Patent ID: 9716283
Date: 2017-07-25
CPC Classifications: H01M,Y02E

Claim:
1. A method of starting a fuel cell system comprising: a fuel cell that generates electricity by a fuel of an anode and an oxidant of a cathode; a fuel gas supply unit that supplies a fuel gas containing the fuel to the anode; an oxidant gas supply unit that supplies an oxidant gas containing the oxidant to the cathode; a connection and disconnection unit capable of completely switching connection and disconnection between the fuel cell and an electric load; a hydrogen pump that circulates the hydrogen through a fuel gas circulation path; a purge valve disposed on a fuel gas discharge path; and a control unit that controls the fuel gas supply unit and the oxidant gas supply unit, the method comprising: a hydrogen concentration acquisition process of acquiring a concentration of hydrogen as the fuel in the anode; a threshold value determination process of determining whether or not the concentration of the hydrogen acquired by the hydrogen concentration acquisition process has reached a first threshold value, or a second threshold value, wherein the second threshold value is less than the first threshold value; a starting pressure setting process of setting a pressure of the hydrogen that is supplied from the fuel gas supply unit during execution of starting of the fuel cell for supplying the hydrogen to the anode from the fuel gas supply unit in a state in which the connection and disconnection unit is shut off based on a determination result determined by the threshold value determination process; and a hydrogen substitution process of substituting remaining hydrogen in the anode during shut-down of the fuel cell, with the hydrogen supplied from the fuel gas supply unit when the starting of the fuel cell is executed, wherein in the starting pressure setting process, the method includes the method further comprises a hydrogen pump drive process of driving the hydrogen pump during execution of starting of the fuel cell, the hydrogen pump is continuously driven even after the power generation of the fuel cell stack is initiated, the purge valve is closed after starting of the power generation of the fuel cell stack, and until the starting of the fuel cell is completed and the driving of the hydrogen pump is stopped, in the hydrogen substitution process, the remaining hydrogen in the anode during shut-down of the fuel cell is substituted with the hydrogen supplied from the fuel gas supply unit at the pressure of the hydrogen set in the starting pressure setting process, a start signal of the fuel cell system is received at a time t1, the starting of the fuel cell is executed at a time t2, the hydrogen pressure reaches a predetermined threshold value at a time t3, the execution of the normal power generation occurs at a time t4, and the purge valve is closed and the connection and disconnection unit is in a connected state at the time t4, and the hydrogen pressure remains constant during the execution of the first state or the second state between the time t3 and the time t4.