Wyniki wyszukiwania - BazTech

1

Experimental studies of packed-bed Thermal Energy Storage system performance

Ochmann Jakub, Bartela Łukasz, Rusin Krzysztof, Jurczyk Michał, Stanek Bartosz, Rulik Sebastian, Waniczek Sebastian

Journal of Power Technologies

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2022

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Vol. 102, nr 1

37--44

EN

This paper contains an experimental analysis of a heat storage tank's heat loss and exergy efficiency using a basalt porous bed as a storage material. The basic parameters of the laboratory bench with measuring equipment are presented and the experimental procedure is discussed. The methodology for evaluating the energy potential of the heat storage process for large-scale energy storage systems is described. The main novelty of the presented system is the application of the slenderness of the heat accumulator, which corresponds to the development of the system in a post-mining shaft. Based on the analysis of the experiment, the exergy cycle efficiency of the heat storage unit was determined to equal 52.3%, and the energy efficiency equal to 96.6%.

2

Modeling, exergy analysis and optimization of cement plant industry

Abutorabi Hossein, Kianpour Ehsan

Journal of Mechanical and Energy Engineering

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2022

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Vol. 6, No 1

55--65

EN

This study investigates the recovery of wasted heat in the cement plant industries (Neka Cement Factory) in order to reduce the use of fossil fuels and greenhouse gas emissions. Cement is the most widely used man-made material. The global cement industry produces about 3.3 billion tons of cement annually. A lot of energy is needed to produce cement. About 200 kg of coal is used to produce each ton of cement. The cement industry also produces about five percent of the world's greenhouse gases. The method studied in this research is based on heat recovery from boilers installed at the outlet of a clinker cooler and a preheater in a cement factory. Due to the low temperature of the gases available, three different fluids, i.e. water, R134a and R245fa were considered as the operating fluids. Also, energy and exergy analyses are performed in a Rankin cycle and the selection of optimal parameters is considered by using genetic algorithm. The results of this study showed that water with optimized parameters leads to an increase in the production capacity from 5 to 9 MW. However, fluid R134a with optimized parameters leads to a 4% increase in exergy losses and it also increases the production capacity from 5 to 9 MW.

3

Working Fluid Selection for Simple and Recuperative Organic Rankine Cycle Operating Under Varying Conditions: A Comparative Analysis

Igbong Dodeye, Nyong Oku E., Enyia James, Agba Ambrose

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 4

202--221

EN

The selection of suitable working fluid for simple and recuperative organic Rankine cycle (ORC) operating under subcritical, superheated and supercritical conditions are investigated. 11 fluids with critical temperature above 1500C are considered as potential candidates. Performance screening parameters such as net power output, thermal efficiency, turbine sizing parameter (SP) and volumetric flow ratio (VFR), exegetic parameters like irreversibility rate, fuel depletion ratio, and improvement potential rate of exergy destruction were also evaluated. Results indicate that R600a, R236fa and R1233dz(E) demonstrated the best performance for subcritical, superheated and supercritical simple ORC, respectively. R236fa and R1233dz(E) proved more suitable for subcritical/superheated and supercritical recuperative cycles, respectively. The system exegetic efficiency is reveal to be significantly higher in subcritical/superheated (61-65%) cycles compared to the supercritical (35-45%) cycle, the evaporator seen as the main source of exergy destruction, accounting for 17-37% of inlet exergy destroyed and about 8-24% in the turbine.

4

Energetic & exergetic analysis of a parabolic trough: concentrated solar power plant

Nagpal Mohit, Maithani Rajesh, Kumar Suresh

Acta Innovations

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2021

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no. 40

19--30

EN

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.

5

Evaluation of the extractive gold process: open-pit mining through exergy analysis

Velasquez Hector I., Orozco Loaiza Carlos Andres, Hasenstab Christian, Cano Natalia A.

