Category: Alfa Laval

Main benefits

• Reduced fuel consumption, leading to remarkable cost

savings and lower CO2 emissions

• Natural circulation: high availability, low operational and

maintenance costs

• Compact heating surface, optimizable for different

applications

• Small water volume inside the boiler allows it to respond

quickly to load changes

• Freedom of scope: shop-assembled, or with maximised

scope for local outsourcing (e.g., insulations, platforms,

inter-connecting pipes etc.)

Boiler design

The boiler’s compact and flexible design, which makes it easy to

install, also allows cleaning during operation, which minimizes

engine shutdowns and increases plant availability.

Designed with extended heating surface, Aalborg AV-6N is

compact and cost-effective. The possibility of cleaning during

operation minimizes the need for engine shutdowns and

increases the overall plant availability.

Natural circulation is used in the standard steam configuration

with resulting advantages for reliability, safety and energy

efficiency, although traditional forced-circulation models are

available if specifically requested.

Introduction

Aalborg AV-6N boiler efficiently recovers waste heat from exhaust

gases, making it ideal for steam and/or hot water production. This

boiler is constructed to recover heat from diesel and gas engines,

gas turbines or other heat sources.

The robust and highly efficient water tube boiler significantly

enhances the overall efficiency of power and industrial plants and

reduce the use of fuel, leading to remarkable cost savings and

lower CO2 emissions.

By utilizing heat energy from engine/gas turbine exhaust or

process industry flue gas that would otherwise be released

into the atmosphere, the Aalborg AV-6N contributes to a more

sustainable operation.

Application

As the marine industry decarbonizes, more ports around the

globe are investing in shore power installations. Yet while shore

power provides electricity during a port stay, the vessel’s need for

steam remains. Although fired boilers can generally be used in

port, direct emissions are best kept to a minimum.

With the Aalborg electric steam boiler, vessels can meet the

needs of steam consumers without resorting to combustion.

The boiler can use either the onshore grid or the extra electricity

available on board, such as the surplus on LNG carriers and

FSRUs that comes from using the gensets to manage boil-off

gas (BOG). In both cases, it improves fuel economy and the

vessel’s green profile.

Benefits

• Steam or hot water production without direct emissions

• Reduced overall emissions and carbon footprint

• Reduced fuel consumption and associated costs

• Small installation footprint

• High turn-down ratio for increased efficiency

Working principle

The Aalborg electric steam boiler is much simpler in design and

operation than a traditional fired boiler. It comprises electric

heating elements that work in steps, with each element supply

ing six stages. Load regulation is possible down to 60 kW.

When steam is required, the relay-based control system en ables

the heating elements incrementally until the demand is met.

If the boiler is used at sea, where the electricity supply varies, it

can be signalled to start only when sufficient power is available.

Benefits

• Steam or hot water production without direct emissions

• Reduced overall emissions and carbon footprint

• Reduced fuel consumption and associated costs

• Small installation footprint

• High turn-down ratio for increased efficiency

Aalborg electric steam boiler

Onboard steam production using shore power or surplus

electricity

The Alfa Laval Aalborg electric steam boiler is a simple, com pact

and combustion-free solution for meeting vessel steam needs.

By utilizing shore power or the electricity already on board, it

delivers steam without producing additional emissions. When

the vessel is connected to the onshore grid, the fired boiler can be

shut down completely, reducing emissions from tank to wake.

Installation

The boiler is compact and has a small footprint that sim plifies

placement on board. Available in three size configurations, it is

delivered as loose compo nents and installed horizontally.

Maintenance

No regular maintenance is required. However, the boiler should

be inspected once per year to ensure that its heating elements

are working properly.

Approvals

The Aalborg electric steam boiler is type approved by all major

marine classification societies.

The Aalborg XW-TG can be arranged in many different confi

gurations, e.g. for a single pressure or dual pressure system,

according to each individual requirement for steam and power

output.

We have developed and supplied the Turbo Compound System

in co-operation with Dresser Rand, Siemens AG and Wärtsilä

Corporation. Naturally, the system works equally well with other

diesel main engines, e.g. MAN engines. The Turbo Compound

System generates electric power equal or up to more than

11% of the main engine output on large container ships from

waste heat while at the same time reducing emission of harmful

exhaust gases like CO2. SOX and NOX into the environment.

We have achieved documented fuel savings and thereby

reduced CO2 emissions in double digit percentages.

Besides container ships, the Turbo Compound System can

also be applied with advantage to other ship types such as

VLCCs, bulk carriers, etc.

For enhancement of an efficient, safe and reliable operation, the

Aalborg XW-TG is therefore among other things supplied with the

following equipment (advantageous for ordinary economizers as

well):

• Steam drum(s) for efficient separation of dry steam for

superheating

• High-efficient, electrical operated sootblowers using steam

or compressed air as blowing medium for on-load cleaning

• Fixed nozzle pipes for off-load water washing

• Extended monitoring equipment (e.g. exhaust gas pressure

drop/temperatures and fire detection)

• Dampers for by-passing of exhaust gas at low load operation

(and in case of emergency)

• Circulation pumps of canned motor type (with external

cooling) with flow monitoring system

• PLC based control system including online performance

monitoring and  help functions

The Aalborg XW-TG is a water tube, forced circulation exhaust

gas economizer designed to utilize thermal energy in diesel

engine exhaust gas. The standard Aalborg XW design has

been enhanced to more efficiently utilize the wasted energy

after large diesel engines with saved fuel consumption and

reduced CO2 emissions as a result.

Aalborg XW-TG generates superheated steam for power

generation by means of a steam turbine driven generator

(turbo generator).

The Aalborg XW-TG is based on and has the same charac

teristics as our well-known Aalborg XW which is a water tube,

forced circulation exhaust gas economizer with double gilled

tubes specially designed for heat recovery from diesel engine

exhaust gas.

When applied for large heat recovery rates, the heating surfaces

are required to be much increased in size and it is increasing

ly more important to focus on operation reliability to provide

full benefit of the relatively high investment.

The Aalborg XW is a water tube, forced circulation exhaust gas

economizer. It is specially designed to utilize thermal energy in

diesel engine exhaust gas but the basic design suits numerous

applications.

Boiler characteristics:

•  Forced-circulation exhaust gas economizer

•  Water tube economizer with gilled tubes for exhaust gas

heat recovery

•  Robust, well-proven construction, able to withstand

vibrations and exhaust gas pulsation

•  Heating surface composition which ensures the required

output from the most compact unit

•  Efficient, well-proven cleaning system with steam or air

soot blowers

•  Superheater and preheater as an option

The Aalborg XW is a water tube, forced circulation exhaust gas

economizer. It is specially designed to utilize thermal energy in

diesel engine exhaust gas but the basic design suits numerous

applications.

Steam capacity: 0.2 – 17.0 t/h

Design pressure: 18 bar(g) or 24 bar(g)

Description

The Aalborg XW is a water tube, forced circulation exhaust

gas economizer. It is specially designed for heat recovery

from diesel engine exhaust gas but the basic design suits

numerous applications.

The heating surface is made of double gilled tubes with a

spacing which minimizes soot build-up. It is supplied with an

efficient cleaning system with steam or with compressed

air sootblowers.

The economizer can be supplied with a dividing wall system

for connection of several exhaust gas sources to one econo

mizer.

The Aalborg XW may be used in conjunction with an oil-fired

auxiliary boiler or a separate steam drum, in both cases act

ing as a steam/water separator.