Provided are a method and system for correcting an offset of a hydrogen pressure sensor. The method includes constantly supplying the hydrogen to the fuel cell stack, determining whether an offset of the hydrogen pressure sensor needs to be corrected based on a stop time before the fuel cell stack starts and a magnitude of an output voltage of the fuel cell stack, calculating an offset correction value when the offset of the hydrogen pressure sensor needs to be corrected, and correcting the offset of the hydrogen pressure sensor and performing the starting of the fuel cell stack.

A process for starting a PEM fuel cell module includes blowing air through the cathode side of the module using external power. An amount hydrogen is released into the anode side of the module under a pressure greater than the pressure of the air on the cathode side, while the anode is otherwise closed. Cell voltages in the module are monitored for the appearance of a charged state sufficient to start the module. When the charged state is observed, the module is converted to a running state.

A power system for an unmanned surface vehicle includes a fuel cell including a fuel cell stack, where the fuel cell stack includes a fuel inlet. The power system also includes a fuel storage including at least one fuel-storage module fluidly connected to the fuel inlet of the fuel cell stack. The fuel-storage module is a source of energy for the fuel cell. The power system also includes a fuel and thermal management system fluidly connected to the fuel inlet of the fuel cell stack. The fuel and thermal management system includes a heat exchanger in thermal communication with the fuel cell stack for removing waste heat produced by the fuel cell stack during operation. The fuel and thermal management system also includes a flow valve, a pressure regulator, and a conduit.

A reforming element for a molten carbonate fuel cell stack and corresponding methods are provided that can reduce or minimize temperature differences within the fuel cell stack when operating the fuel cell stack with enhanced CO.sub.2 utilization. The reforming element can include at least one surface with a reforming catalyst deposited on the surface. A difference between the minimum and maximum reforming catalyst density and/or activity on a first portion of the at least one surface can be 20% to 75%, with the highest catalyst densities and/or activities being in proximity to the side of the fuel cell stack corresponding to at least one of the anode inlet and the cathode inlet.

A vehicle includes a fuel cell, an inlet valve, a purge valve, and a controller. The fuel cell has an anode side configured to receive hydrogen. The inlet valve is configured to open to deliver the hydrogen to the anode side. The purge valve is configured to open to purge water and nitrogen from the anode side. The controller is programmed to, operate the inlet valve to inject hydrogen into the anode side via opening the inlet valve followed by closing the inlet valve. The controller is further programmed to, in response to a concentration of the hydrogen in the anode side being less than threshold, open the purge valve to purge water and nitrogen from the anode side.

The disclosure relates to a vehicle with a traction battery and a fuel cell system, and a controller programmed to purge the fuel cell system by flowing air through it to remove moisture from the fuel cell system. The controller is configured to initiate the purge based on a distance of the vehicle from a destination, a state of charge of the traction battery, and ambient temperature conditions at the destination. The freeze preparation process can be initiated when the vehicle is approaching its destination and can be predicted using connectivity and communication with off-board sources.

Presented are intelligent fuel cell systems (FCS) with logic for evacuating water from anode headers of a fuel cell stack, methods for making/using such systems, and vehicles equipped with such systems. A method of operating an FCS includes a system controller confirming the FCS is running and, once confirmed, receiving a bleed request to remove exhaust gas from exhaust output by the anode. Responsive to the bleed request, the controller determines a total bleed valve use (TBVU) indicating prior bleed requests completed by an anode bleed valve, and thereafter determines if the TBVU is less than a maximum bleed valve use (MBVU). If so, the controller responsively commands the bleed valve to bleed the exhaust gas from the anode exhaust. If TBVU is not less than MBVU, the controller commands a header drain valve to bleed the exhaust gas from the anode exhaust and drain water from the anode header.

The present disclosure provides a system and a method for purging the condensate water and hydrogen of a fuel cell stack, which may allow the condensate water and hydrogen discharged from a stack to be directly bypassed to an exhaust line of a humidifier rather than a shell side of the humidifier to be purged to the atmosphere according to the operation state and operation condition of the stack, thereby solving a problem in that an inverse voltage is generated upon cold operation of a fuel cell system, a flooding phenomenon occurs in the stack, or the like to improve the operation stability of the stack and the operation efficiency of the fuel cell system.

A fuel cell system includes a fuel cell including a plurality of stacked cells, a fuel gas supply unit configured to supply fuel gas to a supply port of the fuel cell and return the fuel gas exhausted through an exhaust port of the fuel cell, and a controller configured to control an operation of the fuel gas supply unit. The controller is configured to execute a drain process for draining residual water accumulated in the fuel cell through the exhaust port. In the drain process, a first process in which the fuel gas is supplied to the fuel cell until a pressure in the fuel cell reaches a predetermined threshold pressure and a second process in which the pressure in the fuel cell is reduced after the first process are repeatedly executed.

A vehicle includes a fuel-cell system having a fuel cell, a purge valve, and a drain line extending from the purge valve. A controller is programmed to open the purge valve according to a baseline purge routine when the drain line slopes away from the purge valve, and open the purge valve according to an enhanced purge routine when the drain line slopes towards the purge valve.