A fuel cell system configured to enhance the life of a fuel cell is provided. The fuel cell system a fuel cell, an oxidant gas supplier configured to supply oxygen-containing oxidant gas to a cathode of the fuel cell, a fuel gas supplier configured to supply hydrogen-containing fuel gas to an anode of the fuel cell, an oxygen partial pressure estimator configured to estimate an oxygen partial pressure of the cathode of the fuel cell, a hydrogen partial pressure estimator configured to estimate a hydrogen partial pressure of the anode of the fuel cell, and a controller, wherein the controller calculates a target hydrogen partial pressure by a given equation (1), and wherein the controller controls the hydrogen partial pressure of the anode to the target hydrogen partial pressure.

The power controller starts imposing the current limit when a condition for the current limit is met the condition, the condition being that the fuel cell does not generate to fulfill the requested amount of power generation while the fuel cell generates power at an upper limit of the supply capability of the fuel gas supply unit, and the power controller removes the current limit at a first predetermined increase rate determined when the requested amount of power generation exceeds a predetermined threshold below a rated power generation amount of the fuel cell and at a second increase rate higher than the first increase rate when the requested amount of power generation is the threshold or less, after the condition for the limit is dissolved.

A fuel cell system includes a fuel cell, a supply flow passage and a discharge flow passage for anode gas, a gas-liquid separator, a discharge valve, a differential pressure detection unit configured to detect a differential pressure between an upstream side and a downstream side of the discharge valve, and a control unit. The control unit is configured to estimate an effective cross-sectional area of the discharge valve for the anode off-gas, which is decreased by an amount of water flowing into the gas-liquid separator and flowing out from the discharge valve, based on the differential pressure, and to estimate a discharge amount of the anode off-gas based on the estimated effective cross-sectional area.

A fuel cell system includes a fuel cell stack, a compressor, an air supply passage, a bypass passage, a bypass valve, an opening degree sensor, and a controller. The air supply passage guides the air discharged from the compressor to the fuel cell stack. The bypass passage branches from an intermediate point of the air supply passage to guide the air discharged from the compressor to a discharge passage without passing through the fuel cell stack. The bypass valve is provided in the bypass passage, the bypass valve being configured to open when an upstream pressure of the bypass valve exceeds a set pressure. The controller estimates a pressure of the air supply passage based on an opening degree of the bypass valve.

A humidifier for a fuel cell is configured to humidify dry air to be supplied to a fuel cell stack with wet air discharged from the fuel cell stack. The humidifier includes a housing provided such that the dry air and the wet air pass therethrough, a moisture transfer member provided in the housing to transfer moisture in the wet air to the dry air, a bypass flow path provided to guide a part of the dry air to bypass the housing, and a flow regulating valve provided to be driven using a pressure difference between the inside and outside of the housing as a power source to adjust a flow rate of the dry air passing through the bypass flow path.

The invention relates to a method for checking at least two sensors within an anode path (4) of a fuel cell system (1), having the steps of shutting down the fuel cell system (1); closing the shut-off valve (32) and the purge valve (41); opening an internal valve (34); detecting the pressure values by means of at least two sensors (50, 51, 52, 53, 54) within the anode path; checking whether the pressure values of the at least two sensors (50, 51, 52, 53, 54) differ.

A fuel supply control system and method for a fuel cell are disclosed. The system includes: a fuel cell configured to receive a fuel gas and an oxidation gas and generate electric power; a recirculation line configured to circulate gas containing the fuel gas and connected to a fuel electrode of the fuel cell; a discharge valve provided in the recirculation line and configured to allow the gas to be discharged to the outside when open; a discharge amount estimator configured to estimate a discharge amount of the discharged gas based on a supply amount of the fuel gas supplied to the recirculation line, a consumption amount of the fuel gas consumed in the fuel cell, and a change in the amount of the gas in the recirculation line; an offset calculator configured to calculate the discharge amount of the gas estimated by the discharge amount estimator with the discharge valve closed, as a discharge offset; and a controller configured to control opening/closing of the discharge valve.

The present disclosure generally relates to systems and methods for operating a fuel cell system including a three-port differential pressure switch in a recirculation loop of the fuel cell system comprising a blower and an ejector. A sensor in the three-port differential pressure switch is activated when a pressure ratio of a first pressure difference and second pressure difference exceeds a threshold ratio.

A novel electrochemical cell is disclosed in multiple embodiments. The instant invention relates to an electrochemical cell design. In one embodiment, the cell design can electrolyze water into pressurized hydrogen using low-cost materials. In another embodiment, the cell design can convert hydrogen and oxygen into electricity. In another embodiment, the cell design can electrolyze water into hydrogen and oxygen for storage, then later convert the stored hydrogen and oxygen back into electricity and water. In some embodiments, the cell operates with a wide internal pressure differential.

A fuel cell system includes a fuel cell. The fuel cell includes an anode having an anode inlet configured to receive anode feed gas, and an anode outlet configured to output anode exhaust. The fuel cell further includes a cathode having a cathode inlet and a cathode outlet. The fuel cell system further includes an anode blower configured to receive the anode exhaust and output a higher-pressure anode exhaust. The fuel cell system further includes an anode blower recycle line configured to receive a portion of the higher-pressure anode exhaust downstream from the anode blower and to output the portion of the higher-pressure anode exhaust upstream from the anode blower. The fuel cell system further includes a first valve disposed in the blower recycle line, the first valve configured to open when the anode of the fuel cell is under-pressurized.