Influence of Active Cooling Thermal management Valve on Fuel Consumption and Engine Warm-up: Simulation and Tests

Thermal management technologies are increasingly developed to lower fuel consumption and pollutant emissions whilst keeping the same driving and thermal comforts. This entails reducing warm-up time and friction losses without detriment to fuel consumption. A new technology for engine cooling systems named ACT valve (Active Cooling Thermal management valve) is developed by MANN+HUMMEL. It allows first to implement a no flow strategy to decrease the warm-up time and to enhance thermal comfort. It is also able to accurately control the coolant flow and temperature depending on engine operating load and speed, and so to decrease friction and heat losses. In order to quantify the fuel consumption potential, a complete engine co-simulation has been developed. It consists of a coupled simulation between AMESim (coolant and oil circuit, thermal exchanges), GT-Power (gas dynamics, combustion) and Simulink (temperature regulation strategy, ACT valve control and software link). Tests performed in the laboratory and on an engine bench enabled to tune the combustion and thermal parameters. Furthermore, road tests are performed with an instrumented vehicle. These are performed with the series wax-thermostat then with the ACT solution. Fuel consumption benefits using a thermal management system depending on real driving conditions is assessed. The road tests also served as model calibration data and were reproduced by simulation. The obtained fuel consumption benefits are compared to test results. Simulations on standard driving cycles are then performed with the ACT valve to evaluate the influence of the temperature regulation strategy on CO2 emissions and thermal comfort.