Energy and Exergy Analysis of the Condensate Pump During Internal Leakage from the Marine Steam Propulsion System

Poljak, Igor; Orović, Josip; Mrzljak, Vedran

doi:10.31217/p.31.2.12

Cited by 7 publications

(5 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As for the majority of steam power plant components [37], for the entire main marine propulsion turbine energy losses also show a trend of continuous increase during the increase in turbine load, Fig. 7.…”

Section: The Results Of Energy Analysis Of Marine Main Propulsion Stementioning

confidence: 97%

See 1 more Smart Citation

Energy Analysis of Main Propulsion Steam Turbine from Conventional LNG Carrier at Three Different Loads

Mrzljak

Poljak

2019

Naše more

Self Cite

View full text Add to dashboard Cite

This paper presents energy analysis of entire marine main propulsion steam turbine and both of its cylinders at three different loads. Marine steam propulsion plant in which main turbine operates is described in detail. Measured data from real exploitation at each required turbine operating point enables calculation of energy losses and efficiencies. Real developed power distribution between both turbine cylinders is not the same at all observed loads. Energy losses and efficiencies of main turbine cylinders and entire main steam turbine increases during the increase in turbine load. An increase in turbine load resulted with in a sharp increase in energy efficiency of HPC (High Pressure Cylinder) from 51.01 % to 74.13 %, while the increase in energy efficiency of LPC (Low Pressure Cylinder) is not as sharp (from 73.88 % to 78.50 %). The change in energy efficiency of the entire main steam turbine during the load increase (from 65.54 % to 79.45 %) is mostly influenced by a change in energy efficiency of HPC. Energy loss and real developed power ratio is reversely proportional to energy efficiencies and losses of both steam turbine cylinders and the entire turbine. Sažetak Ovaj članak prikazuje energijsku analizu čitave glavne propulzijske parne turbine i oba njezina kućišta pri trima različitim opterećenjima. Opisuje se podrobno, brodsko parno propulzijsko postrojenje u kojemu radi glavna turbina. Izmjereni podatci stvarne eksploatacije za svaku zahtijevanu radnu točka turbine omogućavaju izračun energijskih gubitaka i učinkovitosti. Stvaran raspored distribucije snage između oba kućišta turbine nije isti na svim promatranim opterećenjima. Energijski gubici i učinkovitosti turbinskih kućišta i cijele glavne turbine, povećavaju se za vrijeme porasta opterećenja turbine. Povećanje opterećenja turbine rezultira naglim rastom energijske učinkovitosti HPC (High Pressure Cylinder = kućište visokoga tlaka) od 51.01 % do 74.13 % dok povećanje energijske učinkovitosti LPC (Low Pressure Cylinder = kućište niskoga tlaka) nije tako naglo (od 73.88 % do 78.50 %). Promjena energijske učinkovitosti cijele glavne parne turbine, za vrijeme povećanja opterećenja (od 65.54 % do 79.45 %), najviše je pod utjecajem promjene energijske učinkovitosti HPC. Gubitak energije i stvarni omjer razvijene snage obrnuto je proporcionalan energijskim učinkovitostima i gubicima za oba kućišta i cijelu parnu turbinu. KEY WORDS main marine steam turbine marine propulsion plant energy analysis change in load conditions KLJUČNE RIJEČI glavna brodska parna turbina brodsko propulzijsko postrojenje energijska analiza promjena opterećenja

show abstract

Section: The Results Of Energy Analysis Of Marine Main Propulsion Stementioning

confidence: 97%

“…(3) A type and characteristics of any control volume define its energy efficiency. Therefore, energy efficiency in general can take different forms [37], [38]. In the most of the cases, energy efficiency can be defined as:…”

Section: Energy Analysis General Equations For Any Control Volume / Omentioning

confidence: 99%

Energy Analysis of Main Propulsion Steam Turbine from Conventional LNG Carrier at Three Different Loads

Mrzljak

Poljak

2019

Naše more

Self Cite

View full text Add to dashboard Cite

show abstract

“…Two-stage compressor is evaluated for energy efficiency according to recommendations in the following literature [ 44 , 45 , 46 , 47 , 48 ]. Energy efficiency formulation with referring to Figure 1 is given below.…”

Section: Thermodynamic Efficiency Analysismentioning

confidence: 99%

Energy and Exergy Evaluation of a Two-Stage Axial Vapour Compressor on the LNG Carrier

Poljak

Orović

Mrzljak

et al. 2020

Entropy

Self Cite

View full text Add to dashboard Cite

Data from a two-stage axial vapor cryogenic compressor on the dual-fuel diesel–electric (DFDE) liquefied natural gas (LNG) carrier were measured and analyzed to investigate compressor energy and exergy efficiency in real exploitation conditions. The running parameters of the two-stage compressor were collected while changing the main propeller shafts rpm. As the compressor supply of vaporized gas to the main engines increases, so does the load and rpm in propulsion electric motors, and vice versa. The results show that when the main engine load varied from 46 to 56 rpm at main propulsion shafts increased mass flow rate of vaporized LNG at a two-stage compressor has an influence on compressor performance. Compressor average energy efficiency is around 50%, while the exergy efficiency of the compressor is significantly lower in all measured ranges and on average is around 34%. The change in the ambient temperature from 0 to 50 °C also influences the compressor’s exergy efficiency. Higher exergy efficiency is achieved at lower ambient temperatures. As temperature increases, overall compressor exergy efficiency decreases by about 7% on average over the whole analyzed range. The proposed new concept of energy-saving and increasing the compressor efficiency based on pre-cooling of the compressor second stage is also analyzed. The temperature at the second stage was varied in the range from 0 to −50 °C, which results in power savings up to 26 kW for optimal running regimes.

show abstract

“…For a control volume (or system) in steady state operation, main exergy balance equation, according to [19] can be defined as: Rotor steps number 10…”

Section: Overall Exergy Analysis Equations Of a Control Volume Or Systemmentioning

confidence: 99%

Exergy analysis of marine steam turbine labyrinth (gland) seals

et al. 2019

Self Cite

View full text Add to dashboard Cite

The paper presents an exergy analysis of marine steam turbine labyrinth (gland) seals - an inevitable component of any marine steam turbine cylinder, in three different operating regimes. Throughout labyrinth seals, steam specific enthalpy can be considered as a constant because the results obtained by this assumption do not deviate significantly from the results of complex numerical models. Changes in labyrinth seals exergy efficiency and specific exergy destruction are reverse proportional. The analyzed labyrinth seals have high exergy efficiencies in each observed operating regime at the ambient temperature of 298 K (above 92%), what indicates seals proper operation. An increase in the ambient temperature resulted with a decrease in labyrinth seals exergy efficiency, but even at the highest observed ambient temperature of 318 K, seals exergy efficiency did not fall below 90.5% in each observed operating regime.

show abstract

Energy and Exergy Analysis of the Condensate Pump During Internal Leakage from the Marine Steam Propulsion System

Cited by 7 publications

References 34 publications

Energy Analysis of Main Propulsion Steam Turbine from Conventional LNG Carrier at Three Different Loads

Energy Analysis of Main Propulsion Steam Turbine from Conventional LNG Carrier at Three Different Loads

Energy and Exergy Evaluation of a Two-Stage Axial Vapour Compressor on the LNG Carrier

Exergy analysis of marine steam turbine labyrinth (gland) seals

Contact Info

Product

Resources

About