CFD-based thermal flow field analysis and structural optimization in the drying chamber of a yellow ginger heat pump dryer

doi:10.13733/j.jcam.issn.2095-5553.2025.03.020

Abstract

Abstract:

The uneven distribution of thermal flow fields in yellow ginger heat pump dryers during the drying process leads to inconsistent material quality and extended drying times due to localized low wind speed and temperature. These factors result in low drying efficiency. To enhance the uniformity of the dried material quality and improve the drying efficiency, the thermal flow field distribution of the ginger heat pump dryer needs to be optimized. Using SolidWorks for modeling, the basic assumptions are proposed. Numerical simulations of the thermal flow field inside the drying chamber of the heat pump dryer are conducted with the help of computational fluid dynamics （CFD Fluent） simulation software to analyze the non-uniformity in the distribution of the thermal flow fields and to improve the material quality and drying efficiency by modifying the internal structure. The results show that the initial equipment has localized high temperatures and high wind speeds, with significant non-uniformity in the material distribution within the chamber. By optimizing the air inlet and outlet into a rectangular air inlet and a gird-shaped outlet, the uniformity of the thermal flow fields is significantly enhanced, with the speed and temperature non-uniformity coefficients reduced from 66.5% and 61.7% to 40.5% and 39.1%, respectively. In a test with the same wind speed and temperature, the quality score of the dried material improved from 6.16 in the initial setup to 8.32 after optimization.

Key words: heat pump dryer, computational fluid dynamics, thermal flow fields, non-uniformity coefficient

摘要：

黄姜热泵干燥机在干燥过程中存在热流场分布不均匀等问题，使得干燥后的物料品质不均匀，同时局部风速和温度过低使每批次的干燥时间增加，导致干燥效率低。为提高干燥物料品质均匀性和干燥效率，需要改善黄姜热泵干燥机的热流场均匀性。通过SolidWorks建模，提出基本假设，借助计算流体力学（CFD Fluent）仿真软件对热泵干燥机干燥室内热流场进行数值模拟，分析热流场分布不均匀问题，并通过改进干燥机内部结构来提高干燥物料品质和干燥效率。结果表明：初始设备的干燥室内部热流场存在局部高温高风速等情况，物料区域上下分布不均匀性较大，通过将进风口和出风口优化成矩形进风口和格栅形出风口后，干燥室热流场明显得到改善，均匀性大幅度提高，速度不均匀系数和温度不均匀系数分别从66.5%、61.7%降低到40.5%、39.1%。取相同风速和温度的一组试验，品质得分由初始设备的6.16提高到优化改善后的8.32。

关键词: 热泵干燥机, 计算流体力学, 热流场, 不均匀系数

CLC Number:

S229.3

Kang Hongbin, , , Chen Siqin, , Hu Shuxu, , Wang Lei, , Xiao Bo, Wang Benyi. CFD-based thermal flow field analysis and structural optimization in the drying chamber of a yellow ginger heat pump dryer[J]. Journal of Chinese Agricultural Mechanization, 2025, 46(3): 133-138.

康宏彬, 陈锶钦, 胡书旭, 王雷, 肖波, 王本义. 基于CFD的黄姜热泵干燥机干燥室热流场分析及结构优化[J]. 中国农机化学报, 2025, 46(3): 133-138.

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