Journal of Sustainable Mining

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2020

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Vol. 19, iss. 3

166--181

EN

The Colombian mining sector is characterized by the production of coal, nickel, emeralds, gold, and construction materials. It is considered by the National Development Plan of Colombia 2018-2022 as an economic agent that boosts development in the region and one that requires the strengthening of its policies and environmental liability. Therefore, this paper aims to show the importance of implementing methodologies based on the logic of nature (exergy) that objectively indicate the environmental impact of an extractive gold activity, such as open-pit gold mining. The extractive activity or process to be studied consists of the following stages: topsoil removal by using machinery and explosives to create craters and to access the mineral present in the subsoil; the physical transformation of the extracted material through crushing, grinding, gravimetric separation, flotation, leaching, adsorption, elution, and electrodeposition, along with smelting and casting to obtain gold and silver ingots. Thus, this paper analyzes the exergy performance of each unit process of the open-pit extractive process. The obtained results are used in a sensitivity analysis, which determines the system efficiency, by assuming the increase of gold in the extracted material in the exploitation stage, by using the same supplies and input of the current process. In other cases, the open-pit mining process is analyzed by changing its technologies in the mining process and assuming that this change reduces the inlet ore to 60%, by discarding 40% of material without gold and by reducing supply consumption by 25%. By improving the system efficiency, the exergy destroyed is reduced and the emissions to the environment diminish. Therefore, this method may be implemented as a basic guideline when it comes to decision-making processes in the planning of the extractive processes by integrating the environmental component with gold production.

6

Europejski Zielony Ład – merytoryczne podstawy neutralności klimatycznej w aspekcie gospodarki surowcowej

Słupik Tomasz

Energetyka

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2020

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nr 11

615--621

PL

Europejski Zielony Ład zakłada osiągnięcie neutralności klimatycznej do 2050 roku. Na temat tego zagadnienia oraz mechanizmów prowadzących do osiągnięcia wspomnianego celu wiele się mówi, jednakże prawie wcale nie wspomina się o metodach monitorowania postępów i ocenie poszczególnych technologii na etapie budowania wspomnianego nowego zielonego porządku. Warto zatem poświęcić trochę czasu na zastanowienie się i przegląd aspektów związanych z dążeniem do osiągnięcia celu neutralności klimatycznej. Cel w tym przypadku można definiować jako pewnego rodzaju stan wyidealizowany, do którego dążenie jest obowiązkiem naszych czasów wobec przyszłych pokoleń. Taka optyka wymusza jednak stosowanie narzędzi inżynierskich, które pozwolą na kompleksowe ujęcie podejmowanych aktywności w kontekście oceny wpływu danej technologii i produktu na środowisko naturalne. Z racji rozległości zagadnień nieodłącznie związanych z różnego typu aktywnościami gospodarczymi w artykule skupiono się jedynie na wąskim, aczkolwiek kluczowym dla całej gospodarki, obszarze wytwarzania/przetwarzania energii.

EN

The European Green Deal assumes the achievement of climate neutrality by 2050. There is much talk now about this issue and mechanisms leading to this goal but next to nothing is mentioned about methods of progress monitoring and assessment of particular technologies at the stage of implementing the new green deal. Therefore, it is worth devoting some time to consider and review issues related to the pursuit of the goal, i.e.: climate neutrality. The goal in this case may be defined as a kind of idealized state, which we should strive to achieve as it is our duty to future generations. Yet, this approach forces the application of engineering tools to allow complex estimation of activities undertaken in relation to the assessment of the impact of the specific technology and product on the natural environment. Due to a great diversity of aspects inextricably linked with various types of economic activity, the paper focuses only on a narrow concern, i.e.: energy generation/processing, which is, however, vital to the whole economy.

7

My pursuit of truth in building materials engineering

Czarnecki L.

Archives of Civil Engineering

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2020

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Vol. 66, nr 3

3--35

EN

The paper presents pursuits of the truth in building materials engineering. Some definitions of “what truth is” were presented. Partial truths were specified: the truth of scientific reasoning, the truth of scientific assessment, the truth of development directions and the splendour of scientific truth. All categories are addressed to the building materials engineering. In the chapter “Load capacity and stability vs entropy” definitions of entropy and exergy were presented followed by their influence on building construction, illustrated by the “Seneca cliff” and “Energy pyramid”. Chapter 3 presents the truth of scientific reasoning was presented. Three partial truths were indicated: the truth of experimental fact, the truth of scientific reasoning and the truth of scientific presentation. In the chapter “Truth of scientific assessment” two main assessment methods were presented: peer review and a bibliometric parametric assessment as well as their impact on the results and authors. The risks associated with the sole parametric assessment were shown as the two basic factors of a parametric assessment – citation number and Hirsch index – need time to "mature". Additionally, the influence of digitalisation of the assessment of a scientist and a scientific unit on the commoditisation and dehumanisation of science was outlined. In the chapter “Truth of development directions: defined past – fuzzy future” the megatrends observed in technology in the last few decades years were indicated along with new possible trends. Milestones in the development of C-PCs (Concrete-Polymer Composites) were presented. The new paradigm for the new development cycle was proposed.

