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Wyświetlanie 1-14 z 14
Tytuł:
Thermodynamic analysis of a combined cycle power plant located in Jordan: A case study
Autorzy:
Bataineh, Khaled
Khaleel, Bara A.
Powiązania:
https://bibliotekanauki.pl/articles/240565.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
combined cycle power plant
energy efficiency
exergy efficiency
exergy destruction
exergy losses
Opis:
Efficiency and electrical power output of combined cycle power plants vary according to the ambient conditions. The amount of these variations greatly affects electricity production, fuel consumption, and plant incomes. Obviously, many world countries have a wide range of climatic conditions, which impact the performance of power plants. In this paper, a thermodynamic analysis of an operating power plant located in Jordan is performed with actual operating data acquired from the power plant control unit. The analysis is performed by using first and second laws of thermodynamics. Energy and exergy efficiencies of each component of the power plant system are calculated and the effect of ambient temperature on the components performance is studied. The effects of gas turbine pressure ratio, gas turbine inlet temperature, load and ambient conditions on the combined cycle efficiency, power outputs and exergy destruction are investigated. Energy and exergy efficiencies of the combined cycle power plant are found as 45.29%, and 42.73% respectively when the ambient temperature is 34°C. Furthermore, it is found that the combustion chamber has the largest exergy destruction rate among the system components. The results showed that 73% of the total exergy destruction occurs in the combustion chamber when the ambient temperature is 34°C. Moreover, the results show that the second major exergy loss is in HRSC. The results show that the energy and exergy efficiency of the combined cycle power plant decreases as the ambient temperature increases. According to the calculation results, improvement and modification suggestions are presented.
Źródło:
Archives of Thermodynamics; 2020, 41, 1; 95-123
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergetic performance analysis of solar air heater with inverted L-shape ribs as roughness element
Autorzy:
Chaudhari, Manmohan
Sharma, Sohan Lal
Debbarma, Ajoy
Powiązania:
https://bibliotekanauki.pl/articles/27312231.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
solar air heater
heat transfer
exergy loss
exergy efficiency
thermal efficiency
Opis:
Improvement in the exegetic efficiency of a solar air heater (SAH) can be done by enhancing the rate of heat transfer. In this work, the exergetic efficiency optimization of an artificially roughened solar air heater having an inverted L-shape rib has been performed. The numerical analysis of the exergetic performance of the solar air heater was carried out at a constant heat flux of 1000 W/m2 . The study was conducted to investigate the effect of different relative roughness pitch (7.14–17.86) on the exergy losses, under the Reynolds number range of 3000 to 18 000. The roughness parameter of this geometry has been optimized and found to be among functional operating parameters like average solar intensity and temperature rise across the collector. The optimized value of relative roughness pitch is 17.86 at the isolation of 1000 W/m2 , and the parameter of temperature rise ranges from 0.005 to 0.04.
Źródło:
Archives of Thermodynamics; 2023, 44, 3; 241--267
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance analysis of multipurpose refrigeration system (MRS) on fishing vessel
Autorzy:
Ust, Y.
Karakurt, A.
Gunes, U.
Powiązania:
https://bibliotekanauki.pl/articles/258796.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
refrigeration cycles
exergy analysis
exergetic performance coefficient
COP
exergy efficiency
Opis:
The use of efficient refrigerator/freezers helps considerably to reduce the amount of the emitted greenhouse gas. A two-circuit refrigerator-freezer cycle (RF) reveals a higher energy saving potential than a conventional cycle with a single loop of serial evaporators, owing to pressure drop in each evaporator during refrigeration operation and low compression ratio. Therefore, several industrial applications and fish storage systems have been utilized by using multipurpose refrigeration cycle. That is why a theoretical performance analysis based on the exergetic performance coefficient, coefficient of performance (COP), exergy efficiency and exergy destruction ratio criteria, has been carried out for a multipurpose refrigeration system by using different refrigerants in serial and parallel operation conditions. The exergetic performance coefficient criterion is defined as the ratio of exergy output to the total exergy destruction rate (or loss rate of availability). According to the results of the study, the refrigerant R32 shows the best performance in terms of exergetic performance coefficient, COP, exergy efficiency, and exergy destruction ratio from among the other refrigerants (R1234yf, R1234ze, R404A, R407C, R410A, R143A and R502). The effects of the condenser, freezerevaporator and refrigerator-evaporator temperatures on the exergetic performance coefficient, COP, exergy efficiency and exergy destruction ratios have been fully analyzed for the refrigerant R32.
