0000000000900365
AUTHOR
A. Piacentino
A novel renewable system supplying energy and water to the island of Pantelleria
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 energy and capable to supply electricity, desalinated water, heat and cooling energy. System layout includes a Parabolic Through Collector (PTC) field, geothermal wells, an Organic Rankine Cycle (ORC) unit and a Multi-Effect Desalination (MED) system. A model of a typical building of Pantelleria urban area and a heating and cooling system based on fan coils have been modelled and linked to the plant model in TRNSYS environment. A detailed system control has been implemented in t…
Exergy analysis of electrodialysis for water desalination: Influence of irreversibility sources
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…
Thermoeconomic diagnosis of air conditioning systems: experimental assessment of performance for improved reliability
Thermoeconomic diagnosis is an exergy-based fault detection and diagnosis technique which has been recently extended to air conditioning systems. So far, developments of this technique have relied only on simulation data without being evaluated using real data. For the first time, this work aims at assessing the performance of thermoeconomic diagnosis using experimental data obtained from a five-ton packaged rooftop air conditioning unit (RTU) installed at Herrick Laboratories, Purdue University. The RTU was tested in psychrometric chambers under a wide range of operating conditions and fault levels. The following faults were investigated: (i) evaporator fouling, (ii) condenser fouling and …
Modelling Reverse Electrodialysis process via Exergy Analysis
Salinity Gradient Power Heat Engines (SGP-HEs) represent a novel technology to convert low grade waste heat into electricity. Reverse Electrodialysis Heat Engine (REDHE) is one of the possible application of this concept, where a common RED unit is coupled with a thermal regeneration unit supplied with waste heat to restore the salinity gradient of the streams to be fed back to the RED unit. In a RED unit, anion and cation exchange membranes (AEMs and CEMs) are alternatively stacked and interposed between salt solutions at different concentration generating an electric potential difference over each membrane along with a selective transport of cations and anions from the concentrated soluti…
Performance maps for an air-cooled air conditioning system as a preliminary instrument for the diagnosis of evaporator fouling
During the past few decades, there has been increased interest in the development of automated approaches for detecting and diagnosing faults in air conditioning systems. One diagnostic approach involves the use of exergy analysis. As a first step towards understanding the application of exergy analysis to diagnostics, this work is focused on the thermodynamic and exergy analysis of a direct expansion air conditioning system used in small commercial building applications. The analysis was carried out by means of experimental activities on a 17.5 kW rooftop unit installed at the Herrick Laboratories, Purdue University, Indiana (USA). The system under investigation was equipped with a variabl…
Hierarchizing Energy Saving Strategies in Wine Industry by Advanced Modelling of Chilling Units Operation
Wineries are energy intensive industries and in order to make the production process more sustainable, solutions for an efficient use of energy should be implemented. Large surveys conducted in the wineries sector have highlighted the importance of performing accurate energy audits and have identified in the installation of efficient cooling/refrigeration systems the most promising solutions in a variety of cases. Unfortunately, the savings achieved by such energy efficient solutions is often calculated by highly simplified approaches, which do not take into consideration the actual operating conditions of the equipment (highly variable on a seasonal and daily basis). In this paper a system…
CHP retrofit for a large Med-Tvc Desalination Plant: High efficiency assessment for different design options under the current legislative EU framework
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 Solver, a …
An agent-based model to support the preliminary design and operation of heating and power grids with cogeneration units and photovoltaic panels in densely populated areas
The increase in the energy demands of residential neighborhoods constitutes a huge challenge to be faced. A viable option lies in the insertion of both renewable energy production systems and cogeneration units within urban territories. On-site production allows for the satisfaction of the heating and electrical demands of end-users and favors the distribution of produced energy within the neighborhood, especially under the regulatory framework of energy communities. This paper proposes a tool to model heating and electricity networks integrated with cogeneration units and PV panels installed in urban areas. The tool accounts for the following possibilities: (i) energy flow management and p…
Energy assessment of a dish-Stirling system powering a reverse osmosis plant for seawater desalination
Water scarcity in many regions of the world and the global demographic growth make the desalination of seawater and/or brackish an effective solution to meet the growing demand for freshwater. Nowadays, reverse osmosis has the largest share of the global installed desalination capacity. The impelling need to reduce greenhouse gas emissions has been pushing the search for sustainable technologies to produce the electricity needed to power reverse osmosis plants. Among solar technologies, little attention has been paid to the possibility of powering reverse osmosis with electricity from the dish-Stirling concentrator. To fill this knowledge gap, this paper assesses the energy-saving potential…