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

Pomorstvo ◽  
2018 ◽  
Vol 32 (2) ◽  
pp. 268-280
Author(s):  
Igor Poljak ◽  
Josip Orović ◽  
Vedran Mrzljak
Keyword(s):  
Exergy Analysis ◽  
Pump Energy ◽  
Propulsion System ◽  
Normal Operation ◽  
Energy Losses ◽  
Load Range ◽  
Condensate Pump ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Exergy Losses

An energy and exergy analysis of the condensate pump from the marine steam propulsion system during the condensate leakage between pump stages is presented in this paper. Measurements from the steam propulsion system during exploitation were necessary for collecting all the data for the condensate pump analysis. Due to condensate leakage inside the pump casing, the producer specified condensate pressures at the pump outlet could not be obtained during the exploitation. Low condensate pressure at the pump inlet and condensate temperature slightly above the atmospheric significantly influences the pump exergy analysis. Increase in pump load resulted in an increase of pump energy and exergy losses and efficiencies. In the observed load range during the leakage, pump energy losses are between 19.88 kW and 24.78 kW, while pump energy efficiencies are between 11.12 % and 41.54 %. Pump exergy losses are slightly higher, while exergy efficiencies are slightly lower when compared to energy losses and efficiencies. During normal operation, without leakage, the pump energy efficiencies are from 5 % to 20 % higher in comparison with pump operation when the leakage occurs.

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

Pomorstvo ◽  
2018 ◽  
Vol 31 (1) ◽  
pp. 268-280
Author(s):  
Igor Poljak ◽  
Josip Orović ◽  
Vedran Mrzljak
Keyword(s):  
Exergy Analysis ◽  
Pump Energy ◽  
Propulsion System ◽  
Normal Operation ◽  
Energy Losses ◽  
Load Range ◽  
Condensate Pump ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Exergy Losses

An energy and exergy analysis of the condensate pump from the marine steam propulsion system during the condensate leakage between pump stages is presented in this paper. Measurements from the steam propulsion system during exploitation were necessary for collecting all the data for the condensate pump analysis. Due to condensate leakage inside the pump casing, the producer specified condensate pressures at the pump outlet could not be obtained during the exploitation. Low condensate pressure at the pump inlet and condensate temperature slightly above the atmospheric significantly influences the pump exergy analysis. Increase in pump load resulted in an increase of pump energy and exergy losses and efficiencies. In the observed load range during the leakage, pump energy losses are between 19.88 kW and 24.78 kW, while pump energy efficiencies are between 11.12 % and 41.54 %. Pump exergy losses are slightly higher, while exergy efficiencies are slightly lower when compared to energy losses and efficiencies. During normal operation, without leakage, the pump energy efficiencies are from 5 % to 20 % higher in comparison with pump operation when the leakage occurs.

Thermal Analysis of a Solar Powered ORC in Libya

2015 ◽  
Vol 789-790 ◽  
pp. 391-397
Author(s):  
Ratha Z. Mathkor ◽  
Brian Agnew ◽  
Mohammed A. Al-Weshahi ◽  
Saleh Etaig
Keyword(s):  
Exergy Analysis ◽  
Heat Engine ◽  
Organic Rankine Cycle ◽  
Weather Conditions ◽  
Rankine Cycle ◽  
Parabolic Trough ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Solar Powered ◽  
Exergy Losses

The paper presents a study of a thermal assessment of an Organic Rankine Cycle (ORC) energized by heat absorbed from a parabolic trough collector (PTC) located in Derna, Libya. Both the ORC and PTC are modeled using the IPSEpro software. The simulation results are used to evaluate the system performance using energy and exergy analysis. The study showed the PTC collector was the main contributor of the energy and exergy losses within the PTC system and the evaporator within in the ORC. At this specific weather conditions, the ORC was able to produce about 3 MW electrical powers from the powered PTC heat. Moreover, exergy efficiency of the PTC was 47.7 %, the heat engine was 23.3 % and for the overall system (PTC and ORC) was 11.1 %.

Exergy Analysis of a Compressed Natural Gas Turbocharged Spark Ignited Engine

2010 ◽  
Author(s):  
S. M. Mirsalim ◽  
A. Hajialimohammadi ◽  
M. Ehteram ◽  
V. Fakhari
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Exergy Analysis ◽  
Gasoline Engine ◽  
Compressed Natural Gas ◽  
Engine Efficiency ◽  
Fuel Flow ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Exergy Losses

Turbo charging the CNG fueled engine is a new concept for development of the natural gas vehicles. Investigating the performance of this type of engine based on the thermodynamic laws is a useful way that can help to improve the methods of exploiting the useful work from energy and exergy losses. In this study, energy and exergy analysis are applied to the experimental data of a turbo charged CNG fueled engine. The engine was EF7 TC, which is four stroke bi-fuel CNG-gasoline engine. The data are collected using an engine test unit which enables accurate measurements of fuel flow rate, combustion air flow rate, engine speed and all the relevant temperatures. Energy and exergy efficiencies are calculated for different engine speeds and compared. Results indicate that exergy efficiency is maximum at a speed of 2500 rpm and the speed in which the maximum exergy and energy occur are not the same. It is concluded that using the unused output energy of the engine can increase useful work and therefore improve engine efficiency.

Energy and Exergy Analysis of a Biomass Power Plant

2016 ◽  
Author(s):  
João Silva ◽  
Senhorinha F. Teixeira ◽  
Simone Preziati ◽  
José Carlos Teixeira
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Exergy Analysis ◽  
Thermal Power ◽  
Normal Operation ◽  
Strong Incentive ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Dry Climates ◽  
Biomass Power Plant

The fulfilment of energy targets regarding the use of renewable energy has been a strong incentive to the development of dedicated power plants using biomass. Because these facilities operate with low value residues, this orientation has also received a strong incentive by the quest to reduce the amount of fuel in the woods and lowering the risk of fire. This issue is a major problem in dry climates. Although the number of plants planned for Portugal was very large, the actual number of units in operation is small. The first plant to enter production in Portugal was the thermal power plant of Mortágua. In this paper the energy and exergy analysis in this plant is presented. The objective of this work is to develop an analysis for the energy conversion in the plant. This is based on parameters that were retrieved during its normal operation and include: biomass and air flow rate, temperature measurements of the flue gases throughout the facility including the economizer, the two superheaters and flue gas composition. The elemental analysis of the biomass resulting from a blend of various sources was measured in addition to its moisture (ranging between 20 and 45% depending on the sources). The analysis was carried out for a fuel batch with a moisture of 35%. The plant was operated at three loads (full load, 80% and 65% load) and from the energy/mass balances the overall efficiency was calculated to be approximately 26%. The data were also used to perform a second law analysis of the plant which enables the calculation of the exergy destruction in the various components of the facility, including the external irreversibility. It was observed that the combustion chamber is the prime contributor to the overall loss of efficiency. The exergy efficiency was found approximately 22%.

Sign in / Sign up

Export Citation Format

Share Document