Fuel cell system with variable Coanda amplifiers for gas recirculation and system pressure regulation

摘要

A Coanda flow amplifier has a suction intake, an outlet, a fluid channel extending between the suction intake and the outlet, and a drive-flow inlet, which is fluidly connected to the fluid channel via a drive-flow discharge slit, whereby the flow cross section of the drive-flow discharge slit is variably adjustable. In a method to operate the Coanda flow amplifier, the variably adjustable flow cross section of the drive-flow discharge slit is chosen such that a pressure ratio between an output pressure of the drive flow when it leaves the drive-flow discharge slit, and an intake pressure of the drive flow when it enters the drive-flow discharge slit, does not exceed a critical pressure ratio. A fuel cell system comprises at least one fuel cell, a fluid source, a fluid line, and a Coanda flow amplifier arranged in the fluid line, whereby the Coanda flow amplifier is equipped with a drive-flow discharge slit with a variably adjustable flow cross section.

主权项

1. A Coanda flow amplifier, comprising:
a suction intake; an outlet; a fluid channel extending between the suction intake and the outlet; a drive flow inlet that is in fluid flow communication with the fluid channel via a drive-flow discharge slit; and an electronic control unit that adjusts the flow cross section of the drive-flow discharge slit after assembly of the Coanda flow amplifier such that a pressure ratio between an output pressure of the drive flow that leaves the drive-flow discharge slit and an intake pressure of the drive flow that enters the drive-flow discharge slit does not exceed a critical pressure ratio.