CCR_2011_Layout 1 16.01.

12 16:50 Seite 1

Cat Common Rail The Benefits

With Cat Common Rail, the injection pressure is independent from load and speed.
Utilizing injection maps the injection
characteristics are optimized for every
engine operating point.
For areas that are especially emissionssensitive, soot emissions at low engine
load remain well below the visibility
limit. Furthermore, during normal load
operation NOx emissions can be reduced
without sacrificing fuel consumption.
Depending on application, as well as
operating conditions, engines equipped
with Cat Common Rail fuel system
technology can positively impact the
transient response.
In general, the Cat Common Rail fuel
system enables vessel operation without visible soot throughout the whole
operating range.

Cat Common Rail

In addition to that, the fuel system is

capable of multiple injection. Multiple
injection allows optimal combustion and
low emissions at all loads. Characteristic
of Cat Common Rail is the approach of
using the fuel (whether its heavy fuel
oil, marine diesel oil or diesel oil) as the
control fluid for the injector, thus avoiding
the added complexity of a separate
control fluid system.

Significant decrease of specific

fuel oil consumption:
for main propulsion engine M 32 C
with Cat CR up to 3% improvement,
for generating set M 32 C with Cat CR
up to 2% improvement,
optimized combustion.

Less Fuel and Reduced Emissions Mean More Environmental Care

During the development, the retrofit

aspect of the complete system has been
emphasized. As a result, the Cat Common
Rail fuel system can be retrofitted to
existing M 32 C engines. This means
increased customer value to reach future
environmental regulations.

Rail Segment with Three Injectors

Cat CR

Caterpillar Marine Power Systems

Headquarters

Europe, Africa, Middle East

Americas

Asia Pacific

Caterpillar Marine
Power Systems
A Division of
Caterpillar Motoren GmbH & Co.KG
Neumhlen 9
22763 Hamburg/Germany

Caterpillar Marine
Power Systems
A Division of
Caterpillar Motoren GmbH & Co.KG
Neumhlen 9
22763 Hamburg/Germany

MaK Americas Inc.

Caterpillar Marine Trading

(Shanghai) Co., Ltd.

3450 Executive Way

25/F, Caterpillar Marine Center
Miramar Park of Commerce 1319, Yanan West Road
Miramar, FL. 33025/USA
200050 Shanghai/P. R.China

No. 5 Tukang Innovation Grove

Singapore 618304
Republic of Singapore

Phone: +49 40 2380-3000

Telefax: +49 40 2380-3535

Phone: +49 40 2380-3000

Telefax: +49 40 2380-3535

Phone: +1 954 885 3200

Telefax: +1 954 885 3131

Phone: +65 68287-600

Telefax: +65 68287-625

For more information please visit our website:

MARINE.CAT.COM

Subject to change without notice.

Leaflet No. 245 12.11 e L+S VM3

Phone: +86 21 6226 2200

Telefax: +86 21 6226 4500

Caterpillar Marine Asia

Pacific Pte Ltd

2011 Caterpillar All Rights Reserved. Printed in Germany. CAT, CATERPILLAR, their
respective logos, ACERT, ADEM, Caterpillar Yellow and the POWER EDGE trade
dress, as well as corporate identity used herein, are trademarks of Caterpillar and
may not be used without permission
TM

Caterpillar Marine Power Systems is committed to sustainability. This document

is printed on PEFC certificated paper.

CCR_2011_Layout 1 16.01.12 16:51 Seite 2

Cat Common Rail Fuel System

Cat Common Rail Technology

From its introduction the MaK long-stroke generation of main diesel engines has been recognized for good
performance and reasonable fuel consumption, alongside outstanding reliability and long component life.
MaK engines are compliant with current emission regulations without the need for additional aftertreatment.
To fulfil the upcoming emission legislations the development of new combustion process supporting technologies is necessary.

