摘要
在内径为2 mm的水平不锈钢微通道内对制冷剂R290的沸腾换热特性进行了实验研究。实验工况为:制冷剂质量流率分别为150和330 kg/(m^2·s),测试段热流密度分别为43和76 k W/m^2,制冷剂干度的范围为0.1-0.7,测试段制冷剂的饱和温度为15和26℃,测试段制冷剂的入口干度范围为0-0.65。在相同干度情况下,将制冷剂进入测试段前未进行预热而获得的换热系数与制冷剂进入测试段前进行预热后获得的换热系数进行了对比。研究结果表明:制冷剂进入测试段前进行预热会使换热系数产生偏差,偏差的平均值达到了14.2%;在实验范围内,随着制冷剂在测试段入口以及制冷剂在测试段内干度的上升,预热所引起的换热系数偏差将逐步下降。
In a stainless steel-made micro channel having an inner diameter of 2 mm,an experimental study of the boiling heat exchange characteristics of the refrigerant R 290 was performed. The test conditions were given as follows: the mass flow rates of the refrigerant were 150 and 330 kg / m^2. s respectively,the heat flux densities of the refrigerant in the section tested were 43 and 76 k W / m2 respectively,the dryness of the refrigerant ranged from 0. 1 to 0. 7,the saturation temperature of the refrigerant in the section tested was in a range from 15 ℃ to 26 ℃ and the dryness of the refrigerant at the inlet of the section tested fell in a range from 0 to 0. 65. Under the condition of the dryness being kept identical,a comparison was made of the heat exchange coefficient of the refrigerant obtained when it had not been preheated before entering into the section tested with that obtained when it had been preheated before entering into the section tested. It has been found that to preheat the refrigerant before it enters into the section tested can make its heat exchange coefficient produce a deviation,of which the average value can reach 14. 2%. In the range tested,with an increase of the dryness of the refrigerant at the inlet of the section tested and inside the section mentioned above,the deviation of the heat exchange coefficient arisen from the preheating will go down step by step.
出处
《热能动力工程》
CAS
CSCD
北大核心
2016年第1期42-47,130-131,共6页
Journal of Engineering for Thermal Energy and Power
关键词
预热R290
微通道
沸腾换热系数
干度
preheating
R290
micro channel
boiling heat exchange coefficient
dryness
