Search results for "Exergy analysi"
showing 10 items of 13 documents
Exergy analysis of electrodialysis for water desalination: Influence of irreversibility sources
2022
The increasing freshwater demand is pushing the development and adoption of desalination technologies. In this framework, electrodialysis has a consolidated role in brackish water desalination, but to make it competitive with other technologies for the desalination of more concentrated solutions (e.g., seawater), the specific energy consumption should be reduced. Exergy analysis provides a useful tool for determining the contribution of each thermodynamic inefficiencies on the process efficiency and the specific energy consumption. In this regard, this paper presents an exergy analysis of the electrodialysis process. A 1-D model is used for evaluating the performance of industrial-scale sys…
INNOVATIVE APPLICATIONS OF EXERGY ANALYSIS AND THERMOECONOMICS IN CHEMICAL, THERMAL AND COOLING ENERGY CONVERSION SYSTEMS
Since 70s, the world has been becoming more and more concerned about energy and environmental issues. The need of meeting the current energy demand by guaranteeing the ability of future generation to satisfy theirs have been pushing research not only to exploit alternative energy sources such as renewable energies, but also to improve the efficiency of energy conversion systems. To this regard, developing systems that use efficiently energy is of paramount importance especially in those countries which rely on non-renewable energy sources such as oil, natural gas, and coal. In fact, the reduction of energy consumption will lead not only to the saving of unrestorable and limited energy resou…
Introducing exergy analysis in life cycle assessment: A case study
2018
Life Cycle Assessment (LCA) is a methodology for assessing the potential environmental aspects associated with a product or service along its life cycle. However, in the case of energy technologies, it is suggested that the LCA of a product encompasses also further aspects other than environmental aspects and primary energy calculations. In particular, to optimize the reduction of raw materials during the whole life cycle, it is important to introduce the assessment of the irreversibility, applying the exergy analysis. In this paper, an integrated approach of exergy analysis and LCA is proposed, developing the Life-cycle quality index able to suggest potential exergy inefficiencies and the …
Thermoeconomic optimization of a renewable polygeneration system serving a small isolated community
2015
During the last years, special attention has been paid to renewable polygeneration technologies, able of simultaneously producing thermal, cooling, electrical energy and desalinated water from seawater. This paper focuses on an innovative polygeneration system driven by renewable energy sources, including the following technologies: hybrid photovoltaic/thermal collectors, concentrating parabolic trough (CPVT), a biomass heater, a single-stage absorption chiller and a multiple-effect distillation desalination system. The system is designed to cover the base load of an isolated small community. In previous papers, the dynamic simulation model about plant operation is discussed. In this paper,…
Exergetic and exergoeconomic analysis of a renewable polygeneration system and viability study for small isolated communities
2015
Abstract A great interest has recently arisen for the sustainable supply of energy and fresh water, due to the growing demand from developing countries. Facing this demand by traditional technologies implies evident risks related with the high cost of fossil fuels and their environmental impact. Then, alternative solutions based on the use of renewable sources and innovative technologies must be considered. In this paper a renewable polygeneration system is examined, which includes a solar field based on parabolic trough photovoltaic/thermal collectors, a biomass heater, an absorption chiller and a Multiple Effect Distillation desalination unit. Plant operation under dynamic conditions has …
Exergy analysis and thermoeconomic cost accounting of a Combined Heat and Power steam cycle integrated with a Multi Effect Distillation-Thermal Vapou…
2017
Abstract In this paper an exergy analysis and thermoeconomic cost accounting of a Combined Heat and Power steam cycle integrated with Multi Effect Distillation-Thermal Vapour Compression plant is performed; the goal of the study is to show how these methodologies provide a rational criterion to allocate production costs on electricity and freshwater in such a dual purpose system. After a brief overview on the methodology and a description of reference plant, exergy analysis is carried out to calculate exergy flows and exergy efficiencies at component level. A detailed description of the adopted thermoeconomic model is given. In a first scenario, cost accounting is performed assuming that th…
Thermodynamic, Exergy, and Thermoeconomic analysis of Multiple Effect Distillation Processes
2018
Abstract Multiple effect distillation (MED) is nowadays the preferred technology for the construction of new plants based on thermal processes in the growing desalination market. MED technology, in fact, presents a number of advantages with respect to the more traditional multistage flash technology, among all the lower energy consumption achievable in MED plants. However, a large potential for improvement in terms of lowering production costs still exists, which stimulates further efforts on process optimization from companies and researchers involved in the field. Thermodynamic and exergy analysis provides useful insights regarding the identification of main inefficiencies and the margins…
Exergy analysis of reverse electrodialysis
2018
Abstract Reverse electrodialysis in closed loop configurations is a promising membrane technology in the energy conversion and storage fields. One of the main advantages of closed-loop reverse electrodialysis is the possibility of using a wide range of operating concentrations, flow rates and different salts for generating the salinity gradient. In this work, an original exergy analysis of the reverse electrodialysis process was carried out in order to investigate reverse electrodialysis performance in terms of energetic and exergetic efficiency parameters in a wide range of operating conditions. A mono-dimensional model of the reverse electrodialysis process was developed, in which all sou…
Recent advances in methods, policies and technologies at sustainable energy systems development
2022
Following the 2015 Paris Agreement and other agreements which have been signed after, sustainable energy development is becoming the major goal in many countries. EU have set the targets to reduce the annual greenhouse gas emission by 40% in 2030 and 80% for 2050 compared with 1990 levels. For achieving this ambitious energy policy, three major technological changes are available: energy savings on the demand side, efficiency improvements in the energy production, and replacement of fossil fuels by various sources of renewable energy. Also, for realization cited three major technological changes the support of the multi-disciplinary scientific knowledge is needed. Therefore, from the beginn…
Cold recovery during regasification of LNG part one: Cold utilization far from the regasification facility
2010
The paper deals with cold recovery during LNG regasification. The applications analyzed pertain to the use in deep freezing agro food industry and in space air conditioning facilities in commercial sector (Supermarkets and Hypermarkets) of cold recovered from the regasification process. A modular LNG regasification unit is proposed having the regasification capacity of 2 billion standard cubic meters/year of gas and it is based on use of a Power Cycle working with Ethane, this unit allows operation of cold energy transfer, contained in LNG to be regasified, in a range of temperatures suitable for multipurpose use of cold, reducing regasification process irreversibility. Some electric energy…