||Back To The Future With The BMW Steamer
BMW Group Research and Engineering has combined heat and power to improve
performance and efficiency in a car for the first time.
Enhancing efficiency by up to 15 percent feasible through the principle of the steam engine.
Munich. December 7, 2005: Using an innovative concept, BMW Group Research and Engineering
has succeeded in harnessing the biggest and as yet untapped source of energy in the car: Heat.
Combining an innovative drive assist with a 1.8 liter BMW four-cylinder engine on the test
rig reduced consumption by up to 15 percent while generating nearly 14 additional horsepower.
At the same time, up to 15 lb-ft more torque was measured. This increased power and efficiency
comes free of charge. The reason is that the energy is derived exclusively from the waste heat
present in the exhaust gases and cooling system and doesn't cost you a single drop of fuel.
The research project meets all the conditions espoused by the philosophy of BMW Efficient
Dynamics - lower emissions and consumption combined with more dynamic driving and performance.
Up to fifteen percent greater overall efficiency for the gas engine. The Turbosteamer - as the project
is known - is based on the principle of the steam engine: Fluid is heated to form steam in two circuits
and this is used to power the engine. The primary energy supplier is the high-temperature circuit
which uses exhaust heat from the internal combustion engine as an energy source via heat exchangers.
More than 80 percent of the heat energy contained in the exhaust gases is recycled using this technology.
The steam is then conducted directly into an expansion unit linked to the crankshaft of the internal
combustion engine. Most of the remaining residual heat is absorbed by the cooling circuit of the engine,
which acts as the second energy supply for the Turbosteamer. This innovative drive assist verifiably
increases the efficiency of the combined drive system by up to 15 percent. "The Turbosteamer reinforces
our confidence that the internal combustion engine is undoubtedly a technology fit for the future,"
comments Professor Burkhard Göschel, Member of the Board of Management responsible for development
and purchasing at BMW AG.
Adequate space in today's vehicle concepts. The development of this new drive assist has reached
the phase involving comprehensive tests on the test rig. The components for this drive system have
been designed so that they are capable of being installed in existing model series. Tests have been
carried out on a number of sample packages to ensure that a car such as the BMW 3 Series provides
adequate space. The engine compartment of a four-cylinder model offers enough space to allow the
expansion units to be accommodated.
System ready for volume production within ten years Ongoing development of the concept is focusing
initially on making the components simpler and smaller. The long-term development goal is to have
a system capable of volume production within ten years.
The big picture: project BMW Efficient Dynamics. BMW Group Research and Engineering has demonstrated
the medium-term perspectives of the project BMW Efficient Dynamics. "This project resolves the apparent
contradiction between consumption and emission reductions on the one hand and performance and agility
on the other," is how Professor Burkhard Göschel summarizes the core concept of the programme.
The BMW Group is committed to the principle that a reduction in consumption amounting to a few percentage
points over the entire model range exerts higher overall effects on the general population than high
percentage points for a niche model. BMW is focusing on making the latest technologies for reduced
consumption accessible to as many people as possible.
This is the translation. Please excuse my terrible Enlish! - - - Heiner Rossler
BMW 4cylinder uses waste heat for increased performance
Motor with Turbine
Roundabout two thirds of the energy content of petrol gets converted into waste heat by an petrol engine.
It disappeares either in the cooling system or via the exhaust. In future BMW intends to use part of this
energy to increase efficiency up to 15%. To achieve this development engineers on a research vehicle
combined a 1,8 litre 4 cylinder engine with a two stage steam turbine which acts on the crankshaft.
Superheated steam is made in two heat exchangers in the exhaust system. A second water circuit (not
shown in the diagram) takes heat from the cooling system. Thus either power and torque could be increased
or fuel consumption lowered. On the prototype 14 additional HP together with an increased torque of 20 Nm
was measured. About 1,5 litre/100 km lower fuel consumption coul be realized too.
BMW named the new steam system Turbosteamer.
1) Steam generator/Superheater.
4) Steam generator/Condenser.
5) High temperature turbine.
6) Low temperature turbine.
7) High temperature circuit.
Probably the writer in the well known magazine Auto Motor und Sport had no idea what he was writing about,
but I think the idea is understandable.