PL

Artykuł jest osobistą refleksją autora nad wywiązaniem się ze ślubowań akademickich dociekać prawdy, głosić ją oraz dawać świadectwo, a także doktorskich - aby szerzyła się coraz bardziej prawda, od której zawisła przyszłość i szczęście rodzaju ludzkiego. Rozważania te są zaadresowane do Inżynierii Materiałów Budowlanych – obszaru nauki, który formalnie nie był zdefiniowany ani wyodrębniony w momencie składania ślubowań. Nauka może być zdefiniowana jako dążenie do prawdy; w prawdzie zaklęty jest cel, ale i etos nauki. Postęp nauki nie zawsze prowadzi prostą drogą do prawdy. Często odpowiadamy tylko na pytanie czy model opisujący dane zjawisko jest wystarczająco prawdziwy. Prawda inżynierii materiałów budowlanych ma nie tylko wymiar wartości, ale również waży materialnie. „Prawdziwość” metody pomiaru może decydować o bezpieczeństwie konstrukcji, ale również istotnie znaczy w jej koszcie. Obszar rozważań został określony jako relacja „materiał – konstrukcja” i przypisano tu myśl przewodnią „nośność i stateczność a entropia”.

8

The critical role of advanced sustainability assessment tools in enhancing the real-world application of biofuels

Tabatabaei Meisam, Aghbashlo Mortaza

Acta Innovations

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2020

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no. 37

67--73

EN

Sustainability has become of paramount importance in the biofuel industry. Accordingly, various ‎sustainability assessment schemes such as emergy analysis, techno-economic analysis, life ‎cycle ‎assessment, energy accounting, and exergy analysis and its extensions (exergoeconomic, ‎exergoenvironmental, and ‎exergoeconoenvironmental analyses) are being employed increasingly for decision-‎making on biofuel production and consumption systems. In this opinion paper, after classifying ‎and describing biofuel generations, the developed sustainability assessment tools are critically ‎explained, and their pros and cons are discussed. Overall, among the various sustainability assessment approaches introduced so far, exergy-based methods appear to be ‎the most promising tools for developing ‎sustainable biofuel systems. This can be attributed to the fact that the exergy ‎concept is deeply ‎rooted in the well-defined principles of thermodynamics.‎

9

Integrated anaerobic digestion and gasification processes for upgrade of ethanol biorefinery residues

Nogueira Nakashima Rafael, Flórez-Orrego Daniel, Oliveira, Jr Silvio de

Journal of Power Technologies

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2019

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Vol. 99, nr 2

104--114

EN

The upgrading of the biorefineries residues is a possible way to increase the overall process efficiency while attaining economical revenues from wastes that otherwise would be discarded. In this sense, anaerobic digestion and gasification represent interesting alternatives to convert organic residues into biofuels, electricity or other bioproducts. However, few studies have explored energy integration possibilities between those options or evaluated various final product pathways. Thus, in this work, various scenarios aimed at capitalizing the main residues of the sugarcane ethanol industry (vinasse and bagasse) are investigated. Two process layouts combining anaerobic digestion and gasification are proposed for each desired product (methane, hydrogen or power). The highest exergy efficiency (48%) was obtained for the configuration focused on methane production and using a combined cycle, since it requires fewer resources and separation steps to convert feedstock into exportable products. On the other hand, exergy was primarily destroyed in vinasse disposal, since a significant fraction of its organic wastes are inert to anaerobic digestion, followed by the bagasse gasifier and utility systems, due to the irreversible reactions occurring in these processes. In short, this study points to some improvement opportunities and reinforces the advantages of the waste capitalization concept.

