Mingjie Zhang, Kai Yang, Le Qin, Xiaole Yao, Qian Liu, Xing Ju

Frontiers in Heat and Mass Transfer (FHMT) 19 - 13 (2022)

Lithium-ion batteries used for energy storage systems will release amount of heat during operation. It will cause serious consequences of thermal runaway if not dissipate in time. In this study, a self-forming air-cooled battery rack of the energy storage system is established based on the normal battery rack for energy storage and the shape of the energy storage battery itself. The frames of the battery rack acts as air ducts, which greatly reduce the system complexity. In this paper, the heat generation model is established based on the experiment, and the four battery rack forms are studied by CFD simulation. The flow uniformity of the two-level shunt structure, the maximum temperature of the battery, the temperature difference and the overall pressure drop of the battery rack are analyzed. It was found that the self-forming battery rack in the form of Case Ⅳ has the highest flow rate and temperature uniformity due to the tapered air ducts. Case Ⅳ can also resist flow non-uniformity when increase the flow rate. The maximum temperature can be maintained at 33.77 oC at 0.5 C under the 46 g/s flowrate. Where the maximum bulk temperature difference between batteries and inside a single battery is less than 3.81 oC and 0.98 oC, respectively. The pressure drop is only 4.83 Pa. What’s more, Case Ⅳ achieves optimal cooling performance at a 92 g/s flow rate, under which the maximum bulk temperature is 31.75 oC with the pressure drop of 19.54 Pa.