Fuel Filter Pressure Control via Overflow Conduit
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Solution Overview
Problem
Frequent start-stop cycles of internal combustion engines cause significant pressure fluctuations in fuel systems, leading to the risk of impurities being pushed through fuel filters, potential engine disruptions, and damage to the fuel filter due to high pressure, which existing solutions have not adequately addressed.
Innovation Solution
A fuel system design incorporating a low-pressure pump operated by an electric motor, a control device, and an overflow conduit that maintains fuel flow back to the tank when the engine is off, reducing pressure fluctuations by maintaining a stable pressure in the fuel filter during engine shutdowns and startups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the internal combustion engine is frequently started and stopped, then fuel consumption and emissions are reduced, but pressure fluctuations in the fuel system increase causing filter damage and impurity breakthrough
Solution Approach 1:
The control device activates the low pressure pump before the engine start-up to pre-build pressure in the fuel system and fuel filter. This preliminary action ensures that when the engine starts, the fuel filter is already pressurized and ready to filter impurities, preventing filter collapse and impurity breakthrough during the pressure transient phase.
Solution Approach 2:
The invention maintains a residual pressure in the fuel system during engine shutdown by controlling the low pressure pump to operate at reduced speed or intermittently. This beforehand cushioning of pressure prevents the drastic pressure drop that would otherwise cause fuel filter collapse and impurity penetration when the engine is restarted.
2Productivity
If high pressure is applied to supply fuel during engine start, then sufficient fuel supply is achieved quickly, but the fuel filter may be damaged or collapse
Solution Approach 1:
The control device dynamically adjusts the low pressure pump speed based on engine operating state. During engine start-up, the pump speed is increased to provide high pressure for quick fuel supply. During normal operation and shutdown, the pump speed is reduced or adjusted intermittently to maintain moderate pressure, preventing fuel filter damage while ensuring adequate fuel supply when needed.
Solution Approach 2:
The invention changes the pressure parameter in the fuel system by controlling the low pressure pump operation. The control device modulates pump speed and activation timing to create appropriate pressure levels: higher pressure during start-up for quick fuel supply, and moderated pressure during operation and shutdown to protect the fuel filter from collapse and damage.
3Use of energy by moving object
If the low pressure pump is deactivated when the engine is off, then energy consumption is reduced, but pressure fluctuations occur during engine restart
Solution Approach 1:
The control device implements periodic or intermittent operation of the low pressure pump when the engine is shut off. Instead of continuous operation, the pump is activated in periodic cycles to maintain residual pressure in the fuel system. This periodic action consumes less energy than continuous operation while still preventing drastic pressure fluctuations during engine restart.
Solution Approach 2:
The fuel system is designed to maintain its own pressure stability through controlled pump operation. The control device monitors system pressure and activates the low pressure pump only when pressure drops below a threshold, allowing the system to self-regulate pressure without continuous energy input, thus balancing energy consumption with pressure stability.
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 minimizes the risk of operational disruptions and filter damage by reducing pressure spikes and maintaining a stable pressure in the fuel filter, ensuring efficient engine operation and extending filter lifespan.
Implementation Method 1
a low pressure pump (22) operated by an electric motor (M1) arranged in a fuel system (4) for an internal combustion engine (2)
Implementation Method 2
an overflow conduit (56) arranged in connection with a deaerating outlet (54) arranged in the fuel filter device (12) and the fuel tank (20), so that fuel may flow from the fuel filter device (12), via the deaerating outlet (54) and the overflow conduit (56), back to the fuel tank (20)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a fuel system (4) for an internal combustion engine (2), which fuel system (4) comprises a first fuel tank (20), a fuel filter device (12), arranged between a low pressure pump (22) operated by an electric motor and a high pressure pump (14), a first fuel conduit (24), through which the low pressure pump (22) is arranged to supply fuel to the fuel filter device (12), and a control device (26), arranged in connection with an electric motor (M1 ) operating the low pressure pump (22). Furthermore, an overflow conduit (56) is arranged in connection with a deaeration outlet (54), arranged in the fuel filter device (12) and the first fuel tank (20), and the control device (26) is arranged to control the electric motor (M1), in such a way that the low pressure pump (22) is active when the internal combustion engine (2) is turned off for a limited period, whereby fuel may flow from the fuel filter device (12) via the deaeration outlet (54) and the overflow conduit (56), back to the first fuel tank (20). The invention also relates to an internal combustion engine (2) comprising such a fuel system (4), a vehicle (1) comprising such a fuel system (4) and a method to lessen pressure fluctuations in the fuel filter device (12) in such a fuel system (4).