49 results on '"Frazzica, A."'
Search Results
2. Comparative analysis of thermal energy storage technologies through the definition of suitable key performance indicators
- Author
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Palomba, Valeria and Frazzica, Andrea
- Published
- 2019
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3. Assessment of the hydration/dehydration behaviour of MgSO4∙7H2O filled cellular foams for sorption storage applications through morphological and thermo-gravimetric analyses
- Author
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Calabrese, Luigi, Brancato, Vincenza, Palomba, Valeria, Frazzica, Andrea, and Cabeza, Luisa F.
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- 2018
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4. Synthesis of SAPO-34/graphite composites for low temperature heat adsorption pumps
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Bonaccorsi, L., Calabrese, L., Proverbio, E., Frazzica, A., Freni, A., Restuccia, G., Piperopoulos, E., and Milone, C.
- Published
- 2013
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5. Recent advancements in sorption technology for solar thermal energy storage applications.
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Palomba, Valeria and Frazzica, Andrea
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HEAT storage , *SOLAR thermal energy , *TECHNOLOGY assessment , *SORPTION , *SOLAR technology , *PHYSISORPTION , *MOISTURE content of food , *COMPOSITE columns - Abstract
• Review focusing on the most recent advancements in the sorption TES field. • Analysis of activities at materials and systems levels is reported. • Most recent international activities and funded projects in the sorption TES field are also highlighted. Sorption thermal energy storage (STES) technology, belonging to the wider class of thermochemical TES, represents a promising alternative to common sensible and latent TESs, especially for applications at low-medium temperature (i.e. below 130 °C). The interest towards this technology is confirmed by the huge amount of research and development activities ongoing, represented by scientific publications as well as funded projects and international working groups. In such a context, the present paper reports about the most recent activities in the STES field. Particularly, it focuses on the analysis of innovative sorbent materials currently under development, comprising liquid absorption, physical adsorption, chemical reactions in pure salts and composite sorbents. Analysis of critical issues like achievable storage density, stability and corrosiveness were reported for each sorbent material. Furthermore, prototypes recently developed for each of the sorbent classes above reported were presented, highlighting the achievable performance, with particular attention towards the TES density attained under typical working conditions for heat and cold storage applications, both with open and closed TES systems. Finally, the most recent international activities focusing on the further development of STES, to help achieving higher Technology Readiness Level (TRL) were reported. These mainly comprise funded R&D projects and international working groups supported by intergovernmental organizations and research and innovations alliances. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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6. Thermal performance of hybrid cement mortar-PCMs for warm climates application.
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Frazzica, Andrea, Brancato, Vincenza, Palomba, Valeria, La Rosa, Davide, Grungo, Francesco, Calabrese, Luigi, and Proverbio, Edoardo
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HYBRID systems , *MORTAR , *PHASE change materials , *MICROENCAPSULATION , *PHYSICS experiments , *TEMPERATURE measurements - Abstract
Abstract In this paper, composites based on a standard mortar and two commercial microencapsulated phase change materials (PCMs) with nominal melting point of 23 °C and 26 °C in different percentage were produced and characterized. To this aim, an innovative experimental setup, able to contemporarily test two different samples subjected to the same temperature profile was designed and realized. The experimental results were then used to validate a numerical model, implemented in COMSOL Multiphysics. Finally, a parametric analysis was carried out to define optimized melting temperature for the PCM for Mediterranean application, aiming at reducing the overall energy consumption as well as to improve the comfort conditions inside buildings both during winter and summer. The results demonstrated that an optimal melting temperature of 27 °C is achieved under Sicilian climatic condition. Furthermore, adding 15 wt% of optimized PCM allows to improve the comfort conditions of about 15% compared to standard solutions based on pure cement mortars. Highlights • Experimental characterization of PCM-mortar composites for Mediterranean climates. • Development of a test setup for differential evaluation of composites and pure mortar. • Experimental validation under static and dynamic conditions for winter and summer. • Numerical modelling of the heat transfer efficiency inside PCM-mortar composite. • Estimation of the comfort conditions for Mediterranean applications. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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7. Potential of thermal storage for hot potable water distribution in cruise ships.
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Manzan, Marco, Pezzi, Amedeo, Zorzi, Ezio Zandegiacomo de, Freni, Angelo, Frazzica, Andrea, Vaglieco, Bianca Maria, Lucio, Zentilomo, and Claudio, Deluca
- Abstract
Abstract Hot potable water preparation in ships requires lots of energy from the power plant; this is particularly true in modern cruise ships with a high demand of potable water for people, restaurants, spa and pools. Usually the required amount of hot water is instantly produced using a number of different energy sources available on board. However, the use of direct heaters on peak demand conditions increases fuel consumption and greenhouse gas emissions. This is especially important in the case of ship in port configuration, due to the reduced number of active engines and therefore the reduced amount of waste heat from the cooling line usually employed for this task. This paper investigates possible solutions to size a hot water thermal storage in order to compensate the mismatch between heat generation during cruise and heat required during ship in port configuration. The performances of different solutions are compared using dynamic thermal simulations of the ship's hot water distribution system with different regimes and time dependent heat requirements. Moreover it will be introduced the use of PCM materials with the aim to further improve system's performance. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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8. Characterisation and comparative analysis of zeotype water adsorbents for heat transformation applications.
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Brancato, Vincenza and Frazzica, Andrea
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SORBENTS , *REFRIGERANTS , *ADSORPTION (Chemistry) , *WATER vapor , *HEAT storage - Abstract
This paper presents the experimental characterisation of three zeotype materials, namely, AlPO-18, FAPO-34 and SAPO-34, suitable for adsorption heat transformation applications, employing water as refrigerant. Morphological and thermo-physical analyses were performed on each sample. In particular, the adsorption capacity of each material was evaluated by measuring a complete set of water vapour adsorption/desorption isotherms, in order to investigate the hysteresis effect. The obtained equilibrium data were fitted by means of Dubinin-Astakhov equation, both for adsorption and desorption branches. Finally, a thermodynamic analysis of the achievable performance of these three working pairs was performed under three main operating conditions, namely, thermal energy storage, air conditioning and heat pumping. The achieved results confirmed the potentiality of these adsorbents, showing promising cooling and thermal COP, up to 0.80 and 1.60 respectively, and heat storage capacities both for daily and seasonal operation. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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9. Dynamic simulation of a multi-generation system, for electric and cooling energy provision, employing a SOFC cogenerator and an adsorption chiller.
- Author
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Palomba, Valeria, Ferraro, Marco, Frazzica, Andrea, Vasta, Salvatore, Sergi, Francesco, and Antonucci, Vincenzo
- Abstract
Aim of this work is the dynamic simulation of the operation of a small-scale multi-generation system, based on a Solid Oxide Fuel Cell (SOFC) micro-cogenerator (μCHP) coupled to an adsorption chiller, to provide electric and cooling energy to a telecommunication shelter. The dynamic simulation model has been implemented in TRNSYS environment. The μCHP has nominal electric power of 2.5 kW and its thermal output is used to drive a thermally driven adsorption chiller, with nominal cooling power of 10 kW. The performance of both components were experimentally validated under controlled lab conditions. The developed model allowed to optimize the system configuration and to perform an energy and environmental analysis. This analysis demonstrated the possibility of achieving global energy efficiency up to 63% with a CO
2 reduction proportional to the electric and cooling load of the telecommunication shelter. [ABSTRACT FROM AUTHOR]- Published
- 2017
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10. Experimental comparison of two heat exchanger concepts for latent heat storage applications.
- Author
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Frazzica, Andrea, Palomba, Valeria, Rosa, Davide La, and Brancato, Vincenza
- Abstract
In the present work, two different types of heat exchangers are experimentally compared, namely a fin-and-tubes custom made HEX and a commercial asymmetric plate heat exchanger, for the application with phase change materials. In particular, the two devices were tested in a specifically designed testing rig located at CNR-ITAE and suitable for the characterization of thermal energy storages. The testing bench allows simulating a heat source up to 100°C (e.g. solar thermal collectors, low-grade waste heat) and to set the desired discharge temperature in the range 20°C-80°C. The phase change material with which the exchangers were filled, is a commercial paraffin (Plus ICE A82), having a nominal melting temperature of 82°C. The experimental results on charge and discharge tests, realized with the same protocol, were used for a comparison of the systems, through the identification of suitable performance figures and Key Performance Indicators, such as material-to-metal ratio, heat storage density, maximum and average power achievable and effectiveness of the system. The results show that, for the tested material, characterised by a very low thermal conductivity (i.e. about 0.2 W/mK), the selected plate heat exchanger allows a better exploitation of the heat stored inside the material, letting at the same time to reach a power output in the range 1-10 kW. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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11. Adsorbent working pairs for solar thermal energy storage in buildings.
