Vapor generator and control therefor

Claim 2

A vapor generator for a vapor engine using organic working fluid, said vapor generator comprising: a. means forming a sealed, fluid-tight enclosure of annular configuration forming a combustion chamber in the center of the annulus; b. heat transfer fluid non-decomposable at the anticipated maximum working temperature of said vapor generator partially filling said enclosure in the liquid state, said enclosure being at least partially evacuated of non-condensables to establish a pressure level therein not substantially above the vapor pressure of said heat transfer fluid; c. conduit means for conducting organic working fluid into heat exchange relationship with the interior of said enclosure; and d. heat source means for directing a combustible mixture into said annulus and pool boiling said heat transfer fluid at a temperature level equivalent to or above the boiling point of said organic working fluid whereby heat energy is transferred through the wall of said conduit means to said organic working fluid.

Claim 3

A vapor generator according to claim 1 wherein said annular enclosure comprises concentric side walls and top and bottom annular end walls, further comprising: a. an annular exhaust passage substantially coextensive with said annular enclosure and extending downwardly from said bottom end wall; b. means forming at least one entrance opening between said combustion chamber and said exhaust passage to admit combustion products to said exhaust passage; and c. means in said exhaust passage forming at least one exit opening remote from said entrance opening for discharging exhaust gases, whereby exhaust gases travel from said combustion chamber, along a path adjacent the bottom end wall of said enclosure, before being discharged.

Claim 4

A vapor generatr according to claim 2 wherein said exit opening is situated 180* from said entrance opening.

Claim 5

A vapor generator according to claim 2 further comprising: a. heat transfer fins extending upward from said bottom end wall into said heat transfer fluid; and b. heat transfer fins extending doWnward from said bottom end wall into said exhaust passage.

Claim 6

A vapor generator according to claim 4 wherein said downwardly extending heat transfer fins comprise elongated plate-like members for directing the flow path in said exhaust passage.

Claim 7

A vapor generator according to claim 2 further comprising thermal insulation along the common wall between said enclosure and said annular space restricted substantially to the portion of said common wall above the level of liquid in said enclosure.

Claim 8

A vapor generator according to claim 1 further comprising means responsive to the pressure in said enclosure for controlling the heat input to said heat transfer fluid, to thereby maintain a predetermined operating temperature level in said vapor generator.

Claim 9

A vapor generator according to claim 1 further comprising: a. pressure actuated means for controlling the heat input to said heat transfer fluid; b. means for applying a signal proportional to the pressure internal of said enclosure to said pressure actuated means, said signal providing the total information required for enabling said pressure actuated means to variably control said heat input and maintain working fluid vapor discharged from said vapor generator at a predetermined temperature level.

Claim 10

A vapor generator for closed cycle vapor engine utilizing a thermally sensitive organic working fluid, said vapor generator comprising: a. means forming a substantially rigid, sealed, fluid-tight enclosure of substantially constant volume, substantially devoid of fluids which are non-condensable over the working temperature range of said vapor generator, partially filled throughout said range with a heat transfer fluid in the liquid state, said heat transfer fluid being non-decomposable throughout said range; b. heat source means for vaporizing a portion of said heat transfer fluid; c. conduit means extending through said enclosure with at least a portion thereof out of contact with said heat transfer fluid in the liquid state and forming a condensing surface upon which vaporized heat transfer fluid condenses to transfer thereto its latent heat of vaporization, said conduit means having an inlet for admitting working fluid into heat exchange relationship with the interior of said enclosure and an outlet for discharging working fluid from said heat exchange relationship; and d. pressure responsive control means, responsive only to the vapor pressure within said enclosure, coupled to said heat source means for controlling the output thereof to maintain the heat transfer fluid vapor, and thereby the entire condensing surface, at a temperature level not lower than the boiling point of said working fluid and below the temperature at which an unacceptable amount of thermal degradation of said working fluid occurs, whereby said vapor generator is enabled to heat working fluid at said outlet to vaporization without producing thermal decomposition thereof.

Claim 11

A vapor generator for closed cycle vapor engine utilizing a thermally sensitive organic working fluid, said vapor generator comprising: a. means forming a substantially rigid, sealed, fluid-tight enclosure of substantially constant volume, substantially devoid of fluids which are non-condensable over the working temperature range of said vapor generator, partially filled throughout said range with a heat transfer fluid in the liquid state, said heat transfer fluid being non-decomposable throughout said range; b. heat source means for vaporizing a portion of said heat transfer fluid; c. conduit means extending through said enclosure with at least a portion thereof out of contact with said heat transfer fluid in the liquid state and forming a condensing surface upon which vaporized heat transfer fluid condenses to transfer thereto its latent heat of vaporization, said conduit means having an inlet for admitting working fluid into heat exchange relationship with the interior of said enclosure and an outlet for discharging working fluid from said heat exchange relationship; and d. pressure responsive control means, responsive only to the vapor pressure within said enclosure, coupled to said heat source means for controlling the output thereof to maintain the heat transfer fluid vapor, and thereby the entire condensing surface, at a temperature level not lower than the boiling point of said working fluid and below the temperature at which an unacceptable amount of thermal degradation of said working fluid occurs, whereby said vapor generator is enabled to heat working fluid at said outlet to vaporization without producing thermal decomposition thereof.

Claim 12

A heat transfer device according to claim 9 wherein said heat transfer fluid comprises biphenyl and biphenyl oxide.

Claim 13

A heat transfer device according to claim 9 wherein said pressure responsive means comprises a variable control for selecting the operating temperature of said condensing surface.