硅酸盐学报, 2023, 51 (10): 2644, 网络出版: 2023-11-26
纳米SiC改性Na2SO4·10H2O-Na2HPO4·12H2O共晶盐纳米相变流体制备及其性能影响
Preparation and Performance of Na2SO4·10H2O-Na2HPO4·12H2O Eutectic Hydrated Salt Phase Change Nanofluids Modified by Nano-SiC
纳米碳化硅 表面改性 共晶盐 纳米相变流体 nano silicon carbide surface modified eutectic hydrated salt phase change nanofluids
摘要
为提升水合盐相变材料的性能,以Na2SO4·10H2O-Na2HPO4·12H2O共晶盐(EHS)作为基体材料,采用HF/HNO3刻蚀法制备亲水性纳米碳化硅(Nano-SiC),并以Na2SiO3·9H2O和改性Nano-SiC作为复合添加剂制备复合纳米相变流体材料(Nano-SiC EHS PCMs)。结果表明:改性后Nano-SiC在EHS PCMS中具有良好的分散稳定性,同时Na2SiO3·9H2O和Nano-SiC 协同作用下使得EHS PCMs过冷度降低到0.3 ℃,无相分层现象。Nano-SiC EHS PCMs在固液相变体系中热导率均有提升,同时添加0.2% (质量分数)Nano-SiC后EHS PCMS储能时间缩短了21.8%。添加质量分数为0.15% Nano-SiC的EHS PCMs熔融焓和结晶焓分别为267.3 J/g和231.4 J/g,经过1 000次冷热循环后焓值变化甚小,该体系具有良好的循环稳定性。
Abstract
It is important to enhance their performance of supercooling and low thermal conductivity in hydrate salt phase change materials. A hydrophilic silicon carbide (nano-SiC) was prepared via treating SiC nanoparticles in HF/HNO3 with Na2SO4·10H2O-Na2HPO4·12H2O eutectic hydrated salt as basic materials, and the phase change nanofluids materials (nano-SiC EHS PCMs) with Na2SiO3·9H2O and nano-SiC were composited. The results show that the modified nano-SiC can be dispersed in EHS PCMs. The synergistic effect of Na2SiO3·9H2O and nano-SiC can reduce the supercooling degree to 0.3 ℃ without the phase separation. The thermal conductivity of nano-SiC EHS PCMs enhances both in solid and liquid. The energy storage time of EHS PCMS with 0.2% (in mass) nano-SiC is decreased by 21.8%. The enthalpy of melting and crystallization of EHS PCMs with 0.15% nano-SiC is 267.3 J/g and 231.4 J/g, respectively. The enthalpy of nano-SiC EHS PCMs is stable after 1 000 heating and cooling cycles, indicating that nano-SiC EHS PCMs have a great thermal cyclic stability.
孙增宝, 柳馨, 铁生年. 纳米SiC改性Na2SO4·10H2O-Na2HPO4·12H2O共晶盐纳米相变流体制备及其性能影响[J]. 硅酸盐学报, 2023, 51(10): 2644. SUN Zengbao, LIU Xin, TIE Shengnian. Preparation and Performance of Na2SO4·10H2O-Na2HPO4·12H2O Eutectic Hydrated Salt Phase Change Nanofluids Modified by Nano-SiC[J]. Journal of the Chinese Ceramic Society, 2023, 51(10): 2644.