چكيده به لاتين
The use of electric and hybrid vehicles is considered to be one of the effective ways to reduce the risks and effects of pollutants and oil crises. In this regard, the discussion of the battery, its capacity and thermal management in this major threat has usually been and is an obstacle to the expansion of the design and use of electric vehicles. Lithium-ion batteries Valentine-polymer are considered to be the best types of batteries for automotive applications. However, the destructive effects of increasing and decreasing temperature differences in cells, including reduced efficiency, reduced capacity, and increased chain temperature, have been extensively discussed and proven. Various models are provided to simulate the production and transfer of heat in these batteries, including electric-chemical models, equivalent circuit and electric-chemical coupling with electric-thermal models. In order to homogenize and keep the temperature of the battery pack cells constant, several thermal management methods have been developed and used. These methods can be divided into three general categories: active cooling, inactive cooling, and hybrid cooling. In the active method, energy is used for cooling, such as water-cooling systems and ethylene glycol, which can be seen in high-performance cars. Inactive cooling is done without energy consumption, such as the use of materials with high thermal storage capacity, such as phase change materials, the disadvantage of which is the lack of controllability of cooling and low efficiency in some situations. Combined methods, meanwhile, try to produce the optimal system for greater efficiency by taking advantage of the advantages and disadvantages of both methods. This study also examines the cooling method with refrigerant-air and phase change materials in several cases by making a test device. In this study, the effect of ambient temperature on very hot weather conditions, the use of fin and phase change materials were tested. Heat elements are used to simulate heat, and ceramic is used as the core of the element to compensate for the thermal capacity of the lithium-ion battery. In summary, the use of refrigeration cycles to manage battery heat is critical when the ambient temperature is between 40 and 45 degrees Celsius. On the other hand, this system alone creates significant temperature gradient in the batteries and eliminates their thermal uniformity, which in turn reduces the capacity and battery life, but this non-uniformity can be eliminated by using phase change materials. Finally, by examining the types of fins, the type of helix was more effective than the radial and longitudinal types in the heat exchange of the phase change materials as well as the batteries.
