• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2016, Vol. 52 ›› Issue (4): 141-147.doi: 10.3901/JME.2016.04.141

• 可再生能源与工程热物理 • 上一篇    下一篇

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车用小通道平行流换热器传热流动试验与分析

王婷1, 谷波1, 钱程1, 马洪涛2   

  1. 1. 上海交通大学制冷及低温工程研究所 上海 200240;
    2. 上海汽车集团前瞻技术研究部 上海 201805
  • 出版日期:2016-02-15 发布日期:2016-02-15
  • 作者简介:王婷,女,1986年出生,博士研究生。主要研究方向为新能源汽车热管理系统。E-mail:tingwang@sjtu.edu.cn;谷波(通信作者),男,1964年出生,博士,教授,博士研究生导师。主要研究方向为制冷空调系统数字化设计与模型分析、新能源汽车热管理系统。E-mail:gubo@sjtu.edu.cn
  • 基金资助:
    国家科技支撑计划资助项目(2013BAG03B01)

Experimental and Theoretical Analysis for Heat Transfer and Flow Performance of Mini-channel Parallel Flow Heat Exchanger in Vehicle

WANG Ting1, GU Bo1, QIAN Cheng1, MA Hongtao2   

  1. 1. Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240;
    2. Division of Research and Advanced Technology, SAIC Motor Corporation, Shanghai 201805
  • Online:2016-02-15 Published:2016-02-15

摘要: 小通道平行流换热器是燃料电池汽车的主要散热部件。吸收了电堆废热的冷却液(50%乙二醇溶液),流过小通道换热管,由换热器外侧空气冷却。在进液温度、进风温度、冷却液流量以及风速变化的试验工况下,测试了换热器的传热流动性能。引入量纲一参数κ,评估了各工况参数对换热量、阻力影响的强弱。接着,分析液侧努谢尔数Nu和摩阻系数f随雷诺数Re的变化趋势,结果显示:在小通道内(当量直径D=2.685 mm),冷却液从层流到湍流的转淚点Rec=1 750,介于微尺度与常规尺度的临界值之间。在此基础上,通过多元回归法,拟合得到层流和湍流的液侧换热系数,摩阻系数的关联式,以及空气侧阻力fa公式。Nuf的计算值与试验值误差分别在[-7.06%,5.93%]和[-3.95%,4.11%]内,fa的误差在[-2.22%,3.62%]内。基于这些关联式,建立数学模型,可在广泛多变的运行条件下,对换热器的运行性能进行理论预测和评估。

关键词: 变工况, 传热, 平行流换热器, 燃料电池汽车, 小通道

Abstract: The parallel flow heat exchanger with mini-channel is used as the major radiator for fuel cell vehicle (FCV) to dissipate the waste heat, product by fuel cell stack, from the coolant, a glycol-water mixture with volume concentration of 50%, to the air. Under the operating conditions with varied inlet temperatures of air and coolant, coolant volume flow rate and air velocity, the flow and heat transfer characteristics of the heat exchanger is investigated experimentally. Then, a dimensionless parameter, κ, is defined to quantify the influences of the condition parameters on heat transfer and pressure drop. The trends of coolant-side Nusselt number Nu and friction factor f with Reynolds number Re are investigated. It is observed that the flow transition from laminar to turbulent in the mini-channels (D=2.685 mm) of the heat exchanger occurred at the critical Reynolds number , Rec=1 750, which is lower than that in conventional channels and higher than that in micro-channels. Furthermore, the coolant-side correlations are developed in different forms for laminar and turbulent flows to predict the heat transfer coefficients and friction factors. The correlation of air-side friction coefficient fa is also present. Great agreements between the predicted and experimental values are observed. The deviations of Nu and f are within [-7.06%,5.93%] and [-3.95%,4.11%]. And the errors of fa ranged from -2.22% to 3.62%. Base on these correlations, a mathematical model is built to predict performance of FCV radiators under various operating conditions, especially some extreme but significant conditions that could not realize at labs.

Key words: fuel cell vehicle, heat transfer, mini-channel, parallel flow heat exchanger, various conditions

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