Reversed-domed Piston and Bypass Valves for Alpha-type
Posted: Wed Feb 08, 2012 2:56 pm
I was wondering if it was fundamentally sound to consider constructing a stirling engine using components similar to regular car engines, such as aluminum cylinders, blocks and heads.
Where instead of heating the hot side by heating the cylinder walls, and or cylinder top, or by heating outside of the cylinder space you could have the heat exchanger protruding from the cylinder head straight down into the block. Where at top dead center a piston with a deep depression in its face that would fit the heating exchanger like a hand and glove (for minimal dead space). Inside the protrusion would be piping for the working gas to go from the regenerator to the middle of the protruding heat exchanger (which is hermatically sealed from the source heat) and then out into the cylinder space. I'm thinking that could allow for the hot side to use components similar to standard car engines. The edges or the top of the piston act as a "shield" to protect the working gas from the cold cylinder walls, and a tapered, protruding heat exchanger would allow the distance between protrusion to the piston to always be less than that of the actual stroke length of the piston and this can allow for a more efficient transfer of heat to the working gas as there would be less of an area of the gas to 'find somewhere to cool down' as the power stroke nears the bottom.
I was thinking that similar protruding heat exchanger can be used for the cold piston.
Also, on the compression stroke of the hot piston why pipe the working gas through the heater? why not have camshafts like on a 4 cycle engine that would divert the gas directly into the regenerator? and for the power stroke of the hot piston why not have the hot gas diverted into the heater just before top dead center similar to how car engines have spark advance? I was thinking that cams could be ground to allow heating possible until the cold piston reaches BDC and then a cam can divert working gas through the cooling heat exchanger through roughly the entire compression stroke of the cold side.
Perhaps a smaller diameter cold piston (for increased compressive pressure) and taking advantage of the exposed cold walls of the hot cylinder in it compression stroke could be used to make a more powerful stirling engine.
Where instead of heating the hot side by heating the cylinder walls, and or cylinder top, or by heating outside of the cylinder space you could have the heat exchanger protruding from the cylinder head straight down into the block. Where at top dead center a piston with a deep depression in its face that would fit the heating exchanger like a hand and glove (for minimal dead space). Inside the protrusion would be piping for the working gas to go from the regenerator to the middle of the protruding heat exchanger (which is hermatically sealed from the source heat) and then out into the cylinder space. I'm thinking that could allow for the hot side to use components similar to standard car engines. The edges or the top of the piston act as a "shield" to protect the working gas from the cold cylinder walls, and a tapered, protruding heat exchanger would allow the distance between protrusion to the piston to always be less than that of the actual stroke length of the piston and this can allow for a more efficient transfer of heat to the working gas as there would be less of an area of the gas to 'find somewhere to cool down' as the power stroke nears the bottom.
I was thinking that similar protruding heat exchanger can be used for the cold piston.
Also, on the compression stroke of the hot piston why pipe the working gas through the heater? why not have camshafts like on a 4 cycle engine that would divert the gas directly into the regenerator? and for the power stroke of the hot piston why not have the hot gas diverted into the heater just before top dead center similar to how car engines have spark advance? I was thinking that cams could be ground to allow heating possible until the cold piston reaches BDC and then a cam can divert working gas through the cooling heat exchanger through roughly the entire compression stroke of the cold side.
Perhaps a smaller diameter cold piston (for increased compressive pressure) and taking advantage of the exposed cold walls of the hot cylinder in it compression stroke could be used to make a more powerful stirling engine.