Evaluation of the incidence of optical and physical characteristics on the performance of a Fresnel Linear Collector prototype

This article aims to evaluate the optical and thermal behavior of a small Fresnel linear concentrator prototype developed under the appropriate technology paradigm. The system was developed by the Energy, Automation and Control Systems Research Group of the Technological Units of Santander, Colombia for water heating. The study of the device was developed from a series of simulations that took into account the optical and thermal factors of the real system, and a series of alternative scenarios that seek to improve the performance of the device were evaluated. The simulation process was carried out by applying the "TRNSYS" Software in order to study the dynamic behavior of the concentrator and the "Soltrace" Software applying the Monte Carlo Ray Tracing method. The results obtained showed that the improvement scenarios proposed to evaluate the optical characteristics of the primary reflection system do not significantly increase the performance of the device, while the optical characteristics applied to the secondary reflection system do reflect a significant increase. Finally, the variation of flow and the area of the preheater show a direct relationship in performance, reaching values that predict the ideal value of the operating variable

Estudio del comportamiento del panel fotovoltaico según la superficie instalada

This article focuses on the study of the behavior of electrical variables (Power, Voltage, Current) and the temperature incidence of a monocrystalline photovoltaic panel (PFV), installed on a wooden and drywall surface and another installed on standard surface (Cement), to contrast them, and obtain the behavior of these variables, in order to determine which of the two surfaces on which the monocrystalline photovoltaic panels are installed provides the greatest power.The methodological phase was advanced on the terrace of the Santander Technological Units, applying both scientific and comparative research methods, which, a prototype is designed for the measurement of the data by installing elements that constitute a photovoltaic solar system, and measuring instruments for capturing and taking data from the variables to be studied. Data capture is performed for 60 days, for subsequent comparative analysis of each of the electrical variables presented by THE PVFs.As results of this research, comparative graphs of the electrical and thermal behavior of the photovoltaic panels are obtained on the two installed surfaces. This article focuses on the study of the behavior of electrical variables (Power, Voltage, Current) and the temperature incidence of a monocrystalline photovoltaic panel (PFV), installed on a wooden and drywall surface and another installed on standard surface (Cement), to contrast them, and obtain the behavior of these variables, in order to determine which of the two surfaces on which the monocrystalline photovoltaic panels are installed provides the greatest power.El presente artículo centra en el estudio del comportamiento de las variables eléctricas (Potencia, Voltaje, Corriente) y la incidencia de la temperatura que presenta un panel fotovoltaico monocristalino(PFV), instalado en una superficie de madera y drywall y otro instalado en superficie estándar (hormigón), para contrastarlos, y obtener la conducta de estas variables, para así determinar cuál de las dos superficies en las que se instalan los paneles fotovoltaicos monocristalinos provee mayor potencia.La fase metodológica se adelantó en la terraza de las Unidades Tecnológicas de Santander, aplicando métodos investigativos tanto científico como comparativo, la cual, se diseña un prototipo para la medición de los datos instalando elementos que constituyen un sistema solar fotovoltaico, y los instrumentos de medición para la captura y toma de datos de las variables a estudiar. La captura de datos se realiza durante 60 días, para el posterior análisis comparativo de cada una de las variables eléctricas que presentan los PVF.Como resultados de la presentes investigación se obtienen la graficas comparativas del comportamiento eléctrico y térmico de los paneles fotovoltaicos en las dos superficies instaladas. El presente artículo centra en el estudio del comportamiento de las variables eléctricas (Potencia, Voltaje, Corriente) y la incidencia de la temperatura que presenta un panel fotovoltaico monocristalino(PFV), instalado en una superficie de madera y drywall y otro instalado en superficie estándar (hormigón), para contrastarlos, y obtener la conducta de estas variables, para así determinar cuál de las dos superficies en las que se instalan los paneles fotovoltaicos monocristalinos provee mayor potencia

Descripción de los procesos industriales energéticamente críticos en la producción de cacao en Santander

The objective of this research is to describe the energetically critical processes in cocoa production in Santander due to the growth of industrial activities that have generated a higher energy consumption. Additionally, a descriptive methodology with a quantitative approach was proposed through the data analysis technique that seeks to identify the processes with the highest consumption within the production lines. Subsequently, a description of the processes involved in cocoa production was made considering the technical data and operation of the equipment, the calculation was proposed for the operation of the same equipment for 24 hours and 30 days for power factors of 0.75 and 0.95.  Finally, through analysis, calculations, and the application of the Pareto methodology, it was found that the energy potential with the highest consumption of active, reactive, and apparent energy is in the cocoa refining process. Esta investigación tiene como objetivo describir los procesos energéticamente críticos en la producción de cacao en Santander a causa del crecimiento de las actividades industriales que ha generado un mayor consumo de energía. Adicionalmente, se planteó una metodología descriptiva con enfoque cuantitativo mediante la técnica de análisis de datos que busca identificar los procesos con mayor consumo dentro de las líneas de producción. Posteriormente, se realizó la descripción de los procesos involucrados en la producción de cacao teniendo en cuenta los datos técnicos y funcionamiento de los equipos, el cálculo se planteó para el funcionamiento de estos equipos durante 24 horas y 30 días para factores de potencia de 0.75 y 0.95. Finalmente, mediante el análisis, la realización de cálculos y la aplicación de la metodología de Pareto se encontró que el potencial energético de mayor consumo de energía activa, reactiva y aparente se localiza en el proceso de Refinado de cacao

Analysis of the thermal sensation in single-family home from microclimatic monitoring: Case study Bucaramanga Colombia

The present work describes the experimentation of monitoring for the finding of the heat index and the individual thermal sensation, where the behavior of the real temperature in the exterior and interior of a conventional single-family house with a warm and temperate climate in Colombia was analyzed. The detailed monitoring campaign is carried out for 2880 hours, where the conditions of the interior area of the house and the local climatic conditions of the area are recorded, through the implementation of a thermohydrometers registration system. The methodology for the calculation of the sensation of heat and thermal comfort was determined under the adjusted equation of cooling power of Leonardo Hill and Morikofer-Davos, applied in the analyses of the Institute of Hydrology, Meteorology and Environmental Studies - IDEAM. The results showed a thermal sensation of dissatisfaction of 97.7%, because with the monitored temperature the thermal sensation is calculated yielding in 1382.4 hours with very hot, 1151.6 hours of hot and 280.8 hours of warm thermal sensation

Simulation of a flat solar collector with thermal storage for drying food : Simulación de un colector solar plano con almacenamiento térmico para el secado de alimentos

This research addresses the numerical simulation of a working fluid, using specialized SolidWorks Flow Simulation Software, analyzing the behavior of a drying air in a flat solar collector with thermal energy storage. In addition, one of the main centers of computational study is the relationship between flow, air temperature at the outlet of the collector and efficiency; This study allows researchers a vision of the principles of the design of these technologies, especially if it focuses on the drying of food. Then, a proposal is made on the requirements to be taken into account for the sizing of collectors based on the requirements of the product to be dried. Among the results obtained, it is established that a correctly designed collector and under a variable air flow, based on the intensity of the irradiation in specific coordinates and location, can reach efficiencies close to 30% with temperatures close to 60 ° C, being ideal for injecting this fluid into a drying chamber, where the food to be dehydrated is available. For the selection of the volume of the material for energy storage, it is recommended to take the melting temperatures as a base, with a constant flow of air, it is normal that within the system, the temperature varies depending on the position, therefore it is recommending the application of materials with different melting temperatures, which are strategically located within the storage tank.Esta investigación aborda la simulación numérica de un fluido de trabajo, utilizando el software especializado SolidWorks Flow Simulation, analizando el comportamiento de un aire de secado en un colector solar plano con almacenamiento de energía térmica. Además, uno de los principales centros de estudio computacional es la relación entre caudal, temperatura del aire a la salida del colector y eficiencia; Este estudio permite a los investigadores una visión de los principios del diseño de estas tecnologías, especialmente si se enfoca en el secado de alimentos. A continuación, se hace una propuesta sobre los requisitos a tener en cuenta para el dimensionamiento de los colectores en función de los requisitos del producto a secar. Entre los resultados obtenidos, se establece que un colector correctamente diseñado y bajo un flujo de aire variable, en función de la intensidad de la irradiación en coordenadas y ubicación específicas, puede alcanzar eficiencias cercanas al 30% con temperaturas cercanas a los 60 ° C, siendo ideal para inyectar este fluido en una cámara de secado, donde se encuentra disponible el alimento a deshidratar. Para la selección del volumen del material para almacenamiento de energía, se recomienda tomar como base las temperaturas de fusión, con un flujo de aire constante, es normal que, dentro del sistema, la temperatura varíe dependiendo de la posición, por lo tanto, recomienda la aplicación de materiales con diferentes temperaturas de fusión, los cuales se encuentran estratégicamente ubicados dentro del tanque de almacenamiento

