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.
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- 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.
- Process Intensification of antisolvent crystallization using a coiled flow inverter(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-15) Benítez Chapa, Andrea Georgina; Álvarez Guerra, Alejandro Juan; López Guajardo, Enrique Alfonso; Montesinos Castellanos, AlejandroThe current scenario of the pharmaceutical industry, where final product quality has a fundamental priority, justifies the need for process intensification in order to shift from inefficient conventional batch production to continuous production methods. An alternative to reducing energy consumption in the purification step of pharmaceutical products is antisolvent continuous crystallization, a separation and purification technique that aims to produce particles of controlled size and purity by controlling the antisolvent addition rate, on which crystal birth and growth rates depend. This work experimentally studies the antisolvent continuous crystallization process of flufenamic acid, an active pharmaceutical ingredient (API), using the coiled flow inverter (CFI) as a novel crystallization device. Two strategies were studied as means to control crystal size distribution in the CFI technology: multistage antisolvent addition and a varied number of the reactor’s 90-degree bends. Experimental results show that mean crystal size of the studied API, increased with an increasing number of antisolvent addition points, thus suggesting a growth dominated process. On the other hand, mean crystal size decreased as the number of 90-degree bends increased, suggesting a nucleation dominated process. A narrower crystal size distribution (CSD) was also observed with an increased number of 90-degree bends. When compared to the CFI, mean crystal size and coefficient of variation were, in average, 1.8 and 3.5 times larger for the Kenics type crystallizer, respectively. This can be attributed to the high supersaturation induced by the effective mixing. Using the Population Balance Equation, as a mathematical model to describe the plug flow crystallization, crystal mass population density was calculated and compared with the obtained experimental data. High regression coefficients were obtained (0.96-0.99), which indicate that near plug flow behavior was achieved. Consequently, undesired crystallization process phenomena such as agglomeration, dissolution and breakage were successfully avoided, as they can lead to operational problems and a broad CSD. Process intensification (PI) was measured considering mean crystal size (µm) and coefficient of variation (CV) as product quality indicators. On the other hand, crystallization and pre-expansion temperatures, as well as extraction pressure, were considered as both energy savings and operational safety indicators. Six crystallizers of flufenamic acid were compared (batch, reactor without static mixers, Kenics type crystallizer, Kenics optimized, helical coil and RESS) to a CFI with three 90-degree bends. The CFI was the most intensified technology of all six, with IFtotal ranging from 2 (helical coil) to 392 (RESS). For this reason, it can be concluded that the main objective of this thesis, which was to intensify antisolvent crystallization processes, was achieved.
- Characterization of arc extinction in direct current residential circuit breakers(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-15) Bautista Cruz, Julio César; Viramontes Brown, Federico Ángel; Rivera Solorio, Carlos Iván; Gutiérrez Villanueva, Efrain; Suarez Guevara, José CarlosBreak the current in a direct current (DC) network is a challenging theme since the current does not exhibit a zero crossing point, making it difficult to interrupt. Regardless of the method, the physical effect of switching is the formation of an electric arc, causing high levels of temperature, strong magnetic fields, current of several tens of KA, added to mechanical stress and overpressure on the walls. Due to this reason, physical phenomena should be studied to determine a suitable design. This thesis starts by understanding the arc in alternating current (AC), then proceeds to DC. A theoretical description of the electric arc is outlined, based on plasma physics. The Magneto-Hydrodynamic (MHD) model is proposed, which allows modeling a plasma as an electric fluid, allowing coupling the equations of fluid mechanics and magnetic fields.
- Operation of a photovoltaic system in the mexican electricity market(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-15) Gutiérrez Andrews, Carlos Alberto; Viramontes Brown, Federico Ángel; Hernández Ramírez, José Martín; Llamas Terrés, Armando Rafael; Gutiérrez Villanueva, EfrainTaking as a study case a Photovoltaic (PV) System installed in the Development and Innovation Center of Schneider Electric a whole study was realized. The main objective was to analyze the operation of a PV system in the Mexican Electricity Market and develop tools that can make easier to evaluate the performance of the installation. It produces less than 0.5 MW, in the current regulation is consider as Distributed Generation (DG). This kind of Power Plants (PP) can be interconnected to the grid and the owner has three contract options: Net Metering, Net Billing and Total Sale of Energy. In this case the better is Net Metering because the building consumes all the energy produced, but by having a contract with a supplier this field could earn Clean Energy Certificates (CEL). Three tools were developed to evaluate the economic and technical performance. The first tool is to graph the downloaded data acquired by the monitoring system. That daily data cannot be graph as detailed by the inverter’s provided interface after a day as if the user downloads the information. The second tool is required to find the greatest values of Irradiance, Temperature or Power in a month. When this tool is feed with the files of the month, each file will be paste in a new Excel workbook’s sheet, but in the first sheet the user, has a recapitulation per day of the greatest values. With all this ordered information could be prepare a generation profile of the area, and that stats can be used in future investment decision and forecasting. Finally, the third tool is dedicated to calculated financial indicators such as Payback and IRR. Some scenarios were studied and after applying some stimulus offered by the government that are reflected in the taxes payment, better results were obtained. With this tool is possible run scenarios and evaluate the profitability of new investments.
- Assessment of the opportunities for integrating a Dynamic Line Rating System in the Mexican National Electric Grid(2017-12-04) Tarín Santiso, Ana Victoria; Probst, Oliver; Llamas Terrés, Armando Rafael; Osvaldo Miguel Micheloud Vernackt