| 摘要 |
The firefighting system uses carbon dioxide, nitrogen or some other suitable inert gas to flood a room which is on fire. Output of gas from a pressure vessel dilutes the oxygen concentration in the room from the normal 21% by volume to below e.g. 12%. - The flooding phase (t0,t1,t2) may take approximately 120 seconds, after which the oxygen level reaches a lower threshold (Unterer Schwellwert) and the gas is turned off. Air may leak in, raising the oxygen level. When it reaches an upper threshold (Oberer Schwellwert), the gas is turned on again until the lower level is reached. After a given time (t3), the primary source of inert gas is exhausted, and the oxygen concentration slowly rises toward a maximum safe level (Sicherheits Abschlag S). |
