Water Management in PEM Fuel Cells: Controllability Analysis and Steady-state Optimization for Temperature Control

This paper presents a controllability study of the water management inside anode channel by regulating the stack temperature for PEM fuel cell systems with dead-ended anode. Moreover, this work includes the design of a steady-state target optimizer which calculates the temperature set-point profiles that minimize the stack degradation and the hydrogen leaks. The control architecture is successfully simulated and the results show promising performanc

Improving productivity through variability reduction of process inputs in manual assemblies

El control de las entradas y del proceso para mejorar la productividad de los sistemas industriales de fabricación son conceptos ampliamente conocidos pero llevados a la práctica con poca efectividad. Dicha falta de efectividad es una fuente de variabilidad en el resultado. El caso de estudio, tomado de una fábrica de ensamble de automóviles, refleja como la identificación y control adecuado de las entradas del sistema tiene un impacto importante en la calidad del producto terminado y como se puede integrar este concepto al modelo de gestión de la fábrica.Controlling inputs and process to improve a system result is a widely known concept but not taken into practice with effectiveness on assembly operations. This lack of effectiveness is a source of variation that affects the output. The study case, based on a vehicle assembly plant, shows, in practice, how identifying and controlling system inputs has a relevant impact on end product quality and how this concept can be integrated to the assembly plant management model

Solar Thermal Plants Integration in Smart Grids

Solar energy penetration has been increasingly growing in recent years. Since solar energy is intermittent its integration in existing grids is difficult. This paper deals with the optimal integration of solar power plants in grids. The paper proposes a modification of energy hubs which allows to solve the optimization problem with a mixed integer programming algorithm in a distributed way. An introductory simulation study case is givenMinisterio de Educación DPI2008-05818Junta de Andalucía P07-TEP-02720Comisión Europea HD-MP

Determinantes del aprendizaje organizativo en la creación de competencias distintivas tecnológicas

Este trabajo presenta un análisis de la influencia del AO entendido como un proceso de creación de conocimiento, sobre el desarrollo de competencias distintivas tecnológicas (CT). Asimismo, se examina cómo la existencia de determinadas variables organizativas clave en el proceso de AO, favorecen de forma significativa al AO e influyen sobre la generación de CT. Las hipótesis propuestas a este respecto se contrastan sobre una muestra de 140 empresas industriales, aplicando un modelo de ecuaciones lineales estructurales según la metodología Partial Least Squares (PLS). Los resultados alcanzados indican que variables como la orientación emprendedora de la organización (OE), su orientación al aprendizaje (OA) y las tecnologías de la información (TI) tienen un impacto positivo sobre el AO; mientras que las competencias distintivas tecnológicas son el resultado del AO. Por otra parte, la OE y las TI juegan un papel importante en el proceso de creación de CT.This paper presents an analysis of the influence of the organizational learning (OL), as a process of knowledge creation on the development of technological distinctive competencies (TCs). We also examine how the existence of certain organizational key variables in the OL process, positively affects on OL and influences on the generation of TCs. The hypotheses proposed in this respect are tested on a sample of 140 industrial companies, applying a structural linear equation model according to the methodology named Partial Least Squares (PLS). Our findings indicate that variables such as entrepreneurial orientation of the organization (EO), its learning orientation (LO) and information technology (IT) have a positive impact on OL; whereas, the technological distinctive competences are the result of the OL. On the other hand, the EO of the organization and the IT play an important role in the creation process of TCs

Control-oriented modelling of three-way catalytic converter for fuel-to-air ratio regulation in spark ignited engines

