Search results for "Thermoeconomics"
showing 8 items of 18 documents
Advanced energetics of a Multiple-Effects-Evaporation (MEE) desalination plant. Part II: Potential of the cost formation process and prospects for en…
2010
This paper represents the 2nd part of a paper in two parts. In part I a 2nd Principle analysis of a Multiple- Effects-Evaporation (MEE) process has been proposed. In this Part II perspectives for process improvement will be investigated, along two distinct research lines: the thermoeconomics-aided optimization of a new system and the increase of thermal efficiency for existing systems by a pinch-based plant retrofit. As concerns the first research line, a detailed productive structure for the plant stage (i.e. effect) examined in Part I is presented; the cost formation structure is then used to improve a simplified optimization process, revealing capable to properly reflect the interactions…
A thermoeconomics-based approach to the integrated optimization of design and operation for decentralised energy systems and variable load conditions
2006
The many comprehensive approaches formulated for the optimization of large industrial energy systems have been rarely applied to small and medium scale units, because of the difficulties in handling a continuously variable energy demand and of the lower margins for energy and emissions saving. Today, the growing interest for decentralised energy systems in the civil sector stimulates major efforts for the optimization of such plants, with a particular focus on the control system and on a management strategy able to exploit the opportunities existing in the free energy market. In this paper a methodology is proposed for the optimization of design and operation of variable demand systems supp…
Criteri e metodi per l'ottimizzazione di sistemi di poligenerazione di piccola e media taglia - Criteria and methodologies for the optimization of sm…
2011
L'Unione Europea ha individuato nella produzione combinata di energia elettrica e calore una delle tecnologie ad alta efficienza di maggior interesse, fissando per il 2010 il target del 18% della produzione elettrica totale dell'Unione da sistemi cogenerativi (COM/97/0514). Dati recenti rivelano la non attualità di tale target (al 2005 si è raggiunto il 12% di penetrazione); rimane tuttavia evidente la volontà, esistente sia a livello comunitario che in molti Stati Membri, di perseguire la via della promozione della poligenerazione. Le ragioni di questo interesse sono evidenti: l'elevata efficienza di conversione garantita dal recupero dei cascami termici di un ciclo diretto consente, a par…
Scope Oriented Thermoeconomic analysis of energy systems. Part II: Formation Structure of Optimality for robust design
2010
This paper represents the Part II of a paper in two parts. In Part I the fundamentals of Scope Oriented Thermoeconomics have been introduced, showing a scarce potential for the cost accounting of existing plants; in this Part II the same concepts are applied to the optimization of a small set of design variables for a vapour compression chiller. The method overcomes the limit of most conventional optimization techniques, which are usually based on hermetic algorithms not enabling the energy analyst to recognize all the margins for improvement. The Scope Oriented Thermoeconomic optimization allows us to disassemble the optimization process, thus recognizing the Formation Structure of Optimal…
Optimal design of cogeneration plants for seawater desalination
2004
Multi-stage flash (MSF) and reverse osmosis (RO) are the most common techniques for seawater desalination. A significant difference between these methodologies consists of their different energy requirements, i.e., thermal energy for MSF and mechanical energy for RO plants. The presence of both desalination systems (MSF and RO) appears to be suitable for cogeneration plants. The reject heat from the power cycle can feed an MSF section, while some power feeds the RO section and the MSF auxiliary equipment; the rest is sold to the grid. A criterion for the optimal design of such tri-functional cogeneration plants is proposed, based on exergo-economics and on profit maximization. In particular…
Optimal design of CHCP plants in the civil sector by Thermoeconomics
2007
The optimization of design and operation of trigeneration plants for civil applications is a very complex task, because of the large number of internal and external variables affecting the energetic and economic results that may be achieved. Further, energy-saving and profit-oriented optimization processes usually lead to different solutions, in terms of plant lay-out, optimal size of components and operation strategy. Thermoeconomic methodologies are very effective theoretical structures for the optimization of industrial energy-systems characterised by regular energy-demand profiles; however, they are hard to use when approaching civil applications and energy systems in unsteady operating…
On the reliability of thermoeconomic diagnosis of fouled evaporators: assessing the influence of geometries, operating conditions and reference state
2015
Thermoeconomic diagnosis of refrigeration systems is a pioneeristic approach, which has been proven to achieve good performances (under favorable conditions) for the detection of specific faults such as condenser and evaporator fouling and compressor valve leakage. In this paper the sensitivity of performance in detecting fouled Direct Expansion (DX) coils is investigated; the examined parameters are the temperature and relative humidity of coil inlet air and the sensible/latent heat ratio of the coil (varied by considering different numbers of rows). As the thermoeconomic model requires splitting the specific exergy of cooling air into “mechanical”, “thermal” and “chemical” fractions, and …
Formation structure of optimality by thermoeconomics: disassembling thermodynamic and external influences in energy systems’ design
2009
In this paper an original thermoeconomic approach for the optimization of complex energy systems is presented, based on a revitalized concept of “scope”, and therefore indicated as Scope Oriented Thermoeconomics (SOT). In plants including dissipative components, it allows to formulate non-arbitrary allocation criteria as concerns marginal costs; consequently, the optimization process is disassembled to recognize the Formation Structure of Optimality, i.e. the specific influences of thermodynamic and economic parameters in the path toward the optimal design. The method is applied to a very didascalic example, that is the optimization of the condensation temperature in a vapour compression ch…