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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.

2

System approach to the analysis of an integrated oxy-fuel combustion power plant

Ziębik A., Gładysz P.

Archives of Thermodynamics

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2014

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Vol. 35, no. 3

39--57

EN

Oxy-fuel combustion (OFC) belongs to one of the three commonly known clean coal technologies for power generation sector and other industry sectors responsible for CO2 emissions (e.g., steel or cement production). The OFC capture technology is based on using high-purity oxygen in the combustion process instead of atmospheric air. Therefore flue gases have a high concentration of CO2 - Due to the limited adiabatic temperature of combustion some part of CO2 must be recycled to the boiler in order to maintain a proper flame temperature. An integrated oxy-fuel combustion power plant constitutes a system consisting of the following technological modules: boiler, steam cycle, air separation unit, cooling water and water treatment system, flue gas quality control system and CO2 processing unit. Due to the interconnections between technological modules, energy, exergy and ecological analyses require a system approach. The paper present the system approach based on the 'input-output' method to the analysis of the: direct energy and material consumption, cumulative energy and exergy consumption, system (local and cumulative) exergy losses, and thermoecological cost. Other measures like cumulative degree of perfection or index of sustainable development are also proposed. The paper presents a complex example of the system analysis (from direct energy consumption to thermoecological cost) of an advanced integrated OFC power plant.

3

Egzergia a materiały wybuchowe

Biegańska J.

Chemik

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2013

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Vol. 67, nr 1

47-52

PL

Egzergia to pojęcie wprowadzone w termodynamice do jakościowego określenia zdolności do wykonania pracy w otoczeniu a związanej z działalnością człowieka. Produkowane przemysłowe materiały wybuchowe mają przeznaczenie głównie do urabiania calizny skalnej, a więc ich stosowanie ma związek z wykonaniem pracy użytecznej. Powinno się rozpatrywać jakie straty egzergii będą związane z pozyskiwaniem masywu skalnego w górnictwie, gdzie stosowane są materiały wybuchowe.

EN

Exergy is a term introduced to thermodynamics to determine ability to perform work in the environment with relation to human activity. Manufactured industrial explosive materials are destined mainly to get unmined stone. Hence, their use is connected with the realization of the effective work. The exergy loss related to obtaining solid stone in mining where explosive materials are used should be taken into consideration.

4

Thermodynamical motivation of the Polish energy policy

Ziębik A.

Archives of Thermodynamics

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2012

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Vol. 33, no. 4

3-21

EN

Basing on the first and second law of thermodynamics the fundamental trends in the Polish energy policy are analysed, including the aspects of environmental protection. The thermodynamical improvement of real processes (reduction of exergy losses) is the main way leading to an improvement of the effectivity of energy consumption. If the exergy loss is economically not justified, we have to do with an error from the viewpoint of the second law analysis. The paper contains a thermodynamical analysis of the ratio of final and primary energy, as well as the analysis of the thermo-ecological cost and index of sustainable development concerning primary energy. Analyses of thermo-ecological costs concerning electricity and centralized heat production have been also carried out. The effect of increasing the share of high-efficiency cogeneration has been analyzed, too. Attention has been paid to an improved efficiency of the transmission and distribution of electricity, which is of special importance from the viewpoint of the second law analysis. The improvement of the energy effectivity in industry was analyzed on the example of physical recuperation, being of special importance from the point of view of exergy analysis.

5

Energia czy egzergia

Szargut J.

Rynek Energii

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2010

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nr 5

3-5

PL

W języku potocznym słowem "energia" określa się zwykle tylko energię podwyższonej jakości. Jakość tę określa egzergia, nie podlegająca prawu zachowania. Straty egzergii są proporcjonalne do entropii generowanej. Należy dążyć do ich zmniejszania w granicach opłacalności ekonomicznej i możliwości technologicznych. Znajomość analizy egzergetycznej jest niezbędna przy projektowaniu i udoskonalaniu procesów energetycznych.

EN

In a colloquial speech the word "energy" is used for the kinds of energy characterized with a higher quality. In a scientitic speech the quality of energy is expressed by means of exergy, exempt from the law of conservation. The losses of exergy are proportional to the generated entropy. For the reduction of these losses it should be striven in the limits of economic profitability and technological possibilities. The knowledge of the exergy analysis is indispensable in the design and improvement of energy processes.

6

Application of exergy analysis for evaluation of CO2 emission from operation of steam power unit

Stanek W., Budnik M.

Archives of Thermodynamics

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2010

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Vol. 31, no. 4

81-91

EN

Szargut proposed the algorithm for determination of the influence of irreversibility of components of thermal process on the emission of CO2 [6]. In the presented paper, basing on Szargut's proposal, the example of analysis of influence of operational parameters of coal fired power plant on the local increase of CO2 emission is presented. The influence of operational parameters on the local exergy losses appearing in components of investigated power plant are simulating making use of the semi-empirical model of power plant.

7

Antropogeniczne i naturalne straty egzergii

Szargut J.

Prace Naukowe Politechniki Warszawskiej. Konferencje

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2002

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T. 4, z. 22

1169-1176

PL

Obliczono naturalne straty egzergii związane z napromieniowaniem Ziemi przez Słońce. Rozpatrzono strumień egzergii reliktowego promieniowania przestrzeni kosmicznej. Wyróżniono naturalne straty egzergii użytkowalnej powstające w pobliżu powierzchni Ziemi i porównano je ze stratami antropogenicznymi spowodowanymi przez działalność człowieka. Wskazano na pozytywne efekty strat naturalnych, które były główną przyczyną ukształtowania ziemskiego środowiska naturalnego.

EN

Natural exergy losses connected with the absorption of solar radiation by the Earth have been calculated. The exergy flow of the relict radiation of cosmic space has been considered too. The natural losses of the utilizable exergy occurring near the Earth's surface have been distinguished and compared with anthropogenic exergy losses caused by the activity of humankind. The positive impact of the natural exergy losses has been pointed out: they were a main cause of the formation of the terrestrial natural environment.