Micro-Turbine Alternator Thermal Isolation for Generator Cooling
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Solution Overview
Problem
Micro-turbine alternators in systems like unmanned aerial vehicles (UAVs) face challenges with thermal exposure from the turbine, which can demagnetize permanent magnets in electric generators, limiting mission duration and efficiency.
Innovation Solution
A thermal isolation system for micro-turbine alternators using forced air cooling and ceramic thermal isolators to protect the electric generator from turbine heat, combined with a unique housing design that positions the generator between the blower and turbine to enhance cooling and stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the generator is positioned close to the turbine for compact design, then device complexity is reduced, but the generator temperature increases causing demagnetization risk
Solution Approach 1:
The housing is divided into a turbine housing and a generator housing that are thermally isolated from each other. The turbine housing contains the turbine and allows hot exhaust to escape, while the generator housing contains the generator and is cooled by air passages. This segmentation creates thermal barriers that prevent heat transfer from the turbine to the generator, solving the contradiction between compact design and temperature control.
Solution Approach 2:
Air passages act as an intermediary cooling medium between the turbine and generator. Cool air is introduced into the generator housing through air passages, absorbing heat from the generator and carrying it away. This intermediary cooling system allows the generator to operate at safe temperatures even when positioned near the hot turbine, resolving the thermal exposure problem while maintaining system compactness.
2Reliability
If conventional internal combustion engines are used for power generation, then reliability is improved, but weight increases and power density decreases
Solution Approach 1:
The invention extracts and eliminates the heavy components of conventional internal combustion engines (pistons, crankshafts, valves, fuel injection systems) and replaces them with a simple micro-turbine design. The micro-turbine uses a straightforward rotating mechanism with a turbine wheel driven by combustion gases, removing unnecessary mechanical complexity and weight while maintaining reliable power generation capability.
Solution Approach 2:
The invention changes the operating parameters and design approach from conventional reciprocating engines to a micro-turbine system operating at higher speeds with continuous rotation. This parameter change enables the system to achieve higher power density and lower weight while maintaining reliability, as the micro-turbine design is optimized for small-scale, high-speed operation without the mechanical limitations of piston engines.
3Device complexity
If batteries are used for power supply, then simplicity is improved, but mission duration is limited due to low energy density
Solution Approach 1:
The micro-turbine system performs preliminary action by generating electrical power continuously during the mission rather than relying on pre-stored battery energy. The system uses a small fuel tank to store chemical energy that is converted to electrical power on-demand through the micro-turbine generator, effectively extending mission duration beyond what batteries alone could provide while maintaining operational simplicity.
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
Effectively reduces generator temperature, increases stiffness, and extends mission duration by preventing demagnetization, allowing for untethered, lightweight power generation.
Implementation Method 1
A micro-turbine alternator system includes a blower, a turbine, an electric generator, a housing, and a radial air passage. The radial air passage is in fluid communication with the blower and the generator such that cool air from the blower is directed to the generator.
Implementation Method 2
A thermal isolation system for micro-turbine alternators using forced air cooling and ceramic thermal isolators to protect the electric generator from turbine heat
Implementation Method 3
A decomposition chamber receives fuel and produces hot gas to drive a turbine
Implementation Method 4
The blower is located radially outward of the turbine shaft disc and radially inward of the housing. The blower includes a blower shaft extending through the turbine shaft disc and connected to the blower.
Data Source
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AI summary
An electrical power generation system (50) including: a micro-turbine alternator (100), including: a decomposition chamber (162); a turbine (152) including blades (125) driven by combustion gases from the decomposition chamber; a blower (142) operably connected to the decomposition chamber to provide a blown airflow thereto; one or more shafts (158; 210) connecting the turbine to the blower such that rotation of the turbine drives rotation of the blower; an electric generator (130) disposed along the one or more shafts such that electrical power is generated via rotation of the one or more shafts; and a housing (106) enclosing the electric generator within a generator cavity (131) formed therein. The blower is configured to blow air through the generator cavity through or around the electric generator. The air is configured to exit the generator cavity to enter the turbine.