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Recalde C.,School of Technology of Chimborazo, Riobamba | Cisneros C.,Polytechnic University Jose Antonio Echeverria | Vaca D.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables | Ramos C.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables
Informacion Tecnologica | Year: 2015

In this work, values of atmospheric transmittance coefficients using heliophany (sunshine hours) and the difference between maximum and minimum temperatures are proposed for a city located in the Andean Ecuadorian zone. First, the extraterrestrial radiation was calculated to study the reliability of the models. Later, statistical techniques were applied to meteorological data measured since June 2007 for a period of almost five years. These data were used to calculate the empirical lineal coefficients between different variables, using three models: one using heliophany and two using the difference between temperatures. The results showed that there is a more consistence relation between solar radiation and sunshine hours. In addition, it was established that it is not adequate to generalize the results to other locations even if they have similar weather characteristics. Source

Martinez-Gomez J.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables | Ibarra D.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables | Villacis S.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables | Cuji P.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables | Cruz P.R.,International University of Ecuador
Food Policy | Year: 2016

This research aims to analyze cooking parameters in liquefied petroleum gas (LPG), electric resistance and induction stoves for eight dishes of the Ecuadorian cuisine. During tests, it has been monitored the temperature, time, electrical grid parameters, concentrations of CO and CO2. In addition it has been studied the microbiological and physiochemical changes produced by the thermal treatment in food and a discriminative triangular test for determining the differences in the consumers perception between samples made with induction and LPG based stoves. The results showed which even with an exhaust hood working, there was still a significant value of concentration of CO and CO2 during cooking with a LPG stoves. As a result of these analyses the induction stove shows a better response during the heating process and energy efficiency which have influence in temperatures, taste, vitamin preservation, cooking times, energy consumption and cost to the user. © 2015 Elsevier Ltd. Source

Soriano G.,ESPOL Polytechnic University | Bravo G.,ESPOL Polytechnic University | Bravo G.,Instituto Nacional Of Eficiencia Energetica Y Energias Renovables | Guevara P.,ESPOL Polytechnic University | And 3 more authors.
WIT Transactions on Engineering Sciences | Year: 2014

An assessment of the use of engineered heat transfer fluids working under constant wall temperature conditions in the turbulent regime is presented. An analysis of entropy generation and pumping power on the system working with different engineered heat transfer fluids is performed. Three types of fluids are considered: multiwalled carbon nanotube (MWCNT) based nanofluids, slurries with microencapsulated phase change materials (MPCM) and a mixture of both fluids. Specific heat, thermal conductivity and viscosity of the fluids are included in the analysis using theoretical and experimental results available in literature. Nanofluids in the system result on greater entropy generation and pumping power consumption when compared with base fluid. MPCMs slurries produce the minimum entropy generation and pumping power consumption. Mixtures are affected by the content of nanofluids resulting in a performance below of MPCMs slurries. The improvement on the heat capacity of the fluid produced by the Microencapsulated phase change material is the main factor in reducing entropy generation and pumping power consumption for the system. Under the conditions assessed, the increase in viscosity offsets the increase in thermal conductivity on the MWCNT based nanofluids. On the other hand in the case of MPCM slurries, the increase in heat capacity outweighs the reduction in thermal conductivity and increase in viscosity. © 2014 WIT Press. Source

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