Tag: car

Energy Management of Automobiles Sankey

Just returned from a short break … trying to get back into the regular blogging mode again. Here is a quick one from my bookmarks.

The Sankey diagram below illustrates a research project at Hannover University on energy management of automobiles. Similar to the Sankey diagram shown in this post it shows how total energy from gasoline is used in different components of a car.

The Sankey diagram is symbolic I assume, still one can see that large portions of the energy are lost in the exhaust gas (“Abgas”) and for motor cooling (“K├╝hler”). Flow quantities are given in Watt, not sure if that is per hour at a given speed or in idle mode.

Engine Efficiency of Cars

The U.S. Department of Energy (DOE) is funding research projects that target the increase of efficiency of car engine.

The Sankey diagram shown in this post on the Green Car Congress blog visualizes that only 25% (green arrow) of the energy from combustion is used as “effective power” for mobility and accessories, while 40% of the energy is lost in exhaust gas.

Projects are being carried out at John Deere, Caterpillar, Detroit Diesel and Mack Trucks, to name just a few.

“Seven of the twelve projects focus on advanced combustion technology with a heavy focus on HCCI (Homogeneous Charge Compression Ignition). There is also an diesel-compressed-air hybrid truck powertrain under development. The remaining projects deal with technologies to convert waste heat from engines to electrical or mechanical energy.”

The inefficient energy use of car engines and other vehicles are the main reason for the transport sector being (next to energy generation and transmission) the sector where most energy is being lost (see this post).