[EN] The purpose of this paper is to introduce a grey-box model of three-way catalytic converter, which is capable of estimating the oxygen storage level to aid the fuel-to-air ratio control in spark ignited engines. As it is well-known, the prime parameter that drives the transient dynamics in current three-way catalytic converter is their capability to store a certain amount of oxygen, then allowing to oxidize some pollutant species such as carbon monoxide or hydrocarbons even at rich conditions during short periods of time. Since oxygen storage level is considered a good indicator of the catalyst state but it cannot be directly measured, a model based real-time capable estimation like the one proposed in this paper could be valuable. The model accounts for oxygen storing as well as oxidation and reduction of the main species involved, taking as inputs fuel-to-air equivalence ratio, air mass flow, temperature and gas composition at three-way catalyst inlet. From these inputs, oxygen storage level and brick temperature are calculated as model states, which finally provide the gas composition downstream of the catalyst as output. In addition, a simplified model of narrowband lambda sensor is included, it provides a voltage from gas composition at the outlet of the catalyst and allows to assess the model behaviour by comparison with the on-board lambda sensor measurements. Finally, the validation of the model performance by means of experimental test as well as different practical cases, where the benefits of oxygen storage level estimation plays a key role, are introduced.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors acknowledge the support of Spanish Ministerio de Economía, Industria y Competitividad through project TRA2016-78717-R.Guardiola, C.; Climent, H.; Pla Moreno, B.; Real, M. (2019). Control-oriented modelling of three-way catalytic converter for fuel-to-air ratio regulation in spark ignited engines. Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering. 233(14):3758-3774. https://doi.org/10.1177/0954407019833822S3758377423314Auckenthaler, T. S., Onder, C. H., & Geering, H. P. (2004). Aspects of Dynamic Three-Way Catalyst Behaviour Including Oxygen Storage. IFAC Proceedings Volumes, 37(22), 331-336. doi:10.1016/s1474-6670(17)30365-8Yang, H., Shu, G., Tian, H., Ma, X., Chen, T., & Liu, P. (2018). Optimization of thermoelectric generator (TEG) integrated with three-way catalytic converter (TWC) for harvesting engine’s exhaust waste heat. Applied Thermal Engineering, 144, 628-638. doi:10.1016/j.applthermaleng.2018.07.091Koltsakis, G. C., Konstantinidis, P. A., & Stamatelos, A. M. (1997). Development and application range of mathematical models for 3-way catalytic converters. Applied Catalysis B: Environmental, 12(2-3), 161-191. doi:10.1016/s0926-3373(96)00073-2Zygourakis, K. (1989). Transient operation of monolith catalytic converters: a two-dimensional reactor model and the effects of radially nonuniform flow distributions. Chemical Engineering Science, 44(9), 2075-2086. doi:10.1016/0009-2509(89)85143-7Coxeter, H. S. M. (1993). Cyclotomic integers, nondiscrete tessellations, and quasicrystals. Indagationes Mathematicae, 4(1), 27-38. doi:10.1016/0019-3577(93)90049-5Konstantas, G., & Stamatelos, A. M. (2007). Modelling three-way catalytic converters: An effort to predict the effect of precious metal loading. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 221(3), 355-373. doi:10.1243/09544070jauto329Pontikakis, G. N., Konstantas, G. S., & Stamatelos, A. M. (2004). Three-Way Catalytic Converter Modeling as a Modern Engineering Design Tool. Journal of Engineering for Gas Turbines and Power, 126(4), 906-923. doi:10.1115/1.1787506Kumar, P., Gu, T., Grigoriadis, K., Franchek, M., & Balakotaiah, V. (2014). Spatio-temporal dynamics of oxygen storage and release in a three-way catalytic converter. Chemical Engineering Science, 111, 180-190. doi:10.1016/j.ces.2014.02.014Auckenthaler, T. S., Onder, C. H., Geering, H. P., & Frauhammer, J. (2004). Modeling of a Three-Way Catalytic Converter with Respect to Fast Transients of λ-Sensor Relevant Exhaust Gas Components. Industrial & Engineering Chemistry Research, 43(16), 4780-4788. doi:10.1021/ie034242uNievergeld, A. J. L., Selow, E. R. v., Hoebink, J. H. B. J., & Marin, G. B. (1997). Simulation of a catalytic converter of automotive exhaust gas under dynamic conditions. Dynamics of Surfaces and Reaction Kinetics in Heterogeneous Catalysis, Proceedings of the International Symposium, 449-458. doi:10.1016/s0167-2991(97)80431-4Oh, S. H., & Cavendish, J. C. (1982). Transients of monolithic catalytic converters. Response to step changes in feedstream temperature as related to controlling automobile emissions. Industrial & Engineering Chemistry Product Research and Development, 21(1), 29-37. doi:10.1021/i300005a006Chan, S. H., & Hoang, D. L. (1999). Heat transfer and chemical reactions in exhaust system of a cold-start engine. International Journal of Heat and Mass Transfer, 42(22), 4165-4183. doi:10.1016/s0017-9310(99)00064-2Sabatini, S., Gelmini, S., Hoffman, M. A., & Onori, S. (2017). Design and experimental validation of a physics-based oxygen storage — thermal model for three way catalyst including aging. Control Engineering Practice, 68, 89-101. doi:10.1016/j.conengprac.2017.07.007Schürholz, K., Brückner, D., Gresser, M., & Abel, D. (2018). Modeling of the Three-way Catalytic Converter by Recurrent Neural Networks. IFAC-PapersOnLine, 51(15), 742-747. doi:10.1016/j.ifacol.2018.09.166Brandt, E. P., Yanying Wang, & Grizzle, J. W. (2000). Dynamic modeling of a three-way catalyst for SI engine exhaust emission control. IEEE Transactions on Control Systems Technology, 8(5), 767-776. doi:10.1109/87.865850Shaw, B. T., Fischer, G. D., & Hedrick, J. K. (2002). A SIMPLIFIED COLDSTART CATALYST THERMAL MODEL TO REDUCE HYDROCARBON EMISSIONS. IFAC Proceedings Volumes, 35(1), 307-312. doi:10.3182/20020721-6-es-1901.01519Bickel, J., Odendall, B., Eigenberger, G., & Nieken, U. (2017). Oxygen storage dominated three-way catalyst modeling for fresh catalysts. Chemical Engineering Science, 160, 34-53. doi:10.1016/j.ces.2016.11.016Kiwitz, P., Onder, C., & Guzzella, L. (2012). Control-oriented modeling of a three-way catalytic converter with observation of the relative oxygen level profile. Journal of Process Control, 22(6), 984-994. doi:10.1016/j.jprocont.2012.04.014Kumar, P., Makki, I., Kerns, J., Grigoriadis, K., Franchek, M., & Balakotaiah, V. (2012). A low-dimensional model for describing the oxygen storage capacity and transient behavior of a three-way catalytic converter. Chemical Engineering Science, 73, 373-387. doi:10.1016/j.ces.2011.12.001Gong, J., Wang, D., Li, J., Currier, N., & Yezerets, A. (2017). Dynamic oxygen storage modeling in a three-way catalyst for natural gas engines: A dual-site and shrinking-core diffusion approach. Applied Catalysis B: Environmental, 203, 936-945. doi:10.1016/j.apcatb.2016.11.005Ramanathan, K., & Sharma, C. S. (2011). Kinetic Parameters Estimation for Three Way Catalyst Modeling. Industrial & Engineering Chemistry Research, 50(17), 9960-9979. doi:10.1021/ie200726jOlsson, L., & Andersson, B. (2004). Kinetic Modelling in Automotive Catalysis. Topics in Catalysis, 28(1-4), 89-98. doi:10.1023/b:toca.0000024337.50617.8eMöller, R., Votsmeier, M., Onder, C., Guzzella, L., & Gieshoff, J. (2009). Is oxygen storage in three-way catalysts an equilibrium controlled process? Applied Catalysis B: Environmental, 91(1-2), 30-38. doi:10.1016/j.apcatb.2009.05.003Rink, J., Meister, N., Herbst, F., & Votsmeier, M. (2017). Oxygen storage in three-way-catalysts is an equilibrium controlled process: Experimental investigation of the redox thermodynamics. Applied Catalysis B: Environmental, 206, 104-114. doi:10.1016/j.apcatb.2016.12.052Auckenthaler, T. S., Onder, C. H., & Geering, H. P. (2002). CONTROL-ORIENTED INVESTIGATION OF SWITCH-TYPE AIR/FUEL RATIO SENSORS. IFAC Proceedings Volumes, 35(1), 331-336. doi:10.3182/20020721-6-es-1901.0152