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Frazzica, Andrea and Freni, Angelo
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BUILDING-integrated photovoltaic systems , *ENERGY storage , *THERMODYNAMICS , *ADSORPTION (Chemistry) , *HEAT exchangers - Abstract
In this study, the thermodynamic analysis of several adsorption working pairs for adsorption heat storage applications at domestic level is presented. The selected working pairs employ different working fluids (i.e. water, ethanol, ammonia, methanol) and different adsorbent materials such as classical zeolites, silica gels, alumino-phosphates, composite sorbents and activated carbons. The simulations have been performed taking into account desorption temperatures in the range between 80 °C and 120 °C, compatible with non-concentrating solar thermal collectors, under seasonal heat storage working conditions. The composite sorbent MWCNT-LiCl with both water and methanol as working fluid showed the highest heat storage density under practical working boundary conditions. Among the standard adsorbents, the zeotype AQSOA Z02 showed promising achievable heat storage densities. Classical working pairs, such as zeolite 13X/water, commonly employed for heat storage applications, are not suitable for this working range. Finally, also the influence of the metal to sorbent mass ratio, due to the heat exchanger, was investigated, demonstrating that it can reduce the achievable amount of heat released to the user up to 30%. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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12. Identification and characterization of promising phase change materials for solar cooling applications.
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Brancato, Vincenza, Frazzica, Andrea, Sapienza, Alessio, and Freni, Angelo
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PHASE change materials , *SOLAR air conditioning , *SOLAR thermal energy , *THERMAL properties of buildings , *HEAT storage - Abstract
Solar cooling technology is an attractive way to use solar thermal energy to produce cooling for buildings. The employment of taphase change materials (PCMs) as heat storage medium, to increase the range of utilization of solar thermal energy, thus improving the overall system performance, is considered very attractive. Nevertheless, in order to allow the development of latent heat storage prototypes for such an application, it is mandatory to verify the thermo-physical performance as well as the long-term stability of the available materials. To this aim, in the present paper, the most attractive commercial PCM as well as neat chemical compounds operating in the temperature range between 80 °C and 100 °C, perfectly suitable for non-concentrating solar cooling systems, have been identified and completely characterized. In particular, several cycles have been performed on each material, to verify possible instabilities in their behavior. Most of the neat materials have confirmed to be promising for this application, thanks to their really high melting enthalpy, up to 255 J/g as showed for Aluminum Ammonium Sulfate Dodecahydrate. Nevertheless, all these materials are still not stable, showing high supercooling, allotropic phase transition, incongruent melting and even absence of re-crystallization, which makes necessary an intense work to bring them to a reliability level sufficient for real application. On the contrary, the commercial PCMs, even if mostly characterized by lower melting enthalpy, ranging between 120 and 150 J/g, confirmed their stability, which makes them ready for practical applications. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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13. Experimental testing of a hybrid sensible-latent heat storage system for domestic hot water applications.
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Frazzica, Andrea, Manzan, Marco, Sapienza, Alessio, Freni, Angelo, Toniato, Giuseppe, and Restuccia, Giovanni
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HEAT storage , *HOT water , *PHASE change materials , *HYDRATES , *PARAFFIN wax , *SIMULATION methods & models - Abstract
Aim of this work is to present the results of the testing of a small scale hybrid sensible/latent storage system (nominal volume 48.6 dm 3 ), consisting of water in which macro-encapsulated phase change materials (PCMs) are added. Two different PCMs were macro-encapsulated, a commercial paraffin and a hydrate salts mixture prepared in the CNR ITAE lab, and loaded inside the tank in order to be tested. Different volume ratios between the PCM and the water were tested. The tests were conducted simulating different domestic hot water draw-off profiles. The resulting data showed an appreciable increase of heat storage capacity per unit of volume, even for limited fractions of PCM employed, reaching up to 10% of heat storage increasing by 1.3 dm 3 of hydrate salts mixture added. Finally, the experimental results were used to test a numerical method of a PCM enhanced tank for dynamic plant simulations in ESP-r environment. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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14. Design, realization and testing of an adsorption refrigerator based on activated carbon/ethanol working pair.
- Author
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Frazzica, A., Palomba, V., Dawoud, B., Gullì, G., Brancato, V., Sapienza, A., Vasta, S., Freni, A., Costa, F., and Restuccia, G.
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REFRIGERATOR design & construction , *ADSORPTION (Chemistry) , *ETHANOL , *ACTIVATED carbon , *THERMODYNAMICS , *GRAVIMETRIC analysis - Abstract
In the present paper design, realization and testing of a novel small scale adsorption refrigerator prototype based on activated carbon/ethanol working pair is described. Firstly, experimental activity has been carried out for identification of the best performing activated carbon available on the market, through the evaluation of the achievable thermodynamic performance both under air conditioning and refrigeration conditions. Once identified the best performing activated carbon, the design of the adsorber was developed by experimental dynamic performance analysis, carried out by means of the Gravimetric-Large Temperature Jump (G-LTJ) apparatus available at CNR ITAE lab. Finally, the whole 0.5 kW refrigerator prototype was designed and built. First experimental results both under reference air conditioning and refrigeration cycles have been reported, to check the achievable performance. High Specific Cooling Powers (SCPs), 95 W/kg and 50 W/kg, for air conditioning and refrigeration respectively, were obtained, while the COP ranged between 0.09 and 0.11, thus showing an improvement of the current state of the art. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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15. Dynamic Simulation and Performance Analysis of Solar Cooling Systems in Italy.
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Vasta, Salvatore, Palomba, Valeria, Frazzica, Andrea, Costa, Fabio, and Freni, Angelo
- Abstract
In this work, a dynamic model for the simulation of solar cooling systems employing adsorption chillers has been evaluated. The model, realised with the commercial software TRNSYS, has been implemented to quantify the effect of different operational and design parameters on the overall performances of solar cooling systems in three different Italian cities (Milan, Rome, Messina). An economic analysis has been performed for an optimised system, in order to evaluate the payback time of the different solutions compared to a traditional air conditioning system, considering also the state incentives introduced since 2012. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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16. Model Development and Validation for a Tank in Tank Water Thermal Storage for Domestic Application.
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Padovan, Roberta, Manzan, Marco, Zorzi, Ezio Zandegiacomo De, Gullì, Giuseppe, and Frazzica, Andrea
- Abstract
The hot water tanks are the typical thermal storage systems in Solar Domestic Hot Water (SDHW) plants. In this paper a new model for ESP-r has been developed, in order to simulate a tank in tank heat storage. The tank in tank system is made up of two tanks in which the smaller, storing potable hot water, is contained in a larger buffer filled with heating-circuit water. The developed model is an enhanced version of a component already available in ESP-r. Experimental results are used to identify some parameters and to perform the validation of the developed code. [ABSTRACT FROM AUTHOR]
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- 2015
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17. Analysis of different heat pumping technologies integrating small scale solid oxide fuel cell system for more efficient building heating systems.
- Author
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Frazzica, A., Briguglio, N., Sapienza, A., Freni, A., Brunaccini, G., Antonucci, V., and Ferraro, M.
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SOLID oxide fuel cells , *ENERGY consumption , *HEAT pumps , *NUMERICAL analysis , *COMPUTER simulation - Abstract
Development of advanced heating systems, able to reduce the energy consumption of buildings is still an open issue. Different technologies, either already at commercial level or in a pre-commercial phase, are available. Among them, heat pumps and fuel cells represent good options, thanks to their high efficiency and flexibility of operation. The present paper analyses one of the possible ways to integrate a heat pump with a micro-Combined Heat and Power (CHP) based on Solid Oxide Fuel Cell (SOFC) technology, in order to increase the overall efficiency of the building heating system. Three different heat pumping technologies (namely vapour compression, absorption and adsorption) have been employed. Starting from performance data of commercial appliances (vapour compression and absorption heat pumps) and from performance experimentally measured at the CNR ITAE for appliances at prototyping level (adsorption heat pump and SOFC), a numerical model has been developed in TRNSYS. Simulations performed demonstrated that the overall yearly efficiency can be improved up to 30%, exploiting the heat released by the micro CHP to reduce the heat produced by the heat pump. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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18. Ethanol adsorption onto carbonaceous and composite adsorbents for adsorptive cooling system.
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Brancato, V., Frazzica, A., Sapienza, A., Gordeeva, L., and Freni, A.
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ETHANOL , *ADSORPTION (Chemistry) , *COOLING systems , *CARBONACEOUS chondrites (Meteorites) , *SILICA gel , *THERMOGRAVIMETRY , *CHEMICAL equilibrium - Abstract
The aim of the present paper is the experimental characterization of adsorbent materials suitable for practical applications in adsorption refrigeration systems, employing ethanol as refrigerant. Different commercial activated carbons as well as a properly synthesized porous composite, composed of LiBr inside a silica gel host matrix, have been tested. A complete thermo-physical characterization, comprising nitrogen physi-sorption, specific heat and thermo-gravimetric equilibrium curves of ethanol adsorption over the sorbents, has been carried out. The equilibrium data have been fitted by means of the Dubinin – Astakhov equation. On the basis of the experimental data, a thermodynamic evaluation of the achievable performance of each adsorbent pair has been estimated by calculating the maximum COP (Coefficient of Performance) under typical working boundary conditions for refrigeration and air conditioning applications. The innovative composite material shows the highest thermodynamic performances of 0.64–0.72 for both tested working conditions. Nevertheless, the best carbonaceous material reaches COP value comparable with the synthesized composite. The results have demonstrated the potential of the chosen adsorbents for utilization in adsorption cooling systems. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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19. Development and experimental testing of an integrated prototype based on Stirling, ORC and a latent thermal energy storage system for waste heat recovery in naval application.
- Author
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Catapano, F., Frazzica, A., Freni, A., Manzan, M., Micheli, D., Palomba, V., Sementa, P., and Vaglieco, B.M.
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HEAT storage , *HEAT recovery , *ENERGY storage , *WASTE storage , *SOLAR thermal energy , *WASTE heat - Published
- 2022
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20. Optimization and testing on an adsorption dishwasher
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Santori, G., Frazzica, A., Freni, A., Galieni, M., Bonaccorsi, L., Polonara, F., and Restuccia, G.
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DISHWASHING machines , *ADSORPTION (Chemistry) , *DRYING agents , *POROUS silica , *SILICA gel , *MATHEMATICAL optimization , *SENSITIVITY analysis , *FACTORIAL experiment designs - Abstract
Abstract: This paper reports experimental testing of an adsorption dishwasher employing different desiccants, such as 13X zeolite, microporous silica gel and SAPO-34 zeolite. Thermodynamic comparison of the selected adsorbents was carried out on the basis of the experimental measurement of the main thermo-physical parameters, such as specific heat, adsorption equilibrium curves and sorption enthalpy. A sensitivity analysis on the adsorption dishwasher parameters was carried out adopting full factorial design (FFD) on a modified dishwasher prototype. Finally, the actual energetic performance for the optimized configuration were experimentally evaluated returning a consumed electrical energy of 0.636 kWh, which is 41% lower than that of standard cycle performed by a standard dishwasher with energy label A. [Copyright &y& Elsevier]
- Published
- 2013
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21. Development of "salt in porous matrix" composites based on LiCl for sorption thermal energy storage.
- Author
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Frazzica, A., Brancato, V., Caprì, A., Cannilla, C., Gordeeva, L.G., and Aristov, Y.I.
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SILICA gel , *HEAT storage , *SOLUTION (Chemistry) , *SORPTION , *MESOPOROUS silica , *CLIMATIC zones , *MESOPOROUS materials - Abstract
In this study, the development and characterization of composite sorbents based on commercial mesoporous silica gels and LiCl for seasonal thermal energy storage (STES) applications is described. The reported activity aims at validating the operation of sorption STES in various cold climatic zones in Europe. Accordingly, the reference boundary conditions were identified by means of a climatic analysis in two climatic zones, namely, Central and Northern Europe. The acquired mesoporous silica gels were characterized, to evaluate the textural properties, i.e. specific pore volume and pore size, needed to define the optimal salt solution compositions to maximize the amount of salt embedded. The synthesized samples were firstly investigated using scanning electron microscopy and nitrogen physisorption that demonstrate the presence of a small quantity of salt over the external surface rather than inside the pores. A hydrothermal treatment, based on slow adsorption followed by a slow desorption step, was defined to solve this issue. Finally, starting from the measured equilibrium isobars, the expected STES density at material level was evaluated, obtaining values as high as 1080 J/g under cold Northern European climatic condition, corresponding to 650 MJ/m3. • Selective Water Sorbents (SWS) materials based on mesoporous silica gel and LiCl for STES. • Morphological analysis of SWS material. • Optimization of synthesis procedure of SWSs material. • Evaluation of performance of Seasonal Thermal Energy Storage (STES) operating in two different boundary conditions. • STES density equals to 1080 J/g was obtained under cold Northern European climatic condition, corresponding to 650 MJ/m3. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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22. Equilibrium vapor pressure properties for absorbent and adsorbent materials.
- Author
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Yang, Zhiyao, Gluesenkamp, Kyle R., and Frazzica, Andrea
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VAPOR pressure , *EQUILIBRIUM , *PROPERTIES of fluids , *WASTE recycling , *WASTE heat , *VAPOR-liquid equilibrium - Abstract
• Vapor pressure correlations compiled for 38 refrigerants and 262 working pairs. • Refrigerants include water, ammonia, CO 2 , alcohols, HFCs, HFOs, and hydrocarbons. • Generalized vapor pressure functional forms enable cross comparisons. • Correlation valid ranges are provided where available. • An enabling dataset for thermodynamic simulations of sorption systems. Sorption devices are important tools for the efficient utilization of fuels and waste heat. Amid a tremendous diversity of cycles and applications, all sorption systems have an equilibrium vapor pressure that depends on the sorbent temperature and composition. The vapor pressure properties of working fluids are reported in the literature in a variety of ways, which impedes wide-ranging cross comparisons or screening studies for novel applications. This work compiles equilibrium vapor pressure properties for 123 liquid absorbents with 31 absorbates and 139 solid adsorbents with 16 adsorbates. The adsorption pairs are represented with six functional forms. Most of the absorption pairs are represented with 10 functional forms, plus several that are represented with custom empirical equations. Because the functional forms used in the literature vary widely, in this work each functional form was generalized. This paper is designed to facilitate comparisons of working fluid properties for screening studies, provide a quick reference to existing research, and present a framework for standardizing the reportage of vapor pressure equilibrium data for existing and future working pairs. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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23. Coupling sorption and compression chillers in hybrid cascade layout for efficient exploitation of renewables: Sizing, design and optimization.
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Palomba, Valeria, Dino, Giuseppe E., and Frazzica, Andrea
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SPACE heaters , *RENEWABLE energy sources , *HEAT , *ELECTRIC power consumption , *SORPTION , *DEW - Abstract
The efficient utilization of renewable energy sources should rely on the exploitation of a mix of thermal and electric energy rather than relying on a single energy source. One way to apply this shared generation concept to space heating/cooling and refrigeration in both residential and industrial sector is through hybrid sorption-compression chillers. However, the experience on these systems is still limited and therefore their design and optimization require some efforts. Starting from the experimental experience on the testing of different hybrid cascade chillers, and integrating the measurement with a dynamic model, some considerations on the sizing, design and optimization of hybrid thermal-electric chillers are reported. In particular, design conditions of pre-commercial or commercial systems are evaluated and optimization at different levels is proposed, i.e. on the core components (through the proper design of relative capacities of the units in the cascade and through proper selection of the refrigerant), on the auxiliaries, to reduce their electricity consumption, and on the overall management of the hybrid chiller. Results demonstrated that the higher is the operating temperature lift between evaporator and condenser the higher are the achievable energy savings of a cascade chiller. • Experimental and numerical experience for the critical analysis of cascade chillers. • Improvements on components, auxiliaries and control are suggested. • Optimal design include the selection of the refrigerant of the compression unit. • The control and management strategies are essential for proper integration of units. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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24. Experimental and numerical analysis of a SOFC-CHP system with adsorption and hybrid chillers for telecommunication applications.
- Author
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Palomba, Valeria, Ferraro, Marco, Frazzica, Andrea, Vasta, Salvatore, Sergi, Francesco, and Antonucci, Vincenzo
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SOLID oxide fuel cells , *ADSORPTION currents , *ELECTRIC power consumption , *CARBON dioxide mitigation , *ENERGY conservation - Abstract
This paper reports about the combined experimental and numerical investigation of a novel small size multi-generation system, for electric (i.e. <10 kW) and cooling (i.e. <20 kW) energy provision to Base Transceiver Stations and small data centers. The proposed concept is based on a high-efficiency natural gas driven SOFC-CHP coupled to commercially available thermally driven adsorption chillers. The main components of the system were experimentally characterized under relevant boundaries and the obtained performance maps were used to implement a TRNSYS model of the whole multi-generation system. The developed model was used to investigate the effect of the sizing of each component as well as the integration of two different commercial thermally driven chillers on the achievable global efficiency. This analysis demonstrated the possibility of getting global energy efficiency up to 0.63 and yearly primary energy savings up to 110 MWh. CO 2 emissions avoided are up to 43 t/y. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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25. Experimental investigation of a latent heat storage for solar cooling applications.
