초록 ▼

An emission control device for use with stationary or mobile gas-fueled internal combustion engines is described, which is placed in the fuel supply line and operates with full fuel authority. An oxygen sensor measures exhaust oxygen content. The valve internally houses a programmable microprocessor

An emission control device for use with stationary or mobile gas-fueled internal combustion engines is described, which is placed in the fuel supply line and operates with full fuel authority. An oxygen sensor measures exhaust oxygen content. The valve internally houses a programmable microprocessor, a pressure transducer and a fuel flow conduit throttled by a balanced poppet valve. Signals to the microprocessor from the oxygen sensor, the pressure transducer indicating outflow gas pressure cause the microprocessor to motivate an actuator to move the valve within the gas stream and thus regulate the outlet pressure and also the gas flow rate to maintain a desired air/fuel ratio to the engine and keep exhaust emissions at an optimum level consistent with the engine operating load requirements and characteristics. Finite incremental control of valve position, preferably assisted by an internal position transducer, permits close control of the exhaust emissions.

대표청구항 ▼

1. Apparatus for control of exhaust emissions of a gas fueled internal combustion engine, said engine having an air intake, an intake conduit for gaseous fuel and an exhaust conduit for gaseous combustion products, which apparatus comprises:a control device comprising a housing having a fuel flow co

