461 results about "Engine cycle" patented technology

In a combined steam and gas turbine engine cycle, a combustion chamber is made durable against high pressure and enlarged in length to increase the operation pressure ratio, without exceeding the heat durability temperature of the system while increasing the fuel combustion gas mass flow four times as much as the conventional turbine system and simultaneously for greatly raising the thermal efficiency of the system and specific power of the combined steam and gas turbine engine.Water pipes and steam pipes are arranged inside the combustion chamber so that the combustion chamber can function as a heat exchanger and thereby convert most of the combustion thermal energy into super-critical steam energy for driving a steam turbine and subsequently raising the operation pressure ratio and the thermal efficiencies of the steam turbine cycle and gas turbine cycle. The combustion gas mass flow can be also increased by four times as much as the conventional turbine system (up to the theoretical air to fuel ratio) and the thermal efficiency and the specific power of the gas turbine cycle are considerably increased.Further, the thermal efficiency of the combined system is improved by installing a magnetic friction power transmission system to transmit the power of the system to outer loads.

An engine system and method are disclosed for controlling pre-ignition of an alcohol fuel. In one embodiment, the fuel injection timing is adjusted to cause the fuel to avoid combustion chamber surfaces. In another embodiment, the fuel injection timing is adjusted to spray the fuel directly onto the piston surface to cool the piston. Also disclosed is a cylinder cleaning cycle in which engine knock is purposely caused for one to hundreds of engine cycles by adjusting the fuel content away from alcohol toward gasoline. Further measures to cause knock which are disclosed: adjusting spark timing, intake boost, exhaust gas fraction in the cylinder, cam timing, and transmission gear ratio.

An internal combustion engine (10) is provided with a port injector (28) and an in-cylinder injector (22). Before a port injection is started, the total amount of fuel to be injected is calculated (at an injection amount calculation timing). The port injection fuel amount and the in-cylinder injection fuel amount are calculated by appropriately dividing the total amount between them. If a change of the operating load on the internal combustion engine (10) is detected after the injection amount calculation timing, the load change is reflected in the amount of fuel to be injected in the current engine cycle by increasing or decreasing the in-cylinder injection fuel amount.

Each cylinder is provided with an ignition plug, two intake valves, an intra-cylinder fuel injector, and a port fuel injector. When homogeneous combustion is demanded, the intra-cylinder fuel injector and port fuel injector inject fuel on the same engine cycle. The port fuel injector is installed so that the amount of fuel directed toward outer regions of the intake valves is larger than that of fuel directed toward inner regions of the intake valves, thereby causing only fresh air to flow to regions near the inner regions of the intake valves.

A system and method for enhanced combustion control in an internal combustion engine is disclosed. A fuel supply system has a fuel injector positioned to directly inject fuel into a combustion chamber, and it is capable of performing a split injection wherein a first fuel injection in each engine cycle precedes a second fuel injection that occurs during compression stroke in the same engine cycle. A spark plug produces a spark to ignite a first air/fuel mixture portion created due to the second fuel injection, initiating a first stage combustion. The first stage combustion raises temperature and pressure high enough to cause auto-ignition of a second air/fuel mixture portion surrounding the first air-fuel mixture portion, initiating a second stage combustion. An engine controller is programmed to perform control over initiation timing of the second stage combustion in response to at least one of the engine speed and load. This control is accomplished by varying at least one of a fuel injection timing of the first fuel injection, a fuel injection timing of the second fuel injection, spark timing, a proportion of fuel quantity of the second fuel injection to the total fuel injected in each engine cycle, and an EGR rate in response to at least one of engine speed and load.

A system and method to control engine valve timing to during the start of an internal combustion engine. Electromechanical valves are controlled in a manner to reduce engine vibration and hydrocarbon emissions during the start of an internal combustion engine. The method controls valves without an explicit four-stroke engine cycle during a start.

A method of operating an electronically controlled dual fuel compression ignition engine includes injecting a pilot ignition quantity of liquid fuel into an engine cylinder from a dual fuel injector in an engine cycle during an auto ignition condition. An amount of gaseous fuel is also injected into the engine cylinder from the dual fuel injector in the same engine cycle. The amount of gaseous fuel is divided between a pre-mix quantity of gaseous fuel, which may be injected about 90° before top dead center, and a post ignition quantity of gaseous fuel that may be injected after top dead center, with both quantities being greater than zero. An engine controller may change a ratio of the pre-mix quantity of gaseous fuel to the post ignition quantity of gaseous fuel responsive to changing from a first engine speed and load to a second engine speed and load. The pilot ignition quantity of liquid fuel is compression ignited, which in turn causes the gaseous fuel to be ignited. A pre-mix quantity of liquid fuel may also be included in order to speed the combustion process at higher engine speeds.

A generic technique for the detection of air-fuel ratio (or torque) imbalances in a 4-cylinder engine equipped with either a production oxygen sensor or a wide-range A/F sensor (or a crankshaft torque sensor) is developed. The method is based on a novel frequency-domain characterization of pattern of imbalances and its geometric decomposition into four basic templates. Once the contribution of each basic template to the overall imbalances is computed, templates of opposite direction are imposed to restore air-fuel ratio (or torque) balance among cylinders. At any desired operating condition, elimination of imbalances is achieved within few engine cycles. The method is applicable to current and future engine technologies with variable valve actuation, fuel injectors and/or individual spark control.

