79 results about "Miller cycle" patented technology

A system for chilling the pressurized charge air to a reciprocating engine is disclosed wherein the chilling is provided by a thermally activated refrigeration cycle powered by waste heat from the engine system. This reduces the required compression power, and also retards knock, making higher compression ratios possible. The chilling system is designed to minimize the amount of chilling required, and also to enable use of compression heat to power the chiller. The disclosed improvement also accommodates exhaust gas recirculation, plus providing activation heat from the exhaust gas, plus Miller cycle timing of the intake valves. Referring to FIG. 1, the charge air from turbocharger 5 is cooled in three stages: heat recovery stage 10; ambient-cooled stage 11; and chilling stage 12. Condensed moisture is removed from the charge air by valve 14 before the charge is supplied to inlet manifold 2.

A compound cycle engine system has a rotary engine, which rotary engine generates exhaust gas. The system further has a compressor for increasing the pressure of inlet air to be supplied to the engine to a pressure in the range of from 3.0 to 5.0 atmospheres and an intercooler for providing the inlet air to the engine at a temperature in the range of from 150 to 250 degrees Fahrenheit. The system further has one or more turbines for extracting energy from the exhaust gas. The Miller Cycle is implemented in the rotary engine, enabling the compression ratio to be lower than the expansion ratio, allowing the overall cycle to be optimized for lowest weight and specific fuel consumption.

The present invention mitigates restriction due to the fact that the opening period (angular working range) of the intake valve becomes smaller in the early closing Miller cycle operation, in which the intake valve closing timing occurs before the bottom dead center. The crankshaft center O1 is offset on one side from the cylinder central axis X. The top dead center and the bottom dead center of the piston occur when the three points, namely the crankshaft center O1, the crankpin center O2, and the piston pin center O3 are aligned in one line. At this time, the connecting rod and the crank arm are inclined relative to the axis X. The inclination angle .theta..sub.bdc at the bottom dead center is greater than the inclination angle .theta..sub.tdc at the top dead center. Therefore, as the crankshaft rotates in the direction of arrow .omega., the intake process and the expansion process become greater than 180.degree. CA, while the compression process and the exhaust process become smaller than 180.degree. crank angle. Accordingly, the angular working range of the intake valve is enlarged. Therefore, the restriction to the valve lift curve is mitigated.

A cam-driven hydraulic fully variable valve mechanism of an internal combustion engine belongs to the technical field of engines. An inlet end of an oil tube III is arranged in an oil tank I, an outlet end of the oil tube is fixedly connected with an oil inlet hole I. The inlet end of the oil tube III is provided with a filter. An oil pump, an inlet end of an oil tube II and a check valve I are connected with the oil tube III in series. An overflow valve and an outlet end of an oil tube I are connected with the oil tube II in series. An outlet end of the oil tube II is arranged in the oil tank I. An inlet end of the oil tube I is fixedly connected with an oil drainage hole. The middle of the oil tube I is provided with a check valve II. The inlet end of an oil tube V is fixedly connected with an oil drainage hole II. The outlet end of the oil tube V is arranged in the oil tank II. An electro-hydraulic proportional valve is arranged adjacent to the inlet end of the oil tube V. The two ends of an oil tube IV are respectively communicated with a connecting hole and an oil inlet hole II of a tappet group. A check valve II is arranged in the middle of the oil tube IV. The cam-driven hydraulic fully variable valve mechanism of the internal combustion engine can realize continuous variable of valve lift and valve timing and throttle-free load control of a gasoline engine, reduce pumping loss, improve the volumetric efficiency, realize the Miller cycle, achieves the effect of energy saving and emission reduction, and is simple in structure and flexible in control.

A Miller cycle combustion engine capable of operating on multiple fuel types, and a method of operating the engine, is provided. The engine includes a fuel type determiner to determine the fuel type, and a compression adjustor to adjust the compression of a first cylinder of the engine to match the requirement of the determined fuel type. The compression adjustor is a variable valve timing system that provides a maximum compression when a fuel type requiring maximum compression is determined, and that advances or retards the opening of the intake valve to provide lower compression when a fuel type requiring lower compression is determined.

A miller cycle engine system is provided, which includes a motorized supercharger, and a miller cycle engine (having low compression and high explosion) having the motorized supercharger mounted thereon to improve a low-revolution performance of an engine using a scavenging phenomenon due to an operation of a variable valve device (variable valve timing, variable valve lift and variable valve duration) during an operation of the motorized supercharger and to improve a fuel efficiency through down-speeding of a gear ratio of a vehicle.

Engines and methods of controlling an engine may involve at least one fluid actuators associated with one or more engine intake and/or exhaust valves. Timing of valve closing/opening and use of an air supply system may enable engine operation according to a Miller cycle.

The invention discloses a Miller cycle diesel oil-natural gas dual fuel engine and a control method thereof, and relates to the technical field of engines. An early closing mode of an intake valve is realized through adjusting an intake valve adjusting mechanism; and a compression ratio is changed to separate from an expansion ratio, so that the cooling of mixed gas is facilitated, the thermal load of the engine is reduced, the positive suction power is generated in the expansion process to improve the thermal efficiency of the engine, and the fuel economy is preferably improved. The new control method is used for converting high/low compression ratio more flexibly, so that the diesel oil-natural gas dual fuel engine can achieve high-efficiency combustion operation in a full-load range.