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Palomba, Valeria, Brancato, Vincenza, and Frazzica, Andrea
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LATENT heat , *HEAT storage , *SOLAR air conditioning , *STAINLESS steel , *MELTING - Abstract
The paper presents the realization and experimental characterization of a lab-scale latent heat storage, specifically developed for solar cooling applications. The latent heat storage is based on a compact fin-and-tube stainless steel heat exchanger (HEX) and a commercial paraffin blend, having a nominal melting temperature of 82 °C, suitable for solar cooling plants employing non-concentrating solar collectors technology. The realised heat storage has been experimentally characterised in lab, by means of a test rig able to simulate the working boundary conditions of a solar cooling plant. Charging and discharging tests have been performed both simulating a completed charge phase followed by a complete discharge phase, to analyse system efficiency and achievable energy storage density. Furthermore, dynamic tests, simulating short consecutive charge/discharge phases (with incomplete phase change), have been accomplished, to analyse the heat transfer efficiency inside the reactor. Main results confirmed that the heat storage density increases of about 50%, compared to sensible water storages. Satisfactory discharge efficiency, ranging between 45% and 60% has been obtained under analysed working conditions. Average discharging power between 0.7 and 1.2 kW has been measured, which confirms the necessity to further optimize the HEX efficiency as well as the thermal conductivity of the employed PCM. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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26. Holistic investigation for historical heritage revitalization through an innovative geothermal system.
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Cavagnoli, Silvia, Bonanno, Antonino, Fabiani, Claudia, Palomba, Valeria, Frazzica, Andrea, Carminati, Mattia, Herrmann, Ralph, and Pisello, Anna Laura
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HEAT pumps , *RETROFITTING of buildings , *INDUSTRIALIZED building , *HEAT sinks , *ENERGY dissipation , *HISTORIC buildings , *GROUND source heat pump systems - Abstract
Italy's architectural heritage boasts numerous historic buildings, which are an integral part of the country's cultural fabric and public assets. However, these structures inevitably deteriorate over time and require various types of intervention, particularly to mitigate energy dissipation. Yet, retrofitting historic buildings poses a challenge as preserving their historical features requires non-invasive strategies. To address this challenge, the present study introduces the incorporation of an innovative geothermal system tailored for the energy retrofit of an Italian historic building. This innovative system respects the building's landscape and constraints due to the archeological status of the building. It consists of a hybrid heat pump connected to a gas boiler, interfacing with a geothermal field to leverage it as either a heat source or sink. An in-depth analysis of this system was conducted, first in a specialized laboratory to assess its performance and then following its installation inside the historic building, thus interfacing it with a historical context and a real geothermal field. Notably, the comparative evaluation of the Coefficient of Performance (COP) between laboratory simulations and real-world deployment revealed striking similarity, affirming the system's consistent performance across contexts. Moreover, for a comprehensive analysis of the system, a techno-economic evaluation was carried out, which highlighted the many advantages of this installation. • A new energy retrofit strategy is proposed for a historic Italian building • A hybrid heat pump connected to a geothermal field is analyzed • Detailed analysis of the heat pump: in-lab and in-field (installed in the building) • Techno-economic analysis of the proposed system [ABSTRACT FROM AUTHOR]
- Published
- 2024
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27. Understanding the effect of materials, design criteria and operational parameters on the adsorption desalination performance – A review.
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Zhang, Yannan, Palomba, Valeria, and Frazzica, Andrea
- Subjects
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SALINE water conversion , *ADSORPTION kinetics , *ADSORPTION (Chemistry) , *WATER shortages , *OIL field brines , *MASS transfer - Abstract
[Display omitted] • Adsorption equilibrium and kinetics of the materials are presented and compared. • Advanced working cycles and strategies are summarized and discussed. • Innovative design approaches of the adsorber are reported. • Influence factors on performance indicators are discussed. • Possible future investigation directions are given based on the current studies. Adsorption desalination is considered as a promising alternative to solve the problem of water scarcity, owing to the remarkable advantages of energy-saving, low cost, limited environmental effect and high-quality produced water driven by renewable low-temperature thermal energy. However, this technology is still in the early laboratory research stage, further endeavor is required to facilitate the marketization based on a comprehensive summary of the current investigation achievements. Herein, this review summarizes the main achievements of adsorption desalination technology, involving sorption materials, system configurations and operation performances. So far, physical adsorbents, salt hydrates and composite adsorbents have been adopted, and, according to the most recent findings, composite adsorbents showed better thermodynamic desalination performance. Several advanced working cycles and strategies have been proposed and validated through experimental testing and simulations, like heat and mass recovery and multi-stage cycle, they contribute to improving the performance of the system by increasing the water production, broadening the working conditions or enhancing the output delivering power. Furthermore, the most recent innovative design approaches of the adsorber have been reported. Finally, the influence of operating conditions, like heat source temperature and cycle time, on specific daily water production, specific cooling power and coefficient of performance derived from the experiment and simulation results were discussed. Market aspects and the implementation of the different solutions in terms of cost and engineering complexity were also discussed. Possible future investigation directions include developing high-performance adsorbents with low desorption temperature (<50 °C), designing reactors with less heat and mass transfer resistance, using seawater or brine water in testing prototypes and validating the operation of real-scale prototypes under real operating conditions. [ABSTRACT FROM AUTHOR]
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- 2022
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28. Water adsorption dynamics on representative pieces of real adsorbers for adsorptive chillers.
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Santamaria, Salvatore, Sapienza, Alessio, Frazzica, Andrea, Freni, Angelo, Girnik, Ilya S., and Aristov, Yuri I.
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CHILLERS (Refrigeration) , *DIFFUSION , *COOLING , *HEATING , *MATHEMATICAL optimization , *GRAVIMETRIC analysis - Abstract
Dynamic optimization of adsorbent-heat exchangers (Ad-HExs) represents a key issue for the broader diffusion of adsorption cooling and heating (ACH) technologies. This paper is a sequel to an earlier one (Sapienza et al., 2014) that described the study of an ideal Ad-HEx configuration (loose adsorbent grains placed on a flat metal plate) by a new gravimetric version of the large temperature jump method. In the present paper, the study is extended to analyse the dynamic behaviour of HExs with much more complex geometry, namely, small but representative pieces of a finned flat-tube HEx. The Ad-HEx configuration tested is obtained by filling these small HExs with loose grains of AQSOA FAM Z02. The aim of the study is to evaluate the effect of the HEx geometry, grain size and flow rate of heat transfer liquid. The results obtained are compared with a reference flat Ad-HEx configuration. The ad-/desorption dynamics is found to be nearly exponential that proves the applicability of a modified Linear Driving Force model to characterize the water ad-/desorption rate. The majority of the tests have revealed the existence of the “grain size insensitive” regime for grains of 0.3–0.7 mm size. Under this mode, the dynamic behaviour is only function of the ratio ( S / m ) = 〈heat transfer surface〉/〈absorbent mass〉. This leads to a practically important conclusion that it is not necessary to precisely select the adsorbent grain size. When the grain size becomes too small or too large the rate reduction was found that is due to inter- or intra-grain mass transfer resistances. The tested Ad-HEx configuration is proved to be quite efficient: the specific cooling power amounts to 50–66% of that obtained with the reference (ideal) one, and the average specific cooling power W 80% can reach 2.3 kW kg −1 . This power is 6–8 times higher than those reported in the literature for full scale Ad-HExs with similar cell geometry. Thus, the study showed that there is still a big room for significant dynamical improvement of real ACH units. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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29. Dynamic study of adsorbers by a new gravimetric version of the Large Temperature Jump method.
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Sapienza, Alessio, Santamaria, Salvatore, Frazzica, Andrea, Freni, Angelo, and Aristov, Yuri I.
