Hydrogen supply system for fuel cell and method for controlling the same

Abstract

The present invention provides a hydrogen supply system including a plurality of hydrogen tanks, in which an in-tank regulator is mounted only on one hydrogen tank and a solenoid valve is mounted on each of the other hydrogen tanks so that a reduction in manufacturing cost is realized and hydrogen is stably supplied to a fuel cell stack by controlling the solenoid valves during driving, and a method for controlling the same.

1 . A method for accelerating activation of a fuel cell, the method comprising:
 a first step of supplying hydrogen to a fuel electrode of a fuel cell and air to an air electrode of the fuel cell and maintaining a cell voltage at an opening-circuit voltage of a predetermined level;   a second step of cutting off air supply to the air electrode;   a third step of reducing the cell voltage from the predetermined level of the opening-circuit voltage to a threshold level after cutting off the air supply to the air electrode;   a fourth step of supplying air to the air electrode again to increase the opening-circuit voltage to the predetermined level when the opening-circuit voltage is reduced to the threshold level;   a fifth step of supplying a sufficient amount of hydrogen and air to the fuel electrode and the air electrode, respectively, and operating the fuel cell in a constant current or constant voltage operation mode; and   a sixth step of repeating the first to fifth steps for a predetermined number of times.   
   
   
       2 . A method for accelerating activation of a fuel cell, the method comprising:
 a first step of supplying hydrogen to a fuel electrode of a fuel cell and air to an air electrode of the fuel cell and maintaining a cell voltage at a predetermined level, which is lower than an opening-circuit voltage, by applying a current load;   a second step of cutting off air supply to the air electrode;   a third step of reducing the cell voltage to a threshold level after cutting off the air supply to the air electrode;   a fourth step of supplying air to the air electrode again and increasing the opening-circuit voltage to the predetermined level by applying a current load when the opening-circuit voltage is reduced to the threshold level;   a fifth step of supplying a sufficient amount of hydrogen and air to the fuel electrode and the air electrode, respectively, and operating the fuel cell in a constant current or constant voltage operation mode; and   a sixth step of repeating the first to fifth steps for a predetermined number of times.   
   
   
       3 . The method of  claim 1  or  2 , wherein, in the first and fourth steps, the opening-circuit voltage of the predetermined level is 0.95 to 1.2 V, the cell voltage is 0.8 to 1.23 V, which is lower than the opening-circuit voltage and, in the first step, the opening-circuit voltage of the predetermined level is maintained for several seconds. 
   
   
       4 . The method of  claim 1  or  2 , wherein, in the third step, the opening-circuit voltage of the threshold level is 0.2 V, and the cell voltage of the threshold level is 0.2 V. 
   
   
       5 . The method of  claim 1  or  2 , wherein, in the fifth step, an operation voltage of the constant current or constant voltage operation mode is 0.1 to 0.8 V per fuel cell. 
   
   
       6 . A method for accelerating activation of a fuel cell, the method comprising:
 supplying hydrogen to a fuel electrode of a fuel cell and air to an air electrode of the fuel cell and maintaining a cell voltage at a predetermined level, which is lower than an opening-circuit voltage;   cutting off air supply to the air electrode;   reducing the cell voltage to a threshold level after cutting off the air supply to the air electrode;   supplying air to the air electrode again and increasing the opening-circuit voltage to the predetermined level; and   supplying a sufficient amount of hydrogen and air to the fuel electrode and the air electrode, respectively.   
   
   
       7 . The method of  claim 6 , wherein the supplying hydrogen to a fuel electrode of a fuel cell and air to an air electrode of the fuel cell is carried out by applying a current load. 
   
   
       8 . The method of  claim 6 , wherein the supplying air to the air electrode again and increasing the opening-circuit voltage to the predetermined level is carried out by applying a current load. 
   
   
       9 . The method of  claim 8 , wherein the current load is applied when the opening-circuit voltage is reduced to the threshold level. 
   
   
       10 . The method of  claim 6 , wherein the fuel cell is operated in a constant current or constant voltage operation mode 
   
   
       11 . The method of  claim 6 , wherein supplying hydrogen to a fuel electrode of a fuel cell and air to an air electrode of the fuel cell and maintaining a cell voltage at a predetermined level and supplying a sufficient amount of hydrogen and air to the fuel electrode and the air electrode, respectively, and operating the fuel cell in a constant current or constant voltage operation mode, are repeated for a predetermined number of times. 
   
   
       12 . A motor vehicle comprising a fuel cell activated by the method of  claim 1 . 
   
   
       13 . A motor vehicle comprising a fuel cell activated by the method of  claim 6 .