Alfa Laval Aalborg OS-TCi Self-cleaning fired boiler with multi-fuel and hybrid options

Aalborg OS-TCi

Self-cleaning fired boiler with multi-fuel and hybrid options

Intended for auxiliary use, the Alfa Laval Aalborg OS-TCi

is a fired marine boiler for producing steam. Designed with

helix tubes that provide a larger heat transfer area than

conventional solutions, it offers fuel-saving efficiency.

Ready for the fuel transition, the OS-TCi 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

• Energy efficiency maintained through self-cleaning TCi

(Turbo Clean, intelligent) technology

• Trouble-free uptime, secured through robust design

and user-friendly control

Application

The Aalborg OS-TCi is a flexible marine boiler that can support

vessel operations in multiple ways:

• Steam generation:

The Aalborg OS-TCi is primarily used to provide steam for:

– Tank cleaning– HVAC– Engine room consumers

• Shared steam drum:

The Aalborg OS-TCi 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 OS-TCi 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

Design

Compact and easy to install, the Aalborg OS-TCi operates

on oils and biofuels and can also be configured for one alternative

fuel: LNG, methanol or ammonia.* It is delivered with a preassem

bled Aalborg burner built on Alfa Laval’s innovative MultiFlame

(MF) concept. The boiler and burner are both engineered and

produced in-house to ensure the highest reliability.

• Aalborg OS-TCi boiler:

The Aalborg OS-TCi is a side-fired, two-drum boiler with a

combustion section comprised of helix tubes. This tube design

provides more heat transfer area than competing solutions,

which results in fuel-saving efficiency. A baffle plate in the

steam space forces the steam to pass through the tube

bundle twice, ensuring that the steam is absolutely dry.

Combustion heat from the burner is distributed uniformly

through the boiler’s combustion section. This ensures

optimal heat transfer and reduces damaging thermal

stress inside the boiler.

• Aalborg MF PA burner:

The Aalborg MF PA is a side-fired, pressure-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.

• Aalborg MF SAS burner:

The Aalborg MF SAS is a side-fired, steam/air-atomizing

burner that supports conventional fuels and methanol.

Electric hybrid capability (option)

Besides serving as a fired boiler, the Aalborg OS-TCi can be

configured as a hybrid boiler, allowing it to operate on electrici

ty. This lets it utilize shore power or surplus electricity on board,

producing steam or hot water without direct emissions. It also

enhances the boiler’s turn-down ratio, which improves startup

time and reduces maintenance by enabling continuous

operation at lower loads.

The optional electric heater comprises one or two heating

elements, each 600 kW in capacity. To incorporate it, the

boiler interior must be modified. This has no impact on the

boiler’s high efficiency, but it may require small adjustments

in height or diameter.

Ready options for later conversion

To support decarbonization at any pace, the Aalborg OS-TCi

can be delivered in a multi-fuel-ready and/or hybrid-ready

configuration. The necessary connections, space and internal

adjustments are all prepared in the boiler design, so that

components for a selected alternative fuel or electric hybrid

operation can be added later. This future-proof solution reduces

investment cost while enabling easy and cost-effective

conversion at an ideal time.

Working principle

During fired operation, heat from fuel combustion is transferred

to the furnace shell, mainly through radiation. Flue gases leaving

the furnace enter vertical uptakes where the heat is transferred

to helix tubes, mainly through convection.  If the boiler is config

ured as a hybrid, the electric heater provides an alternative

heat source.

Heat transferred through the furnace shell or the helix tube walls

evaporates the adjacent saturated water on the boiler’s water

side. This causes steam bubbles to form. Because the steam

bubbles have a much lower specific density than the water, they

rise rapidly into the steam space, where the water and steam

are separated.

Control

Like other Alfa Laval equipment on board, the Aalborg OS-TCi

uses Alfa Laval Touch Control. This recognizable, user-friendly

interface features a graphical touchscreen with intuitive navi

gation, making it easy for the crew to learn and use it correctly.

Robust and PLC-based, the control system offers future-proof

expansion possibilities and support for remote troubleshooting.

Maintenance

The Aalborg OS-TCi is effectively self-cleaning thanks to its

TCi (Turbo Clean, intelligent) technology, which keeps the boiler

running efficiently and prolongs its service life. The TCI cleaning

process is fully automatic.