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CHEMICAL adsorbers , *GRAVIMETRIC analysis , *TEMPERATURE effect , *ADSORPTION (Chemistry) , *COOLING , *KINETIC energy - Abstract
Highlights: [•] We have carried out a dynamic study of adsorbers. [•] Activity performed by new gravimetric version of the Large Temperature Jump method. [•] The kinetics measurements have been carried out under real operating conditions. [•] Results can support the design of adsorbers for adsorption cooling systems. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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30. Influence of the management strategy and operating conditions on the performance of an adsorption chiller
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Sapienza, Alessio, Santamaria, Salvatore, Frazzica, Andrea, and Freni, Angelo
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REFRIGERATORS , *ADSORPTION (Chemistry) , *SYSTEM analysis , *MANAGEMENT science , *EXPERIMENTS , *PERFORMANCE evaluation , *MATHEMATICAL optimization , *TESTING - Abstract
Abstract: The aim of this experimental work was to study the influence of the operation mode (i.e. cycle time and relative duration of ads-/desorption phases, R) as well as of the operating conditions on the performance of an adsorption chiller. The testing campaign demonstrated that the management optimization strongly improves the performance of such kind of machines. The Coefficient of Performance (COP) and the Specific/Volumetric Cooling Power (SCP, VCP) vary, respectively, in a range of ±133% and ±43% when the cycle time (τcycle) increases from 5 to 20 min at fixed boundary conditions (T e = 15 °C, T c = 35 °C, T h = 90 °C) while a further increasing in performance (up to 15%) is reached, at fixed cycle time, by protracting the duration of the adsorption phase at the expense of the desorption one. The complete set of results allowed to draw a map of performance suitable for the optimization of the management mode taking into account the specific application. At T e = 15 °C, T c = 35 °C, T h = 90 °C, if high SCP is required (e.g. automotive air conditioning), the optimal choice is τ cycle = 7 min and R = 2.5 (SCP = 394 W/kg, COP = 0.60, VCP = 223 W/m3) while to assure a good efficiency (e.g. solar cooling) the proper management is τ cycle = 20 min and R = 1 (SCP = 204 W/kg, COP = 0.69, VCP = 116 W/m3). [Copyright &y& Elsevier]
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- 2011
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31. Implementation of a solar-biomass system for multi-family houses: Towards 100% renewable energy utilization.
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Palomba, Valeria, Borri, Emiliano, Charalampidis, Antonios, Frazzica, Andrea, Cabeza, Luisa F., and Karellas, Sotirios
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ENERGY consumption , *APARTMENT buildings , *WARMUP , *SOLAR collectors , *HEAT pumps , *SOLAR houses - Abstract
The decarbonization of the building sector cannot preclude from the vast diffusion of renewable-sourced polygeneration systems for covering both heating and cooling demand. In this context, this study shows the potentialities of a system based on solar thermal collectors, a biomass boiler and an innovative reversible hybrid heat pump/ORC concept for addressing heating, cooling and domestic hot water demand of residential buildings. The potential is investigated in three cities (Madrid, Berlin and Helsinki), representative of the different European climates. The share of renewables in different seasons and building typologies is presented and the possibility of obtaining a 100% renewable system when the solution proposed is installed in new and renovated buildings is discussed. The results show that in standard multi-family houses, up to 70% of heating demand and 100% of cooling demand can be covered by the system in warmer climates and up to 60% share of renewables can be reached in Northern climates. Moreover, the flexible configuration of the system shows the potential for the application in the future energy system of the EU. Image 1 • A solar-biomass system for heating, cooling and electricity is investigated in different climates. • Energy flow analysis is used to show the overall share of renewables. • A 100% scenario exists under optimized control and sizing conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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32. Thermal performance of a latent thermal energy storage for exploitation of renewables and waste heat: An experimental investigation based on an asymmetric plate heat exchanger.
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Palomba, Valeria, Brancato, Vincenza, and Frazzica, Andrea
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PLATE heat exchangers , *HEAT storage devices , *HEAT storage , *WASTE heat , *IRON & steel plates , *PHASE change materials , *HEAT exchangers , *HEAT transfer fluids - Abstract
• A PCM storage with a commercial paraffin inside an asymmetric plate heat exchanger was developed. • Experimental characterization under full load and partial load conditions was accomplished. • Energy storage densities of 116–198 kJ kg−1 were measured in the range 70–86 °C. • Charging/discharging the storage at 80% of max energy saves 50% of time. • The thermal resistance in the PCM is relevant only when it is solidified. In this paper, the experimental characterization of a latent heat storage prototype working in the range of 70–90 °C and characterized by an innovative configuration is presented. The storage consists of a Phase Change Material (PCM), namely a commercial paraffin, embedded in an asymmetric plate heat exchanger. The testing campaign was aimed at defining the effect of operating conditions (flow rate of the heat transfer fluid, charge and discharge temperatures), in terms of energy stored, power supplied to the user and storage efficiency. The results showed that the energy density stored is between 116 and 198 kJ kg−1, whereas power output during discharge varies between 4 and 10 kW. Subsequently, an analysis on part load operation was carried out, which evidenced that properly managing the storage, limiting the discharging to 80% of its maximum storage capacity, allows saving around 50% of time, thus increasing the power density. A thermal network model was proposed to study the contributions of the heat exchanger and phase change material to the overall heat transfer, demonstrating that the phase change material is limiting the heat transfer only when it is in the solid state. Finally, the storage was compared to another prototype developed by the authors employing the same material and a different heat exchanger (a fin-and-tube heat exchanger) according to different structural, energy and dynamic performance indicators. The results highlighted that the present system is especially suitable for applications with a high power demand from the user. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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33. Corrosion assessment of promising hydrated salts as sorption materials for thermal energy storage systems.
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Fernández, Angel G., Fullana, Margalida, Calabrese, Luigi, Palomba, Valeria, Frazzica, Andrea, and Cabeza, Luisa F.
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HEAT storage , *ENERGY storage , *STAINLESS steel , *CARBON steel , *SORPTION , *SALTS - Abstract
Salt hydrates are an appealing option to be used as sorption materials in thermal energy storage (TES). In this work, strontium bromide and magnesium sulphate have been selected as one of the most promising salt hydrates since they present high energy storage density (>130 kWh/m3) and efficiency (>20%). One of the main drawbacks of sorption materials rely on control the hydratation-dehydratation process but there are other parameters that can modify this behaviour as the corrosive potential of these salts in contact with the container material selected for the application. Hence, four different metal container materials, specifically stainless steel, copper, aluminium, and carbon steel have been tested in SrBr 2 ·6H 2 O and MgSO 4 ·7H 2 O hydrate salts, during 100 h at dehydratation conditions. After the gravimetric and micrograph analysis carried out via scanning electron microscopy (SEM) study, only carbon steel is not recommended for this application in contact with SrBr 2 ·6H 2 O, obtaining a corrosion rate of 0.038 mm/year, with a metallographic corrosion layer thickness of 25.2 μm. Aluminium, copper and stainless steel showed a better corrosion resistance also in SrBr 2 ·6H 2 O and MgSO 4 ·7H 2 O with corrosion rates below 0.008 mm/year. • Salt hydrates as sorption materials in TES main drawback is corrosion. • Four different metal container materials are tested. • SrBr 2 ·6H 2 O and MgSO 4 ·7H 2 O are the salts tested. • Only carbon steel is not recommended in contact with SrBr 2 ·6H 2 O. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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34. Modeling of a bidirectional substation in a district heating network: Validation, dynamic analysis, and application to a solar prosumer.
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Dino, Giuseppe Edoardo, Catrini, Pietro, Buscemi, Alessandro, Piacentino, Antonio, Palomba, Valeria, and Frazzica, Andrea
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- *
RENEWABLE energy sources , *VALVES , *SOLAR heating , *ENERGY development , *SOLAR collectors , *HEAT exchangers , *FOSSIL fuels , *SOLAR energy - Abstract
Thermal grids will play a key role in the development of local energy communities and the achievement of 100% renewable societies. Such systems allow excess heat produced by distributed producers through renewable energy sources (also referred to as "thermal prosumers") to be shared among other consumers characterized by high heat demand or who still depend on fossil fuels. However, to achieve more reliable results when performing energy analyses, it is of utmost importance to develop models of prosumers' substations, where technical details (e.g., type of connections, heat exchangers, valves, etc.) and controllers are accounted for. Starting from the layout of a bidirectional substation for a thermal energy network proposed in the literature, this paper proposes a dynamic model that replicates the experimental setup in the TRNSYS environment. Validation results show a good matching between simulation and experiments in terms of dynamic behavior and energy balance. To show the capabilities of the proposed model, a prosumer with heat available from 205 m2 solar thermal collectors is considered as a case study. The analysis is performed by assuming two locations characterized by different irradiation values, i.e., Palermo (Italy) and Berlin (Germany). The results show that exchanging the excess heat produced on-site with a heating network allows the solar collectors to reach peak heat production, which is 130 kW and 110 kW for Palermo and Berlin, respectively. The surplus heat sold to the network is equal to 66% and 29% of the total energy exchange within the substation for Palermo and Berlin, respectively. Conversely, the self-consumption of the produced heat accounts for 21.2% and 30.6%, respectively. The model prospectively represents a valuable tool to develop feasibility studies in Thermal Energy Communities and assess the potential of innovative energy- and cost-effective operation strategies. • A model of a thermal prosumer substation exchanging with a District Heating Network (DHN) was created in TRNSYS • The virtual model was validated through experimental data by showing a good matching between simulation and experiments • To show the capabilities of the model, a prosumer equipped with 205 m2 solar thermal collectors is considered as a case study • Results showed that the prosumer substation allowed for optimal exploitation of the heat produced by the solar collectors • The proposed model represents a viable tool to perform analyses applied to renewable energy systems in prosumers networks [ABSTRACT FROM AUTHOR]
- Published
- 2023
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35. Experimental characterization of the LiCl/vermiculite composite for sorption heat storage applications.
