Thermal management in vehicle integration

One central effect of Active Thermal Management is the significantly faster powertrain warm up. The warm up operation strategy is divided into two parts – the first step is Zero Flow, which is the fastest passive engine warm up method, and is followed by the warm up mode with speed controlled operation of the electrical water pump (eWAPU).Regarding Zero Flow the avoidance of coolant boiling represents an enabler for aggressive AND safe operation. The analysis of multiple temperatures led to the result that a temperature location “A” correlates directly with coolant boiling. Robustness had been ensured by performing experiments with plenty of Zero Flow tests in combination with an appropriate noise strategy. In parallel a physical temperature model had been developed to simulate the proper location.