An internal combustion engine is operated in accordance with a Miller cycle. The engine includes a piston disposed in the engine cylinder and configured to reciprocate between a top dead center position and a bottom dead center position of the engine cylinder. An air intake valve is coupled to the cylinder. The air intake valve is closed when the piston is about the bottom dead center position in the engine cylinder. An exhaust valve is coupled to the engine cylinder. The exhaust valve is opened for a predetermined time period when the piston is about the bottom dead center position of the engine cylinder after closing the intake valve so as to exhaust a predetermined quantity of fresh charge from the engine cylinder via the exhaust valve.

The invention provides a variable valve control device. In a traditional electro-hydraulic variable valve mechanism, a plunger type oil leakage control mechanism is arranged between a valve train cam and a hydraulic cavity, oil leakage time is controlled by adjusting the relative position between a spiral groove and an oil leakage hole in the plunger type oil leakage control mechanism, and the valve stroke and timing variability are achieved. The invention further provides a variable valve control method. The method can judge function requirements according to whole vehicle and engine operation states and comprises the steps of heat management, miller cycle, exhaust braking and cylinder deactivation and oil cut, and the function requirements are met according to the variable valve control device. The device and the method can be applied to a side-arranged cam shaft engine, and the structure is simple.

The invention provides a control method and device for a variable valve timing system of a Miller cycle engine. In the control method, a first VVT MAP taking economical efficiency as a target and a second VVT MAP taking dynamic property as a target are previously demarcated, and when the engine is in a running state under a steady-state working condition, the variable valve timing system is controlled by virtue of the first VVT MAP, and the economical efficiency of the engine is realized; and when the engine is in a running state under a transient accelerated loading working condition, the variable valve timing system is controlled by virtue of the second VVT MAP, and the dynamic property of the engine is realized, and in this way, when the working conditions of the engine are different, the different VVT MAPs are chosen to control the variable valve timing system. Compared with the purpose of realizing the economical efficiency of the engine in the prior art, the control method and device for the variable valve timing system of the Miller cycle engine give consideration to the economical efficiency and the dynamic property of the engine simultaneously, and improves the acceleratedloading capacity under the transient working condition of the engine.

A system and a method for actuating intake valves of an internal combustion engine. The system includes a hydraulic circuit including a master cylinder, a control valve, an accumulator, a first one-way valve and a slave cylinder. The slave cylinder accommodates a slave piston, which is coupled to the intake valves. The control valve is disposed upstream of the accumulator for controlling flow from the hydraulic circuit to the accumulator. The first one-way valve is disposed downstream of the accumulator for permitting flow from the accumulator to the hydraulic circuit and for preventing flow from the hydraulic circuit to the accumulator without first passing through the control valve. The control valve has an open position that provides communication between the hydraulic circuit and the accumulator for a Miller cycle or Miller-like cycle operation. The control valve also has a closed position that prevents communication between the hydraulic circuit and the accumulator during Otto cycle operation.

The method for controlling the operation of an internal combustion engine comprises at least two operating modes. In a first operating mode, the intake valve is closed at a first predetermined crank angle, in accordance with the Miller cycle, before the piston reaches bottom dead center during the intake stroke for reducing pressure in the cylinder, and fuel is injected using first fuel injection means optimized for large amounts of fuel. In a second operating mode the intake valve is closed at a second predetermined crank angle, in accordance with conventional intake valve closing timing, after or slightly before the piston has passed bottom dead center, and fuel is injected using second fuel injection means optimized for small amounts of fuel. The invention also concerns an internal combustion engine.

The invention provides a valve electro-hydraulic driving system and method for achieving Miller cycle of an engine. A crankshaft position sensor is connected with an ECU, the ECU is connected with a two-position three-way electromagnetic valve and a normally-open electromagnetic valve, the two-position three-way electromagnetic valve is connected with a high-pressure oil tank, a low-pressure oil tank and a conical slide valve, a feedback piston cylinder is fixed to a main piston cylinder, a feedback piston and a main piston are fixedly connected through a piston rod, the main piston is connected with an inlet valve, a spring is installed between the main piston and the main piston cylinder below the main piston, the conical slide valve is connected with an upper feedback cavity, a main upper cavity and a main lower cavity, a limiting hole is formed in the main lower cavity, the normally-open electromagnetic valve is connected with the upper feedback cavity, and the limiting hole and the normally-open electromagnetic valve are connected with the low-pressure oil tank through the same pipeline. The system and method are used for achieving Miller cycle of the engine, and technology universality and transferability are high.

