Category: Industry Trends

The successful commissioning of the Aalborg marine boiler

for methanol marks a significant achievement in the maritime

industry. As the first-ever methanol boiler installed on board a

vessel, this groundbreaking project demonstrates Alfa Laval’s

ability to undertake complex projects that require a high level of

technical expertise, planning, and close collaboration between

Alfa Laval and the shipyard.

In early 2023. Alfa Laval secured the world’s first order for

methanol dual-fuel boilers for four 16.000 TEU container ships

supporting a leading Chinese shipowner in its ambitious de

carbonization journey. By the end of 2024. methanol bunkering

was completed, and the vessel was ready for commissioning.

With the shipyard operating on a tight schedule, the boiler’s

commissioning and inspection had to be finalized by early 2025.

demanding precise time management, technical execution,

and close collaboration.

Alfa Laval is taking a pivotal role in driving

the marine industry’s transition with its

methanol-capable solutions. With the

successful commissioning of the first boiler

system for methanol, we have proven our

expertise in handling complex installations,

showcasing our ability to deliver innovative

and advanced solutions that support

shipowners in their decarbonization journey.”

Design

Easy to install, the Aalborg OL operates on oils and biofuels and

can also be configured for one alternative fuel: LNG, methanol

or ammonia.* As standard, it is delivered with a preassembled

Aalborg MF SA burner for LNG operation.** The boiler and

burner are both engineered and produced in-house to ensure

the highest reliability.

• Aalborg OL boiler:

The Aalborg OL is a top-fired, two-drum boiler with a

design pressure of 9 or 18 bar(g). Its furnace, which contains

minimal refractory, is shaped to provide optimal combustion

conditions. Membrane walls with gas-tight polygonal panels

make the furnace resistant to gas pulsations.

The boiler’s combustion section comprises straight pin

tubes with bent pins, which provide a high coefficient of heat

transfer and reduce pressure loss. Combustion heat from

the burner is distributed uniformly through the combustion

section, which ensures optimal heat transfer and reduces

damaging thermal stress inside the boiler.

• Aalborg MF SA burner:**

Built with Alfa Laval’s innovative MultiFlame (MF)

concept, the Aalborg MF SA is a steam-atomizing burner

that supports conventional fuels and gas fuels like LNG.

By pre-mixing air and gas, it reduces the production of

CO2. NOx and other emissions.

Application

The Aalborg OL is a flexible marine boiler that can support

vessel operations in multiple ways:

• Steam and hot water generation:

The Aalborg OL is primarily used to provide steam

and hot water for:– Cargo tank heating– Tank cleaning–

HVAC– Engine room consumers

• Shared steam drum:

The Aalborg OL can support one or more exhaust gas

economizers, serving as a shared steam drum for waste

heat recovery.

• LNG safety:

On vessels using LNG as fuel, the Aalborg OL can:– Support

boil-off gas (BOG) management by safely

combusting BOG that cannot be consumed by an

auxiliary engine or genset– Combust a free flow from the LNG

tank if the vessel’s compression train should fail

– Combust the mix of inert gas and methane that arises

before and after tank inspection, eliminating detours

for gas disposal

The Alfa Laval Aalborg OL is a high-capacity, fired marine

boiler for producing large amounts of steam or hot water.

Available in two design pressures, it has a top-fired design

that maximizes heat transfer and minimizes pressure loss.

Ready for the fuel transition, the OL can use oils, biofuels

and one alternative fuel of your choice. Additionally, it can

be configured as an electric hybrid. These options can be

implemented directly, or the boiler can be prepared for their

installation later.

Benefits

• Configuration for your choice of alternative fuels  – 

implemented now or later

• Hybrid and hybrid-ready options for electric operation

• Trouble-free uptime, secured through robust design

and user-friendly control

• Optimized furnace design with easy inspection access

Scope of supply

• Pressure part with insulation

• Monoblock burner – gas, light oil or gas/light oil

• Feed water system (one pump)

• On-off water level control

• Steam outlet, blow-down and safety valves

• Control panel

• Start-up/commissioning

Optional

• Stand-by feed water pump

• Automatic blow down valves

• Sample cooler

• Stack

• Feed water tank

• Blow down tank

• Chemical dosing system

• Feed water treatment

Accessories

The Aalborg 3-Pass Mini comes with pressure part with insulation, Monobloc

burner, feed water pump, on/off/ water level control, steam outlet, blow down

and safety valves as well as control panel as standard. As optional extras, you

may be supplied with a stand-by feed water pump, automatic blow-down valves,

sample cooler, stack, feed water tank, blow-down tank, chemical dosing system

as well feed water treatment equipment.

