feather diesel services ltd - btac · feather diesel services ltd ¾steve smith - md ¾specialist...

Feather Diesel Services LtdSteve Smith - MDSpecialist repairs of Diesel fuel injection equipment.Established 1954.

Diesel Fuel Injection

Modern Diesel engines have to meet stringent emissions regulations. The fuel injection equipment that control the timing and flow of Diesel to the combustion chambers are critical to the performance, emissions and fuel consumption of a Diesel vehicle.Diesel Fuel Injection technology has evolved to meet these emissions regulations.

Diesel Fuel Injection

Past – now historic• Mechanical – fuelling physically set with mechanical

stops. Operating pressure up to 900 bar.

Present – now past• EDC – fuelling controlled by vehicle ECU which

allows adjustments. Operating pressure up to 1150 bar.

Future – now present• VP and Common Rail – greater control on fuel delivery

and timing. Operating pressure 1350 to 2000 bar.

Reducing Emissions – TechnologyDelphi AutomotiveDelphi Automotive

Common RailCommon Rail

ConclusionConclusion

QuestionsQuestions

Evolution of Diesel systems.Delphi AutomotiveDelphi Automotive

Common Rail Common Rail


QuestionsQuestions

Delphi AutomotiveDelphi Automotive



QuestionsQuestions

Reducing Emissions – Technology

Low-pressure fuel circuit with Electric Fuel-pump

1 = Electric fuel-pump2 = Fuel filter3 = Overflow valve4 = Return-fuel accumulator5 = High-pressure pump CP1

6 = High-pressure regulation valve7 = Rail-pressure sensor8 = Rail (distribution duct)9 = Injectors

10 = EDC 15 C control-unit11 = Fuel-temperature sensor12 = Other sensors

The pre-supply pump is an in-tank electric fuel-pump and also performs the safety shut-off.

Low-pressure fuel circuit with Electric Fuel-pump

1 = Driveshaft2 = Eccentric cam3 = Pump element4 = Intake valve5 = Element-shutdown valve

6 = Outlet valve7 = Seal8 = High-pressure connection to

rail9 = Pressure-control valve

10 = Ball valve11 = Fuel return12 = Fuel intake13 = Throttle valve (safety valve)14 = Low-pressure passageElement-shutdown active, 12 Volt.

CP1 Principle of Operation

1 = Eccentric driveshaft 2= Polygon ring (cam)3 = Pumping element

4 = Inlet valve5 = Outlet valve6 = Inlet

The rotation of the driveshaft produces an eccentric motion of the polygon ring, thuscreating a pumping action to the plungers

CP1 Principle of Operation

The filter on the control side must not be touched because it will become blocked and impair the operation of the regulating valve

5 micron filter

Electro-magnetic control

1 = Fuel return2 = Valve spring 3 = Electromagnet 4 = High-pressure

connection 5 = Valve armature6 = Valve ball7 = Output throttle8 = Control chamber9 = Inlet throttle

10 = Valve control-plunger11 = Nozzle needle12 = Injector nozzlea = Injector closedb = Injector opened

(injection)

Common Rail

• Injection cycle – less than 100 microseconds between injections

• Design enables:– Pre-injection– Post-injection

– Currently developing a system with seven separate fuel injections per cycle!




QuestionsQuestions

Injector Assembly

Nozzle Needle

Servo Control Valve Assembly

Piezo Assembly

Hydraulic Damper

ElectricalConnect

or

Inlet/Outlet and Bypass Assembly

Overflow Connector

High Pressure Gallery

Diaphragm

Injector Actuator

Inlet orifice(INO)

Dia 0.25mm

Nozzle Path Orifice

Dia 1.00 mmBy Pass Orifice

Dia 0.2mm




QuestionsQuestions

Actuator tolerances

Actuator lift - 0.028 mm

Bore Dia -2.0 mm

Operating clearance 0.002 mm

Bore Dia 0.40 mm




QuestionsQuestions

Diesel Fuel Injection Equipment ManufacturersCommon Position Statement on Fatty Acid Methyl Ester (FAME)Fuels as a Replacement or Extender for Diesel FuelsJanuary 2007

