2012 Fiscal Year Final Research Report
Analysis on Self-ignition hazards during discharge of high-pressure flammable gas
| Project/Area Number |
23710190
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Social systems engineering/Safety system
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
MOGI Toshio 東京大学, 大学院・工学系研究科, 講師 (50392668)
|
|---|
| Project Period (FY) |
2011 – 2012
|
| Keywords | 高圧水素 / 衝撃波 / 自己着火 |
|---|
| Research Abstract |
When high-pressure hydrogen is suddenly discharged into air, it is possible to be spontaneously ignited. Many researches were carried out on this phenomenon recently. Among those lab-scale experimental works, the maximum value for hydrogen release pressure was 14.7 MPa. In order to investigate into the behavior of 70MPa hydrogen, we adopted a new method of enlarging pressure ratio by vacuuming the air. It was found that this method to imitate high pressure hydrogen release is only valid when the pressure of air is larger than 0.07 MPa. Another major contributing factor in self-ignition is the mixing of hydrogen and air. It was discovered that hydrogen blends into the heated air before the contact surface of two gases arrives. We also tested the effect of enforced gas mixing. Hydrogen was discharged through pipes with various geometries. The onset pressures for ignition were lower than the pressure when hydrogen was released in a straight pipe. A simple way to estimate the minimum pressure for self-ignition was proposed and validation was attempted.
|
