The pre-heating of engine coolant using electrical and fuel-based pre-heaters has been practiced for decades. There are many valid reasons for pre-heating engines such as increasing fuel economy, reducing pollution from combustion, reducing engine wear and increasing comfort. Those reasons are particularly true in colder climates where cars are used for short trips of up to 10 minutes or 5 kilometers.
In this paper an unconventional approach for pre-heating engines before starting is studied. The pre-heating is accomplished by assuming storage of a certain amount of the engine’s hot coolant in an insulated storage system when not operating the vehicle, and pumping it back into the engine’s coolant system before restarting. The approach does not rely on external power sources, except for control and pumping of the coolant.
The paper presents results from experimental tests made to evaluate the approach. The experimental tests were run with different settings. In one setting the system produced an average of 26 kW for fifty seconds (peaking at 41 kW). This power is considerably higher than the 2–6 kW provided by common commercial electrical and fuel-powered pre-heaters. Although 50 second pre-heating using the approach presented here will not match all commercial systems using 8–10 minutes heating time, the approach has room for improvement.