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Clean combustion technologies, based on reactant dilution, have shown very peculiar and innovative characteristics. Reduction of light and noise emission and uniformity of temperature and composition distribution inside the combustion chamber, related to an extension of the reaction zone, make these processes very promising in several technological fields. Analysis of combustion in very diluted conditions is needed for a general understanding of these processes, which remain unknown from many aspects. The study is also useful for the identification of practical constraints which define the most suitable reactor configurations and working parameters for process reliability. The present work deals with a theoretical analysis of methane oxidation in diluted conditions using one of the detailed kinetic schemes available in the literature. A well-stirred reactor (WSR) configuration has been considered as a first attempt of process schematization. This choice is consistent with the experimental characterization of the flameless combustion processes. The influence of residence time, C/O ratio, and inlet temperature on the steady state was studied for an oxygen molar fraction (0.05), chosen as representative of flameless combustion processes. It has been pointed out that only rich conditions (C/O ? 0.25) are possible for WSR creation, because they allow partial methane conversion. Three kinetic regimes, related to different temperature ranges, have been identified on the basis of product distribution analysis. Both the oxidation and pyrolitic regimes, occurring respectively in low- and high-temperature ranges, are the most interesting working conditions for diluted combustion. The former, leading to CO and H2O as main reaction products, is suitable for reburning technology. The latter, which corresponds to large production of CO and H2, has been shown to be a reasonable explanation of flameless combustion. Advantages and potentials of this innovative process are analyzed, taking into account the kinetic pathway followed in the different working conditions.

Artículos en revistas Large frequency deviations due to a number of disturbances are frequent in small isolated power systems. The maximum frequency deviation in the system is limited to prevent other generator tripping. It is important to have an accurate model to calculate it, both for system planning and operation. A new simplified model to calculate the maximum frequency deviation when either a generator or load-related disturbance occurs in these systems is presented. This model takes into account the response of governor- prime mover even when different technologies are present in the power system. Model parameters can be easily obtained from either more complex models or from test records. Simulation results for an actual power system aimed at checking the model accuracy are presented. High accuracy is obtained while computation time is reduced due to the simplicity of the model. info:eu-repo/semantics/publishedVersion

This deliverable presents the detailed design of the SunDial concentrators for two case-studies: AMTP, in Iasi (Romania), and MAN, in Corinth (Greece). The design of the concentrator is different for both cases due to two reasons: first, the location in Iasi has a high latitude that implies the need of a design specifically suited to a lower mean sun altitude; second, in order to increase the performance of the concentrator for high latitudes a two-axis tracking system has been selected, which leads to a completely different layout of mirrors and receivers within the rotating platform compared to low latitudes, where one-axis tracking is used. The size of the platforms, which resulted from the analytical studies presented in deliverables D3.1 and D3.2, is 8-9 m per collector side, too large be shipped as a whole module. Therefore, the design of the concentrators has sought a system modularity that enables an easy transportation and installation. The design of the concentrators can be divided into three sub-systems: the rotating platform, the mirrors, and the receivers. A CAD software is used in order to design all of them. The connection between the sub-systems is included in the design. Images resulting from the CAD design are used in order to describe the design concept of each subsystem, whereas the final drawings, which are the main outcome of the deliverable, are presented in the annexes. Also, the CAD design is used to provide the elements inventory of the concentrators, including the materials selected and the manufacturing process used.

Abstract In recent years, the overall energy consumption is increasing significantly and the energy consumption in the building sector represents over 30% of the global ones in developed countries. Thermal energy storage (TES) using phase change materials (PCM), which are materials able to store high amounts of energy as latent heat, is suggested as a possible solution to decrease the energy consumption. The authors of this paper developed materials able to encapsulate/stabilize PCM in addition to isolate an industrial residue from the steel recycling process: electrical arc furnace dust (EAFD). This waste is a hazardous dust, and when it is combined with a polymeric matrix produce dense sheet materials suitable for multilayered constructive systems. In this paper the physical, mechanical, thermal and acoustical characterization of two new materials with EAFD and PCM in a polymeric matrix for constructive system is presented. The results are compared with those obtained for one commercial dense sheet material available in the market, Texsound commercialized by TEXSA (Spain). The new dense sheet materials developed in this paper have similar acoustic properties compared to the results obtained for the commercial material and are competitive with it, even better because the new material incorporates PCM which increases the thermal inertia of final constructive system.

Abstract We provide a detailed description of a numerically stable and efficient coupling scheme for steady-state Monte Carlo neutronic calculations with thermal–hydraulic feedback. While we have previously derived and published the stochastic approximation based method for coupling the Monte Carlo criticality and thermal–hydraulic calculations, its possible implementation has not been described in a step-by-step manner. As the simple description of the coupling scheme was repeatedly requested from us, we have decided to make it available via this note.

Artículos en revistas This paper describes the long term transmission expansion planning model CHOPIN. In CHOPIN, the network expansion is formulated as the static optimization problem of minimizing the global annual cost of electricity production, which is obtained as the sum of the annualized network investment cost, the operation cost and the reliability cost. The solution method takes advantage of the natural decomposition between the investment and operation submodels. The investment submodel is solved by a new heuristic procedure that in practice has invariably yielded the optimal plan. At the operation level CHOPIN optimizes over a multiplicity of scenarios which are characterized by the demand, the hydraulicity and the availability of components. The network is represented by any one out of four options: DC load flow (DCLF), transportation model and two hybrid models. Any of these models may consider the ohmic losses. The model is very efficient computationally; this fact was verified on rest examples, as well as on the actual transmission expansion planning of the Spanish system. info:eu-repo/semantics/publishedVersion

Artículos en revistas This paper presents a continuation and optimization based algorithm to detect power flow unsolvability. In addition, the algorithm obtains the power flow solution, if it exists, no matter how ill-conditioned the power system is. The proposed algorithm is based on the parameterization of the distance from the starting point to the real power flow to be solved, using a convergence margin. The performance of the algorithm is illustrated considering an highly loaded scenario of the operation of the Spanish power system. info:eu-repo/semantics/publishedVersion

Capítulos en libros This paper presents a method for calculation of stationary Power Quality Disturbances-PQD based on measurements, distribution system modeling and Monte Carlo techniques. A method to simulate PQD with specific random behavior based on Perfect Sampling is proposed. Three non-sinusoidal conditions power quantities are employed to illustrate the proposed methodology, and a proposal for statistical interpretation of simulated results is presented as well. info:eu-repo/semantics/publishedVersion