Enginyeria Industrial i de l’Edificació
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A partir del curs 2022/2023 la denominació oficial és Departament d'Enginyeria Industrial i de l’Edificació (Aprovat per l'acord 12/2023 del Consell de Govern en la sessió de 28.02.2023), com a continuació d'una part del Departament d'Informàtica i Enginyeria Industrial .
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- ItemRestricted128 x 128 CMOS Image Sensor With Analog Memory for Synchronous Image Capture(Institute of Electrical and Electronic Engineers, 2002) Chapinal, Genis; Bota, Sebastian A.; Moreno, Mauricio; Palacín Roca, Jordi; Herms, AtilàA 128 x 128 CMOS imager that permits synchronous capture is presented. The sensor combines the best of CMOS imagers (low-power, random readout, nondestructive readout, single supply voltage…) and synchronous capture [available in high-end charge coupled device (CCD) imagers]. The key point in obtaining such characteristics is the separation of the photosensor and the storage element. Although some sensors with these characteristics have been reported, in this sensor, the storage capability has been brought a step further, having storage times in the order of tens of seconds, and being able to use the array itself as a random access memory (RAM). This could avoid the use of external RAM, making the system simpler, more compact, and of low-power consumption.
- ItemOpen Access3D characterization of a Boston Ivy double-skin green building facade using a LiDAR system(Elsevier, 2021-09-02) Pérez Luque, Gabriel; Escolà i Agustí, Alexandre; Rosell Polo, Joan Ramon; Coma Arpón, Julià; Arasanz Riba, Roger; Marrero Farré, Bernat; Cabeza, Luisa F.; Gregorio López, EduardOn the way to more sustainable and resilient urban environments, the incorporation of urban green infrastructure (UGI) systems, such as green roofs and vertical greening systems, must be encouraged. Unfortunately, given their variable nature, these nature-based systems are difficult to geometrically characterize, and therefore there is a lack of 3D objects that adequately reflect their geometry and analytical properties to be used in design processes based on Building Information Modelling (BIM) technologies. This fact can be a disadvantage, during the building's design phase, of UGIs over traditional grey solutions. Areas of knowledge such as precision agriculture, have developed technologies and methodologies that characterize the geometry of vegetation using point cloud capture. The main aim of this research was to create the 3D characterization of an experimental double-skin green facade, using LiDAR technologies. From the results it could be confirmed that the methodology used was precise and robust, enabling the 3D reconstruction of the green facade's outer envelope. Detailed results were that foliage volume differences in height were linked to plant growth, whereas differences in the horizontal distribution of greenery were related to the influence of the local microclimate and specific plant diseases on the south orientation. From this research, along with complementary previous research, it could be concluded that, generally speaking, with vegetation volumes of 0.2 m3/m2, using Boston Ivy (Parthenocissus Tricuspidata) under Mediterranean climate, reductions in external building surface temperatures of around 13 °C can be obtained and used as analytic parameter in a future 3D-BIM-object.
- ItemOpen AccessA comparative life cycle assessment (LCA) of different insulation materials for buildings in the continental Mediterranean climate(Elsevier, 2020) Llantoy, Noelia; Chàfer, Marta; Cabeza, Luisa F.The construction industry is one of the less sustainable activities on the planet, constituting 40% of the total energy demand and approximately 44% of the total material use and the generation of 40-50% of the global output of greenhouse gases. The biggest environmental impact caused by buildings is generated during their operational phase due to the energy consumption for thermal conditioning. Hence, in order to reduce this energy consumption, insulation materials must be used and from a life-cycle perspective, the use of insulation materials reduces the building impact over time. This paper develops a comparative life cycle assessment (LCA) of different insulation materials (polyurethane, extruded polystyrene, and mineral wool) to analyse the environmental profile of each insulation material type in the Mediterranean continental climate. Significantly, all three insulation materials demonstrated a net positive benefit over a fifty-year life span due to the reduced heating requirements of the building. Results showed that the highest environmental impact was associated with the polystyrene insulation material and the best environmental performance was for the mineral wool. Moreover, regarding the consumption, polyurethane and mineral wool had similar thermal performance during the whole year. Furthermore, the environmental payback period shows that the cubicles with insulation material are environmentally efficient, if they are used for at least 7 years (for mineral wool), 10 years (polyurethane), and 12 years (extruded polystyrene). The results of this research give new insights into the effect on building insulation materials.
- ItemEmbargoA comparative life cycle assessment between green walls and green facades in the Mediterranean continental climate(Elsevier, 2021) Chàfer, Marta; Pérez Luque, Gabriel; Coma Arpón, Julià; Cabeza, Luisa F.The building and construction sector is a large contributor to anthropogenic greenhouse gas emissions and consumes vast natural resources. Improvements in this sector are of fundamental importance for national and global targets to combat climate change. In this context, vertical greenery systems (VGS) in buildings have become popular in urban areas to restore green space in cities and be an adaptation strategy for challenges such as climate change. However, only a small amount of knowledge is available on the different VGS environmental impacts. This paper discusses a comparative life cycle assessment (LCA) between a building with green walls, a building with green facades and a reference building without any greenery system in the continental Mediterranean climate. This life cycle assessment is carried according to ISO 14040/44 using ReCiPe and GWP indicators. Moreover, this study fills this gap by thoroughly tracking and quantifying all impacts in all phases of the building life cycle related to the manufacturing and construction stage, maintenance, use stage (operational energy use experimentally tested), and final disposal. The adopted functional unit is the square meter of the facade. Results showed that the operational stage had the highest impact contributing by up to 90% of the total environmental impacts during its 50 years life cycle. Moreover, when considering VGS, there is an annual reduction of about 1% in the environmental burdens. However, in summer, the reduction is almost 50%. Finally, if the use stage is excluded, the manufacturing and the maintenance stage are the most significant contributors, especially in the green wall system.
- ItemOpen AccessA comparative life cycle assessment of single-use fibre drums versus reusable steel drums(Wiley, 2009-06) Raugei, Marco; Fullana i Palmer, Pere; Puig, Rita; Torres, AlejoThis paper deals with a comparative analysis of two different packaging and transport scenarios, which exemplifies the implications of choosing between single-use and reusable packaging. In particular, transport of a batch of chemicals by means of disposable fibre drums vs. reusable steel drums is investigated from a life cycle perspective, and the associated environmental impact in terms of Global Warming Potential, Acidification Potential, Gross Energy Requirement and solid waste generation is assessed. Results prove beyond reasonable doubt that, even in the case of durable packaging containers requiring the use of comparatively energy-intensive materials for their production, the reuse scenario is characterized by lower environmental impact indicators across the board, and as such is the most advisable and environmentally sound option.
- ItemOpen AccessA comprehensive review on sub-zero temperature cold thermal energy storage materials, technologies, and applications: State of the art and recent developments(Elsevier, 2021) Yang, Lizhong; Villalobos, Uver; Akhmetov, Bakytzhan; Gil, Antoni; Khor, Jun Onn; Palacios, Anabel; Li, Yongliang; Ding, Yulong; Cabeza, Luisa F.; Tan, Wooi Leong; Romagnoli, AlessandroThe energy industry needs to take action against climate change by improving efficiency and increasing the share of renewable sources in the energy mix. On top of that, refrigeration, air-conditioning, and heat pump equipment account for 25-30% of the global electricity consumption and will increase dramatically in the next decades. However, some waste cold energy sources have not been fully used. These challenges triggered an interest in developing the concept of cold thermal energy storage, which can be used to recover the waste cold energy, enhance the performance of refrigeration systems, and improve renewable energy integration. This paper comprehensively reviews the research activities about cold thermal energy storage technologies at sub-zero temperatures (from around 270 ◦C to below 0 ◦C). A wide range of existing and potential storage materials are tabulated with their properties. Numerical and experimental work conducted for different storage types is systematically summarized. Current and potential applications of cold thermal energy storage are analyzed with their suitable materials and compatible storage types. Selection criteria of materials and storage types are also presented. This review aims to provide a quick reference for researchers and industry experts in designing cold thermal energy systems. Moreover, by identifying the research gaps where further efforts are needed, the review also outlines the progress and potential development directions of cold thermal energy storage technologies.
- ItemOpen AccessA correlation of the convective heat transfer coefficient between an air flow and a phase change material plate(Elsevier, 2013) Gracia Cuesta, Alvaro de; David, Damien; Castell, Albert; Cabeza, Luisa F.; Virgone, JosephThis paper provides a new correlation to determine the heat transfer coefficient between an air flow and a plate made of phase change material (PCM). This correlation was built for the simulation of heat storage units containing PCM plates subjected to an inlet temperature step. The presented correlation has the following form: NuPCM x;t ¼ NuPSM$f PCM. The first term NuPSM is for a plate made of traditional material. The term fPCM is a perturbation due to the phase change in the plate. Each term depends on 5 non-dimensional parameters. One of them represents the advance in the total heating or cooling process, in order to take into account the transient evolution of the convective coefficient. The correlations are built using the Least Squares Method, from series of CDF simulation data. The shape of the perturbation fPCM reveals a complex evolution of the temperature repartition in the PCM plate. Finally, a nodal model of the plate has been developed in order to test the provided new correlation and other correlations available in the literature. The results obtained with the present correlation show better agreements with the CFD results, which make this correlation suitable for the simulation of PCM heat storage systems.
- ItemOpen AccessA critical review of superfoods from a holistic nutritional and environmental approach(Elsevier, 2022-10) Fernández Rios, Ana; Laso, Jara; Hoehn, Daniel; Amo Satién, Francisco José; Abajas, Rebeca; Ortego-Mate, Carmen; Fullana i Palmer, Pere; Bala, Alba; Batlle Bayer, Laura; Balcells Fluvià, Mercè; Puig, Rita; Aldaco, Rubénn a global arena in which the identification of healthier and cleaner nutrient sources is practically mandatory, superfoods, known as foods of high nutritional and biological value with satisfactory bioavailability and bioactivity within the body due to extraordinary concentrations of nutrients and bioactive ingredients, can play a key role. These products are highly connected with sustainability, which is composed of an economic, envi- ronmental, and social balance, mainly translated in meeting nutritional needs. Focusing on the two latter aspects, this article is intended to provide a breakthrough in the knowledge by assessing the nutritional characteristics and environmental performance of superfoods. Firstly, a selection is made by revising the nutritional profile of different products. Secondly, a review of life cycle assessment (LCA) studies aims to establish guidelines for future analyses, based on the current state-of-art and possible recommendations, as well as to provide infor- mation on the impacts of these novel products. 40 superfoods are identified, of which only 15 have environ- mental analysis. The LCA revision enable to recognize methodological vulnerabilities based on the lack of definition of the function, allocations, uncertainty and quality assessments, as well as a weak justification on the selection of data sources and impact categories. Other recommendations include the possibility of using nutrient- based functional unit, extending system boundaries up to retailer, applying high quality primary data and standardized databases, and analyzing a wider range of indicators. Finally, this scientific field is still little explored, so the suitability of superfoods from an environmental perspective cannot be concluded, thus encouraging the use of LCA to fill this scientific gap.
- ItemOpen AccessA detailed energy analysis of a novel evaporator with latent thermal energy storage ability(Elsevier, 2021) Mselle, Boniface Dominick; Zsembinszki, Gabriel; Vérez, David; Borri, Emiliano; Cabeza, Luisa F.The direct integration of phase change materials (PCM) into refrigeration and air conditioning systems through compact modules is an identified literature gap. In response to the literature gap, this paper provides a detailed energy analysis of a novel compact thermal energy storage module, that allows its direct integration into a refrigeration system as the evaporator. The study addresses key aspects of thermal energy storage (TES) and heat transfer mechanism that complement the previous analyses of the novel concept. Here the total energy stored in the module (including in all auxiliary parts), the charging/discharging power, and the behaviour of the module when used as a TES module and as a heat exchanger (HEX) are assessed. The results demonstrate the feasibility of the module to work as a TES and as a HEX. When working as a TES, complete charging and discharging was achieved, and 54% of the total energy was stored in the PCM although the PCM only accounts for around 14% of the total mass. Moreover, the highest charging/discharging power was obtained within the temperature range where most of the phase change occurred. When the module works as a HEX, it initially charges/discharges partially until a thermal equilibrium is achieved and the level of charge responds to the variation in the energy supply and demand.
- ItemOpen AccessA Dynamic Wheelchair Armrest for Promoting Arm Exercise and Mobility After Stroke(IEEE, 2022) Comellas Andrés, Martí; Chan, Vicky; Zondervan, Daniel K.; Reinkensmeyer, David J.Arm movement recovery after stroke can improve with sufficient exercise. However, rehabilitation therapy sessions are typically not enough. To address the need for effective methods of increasing arm exercise outside therapy sessions we developed a novel armrest, called Boost. It easily attaches to a standard manual wheelchair just like a conventional armrest and enables users to exercise their arm in a linear forward-back motion. This paper provides a detailed design description of Boost, the biomechanical analysis method to evaluate the joint torques required to operate it, and the results of pilot testing with five stroke patients. Biomechanics results show the required shoulder flexion and elbow extension torques range from −25% to +36% of the torques required to propel a standard pushrim wheelchair, depending on the direction of applied force. In pilot testing, all five participants were able to exercise the arm with Boost in stationary mode (with lower physical demand). Three achieved overground ambulation (with higher physical demand) exceeding 2 m/s after 2–5 practice trials; two of these could not propel their wheelchair with the pushrim. This simple to use, dynamic armrest provides people with hemiparesis a way to access repetitive arm exercise outside of therapy sessions, independently right in their wheelchair. Significantly, Boost removes the requirements to reach, grip, and release the pushrim to propel a wheelchair, an action many individuals with stroke cannot complete.
- ItemOpen AccessA framework for sustainable evaluation of thermal energy storage in circular economy(Elsevier, 2021) Abokersh, Mohamed Hany; Norouzi, Masoud; Boer, Dieter; Cabeza, Luisa F.; Gasa, Gemma; Prieto, Cristina; Jiménez, Laureano; Vallès Rasquera, J. ManelThe circular economy can be promoted as a solution to support the sustainability market position of renewable energy systems. To design a circular and sustainable system, a structured approach is needed. The present study develops a methodology framework for sustainable circular system design (SCSD), aiming to assess thermal energy storage (TES) technologies from a sustainable perspective. To this end, a composite indicator, namely, environmental sustainability and circularity indicator (ESC) is provided. This indicator combines the environmental impacts of the TES system via the conduction of a life cycle assessment and its circulatory performance using the product-level material circularity indicator (MCI). The developed methodology is applied to a case study of high-temperature TES using molten salts as a part of a concentrated solar power plant. The SCSD embraces the analysis for the most relevant processes through proposing different ecological scenarios including, increasing the recycling rates (Modest Scenario), increasing the reuse rates (Medium Scenario), and a combination of both (Optimistic scenario). The circularity analysis showed that for the Modest, Medium and optimistic scenarios, the MCI moves from 20.6% for the current situation to 30.3%, 38.6%, and 46.4%, respectively. Accordingly, the optimistic scenario showed the most environmentally sustainable and circular scenario with ESC of 7.89%, whereas the Modest and Medium scenarios exhibited ESCs of 1.20% and 2.16%, respectively. A major obstacle for substantial improvement of the circulatory and ESC is the high share of unrecyclable molten salts in the system and therefore, any effort to improve the circulatory and the environmental benefits of this system can be reached by using more environmentally friendly alternative materials. The study concludes that the integration of reusing and recycling at the initial design should be sought in order to achieve a more environmentally sustainable and circular outcome.
- ItemOpen AccessA framework for the optimal integration of solar assisted district heating in different urban sized communities: A robust machine learning approach incorporating global sensitivity analysis(Elsevier, 2020) Abokersh, Mohamed Hany; Vallès Rasquera, J. Manel; Cabeza, Luisa F.; Boer, DieterA promising pathway towards sustainable transaction to clean energy production lies in the adoption of solar assisted district heating systems (SDHS). However, SDHS technical barriers during their design and operation phases, combined with their economic limitation, promote a high variation in quantifying SDHS benefits over their lifetime. This study proposes a complete multi-objective optimization framework using a robust machine learning approach to inherent sustainability principles in the design of SDHS. Moreover, the framework investigates the uncertainty in the context of SDHS design, in which the Global Sensitivity Analysis (GSA) is combined with the heuristics optimization approach. The framework application is illustrated through a case study for the optimal integration of SHDS at different urban community sizes (10, 25, 50, and 100 buildings) located in Madrid. The results reveal a substantial improvement in economic and environmental benefits for deploying SDHS, especially with including the seasonal storage tank (SST) construction properties in the optimization problem, and it can achieve a payback period up to 13.7 years. In addition, the solar fraction of the optimized SDHS never falls below 82.1% for the investigated community sizes with an efficiency above 69.5% for the SST. Finally, the GSA indicates the SST investment cost and its relevant construction materials, are primarily responsible for the variability in the optimal system feasibility. The proposed framework can provide a good starting point to solve the enormous computational expenses drawbacks associated with the heuristics optimization approach. Furthermore, it can function as a decision support tool to fulfill the European Union energy targets regarding clean energy production.
- ItemOpen AccessA global horizon scan of the future impacts of robotics and autonomous systems on urban ecosystems(Nature Research, 2021) Pérez Luque, Gabriel; Goddard, Mark A.; Davies, Zoe G.; Guenat, Solène; Ferguson, Mark J.; Fisher, Jessica C.; Akanni, Adeniran; Ahjokoski, Teija; Anderson, Pippin M.L.; Angeoletto, FabioTechnology is transforming societies worldwide. A major innovation is the emergence of robotics and autonomous systems (RAS), which have the potential to revolutionize cities for both people and nature. Nonetheless, the opportunities and challenges associated with RAS for urban ecosystems have yet to be considered systematically. Here, we report the findings of an online horizon scan involving 170 expert participants from 35 countries. We conclude that RAS are likely to transform land use, transport systems and human–nature interactions. The prioritized opportunities were primarily centred on the deployment of RAS for the monitoring and management of biodiversity and ecosystems. Fewer challenges were prioritized. Those that were emphasized concerns surrounding waste from unrecovered RAS, and the quality and interpretation of RAS-collected data. Although the future impacts of RAS for urban ecosystems are difficult to predict, examining potentially important developments early is essential if we are to avoid detrimental consequences but fully realize the benefits.
- ItemOpen AccessA Materials Screening Test of Corrosion Monitoring in LiNO3 Containing Molten Salts as a Thermal Energy Storage Material for CSP Plants(MDPI, 2020) Mallco, Abdiel; Portillo, Carlos; Kogan, Marcelo J.; Galleguillos, Felipe; Fernández, Ángel G.Concentrated solar power (CSP) plants, in the context of thermal energy storage (TES) upgrades, need to provide a timely and effective response to the corrosion process that occurs due to the effect of high temperatures, where one of the main challenges is to control its effect, and thus the costs related to the materials used. Electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LPR) were applied in this study as a corrosion monitoring technique. The electrochemical tests were carried out on the materials AISI304, AISI430, and HR-224 immersed in a mixture of ternary salt composed of 57 wt.% KNO3 + 13 wt.% NaNO3 + 30 wt.% LiNO3 at 550 °C during 100 h of exposure and subsequently compared with solar salt. The test was also carried out on the VM12 alloy in the ternary salt with lithium content at 100 and 1000 h of exposure at 550 °C. The corrosion tests show that the materials conform to a model of protective layer in which the same results were contrasted with the chemical corrosion mechanism of nitrate mixture. According to the results obtained in this research, electrochemical techniques could be an interesting option to control corrosion in CSP plants and reduce operational risks during operation.
- ItemOpen AccessA methodology for developing Distributed Generation scenarios in urban areas using geographical information systems(Inderscience, 2008) Medrano Martorell, Marc; Brouwer, Jack; Carreras-Sospedra, Marc; Rodriguez, Marco A.; Dabdub, Donald; Samuelsen, G. ScottThe implementation of Distributed Generation (DG) may lead to increased pollutant emissions that adversely affect air quality. This work presents a systematic methodology to characterise DG installation in urban basins. First, a set of parameters that characterise a DG implementation scenario is described. Second, a general approach using Geographic Information Systems (GIS) data is presented. Third, the methodology is demonstrated by application to the South Coast Air Basin (SoCAB) of California. Results show that realistic scenarios in the SoCAB concentrate DG technologies nearby industrial zones and introduce pollutant mass increments no larger than 0.43% with respect to baseline emissions.
- ItemRestrictedA MOF-Compliant Approach to Software Quality Modeling(Springer Verlag, 2005) Burgués i Illa, Xavier; Franch, Xavier; Ribó i Balust, Josep M. (Josep Maria)Software quality is a many-faceted concept that depends on the kind of artifact to be measured, the context where measurement takes place, the quality framework used, and others. Furthermore, there is a great deal of standards, white papers, and in general proposals of any kind related to software quality. Consequently, a unified software quality framework seems to be needed to compare, combine or select these proposals and to define new ones. In this paper we propose a MOF-compliant approach for structuring quality models in order to formalise software quality issues and deal with quality information modelling. We propose two types of models: a generic model, situated in the M2 MOF layer; and a hierarchy of reference models, defined in the M1 and M0 MOF layers. The generic model elements are derived from the UML metamodel by specialization. Then, we can instantiate them to get reference models that formalise (combinations of) existing proposals which may be further refined for defining quality frameworks to be used in different experiences. Each of these models is divided into three parts, namely fundamental concepts, metrics and context. We illustrate our proposal providing a multi-level reference model in the context of collection libraries quality evaluation.
- ItemOpen AccessA new methodological approach for the evaluation of scaling up a latent storage module for integration in heat pumps(MDPI, 2021) Zsembinszki, Gabriel; Mselle, Boniface Dominick; Vérez, David; Borri, Emiliano; Strehlow, Andreas; Nitsch, Birgo; Frazzica, Andrea; Palomba, Valeria; Cabeza, Luisa F.A clear gap was identified in the literature regarding the in-depth evaluation of scaling up thermal energy storage components. To cover such a gap, a new methodological approach was developed and applied to a novel latent thermal energy storage module. The purpose of this paper is to identify some key aspects to be considered when scaling up the module from lab-scale to full-scale using different performance indicators calculated in both charge and discharge. Different normalization methods were applied to allow an appropriate comparison of the results at both scales. As a result of the scaling up, the theoretical energy storage capacity increases by 52% and 145%, the average charging power increases by 21% and 94%, while the average discharging power decreases by 16% but increases by 36% when mass and volume normalization methods are used, respectively. When normalization by the surface area of heat transfer is used, all of the above performance indicators decrease, especially the average discharging power, which decreases by 49%. Moreover, energy performance in charge and discharge decreases by 17% and 15%, respectively. However, efficiencies related to charging, discharging, and round-trip processes are practically not affected by the scaling up.
- ItemOpen AccessA newflat-plate radiative cooling and solar collector numerical model: Evaluation and metamodeling(Elsevier, 2020-05-01) Vall Aubets, Sergi; Johannes, Kevyn; David, Damien; Castell, AlbertRadiative cooling is a renewable technology that can complement or partially replace current cooling technologies. Coupling radiative cooling with another technology, such as solar collection could foster its development and implementation in the market. Therefore, a numerical model capable to simulate the behavior of a coupled radiative cooling and solar collection system is developed and presented in this paper. The model is validated with experimental data for both solar collection and radiative cooling operation, and a sensitivity analysis is performed in order to determine the most influencing parameters. Results show the potential of the device to perform the double functionality: solar thermal collector and radiative cooler. As expected the heating power (17.11 kWh/m^2) is one order of magnitude higher than the cooling one (2.82 kWh/m^2). The sensitivity analysis determined the existence of an important role played by 5 parameters (air gap thermal conductivity, absorptivity/emissivity of the radiator at 7-14 µm wavelength range, transmissivity of the cover material 2 at 7-14 µm wavelength range, water inlet temperature, and water inlet flow) and 4 combinations of these parameters in the radiative cooling mode.
- ItemOpen AccessA novel numerical methodology for modelling simple vapour compression refrigeration system(Elsevier, 2017) Zsembinszki, Gabriel; Gracia Cuesta, Alvaro de; Moreno Argilés, Pere; Rovira, Ricard; González, Miguel Ángel; Cabeza, Luisa F.The extended use of cooling and refrigeration systems in industrial, building and transport sectors may have a negative impact on the climate change and ozone depletion. Thus, important aspects related to these systems, such as refrigerant charge level, malfunction, or refrigerant leakage, must be taken into account. In this sense, the study of refrigeration system performance under different conditions can be very useful. In this paper, a novel methodology for modelling a simple compression refrigeration system is described. Starting from three input parameters, i.e. the ambient air temperature, the cold room air temperature, and the degree of superheating, a calculation algorithm based on iterative loops is used in the model to determine the operating point of the system. An experimental set-up consisting of a walk-in freezer unit was used for the development and validation of the model. The model is system dependent, i.e. empirical correlations must be derived for determining some of the features of system components. The numerical results are in good agreement with the experiment, therefore the model can be a reliable tool for the detection of a system malfunction.
- ItemOpen AccessA Numerical Parametric Study of a Double-Pipe LHTES Unit with PCM Encapsulated in the Annular Space(MDPI, 2022-10-17) Paroutoglou, Evdoxia; Fojan, Peter; Gurevich, Leonid; Furbo, Simon; Fan, Jianhua; Medrano Martorell, Marc; Afshari, AlirezaLatent heat thermal energy storage (LHTES) with Phase Change Materials (PCM) represents an interesting option for Thermal Energy Storage (TES) applications in a wide temperature range. A tubular encapsulation model of an LHTES with PCM was developed, and the calculated data were analyzed. In addition, a parametric analysis for the preferable system geometry is presented. Organic paraffin RT18 with a melting point of 18 °C was utilized as PCM for different geometries of LHTES, and the addition of internal and external fins and their influence on LHTES thermal conductivity was investigated. One-step heat exchange from outdoor air to PCM and from PCM to water characterizes the LHTES system in solidification and melting processes, respectively. A 2D axisymmetric model was developed using Comsol Multiphysics 6.0. The LHTES unit performance with PCM organic paraffin RT18 encapsulated in electrospun fiber matrices was analyzed. The study results show that longer internal fins shorten the melting and solidification time. Direct contact of PCM electrospun fiber matrix with 23 °C water showed instant melting, and the phase change process was accelerated by 99.97% in the discharging cycle.