Fuel cell system and control method of same

A fuel cell system, comprising:

• a fuel cell which generates electric power by being supplied with fuel gas and oxygen;
• an off-gas passage through which an off-gas of the fuel gas discharged from the fuel cell passes;
• a gas/liquid separation device which is provided in the off-gas passage and which separates water from the off-gas and accumulates the water;
• a discharge valve which is connected to the gas/liquid separation device and which can discharge the off-gas to an outside of the fuel cell system along with the water accumulated in the gas/liquid separation device;
• and
• a controller controls that an opening/closing operation of the discharge valve, wherein
• the controller estimates an amount of water accumulated in the gas/liquid separation device based on an amount of water generated in the fuel cell which is calculated based on an amount of electric power generated by the fuel cell, and decides a closing time at which the discharge valve is closed based on the estimated amount of accumulated water.

A control method for a fuel cell system including a gas/liquid separation device which is provided in an off-gas passage that is a passage through which fuel gas discharged from a fuel cell passes, and which separates water from an off-gas of the fuel gas and accumulates the water;

• and a discharge valve which is connected to the gas/liquid separation device and which can discharge the off-gas to an outside of the fuel cell system along with the water accumulated in the gas/liquid separation device, comprising the steps of:
• obtaining an amount of change in pressure at a portion upstream of the discharge valve, which occurs due to an opening operation of the discharge valve;
• deciding a closing time at which an integral value obtained by integrating the amount of change in the pressure with respect to time from when the discharge valve is opened or a parameter value corresponding to the integral value reaches a predetermined value;
• and
• closing the discharge valve at the closing time.

A control method for a fuel cell system including a gas/liquid separation device which is provided in an off-gas passage that is a passage through which fuel gas discharged from a fuel cell passes, and which separates water from an off-gas of the fuel gas and accumulates the water;

• and a discharge valve which is connected to the gas/liquid separation device and which can discharge the off-gas to an outside of the fuel cell system along with the water accumulated in the gas/liquid separation device, comprising the steps of:
• estimating an amount of water accumulated in the gas/liquid separation device based on an amount of water generated in the fuel cell, which is calculated based on an amount of electric power generated by the fuel cell;
• and
• deciding a closing time at which the discharge valve is closed based on the estimated
• amount of accumulated water.

A fuel cell system, comprising:

• a fuel cell which generates electric power by being supplied with fuel gas and oxygen;
• an off-gas passage through which an off-gas of the fuel gas discharged from the fuel cell passes;
• a gas/liquid separation device which is provided in the off-gas passage and which separates water from the off-gas and accumulates the water;
• a discharge valve which is connected to the gas/liquid separation device and which can discharge the off-gas to an outside of the fuel cell system along with the water accumulated in the gas/liquid separation device;
• and
• control means for controlling an opening/closing operation of the discharge valve, wherein
• the control means detects or estimates a change in pressure at a portion upstream of the discharge valve, decides a closing time at which an integral value that is obtained by integrating an amount of change in the pressure at the portion upstream of the discharge valve with respect to time from when the discharge valve is opened or a parameter value corresponding to the integral value reaches a predetermined value, and closes the discharge value at the closing time.

A fuel cell system, comprising:

• a fuel cell which generates electric power by being supplied with fuel gas and oxygen;
• an off-gas passage through which an off-gas of the fuel gas discharged from the fuel cell passes;
• a gas/liquid separation device which is provided in the off-gas passage and which separates water from the off-gas and accumulates the water;
• a discharge valve which is connected to the gas/liquid separation device and which can discharge the off-gas to an outside of the fuel cell system along with the water accumulated in the gas/liquid separation device;
• and
• control means for controlling an opening/closing operation of the discharge valve, wherein
• the control means estimates an amount of water accumulated in the gas/liquid separation device based on an amount of water generated in the fuel cell which is calculated based on an amount of electric power generated by the fuel cell, and decides a closing time at which the discharge valve is closed based on the estimated amount of accumulated water.