439 research outputs found

    Estudio del comportamiento de diversos residuos de catalizadores de craqueo catalítico (FCC) en cemento Portland

    Get PDF
    The fluidized-bed catalytic cracking catalyst (FCC) it is a residue from the industry of the petroleum that shows a high pozzolanic reactivity and, in cementing matrix, it significantly improves their mechanical behaviour as well as durability. In this research a comparative study on residues of catalyst from different sources has been carried out, in order to know if these residues can be used jointly in an indiscriminate way or, on the contrary, it is necessary to classify them according to their characteristics. Thus, a study on five different FCC residues, supplied from different companies, has been carried out, and their physical-chemical characteristics, pozzolanic reactivity by means of thermogravimetric analysis and the evolution of the mechanical strength of mortars were studied. After analyzing all the aspects, it can be concluded that no significant differences among the different tested catalysts were found.El catalizador de craqueo catalítico (FCC) es un residuo de la industria del petróleo que posee una elevada reactividad puzolánica y en matrices cementicias mejora de manera importante los aspectos mecánicos así como de durabilidad. En este trabajo se realiza un estudio comparativo sobre residuos de catalizador de distintos orígenes, para poder conocer si se pueden utilizar conjuntamente de forma indiscriminada o por el contrario hay que catalogarlos según su origen. Para ello, se realizó un estudio sobre cinco residuos de catalizador de craqueo catalítico distintos, suministrados por diferentes empresas y se estudiaron sus características fisicoquímicas, reactividad puzolánica a través de estudios termogravimétricos y la evolución de las resistencias mecánicas en morteros. Tras analizar todos los aspectos se concluye que no existen diferencias significativas entre los distintos catalizadores empleados

    Dynamic autonomous set-up of relays in Bluetooth mesh

    Get PDF
    BLE-based mesh networks are based on a simple flooding algorithm with some mechanisms to reduce network saturation, called managed flooding. The operating parameters of the network establish its performance, but in an industrial environment the operating conditions are not permanent, so a system that can adjust to these changes is necessary. A global decision system is not valid since each part of the network may have different properties. An autonomous system that does not introduce an overhead of message exchange is necessary for its operation. This paper proposes an algorithm based on the information provided by a single control message exchange that allows each node to autonomously select its operating parameters to improve the quality of links with neighbouring nodes and thus improve the overall performance of the network

    El Carmelo

    Get PDF
    Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 201

    Dynamic Modelling and Techno-Economic Assessment of a Compressed Heat Energy Storage System: Application in a 26-MW Wind Farm in Spain

    Full text link
    [EN] One of the main challenges for a further integration of renewable energy sources in the electricity grid is the development of large-scale energy storage systems to overcome their intermittency. This paper presents the concept named CHEST (Compressed Heat Energy STorage), in which the excess electricity is employed to increase the temperature of a heat source by means of a high-temperature heat pump. This heat is stored in a combination of latent and sensible heat storage systems. Later, the stored heat is used to drive an organic Rankine cycle, and hereby to produce electricity when needed. A novel application of this storage system is presented by exploring its potential integration in the Spanish technical constraints electricity market. A detailed dynamic model of the proposed CHEST system was developed and applied to a case study of a 26-MW wind power plant in Spain. Different capacities of the storage system were assessed for the case under study. The results show that roundtrip efficiencies above 90% can be achieved in all the simulated scenarios and that the CHEST system can provide from 1% to 20% of the total energy contribution of the power plant, depending on its size. The CHEST concept could be economically feasible if its capital expenditure (CAPEX) ranges between 200 and 650 k€/MWThis work has been partially funded by the grant agreement No. 764042 (CHESTER project) of the European Union's Horizon 2020 research and innovation program.Sánchez Canales, V.; Payá-Herrero, J.; Corberán, JM.; Hassan, A. (2020). Dynamic Modelling and Techno-Economic Assessment of a Compressed Heat Energy Storage System: Application in a 26-MW Wind Farm in Spain. Energies. 13(18):1-18. https://doi.org/10.3390/en13184739S1181318Nikolaou, T., Stavrakakis, G. S., & Tsamoudalis, K. (2020). Modeling and Optimal Dimensioning of a Pumped Hydro Energy Storage System for the Exploitation of the Rejected Wind Energy in the Non-Interconnected Electrical Power System of the Crete Island, Greece. Energies, 13(11), 2705. doi:10.3390/en13112705Shi, J., Yang, Y., & Deng, Z. (2009). A reliability growth model for 300 MW pumped-storage power units. Frontiers of Energy and Power Engineering in China, 3(3), 337-340. doi:10.1007/s11708-009-0032-yArgyrou, M. C., Christodoulides, P., & Kalogirou, S. A. (2018). Energy storage for electricity generation and related processes: Technologies appraisal and grid scale applications. Renewable and Sustainable Energy Reviews, 94, 804-821. doi:10.1016/j.rser.2018.06.044Jockenhöfer, H., Steinmann, W.-D., & Bauer, D. (2018). Detailed numerical investigation of a pumped thermal energy storage with low temperature heat integration. Energy, 145, 665-676. doi:10.1016/j.energy.2017.12.087Steinmann, W.-D. (2017). Thermo-mechanical concepts for bulk energy storage. Renewable and Sustainable Energy Reviews, 75, 205-219. doi:10.1016/j.rser.2016.10.065Thess, A. (2013). Thermodynamic Efficiency of Pumped Heat Electricity Storage. Physical Review Letters, 111(11). doi:10.1103/physrevlett.111.110602Guo, J., Cai, L., Chen, J., & Zhou, Y. (2016). Performance optimization and comparison of pumped thermal and pumped cryogenic electricity storage systems. Energy, 106, 260-269. doi:10.1016/j.energy.2016.03.053Attonaty, K., Stouffs, P., Pouvreau, J., Oriol, J., & Deydier, A. (2019). Thermodynamic analysis of a 200 MWh electricity storage system based on high temperature thermal energy storage. Energy, 172, 1132-1143. doi:10.1016/j.energy.2019.01.153Frate, G. F., Antonelli, M., & Desideri, U. (2017). A novel Pumped Thermal Electricity Storage (PTES) system with thermal integration. Applied Thermal Engineering, 121, 1051-1058. doi:10.1016/j.applthermaleng.2017.04.127Mateu-Royo, C., Mota-Babiloni, A., Navarro-Esbrí, J., Peris, B., Molés, F., & Amat-Albuixech, M. (2019). Multi-objective optimization of a novel reversible High-Temperature Heat Pump-Organic Rankine Cycle (HTHP-ORC) for industrial low-grade waste heat recovery. Energy Conversion and Management, 197, 111908. doi:10.1016/j.enconman.2019.111908Benato, A. (2017). Performance and cost evaluation of an innovative Pumped Thermal Electricity Storage power system. Energy, 138, 419-436. doi:10.1016/j.energy.2017.07.066Benato, A., & Stoppato, A. (2019). Integrated Thermal Electricity Storage System: Energetic and cost performance. Energy Conversion and Management, 197, 111833. doi:10.1016/j.enconman.2019.111833Maximov, S., Harrison, G., & Friedrich, D. (2019). Long Term Impact of Grid Level Energy Storage on Renewable Energy Penetration and Emissions in the Chilean Electric System. Energies, 12(6), 1070. doi:10.3390/en12061070Steinmann, W. D. (2014). The CHEST (Compressed Heat Energy STorage) concept for facility scale thermo mechanical energy storage. Energy, 69, 543-552. doi:10.1016/j.energy.2014.03.049Hu, B., Wu, D., Wang, L. W., & Wang, R. Z. (2017). Exergy analysis of R1234ze(Z) as high temperature heat pump working fluid with multi-stage compression. Frontiers in Energy, 11(4), 493-502. doi:10.1007/s11708-017-0510-6He, Y.-L., Wang, R., Roskilly, A. P., & Li, P. (2017). Efficient use of waste heat and solar energy: Technologies of cooling, heating, power generation and heat transfer. Frontiers in Energy, 11(4), 411-413. doi:10.1007/s11708-017-0525-zHassan, A. H., O’Donoghue, L., Sánchez-Canales, V., Corberán, J. M., Payá, J., & Jockenhöfer, H. (2020). Thermodynamic analysis of high-temperature pumped thermal energy storage systems: Refrigerant selection, performance and limitations. Energy Reports, 6, 147-159. doi:10.1016/j.egyr.2020.05.010Steinmann, W.-D., Bauer, D., Jockenhöfer, H., & Johnson, M. (2019). Pumped thermal energy storage (PTES) as smart sector-coupling technology for heat and electricity. Energy, 183, 185-190. doi:10.1016/j.energy.2019.06.058Pereira da Cunha, J., & Eames, P. (2016). Thermal energy storage for low and medium temperature applications using phase change materials – A review. Applied Energy, 177, 227-238. doi:10.1016/j.apenergy.2016.05.097Cecchinato, L. (2010). Part load efficiency of packaged air-cooled water chillers with inverter driven scroll compressors. Energy Conversion and Management, 51(7), 1500-1509. doi:10.1016/j.enconman.2010.02.008The Turbocor Family of Compressors Model TT300, Danfoss TURBOCOR. Datasheetwww.turbocor.com,USAPalkowski, C., Zottl, A., Malenkovic, I., & Simo, A. (2019). Fixing Efficiency Values by Unfixing Compressor Speed: Dynamic Test Method for Heat Pumps. Energies, 12(6), 1045. doi:10.3390/en12061045Estadísticas del Sistema Eléctrico | Red Eléctrica de Españahttps://www.ree.es/es/estadisticas-del-sistema-electrico/3015/3001OMIP Operador del Mercado Ibérico de Energía—Polo Portuguéshttps://www.omip.pt/El Mercado de Restricciones Técnicashttp://mifacturadeluz.com/mercado-de-restricciones-tecnicas/Puerto Escandón (España)—Parques eólicos—Acceso en línea—The Wind Powerhttps://www.thewindpower.net/windfarm_es_2253_puerto-escandon.phpFederico Bava DS D2.1 Case studies: User Requirements and Boundary Conditions Definition. CHESTERhttps://www.chester-project.eu/wp-content/uploads/2018/11/CHESTER_D2.1_Case-Studies_v5.0.pdfEstado actual de la energía termosolar (CSP)—HELIONOTICIAShttp://helionoticias.es/estado-actual-de-la-energia-termosolar-csp/Gallo, A. B., Simões-Moreira, J. R., Costa, H. K. M., Santos, M. M., & Moutinho dos Santos, E. (2016). Energy storage in the energy transition context: A technology review. Renewable and Sustainable Energy Reviews, 65, 800-822. doi:10.1016/j.rser.2016.07.028Smallbone, A., Jülch, V., Wardle, R., & Roskilly, A. P. (2017). Levelised Cost of Storage for Pumped Heat Energy Storage in comparison with other energy storage technologies. Energy Conversion and Management, 152, 221-228. doi:10.1016/j.enconman.2017.09.04

    Thermal characterisation of compact heat exchangers for air heating and cooling in electric vehicles

    Full text link
    [EN] The use of air conditioning in all-electric cars reduces their driving range by 33% in average. With the purpose of reducing the energy consumption of the vehicle and optimising the performance of the batteries, the mobile air-conditioning can be integrated with the temperature control system of the powertrain by means of a coolant loop. In such layouts, the air-to-coolant heat exchangers must operate efficiently in both air heating and cooling modes. Dynamic simulation tools comprising the entire thermal system are essential to assess its performance. In this context, fast but accurate models of the system components are required. This paper presents the thermal characterisation of a commercial compact louvered-fin flat-tube heat exchanger (heater core) for this novel application, based on an experimental campaign comprising 279 working points that reflect real air-conditioning (heating and cooling) working conditions. A general methodology to fit a single correlation of the global heat transfer coefficient for both dry and wet working conditions is explained. The semiempirical correlation developed is employed in a single-node model of the heat exchanger that requires minimal computation time. The present model predicts the heat transfer rate with an average deviation of 3.5% in the cases with dehumidification and 1.9% in the cases when the heat exchanger remains dry.This work has been supported by the European Commission under the 7th European Community framework program as part of the ICE project ‘‘MagnetoCaloric Refrigeration for Efficient Electric Air-Conditioning”, Grant Agreement no. 265434. B. Torregrosa-Jaime acknowledges the Spanish Education, Culture and Sport Ministry (Ministerio de Educación, Cultura y Deporte) for receiving the Research Fellowship FPU ref. AP2010-2160.Torregrosa-Jaime, B.; Corberán, JM.; Payá-Herrero, J.; Delamarche, JL. (2017). Thermal characterisation of compact heat exchangers for air heating and cooling in electric vehicles. Applied Thermal Engineering. 115:774-781. https://doi.org/10.1016/j.applthermaleng.2017.01.017S77478111

    Theory of Caroli-de Gennes-Matricon analogs in full-shell nanowires

    Full text link
    Full-shell nanowires are hybrid nanostructures consisting of a semiconducting core encapsulated in an epitaxial superconducting shell. When subject to an external magnetic flux, they exhibit the Little-Parks (LP) phenomenon of flux-modulated superconductivity, an effect connected to the physics of Abrikosov vortex lines in type-II superconductors. We show that full-shell nanowires can host subgap states that are a variant of the Caroli-de Gennes-Matricon (CdGM) states in vortices. These CdGM analogs are in fact shell-induced Van Hove singularities in propagating core subbands. We elucidate their structure, parameter dependence and behavior in tunneling spectroscopy through a series of models of growing complexity. We show through microscopic numerical simulations that they exhibit a characteristic skewness towards high magnetic fields inside non-zero LP lobes resulting from the interplay of three ingredients. First, core subbands exhibit a diamagnetic response, so that they disperse with flux depending on their generalized angular momentum. Second, the band bending at the core/shell interface induces a ring-like profile on the CdGM analog state wavefunctions with average radius smaller than the core radius. And last, degeneracy points emerge where all the CdGM Van Hove singularities coalesce. This happens when the flux threading each wavefunction is equal to an integer multiple of the flux quantum, a condition that shifts the degeneracy points away from the center of the LP lobes, skewing the CdGM analogs. Our analysis unlocks a transparent analytical description that allows to extract precise microscopic information about the nanowire by measuring the energy and skewness of CdGM analogs.Comment: 15 pages, 9 figure

    A high-temperature heat pump for compressed heat energy storage applications: Design, modeling, and performance

    Get PDF
    The current paper presents the design and performance of a high-temperature heat pump (HTHP) integrated in an innovative, sensible, and latent heat storage system. The HTHP has been designed to work between a heat source from 40 to 100 °C and a heat sink above 130 °C. An initial refrigerant analysis has revealed that R-1233zd(E) is the best candidate to meet the required performance and environmental considerations. The first part of this paper deals with the sizing and selection of the main components while discussing the challenges and working limits. A numerical model is also presented and validated. The second part of the paper is dedicated to develop parametric studies and performance maps under different operating conditions. The results show that the current HTHP, at a source temperature of 80 °C, consumes from 3.23 to 9.88 kW by varying the compressor’s speed from 500 to 1500 rpm. Heat production is achieved in the form of latent heat (7.40 to 21.59 kW) and sensible heat (from 6.35 to 17.94 kW). The heating coefficient of performance (COPHTHP) is around 4.This work has been partially funded by grant agreement No. 764042 (CHESTER project) of the European Union’s Horizon 2020 research and innovation program. The authors would like to express their deep gratitude to Prof. Dr. Jose Miguel Corberán Salvador for his perseverance, encouragement, and invaluable guidance during this work

    Hydronium Detection in Hardened Concrete

    Get PDF
    [EN] The monitoring of reinforced concrete structures allows us to detect the presence of aggressive agents into of the concrete matrix, on site and in a real time. These aggressive agents can produce the unexpected failure of the structures, thus discovering their presence is a fundamental aspect in the preservation of people safety and the durability of the structure. On the other hand, helps to reduce the cost of maintenance and repair operations, due to allow us to identify the problems faster, minimizing the intervention to be done. The present research paper was focused in the hydronium detection; the reduction of this species generates hydrogen, the hydrogen produces the embrittlement and cracking of the steel, which seriously compromises the right behaviour of the structure. The problem of hydrogen appears in industries such as ammonia processing or petrochemistry industries and nuclear power plants. All of them are industries in which a failure seriously compromises the welfare of people and the environment. Therefore, the detection of hydrogen penetration in reinforcement concrete structures in these cases are very interesting. In this study, with the purpose to detect the hydronium or hydrogen in the hardened concrete matrices is proposed the use of voltammetric sensor, which is part of a multisensory system called Electronic-Tongue. This is a preliminary study. The objective of these initial steps was to evaluate the detection capability of the sensor. Currently, have been designing a sequential test in order to evaluate the sensor in different partial hydrogen pressures with the purpose to develop mathematical models to the hydronium or hydrogen detection and quantification in hardened concrete matrix.The authors would like to express their gratitude to the Spanish Ministry of Science and Innovation for the pre-doctoral scholarship granted to Ana Martínez Ibernón (FPU 16/00723). Also, to the Universitat Politècnica de València for the financial support in the project ¿Ayudas a Primeros Proyectos de Investigación (PAID-06-18)Martínez-Ibernón, A.; Gandía-Romero, JM.; Gasch, I.; Valcuende Payá, MO. (2020). Hydronium Detection in Hardened Concrete. International Center for Numerical Methods in Engineering (CIMNE). 843-850. https://doi.org/10.23967/dbmc.2020.151S84385
    corecore