摘要
以热力学第二定律为基础讨论了波纹翅片管换热器的不可逆损失 ,重点考察了换热器的几何尺寸对换热过程中不可逆损失的影响 .不可逆损失用温差传热和流动摩阻所引起的熵产之和来表征 .计算结果表明 :换热器单位换热量的熵产随翅片波纹角的增加略有增加 ,但几乎不受翅片间隔的影响 .当管的排数增加时 ,单位换热量的熵产先减后增 ,在特定管排数处取得极小值 .单位换热量的熵产随空气流速的增加而单调增加 .
This paper deals with a wavy finned tube heat exchanger working as an air-cooling condenser. The effects of the exchanger geometric dimensions on the irreversible loss in the exchanger are discussed based on the second law of thermodynamics. The irreversible loss is characterized by the sum of the entropy generation caused by the temperature difference between the airflow and exchanger surface and that caused by the air friction pressure drop. The calculation results show that the entropy generation per unit heat transfer rate (AS/Q) increases gently with the increasing corrugation angle of the fin but is nearly independent of the fin pitch. When the number of tube rows (N) is increased, the AS/Q initially decreases, but turns to increase after reaching a minimum at a certain N. The AS/Q increases monotonously as the air velocity increases.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2003年第11期1513-1517,共5页
CIESC Journal
基金
国家重点基础研究发展规划项目(No G2 0 0 0 0 2 63 0 1)~~
关键词
换热器
波纹翅片
熵分析
不可逆损失
Cooling systems
Entropy
Fins (heat exchange)
Heat losses
Heat transfer
Thermodynamic properties
