ON THE BEHAVIOR OF PHASE CHANGE MATERIALS WITH SUDDEN CHANGE OR PERIODIC OSCILLATION IN THE EXTERNAL TEMPERATURE CONDITIONS

Abstract

ABSTRACT The use of organic phase change materials (PCM – O) for thermal conditioning of agricultural products is proposed here. In particular, the capacity of PCM – O for controlling temperature is studied for sudden variation of external temperature conditions. Two different situations (a thermal jump and a periodic oscillation) using a simple and appropriate simulation model are presented. This model allows the evaluation of the temperature distribution and the interface position as a time function in the PCM. The obtained results show that the use of these substances is appropriate to control the required temperature of the agricultural products. Besides, these substances can reduce the cost during the transport of these products. PRACTICAL APPLICATIONS Several agricultural products, such as fruits and vegetables, need adequate conditions of storage and transport. It is necessary to maintain certain conditions of temperature and controlled atmosphere. Each product needs different temperature conditions. Temperatures must be maintained within a range that would guarantee the preservation of a product's organoleptic characteristics during a certain period. Thus, the use of phase change materials (PCM) for these purposes has been proposed, to reduce the energy consumption and, accordingly, the cost of transportation. Agricultural products can suffer thermal stress when they are exposed to extreme conditions, such as a sudden change or an oscillation in the external temperature. PCM can control and attenuate the influence of the external temperature on the agricultural product.