Ship Power Plants 

DOI: https://dx.doi.org/10.24866/2227-6858/2019-2-8

Stenin V., Ershova I.

VALERY STENIN, Doctor of Engineering Sciences, Professor, e-mail: stenin61@yandex.ru
Department of Ocean Technics and Power Plants
IRINA ERSHOVA, Senior Teacher, Postgraduate Student, e-mail: Irina-124@yandex.ru
Department of Mathematics and Information Technology
Institute of Shipbuilding and Arctic Marine Engineering
Northern (Arctic) Federal University named after M.V. Lomonosov
17 Naberezhnaya Severnoi Dviny St., Arkhangelsk, 163002, Russia

Influence of marine boiler vibroactivity on the boiler brickworks

Abstract: Many years of ship boiler operation have indicated that furnace brickwork failure is one of the most common reasons of boiler breakdown that often leads to boilers being out of service. Watertube boilers used at large and medium deadweight vessels have proved to be cost-efficient, effective and reliable equipment. However, watertube boilers have been upgraded to operate as multi-fuel power plants and this caused the issues related with damages to boiler brickworks.

When selecting a material for boiler brickwork and defining brick laying procedure, the properties of refractory bricks, such as heat resistance, thermal stability and mechanical strength, are to be taken into consideration. Therefore, analysis of some other probable technical reasons of rapid damages to boiler brickworks is of certain interest.

Surely, probable thermal and dynamic impact on brickwork is included in the upgrading project as well. However, at the design stage the issues related to the impact of marine boiler vibration on the state of its brickwork are virtually ignored.

To improve the reliability of boiler plants the authors have made vibration analysis based on the boiler design and shown that boiler vibration uptake depends on the vibration level of external sources that may include operating vessel machinery (structural noise), vibrating fuel combustion and acoustic pressure of air noise. The article states that one of the most probable reasons of brickwork breakdown is combined action resonance of vibrating combustion and acoustic pressure of air noise at forced mode operation, when compressor rotor rpm and acoustic pressure are going up and source oscillation frequency coincides with heat supply own frequency of diesel fuel combustion and a private frequency masonry element (fireclay bricks). Scientific novelty of the research is that the authors analyzed and identified vibration sources of the ship's boiler, defined frequency ranges and levels of vibration impacts of sources, as well as experimentally evaluated the natural frequency elements of a boiler brickwork.

Keywords: ship boiler, brickwork, vibrating effects, structural noise, vibrating combustion, acoustic pressure, breakdown, forced mode operation.

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