模擬電動車鋰離子電池模組佈置的熱流特性

The Simulation of Thermofluid Characteristics in the Layout of Li-ion Battery Module for Electric Vehicle

宋秉儒(Bing-Zu Song)

指導教授 ： 吳俊諆

國立中央大學/工學院/機械工程學系/碩士(2011年)

摘要

本文利用FLUENT 軟體進行電動車鋰離子電池模組的三維熱流分析，目的在建立一合理的電池模組的熱管理模型來預測電池模組的熱流性能。分析類型共有三種電池模組（簡化型、圓柱形及長條形電池芯的完整模組），建立簡化型電池模組目的為驗證紊流模型及電化學模型。另外，完整電池模組採用圓柱形或長條形鋰離子電池，以交錯方
式排列於模組內部形成散熱之流道，並比較兩種電池類型對於模組散熱效率之影響。
本文先應用三種紊流模型進行模擬並和模組的入/出口壓差量測值做比較，預測顯示RNG k-ε模式較準確，數值解與實驗壓差的最大誤差值僅8%。接著以不同入口風速之情況進行電池溫度之驗證，模擬顯示與實驗溫差最大約1oC。最後探討圓柱形及長條形電池模組流場及溫度場之特性。整體而言，圓柱形電池模組的流場為非對稱分佈。當入口速度增加到2 m/s 時，圓柱形電池模組內流體通過第2 排電池後，流向會往左上偏移，同時也改變接觸點及分離點之角度。相對來講，長條形電池模組流場較平順且阻風面積較小，它的散熱效率較圓柱形電池模組佳。

關鍵字

數值模擬 ； 電動車 ； 鋰離子電池 ； 電化學模型 ； 熱傳

並列摘要

This paper presents the 3-D numerical simulation of electric vehicle lithium-ion battery module by using computational software FLUENT. The purpose is to develop a reasonable thermal management model for prediction of thermal flow performance of battery module. Three simulation cases are conducted (simplified type, cylindrical and strip cell layout of a complete battery module), and the simplified battery module is designed for validating turbulence model and electrochemical model. In additional, the complete battery module consists of either cylindrical and strip Li-ion cell, and arranged in a staggered layout to yield cooling flow channel. Comparison of heat dissipation of battery module between these two
cells is also made.
Three turbulence models are simulated and compared with experimental pressure difference between inlet and exit of battery module, and prediction shows that RNG k-ε model has better accuracy with maximum error of pressure difference 8%. Then, the inlet velocity into the battery module is changed to validate the computed and experimental temperature, and agreement of both results is good within 1oC. Finally, the numerical result shows the flow and temperature pattern characteristics between the cylindrical and strip type of battery module. Overall, the flow inside the cylindrical cell of batter module is unsymmetrical. When the inlet velocity increases to 2 m/s, the flow direction of cylinder shape battery module divert
to upper left after flow passes through the second row of battery, and this also change the contact point and separation point. On the other hand, the strip type of battery module generates relatively smooth and smaller flow resistance, so it has better dissipation efficiency than that of the cylinder battery module.

並列關鍵字

Heat transfer ； Lithium-ion battery ； Numerical simulation ； Electrochemical model ； Electric vehicle

參考文獻

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