Energy and exergy inventory in aluminum smelter from a thermal integration point-of-view

2016 ◽  
Vol 40 (10) ◽  
pp. 1321-1338 ◽  
Author(s):  
Ruijie Zhao ◽  
Cassandre Nowicki ◽  
Louis Gosselin ◽  
Carl Duchesne
Keyword(s):  
Point Of View ◽  
Aluminum Smelter ◽  
Integration Point ◽  
Energy And Exergy ◽  
Thermal Integration

Exergy Quality of Buildings

2014 ◽  
Vol 899 ◽  
pp. 30-35 ◽  
Author(s):  
Ferenc Kalmár
Keyword(s):  
Energy Content ◽  
Residential Buildings ◽  
Building Energy ◽  
Primary Energy ◽  
Point Of View ◽  
Specific Method ◽  
Energy And Exergy ◽  
Country Specific

Energy labeling of buildings is accepted and used in all European countries. Depending on the yearly specific primary energy consumption the energy quality of a building is expressed using a country specific method. Consequently primary energy is the basis of building energy class. Primary energy is obtained using different country specific transformation factors for gas, electricity, wood, biomass etc. However different quantities of warm water and steam can have the same energy content. Calculating the exergy content of used energy a better classification of buildings can be achieved. This paper presents a method to analyze residential buildings from exergy point of view. It was found a transformation factor between energy and exergy: 0.075.

NEW REALIZATIONS OF VOLTAGE-MODE QUADRATURE OSCILLATORS USING CURRENT DIFFERENCING BUFFERED AMPLIFIERS

2010 ◽  
Vol 19 (05) ◽  
pp. 1069-1076 ◽  
Author(s):  
ABHIRUP LAHIRI
Keyword(s):  
Point Of View ◽  
Passive Components ◽  
Voltage Mode ◽  
Sinusoidal Oscillators ◽  
Integration Point ◽  
Condition Of Oscillation ◽  
Simulation Results ◽  
Quadrature Oscillators

A number of sinusoidal oscillators using current differencing buffered amplifiers (CDBAs) have been reported in the literature. However, only three of them are canonic quadrature oscillators (i.e., requiring two capacitors). The aim of this letter is to present additional realizations of single/dual-resistance-controlled quadrature oscillators using CDBAs. Four voltage-mode quadrature oscillators are proposed, which provide the following advantageous features: (i) use of reduced and canonic component count, viz. two CDBAs, three/four resistors and two capacitors, (ii) all passive components are grounded or virtually grounded, which is favorable from integration point of view and (iii) independent and non-interactive resistor control of the condition of oscillation (CO) and the frequency of oscillation (FO). Simulation results verifying the workability of the proposed circuits have been included.

Exergy Analysis of an Integrated Gas Turbine Thermoacoustic Engine

2010 ◽  
Author(s):  
Kaveh Ghorbanian ◽  
Mohsen Karimi
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Exergy Analysis ◽  
Waste Heat ◽  
Point Of View ◽  
Thermoacoustic Engine ◽  
Exhaust Gases ◽  
Energy And Exergy

An attempt is made to utilize exhaust gases of a small gas turbine in augmenting power output through the employment of a thermoacoustic system. It is assumed that the thermoacoustic system is powered only by the waste heat of the gas turbine. A comprehensive cycle analysis of the integrated gas turbine thermoacoustic engine “IGTTE” is carried out from energy and exergy point of view. Results indicate the thermodynamic advantages of the IGTTE.

scholarly journals Design and Operation of a Polygeneration System in Spanish Climate Buildings under an Exergetic Perspective

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7636
Author(s):  
Ana Picallo-Perez ◽  
Jose Maria Sala-Lizarraga
Keyword(s):  
Energy Savings ◽  
Energy Performance ◽  
Point Of View ◽  
Office Building ◽  
Air Handling Unit ◽  
Depth Analysis ◽  
Energy And Exergy ◽  
Polygeneration System ◽  
Almost All

This work defines and analyzes the performance of a polygeneration system in five different locations in Spain to maintain the thermal comfort and air quality of an office building. The facility is based on a chiller and a CHP engine with PV panels that provide almost all the electricity demand of the chiller. According to the energy performance analysis results, the installation working in Bilbao is a full polygeneration system since no electricity needs to be imported from the grid in summer. To quantify the energy savings related to a separated production facility, polygeneration indicators (percentage of savings PES/PExS and equivalent electric efficiency EEE/EExE) have been calculated in energy and exergy terms. The main motivation for using exergy is based on the ambiguity that can arise from the point of view of the First Law. As expected, the exergetic indicators have lower values than the energetic ones. In addition, an in-depth analysis was conducted for the air-handling unit components. The study shows the behavior of components over the year and the efficiency values from both an energy and exergy point of view. From these facts, the need arises to develop methodologies based on exergy.

scholarly journals TECHNO-ECONOMIC INVESTIGATION OF DIFFERENT ALTERNATIVES OF IMPROVING SIMPLE GAS TURBINE INTEGRATION OPTIONS

