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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- Numerical study of heat transfer of a double layered PCM building roof in a semi-arid climate(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2023-12-05) Contreras Aguilar, José Alberto; Gijón Rivera, Miguel Ángel; emimmayorquin; Rivera Solorio, Carlos Iván; Godoy Rangel, Caribay; School of Engineering and Sciences; Campus MonterreyThe thermal performance of a concrete roof with a double phase change material (PCM) layer on the interior concrete surface under the semi-arid weather of Monterrey´s city is presented. The roof was numerically analyzed based on a computational fluid dynamic (CFD) simulation with three types of models: The base concrete case (RC), the concrete roof with one PCM layer (RC-PCMi), and the concrete roof adding a double PCM layer (RC-PCMi-PCMj). The numerical CFD simulations were conducted during the warmest, coldest and typical day of the year. The software used for the simulation was Ansys Fluent. The results indicate that the RC-PCM29 has the lowest thermal values during the warmest day reducing the indoor energy by 96.51 W/m2 representing a 7.4% reduction. In the other hand the RC-PCM25 obtained the best performance for the coldest day, reducing indoor energy by 300.29 Wh/m2 or 32.7% reduction. Furthermore, the RC-PCM29-PCM25 double PCM configuration resulted in the best thermal performance, reducing the annual energy to the indoor by 3,613.89 kWh or 26.2%. Also, considering a roof area of 36 m2 of a building located in Monterrey city, the payback period will be up to 3.45 years with an internal rate of return of 29.0%, resulting a cost-effective use of the double PCM layer. Besides the annual carbon emission savings are 1 572 04 𝑘𝑔 𝐶𝑂 2 𝑒𝑞. Therefore, it is recommended that the RC-PCM29-PCM25 will improve the thermal behavior of buildings located in Monterrey.
- Case studies in electric arc furnace Off-gases transport and steam explosion onset(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-15) Contreras Serna, Jorge; García Cuéllar, Alejandro Javier; Rivera Solorio, Carlos Iván; López Salinas, José LuisSteel production in an EAF may pose a serious security risk in the event of water leaks into the molten steel, causing violent steam explosions. This thesis presents two important topics related to the Steel Making Industry. The first one is about the detection of water vapor (steam) inside the off-gas duct of an Electric Arc Furnace (EAF). And the Second one is about knowing the preconditions of melt fragmentation in a steam explosion. A way to detect the presence of large quantities of water inside the EAF is by monitoring its off-gas duct content of water vapor. Determining where to place a probe for water vapor detection inside the duct, is of the greatest importance as this might be the first warning for the appearance of a risk situation. A computational fluid dynamics (CFD) simulation is carried out using ANSYS Fluent software to obtain the point with highest concentration of water vapor. Water vapor channeling is assumed in the inlet of the off-gas duct so that a worst-case scenario is presented. Three-dimensional simulations were run with the inlet gas containing CO2, CO, H2O (steam), and air. The first three components enter through the duct while air enters through small gaps in the duct. Different combinations of the inlet position of CO2, CO and H2O were considered to estimate a pattern for the water vapor flow through the duct. The results show that if the steam enters in a channelized way, it will tend to continue in that path along the duct. The simulation results show the zones of the off-gas duct with a higher concentration of steam. These results can guide locating the gas probe and provide a better warning of a water leak. About the other topic, fragmentation of molten metal is an important process in steam explosions caused by melt-coolant interactions. This part of the research is dedicated to investigating how the fragmentation of the melt droplets occurs and melt jets formation in different mechanisms like a metal droplet falling in water or in a stratified water/liquid metal system. Also, an explanation of the most significant parameters in these processes is performed. 2-D computational fluid dynamics (CFD) simulations are carried out using ANSYS Fluent software to study these phenomena. The results show that the larger the pressure or density, the greater the melt jet length for a stratified system. And the larger velocity or density, the greater deformation for a melt droplet in a water pool. The formation of melt jets of Ciccarelli and Frost’s experiments is observed, and fragmentation of melt droplets was also observed during current simulations.