Caterpillar has chosen inside the engine measures as the technology with
the highest customer value. In combination with the long-stroke concept and
high performance air systems the Cat
Common Rail (Cat CR) fuel system is
the most effective technology to meet
emission regulations and customer
expectations.
The key features of the Cat Common Rail
technology are:
Well adapted injection pressure over
the entire engine operating range.
Fully flexible fuel injection system
enabling optimized emissions and
engine performance.
Suitable for HFO, MDO and DO.
100% retrofittable system.

1,5

Caterpillar has made a huge investment

to develop an emission reduction technology now marketed as ACERT Technology for Caterpillar high-speed engines.
After a successful demonstration in
the on-highway high-speed engines,
Caterpillar embarked on a stepwise
migration of selected elements of ACERT
Technology across the entire product line
and range of applications. The broad
range of Caterpillars marine program
calls for a differentiated approach.

FCT Switch Point

1,25

Soot Emissions (FSN)

Soot Emission
of M 32 C Cat CR,
IMO II,
constant speed

IMO I
IMO II w/o FCT
IMO II with FCT
IMO II Cat CR w/o FCT

1,0
0,75

Visibility Limit

0,5
0,25
0
0

40

20

80

60

100

Power Output (%)

Key criteria are:

Prevailing emission limits for the
respective power range and timing
of their introduction.
Customer expectations in terms of
engine performance, maintenance
practices, fuel quality and mode of
operation.

Keeping in mind the high reliability expectations of customers, Caterpillar decided

to adopt a two step approach providing
the most effective solutions with lowest
complexity.
Flexible Camshaft Technology (FCT) has
been developed and put into production.
The next milestone in emissions technology is a fully flexible fuel system suitable
for HFO, MDO and DO, called the Cat
Common Rail (Cat CR) fuel system. Cat
Common Rail is considered one major
building block towards low emissions,
high performance and highest customer
value.

By adopting well proven elements of this

technology for medium-speed engines, it
is our goal to meet and exceed customer
expectations by maximizing product value
through:
Superior reliability in heavy fuel
operation.
Best fuel efficiency in its class.
Lowest engine emissions with
minimum additional complexity.

The goals are:

Invisible smoke under all engine
operating conditions.
Reduce emissions beyond current
and future IMO regulations, offering
an attractive technology for emissions
sensitive areas.
Maintain or improve engine performance by taking advantage of the
capabilities and benefits of a fully
flexible fuel system.
Continue to meet the level of reliability
in heavy fuel operation expected by
our marine customers.

In addition Caterpillars expertise in electronics is a major asset to the Cat Common Rail technology.

Safety considerations and high customer

value were the main focus throughout the
development, resulting in a state-of-theart design with the following features:
Two high pressure pumps for
redundancy.
Double-walled lines and rails.

Specific Fuel Oil Consumption M 32 C Cat CR @ 600 rpm

( from 1% up to 2% Improvement )

240

The main components of the Cat Common

Rail fuel system are a high pressure (HP)
pump, rail, injector and electronics. Caterpillars broad experience with electronically controlled engines, range of product
lines and in-house design and analysis
expertise allow for a unique system
approach. All components are developed
under Caterpillar design control.

Safety Concept

Less Fuel and Reduced Emissions Mean More Environmental Care:

Specific Fuel Oil Consumption M 32 C Cat CR IMO II
( from 0,6% up to 3% Improvement )

Cat CR System

Cat Common Rail Technology

Furthermore, redundant speed pick-ups

and pressure sensors, a safety gear
between pump and engine, a pressure
relief valve and flow limiters all increase
operational safety.

Injector

Pump Drive

Caterpillar has chosen a simple and

robust approach by using the actual fuel
as control fluid, thereby eliminating the
need for a separate control fluid system.
The injector nozzle is cooled by lube oil,
a typical feature for heavy fuel operation.
For the Cat CR injector, the lube oil circuit
has been extended to provide cooling to
the electrical components within the injector, thereby increasing the lifetime.
The injector design is simple, robust and
compact; the key features are:
Electronically controlled.
Flexible injection timing and duration.
Capability of multi shot injections.

