Stationary Battery Thermal Management: Analysis of Active Cooling Designs

Abstract

Stationary battery systems are becoming more prevalent around the world, with both the quantity and capacity of installations growing at the same time. Large battery installations and uninterruptible power supply can generate a significant amount of heat during operation; while this is widely understood, current thermal management methods have not kept up with the increase of stationary battery installations. Active cooling has long been the default approach of thermal management for stationary batteries; however, there is no academic research or comparative studies available for this technology. The present work presents assessment of different active cooling methods through an experimentally validated computational fluid dynamics simulation. Following model validation, several cooling system configurations were analyzed, including effects from implementing either a perforated vent plate or vortex generators. The vent plate was observed to greatly increase cooling performance while simultaneously promoting temperature uniformity between batteries. Vortex generators were shown to marginally increase cooling performance, yet, future research is recommended to study the effects and improvement of the design. The average battery temperature for the vented model is reduced by approximately 5.2 °C, while the average temperature differential among the batteries was only 2.7 °C, less than the recommend value (3 °C) by ASHRAE/IEEE Standards.

Battery Hazards for Large Energy Storage Systems

“…In contrast to small portable batteries, large stationary batteries do not have a comparable surface area to passively dissipate heat through natural convection and can reach unsafe high temperatures if not cooled properly. 32 Therefore, active cooling is a recommended approach for thermal management in large stationary batteries.…”

“…32 Ventilation systems are well-understood, simple to implement and manage, and dependable as a technology. 32,33 To minimize temperature differences among the cells in a battery, direct air cooling is not recommended, as it can cause temperature differences within the batteries or spot cooling. 32 Different geometric configurations and various kinds of vent plates and vortex generators attached to the battery racks have been studied to evenly distribute air flow within the battery enclosure to ensure efficient cooling and a uniform temperature distribution.…”

“…32,33 To minimize temperature differences among the cells in a battery, direct air cooling is not recommended, as it can cause temperature differences within the batteries or spot cooling. 32 Different geometric configurations and various kinds of vent plates and vortex generators attached to the battery racks have been studied to evenly distribute air flow within the battery enclosure to ensure efficient cooling and a uniform temperature distribution. 32,33 Liquid cooling is rare in stationary battery systems even though it is widely used in electric vehicle batteries.…”

“…Liquid cooling can provide superior thermal management, but the systems are more expensive, complex, and prone to leakages, which restricts their use in large stationary systems. 32 Passive cooling using phase-change materials is also under research but is not used to date in commercial ESS batteries.…”

“…Therefore, a cooling system, which can be either passive (uses heat-absorbing or dissipating materials and the ambient environment and natural convection) or active (uses built-in devices to force the movement of cooling media), is needed. In contrast to small portable batteries, large stationary batteries do not have a comparable surface area to passively dissipate heat through natural convection and can reach unsafe high temperatures if not cooled properly . Therefore, active cooling is a recommended approach for thermal management in large stationary batteries.…”