The invention relates to a
hydrogen safety
system of a fuel
cell engine, which comprises a
hydrogen pressure reduction protecting device. The
hydrogen pressure relief protecting device is arranged between a disconnecting valve and a pressure maintaining valve; the
hydrogen pressure relief protecting device comprises an ejector pump, a baffle plate, a spring, a
piston and a
pressure difference transducer; the baffle plate, the spring and the
piston are arranged in a channel at the lower end of the ejector pump; the baffle plate is connected with the
piston through the spring; the outlet of the channel at the lower end of the ejector pump is connected with the outlet of a channel at the right end of the ejector pump through a pipeline to ensure that the pressure of the lower surface of the piston is identical with that of the outlet position on the right side of the ejector pump; the baffle plate is provided with an air hole to ensure that the pressure of the upper surface of the piston is identical with that of the upper part of the baffle plate; a
pressure difference is generated between the upper surface and the lower surface of the piston; the
pressure difference or the deformation of the spring is transmitted to a controller through a
transducer; the controller can control the opening and the closing of the disconnecting valve; when the hydrogen rate exceeds the maximum allowable value, the disconnecting valve is driven to automatically close, and the hydrogen source is
cut off. Compared with the prior art, the invention has the advantages of simple structure, safety,reliability, and the like.