Reciprocating Expanders

"Reciprocating Expander" is a technical name for the conventional piston steam engine. This arrangement has proven successful for a couple hundred years, and is being used for the majority of new engine designs today.

Basic Cycle

 * 1) Admission: Valve opens allowing high pressure steam into the cylinder.  Usually the admission valve is set to start opening before the piston reaches TDC.  This allows time for the valve to more fully open by the time the piston reaches TDC.
 * 2) Cutoff: Admission valve closes as piston travels down the cylinder.  No more steam is admitted, and steam trapped in the cylinder expands while doing work on the piston.
 * 3) Exhaust: Shortly before the piston reaches BDC the exhaust valve opens, allowing steam in the cylinder to flow out to the exhaust.  Steam flows out of the cylinder until the cylinder pressure approximately equals the exhaust pressure.
 * 4) Exhaust valve closes: As the piston is travelling back up the cylinder the exhaust valve closes.  Some steam remains trapped in the cylinder.
 * 5) Compression: The piston compresses the trapped steam, increasing its pressure and temperature.



Engine Details

 * 1) Types of Engines: Single & double acting; counterflow & uniflow; simple & compound; condensing; self-starting; reversing.
 * 2) Valve Types: How steam gets in to and out of cylinders.
 * 3) Valve Gear: Mechanisms that make the valves open and close.
 * 4) Engine Components: Cylinders, pistons, rings, bearings, seals, etc.
 * 5) Engine Calculations: Torque, power, etc.
 * 6) New engine designs:
 * 7) Voith SteamTrac
 * 8) BMW TurboSteamer
 * 9) Honda waste heat engine
 * 10) Exoes (France)
 * 11) Bosch (Germany)
 * 12) etc, etc.