WÄRTSILÄ 31SG User manual

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PRODUCT GUIDE
Wärtsilä 31SG

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© Copyright by WÄRTSILÄ FINLAND Oy
All rights reserved. No part of this booklet may be reproduced or copied in any form or by
any means (electronic, mechanical, graphic, photocopying, recording, taping or other
information retrieval systems) without the prior written permission of the copyright owner.
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COVERED AS WAS AVAILABLE AT THE TIME OF PRINTING. HOWEVER, THE
PUBLICATION DEALS WITH COMPLICATED TECHNICAL MATTERS SUITED ONLY
FOR SPECIALISTS IN THE AREA, AND THE DESIGN OF THE SUBJECT-PRODUCTS
IS SUBJECT TO REGULAR IMPROVEMENTS, MODIFICATIONS AND CHANGES.
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PUBLICATION CAN NOT ACCEPT ANY RESPONSIBILITY OR LIABILITY FOR ANY
EVENTUAL ERRORS OR OMISSIONS IN THIS BOOKLET OR FOR DISCREPANCIES
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PRODUCT BEING DIFFERENT FROM THOSE SHOWN IN THIS PUBLICATION.THE
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HELD LIABLE FOR ANY FINANCIAL CONSEQUENTIAL DAMAGES OR OTHER LOSS,
OR ANY OTHER DAMAGE OR INJURY, SUFFERED BY ANY PARTY MAKING USE OF
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Copyright text
COPYRIGHT © 2019 BY WÄRTSILÄ FINLAND Oy
ALL RIGHTS RESERVED. NO PART OF THIS PUBLICATION MAY BE REPRODUCED
OR COPIED IN ANY FORM OR BY ANY MEANS, WITHOUT PRIOR WRITTEN
PERMISSION OF THE COPYRIGHT OWNER.

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Introduction
This Product Guide provides data and system proposals for the early design phase of
marine engine installations. For contracted projects specific instructions for planning the
installation are always delivered. Any data and information herein is subject to revision
without notice.
Issue Published Updates
9/2019 n/a First Version
9/2019
9/2019
9/2019
10/2019
12.9.2019
18.9.2019
30.9.2019
3.10.2019
2nd Version
3rd Version
4th Version
5th Version
Wärtsilä, Marine Solutions
Vaasa, September 2019

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Table of Contents
1. Main Data and Outputs ............................................................................................................................ 9
1.1 Maximum continuous output ............................................................................................................ 9
1.2 Reference conditions...................................................................................................................... 10
1.3 Operation in inclined position ......................................................................................................... 10
1.4 Dimensions and weights ................................................................................................................ 11
2. Operating Ranges .................................................................................................................................. 15
2.1 Engine operating range .................................................................................................................. 15
2.2 Loading capacity ........................................................................................................................... 15
2.3 Low load operation ......................................................................................................................... 19
2.4 Low air temperature ....................................................................................................................... 20
3. Technical Data ........................................................................................................................................ 22
3.1 Introduction ..................................................................................................................................... 22
3.1.1 Engine driven pumps...................................................................................................................... 22
3.2 Wärtsilä 8V31SG ............................................................................................................................ 23
3.3 Wärtsilä 10V31SG .......................................................................................................................... 26
3.4 Wärtsilä 12V31SG .......................................................................................................................... 29
3.5 Wärtsilä 14V31SG .......................................................................................................................... 32
3.6 Wärtsilä 16V31SG .......................................................................................................................... 35
4. Description of the Engine ..................................................................................................................... 38
4.1 Definitions ....................................................................................................................................... 38
4.2 Main components and systems ...................................................................................................... 38
4.3 Time between Inspection or Overhaul & Expected Life Time ........................................................ 42
4.4 Engine storage ............................................................................................................................... 42
5. Piping Design, Treatment and Installation .......................................................................................... 44
5.1 Pipe dimensions ............................................................................................................................. 44
5.2 Pressure class ............................................................................................................................... 45
5.4 Pipe class ....................................................................................................................................... 46
5.5 Insulation ........................................................................................................................................ 47
5.6 Local gauges .................................................................................................................................. 47
5.7 Cleaning procedures ...................................................................................................................... 47
5.8 Flexible pipe connections ............................................................................................................... 48
5.9 Clamping of pipes ........................................................................................................................... 50
6. Fuel System............................................................................................................................................ 53
6.1 Acceptable fuel characteristics ....................................................................................................... 53
6.2 Operating principles ....................................................................................................................... 53
6.3 Fuel gas system ............................................................................................................................. 54
7. Lubricating Oil System .......................................................................................................................... 63
7.1 Lubricating oil requirements ........................................................................................................... 63
7.2 External lubricating oil system ........................................................................................................ 63

