a blowing mode for removing moisture or condensate in the fuel cell stack 4 is performed.

2, the compressed air is blown into the stack connection line 10, passed through the fuel cell stack 4, and then discharged into the stack discharge line 12 to absorb moisture in the stack 4. B. Condensate is removed. To this end, the ECU is provided with the first, second and third control valves a, b, and c provided in the stack connection line 10 and the condensate return line 13 to secure an air supply passage. While opening the fifth control valve e, the other fourth, sixth and seventh control valves d, f and g are closed.

At this time, the ECU performs a process of removing the moisture or condensate in the humidifier (3), the fuel cell stack (4) and the cooling water line while blowing the air and then sucking the air again.

That is, when the ECU drives the compressor 2 to blow compressed air, the compressed air passes through the fuel cell stack 4 through the humidifier 3 through the stack connection line 10 and then the stack discharge line ( In this case, the compressed air is introduced into the cathode region and the cooling water line partitioning the humidifier 3 and the fuel cell stack 4 provided in the stack connection line 10.

The compressed air supplied as described above discharges water again from the humidifier 3 and the humidifier connection line 11 connected thereto, and discharges moisture or condensed water to the outside while passing through the cathode region of the fuel cell stack 4. Given.

Subsequently, the ECU drives the compressor 2 to form a vacuum negative pressure to make the inside of the fuel cell stack 4 low pressure, and the anode region partitioning the inside of the fuel cell stack 4 due to the vacuum negative pressure thus formed. The remaining moisture or condensate is sucked out, thereby removing both the air electrode and the remaining moisture or condensate in the fuel electrode stack 4.

Subsequently, after fuzzing the humidifier 3 and the fuel cell stack 4 as shown in FIG. 5, the compressor 2 may be caused by a sudden pressure fluctuation due to the opening and closing of each control valve. Temporary Stop Mode is used to prevent damage.

This is called a compressor pause mode or a low speed drive mode, as shown in FIG. 3. To this end, the ECU closes the first, second and third control valves a, b, and c provided in the stack connection line 10. While not driving the compressor (2), while the seventh control valve (g) is opened and the air introduced from the air cleaner (1) is supplied to the fuel cell stack (4) through the stack auxiliary connection line (15), Pass through the fuel cell stack 4 is discharged to the outside through the stack discharge line (12).

At this time, since the stack auxiliary connection line 15 is a custom pipe (small diameter pipe) for supplying a small amount of air to the fuel cell stack 4, the pressure change inside the fuel cell stack 4 does not occur much. .

In addition, the ECU opens the sixth control valve f, but since the compressor 2 does not operate, air flow through the compressor connection line 14 does not occur, and the open fifth control valve e is gas-liquid. Of course, the separator 5 discharges moisture or condensed water into the water tank 6 through the condensate return line 13.

Subsequently, as shown in FIG. 5, a suction mode is performed to remove moisture or condensed water through a small compressor 2 load while decompressing the inside of the fuel cell stack 4 to prepare a normal operation mode.

That is, as shown in FIG. 4, after a small amount of air is supplied to the fuel cell stack 4 through the stack auxiliary connection line 15 without passing through the stack connection line 10, the stack discharge line 12 and the stack discharge line 12 are again provided. The compressor is connected to the compressor 2 through the compressor connection line 14 connecting the stack connection lines 10 to be controlled to be discharged to the outside through the water tank 6 through the humidifier connection line 11.

To this end, the ECU opens the second and fourth control valves b and d while closing the first and third control valves a and c such that the stack connection line 10 and the humidifier connection line 11 communicate with each other. After the small amount of air is supplied through the stack auxiliary connection line 15, the 6 · 7 control valves f and g are opened to return to the compressor 2 again.

At this time, the fifth control valve (e) provided in the condensate recovery line 13 between the gas-liquid separator 5 and the water tank 6 is also maintained in an open state.

As such, when the ECU drives the compressor 2 to suck air as the air flow passage is formed, the compressor connection line 14, the stack discharge line 12, and the fuel cell are driven by the suction force of the compressor 2. A vacuum negative pressure is formed on the stack 4 and the stack auxiliary connection line 15, whereby air passing through the air cleaner 1 passes through the fuel cell stack 4 through the stack auxiliary connection line 15. Through the stack discharge line 12 and the compressor connection line 14 is introduced into the compressor (2).

Subsequently, the air flowing into the compressor 2 is introduced into the humidifier 3 via the stack discharge line 10, and then in the water tank 6 through the humidifier connecting line 11 connected to the humidifier 3. It will have a path to the outside.

At this time, the inside of the fuel cell stack 4 is decompressed by the suction force of the compressor 2 and a small amount of air introduced through the stack auxiliary connection line 15, and thus inside the fuel cell stack 4. Decompression will remove moisture and condensate.

