Patent ID: 9722265
Date: 2017-08-01
CPC Classifications: H01M,Y02E

Claim:
1. A liquid-level control system for a fuel cell power plant, the system comprising: a fuel cell stack assembly, including a fluid flow path extending therethrough; a controllable liquid management arrangement operatively connected to the fuel cell stack assembly and including said fluid flow path; a pressure sensor adapted to sense pressure of fluid in the fluid flow path of the fuel cell stack assembly and provide a fluid pressure signal commensurate therewith; and a voltage sensing arrangement adapted to measure a voltage when a liquid in the fluid flow path of the cell stack assembly attains a predetermined level and provide a voltage-based signal indicative thereof, and the liquid management arrangement being operably connected to and at least indirectly responsive to the fluid pressure signal, the liquid management arrangement being configured to regulate a level of liquid in the fuel cell stack assembly based on the fluid pressure signal at least during start-up and during shut-down of the fuel cell stack assembly, and when the fuel cell stack assembly does not provide a measurable voltage, and the liquid management arrangement being operably connected to and at least indirectly responsive to the voltage-based signal, the liquid management arrangement being configured to regulate the level of liquid in the fuel cell stack assembly based on the voltage-based signal at least during steady state operation of the fuel cell stack assembly and when the fuel cell stack assembly provides a measurable voltage, and the liquid management arrangement configured to automatically transition from regulating the level of liquid in the fuel cell stack assembly based on the fluid pressure signal to regulating the level of liquid in the fuel cell stack assembly based on the voltage-based signal when the fuel cell stack assembly provides a measurable voltage, and configured to automatically transition from regulating the level of liquid in the fuel cell stack assembly based on the voltage-based signal to regulating the level of liquid in the fuel cell stack assembly based on the fluid pressure signal when the fuel cell stack assembly does not provide a measurable voltage.