US5791145A
Expired / Lapsed
US
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Natural gas engine control system
Assignee: Rolls Royce Energy Systems Inc
•
Filing: 1996-10-25
•
Granted: 1998-08-11
•
Expires: 2016-10-25
Abstract
Abstract A control system for an internal combustion engine can include a fuel molecular weight sensor to determine an actual and a desired Excess Air Ratio for an air/fuel mixture supplied to the engine. To prevent engine overload, the control system limits the amount of fuel delivered to the engine based on the amount of air available to the engine. High pressure exhaust gas can drive an air compressor which pressurizes inlet air. A exhaust bypass valve controls the amount of power delivered to the compressor, and the pressure and amount of inlet air delivered to the engine. Independent control of the main fuel flow and pilot fuel flow allows the control system to maintain a desired air/fuel ratio in the main combustion chamber and in the precombustion chamber.
Inventors
- 👤 Paul Douglas Freen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:39
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/0025; F02D41/0027; F02B; F02B29/00; F02B29/04; F02B29/0406; F02B29/0412; F02B29/0437; F02B33/00; F02B33/44; F02B37/00; F02B37/12; F02B37/18; F02D19/00; F02D19/02; F02D19/021; F02D19/022; F02D19/023; F02D19/026; F02D19/027; F02D19/029; F02M; F02M21/00; F02M21/02; F02M21/0203; F02M21/0215; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/30
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
76 words
A control system for an internal combustion engine comprising: means for detecting an air flow rate; a fuel quality sensor for detecting a fuel quality; a device for determining a fuel flow rate set point; means for computing a maximum fuel flow rate based on the detected air flow rate and the detected fuel quality; and means for controlling a fuel flow based on the maximum fuel flow rate and the fuel flow rate set point.
Claim 2
Dependent Claim
76 words
A control system for an internal combustion engine comprising: means for detecting an air flow rate; a fuel quality sensor for detecting a fuel quality; a device for determining a fuel flow rate set point; means for computing a maximum fuel flow rate based on the detected air flow rate and the detected fuel quality; and means for controlling a fuel flow based on the maximum fuel flow rate and the fuel flow rate set point.
Claim 3
Dependent Claim
21 words
The control system of claim 1, wherein the maximum fuel flow rate is computed based also on a predetermined air/fuel ratio.
Claim 4
Dependent Claim
53 words
The control system of claim 1, further comprising: an exhaust turbine which drives an inlet air compressor; and an exhaust bypass valve which allows exhaust gas to bypass the exhaust turbine, wherein the computing means is adapted to control the exhaust bypass valve to supply a desired air flow rate to the engine.
Claim 5
Dependent Claim
44 words
The control system of claim 1, further comprising a main fuel rate control valve for controlling a main fuel rate and a pilot fuel rate control valve for controlling a pilot fuel rate, each of the valves being independently controllable by the control system.
Claim 6
Dependent Claim
47 words
The control system of claim 4, further comprising means for determining a stoichiometric air/fuel ratio, wherein the pilot fuel flow rate is controlled based on the stoichiometric air/fuel ratio, and the main fuel flow rate is controlled so as not to exceed the maximum fuel flow rate.
Claim 7
Dependent Claim
51 words
The control system of claim 1, further comprising: means for detecting an actual engine speed; means for setting a desired engine speed; and wherein the means for computing the maximum fuel flow rate computes the maximum fuel flow rate based also on the actual engine speed and the desired engine speed.
Claim 8
Dependent Claim
34 words
The control system of claim 1, wherein the fuel quality sensor comprises a molecular weight sensor which computes a molecular weight of fuel based on a propagation speed of a wave through the fuel.
Claim 9
Dependent Claim
59 words
A control system for an internal combustion engine comprising: a fuel molecular weight sensor for detecting a molecular weight of a fuel; means for computing a maximum fuel flow rate based on the detected fuel molecular weight; and means for limiting a flow rate of fuel supplied to the internal combustion engine based on the maximum fuel flow rate.
Claim 10
Dependent Claim
59 words
A control system for an internal combustion engine comprising: a fuel molecular weight sensor for detecting a molecular weight of a fuel; means for computing a maximum fuel flow rate based on the detected fuel molecular weight; and means for limiting a flow rate of fuel supplied to the internal combustion engine based on the maximum fuel flow rate.
Claim 11
Dependent Claim
45 words
The control system of claim 8, further comprising: means for detecting an air flow rate; and wherein the means for computing a maximum fuel flow rate computes the maximum fuel flow rate based also on the detected air flow rate and a predetermined air/fuel ratio.
Claim 12
Dependent Claim
77 words
The control system of claim 8, wherein the molecular weight sensor comprises: a transducer for transmitting a wave through a sample of the fuel and for receiving the wave after the wave has travelled a predetermined distance through the fuel; means for measuring a speed of the wave based on a time of transmission and reception of the wave; and means for computing the molecular weight of the fuel based on the measured speed of the wave.
Claim 13
Dependent Claim
82 words
The control system of claim 10, wherein the molecular weight sensor further comprises a temperature sensor for measuring a temperature of the fuel, and wherein the means for computing the molecular weight of the fuel computes the molecular weight of the fuel based on the following equation: molecular weight=k*R*T.sub.fuel /S.sup.2 where k is the specific heat ratio of the fuel, R is the universal gas constant, T fuel is the temperature of the fuel, and S is the speed of the wave.
Claim 14
Dependent Claim
13 words
The control system of claim 10, wherein the transducer is an ultrasonic transducer.
Claim 15
Dependent Claim
36 words
The control system of claim 8, wherein the means for computing a maximum fuel flow rate computes the maximum fuel flow rate based on the detected fuel molecular weight such that engine knock does not occur.
Claim 16
Dependent Claim
16 words
The control system of claim 8, further comprising means for detecting an actual air flow rate.
Claim 17
Dependent Claim
28 words
The control system of claim 14, wherein the maximum fuel flow rate is computed based also on an input air fuel ratio and the actual air flow rate.
Claim 18
Dependent Claim
22 words
A control system of claim 15, further comprising means for determining a fuel flow set point based on an input engine speed.
Claim 19
Dependent Claim
35 words
The control system of claim 16, wherein the limiting means limits the flow rate of fuel supplied to the internal combustion engine based on the maximum fuel flow rate and the fuel flow set point.
Claim 20
Dependent Claim
38 words
The control system of claim 16, wherein the limiting means limits the flow rate of fuel supplied to the internal combustion engine based on the lower of the maximum fuel flow rate and the fuel flow set point.
Claim 21
Dependent Claim
46 words
The control system of claim 8, further comprising means for determining a maximum torque output for the engine based on the molecular weight of the fuel such that engine knock does not occur, the maximum fuel flow rate being computed based on the maximum torque output.
Claim 22
Dependent Claim
69 words
The control system of claim 8, further comprising means for determining an actual air fuel ratio, means for determining a target air flow based on an input air fuel ratio and the actual air fuel ratio, and means for directing an amount of exhaust gas to an exhaust turbine which drives an inlet air compressor such that an actual air flow rate substantially equals the target air flow rate.
Claim 23
Dependent Claim
116 words
A control system for an internal combustion engine comprising: means for detecting an air flow rate; a control unit for computing a maximum fuel flow rate based on the detected air flow rate and a predetermined air/fuel ratio; an exhaust turbine which drives an inlet air compressor; an exhaust bypass valve which allows exhaust gas to bypass the exhaust turbine, wherein the control unit controls the exhaust bypass valve to supply a desired air flow rate to the engine; means for detecting an actual engine speed; means for setting a desired engine speed; and wherein the control unit computes the maximum fuel flow rate based also on the actual engine speed and the desired engine speed.
Claim 24
Dependent Claim
116 words
A control system for an internal combustion engine comprising: means for detecting an air flow rate; a control unit for computing a maximum fuel flow rate based on the detected air flow rate and a predetermined air/fuel ratio; an exhaust turbine which drives an inlet air compressor; an exhaust bypass valve which allows exhaust gas to bypass the exhaust turbine, wherein the control unit controls the exhaust bypass valve to supply a desired air flow rate to the engine; means for detecting an actual engine speed; means for setting a desired engine speed; and wherein the control unit computes the maximum fuel flow rate based also on the actual engine speed and the desired engine speed.
Claim 25
Dependent Claim
39 words
The control system of claim 21, wherein the control unit calculates the desired air flow rate based on a detected air/fuel ratio and the predetermined air/fuel ratio such that the detected air/fuel ratio substantially equals the predetermined air/fuel ratio.