Źródło:
Polish Maritime Research; 2016, 2; 48-56
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic assessment of crude distillation units: case studies of Nigeria refineries
Autorzy:
Osuolale, Funmilayo Nihinlola
Anozie, Ambrose Nwora
Powiązania:
https://bibliotekanauki.pl/articles/240552.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
crude distillation unit
exergy efficiency
refineries
thermodynamic analysis
Opis:
This paper presents the results of thermodynamic analysis of the crude distillation units of two refineries in Nigeria. The analysis was intended to assess the thermodynamic efficiencies of the refineries and proffer methods of improving the efficiencies. Presented results show the atmospheric distillation units of the refineries have 33.3% and 31.6% exergetic efficiencies and 86.5% and 74.6% energetic efficiencies, respectively. Modifications of the operating and feed conditions of the refineries resulted in increased exergetic efficiencies for as much as 62.3% and 38.7% for the refineries. Thermodynamic analysis of the refineries can bring about efficiency improvement and effectiveness of the refineries.
Źródło:
Archives of Thermodynamics; 2019, 40, 4; 83-102
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conceptual Design and Performance Analysis of an Exhaust Gas Waste Heat Recovery System for a 10000TEU Container Ship
Autorzy:
Ma, Zheshu
Yang, Dong
Guo, Qiang
Powiązania:
https://bibliotekanauki.pl/articles/259008.pdf
Data publikacji:
2012
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
exergy efficiency
marine diesel engine
thermal efficiency
waste heat recovery system
Opis:
According to operation characteristics of the main engine 9K98ME-C7, a combined turbines-exhaust gas waste heat recovery system is proposed to recover waste heat and increase system energy efficiency. Thermodynamic models based on the first thermodynamic law and the second thermodynamic law are formulated. The superheated steam yield, the total electric power yield, the first thermodynamic law efficiency, the exergy efficiency at different exhaust gas boiler working pressure, and the variation of the exergy efficiency under different feed water temperature and different steam turbine back pressure are analyzed. Thermodynamic results indicate that the most appropriate exhaust gas boiler pressure is 0.8MPa for studied main engine and the total thermal efficiency with combined turbines arrangement has climbed up to 53.8% from 48.5%.
Źródło:
Polish Maritime Research; 2012, 2; 31-38
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technology for development of methane-hydrate deposits jointly with receiving fresh water
Autorzy:
Denysov, Y.
Klymenko, V.
Martynenko, V.
Rybicki, Cz.
Powiązania:
https://bibliotekanauki.pl/articles/298671.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
gas hydrates
gas hydrate deposit
methane
carbon dioxide
fresh water
exergy efficiency
economic efficiency
Opis:
The technology of development of bottom gas-hydrate deposits, which allows to receive fresh water simultaneously with methane, is presented. Principal schemes are presented and methods of operation of dualpurpose plants implementing this technology and described on the basis of the methods of gas production from methane hydrates that are most prepared for practical implementation: 1) injection of warm water into the well; 2) depressive effect on the deposit; 3) replacement of methane in hydrates with carbon dioxide injected into the reservoir. The magnitude of the decrease in temperature with the depression effect on the deposit is determined. It is shown that, the amount of fresh water obtained in dual-purpose plants operating with the replacement of methane in hydrates with carbon dioxide is proportional to the coefficient of the recycling rate of CO2. For the considered schemes of dual-purpose plants, processes of decomposition of methane hydrates in the gas-hydrate formation are analyzed, an exergic efficiency estimation is performed. Such installations. The economic efficiency of a single-purpose and dual-purpose gas-producing units operating according to an approved method of depression is considered. It is shown that the most effective are dual-purpose facilities operating using the method of methane replacement in hydrates with carbon dioxide, and the coefficients of economic efficiency of dual-purpose installations are at least 1.2 times higher than similar coefficients of single-purpose gas production facilities.
Źródło:
AGH Drilling, Oil, Gas; 2017, 34, 2; 531-542
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy efficiency – selected thermo-ecological problems
Autorzy:
Ziębik, Andrzej
Stanek, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/239928.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
energy efficiency
system analysis
exergy
thermo-ecology
energy ecological
efficiency
Opis:
The paper is devoted to some problems connected with last modification of EU directive on energy efficiency, viz.: free choice of the measure concerning the improvement of energy efficiency, i.e. final or primary energy consumption, corresponding energy savings or energy-consumption index; however without cumulative consumption or cumulative savings of primary energy. In EU directive it has been stressed the importance of measurements systems (reliable measurement information); but has not been recommended any advanced validation of measurements results, nor energy auditing or algorithms of calculating the energy savings due to improvement of energy efficiency concerning large industrial plants. Evaluation of complex buildings should be realized by means of the system method (input-output analysis). The separate problem is devoted to application of thermo-ecological approach in the analysis of complete results of improving the energy efficiency. Human activity is connected with the depletion of nonrenewable resources, including primary energy, due to not only production of consumer goods but also the necessity of compensating the unfavourable effects of harmful emissions from energy-technological processes. Therefore the index of energy-ecological efficiency has been proposed as the most competent evaluation of improvement energy efficiency of production processes and systems.
Źródło:
Archives of Thermodynamics; 2020, 41, 2; 277-299
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergetic analysis of the chitosan-based treatment process for removing polycyclic aromatic hydrocarbons from seawater and sediments
Autorzy:
Cantillo-Figueroa, Maileth
Moreno-Sader, Kariana A.
Gonzalez-Delgado, Angel D.
Powiązania:
https://bibliotekanauki.pl/articles/1844377.pdf
Data publikacji:
2021
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
efficiency
exergy
polycyclic aromatic hydrocarbons
PAHs
sensitivity analysis
Opis:
The Bay of Cartagena (Colombia) is a site of commercial interest owing to its privileged location for maritime operations; however, the discharge of wastewaters from industrial activities and domestic sewage are affecting the water quality, and consequently, the biodiversity of coastal ecosystems. The polycyclic aromatic hydrocarbons (PAHs) are found in sediments and water of main ports, causing severe damage to the ecosystem. Thus, alternatives for the treatment of the Bay of Cartagena’s water and sediments are needed. In this paper, we performed the exergetic analysis of removing PAHs from water and sediments in the Bay of Cartagena using an adsorption-based treatment process with chitosan microbeads and magnetic nanoparticles (CM-TiO2/Fe3O4). The outcomes of exergy of utilities, irreversibilities and exergy losses were calculated using process data and exergy of substances. The Aspen plus V10 software provided the physical exergies, while chemical exergies were gathered from the literature. Overall exergy efficiency of 0.3% was determined for the seawater and sediment treatment facility. A sensitivity analysis was performed to identify the impact and viability of different design alternatives.
Źródło:
Journal of Water and Land Development; 2021, 48; 88-93
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Innovation model for energy effective investigations of air conditioning systems for cleanrooms
Autorzy:
Labay, V.
Harasym, D.
Powiązania:
https://bibliotekanauki.pl/articles/410772.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
exergy balance
air conditioning systems
cleanrooms
energy efficiency
Opis:
Innovation mathematical research model of the central straight flow air conditioning system for cleanroom in order to computer’s estimation its energy effective by virtue of exergetic output-input ratio depending on different factors, which have influence on its work, was presented in this article. The dependence of exergetic output-input ratio for chosen air conditioning system on parameters of external air was defined thanks to this model.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2014, 3, 2; 47-52
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergetic Analysis For A Complete Node Of Fluidised-Bed Drying Of Poppy Seeds
Autorzy:
Skoneczna-Łuczków, J.
Ciesielczyk, W.
Powiązania:
https://bibliotekanauki.pl/articles/185488.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fluidised drying
efficiency
exergy
poppy seed
suszenia fluidalnego
wydajność
egzergia
Opis:
The article presents an experimental-theoretical analysis of fluidised-bed drying of poppy seeds directed on minimisation of energy. The analysis was performed for a complete drying node incorporating a heat exchanger and a fan. Two complementary factors were used in the exergetic evaluation: exergy efficiency and unit consumption of exergy. An analysis of drying in stationary bed was carried out for comparison purposes. Results of the exergetic analysis can become a basis for innovative works focused on decreasing energy consumption of a technological node being analysed, e.g. by the use of recirculation of fluidising-drying medium.
Źródło:
Chemical and Process Engineering; 2015, 36, 4; 437-447
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of LNG processes to determine the effect of end flash systems on efficiency
Autorzy:
Akinsipe, Oluwagbemisola
Anozie, Ambrose
Babatunde, Damilola
Powiązania:
https://bibliotekanauki.pl/articles/240578.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
C3MR
DMR
Efficiency
Exergy destruction
End flash
LNG
Opis:
This paper describes the simulation, exergy analysis and comparison of two commonly applied liquefaction of technologies natural gas, namely: propane precooled mixed refrigerant process (C3MR) and dual mixed refrigerant process (DMR) alongside two modifications of each employing end flash systems. The C3MR and DMR process schemes were simulated using the commercial software to mathematically model chemical processes. These schemes were then analysed using energy and exergy calculations to determine their performances. The exergy efficiency for the C3MR processes without end flash system, with simple end flash system and extended end flash system were evaluated as 29%, 31%, and 33%, respectively, while the exergy efficiency for the DMR processes without end flash system, with simple end flash system, and extended end flash system were evaluated as 26%, 25.5%, and 30%, respectively. The results achieved show that the extended end flash system versions of the schemes are most efficient. Furthermore, the exergy analysis depicted that the major equipment that must be enhanced in order to improve the cycle exergy efficiencies are the compressors, heat exchangers, and coolers.
Źródło:
Archives of Thermodynamics; 2020, 41, 2; 35-63
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energetic & exergetic analysis of a parabolic trough: concentrated solar power plant
Autorzy:
Nagpal, Mohit
Maithani, Rajesh
Kumar, Suresh
Powiązania:
https://bibliotekanauki.pl/articles/2142893.pdf
Data publikacji:
2021
Wydawca:
Centrum Badań i Innowacji Pro-Akademia
Tematy:
solar energy
exergy
thermal efficiency
heat gain
heat losses
parabolic trough
collectors
energia słoneczna
egzergia
wydajność termiczna
zyski ciepła
straty ciepła
kolektory
Opis:
Solar energy is the most affordable source of energy. Parabolic trough systems are used to concentrate and extract heat, therefore it’s very significant to analyse its performance in terms of energy and exergy. Exergy based analysis of the system ensures the eradication of losses, resulting in the yield of energy of the highest quality. In this paper, an investigation has been carried out using numerical simulation with an objective of analysis of Parabolic Trough Collectors on the basis of energy and exergy. Detailed second law analysis has been performed by varying the system and operating parameters through computer simulation. Exergy output has been determined by analysing the effect of major system parameters, namely, mirror reflectivity, glass transmissivity, absorptivity, the diameter of glass envelop, and the receiver. The operating parameters considered in the investigation are insolation and temperature rise parameters. The extensive investigation of the parabolic trough of a concentrated solar power plant for various design parameters in the range of operating parameters reveals that it is beneficial to operate the system at higher temperature as opposed to the preference of the operating system at lower temperature from purely thermal considerations.
Źródło:
Acta Innovations; 2021, 40; 19-30
2300-5599
Pojawia się w:
Acta Innovations
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Air bottoming combined cycle performance analyses by the combined effect of variable parameters
Autorzy:
Khan, Mohammad N
Alzafiri, Dhare
Powiązania:
https://bibliotekanauki.pl/articles/27309845.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
topping cycle
air bottoming cycle
net power output
thermal efficiency
total exergy
destruction
exergetic efficiency
cykl uzupełniania
cykl opadania powietrza
moc wyjściowa netto
wydajność termiczna
całkowita egzergia
zniszczenie
efektywność egzergetyczna
Opis:
To meet the continuous demand for energy of industrial as well as commercial sectors, researchers focus on increasing the power generating capacity of gas turbine power plants. In this regard, the combined cycle is a better solution in terms of environmental aspects and power generation as compared to a simple gas turbine power plant. The present study is the thermodynamic investigation of five possible air bottoming combined cycles in which the topping cycle is a simple gas turbine cycle, regenerative gas turbine cycle, inter-cool gas turbine cycle, reheat gas turbine cycle, and intercool-reheat gas turbine cycle. The effect of pressure ratio of the topping cycle, the turbine inlet temperature of topping cycle, and ambient temperature on net power output, thermal efficiency, total exergy destruction, and exergetic efficiency of the combined cycle have been analyzed. The ratio of the net power output of the combined cycle to that of the topping cycle is maximal in the case when the topping cycle is a simple gas turbine cycle. The ratio of net power output and the total exergy destruction of the combined cycle to those of the topping cycle decrease with pressure ratio for all the combinations under study except for the case when the topping cycle is the regenerative gas turbine cycle.
Źródło:
Archive of Mechanical Engineering; 2022, LXIX, 3; 497--517
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid cascade refrigeration systems for refrigeration and heating
Autorzy:
Megdouli, K.
Ezzaalouni, Y.
Nahdi, E.
Mhimid, A.
Kairouani, L.
Powiązania:
https://bibliotekanauki.pl/articles/240448.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ejector cycle
heat pump
comparison
refrigerant
coefficient of performance
irreversibility
exergy loss
second law efficiency
pompa ciepła
porównanie
czynnik chłodniczy
współczynnik
efektywność
nieodwracalność
Opis:
In this study a cooling ejector cycle coupled to a compression heat pump is analyzed for simultaneous cooling and heating applications. In this work, the influence of the thermodynamic parameters and fluid nature on the performances of the hybrid system is studied. The results obtained show that this system presents interesting performances. The comparison of the system performances with hydrofluorocarbons (HFC) and natural fluids is made. The theoretical results show that the a low temperature refrigerant R32 gives the best performance.
Źródło:
Archives of Thermodynamics; 2018, 39, 2; 73-95
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-14 z 14

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