Search results for "Thermal energy"
showing 10 items of 126 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…
Performance evaluation of hybrid RO/MEE systems powered by a WTE plant
2008
Abstract The solid waste management is, in different contexts, a very critical issue. The use of landfills can no longer be considered a satisfactory environmental solution, therefore new methods have to be chosen and waste-to-energy (WTE) plants would provide an answer. Today's WTE plants are a far cry from their polluting predecessors. Using modern combustion and pollution control technology, WTE plants are able to retrieve considerable amounts of energy from waste combustion while minimizing emissions. As we know, is possible to recover thermal energy by combusting municipal solid waste (MSW) for electricity generation and district heating. However, with everincreasing population and rap…
Prediction of friction and heat flow in machining incorporating thermophysical properties of the coating–chip interface
2004
Abstract This paper deals with an experimental and analytical investigation into the thermodynamically activated effects influencing the behaviour of the multi-layered coated tool rake face during orthogonal cutting of ferromagnetic and paramagnetic steels. Temperature measurements on the tool rake face using a thermocouple-based technique and identification of the contact zone by means of computer image processing were carried out. New methodology for assessing friction and the amount of thermal energy generated when machining with a coated tool insert with natural and restricted contact coupled with a metallic chip, using thermophysical properties of the sliding materials is developed in …
PCM thermal storage design in buildings: Experimental studies and applications to solaria in cold climates
2017
Abstract As energy availability and demand often do not match, thermal energy storage plays a crucial role to take advantage of solar radiation in buildings: in particular, latent heat storage via phase-change material is particularly attractive due to its ability to provide high energy storage density. This paper analyzes the performance of a building-integrated thermal storage system to increase the energy performances of solaria in a cold climate. A wall opposing a highly glazed facade (south oriented) is used as thermal storage with phase change materials embedded in the wall. The study is based on both experimental and simulation studies. The concept considered is particularly suited t…
The BAC factor method: Application to a real Italian not-residential building
2016
The paper focuses the evaluation of the impact of Building Automation Control (BAC) systems on not-residential buildings. In particular, this work shows how the control, monitoring and automation actions considered by the European Standard EN 15232 can influence the electric and thermal energy consumptions of the University of Palermo DEIM (Department of Energy, Information Engineering and Mathematical Models) building. After evaluating the building energy consumptions, by using the CEI Guide 205-18, the BAC systems are chosen and sized and an economic evaluation of their installation cost is also carried out.
On the Efficacy of PCM to Shave Peak Temperature of Crystalline Photovoltaic Panels: An FDM Model and Field Validation
2013
The exploitation of renewable energy sources and specifically photovoltaic (PV) devices have been showing significant growth; however, for a more effective development of this technology it is essential to have higher energy conversion performances. PV producers often declare a higher efficiency respect to real conditions and this deviation is mainly due to the difference between nominal and real temperature conditions of the PV. In order to improve the solar cell energy conversion efficiency many authors have proposed a methodology to keep the temperature of a PV system lower: a modified crystalline PV system built with a normal PV panel coupled with a Phase Change Material (PCM) heat stor…
Fatigue crack growth behaviour of four structural steels in air and in a geothermal fluid environment
1992
Abstract In recent years the exploitation of geothermal energy has expanded rapidly in Italy. This has created a requirement for improved drilling technology, to reduce the number of failures occuring in the drills, which is more frequent than in oil wells. This paper deals with the results obtained in FCCR tests of four materials both in air and in two types of aggressive environments. Deterioration takes place by fatigue, corrosion fatigue and hydrogen embrittlement. It is concluded that the steel G105 is a suitable substitute for S135 in drill pipes, and inspections between drillings may be adequate to prevent failure for small-curvature wells.
PCM Thermal Energy Storage in Buildings: Experimental Study and Applications
2015
Abstract The study aims at analyzing the performance of Phase Change Materials (PCMs) in residential housing for different climates. This paper presents the results of an experiment performed in the Concordia University Solar Simulator and Environmental Chamber research facility (SSEC, Montreal, Canada). PCM boards were embedded on the back wall of a test hut placedin the climatic chamber. Several experiments were performed to explore the potential for verification of the proposed analysis and to produce enough data to perform model calibrations. Results show a strong increase in the apparent thermal inertia of the room allowing for a reduction in daily temperature fluctuations in the test …
Phase Change Materials Applications to Optimize Cooling Performance of Buildings in the Mediterranean Area: A Parametric Analysis
2015
Abstract Building integrated thermal energy storage systems cover a wide range of techniques and solutions depending on technology applications and aims. They however all have in common the concept behind: being able to store energy for later use in order to reduce the time mismatch between energy availability and demand. In this context, Phase Change Materials (PCMs) fit the above description, since they would allow for mostly isothermal phase change within normal thermal comfort range. In order to face the typical challenges of the Mediterranean climate, the following concept was elaborated: the idea is to use the phase change mechanics as a substitute to the thermal inertia of massive wa…
Finite difference thermal model of a latent heat storage system coupled with a photovoltaic device: Description and experimental validation
2014
Abstract The use of photovoltaic (PV) systems has been showing a significant growth trend but for a more effective development of this technology it is essential to have higher energy conversion performances. Producers of PV often declare an higher efficiency respect to real conditions and this deviation is mainly due to the difference between nominal and real temperature conditions of the PV. To improve the solar cell energy conversion efficiency many authors have proposed a methodology to keep lower the temperature of a PV system: a modified PV system built with a normal PV panel coupled with a Phase Change Material (PCM) heat storage device. In this paper is described a thermal model ana…