Performance analysis of cold storage system with nanofiller phase change material

The rapid increase in technological development and the population of the world is ac-companied by increased energy consumptions, leading to higher and higher electricity and heat generation demand. This present research investigates the performance of a cold storage system integrated with low-cost surface functionalized biochar nanoparticle-based phase change material (PCMs) for space cooling and some experimental investigations to enhance the thermal performance for a refrigeration provided with subcooled cold storage unit. The biochar nanoparticle of size < 100 nm were surface functionalized using 3-Aminopropyl)triethoxysilane (APTMS) via aqueous solution method. The subcooled cold storage unit was equipped with an energy storage tank provide with phase change materials (PCM), heat exchanger, and heat pipes. During off-peak period, when the cooling load requirement was lesser than the rated cooling capacity of the system, the excess cold energy and the atmospheric temperature gradient extracted by heat pipes during night were stored in the energy storage tank of subcooled unit with the help of PCM. The energy stored in the PCM of energy storage tank was utilized during peak hours and hence the cooling effect and coefficient of performance (COP) of the system are increased. A decrease in evaporator temperature by 0.1 °C resulted in increase of overall thermal performance of the system by 10% and also minimizes the electrical load by 9% for the period of 337 h. It is observed that the cold storage room with PCM consumes less energy and it has energy saving potential of 9% compared to system without thermal storage unit and it is having an annual energy saving of 691.1 kWh. These performance improved cold storage units could be used in agriculture, fisheries, horticulture, and medical to store the food grains, fruits, vegetables, fish products, and medicines when they need to be preserved at deep freeze for a long span usage.