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This study focuses on the development and testing under lab-controlled conditions of a hybrid sensible–latent thermal energy storage (TES) system for domestic hot water (DHW) provision in residential buildings. The TES system's design is based, for the first time in the literature, on a commercial tank-in-tank architecture integrating a macro-encapsulated commercial phase change material (PCM) inside the external tank to guarantee the safe provision of DHW and increase overall energy storage density at a reasonable cost. The PCM is a salt hydrate with a nominal melting temperature of 58 °C. The overall tank-in-tank TES volume is about 540 dm3. Almost one tenth of this volume is occupied by the PCM macro-capsules. The developed TES system was comparatively tested against the same configuration operated as a sensible TES. The obtained results showed the ability of the PCM to increase the thermal inertia inside the external tank, thus guaranteeing the quite stable provision of heat to the integral DHW tank during the stand-by periods. This effect was confirmed by the PCM's ability to achieve an energy storage capacity up to 16% higher than the reference sensible TES system. [ABSTRACT FROM AUTHOR]

In this study, the development and testing of a hybrid thermal energy storage (TES) including phase change material (PCM) macro-capsules inside a vertical sensible tank is presented. The storage was specifically developed for delivering hot water on board of ships. Accordingly, a commercial PCM was selected and tested. Subsequently, the hybrid TES was designed and tested under mimicked boundary conditions at lab scale, showing the possibility of increasing the volumetric energy storage density up to 30% compared to the sensible configuration. On this basis, two numerical models were developed: a detailed one, implemented in a Fluent environment, aiming at investigating the main parameters affecting the heat transfer efficiency inside the TES and a second one, implemented in an ESP-r environment to simulate the TES as a component to be implemented inside a more complex system, thus helping its accurate design and operation through a reliable modelling phase. Both models were satisfactorily validated against the experimental results, thus being made available for future investigations and design optimization. [ABSTRACT FROM AUTHOR]

The contribution focuses on the analysis of the distribution of skills in the Sicilian Region and the effects of smart working (SW). The objectives are: 1) the analysis of the distribution of implicit and explicit competences; 2) the evaluation they themselves attribute to the quality of these competences; 3) the relationship existing between these competences, the awareness of them, the evaluation on them and SW. [ABSTRACT FROM AUTHOR]

• 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]

Summary: This paper presents an experimental protocol for the cycling stability of adsorbent materials for thermal energy storage (TES) applications under hydrothermal conditions. Two different aging conditions were identified, namely, cycle and shelf test. The former one mimicking the cycling between desorption and adsorption conditions, while the latter one keeping a constant temperature for long time under constant water vapor pressure. A flexible experimental setup was then designed and realized to contemporarily perform both aging condition under selectable operating conditions. The protocol defines different characterization methods to compare the fresh and the aged samples. The measurement of the water vapor adsorption equilibrium isobars represents the main parameter to directly highlight possible degradation phenomena. Subsequently, X‐ray diffraction patterns (XRD), nitrogen physisorption, and scanning electron microscopy coupled to energy dispersive x‐ray (SEM–EDX), are used to evaluate structural, textural, morphological, and elemental composition variation that can help in identifying the causes of possible degradation. The proposed protocol was employed to validate the stability of a commercial adsorbent, AQSOA Z02, that proved a quite stable behavior both under cycle and shelf investigated conditions. [ABSTRACT FROM AUTHOR]

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]

Abstract The importance of Thermal Energy Storage (TES) inside efficient and renewables-driven systems is growing. While different technologies from traditional sensible TES are entering the market or moving towards commercialisation, a common basis for fair comparison and evaluation of these systems is lacking. Aim of the present paper is the definition of a set of KPIs that can be used for the comparative analysis of different TES. A review of methodologies used for the definition of KPIs in different sectors was realised and a novel methodology, based on the comparative assessment of literature analysis and evaluation of technology roadmaps was proposed. According to this methodology, the technical, socio-economic and environmental constraints defined by researchers and policy makers were identified and translated into KPIs. The set of parameters suggested was then applied to different cases studies within the same application, namely covering heating demand in residential buildings. The different technologies were compared and the results evaluated: a significant non-uniformity in the data available and the way they are presented was found, mainly linked to the different level of maturity of the technologies investigated. This strongly confirmed the need for a shared framework of data definition and reduction. Nonetheless, it was possible to calculate the majority of parameters and derive some general trends, thus proving the effective usefulness of the KPIs defined. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

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]

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]

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]

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]

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]

Based on the observations from the judicial and investigative evidence provided by prosecutors in Camorra areas in Italy, this investigation provides an estimate of the economic impact of extortion racket to businesses. In particular, the estimates refer to the total and average withdrawal of monetary amounts from the businesses victimised by Camorra clans. Further insights are provided in terms of economic activities mostly victimised, and specifically the construction sector, which is subject to a different type of extortion racket. [ABSTRACT FROM PUBLISHER]

This paper presents the potential for the analysis of texts when applied to interceptions carried out with the help of next-generation software. In order to do this, after a brief explanation of some of the main procedures, the article presents the results of an investigation into text data extracted from wiretapping and in-person conversations found in judicial documents. The amount of data, obtained through wiretapping and the use of bugs, has made it possible to gather important information about the dynamics that characterise how criminal organisations work. The use of wiretaps and bugs are, therefore, vital tools without which it would undoubtedly not have been possible to achieve the results now apparent to everyone. Thanks to a careful analysis, it has been possible to reconstruct the kind of relationships between the members of organised crime, highlighting the roles they hold and the strategies used for territorial control. [ABSTRACT FROM PUBLISHER]

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]

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]

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]

The study of flows with a high degree of turbulence in boundary layers, near-wall jets, gas curtains, separated flows behind various obstacles, as well as during combustion is of great importance for increasing energy efficiency of the flow around various elements in the ducts of gas-dynamic installations. This paper gives some general characteristics of experimental work on the study of friction and heat transfer on a smooth surface, in near-wall jets, and gas curtains under conditions of increased free-stream turbulence. Taking into account the significant effect of high external turbulence on dynamics and heat transfer of separated flows, a similar effect on the flow behind various obstacles is analyzed. First of all, the classical cases of flow separation behind a single backward-facing step and a rib are considered. Then, more complex cases of the flow around a rib oriented at different angles to the flow are analyzed, as well as a system of ribs and a transverse trench with straight and inclined walls in a turbulent flow around them. The features of separated flow in a turbulized stream around a cylinder, leading to an increase in the width of the vortex wake, frequency of vortex separation, and increase in the average heat transfer coefficient are analyzed. The experimental results of the author are compared with data of other researchers. The structure of separated flow at high turbulence—characteristic dimensions of the separation region, parameters of the mixing layer, and pressure distribution—are compared with the conditions of low-turbulent flow. Much attention is paid to thermal characteristics: temperature profiles across the shear layer, temperature distributions over the surface, and local and average heat transfer coefficients. It is shown that external turbulence has a much stronger effect on the separated flow than on the boundary layer on a flat surface. For separated flows, its intensifying effect on heat transfer is more pronounced behind a rib than behind a step. The factor of heat transfer intensification by external turbulence is most pronounced in the transverse cavity and in the system of ribs. [ABSTRACT FROM AUTHOR]

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]

The thermal masses of components influence the performance of many adsorption heat pump systems. However, typically when experimental adsorption systems are reported, data on thermal mass are missing or incomplete. This work provides original measurements of the thermal masses for experimental sorption heat exchanger hardware. Much of this hardware was previously reported in the literature, but without detailed thermal mass data. The data reported in this work are the first values reported in the literature to thoroughly account for all thermal masses, including heat transfer fluid. The impact of thermal mass on system performance is also discussed, with detailed calculation left for future work. The degree to which heat transfer fluid contributes to overall effective thermal mass is also discussed, with detailed calculation left for future work. This work provides a framework for future reporting of experimental thermal masses. The utilization of this framework will enrich the data available for model validation and provide a more thorough accounting of adsorption heat pumps. [ABSTRACT FROM AUTHOR]

In this study, the definition of a new methodology for a preliminary evaluation of the working boundary conditions under which a seasonal thermal energy storage (STES) system operates is described. The approach starts by considering the building features as well as the reference heating system in terms of solar thermal collectors' technology, ambient heat sinks/source, and space heating distribution systems employed. Furthermore, it is based on a deep climatic analysis of the place where the STES needs to be installed, to identify both winter and summer operating conditions. In particular, the STES energy density is evaluated considering different space heating demands covered by the STES (ranging from 10% up to 60%). The obtained results demonstrate that this approach allows for the careful estimation of the achievable STES density, which is varies significantly both with the space heating coverage guaranteed by the STES as well as with the ambient heat source/sink that is employed in the system. This confirms the need for careful preliminary analysis to avoid the overestimation of the STES material volume. The proposed approach was then applied for different climatic conditions (e.g., Germany and Sweden) and the volume of one of the most attractive composite sorbent materials reported in the literature, i.e., multi-wall carbon nanotubes (MWCNT)-LiCl, using water as the working fluid, needed for covering the variable space heating demand in a Nearly Zero Energy Building (NZEB) was calculated. In the case of Swedish buildings, it ranges from about 3.5 m3 when 10% of the space heating demand is provided by the STES, up to 11.1 m3 when 30% of the space heating demand is provided by the STES. [ABSTRACT FROM AUTHOR]

• 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]

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]

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]

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]

In this paper, cement mortar IN200 integrated with solid–solid PlusIce X25 commercial PCM was fully characterized for the first time via experimental tests and numerical simulations. An experimental setup was designed and built to evaluate the thermal performance of the composite. Experimental results confirmed the expected advantages of the PCM-loaded plaster in terms of inner surface temperature, inbound heat flux reduction, and the enhanced damping effect on the average temperature. The experimental results were used to validate and calibrate a finite element model implemented in COMSOL Multiphysics® 5.6. The model was adopted to carry out a parametric analysis assessing the influence of PCM mass fraction, phase transition temperature, and PCM mortar thickness. The composite thickness was the most influential parameter, resulting in an energy saving increase from 3.29% to 72.72% as it was increased from 10 mm to 30 mm. Moreover, the model was used in a set of dynamic simulations, reproducing real Mediterranean climatic conditions to capture the transition process for a long period in buildings. The PCM mortar located on the interior side exhibited the highest reduction in both heat flux and inner surface temperature, representing a simple approach to achieving the best thermal comfort conditions. [ABSTRACT FROM AUTHOR]

Solar cooling systems might represent a viable alternative for space cooling in residential buildings because the peak of cooling demand matches the availability of solar radiation. The use of adsorption chillers in this field gives another environmental benefit, since they employ natural refrigerants as water. However, the design of such systems is critical because it relates to several parameters and cannot be easily accomplished using traditional tools. In this work, a dynamic model for the simulation of a small solar cooling system employing adsorption chillers has been evaluated. The model, realized 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, and Messina). Particular focus was put on the comparison of different heat rejection systems, which was found to be a critical aspect in the design of such systems. In addition, an economic analysis has been performed for an optimized system, in order to evaluate the payback time of the systems compared to a traditional air conditioning system and provide indication on the possible outlooks by means of a sensitivity analysis. [ABSTRACT FROM AUTHOR]

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]

[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]

Phase change slurries (PCSs) have great potential as both a heat transfer fluid and an energy storage medium for cooling processes, cold energy storage, and cold energy transportation due to desirable thermophysical properties. One of the major benefits of PCSs compared to pure phase change materials is their fluidity, thus making them cooled or heated by a heat exchanger, pumped through pipes, discharged, and stored directly in a thermal energy storage tank. The use of encapsulated phase change slurries and gas hydrate slurry has thus attracted considerable interest as reflected in the literature with a rising number of publications and institutions involved in the area. The use of bibliometric techniques has found a recent interest in the literature to define the progress of different scientific topics and inspire researchers to identify novelties. In this paper, bibliometric analysis and a detailed systematic review are carried out to show the state-of-the-art development of PCSs for cooling applications. Research gaps and hotspots are identified to help define future perspectives on this topic. [ABSTRACT FROM AUTHOR]

Solar thermal energy coupled to a seasonal sorption storage system stands as an alternative to fossil fuels to supply residential thermal energy demand in climates where solar energy availability is high in summer and low in winter, matching with a high space heating demand. Sorption storage systems usually have a high dependency on weather conditions (ambient temperature and solar irradiation). Therefore, in this study, the technical performance of a solar-driven seasonal sorption storage system, using an innovative composite sorbent and water as working fluid, was studied under three European climates, represented by: Paris, Munich, and Stockholm. All scenarios analyses were simulation-based under optimal system control, which allowed to maximize the system competitiveness by minimizing the system operational costs. The optimal scenarios profit from just 91, 82 and 76% of the total sorption system capacity, for Paris, Munich, and Stockholm, respectively. That means that an optimal control can identify the optimal sorption storage size for each location and avoid oversizing in future systems, which furthermore involves higher investment costs. The best coefficient of performance was obtained for Stockholm (0.31), despite having the coldest climate. The sorption system was able to work at minimum temperatures of −15 °C, showing independence from ambient temperature during its discharge. In conclusion, a seasonal sorption system based on selective water materials is suitable to be integrated into a single-family house in climates of central and northern Europe as long as an optimal control based on weather conditions, thermal demand, and system state is considered. [ABSTRACT FROM AUTHOR]

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]

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]

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]

In order to reduce greenhouse gas emissions, current and future energy systems need to be made more efficient and sustainable. This change can be accomplished by increasing the penetration of renewable energy sources and using efficient technologies in energy generation systems. One way to improve the operation of the whole energy system is through the generation and end-use sector coupling. Power-to-heat energy conversion and storage technologies, in this view, are enabling technologies that can help in balancing and improving the efficiency of both thermal and electric grids. In the present paper, a comprehensive analysis of the role of heat pumps and thermal energy storage for sector coupling is presented. The main features of the analyzed technologies are presented in the context of smart electric grid, district heating and cooling and multi-carrier energy systems, and recent findings and developments are highlighted. Finally, the technical, social, and economic challenges in the adoption of investigated technologies are discussed. [ABSTRACT FROM AUTHOR]

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]

• 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]

The lack of robust and low-cost sorbent materials still represents a formidable technological barrier for long-term storage of (renewable) thermal energy and more generally for Adsorptive Heat Transformations—AHT. In this work, we introduce a novel approach for synthesizing cement-based composite sorbent materials. In fact, considering the number of available hygrosopic salts that can be accommodated into a cementitious matrix—whose morphological properties can be also fine-tuned—the new proposed in situ synthesis paves the way to the generation of an entire new class of possible sorbents for AHT. Here, solely focusing on magnesium sulfate in a class G cement matrix, we show preliminary morphological, mechanical and calorimetric characterization of sub-optimal material samples. Our analysis enables us to theoretically estimate one of the most important figures of merit for the considered applications, namely the energy density which was found to range within 0.088–0.2 GJ/m3 (for the best tested sample) under reasonable operating conditions for space heating applications and temperate climate. The above estimates are found to be lower than other composite materials in the literature. Nonetheless, although no special material optimization has been implemented, our samples already compare favourably with most of the known materials in terms of specific cost of stored energy. Finally, an interesting aspect is found in the ageing tests under water sorption-desorption cycling, where a negligible variation in the adsorption capability is demonstrated after over one-hundred cycles. [ABSTRACT FROM AUTHOR]

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]

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]

• 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]

The present paper presents the development of a thermal energy storage system for application with non-concentrating solar plants using phase change materials (PCMs). The outcomes of an experimental analysis on commercial PCMs and laboratory-grade chemical compounds suitable for latent heat storages in a temperature range of 80–100°C is presented, with main focus on to the enthalpy and the cycle stability of the materials. Particularly, a first evaluation of possible degradation mechanisms in hydrated salts was investigated by means of nuclear magnetic resonance spectroscopy. The best performing materials have been implemented in a numerical model, based on the enthalpy method, used for the design of a thermal storage system. The configuration of the system, starting from a simple shell-and-tube layout, has been optimized by inserting asymmetric fin-and-tubes and the results with two selected materials have been compared. The analysis has shown that the most promising materials are the commercial ones belonging to the classes of paraffinic materials and hydrated salts and that, with the designed configuration, it is possible to store up to 200 kJ/m3 and get a peak power during discharge of about 1.5 kW. [ABSTRACT FROM AUTHOR]

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]

• 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]

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]

Thermal energy storage (TES) is a key technology to enhance the efficiency of energy systems as well as to increase the share of renewable energies. In this context, the present paper reports a literature review of the recent advancement in the field of adsorption TES systems. After an initial introduction concerning different heat storage technologies, the working principle of the adsorption TES is explained and compared to other technologies. Subsequently, promising features and critical issues at a material, component and system level are deeply analyzed and the ongoing activities to make this technology ready for marketing are introduced. [ABSTRACT FROM AUTHOR]

Imaging in the infrared wavelength range has been fundamental in scientific, military and surveillance applications. Currently, it is a crucial enabler of new industries such as autonomous mobility (for obstacle detection), augmented reality (for eye tracking) and biometrics. Ubiquitous deployment of infrared cameras (on a scale similar to visible cameras) is however prevented by high manufacturing cost and low resolution related to the need of using image sensors based on flip-chip hybridization. One way to enable monolithic integration is by replacing expensive, small-scale III-V-based detector chips with narrow bandgap thin-films compatible with 8- and 12-inch full-wafer processing. This work describes a CMOS-compatible pixel stack based on lead sulfide quantum dots (PbS QD) with tunable absorption peak. Photodiode with a 150-nm thick absorber in an inverted architecture shows dark current of 10-6 A/cm2 at -2 V reverse bias and EQE above 20% at 1440 nm wavelength. Optical modeling for top illumination architecture can improve the contact transparency to 70%. Additional cooling (193 K) can improve the sensitivity to 60 dB. This stack can be integrated on a CMOS ROIC, enabling order-of-magnitude cost reduction for infrared sensors. [ABSTRACT FROM AUTHOR]

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]

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]