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7.3 Crankcase ventilation system ........................................................................................................ 69
7.4 Flushing instructions....................................................................................................................... 70
8. Compressed Air System ........................................................................................................................ 73
8.1 Instrument air quality ...................................................................................................................... 73
8.2 External compressed air system .................................................................................................... 73
9. Cooling Water System ........................................................................................................................... 76
9.1 Water quality .................................................................................................................................. 76
9.2 External cooling water system ....................................................................................................... 76
10. Combustion Air System ......................................................................................................................... 84
10.1 Engine room ventilation .................................................................................................................. 84
10.2 Combustion air system design ......................................................................................................... 85
11. Exhaust Gas System ............................................................................................................................. 88
11.1 Exhaust gas outlet ............................................................................................................................ 88
11.2 External exhaust gas system ............................................................................................................ 89
12. Turbocharger Cleaning ......................................................................................................................... 96
12.1 Turbine cleaning system ................................................................................................................ 96
12.2 Compressor cleaning system ......................................................................................................... 97
13. Exhaust Emissions ................................................................................................................................ 99
13.1 Gas engine exhaust components ................................................................................................... 99
13.2 Marine exhaust emissions legislation ............................................................................................. 99
13.3 Methods to reduce exhaust emissions ........................................................................................... 99
14. Automation System ............................................................................................................................. 100
14.1 Technical data and system overview ........................................................................................... 100
14.2 Functions ........................................................................................................................................ 104
14.3 Alarm and monitoring signals ....................................................................................................... 105
14.4 Electrical consumers .................................................................................................................... 105
14.5 System requirements and guidelines for gas-electric propulsion ................................................ 107
15. Foundation ............................................................................................................................................ 110
15.1 Mounting of generating sets ........................................................................................................... 110
15.4 Flexible pipe connections ............................................................................................................. 112
16. Vibration and Noise ......................................................................................................................... 114
16.1 External forces & couples ............................................................................................................ 114
16.2 Mass moments of inertia .............................................................................................................. 116
16.3 Air borne noise ............................................................................................................................. 116
16.4 Exhaust noise ............................................................................................................................... 117
17. Power Transmission ............................................................................................................................ 118
17.1 Flexible coupling ........................................................................................................................... 118
17.2 Input data for torsional vibration calculations ............................................................................... 118
17.3 Turning gear ................................................................................................................................. 118
18. Engine Room Layout ............................................................................................................................ 120
18.1 Crankshaft distances .................................................................................................................... 120

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18.2 Space requirements for maintenance .......................................................................................... 121
18.3 Transportation and storage of spare parts and tools ................................................................... 121
18.4 Required deck area for service work ............................................................................................ 121
19. Transport Dimensions and Weights ................................................................................................... 125
19.1 Lifting of generating sets .............................................................................................................. 125
19.2 Engine components ..................................................................................................................... 126
20. Product Guide Attachments ............................................................................................................ 128
21. ANNEX .................................................................................................................................................. 130
21.1 Unit conversion tables .................................................................................................................. 130
21.1.1 Prefix ............................................................................................................................................ 131
21.2 Collection of drawing symbols used in drawings ......................................................................... 132

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1. Main Data and Outputs
The Wärtsilä 31SG is a 4-stroke, non-reversible, turbocharged and intercooled gas engine.
Cylinder bore ....................... 310 mm
Stroke .................................. 430 mm
Number of valves ................ 2 inlet valves, 2 exhaust valves
Cylinder configuration ......... 8, 10, 12, 14 and 16
V-angle ................................ 50°
Direction of rotation ............. Clockwise
Speed .................................. 720, 750 rpm
Mean piston speed .............. 10.32 - 10.75 m/s
1.1 Maximum continuous output
Table 1-1 Rating table for Wärtsilä 31SG
The mean effective pressure Pe can be calculated as follows:
where:
Pe = mean effective pressure [bar]
P = output per cylinder [kW
n = engine speed [r/min]
D = cylinder diameter [mm]
L = length of piston stroke [mm]
c = operating cycle (4)
Cylinder
configuration
Generating sets
720 rpm 750 rpm
Engine
[kW]
Generator
[kVa]
Engine
[kW]
Generator
[kVa]
W 8V31SG 4240 5090 4400 5280
W 10V31SG 5300 6360 5500 6600
W 12V31SG 6360 7630 6600 7920
W 14V31SG 7420 8900 7700 9240
W 16V31SG 8480 10180 8800 10560

