Modelo de transferencia de calor para concentradores solares con flujo bifásico

In this work, a dynamic mathematical model of heat transfer through the absorber tube of a Fresnel solar concentrator type, which uses water as working fluid, is developed. The water is considered to change phase as it flows through the absorber tube, giving rise to a monophasic region and a biphasic region. The model is validated with experimental data, published in the literature, and the thermal efficiency is analyzed as a function of the solar resource in this concentrator.En este trabajo se desarrolla un modelo matemático dinámico de la transferencia de calor a través del tubo absorbedor de un concentrador solar Fresnel, que emplea como fluido de trabajo agua. Se considera que el agua cambia de fase a medida que fluye a través del tubo absorbedor, dando lugar a una región monofásica y una región bifásica. El modelo es validado con datos experimentales, publicados en la literatura, y se analiza la eficiencia térmica en función del recurso solar en este concentrador

Efecto térmico de las azoteas verdes en la Ciudad de México, Yucatán y Coahuila

In this work, a mathematical heat transfer model is presented to evaluate the thermal effect of the implementation of extensive green roofs for the rehabilitation of poorly insulated buildings subjected to the climatic conditions of Mexico City, Yucatan and Coahuila. The model, which requires a few amounts of input data, is solved numerically and implemented in Python. The results show that the implementation of a green roof contributes to decrease the amplitude of internal temperature oscillation of the building, decreases the average indoor temperature and reduces the consumption of electrical energy for air conditioning. En este trabajo, se presenta un modelo matemático de transferencia de calor para evaluar el efecto térmico de la implementación de azoteas verdes extensivas para la rehabilitación de edificaciones mal aisladas sometidas a las condiciones climáticas de la Ciudad de México, Yucatán y Coahuila. El modelo, que requiere pocos datos de entrada, es resuelto numéricamente e implementado en Python. Los resultados muestran que la implementación de una azotea verde contribuye a disminuir la amplitud de oscilación en la temperatura interna de la edificación, disminuye la temperatura media interior, y reduce el consumo de energía eléctrica destinada al acondicionamiento de aire

Data for: Novel Numerical Solution to the Fractional Neutron Point Kinetic Equation in Nuclear Reactor Dynamics

Implementation in MATLAB, of the numerical solution developed for the solution of the integro-differential equation developed in the work

Data for: Local dynamic analysis in boiling water reactor

Local dynamic analysis of a nuclear boiling water reactor considering feedback reactivity effects

Síndrome de boca ardorosa en pacientes geriátricos con hipertensión arterial causado por fármacos antihipertensivos

Tesina (Licenciatura en Odontología), Instituto Politécnico Nacional, CICS-UMA, 2016, 1 archivo PDF, (65 páginas). tesis.ipn.m

Data for: Local dynamic analysis in boiling water reactor

Local dynamic analysis of a nuclear boiling water reactor considering feedback reactivity effects.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Dynamic mathematical heat transfer model for two-phase flow in solar collectors

In the present study, a dynamic heat transfer model is developed for two-phase flow through the absorber tube of linear solar collectors, where the heat transfer fluid is water. The model considers that thermophysical properties, such as viscosity, thermal conductivity, densities, and specific heat, depend on temperature; this dependency is reflected in the value of the convective heat transfer coefficient. The governing partial differential equations for the fluid are solved using the finite difference method in an explicit scheme, the heat transfer equation for the absorber tube uses an implicit scheme, whose solution is implemented in C++ compiler. The model is validated with experimental data from a solar collector using a Solar Fresnel Reflector type, with an error related to the steam quality lower than 4.28% at the outlet of the collector and a better fit with the temperature profile through the collector in comparison with previous studies. The results show that as the phase change occurs, increasing the quality of steam in the absorber tube, the collector efficiency decreases. This is due to that the convective heat transfer coefficient of the absorber decreases, since the thermophysical properties of the liquid-steam mixture do not favor heat transfer