基于液冷策略的鋰離子電池組安全管理研究
發(fā)布時(shí)間:2018-06-09 01:54
本文選題:鋰離子電池 + 熱管理系統(tǒng); 參考:《中國科學(xué)技術(shù)大學(xué)》2017年碩士論文
【摘要】:鋰離子電池的容量、內(nèi)阻以及電壓對(duì)所處的工作溫度十分敏感。因此,電池組內(nèi)部溫度的不均一性會(huì)明顯降低電池組的性能并且縮短電池的壽命周期。此外,鋰離子電池在高度集成后,電池產(chǎn)生的熱量在電池組內(nèi)積聚,由于自身結(jié)構(gòu)抗濫用性較差,容易發(fā)生熱失控進(jìn)而引起火災(zāi)或者爆炸事故。本文通過有限元數(shù)值模擬方法和小尺寸的實(shí)驗(yàn)對(duì)鋰離子電池的液冷管理以及安全防護(hù)技術(shù)進(jìn)行研究,旨在提出鋰離子電池組優(yōu)化設(shè)計(jì)方法,建立滅火-冷卻一體化系統(tǒng),為電池組均衡管理與消防滅火提供技術(shù)支撐。在開放環(huán)境下分別對(duì)單電池、自然對(duì)流電池組以及使用液冷策略的電池組進(jìn)行動(dòng)態(tài)充放電測試,并研究電池的溫度分布、電壓以及電流的變化規(guī)律。結(jié)果表明,鋰離子電池在動(dòng)態(tài)循環(huán)中至少存在2個(gè)溫度峰,隨著電流倍率的增加,電池溫度相應(yīng)升高,溫度峰發(fā)生了兼并。擱置工況一定程度上對(duì)電池升溫過程進(jìn)行緩沖,優(yōu)化電池使用性能。在鋰離子電池成組后,每個(gè)測點(diǎn)的波峰與波谷的出現(xiàn)存在時(shí)間差,溫度極值以及溫度波動(dòng)呈現(xiàn)不同程度的增加。在0.5C、1C和3C循環(huán)倍率下系統(tǒng)中最高溫度分別為27.4℃、38.5℃和62.9℃,最大溫升分別為8.9℃、16.3℃和37.7℃,最大溫差分別為4.9℃、4.2℃和13.7℃。使用液冷方案時(shí),在同樣的動(dòng)態(tài)循環(huán)工況下,每個(gè)測點(diǎn)的時(shí)間差現(xiàn)象出現(xiàn)了明顯的改善,系統(tǒng)的熱均衡能力得到提高。在0.5C、1C和3C循環(huán)倍率下系統(tǒng)中最高溫度分別為31.8℃、38.5℃和 56.2℃,最大溫差分別為 1.6℃、3.5℃和 29.5℃;诮(jīng)典的傳熱理論以及電化學(xué)模型中提供的數(shù)學(xué)物理方法,利用多物理場仿真軟件構(gòu)建模型,對(duì)在開放環(huán)境中動(dòng)態(tài)循環(huán)的單電池以及基于液冷策略動(dòng)態(tài)循環(huán)的電池組進(jìn)行了模擬與驗(yàn)證。結(jié)果表明,在動(dòng)態(tài)循環(huán)過程中實(shí)驗(yàn)得到的單電池溫度分布與模擬結(jié)果吻合較好,但模擬的充電電壓比實(shí)驗(yàn)值偏高,最大值之間相差0.15V,同時(shí)在充電階段模擬得到的溫度峰也寬于實(shí)驗(yàn)溫度峰;谝豪洳呗,模擬得到的電池組溫度分布與實(shí)驗(yàn)值變化趨勢相同。由于熱物性參數(shù)和動(dòng)力學(xué)參數(shù)都是溫度的函數(shù),而模擬中所使用的為常量,導(dǎo)致模擬溫度值低于實(shí)驗(yàn)值。在0.5C、1C和3C循環(huán)倍率下系統(tǒng)中模擬溫度與實(shí)驗(yàn)溫度最大誤差分別為1.79℃、4.44℃和23.09℃。電池模組中外側(cè)電池的模擬溫度值與實(shí)驗(yàn)值相似。在0.5C、1C和3C循環(huán)倍率下的外側(cè)電池模擬溫度與實(shí)驗(yàn)測量值最大誤差分別為1.1℃、3.09℃和 7.15℃。研究了火探管自身的熱響應(yīng)行為以及火探管滅火系統(tǒng)對(duì)鋰離子電池火災(zāi)的滅火效率,根據(jù)實(shí)驗(yàn)結(jié)果提出火探管復(fù)合滅火系統(tǒng)方案。結(jié)果表明,火探管處于火焰區(qū)時(shí)響應(yīng)時(shí)間較短,破裂降溫較明顯。當(dāng)火探管滅火系統(tǒng)直接布置在電池正上方時(shí),能在起火后的5.6s內(nèi)有效控制火情,隨著滅火劑用量增加體系溫度將顯著降低。火探管滅火系統(tǒng)是點(diǎn)式滅火系統(tǒng),在滅火劑噴放后僅能冷卻局部區(qū)域的電池單元,當(dāng)覆蓋區(qū)域外的電池發(fā)生失控后將作為熱源繼續(xù)加熱臨近電池,引發(fā)連鎖熱失控,也可能引起滅火區(qū)域內(nèi)電池的復(fù)燃,造成滅火系統(tǒng)失效。根據(jù)實(shí)驗(yàn)結(jié)果,提出滅火技術(shù)與熱均衡技術(shù)耦合的方法。
[Abstract]:The capacity, resistance and voltage of a lithium ion battery are very sensitive to the working temperature of the battery. Therefore, the inhomogeneity of the internal temperature in the battery group can obviously reduce the performance of the battery and shorten the life cycle of the battery. In addition, after the lithium ion battery is highly integrated, the heat generated by the battery is accumulated in the battery group, because of its own structure resistance. In this paper, the liquid cooling management and safety protection technology of lithium ion batteries are studied by the finite element numerical simulation method and small size experiment. The aim of this paper is to put forward the optimization design method of lithium ion battery group and establish an integrated fire extinguishing and cooling system, which is a battery pack. The dynamic charge and discharge test of single battery, natural convection battery group and liquid cooling strategy are carried out in the open environment, and the temperature distribution, voltage and current change law of the battery are studied. The results show that there are at least 2 temperatures in the dynamic cycle of the lithium ion battery. With the increase of the current ratio, the temperature of the battery increases and the temperature peak is annexed. The heating process of the battery is buffered to a certain extent, and the performance of the battery is optimized. After the lithium ion battery is set up, the time difference exists between the peak and the trough of each test point, the temperature extreme value and the temperature fluctuation show different range. The