Sankey Diagrams » engine

Diesel Engine Sankey Diagram

phineas — Wed, 10 Jun 2009 16:14:00 +0000

Just back from a few days at the beach, here is just a quick one…

User BoH created a Sankey diagram for a diesel engine and uplodad it to the WikiCommons. It is in Dutch and shows the energy efficiency of the fuel being burnt in the motor.

49.3% of the energy is useful energy transformed into motion, while the rest is lost. The main losses (30.45%) occur at the exhaust gases, and with cooling water (approx 10.5%).

The smaller arrows are not to scale (see the 0.76% arrow branching off on the left side compared to the one representing 1.5% (smeeroliekoeling, cooling of lubricant oil)). Also, I am not sure whether the author forgot an arrow at the blue node labeled “Lucht” (air).

Anyway, apart from these flaws it is a neat diagram. I particularly like the color gradient from ‘red hot’ to ‘cool green’.

Efficiency Diagram for Ship Engines

phineas — Mon, 02 Mar 2009 16:06:34 +0000

MAN Diesel, a renown producer of marine and power plant diesel engines, has been working on improving fuel efficiency of its engines. Today, the fuel energy efficiency is about 50%. The MAN Turbo Efficiency System (TES) allows to recover of heat from the exhaust gas, which is responsible for about 50% of the energy losses.

Here is a Sankey diagram that shows the recovery of energy from exhaust gas.

Download a description of the TES here (PDF, 291 KB) or view a high resolution version of the above Sankey diagram from their press picture gallery.

Engine Efficiency of Cars

phineas — Thu, 21 Jun 2007 11:02:13 +0000

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).