Exergy Costing in Exergoeconomics

1993 ◽  
Vol 115 (1) ◽  
pp. 9-16 ◽  
Author(s):  
G. Tsatsaronis ◽  
L. Lin ◽  
J. Pisa
Keyword(s):  
Previous History ◽  
Energy Systems ◽  
Process Step ◽  
New Approach ◽  
Chemical Exergy ◽  
Recent Developments ◽  
History Of ◽  
Exergoeconomic Analysis ◽  
The Cost ◽  
Objective Methodology

Existing methods of exergoeconomic analysis and optimization of energy systems operate with single average or marginal cost values per exergy unit for each material stream in the system being considered. These costs do not contain detailed information on (a) how much exergy, and (b) at what cost each exergy unit was supplied to the stream in the upstream processes. The cost of supplying exergy, however, might vary significantly from one process step to the other. Knowledge of the exergy addition and the corresponding cost at each previous step can be used to improve the costing process. This paper presents a new approach to exergy costing in exergoeconomics. The monetary flow rate associated with the thermal, mechanical and chemical exergy of a material stream at a given state is calculated by considering the complete previous history of supplying and removing units of the corresponding exergy form to and from the stream being considered. When exergy is supplied to a stream, the cost of adding each exergy unit to the stream is calculated using the cost of product exergy unit for the process or device in which the exergy addition occurs. When the stream being considered supplies exergy to another exergy carrier, the last-in-first-out (LIFO) principle of accounting is used for the spent exergy units to calculate the cost of exergy supply to the carrier. The new approach eliminates the need for auxiliary assumptions in the exergoeconomic analysis of energy systems and improves the fairness of the costing process by taking a closer look at both the cost-formation and the monetary-value-use processes. This closer look mainly includes the simultaneous consideration of the exergy and the corresponding monetary values added to or removed from a material stream in each process step. In general, the analysis becomes more complex when the new approach is used instead of the previous exergoeconomic methods. The benefits of using the new approach, however, significantly outweigh the increased efforts. The new approach, combined with some other recent developments, makes exergoeconomics an objective methodology for analyzing and optimizing energy systems.

Local Exergy Cost Theory

2004 ◽  
Author(s):  
V. H. Rangel ◽  
S. Uson ◽  
A. Valero ◽  
C. Cortes
Keyword(s):  
Cost Allocation ◽  
Energy Systems ◽  
Discrete Systems ◽  
Space Time ◽  
Time Function ◽  
Point Of View ◽  
Continuous Systems ◽  
New Approach ◽  
New Formalism ◽  
The Cost

The Exergy Cost Theory (ECT) is a technique extensively applied to optimizing, diagnosing and designing energy systems. But, despite of its wide applications it has its limitations. Such limitations have to do partly with the application to discrete systems solely and partly with the cost allocation problem. Thus in the present paper we go a step further in the scope of the ECT and propose to enlarge its applicability to continuous systems. Essentially, this is carried through by taking the concept of the exergy cost to a microscopic point of view. To put it another words, the exergy costs are connected to the law of continuum physics so that all phenomenological effects can be taken into account. This new formalism may be called as Local Exergy Cost Theory (LECT). The LECT method departs from the hypothesis that unit exergy costs for distinct exergy fluxes, e.g. heat, work, etc., are given the same cost in absence of external evaluations. From this new approach, it will be possible to model an space-time function of the unit exergy cost, k* ((r), t), besides it will be helpful in providing the rules of cost allocation with physical grounds otherwise to propose new ones. Theoretical aspects of this method are succinctly explained throughout the paper. Most importantly, in order to show the practical bias of the theory a series of proposed examples which are outlined are provided. By and large, results show that the unit exergy cost locally yielded contains a lot of useful information as, for instance, precise pinpointing of the points where exergy is destroyed and what is most importantly, the costs at those points. Lastly, by means of the LECT we can build up exergy cost maps for a particular system.

Reprocessing of Sintered and Melt High Temperature Superconducting Materials

1994 ◽  
Vol 344 ◽  
Author(s):  
C. Vipulanandan ◽  
B. Martinz
Keyword(s):  
High Temperature ◽  
Past History ◽  
Silver Powder ◽  
Previous History ◽  
High Temperature Superconducting ◽  
Melting Temperatures ◽  
Bulk Ybco ◽  
Barium Copper ◽  
History Of ◽  
The Cost

AbstractIncreasing use of High Temperature Superconducting Ceramics (HTSC) in various applications and the cost of the new superconducting powder dictated the need for evaluating the potential of reusing the old HTSC material (yittrium-barium-copper oxide (YBCO); YBa2Cu3O7-x) with minimum reprocessing. This study examined various methods to reprocess two years old sintered and melt bulk YBCO ceramics. YBCO components were ground and processed with and without adding various amount of silver powder, organic binders and new YBCO powder. The reprocessed YBCO powder was also characterized at every step of processing using X-ray diffraction (XRD) and Differential Thermal Analysis (DTA) to identify impurities.The old YBCO components were first crushed and then ground using automatic grinder and a jet-mill. The ground powder was then mixed with additives and/or binders and compacted uniaxially to 45 ksi. The range of sintereing temperatures from 905 °C to 980 °C were selected based on the past history of sintering/melting temperatures. The reground powder was found to have impurity phases due to its exposure to carbon dioxide and humidity in the atmosphere. Addition of Ag powder resulted in higher relative densities at lower sintering temperatures. The need for re-calcination of used powders was also considered to improve the performance of reprocessed powders. The sintering temperature was selected based on achieving 85% relative density. The results show that the reprocessed powders have to be sintered at higher temperatures than their previous history. The sintered and melt-textured YBCO made from reprocessed powder had similar or better superconducting properties compared to the new powder.

