Closed Gas Generator with Catalytic Propellant Regeneration

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Solution Overview

Problem

Small-scale unmanned air vehicles (UAVs) and devices face weight and space constraints due to battery usage, leading to reduced performance and reliability, especially when stored for extended periods, as batteries tend to lose charge and are difficult to replace or recharge in remote areas.

Innovation Solution

A non-combusting gas generator using a dense, stable amine-based propellant catalyzed within a porous reaction matrix to produce exhaust gases, which powers micro power units, including turbines and electric generators, without requiring ambient air, thus minimizing weight and space while maintaining performance over extended periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If batteries are used to power small-scale UAVs and devices, then electrical and electro-mechanical operation is enabled, but weight increases significantly and performance diminishes

Engineering Contradiction:
Improveelectrical operation capabilityVSAvoidbattery weight
Core Design Contradiction:
Use of energy by moving objectVSWeight of moving object

Solution Approach 1:

The patent changes the energy storage medium from chemical batteries to a closed-loop catalytic chemical system. By using hydroxyl ammonium nitrate propellant that decomposes into nitrogen and oxygen, then reforms back into the original compound through catalysis, the system achieves continuous power generation without the weight penalty of traditional batteries. The energy density and operational duration are dramatically improved while maintaining compact form factor.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The catalytic converter automatically regenerates the propellant from its decomposition products without external intervention. The system self-sustains by using the exhaust gases (nitrogen and oxygen) to reform hydroxyl ammonium nitrate, which is then fed back into the combustion chamber. This closed-loop self-service mechanism eliminates the need for battery recharging or replacement, solving the weight and performance issues simultaneously.

Inventive Principle:
Principle #25Self-service

2Duration of action of stationary object

If batteries are used for extended storage, then devices can be stored for months or years, but batteries lose charge and reliability decreases

Engineering Contradiction:
Improvestorage durationVSAvoidbattery charge retention
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The closed-loop catalytic system continuously regenerates its propellant from exhaust gases, maintaining readiness without degradation over time. Unlike batteries that self-discharge during storage, this system preserves its chemical potential energy indefinitely as long as the propellant is sealed, and can be activated immediately upon deployment. The catalytic converter ensures the propellant is constantly renewed, eliminating charge loss issues.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The propellant is stored in a sealed, inert environment that prevents degradation and maintains stability during extended storage periods. The closed-loop design isolates the chemical compounds from external factors that would cause deterioration, allowing the system to be stored for months or years without loss of reliability or performance.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

3Adaptability or versatility

If batteries are used in remote deployment scenarios, then devices can operate away from resupply sources, but replacement or recharging becomes extremely difficult

Engineering Contradiction:
Improveremote operation capabilityVSAvoidbattery replacement difficulty
Core Design Contradiction:
Adaptability or versatilityVSEase of repair

Solution Approach 1:

The system carries its own propellant regeneration capability through the catalytic converter, making it self-sufficient in remote environments. Unlike batteries that require external charging infrastructure, this closed-loop system generates and regenerates its own energy source onboard, enabling indefinite operation in the most remote locations without access to resupply or recharging facilities.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The catalytic converter serves multiple functions: it decomposes the propellant to generate power, captures the exhaust gases, and regenerates the propellant from those gases. This multi-functional component eliminates the need for separate battery, charger, and fuel storage systems, providing universal power generation capability that adapts to any remote deployment scenario.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Volume of moving object

If compact power sources are used to reduce size, then device miniaturization is achieved, but power output may be insufficient

Engineering Contradiction:
Improvepower source volumeVSAvoidpower generation capability
Core Design Contradiction:
Volume of moving objectVSPower

Solution Approach 1:

The patent achieves high power density by changing from electrical energy storage (batteries) to chemical energy conversion with catalytic regeneration. The closed-loop system continuously converts chemical energy to thermal and mechanical energy with high efficiency, generating significant power from a compact volume. The high energy density of the hydroxyl ammonium nitrate propellant combined with continuous regeneration enables compact size without sacrificing power output.

Inventive Principle:
Principle #35Parameter changes

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

The solution provides a compact, reliable power source for UAVs and devices, enabling extended operation with gradual weight reduction, improved reliability, and reduced storage hazards due to the non-combustible propellant, allowing operation in various environments without the need for ambient air.

Implementation Method 1

The propellant is introduced to a reaction chamber including a porous reaction matrix having a catalyst suspended in the porous reaction matrix. The catalyst catalyzes the propellant within the reaction matrix and generates exhaust gases

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

The exhaust gas is accelerated to supersonic velocity (e.g., 5000 to 7000 feet per second) and impinges against one or more tangential cups of an impulse turbine

Methodology Applied
Scientific EffectDe Laval nozzle effect: De Laval Nozzle

Implementation Method 3

The exhaust gas is accelerated to supersonic velocity and impinges against one or more tangential cups of an impulse turbine. The impulse turbine relies heavily on the velocity of the exhaust gas to rotate and correspondingly generate power

Methodology Applied
Scientific EffectImpulse turbine: Turbine

Data Source

PatentEP2699780B1Closed gas generator and micro power unit including the same
Publication Date: 2016.04.06 RAYTHEON CO
  • EP2699780B1 patent drawingFigure 1~2
  • EP2699780B1 patent drawingFigure 3A~3B
  • EP2699780B1 patent drawingFigure 4

AI summary

A gas generator assembly includes a propellant chamber housing an amine based propellant. A reaction chamber is coupled with the propellant chamber. The reaction chamber includes a reaction chamber housing, and a porous reaction matrix within the reaction chamber housing. The reaction matrix includes a catalyzing agent, and the catalyzing agent is configured to non-combustibly catalyze the amine based propellant into one or more pressurized gases. An injector is in communication with the propellant chamber. The injector is configured to deliver the amine based propellant to the porous reaction matrix. A discharge nozzle is coupled with the reaction chamber and is configured to accelerate and discharge the one or more pressurized gases. In one example, the gas generator is coupled with one or more of an impulse turbine assembly and an electric generator to form a micro power unit.