The working principle of a composite boiler revolves around utilizing both exhaust gases from the main engine of a vessel and the heat generated from a supplementary burner. This innovative design aims to maximize energy efficiency and minimize fuel consumption in marine applications.

Exhaust gases from the ship's main engine are channeled through the boiler's economizer section, where heat is extracted from the gases before they are released into the atmosphere. The extracted heat is used to preheat the water which will eventually be converted into steam.

Simultaneously, a separate burner system, often utilizing diesel fuel or other suitable alternatives, is integrated into the boiler structure. This burner serves as an additional heat source to raise the temperature of the water to its boiling point, creating steam.

The two sources of heat, namely the recovered heat from exhaust gases and the heat generated by the burner, combine to produce steam within the composite boiler. This steam can then be utilized for various purposes on the vessel, including heating, power generation, and auxiliary machinery operations.

The composite boiler's ability to efficiently harness both exhaust heat and burner-generated heat makes it a preferred choice in marine applications, where space and fuel efficiency are crucial considerations. By ingeniously blending these heat sources, the composite boiler optimizes energy utilization, contributing to enhanced operational sustainability and cost-effectiveness in the maritime industry.