Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Exergy analysis" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 21
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:
Exergetic sustainability indicators of a polymer electrolyte membrane fuel cell at variable operating conditions
Autorzy:
Xu, Bing
Chen, Yan
Ma, Zheshu
Powiązania:
https://bibliotekanauki.pl/articles/1845491.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PEM fuel cell
exergy balance
exergy analysis
exergetic sustainability indicators
Opis:
Based on the exergetic sustainability indicators of polymer electrolyte membrane (PEM) fuel cell, this paper studied the effects of irreversibility of thermodynamics on some exergetic sustainability indicators of PEM fuel cell under changing operating temperature, operating pressure and current density. Some conclusions are drawn by analyzing the curves. As the operating temperature increases, the negative impact of PEM fuel cell on various parameters due to irreversibility decreases; As the operating pressure increases, the negative impact of PEM fuel cell on various parameters due to irreversibility decreases; On the other hand, with the increase of current density, the negative impact of the PEM fuel cell on various parameters due to irreversibility increases.
Źródło:
Archives of Thermodynamics; 2021, 42, 1; 183-204
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An experimental study of solar air heater using arc shaped wire rib roughness based on energy and exergy analysis
Autorzy:
Ghritlahre, Harish Kumar
Powiązania:
https://bibliotekanauki.pl/articles/1955008.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
artificial roughness
energy analysis
exergy analysis
solar air heater
Opis:
In the present study, energy and exergy analysis has been evaluated for roughened solar air heater (SAH) using arc shaped wire ribs. To achieve this aim, two different types of flow arrangement have been considered. These arrangements are: apex upstream flow and apex downstream flo. In addition to this, a smooth duct SAH has been used for comparative study. The experiments were performed using the mass flow rate of 0.007– 0.022 kg/s on outdoor condition at Jamshedpur city of India. The absorber plate roughness geometry has been designed with relative roughness height 0.0395, rib size 2.5 mm, relative roughness pitch 10 and arc angle 60◦ . The energetic and exergetic performances have been examined on the basis of the first and second law of thermodynamics. According to the results, there is observed to be the maximum thermal efficiency and exergy efficiency as 73.2% and 2.64%, respectively, for apex upstream flow SAH at 0.022 kg/s, while, at same mass flow rate the maximum thermal efficiency and exergy efficiency is obtained as 69.4% and 1.89%, respectively, for apex downstream flow SAH. In addition to this, results reported that the maximum outlet temperature and temperature difference observed at lower mass flow rate. Also examined the outlet air temperature of SAH with various mass flow rates is very important for both analysis.
Źródło:
Archives of Thermodynamics; 2021, 42, 3; 115-139
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance of a combined cycle power plant due to auxiliary heating from the combustion chamber of the gas turbine topping cycle
Autorzy:
Khan, Mohammad Nadeem
Powiązania:
https://bibliotekanauki.pl/articles/1845501.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pressure ratio
air-fuel ratio
supplement heating
exergy analysis
energy analysis
Opis:
Energy demand is increasing exponentially in the last decade. To meet such demand there is an urgent need to enhance the power generation capacity of the electrical power generation system worldwide. A combined-cycle gas turbines power plant is an alternative to replace the existing steam/gas electric power plants. The present study is an attempt to investigate the effect of different parameters to optimize the performance of the combined cycle power plant. The input physical parameters such as pressure ratio, air fuel ratio and a fraction of combustible product to heat recovery heat exchanger via gas turbine were varied to determine the work output, thermal efficiency, and exergy destruction. The result of the present study shows that for maximum work output, thermal efficiency as well as total exergy destruction, extraction of combustible gases from the passage of the combustion chamber and gas turbine for heat recovery steam generator is not favorable. Work output and thermal efficiency increase with an increase in pressure ratio and decrease in air fuel ratio but for minimum total exergy destruction, the pressure ratio should be minimum and air fuel ratio should be maximum.
