Gas Temperature Rise in a High-Pressure Gas Tube by an Adiabatic Compression

Abstract

Serious fire accidents have occurred in oxygen supplying systems in which an adiabatic compression of oxygen has been identified as an ignition source. For exploring the ignition mechanism of oxygen compression, a fluid flow in a tube having a closed end has been studied by experimental and CFD approaches. The simulation results on gas pressure history are in good agreement with the experimental results; whereas the simulated gas temperature history was not in agreement with the experimental results. Ignition tests for a small sample piece placed at the end of the tube were conducted under the same adiabatic compression conditions. Nylon 6,6 and PTFE are used as the polymeric samples. The ignitions for Nylon 6,6 samples have been observed more frequently with higher initial pressures. It should be also noted that the maximum temperature simulated by CFD at the initial pressure of 25 MPa is close to the autogenous ignition temperature of Nylon 6,6, suggesting that the gas temperature simulated by CFD would be more realistic than that in experimental results because of the difficulty in keeping the adiabatic condition in experiments.