conferenza del dipartimento diitet 26 e 27 maggio 2014 romeo bernini irea il progetto safuel (safer...

Conferenza del Dipartimento DIITET 26 e 27 maggio 2014

Romeo Bernini IREA

Il progetto Safuel (Safer Fuel Systems)

CONSIGLIO NAZIONALE DELLE RICERCHE

26 e 27 Maggio, 2014Convegno del Dipartimento di Ingegneria, ICT e Tecnologie per l’Energia e i Traporti

Conferenza del Dipartimento Roma, 26 e 27 maggio 2014

Introduction

© Copyright SAFUEL Consortium


SAFUEL Project



Rationale



Objectives




Realize a new metal-free fiber optic level sensor with comparable performances with traditional Jet-Fuel Level sensors.

IREA Objectives

Main critical requirements No sensor degradation from -55°C to +70°C. Correct operation and no degradation with Vibration 10-2000 Hz 14Grms. The sensor shall operate correctly and not be damaged when partially or totally exposed to

presence of condensed water on its surface. The sensor shall operate with an optical power not exceeding 35mW. The sensor shall measure the height of fuel with following accuracy: ±1.5mm when tank

empty up to ±3mm when tank is full. No calibration on A/C allowed. Particular installation constraints on sensor shall be identified (e.g. volume, installation

angle, clearance to structure, bonding to structure…). The jet fuel, depending on the type and/or the producer, exhibits different refractive index

value that ranges from about 1.432 of Sasol fuel to about 1.455 of conventional fuels, depending on density.



Four sensing configuration have been evaluated Sensor based on radiation losses Sensor based on radiation losses TIR Sensor based on fuel absorption Sensor based on floating mirror

Three distributed interrogator have been tested- Photon-counting Optical Time Domain Reflectometry (PC-OTDR)- Optical Frequency Domain Reflectometry (OFDR)- Optical Time Domain Reflectometry (OTDR)

Sensing principle selection Sensing mechanism that are insensitive to temperature and to the refractive

index (Bragg grating, interferometers, …) and more in general that don’t require particular compensations in order to increase the fail safety of the system.

Sensing principles



Conventional TIR sensor are unable to distinguish fuel from water

Fiber optic input

Fiber optic output

TIR Sensors



Sensor Design parameters:• Prism angle 60°• Refractive index n=1.59• Incident angle 60°• Air TIR angle 50°• Water TIR angle 54°• Fuel TIR angle 65°

With a suitable choice of the TIR angle the sensor is sensitive to the fuel and insensitive the water.

Novel TIR Sensor design



The sensor is insensitive to the water but it works with any jet fuel

-40 -20 0 20 40 60 80 100

1.38

1.4

1.42

1.44

1.46

1.48

1.5

T [°C]

Ref

ract

ive

Inde

x

Refractive Index fuel vs Temperature

TIR ConditionJP5JP8, JetA, JetA-1JP7JPB-JP4

Novel TIR Sensor design



TIR Sensor prototype

Single Sensor Sensor multiplexing



TIR OTDR Measurements



Optical Power Response vs Liquid Level



Jet-Fuel vs Water Detection



Prototype under construction



Thank you

conferenza del dipartimento diitet 26 e 27 maggio 2014 romeo bernini irea il progetto safuel (safer...

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