Thermally activated safety valve for pressure vessels

A pressure vessel comprising:

• an outer support layer having an inner surface;
• a composite wrap disposed adjacent to the inner surface;
• a polymeric liner disposed adjacent to the composite wrap, an inner surface of the liner defining a closed cavity within the pressure vessel;
• an adapter disposed at a first end of the pressure vessel and configured for charging the cavity with a compressed fuel, wherein the adapter includes a first pressure relief device;
• a second pressure relief device disposed in the outer support layer, the second pressure relief device having:
• a main body with a chamber enveloping a chamber material, the chamber material filling the chamber, and
• a diaphragm abutting the liner and disposed between the chamber and the cavity, the chamber material abutting the diaphragm and supporting the diaphragm against a pressure of the cavity,
• wherein the diaphragm is adapted to rupture upon activation of the second pressure relief device and facilitate an evacuation of the chamber material and a compressed fuel from the cavity through the second pressure relief device.

A fuel cell propulsion system comprising:

• a fuel cell system having a fuel cell stack including a plurality of fuel cells, the fuel cell stack being configured to receive a compressed fuel from a pressure vessel;
• the pressure vessel comprising:
• an outer support layer having an inner surface;
• a composite wrap disposed adjacent to the inner surface;
• a liner disposed adjacent to the fiber composite wrap, an inner surface of the liner defining a closed cavity within the pressure vessel;
• an adapter disposed at a first end of the pressure vessel and configured for filling the cavity formed by the liner with the compressed fuel, wherein the adaptor includes a first pressure relief device;
• and a second pressure relief device disposed at a second end of the pressure vessel and forming a passage through the outer support layer and the composite wrap,
• the second pressure relief device having:
• a main body with a chamber enveloping a chamber material, the chamber material filling the chamber, and
• a diaphragm abutting the liner and disposed between the chamber and the cavity, the chamber material abutting the diaphragm and supporting the diaphragm against a pressure of the cavity,
• wherein the diaphragm is adapted to rupture upon activation of the pressure relief device and facilitate an evacuation of the chamber material and a compressed fuel from the cavity through the pressure relief device.