陶瓷基复合储热材料的制备与动态高温热流作用下的性能研究OA

Under long-term,dynamic high-temperature heat flow charging and discharging conditions,the leakage amount of shape-stabilized composite phase change materials(CPCMs)is much greater than that under stable conditions.Herein,the preparation process and unit structure of a ceramic-based CPCM were optimized to enhance their thermal cycling stability under dynamic high-temperature heat flow.Hollow stainless-steel balls were used to encapsulate the spherical skin-flesh structure of the CPCM,and carbon powder was introduced between the two components to reduce thermal resistance.A continuous 12-h experiment at 400℃was designed and conducted to compare the leakage behavior of different CPCMs.The optimized ceramic-based CPCM exhibited a mass attenuation rate of only 0.73%,while its effective heat storage capacity was reduced by just 0.68%.In addition,it demonstrated an excellent heat transfer rate.These improvements are attributable to the strong adsorption force of the porous ceramic framework,enhanced heat transfer,and the uniform heating provided by the spherical stainless-steel shell.Moreover,a series of experiments was conducted to evaluate the heat transfer performance of the new CPCM in a packed bed latent thermal energy storage system.The complete charging and discharging times were 27 min and 14 min,respectively.The overall thermal efficiency reached 71.4%,and the exergy efficiency was 64.8%,both of which were much higher than those of the diatomite-based CPCM and directly stainless-steel-encapsulated molten salt.These results provide important guidance and references for the practical application of shape-stabilized CPCMs in fields such as waste heat recovery and photothermal utilization.