1. Apparatus for control of exhaust emissions of a gas fueled internal combustion engine, said engine having an air intake, an intake conduit for gaseous fuel and an exhaust conduit for gaseous combustion products, which apparatus comprises:a control device comprising a housing having a fuel flow conduit therethrough, said fuel flow conduit being aligned with said intake conduit when said device is incorporated into said intake conduit with said conduits forming a continuous flow path for all fuel flowing to said engine and having disposed within said housinga programmable microprocessor;a gas flow metering valve;a pressure sensor having electrical signal communication with said microprocessor; andan actuator having electrical signal communication with said microprocessor and directly motivating said gas flow control valve; anda sensor disposed in said exhaust conduit for sensing of a gaseous component of said exhaust and having signal communication with said microprocessor; andan electrical power supply to said microprocessor, pressure transducer and actuator;whereby in response to a signal received from said sensor or from said pressure sensor indicative of engine operating conditions in which an unacceptable level of exhaust emissions exists, said microprocessor controls said actuator to incrementally motivate said gas flow metering valve to change outlet pressure and in turn flow rate of said fuel to said engine to create a air/fuel ratio in combustion chambers of said engine in a manner to restore emissions content level in said exhaust gas to an acceptable level of such exhaust emissions.2. Apparatus as in claim 1 further comprising a position transducer in said housing having signal communication with said microprocessor for maintaining said gas flow metering valve at a constant position in the absence of motivation of said actuator by said microprocessor.3. Apparatus as in claim 1 further comprising said fuel flow conduit having a fuel flow orifice disposed therein and said gas flow metering valve controls flow rate of said fuel to said engine by full or partial restriction of fuel flow through said orifice.4. Apparatus as in claim 3 wherein flow rate control is determined by incremental movement of said gas flow metering valve to produce different degrees of blockage of said orifice by said gas flow metering valve in order to control the valve outlet pressure and in turn alter fuel flow.5. Apparatus as in claim 1 wherein air and fuel are provided to said engine and said fuel is controlled by said device to maintain a stoichiometric air/fuel mixture at the outlet of a fuel mixing unit from which said mixture is distributed to cylinders of said engine.6. Apparatus as in claim 5 wherein said fuel mixing unit comprises a carburetor or a fuel injection system.7. Apparatus as in claim 5 further comprising a turbocharger disposed ahead of said fuel mixing unit in said air intake conduit or between said fuel mixing unit and said cylinders of said engine in a conduit through which said air/fuel mixture is distributed.8. Apparatus as in claim 7 wherein said turbocharger is disposed ahead of said fuel mixing unit in said air intake conduit and said apparatus further comprises an external reference source of air intake pressure in fluid communication with said pressure transducer to correlate with increased air pressure at the inlet of said fuel mixing unit produced by said turbocharger.9. Apparatus as in claim 1 wherein air and fuel are provided to said engine and said fuel is controlled by said device to maintain a non-stoichiometric air/fuel mixture at the outlet of a fuel mixing unit from which said mixture is distributed to cylinders of said engine.10. Apparatus as in claim 9 wherein said fuel mixing unit comprises a carburetor or a fuel injection system.11. Apparatus as in claim 9 further comprising a turbocharger disposed ahead of said fuel mixing unit in said air intake conduit or between said fuel mixing unit and said cylinders of said engine in a conduit through which said air/fuel mixture is distributed.12. Apparatus as in claim 11 wherein said turbocharger is disposed ahead of said fuel mixing unit in said air intake conduit and said apparatus further comprises an external reference source of air intake pressure in fluid communication with said pressure transducer to correlate with increased air pressure at the inlet of said fuel mixing unit produced by said turbocharger.13. Apparatus for control of exhaust emissions of a gas fueled internal combustion engine, said engine having an air intake, an intake conduit for gaseous fuel and an exhaust conduit for gaseous combustion products, which apparatus comprises:a housing having a fuel flow conduit therethrough, said fuel flow conduit being aligned with said intake conduit when said device is incorporated into said intake conduit with said conduits forming a continuous flow path for all fuel flowing to said engine;a programmable microprocessor disposed within said housing;a gas flow metering valve in said housing for incrementally controlling the size of a fuel flow orifice in said fuel flow conduit;a pressure sensor in said housing having electrical signal communication with said microprocessor, said microprocessor being programmed with a desired set point for said pressure sensor signal;an actuator in said housing having electrical signal communication with said microprocessor and directly controlling incremental movement of said gas flow control valve;an exhaust sensor disposed in said exhaust conduit for sensing of a gaseous component of said exhaust and having signal communication with said microprocessor; andan electrical power supply to said microprocessor, pressure transducer and actuator;whereby in response to a signal received from said sensor or from said pressure sensor indicative of engine operating conditions in which an unacceptable level of exhaust emissions exists, said microprocessor controls said actuator to incrementally motivate said gas flow metering valve to change outlet pressure and in turn flow rate of said fuel to said engine to create a air/fuel ratio in combustion chambers of said engine in a manner to restore emissions content level in said exhaust gas to an acceptable level of such exhaust emissions; andsaid set point for said pressure sensor being adjusted by said microprocessor based on an external signal to said microprocessor in anticipation of a change in said exhaust sensor input, said microprocessor in response to said external signal motivating said gas flow metering valve for principal adjustment of said gas flow metering valve of said fuel flow rate and subsequently in response to said signal from said exhaust sensor motivating said gas flow metering valve for remaining adjustment of said gas flow metering valve of said fuel flow rate.14. Apparatus as in claim 13 wherein