Battery Air Cooling System

2023/10/19 分類業界ニュース 269 0

Battery Air Cooling System

The battery air cooling system has a simple structure, light weight, low cost, and no risk of harmful gas accumulation or leakage. However, its disadvantages are low heat dissipation efficiency, difficult sealing design, and poor dustproof and waterproof effects. Depending on whether the cooling air source is introduced using an additional device, the battery air cooling system is divided into natural air cooling and forced air cooling.

1. Natural air cooling

The method of direct cooling by directing the wind generated during vehicle driving through the guide tube into the internal channel of the battery pack is called natural air cooling. This method does not require an auxiliary motor, has a simple structure, and is easy to use. However, the cooling air flow will be unstable due to changes in vehicle speed, and the cooling effect will vary greatly. Moreover, the heat capacity and thermal conductivity of the air are very low, and the natural convection surface heat transfer coefficient is small. . Natural air cooling is suitable for vehicles with low power battery discharge rate and low heat production rate. Due to factors such as battery pack cost, vehicle cruising range, and component systems, most domestic pure electric vehicles with a cruising range of less than 300 km currently use natural air cooling.

Battery Air Cooling System

2. Forced air cooling

At the cost of consuming battery energy, the method of using fans or air pumps to promote air flow and form forced convection to enhance heat transfer is called forced air cooling. This method can provide stable cooling air flow, but the structure is relatively complex. Natural air cooling generally requires that the power battery itself generates low heat and the air flows smoothly in the layout space. The current battery manufacturing capacity in China cannot reach this level, so forced air cooling is the mainstream type of air cooling in China. Forced air cooling was widely used in early electric passenger cars abroad.

According to different air sources, forced air cooling systems can be divided into ambient air cooling and air conditioning air cooling. Power batteries are mostly installed under the vehicle floor, and ambient air cooling has not been seen in mass-produced models due to insulation failures and other factors. Therefore, forced air cooling mostly refers to air-conditioning air cooling. According to the different sources of air-conditioning air, it is divided into two forms:

(1) Induced draft type in the cabin: The ambient air enters the passenger compartment after being cooled by the vehicle air conditioner, and then flows from the passenger compartment into the power battery, and is finally discharged into the environment by a fan.

(2) Independent air-cooling type: The ambient air is directly introduced after being cooled by the battery system’s own air conditioner. The heat dissipation efficiency is relatively high, and it also avoids the negative pressure feeling in the passenger compartment when the air volume demand is large, but it increases the cost and energy consumption accordingly.