Cryogenic Engine Ignition via Plasma Film Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cryogenic engines with liquid oxygen/methane propellant combinations face challenges in ignition reliability and thermal structure safety, particularly for low-thrust attitude control engines requiring thousands of pulse ignitions and long service life, due to electrode ablation and instability in ignition processes.
Innovation Solution
The cryogenic engine design incorporates a combination of inclined core and swirl injector elements, a like-impinging primary injector, annular secondary injector, and swirl injector elements to control mixing ratios and prevent electrode ablation, ensuring reliable ignition and thermal safety through staged combustion and plasma formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pre-combustion chamber ignition structure with a central electrode is used, then ignition capability is achieved, but the electrode is easily ablated, reducing equipment reliability
Solution Approach 1:
The patent introduces a combustion improver (inert gas) as an intermediary substance that mediates between the electrode and the main propellant combustion. The combustion improver is injected to form a stable ignition kernel that reduces direct exposure of the electrode to high-temperature combustion gases, thereby reducing ablation while maintaining ignition capability
Solution Approach 2:
The patent changes the chemical composition parameters of the combustion environment by introducing a combustion improver with specific properties (inert gas or vapor). This parameter change creates a more favorable ignition environment that reduces electrode erosion while maintaining reliable ignition performance
2Productivity
If liquid oxygen is directly injected into the combustion chamber, then combustion efficiency is improved, but ignition stability deteriorates due to poor vaporization
Solution Approach 1:
The patent applies preliminary action by pre-vaporizing liquid oxygen in a dedicated vaporization chamber before it enters the main combustion chamber. This preliminary vaporization ensures stable ignition conditions are established before main combustion begins, preventing ignition instability while maintaining high combustion efficiency
Solution Approach 2:
The patent segments the combustion process into distinct stages: a pre-combustion chamber for initial vaporization and ignition kernel formation, and a main combustion chamber for efficient combustion. This segmentation allows optimization of each stage independently - stable vaporization in the first stage, high efficiency in the second stage
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 design achieves reliable ignition with unlimited pulse ignition capabilities and extended service life by fully vaporizing liquid oxygen, forming stable plasma flows, and creating a uniform oxygen film for stable combustion and cooling, addressing the limitations of prior art engines.
Implementation Method 1
The combustion improver is liquid oxygen, and the combustible agent is one of liquid methane, liquid hydrogen or kerosene... fully vaporizing liquid oxygen
Implementation Method 2
a spark plug, where the injector body is provided therein with an accommodating space; and the spark plug is provided on one side of the injector body, and an electrode provided on the spark plug extends into the accommodating space
Implementation Method 3
forming stable plasma flows
Implementation Method 4
High-performance, non-toxic cryogenic chemical propulsion technology has become the mainstream development direction of liquid-propellant rocket engines
Data Source
AI summary
A cryogenic engine for a space apparatus is provided. The cryogenic engine includes an injector body, a thrust chamber, and a spark plug, where the injector body is provided therein with an accommodating space; the spark plug is provided on one side of the injector body, and an electrode provided on the spark plug extends into the accommodating space; the thrust chamber is provided on the other side of the injector body and is communicated with the accommodating space; the injector body is provided with a combustion improver flow channel and a combustible agent flow channel; and the combustion improver flow channel and combustible agent flow channel are connected with the accommodating space.