Evaluation of the thermal performance of housing envelopes as passive cooling systems

Over the years, climate change has generated an increase in the average temperature of the planet, which has led to greater consumption of electrical energy for the use of air conditioning systems. Insulating envelope materials are considered a viable passive solution as they offer internal air conditioning, cooling, and/or heating of buildings that lead to thermal comfort with reduced energy consumption. This article compares the application of different insulating materials in an existing single-family home located in a hot-dry climate. To this end, the procedural methodology has been applied by carrying out a bibliographic review of different involutes currently used in the construction of the buildings and 14 models are proposed that will be simulated under the same input variables of the base model and meteorological data of the city of Bucaramanga validated from a meteorological station located on site. The results of the simulations show that all 14 models show a decrease in temperature with reference to the "base model"; This difference can be explained by the presence of the selected materials that slightly change the thermal properties of the wall. Finally, this research allowed us to determine that the occupants of the simulated spaces in the base model are inside the thermal comfort range by 61.96%, which represents 5,438 hours of the modeled year, having 38.03% of hours of discomfort in the measured time. This study can be useful for the selection of envelopes and different buildings with passive cooling requirements

Simulation of a flat solar collector with thermal storage for drying food : Simulación de un colector solar plano con almacenamiento térmico para el secado de alimentos

This research addresses the numerical simulation of a working fluid, using specialized SolidWorks Flow Simulation Software, analyzing the behavior of a drying air in a flat solar collector with thermal energy storage. In addition, one of the main centers of computational study is the relationship between flow, air temperature at the outlet of the collector and efficiency; This study allows researchers a vision of the principles of the design of these technologies, especially if it focuses on the drying of food. Then, a proposal is made on the requirements to be taken into account for the sizing of collectors based on the requirements of the product to be dried. Among the results obtained, it is established that a correctly designed collector and under a variable air flow, based on the intensity of the irradiation in specific coordinates and location, can reach efficiencies close to 30% with temperatures close to 60 ° C, being ideal for injecting this fluid into a drying chamber, where the food to be dehydrated is available. For the selection of the volume of the material for energy storage, it is recommended to take the melting temperatures as a base, with a constant flow of air, it is normal that within the system, the temperature varies depending on the position, therefore it is recommending the application of materials with different melting temperatures, which are strategically located within the storage tank.Esta investigación aborda la simulación numérica de un fluido de trabajo, utilizando el software especializado SolidWorks Flow Simulation, analizando el comportamiento de un aire de secado en un colector solar plano con almacenamiento de energía térmica. Además, uno de los principales centros de estudio computacional es la relación entre caudal, temperatura del aire a la salida del colector y eficiencia; Este estudio permite a los investigadores una visión de los principios del diseño de estas tecnologías, especialmente si se enfoca en el secado de alimentos. A continuación, se hace una propuesta sobre los requisitos a tener en cuenta para el dimensionamiento de los colectores en función de los requisitos del producto a secar. Entre los resultados obtenidos, se establece que un colector correctamente diseñado y bajo un flujo de aire variable, en función de la intensidad de la irradiación en coordenadas y ubicación específicas, puede alcanzar eficiencias cercanas al 30% con temperaturas cercanas a los 60 ° C, siendo ideal para inyectar este fluido en una cámara de secado, donde se encuentra disponible el alimento a deshidratar. Para la selección del volumen del material para almacenamiento de energía, se recomienda tomar como base las temperaturas de fusión, con un flujo de aire constante, es normal que, dentro del sistema, la temperatura varíe dependiendo de la posición, por lo tanto, recomienda la aplicación de materiales con diferentes temperaturas de fusión, los cuales se encuentran estratégicamente ubicados dentro del tanque de almacenamiento