2017 ◽  
Vol 36 (3) ◽  
pp. 849-857
Author(s):  
MA Sulaiman ◽  
MA Waheed ◽  
WA Adesope ◽  
A Noike
Keyword(s):  
Gas Turbine ◽  
Exergy Analysis ◽  
Point Of View ◽  
Air Cooling ◽  
Levelized Cost Of Electricity ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Specific Emissions ◽  
Gas Turbine Power Plant ◽  
Wasted Energy

This study investigated the effect of integrating various models proposed to improve a simple gas turbine power plant. A computer program was developed in Matlab software was used to simulate the performance parameters. The energy and exergy analysis of the plant was carried out. The energy and exergy analysis result revealed that both energy and exergy efficiency of plant is low as a result three improvement options were considered. They include Model 1: reducing inlet air cooling (IAC) of the compressor by using the wasted energy in the natural gas pressure drop station. Model 2: recovering wasted energy in the exhaust through heat recovery steam generator (HRSG) and injecting steam into the combustion chamber and lastly Model 3: by combining the two methods. The result showed that among the three methods of improving the plant investigated Model 3 was found to boost power output of the plant from 28.3 MW to 78.4 MW while the thermal and exergetic efficiency improved by 25.5 and 23.6% respectively. Furthermore, from economic and environmental point of view, the lowest levelized cost of electricity as well as the specific emissions was observed in Model 3. Consequently, Model 3 is selected as the best option in improving the simple gas turbine.  http://dx.doi.org/10.4314/njt.v36i3.27

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

How a sheperd guides a sheep herd?

1984 ◽  
Vol 75 ◽  
pp. 331-337
Author(s):  
Richard Greenberg
Keyword(s):  
Point Of View ◽  
Single Ring ◽  
Damping Effects ◽  
Ring Particle

ABSTRACTThe mechanism by which a shepherd satellite exerts a confining torque on a ring is considered from the point of view of a single ring particle. It is still not clear how one might most meaningfully include damping effects and other collisional processes into this type of approach to the problem.

The growth of mica polytypes as studied by conventional and high-resolution TEM

1983 ◽  
Vol 41 ◽  
pp. 174-177
Author(s):  
A. Baronnet ◽  
M. Amouric
Keyword(s):  
Water Pressure ◽  
Point Of View ◽  
Temperature Fields ◽  
Natural Occurrence ◽  
Growth Mechanisms ◽  
Long Period ◽  
High Resolution Tem ◽  
Layer Stacking ◽  
Experimental Works ◽  
Potential Use

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.

Radiation Damage in Ceramics

1982 ◽  
Vol 40 ◽  
pp. 600-603
Author(s):  
T. E. Mitchell ◽  
M. R. Pascucci ◽  
R. A. Youngman
Keyword(s):  
Radiation Damage ◽  
Outer Space ◽  
Point Of View ◽  
Nuclear Waste Storage ◽  
Waste Storage ◽  
Storage Media ◽  
Transmission Electron ◽  
Fundamental Point ◽  
Small Defect ◽  
Present Understanding

1. Introduction. Studies of radiation damage in ceramics are of interest not only from a fundamental point of view but also because it is important to understand the behavior of ceramics in various practical radiation enyironments- fission and fusion reactors, nuclear waste storage media, ion-implantation devices, outer space, etc. A great deal of work has been done on the spectroscopy of point defects and small defect clusters in ceramics, but relatively little has been performed on defect agglomeration using transmission electron microscopy (TEM) in the same kind of detail that has been so successful in metals. This article will assess our present understanding of radiation damage in ceramics with illustrations using results obtained from the authors' work.

Structural aspects of osmoregulation in porphyra

1978 ◽  
Vol 36 (2) ◽  
pp. 412-413
Author(s):  
C. Wiencke ◽  
A. Lauchli
Keyword(s):  
Culture Medium ◽  
Point Of View ◽  
Chemical Fixation ◽  
Cellular Organization ◽  
Osmotic Adaptation ◽  
Osmotic Balance ◽  
Activity Of Enzymes ◽  
Osmotic Agents ◽  
Vacuolar System ◽  
Structural Aspects

Osmoregulatory mechanisms in algae were investigated mainly from a physiological point of view (KAUSS 1977, HELLEBUST 1976). In Porphyra two osmotic agents, i. e. floridoside/isofloridoside (KAUSS 1968) and certain ions, such as K+ and Na+(EPPLEY et al. 1960) are considered for osmotic balance. Accumulations of ions (particularly Na+) in the cytoplasm during osmotic adaptation is improbable, because the activity of enzymes is generally inhibited by high ionic concentrations (FLOWERS et al. 1977).The cellular organization of Porphyra was studied with special emphasis on the development of the vacuolar system under different hyperosmotic conditions. Porphyra was cultivated at various strengths of the culture medium ASP 12 (PROVASOLI 1961) ranging from normal to 6 times concentrated (6x) culture medium. Por electron microscopy freeze fracturing was used (specimens fixed in 2% glutaraldehyde and incubated in 30% glycerol, preparation in a BALZERS BA 360 M apparatus), because chemical fixation gave poor results.

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