Liquid Air Injection Control for Reciprocating Engine Vibration
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Solution Overview
Problem
Reciprocating internal combustion engines face inefficiencies in power stroke management and variable compression ratio control, particularly when using different fuels, leading to potential engine vibration and wear issues.
Innovation Solution
A system that includes a controller to manage the injection of liquid air and fuel into the engine's cylinder, allowing for additional power strokes and variable compression ratios by determining the quantity of liquid air based on user input and sensor data, and controlling the injection timing to optimize engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If liquid air is injected into the cylinder to provide additional power strokes, then engine power and thermodynamic efficiency are improved, but engine vibration and wear increase
Solution Approach 1:
The system implements periodic power strokes by alternately injecting liquid air and fuel into the cylinder. The controller manages multiple injection events per engine cycle, creating a rhythmic pattern of power generation that balances power output with mechanical stress reduction, thereby improving reliability while maintaining power.
2Use of energy by moving object
If liquid air is injected at low engine temperatures, then combustion efficiency is improved, but fuel may freeze
Solution Approach 1:
The system performs preliminary heating of the cylinder and injected substances before combustion occurs. The controller monitors engine temperature and adjusts injection timing and quantities to ensure that fuel and liquid air are introduced only when thermal conditions are sufficient to prevent freezing, thereby eliminating the harmful effect while maintaining combustion efficiency.
3Ease of manufacture
If the engine operates with fixed compression ratio, then engine design is simplified, but adaptability to different fuels is reduced
Solution Approach 1:
The system dynamically adjusts the compression ratio by varying the quantity of liquid air injected into the cylinder. The controller modifies injection quantities based on detected engine operating conditions and fuel type, enabling the engine to adapt its compression characteristics in real-time without requiring multiple fixed compression ratio configurations, thus maintaining design simplicity while achieving fuel versatility.
4Productivity
If multiple injection events are implemented per cycle, then engine performance is optimized, but control system complexity increases
Solution Approach 1:
The controller autonomously manages multiple injection events by detecting engine operating conditions and automatically determining optimal injection timing and quantities for both liquid air and fuel. The system self-regulates the complex multi-injection sequence without requiring external intervention or complex manual control mechanisms, thereby achieving optimized performance while keeping the control architecture manageable through intelligent automation.
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 system enables more balanced engine operation, reduces vibration, prevents fuel freezing, and extends engine life by allowing for optimized fuel combustion and thermodynamic cycles with two power strokes, while accommodating various fuels and improving component temperature management.
Implementation Method 1
controlling injection of a determined quantity of liquid air into a reciprocating internal combustion engine
Implementation Method 2
The pressure generated by the combustion of the hydrocarbon fuel causes the piston to move reciprocally within the cylinder
Data Source
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AI summary
A method of controlling a reciprocating internal combustion engine comprising: a cylinder defining a cavity having a first end and a second end; and a piston moveable within the cavity of the cylinder between the first end and the second end, the method comprising: receiving at least a first signal; determining a quantity of liquid air to be injected using at least the received first signal; controlling injection of the determined quantity of liquid air into the first end of the cavity at a first time when the piston is closer to the first end than the second end.