Steam Engine Specifications

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Summary

• Deliverable: a one cylinder prototype module with scalability, to constitute a single stage of a stageable system (compound or 3 stage) which uses the same module that is scaled to make other stages
• System consists of cyliner, crank arm, mechanical valve, automatically adjusted cutoff ratio, and constitutes a Steam Engine Construction Set
  • Cutoff ratio controlled by closed loop electronic feedback with some type of linear actuator
• Applications to stationary, mobile, and solar power

Cost-Related Features

• Lowest materials cost for a given performance
• Simplest to fabricate, therefore lowest fabrication cost
• Advanced techniques of fabrication utilized only when necessary to achieve cost
• Fabrication tooling preferably simple, but secondary to fabrication cost
• Uses commonly available parts
• Replicable
• Materials cost of $50/hp

Materials Calculations

• 20 pounds of weigh per horsepower

Flexibility and Performance

• Scalable in power output from 1 - 100 hp by scaling or adding modules
• Power density of 1 hp/10 lb
• Pressure up to 500 psi
• Scalable cylinder dimensions, uncoupled staging, and tandem operation allows scaling of power and eficiency from 1-100 hp and up to 25% efficiency
  • Multiple cylinder, in-line configuration is possible by bolting several cylinders together

See the following for steam engine calculations:

• Steam Engine Construction Set Calculations
• Steam Engine Efficiency Calculations
• Steam Engine Efficiency

Lifecycle

• Long lifetime under continuous use (50 years)

Ecology

• Compatible with stationary, solar, and mobile power applications
  • LifeTrac power source
  • Solar Power Generator heat engine
  • CHP with space heating

Sources

• Steam Engine Specifications/Piston Ring Sources
• Steam Engine Specifications/Cylinder Liner Sources
• Steam Engine Specifications/Bearing Sources
• Steam Engine Specifications/Valve Spring Sources

Fabrication

Steam Engine Elements:

• Elements to be Purchased
  • Cylinder Assembly
    • Cylinder Liner
    • Cylinder Bolts (4) - 3 sizes
    • Water Drain Plug
    • Exhaust Plenum Bolts (4)
  • Piston Assembly
    • Piston Rings (2)
  • Valve Assembly
    • Valve Springs (2)
    • Valve Spring Bolts (2)
  • Base Plate Bolts (4)

• Elements to be Fabricated
  • Cylinder Assembly
    • Cylinder
    • Cylinder mounting bracket
    • Cylinder end cap with valve seats
    • Cylinder end cap and end mount
    • Exhaust Plenum - 2 pieces
  • Piston Assembly
    • Piston Head
    • Bump Valve Pins (2)
    • Piston Connector Rod
  • Valve Assembly
    • Valves (2)
  • Base Plate
  • Oil Dribbler

Crankshaft design diagram.

Crankshaft Elements:

• Crankshaft
  • Shaft pieces (2)
  • Offset plates (2)
  • Crank piece (1)
  • Couplers (2)
  • Screws
  • Crankshaft support assembly

• no welding in this design.
• does require tapping holes for machine screws.
• needs counterbalance to not vibrate.

Techniques and Stock:

• Casting used for body
• Stock parts wherever feasible
• Lathing for bore

Other:

Things to Spec

There are a few key dimensions that need to be specified before the full dimensions of the engine and it's parts are known. These include:

• Valve Gap - the amount of space open in the valves at top dead center.
  • Initially, we shall use 1/8" (0.125"). This can be adjusted by changing the valve pin length.
• I.D. of a half inch bolt - needed to determine valve spring holes and valve stem diameter.
  • O.D. is 0.515", I.D. is 0.482". However, this might not be the size of the hole we need. See valve spring size.
• Cylinder clearance - space remaining in the bore at top dead center.
  • "Steam Engines" recommends 3-8% of the piston displacement, which is 4". If we assume 6%, this is a clearance of 0.24, which we can round off to 0.25 (1/4 inch).
• Exhaust port locations - near bottom dead center
  • We will use 3.6" from T.D.C as the left edge of the exhaust holes, which shall be 0.25" in diameter..