Dual-Loop Aircraft Thermal Management Using Liquid Hydrogen Cooling
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Solution Overview
Problem
Aircraft using hydrogen fueled fuel cells face challenges in thermal management, particularly in efficiently cooling the fuel cell stacks and other heat loads, while minimizing weight and drag.
Innovation Solution
The implementation of a dual-loop thermal management system, comprising a high temperature loop for managing the fuel cell stack temperature using a nacelle heat exchanger and a low temperature loop for cooling other heat loads using the heat capacity of liquid hydrogen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional thermal management system with separate cooling systems for fuel cell stacks and other heat loads is used, then reliable cooling is achieved, but system complexity and weight increase due to multiple heat exchangers
Solution Approach 1:
The patent combines the cooling of fuel cell stacks and other heat loads into a single integrated thermal management system. The high temperature loop coolant simultaneously cools the fuel cell stack through a stack heat exchanger and other nacelle components through a combined heat exchanger, eliminating the need for separate cooling systems and reducing overall system complexity while maintaining reliable cooling for all components
2Temperature
If additional heat exchangers are added to cool both fuel cell stacks and other heat loads separately, then adequate cooling is provided, but weight and drag increase
Solution Approach 1:
The patent merges multiple cooling functions into a single high temperature loop that uses one stack heat exchanger and one combined heat exchanger to cool both the fuel cell stack and other nacelle components. This integration significantly reduces the number of heat exchangers required, thereby reducing system weight and drag while maintaining adequate cooling effectiveness for all heat loads
Solution Approach 2:
The high temperature loop coolant serves multiple functions simultaneously: it cools the fuel cell stack through the stack heat exchanger, cools other nacelle components through the combined heat exchanger, and can provide heating to the liquid hydrogen tanks. This multi-functionality eliminates the need for separate dedicated cooling systems for each component, reducing overall system weight
3Weight of moving object
If a simple cooling system is used, then weight is minimized, but the ability to manage both fuel cell stack temperature and other heat loads efficiently is reduced
Solution Approach 1:
The high temperature loop is designed as a universal thermal management system that can simultaneously handle multiple thermal loads: cooling the fuel cell stack, cooling other nacelle components, and providing heating to liquid hydrogen tanks. This multi-functional design maintains high adaptability and versatility while minimizing system weight by using a single integrated loop instead of multiple separate systems
Solution Approach 2:
The thermal management system is segmented into two temperature loops: a high temperature loop for cooling fuel cell stacks and other heat loads, and a low temperature loop for cooling electronic components. This segmentation allows each loop to be optimized for its specific temperature range and cooling requirements, improving overall thermal management efficiency while keeping the system lightweight
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 dual-loop system effectively manages the temperature of both the fuel cell stacks and other heat loads, reducing the need for additional heat exchangers and minimizing weight and drag, while maintaining efficient cooling and heating processes.
Implementation Method 1
The high temperature loop is configured to manage a temperature of a fuel cell stack in a nacelle using a nacelle heat exchanger
Implementation Method 2
The low temperature loop is configured to cool a number of heat loads in a nacelle using a heat capacity of liquid hydrogen
Implementation Method 3
The ram air cooler in a nacelle comprises a nacelle heat exchanger and a set of fans configured to increase airflow through the nacelle heat exchanger
Implementation Method 4
The high temperature loop is configured to remove heat from the fuel cell stack and send heat removed from the fuel cell stack into ambient air as part of exhaust air exiting the nacelle
Data Source
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AI summary
An aircraft thermal management system comprising a high temperature loop and a low temperature loop. The high temperature loop is configured to manage a temperature of a fuel cell stack in a nacelle using a nacelle heat exchanger. The low temperature loop is configured to cool a number of heat loads in a nacelle using a heat capacity of liquid hydrogen.