High Pressure Pump

Two high pressure pumps deliver the

required amount of fuel to the rail and
provide the desired rail pressure in closed
loop control. The pump itself is based on
a proven design and has been modified
for HFO operation. By having two pumps
for all in-line engines the amount of HP
connections and components is drastically reduced and thus increases reliability.
The inlet metering control of the pump
ensures a high pump efficiency.
The key features are:
Two pumps for redundancy.
Inlet metering control.
Well adapted injection pressure.
Closed loop control of rail pressure.

Rail and Cylinder

Rail

The double-walled rails are pressurized

and act as an accumulator, with one rail
segment feeding fuel to three injectors,
i. e. a nine cylinder engine has only three
rail segments, an eight cylinder engine
has two rail segments, each feeding four
injectors. This layout reduces the number
of parts and the number of high pressure
connections. Flow limiters prevent the
cylinders from overfueling; a safety valve
acts as pressure relief in case of an unwanted overpressurized rail.

Having in-house expertise for core electronic components and software puts
Caterpillar in a unique position and allows
for an advantageous systems approach.
Injector

220
210
200
190
180

Standard Engine
Common Rail
Common Rail Partload Optimized

230
220

sfoc [g/kWh]

sfoc [g/kWh]

240

Based on existing software and engine

control strategies, the specific needs of
heavy fuel burning engines and applications can be easily adopted. Depending
on engine type, application and boundary
conditions, a tailor made version allows
for optimal operation.

Gateway Communications Module

(PL1000E)

M 32 C
M 32 C Common Rail System

Constant Speed Common Rail

Combinator Curve VD 8744-4 Common Rail Optimized
Constant Speed Standard Engine
Combinator Curve VD 8744-4 StandardEengine

Electronics

The key component is the Caterpillar

A4E4 (or ADEM) Electronic Control
Module (ECM). The ECM acts as the brain
of the Cat Common Rail fuel system. Pioneered by Caterpillar 20 years ago, the
ADEM controller coordinates and enhances fuel delivery, air supply and other
engine functions to maximize overall performance and reduce emissions output.

250

230

Injector Cable

J1939

The engine protection system operates

independently of the engine control system
and has its own independent sensor equipment. This ensures that engine operation
is monitored independently of other control
systems.
The ECM functions can be divided into a
core system and a performance system.
The core system consists of:
Control device A4E4.
One crankshaft speed pick-up.
Two camshaft speed pick-ups.
Two high-pressure sensors.
Inlet metering valve.
Injector drivers.

The performance system ensures optimal

engine settings under all operating conditions, using information like exhaust gas
temperature, charge air pressure, ambient
conditions and lube oil temperature.

External to Control System

supplied by Caterpillar Motoren or OEM
Modbus

J1

Modbus FieldBus
Module

Cat CR Pump 1

210

J2

J1
Atmospheric Pressure

200
190

Cat CR Pump 2

Intake Manifold Pressure

180

170

170

160

160
0

50

100

150

200

250

300

350

400

450

500

Power [ kW/cyl]

Main Propulsion (Inline engine M 32 C Cat CR with kW/cyl. @ 600 rpm; ISO 3046/1
and LCV 42,7 MJ/kg; 5% tolerance, + 1% engine driven pump). Values for information only.

550

Dual Cam Speed/Timing

Secondary Cam

10%

20%

30%

40%

50%

60%

70%

80%

90% 100% 110%

Power [ kW/cyl]

Generator Set (6, 8 and 9 M 32 C Cat CR IMO II; SFOC acc. ISO 3046/1, LCV 42,7
MJ/KG; 5% tolerance, + 1% engine driven pump). Values for information only.

High Pressure Pump

Safety Gear

Engine
Electronic
Controle Module
(A4E4v2)

Intake Manifold Air Temperature

Engine Coolant Block

Outlet Temperature

Primary Cam
Fuel Rail Pressure I

Fuel Rail Temperature

Single Crank Speed/Timing

Fuel Rail Pressure II

Turbine Inlet Temperature LH

Control Device A4E4