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Moraga N.O.,University of La Serena | Xaman J.P.,CENIDET | Araya R.H.,University of La Serena
Applied Thermal Engineering | Year: 2016

A numerical study of the unsteady phase change convection-conduction heat transfer of an ion-lithium battery with volumetric heat generation used in solar vehicles is presented. The cooling process is investigated for a total of seven arrays of phase change material (PCM): capric acid (PCM 1), eicosane (PCM 2), decahydrated sodium carbonate (PCM 3) and octadecane (PCM 4) located in one or three layers around the battery. The results show that heat conduction predominates in the battery with a PCM and the liquid phase fraction of the PCM indicates that the melting initiates after 7 min, reaching totally liquid state after 14.25 min. From the different configurations of PCM around the battery, the configuration “B” (multiple PCM: PCM 1 (5 mm) + PCM 3 (2.9 mm) + PCM 2 (4.3 mm)) and the configuration with a single layer of PCM 3 (14.3 mm) respectively reduce the maximum temperature of the battery about 20.9 and 23.2 K compared with the temperature reached by the battery without PCM. This result occurs because of the Decahydrated Sodium Carbonate PCM, since it has the highest latent heat and has a low melting point. © 2016


Astorga-Zaragoza C.M.,CENIDET | Theilliol D.,University of Lorraine | Ponsart J.C.,University of Lorraine | Rodrigues M.,CNRS Automation and Process Engineering Laboratory
International Journal of Adaptive Control and Signal Processing | Year: 2012

In this paper, a model-based fault estimation method for a particular class of discrete-time descriptor linear parameter-varying systems is developed. The main contribution of this work consists in the design of an observer that performs simultaneously both, the states estimation and the fault magnitude vectors, considered as unknown inputs. The conditions for the existence of such observer are given. Such conditions guarantee the observer stability and they are proved through a Lyapunov analysis combined with a linear matrix inequalities formulation. The fault estimation scheme is evaluated through numerical simulations. © 2011 John Wiley & Sons, Ltd.


Chan F.,University of Quintana Roo | Calleja H.,CENIDET
IEEE Transactions on Industrial Electronics | Year: 2011

This paper presents the reliability estimation of the power stages in three grid-connected photovoltaic systems. The circuits analyzed are an integrated topology, a two-stage configuration, and a three-stage one, all commutating in the hard-switching mode. The reliability-related parameters, such as the failure rate, are calculated following the procedure outlined in MIL-HDBK 217. A comparison between the topologies is performed, and both the components and the stress factor with the highest contribution to the failure rate are identified. The methods to calculate junction temperature variations are included. © 2006 IEEE.


Rodriguez-Blanco M.A.,Autonomous University of Carmen | Claudio-Sanchez A.,CENIDET | Theilliol D.,University of Lorraine | Vela-Valdes L.G.,CENIDET | And 3 more authors.
IEEE Transactions on Industrial Electronics | Year: 2011

In this paper, a novel failure-detection technique and its analog circuit for insulated gate bipolar transistors (IGBTs), under open- and short-circuit failures, are proposed. This technique is applied to a three-phase induction-motor (IM) drive system. The detection technique is adapted to detect failures of short-circuit and open-circuit in the IGBT, which is based on gate-signal monitoring. The most important issue of this technique is the reduction of time for fault detection. This is very important in a failure-tolerant IM drive based on the material-redundancy approach or protection systems since the detection must be done before the device is damaged, in approximately less than 10 μ . The experimental test and simulations are presented in order to validate the proposed fault-detection technique, and it is validated, achieving replacement of the damaged element in the most suitable time. © 2010 IEEE.


Lvarez G.,CENIDET | Heras M.R.,CIEMAT
Journal of Solar Energy Engineering, Transactions of the ASME | Year: 2013

In this paper we present a theoretical study of a small solar chimney. The dimensions of the solar chimney channel are 1.95 m high, 1.70 m wide, and 0.24 m deep. The channel of the solar chimney has in its backside a metallic plate as a solar heat absorber, and it is attached to a concrete wall, which acts as storage and thermal insulation. On the front part of the chimney a glass cover is used to decrease the heat losses to the exterior. For this theoretical study, the steady-state energy balance equations were solved numerically for each element of the solar chimney. The results showed the temperature profiles for the glass cover, the air inside the channel, and the metallic plate. Also, the air mass flow rate was determined. When solar irradiance increases from 100 to 700 W/m 2, the maximum instantaneous efficiency of the system varies from 28 to 37, and also, the volumetric flow rate increases from 61 to 147 m 3/h. © 2012 American Society of Mechanical Engineers.


Juarez J.O.,University of Sonora | Hinojosa J.F.,University of Sonora | Xaman J.P.,CENIDET | Tello M.P.,University of Sonora
International Journal of Thermal Sciences | Year: 2011

In this work the numerical results of heat transfer calculations in an open cavity considering natural convection and temperature-dependent fluid properties are presented. The overall continuity, momentum, and energy equations in terms of primitive variables were solved numerically using the finite-volume method. Numerical calculations were conducted for Rayleigh number (Ra) values in the range of 104-107. The temperature difference between the hot wall and the bulk fluid (ΔT) was varied between 10 and 500 K, and was represented as a dimensionless temperature difference (ε) for the purpose of generalization of the trends observed. The results show that the thickness of the hydrodynamic boundary layer in the vicinity of the hot wall increases as ε increases from 0.03 to 1.6. The average Nusselt number in the cavity (Nu) was found to increase by 807% (ε = 0.03) and 1105% (ε = 1.6) as the Ra number varied from 104 to 107. Likewise, the average Nu number in the cavity decreased by 39% (Ra = 104) and 18% (Ra = 106) as ε was varied from 0.03 to 1.6. © 2011 Elsevier Masson SAS. All rights reserved.


