Choi Hundong, Jeong Subin, Lee Kwon-Yeong
Department of Mechanical and Contol Engineering, Handong Global University, 558 Handong-Ro, Pohang-si 37554, Korea.
Nanomaterials (Basel). 2022 Mar 21;12(6):1033. doi: 10.3390/nano12061033.
This study investigates the quenching behavior and heat transfer characteristics of a copper cube immersed in cellulose nanofiber (CNF) solutions. The heat transfer performance of CNF solutions during boiling has been examined in several studies, but the quenching behavior of CNF solutions, which is an important heat transfer method, has not been evaluated. In this study, four copper cubes with the same dimensions and four different quenchants (deionized water and 0.01%, 0.1% and 0.5% CNF solutions) were prepared. A copper cube heated to greater than 600 °C was submerged three times in the quenchant. This was repeated with different copper cubes in each of the quenchants. The time at which the heated copper cube convectively transferred heat to the surroundings was recorded. The cooling time was shortest when the cube was immersed in a 0.5% CNF solution for the first time. The average cooling time for quenching in the 0.5% CNF solution was 30.3% shorter than that in DI water. In this study, film boiling during quenching was thoroughly observed and analyzed to explain the cause of enhancement in heat transfer efficiency.
本研究考察了浸没在纤维素纳米纤维（CNF）溶液中的铜立方体的淬火行为和传热特性。多项研究已对CNF溶液在沸腾过程中的传热性能进行了考察，但作为一种重要传热方式的CNF溶液的淬火行为尚未得到评估。在本研究中，制备了四个尺寸相同的铜立方体以及四种不同的淬火介质（去离子水和0.01%、0.1%和0.5%的CNF溶液）。将加热至600℃以上的铜立方体在淬火介质中浸没三次。对每种淬火介质中的不同铜立方体重复此操作。记录加热后的铜立方体将热量对流传递至周围环境的时间。当立方体首次浸入0.5%的CNF溶液中时，冷却时间最短。在0.5%的CNF溶液中淬火的平均冷却时间比在去离子水中短30.3%。在本研究中，对淬火过程中的膜态沸腾进行了全面观察和分析，以解释传热效率提高的原因。
