摘要:
An electrochemical fuel cell assembly (1) includes a fuel cell stack (2) having a fuel delivery inlet (3) and a fuel delivery outlet. The fuel cell has a membrane-electrode assembly and a fluid flow path coupled between the fuel delivery inlet and the fuel delivery outlet for delivery of fuel to the membrane-electrode assembly. A fuel delivery conduit (6) is coupled to the fuel delivery inlet (3) for delivery of fluid fuel to the fuel cell stack (2). A flow control device (11) in the fluid delivery conduit (6) is configured to provide a pulse modulated inlet pressure at the fuel delivery inlet (3). The pulse modulation may be provided as a function of fuel cell operating conditions. The amplitude and frequency of the pulse modulation may be selected to create sufficient flow disturbance to encourage disturbance and dislodgement of water collecting in the fluid flow path.
摘要:
During power reduction transitions of a fuel cell power plant, the excess electric energy generated by consumption of reactants is extracted, during one or more periods of time, by a voltage limiting device control (200) in response to a controller (185) as i) energy dissipated in a resistive auxiliary load or ii) as energy applied to an energy storage system (201 ) (a battery), in boost and buck embodiments. The controller operates the voltage limiting device control in response to the positive time derivative of the voltage of one or more of the fuel cells exceeding a predetermined limiting value.
摘要:
Système de refroidissement pour pile à combustible (2), comprenant un circuit principal de fluide caloporteur comportant une pompe de circulation principale (6) et un échangeur thermique avec l'extérieur (8), qui alimentent une canalisation amont (12) délivrant ce fluide aux cellules (4) de la pile à combustible, le fluide ressortant des cellules par une canalisation aval (14) pour revenir vers cette pompe principale, caractérisé en ce qu'un circuit secondaire comportant un dispositif de circulation secondaire (30) réalisant une circulation alternée du fluide, est connecté en parallèle avec le circuit principal sur les canalisations amont (12) et aval (14), et en ce qu'une ou plusieurs vannes pilotées (10, 16) permettent d'établir un fonctionnement indépendant du circuit principal ou du circuit secondaire.
摘要:
Système de refroidissement pour pile à combustible, comprenant un circuit principal de fluide caloporteur comportant une pompe de circulation (6) et un échangeur thermique avec l'extérieur (8), qui alimentent une canalisation amont (12) délivrant ce fluide aux cellules (4) de la pile à combustible, le fluide ressortant des cellules par une canalisation aval (14) pour revenir vers la pompe de circulation, caractérisé en ce que le circuit principal comporte sur chaque canalisation amont (12) et aval (14), une vanne pilotée à trois voies (10, 16), la troisième voie disponible (10c) de la canalisation amont (12) étant raccordée sur l'entrée de la pompe (6), et la troisième voie disponible (16c) de la canalisation aval (14) étant raccordée sur la sortie de la pompe, pour établir un circuit secondaire de fluide.
摘要:
Disclosed herein is a system for managing water and fuel in a polymer electrolyte membrane fuel cell operated in dead- end mode. In the system for managing water and fuel in a polymer electrolyte membrane fuel cell operated in dead-end mode, a fuel cell system operated in dead-end mode in which an anode to which fuel is supplied and a cathode to which oxidizer is supplied are formed, and a polymer electrolyte membrane is formed between the anode and the cathode, and which is operated in a state in which a exhaustion flow path of the cathode is interrupted, the system comprises a pulsator means connected to an exhaustion flow path of the cathode for generating pulsation having predetermined amplitude and period at the cathode; a voltage measurement means for measuring voltage generated at the fuel cell; and a controller for controlling the amplitude and period of the pulsator means. According to the present invention, there are advantages in that water accumulated in the interior of the fuel cell is exhausted thereby preventing loss in fuel and oxidizer and enhancing the efficiency of the fuel cell.