GEM – A SOFTWARE FOR STABILITY VERIFICATION OF NON-UNIFORM MEMBERS, Adaptation of the general method procedure to fire design

There is currently no specific rules in Part 1-2 of Eurocode 3 for the stability verification of non-uniform members under fire conditions. For normal temperature, Part 1-1 of the same code provides a General Method to check the stability against lateral and lateral-torsional buckling for these type of members, though it requires some extensive calculations. It is here demonstrated in this paper how both problems can be addressed, by exposing a procedure that accounts for the modifications of the method at elevated temperatures, and by showing its implementation within a computer program. It is also shown how the program can be used to assess the study of the method itself, by applying it to a case of a web-tapered beam-column and comparing it to numerical results

FIRE DESIGN OF STEEL BEAMS WITH SLENDER CROSS-SECTION, The influence of loading

The present paper addresses the study of laterally unrestrained steel beams with slendercross-sections for the case of fire with special focus on the influence of loading. A numerical investigation of several beams submitted to triangular and bi-triangular end-moment distribution and uniformly distributed loads is carried out at elevated temperatures usingshell finite elements. The results are compared with the existing simplified beam design rules of Part 1.2 of Eurocode 3 and recent developments on the subject, as well as the utilization of the factor “f” which was developed to take into account the non-uniform bending diagrams but for stocky cross-sections (Class 1 and 2)