Ejector Pressure Regulator for Deep Vacuum Generation
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Solution Overview
Problem
Typical ejectors cannot produce suction pressure below atmospheric pressure when motive pressure exceeds 192 kPa absolute and lack control over motive flow rate, especially in vehicles with fluctuating boost pressures from turbo- or super-chargers.
Innovation Solution
The introduction of a pressure regulator in fluid communication with the ejector, which includes a valve mechanism and Venturi gaps to control the flow of boost pressure, ensuring a constant flow rate and deeper vacuum generation across varying boost pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a typical ejector is used with high motive pressure, then vacuum can be generated, but the suction pressure cannot go below atmospheric pressure and the motive flow rate cannot be controlled
Solution Approach 1:
A pressure regulator valve is introduced as an intermediary device between the motive pressure source and the ejector. This valve controls the flow rate of motive pressure into the ejector, enabling regulated vacuum generation without requiring complex modifications to the ejector itself. The pressure regulator acts as a mediator that translates uncontrolled high-pressure flow into controlled flow suitable for the ejector.
2Stress or pressure
If boost pressure is increased to improve vacuum depth, then more vacuum can be generated, but the ejector cannot produce suction below atmospheric pressure when motive pressure exceeds 192 kPa
Solution Approach 1:
The system dynamically adjusts the motive flow rate to match varying boost pressure conditions. The pressure regulator valve responds to changes in boost pressure by automatically modulating the flow rate, allowing the ejector to operate effectively across a wide range of pressures. This dynamic control enables deep vacuum generation when boost pressure is high while maintaining operational effectiveness when boost pressure fluctuates.
Solution Approach 2:
The system changes the parameter of motive flow rate based on boost pressure conditions. By regulating the flow rate of motive pressure into the ejector, the system optimizes vacuum depth for different operating conditions. This parameter adjustment allows the ejector to achieve suction pressures below atmospheric pressure across a broader range of boost pressures.
3Reliability
If unregulated boost pressure is supplied to the ejector, then the system is simpler, but the vacuum generation is inconsistent due to fluctuations in boosted pressure
Solution Approach 1:
The pressure regulator valve incorporates feedback mechanisms that respond to variations in boost pressure and regulate the flow rate accordingly. This feedback control ensures consistent vacuum generation despite fluctuations in the unregulated boost pressure source. The system continuously monitors and adjusts the motive flow to maintain stable ejector operation and reliable vacuum output.
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 provides improved control over boost pressure, enabling the generation of a usable vacuum over a broader range of pressures, enhancing the performance of ejector assemblies in engine systems.
Implementation Method 1
the pressure regulator may include a spring biasing the piston into a maximum open position
Implementation Method 2
the pressure regulator receives boost pressure and selectively allows the boost pressure to pass through a valve opening therein
Implementation Method 3
By passing pressurized air through the ejector, a low pressure region may be created within the ejector so that air can be drawn from a vacuum reservoir
Implementation Method 4
The noise attenuating unit houses a porous sound attenuating member through which the regulated boost pressure flows
Implementation Method 5
a porous sound attenuating member through which the regulated boost pressure flows
Data Source
AI summary
Ejector assemblies and engine systems have a pressure regulator in fluid communication with an ejector. The pressure regulator receives boost pressure and selectively allows the boost pressure to pass through a valve opening therein under selected engine conditions and into the ejector as regulated boost pressure. Both the pressure regulator and the ejector each have a conduit defining a passageway that includes a Venturi gap separating the passageway into a converging section and a first diverging section that both narrow toward the Venturi gap. The pressure regulator has a piston operatively connected to a valve mechanism positioned for movement therewith to control the passage of the boost pressure through the valve opening, and the valve mechanism defines a passage therethrough that includes a gradually narrowing portion that is narrower than the valve opening.