Exhaust gas boiler
Exhaust gas boilers on ships use the 250 - 400 ° C exhaust gases from the main diesel engine that drives the ship's propeller. Flue gas boilers are used to generate heating steam, which is mainly used to preheat the heavy oil to 120 - 135 ° C. In addition, the steam is used to heat the lubricating oil separators , to heat living areas or air conditioning and to heat water.
The exhaust gas boilers are usually operated in the pressure range from 5 to 9 bar, either as smoke tube boilers or as water tube boilers. Finned tube boilers only play a subordinate role due to the pollution problems caused by heavy oil operation. The heat transfer takes place predominantly by convection , the radiation component is low. Depending on the type of water flow, a distinction is made between natural circulation boilers and forced circulation boilers ; depending on the flue gas flow, a distinction is made between a smoke tube boiler or a water tube boiler .
In ships with high engine outputs, exhaust gas is used to a greater extent in order to generate electricity with the use of a steam turbo generator . The exhaust gas boiler then often has an additional heating surface for steam overheating, the superheater . A preheater heating surface is also often installed to preheat the feed water.
literature
- J. Jung: Use of heat and exhaust gases and cooling water in diesel systems. In: Yearbook of the Shipbuilding Society . Volume 53, 1959, pp. 284-296.
- F. Deichmann, K.-H. High-rise building: Experience with the electrical energy supply on diesel-powered merchant ships with turbo-generator and auxiliary diesel. In: Hansa . No. 19/20, 1989.