Naslov
Energy and exergy analysis of the turbo-generators and steam turbine for the main feed water pump drive on LNG carrier

Autori
Mrzljak, Vedran ; Poljak, Igor ; Mrakovčić, Tomislav

Izvornik
Energy conversion and management (0196-8904) 140 (2017); 307-323

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Turbo-generator ; Main feed water pump ; Energy efficiency ; Exergy efficiency ; Exergy destruction

Sažetak
Nowadays, marine propulsion systems are mainly based on internal combustion diesel engines. Despite this fact, a number of LNG carriers have steam propulsion plants. In such plants, steam turbines are used not only for ship propulsion, but also for electrical power generation and main feed water pump drive. Marine turbo-generators and steam turbine for the main feed water pump drive were investigated on the analyzed LNG carrier with steam propulsion plant. The measurements of various operating parameters were performed and obtained data were used for energy and exergy analysis. All the measurements and calculations were performed during the ship acceleration. The analysis shows that the energy and exergy efficiencies of both analyzed low-power turbines vary between 46% and 62% what is significantly lower in comparison with the high-power steam turbines. The ambient temperature has a low impact on exergy efficiency of analyzed turbines (change in ambient temperature for 10 °C causes less than 1% change in exergy efficiency). The highest exergy efficiencies were achieved at the lowest observed ambient temperature. Also, the highest efficiencies were achieved at 71.5% of maximum developed turbo-generator power while the highest efficiencies of steam turbine for the main feed water pump drive were achieved at maximum turbine developed power. Replacing the existing steam turbine for the main feed water pump drive with an electric motor would increase the turbo-generator energy and exergy efficiencies for at least 1–3% in all analyzed operating points.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

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