LPG-DME blend fuel market (for cooking and transportation fuels) Industrial boiler (district heating) Diesel alternative fuel (Bus, Truck)

Transcription

1 7th Asian DME Conference Development of Fuel System and Combustion Technique for DME as a Alternative Fuel

2 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 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. 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.

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 Property DME Diesel Propane Chemical structure CH 3 -O-CH 3 - C 3 H 8 Lower heating value (MJ/kg) Liquid density(kg/ m3 ) Cetane number > Air-Fuel Ratio Ignition Temperature ( ) Boiling Point ( ) / Latent heat of gasification (kj/kg) 460(-20 ) % wt. Carbon % wt. Hydrogen % wt. Oxygen

4 Merit High Thermal Efficiency : Equal to DI Diesel E/G Compression Ignition : about 60 of Cetane Number Smokeless Combustion : nearly Zero PM High EGR Tolerance : NOx can be Reduced Combustion Noise Reduced LPG Infra can be Used : Liquefied at 5 6 bar Demerit Low Lubricity & Viscosity : Wear & Leakage Problem High Compressibility : Difficult to Injection Control Elastomer Attack : Sealing Problem

5 LPG-DME blend fuel market (for cooking and transportation fuels) Industrial boiler (district heating) Diesel alternative fuel (Bus, Truck) (Unit : 1000ton) For family use- LPG DME(20%) Transportation- LPG DME(5%) Industrial Boiler (district heating) Diesel alternative Fuel (Bus, Truck) ,046 Total ,017 1,222 1,324 1,427 1,532 1,637 DME Prospects in Korea (KOGAS)

6 Fundamental study, simulation study, and combustion study of DME engine Study of DME Engine and Vehicle (Korea) 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)

7 Objectives Development of Fuel System and Combustion Technique for DME as a Alternative Fuel Contents Development of High Pressure Pump and Injector for DME Fuel Development of Common-rail DME Fuel Supply System Development of 3-liter Common-rail DME Engine Evaluation of Power and Emission Performance for DME Engine Investigation of Common-rail DME Vehicle

8 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 Nozzle Design of DME Injector Production of DME Injector Nozzle Design (Type II) Nozzle Design (Type III & IV) 3D Design Processing of Nozzle Hole Specifications of Injectors

9 Leak, Response, Injection Rate, Fluctuation Rate of DME Injector Pulsation of Fuel Pressure Experimental Set-up Test Results of DME Injector Leak Test Injection Rate Multi-Injection (I) Multi-Injection (II)

10 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 Spray Development and Pattern Comparison of Test with Analysis Experiment & analysis condition Fuel pressure : 350 bar Ambient pressure : 50 bar

11 Design and production of high pressure pump for DME fuel DME High Pressure Pump 1 st DME High pressure pump (3L) 2 nd DME High pressure pump (3L) Type Eccentric cam Wobble plate No. of plunger 2 5 Bore (mm) Stroke (mm) 10 - Flow rate (kg/h) 50@1,000 rpm 135@2,000 rpm System pressure (bar) Speed (rpm) 2,000 2,000 Photo

12 Specification analysis of high pressure pump Performance test on effect of inlet metering valve, inlet fuel pressure, and common-rail pressure Experiment Setup Test Results of DME HP Pump Analysis of Required Flow Rate Effect of C/rail Pressure Effect of Inlet Pressure

13 Specification of Common-rail DME Engine Item Displacement Volume Bore Stroke Specification 2,902cc 98 mm 101.5mm Compression Ratio 17.4 : 1 Idle speed 800 ± 10 rpm Intake timing BTDC 26 / ABDC 50 Exhaust timing BBDC 72 / ATDC 32 Performance Test of DME Engine Fuel system Common-rail direct injection Installation of DME HP Pump Installation of DME Injector

14 Calibration of fuel rate, fuel pressure, injection timing, injection duration, boost pressure, and EGR rate Development and application of control logic for cold starting ECU System of DME Engine Universal ECU : MotoTron Built-in Algorithm : CI Base(Diesel) Engine Controller MotoTune : ECU Calibration Tools Universal Injector Driver : Control of DME Injector ECU System of DME Engine ECU Calibration of DME Engine

15 Common-rail DME Engine

16 DME Fuel Supply System

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19 Emission of DME Engine (Tailpipe-out )

20 Optimization of Flow Rate, Injection Timing, Injection Duration, Fuel Pressure and EGR rate of DME Engine DME Engine Calibration Fuel Consumption EGR Rate Main Injection Timing Injection Duration

21 1.7 times for Fuel Consumption of Base Diesel Engine Fuel Consumption of DME Engine

22 80% for CO 2 Emission of Base Diesel Engine CO 2 Emission of DME Engine

23 Emission DME Engine (Engine-out)

24 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 Vehicle

25 Common-rail DME Vehicle Road Test NEDC Mode Test

26 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.

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