Particulate Emissions from a Low-Speed Marine Diesel Engine

Figures & data

FIG. 1 Photograph of the RTX-3 test engine.

TABLE 1 Engine specifications

Type	2-stroke marine diesel engine	4-stroke VW 1.9l TDI
Application	Tanker propulsion	Passenger Car
Injection system	Direct Injection	Direct Injection
Cylinder	4	4
Bore	580 mm	79.5 mm
Piston stroke	2416 mm	95.5 mm
Piston displacement	640 l	1.896 l
Power	8500 kW	66 kW
Speed	105 rpm	4150 rpm
Mean effective pressure	19 bar	15.5 bar
Weight	ca. 230 t	150 kg
Height	11 m

TABLE 2 Operation points and associated corresponding exhaust gas temperatures, which were recorded during measurement

Load	100%	75%	50%	25%	1%
Speed (rpm)	105	95.4	83.3	66.1	22.6
Exhaust gas temperature (°C)	285	281	320	370	100

TABLE 3 Major fuel specifications

	Marine diesel oil (MDO)	Heavy fuel oil (HFO)	Diesel oil
Viscosity @ 40°C (mm2/s)	3.21	858	2.6
Density @ 15°C (g/ml)	0.8508	1.0006	< 0.845
Sulfur content (%m)	0.155	0.6	0.0047
Iron (mg/kg)	< 1	9
Nickel (mg/kg)	< 1	20
Vanadium (mg/kg)	< 1	9
Sodium (mg/kg)	< 1	4
Calcium (mg/kg)	< 1	7
Water (%m)	< 0.05	< 0.05
Ash content (%m)	< 0. 010	0.014	0.0005
Asphaltenes (%m)		6.1
Total sediment		0.03

FIG. 2 Experimental setup: right unit for taking filter samples, left unit for measuring the particle size distribution. The left-most path is necessary to assure the correct flow rate for isokinetic sampling (MFC: mass flow controller).

TABLE 4 Temperature settings of the experiment

	Temperature (standard experiment)	Temperature (special trial)
Sampling lines	150°C	150°C
First ejector diluter	150°C	350°C
Second ejector dilutor	Ambient temp.	Ambient temp
TD	350°C	400°C

FIG. 3 Average SMPS size distributions as measured at 1% load with (thin line and thin line with cross) and without TD (thick line and dotted line). The measurement was performed twice.

FIG. 4 Average SMPS size distributions as measured at 100% load with (thin line) and without TD (thick line).

FIG. 5 Average SMPS size distributions as measured at 75% load with (thin line) and without TD (thick line).

FIG. 6 Average SMPS size distributions as measured at 50% load with (thin line) and without TD (thick line).

FIG. 7 Average SMPS size distributions as measured at 25% load with (thin line) and without TD (thick line).

FIG. 8 Total number concentrations as calculated from the size distributions for each load point.

FIG. 9 Particle diameter as function of engine load. Measurements were performed with and without TD.

FIG. 10 Typical number size distributions for this marine diesel engine (circles) at 100% load and a diesel passenger car (triangles) at 100% load.

TABLE 5 Comparison of gravimetric particle mass from filter samples and masses as calculated from number size distributions measured with and without TD. Mass unit is corrected for ambient conditions and given in mg/Nm³ (milligram/norm cubic centimeter) unless otherwise indicated

Load	Quarz filter	Teflon filter	Mass from coulometry (mg/Nm3)	Residue PM	PM SMPS (ρ = 1)	PM SMPS TD (ρ = 1)	ΔPM SMPS w/wo TD
1%	8.5	8.0	13.5	2.6	3.2	1.1	65.7%
25%	12.1	9.3	9.2	3.0	26.2	3.5	86.7%
50%	24.4	18.8	30.3	3.5	72.0	11.2	84.5%
75%	23.8	29.2	49.9	3.5	79.0	31.6	60.1%
100%	37.7	33.0	50.0	8.4	83.0	9.4	88.6%

FIG. 11 Summary of results from coulometric analysis and extraction of organic material (OC, organic fraction; EC, elemental carbon; SOF, soluble organic fraction; WSF, water soluble fraction).

FIG. 12 (a) Total number concentrations as calculated from number size distributions and (b) mean particle diameter as measured at 1% load with both fuels.

FIG. 13 Absolute masses as extracted from filters sampled at 1% load with both fuels.

FIG. 14 (a) Total number concentrations as calculated from number size distributions and (b) mean particle diameter as measured at 100% load with both fuels.

FIG. 15 Absolute masses as extracted from filters sampled at 100% load with both fuels.