Battery pack immersion liquid cooling solution in new energy area

          In recent years, the electric vehicle market has developed vigorously. In this kind of vehicle, the thermal management technology of power battery pack is the key technology of pure electric vehicle. In order to ensure the power performance and safety of electric vehicles, the thermal management of battery system has the following objectives:

1. Ensure that the single battery is in a suitable working temperature range, and can transfer heat in time in a high-temperature environment, and quickly heat or heat preservation in a low-temperature environment;

2. Reduce the temperature difference between different parts of the single battery to ensure uniform temperature distribution of the single battery.

3. Keep the temperature inside the battery pack balanced to avoid the imbalance between batteries and reduce the performance.

4. Eliminate the danger of battery failure or even explosion caused by thermal runaway.

5. Meet the light and compact requirements of electric vehicles, low cost, simple installation and maintenance.

6. Effective ventilation ensures that the potential harmful gas generated by the battery can be discharged in time to ensure the safety of the battery.

7. Realize accurate and sensitive monitoring and management of temperature and other related parameters, and formulate reasonable countermeasures for abnormal conditions.

    The thermal management of battery includes many directions: starting from the battery body, study more temperature resistant battery materials, including high-temperature and low-temperature resistant electrode materials and electrolyte materials; 

     Secondly, more efficient materials are studied to make the battery have lower calorific value on the premise of meeting the requirements of vehicle charge and discharge power; 

     Finally, from the perspective of the thermal management system design of the battery pack, the temperature of the battery pack is controlled by designing natural heat dissipation, forced air cooling or liquid cooling. 

      The first two belong to the research field of materials and battery cells, and the latter is the focus of thermal design engineers.

        Just like conventional electronic products, the thermal management of batteries is also divided into three types: passive air cooling, active air cooling and liquid cooling. The car is moving during driving, and the external environment automatically forms a high wind speed. Therefore, the passive air cooling thermal solution in the automotive system is different from the air cooling heat dissipation of traditional electronic products, that is, the battery pack with passive air-cooled heat dissipation may still have high wind speed. Therefore, the thermal management of the battery is described here according to two schemes, namely, air cooling and liquid cooling.

     In fact, these cooling solutions are not fundamentally different from traditional communication equipment and power electronics. The form of heat management is from the heating body - heat conduction interface material - radiator. However, as we all know, immersion liquid cooling has been applied in electronic products, and the pue value is close to the limit of 1.0 In addition to high cooling efficiency and good reliability, another key advantage of immersion liquid cooling in power battery is safety. The following video shows its security well.