摘要
为了研究双U型管束模型换热器的流动和传热性能,通过低速高温风洞的模型实验和Fluent-CFD数值计算,得到了换热器的管型和安装角对换热器压降和回热效率的影响规律。结果表明：在相同的双U型管管内气流平均流动速度下,椭圆管换热器的管内流动压降高于圆管换热器的,相对增加幅度在50%~60%之间;对于外部流动,换热器安装角度增大所诱导的外部流动压降显著增加,在换热器30°的安装角下,椭圆形管束的低阻流动型面得以充分体现,其外部流动压降较圆形管束换热器可以降低约50%;随着换热器安装角的增加,换热器回热效率具有明显的提高;相对换热器安装角,换热器管型对回热效率的影响较小,集气管的进气-出气方式对双U型管束换热器的回热效率具有较显著的影响。
In order to investigate the flow and heat transfer performances of double U-shaped-tubes modeled heat exchanger,model experiments were conducted in a low-speed high-temperature wind tunnel and numerical calculations were also conducted using Fluent-CFD software.The effects of tube cross-sectional shape and heat exchanger inclined angle on the pressure drop and recuperator effectiveness were obtained.The results show that the internal pressure drop for the elliptictube heat exchanger is increased by about 50%-60%relative to the circular-tube heat exchanger at the same averaged flow velocity inside the U-shaped tube.For the external flow,the pressure drop is significantly increased as the increase of heat exchanger inclined angle.At inclined angle of 30°,the pressure drop outside the elliptic-tube heat exchanger is significantly lower than that of the circular-tube heat exchanger with approximately 50% decrease.As the heat exchanger inclined angle increases,the recuperator effectiveness is significantly improved.By comparison with the effect of inclined angle,the tube shape has a weak influence on the recuperator effectiveness.The internal flow entering-gathering mode has moderate effect on the recuperator effectiveness of U-shaped-tubes heat exchanger.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2015年第12期3832-3842,共11页
Acta Aeronautica et Astronautica Sinica
关键词
U型管换热器
安装角度
管截面形状
压降
回热效率
U-shaped-tubes heat exchanger
inclined angle
tube cross-sectional shape
pressure drop
recuperator effectiveness