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1.2 Reference conditions
The output is available within a range of ambient conditions and coolant temperatures
specified in the chapter Technical Data. The required fuel quality for maximum output is
specified in the section Fuel characteristics. For ambient conditions or fuel qualities outside
the specification, the output may have to be reduced.
The specific fuel consumption is stated in the chapter Technical Data. The statement
applies to engines operating in ambient conditions according to ISO 15550:2002 (E).
total barometric pressure 100 kPa
air temperature 25 °C
relative humidity 30 %
charge air coolant temperature 25 °C
Correction factors for the fuel oil consumption in other ambient conditions are given in
standard ISO 15550:2002 (E).
1.3 Operation in inclined position
The engine is designed to ensure proper engine operation at inclination positions.
Inclination angle according to IACS requirement M46.2 (1982) (Rev.1 June 2002) - Main
and auxiliary machinery.
Max. inclination angles at which the engine will operate satisfactorily:
Table 1-2 Inclination with Normal Oil Sump

Permanent athwart ship inclinations (list)
15°
 Temporary athwart ship inclinations (roll) 22.5°
 Permanent fore and aft inclinations (trim) 10°
 Temporary fore and aft inclinations (pitch) 10°

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1.4 Dimensions and weights
1.4.1 Generating sets
Fig 1-1 W8V31SG & W10V31SG engine dimensions
Engine L1 L1* L2 L3 L3* L4 L4* L5 L6 L6*
W 8V31SG 6087 6196 3560 1650 1650 877 986 300 500 500
W 10V31SG
6726 6836 4200 1650 1650 877 986 300 500 500
Engine H1 H1* H2 H3 H4 W1 W1* W2 W3 W4 W5 W5* Weight
Engine
**
Weight
liquids
W 8V31SG 3205 3205 4701 1796 650 3115 3115 1600 1153 1585 67 -67 53.5 /
54.2*
3.3
W 10V31SG
3205 3205 4701 1496 650 3115 3115 1600 1153 1585 67 -67 62.2 3.95

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Fig 1-2 W12V31SG, W14V31SG & W16V31SG engine dimensions
Engine L1 L1* L2 L3 L3* L4 L4* L5 L6 L6*
W 12V31SG 7840 8090 4840 2000 2000 1000 1250 300 908 908
W 14V31SG
8480 8730 5480 2000 2000 1000 1250 300 908 908
W 16V31SG
9120 9370 9120 2000 2000 1000 1250 300 908 908
Engine H1 H1* H2 H3 H4 W1 W2 W3 W4 W5 Weight
Engine
**
Weight
liquids
W 12V31SG 2926 2926 4633 1496 650 3500 1600 1153 698 1750 72.8 4.95
W 14V31SG
2926 2926 4633 1496 650 3500 1600 1153 698 1750 79.8 5.5
W 16V31SG
2926 2926 4633 1496 650 3500 1600 1153 698 1750 87.9 6.25

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* Turbocharger at flywheel end;
** Weight without liquids, damper and flywheel (as a rule of thumb, add 60kg per cylinder
on top of 8 and or 10V engine weight or, add 50kg per cylinder for 12, 14 and 16V engines
for additional gas components weight);
All dimensions in mm, weights in tonne.

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2. Operating Ranges
2.1 Engine operating range
Running below nominal speed the load must be limited according to the diagrams in this
chapter in order to maintain engine operating parameters within acceptable limits.
Operation in the shaded area is permitted only temporarily during transients. Minimum
speed is indicated in the diagram, but project specific limitations may apply.
2.2 Loading capacity
Controlled load increase is essential for highly supercharged engines as the turbocharger
needs time to accelerate before it can deliver the required amount of air. A slower loading
ramp than the maximum capability of the engine permits a more even temperature
distribution in engine components during transients.
The engine can be loaded immediately after start, provided that the engine is pre-heated
to:
● High Temperature (HT) water temperature is minimum 70°C
● Lubricating oil temperature is minimum 40°C
The ramp for normal loading applies to engines that have reached normal operating
temperature.

