Search results for "Desalination"
showing 10 items of 131 documents
A novel renewable polygeneration system for a small Mediterranean volcanic island for the combined production of energy and water: Dynamic simulation…
2014
Abstract This paper investigates the integration of solar and geothermal energy in a novel polygeneration system producing simultaneously: electricity, thermal energy, cooling energy and fresh water. The polygeneration system under analysis includes concentrating photovoltaic/thermal solar collectors (CPVT), a Geothermal Well (GW) a multi-effect distillation (MED) system for seawater desalination, a single-stage LiBr–H2O absorption chiller and additional components, such as: storage tanks, heat exchangers and balance of plant devices. The CPVT produces simultaneously electrical energy and thermal energy, at a maximum temperature of about 100 °C. The electrical energy is delivered to the gri…
CHP (combined heat and power) retrofit for a large MED-TVC (multiple effect distillation along with thermal vapour compression) desalination plant: H…
2016
Abstract Integrated power plants in “dual purpose” configuration may represent a viable option for energy cost abatement of desalted water produced by MED-TVC (Multiple Effect Distillation along with Thermal Vapour Compression). In this paper an existing large MED-TVC plant with a 36,000 m 3 /day capacity is studied: a plant retrofit is designed, based on a steam power plant with condensation and steam extraction used to drive the steam ejector. As the plant operates in CHP (Combined Heat and Power) mode, the possibility to assess the integrated “CHP + MED-TVC” as high efficiency cogeneration according to Directive 2004/8/EC is discussed. Based on a model developed in Engineering Equation S…
The Desalination Process Driven by Wave Energy: A Challenge for the Future
2016
The correlation between water and energy is currently the focus of several investigations. In particular, desalination is a technological process characterized by high energy consumption; nevertheless, desalination represents the only practicable solution in several areas, where the availability of fresh water is limited but brackish water or seawater are present. These natural resources (energy and water) are essential for each other; energy system conversion needs water, and electrical energy is necessary for water treatment or transport. Several interesting aspects include the study of saline desalination as an answer to freshwater needs and the application of renewable energy (RE) devic…
Optimization of Osmotic Desalination Plants for Water Supply Networks
2016
Water scarcity and the poor quality of water resources are leading to a wider diffusion of desalination plants using the Reverse Osmosis (RO) process. Unfortunately, the cost of a cubic meter of fresh water produced by an RO plants is still high and many efforts are in progress to increase the efficiency of the membranes used in osmotic plants and to limit the energy required by the process. A further reduction of the energy cost could be obtained by an optimal operation of the desalination plant so reducing the hourly energy cost, or by coupling the RO plant with an energy production plant based on direct osmosis (Pressure Retarded Osmosis PRO). The economic viability of the desalination p…
A novel hybrid polygeneration system supplying energy and desalinated water by renewable sources in Pantelleria Island
2017
Abstract In this paper a thermoeconomic analysis of a novel hybrid Renewable Polygeneration System connected to a district heating and cooling network is presented. The plant is powered simultaneously by solar and geothermal sources, producing electricity, desalinated water, heat and cooling energy. System layout includes Parabolic Through Collector (PTC) field, geothermal wells, Organic Rankine Cycle (ORC) unit and a Multi-Effect Desalination (MED) system. Cooling and thermal demands are calculated by suitable building dynamic simulation models, calibrated for Pantelleria Island. Electrical demand is obtained by measured data. A detailed control strategy has been implemented in order to pr…
Thermoeconomic analysis of a coupled municipal solid waste thermovalorization–MSF desalination plant: an Italian case study
2006
Abstract A thermoeconomic analysis of a cogenerative system with steam bleedings produced starting from the thermal energy recovered in a municipal solid waste thermovalorization plant is presented. The authors assume that the bled steam is used to feed a seawater multi-stage flash (MSF) desalination plant. A case study was carried out for the desalination plant, which operates in Raffineria di Gela (Sicily). In particular, the MSF process is described and the most significant features of the plant are presented. Besides, an economic analysis of a hypothetically coupled MSW thermovalorization–MSF plant was carried out to estimate the capital and operating costs and the gain derived from the…
Assessment of methodologies and data used to calculate desalination costs
2017
Abstract In desalination, similarly with other industries, the cost of the final product is one of the most important criteria that define the commercial success of a specific technology. Therefore, when new projects are planned or new technologies are proposed, the analysis of the expected costs attracts a lot of attention and is compared to (perceived) costs of state-of-the-art desalination or costs of alternative fresh water supply options. This comparison only makes sense if the cost assessment methodologies are based on the same principles and use common assumptions. This paper assesses: (i) the methodologies used to calculate the water cost; (ii) the boundary conditions and (iii) the …
MED parallel system powered by concentrating solar power (CSP): model and case study: Trapani, Sicily
2014
Abstract: This work presents an overlook on a new model that simulates the physical operation in steady state of a multi-effect distillation (MED) plant with parallel-feed (P) configuration. This model includes the consumption of steam with steam ejectors, and its validation was done using data from a real MED industrial plant using a thermal vapor compressor (TVC) operating in Italy, in the Sicilian city of Trapani. Results show that the MED model returns accurate predictions of the plant behavior, very useful for a first analysis on such type of investments. This MED model was also integrated into the system advisor model developed by the US National Renewable Energy Laboratory. Simulatio…
A novel solar-geothermal trigeneration system integrating water desalination: Design, dynamic simulation and economic assessment
2016
Abstract In this paper, an innovative solar-geothermal polygeneration system is investigated. The system supplies a small community with electricity, desalinated water and space heating and cooling through a district network. The hybrid multi-purpose plant, based on an Organic Rankine Cycle (ORC) supplied by medium-enthalpy geothermal energy and by solar energy; this latter is provided by Parabolic Trough Collectors (PTC). The geothermal brine is first used to drive the ORC loop, then to provide space heating at around 85÷90 °C (in the winter), or cooling (in the summer, by means of a single-effect absorption chiller). Finally, the geothermal brine drives a Multi-Effect Distillation (MED) s…
A dynamic model for MED-TVC transient operation
2017
Abstract The Multi Effect Distillation (MED) process is often proposed as a key technology for the construction of new thermal desalination plants, especially within solar-powered cogeneration schemes. With this respect, the need for transient behaviour analysis requires the development of dynamic models for the MED process. Only a few have been presented so far in the literature, in which, however, several simplifying assumptions and constrains are still limiting their potential use. The model here proposed addresses most of the aspects still limiting previous models formulations. The powerful equation-based process simulator gPROMS® was chosen for the implementation of the model, develope…