Professor Martti Larmi May 7, 2015

Fuels and Engines

Presentation contentEngine combustion basics

• SI Engines, turbulent premixed combustion• CI Engines, turbulent mixing controlled combustion• Others: HCCI, RCCI, Dual Fuel, PPC

SI and CI Engine Fuels• SI Engine fuels• CI Engine fuels

Bio Fuels• CI Engine Bio Fuels• SI Engine Bio Fuels

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http://www.sandia.gov/ecn/tutorials/visualization/siGasoline.php

SI Engines, turbulent premixed combustion

Liner

Piston Extension

45° Mirror

Protection Glass

Cylinder Head

CCD Camera

Mechanical Shutter

Common Rail

Aalto University Optical Engine

Laminar and turbulent flame speeds, note the scales

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CI engines, turbulent mixing controlled combustion

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http://www.sandia.gov/ecn/tutorials/visualization/ciDiesel.php

Aalto University Optical Engine

New Combustion Regimes

• Homogenous Charge Compression Ignition (HCCI)• Reactivity Controlled Compression Ignition (RCCI)• Dual Fuel Combustion (DF)• Partially Premixed Combustion (PPC)

Low Temperature Combustion (LTC) idea is for common for allof these.

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http://www.sandia.gov/ecn/tutorials/visualization/hcci.php

7.5.2015Gurpreet Singh, DOE, USA

SI Engine Fuels

• Easy mixing with air• Resistance for autoignition

SI Engine Fuels

• Lower heating value LHV• Density• VIscosity• Vapor pressure• Heat of evaporation• Molar mass• Oxygen content• Reactivity resistance i.e. low

reactivity, Octane Number (ON)

Gasoline Carbon Number = 4-12

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CI Engine Fuels

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• Easy injection with high momentumand good spray formation

• Good ignitability: high reactivity

CI Engine Fuels

• Lower heating value LHV• Density• Viscosity• Vapor pressure• Heat of evaporation• Molar mass• Oxygen content• Reactivity: high reactivity,

Cetane Number (CN)

Diesel Oil Carbon Number = 15–19

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Bio Fuels for CI Engines1. ”Biodiesel” = Fatty Acid Methyl Ester (FAME). Typical

example is Rape Seed Methyl Ester (RME)

2. Renewable Diesel: Paraffinic high Cetane Number fuels likeHydrotreated Vegetable Oil (HVO) or Gas to Liquid (GTL) diesel fuel trough Fischer-Tropsch process

3. Straight Vegetable Oil (SVO)

4. BioDME

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Bio Fuels for CI Engines

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Bio Fuels for CI Engines1. ”Biodiesel” = Fatty Acid Methyl Ester (FAME), LVH 38 MJ/kg,

density 880 kg/m3, viscosity 4.5 mm2/s @ 40 C, high CN 2. Renewable Diesel: Paraffinic diesel fuel from synthesis or

hydrotreatment C15 ... C18, LHV 44 MJ/kg, density 780 kg/m3, viscosity 3 mm2/s @ 40 C, very high CN, Carbon number 15…18

3. Straight Vegetable Oil (SVO), High density 900 kg/m3 and very high viscosity 70 mm2/s @ 20 C (Rapeseed Oil), low ignitability CN -, acid value

4. DME close to LPG, but high reactivity = good diesel fuel

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FAME Process

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Distillation

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PM and Soot

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Straight Vegetable Oil (SVO)Straight Vegetable Oil (SVO) i.e. Vegetable Oil orPure Vegetable Oil (PVO) or Pure Plant Oil(PPO). • vegetable oil produced through pressing,

cold or hot extraction, solvent extraction or comparable procedures, crude or refined but chemically unmodified,

• Can be used in modified heavy-duty diesel engines only, comparable to heavy fuel oil!

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Bio Fuels for SI Engines1. Ethanol2. Methanol3. Higher Alcohols4. BioGas

Knocking resistance and short heat release key to highefficiency and high power density. Dual Fuel combustionconcept is very promising is this respect.

https://www.youtube.com/watch?v=WvISTEeckto

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Special Thanks• Seppo Mikkonen, Neste• Kai Juoperi Wärtsilä• Tuomo Hulkkonen, Aalto• Harri Hillamo, Helen• Gurpreet Singh, DOE• Mark Musculus, Sandia• Sibendu Som, Argonne• Aki Tilli, Aalto• Ossi Kaario, Aalto• Teemu Sarjovaara, Aalto• Ville Vuorinen, Aalto• Armin Wehrfritz, Aalto

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References• HVO Handbook Original, NESTE Oil 2014• European pre-standard CEN TS 15940• John Heywood: Internal Combustion Technology• van Basshuysen, R., Schäfer, F., Internal Combustion Engine

Handbook• Warnatz, Maas, Dibble: Combustion

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