【摘要】：前期的大量試驗(yàn)探究表明泡沫銅可以強(qiáng)化熱管的換熱性能,但是影響熱管換熱性能的因素很多,對(duì)于泡沫銅強(qiáng)化熱管換熱的解釋大多是宏觀解釋,本文旨在研究不同構(gòu)造參數(shù)泡沫銅在不同壓力下對(duì)蒸發(fā)段沸騰換熱性能的影響,并通過可視化實(shí)驗(yàn)臺(tái)架觀測(cè)汽泡生成特點(diǎn),為泡沫銅在換熱器中的應(yīng)用提供指導(dǎo)。本文首先設(shè)計(jì)并成功搭建了測(cè)試不同種類加熱表面沸騰換熱性能的實(shí)驗(yàn)臺(tái)架,然后制備了光滑表面,不同孔密度泡沫銅,不同厚度泡沫銅和梯度孔泡沫銅,并對(duì)泡沫銅進(jìn)行了表征。試驗(yàn)方面,本文首先做了一組光滑表面和泡沫銅表面的沸騰換熱試驗(yàn),試驗(yàn)結(jié)果表明:泡沫銅起始沸騰點(diǎn)所需的過熱度比光滑平板低3℃左右,其臨界熱流密度為136.7W/cm2,是光滑表面的1.2倍。緊接著本文進(jìn)一步探究了不同構(gòu)造參數(shù)泡沫銅對(duì)沸騰換熱性能的影響,在試驗(yàn)參數(shù)范圍內(nèi),試驗(yàn)結(jié)果表明:(1)泡沫銅的沸騰換熱性能隨孔密度的增大先增大后減小,(2)泡沫銅的沸騰換熱性能隨厚度的增加先減小后增大。(3)高孔密度泡沫銅的沸騰換熱性能在低熱流密度區(qū)優(yōu)勢(shì)明顯,但在高熱流密度區(qū),其沸騰換熱性能不明顯,甚至惡化。相對(duì)于低熱流密度區(qū),低孔密度泡沫銅在高熱流密度區(qū)的沸騰換熱性能較好,但在整個(gè)熱流密度區(qū)的沸騰換熱性能只是略微優(yōu)于光滑壁面。而梯度孔泡沫銅的沸騰換熱性能同時(shí)兼?zhèn)淞烁呖酌芏扰菽~和低孔密度泡沫銅的沸騰換熱優(yōu)點(diǎn),在整個(gè)熱流密度區(qū),梯度孔泡沫銅的沸騰換熱性能均明顯優(yōu)于光滑壁面。最后本文探究了壓力對(duì)光滑壁面和不同構(gòu)造參數(shù)泡沫銅沸騰換熱性能的影響,在試驗(yàn)參數(shù)范圍內(nèi),試驗(yàn)結(jié)果表明:(1)光滑壁面和低孔密度泡沫銅的沸騰換熱性能均隨壓力的提高而增強(qiáng),但高孔密度泡沫銅在高熱流密度區(qū)的沸騰換熱性能隨壓力的增大而降低。(2)在不同壓力下,不同厚度泡沫銅的沸騰換熱系數(shù)曲線和光滑壁面相似。(3)相對(duì)單一孔密度泡沫銅,梯度孔泡沫銅的沸騰換熱性能在不同壓力工況下表現(xiàn)的比較穩(wěn)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，

本文編號(hào)：2400003