405: Previous History of Bladder Cancer is an Independent Prognostic Factor for Upper Tract Transitional Cell Carcinoma

2007 ◽  
Vol 177 (4S) ◽  
pp. 135-135
Author(s):  
Eiji Kikuchi ◽  
Akira Miyajima ◽  
Ken Nakagawa ◽  
Mototsugu Oya ◽  
Takashi Ohigashi ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Prognostic Factor ◽  
Transitional Cell Carcinoma ◽  
Cell Carcinoma ◽  
Transitional Cell ◽  
Previous History ◽  
Independent Prognostic Factor ◽  
Upper Tract ◽  
History Of

Popliteal artery thrombosis secondary to a tibial osteochondroma

VASA ◽  
2011 ◽  
Vol 40 (3) ◽  
pp. 251-255 ◽  
Author(s):  
Gruber-Szydlo ◽  
Poreba ◽  
Belowska-Bien ◽  
Derkacz ◽  
Badowski ◽  
...  
Keyword(s):  
Case Report ◽  
Magnetic Resonance Angiography ◽  
Popliteal Artery ◽  
Doppler Ultrasonography ◽  
Histopathological Examination ◽  
Previous History ◽  
Plain Radiography ◽  
Artery Thrombosis ◽  
History Of ◽  
The Right

Popliteal artery thrombosis may present as a complication of an osteochondroma located in the vicinity of the knee joint. This is a case report of a 26-year-old man with symptoms of the right lower extremity ischaemia without a previous history of vascular disease or trauma. Plain radiography, magnetic resonance angiography and Doppler ultrasonography documented the presence of an osteochondrous structure of the proximal tibial metaphysis, which displaced and compressed the popliteal artery, causing its occlusion due to intraluminal thrombosis..The patient was operated and histopathological examination confirmed the diagnosis of osteochondroma.

Rhabdomyolysis in DOMS

1999 ◽  
Vol 38 (05) ◽  
pp. 164-168 ◽  
Author(s):  
Gloria Ruiz Hernandez ◽  
C. Sanchez Marchori ◽  
J. Munoz Moliner ◽  
C. Martinez Carsi
Keyword(s):  
Bone Scintigraphy ◽  
Previous History ◽  
Biochemical Studies ◽  
History Of ◽  
Increased Activity

SummaryA 26-year-old man with a previous history of external twin bursitis was remitted to our Department for a bone scintigraphy. Before the study, the patient performed an elevated number of intense sprints. Bone scintigraphy showed a bilaterally increased activity in both anterior rectum muscles suggesting rhabdomyolysis. Biochemical studies and MRT confirmed the diagnosis.

Exergoeconomic analysis of renewable multi-generation system

2020 ◽  
pp. 99-111
Author(s):  
Vontas Alfenny Nahan ◽  
Audrius Bagdanavicius ◽  
Andrew McMullan
Keyword(s):  
Capital Investment ◽  
Combined Cycle ◽  
Asian Countries ◽  
Generation System ◽  
Integrated Gasification Combined Cycle ◽  
Heating And Cooling ◽  
Integrated Gasification ◽  
Exergoeconomic Analysis ◽  
Main Components ◽  
The Cost

In this study a new multi-generation system which generates power (electricity), thermal energy (heating and cooling) and ash for agricultural needs has been developed and analysed. The system consists of a Biomass Integrated Gasification Combined Cycle (BIGCC) and an absorption chiller system. The system generates about 3.4 MW electricity, 4.9 MW of heat, 88 kW of cooling and 90 kg/h of ash. The multi-generation system has been modelled using Cycle Tempo and EES. Energy, exergy and exergoeconomic analysis of this system had been conducted and exergy costs have been calculated. The exergoeconomic study shows that gasifier, combustor, and Heat Recovery Steam Generator are the main components where the total cost rates are the highest. Exergoeconomic variables such as relative cost difference (r) and exergoeconomic factor (f) have also been calculated. Exergoeconomic factor of evaporator, combustor and condenser are 1.3%, 0.7% and 0.9%, respectively, which is considered very low, indicates that the capital cost rates are much lower than the exergy destruction cost rates. It implies that the improvement of these components could be achieved by increasing the capital investment. The exergy cost of electricity produced in the gas turbine and steam turbine is 0.1050 £/kWh and 0.1627 £/kWh, respectively. The cost of ash is 0.0031 £/kg. In some Asian countries, such as Indonesia, ash could be used as fertilizer for agriculture. Heat exergy cost is 0.0619 £/kWh for gasifier and 0.3972 £/kWh for condenser in the BIGCC system. In the AC system, the exergy cost of the heat in the condenser and absorber is about 0.2956 £/kWh and 0.5636 £/kWh, respectively. The exergy cost of cooling in the AC system is 0.4706 £/kWh. This study shows that exergoeconomic analysis is powerful tool for assessing the costs of products.

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