EV CHARGING High-pressure heat exchanger ensures shorter charging times for electric vehicles
Battery charging time is one of the key issues in electromobility. Up to now, however, the large amount of heat generated during charging at fast charging stations has proven to be an obstacle. With its high-pressure heat exchanger, BENTELER now offers an innovative solution for particularly effective and fast cooling.
"Car owners don't like the fact that the charging process currently still takes a relatively long time. They feel that this restricts their mobility and flexibility," explains Dr. Rainer Lübbers, Executive Vice President of the responsible business unit at BENTELER Automotive. Shorter charging times are therefore a factor in promoting the politically desirable broad acceptance of electric vehicles.
"Keeping the battery as cool as possible during the charging process is crucial for reducing charging time," explains Jens-Eike Jesau, the developer responsible: "Our system makes this possible and thereby accelerates charging." The high-pressure heat exchanger is installed in the air conditioning circuit.
"Coupling battery cooling and air conditioning in this way increases the cooling power available during charging. This shortens the battery charging time," says Jesau. Another plus: On the one hand, the battery and car interior can be optimally cooled while, on the other, the battery heat can be used to heat the passenger compartment when necessary. The high pressure heat exchanger has an output of 12KW. At the same time, its design is very compact – itr is about the size of a cigarette pack thereby simplifying its integration in the vehicle.
The heat exchanger uses CO2 (R744 refrigerant) as the cooling medium. The system pressure is ten times higher than in conventional heat exchangers, which significantly increases the cooling capacity: 60 bar in the heat pump system liquefies the CO2 before it enters the cooler. There it evaporates and absorbs the waste heat from the battery charging process. Thanks to the completely sealed system, no CO2 can escape.