In addition, since the air flow rate flowing through the stack auxiliary connection line 15 is small, the air flow rate flowing into the compressor 2 is also reduced, which serves to reduce the load of the compressor 2.

In addition, since the air discharged through the compressor 2 is discharged to the humidifier connection line 11 through the humidifier 3, the stack connection line 10 and the humidifier 3 and the humidifier connection line 11 in this way. Moisture or condensate will drain back.

As such, after all the purging modes are performed, the operation mode is performed, which supplies hydrogen and cooling water to the fuel cell stack 4 and simultaneously supplies air to the electric energy load generated in the stack 4. The motor is driven to drive the vehicle (V).

That is, as shown in FIG. 6, the ECU opens the first, second and third control valves a, b, and c so that the air according to the compressor 2 is driven through the stack connection line 10. Through the compressor (2) and the humidifier (3) is supplied to the fuel cell stack (4), at this time air does not flow into the stack auxiliary connection line (15) bypassing the stack connection line (10) (Bypass) Of course, the seventh control valve (g) is closed so as not to.

In addition, the ECU closes the sixth control valve (f) so that the gas discharged through the stack discharge line 12 does not flow into the compressor (2) of course.

In addition, the ECU opens the fifth control valve (e) and the moisture or condensed water in the gas discharged through the condensate recovery line 13 is separated from the gas-liquid separator 5 and the water tank 6 through the condensate recovery line 13. Of course, to be discharged.

In addition, the humidifier 3 is to heat the air to an appropriate temperature to remove the moisture in the air introduced.

On the other hand, the purging may be performed before starting the vehicle when the external temperature is 4 ° C. or lower when the vehicle V is driven again after stopping the vehicle V to remove moisture or condensed water remaining in the fuel cell stack 4 and related parts. do.

If the external temperature is 4 ° C. or higher, the drive is performed immediately without performing the purging process. However, if the external temperature is 4 ° C. or lower during a temporary stop, the purging process is necessarily performed.

As described above, according to the present invention, the condensed water remaining in the gas flow path and the electrode of the fuel cell stack is effectively removed when the fuel cell is stopped, and the flow path is blocked due to water condensation even when left for a long time under low external temperature (below freezing point). In addition, the fuel cell stack can improve the low temperature startability of the fuel cell stack, and also increase the durability by eliminating the stress of the catalyst layer and the gas diffusion layer.

Claims (12)

