Development of Fuel System and Development of Fuel System and

Combustion Technique for DME Combustion Technique for DME

as a Alternative Fuelas a Alternative Fuel

77thth Asian DME ConferenceAsian DME Conference

q What is DME ?

§ A liquified gas with handling characteristics similar to those of LPG

§ Produced from a variety of feed-stock such as natural gas, crude oil, residual oil,

coal, waste products and bio-mass

§ An excellent and efficient alternative fuel for use in a diesel engine, with almost

smoke-free combustion

q DME engine does not need DPF because DME is the PM-free fuel. But, that has

emitted CO, HC, and NOx. Therefore, it is necessary to the development of

combustion technique in order to meet EURO-5 emission limit.

q Common-rail fuel injection equipment for DME fuel has the lubrication problem.

DME needs the improvement of lubricity because the viscosity of DME is lower

than that of diesel.

q What is DME ?

§ A liquified gas with handling characteristics similar to those of LPG

§ Produced from a variety of feed-stock such as natural gas, crude oil, residual oil,

coal, waste products and bio-mass

§ An excellent and efficient alternative fuel for use in a diesel engine, with almost

smoke-free combustion

q DME engine does not need DPF because DME is the PM-free fuel. But, that has

emitted CO, HC, and NOx. Therefore, it is necessary to the development of

combustion technique in order to meet EURO-5 emission limit.

q Common-rail fuel injection equipment for DME fuel has the lubrication problem.

DME needs the improvement of lubricity because the viscosity of DME is lower

than that of diesel.

Property DME Diesel Propane

Chemical structure CH3-O-CH3 - C3H8

Lower heating value (MJ/kg) 27.6 42.5 46.3

q High oxygen content and the absence of C-C bonds

: high oxidation rates and smokeless combustion

q Low boiling point : quick evaporation in a combustion chamber

q High cetane number : low auto-ignition temperature and instantaneous

vaporization

Lower heating value (MJ/kg) 27.6 42.5 46.3

Liquid density(kg/㎥) 667 831 500

Cetane number >55 40∼55 -

Air-Fuel Ratio 9.0 14.6 15.8

Ignition Temperature (℃) 235 250 470

Boiling Point (℃) -20 180/370 -42

Latent heat of gasification (kJ/kg) 460(-20℃) 250 372

% wt. Carbon 52.2 86.0 82

% wt. Hydrogen 13.0 14.0 18

% wt. Oxygen 34.8 0 0

MeritHigh Thermal Efficiency

: Equal to DI Diesel E/GCompression Ignition

: about 60 of Cetane NumberSmokeless Combustion

: nearly Zero PMHigh EGR Tolerance

: NOx can be ReducedCombustion Noise ReducedLPG Infra can be Used

: Liquefied at 5∼6 bar

DemeritLow Lubricity & Viscosity : Wear & Leakage Problem High Compressibility : Difficult to Injection Control Elastomer Attack : Sealing Problem

MeritHigh Thermal Efficiency

: Equal to DI Diesel E/GCompression Ignition

: about 60 of Cetane NumberSmokeless Combustion

: nearly Zero PMHigh EGR Tolerance

: NOx can be ReducedCombustion Noise ReducedLPG Infra can be Used

: Liquefied at 5∼6 bar

2013 2014 2015 2016 2017 2018 2019 2020 2021

For family use-LPG DME(20%)

254 241 228 215 204 193 182 172 163

(Unit : 1000ton)

LPG-DME blend fuel market (for cooking and transportation fuels)

Industrial boiler (district heating)

Diesel alternative fuel (Bus, Truck)

For family use-LPG DME(20%)

254 241 228 215 204 193 182 172 163

Transportation-LPG DME(5%)

265 275 286 297 309 321 334 347 360

Industrial Boiler (district heating)

99 94 90 86 82 78 75 71 68

Diesel alternative Fuel (Bus, Truck)

105 209 314 418 628 732 837 941 1,046

Total 723 819 918 1,017 1,222 1,324 1,427 1,532 1,637

※ DME Prospects in Korea (KOGAS)

Study of DME Engine and Vehicle (Korea)Study of DME Engine and Vehicle (Korea)

Fundamental study, simulation study, and combustion study of DME engine

HD DME Engine & Vehicle with IDI Fuel System (KIER) Spray Visualization of DME Fuel (Hanyang Univ.)

DME HP Pump of common-rail system (KATECH) Combustion Characteristics of DME Engine (KAIST)

ContentsContents

ObjectivesObjectives

Development of Fuel System and Combustion Technique for DME

as a Alternative Fuel

Development of High Pressure Pump and Injector for DME FuelDME Fuel

Development of CommonDevelopment of Common--rail rail DME Fuel Supply System

Development of 3Development of 3--liter Commonliter Common--rail DME Engine rail DME Engine

Evaluation of Power and Emission Evaluation of Power and Emission Performance Performance for DME Enginefor DME Engine

Investigation of CommonInvestigation of Common--rail DME Vehicle rail DME Vehicle

NozzleDesign of DME InjectorNozzleDesign of DME Injector Production of DME InjectorProduction of DME Injector

Design of Injector Nozzle and Needle using Nozzle Flow Model

Production of DME Injector Prototype by 3D Design and Numerical Analysis

Enlargement of DME Flow Rate

3D Design3D Design Processingof Nozzle HoleProcessingof Nozzle HoleNozzle Design (Type II)Nozzle Design (Type II) Nozzle Design (Type III & IV)Nozzle Design (Type III & IV)

