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Preliminary analysis of the use of solid biofuels in a ship’s power system

Zeńczak Wojciech, Krystosik-Gromadzińska Agata

Polish Maritime Research

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2020

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nr 4

. 67--79

EN

This paper presents the results of applying ennobled solid biomass via mechanical compaction or torrefaction as fuel for ships, in terms of fire safety, environmental protection, the increase in liquid fuel prices and the dwindling resources of crude oil. The object of investigation is a ship of the ro-pax ferry type, with low cruising range, which is intended for service on the Baltic Sea. The ship’s power system is discussed and the results of calculations of the thermal cycle for a steam turbine power plant are presented. We present a simplified comparative analysis of a fuel bunker for a ship with a power plant including biomass fired boilers, and for a ship with a conventional solution of a motor power plant supplied by ultra-low sulphur fuel originating from crude oil. The advantages of applying a fluidised bed biomass fired boiler are highlighted, and selected results from tests of this boiler are presented. In addition, we assess potential fire hazards on the ship resulting from the storage and transport of pellets, and from pellets after torrefaction.

2

The selected results of the experimental research of solid fuel pneumatic transportation to ship’s boiler

Luschtinetz Thomas, Zeńczak Wojciech, Łuszczyński Daniel

Management Systems in Production Engineering

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2019

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nr 3 (27)

144--148

EN

The article presents the problems related to the application of alternative fuel like solid biomass in the shipbuilding. The decreasing resources of the crude oil, the requirements regarding environmental protection as well as the increase of the liquid fuel prices were the reason for the study. The solid biomass comparing to the liquid or gaseous forms has relatively low calorific value. In order to increase this value the solid biomass is subject to the densification or torrefaction process and most often occurs in the shape of pellets. In this form it could be useful on ships. A test stand has been characterised where it can be experimentally verified whether ship’s rolling does affect the changes in flow resistance values during the pneumatic transportation of solid fuel from the storage facility to the boiler. On the basis of the measurements the hydraulic characteristics have been provided for the piping located on the movable platform with and without granular material. The changes in the platform oscillation period have influence on the change in the pressure inside transport piping for each investigated material. The results also show that the platform constantly inclinations do exert an influence on the pressure drop in the transport pipeline during transporting the granular material. It is smaller when the position is inclined. Comparing the results obtained for the different transported materials of a similar nature of the pressure fluctuations could be observed.

3

Simplified exergy analysis of ship heating systems with different heat carriers and with the recovery of waste heat

Zeńczak Wojciech

Archives of Thermodynamics

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2019

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Vol. 40, no 3

211-228

EN

The application of waste heat from exhaust gas of ship’s main engines has become widely practiced as early as in the 1930s. Thus the increase of ship’s overall efficiency was improved. Nowadays all newly built ships of the 400 gross tonnage and above must have specified energy efficiency design index, which is a measure for CO2 emissions of the ship and its impact on the environment. Therefore, the design of waste heat recovery systems requires special attention. The use of these systems is one of the basic ways to reduce CO2 emissions and to improve the ship’s energy efficiency. The paper describes the ship’s heating systems designed for the use of waste heat contained in the exhaust gas of self-ignition engines, in which the heat carriers are respectively water vapor, water or thermal oil. Selected results of comparative exergy analysis of simplified steam, water and oil heating systems have been presented. The results indicate that the oil heating system is comparable to the water system in terms of internal exergy losses. However, larger losses of exergy occur in the case of a steam system. In the steam system, a significant loss is caused by the need to cool the condensate to avoid cavitation in boiler feed pumps. This loss can in many cases cause the negative heat balance of ship during sea voyage while using only the exhaust gas boilers.