CONTROLLED PROCESS GAS PRESSURE DECAY AT SHUT DOWN

摘要

A back pressure regulating device can be incorporated into a fuel cell test station or a fuel cell power module. For each of fuel can oxidant lines, it provides a gas pressure regulator. The pressure regulator is controlled by a pilot gas, supplied through a pressure regulating valve and a three-way valve. Another port of the three-way valve provides a vent through a check valve and a needle valve. The needle valve is connected to both check valves for the pilot gas lines for the fuel and oxidant. In normal operation, the pilot gas pressure, regulated by the pressure regulating valve, is supplied to the appropriate pressure regulator to control the respective fuel and oxidant gas pressures. On shut down, the three-way valve connects the pressure regulator through the respective check valve to the needle valve. This provides controlled decay of the pressures of the fuel and oxidant gases.