Development of a new high performance heat exchanger using a surfactant water solution

使用表面活性剂水溶液开发新型高性能热交换器

• 批准号: 12650199
• 负责人: KUMADA Masaya
• 金额: $ 2.3万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650199/
• 关键词: Tom's effect; Drag redaction; Heat transfer enhancement; Turbulence promoter; Performance evaluation based on a constant pump power; Surfactant solution; Heat exchanger; 三角リブ

An experiment was conducted to investigate the drag-reduction and the heat transfer characteristics in a surfactant water solution flow. It was confirmed that the percentage of the drag-reduction was more than 70 % and simultaneously, the heat transfer coefficient was reduced at the same rate. In order to promote the heat transfer for the surfactant water solution flow, an enhancement method using a triangular rib was proposed. Comparing with the case without rib, it was found that the dependence of the drag-reduction and the heat transfer characteristics on Re and C was similar, but the critical Reynolds number at which the drag reduction reaches a maximum was smaller. Further, by the performance evaluation based on a constant pump power, it was verified that the compound method by the surfactant and the triangular rib is effective to improve the performance of heat exchangers.To investigate the temperature dependence of the Tom's effect, measurements of velocity and temperature profi … More les in a two-dimensional channel were done as parameters of inlet velocity, temperature of the working fluid and wall surface. It was found that the velocity profiles vary clearly with temperature of the wall surface as comparing with the temperature profiles. However, the Tom's effect does not stop working, when the temperature in the thermal boundary layer is that it stops working. The Tom's effect is very sensitive for the temperature, on the other hand it is suggested that the varying process is complex.The rate of drag reduction of a single pipe with, roughness surface using the air-conditioner was measured, because the triangle rib as mentioned above is too expensive to apply to a real-product heat exchanger. It was found that the appearance of the Toms effect is observed as similar with previous results. As concerning the heat exchanger, the rate of drag reduction of the radiator on the market with using roughness pipe is measured. It is decreased by the header part of the radiator, however the roughness pipe is still useful for the drag reduction. Less

对表面活性剂水溶液流动的减阻与传热特性进行了实验研究。实验结果表明，在相同的减阻率下，减阻率可达70%以上，同时传热系数也以相同的速率降低。为了强化表面活性剂水溶液流动的传热，提出了一种三角形肋强化方法。与无肋情况相比，肋的减阻效果和换热特性与Re和C的关系相似，但减阻达到最大值的临界雷诺数较小。在此基础上，通过恒泵功率下的性能评价，验证了表面活性剂与三角形肋片复合的方法对提高换热器性能的有效性。 ...更多信息 以进口速度、工质温度和壁面为参数，对二维通道进行了大涡模拟。结果表明，与温度分布相比，速度分布随壁面温度变化明显。然而，汤姆效应并不停止工作，当热边界层中的温度是，它停止工作。汤姆效应对温度变化非常敏感，但其变化过程复杂.由于三角形肋片价格昂贵，不能应用于实际产品的换热器，因此，利用空调器对粗糙表面单管的减阻率进行了测量.结果发现，汤姆斯效应的外观观察到与以前的结果相似。在换热器方面，对市场上的散热器采用粗糙管后的减阻率进行了测量。散热器的集管部分使阻力减小，但是粗糙度管仍然对减阻有用。少