Fuel Valve Priming via Conveying Pump to Remove Vapor Bubbles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vapor bubble formation in fuel systems with low pressure, particularly in fuel systems with a fuel valve, makes it difficult or prevents the starting of internal combustion engines, especially after shutdown when after-heating occurs without cooling air.
Innovation Solution
A conveying pump is arranged in the feed line to the fuel chamber of the fuel valve, connected to a relief line with a first valve, which primes the fuel chamber, flushing out vapor bubbles and maintaining desired pressure, preventing new bubble formation through controlled actuation based on pressure, temperature, or engine speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the fuel system operates at minimal pressure (1- few bar above ambient), then the fuel system can operate with low energy consumption, but vapor bubble formation occurs in the fuel valve making engine starting difficult or impossible
Solution Approach 1:
The conveying pump performs preliminary action by forcing fuel through the fuel valve and into the fuel tank before engine startup, priming the fuel system and removing vapor bubbles in advance. This preliminary priming action ensures the fuel valve is free of vapor bubbles when the engine starts, resolving the starting reliability issue while maintaining low operating pressure.
Solution Approach 2:
The conveying pump operates periodically during engine shutdown and startup phases to flush vapor bubbles from the fuel system. The periodic operation includes forcing fuel through the fuel valve into the fuel tank during shutdown, and additional flushing during startup if vapor bubbles are detected, maintaining energy efficiency while ensuring reliable starting.
2Reliability
If the fuel valve is primed with fuel under high pressure, then vapor bubbles are effectively removed and cooling is improved, but the pressure regulator cannot limit the pressure supplied by the conveying pump
Solution Approach 1:
A bypass line with a second valve serves as an intermediary pressure control mechanism. When the first valve in the relief line is open during priming, the bypass line with the second valve provides an alternative path to maintain pressure control. The second valve can be actuated to limit pressure in the bypass line, preventing excessive pressure buildup while allowing the main relief line to function at higher pressures for effective vapor bubble removal.
3Stress or pressure
If the conveying pump is arranged downstream of the pressure regulator, then the pressure regulator limits the pressure supplied to the fuel valve, but the fuel chamber cannot be primed at significantly higher pressure than operating pressure
Solution Approach 1:
The fuel system is segmented into two independent paths: the main path through the pressure regulator for normal operation, and a separate priming path through the bypass line with the second valve. This segmentation allows the priming path to operate at higher pressures independent of the pressure regulator's limitations, enabling effective vapor bubble removal while maintaining normal pressure control in the operational path.
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 primes the fuel system, ensuring reliable engine starting by removing vapor bubbles and maintaining pressure, thus enhancing the starting behavior of internal combustion engines.
Implementation Method 1
a conveying pump for forced conveyance of fuel into the fuel system
Implementation Method 2
the fuel chamber is connected to a relief line in which a first valve is arranged... By means of the first valve that is arranged in the relief line, the desired pressure in the fuel system can be maintained in operation
Implementation Method 3
by priming the fuel valve with fuel, an effective cooling action of the fuel valve is achieved in a simple way and this prevents new vapor bubbles from being formed
Implementation Method 4
priming of the fuel chamber in the injection valve can be done at a pressure significantly higher than operating pressure in the fuel system. In this way, an effective priming action and removal of gas or vapor bubbles, possibly contained in the fuel chamber, is enabled
Data Source
AI summary
An internal combustion engine has a fuel system that has a fuel valve with a housing, wherein in the housing a fuel chamber is formed. A fuel pump pumps fuel from a fuel tank into the fuel chamber. A conveying pump provides forced conveyance of fuel into the fuel system. A feed line is connected to the fuel chamber of the fuel valve. The conveying pump is arranged in the feed line and supplies fuel to the fuel chamber. A relief line is connected to the fuel chamber of the fuel valve and a first valve is arranged in the relief line.