Fire Extinguisher Thermal Coupling for Flow Stability
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Solution Overview
Problem
Fire suppression systems face complexity and cost issues due to the need for flow control devices to accommodate varying temperature ranges caused by pressure decay of fire suppressant agents, which affects the continuous flow rate during low rate discharge.
Innovation Solution
A fire extinguisher design that thermally couples the expanded fire suppressant flow with the pressurized flow entering the flow control device using a heat exchanger or common wall segment, allowing heat communication between the two flows to stabilize the temperature range experienced by the flow control device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flow control devices are designed to accommodate varying temperature ranges caused by pressure decay, then continuous flow rate is maintained, but device complexity and cost increase
Solution Approach 1:
A heat exchanger is introduced as an intermediary component between the expanded fire suppressant flow and the pressurized fire suppressant source. The heat exchanger mediates thermal energy transfer, using the cold expanded flow to pre-cool the pressurized flow, thereby stabilizing the temperature range experienced by the flow control device and simplifying its design requirements
2Reliability
If flow control devices include variable apertures and throttle valves to handle temperature variations, then continuous flow is achieved, but manufacturing cost increases
Solution Approach 1:
The heat exchanger serves as a thermal intermediary that pre-conditioned the pressurized fire suppressant before it reaches the flow control device. This eliminates the need for complex variable apertures and throttle valves, allowing the use of simpler, more cost-effective flow control components while maintaining continuous flow stability
3Temperature
If heat exchanger is added to thermally couple expanded and pressurized flows, then temperature range is limited, but device complexity increases
Solution Approach 1:
The system utilizes the cold expanded fire suppressant flow itself as the cooling medium for the heat exchanger, rather than requiring an external refrigeration system or separate cooling apparatus. The expanded flow automatically serves its dual purpose of fire suppression and thermal conditioning, eliminating the need for additional active cooling components and reducing overall system complexity
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 design simplifies and reduces the cost of flow control devices by limiting the temperature range, ensuring a constant mass flow rate of fire suppressant during decay of pressure, thereby enhancing the reliability and efficiency of fire suppression systems.
Implementation Method 1
a heat exchanger arranged along the source conduit and the supply conduit, wherein the supply conduit is thermally coupled to the source conduit be the heat exchanger
Implementation Method 2
the supply conduit is thermally coupled to the source conduit to communicate heat between an expanded fire suppressant flow issued by the flow control device and a pressurized fire suppressant flow entering the flow control device
Implementation Method 3
the magnitude of the Joule-Thompson temperature of the expansion varies according to pressure
Data Source
AI summary
A fire extinguisher includes a source conduit, a flow control device connected to the source conduit, and a supply conduit. The supply conduit is connected to the flow control device, is fluidly coupled therethrough to the source conduit, and is thermally coupled to the source conduit to communicate heat between pressurized fire suppression agent entering the flow control device through the source conduit and expanded fire suppression agent issuing from the flow control device through the supply conduit. Fire suppression systems and methods of controlling flow of fire suppressant agents are also described.