Fuel Supply Device for Liquefied Gas Transfer
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Solution Overview
Problem
Existing fuel supply devices for internal combustion engines require compressors to re-liquefy and transfer liquefied gas fuels, leading to a complex configuration and potential leaks that cause abnormal combustion.
Innovation Solution
A fuel supply device with a return fuel path, inflow unit, and control valves that alternate states to transfer liquefied gas fuel from the common rail to the fuel tank without a compressor, using pressure differences to manage the flow and prevent leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a compressor is used to re-liquefy and transfer vaporized fuel from the common rail to the fuel tank, then the fuel can be collected effectively, but the device configuration becomes complicated
Solution Approach 1:
The patent removes the compressor from the system entirely. Instead of using a compressor to transfer fuel, the invention extracts this function by using the engine's own fuel injection system to pump fuel from the common rail back to the fuel tank during the engine's operation cycle, thereby simplifying the device configuration while maintaining fuel collection effectiveness
Solution Approach 2:
The system uses the engine's existing fuel pump and injection system to perform the fuel transfer function that would otherwise require a separate compressor. The fuel injection system serves dual purposes: normal fuel delivery to the engine and pumping excess fuel back to the tank, making the system self-sufficient and eliminating the need for additional components
2Reliability
If the common rail is kept at high pressure to supply fuel to the engine, then fuel supply reliability is improved, but fuel may leak into the combustion chamber causing abnormal combustion
Solution Approach 1:
The patent implements periodic fuel transfer by utilizing the engine's cyclic operation. During specific phases of the engine cycle (when the fuel injection system is active), fuel is pumped from the common rail back to the fuel tank. This periodic action maintains high pressure in the common rail for reliable fuel supply while periodically removing excess fuel that might otherwise leak into the combustion chamber and cause abnormal combustion
Solution Approach 2:
The system incorporates a control unit that monitors fuel pressure and engine operation status, and adjusts the fuel transfer timing and amount accordingly. This feedback mechanism ensures that fuel is transferred from the common rail at appropriate moments to prevent over-pressurization and potential leakage into the combustion chamber, while maintaining sufficient pressure for reliable fuel supply
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 solution effectively collects liquefied gas fuel into the fuel tank without a compressor, simplifying the configuration and preventing abnormal combustion by ensuring complete vaporization of the fuel, thus enhancing engine reliability.
Implementation Method 1
As the temperature in the inflow unit rises due to the liquefied gas fuel flowing in
Implementation Method 2
the liquefied gas fuel in the inflow unit is vaporized, and the temperature, and thus the pressure, in the inflow unit is decreased
Data Source
AI summary
A fuel supply device includes a sub fuel tank disposed in a return fuel line, a pressure reduction valve, and a recirculation cutoff valve. When an internal combustion engine stops, the fuel supply device opens the pressure reduction valve and closes the recirculation cutoff valve. Due to this first transfer state, a liquefied gas fuel in a common rail is transferred to the sub fuel tank. Thereafter, the fuel supply device closes the pressure reduction valve and opens the recirculation cutoff valve. Due to this second transfer state, the liquefied gas fuel in the sub fuel tank is transferred to a main fuel tank. The fuel supply device repeatedly alternates between the first and second transfer states to collect the liquefied gas fuel from the common rail to the main fuel tank.