A fuel cell vehicle is provided. The fuel cell vehicle includes a fuel cell including a cell stack configured such that a plurality of unit cells is stacked, a drive motor unit disposed below the fuel cell, a purge valve / drain valve assembly configured to discharge unreacted hydrogen and first condensate water flowing together out of the fuel cell, an air exhaust line configured to discharge unreacted oxygen and second condensate water flowing together out of the fuel cell, and a hydrogen exhaust line connecting the purge valve / drain valve assembly to the air exhaust line and disposed so as to avoid interference with the drive motor unit.

When a first timing at which a fuel gas is injected to a fuel gas supply flow path by an injector and a second timing at which water residing on a circulation flow path is discharged by controlling rotating speed of a circulation pump coincide with each other, a controller performs either: (i) a first process of operating the circulation pump at a preset RPM without injecting the fuel gas to the fuel gas supply flow path by the injector; or (ii) a second process of injecting the fuel gas to the fuel gas supply flow path by the injector and operating the circulation pump at an RPM lower than the preset RPM.

A cooling system is provided for use with a fuel cell. The cooling system comprises a first heat exchanger fluidly connected to an outlet passage of the fuel cell. The first heat exchanger can be configured to condense at least a portion of a fluid passing through the outlet passage of the fuel cell into liquid water. The cooling system can also comprise a second heat exchanger fluidly connected to an outlet passage of the first heat exchanger and an inlet passage of the fuel cell. The second heat exchanger can be configured to cool a fluid passing into the inlet passage of the fuel cell. In addition, the outlet passage of the fuel cell and the inlet passage of the fuel cell can be fluidly connected to a cathode of the fuel cell, and the inlet passage of the fuel cell can be configured to supply water to the cathode.

A fuel cell apparatus (10) and method (50) of operating a fuel cell are provided. The fuel cell apparatus (10) includes a fuel cell assembly (12) having a first outlet (26) and a first vessel (34) coupled to the first outlet (26) and forming a first dead end. The first vessel (34) is arranged to receive and hold a portion of a first reactant and water when a supply of the first reactant is being fed to the fuel cell assembly (12) and to return the first reactant in the first vessel (34) to the fuel cell assembly (12) via the first outlet (26) when the supply of the first reactant to the fuel cell assembly (12) is cut off.

The present invention provides a relative humidity and condensed water estimator for a fuel cell and a method for controlling condensed water drain using the same. Here, the relative humidity and condensed water estimator is utilized in control of the fuel cell system involving control of anode condensed water drain by outputting at least two of signals comprising air-side relative humidity, hydrogen-side relative humidity, air-side instantaneous or cumulative condensed water, hydrogen-side instantaneous or cumulative condensed water, instantaneous and cumulative condensed water of the humidifier, membrane water contents, catalyst layer oxygen partial pressure, catalyst layer hydrogen partial pressure, stack or cell voltage, air-side catalyst layer relative humidity, hydrogen-side catalyst layer relative humidity, oxygen supercharging ratio, hydrogen supercharging ratio, residual water in a stack, and residual water in a humidifier.

A method for performing one or more proactive remedial actions to prevent anode flow-field flooding in an anode side of a fuel cell stack at low stack current density. The method includes identifying one or more trigger conditions that could cause the anode flow-field to flood with water, and performing the one or more proactive remedial actions in response to the identified trigger conditions that removes water from the anode side flow-field prior to the anode flooding occurring.

A fuel cell system that generates electric power by supplying anode gas and cathode gas to a fuel cell includes a control valve adapted to control the pressure of the anode gas to be supplied to the fuel cell; a buffer unit adapted to store the anode-off gas to be discharged from the fuel cell; a pulsation operation unit adapted to control the control valve in order to periodically increase and decrease the pressure of the anode gas at a specific width of the pulsation; and a pulsation width correcting unit adapted to correct the width of the pulsation on the basis of the temperature of the buffer unit.

A fuel cell system includes an anode configured to output an anode exhaust stream comprising hydrogen, carbon dioxide, and water; and a membrane dryer configured to receive the anode exhaust stream, remove water from the anode exhaust stream, and output a membrane dryer outlet stream. The membrane dryer includes a first chamber configured to receive the anode exhaust stream; a second chamber configured to receive a purge gas; and a semi-permeable membrane separating the first chamber and the second chamber. The semi-permeable membrane is configured to allow water to diffuse therethrough, thereby removing water from the anode exhaust stream. The membrane dryer may further be configured to remove hydrogen from the anode exhaust stream.

A method of operating a fuel cell system includes providing an anode exhaust from a fuel cell stack to a water injector, supplying water to the water injector, and injecting the water from the water injector into the anode exhaust to vaporize the water and generate a humidified anode exhaust.

A turbomachine includes a rotating group with a turbine wheel. The turbomachine also includes a housing that houses the rotating group, wherein the housing defines a turbine outlet passage for exhaust from the turbine wheel. The turbine outlet passage is directed in a downstream direction along an axis of the turbine outlet passage. The turbomachine includes an air bearing system with at least one bearing component that supports the rotating group for rotation relative to the housing. The air bearing system includes a bearing cooling path that is fluidly connected to the at least one bearing component and that has a bearing air line outlet. The bearing air line outlet is fluidly connected to the turbine outlet passage and is directed in the downstream direction along the axis.