Energy Storage Science and Technology ›› 2023, Vol. 12 ›› Issue (2): 349-356.doi: 10.19799/j.cnki.2095-4239.2022.0531

• Energy Storage Materials and Devices • Previous Articles     Next Articles

Phase change characteristics and proportion adjustment of fatty acid binary energy storage materials

Jinmei DONG1,2(), Qiyuan LIU1,2,3, Fang WU1,2, Lirui JIA4, Jing WEN1,2, Chenggong CHANG1,2, Weixin ZHENG1,2, Xueying XIAO1,2()   

  1. 1.Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lake, Chinese Academy of Sciences
    2.Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Xining 810008, Qinghai, China
    3.University of Chinese Academy of Science, Beijing 100049, China
    4.Qinghai Agricultural Product Quality and Safety Inspection Center, Xining 810000, Qinghai, China
  • Received:2022-09-19 Revised:2022-10-23 Online:2023-02-05 Published:2023-02-24
  • Contact: Xueying XIAO E-mail:dongda839@isl.ac.cn;xxy@isl.ac.cn

Abstract:

Aiming to solve the problem that the phase change temperature of a single fatty acid is fixed and difficulty in matching the actual demand, we propose taking five common fatty acids—decanoic acid (CA), lauric acid (LA), tetradecanoic acid (MA), palmitic acid (PA) and stearic acid (SA)—as phase change materials and compound them in pairs. The lowest melting point and theoretical mass ratio of 10 binary composite systems are calculated using the low melting theory. A binary low eutectic composite system was prepared by melt blending, and the mass ratio was adjusted by 3%—6% above and below its low eutectic point. The phase change characteristics of the binary low eutectic composite system were measured by DSC. Experimental results show that the theoretical phase change temperature range of the binary low eutectic system is 21.58—53.90 ℃, and the theoretical phase change latent heat range is 157.64—191.85 J/g. Compared with the thermal properties of the five single fatty acids, the phase change temperature is reduced by about 10—15 ℃, and the phase change latent heat value has no obvious change. The phase change temperatures of the 10 binary low eutectic systems range from 19.94 to 56.49 ℃, with a deviation of 1.93%—14.72% from the theoretical phase change temperature. The phase change latent heat range is 125.78—181.45 J/g and the deviation from the theoretical phase change latent heat range is 0.18%—19.86%. The theoretical phase change temperature range of CA binary systems is 21.58—30.11 ℃, which is applicable to the field of building energy conservation. The theoretical phase change temperature range of LA binary systems is 35.87—41.15 ℃, which is suitable for the thermal management of electronic devices or temperature-regulating textiles. The theoretical phase change temperature range of MA and PA binary systems is 46.05—53.9 ℃, which is suitable for the temperature control field of mass concrete. By adjusting the ratio near the eutectic point, we found that the deviation between the optimal ratio and the theoretical calculation of the eutectic ratio was within 4%, verifying the accuracy and feasibility of the theoretical calculation. The results of this study can provide a technical reference for the specific application range of fatty acid binary composite phase change materials.

Key words: organic phase change materials, fatty acids, binary low confluence, phase change characteristics

CLC Number: