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Drawing of the 2 times doubble acting Stirlingengine the so called double double U engine
Legend of this drawing:
KW = crankshaft with flywheel, KU1= lower crankgear, KU2= upper crankgear,
M = clutch
H1 : Expansion cylinder, K1 : Compression cylinder of 1'st partial engine
H2 : Expansion cylinder, K2 : Compression cylinder of 2'nd partial engine
H3 : Expansion cylinder, K3 : Compression cylinder of 3'nd partial engine
H4 : Expansion cylinder, K4 : Compression cylinder of 4'nd partial engine
WH1 - WH4 : external heatexchangers for the hot cylinders H1 - H4
WK1 - WK4 : external cooler for the cold cylinders K1 - K4
RC regulator-cylinder (only sketched here for the cold cylinders K4 und K3). For detailed information see the chapter Power Control in the site: Report of the engine.
The Regenerator tubes "R" between the hot "H" - and the cold "K"- cylinders are atonce counter flow heat exchangers.
Every 2 cylinders -which have the same digit in its names- are connected by a regenerator - tube; this is a partial engine e.g. cylinders H1 and K1. The complete engine is 2 times doubble acting and consists of 4 of these partial engines, each with an expansion cylinder "H" , a regenerator "R" and a compression cylinder "K" . These partial engines are named by "H1-K1" , "H2-K2" , "H3-K3" and "H4-K4" . All the 4 single partial engines are connected by their pistonrods to the crankgears, so there are 4 working strokes at 1 crankshaft revolution. The complete engine therefore is selfstarting.
In each cylinders head there are nozzles for sprinkling the pressurized gas with hot or cold working liquid. This draining performs the heattransmission or cooling of the gas.
The next picture shows a 3D-model of this twice double acting engine. All cylinders and the cylinderheads of H1 and K1 are made transparent, so You can see the pistons and the spray-nozzle within the cylinderheads. For a better overwiev the external heatexchangers WH1 - WH4 and WK1 - WK4 are not shown here.
See also the animation of the engine
The other kind of heattransfer is demonstrated by this sketch .
