Vehicle propulsion system

Claim 2

A vehicle propulsion system which minimizes pollutant emissions but provides good fuel economy over typical vehicle load and speed ranges, said system comprising: an internal combustion engine, including means for providing the cylinders thereof with a fuel-air mixture in which the fuel-air ratio is substantially greater than the stoichiometric fuel-air ratio, in order to produce a combusted exhaust gas from said internal combustion engine which is low in oxides of nitrogen content and rich in combustibles content, said internal combustion engine having a displacement substantially less than would be necessary for a pure internal combustion engine having a power output equivalent to the power output of said propulsion system, said internal combustion engine further being operated at relatively high cylinder pressures; means for adding air to the exhaust gas from said internal combustion engine; combustion means coupled to receive the air and exhaust gas to complete the combustion of the exhaust gas; a steam generator coupled in heat exchange relationship with the combusted exhaust gas from said combustion means; a steam expander coupled to receive steam from said steam generator and to thereby generate mechanical power; means for continuously mechanically coupling said internal combustion engine and said steam expander so that both act together to propel the vehicle under steady-state load requirements; and a first control means to operate said internal combustion engine at a power level substantially less than the steady-state system load power requirements but at a power level nearer that required for maximum fuel efficiency in the internal combustion engine, said steam expander providing the remaining steady-state system load power requirements, whereby the fuel consumption of said system is substantially less than that of the pure internal combustion engine of equivalent power.

Claim 3

A vehicle propulsion system as set forth in claim 1, wherein said steam generator has sufficient heat capacity to act as an energy reservoir, and further including a second control means to operate said steam expander at a power level substantially less than the peak power capacity of said steam expander, but sufficient to furnish said remaining steady-state system load power requirements and to operate said steam expander at increased power levels to furnish additional load power for short periods of peak power when rapid acceleration is required, the stored energy being converted to additional mechanical power in said steam expander.

Claim 4

A vehicle propulsion system as set forth in claim 1, wherein said exhaust gas combustion means comprises an afterburner.

Claim 5

A vehicle propulsion system as set forth in said claim 1, wherein said steam generator comprises a boiler mounted downstream from said combustion means in the exhaust gas stream.

Claim 6

A vehicle propulsion system as set forth in claim 4, wherein said steam generator further comprises a superheater connected in series with said boiler and positioned to receive the exhaust gas from said combustion means upstream of said boiler.

Claim 7

A vehicle propulsion system as set forth in claim 1, wherein: said internal combustion engine further includes a water cooling jacket; and said system further includes means for deriving steam from said jacket and applying it to said steam expander.

Claim 8

A vehicle propulsion system as set forth in claim 6, wherein said means for deriving steam from said cooling jacket comprises: means for separating steam from water in said jacket; and means for mixing this steam with steam from said steam generator for application to said steam expander.

Claim 9

A vehicle propulsion system as set forth in claim 1, wherein said internal combustion engine includes means for establishing a fuel-air ratio in the range of 0.075 to 0.125.

Claim 10

A vehicle propulsion system as set forth in claim 8, wherein said means for establishing a fuel-air ratio establishes the ratio at approximately 0.09.

Claim 11

A vehicle propulsion system as set forth in claim 1, wherein: said steam expander comprises a compound unit having a high pressure section and a low pressure section; and said steam generator further includes a boiler connected to supply steam to said high pressure section, and a reheater connected to receive exhausted steam from said high pressure section and to apply it to said low pressure section after reheating.

Claim 12

A vehicle propulsion system as set forth in claim 10, wherein said reheater is located to absorb heat from the exhaust gas stream downstream of said steam generator boiler.

Claim 13

A vehicle propulsion system as set forth in claim 10, wherein said steam generator further includes an economizer positioned in heat transfer relationship with the exhaust gas downstream of said boiler, for preheating water with heat drawn from the exhaust gas prior to the introduction of the water to said boiler.

Claim 14

A vehicle propulsion system as set forth in claim 10, wherein said high pressure section of said steam expander comprises a first stage and a second or intermediate pressure stage, said first stage feeding exhaust steam into said second or intermediate pressure stage.

Claim 15

A vehicle propulsion system as set forth in claim 10, wherein said high pressure section of said steam expander comprises a first high pressure cylinder and a second intermediate pressure cylinder, and said low pressure section of the steam expander comprises a pair of low pressure cylinders of approximately equal displacement.

