立式花瓣管外空气螺旋流动传热及流阻性能研究  

Heat Transfer and Fluid Flow Performance of Air Flowing through the Helical Channel outside a Vertical Petal-shaped Fin Tube

作　　者：高学农[1] 黄玉优[1] 陈姝[2] 

机构地区：[1]华南理工大学传热强化与过程节能教育部重点实验室,广东广州510640 [2]仲恺农业技术学院机电工程系,广东广州510225

出　　处：《高校化学工程学报》2006年第4期653-656,共4页Journal of Chemical Engineering of Chinese Universities

基　　金：973项目(G20000263);国家自然科学基金(20306005);广东省科技攻关项目(2004B10201008)。

摘　　要：螺旋隔板花瓣管换热器具有优异的换热性能，但由于目前基础数据不足，螺旋隔板花瓣管抉热器的应用还未能普及，研究花瓣管几何结构参数对换热过程的影响规律及传热机理，可为该类型换热器提供设计依据。今在实验中通过采用空气在缠绕金属螺旋片的换热管外套管环隙中的换热来模拟螺旋隔板换热器的换热过程，研究了空气在缠绕螺旋片的立式光滑管和不同翅片高度与间距的立式花瓣管外螺旋流动的传热与流阻性能，分析了花瓣管翅片高度和间距等主要几何结构参数以及管外空气流速对传热与流阻性能的影响。实验结果表明：翅片高1．5mm、间距1．0mm的花瓣管具有最佳的传热性能，花瓣管外空气对流换热系数是光滑管的1．48-3．24倍；在实验范围内，随着空气流速的增加，花瓣管外空气对流抉热系数与流动阻力也相应增加，但综合换热性能下降并在空气流速为36．0-42．2m．s^-1时达到最低值。Although it is known that the helical-baffled heat exchanger with petal-shaped fin tubes has excellent heat transfer performance, the shortage of performance data used for design causes it has not been widely used yet in industries. Experimental studies on the influences of the helical-baffle and petal-shaped fin tube geometrical parameters on the heat transfer and fluid flow resistance performances may offer some basic data for the design of the helical-baffled heat exchanger with petal-shaped fin tubes. For simulating the heat transfer and fluid flow in the shell side of the helical-baffled heat exchanger, a sheet metal was twisted on the petal-shaped fin tube to force the air flow helically in the channel between the heat transfer tube and adiabatic shell. The heat transfer and fluid flow resistance performances of the air flowing helically outside of a smooth tube and five petal-shaped fin tubes with different fin geometrical parameters were studied, respectively. The influences of the air velocity and geometrical parameters of the petal-shaped fin tube on the heat transfer and fluid flow resistance performances were also discussed. The experimental results show that the convective heat transfer coefficients between the air and petal-shaped fin tube are about 1.48-3.24 times of that between the air and smooth tube, and that the petal-shaped fin tube with l.Smm fin height and 1.0mm fin spacing has the best heat transfer performance. In the experimental range, as the fluid velocity increases, the convective heat transfer coefficient h0 and fluid flow resistance of air Ap increase too, but the combining heat exchanging performance h0/△p decreases and it will reach a minimum value at the air velocity of 36.00-42.2m.s^-1.

关 键 词：传热强化 螺旋隔板 花瓣管 空气 

分 类 号：TK124[动力工程及工程热物理—工程热物理] TQ021.3[动力工程及工程热物理—热能工程]