Search results for "Thermal energy"
showing 10 items of 126 documents
Magnetic Polyurethane Microcarriers from Nanoparticle-Stabilized Emulsions for Thermal Energy Storage
2020
Hydrated inorganic salts are phase change materials (PCMs) with promising thermal energy storage capacity. However, their application is commonly restricted because of problems of phase segregation...
Latent Heat of Spontaneous-Curvature-Induced Lamellar-to-Microemulsion Transitions
1995
Using differential scanning microcalorimetry we examine the latent heat of the temperature-induced structural transition from a lamellar to a microemulsion phase in a H2O/n-octane/C12E5 (n-dodecyl pentanethyleneglycol ether) system. The associated latent heat increases strongly with surfactant concentration yielding heat changes up to 1kB T per surfactant molecule. These large values are quantitatively described by an interfacial model which takes into account the temperature dependence of the spontaneous curvature. The model explains our data points without considering contributions to the free energy by thermal fluctuations, entropy of mixing, undulations of the lamellae and renormalizati…
Combined heat and power generation with a HCPV system at 2000 suns
2015
In the framework of the FAE “Fotovoltaico ad Alta Efficienza” (“High Efficiency Photovoltaic”) Research Project funded by the Sicilian Region under the program PO FESR Sicilia 2007/2013 4.1.1.1, we have developed an innovative solar CHP system for the combined production of heat and power at the high concentration level of 2000 suns [1]. This work shows the experimental results obtained on FAE-HCPV modules and analyses the behaviour of the system. The solar radiation is concentrated on commercial InGaP/InGaAs/Ge triple-junction solar cells designed for intensive work. The primary optics is a rectangular off-axis parabolic mirror (with a size of 46x46 = 2116 cm2 in a projection normal to the…
Performance increase of membrane distillation pilot scale modules operating in vacuum-enhanced air-gap configuration
2019
Abstract This paper presents the first experimental evaluation at pilot scale of the operation of vacuum-enhanced air-gap membrane distillation (V-AGMD) using two commercial spiral-wound modules at Plataforma Solar de Almeria's solar desalination test facilities. The main difference between the modules was the channel length (1.5 and 2.7 m) as a result of having different membrane surface area (7.2 m2 and 25.9 m2 respectively) and different number of envelopes. Suction of air from the gap improved the vapour transfer through the membrane pores and the performance of the modules was significantly increased in relation to common air-gap (AGMD) operational mode, especially in the treatment of …
An Investigation of the Thermal Effects in Orthogonal Cutting Associated with Multilayer Coatings
2001
Abstract This paper deals with an experimental and analytical investigation into the tool-chip interface behaviour, influencing the temperature and heat transfer at the multilayered coated-tool rake face during orthogonal cutting of carbon and stainless steels. New methodology for assessing 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 this study. It was proven, based on the heat flux analysis, that the use of advanced coatings with an intermediate Al 2 O 3 layer can substantially improve the heat flow into the chip at d…
Prediction models to analyse the performance of a commercial-scale membrane distillation unit for desalting brines from RO plants
2018
Abstract Desalting brines from Reverse Osmosis (RO) plants is one of the most promising applications of Membrane Distillation (MD) systems. The development of accurate models to predict MD system performances plays a significant role in the design of this kind of industrial applications. In this paper, a commercial-scale Permeate-Gap Membrane Distillation (PGMD) module was modelled by means of two different approaches: Response Surface Methodology (RSM) and Artificial Neural Networks (ANN). Condenser inlet temperature, evaporator inlet temperature, feed flow rate and feed water salt concentration were selected as inputs of the model, while permeate flux and Specific Thermal Energy Consumpti…
Life cycle assessment of solar communities
2020
Abstract This study presents the comparison of the life cycle performance of two different urban energy systems, applied to a large mixed-use community, in Calgary (Canada). The two systems investigated consist of an energy efficient conventional system, using heat pumps for heating, cooling and domestic hot water; the second design widely deploys solar thermal panels coupled to district heating infrastructure and a borehole seasonal thermal storage. The analysis is based on the Life Cycle Assessment methodology and includes the stages of raw materials and energy supply, system manufacturing, use stage of the systems, generation and use of energy on-site, maintenance and components’ substit…
A 2.6 V-10 μa Nanorectenna Harvester based on thermal radiation of the car exhaust system
2021
In this paper, for the first time, the design and simulation of a thermal nanorectenna energy harvester for harvesting the electromagnetic energy from the car exhaust system is presented. The nanorectenna system is composed of three gold arrow-bowtie nanoantennas with different resonance frequencies and a geometric nanodiode in the feed gap of each nanoantenna. The resonance frequencies at about 50 THz, 65 THz, and 83 THz correspond to the frequencies of the thermal radiation emitted from the exhaust tailpipe, catalytic converter, and manifold, respectively. The proposed $2.6 mathbf{V}-10 mumathbf{A}$ Energy Harvester with a nanoarray area of about 0,05 mm2 represents an optimum solution to…
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…
Exergetic and exergoeconomic analysis of a novel hybrid solar-geothermal polygeneration system producing energy and water
2016
Abstract A dynamic simulation model of a novel solar–geothermal polygeneration system and the related exergetic and exergoeconomic analyses are presented in this paper. The plant is designed in order to supply electrical, thermal and cooling energy and fresh water for a small community, connected to a district heating and cooling network. The hybrid system is equipped with an Organic Rankine Cycle fueled by medium-enthalpy geothermal energy and by a Parabolic Trough Collector solar field. Geothermal brine is also used for space heating and cooling purposes. Finally, geothermal fluid supplies heat to a Multi-Effect Distillation unit, producing also desalinized water from seawater. Dynamic si…