maximum temperature of the system at 0.5C, 1C and 3C cycles is 27.4, 38.5 and 62.9, respectively 8.9, 16.3 and 37.7, and the maximum temperature difference is 4.9, 4.2 and 13.7, respectively. When the liquid cooling scheme is used, the time difference phenomenon of each point in the same dynamic cycle is obviously changed. The thermal equilibrium ability of the system is improved. The maximum temperature of the system at 0.5C, 1C and 3C cycles is 31.8, 38.5 and 56.2, respectively 1.6, 3.5 and 29.5, respectively. Based on the classical heat transfer theory and the mathematical and physical methods provided in the electrochemical model, the model is constructed using the multi physical field simulation software. The simulation and verification of the single cell and the battery group based on the dynamic cycle of the liquid cooling strategy in the open environment are simulated and verified. The results show that the temperature distribution of the single cell obtained in the dynamic cycle is in good agreement with the simulation results, but the simulated charge voltage is higher than the actual test value, and the difference between the maximum values is 0.15V, and at the same time, The temperature peak of the simulation is also wider than the experimental temperature peak. Based on the liquid cooling strategy, the simulated temperature distribution of the battery group is the same as the experimental value. Because the thermal physical parameters and the kinetic parameters are the functions of the temperature, the simulated temperature is lower than the experimental value. The simulation temperature is lower than the experimental value. It is in 0.5C, 1C and 3C. The maximum error of simulated temperature and experimental temperature in the system is 1.79, 4.44 and 23.09. The simulated temperature of the battery module in the battery module is similar to the experimental value. The maximum error between the simulated temperature and the measured value at 0.5C, 1C and 3C cycle ratio is 1.1, 3.09 and 7.15. According to the experimental results, the thermal response behavior of the fire detection system and the fire extinguishing system for the lithium ion battery fire are proposed. The results show that the response time is shorter and the fracture temperature is more obvious when the fire probe is in the flame area. The temperature of the fire in the 5.6S after the fire will be effectively controlled, with the increase of the temperature of the system with the increase of the amount of fire extinguishing agent. The fire detection system is a point type fire extinguishing system. After the fire extinguishing agent is sprinkled, it can only cool the cell unit in the local area. When the battery outside the covering area is out of control, it will continue to heat near the battery as a heat source and cause the chain heat loss. The control may also cause the re ignition of the battery in the fire extinguishing area, resulting in the failure of the fire extinguishing system. Based on the experimental results, the coupling method of the fire extinguishing technology and the thermal equalization technology is put forward.
【學(xué)位授予單位】:中國科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2017
【分類號(hào)】:TM912
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 虞啟義;徐良斌;虞偉;;火探管式自動(dòng)探火滅火系統(tǒng)的探討[J];山西建筑;2009年13期
2 陳仕玉;王兆翔;趙海雷;陳立泉;;鋰離子電池安全性添加劑[J];化學(xué)進(jìn)展;2009年04期
相關(guān)博士學(xué)位論文 前1條
1 平平;鋰離子電池?zé)崾Э嘏c火災(zāi)危險(xiǎn)性分析及高安全性電池體系研究[D];中國科學(xué)技術(shù)大學(xué);2014年
相關(guān)碩士學(xué)位論文 前2條
1 孫秋娟;鎳鈷錳酸鋰/鈦酸鋰電池?zé)嵝?yīng)的實(shí)驗(yàn)與模擬研究[D];中國科學(xué)技術(shù)大學(xué);2015年
2 趙學(xué)娟;鋰離子電池在絕熱條件下的循環(huán)產(chǎn)熱研究[D];中國科學(xué)技術(shù)大學(xué);2014年
,本文編號(hào):1998282
本文鏈接:http://www.sikaile.net/kejilunwen/dianlidianqilunwen/1998282.html
最近更新
教材專著