Źródło:
Archives of Thermodynamics; 2021, 42, 1; 147-162
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comprehensive review on energy and exergy analysis of solar air heaters
Autorzy:
Ghritlahre, Harish Kumar
Sahu, Piyush Kumar
Powiązania:
https://bibliotekanauki.pl/articles/240351.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solar energy
energy
exergy analysis
solar air heater
thermal performance
Opis:
For economic growth of nation, the energy plays an important role. The excessive use of fossil fuels results the increase in global warming and depleting the resources. Due to this reason, the renewable energy sources are creating more attraction for researchers. In renewable energy sector, solar energy is the most abundant and clean source of energy. In solar thermal systems, solar air heater (SAH) is the main system which is used for heating of air. As it is simple in construction and cheaper in cost, it is of main interest for the researchers. The concept of first law and second law of thermodynamics is used for the study of the energy and exergy analysis respectively. The energy analysis is of great importance for the study of process effectiveness while the exergetic analysis is another significant concept to examine the actual behavior of process involving various energy losses and internal irreversibility. For efficient utilization of solar energy, the exergy analysis is very important tool for optimal design of solar air heaters. The aim of the present work is to review the works related to energy and exergy analysis of various types of solar air heaters and to find out the research gap for future work.
Źródło:
Archives of Thermodynamics; 2020, 41, 3; 183-222
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy efficiency analysis of styrene production by adiabatic ethylbenzene dehydrogenation using exergy analysis and heat integration
Autorzy:
Ali, E.
Hadj-Kali, M.
Powiązania:
https://bibliotekanauki.pl/articles/949461.pdf
Data publikacji:
2018
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Styrene production
Ethylbenzene dehydrogenation
Exergy analysis
Heat Integration
Pinch Analysis
Heat Recovery
Opis:
Styrene is a valuable commodity for polymer industries. The main route for producing styrene by dehydrogenation of ethylbenzene consumes a substantial amount of energy because of the use of high-temperature steam. In this work, the process energy requirements and recovery are studied using Exergy analysis and Heat Integration (HI) based on Pinch design method. The amount of steam plays a key role in the trade-off between Styrene yield and energy savings. Therefore, optimizing the operating conditions for energy reduction is infeasible. Heat integration indicated an insignificant reduction in the net energy demand and exergy losses, but 24% and 34% saving in external heating and cooling duties, respectively. When the required steam is generated by recovering the heat of the hot reactor effluent, a considerable saving in the net energy demand, as well as the heating and cooling utilities, can be achieved. Moreover, around 68% reduction in the exergy destruction is observed.
Źródło:
Polish Journal of Chemical Technology; 2018, 20, 1; 35-46
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergy analysis of the coal gasification process in ex-situ conditions
Autorzy:
Janoszek, T.
Powiązania:
https://bibliotekanauki.pl/articles/91916.pdf
Data publikacji:
2013
Wydawca:
Główny Instytut Górnictwa
Tematy:
coal gasification
exergy analysis
fossil fuel
zgazowanie węgla
analiza egzergii
paliwo konwekcyjne
Opis:
In this article the possibilities of implementing exergy analysis of coal gasification processes in ex-situ conditions was presented. The analysis was performed in order to detect the sources of exergy loss. The experimental results of the coal gasification process are also presented and was used as input data to perform the exergy analysis of the coal gasification process.
