Clean Air Power, Inc.

Servojet Products International

Servoject Products International

Hoi Ching Wong

Kresimir Gebert

Niels J Beck

Niel Lenannes Beck

William P Johnson

N John Beck

Madhusudhan Chellappa

John Payne

Robert Oalen

Carlos Gamez

Niels Johannes Beck

The timing of a controlled event is advanced or retarded in an IC engine by emulating the engine speed and position signal pattern prior to transmission of that signal pattern to an output such as a fuel injector. In a multi-controller engine in which a second controller is controlled at least in part by signals delivered by first controller, the signal preferably is emulated in the first controller prior to transmission to the second engine controller in order to allow the shifting of a timing of a controlled event without direct data transfer from the second controller to the first controller. The technique is particularly well-suited for controlling diesel fuel injection in a dual fuel or other multi-fuel engine. In this case, the first controller must be a dual fuel controller and the second controller may be a diesel controller.

Modification of engine control signal timing by emulation of engine position sensors

A computer-implemented method is used to correct deviations between a predicted gas excess air ratio and a calculated excess air ratio in a dual fuel engine or other gas fueled compression ignition engine. The method includes determining gas excess air ratio for the engine based at least in part on at least one detected current operating parameter and calculating a predicted exhaust gas oxygen concentration engine based on the predicted gas excess air ratio. A time based filtered predicted exhaust gas oxygen concentration value may then be calculated and compared to a time-based filtered measured exhaust gas oxygen concentration value. The resultant oxygen concentration deviation value may be used to generate a corrected predicted gas excess air ratio.

Method and apparatus for adaptive feedback control of an excess air ratio in a compression ignition natural gas engine

At least one engine operating parameter other than total fuel energy content is taken into account when transitioning between operating modes in a dual fuel or other multimode engine () in order to maintain a smooth transition between modes. The parameter preferably comprises at least one of primary fuel excess air ratio (lambda) and ignition timing and preferably is controlled in addition to total fuel energy content control. Lambda control is especially beneficial because it permits the control system to compensate for the engine's inability to substantially alter the instantaneous air mass in the combustion chamber during the transition period. For instance, during a transition from pilot ignited gaseous fuel mode to diesel mode, the controlled parameter preferably comprises diesel lambda, and the controlling step comprises setting diesel lambda at a relatively high value at the beginning of the transition period and thereafter reducing diesel lambda during the transition period.

Method and apparatus for controlling transition between operating modes in a multimode engine

An EGR equipped internal combustion engine is controlled to maximize the beneficial effects and minimize the detrimental effects of EGR on engine operation. Specifically, at least one parameter indicative of the Oconcentration in the intake mixture and/or at least one parameter indicative of the HO concentration in the intake mixture is monitored, and the monitored parameter is relied on to control one or more aspects of engine operation by open loop adjustment of other control strategies and/or by a separate closed loop control strategy. These controls are applicable to virtually any engine, and are particularly beneficial to lean burn engines such as diesel (compression ignition) engines, spark ignited natural gas engines, and dual fuel or other compression ignited natural gas engines. The engine may be equipped with either actively controllable EGR or passive and uncontrolled EGR.

Optimized combustion control of an internal combustion engine equipped with exhaust gas recirculation

EGR mass fraction or a value indicative thereof can be calculated based on temperature measurements rather than mass flow and/or pressure measurements, hence negating the need for expensive and relatively unreliable measurement devices in an active EGR system for an internal combustion engine. The EGR system may be a low pressure EGR system configured to direct cooled, filtered EGR to the engine's air intake system using an effective, simple venturi and/or a continuously regenerated catalytic particulate trap. The resultant system can reduce NOx emissions in a diesel engine on the order of 50% and approximately 90% for CO, HC, and PM. NOx and other emissions can be reduced still further when the EGR system is combined with other pretreatment and/or after treatment devices. Many components of the low pressure EGR system are also usable in a passive EGR system.