Claim 16

A vehicle propulsion system as set forth in claim 14, wherein said high pressure cylinder has a displacement of approximately 6 cubic inches, said intermediate pressure cylinder has a displacement of approximately 20 cubic inches and said low pressure cylinders each have a displacement of approximately 50 cubic inches.

Claim 17

A vehicle propulsion system as set forth in claim 2, wherein said first control means comprises power control means for controlling the rate of fuel-air mixture input to said internal combustion engine and said second control means comprises means for controlling the rate of steam input to said steam expander.

Claim 18

A vehicle propulsion system as set forth in claim 16, and further comprising means for coordinating the operation of said first and second control means in accordance with the availability of steam from said steam generator.

Claim 19

A vehicle propulsion system as set forth in claim 1, wherein said means for mechanically coupling said internal combustion engine and said steam engine includes an over-running clutch coupled between said internal combustion engine and said steam expander.

Claim 22

A method as set forth in claim 19, and further including the steps of; storing heat energy in the steam generator during periods of steady-state operation at average and low power demands; and removing the energy stored in said storing step, during short periods of peak power demand, to provide additional mechanical power from the steam expander.

Claim 23

A method as set forth in claim 19, wherein said step of mixing fuel and air comprises mixing the fuel and air in a ratio in the range of 0.075 to 0.125.

Claim 24

A method as set forth in claim 21, wherein the fuel and air are mixed in the ratio of approximately 0.09.

Claim 25

A method as set forth in claim 19, wherein said step of generating steam from the heat of combusted exhaust gas includes applying the gas to a superheater, a boiler and an economizer in succession, the superheater, boiler and economizer being coupled in series relationship with respect to the flow of an evaporative fluid therethrough.

Claim 26

A method as set forth in claim 19, and further comprising the steps of: generating steam from the heat of the internal combustion engine; and further heating that steam for application to the steam expander.

Claim 27

A vehicle propulsion system providing low pollutant emissions while maintaining good fuel economy, said system comprising: an internal combustion engine having a substantially smaller displacement than a conventional internal combustion engine of equivalent power to said vehicle propulsion system, said internal combustion engine being normally operated at higher cylinder pressures and a higher efficiency than such conventional engine, when subjected to the same load and speed conditions, said internal combustion engine including means for establishing a fuel-air ratio substantially greater than the stoichiometric ratio, in order to produce an exhaust gas which is low in oxides of nitrogen content and rich in combustibles content; means for adding air to the exhaust gas from said internal combustion engine; combustion means coupled to receive air and exhaust gas to complete combustion of the exhaust gas; a steam engine, including a steam generator coupled in heat exchange relationship with the combusted exhaust gas from said combustion means, and a steam expander coupled to receive steam from said steam generator and to generate mechanical power therefrom, said steam engine being operable to provide sufficient steady-state power to supplement said internal combustion engine adequately for most vehicle operating conditions, and said steam generator having sufficient heat capacity to act as an energy storage reservoir which may be drawn upon for short periods of vehicle acceleration; means for mechanically coupling said internal combustion engine and said steam engine to propel the vehicle; first and second power control means for controlling the fuel-air mixture input to said internal combustion engine and the steam input to said steam expander, respectively; and means for coordinating the operation of said power control means in accordance with the availability of steam from said steam generator, said coordinating means having a linkage mechanism for driving said first and second power control means in unison in response to operator control input while adjusting the operation of one power control means relative to the other in accordance with the availability of steam from said steam generator.

Claim 28

A vehicle propulsion system providing low pollutant emissions while maintaining good fuel economy, said system comprising: an internal combustion engine having a substantially smaller displacement than a conventional internal combustion engine of equivalent power to said vehicle propulsion system, said internal combustion engine being normally operated at higher cylinder pressures and a higher efficiency than such conventional engine, when subjected to the same load and speed conditions, said internal combustion engine including means for establishing a fuel-air ratio substantially greater than the stoichiometric ratio, in order to produce an exhaust gas which is low in oxides of nitrogen content and rich in combustibles content; means for adding air to the exhaust gas from said internal combustion engine; combustion means coupled to receive air and exhaust gas to complete combustion of the exhaust gas; a steam engine, including a steam generator coupled in heat exchange relationship with the combusted exhaust gas from said combustion means, and a steam expander coupled to receive steam from said steam generator and to generate mechanical power therefrom, said steam engine being operable to provide sufficient steady-state power to supplement said internal combustion engine adequately for most vehicle operating conditions, and said steam generator having sufficient heat capacity to act as an energy storage reservoir which may be drawn upon for short periods of vehicle acceleration; means for mechanically coupling said internal combustion engine and said steam engine to propel the vehicle; first and second power control means for controlling the fuel-air mixture input to said internal combustion engine and the steam input to said steam expander, respectively; and means for coordinating the operation of said power control means in accordance with the availability of steam from said steam generator, said coordinating means having a linkage mechanism for driving said first and second power control means in unison in response to operator control input while adjusting the operation of one power control means relative to the other in accordance with the availability of steam from said steam generator.