- Author
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Brancato, Vincenza, Gordeeva, Larisa G., Sapienza, Alessio, Palomba, Valeria, Vasta, Salvatore, Grekova, Alexandra D., Frazzica, Andrea, and Aristov, Yuri I.
- Subjects
- *
SORPTION , *VERMICULITE , *HEAT storage , *SORBENT testing , *SPECIFIC heat , *MATERIALS testing , *MOISTURE content of food - Abstract
• Experimental characterization of sorption composite for thermal energy storage applications. • Evaluation of sorption enthalpy, cycling stability and sorption kinetic. • Results validation by means of a lab-scale prototype operating under seasonal storage conditions. The present paper reports about the experimental characterization of a recently developed composite sorbent of water, LiCl/vermiculite, for thermal energy storage applications. The sorption ability as well as the thermal storage capacity (TSC) of the material itself were tested in a dedicated TG/DSC apparatus, under two relevant boundary conditions, namely, seasonal (SS) and daily (DS) storage applications. The dynamic behavior of the composite sorbent was tested by means of a G-LTJ apparatus in flat-plate adsorber configuration, under both SS and DS working conditions. Finally, preliminary tests on a lab-scale TES configuration were performed and reported. The main outcomes confirm that the composite is promising for TES applications, reaching the TSC up to 2.15 kJ/g under SS conditions. The stability of the composite was proven for 14 consecutive sorption/desorption cycles under conditions similar to those at real SS and DS cycles. The kinetic adsorption tests confirmed a slowdown of the sorption dynamics when passing from 1.7–2.0 mm to 2.36–2.80 mm of the grain size. Furthermore, the adsorption kinetic under SS mode is faster than of DS one. The preliminary testing in the lab-scale TES at SS cycle allowed getting TSC up to 1.25 kJ/g with a specific power up to 2.1 kW/kg. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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36. Water adsorption equilibrium and dynamics of LICL/MWCNT/PVA composite for adsorptive heat storage.
- Author
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Brancato, Vincenza, Gordeeva, Larisa G., Grekova, Alexandra D., Sapienza, Alessio, Vasta, Salvatore, Frazzica, Andrea, and Aristov, Yuri I.
- Subjects
- *
MULTIWALLED carbon nanotubes , *HEAT storage , *BINDING agents , *GRANULATION , *GRAPHENE - Abstract
Abstract Recently, a new composite "LiCl inside Multi-Wall Carbon NanoTubes" (LiCl/MWCNT) has been suggested as water sorbent for Adsorption Thermal Energy Storage (ATES), because it has a large thermal storage capacity of 1.7 kJ/g for a daily heat storage cycle. This work addresses the results of the study of water sorption dynamics on the novel composite loaded into representative small scale fragments of a common finned flat-tube HEx. The study consists of four parts: (1) shaping the LiCl/MWCNT composite as grains using polyvinyl alcohol (PVA) as a binder; (2) analysis of sorption equilibrium for the pair "LiCl/ MWCNT/PVA – water"; (3) measuring the thermal storage capacity of the granulated LiCl/ MWCNT/PVA composite; (4) investigation of water sorption dynamics on the LiCl/MWCNT/PVA under typical conditions of the daily storage cycle. It is shown that the thermal storage capacity of the LiCl/MWCNT/PVA composite equals 1.5–1.6 kJ/g. The specific power reaches 4.2 and 9.8 kW/kg of the heat release and thermal storage stages, respectively. The results obtained show that the working pair "LiCl/MWCNT/PVA – water" appears to be advantageous for ATES. Highlights • A composite sorbent based on Multi Wall Carbon Nanotubes, LiCl and Polyvinyl Alcohol was synthesized. • The thermal storage capacity was experimentally evaluated by a coupled TG/DSC apparatus. • Water sorption dynamics on the composite were investigated under typical daily storage cycle conditions. • High storage capacity, up to 1.6 kJ/g and specific power, up to 4.2 kW/kg were experimentally measured. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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- View/download PDF
37. Numerical modelling and evaluation of a novel sorption module for thermally driven heat pumps and chillers using open-source simulation library.
- Author
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Velte-Schäfer, Andreas, Zhang, Yannan, Nonnen, Thomas, Wittstadt, Ursula, Frazzica, Andrea, Füldner, Gerrit, and Palomba, Valeria
- Subjects
- *
HEAT pumps , *MASS transfer , *COOLING systems , *SORPTION , *HEAT exchangers , *ROOT-mean-squares , *HEAT transfer - Abstract
• Adsorption heat exchanger based on directly crystallized flat tube-lamella design. • Created numerical model for modules with combined evaporator-condenser in Modelica. • Rigorous calibration and validation - outlet temperatures differ 1.1...1.9 K on average. • Simulated efficiency matches the experiment within uncertainty ± 0.02 (±5 %). • Evaluation of heat and mass transfer resistances reveals limitation in the evaporation. Sorption modules are the core component of thermally driven heat pumps and chillers. The efficiency of these devices strongly depends on the advantageous design of sorption modules. In this paper a calibrated and validated numerical model for an innovative sorption module with a combined evaporator-condenser is presented. The adsorption heat exchanger is based on flat tube-lamella design directly crystallized with the zeotype adsorbent silico-alumino-phosphate-34. The prediction quality of the model regarding the efficiency is within the measurement uncertainty (±0.02 kJ/kJ). Besides the good prediction quality of this integral performance indicator, the root mean square deviation of the transient outlet temperatures is in the range of 1.1...1.9 K, which is a very good agreement. Since the performance indicators efficiency and power density strongly depend on the temperature boundary conditions and half cycle times, an in-depth analysis of the experimental data using the method of heat and mass transfer resistances is suggested that overcomes this limitation. This analysis allows for a direct comparison with other sorption module designs. In a first step this analysis revealed that the evaporator-condenser component limits the sorption process during evaporation. Compared to other designs the evaporator-condenser has a 3–5 times higher volume scaled heat and mass transfer resistance (17 dm3K/kW) in the evaporation phase underlining the necessity to further optimize this component in future modules. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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38. MgSO4·7H2O filled macro cellular foams: An innovative composite sorbent for thermo-chemical energy storage applications for solar buildings.
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Brancato, Vincenza, Calabrese, Luigi, Palomba, Valeria, Frazzica, Andrea, Fullana-Puig, Margalida, Solé, Aran, and Cabeza, Luisa F.
- Subjects
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SORBENTS , *CHEMICAL energy , *ENERGY storage , *FOAM , *SOLAR buildings - Abstract
Highlights • Polymeric foams filled by MgSO 4 ·7H 2 O for seasonal TES applications. • Evaluation of foam features. • Evaluation of foam efficiency for TES application. Abstract For seasonal energy storage using solar energy in buildings heating and DHW, thermochemical technology represents the most promising alternative due to the virtually absence of heat losses during storage period. This work focuses on silicone foams, filled by MgSO 4 ·7H 2 O, as innovative composite sorbents for sorption thermal energy storage applications. The necessity to enclose the salt hydrate in the polymeric foam arises for overcoming the issue of swelling, agglomeration, and/or deliquescence of the salt during its de/hydration process. Indeed, the foam with its flexible structure allows the safe volume expansion during the hydration phase of the salt. The foam samples presented in this paper were obtained by mixing the salt hydrate at various percentages (from 40 wt% up to 70 wt%) with a mixture of two water vapour permeable silicones. The foams were characterized by a complete physicochemical and morphological examination in order to evaluate their actual application in sorption energy storage systems. It was demonstrated that a good link seems to be established between the foam and the salt, and that the de/hydration capacity of the salt is not hindered by the foaming process, storage ability and storage density of the composites are expected to be in line with those of the pure material. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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39. “Water - Silica Siogel” working pair for adsorption chillers: Adsorption equilibrium and dynamics.