EGR control system and method for an internal combustion engine

The performance of a compression ignition internal combustion engine is improved by optimizing excess air ratio (lambda) and/or intake air charge temperature (ACT) on a full time, fall range basis. The basic procedure is to first determine the desired or optimum lambda and then to control ACT and intake manifold absolute pressure (MAP) to maintain them at the optimum values for the fuel quantity required at a particular operating point. This approach allows control of both temperature and pressure of the air entering the engine. Full range control requires that lambda and ACT be controlled both upward and downward to achieve optimal engine performance. Control of both lambda and ACT is further enhanced through the use of a supercharger with adjustable input power installed in series with a standard turbocharger compressor of the engine. Supercharger control may if desired be supplemented with turbo air bypass (TAB) control, turbocharger variable area nozzle or wastegate, turboexpander control, and intake and exhaust valve control including skip fire of both fuel and air. The essence of optimized lambda control is to measure the physical properties of the working fluid in the intake manifold, exhaust manifold, or both, compute the actual value of lambda, and compare that actual value with an optimum value for the prevailing engine operating conditions. This comparison yields an error signal which is then used to control the magnitude of the required adjustment in turbocharger pressure or other engine operating parameter.

Optimized lambda and compression temperature control for compression ignition engines

The performance of a compression ignition internal combustion engine is improved by optimizing excess air ratio (lambda) and/or intake air charge temperature (ACT) on a full time, full range basis. The basic procedure is to first determine the desired or optimum lambda and then to control ACT and intake manifold absolute pressure (MAP) to maintain them at the optimum values for the fuel quantity required at a particular operating point. This approach allows control of both temperature and pressure of the air entering the engine. Full range control requires that lambda and ACT be controlled both upward and downward to achieve optimal engine performance. Control of both lambda and ACT is further enhanced through the use of a supercharger with adjustable input power installed in series with a standard turbocharger compressor of the engine. Supercharger control may if desired be supplemented with turbo air bypass (TAB) control, turbocharger variable area nozzle or wastegate, turboexpander control, and intake and exhaust valve control including skip fire of both fuel and air. The essence of optimized lambda control is to measure the physical properties of the working fluid in the intake manifold, exhaust manifold, or both, compute the actual value of lambda, and compare that actual value with an optimum value for the prevailing engine operating conditions. This comparison yields an error signal which is then used to control the magnitude of the required adjustment in turbocharger pressure or other engine operating parameter.

A pintle nozzle, preferably an unthrottled pintle nozzle, is provided in which a negative interference angle is formed between the conical tip of the nozzle needle and the mating conical valve seat so that the needle seat is located at the bottom of the valve seat rather than at the top. The resulting nozzle lacks any velocity drop downstream of the needle seat, even at very low needle lifts, so that virtually all of the energy used to pressurize the fuel is converted to kinetic energy. Spray dispersion and penetration at low needle lifts therefore are significantly enhanced. Fuel flow through the converging-diameter discharge passage located between the conical needle tip and conical needle seat also self-centers the nozzle needle at low lifts, thereby helping to assure a symmetric spray and to further enhance spray characteristics. These and other advantages render the nozzle particularly useful for applications which require very small injection quantities such as the injection of fuel into small two-stroke gasoline engines or into pilot-ignited gas-fueled engines.

Bottom seated pintle nozzle

The performance of a gas-fueled unthrottled internal combustion engine is improved by optimizing excess air ratio (lambda) in the engine. Lambda is optimized by selecting automatically and continuously the optimum fraction of cylinders firing (OFF) as a function of engine operating parameters, eliminating the fuel charge from one or more cylinders to obtain firing in the OFF, and distributing the unused fuel to the OFF, thereby decreasing lambda in the firing cylinders to an optimum level. OFF may be calculated according to mathematically derived and empirically weighted equations, or obtained with reference to suitable look-up tables. In addition, optimum lambda and OFF may be adjusted to take into account the effects of exhaust gas recirculation (egr), engine speed, and/or engine timing. Further lambda adjustment can be performed by suitable control of egr, ignition timing, and/or turbo air bypass (TAB).

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San Diego, CA, United States of America

Hoi Ching Wong