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2.2.2 Diesel electric propulsion and auxiliary engines
2.2.2.1 Loading rates Constant speed engines (DE / Aux)
Normal loading rate, constant speed engines, 720/750 rpm (DE / Aux)
Table 2-1 Normal Loading rate
Engine load
[% of MCR]
Nominal loading
[s]
Fast loading
(MN70) [s]
Fast loading
(MN80) [s]
Emergency,
Hybrid operation
only [s]
0 0 0 0 0
100 300 90 70 20
Fig 2-1 Normal Loading rate, constant speed engines, 720/750 rpm (DE / Aux / CPP)
NOTE
If normal loading rate is chosen low load running is limited to normal low load restriction
curve. Please see chapter
Normal Low load operation
-
Normal load acceptance
.

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Unloading rate, constant speed engines, 720/750 rpm (DE / Aux / CPP)
Table 2-2 Unloading rate
Engine load [%
of MCR] Nominal unloading [s] Fast unloading [s]
Emergency, Hybrid
operation only [s]
100 0 #N/A 0
0 60 #N/A 15
Fig 2-2 Unloading rate, constant speed engines, 720/750 rpm (DE / Aux / CPP)
In gas electric installations loading ramps are implemented both in the propulsion control
and in the power management system, or in the engine speed control in case isochronous
load sharing is applied. If a ramp without knee-point is used, it should not achieve 100%
load in shorter time than the ramp in the figure. When the load sharing is based on speed
droop, the load increase rate of a recently connected generator is the sum of the load
transfer performed by the power management system and the load increase performed by
the propulsion control.
The “emergency” curve is close to the maximum capability of the system and it shall not be
used as the normal limit for the engine. In dynamic positioning applications loading ramps
corresponding to 20-30 seconds from zero to full load are however normal. If the vessel
has also other operating modes, a slower loading ramp is recommended for these
operating modes.
In typical auxiliary engine applications there is usually no single consumer being decisive
for the loading rate. It is recommended to group electrical equipment so that the load is
increased in small increments, and the resulting loading rate roughly corresponds to the
“normal” curve.
In normal operation the load should not be reduced from 100% to 0% in less than 15
seconds. If the application requires frequent unloading at a significantly faster rate, special
arrangements can be necessary on the engine. In an emergency situation the full load can
be thrown off instantly when capacity of an ESS is dimensioned accordingly.

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2.2.2.2 Instant Load Application
The maximum permissible load step which may be applied at any given load can be read
from the figure below. The values are valid for engines operating in island mode (speed
control). Furthermore, the stated values are limited to a running engine that has reached
nominal operating temperatures, or for an engine which has been operated at above 30%
load within the last 30 minutes. If higher load step capability is required, then the
dimensioning of the Energy Storage System needs to be applied. Following Hybrid load
step graph illustrates load step capability on system level.
Cyclic (wave) load-taking capability can be evaluated from the figures below:
 Max instant load step = cyclic load amplitude
o Example: With cyclic loading at average load 57% the load variation
amplitude can be 14%, i.e ±7% (=50% + 14%/2)
Fig 2-3 Load steps 750 rpm CS
Fig 2-4 Unloading Steps, CS 750 rpm

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2.3 Low load operation
2.3.1 Normal Low load operation - Normal load acceptance
In order to avoid fouling of the engine, recommended limits to the low load operation are
given. Low load operation is all loads below 15% load. Cumulative low load operation
should not exceed the recommended values given in the chart and table. The time is reset
after a cleaning run at minimum 70% load for a minimum of 1 hour.
If recommended time limits are exceeded, then engine shall not be loaded faster than the
nominal loading curve in the chapter loading performance. Absolute idling time 10 minutes
if the engine is to be stopped, 5 hours in gas mode if engine is loaded afterwards.

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Table 2-4 Max continuous low load operation time for load acceptance according to
Normal Load acceptance chapter
Engine load % 0 2 5 10 15
W31SG on Gas 550kW/cyl h 8 8 10 48 96
Fig 2-5 Low load operating restrictions
2.3.2 Absolute idling
Absolute idling (disconnected generator)
● Maximum 10 minutes if the engine is to be stopped after the idling. 3-5 minutes idling
before stop is recommended.
● Maximum 8 hours if the engine is to be loaded after the idling.
NOTE
Operating restrictions on SCR applications in low load operation to be
observed.
2.4 Low air temperature
In standard conditions the following minimum inlet air temperatures apply:
● Standard + 5ºC
● With Arctic package -40ºC
For further guidelines, see chapter Combustion air system design.