Xaman J.,CENIDET | Ortiz A.,CENIDET | Alvarez G.,CENIDET | Chavez Y.,CENIDET
Energy | Year: 2011

In this paper, the results obtained from the analysis of the heat and mass transfer of an Air-Carbon Dioxide mixture (CO2) inside a ventilated cavity in laminar flow regime are presented. A ventilated cavity is usually the way to model a ventilated room as a first approximation. Different configurations of the cavity were analyzed regarding the location of the mixture outlet gap, in order to study the thermal behavior and the air quality inside the cavity considering three different values for the CO2 contaminant source (1000, 2000, 3000ppm). The air inlet gap is located on the lower side of the right vertical wall of the cavity. The inlet air velocity is a function of the Reynolds number (10≤Re≤500). The location of the mixture outlet gap was considered in four different positions: Case A, the outlet gap is on the upper side of the left wall; Case B, the outlet is on left of the top wall; Case C, the outlet is at the middle of the top wall and Case D, the outlet is on right of the top wall of the cavity. Based on the results, it was concluded that, from a thermal comfort point of view and air quality, configuration D shows the best performance in the interval 50≤Re≤100, with an exception for the case when a contaminant source of 1000ppm is present where configuration C is recommended. This study aims to provide guidelines for construction builders towards better design of buildings in order to achieve better air quality. © 2011 Elsevier Ltd.


Alvarado-Juarez R.,CENIDET | Alvarez G.,CENIDET | Xaman J.,CENIDET | Hernandez-Lopez I.,CENIDET | Hernandez-Lopez I.,Zacatepec Institute of Technology
Desalination | Year: 2013

Double-diffusive natural convection and surface thermal radiation in an inclined cavity that simulates a solar still device is studied numerically. The parameters considered were 103≤RaT (RaM)≤106, 8≤A≤16 and 15°≤θ≤35°. The steady state 2-D governing equations have been solved by the finite volume method. Streamlines, isotherms, isolines of water vapor, mass flow rate of distillate and average Nusselt and Sherwood numbers as a function of Rayleigh number for different inclination angle are presented. The results show that surface thermal radiation modifies the fluid flow from one-cell to multi-cellular pattern due to the surface thermal radiation increases the velocity near the walls, as a consequence the average convective Nusselt number, the total Nusselt number and the Sherwood number were increased about 25%, 175% and 15%, respectively. The mass flow rate of distillate increases as A, Ra and θ increase. The most suitable case for a solar still device is that for RaT=106, A=16 and θ≤25°. © 2013 Elsevier B.V.


Ramirez-Davila L.,CENIDET | Xaman J.,CENIDET | Arce J.,CENIDET | Alvarez G.,CENIDET | Hernandez-Perez I.,CENIDET
Energy and Buildings | Year: 2014

A numerical study was conducted for prediction the thermal behavior of an Earth-to-Air Heat Exchanger (EAHE) for three cities in México. The climate conditions correspond to an extreme heat in summer and low temperature in winter (Cd. Juárez, Chihuahua), mild weather (México city) and hot weather (Mérida, Yucatán). A Computational Fluid Dynamics code based on the Finite Volume Method has been developed in order to model the EAHE. Simulations have been conducted for sand, silt and clay soil textures for the cities of Cd. Juárez, México city and Mérida, respectively. Also, for different Reynolds numbers, Re = 100, 500, 1000, 1500 through one year. For Cd. Juárez, and México city, simulation results reveal that the thermal performance of the EAHE is better in summer than in winter, decreasing the air temperature in an average of 6.6 and 3.2 °C for summer and increasing it in 2.1 and 2.7°C for winter, respectively. By contrast for Mérida, EAHE had its best thermal performance in winter, increasing the air temperature in 3.8°C. It is concluded that the use of EAHEs is appropriate for heating or cooling of buildings in lands of extreme and moderate temperatures where the thermal inertia effect in soil is higher. © 2014 Elsevier B.V.


Serrano-Arellano J.,CENIDET | Xaman J.,CENIDET | Alvarez G.,CENIDET
International Journal of Heat and Mass Transfer | Year: 2013

Numerical results obtained from the analysis of the conjugated heat and mass transfer of an Air-Carbon Dioxide mixture (CO2) inside a ventilated cavity in turbulent flow regime are presented. Different configurations of the cavity were analyzed regarding the location of the mixture outlet gap in order to study the thermal behavior and the air quality inside the cavity and to determine a good ventilation configuration. Four different values for the CO2 contaminant source (500, 1000, 2000, 3000 ppm) are considered. The air inlet gap is located on the lower side of the right vertical wall of the cavity. The inlet air velocity is a function of the Reynolds number (5 × 102 ≤ Re ≤ 4 × 10 4). The location for the mixture outlet gap was considered in four different positions: Case A, the outlet gap is on the upper side of the left wall; Case B, the outlet is on left of the top wall; Case C, the outlet is at the middle of the top wall and Case D, the outlet is on right of the top wall of the cavity. From the results, it was concluded that, from a thermal comfort point of view and air quality, configuration D shows the best performance. In general, it is concluded that in order to obtain values that fulfill regulations of temperature and contaminant concentrations, it is required to have mixed convection with a Reynolds value of Re = 10,000. © 2013 Elsevier Ltd. All rights reserved.

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