Relationship between force signal and superficial electromyographic signals associated to hand movements

The analysis of electromyographic signals is applied both to the diagnosis of pathologies and to the recognition of movement patterns. Variables such as force and speed of movement are factors that affect the characteristics of the signals of surface electromyography (SMEG). The naturalness of the movements of the hand are also associated with strength and speed. Current work assessment 96 records of SEMG -Force). The objective was to obtain a linear model that would allow the relation of the force signal with the tone of the forearm SEMG signals. The work results show models at the determination coefficient R2 - median 0.78. The SEMG signal would contribute to the variation of the strength signal. However, there are appreciable differences in relation to the model in each type of hand movement

Design and construction of a solar tracking system for Linear Fresnel Concentrator

An open circuit solar tracking system has been designed, manufactured, simulated and implemented for a handcrafted prototype of a small scale linear Fresnel reflector with a single axis of motion. The electronic control system is governed by an Arduino UNO R3 board and two main auxiliary systems; a Microstep Driver TB6600 and an RTC DS1302 module. Further, a mechanism was implemented that joins the reflectors to a stepper motor that executes a single movement per sequence, to move the set of reflector mirrors that make up the reflection system of the device. The positioning angles of the reflectors determined by the control algorithm models for solar tracking, allowed to feed the TONATIUH software to evaluate the path of the solar rays through the 3D modeling of the Linear Fresnel reflector on a real scale. The software was designed to follow the path of the sun by means of astronomical equations. In this way, the mirrors of the Linear Fresnel reflector can follow the solar path on a single axis from 7 am to 5 pm, making changes in the position of each element in 15-minute intervals. The percentage of position deviation of the reflectors does not exceed 1% between the location of the full-scale system mirrors and the position angles provided by the control algorithm. The efficiency of the implemented automatic solar tracking system increased by more than 50% compared to the manual tracking system

Prototipo de colector solar lineal Fresnel: Sistema artesanal para la producción de agua caliente y/o vapor de agua

The development of a prototype linear solar collector Type Fresnel, has a purpose the use of direct solar heat radiation for water heating and/or steam production, as an alternative to supply conventional water heating systems or steam generators, which consume energy from fossil fuels. For the development of the system, used the solar radiation of the UTS, located in Bucaramanga, Colombia, is identify the mathematical models to perform the sizing, then materials based on technical specifications and availability in Colombia, in order to perform the assembly and field tests, measuring the ambient and in the collector temperature to determine the efficiency of the model. It should be noted that, the model presented does not have a control system for flow, temperature, pressure and level, it has no solar tracking of any kind; Its movement was done manually with each reflex. Finally, the model does not have a hydraulic system forced, and has a preheater at the entry of the concentration point.El desarrollo de un prototipo de colector solar lineal Tipo Fresnel tiene como finalidad el aprovechamiento de la radiación solar directa en calor para el calentamiento de agua y/o la producción de vapor, como alternativa para suplir los sistemas de calentamiento de agua o generadores de vapor convencionales, que consumen energía proveniente de combustibles fósiles. Para el desarrollo del sistema, se utiliza la radiación solar de las UTS, ubicada en Bucaramanga, Colombia, se identifican los modelos matemáticos para realizar el dimensionamiento, posteriormente se seleccionan materiales basados en especificaciones técnicas y disponibilidad en Colombia, con el fin de realizar el montaje y realizar pruebas en campo, midiendo la temperatura ambiente y en el colector para determinar la eficiencia del modelo.   Cabe resaltar, que el modelo presentado no cuenta con sistema de control de flujo, temperatura, presión y nivel, no tiene seguimiento solar de ningún tipo; el movimiento del mismo se realizó manualmente con cada reflecto. Por último, el modelo no cuenta con sistema hidráulico de tiro forzado, y tiene un precalentador a la entrada del punto de concentración