Fuel Pump Cavitation Mitigation via Torque Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cavitation in fuel pumps, exacerbated by higher fuel volatility, ambient temperature, and lower atmospheric pressure, leads to engine hesitation, torque loss, and potential engine stalls in hybrid and start-stop vehicles, compromising engine operation and drivability.
Innovation Solution
A method that detects cavitation based on measured engine torque and ambient conditions, adjusting engine and fuel pump operations by activating and deactivating the fuel pump, operating it at higher speeds, and delaying engine start to mitigate cavitation, thereby alleviating adverse effects on engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fuel pump operates continuously at normal speed, then fuel delivery is maintained, but cavitation occurs under high volatility and temperature conditions causing torque loss
Solution Approach 1:
The fuel pump is activated and deactivated repeatedly for a predetermined duration to mitigate cavitation. This periodic operation allows the pump to clear vapor bubbles from the fuel line by cycling on and off, resolving the cavitation issue while maintaining reliable fuel delivery to the engine.
Solution Approach 2:
The fuel pump operates at a higher speed for a predetermined duration when cavitation is detected. By changing the operational parameter (speed) of the pump, the system increases fuel flow velocity to prevent vapor bubble formation and collapse, thereby eliminating cavitation and its harmful effects on engine operation.
2Use of energy by moving object
If the fuel pump is deactivated for extended periods to save energy, then energy consumption is reduced, but cavitation occurs due to fuel vaporization in the tank
Solution Approach 1:
The system performs preliminary assessment of cavitation risk based on ambient conditions (temperature, pressure, fuel volatility) before engine start. When cavitation is predicted, the fuel pump is activated in advance to prime the fuel line and prevent vapor bubble formation, ensuring reliable engine start without excessive energy consumption.
Solution Approach 2:
The system continuously monitors ambient conditions and engine torque to detect cavitation. Based on this feedback, the control system adjusts fuel pump operation dynamically - activating the pump when cavitation is detected and deactivating it when conditions are favorable, thereby optimizing energy consumption while preventing cavitation.
3Reliability
If engine start is delayed to allow fuel pump to operate at higher speed, then cavitation is mitigated, but engine start time is increased
Solution Approach 1:
The fuel pump operates at higher speed periodically for predetermined durations rather than continuously delaying engine start. This approach mitigates cavitation through intermittent high-speed operation while minimizing the impact on engine start time, achieving a balance between reliability and time loss.
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 approach effectively reduces the likelihood of engine stalls and enhances engine performance and drivability by addressing cavitation-related torque losses and improving fuel delivery efficiency.
Implementation Method 1
a fuel system including a fuel pump and a fuel tank
Implementation Method 2
cavitation may occur by the formation of vapor bubbles in the fuel pump. Further, cavitation may be exacerbated by using fuels with higher volatility (e.g., a higher Reid Vapor Pressure), as well as due to higher ambient temperatures
Implementation Method 3
Cavitation may occur by the formation of vapor bubbles in the fuel pump. Engine operation may be adversely affected by cavitation and the engine may experience issues such as engine hesitation, an unexpected loss of torque, and potential engine stall.
Data Source
AI summary
Methods and systems are provided for mitigating loss of engine torque due to cavitation in a fuel pump. One example approach is adjusting engine operation or fuel pump operation based on ambient conditions and a measured engine torque being lower than a desired engine torque after a pre-determined duration. The ambient conditions may include one or more of ambient temperature being higher than a temperature threshold, barometric pressure lower than a threshold pressure, and fuel volatility higher than a threshold volatility.