- Author
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Sapienza, Alessio, Velte, Andreas, Girnik, Ilya, Frazzica, Andrea, Füldner, Gerrit, Schnabel, Lena, and Aristov, Yuri
- Subjects
- *
CHILLERS (Refrigeration) , *ADSORPTION (Chemistry) , *SILICA gel , *HEAT transfer , *RENEWABLE energy sources - Abstract
The aim of this paper is to study the equilibrium and dynamics of water adsorption on a commercial silica gel Siogel. This adsorbent has recently been suggested and tested for adsorptive transformation and storage of low temperature heat. The original data on the water vapour equilibrium and dynamics are compared with those earlier reported for the Fuji silica RD. This database can be used for theoretical analysis, mathematical modeling and evaluation of adsorptive cycles based on the working pair “water – Siogel” and driven by heat from renewable heat sources. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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40. Susceptibility to corrosion of aluminium alloy components in ethanol adsorption chiller.
- Author
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Proverbio, Edoardo, Calabrese, Luigi, Caprì, Angela, Bonaccorsi, Lucio, Dawoud, Belal, and Frazzica, Andrea
- Subjects
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CHILLERS (Refrigeration) , *ETHANOL , *REFRIGERANTS , *ALUMINUM alloys , *CORROSION & anti-corrosives - Abstract
Methanol, and more recently ethanol, have been deeply employed as adsorbate phase (refrigerant) in adsorption chiller and heat pump applications (e.g. refrigerator adsorption ice maker). The use of anhydrous alcohols however can cause several problems related to the corrosiveness of such molecules towards light alloys (from titanium to aluminium). The problem was already highlighted in bio-fuel technology where bio-ethanol was considered as a promise alternative to fossil hydrocarbons. Water content was observed as one of the main factors influencing corrosion rate. In the present works several accelerated corrosion tests on 6061 Aluminium alloy have been carried out in autoclave in a temperature range from 110 to 135 °C with different ethanol to aluminium mass ratio. Highly exothermic reactions related to aluminium oxidation, coupled to hydrogen evolution, have been recorded. The main drawback of hydrogen evolution is the formation of a stagnant layer over the heat exchangers surface, which can limit the ethanol vapour diffusion, thus reducing adsorption/condensation rate. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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41. On the impact of different management strategies on the performance of a two-bed activated carbon/ethanol refrigerator: An experimental study.
- Author
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Palomba, V., Dawoud, B., Sapienza, A., Vasta, S., and Frazzica, A.
- Subjects
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REFRIGERATORS , *ACTIVATED carbon , *ETHANOL , *BOUNDARY value problems , *COOLING power (Meteorology) - Abstract
In the present work, an experimental study on a lab-scale adsorption refrigerator, based on activated carbon/ethanol working pair is reported. An extensive testing campaign has been carried out at the CNR ITAE laboratory, with multiple aims. First, the performance has been evaluated in terms of both COP and Specific Cooling Power (SCP), under different boundary conditions, including both air conditioning and refrigeration applications. Attractive SCPs, up to 180 W/kg and 70 W/kg for air conditioning and refrigeration, respectively, were measured. Under the same conditions, COP between 0.17 and 0.08 were obtained. In addition, different management strategies, namely, heat recovery between adsorbers and re-allocation of phase durations, were evaluated to identify their influence on the system. Both strategies confirmed the possibility of increasing COP and SCP up to 40% and 25%, respectively. Moreover, a design analysis based on the experimental results has been carried out, to suggest possible improvements of the system. The obtained results demonstrated the possibility of employing a non-toxic refrigerant like ethanol reaching performance comparable with other harmful refrigerants like ammonia and methanol. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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42. Wave analysis method for air humidity assisted sorption thermal battery: A new perspective.
- Author
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Lin, Y.C., Fan, Y.B., Chen, S., Zhang, X.J., Frazzica, A., and Jiang, L.
- Subjects
- *
THERMAL batteries , *WAVE analysis , *HUMIDITY , *AIR analysis , *SORPTION , *RESPONSE surfaces (Statistics) - Abstract
• Wave analysis method is initially introduced to estimate steady heat output. • Relationship between sorption process and output stages are established. • Influence of isotherms and design parameters on wave parameters is determined. • The maximum energy storage density through this method reaches 191.4 kWh·m−3. Sorption thermal battery has attracted burgeoning attention which is considered as a promising method to reduce energy consumption for space heating. Sorption "reaction wave" model could be used to find the criteria for stable output. However, mechanism of sorption process evolution in reactor is still unclear since the method cannot derive more reaction details. The paper initially proposes a comprehensive wave analysis method which could bring more insights of sorption thermal battery from a heat and mass transfer perspective. The wave parameters are analysed and orthogonal experiments are then carried out. Results indicate that solid sorbents with type I and V isotherms have the advantage of stable heat supply. Air velocity and inlet relative humidity have the most significant influence on the output parameters. Besides, response surface methodology is adopted to evaluate the critical parameters, e.g., relative humidity, flow rate, temperature of inlet air. The optimal system energy storage density could reach 191.7 kWh·m−3 when sorption reactor length is 0.178 m and the relative humidity is 70 % using zeolite 13X as sorbents. Therefore, the proposed wave analysis method is expected to become a potential solution which would guide sorbent selection and reactor design for sorption thermal battery. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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43. Heat pump assisted open three-phase sorption thermal battery for efficient heat storage.
- Author
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Fan, Y.B., Jiang, L., Zhang, X.J., Xu, X.G., and Frazzica, A.
- Subjects
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THERMAL batteries , *HEAT pumps , *HEAT storage , *ENERGY storage , *ENERGY density , *WEIGHING instruments - Abstract
• Heat pump assisted open three-phase sorption thermal battery is proposed. • System performs three patterns in liquid desorption, crystallization and dehydration stages. • The maximum average system COP is 7.54, corresponding charging temperature is 40 °C. • The optimal end state of sorbent for LiCl is either liquid desorption or dehydration stage. Open three-phase sorption thermal battery has recently received particular attention for its high energy storage density. Meanwhile, air source heat pump can be considered a potential heat source for open three-phase sorption thermal battery due to its broad applicability and high energy efficiency. However, research on the intergration of these two systems are rarely reported. A heat pump assisted sorption thermal batttery is proposed and evaluated based on a general thermodynamic analysis for charging process. Three indicators are targeted in terms of coefficient of performance (COP), energy storage rate and energy storage density. Results show that system characteristics present three different patterns, i.e., liquid desorption, crystallization and dehydration stages. When ambient condition is 20 °C and 60% RH, the maximum system average COP is 7.53, the corresponding charge temperature is 40 °C and end-state sorption capacity is 2.33 g/g. The optimal charging condition for comprehensive performance index is greatly affected by the weights of basic indicators. When the weight of energy storage density is dominating, three-phase sorption performs better. Within the range of this study, the optimal sorbent end state locates on either liquid desorption stage or dehydration line. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
44. Thermal performance assessment and control optimization of a solar-driven seasonal sorption storage system for residential application.
- Author
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Crespo, Alicia, Fernández, Cèsar, Vérez, David, Tarragona, Joan, Borri, Emiliano, Frazzica, Andrea, Cabeza, Luisa F., and de Gracia, Alvaro
- Subjects
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SINGLE family housing , *HEAT storage , *SORPTION , *ENERGY storage , *SOLAR technology , *SEASONS , *SOLAR air conditioning - Abstract
The present paper analyzed the thermal performance and control optimization of a solar system based on seasonal sorption storage for domestic applications. The system control, which could choose between 41 operational modes, was optimized based on operational costs and maximization of sorption system use. The system was composed by 17.5 m2 of evacuated tube collectors, 3.6 m3 of composite sorbents based on lithium chloride and a stratified water tank. High efficiency of a sorption storage system was obtained when continuous charges or discharges occur, which, in this study, depended on weather conditions (ambient temperature and solar irradiation). The operational economic benefits were maximized using a sorption system with 9% less capacity and, therefore, less storage volume. The sorption thermal energy storage system obtained energy densities of 90 and 106 kWh/m 3. The whole system could supply 35% of the total thermal demand of a single family house in Nuremberg. The study concluded that the control optimization of a seasonal sorption system is a key factor to make the technology competitive, define its optimal size and, therefore, maximize its energy density in further designs. • A solar-driven seasonal sorption storage system was analyzed under optimal control. • 35% of the thermal demand of a single-family house located in Central Europe was supplied. • Maximum energy density of the sorption storage system of 106 kWh/m 3 was obtained. • Control optimization showed minimum operational costs with 9% less sorption storage size. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. An innovative adsorptive chiller prototype based on 3 hybrid coated/granular adsorbers.
