FUEL CELL STACKS AND SYSTEMS WITH FLUID-RESPONSIVE TEMPERATURE REGULATION

Fuel cell stacks and systems with thermal management systems to deliver a liquid heat exchange fluid into thermal communication with the stack and thereafter recycle the stream. In some embodiments, the system is adapted to selectively apportion the recycled liquid stream between a stream that, prior to reuse as a heat exchange stream, is returned to a fluid reservoir and/or selectively cooled, and/or selectively returned to the reservoir and mixed with heat exchange fluid in the reservoir, and a stream that is returned into thermal communication with the stack without returning the stream to the reservoir and/or without heating or cooling and/or without being mixed with additional heat exchange fluid. In some embodiments, the system is adapted to automatically apportion the recycled stream responsive to its temperature. In some embodiments, the system includes a thermostatic valve and/or selectively apportions the recycled stream without requiring an electronic controller or manual input. Pilas y sistemas de celdas de combustible con sistemas de manejo termico para distribuir un fluido liquido de intercambio de calor en comunicacion termica con la pila y reciclar posteriormente la corriente. En algunas modalidades, el sistema se adapta para repartir selectivamente la corriente liquida reciclada entre una corriente que, antes de reutilizarse como una corriente de intercambio de calor, se retorna a un deposito de fluido y/o enfriada selectivamente, y/o regresada selectivamente al deposito y mezclada con el fluido de intercambio de calor en el deposito, y una corriente que se retorna en comunicacion termica con la pila sin regresar la corriente al deposito y/o sin calentar o enfriar y/o sin que se mezcle con fluido de intercambio de calor adicional. En algunas modalidades, el sistema se adapta para repartir automaticamente la corriente reciclada en respuesta a su temperatura. En algunas modalidades, el sistema incluye una valvula termostatica y/o reparte selectivamente la corriente reciclada sin requerir un controlador electronico o entrada manual.