Benefits

• Highly efficiency boiler

• Symmetric drawing, with stable and uniform evaporation

• Suitable steam space – high steam quality

• Low stress design – longer lifetime

• Spiral tubes – high heat transfer coefficient

• Spiral tubes – small footprint & easy cleaning

• Low emissions

• Based on well-proven and well-known design details from Aalborg 3-pass

• Easy maintenance and inspection

• High efficiency thermal insulation

Easy installation

The boiler is mounted on a skid – ready to be plugged in. Supplied with ready

-mounted burner, control panel, fittings and cables.

Compact design

The small foot-print makes the boiler easy to install.

Easy inspection and maintenance

All boiler connections/valves and inspection doors are located in such manner

that they easily allow access for access for operation and maintenance.

Easy to clean

The smoke tubes are fast and easy to clean thanks to the low number of spiral

tubes. Uniform, high steam quality The boiler is designed with symmetric drawing,

with stable and uniform evaporation and suitable steam space ensuring a high

saturated steam quality Improved combustion The furnace design in conjunction

with the burner ensures an efficient combustion and low atmospheric emissions.

The Aalborg 3-Pass Mini boiler is a gas, LFO or dual fuel industrial boiler with

a 0.5-2.5 ton/hour steam capacity and a design pressure up to 21 barg.

Having a capacity of 0.35-1.90 MW, the Aalborg 3-Pass Mini may be used for

a hot water application as well. This very compact boiler comes as a complete

skid-mounted unit – ready to be installed. Designed and optimised with the

total of Alfa Laval’s technical and innovative competencies in every detail

– inside out.

Pressure parts

The heating surfaces are arranged symmetrically with the furnace in the

centreline of the boiler to secure optimum water circulation. The reversal

chamber is water cooled in order to reduce the refractory to a minimum

and to ensure an optimum noise reduction. The pressure part builds on

well documented design and production concepts. All pressure

parts are manufactured carefully in selected materials with high tensile

steel. The Aalborg 3-Pass Mini boiler is designed according to the EN 12953

or ASME sect. I standards.

Control/security system

The control system/security system incorporates:

• Burner Management System with load and sequence control with starting

sequence/safety interlocks and load control.

• Water level control and safety.

• Motor starter.

Burner

The Aalborg 3-Pass Mini comes with a Monobloc burner which may be used

for gas and LFO or a combination hereof (dual fuel).

Working principles

The Alfa Laval Aalborg HPNC boiler is designed to operate

in a closed loop system, a so called thermo syphon system,

where circulation is ensured through gravity. The steam cycle

is completely sealed off to remove any risk of corrosion.

Steam generation is taking place in two concentrically

arranged coils – the inner coil which forms the furnace and

the outer coil which provides for convective heat transfer

through the second and third gas passes.

Depending on boiler size each coil can consist of one single

flow way or several parallel flow ways. This design ensures

sufficient and reliable circulation and thereby also cooling of

all the heat transfer parts of the boiler.

Standard equipment

As a standard the high pressure boiler is fitted with the required

accessories for a safe and reliable operation, including safety

valve, rupture disc assembly and low water level cut-off

electrodes.

Burner equipment includes pressure jet burner for fuel oil, gas

or a combination hereof as well as the required equipment for

fuel line system.

The boiler system can be filled with water using a vacuum

system or by using the optional high pressure filling pump.

Design features and benefits

The HPNC boiler is supplied in 9 different standard sizes, with

steam effect ranging from 125 to 2.500 kW. The standard boiler

is designed to operate at steam pressures up to 90 barg.

The boiler’s robust coil type design (see illustration page 2)

is based on thermal fluid heaters, which ensure:

• Flexibility in absorbing thermal expansions, a feature that

will ensure low stress levels in the boiler tubes and thereby

also long life time

• Efficient heat transfer as gas flow is perpendicular to tube

direction creating turbulence

• Efficient cooling of tube sections

• Verified pressure loss calculations (water/steam flow) that

provide assurance of cooling and no overheating

Highest possible efficiency is ensured through a compact

design, and reliable operation is guaranteed by using high

quality instrumentation.

Only high pressure grade steel tubes are used to ensure

high reliability.