【作者】 郭鹏；

【导师】 李元媛； 郑立；

【作者基本信息】 华北电力大学(北京) ， 能源动力硕士（专业学位）， 2025， 硕士

【摘要】 随着储能装机量的快速增长,温控系统在锂电池储能系统中扮演着重要的角色。由于储能电池单体容量和功率的增加,高功率密度对温控系统提出了更高的要求。对于大容量储能电池,因其几何尺寸较大,热导率低,单一液冷方式无法兼顾散热能力和均温性需求。相变材料冷却具有良好的均温性,与传统液冷板耦合是解决储能电池热管理瓶颈的重要途径之一。本文采用数值模拟的方法,对液冷耦合相变材料冷却的储能电池热管理系统的控温性能及运行策略展开研究。首先,建立储能电池液体冷却的仿真模型并验证了模型的有效性,对三种结构不同的液冷系统进行分析。结果表明,电池两侧平行流道冷板表现出最优的控温性能,但在较高放电倍率运行时仍不能满足储能电池的温控要求。在两侧放置平行流道冷板的基础上,提出液冷耦合相变材料热管理系统。在1C放电倍率下,对比单一液体冷却,最高温度降低5.19℃,最大温差降低1.88℃。其次,对建立的液冷耦合相变材料热管理系统进行关键参数影响规律研究。结果表明,相变材料热导率对耦合热管理系统性能影响较小,相变材料熔点以及相变潜热对其影响较大。因此,不需要添加高导热材料来提高相变材料的热导率,选择合适的熔点以及增大相变潜热更为重要。针对耦合热管理系统相变材料凝固时间长,提出基于传热路径分析的结构优化。优化后,电池组的最高温度降低0.27℃,最大温差降低14.6%,相变材料完全凝固时间减少了 21.2%。最后,针对储能电池的低、中、高倍率三种典型运行场景,设计了纯被动冷却、延迟冷却、持续液体冷却三种不同的运行策略。结果表明:在低倍率运行场景下,纯被动冷却可以将电池组的温度控制在合适的范围内;在中倍率运行场景下,延迟冷却降低4.2%的系统功耗;在高倍率运行场景下,持续冷却可以将电池组的温度保持在相变材料熔点附近,温度波动更小,温控性能更优。此外,研究了耦合热管理系统在低温环境下的保温性能,与传统铝制液冷板相比,电池组温度维持在0℃以上的时间增加了 24.5%,有效延长电池组的保温时间,降低电池冷启动所需的加热能耗。本文针对大容量储能电池提出了有效的热管理方式,为未来储能电池热管理研究和应用领域提供了理论支撑。更多还原

【Abstract】 With the rapid growth of installed energy storage capacity,temperature control system plays an important role in lithium battery energy storage system.Due to the increase in the capacity and power of the single energy storage battery,the high power density puts forward higher requirements for the temperature control system.For large-capacity energy storage batteries,due to their large geometry and low thermal conductivity,a single liquid cooling method can not take into account the heat dissipation capacity and temperature uniformity requirements.Phase change material cooling has good temperature uniformity,and coupling with traditional liquid cooling plates is one of the important ways to solve the thermal management bottleneck of energy storage batteries.In this paper,numerical simulation is used to study the temperature control performance and operation strategy of the thermal management system for energy storage batteries with liquid cooling coupled with phase change material cooling.First,the simulation model of liquid cooling for energy storage battery is established and the validity of the model is verified,and three liquid cooling systems with different structures are analyzed.The results show that the parallel channel cold plate on both sides of the battery shows the optimal temperature control performance,but it still can’t meet the temperature control requirements of the energy storage battery when operating at higher discharge rate.On the basis of placing parallel channel cold plates on both sides,a liquid cooling system coupled with phase change material cooling is proposed.At a 1C discharge rate,compared to single liquid cooling,the maximum temperature is reduced by 5.19℃,and the maximum temperature difference is reduced by 1.88℃.Second,the influence rules of key parameters of the established liquid-cooled coupled phase change material thermal management system are studied.The results show that the thermal conductivity of the phase change material has a small impact on the cooling performance of the coupled cooling system,the melting point of the phase change material and the latent heat of the phase change material has a greater impact,so it is not necessary to add a high thermal conductivity material to increase the thermal conductivity of the phase change material,selecting a suitable melting point and increasing the latent heat of phase change material is more important.To address the long solidification time of the phase change material in the coupled cooling system,a structural optimization based on heat transfer path analysis is proposed.After the optimization,the maximum temperature of the battery pack is reduced by 0.27℃,the maximum temperature difference is reduced by 14.6%,and the complete solidification time of phase change material is reduced by 21.2%.Finally,for the three typical operating conditions of low,medium and high discharge rates of energy storage batteries,three different operating strategies were designed,namely pure passive cooling,delayed cooling and continuous liquid cooling.The results show that in the low discharge rate scenario,pure passive cooling can control the temperature of the battery pack within an appropriate range;delayed cooling reduces the system power consumption by 4.2%in the medium discharge rate scenario;and sustained cooling reduces the maximum temperature of the battery pack by 4.1℃ and the maximum temperature difference by 1.1℃ in the high discharge rate scenario.In addition,the thermal insulation performance of the coupled cooling system in low temperature environments is investigated.Compared with the traditional aluminum liquid cooling plates,the time for the battery pack temperature to be maintained above 0℃ is increased by 24.5%,which effectively prolongs the battery pack’s thermal insulation time and reduces the heating energy consumption required for battery cold starting.This paper proposes an effective thermal management method for large-capacity energy storage batteries,providing theoretical support for future research and application of thermal management of energy storage batteries.更多还原