Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
Browse
Search Results
- Design of thermoelectric heat exchangers for additive manufacturing(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-06-14) Abrego Flores, Oscar Enrique; Rodríguez, Ciro Ángel; emimmayorquin; Cedeño, Luis Daniel; Escuela de Ingeniería y Ciencias; Campus Monterrey; Martínez, José IsraelThis document presents the thesis of the Design of Heat Exchangers with Additive Manufacturing for Thermoelectric Module Systems for the Master of Science with major in Manufacturing Systems at Tecnológico de Monterrey. This study investigates the overall performance and manufacturing process for a heat exchanger equipped with a thermoelectric module (TEM) for cooling systems. A TEM system is a solid-state power converter consisting of an array of thermocouples connected electrically in series and thermally in parallel. Normally, it is used as an arrangement of many TE modules connected electrically in series and thermally in parallel to maximize the results. However, when it is desired to cool other components, a heat exchanger is attached to transmit the energy. Recently, TEM systems have been proposed to substitute conventional heating, ventilation, and air conditioning (HVAC) systems due to their compact designs, lower maintenance and multiples uses modes. However, TEM systems usually have lower efficiency than conventional HVAC systems. This document explores using additive manufacturing to produce novel heat exchangers with a potential application in TEM devices. In this research was manufactured via Laser Powder Bed Fusion (L-PBF) three heat exchangers from which two are made with a novel design based on gyroid lattice structure in order to compare with traditional heat exchangers. The results indicated a 25% improvement in cooling capacity for a heat exchanger with a gyroid structure with at least 1mm of wall thickness. The methodology followed for this research is presented with a theoretical background, analysis, experimentation and simulation of the heat exchanger in order to evaluate its performance with TEM systems for cooling. The expected contribution of this research is to generate new knowledge about the application of heat exchangers with complex structures (achieved by additive manufacturing) in the application of climatization with thermoelectric systems, since a point of view of production until an improvement on thermal efficiency, also propose an experimental setup that can be replicated by other researchers to test the cooling capacity of novel heat exchangers.
- Study on the influence of geometrical parameters to enhance heat transfer in a finned cylindrical segment, incorporating vortex generators.(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-25) Chilaca Tarango, Anuar Samuel; CHILACA TARANGO, ANUAR SAMUEL; 751168; GARCIA CUELLAR, ALEJANDRO JAVIER; 121668; López Salinas, José Luis; Rivera Solorio, Carlos Iván; Campus MonterreyThe present work addresses the simulation of geometries considering forced convection of turbulent flow for the thermal optimization of a generator of a water-ammonia absorption refrigeration system, for which purpose, several simulations were carried out on ANSYS Fluent, varying the geometric parameters in order to define the optimal design for the generator. In the first part, a geometrical analysis of the previously geometry proposed for the construction of the generator is presented, evaluating those geometrical factors that enhance the heat transfer. The results obtained from the simulations are used to calculate the global heat transfer coefficient by convection, as well as the average Nusselt number. High heat transfer coefficients were found where geometries shows specific arrangements that modify the evolution of the flow, those changes in the flow contributes to the higher mixed and to the heat transfer. The second part of the thesis analyze the modification of arrangement and evaluate the introduction of different types of fin geometries. Realistic and manufacturable geometries were considered for maximization of thermal heat transfer coefficient and also the minimization of friction forces. In order to compare these various geometries, a set of standard conditions were required. Finally, the thesis contemplates the incorporation of Vortex Generators (VG) to enhance the heat transfer along the generator. Vortex generators is one of the passive methods to generate streamwise vortices that create high turbulence in fluid flow over heat transfer surfaces. VG have shown to be an effective way to increase the heat transfer coefficient, decreasing the thermal resistance of the sublayer adjacent to the wall immediately where the viscous effects of the sublayer are dominant. The increase of turbulence of the fluid flow in the main stream have shown positive effects on the heat transfer. The thesis evaluates the present research of VG and contemplate the simulation of the incorporation of an array of VG over the surface of a previously finned- cylindrical geometry of generator, contrasting the immersion of the VG's to baseline geometry, the effects on the pressure drop are also studied. Subsequently, the incorporation of a modified annular winglet vortex generator over the generator surface was also evaluated. The results were compared to the no VG fin type geometry. The results show that the heat transfer increases considerably, but an increase on the pressure drop is also observed.
- Fault detection and diagnosis in a heat exchanger using dynamic principal component analysis and diagnostic observers(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2008-12-01) Tudón Martínez, Juan Carlos; TUDON MARTINEZ, JUAN CARLOS; 229809; Morales Menéndez, Ruben; Acevedo Mascarúa, Joaquín; Guedea Elizalde, Federico; Ramírez Mendoza, Ricardo A.; Graduate Program in Mechatronics and Information Technologies; Division of Mechatronics and Information Technologies; Monterrey CampusQuick detection and correct isolation of soft faults in a control system allow to improve the product quality, particularly in chemical processes, for example: an industrial heat exchanger. According to Venkatasubramanian, the fault methods can be classified as: model-based methods and historical data-based methods. In this thesis, two Fault Detection and Isolation (FDI) systems are designed and validated in the same process, i.e. in a shell and tube industrial heat exchanger. One of them is based on the Dynamic Principal Component Analysis (DPCA) method and the another one on a set of diagnostic observers. The former method requires historical data of the process, whereas, the diagnostic observers use quantitative models. Before testing both methods, they are trained in the same normal operating point. Four kinds of faults are introduced under the same process conditions in order to compare the performance of both diagnostic methods. All these fault cases are considered as soft faults in sensors or actuators; the faults are implemented with abrupt or gradual behavior. Similar metrics are defined in both FDI methods in order to analyze the desirable characteristics of any fault diagnostic system: robustness, quick detection, isolability capacity, explanation facility, false alarm rates and multiple faults identifiability. Experimental results show the principal advantages and disadvantages of both methods and allows to present a comparative table with the achieved performance of each method. This work allows to design and development both methods in parallel. The Recursive Least Squares (RLS) method is used to identify the process through a Random Binary Signal (RBS) test. The reliable model of each fault allows to design a set of diagnostic observers. On the other hand, a statistical analysis based on historical data is designed to know the operating status. The DPCA method projects the data into two new spaces in order to detect any abnormal event using a smaller number of process variables. In this manner, two methods, based on different approaches, are tested under the same experimental data. This work shows that a set of diagnostic observers can detect a soft fault in a sensor or actuator at shorter time than the DPCA method. The diagnostic observers present a lower false alarm rate than the DPCA method, when soft faults in actuators are implemented. Furthermore, diagnostic observers can identify multiple faults, whereas the DPCA method can not associate correctly the errors to the occurred faults. However, the training and testing stages of the diagnostic observers require greater computational resources than the stages of the DPCA method.