Thermal study of a transport container

A thermal study of a container for international transport has been carried out in order to determine the temperature distributions. Several experimental conditions such as cooling modes, the onset of defrosting, the existence of cargo inside the container and two varying set points have been evaluated. It was observed that the difference between the temperature inside the container and the set point raised up to 30% of ambient temperature. Moreover, it was observed that the modulated cooling allowed to obtain a more homogeneous refrigeration. However, temperature differences up to 8 °C were observed under on–off control cooling

Performance of ZigBee-based wireless sensor nodes for real-time monitoring of fruits logistics

Progress in fruit logistics requires an increasing number of measurements to be performed in refrigerated chambers and during transport. Wireless sensor networks (WSN) are a promising solution in this field. This paper explores the potential of wireless sensor technology for monitoring fruit storage and transport conditions. It focuses in particular on ZigBee technology with special regard to two different commercial modules (Xbow and Xbee). The main contributions of the paper relate to the analysis of battery life under cooling conditions and the evaluation of the reliability of communications and measurements. Psychrometric equations were used for quick assessment of changes in the absolute water content of air, allowing estimation of future water loss, and detection of condensation on the product

Revisión. Supervisión de transportes intermodales de frutas mediante redes de sensores

Most of the fruit in Europe is transported by road, but the saturation of the major arteries, the increased demand for freight transport, and environmental concerns all indicate there is a need to change this means of transport. A combination of transport modes using universal containers is one of the solutions proposed: this is known as intermodal transport. Tracking the transport of fruit in reefer containers along the supply chain is the means by which product quality can be guaranteed. The integration of emerging information technologies can now provide real-time status updates. This paper reviews the literature and the latest technologies in this area as part of a national project. Particular emphasis is placed on multiplexed digital communication technologies and wireless sensor networks.La calidad de los productos hortofrutícolas adquiere cada día más importancia. En la Unión Europea la mayor parte de la fruta es transportada en camiones, pero la congestión de la principales carreteras, el aumento de la demanda de transporte de mercancías, estimado en un 38% para los próximos 10 años, y los problemas medioambientales que de ello se derivan hacen necesario modificar los procedimientos de transporte. El transporte intermodal puede ser preciso, flexible y más respetuoso con el medio ambiente. Para asegurar la calidad de las frutas es imprescindible realizar un seguimiento y garantizar la trazabilidad de las mismas durante su transporte a lo largo de la cadena de suministro. Un sistema que integre diferentes tecnologías emergentes puede informar en tiempo real del estado de la carga. Este artículo hace una revisión de las últimas publicaciones y tecnologías aparecidas y recoge una propuesta de desarrollo de una red de sensores en un contenedor frigorífico mediante redes inalámbricas de sensores, buses de campo y sensores inteligentes. También se expone una propuesta de especificaciones para un sistema de supervisión multidistribuido de frutas y hortalizas mediante diferentes sensores y dispositivos electrónicos