Abstract: To study the suppression effect of liquid nitrogen on fires in energy storage cabins, the thermal runaway of battery modules in the energy storage cabin was numerically simulated. The fire extinguishing effects of liquid nitrogen and water mist were compared under normal pressure and low pressure environments, and the influences of the number of nozzles and the spray angle on the fire extinguishing effect of liquid nitrogen in the energy storage cabin were further studied. The research results show that in terms of suppressing the spread of thermal runaway of lithium batteries in the energy storage cabin, liquid nitrogen has a better effect than water mist regardless of whether it is in a normal pressure or low pressure environment. Moreover, as the number of nozzles increases and the spray angle decreases, the fire extinguishing effect of liquid nitrogen is further enhanced. Therefore, by setting nozzles with different numbers and spray angles, the fire extinguishing effect of liquid nitrogen in fires in energy storage cabins can be optimized. The research results can provide a basis for the design of liquid nitrogen fire extinguishing in lithium-ion battery energy storage cabins.

Key words: lithium-ion battery energy storage cabin, liquid nitrogen fire extinguishing, number of nozzles, spray angle, numerical simulation