Steam Engine Specifications

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Main > Energy > Steam Engine


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

Steel weights .2833 pounds per cubic inch

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

Performance-Chart.png

See the following for steam engine calculations:

Lifecycle

  • Long lifetime under continuous use (50 years)

Ecology


Sources


Parts List

The following list of parts is based on the initial set of technical drawings linked from Steam Engine Build Instructions.

Steam Engine Parts

  • Piston Assembly
    • Piston (1)
      • Piston Head (1)
      • Piston Stem (1)
      • Piston Stem Pin (1)
      • Piston Stem Pin Washer (1)
      • Piston Stem Pin Cotter (1)
    • Piston Rings (2)
    • Bump Valve Pins (2)
    • Connector Rod (1)
      • Coupler (1)
      • Rod (1)
      • Bearing Case Assembly (1)
        • Bearing Case Top (1)
        • Bearing Case Bottom (1)
        • Quarter Inch Bolts, 3/4" long (2)
        • Quarter Inch Nuts (2)
        • Quarter Inch Lock Whaters (2)
  • Cylinder Assembly
    • Cylinder Liner (1)
    • Cylinder Case (1)
      • Cylinder Pipe (1)
      • Cylinder Flanges (2) - Flanges are missing four bolt holes
    • Valve Seat Plate (1)
    • [Valve Seat Seal ???] - this is a thin, soft metal seal.
    • Cylinder End Mount (1)
      • Plate (1)
      • Flange (1)
      • Half Inch Base Bolts, 1" long (3)
    • Exhaust Plenum
      • Exhaust Plenum Elements (4)
      • Quarter Inch Plenum Bolts, 1.5" long (4)
      • Quarter Inch Plenum Lock Washers (4)
      • Quarter Inch Plenum Nuts (4)
    • Half Inch Cylinder End Bolts (8) - Bolts can be replaced by a threaded rod.
    • Half Inch Cylinder End Lock Washers (8)
    • Half Inch Cylinder End Nuts (8)
  • Valve Assembly
    • Valves (2)
    • Valve Springs (2)
    • Vavle Spring Base (2)
    • Valve Cover (1) - Cover could be extended to eliminate the mounting bracket
      • Valve Holder (1)
      • Valve Cover Plate (1)
      • Valve Cover Flanges (4)
    • [Valve Cover Seal ???] - this is a thin, soft metal seal.
    • Cylinder Mounting Bracket - has two base plate holes, but cylinder end mount has 3.
      • Upright Plate (1)
      • Flange (1)
      • Half Inch Base Bolts (2?)
    • Half Inch Valve End Bolts (8) - Bolts can be replaced by a threaded rod.
    • Half Inch Valve End Lock Washers (8)
    • Half Inch Valve End Nuts (8)
  • Other
    • Base Plate (1)
    • Oil Dribbler - TBD (1)


Crankshaft Parts

  • Shaft
    • Flywheel Shaft (1)
    • Drive Shaft (1)
  • Crank Assembly (1)
    • Crank Pin (1)
    • Crank Counterweight (2)
    • Crank Arm (2)
    • Nylon Bushings, 0.5" long (2)
  • Pillow Block Assembly (2)
    • Pillow Block Bearings (2)
    • Supoprt Element (1 - 2 total)
    • Support Base (1 - 2 total)
    • Support Rods (2 - 4 total)
    • Half Inch Pillow Block Bolts, 2" long (2 - 4 total)
    • Half Inch Pillow Block Lock Washers (2 - 4 total)
    • Half Inch Pillow Block Nuts (2 - 4 total)
    • Half Inch Base Bolts (2 - 4 total)
  • Flywheel Assembly (1)
    • Flywheel (1)
    • Collar (1)
    • Quarter Inch Set Screws, 0.5" long (2)

Techniques

  • Stock parts wherever feasible
  • Lathing for valves and other parts
  • Milling of exhaust plenum and other parts
  • Hole drilling
  • Cylinder boring may be necessary, depending on stock availability
  • Welding of parts in several places

Specification Decisions

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..