Alfa Laval Aalborg i-OC Modular composite boiler

The Alfa Laval Aalborg i-OC is a high-performance composite boiler, capable of generating

steam through the firing of oil and/or the recovery of waste heat from engine exhaust gas.

Its modular design comprises one oil-fired section and one–three exhaust gas sections.

One of the exhaust gas sections is connected to the main engine, while the two other

exhaust gas sections are optional and can be connected to one or two auxiliary engines.

Application

Able to work with multiple heat sources, the Aalborg

i-OC offers reliable production of steam while sailing and

during port stays. As a composite boiler, it demands

considerably less space than having both oil-fired

and exhaust gas boilers on board. In addition, it has a

smaller footprint and weighs less than older composite

boiler designs.

At its operating pressure of 7 bar(g), the Aalborg i-OC

can produce up to 2500 kg/h of steam with its oilfired

section and up to 1000 kg/h with its exhaust gas

sections.

Benefits

• Composite design – can utilize fuel and/or

exhaust gas

• Minimized footprint and weight

• Internal bypass for regulation of steam

production and back pressure

• Standardized, pre-assembled and easy to install

• Optimized for high self-cleaning effect in the

smoke tubes

• New burner design for easy inspection and

maintenance

Design

The Aalborg i-OC is a vertical and cylindrical boiler

that employs natural circulation of water and steam. Its

pressure sections are manufactured from mild steel that

is able to withstand high temperatures.

The plant is designed according to Alfa Laval’s modular

Aalborg boiler concept, with a main module that

comprises two parts: an oil-fired section and an exhaust

gas section that recovers heat from the main engine.

One or two optional exhaust gas modules (Alfa Laval

Aalborg Micro boilers) can be incorporated for auxiliary

engine waste heat recovery. Handling the auxiliary

exhaust gas with separate but connected modules

ensures flexibility and a stress-free plant design.

• Oil-fired section

The oil-fired section of the main module comprises a

furnace, a steam space and a convection section. The

convection section, through which the flue gas flows,

consists of helix tubes with a turbocleaning effect.

• The modulating-type pressure-atomizing burner

(Aalborg MF PA) is fully integrated with the

convection part of the oil-fired section. The burner

housing is mounted on the boiler front, angled 15°

downwards towards the furnace bottom. It optimizes

the flue gas flow distribution during combustion,

which results in higher performance in the

convection part and lower NOx emissions.

• Main engine exhaust gas section

The main engine exhaust gas section comprises

smoke tubes and an internal bypass damper. The

bypass consists of a plain tube welded to the lower

and upper tube plates, with the automatic damper

installed in the top.

• Auxiliary engine exhaust gas boilers (optional)

The exhaust gas boiler modules for auxiliary engine

waste heat recovery comprise serrated and finned

spiral tubes. Each module has its own exhaust gas

bypass damper. These smaller modules are bolted

directly to the main module, with no piping or other

equipment. All boiler mountings are shared with and

installed on the main module.

Control system

Reliable and intelligent, the user-friendly Alfa Laval Touch

Control system provides fully automatic operation of

the boiler plant and the pressure-atomizing burner.

The system includes controls for the burner load and

sequence, burner motor, water level and safety device,

as well as starters for the fuel heater and fuel oil pumps.

Installation

The Aalborg i-OC is standardized, pre-assembled

and easy to install quickly. Only the burner and the

optional exhaust gas boilers for auxiliary engine waste

heat recovery need to be mounted on site. Installation

is a matter of hooking up pre-mounted fittings with

connections that are almost all situated on the boiler

top. Inlet and outlet boxes are integrated, and the boiler

foundation is prepared for welding to the deck.

Maintenance

The Aalborg i-OC has adequate space for inspection

and maintenance in the steam and water sections. The

boiler can easily be washed with water or mechanically