Showing papers by "Rosenberg J. Romero published in 2019"
TL;DR: In this paper, environmental impacts of an experimental solar absorption air-conditioning system based on a Life Cycle Assessment were evaluated for the first time in Mexico, and the main contribution of environmental impacts in the solar cooling system was the consumption of energy and raw materials for the construction, whereas for the commercial cooling system, the electricity consumption and the use of refrigerant were the major impacts of the operation stage.
32 citations
TL;DR: In this paper, a half-effect absorption cooling system operating with an ammonia/lithium nitrate mixture and based on the first and second laws of thermodynamics, using as energy inputs real data from two geothermal wells located at Las Tres Virgenes volcanic complex, Baja California Sur, Mexico.
Abstract: A thermodynamic analysis of a half-effect absorption cooling system powered by a low-enthalpy geothermal source was carried out. This paper presents modeling of the half-effect absorption cooling system operating with an ammonia/lithium nitrate mixture and based on the first and second laws of thermodynamics, using as energy inputs real data from two geothermal wells located at Las Tres Virgenes volcanic complex, Baja California Sur, Mexico. Plots of coefficients of performance and exergy efficiency against condenser, evaporator, and generator temperatures are presented for the half-effect cooling system. The results showed that the system was able to operate at generation temperatures between 56 and 70 °C, which were supplied by the geothermal wells in order to produce cooling at temperatures as low as −16 °C, achieving coefficients of performance between 0.10 and 0.36, while the exergy efficiency varied from 0.15 to 0.40 depending on the system operating temperatures.
4 citations
01 Jan 2019
TL;DR: In this paper, an energy model to optimize the grid of power plants in the Mexican electricity sector (MES) is presented, which considers indicators and parameters from Mexican Energy Reforms.
Abstract: High electricity demand, as well as emissions generated from this activity impact directly to global warming. Mexico is paying attention to this world difficulty and it is convinced that sustainable economic growth is possible. For this reason, it has made actions to face this problem like as launching constitutional reforms in the power sector. This paper presents an energy model to optimize the grid of power plants in the Mexican electricity sector (MES). The energy model considers indicators and parameters from Mexican Energy Reforms. Electricity demand is defined as a function of two population models and three electricity consumption per capita. Prospectives are presented as a function of total annual cost of electricity generation, an optimal number of power plants—fossil and clean—as well as CO2eq emissions. By mean of the energy model, optimized grid scenarios are identified to meet the governmental goals (energy and environment) to 2050. In addition, this model could be used as a base to identify optimal scenarios which contribute to sustainable economic growth, as well as evaluate the social and environmental impacts of employed technologies.
2 citations
TL;DR: In this paper, the authors proposed new mathematical correlations to predict or estimate the NaOH concentrations and refractive index in aqueous solutions (H2O-NaOH) for an air conditioning absorption system application.
Abstract: Some processes such as air conditioning absorption systems have been developed as a feasible and economical alternative to help reduce the consumption of fossil fuels and prevent the impact of gas emission produced by electrical air conditioning. However, a main disadvantage of these systems is the absorbent’s crystallization phenomenon in the working mixture, which occurs when the absorbent concentration is higher than the saturation point. Among the aqueous working mixtures, NaOH solution shows several advantages for absorption system applications. The aim of this paper is to propose new mathematical correlations to predict or estimate the NaOH concentrations and refractive index in aqueous solutions (H2O–NaOH) for an air conditioning absorption system application. The experimental measurements of NaOH concentration and refractive index were made in situ from aqueous solutions with concentrations from 20 to 50% (weight/weight %, with increases of 5%) and temperatures between 10 and 60 °C (with increment...
2 citations
TL;DR: In this paper, a Rotating cage (RC) and Computational Fluid Dynamics (CFD) software were used to simulate RC flow conditions during the corrosion process, to evaluate wall shear stress.
Abstract: The purpose of this study is to evaluate the corrosion in CO2 using Rotating cage (RC) and Computational fluid dynamics (CFD) software. RC experiments were carried out in a CO2 environment, to evaluate corrosion in a C-Mn Steel. CFD software was used to simulate RC flow conditions during the corrosion process, to evaluate wall shear stress.,The RC is used as a laboratory tool for studies of accelerated corrosion, according to standard ASTM G184-06. Steel corrosion was studied by means of the RC methodology. The hydrodynamics are solved numerically using CFD. Numerical calculations were performed on a 2D geometry of 8 coupons JG, for speeds of 460 and 230 rpm. The flow was analyzed with vector graphics and velocity profiles. The numerical calculations were validated with experimental measurements of the velocity field obtained with the technique of Particle Image Velocimetry (PIV).,Different turbulence models were used, in which CFD simulations were compared with data obtained from PIV. According to this comparison, the best turbulence model was determined.,It was found that experimental flow speeds have closer values with Spalart–Allmaras modeling than K-epsilon and K-kl-omega.
1 citations