正弦型波纹换热管传热特性实验研究

The experimental research on the heat transfer properties of sinusoidal corrugated tubes.

为满足高效换热器的开发研制需要,在波纹管的基础上,改进其表面形状,提出了正弦型波纹换热管,并采用套管式传热实验台,在较低雷诺数(1 800<Re<2 4000)范围内,对3种不同规格的正弦型波纹管进行了汽-水换热单管实验研究.得出正弦型波纹管传热效果明显高于直管,在相同的雷诺数下,管内对流传热系数是光管的2.5～3.5倍;在当量直径相等的前提下,周期越长,幅值越大,其强化传热效果反而不好;在高普朗特数范围内,普朗特数对努赛尔数的影响较大.由实验数据回归出管内对流换热系数准则方程,为正弦型波纹管在石油化工领域的应用提供了参考.

The sinusoidal corrugated tubes, manufactured based on corrugated tubes, were presented for developing high efficiency heat exchangers. By means of vapor-water heat-transfer experiment under low Reynolds numbers (1800< Re< 24 000), the heat transfer properties of 3 sinusoidal corrugated tubes of different sizes were investigated and compared to straight tubes respectively. The result shows that, the heat transfer coefficients increase with the Reynolds numbers and the sinusoidal corrugated tubes can transfer heat more effectively than the straight tubes, and with the same Reynolds number, the heat transfer coefficients of sine-corrugated tubes are 2.5~3.5 times as much as that of straight tubes; under the condition of the same equivalent diameter, the heat transfer coefficients decrease with long pitch and deep peak. In addition, when the Prandtl numbers are in a high range, they are influential to the Nusselt numbers. At last, the criterion equation for heat transfer laws of heat exchanger tubes was derived based on the experiment data.