Claim 29

A vehicle propulsion system as set forth in claim 25, wherein said coordinating means further includes means responsive to steam generator pressure for adjusting the relative control of said first and second power means in response to operator input.

Claim 30

A vehicle propulsion system providing low pollutant emissions while maintaining good fuel economy, said system comprising: an internal combustion engine having a substantially smaller displacement than a conventional internal combustion engine of equivalent power to said vehicle propulsion system, said internal combustion engine being normally operated at higher cylinder pressures and a higher efficiency than such conventional engine, when subjected to the same load and speed conditions, said internal combustion engine including means for establishing a fuel-air ratio substantially greater than the stoichiometric ratio, in order to produce an exhaust gas which is low in oxides of nitrogen content and rich in combustibles content; means for adding air to the exhaust gas from said internal combustion engine; combustion means coupled to receive air and exhaust gas to complete combustion of the exhaust gas; a steam engine, including a steam generator coupled in heat exchange relationship with the combusted exhaust gas from said combustion means, and a steam expander coupled to receive steam from said steam generator and to generate mechanical power therefrom, said steam engine being operable to provide sufficient steady-state power to supplement said internal combustion engine adequately for most vehicle operating conditions, and said steam generator having sufficient heat capacity to act as an energy storage reservoir which may be drawn upon for short periods of vehicle accleration; and means for mechanically coupling said internal combustion engine and said steam engine to propel the vehicle; and wherein said steam engine further includes a condenser coupled to receive exhaust steam from said steam expander, and means for removing non-condensible products from said condenser and directing them to the input of said internal combustion engine for combustion therein.

Claim 31

A vehicle propulsion system providing low pollutant emissions while maintaining good fuel economy, said system comprising: an internal combustion engine having a substantially smaller displacement than a conventional internal combustion engine of equivalent power to said vehicle propulsion system, said internal combustion engine being normally operated at higher cylinder pressures and a higher efficiency than such conventional engine, when subjected to the same load and speed conditions, said internal combustion engine including means for establishing a fuel-air ratio substantially greater than the stoichiometric ratio, in order to produce an exhaust gas which is low in oxides of nitrogen content and rich in combustibles content; means for adding air to the exhaust gas from said internal combustion engine; combustion means coupled to receive air and exhaust gas to complete combustion of the exhaust gas; a steam engine, including a steam generator coupled in heat exchange relationship with the combusted exhaust gas from said combustion means, and a steam expander coupled to receive steam from said steam generator and to generate mechanical power therefrom, said steam engine being operable to provide sufficient steady-state power to supplement said internal combustion engine adequately for most vehicle operating conditions, and said steam generator having sufficient heat capacity to act as an energy storage reservoir which may be drawn upon for short periods of vehicle accleration; and means for mechanically coupling said internal combustion engine and said steam engine to propel the vehicle; and wherein said steam engine further includes a condenser coupled to receive exhaust steam from said steam expander, and means for removing non-condensible products from said condenser and directing them to the input of said internal combustion engine for combustion therein.

Claim 32

A vehicle propulsion system as set forth in claim 27, wherein said means for removing non-condensible products comprises a check valve having a restricted orifice for passing the non-condensible products from said condenser to said internal combustion engine input without disrupting the operation of said internal combustion engine.

Claim 33

A vehicle propulsion system as set forth in claim 1, wherein: the vehicle in which said system is installed has a total weight of approximately 3,500-4,000 lb.; said internal combustion engine has a displacement of approximately 80-100 cubic inches, whereby said internal combustion engine will be operated at relatively high cylinder pressures and at a relatively high efficiency for most driving conditions; said steam expander has a displacement of approximately 100-130 cubic inches, whereby said steam expander supplies approximately the same mechanical steady-state power as said internal combustion engine, thereby substantially reducing the overall fuel consumption of the vehicle.