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This paper presents a comprehensive review of all correlations and experimental studies available in the literature to determine the heat transfer coefficient of supercritical CO2 flowing in heat exchangers. The different applications in which it is used are also reviewed and discussed. The correlations obtained from extensive experimental measurements are presented for different geometries (horizontal, vertical and inclined tubes, closed-loop circular pipes, and mini-channels) and dimensions. The review shows that there is a lack of a unique universal correlation for each geometry, suggesting the need for more work in this area. The work partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER) and ENE2015-64117-C5-3-R (MINECO/FEDER)). The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). This project has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under Grant agreement N°PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 657466 (INPATH-TES), and the funds received by the Royal Society of New Zealand. Alvaro de Gracia would like to thank Ministerio de Economia y Competitividad de España for Grant Juan de la Cierva, FJCI-2014-19940.

This work investigates the potential of the sea breeze for wind energy generation with small wind turbines. For this purpose, we used wind data recorded in the Llobregat Delta (NE of the Iberian Peninsula) from 1993 to 2010 and turbine power curves obtained from QBlade, FAST and AeroDyn freeware tools, and from the manufacturer. The HP-600W turbine, with hub-height 8 m, would deliver 126 kWh in a year (53 kWh during the sea breeze period, i.e., March 1 to September 30, 10 to 19h LT), with average power of 14 W (27 W). The results for the entire year agree with data measured in situ in 2015, but it is not the case for the sea breeze period. Therefore, more research is necessary to validate completely the proposed approach, and to confirm the real potential of the sea breeze for micro-generation in a peri-urban coastal area like the one under study, where large wind farms are not feasible. Peer Reviewed

System codes along with necessary nodalizations are valuable tools for thermal hydraulic safety analysis. In order to assess the safety of a particular power plant, in addition to the validation and veri cation of the code, the nodalization of the system needs to be quali ed. Since most existing experimental data come from tests performed on scaled-down facilities, any quali cation process must therefore address scale considerations. Along these lines, the Group of Thermal Hydraulic Studies at Technical University of Catalonia (GET) developed SCUP, a scaling-up methodology for qualifying full-scale nodalizations through a systematic procedure based on the extrapolation of post-test simulations of Integral Test Facilities (ITF) experiments. For that purpose, GET created the

The aim of this study is to perform a review of the state-of-the-art of the reactors available in the literature, which are used for solid–gas reactions or thermal decomposition processes around 1000 °C that could be further implemented for thermochemical energy storage in CSP (concentrated solar power) plants, specifically for SPT (solar power tower) technology. Both direct and indirect systems can be implemented, with direct and closed systems being the most studied ones. Among direct and closed systems, the most used configuration is the stacked bed reactor, with the fixed bed reactor being the most frequent option. Out of all of the reactors studied, almost 70% are used for solid–gas chemical reactions. Few data are available regarding solar efficiency in most of the processes, and the available information indicates relatively low values. Chemical reaction efficiencies show better values, especially in the case of a fluidized bed reactor for solid–gas chemical reactions, and fixed bed and rotary reactors for thermal decompositions.

The research elects as its theme the energy efficiency at univeristies buildings located at different cities of Brazil. Based on the recent Brazilian's university spread, the object of study elected is three classroom pavilion built at different inner cities of Bahia-Brazil (Barreiras, Cruz das Almas and Victória de Conquista) based upon the same architectural project. It will be evaluated the envelope's energy performance of these three buildings and their thermal impact into the classrooms. The energy analysis carried out until now are based on thecnical data of these three classroom pavilions, some of them collected in situ, and on computational simulations. From this analysis it is possible to point out some encelope's weak characteristics of each building and the major quidelines for a future retrofit.

Converters are the key for increasing the development of renewable energy generation but their dynamic interaction with the grid has an important impact on stability. Oscillatory instabilities in different grid‐connected converter systems at several frequency ranges are reported. In particular, sub and supersynchronous oscillatory instabilities in AC power systems with type‐3 and type‐4 wind turbine generators (WTGs) were recently registered at several wind farm areas. A number of works based on eigenvalue analysis and frequency domain approaches are carried out to analyse this new stability issue and more research is going on to analyse in detail the electric and control parameters that may affect this phenomenon. This study contributes analysing in detail the influence of system parameters on the subsynchronous oscillations (SSOs) in AC power systems with type‐4 WTGs. This study is based on a new approach for subsynchronous stability assessment which could also be used for analysing other types of SSOs (e.g. subsynchronous control interactions between doubly‐fed induction generators and series‐compensated networks) as well as supersynchronous oscillations. A representative example of weak AC grids with type‐4 WTGs is used to illustrate the contributions of the study. Results are validated with PSCAD/EMTDC time‐domain simulations.