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为了将纳米颗粒的强化传热传质作用应用于氨水吸收制冷中,提出了在氨水溶液中添加Fe_2O_3纳米颗粒和表面活性剂十二烷基苯磺酸纳(SDBS)的纳米流体的配制方法,并通过沉降试验和吸光度测试方法对其稳定性进行了实验研究。研究了活性剂质量分数、超声分散时间和氨水浓度对稳定性的影响,确定了Fe_2O_(3-)氨水纳米流体分散的最佳工艺为:SDBS质量分数为0.8%,超声时间为30min,基液为25%的氨水。最后根据双电层原理分析了活性剂质量分数对悬浮液的稳定性的影响。结果表明在悬浮液的稳定性条件下,活性剂存在最佳质量分数,此结论与实验结果一致。
In order to apply the enhanced heat and mass transfer of nano-particles to ammonia absorption refrigeration, a method for preparing nanofluid with Fe 2 O 3 nanoparticles and surfactant SDBS (sodium dodecyl benzene sulfonate) in ammonia solution was proposed. And its stability was experimentally studied by sedimentation test and absorbance test. The effects of active agent concentration, ultrasonic dispersion time and ammonia concentration on the stability were studied. The optimum conditions for the dispersion of Fe_2O_ (3-) aqueous ammonia nanofluids were determined as follows: the mass fraction of SDBS was 0.8%, the ultrasonic time was 30 min, 25% ammonia. Finally, according to the principle of electric double layer, the effect of active agent mass fraction on the stability of suspension was analyzed. The results show that under the condition of the stability of the suspension, the active agent has the best mass fraction, which is consistent with the experimental results.