不同构造参数泡沫铜在不同压力下沸腾换热试验研究
发布时间：2019-01-04 07:54
【摘要】：前期的大量试验探究表明泡沫铜可以强化热管的换热性能,但是影响热管换热性能的因素很多,对于泡沫铜强化热管换热的解释大多是宏观解释,本文旨在研究不同构造参数泡沫铜在不同压力下对蒸发段沸腾换热性能的影响,并通过可视化实验台架观测汽泡生成特点,为泡沫铜在换热器中的应用提供指导。本文首先设计并成功搭建了测试不同种类加热表面沸腾换热性能的实验台架,然后制备了光滑表面,不同孔密度泡沫铜,不同厚度泡沫铜和梯度孔泡沫铜,并对泡沫铜进行了表征。试验方面,本文首先做了一组光滑表面和泡沫铜表面的沸腾换热试验,试验结果表明:泡沫铜起始沸腾点所需的过热度比光滑平板低3℃左右,其临界热流密度为136.7W/cm2,是光滑表面的1.2倍。紧接着本文进一步探究了不同构造参数泡沫铜对沸腾换热性能的影响,在试验参数范围内,试验结果表明:(1)泡沫铜的沸腾换热性能随孔密度的增大先增大后减小,(2)泡沫铜的沸腾换热性能随厚度的增加先减小后增大。(3)高孔密度泡沫铜的沸腾换热性能在低热流密度区优势明显,但在高热流密度区,其沸腾换热性能不明显,甚至恶化。相对于低热流密度区,低孔密度泡沫铜在高热流密度区的沸腾换热性能较好,但在整个热流密度区的沸腾换热性能只是略微优于光滑壁面。而梯度孔泡沫铜的沸腾换热性能同时兼备了高孔密度泡沫铜和低孔密度泡沫铜的沸腾换热优点,在整个热流密度区,梯度孔泡沫铜的沸腾换热性能均明显优于光滑壁面。最后本文探究了压力对光滑壁面和不同构造参数泡沫铜沸腾换热性能的影响,在试验参数范围内,试验结果表明:(1)光滑壁面和低孔密度泡沫铜的沸腾换热性能均随压力的提高而增强,但高孔密度泡沫铜在高热流密度区的沸腾换热性能随压力的增大而降低。(2)在不同压力下,不同厚度泡沫铜的沸腾换热系数曲线和光滑壁面相似。(3)相对单一孔密度泡沫铜,梯度孔泡沫铜的沸腾换热性能在不同压力工况下表现的比较稳定。
[Abstract]:A large number of previous experiments show that foam copper can enhance the heat transfer performance of heat pipe, but there are many factors that affect the heat transfer performance of heat pipe. The explanation for heat transfer of foam copper strengthened heat pipe is mostly macro explanation. The purpose of this paper is to study the effect of different structural parameters on the boiling heat transfer of evaporative section under different pressures, and to observe the characteristics of bubble formation by using a visual experimental bench to provide guidance for the application of foamed copper in heat exchangers. In this paper, an experimental bench was designed and successfully constructed to test the boiling heat transfer properties of different kinds of heated surfaces. Then the smooth surface, different pore density foam copper, different thickness foam copper and gradient porous copper foam were prepared. The copper foam was characterized. In the experiment, a group of boiling heat transfer tests on the smooth surface and the copper foam surface are carried out. The experimental results show that the superheat required for the initial boiling point of the copper foam is about 3 鈩，
本文编号：2400003
[Abstract]:A large number of previous experiments show that foam copper can enhance the heat transfer performance of heat pipe, but there are many factors that affect the heat transfer performance of heat pipe. The explanation for heat transfer of foam copper strengthened heat pipe is mostly macro explanation. The purpose of this paper is to study the effect of different structural parameters on the boiling heat transfer of evaporative section under different pressures, and to observe the characteristics of bubble formation by using a visual experimental bench to provide guidance for the application of foamed copper in heat exchangers. In this paper, an experimental bench was designed and successfully constructed to test the boiling heat transfer properties of different kinds of heated surfaces. Then the smooth surface, different pore density foam copper, different thickness foam copper and gradient porous copper foam were prepared. The copper foam was characterized. In the experiment, a group of boiling heat transfer tests on the smooth surface and the copper foam surface are carried out. The experimental results show that the superheat required for the initial boiling point of the copper foam is about 3 鈩，
本文编号：2400003
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