烧结型涂层管内R410A流动沸腾换热实验研究

Experimental Study on R410A Flow Boiling Heat Transfer Performance Inside a Sintered Porous Coating Tube

文实验研究了制冷剂R410A在长1.3 m,内径4 mm的不锈钢光管和不锈钢烧结多孔涂层管内的流动沸腾换热与压降特性。实验饱和温度为10℃,进出口干度变化范围从0.1至0.9,质量流速变化范围为270~620 kg·m^(-2)·s^(-1)。实验结果表明:在进出口干度固定在0.1和0.9的工况下,烧结涂层管的流动沸腾换热系数随着质量流速的增加而降低,但是光管的1.2至1.5倍;分别固定质量流速为350和450 kg·m^(-2)·s^(-1),进出口干度差值维持在0.2时,烧结涂层管和光管的换热系数均随着干度增加先增加后急剧下降。在此工况下,烧结涂层管的流动沸腾综合强化效果是光管的2.11至3.58倍,并在高干度区域达到最大值。

An experimental investigation of R410A flow boiling inside a 1.3 meter long smooth stainless steel tube and a sintered porous surface coating tube with the same inner diameter of 4 mm was performed.Saturation temperature was maintained at 10℃,inlet and outlet vapor quality of the test section varied from 0.1 to 0.9,and mass flux ranged from 270kg·m^(-2)·s^(-1) to 620 kg·m^(-2)·s^(-1).The experimental results showed that heat transfer coefficient(HTC)of sintered porous surface coating tube decreased with increasing mass flux under a fixed inlet vapor quality of 0.1 and outlet vapor quality of 0.9.But the HTC of sintered porous surface coating tube was still 1.2 to 1.5 times that of the smooth tube under that test condition.When vapor quality difference was maintained at 0.2 along the test tube and mass flux was fixed both at 350 and 450 kg·m^(-2)·s^(-1),the measured HTCs of smooth tube and sintered porous surface coating tube both increased initially with increasing vapor quality and decreased sharply.Under this test condition,the overall heat transfer performance factor(PF)was 2.11 to 3.58 times higher than that of smooth tube,and the PF reached the maximum value at high vapor quality region.