在前幾天的Green Car Congress的報道里面，有一則寶馬在設計在優化快充條件下的熱管理的主意的報道，是值得一讀的。面向下一代熱管理，核心的問題在于考慮在快充階段的發熱（面向快充的200-300kW），在車輛停置條件下，把大量的熱量散出去

備注:之前的熱管理主要以放電為主，沒有把充電的要求作為獨立的分支，因為散熱量也不大

BMW is seeking alternative cooling technologies for vehicle batteries to further improve peak cooling capacity during fast charging while reducing cooling components’ vibration and noise emission.Faster charging creates more heat to be dissipated within a short period of time.

現有方案和缺點：使用冷媒直冷的方案在快充條件下的噪聲比較大

Current technologies use electric refrigerant compressors.Rising cooling capacities would generate significantly higher vibrations through fans and other moving components. The thus generated acoustic emissions during faster charging would need sophisticated damping measures to allow pleasant circumstances for people and the surrounding environment.

For example, if you are having a conversation in a charging car, noise above 25 dB(A) is considered uncomfortable. If you are standing close to a charging car, noise from the HVAC System including the radiator above 35 dB(A) is perceived as discomfort.

寶馬的考慮的要求包括：

冷卻技術主要針對的是把電池表面的溫度導熱到外部去，溫度范圍涉及到-20至45°

Cooling technology working with temperature gradients between battery surface and ambient temperature, operating temperature range -20 °C to +45 °C.

Scalable for future battery capacities and heat dissipation. As a starting point for the challenge, solutions should assume needing a cooling power > 20 kW during the fast charging with 200-300 kW.

Low noise production, not beyond 35 dB(A).

Power density: realizable thermal performance compared to the component volume.

Peak cooling performance is not required 24/7. Instead the proposed solution has to operate only within the limited time period of fast charging.

The vehicle will not be moving while charging, so there is no circulating air for cooling available. The heat flux to ambient air must also be implemented by the system.

也給出了一些技術的方向：

Magnetocaloric technologies

Electrochemical cooling

Schukey machine applications

Thermoacoustic cooling

Absorption cooling

The use of phase change materials (vapor cooling)

Innovative compression methods

Cooling medium is not specified

BMW will not consider passsive cooling technologies requiring high temperature gradients between battery surface and ambient temperature（這里的意思是很堅決）technologies harmful to the environment, or technologies with high service and maintenance requirements.

根據前端時間倪總他們的測試，350A的情況下，充電接口溫升20攝氏度，在當前的電池溫升就成了個瓶頸，在350Ah流過電池，這些熱量咋辦。

小結：隨著充電接口的問題解決，電池的瓶頸特別是電池的散熱作為一個課題會獨立的出來。