Investigation of Maximum Temperature Rise on High Pressure Common Rail Injector Nozzle

The heat that a nozzle generates under the multi-cycle working conditions and the large pressure difference at the orifice cause the temperature of the nozzle to rise, which affects the injection characteristics. Therefore, an infrared thermal camera was used in this study to examine the temperature distribution in a Bosch common rail injector and the variations of the nozzle maximum temperature rise. The results showed that transient temperature at the nozzle of the injector and the steady-state temperature rise with the increase in the injection pressure and frequency. The effect of the injection pressure was the most significant, and the effect of the injection frequency was small. At different injection frequencies and injection pressures, the maximum temperature rise at the nozzle increased rapidly in the first 10 min, after which it slowly increased. The temperature at the nozzle reach the equilibrium after 30 min of injector operation.