EN14214 provides the minimum requirements for FAME quality whether used as pure FAME or as a blend component. FAME may be currently blended in quantities of up to 5% in European diesel fuel according to the EN590 specification. In order to reduce the risk of premature failure of the fuel system FAME must conform to EN 14214. Increasing biodiesel production capacities in the EU have enabled legislative authorities to consider increasing the maximum biodiesel blending level from 5 to 10 percent. Activities are ongoing to standardize and validate biodiesel blends with up to 10 percent biodiesel (B10) in the EU. The FIE industry considers it as essential to maintain the fuel stability level of EU-B5 (IP 20h acc. to modified EN14112) also for future B10 blends. In any case an approval of B10 requires positive validation of B10 specific issues additionally.


To date, experience in Europe has been mainly associated with the methyl esters of rapeseed oil. Whether or not the service experience with these fuels will apply/extend to all FAMES (like those derived from soybean, tallow and used frying oil) has yet to be determined.

FIE Manufacturers Concerns:FAMEs are derived from a wide range of base stocks, resulting in a similarly wide range

of finished fuel characteristics.

Amongst the concerns of the FIE manufacturers are the following fuel characteristics:• free methanol - water• free glycerine• mono, di- and triglycerides• free fatty acids• total solid Impurity level• alkali/alkaline earth metals• oxidation stability


All FAMES are less stable than mineral oil derived fuels. FAMEs are readily "bio-degradable" in the event of accidental spillage or leakage, which is claimed to be a marketing advantage. On the other hand, the reduced thermal oxidative stability is of major concern to the FIE manufacturers, as the products of fuel ageing can be potentially harmful to the fuel system.

Tests have shown that fuel deterioration can take place in the fuel supply chain and in the vehicle fuel system. Fuel ageing is accelerated in the presence of heat, oxygen, water, metal ions and other impurities. The products of oxidative ageing have been shown to be, corrosive (e.g. organic acids like formic and acetic acids and acids of higher molecular weight). Polymerisation products are also formed and can drop out.


The required quality of the FAME fuel is defined in European standard EN14214, which covers relevant impurities and tramp chemicals from the processing, Suppliers of FAME fuels must be able to demonstrate compliance to this standard at the filling station. There are several risks associated with possible supply chains.

For the FIE manufacturers a key property of any FAME fuel is the resistance to oxidation. Aged or poor quality FAME contains organic acids like formic and acetic acids and acids of higher molecular weight as well as polymerization products which attack many components, drastically reducing the service life of the FIE. A list of issues which have been witnessed in service is detailed in the attachment to this document.


The FIE manufacturers can accept no legal liability for failure attributable to operating their products with fuels for which the products were not designed, and no warranties or representationsare made as to the possible effects of running these products with such fuels.

Non-compliance of the fuel to standards agreed by the FIE manufacturers, whether being evident by appearance of the known degradation products of these fuels, or their known effects within the fuel injection equipment, (see attached list of known issues) will render the FIE Manufacturers'

guarantee null & void,


Fuel Injection Equipment — Potential Problems with FAME,

(Non-exhaustive list)See Hand out!!!!

Diesel Fuel Injection Equipment

Biodiesel is known to break down deposits of residue in fuel lines where petrodiesel has been used – leading to filter plugging.Biodiesel may contain small but problematic quantities of water.(due to persistence of mono and diglycerides which act as an emulsifier allowing water to mix with biodeisel.)Water can be residual amounts from processing or from storage tank condensation.


Water related problems include: Reduced heat of combustion – increased smoke lower power and hard starting.Corrosion of fuel injection equipment.Water and microbes cause filters to rot – pass larger particles to FIE.Water content causes premature ice crystallisation and fuel gelling.Water accelerates growth of microbe colonies.Water can cause piston crown pitting.


Review – Damage caused by unsuitable fuels.

Thank You

Thank you for your valuable time.Any other questions.Special thanks to Robert Bosch and Delphi.

THE COMPLETE SOLUTION

feather diesel services ltd - btac · feather diesel services ltd ¾steve smith - md ¾specialist...

Documents