said external signal received by said microprocessor is indicative of load on said engine.15. Apparatus as in claim 13 wherein said microprocessor is self programmed with a correlation between corresponding signal values of said pressure sensor and of said external signal such that response of said microprocessor to said external signal substantially anticipates response of said microprocessor to said signal from said exhaust sensor.16. Apparatus as in claim 13 wherein said signal received by said microprocessor from said pressure sensor is indicative of deviation of value of outflow pressure of said fuel within said fuel flow conduit downstream of said fuel flow orifice from said desired set point value of said outflow pressure.17. Apparatus as in claim 13 wherein said signal received by said microprocessor from said sensor in said exhaust conduit is indicative of deviation of value of said air/fuel ratio of fuel and air to said engine from a desired reference value for said air/fuel ratio.18. Apparatus as in claim 1 wherein said sensor in said exhaust conduit is responsive to content of oxygen, a carbon oxide, a nitrogen oxide or a hydrocarbon in said exhaust.19. Apparatus as in claim 18 wherein said sensor in said exhaust conduit is responsive to content of oxygen in said exhaust.20. Apparatus as in claim 1 wherein said exhaust conduit contains a catalytic converter and said sensor is disposed ahead of said catalytic converter in said exhaust conduit.21. Apparatus as in claim 1 wherein said exhaust conduit contains a catalytic converter and said sensor is disposed following said catalytic converter in said exhaust conduit.22. Apparatus as in claim 1 further comprising a signal input port for transmission to said programmable microprocessor of a programming signal generated externally of said housing in addition to said exhaust sensor signal.23. Apparatus as in claim 22 wherein said programming signal is generated by a computer.24. Apparatus as in claim 23 wherein said programming signal comprises a signal setting a desired reference value for content of oxygen, a carbon oxide, a nitrogen oxide or a hydrocarbon in said gaseous combustion products in said exhaust conduit, a signal setting a desired reference value for air/fuel ratio of fuel and air to said engine or a signal setting a desired reference value of outflow pressure of said fuel within said fuel flow conduit downstream of a fuel flow orifice disposed therein.25. Apparatus as in claim 24 wherein said content is content of oxygen.26. Apparatus as in claim 24 wherein said signal received by said microprocessor from said sensor is indicative of deviation of content value of said oxygen, a carbon oxide, a nitrogen oxide or a hydrocarbon from a respective desired reference value for said oxygen, carbon oxide, nitrogen oxide or hydrocarbon.27. Apparatus as in claim 26 wherein said content is content of oxygen.28. Apparatus as in claim 1 wherein said gas flow metering valve comprises a balanced poppet valve.29. Apparatus as in claim 1 wherein said fuel whose flow rate in said fuel flow conduit in controlled comprises a gaseous hydrocarbon.30. Apparatus as in claim 29 wherein said fuel whose flow rate in said fuel flow conduit is controlled comprises natural gas, propane or butane.31. Apparatus as in claim 1 wherein said housing comprises an upper part and a lower part releasably secured to said upper part, the fuel flow conduit being located in said lower part of said housing which is separable from the remainder of said housing and said microprocessor, metering valve, pressure sensor, and actuator being mounted in said upper part of said housing, said upper and lower parts having a communicating passageway and said metering valve extending through said passageway into said fuel flow conduit to control outlet pressure.32. Apparatus as in claim 1 wherein said engine comprises a stationary or mobile engine.33. Apparatus as in claim 32 wherein said engine comprises a stationary engine.34. Apparatus as in claim 1 further comprising an exhaust analyzer in said exhaust conduit.35. Apparatus as in claim 34 further comprising cooperation of said microprocessor with said exhaust analyzer to permit said microprocessor to further control said actuator with respect to positioning of said valve for control of said fuel flow rate.36. Apparatus as in claim 1 further comprising at least one additional sensor for detection and valuation of at least one of the parameters of engine load, air/fuel ratio, manifold pressure, engine speed, fuel heating value or gas composition and transmittal of a signal to said microprocessor for enhancement of control by said microprocessor of said actuator.37. Apparatus for control of exhaust emissions of a gas fueled internal combustion engine, said engine having an air intake, an intake conduit for gaseous fuel and an exhaust conduit for gaseous combustion products, which apparatus comprises:a housing having a fuel flow conduit therethrough, said fuel flow conduit comprising means for incorporation in said intake conduit with said conduits forming a continuous flow path for all fuel flowing to said engine and said fuel flow conduit providing full fuel authority whereby all fuel supplied from a fuel source to said intake conduit passes through said fuel flow conduit;said fuel flow conduit having a fuel flow orifice and a valve seat at said orifice;a gas flow metering valve movably mounted in said housing for incremental movement towards and away from said valve seat and thereby controlling the size of said fuel flow orifice;a programmable microprocessor mounted in said housing for controlling operation of said valve;a pressure sensor in said housing having electrical signal communication with said microprocessor;an actuator in said housing having electrical signal communication with said microprocessor and directly controlling said incremental movement of said gas flow control valve in response to signals received from said microprocessor;a sensor disposed in said exhaust conduit for sensing of a gaseous component of said exhaust and having electrical signal communication with said microprocessor; andan electrical power supply to said microprocessor, pressure transducer and actuator;whereby in response to a signal received from said sensor or from said pressure sensor indicative of engine operating conditions in which an unacceptable level of exhaust emissions exists, said microprocessor controls said actuator to move said gas flow metering valve incrementally towards or away from said valve seat to vary the size of said fuel flow orifice in order to change outlet pressure and in turn flow rate of said fuel to said engine to create a air/fuel ratio in combustion chambers of said engine in a manner to restore emissions content level in said exhaust gas to an acceptable level of such exhaust emissions.