Causes of difficult diesel engine cold start after installing parking heater
In order to find out the reasons for the difficulty of diesel engine cold start after the parking heater was installed, a number of cold start tests under the same conditions were carried out, and various engine state parameters and electronic control system control parameters were carried out before, after and during starting. Monitoring and recording. The main measurement parameters include ambient temperature, coolant temperature, intake air temperature, engine speed, battery voltage, starting fuel injection, starting timing, starting rail pressure, etc. The test results show that the heated coolant temperature has an adverse effect on the ECU control parameters during starting.
The study found that the heating of the parking heater does not heat all the coolant in the cooling system at the same time. Although the water pump of the parking heater drives the coolant to circulate in the engine cooling system pipeline, it is The working capacity of the heater water pump is limited. At this time, the coolant circulation flow rate is much smaller than the circulation flow rate after the engine is on fire, and as the circulation distance increases, the temperature of the coolant heated by the parking heater also gradually decreases. The heating capacity of the engine is also gradually decreasing. Therefore, during the same heating time, the part of the engine closer to the hot water outlet of the parking heater has a higher temperature rise than the part far from the inlet, that is, the temperature of each part of the engine is uneven at this time.