10

Analiza energetyczno-środowiskowa lokalnego systemu ciepłowniczego wykorzystującego niskotemperaturowe geotermalne źródło energii

Nitkiewicz Anita, Sekret Robert

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2019

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T. 50, nr 3

83--89

PL

W artykule przedstawiono energetyczno-ekologiczną analizę 9 wariantów lokalnego systemu ciepłowniczego współpracującego z niskotemperaturowym geotermalnym źródłem energii. Dla zbiorowości budynków użyteczności publicznej stworzono koncepcję sieci ciepłowniczej, dla której rozważono trzy warianty źródeł ciepła: sprężarkową pompę ciepła, absorpcyjną pompę ciepła oraz jako wariant bazowy kondensacyjny kocioł gazowy. Analizę przeprowadzono dla trzech różnych wartości temperatury zasilania i powrotu sieci tj. 60/50°C, 50/40°C oraz 40/30°C. Określono straty egzergii, zapotrzebowanie na energię pierwotną oraz sprawność egzergetyczną. Analiza ekologiczna obejmowała analizę oddziaływania na środowisko rozpatrywanych źródeł ciepła w całym cyklu życia (analiza LCA). Na podstawie uzyskanych wyników stwierdzono m.in., że najmniejszym oddziaływaniem na środowisko w całym cyklu życia charakteryzuje się sprężarkowa pompa ciepła współpracująca z lokalną siecią ciepłowniczą o temperaturze pracy 50/40°C i 40/30°C. Poprawę sprawności egzergetycznej systemu ze sprężarkową pompą ciepła, jak i zmniejszenie oddziaływania na środowisko w całym cyklu życia można osiągnąć przez zwiększenie sprawności oraz udziału źródeł energii odnawialnej w procesach wytwarzania energii elektrycznej.

EN

The paper presents an energetic and ecological analysis of 9 variants of a local heating system cooperating with a lowtemperature geothermal energy source. For the community of public buildings, the concept of a heating network was created, for which three variants of heat sources were considered: a compressor heat pump, an absorption heat pump and, as a base variant, a condensing gas boiler. The analysis was carried out for three different supply and return temperatures, i.e. 60/50°C, 50/40°C and 40/30°C. Exergy losses, primary energy demand and exergy efficiency were determined. The ecological analysis included an analysis of the environmental impact of the considered heat sources in the life cycle (LCA analysis). On the basis of the obtained results it was stated, among others, that the smallest impact on the environment in the whole life cycle is characterized by a compressor heat pump cooperating with the local heating network with operating temperatures of 50/40°C and 40/30°C. The improvement of the exergy efficiency of the compressor heat pump system as well as the reduction of the environmental impact throughout the life cycle can be achieved by increasing the efficiency and share of renewable energy sources in the electricity generation processes.

11

Dobór układu odzysku egzergii chłodu z regazyfikacji LNG

Andryka Jakub

Archiwum Instytutu Techniki Cieplnej

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2019

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Vol. 6

7--54

PL

Celem projektu był dobór układu odzysku egzergii chłodu z regazyfikacji skroplonego gazu ziemnego (LNG). Podstawowymi założeniami analizy były małe rozmiary takiego układu jak i jego możliwa mobilność. Stworzono kilka wariantów takiej instalacji składających się z układu ORC, mikro turbiny gazowej lub gazowego silnika tłokowego, którego spaliny dostarczają ciepło do układu ORC odparowując czynnik obiegowy, oraz instalacji odparowania skroplonego gazu ziemnego, którą tworzą wymiennik odparowujący go, który pełni jednocześnie rolę skraplacza czynnika obiegowego w układzie ORC, oraz cysterna z LNG. Następnie każdy z wariantów poddano analizie termodynamicznej oraz oszacowano powierzchnię wymiany ciepła poszczególnych wymienników.

EN

The aim of the project was to select the recovery system of cold exergy from regasification of liquefied natural gas (LNG). The basic assumptions of the analysis were the small size of such a system as well as its possible mobility. Several variants of such installation have been created consisting of an ORC system, a micro gas turbine or a gas piston engine, whose exhaust gas supplies heat to the ORC by evaporating the working fluid and a liquefied natural gas evaporation installation, which is created by the evaporation heat exchanger, which also acts as a condenser of working fluid in the ORC system and the LNG tanker Then, each of the variants was subjected to thermodynamic analysis and the heat exchange surface area of individual heat exchangers was estimated.

