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.

Experimental Evaluation of the Thermal Behavior of a Vertical Solar Tank Using Energy and Exergy Analysis

2005 ◽  
Author(s):  
Ali A. Dehghan ◽  
Mohammad H. Hosni ◽  
S. Hoda Shiryazdi
Keyword(s):  
Temperature Distribution ◽  
Flow Rate ◽  
Storage Tank ◽  
Thermal Stratification ◽  
Exergy Analysis ◽  
Hot Water ◽  
Second Law ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Hot Water Supply

The thermal performance of a Thermosyphon Domestic Solar Water Heater (DSWH) with a vertical storage tank is investigated experimentally. The system is installed on a roof - top of a four person family house and its thermal characteristics is evaluated by means of carefully measuring the temperature distribution of water inside the storage tank, solar collector flow rate and its inlet and outlet temperatures as well as load/consumption outlet and inlet temperatures and the corresponding water flow rate under a realistic operating conditions. The measurements are conducted every hour starting from morning until late night on a daily basis and continued for about 120 days during August until November 2004. It is seen that thermal stratification is well established inside the tank from 11 AM until 10 PM especially during August to September enabling the tank to provide the necessary amount of hot water at an acceptable temperature. However, thermal stratification is observed to start degrading from mid-night until morning when there is no hot water supply from the collector and due to the diffusion of heat from the top hot water layers to the bottom cold region and conduction through tank’s wall. The thermal behavior of the storage tank is also assessed based on both energy and exergy analysis and its first and second law efficiencies are calculated. It is observed that the storage tank under study has an average first law efficiency of 47.8% and is able to supply the required amount of hot water at a proper temperature. The average second law efficiency of the storage tank is observed to be 28.7% and, although is less than its first low efficiency, but is high enough to ensure that the quality of the hot water supply is well preserved. The proper level of second law efficiency is due to the preservation of the thermal stratification inside the storage tank, leading to supply of hot water at highest possible temperature and hence highest possible energy potential. Experiments are also done for no-load conditions when the storage tank only interacts with the collector, without hot water withdrawal from the tank. It is seen that for no-load condition, thermal stratification continuously develops from morning until around 16 PM after which no noticeable changes in the temperature distribution inside the tank is observed.

scholarly journals Energy and Exergy Analysis of Different Exhaust Waste Heat Recovery Systems for Natural Gas Engine Based on ORC

2019 ◽  
Author(s):  
Guillermo Valencia ◽  
Armando Fontalvo ◽  
Yulineth Cardenas ◽  
Jorge Duarte ◽  
Cesar Isaza
Keyword(s):  
Natural Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Exergy Analysis ◽  
Waste Heat ◽  
Natural Gas Engine ◽  
Exhaust Waste Heat ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Net Power Output

One way to increase overall natural gas engine efficiency is to transform exhaust waste heat into useful energy by means of a bottoming cycle. Organic Rankine cycle (ORC) is a promising technology to convert medium and low grade waste heat into mechanical power and electricity. This paper presents an energy and exergy analysis of three ORC-Waste heat recovery configurations by using an intermediate thermal oil circuit: Simple ORC (SORC), ORC with Recuperator (RORC) and ORC with Double Pressure (DORC), and Cyclohexane, Toluene and Acetone have been proposed as working fluids. An energy and exergy thermodynamic model is proposed to evaluate each configuration performance, while available exhaust thermal energy variation under different engine loads was determined through an experimentally validated mathematical model. Additionally, the effect of evaportating pressure on net power output , absolute thermal efficiency increase, absolute specific fuel consumption decrease, overall energy conversion efficiency, and component exergy destruction is also investigated. Results evidence an improvement in operational performance for heat recovery through RORC with Toluene at an evaporation pressure of 3.4 MPa, achieving 146.25 kW of net power output, 11.58% of overall conversion efficiency, 28.4% of ORC thermal efficiency, and an specific fuel consumption reduction of 7.67% at a 1482 rpm engine speed, a 120.2 L/min natural gas Flow, 1.784 lambda, and 1758.77 kW mechanical engine power.

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.

Energy and exergy analysis on gasoline engine based on mapping characteristics experiment

2013 ◽  
Vol 102 ◽  
pp. 622-630 ◽  
Author(s):  
Jianqin Fu ◽  
Jingping Liu ◽  
Renhua Feng ◽  
Yanping Yang ◽  
Linjun Wang ◽  
...  
Keyword(s):  
Exergy Analysis ◽  
Gasoline Engine ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis

Low temperature techniques for natural gas purification and LNG production: An energy and exergy analysis

2016 ◽  
Vol 180 ◽  
pp. 546-559 ◽  
Author(s):  
Margaret Baccanelli ◽  
Stefano Langé ◽  
Matteo V. Rocco ◽  
Laura A. Pellegrini ◽  
Emanuela Colombo
Keyword(s):  
Low Temperature ◽  
Natural Gas ◽  
Exergy Analysis ◽  
Gas Purification ◽  
Natural Gas Purification ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis

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 %.

Energy and exergy analysis of reciprocating natural gas expansion engine based on valve configurations

Energy ◽  
2018 ◽  
Vol 158 ◽  
pp. 986-1000 ◽  
Author(s):  
Mohsen Jannatabadi ◽  
Mahmood Farzaneh-Gord ◽  
Hamid Reza Rahbari ◽  
Abolfazl Nersi
Keyword(s):  
Natural Gas ◽  
Exergy Analysis ◽  
Expansion Engine ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Gas Expansion

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.

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