Specifications of InjectorsSpecifications of Injectors

Leak, Response, Injection Rate, Fluctuation Rate of DME Injector

Pulsation of Fuel Pressure

Experimental Set-upExperimental Set-up Test Results of DME InjectorTest Results of DME Injector

Leak TestLeak Test Injection RateInjection Rate

Multi-Injection (I)Multi-Injection (I) Multi-Injection (II)Multi-Injection (II)

Spray Development and PatternSpray Development and Pattern Comparison of Test with Analysis Comparison of Test with Analysis

Comparison of spray visualization test results with numerical analysis

Breakup and evaporation of DME droplet occur rapidly in the early period of injection

Momentum magnitude of droplet is directly related to the droplet break-up

※ Experiment & analysis condition Fuel pressure : 350 barAmbient pressure : 50 bar

DME High Pressure PumpDME High Pressure Pump

Design and production of high pressure pump for DME fuel

11stst DME High pressure pump (3L)DME High pressure pump (3L) 22ndnd DME High pressure pump (3L)DME High pressure pump (3L)

TypeType Eccentric cam Wobble plate

No. of plungerNo. of plunger 2 5

Bore (mm)Bore (mm) 9 10.5

Stroke (mm)Stroke (mm) 10 -Stroke (mm)Stroke (mm) 10 -

Flow rate (kg/h)Flow rate (kg/h) 50@1,000 rpm 135@2,000 rpm

System pressure (bar)System pressure (bar) 600 500

Speed (rpm)Speed (rpm) 2,000 2,000

PhotoPhoto

Specification analysis of high pressure pump

Performance test on effect of inlet metering valve, inlet fuel pressure, and

common-rail pressure

Experiment SetupExperiment Setup Test Results of DME HP PumpTest Results of DME HP Pump

Analysis of Required Flow RateAnalysis of Required Flow Rate Effect of C/rail PressureEffect of C/rail Pressure

Effect of Inlet PressureEffect of Inlet Pressure

Specification of Common-rail DME EngineSpecification of Common-rail DME Engine

Item Specification

Displacement Volume 2,902cc

Bore × Stroke 98 mm × 101.5mm

Compression Ratio 17.4 : 1

Idle speed 800 ± 10 rpm

Intake timing BTDC 26° / ABDC 50°

Installation of DME HP Pump Installation of DME Injector

Performance Test of DME Engine

Intake timing BTDC 26° / ABDC 50°

Exhaust timing BBDC 72° / ATDC 32°

Fuel system Common-rail direct injection

ECU System of DME EngineECU System of DME Engine

Calibration of fuel rate, fuel pressure, injection timing, injection duration, boost pressure, and EGR rateDevelopment and application of control logic for cold starting

ECU System of DME EngineECU System of DME EngineUniversal ECU : MotoTronBuilt-in Algorithm : CI Base(Diesel) Engine ControllerMotoTune : ECU Calibration ToolsUniversal Injector Driver : Control of DME Injector

Universal ECU : MotoTronBuilt-in Algorithm : CI Base(Diesel) Engine ControllerMotoTune : ECU Calibration ToolsUniversal Injector Driver : Control of DME Injector

ECU Calibration of DME EngineECU Calibration of DME Engine

Common-rail DME EngineCommon-rail DME Engine

DME Fuel Supply SystemDME Fuel Supply System

Emission of DME Engine (Tailpipe-out )Emission of DME Engine (Tailpipe-out )

DME Engine Calibration DME Engine Calibration

Optimization of Flow Rate, Injection Timing, Injection Duration, Fuel Pressure and EGR rate of DME Engine

Fuel ConsumptionFuel Consumption EGR RateEGR Rate

Injection DurationInjection DurationMain Injection TimingMain Injection Timing

Fuel Consumptionof DME EngineFuel Consumptionof DME Engine

1.7 times for Fuel Consumption of Base Diesel Engine

CO2 Emission of DME EngineCO2 Emission of DME Engine

80% for CO2 Emission of Base Diesel Engine

Emission DME Engine (Engine-out)Emission DME Engine (Engine-out)

Common-rail DME VehicleCommon-rail DME Vehicle

Installed DME Fuel Supply System for DME Vehicle

Developed Drivability of DME Vehicle using Calibration Data of DME Engine

Max. DME Vehicle Speed : 110km/h

Fuel Economy of DME Vehicle : 5.7km/L

Common-rail DME VehicleCommon-rail DME Vehicle

Road Test

NEDC Mode Test

The injector and high pressure pump for DME fuel were developed, and the

DME-fueled engine was made with 3-liter diesel engine of a common-rail direct

injection system.

The ECU system for common-rail DME engine was developed, and the power

performances and emission characteristics of DME engine were investigated with

this system.

DME engine had over 90% full torque performance in comparison with base

diesel engine.

The emission performance of DME engine is the same as that of base diesel

engine under equal EGR rate by the optimization of injection timing, injection

duration, and fuel pressure of DME engine.

The drivability of DME vehicle was developed using calibration data of DME

engine and DME fuel supply system. 5.7km/L was achieved in the fuel economy

of DME vehicle.

The injector and high pressure pump for DME fuel were developed, and the

DME-fueled engine was made with 3-liter diesel engine of a common-rail direct

injection system.

The ECU system for common-rail DME engine was developed, and the power

performances and emission characteristics of DME engine were investigated with

this system.

DME engine had over 90% full torque performance in comparison with base

diesel engine.

The emission performance of DME engine is the same as that of base diesel

engine under equal EGR rate by the optimization of injection timing, injection

duration, and fuel pressure of DME engine.

The drivability of DME vehicle was developed using calibration data of DME

engine and DME fuel supply system. 5.7km/L was achieved in the fuel economy

of DME vehicle.