چكيده به لاتين
The use of phase change materials (PCM) in the walls of refrigerated containers has been proposed as an innovative method to reduce energy consumption during transportation. PCMs keep the internal temperature of the container in a stable range by absorbing and releasing thermal energy during phase change. This feature leads to reducing temperature fluctuations, reducing environmental pollution, maintaining optimal temperature and increasing the useful life of food products. In addition to improving thermal efficiency, the use of PCMs reduces the energy consumption of cooling systems and optimizes operating costs. Also, this technology helps to reduce food waste and maintain the quality of temperature-sensitive products, such as fruits, vegetables, meat and dairy products. As a result, the use of PCM in the walls of refrigerated containers is considered an effective and sustainable solution for improving the transportation of food products. For this purpose, three types of PCM named dodecane, paraffin and ice have been used in the wall of ISO20 refrigerated container. In this research, the train carrying the refrigerated container under different temperature conditions, including the climate of Sharjah, Sardsir, and the desert, which is encountered on the way from Imam Khomeini Port (RA) to Tehran, and with three different types of products, frozen fish meat, Oranges and apples were investigated. To start the work, thermodynamic equations were used for the container without PCM and with PCM assuming that the refrigeration system is off, and the results were compared with each other, and the ideal temperature retention time of products with PCM was calculated. Then, by changing the speed of the train and keeping the phase change material constant, the effect of speed on the melting time of PCM was investigated, and in the last step, using numerical analysis with the help of Abaqus software, the numerical analysis of the container equipped with PCMs by applying the environmental conditions of the mentioned railway track Taking into account the sun's radiation, temperature changes and the speed of the train, the amount of temperature distribution in different points of the container during the journey was obtained and compared with the results of thermodynamic calculations. The results indicate that if PCM is used, the products inside the refrigerated container, such as frozen fish, can travel without the need for a refrigeration system for up to 2.5 hours after movement without temperature threat. Also, this has led to the reduction of energy losses and fuel consumption.