Źródło:
Journal of Sustainable Mining; 2013, 12, 3; 32-37
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergy-based control strategy in a dwelling ventilation system with heat recovery
Oparta na egzergi strategia sterowania systemem wentylacji mieszkań z odzyskiem ciepła
Autorzy:
Voloshchuk, Volodymyr
Polishchuk, Mariya
Powiązania:
https://bibliotekanauki.pl/articles/407846.pdf
Data publikacji:
2020
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
ventilation system
exergy analysis
control
heat recovery
exergy saving
system wentylacji
analiza egzergii
kontrola
odzysk ciepła
oszczędność egzergii
Opis:
The paper presents energy and exergy analysis of a typical dwelling ventilation system with heat recovery for Ukrainian climatic conditions using a quasi-steady state approach over 24-hour time-steps. Evaluation of such systems on the base of the first law of thermodynamics demonstrates that heat recovery is beneficial for the whole variety of operational modes. Such methodology identifies as a thermodynamic inefficiency only energy losses to the surroundings with the exhaust air. The exergy-based analysis can detect additional inefficiencies due to irreversibilities within the components of the system. As a result the exergetic investigations show that for the ventilation systems there are operating conditions for which heat recovery increases exergy of fuel expended to provide the ventilation air compared to cases without bringing any recovery of heat and additional power consumption to drive the air flow by the fans. For the specified system, in case of switching ventilation unit to the operation mode of lower values of spent fuel exergy it is possible to provide annual saving of the primary energy sources from 5 to 15%.
W pracy przedstawiono analizę energetyczną i egzergetyczną typowego systemu wentylacji mieszkań z odzyskiem ciepła dla ukraińskich warunków klimatycznych z zastosowaniem podejścia quasi-stabilnego w 24-godzinnych krokach czasowych. Ocena takich systemów w oparciu o pierwsze prawo termodynamiki wykazuje, że odzysk ciepła jest korzystny dla całego szeregu trybów pracy. Taka metodologia identyfikuje jako nieefektywne termodynamicznie tylko straty energii do otoczenia wraz z powietrzem wylotowym. Analiza egzergetyczna może wykryć dodatkowe nieefektywności wynikające z nieodwracalności elementów systemu. W rezultacie badania egzergetyczne wykazują, że w systemach wentylacyjnych występują warunki pracy, dla których odzysk ciepła zwiększa egzergię paliwa zużytego do dostarczenia powietrza wentylacyjnego w porównaniu do przypadków, w których nie występuje żaden odzysk ciepła i dodatkowe zużycie energii elektrycznej do napędzania przepływu powietrza przez wentylatory. Dla określonego systemu, w przypadku przełączenia urządzenia wentylacyjnego na tryb pracy o niższych wartościach egzergii zużytego paliwa możliwe jest zapewnienie rocznych oszczędności pierwotnych źródeł energii od 5 do 15%.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2020, 10, 2; 44-47
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergy analysis of the Szewalski cycle with a waste heat recovery system
Autorzy:
Kowalczyk, T.
Ziółkowski, P.
Badur, J.
Powiązania:
https://bibliotekanauki.pl/articles/240278.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Szewalski cycle
binary vapour cycle
exergy analysis
waste heat
idea Szewalskiego
analiza egzergii
ciepło odpadowe
Opis:
The conversion of a waste heat energy to electricity is now becoming one of the key points to improve the energy efficiency in a process engineering. However, large losses of a low-temperature thermal energy are also present in power engineering. One of such sources of waste heat in power plants are exhaust gases at the outlet of boilers. Through usage of a waste heat regeneration system it is possible to attain a heat rate of approximately 200 MWth, under about 90°C, for a supercritical power block of 900 MWel fuelled by a lignite. In the article, we propose to use the waste heat to improve thermal efficiency of the Szewalski binary vapour cycle. The Szewalski binary vapour cycle provides steam as the working fluid in a high temperature part of the cycle, while another fluid – organic working fluid – as the working substance substituting conventional steam over the temperature range represented by the low pressure steam expansion. In order to define in detail the efficiency of energy conversion at various stages of the proposed cycle the exergy analysis was performed. The steam cycle for reference conditions, the Szewalski binary vapour cycle as well as the Szewalski hierarchic vapour cycle cooperating with a system of waste heat recovery have been comprised.
Źródło:
Archives of Thermodynamics; 2015, 36, 3; 25-48
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Exergy Analysis to Textile Printing Process
Analiza zużycia energii w procesie druku
Autorzy:
Cay, A.
Ozguney, A. T.
Yavas, A.