12

Energetic and exergetic analysis of a triple-pressure reheat combined cycle power using different primary movers

Almutairi Abdulrahman, Alhajeri Hamad, Alenezi Abdulrahman

Archives of Thermodynamics

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2019

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Vol. 40, no 2

87--105

EN

In this work, actual operating data for Sabiya combined cycle power plant located in Kuwait were used to conduct the performance evaluation based on the energetic and exergetic analysis. The proposed system consist of an advanced gas turbine engines, with two triple pressure reheat heat recovery steam generator, and one steam turbine. Three types of primary movers were selected carefully, in order to cover different types, sizes and technologies. The movers are gas turbine engine frame 9FA, LM6000 and GT26. The proposed models have been developed using specialised software and validated with the manufacturer’s data featuring a high level of compatibility. The performance of a combined cycle power plant was investigated for different operating conditions. The result shows that the highest exergy destruction takes place in 9FA engine due to high irreversibility in combustion chamber because of low-pressure ratio, which causes low inlet temperature of compressed air to the combustion chamber. The 9FA engine also has the highest exergy loss due to high exhaust gases temperature, which is caused high useful work from a steam turbine. The GT26-reheat gas turbine engine constitute the best choose as primary mover due to low waste exergy, which is equal to 43.93% whereas 9FA and LM6000 equal to 47.27% and 45.17%, respectively. LM6000 aeroderivative gas turbine is considered the second best choice but the combined cycle power plant will consist of a large number of engines compared to other industrial gas turbine engine, and that may increase the number of auxiliary equipment, capital and maintenance cost.

13

Exergoeconomic analysis for a two-shaft industrial gas turbine engine

Almutairi A., Alhajeri H., Alenezi A., Zedan M., Al-Asousi M.

Mechanics and Mechanical Engineering

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2018

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Vol. 22, nr 2

379--395

EN

In this work, the performance of a two-shaft industrial gas turbine engine inspired by SGT-750 , one of best technology at Siemens, is analyzed thermodynamically and economically. The modelling and analyzing process for the proposed system was executed through a software package called IPSEpro and validated with manufacturers’ published data. Exergy analysis, based thermodynamics laws with mass conservation, provides valuable information about locations, magnitudes and types of wastes energy in the thermal systems. Exergoeconomic analysis, the amalgamation of exergy with economics, is useful tool to appraise the gas turbine engine cost-effectiveness. The Specific Exergy Costing method is selected in exergoeconomic evaluation because it is the most widely used reported in the literature and provides reliable results. The performance of a gas turbine engine was investigated for different load variation and climatic conditions. The result shows that the main source of irreversibilities take place in the combustion chamber, compressor and high-pressure turbine, respectively, which constitute to about 96 % of total exergy destruction. The exergetic efficiency and exergy loss rate of the proposed system are about 38.4% and 11.8% respectively. The combustion chamber has the highest value of cost (1312.9 $/h) among other components and the source losses may attribute to the component performance. The production cost of the gas turbine engine based on exergoeconomic evaluation is 12.1 US$/GJ.

14

Analiza egzergetyczna pracy strumienicy dwufazowej w układach chłodniczych sprężarkowych

Dudar A.

Instal

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2018

|

nr 12

26--31

PL

W wielu gałęziach gospodarki poszukuje się rozwiązań umożliwiających zmniejszenie, w różnej formie, zużycia energii bądź też jej efektywniejszego wykorzystania. Podobne prace trwają również w dziedzinie chłodnictwa i pomp ciepła. W pracy zaprezentowano metodę podniesienia efektywności energetycznej obiegów lewobieżnych poprzez zastosowanie strumienicy dwufazowej pracującej jako podprężarka. Przedstawiono efekty analizy teoretycznej pracy układu sprężarkowego jak również jego współpracy z ze strumienicą dwufazową dla wybranych czynników.

EN

In many branches of the economy, solutions are sought for reducing, in various forms, energy consumption or its more efficient use. Similar work also continues in the field of refrigeration and heat pumps. The paper presents a method of increasing the energy efficiency of the left-side cycles by using a two-phase injector working as a compressor. The results of the theoretical analysis of the operation of the compressor system as well as its cooperation with a two-phase streamer for selected factors are presented.

