Automobile preheating system-Air heating

What is the principle of firewood warm come to understand it？
1. Basic principle: The diesel pump sucks out the diesel from the tank and sends it to the combustion chamber to ignite the mixture by the ignition plug. The exhaust gas of the diesel combustion in the combustion chamber is discharged from the exhaust port. The blower blows directly against the combustion chamber to send the hot air out.

2. The part with fins is the combustion chamber, and the fan is on the left. After the fan works, the heat generated by the combustion chamber is sent to the outlet.