Improvement of response time for vehicle thermostats

Today, decreasing total emissions of the harmful gases for environment from internal combustion engines is biggest design concerns because of the regulations. In the phases that engines run in different temperatures than the designed temperature range, engines release harmful gases in high level emission values. For this reason to ensure engine run in proper temperature range, stabilising of coolant temperature and engine temperature helps an efficient fuel burning and decreasing harmful gas emission release. In the study performed, CFD analyzes were used to optimize response time and the results were confirmed with experimental data. Analyzes for design optimization were performed using the ANSYS-CFX 12.1 software. According to the CFD results, the new mechanical design, whose heat contact surface was increased, showed that the thermostat reacted early by delivering the heat to the wax center in a shorter time than the current design. In the mixture study, paraffin was synthesized with four different weight percentages of nano-graphene particles, which are 5%, 10%, 15%, 20% and 25% respectively. The thermal conductivity of the samples was measured with the help of the thermal properties analyzer. As a result of the measurement, it has proven that nanoparticles greatly improve the thermal conductivity of the base paraffin. Prototype production was realized by assembling with this new mechanical design and new mixture of parafin/nano-grafen. Test studies have been carried out with prototype production and it has been concluded that the reaction time of this new design has increased approximately 4 times compared to the traditional thermostat.