System and method for controlling steam in a fuel system with a fuel processor

摘要

A control system controls steam in a fuel cell system including a fuel processor. A fuel cell has run, standby and shutdown operating modes. A fuel processor provides reformate to the fuel cell. A pressure sensor generates a pressure signal based on a pressure of steam supplied to the fuel processor. A valve directs steam to or vents steam away from the fuel processor. A controller communicates with the pressure sensor, the fuel cell and the valve and controls the valve based on the operating mode of the fuel cell and the pressure signal. The controller opens the valve during the shutdown mode. The controller closes the valve during the run operating mode. The controller initially closes the valve during the standby mode. The controller opens the valve if the pressure signal exceeds a first predetermined pressure value and closes the valve when the pressure falls.