15

Analiza termodynamiczna wykorzystania egzergii gazu wielkopiecowego w turbinie odzyskowej suchej i mokrej

Nyżnyk Łukasz

Archiwum Instytutu Techniki Cieplnej

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2018

|

Vol. 4

107--126

PL

Proces wielkopiecowy jest wciąż technologią dominującą w światowej produkcji stali, dlatego szczególnie istotne jest prowadzenie prac mających na celu zmniejszenie jego energochłonności jak i sprawienie by był on bardziej przyjazny dla środowiska naturalnego. W niniejszym projekcie inżynierskim przedstawiono algorytm oraz wyniki obliczeń, które dotyczączą dwóch wariantów wykorzystania egzergii produkowanego gazu wielkopiecowego-turbiny odzyskowej suchej (w układzie z mokrą oczyszczalnią gazu i palnikiem strumienicowym) oraz mokrej. Następnie porównano obie technologie m.in. z uwagi na bezpośrednią korzyść wynikającącą z instalacji turbozespołów (produkcja energii elektrycznej) oraz korzyści ekologiczne (zmniejszenie emisji CO2). Wyniki obliczeń świadczą o tym, że zastosowanie obu technologii wpływa na oszczędność energii chemicznej w krajowej gospodarce energetycznej oraz zmniejszenie emisji CO2 względem kondensacyjnej elektrowni odniesienia, której sprawności wytwarzania energii elektryczneji przesyłu energii założono. Dokładna analiza obu przypadków znajduje się w Rozdziale 4.

EN

Blast furnace processis still most popular steel production method in the world, so it is important to make itless energy-intensive an dless harmful for environment. This thesis shows algorithm and results of calculations for both variants of blast furnace gasexergy usage–dry recovery turbine (layout with wet gas cleaning system and ejector burner) and wet recovery turbine. Both technologies were compared for the direct benefit of turbine (electricity generation) and ecological benefits (reductionof CO2 emission). The results of the calculations show that the use of both technologies affects the energy savings of the national energy economy and the reduction of CO2 emissions relative to the condensing power plant which efficiency of electricity generation and transmission were assumed. More complex analysisis showed in Chapter 4.

16

Thermodynamic analysis of a new dual evaporator CO2 transcritical refrigeration cycle

Abdellaoui E. Y., Kairouani L. K.

Archives of Thermodynamics

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2017

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Vol. 38, no. 1

39--62

EN

In this work, a new dual-evaporator CO2 transcritical refrigeration cycle with two ejectors is proposed. In this new system, we proposed to recover the lost energy of condensation coming off the gas cooler and operate the refrigeration cycle ejector free and enhance the system performance and obtain dual-temperature refrigeration simultaneously. The effects of some key parameters on the thermodynamic performance of the modified cycle are theoretically investigated based on energetic and exergetic analysis. The simulation results for the modified cycle indicate more effective system performance improvement than the single ejector in the CO2 vapor compression cycle using ejector as an expander ranging up to 46%. The exergetic analysis for this system is made. The performance characteristics of the proposed cycle show its promise in dual-evaporator refrigeration system.

17

Straty egzergii w okrętowym kotle opalanym

Matuszak Z., Jaśkiewicz M.

Autobusy : technika, eksploatacja, systemy transportowe

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2016

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R. 17, nr 11

98--102

PL

Na przykładzie okrętowego kotła opalanego (jednego z jego typów, instalowanych na statkach transportowych) scharakteryzowano rodzaje strat egzergii w poszczególnych elementach składowych kotła, jak i w procesie wytwarzania czynnika - pary technologicznej. Podstawą analizy jest struktura funkcjonalna kotła opalanego odpowiadająca jego pracy na jednostce pływającej. Analizę poprzedza zdefiniowanie podstawowych pojęć związanych z użytymi do analizy określeniami i wielkościami nt. strat egzergii i sprawności kotła. W końcowej części przedstawiono trudności z oszacowaniem wielkości strat ezgergii i sprawności egzergetycznej okrętowego kotła opalanego w rzeczywistych warunkach eksploatacyjnych.

