Cryogenic Tank Recirculation Conduit for Pressure Regulation
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Solution Overview
Problem
Cryogenic tanks used in aircraft experience pressure variations due to decreasing LNG levels, leading to performance issues and pump cavitation, which affect engine operation and increase costs.
Innovation Solution
A cryogenic tank assembly with a recirculation conduit that transfers heat from the ambient environment to LNG, changing it to natural gas and injecting it back into the tank to regulate pressure, thereby maintaining a more uniform pressure and preventing cavitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LNG is stored in a cryogenic tank and dispensed through a pump, then the aircraft engine can be supplied with natural gas, but as the LNG level decreases the pressure within the tank decreases causing pressure variations downstream and pump cavitation
Solution Approach 1:
The patent introduces a pressurization system that actively maintains the pressure parameter within the cryogenic tank at a substantially constant level. This system includes a pressurization fluid source and a control system that regulates the pressure by adding pressurization fluid or preventing its removal, thereby resolving the pressure decrease issue as LNG level drops
Solution Approach 2:
The control system continuously monitors the pressure within the cryogenic tank and adjusts the pressurization fluid addition accordingly. This feedback mechanism ensures that pressure variations are detected and corrected in real-time, maintaining substantially constant pressure and preventing pump cavitation
2Reliability
If the pressure within the cryogenic tank decreases, then the pump may cavitate, but increasing pressure requires additional system complexity
Solution Approach 1:
The system uses the existing cryogenic tank structure and integrates the pressurization system components (fluid source, control system) that leverage the tank's own environment. The control system automatically regulates pressure without requiring external complex intervention, allowing the system to self-maintain optimal pressure conditions
Solution Approach 2:
The pressurization fluid serves multiple functions: it maintains tank pressure to prevent cavitation, and can be integrated with the existing LNG dispensing infrastructure. The control system also monitors both pressure levels and LNG levels, providing comprehensive system management through a single integrated controller
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 solution delivers a more consistent pressure to the aircraft engine, enhancing performance, reducing cavitation, and increasing the reliability and cost-effectiveness of the pump and delivery system.
Implementation Method 1
transfer heat from the ambient environment to the LNG flow to change the LNG flow to a flow of natural gas
Implementation Method 2
change the LNG flow to a flow of natural gas
Data Source
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AI summary
A cryogenic tank assembly includes a cryogenic tank having an internal volume that is configured to contain liquefied natural gas (LNG). The cryogenic tank includes an inlet and an outlet that are each fluidly connected to the internal volume. The assembly includes a recirculation conduit coupled in fluid communication between the inlet and the outlet. The recirculation conduit extends along a path between the inlet and outlet external to the internal volume of the cryogenic tank such that the path is configured to be exposed to an ambient environment of the cryogenic tank. The recirculation conduit is configured to: receive a flow of LNG from the internal volume through the outlet; transfer heat from the ambient environment to the LNG flow to change the LNG flow to a flow of natural gas; and inject the natural gas flow into the internal volume of the cryogenic tank through the inlet.