A fuel cell vehicle comprising a hydrogen flow system for condensing hydrogen discharged while supplying hydrogen to a fuel cell stack, a cooling water flow system for removing and supplying ions in the cooling water, and an air flow system for supplying air from the outside. The air flow meter is After purifying the outside air sucked through the compressor (2) using the air cleaner (1), the air flowing into the fuel cell stack (4) by passing through the humidifier (3) to remove moisture in the air by heating to a proper temperature. Water from the gas discharged from the stack connection line 10 forming a passage, the humidifier connection line 11 connecting the humidifier 3 and the water tank 6, which is a water reservoir, and the fuel cell stack 4 The condensate separated while passing through the stack discharge line 12 and the gas-liquid separator 5 provided with a gas-liquid separator 5 for separating the gas and a wet temperature sensor 7 for measuring humidity in the exhaust gas, and then recovering the condensed water toward the water tank 6. Condensate recovery line 13 connecting between the gas-liquid separator 5 and the water tank 6, so as to be located in front of the compressor 2 at the rear of the gas-liquid separator 5 installed in the stack discharge line 12. Compressor connection line 14 connected to the stack connection line 10 and the Stack auxiliary connection line 15 branching behind the air cleaner 1 installed in the tack connection line 10 to the rear of the humidifier 3 and bypassing the path of the stack connection line 10 leading to the fuel cell stack 4. Piping line consisting of; A first control valve (a) positioned between the air cleaner (1) and the compressor (2) on the stack connection line (10), and a second control valve (b) installed between the compressor (2) and the humidifier (3). ), A third control valve (c) installed between the humidifier (3) and the fuel cell stack (4) on the stack connection line (10), a fourth control valve (d) located at the humidifier connection line (11), Fifth control valve (e) located in the condensate recovery line (13), the sixth control valve (f) located in the compressor connection line 14 and the seventh control located in the stack auxiliary connection line (15) A control valve consisting of a valve g; An outside temperature sensor 8 for measuring an outside temperature of the vehicle V;  An ECU that performs purging while controlling the control valves to receive low-temperature startability due to freezing before receiving a signal from an outside temperature sensor 8 and various sensors installed in the vehicle V; Condensate purging device of a fuel cell vehicle consisting of. The condensed water of the fuel cell vehicle according to claim 1, wherein the stack auxiliary connecting line 15 is formed of tubules such that the amount of air flowing into the fuel cell stack 4 is relatively smaller than that of the stack connecting line 10. Purging device. An initial condition determination step of determining that the external temperature measured by the outside temperature sensor 8 installed outside the vehicle V is low enough to form water freezing and stops driving; Air blowing to remove water remaining in the front part of the fuel cell stack 4 by circulating air only in front of the fuel cell stack 4 when starting again in a state of satisfying the initial condition determination step. A preliminary purging step of executing a mode; After blowing air through the fuel cell stack 4 after the first purging step, the air is blown to inhale again after blowing air to remove remaining water for the front and rear parts of the fuel cell stack 4. A main purging step of executing a suction mode; After the main purging step, the fuel cell stack 4 without driving the compressor 2 in order to prevent damage to the compressor 2 which supplies compressed air due to a sudden pressure fluctuation caused by the opening and closing operation of each control valve according to the driving of the vehicle. A pause mode step of supplying air to the air; After the pause mode step, the fuel cell stack 4 is formed at a low pressure by the suction force of the compressor 2 driven to have a small load, and the water remaining in the outside air passing through the fuel cell stack 4 is removed again. A driving mode preparation step; A driving step of driving the vehicle V by driving an electric motor with an electric energy load generated in the stack 4 by supplying hydrogen, coolant and air to the fuel cell stack 4 after the operation mode preparation step; Condensate purging method of the fuel cell vehicle performed by. 4. The method of claim 3, wherein in the initial condition determination step, when the external temperature is 4 ° C. or more, the condensate purging method of the fuel cell vehicle is directly driven without performing a purging process. According to claim 3, In the preliminary purging step, the stack connecting line 10 and the humidifier so that the air passing between the stack connection line 10 and the humidifier connection line 11 is discharged to the outside through the water tank (6) A method for purging condensate in a fuel cell vehicle, characterized in that only the first, second, and fourth control valves (a, b, d) provided in the connection line (11) are opened. 4. The main purging step of claim 3, wherein the air supplied to the stack connection line (10) passes through the fuel cell stack (4) and then is discharged to the stack discharge line (12), and from the stack connection line (10). First, second and third control valves provided in the stack connection line 10 such that the sucked air passes through the fuel cell stack 4 through the stack discharge line 12 and depressurizes the inside of the fuel cell stack 4. A method of purging condensate in a fuel cell vehicle, characterized in that only the fifth control valve (e) provided in (a, b, c) and the condensate return line (13) are opened. 5. The method of purging condensate of a fuel cell vehicle according to claim 4, wherein the air supplied to the fuel cell stack (4) in the main purging step passes through the cathode region partitioning the inside of the fuel cell stack (4). 4. The fuel cell vehicle according to claim 3, wherein in the main purging step, compressed air is also blown toward the cooling water line which is connected to the fuel cell stack 4 and supplies the cooling water for cooling the fuel cell stack 4. Method of purging condensate. 7. The method of purging condensate of a fuel cell vehicle according to claim 6, wherein in the suction mode performed in the main purging step, the cathode and the anode region formed inside the fuel cell stack 4 are formed at a low pressure. . The fuel cell stack (4) according to claim 3, wherein in the pause mode step, air introduced from the air cleaner (1) provided at the front end of the stack connection line (10) bypasses the stack connection line (10). A seventh provided in the stack auxiliary connection line 15 so as to flow to the stack auxiliary connection line 15 connected to the air inlet portion of the outlet) and to be discharged to the outside through the stack discharge line 12 through the fuel cell stack 4. A method of purging condensate in a fuel cell vehicle, comprising opening a control valve (g) and closing first and third control valves (a, c) provided in the stack connection line (10). According to claim 3, wherein the operation mode preparation step, after the outside air passing through the air cleaner (1) is supplied to the fuel cell stack (4) through the stack auxiliary connection line 15, Into the compressor (2) through the compressor connection line 14 for connecting between the stack discharge line 12 and the stack connection line 10 again, To be discharged to the outside through the humidifier connection line 11 connecting between the humidifier 3 and the water tank 6 installed on the stack connection line 10, The first and third control valves (a and c) are closed and the second and fourth control valves (b and d) are opened to allow the stack connection line 10 and the humidifier connection line 11 to communicate with each other, and the fuel cell stack 4 And 6) control valves (f, g) are opened to communicate between the compressor and the compressor (2) via a compressor connection line (14). 4. The gas-liquid separator of claim 3, wherein in the preliminary purging step, the main purging step, the pause mode step, and the operation mode preparation step, the gas-liquid separator provided in the stack discharge line 12, which is an exhaust gas passage discharged from the fuel cell stack 4; (5) and a fifth control valve (e) of the condensate return line (13) connecting between the water tank (6) is opened, characterized in that the fuel cell vehicle purging method.

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