Claim 26
Dependent Claim
106 words
A control system for an internal combustion engine comprising: means for detecting an air flow rate; a control unit for computing a maximum fuel flow rate based on the detected air flow rate and a predetermined air/fuel ratio; an exhaust turbine which drives an inlet air compressor; an exhaust bypass valve which allows exhaust gas to bypass the exhaust turbine, wherein the control unit controls the exhaust bypass valve to supply a desired air flow rate to the engine; a fuel quality sensor for sensing a fuel quality, and wherein the control unit computes the maximum fuel flow rate based also on the sensed fuel quality.
Claim 27
Dependent Claim
106 words
A control system for an internal combustion engine comprising: means for detecting an air flow rate; a control unit for computing a maximum fuel flow rate based on the detected air flow rate and a predetermined air/fuel ratio; an exhaust turbine which drives an inlet air compressor; an exhaust bypass valve which allows exhaust gas to bypass the exhaust turbine, wherein the control unit controls the exhaust bypass valve to supply a desired air flow rate to the engine; a fuel quality sensor for sensing a fuel quality, and wherein the control unit computes the maximum fuel flow rate based also on the sensed fuel quality.
Claim 28
Dependent Claim
16 words
The control system of claim 24, wherein the fuel quality sensor comprises a molecular weight sensor.
Claim 29
Dependent Claim
66 words
The control system of claim 24, wherein the molecular weight sensor comprises: a transducer for transmitting a wave through a sample of the fuel and for receiving the wave after the wave has travelled a predetermined distance through the fuel; means for measuring a speed of the wave; and means for computing the molecular weight of the fuel based on the measured speed of the wave.
Claim 30
Dependent Claim
84 words
The control system of claim 25, wherein the molecular weight sensor further comprises a temperature sensor for measuring a temperature of the fuel, and wherein the means for computing the molecular weight of the fuel computes the molecular weight of the fuel based on the following equation: molecular weight=k*R*T fuel /S 2 where k is the specific heat ratio of the fuel, R is the universal gas constant, T fuel is the temperature of the fuel, and S is the speed of the wave.
References Cited (Backward Citations)
US2521634A
Cited
US3575146A
Cited
US3982503A
Cited
US4050428A
Cited
US3871214A
Cited
US4060714A
Cited
US4121455A
Cited
US4140473A
Cited
US4112756A
Cited
US4276600A
Cited
US4245314A
Cited
US4246773A
Cited
US4252097A
Cited
US4220040A
Cited
US4280183A
Cited
US4458529A
Cited
US4357828A
Cited
US4386858A
Cited
US4444337A
Cited
US4416239A
Cited
US4463565A
Cited
US4369651A
Cited
US4445389A
Cited
US4430978A
Cited
US4454852A
Cited
US4583176A
Cited
US4576039A
Cited
US4600993A
Cited
US4496286A
Cited
US4596133A
Cited
US4625697A
Cited
US4736589A
Cited
US4527417A
Cited
US4709334A
Cited
US5093793A
Cited
US4630482A
Cited
US4663977A
Cited
US4829449A
Cited
US5048495A
Cited
US4873961A
Cited
US4892072A
Cited
US4825380A
Cited
US4907556A
Cited
US5052230A
Cited
US5159912A
Cited
US4976241A
Cited
US4993386A
Cited
US5062788A
Cited
US5146886A
Cited
US5131228A
Cited
US5206809A
Cited
US5095877A
Cited
US5129228A
Cited
US5036669A
Cited
US4986243A
Cited
US4951503A
Cited
US5081969A
Cited
US5116356A
Cited
US5136880A
Cited
US5408979A
Cited
US5131224A
Cited
US5237523A
Cited
US5219227A
Cited
US5293852A
Cited
US5148791A
Cited
US5152174A
Cited
US5249453A
Cited
US5216916A
Cited
US5268842A
Cited
US5199394A
Cited
US5172550A
Cited
US5313826A
Cited
US5296196A
Cited
US5137000A
Cited
US5205260A
Cited
US5281915A
Cited
US5275553A
Cited
US5238030A
Cited
US5259424A
Cited
US5201907A
Cited
US5218941A
Cited
US5325703A
Cited
US5311447A
Cited
US5201581A
Cited
US5259239A
Cited
US5421212A
Cited
US5275142A
Cited
US5235954A
Cited
US5343760A
Cited
US5205253A
Cited
JPH06137156A
Cited
US5230322A
Cited
US5253632A
Cited
US5537854A
Cited
US5365902A
Cited
US5386698A
Cited
US5392635A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-10 | 2002-02-09 | 2002-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-10 | 2006-02-09 | 2006-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-10 | 2010-02-09 | 2010-08-11 | $7700.00 | Window Closed / Lapsed |