Multi-stage Inertization Process for Enclosed Space Fire Suppression
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Solution Overview
Problem
Existing inertization processes for fire prevention and extinguishment in enclosed spaces require structural decompression and often supply excessive inert gas, as they lower oxygen concentration uniformly to a full inertization level regardless of fire size or type, leading to inefficiencies and increased storage needs.
Innovation Solution
The process involves maintaining an initial base inertization level and, upon fire detection, gradually lowering oxygen concentration to a first and potentially a second intermediate level before reaching the full inertization level, allowing for precise gas volume adjustment based on fire extent and eliminating the need for structural decompression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxygen concentration is uniformly lowered to full inertization level regardless of fire size, then fire extinguishment is achieved, but excessive inert gas is supplied and storage capacity must be increased
Solution Approach 1:
The system dynamically adjusts the inertization level in multiple stages: first lowering oxygen to a base level (12-17 vol.-%) for fire prevention, then further lowering to a first reduced level (6-11 vol.-%) upon fire detection, and potentially to a second reduced level (3-5 vol.-%) if the fire persists. This dynamic, adaptive approach replaces the static uniform full inertization method, supplying inert gas only to the extent needed for the actual fire severity, thus reducing overall inert gas consumption while maintaining reliable fire extinguishment.
Solution Approach 2:
The invention changes the oxygen concentration parameter in a stepped manner rather than uniformly. The system maintains different oxygen concentration levels at different times and conditions: base inertization level (12-17 vol.-%) during normal operation, first reduced level (6-11 vol.-%) after fire detection, and second reduced level (3-5 vol.-%) if fire continues. This parameter change strategy optimizes inert gas usage by matching the oxygen suppression level to the actual fire threat, eliminating excessive gas supply while ensuring effective fire extinguishment.
2Speed
If oxygen concentration is rapidly lowered to full inertization level in event of fire, then fire extinguishment speed is improved, but structural decompression is required
Solution Approach 1:
The rapid inertization process is segmented into multiple stages: first lowering oxygen to a base level (12-17 vol.-%), then upon fire detection further lowering to a first reduced level (6-11 vol.-%) over a first time period (1-30 minutes), and if necessary further lowering to a second reduced level (3-5 vol.-%) over a second time period (1-60 minutes). This segmentation of the inertization process into gradual steps eliminates the need for rapid single-stage full inertization, thereby removing the requirement for structural decompression openings while still achieving effective fire extinguishment through controlled oxygen reduction.
Solution Approach 2:
The system performs preliminary inertization by maintaining a base oxygen concentration level (12-17 vol.-%) before fire occurrence, which pre-reduces the oxygen availability. When fire is detected, the system continues the preliminary action by further lowering oxygen to reduced levels (6-11 vol.-% or 3-5 vol.-%) rather than starting from atmospheric levels. This preliminary action approach allows for slower, controlled oxygen reduction without requiring structural decompression, while still achieving rapid fire suppression relative to traditional methods.
3Ease of operation
If base inertization level is maintained to allow human entry, then safety for persons is improved, but fire risk remains higher compared to full inertization
Solution Approach 1:
The system dynamically switches between two operational states: a safe state with base inertization level (12-17 vol.-% oxygen) that allows human entry and normal operations, and a fire suppression state with reduced oxygen levels (6-11 vol.-% or 3-5 vol.-%) that eliminates fire risk. During normal operations, the base level maintains safety for persons while providing fire prevention. Upon fire detection through sensors, the system transitions to the reduced oxygen state to suppress the fire. This dynamic switching resolves the contradiction by adapting the oxygen level to the actual operational requirements.
Solution Approach 2:
The system uses fire detection sensors to monitor the protected space continuously and provides feedback to the control unit. When sensors detect fire indicators (smoke, heat, flame), the control unit responds by lowering oxygen from the base level to reduced levels. This feedback mechanism allows the system to maintain the safer base inertization level during normal conditions while automatically transitioning to fire-suppressing reduced oxygen levels when needed, thus balancing human accessibility with fire risk mitigation through real-time monitoring and response.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces inert gas consumption, eliminates the need for decompression openings, and allows for more targeted fire extinguishment by adjusting oxygen levels in response to the fire's severity, enhancing cost-effectiveness and adaptability.
Implementation Method 1
The extinguishing effect resulting from this process is based upon the principle of oxygen displacement. As is known, normal environmental air is made up of 21 vol.-% oxygen, 78 vol.-% nitrogen and 1 vol.-% other gases. To extinguish a fire, the nitrogen concentration in the relevant space is further increased by introducing nitrogen, thereby decreasing the oxygen ratio.
Data Source
AI summary
The present invention relates to an inertization process for decreasing a risk of fire and for extinguishing fires in a protected room, wherein an oxygen concentration in the protected room is first lowered to a specific base inertization level, and wherein the oxygen concentration in the protected room is maintained at the base inertization level. In the event of a fire, additional inert gas is introduced based upon the extent of the fire in the protected room to further decrease from the base inertization level to a first lowered level. The oxygen concentration is maintained at the first lowered level for a first preset time interval, and further decreased from the first lowered level to a full inertization level, if the fire has not yet been extinguished once the first preset time interval has elapsed.