Simulation of a solar assisted counterflow tunnel dehydrator

A widely used class of vegetable dehydration systems are the “tunnel-and-truck” dehydrators, where the prepared material lies over horizontal trays stored in trucks which move discontinuously in opposite direction of the air flow. This way the driest product is facing the inlet hot and dry air blowed to the system. When product of one truck is ready, is removed from the tunnel leaving space for advance the remaining truck one place forward. This way, a new truck full of wet product can be inserted at the end of the tunnel. The hermal energy required for the process can be supplied by several sources including gas, biomass, solar energy or a combination of them. Solar energy is for free but reaches the Earth with quite a low flux and a strongly fluctuating rate. This imposes the need of special designs and control strategies. This paper presents a study based on simulation models of the dehydrator and the solar thermal system. The dehydrator simulation model is tuned to match experimental data from a particular prototype based on fossil fuel. A solar system simulation model is then applied to the analysis of different design options.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A new Variable Curvature concept for Linear Fresnel Reflectors Solar Concentrating Systems

In a Linear Fresnel Reflector (LFR) solar concentrating system [1] a series of single axis linear reflectors target the sunrays to a longitudinal facedown receiver on top of a fixed structure. The LFR technology offers simplicity and reduced costs when compared with the standard Parabolic Trough technology, but it also suffers from reduced optical performance, especially with large incidence angles. The present preliminary study explores the possibilities of a variable curvature geometrical concept for a LFR that would achieve a more focused solar print over the receptor than in a traditional fixed geometry system.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Simulation and Optimization of a counterflow Tunnel Dehydrator

A widely used class of vegetable dehydration systems are the “tunnel-and-truck” dehydrators , where the prepared material lies over horizontal trays stored in trucks which move discontinuously in opposite direction of the air flow. This way the driest product is facing the inlet hot and dry air blowed to the system. When product of one truck is ready, is removed from the tunnel leaving space for advance the remaining truck one place forward. This way, a new truck full of wet product can be inserted at the end of the tunnel. This paper presents a simulation model of a particular dryer design, including the tunnel, a fan and a heating coil. Additionally there is some energy saving equipment like a recovery heat exchanger and recirculation damper. The simulation model is then applied to the determination of optimal operating conditions.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Energyplus simulation model of a zoning regulation system intgegrated with an unitary ducted air-to-air heat pump

En los edificios se pueden distinguir una variedad de zonas con diferentes patrones de utilización y perfiles de cargas térmicas. Los sistemas de climatización zonificados permiten adaptarse a las diferentes demandas térmicas de cada espacio y no climatizar aquellos que no estén siendo utilizados. Recientemente, con el aumento de la disponibilidad de velocidades de ventilador de los principales fabricantes de unidades de expansión directa de pequeña y mediana potencia para conductos, se han desarrollado sistemas que se basan en lo que se denomina una “pasarela de comunicación”, que permite una mayor integración del sistema de zonas con el equipo de climatización, controlando aspectos tales como el encendido y apagado, modo de funcionamiento, velocidad del ventilador, temperatura de consigna del equipo, etc. Este trabajo presenta el desarrollo de un nuevo modelo computacional que integra estos sistemas en el programa de simulación energética EnergyPlusUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec