Ignition Device Inner Housing Thermal Management

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Solution Overview

Problem

Existing ignition devices for continuous operation in harsh environments, such as rocket test benches, face challenges with high heat generation leading to thermal damage and the need for complex cooling systems, which can limit combustion temperature and efficiency.

Innovation Solution

A robust ignition device design featuring a separate high-temperature-resistant inner housing within a body, with a supersonic nozzle arrangement and minimal heat transfer through strategic mounting and insulation, allowing for efficient heat management and prolonged operation without external cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex cooling system is provided to manage high heat generation during continuous operation, then thermal damage to the ignition device is avoided, but the combustion temperature is limited and the device complexity increases

Engineering Contradiction:
Improvethermal damage resistanceVSAvoidcooling system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the cooling function from the main body by introducing a separate, detachable inner housing that can be independently replaced. This separates the thermal management component from the permanent structure, allowing the cooling system to be maintained without replacing the entire ignition device.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The ignition device is segmented into a permanent outer body and a replaceable inner housing. The inner housing contains the combustion chamber and is designed to withstand high temperatures, while the outer body remains cooler and structurally stable. This segmentation allows different parts to be optimized for their specific thermal environments.

Inventive Principle:
Principle #1Segmentation

2Duration of action of stationary object

If the combustion temperature is kept very low to avoid thermal damage, then the ignition device can operate continuously, but sufficiently high temperatures at the outlet cannot be achieved to initiate combustion

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidcombustion temperature
Core Design Contradiction:
Duration of action of stationary objectVSTemperature

Solution Approach 1:

The patent applies local quality by creating distinct thermal zones: the inner housing and combustion chamber are designed to withstand and generate high temperatures locally, while the outer body operates at lower temperatures. This allows high combustion temperatures to be achieved in the combustion zone without causing thermal damage to the entire device, enabling continuous operation.

Inventive Principle:
Principle #3Local quality

3Reliability

If a robust ignition device is designed to withstand harsh environmental conditions, then reliability under cross currents and vacuum is improved, but the device becomes more complex and harder to manufacture

Engineering Contradiction:
Improveextinguishing resistanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies dynamics by designing the inner housing as a detachable component that can be removed and replaced. This dynamic design allows the robust, high-temperature-resistant inner housing to be separated from the outer body, simplifying manufacturing processes and enabling the use of specialized materials without increasing overall device complexity.

Inventive Principle:
Principle #15Dynamics

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 design achieves stable and efficient combustion under harsh conditions, maintaining high temperatures for effective ignition while protecting the device from thermal damage and enhancing operational longevity and efficiency by minimizing heat transfer and using the energy content of the fuel effectively.

Implementation Method 1

The inner housing preferably consists of a high-temperature-resistant material, for example a high-temperature-resistant metal alloy and/or ceramic

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

The nozzle arrangement is designed in such a way that in operation it causes a supersonic flow downstream of the combustion chamber

Methodology Applied
Scientific EffectSupersonic flow: De Laval Nozzle

Implementation Method 3

generating the ignition energy by burning an oxidizer-fuel mixture

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP3677768B1Ignition device and method for operating same
Publication Date: 2022.06.08 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V
  • EP3677768B1 patent drawingFigure 1A
  • EP3677768B1 patent drawingFigure 1B
  • EP3677768B1 patent drawingFigure 2A~2B

AI summary

The invention relates to an ignition device (1) for initiating a combustion process in an ignitable environment (3) by generating the ignition energy through the combustion of an oxidizer-fuel mixture, comprising a body (10) extending along a longitudinal axis (L), a combustion chamber (28) enclosed by the body (10), an oxidizer supply arrangement (12), and a fuel supply arrangement (18), each comprising an opening (16, 26) into the combustion chamber (28) and an outlet (44) arranged downstream of the combustion chamber (28) for connection to the ignitable environment (3). A robust ignition device suitable for continuous operation is provided by arranging the combustion chamber (28) in a separate inner housing (34), which is detachably inserted into a space (30) of the body (10) and which, with a wall (32), delimits the combustion chamber (28) (Fig. 1A).