Patent ID: 7563529
Filing Date: 2009-07-21
Classification: B64C,B64D,H01M,Y02E,Y02P,Y02T

Abstract:
1. A closed loop energy storage system comprising: a fuel tank configured to store dried gaseous fuel; an oxidizer tank configured to store dried gaseous oxidizer; a fuel cell stack configured to react the gaseous fuel with the gaseous oxidizer to produce a liquid product and electrical power; an electrolyzer stack configured to separate the liquid product into a humid fuel including the gaseous fuel and product humidity, and a humid oxidizer including the gaseous oxidizer and product humidity; a system of lines, including fuel lines interconnecting the fuel tank with the fuel cell stack and the electrolyzer stack, and oxidizer lines interconnecting the oxidizer tank with the fuel cell stack and the electrolyzer stack; a heat exchanger in thermal contact with fuel and oxidizer within a portion of the system of lines, and being configured both for heating and freezing the fuel and oxidizer within the portion of the system of lines; and a controller programmed to control the operation of the fuel cell stack, the electrolyzer, and the heat exchanger such that the heat exchanger heats fuel and oxidizer within the portion of the system of lines during operation of the fuel cell stack, and such that the heat exchanger freezes the fuel and oxidizer within the portion of the system of lines during operation of the electrolyzer stack.