System and method for preventing or extinguishing fire
Described herein are an inerting method as well as an inerting system ( 1 ) for preventing and/or extinguishing fire, wherein a gas separation system ( 3, 4 ) is provided to set and/or maintain a predefinable oxygen content, which is reduced compared to normal ambient air, in the spatial atmosphere of an enclosed room ( 2 ), said system separating off at least a portion of the oxygen contained in an initial nitrogen/oxygen gas mixture and thereby provide a nitrogenated gas mixture at the outlet ( 4 a ) of the gas separation system ( 3, 4 ). In order to achieve the setting and maintaining of a predefined inerting level with the lowest possible expenditure of energy, the description herein provides for a control device ( 5 ) designed to control the gas separation system ( 3, 4 ) such that the residual oxygen content of the nitrogenated gas mixture is changed as a function of the oxygen content prevailing at that moment in the spatial atmosphere of the enclosed room ( 10 ).
1. A method comprising:
(a) providing an initial gas mixture comprising oxygen and nitrogen by supplying a portion of ambient air of an enclosed room to a mixing chamber and by mixing the portion of ambient air of the enclosed room with fresh air in the mixing chamber;
(b) flowing the initial gas mixture provided in step (a) to a gas separation system comprising a nitrogen generator;
(c) separating at least a portion of the oxygen from the initial gas mixture via the nitrogen generator, thereby producing a nitrogen-enriched gas mixture having a residual oxygen content; and
(d) flowing the nitrogen-enriched gas mixture of the gas separation system having the residual oxygen content into the enclosed room,
wherein the method further comprises the following steps:
(i) measuring an oxygen level of a spatial atmosphere of the enclosed room;
(ii) measuring the residual oxygen content of the nitrogen-enriched gas mixture at an outlet of the nitrogen generator;
(iii) controlling the operation of the nitrogen generator so as to achieve a gas mixture having a residual oxygen content, wherein the operation of the nitrogen generator is controlled based on the measured oxygen level of the spatial atmosphere of the enclosed room and also based on the measured residual oxygen content of the nitrogen-enriched gas mixture at the outlet of the nitrogen generator.
2. The method according to claim 1 , comprising:
removing, in response to the flowing step (d), ambient air from the enclosed room; and
mixing, outside the enclosed room, the ambient air with fresh air.
3. The method according to claim 2 , wherein the volume of the ambient air of the removing step is equivalent to the volume of the nitrogen-enriched gas mixture of the flowing step (d).
4. The method of claim 1 , wherein the controlling of the operation of the nitrogen generator comprises varying dwell time of the nitrogen generator so as to achieve the residual oxygen content.
5. The method of claim 1 , wherein the controlling of the operation of the nitrogen generator comprises varying pressure of the nitrogen generator so as to achieve the residual oxygen content.
6. A method comprising:
(a) providing an initial gas mixture comprising oxygen and nitrogen by supplying a portion of ambient air of an enclosed room to a mixing chamber and by mixing the portion of ambient air of the enclosed room with fresh air in the mixing chamber;
(b) flowing the initial gas mixture provided in step (a) to a gas separation system comprising a nitrogen generator;
(c) separating at least a portion of the oxygen from the initial gas mixture via the nitrogen generator, thereby producing a nitrogen-enriched gas mixture having a residual oxygen content; and
(d) flowing the nitrogen-enriched gas mixture of the gas separation system having the residual oxygen content into the enclosed room,
wherein the method further comprises the following steps:
(i) measuring an oxygen level of a spatial atmosphere of the enclosed room;
(ii) measuring the residual oxygen content of the nitrogen-enriched gas mixture at an outlet of the nitrogen generator;
(iii) controlling a composition of the initial gas mixture in step (a) by actuating valves based on the measurements of the oxygen level of the spatial atmosphere and the residual oxygen content of the nitrogen-enriched gas mixture.
7. The method according to claim 6 , wherein an oxygen content of an output gas mixture of the mixing chamber is measured for at least one of:
continuously;
at predefined times; and
upon predefined events.
8. The method according to claim 6 , comprising:
removing, in response to the flowing step (d), ambient air from the enclosed room; and mixing, outside the enclosed room, the ambient air with fresh air.
9. The method according to claim 8 , wherein the volume of the ambient air of the removing step is equivalent to the volume of the nitrogen-enriched gas mixture of the flowing step (d).