Alfa Laval Aalborg AV-6N Natural circulation exhaust gas waste heat recovery boiler

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.

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.

Unique boiler construction

A unique supporting arrangement without endplates, enhanced

by computerised analyses ensures a vibration and thermal

stress-free boiler structure sustaining even the most demanding

operational conditions of engine-based heat recovery

applications.

Reliable natural circulation

Alfa Laval offers reliable natural circulation solutions as a

standard for steam applications, eliminating the need for

circulation pumps and providing several advantages. These

include enhanced reliability, minimized risk of soot fires, reduced

power consumption, cost effectiveness, fast site installation,

reduced foundation work, minimized piping and cabling, and

a small footprint. Additionally, conventional forced circulation

boilers are also available.

Easy to clean

The tube arrangement of the Aalborg AV-6N heating surface

ensures easy maintenance and service. Aalborg AV-6N boilers

can be cleaned during operation reducing the need for engine

shut-down. In addition to standard high-efficient steam soot

blowers, an air-type can also be applied.

Design data

• Engine output: No limit, depending on engine

• Engine fuel type: Light oil, liquid biofuel, heavy fuel oil,

natural gas

• Typical exhaust gas flow: 5–60 kg/s

• Exhaust gas temp.: Standard up to 610 ºC

• Operating steam/water pressure: Typically 5-30 bar(g),

max. 65 bar(g)

• Steam/water temperature: Standard up to 450 ºC

• Natural circulation as standard - forced on special demand

• Pinch point: Typical 10 - 20 ºC (min. 5 ºC, limited by

feasibility only)

Hot-water heating for free

Waste heat can also be recovered for use in hot water systems,

typically downstream of gas engines. The boiler module is

available in either vertical or horizontal configurations and

is delivered as a compact, pre-assembled unit. This design

ensures quick and straightforward installation, while providing

optimal access for maintenance and servicing.

• High-efficient counterflow design for heating of hot water

• Proven design to ensure effective and fast cleaning of

condensed lube oil residuals (in gas engine application)

• Compact and flexible layout

• Low operational weight

• Minimized gas pockets