Numerical study on heat transfer characteristics of helically coiled grooved elliptical tube heat exchanger

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow Pub Date : 2024-10-29 DOI:10.1016/j.ijheatfluidflow.2024.109622

Jinxing Wu, Shengguang Lu, Chenxu Wang, Jiawen Li

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引用次数: 0

Abstract

Changing the shape of the heat exchanger tube is an effective method to improve the heat transfer performance of the heat exchanger. However, most of the new heat exchange tubes have complex structures and are difficult to manufacture and apply in engineering. In this paper, a novel type of helically coiled grooved elliptical tube heat exchanger (HCGETHE) which is easy to manufacture is proposed. Using methane as the working fluid, the effects of the dimensionless groove diameter (D_g = 0.222, 0.333, 0.444, 0.556, 0.667), the dimensionless groove height (H_g = 0.6, 0.8, 1.0, 1.2) and the ratio of major axis to minor axis (a/b = 1.440, 1.596, 1.778) on the flow and heat transfer characteristics of the shell side are investigated by numerical simulation in the Reynolds number (Re) range of 10000 ∼ 50000 under the condition of constant wall temperature (t_w = 300 K). The results show that when the working fluid flows through the groove of the grooved elliptical tube, backflow occurs and longitudinal vortices are formed in the groove, which improve heat transfer. As the dimensionless groove diameter increases, Nu decreases and f increases. The dimensionless groove height has little effect on Nu, but a significant effect on f. Both Nu and f decrease with the increase of the ratio of major axis to minor axis. Compared with the helically coiled circular tube heat exchanger (HCCTHE), the PEC of the HCGETHE can be increased by up to 59.53 %. The excellent thermal hydraulic performance proves that it has a good application prospect.

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螺旋盘绕槽形椭圆管热交换器传热特性的数值研究

改变热交换管的形状是提高热交换器传热性能的有效方法。然而，大多数新型换热管结构复杂，难以制造和工程应用。本文提出了一种易于制造的新型螺旋盘绕沟槽椭圆管热交换器（HCGETHE）。以甲烷为工作流体，研究了无量纲沟槽直径 (Dg = 0.222, 0.333, 0.444, 0.556, 0.667)、无量纲沟槽高度 (Hg = 0.6, 0.8, 1.0, 1.2) 和主轴与次轴之比 (a/b = 1. 440, 1.596, 1.6) 的影响。440, 1.596, 1.778）对壳侧流动和传热特性的影响，在壁温恒定（tw = 300 K）条件下，在雷诺数（Re）10000 ∼ 50000 范围内进行了数值模拟研究。结果表明，当工作流体流经沟槽式椭圆管的沟槽时，沟槽内会出现回流并形成纵向涡流，从而改善了传热效果。随着无量纲沟槽直径的增大，Nu 减小，f 增大。无量纲沟槽高度对 Nu 的影响很小，但对 f 的影响很大。与螺旋盘绕式圆管热交换器（HCCTHE）相比，HCGETHE 的 PEC 最高可提高 59.53%。出色的热液压性能证明它具有良好的应用前景。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

International Journal of Heat and Fluid Flow 工程技术-工程：机械

CiteScore

5.00

自引率

7.70%

发文量

131

审稿时长

33 days

期刊介绍： The International Journal of Heat and Fluid Flow welcomes high-quality original contributions on experimental, computational, and physical aspects of convective heat transfer and fluid dynamics relevant to engineering or the environment, including multiphase and microscale flows. Papers reporting the application of these disciplines to design and development, with emphasis on new technological fields, are also welcomed. Some of these new fields include microscale electronic and mechanical systems; medical and biological systems; and thermal and flow control in both the internal and external environment.