Apparatus and method for discharging condensate of a fuel cell stack

Abstract

An apparatus for discharging a condensate of a fuel cell stack, the apparatus includes a condensate storage container for storing the condensate from the fuel cell stack, a condensate level detector for detecting a condensate level in the condensate storage container, a discharge valve configured to be opened and closed to discharge the condensate from the condensate storage container, and a control unit for setting a condensate discharge level differently according to currents of the fuel cell stack, and for controlling the discharge valve to be opened when a condensate level measured by the condensate level detector reaches the condensate discharge level.

What is claimed is: 
     
         1 . An apparatus for discharging a condensate of a fuel cell stack, the apparatus comprising:
 a condensate storage container for storing the condensate from the fuel cell stack;   a condensate level detector for detecting a condensate level in the condensate storage container;   a discharge valve configured to be opened and closed to discharge the condensate from the condensate storage container; and   a control unit for setting a condensate discharge level differently according to currents of the fuel cell stack, and for controlling the discharge valve to be opened when a condensate level measured by the condensate level detector reaches the condensate discharge level.   
     
     
         2 . The apparatus according to  claim 1 , wherein the condensate level detector is configured as a condensate level sensor extending in a gravitation direction. 
     
     
         3 . The apparatus according to  claim 1 , wherein when a current from the fuel cell stack is greater than a reference current, the control unit sets a point in time at which the discharge valve is to be opened to a first condensate discharge level. 
     
     
         4 . The apparatus according to  claim 3 , wherein when the current from the fuel cell stack is lower than the reference current, the control unit sets a point in time at which the discharge valve is to be opened to a second condensate discharge level. 
     
     
         5 . The apparatus according to  claim 4 , wherein the second condensate discharge level is set to a position higher than that of the first condensate discharge level. 
     
     
         6 . A method for discharging a condensate of a fuel cell stack using an apparatus for discharging the condensate of the fuel cell stack having a condensate storage container configured to store the condensate from the fuel cell stack, a condensate level detector for detecting a condensate level in the condensate storage container, and a discharge valve configured to be opened and closed to discharge the condensate from the condensate storage container, the method comprising:
 measuring, by the condensate level detector, a condensate level of the condensate storage container in real time; and   setting a condensate discharge level differently according to a current from the fuel cell stack, and opening the discharge valve when a condensate level measured by the condensate level detector reaches the condensate discharge level.   
     
     
         7 . The method according to  claim 6 , wherein
 when a current from the fuel cell stack is greater than a reference current, a first condensate discharge level corresponding to a point in time at which the discharge valve is to be opened is set, and   when a condensate level in the condensate storage container is higher than the first condensate discharge level, the discharge valve is opened.   
     
     
         8 . The method according to  claim 7 , wherein, after the discharge valve is opened, when a condensate level in the condensate storage container is reduced to be lower than a lower limit value, the discharge valve is closed. 
     
     
         9 . The method according to  claim 6 , wherein
 when a current from the fuel cell stack is smaller than the reference current, a second condensate discharge level corresponding to a point in time at which the discharge valve is to be opened is set, and   when a condensate level in the condensate storage container is higher than the second condensate discharge level, the discharge valve is opened.   
     
     
         10 . The method according to  claim 9 , wherein after the discharge valve is opened, when a condensate level in the condensate storage container is reduced to be lower than a lower limit value, the discharge valve is closed.