EN

The analysis is based on the functional structure of the boiler corresponding to its operation in a vessel. A marine oil-fired boiler (one of the types installed in merchant vessels) is discussed in terms of kinds of exergy losses in particular components of the boiler and in the process of producing the eergy carrier - process steam. The analysis is preceded by the definitions of basic concepts connected with the terms and quantities referring to exergy loss and boiler efficiency. The final part indicates difficulties with the estimation of the amount of exergy losses and oil-fired boiler efficiency in actual operating conditions.

18

Zrozumienie przebiegu procesu produkcyjnego, jako punkt wyjścia przy sporządzaniu audytu energetycznego

Kubski P.

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2015

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T. 46, nr 3

99--102

PL

Wymaganie racjonalnej oceny energetycznej procesów wymusza konieczność zrozumienia przebiegu fizyki procesów, jako punktu startowego przed wykonaniem właściwego audytu. Przypominając podstawowe pojęcia z termodynamiki, w nawiązaniu do pojęcia energii, omówiono pojęcie egzergii oraz jej strat, podkreślając podstawową różnicę między nimi, czego wykładnią jest zasada zachowania wiążąca tylko energię. Podano ogólny sposób wyznaczania strat egzergii, będących miarą nieodwracalności rzeczywistych procesów. Wskazano główne reguły ograniczające poziom potencjalnych strat egzergii. Ograniczenie tych strat przyniesie oczekiwany wzrost efektywności energetycznej.

EN

The requirement of rational energy assessment of processes enforces the need to understand their physics course as a starting point before performing actual audit. Recalling the basic concepts of thermodynamics in relation to energy, the article explains the concept of exergy and its losses, highlighting the fundamental difference between them, and explaining that energy conservation law concerns only energy. A general method is given for determining the exergy losses, which are a measure of the irreversibility of the actual process. The key rules to reduce the level of potential loss of exergy are indicated. Limiting these losses will bring the expected increase in energy efficiency.

19

Exergetic Analysis For A Complete Node Of Fluidised-Bed Drying Of Poppy Seeds

Skoneczna-Łuczków J., Ciesielczyk W.

Chemical and Process Engineering

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2015

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Vol. 36, nr 4

437--447

EN

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.

20

Analiza skumulowanych strat egzergii zintegrowanej elektrowni pracującej według technologii spalania tlenowego

Ziębik A., Gładysz P.

Rynek Energii

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2014

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Nr 1

82--89

PL

Zintegrowana elektrownia pracująca według technologii spalania tlenowego tworzy sieć technologiczną zło-żoną z modułów takich jak: kocioł, obieg parowo-wodny, tlenownia, moduł wody chłodzącej, moduł kondycjonowania spalin, moduł usuwania i sprężania CO2 oraz moduł przygotowania wody uzupełniającej. Każdy z wymienionych modułów charakteryzuje się wytwarzaniem określonego produktu głównego (np. elektryczność, tlen techniczny). Obok produktów głównych wytwarzana są produkty uboczne (np. azot techniczny, ciepło z chłodzenia międzystopniowego sprężarek powietrza z tlenowni oraz sprężarek CO2 w module usuwania i sprężania CO2).W pracy przedstawiono algorytm macierzowy obliczania skumulowanych strat egzergii w przypadku zintegrowanej elektrowni pracującej według technologii spalania tlenowego. Opracowano przykład analizy skumulowanych strat egzergii dla dwóch wariantów technologicznych zintegrowanej elektrowni ze spalaniem tlenowym (tradycyjny układ sprężania CO2 oraz układ z tzw. Shock Wave Compression). Przeprowadzono analizę skumulowanego stopnia doskonałości termodynamicznej dla obu wymienionych wariantów.

EN

Integrated oxy-fuel combustion power plant constitutes energy-technological network consisting the following modules: boiler island, steam cycle, air separation unit, cooling water system, flue gas quality control system, CO2 processing unit and module of make-up water preparation. Every of these module is characterized by production of main product (e.g. electricity, oxygen). Besides main products also by-products are manufactured (e.g. nitrogen, heat from interstage cooling system of air and CO2 compressors). The paper presents matrix algorithm of cumulative exergy losses calculations for integrated oxy-fuel combustion power plant. The examples of cumulative exergy losses analysis have been prepared for two technological variants of integrated oxy-fuel combustion power plant (conventional system of CO2 compressors and system with Shock Wave Compression). The analysis of cumulative degree of thermodynamic perfection for two mentioned above variants has been carried out.