The invention discloses an ultrahigh-supercharging turbo-charging Miller cycle engine which comprises a turbocharger and a Miller cycle engine body. The supercharge ratio of the turbocharger can exceed 2.5, but the compression ratio of the Miller cycle engine body is as low as 4. A turbine in the turbocharger can absorb much power and is a variable turbine geometry (VTG) turbine. The turbocharger can be a centrifugal supercharger, or a roots pump supercharger or a rotor pump and provides the condition that heat work absorbed by the turbine is very close to releasable heat work contained in exhaust gas. The compression ratio of the Miller cycle engine body can be fixed or adjustable. When the Miller cycle engine with fixed compression ratio is adopted, the supercharger is a supercharger with fixed flow, such as a roots pump or a rotor pump. When the supercharger with the fixed flow is adopted, the VTG turbine is connected with a crankshaft of the Miller cycle engine through a transmission. The efficiency of an internal combustion engine is remarkably improved.

The invention discloses a crank-connecting rod mechanism capable of achieving the Miller cycle and a control method. A driving oil channel and a locking oil channel are arranged in a crankshaft, an eccentric connecting rod bearing is arranged on a connecting rod neck of the crankshaft, a driving gear which meshes with an outer meshing gear ring of the eccentric connecting rod bearing through an idle gear is installed in a crankshaft balancing block, a planetary gear is installed in a driving gear hollow shaft, and the driving gear hollow shaft is provided with locking pins capable of locking the hollow shaft and the crankshaft balancing block or locking the hollow shaft and a planetary gear shaft; and the driving gear hollow shaft and the planetary gear shaft are locked by applying hydraulic oil to the driving oil channel to enable the planetary gear shaft to transmit movement to the driving gear and then transmit movement to the outer meshing gear ring of the eccentric connecting rodbearing through the idle gear, the eccentric connecting rod bearing rotates around the connecting rod neck of the crankshaft, and then the compression ratio of an engine is changed. According to the crank-connecting rod mechanism capable of achieving the Miller cycle and the control method, the crank-connecting rod mechanism can achieve synchronous movement with rotation of the engine, compressionratio adjustment of the engine in one working stroke can be achieved, then the Miller cycle is achieved, the control flexibility is high, and control is flexible.

The invention provides a linear range-extending generator driven by a pre-boost gas ventilation and exhaust free piston engine, and relates to engines and generators. Two sets of cylinder bodies are connected to a generator body, and in-cylinder pistons form a group of free pistons through connecting rods; through a full-stroke boosting system, when the pistons reciprocate once, an exhaust valve and an intake valve of each cylinder are opened and closed once, and exhaust gas is flushed and exhausted by using fresh air and air intake is completed; then compression and acting are completed oncewhich mean in-cylinder exhaust gas recirculation is combined with the similar Miller cycle; and by means of a piezoelectric knock sensor and a controller, the highest compression ratio which is reached when the engine is suitable for the current condition is automatically selected, the piston part lubrication is the inner circulation lubrication taking an inertia density difference-driven self-circulating pump as the core, the generator is a cylindrical rare earth permanent magnet reciprocating linear generator comprising two tooth groove-shaped cylinder stators with stator coil windings and aphase difference of 90 degrees, the electric energy output of the generator is realized by a power controlled regulation output circuit, and the generator also serves as a starting motor.

The invention belongs to the technical field of engines, and discloses an optimization method for integrated optimization matching of an EGR system and a pressurization system, and the optimization method for the integrated optimization matching of the EGR system and the pressurization system comprises the steps: building and verifying a simulation model of the working process of a supercharged engine; performing system characteristic simulation analysis on the Miller cycle supercharged engine; constructing an optimization algorithm for integrated optimization matching of the EGR system and the pressurization system; and optimizing the parameters of the EGR system and the supercharging system of the Miller cycle engine based on the genetic algorithm. According to the method, a certain domestic engine is used as a prototype engine for paper research, a mathematical model of the working process of each subsystem of the turbocharged gasoline engine is established, and the gasoline engine simulation calculation model established based on GT-POWER is compared with test data to verify the accuracy of the model; and the design of a high-efficiency domestic hybrid gasoline engine is promoted, the overall performance of the engine is improved, and important academic value significance and engineering application value are achieved.

The invention discloses a multi-cylinder Miller cycle engine synergetic gas intake energy-saving device and a control method thereof. The device comprises a gas storage chamber, a control valve and amechanical movable valve, wherein the gas storage chamber communicates with an inlet valve through a gas inlet branch pipe and is used for storing high-pressure low-temperature combustible mixed gas of a combustion chamber; the control valve is arranged in the gas inlet branch pipe and used for controlling opening and closing of a channel; the mechanical movable valve has the one-way communicatingfunction; gas can get into the combustion chamber from a main gas inlet pipeline, and gas in the combustion chamber cannot return. When the control valve is turned on, the high-pressure low-temperature combustible mixed gas gets into the combustion chamber and is combusted with intake gas of a gas inlet main pipe to do work. The engine synergetic gas intake device provided by the invention can temporarily store the high-pressure low-temperature combustible mixed gas discharged from a Miller engine during compression travel and supplies gas together with the inlet valve when a next cylinder takes in the gas. Meanwhile, according to the turn-on time of the control valve, the whole engine is equivalent to a variable compression ratio engine, and the comprehensive performance of the engine isimproved.