Fuel Supply Flow Control Device with Phase Meter Recirculation

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Solution Overview

Problem

The existing fuel supply circuits for aircraft engines face challenges in managing two-phase flows, leading to potential engine malfunctions due to degassing and cavitation, as manufacturers lack precise information on operating conditions and pipe configurations, resulting in flow regime disturbances that can damage low-pressure pumps.

Innovation Solution

A fuel supply flow control device with a recirculation channel and phase meter system that adjusts the flow rate based on gas content in the upstream pipe, using a calculation unit to control the recirculation valve and maintain optimal pump operation without oversizing the pump or limiting flight envelope.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the flight envelope is limited to avoid low pressure conditions, then pump reliability is improved, but flight performance and operational flexibility deteriorate

Engineering Contradiction:
Improvepump reliabilityVSAvoidflight envelope
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention implements dynamic control of the recirculation valve based on real-time gas content detection. The valve opening degree is continuously adjusted according to the detected gas fraction, allowing the system to adapt to varying flight conditions and maintain reliable pump operation across the entire flight envelope without requiring static limitations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention employs a feedback mechanism where the phase meter continuously monitors gas content in the fuel flow and provides real-time data to the control unit. The control unit then adjusts the recirculation valve accordingly, creating a closed-loop control system that maintains pump reliability while enabling full operational flexibility.

Inventive Principle:
Principle #23Feedback

2Reliability

If the LP pump is oversized to avoid harmful flow regimes, then pump reliability is improved, but propulsion assembly mass increases

Engineering Contradiction:
Improvepump reliabilityVSAvoidpropulsion assembly mass
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention enables the pump system to self-regulate by detecting gas content and automatically adjusting recirculation flow through the controlled valve. This self-service mechanism allows a correctly sized pump to operate reliably across all conditions without requiring an oversized pump design, thereby avoiding unnecessary mass increase.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the operational parameters of the pump system by introducing controlled recirculation flow that varies with gas content. By adjusting the recirculation rate dynamically, the system maintains optimal pump performance without requiring the pump to be oversized for worst-case scenarios.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If precise simulation of fuel supply conditions is performed, then flow regime control is improved, but device complexity increases

Engineering Contradiction:
Improveflow regime controlVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces complex mechanical simulation and specification systems with a straightforward electronic detection and control system. The phase meter electronically detects gas content, and the control unit electronically adjusts the recirculation valve, eliminating the need for complex mechanical simulations and specifications of fuel supply conditions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention creates a universal control system that handles various flight conditions and fuel supply scenarios through a single integrated mechanism. The phase meter and controlled recirculation valve work together to manage all flow regime situations without requiring separate specialized systems for different operating conditions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 regulates fuel flow to prevent harmful flow regimes, ensuring stable engine operation across varying conditions and reducing the risk of pump damage, while avoiding unnecessary mass and size increases in the propulsion system.

Implementation Method 1

a recirculation channel connected as a bypass of the downstream pipe, making it possible to take a certain quantity of fluid from the downstream pipe and to convey the fluid withdrawn from the downstream pipe towards the upstream pipe

Methodology Applied
Scientific EffectRecirculation flow:

Implementation Method 2

a phase meter able to determine the gas content of a two-phase flow arranged in the upstream pipe

Methodology Applied
Scientific EffectPhase detection:

Implementation Method 3

a flow rate adjustment means arranged on the recirculation channel, a calculation unit connected to the phase meter and to the flow rate adjustment means, said calculation unit being configured to control the flow rate adjustment means so as to control a degree of opening thereof

Methodology Applied
Scientific EffectFlow rate control:

Implementation Method 4

a calculation unit connected to the phase meter and to the flow rate adjustment means, said calculation unit being configured to control the flow rate adjustment means so as to control a degree of opening thereof, depending on the value of the gas in the upstream pipe determined by the phase meter

Methodology Applied
Scientific EffectFeedback control: Feedback

Data Source

PatentEP3670867B1Improved device for regulating a power supply flow
Publication Date: 2021.10.13 SAFRAN AIRCRAFT ENGINES SAS
  • EP3670867B1 patent drawingFigure 1~2
  • EP3670867B1 patent drawingFigure 3~4

AI summary

Fuel supply flow control device (10) for a turbomachine, comprising at least one pump (12), an upstream pipe (10a) leading to the pump (12), a downstream pipe (10b) downstream of the pump, a recirculation channel (13) connected in bypass of the downstream pipe, allowing fluid to be drawn from the downstream pipe (10b) and conveyed to the upstream pipe (10a), a flow control means (16, 18) disposed on the recirculation channel (13), a phase meter (30) disposed in the upstream pipe, a calculation unit (40) connected to the phase meter and the flow control means, said calculation unit controlling the flow control means so as to control a degree of opening thereof, depending on the value of the gas content in the upstream pipe.