When the air hits the top, a stagnation region forms. The gas flows sideways from the stagnation region, creating a wall-jet region. The gas then flows out of the battery pack. The air intake gas flow impacts the top of the cell and causes reflection to flow to the sides. External intake changes the direction of the venting flow.
The air intake gas flow impacts the top of the cell and causes reflection to flow to the sides. External intake changes the direction of the venting flow. The gas is blown out of the cell pack. Figure 7. Influence of different ventilation positions on thermal runaway exhaust case 1 has no external intake.
Case 2 has an external intake, which is located in wall5. Wall5 is the mass flow boundary condition with a mass flow rate of 1.5 g/s. The external air intake may be sourced from the car air conditioner. The air conditioner is assumed to provide ventilation during the TR of the battery pack.
The ventilation rate required is 1.0 cfm/sq-ft. An alternative variation of continuous ventilation in air conditioned battery room spaces is to utilize, as makeup air, the conditioned air from other occupied spaces that would require ventilation as part of the indoor air quality requirements.
For low-antimony lead batteries, the required air volume flow is reduced by 50% (f1 = 0.5). For closed lead batteries, the air volume flow is reduced by a further 50% (f2 = 0.5). The ventilation and breathing of electrical operating areas with batteries must be provided directly from/to outside or with dedicated ventilation pipes.
An alternative variation of continuous ventilation in air conditioned battery room spaces is to utilize, as makeup air, the conditioned air from other occupied spaces that would require ventilation as part of the indoor air quality requirements.