Powiązania:
https://bibliotekanauki.pl/articles/234278.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
analiza energii
drukowanie tkanin
parowanie
zużycia energii w procesie druku
exergy analysis
textile printing
steaming
hot air fixation
exergy destruction
Opis:
This study reveals an exergetic analysis of the reactive and pigment printing processes. Exergy models of the printing processes were formed and each step examined in terms of exergetic parameters. In the printing machine, the reactive printing process led to a higher specific exergy use due to the penetration requirement of the printing paste. The exergy efficiency in the subsequent drying after printing was found to be independent of the printing method, but affected by the fabric structure, which was calculated to be between 3.8% and 4.8%. In the fixation step, pigment printing provided the highest exergy efficiency, calculated to be 2.15%, due to the direct heating of the fixation air. It was observed for the fixation step that the boiler unit of the steaming process and the burner of the hot air fixation process led to the highest exergy destruction rates. The total exergy destruction rate in pigment printing was found to be higher than in the washing and final drying stages of reactive printing alone; thus, it was shown that the exergetic improvement of the post-washing and drying of reactive printing is of great importance.
Praca przedstawia analizę zużycia energii w procesie druku reaktywnego i pigmentowego. Skonstruowano modele egzergetyczne procesu druku i przeanalizowano każdy krok pod względem parametrów wpływających na egzergię. W maszynie drukarskiej, reaktywny proces drukowania prowadzi do podwyższenia egzergii w wyniku zapotrzebowania na penetrację pasty drukarskiej. Stwierdzono, że wydajność egzergii w procesie suszenia po drukowaniu jest niezależna od metody drukowania, zależy natomiast od struktury materiału i obliczono, że zawiera się ona w granicach 3.8% do 4.8%. W procesie stabilizacji drukowanie pigmentowe prowadzi do najwyższej egzergii, która wynosi 2.15%, w wyniku bezpośredniego utrwalania w powietrzu. Stwierdzono, że zastosowanie dla fazy utrwalania kotła parowego stosowanego w procesie parowania i palnika w procesie wysokotemperaturowego utrwalania prowadzi do najwyższych wartości destrukcji egzergii. Stwierdzono, że przy druku reaktywnym całkowita wartość destrukcji egzergii w procesie druku pigmentowego była wyższa niż w fazach prania i końcowego suszenia. Wynika z tego, że przy druku reaktywnym bardzo ważnym jest egzergetyczne polepszenie końcowej fazy prania i suszenia.
Źródło:
Fibres & Textiles in Eastern Europe; 2012, 6A (95); 37-42
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergy analysis of the performance of low-temperature district heating system with geothermal heat pump
Autorzy:
Sekret, R.
Nitkiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/240813.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
exergy analysis
low-temperature geothermal water
district heating system
analiza egzergii
niskotemperaturowa woda geotermalna
ciepłownictwo systemowe
Opis:
Exergy analysis of low temperature geothermal heat plant with compressor and absorption heat pump was carried out. In these two concepts heat pumps are using geothermal water at 19.5°C with spontaneous outflow 24 m3/h as a heat source. The research compares exergy efficiency and exergy destruction of considered systems and its components as well. For the purpose of analysis, the heating system was divided into five components: geothermal heat exchanger, heat pump, heat distribution, heat exchanger and electricity production and transportation. For considered systems the primary exergy consumption from renewable and non-renewable sources was estimated. The analysis was carried out for heat network temperature at 50/40°C, and the quality regulation was assumed. The results of exergy analysis of the system with electrical and absorption heat pump show that exergy destruction during the whole heating season is lower for the system with electrical heat pump. The exergy efficiencies of total system are 12.8% and 11.2% for the system with electrical heat pump and absorption heat pump, respectively.
Źródło:
Archives of Thermodynamics; 2014, 35, 1; 77-86
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergy analysis of internal regeneration in supercritical cycles of ORC power plant
Autorzy:
Borsukiewicz-Gozdur, A.
