Fuel cell apparatus

A fuel cell apparatus comprising:

• a stack configured to provide electrical energy based on electrochemical reaction that includes oxygen and hydrogen;
• a reformer configured to provide reformed gas to the stack;
• a stack air blower configured to provide external air;
• an intake channel configured to provide the external air from the stack air blower to the stack;
• a humidifier configured to extract moisture contained in exhaust air from the stack and to provide the extracted moisture to the external air in the intake channel;
• an exhaust channel to connect the stack to the humidifier, and
• configured to receive the exhaust air from the stack and to provide the exhaust air to the humidifier;
• a discharge channel configured to receive the exhaust air from the humidifier and to provide the received exhaust air to an outside of the fuel cell apparatus;
• a first bypass channel to branch from the exhaust channel and to join the discharge channel;
• a first three-way valve disposed at the exhaust channel between the stack and the humidifier, and configured to adjust an opening amount of the exhaust channel at the first three-way value and to adjust an opening amount of the first bypass channel at the first three-way valve;
• a humidity sensor configured to sense a humidity value of the external air to be provided to the stack;
• and
• a controller configured to control the first three-way valve such that the opening amount of the exhaust channel and the opening amount of the first bypass channel are inversely proportional to each other based on the humidity value of the external air sensed by the humidity sensor.