Methods and systems are provided for a boosted engine having a split intake system coupled to a split exhaust system. Aircharges of differing composition, pressure, and temperature may be delivered to the engine through the split intake system at different points of an engine cycle. In this way, boost and EGR benefits may be extended.

An engine control apparatus is disclosed for determining crankshaft position and engine phase of an internal combustion engine (10) through monitoring intake air pressure fluctuations (120). The opening of the intake valve (44) is mechanically linked to the crankshaft position of an engine. When the intake valve (44) opens it creates air pressure fluctuations in the air induction system (14) of the engine (10). The control apparatus is configured to determine intake air pressure fluctuations indicative of an intake air event (100 to 110) and thus a particular crankshaft position, and their corresponding period of the engine cycle. The controller then uses this information to determine crankshaft speed and position for the purpose of fuel injection and ignition timing of the internal combustion engine. Engine phase is also determined on four-stroke engines. The engine may also include a crankshaft position sensor in combination with monitoring intake air pressure fluctuations to increase resolution in determination of crankshaft position.

What is disclosed is a micro-pilot injection ignition type gas engine, whereby an air fuel ratio control in starting the engine is executed with enhanced precision, by means of introducing skip-firing intermittent operations which reflect the engine operation conditions, while an idling time span can be shortened or omitted.

The engine includes: a gas valve that opens and closes a fuel-gas passage in front of each cylinder, so as to arbitrarily control the throat area as well as the opening-closing time span of the gas valve; an engine speed detecting unit to detect the engine speed; a combustion diagnosis unit to detect an engine combustion state through a cylinder pressure distribution along elapsed time, as to each cylinder; an opening-closing control unit as to the gas valve, so as to control the intermittent opening-closing of the gas valve according to the levels of the detected engine speed as well as the cylinder pressure distribution; whereby, in starting the engine, the intermittent opening-closing of the gas-valve enables at least one skip-firing mode that brings an enhanced fuel-supply pressure-pulsation with which a relatively large amount of fuel-gas is supplied per engine cycle with firing so that the air fuel-gas ratio of each cylinder reaches a prescribed target value.

Methods and devices are described for performing engine diagnostics during skip fire operation of an engine while a vehicle is being driven. Knowledge of the firing sequence is used to determine appropriate times to conduct selected diagnostics and/or to help better interpret sensor inputs or diagnostic results. In one aspect, selected diagnostics are executed when a single cylinder is fired a plurality of times in isolation relative to a sensor used in the diagnosis. In another aspect, selected diagnostics are conducted while the engine is operated using a firing sequence that insures that no cylinders in a first cylinder bank are fired for a plurality of engine cycles while cylinders in a second bank are at least sometimes fired. The described tests can be conducted opportunistically, when conditions are appropriate, or specific firing sequences can be commanded to achieve the desired isolation or skipping of one or more selected cylinders.

An improved configuration for internal combustion engine that reduces side forces on pistons during the engine cycle. The improvement is an intermediate and guided bridge element located between pull rods and pistons with articulated connections that allow side forces to be dissipated away from the pistons.

Methods and apparatus for providing bleeder-type and compression-release engine braking in an internal combustion engine are disclosed. For bleeder-type engine braking, the exhaust valve is maintained at a small and relatively constant lift throughout all or much of the engine cycle. The engine braking may be combined with exhaust gas recirculation, variable exhaust brake, and/or operation of a variable geometry turbocharger.

A method of using exhaust gas recirculation (EGR) in an internal combustion engine. At least two of the cylinders are “dual exhaust-ported cylinders” having two exhaust ports. For each of these cylinders, one of the exhaust ports is connected to the EGR loop and the other of the exhaust ports is connected to the main exhaust line. These cylinders are controlled such that one exhaust port is open and the other exhaust port is closed during each engine cycle, and are operated, on a cycle-by-cycle basis so that all of the exhaust produced by a cylinder may be delivered to the EGR loop at any cycle. The number of cylinders operating as EGR cylinders per engine cycle is in response to a desired EGR rate.

A method comprises steps for reconstructing in-cylinder pressure data from a vibration signal collected from a vibration sensor mounted on an engine component where it can generate a signal with a high signal-to-noise ratio, and correcting the vibration signal for errors introduced by vibration signal charge decay and sensor sensitivity. The correction factors are determined as a function of estimated motoring pressure and the measured vibration signal itself with each of these being associated with the same engine cycle. Accordingly, the method corrects for charge decay and changes in sensor sensitivity responsive to different engine conditions to allow greater accuracy in the reconstructed in-cylinder pressure data. An apparatus is also disclosed for practicing the disclosed method, comprising a vibration sensor, a data acquisition unit for receiving the vibration signal, a computer processing unit for processing the acquired signal and a controller for controlling the engine operation based on the reconstructed in-cylinder pressure.

The invention relates to the technical field of electric automobiles, in particular to a heat management system of a range-extending type electric mobile, and a control method. The heat management system comprises an engine circulation subsystem, a drive motor circulation subsystem and an air conditioner refrigeration circulation subsystem, wherein the engine circulation subsystem comprises a range-extending engine, a circulation water pump I, a heat radiator I, a cooling fan, an electromagnetic valve I, a heat radiator II, an air blower, a PTC heater, an electromagnetic valve II and a battery pack; the drive motor circulation subsystem comprises a circulation water pump II, an inverter, a drive motor, a range-extending engine and a heat radiator III; the air conditioner refrigeration circulation subsystem comprises a compressor, a condenser, an electromagnetic valve III, a battery pack, an evaporator and an air blower. The heat management system is safe and reliable and is good in heat management effects.