Bergen Engines AS - 2012 - SINTEF...40 % 60 % 80 % 100 % 120 % 140 % 2.5 6.2 12.5 18.6 24.9 749 749 748 751 749 Relative FSN Engine load [bar] and [rpm] Constant engine speed Reference

©2003 Rolls-Royce plc The information in this document is the property of Rolls-Royce plc and may not be copied or communicated to a third party, or used for any purpose other than that for which it is supplied without the express written consent of Rolls-Royce plc. This information is given in good faith based upon the latest information available to Rolls-Royce plc, no warranty or representation is given concerning such information, which must not be taken as establishing any contractual or other commitment binding upon Rolls-Royce plc or any of its subsidiary or associated companies.

Bergen Engines AS - 2012

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Rolls-Royce data-strictly private

Market Segments

Merchant

Offshore NAVY Naval

Fjord 1

Energy

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• Types: C25:33L6-8-9 • Bore: 250 mm • Stroke: 330 mm • Power: 330 kW / cyl • Speed: 500 – 1000 rpm • Power range: 1500 – 3000 kWmech

• Types: B32:40L6-8-9 & B32:40V12, -16

• Bore: 320 mm • Stroke: 400 mm • Power: 500 kW / cyl • Speed: 500 - 750 rpm • Power range: • 3000 - 8000 kWmech

Bergen C25:33 & B32:40 Liquid fuel – MDO-HFO

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RR-Bergen Diesel Engine Power Range

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• Types: C26:33L6-8-9 • Bore: 260 mm • Stroke: 330 mm • Power: 270 kW / cyl • Speed: 600 – 1000 rpm • Power range: 1400 – 2500 kWmech • Efficiency: 48%mec • Types: B32:40L6-8-9 &

B35:40V12, -16, -20 • Bore: 320 / 350 mm • Stroke: 400 mm • Power: 440 / 480 kW / cyl • Speed: 500 - 750 rpm • Power range: • 2400 - 9600 kWmech • Efficiency: 49 %mec

Bergen C26:33 & B32/35:40 Spark ignited lean-burn gas engine

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RR-Bergen Gas Engine Power Range

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Natural Gas as Fuel for future vessels

NOX ÷ 92 %

CO2 ÷ 23 %

SOX ÷ 100 %

Particulate ÷ 98 %

INVISIBLE

SMOKE 2012

No oil spil!

• 35 daily port calls per vessel= 51000/year


Variable Valve Timing VVT

Low-load operation and Smoke

Variable Valve Timing for the C25:33L engine

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9

Variable Valve Timing, background: Today’s modern engines run so-called Miller cycle. This

means a relatively early closing of the air inlet valve, compared to more traditional engines.

The Miller cycle makes it possible to reduce NOx emissions and still keep a low fuel consumption at medium to full load.

The reduction of air to the cylinder is compensated by an increased charge air pressure.

At medium to low load the turbocharger is loosing it’s effect. The low boost pressure combined with the early closing of the inlet valve results in a starvation of air

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Low air consumption causing: Low load smoke from diesel engines Reduced transient response for both diesel

and gas engines Reduced margin to turbo charger surge limit

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Variable Valve Timing, C-engine

Shifts timing of inlet valve to later opening/closing at low load

Better filling of air to cylinder Established naming of positions of VVT:

Miller position Low load position

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Mechanism

The original C-engine (2000-2008) uses swinging roller followers to drive the inlet and exhaust valves

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Adoption:

The engine was therefore well suited for an upgrade to a VVT mechanism of the type swinging roller follower on an eccentric shaft.

This was introduced with the C25:33L 2. (C mk II), and inherited onto the C-gas.

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Mode of operation: A shaft with eccentric journals that can be rotated 180º.

The inlet swing-arm is mounted on an eccentric journal, while the exhaust swing-arm is mounted on the centre of the shaft.

By rotating the shaft, the inlet swing arm moves from one side of the inlet cam, to the other side.

The shaft is rotated by a pneumatic cylinder.

The cylinder is activated by a solenoid valve, controlled from the PLC

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15 Principle

crankdeg..pu

shro

dlift

Low load position CCW rotating engine

Miller position CW rotating engine

Miller position CCW rotating engine

Low load position CW rotating engine

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Instrumentation / automation / regulation

Sensors on the pneumatic cylinder detects thr end position of the cylinder.

The VVT mechanism can be manually locked, if required. This feature will cater for fault scenarios, such as lack of control air pressure, defect solenoid valve, or a faulty VVT cylinder.

If the engine runs on full load with VVT in low load position, the combustion pressure will be very high. Because of this, a robust control- and alarm-system has been installed.

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Results Smoke

Smoke

400 500 600 700 800 900 1000

rpm

Miller position

Low load position

Miller position & Low load position combined

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Results NOx

NOx

400 500 600 700 800 900 1000

rpm

Miller position

Low load position


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Fuel consumption

400 500 600 700 800 900 1000rpm

Fuel consumptionpropeller law

Miller position

Low load position


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Maximum combustion pressure

P max

400 500 600 700 800 900 1000

rpm

Miller position

Low load position

Miller position & Low load positioncombined


Smoke reduction at low engine load by fuel injection optimization

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22 Reduction of visible smoke

Flow through nozzle reduced by 9% Opening pressure of injector increased by 33% to

compensate for restricted nozzle flow Significantly reduced visible smoke on low-load operation Small increase on high-load operation

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Reduced nozzle flow trough value and increased nozzle opening pressure

100 % 100 % 100 % 100 % 100 %

74 % 81 %

92 %

130 %

120 %

62 %

75 % 82 %

110 %

120 %

0 %

20 %

40 %

60 %

80 %

100 %

120 %

140 %

2.5 6.2 12.5 18.6 24.9

749 749 748 751 749

Rel

ativ

e FS

N

Engine load [bar] and [rpm]

Constant engine speed

Reference nozzle and NOP

Nozzle flow through value reduced by 9%

Nozzle flow through value reduced by 9% andNOP increased by 33%

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Reduced nozzle flow trough value and increased nozzle opening pressure

100 % 100 % 100 % 100 %

78 % 77 %

111 % 105 %

78 % 79 %

122 % 121 %

0 %

20 %

40 %

60 %

80 %

100 %

120 %

140 %

9.9 15.6 20.5 24.9

475 600 682 748

Rel

ativ

e FS

N

Engine load [bar] and [rpm]

Propeller curve

Reference nozzle and NOP

Nozzle flow through value reduced by 9%

Nozzle flow through value reduced by 9% andNOP increased by 33%

Bergen Engines AS - 2012��Market SegmentsBergen C25:33 & B32:40Slide Number 4Bergen C26:33 & B32/35:40Slide Number 6Slide Number 7Variable Valve Timing VVT ��Low-load operation and Smoke�Variable Valve Timing, background:Low air consumption causing:Variable Valve Timing, C-engineMechanismAdoption:Mode of operation:PrincipleInstrumentation / automation / regulationResults SmokeResults NOxFuel consumptionMaximum combustion pressureSmoke reduction at low engine load by fuel injection optimization Reduction of visible smokeReduced nozzle flow trough value and increased nozzle opening pressureReduced nozzle flow trough value and increased nozzle opening pressure

Documents

Bergen Engines AS - 2012 - SINTEF...40 % 60 % 80 % 100 % 120 % 140 % 2.5 6.2 12.5 18.6 24.9 749 749 748 751 749 Relative FSN Engine load [bar] and [rpm] Constant engine speed Reference