Powiązania:
https://bibliotekanauki.pl/articles/239987.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analiza egzergii
nadkrytyczny blok węglowy
ORC
regeneracja ciepła
exergy analysis
internal heat regeneration
supercritical power plant
Opis:
In the paper presented is an idea of organic Rankine cycle (ORC) operating with supercritical parameters and so called dry fluids. Discussed is one of the methods of improving the effectiveness of operation of supercritical cycle by application of internal regeneration of heat through the use of additional heat exchanger. The main objective of internal regenerator is to recover heat from the vapour leaving the turbine and its transfer to the liquid phase of working fluid after the circulation pump. In effect of application of the regenerative heat exchanger it is possible to obtain improved effectiveness of operation of the power plant, however, only in the case when the ORC plant is supplied from the so called sealed heat source. In the present paper presented is the discussion of heat sources and on the base of the case study of two heat sources, namely the rate of heat of thermal oil from the boiler and the rate of heat of hot air from the cooler of the dinkier from the cement production line having the same initial temperature of 260[degrees]C, presented is the influence of the heat source on the justification of application of internal regeneration. In the paper presented are the calculations for the supercritical ORC power plant with R365mfc as a working fluid, accomplished has been exergy changes and exergy efficiency analysis with the view to select the most appropriate parameters of operation of the power plant for given parameters of the heat source.
Źródło:
Archives of Thermodynamics; 2012, 33, 3; 51-63
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simplified exergy analysis of ship heating systems with different heat carriers and with the recovery of waste heat
Autorzy:
Zeńczak, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/240490.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ship’s power plant
heating systems
heat carrier
exergy analysis
systemy siłowni okrętowych
systemy grzewcze
nośnik ciepła
analiza egzergii
Opis:
The application of waste heat from exhaust gas of ship’s main engines has become widely practiced as early as in the 1930s. Thus the increase of ship’s overall efficiency was improved. Nowadays all newly built ships of the 400 gross tonnage and above must have specified energy efficiency design index, which is a measure for CO2 emissions of the ship and its impact on the environment. Therefore, the design of waste heat recovery systems requires special attention. The use of these systems is one of the basic ways to reduce CO2 emissions and to improve the ship’s energy efficiency. The paper describes the ship’s heating systems designed for the use of waste heat contained in the exhaust gas of self-ignition engines, in which the heat carriers are respectively water vapor, water or thermal oil. Selected results of comparative exergy analysis of simplified steam, water and oil heating systems have been presented. The results indicate that the oil heating system is comparable to the water system in terms of internal exergy losses. However, larger losses of exergy occur in the case of a steam system. In the steam system, a significant loss is caused by the need to cool the condensate to avoid cavitation in boiler feed pumps. This loss can in many cases cause the negative heat balance of ship during sea voyage while using only the exhaust gas boilers.
Źródło:
Archives of Thermodynamics; 2019, 40, 3; 211-228
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergy life cycle assessment indicators in Colombian gold mining sector
Autorzy:
Cano, Natalia A.
Hasenstab, Christian
Velásquez, Héctor I.
Powiązania:
https://bibliotekanauki.pl/articles/1839025.pdf
Data publikacji:
2020
Wydawca:
Główny Instytut Górnictwa
Tematy:
exergy analysis
life cycle assessment
mining process
gold extraction sustainability
analiza egzergii
ocena cyklu życia
proces wydobywczy
zrównoważony rozwój wydobycia złota
Opis:
Thermodynamic methods, such as exergy analysis allow the assessment of environmental load (environmental impacts), by calculating the entropy generated or exergy destroyed due to the use of renewable and non-renewable resources along the entire production chain. In this research, exergy analysis will be approached as an extension of LCA to ExLCA (Exergy Life Cycle Assessment), as complementary tools, for sustainability assessment of two gold mining systems in Colombia: open-pit and alluvial mining. It is quantified exergy life cycle efficiencies; Cumulative Energy/ Exergy Demand, by distinguishing between renewable and non-renewable resources used in the process. The energy contained in renewable and non-renewable resources, interpreted as a measure of its utility potential, and which inefficient use generates waste streams with an exergy content that may be a measure of its potential to cause environmental damage. For open-pit mining 53% of exergy consumed comes from fossil energy, and 26% of energetic use of water, while in alluvial mining, 94% of exergy flow comes from water as a resource used within process activities. In order to reduce the environmental impact associated with gold generation life cycle described in this study, four strategies should be implemented; 1) Increasing efficiency, by reducing the exergy required in tails and extraction stages in open-pit mining process and, casting and molding stage in alluvial mining process, where large exergy supplies are required. 2) Increasing efficiency through the reduction of exergy emissions and residues in casting and molding stage in alluvial mining, and stripping stage in open-pit mining. 3) Using external exergy resources, such as renewable resources from nature (solar, wind, hydraulic). 4) Applying the concept of circular economy, which implies the reduction in consumption of resources.
