1,058 research outputs found

    High Temperature PEM Fuel Cells - Degradation and Durability

    Get PDF

    Validez de los contratos sobre tierras indigenas reguladas en la Ley 19.253 segun los principios del derecho civil y la normativa vigente en Chile

    Get PDF
    70 p. La siguiente tesis no es autorizada por el autor para su difusión en formato digitalCon fecha 28 de Septiembre de 1993 se dicta en Chile la Ley Nº 19.253, también llamada Ley Indígena, ley que establece normas sobre protección, fomento y desarrollo de los Indígenas, creando además la Corporación Nacional de Desarrollo Indígena; en esta norma se establecen distintos preceptos que vienen a establecer una legislación definitiva sobre diversas materias, siendo la de nuestro principal interés la regulación de la “Propiedad Indígena”, determinando los requisitos para constituirse como tal, las características de ellas y la forma en que el Estado chileno buscara dar protección a estas mismas. El presente trabajo busca establecer el modo en que la protección que otorga el Estado a las tierras Indígenas se hace efectiva, sus diversas aristas y como esta protección limita el actuar y la facultad de disposición del Indígena en Chile./ ABSTRACT: On September 28th 1993 it is spoken in Chile Law Nº. 19.253, also known as the Indigenous Law, a law that establishes norms for protection, stabilization and development of the Indigenous people, creating also a National Corporation for Indigenous Development; this norm establishes various precepts which establish a definite legislature in regards to various topics, being that of our principal interest the regulation of the “Indigenous Property”, determining the requirements for building such, the characteristics of them and the way in which the Chilean government would find the protection of such. The present work looks to establish that the mode in which the protection is given by the Government to the indigenous lands is indeed effective, the diverse edges and how this protection limits the actions and capacity of dispositions of the Indigenous in Chile

    Exploring Decentralized Ammonia Synthesis for Hydrogen Storage and Transport: A Comprehensive CFD Investigation with Experimental Validation and Parametric Study

    Get PDF
    Hydrogen energy plays a vital role in the transition towards a carbon-neutral society but faces challenges in storage and transport, as well as in production due to fluctuations in renewable electricity generation. Ammonia (NH 3), as a carbon-neutral hydrogen carrier, offers a promising solution to the energy storage and transport problem. To realize its potential and support the development of a hydrogen economy, exploring NH 3 synthesis in a decentralized form that integrates with distributed hydrogen production systems is highly needed. In this study, a computational fluid dynamics (CFD) model for the Ruthenium (Ru) catalysts-based Haber–Bosch reactor is developed. First, a state-of-the-art kinetic model comprehensively describing the complex catalytic reaction is assessed for its sensitivity and applicability to temperature, pressure and conversion. Then, the kinetic model is integrated into the CFD model, and its accuracy is verified through comparison with experimental data obtained from different Ru-based catalysts and operation conditions. Detailed CFD results for a given case are presented, offering a visual understanding of thermal gradients and species distributions inside the reactor. Finally, a CFD-based parametric study is performed to reveal the impacts of key operation parameters and optimize the NH 3 synthesis reactor. The results show that the NH 3 production rate is predominantly influenced by temperature, with a two-fold difference observed for every 30 °C variation, while pressure primarily affects the equilibrium. Additionally, the affecting mechanism of space velocity is thoroughly discussed and the best value for efficient NH 3 synthesis is found to be 180,000 h −1. In conclusion, the CFD model and simulation results provide valuable insights for the design and control of decentralized NH 3 synthesis reactor and operation, contributing to the advancement of sustainable energy technologies.</p

    An EIS alternative for impedance measurement of a high temperature PEM fuel cell stack based on current pulse injection

    Get PDF
    In this paper a method for estimating the fuel cell impedance is presented, namely the current pulse injection (CPI) method, which is well suited for online implementation. This method estimates the fuel cell impedance and unlike electrochemical impedance spectroscopy (EIS), it is simple to implement at a low cost. This makes it appealing as a characterization method for on-line diagnostic algorithms. In this work a parameter estimation method for estimation of equivalent electrical circuit (EEC) parameters, which is suited for on-line use is proposed. Tests on a 10 cell high temperature PEM fuel cell show that the method yields consistent results in estimating EEC parameters for different current pulse at different current loads, with a low variance. A comparison with EIS shows that despite its simplicity the response of CPI can reproduce well the impedance response of the high and intermediate frequencies
    corecore