- Author
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Sapienza, Alessio, Gullì, Giuseppe, Calabrese, Luigi, Palomba, Valeria, Frazzica, Andrea, Brancato, Vincenza, La Rosa, Davide, Vasta, Salvatore, Freni, Angelo, Bonaccorsi, Lucio, and Cacciola, Gaetano
- Subjects
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CHILLERS (Refrigeration) , *SORBENTS , *HEATING & ventilation industry , *COOLING systems , *POWER density , *EVAPORATORS , *HEAT recovery - Abstract
In this paper, an innovative adsorptive chiller based on 3 hybrid adsorbers is presented as well as results of the first testing campaign performed under real HVAC operating conditions. The prototype presents two main innovative features aimed to achieve high values of cooling power density: (i) a new architecture, with 3 adsorbers connected to a single evaporator and condenser, that allows to perform an advanced machine’s management strategy employing unbalanced durations of the isobaric ads-/desorption steps, (ii) hybrid adsorbers realized embedding microporous Silica Gel loose grains into aluminium finned flat tube heat exchangers previously coated with the Mitsubishi AQSOA FAM Z02 sorbent. Water was selected as refrigerant while up to now the machine operates without any mass/heat recovery. A first testing campaign has been carried out at ITAE labs by a test bench specifically developed for thermally driven chillers. Influence of the cycle time as well as the temperature difference between condenser (T M ) and evaporator (T L ) on the overall performance were highlighted. The experimental measurements showed that the chiller is able to deliver an average cooling power (ACP) ranging between 3.4 and 4.4 kW, a volumetric cooling power (VCP) of 7.25–9.36 kW/m 3 , with a COP of 0.3–0.35 at T H = 90 °C, T L ∼ 15–18 °C and T M ∼ 25–28 °C. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
46. Experimental characterization of an innovative hybrid thermal-electric chiller for industrial cooling and refrigeration application.
- Author
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Dino, Giuseppe E., Palomba, Valeria, Nowak, Eliza, and Frazzica, Andrea
- Subjects
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REFRIGERATION & refrigerating machinery , *SOLAR heating , *HYBRID systems , *COOLING , *ELECTRIC power consumption , *ON-chip charge pumps , *INDUSTRIAL energy consumption - Abstract
• A novel hybrid sorption chiller was investigated. • Electricity energy savings from 15% to 25% can be achieved by the hybrid system. • The overall performances are slightly affected by the sorption driving temperature. • Cascade coupling let to enhance performances of hybrid system. The energy demand of industries accounts for about 30–35% of world yearly energy consumption, a relevant percentage is due to the need of heating and cooling demand. Solar heating and cooling technologies can be integrated in industrial processes to reduce the fossil fuels consumption as well as the related greenhouse gas emissions. This paper reports the experimental analysis of a novel hybrid sorption-compression chiller for cooling and refrigeration purposes in cascade layout, which uses silica gel/water for the sorption cycle and a low Global Warming Potential (GWP) refrigerant, i.e. propylene for the compression cycle. The experimental results highlighted the flexibility of the system in terms of performances and operating conditions, these were compared to the theoretical performances and it was found out that electricity energy savings from 15% to 25% can be achieved when using the hybrid system over a compression one with the same cooling capacity. The results were converted in performance maps and processed in a statistical model, in order to get a simplified expression for determining the overall performances of the hybrid system through variables that could be measured by a final user, such as the operating temperatures. Optimization strategies were identified for a further enhancement of the performance of the chiller, i.e. the reduction of the electricity consumption, by controlling the intermediate temperature (evaporation temperature of the sorption chiller) through sorption cycle management and the use of variable speed of the pumps in all the circuits to reduce the parasitic consumption especially at low part loads. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
47. Evaluation of in-situ coated porous structures for hybrid heat pumps.
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Palomba, V., Lombardo, W., Groβe, A., Herrmann, R., Nitsch, B., Strehlow, A., Bastian, R., Sapienza, A., and Frazzica, A.
- Subjects
- *
ALUMINUM foam , *POWER density , *HEAT exchangers , *HEAT transfer , *TESTING equipment , *HEAT pumps - Abstract
One of the main limitations for the wide diffusion of sorption systems, either as stand-alone and in hybrid configurations, is the low heat transfer inside the adsorber, as well as the low volumetric cooling power. In this context, the present paper reports the experimental activity on four different advanced configurations for the adsorber, based on microchannel heat exchangers where the gap between the channels is filled with porous structures where zeotypes of SAPO-34 family were synthetized. The porous structures evaluated are high-density fins, two different aluminium foams and compressed chips from the waste of aluminium machining. The sorption dynamic and cooling power density of each structure were measured through a Gravimetric Large Temperature Jump testing apparatus. The results obtained showed that the best-performing configuration is the one with high-density fins, that, for a 90/30/20 °C cycle showed a Specific Cooling Power up to 1.1 kW/kg. The other structures exhibit a much slower adsorption process, corresponding to power densities of about 0.3 kW/kg. The results were used for sizing a full-scale adsorber, whose expected Volumetric Cooling Power is 500 kW/m3. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. Sustainable adobe bricks with seagrass fibres. Mechanical and thermal properties characterization.
- Author
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Olacia, Elena, Pisello, Anna Laura, Chiodo, Vitaliano, Maisano, Susanna, Frazzica, Andrea, and Cabeza, Luisa F.
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POSIDONIA , *THERMAL properties , *FIBERS , *POSIDONIA oceanica , *NATURAL fibers , *SUSTAINABLE construction - Abstract
• Capability of Posidonia Oceanica seagrass as a reinforcement material in adobe specimens is analysed. • Posidonia Oceanica seagrass is a biomass by-product from the Mediterranean coastlines. • First, the fibres were evaluated to understand their behaviour. • Samples were subjected to mechanical and thermal tests. • Seagrass fibres with their natural long length showed the most suitable mechanical behaviour. There is an incipient necessity and interest of generating sustainable materials for application in green buildings. In this study, the capability of Posidonia Oceanica seagrass, a biomass by-product from the Mediterranean coastlines, is analysed as a reinforcement material in adobe bricks. For this purpose, earthen specimens with these sea-plant fibres were compared with the most traditional additives for this purpose, i.e. straw-based adobes. Both biomass fibres were included with different lengths and quantities. First, to understand their behaviour, the fibres were evaluated; water absorption and tensile strength tests were performed. Test specimens themselves were subjected to mechanical and thermal tests as well as measuring dimensional changes. Tested as fibres, straw presented higher tensile resistance and water absorption than seagrass; but tested within adobe specimens, straw containing samples had worse mechanical behaviour than those containing seagrass. Specially, adobe with Posidonia Ocenaica seagrass fibres with their natural long length showed to be the most suitable in terms of mechanical behaviour. Furthermore, good thermal conductivity results were achieved with this level of biomass reinforcement, generating a sustainable and value-added construction product. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
49. Magnesium sulphate-silicone foam composites for thermochemical energy storage: Assessment of dehydration behaviour and mechanical stability.
- Author
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Calabrese, Luigi, Brancato, Vincenza, Palomba, Valeria, Frazzica, Andrea, and Cabeza, Luisa F.
- Subjects
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ENERGY storage , *FOAM , *HEAT storage , *COMPOSITE structures , *COMPOSITE materials , *DEHYDRATION - Abstract
This paper assesses the mechanical stability and dehydration behaviour of a new composite material constituted by magnesium sulphate hepta-hydrate, used as filler at vary contents, and a porous silicone, used as matrix in order to evaluate its applicability in sorption thermal energy storage field. This new composite was developed to avoid the typical issues of salt hydrates such as swelling, agglomeration and corrosion issues occurring during hydration/dehydration process. A preliminary physical-mechanical characterization, by means of morphological and calorimetric analysis, was carried out to investigate the main properties of the composite foams. The morphological characterization showed that the foam pores were homogenously distributed and well interconnected to each other. Thermo-gravimetric dehydration tests, have demonstrated that the tested samples are able to exchange efficiently water. Static compression tests evidenced a high compression stability of the material, indicating a high flexibility of the cellular silicone structure. Furthermore, cyclic compression test was performed to evaluate the progressive loss of salt at increasing number of the cycles. After 50 cycles, a reduction of salt hydrate up to 13% was observed. This behaviour, that is potentially a critical factor in these composite structures, was studied for showing that the loss of the salt does not compromise considerably the sorption storage performance of the filled silicone foams. Eventually, the assessment of thermo-gravimetric characteristics and mechanical stability was performed on the MgSO 4 ·7H 2 O silicone composite foam. • Polymeric foams filled by MgSO 4 ·7H 2 O for seasonal TES applications. • Evaluation of foam features. • Evaluation of foam efficiency for TES application. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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