Źródło:
Journal of Sustainable Mining; 2020, 19, 3; 151-165
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergetic Analysis of Hybrid Photovoltaic - Thermal Solar Collectors Coupled to Organic Rankine Cycles
Analiza ekologiczna hybrydowego układu fotowoltaika - kolektory słoneczne związanych organicznym cyklem Rankine’a
Autorzy:
Pinto, C.
Mady, C. E.
Powiązania:
https://bibliotekanauki.pl/articles/395979.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
exergy analysis
Organic Rankine Cycle
photovoltaic
thermal collector PV
solar thermal
analiza egzergii
cykl Rankine’a
fotowoltaika
kolektor PV/T
energia słoneczna
Opis:
In this work, the application of hybrid solar modules that combine photovoltaic panels and solar thermal collectors coupled with a low-temperature thermal cycle such as the Organic Rankine Cycle is discussed, their main purpose being an increase in the total electric power production per available area. This work will study the thermal and electrical power production efficiency of the hybrid system, the increase in the PV module electric conversion efficiency due to their cooling through heat transfer to the thermal cycle and the total exergetic efficiency of the system. A simplified simulation of the system in steady state conditions based on a thermal efficiency model will be performed with the aid of the EES (Engineering Equation Solver) software using climate data from Campinas, São Paulo, Brazil. The study shows that while the PV/T+ORC system does fulfill the purpose of increasing the electrical power generation both from the generator coupled to the thermal cycle and from the increase in the PV module efficiency due to its cooling. Thus, there is an increase the overall exergy efficiency of the system compared to uncoupled PV/T collectors.
W pracy omówiono zastosowanie hybrydowych modułów słonecznych łączących panele fotowoltaiczne z kolektorami słonecznymi w połączeniu z niskotemperaturowym cyklem termicznym, takim jak cykl organiczny Rankine'a, którego głównym celem jest zwiększenie całkowitej produkcji energii elektrycznej. W pracy zbadano wydajność produkcji energii cieplnej i elektrycznej w systemie hybrydowym, wzrost sprawności konwersji energii modułu fotowoltaicznego ze względu na ich chłodzenie poprzez przeniesienie ciepła do cyklu termicznego i całkowitą efektywność energetyczną układu. Uproszczona symulacja systemu w warunkach stanu ustalonego w oparciu o model sprawności cieplnej została przeprowadzona za pomocą oprogramowania EES (Engineering Equation Solver) wykorzystującego dane klimatyczne z Campinas, São Paulo, Brazylia. Badania wykazały, że system PV/T + ORC spełnia cel zwiększenia wytwarzania energii elektrycznej zarówno z generatora połączonego z cyklem termicznym, jak i ze wzrostu sprawności modułu PV ze względu na jego chłodzenie. W ten sposób zwiększa się ogólna efektywność egzergii systemu w porównaniu z niezwiązanymi kolektorami PV/T.
Źródło:
Civil and Environmental Engineering Reports; 2018, No. 28(4); 1-12
2080-5187
2450-8594
Pojawia się w:
Civil and Environmental Engineering Reports
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 21

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies