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

[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

[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

Propagación del desgarro de tejido biológico empleado en la construcción de bioprótesis cardíacas en función de la forma y el tipo de sutura

En este trabajo hemos estudiado la fuerza necesaria para propagar un desgarro en un tejido de pericardio de avestruz, tejido alternativo y en estudio para la fabricación de bioprótesis cardiacas. Se analiza la influencia de dos de las suturas más empleadas en cirugía cardiovascular: Prolene® y Gore-Tex®, en este comportamiento mecánico. El tejido se suturó de dos formas distintas borde-borde y en solapa. Para los ensayos se utilizó un péndulo Elmendorf capaz de medir, la fuerza necesaria para propagar el desgarro de un tejido. Se analizaron 106 ensayos, tras aplicar criterios de selección morfológica habituales en estos ensayos y que homogenizaron las muestras por su espesor y las hicieron comparables. La serie de control, no suturada, necesitó 24 N, como valor medio, para propagar el desgarro en 1 cm, mientras que las series suturadas borde con borde, con Gore-Tex® y con Prolene®, necesitaron, para la misma propagación del d-esga-rro, 12.69 N (p=0.001) y 16.18 N respectivamente. Esta pérdida de resistencia no se observó en las series suturadas con solape de 1 cm de longitud, 29.73 N, como valor medio, en la serie suturada con Gore-Tex® y 42.56 N, como valor medio, en la serie suturada con Prolene® (p=0.000). La sutura de Prolene® mostró una mayor resistencia a la propagación del desgarro que la sutura de Gore-Tex®. Una sutura protegida, mediante una zona previa no rasgada, dificulta la propagación del desgarro y puede tener interés desde un punto de vista constructivo en el diseño de las formas de sutura de implantes o bioprótesis

Development and validation of a dynamic thermal model of a minibus using TRNSYS

[EN] The current paper presents a dynamic thermal model of a vehicle including two thermal zones, one for the front region (driver) and one for the back (passengers). The model, developed in TRNSYS, is able to predict the cabin¿s thermal behaviour under variable ambient temperatures and solar radiation. A minibus was used to validate the model using experimental data for ambient temperature, solar radiation and the indoor temperature of a minibus parked both inside and outside a garage in Torino (Italy). The proposed model accurately reproduces the warm-up and cool-down of the cabin. In addition, the model has been used to calculate the cooling load of the cabin during a summer day, and to quantify the thermal loads under variable ambient conditions. In future work, the model will be used to predict the dynamic performance of the A/C system in an urban driving cycle and to optimise the compressor control strategy.Daniela C. Vásconez-Núñez acknowledges the financial support provided by the CONVOCATORIA ABIERTA 2013-SEGUNDA FASE program, which was funded by the SENESCYT (Secretaría Nacional de Educación Superior, Ciencia, Tecnología e Innovación) (Grant No 2014-AR3R7463) of Ecuador.Vásconez-Núñez, DC.; Gonzálvez-Maciá, J.; Corberán, JM.; Payá-Herrero, J. (2018). Development and validation of a dynamic thermal model of a minibus using TRNSYS. International Journal of Vehicle Design. 77(1/2):87-107. https://doi.org/10.1504/IJVD.2018.098272S87107771/

Reproducibility of solidification and melting processes in a latent heat thermal storage tank

This study analyzes the reproducibility of solidification and melting tests in a tank containing 181 kg of paraffin for cold storage at around 8 °C. Firstly, an experimental campaign of 10 identical tests was carried out. The performance is practically the same in terms of PCM temperatures and thermal power, with a maximum deviation of 2% in the capacity of all tests. In a second campaign, the impact of the initial conditions was studied. The results indicate that fixing a same mean PCM temperature at the beginning of the tests is insufficient to ensure an accurate reproducibility. Depending on the heat transfer rate during the preparation tests, the capacity differed in up to 33%. In tanks with such quantities of PCM, fixing a uniform initial PCM temperature is hardly possible, thus it is important to prepare the tank with same operation conditions.Bosholm, F.; López Navarro, A.; Gamarra, M.; Corberán Salvador, JM.; Payá Herrero, J. (2016). Reproducibility of solidification and melting processes in a latent heat thermal storage tank. International Journal of Refrigeration. 62:85-96. doi:10.1016/j.ijrefrig.2015.10.016S85966

Scanning tunneling microscopy of platinum electrode surfaces with different preferred crystallographic orientations

We have used scanning tunneling microscopy to study the surface microtopography of platinum electrodes preferentially oriented by a procedure denoted as electrochemical faceting. The treated specimens show clear reoriented patches on the surface in the form of steps with well-defined orientations separated by terraces of different sizes. The microscopic data obtained by STM correspond well with voltammetric analysis.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Enhancing automatic closed-loop glucose control in type 1 diabetes with an adaptive meal bolus calculator - in silico evaluation under intra- day variability

[EN] Background and Objective: Current prototypes of closed-loop systems for glucose control in type 1 diabetes mellitus, also referred to as artificial pancreas systems, require a pre-meal insulin bolus to compensate for delays in subcutaneous insulin absorption in order to avoid initial post-prandial hyperglycemia. Computing such a meal bolus is a challenging task due to the high intra-subject variability of insulin requirements. Most closed-loop systems compute this pre-meal insulin dose by a standard bolus calculation, as is commonly found in insulin pumps. However, the performance of these calculators is limited due to a lack of adaptiveness in front of dynamic changes in insulin requirements. Despite some initial attempts to include adaptation within these calculators, challenges remain. Methods: In this paper we present a new technique to automatically adapt the meal-priming bolus within an artificial pancreas. The technique consists of using a novel adaptive bolus calculator based on Case-Based Reasoning and Run-To-Run control, within a closed-loop controller. Coordination between the adaptive bolus calculator and the controller was required to achieve the desired performance. For testing purposes, the clinically validated Imperial College Artificial Pancreas controller was employed. The proposed system was evaluated against itself but without bolus adaptation. The UVa-Padova T1DM v3.2 system was used to carry out a three-month in silico study on 11 adult and 11 adolescent virtual subjects taking into account inter-and intra-subject variability of insulin requirements and uncertainty on carbohydrate intake. Results: Overall, the closed-loop controller enhanced by an adaptive bolus calculator improves glycemic control when compared to its non-adaptive counterpart. In particular, the following statistically significant improvements were found (non-adaptive vs. adaptive). Adults: mean glucose 142.2 ± 9.4 vs. 131.8 ± 4.2 mg/dl; percentage time in target [70, 180] mg/dl, 82.0 ± 7.0 vs. 89.5 ± 4.2; percentage time above target 17.7 ± 7.0 vs. 10.2 ± 4.1. Adolescents: mean glucose 158.2 ± 21.4 vs. 140.5 ± 13.0 mg/dl; percentage time in target, 65.9 ± 12.9 vs. 77.5 ± 12.2; percentage time above target, 31.7 ± 13.1 vs. 19.8 ± 10.2. Note that no increase in percentage time in hypoglycemia was observed.This project has been funded by the Welcome Trust.Herrero, P.; Bondía Company, J.; Adewuji, O.; Pesl, P.; El-Sharkawy, M.; Reddy, M.; Toumazou, C.... (2017). Enhancing automatic closed-loop glucose control in type 1 diabetes with an adaptive meal bolus calculator - in silico evaluation under intra- day variability. Computer Methods and Programs in Biomedicine. 146:125-131. https://doi.org/10.1016/j.cmpb.2017.05.010S12513114

Experimental investigation of the temperatures and performance of a commercial ice-storage tank

[EN] This paper presents the results of an experimental installation with an internal melt-ice-on-coil tank which has a total capacity of 172 kWh. The aim of this work is to analyse the freezing process in a tank with counter-current spiral-shaped coils immersed in around 1855l water. An experimental campaign has been performed with different inlet temperatures and mass flow rates of the heat transfer fluid. This study analyses (i) the chiller performance, (ii) the ice-formation process and (iii) the energy consumption of the installation. Supply temperatures between 2.5 C and 5.2 C have been sufficient to charge the tank without using any nucleating agents. The lowest energy consumption has been achieved for the fastest charging tests.The authors gratefully acknowledge ACCIONA Infraestructuras for the financing support and collaboration. Parts of the experimental results used in this work were collected at Federico II University during the project "Layout d'impianto e metodi di controllo innovativi per la refrigerazione domestica, commerciale e professionale". A.W. Mauro acknowledges the financial support provided by Regione Campania.López-Navarro, A.; Biosca Taronger, J.; Torregrosa-Jaime, B.; Martínez Galván, IO.; Corberán, JM.; Esteban-Matías, JC.; Payá-Herrero, J. (2012). Experimental investigation of the temperatures and performance of a commercial ice-storage tank. International Journal of Refrigeration. 36(4):1310-1318. doi:10.1016/j.ijrefrig.2012.09.008S1310131836

Reflexiones sobre el aprendizaje de la histología en biología y en ciencias de la salud

El conocimiento de la estructura, composición y función del organismo es fundamental en la formación de los graduados de Ciencias Biomédicas y de Ciencias de la Salud. Las células y los tejidos son los componentes básicos para comprender el normal funcionamiento del organismo y sus procesos patológicos. Por otra parte, la Histología es una de las disciplinas básicas con mayor cantidad de publicaciones sobre temas relacionados con su docencia. Sin embargo, a pesar de la abrumadora literatura existente, todavía no hay criterios claros sobre la pertinencia de los contenidos, los métodos en el aprendizaje y la evaluación de esta materia. En este trabajo; tras una revisión bibliográfica y a partir de la información aportada por profesores de Histología, se lo analizan las principales cuestiones que plantea el proceso de enseñanza aprendizaje de la Histología en el ámbito de Biomedicina (Biología, Medicina, Veterinaria, Enfermería, Nutrición, Fisioterapia, Biotecnología, etc.), a saber: su pertinencia, los contenidos a impartir, las estrategias y los medios didácticos a emplear y los métodos de evaluación. A partir de todos estos datos se describen los principales puntos fuertes y débiles de la Histología con las correspondientes sugerencias de cambio y adaptación al entorno actual