Internal combustion engine with fuel injection systems and additional chamber for injecting hot gases into cylinder, igniting combustible mixture

Abstract

FIELD: engine building.SUBSTANCE: when burning diesel fuel, the cycle temperature can be reduced thereby reducing the formation of nitrogen oxides in the exhaust gases. An internal combustion engine is proposed, comprising a cylinder 1 having a cylinder head 2 in which a hot gas injection chamber 3 is installed. Hot gases enter the hot gas injection chamber from the previous working stroke in the cylinder and are stored there until injection in the next working stroke, thereby igniting the working mixture in the engine cylinder. The hot gas injection chamber includes a cylinder made of heat-resistant steel, covered with thermal insulation both inside and outside, and a wire with high electrical resistance is laid in the internal thermal insulation, which is constantly heated by current from the battery during starting and during operation of the engine. A valve for supplying hot gases to the combustion chamber of the cylinder is installed in the centre of the injection chamber. The hot gas injection valve is driven by two electromagnets, one of which opens and the other closes. The hot gas injection valve is controlled by an electronic control unit.EFFECT: gasoline engines can switch to high-quality regulation across the entire range.3 cl, 3 dwg

Description

[0001] Currently, two combustion initiation methods are used in piston engines: combustion of a gasoline or gas fuel-air mixture ignited by an electric spark and injection of liquid fuel into the hot air compressed in the cylinder (the diesel cycle). Each cycle has its own significant drawbacks. Spark-ignition engines use quantitative regulation of the fuel-air mixture supply, which leads to a sharp reduction in efficiency at partial loads. Land-based engines, especially in urban areas, typically operate at partial loads. To maintain engine idling, more fuel is added than required for complete combustion, which leads to the formation of carbon monoxide in the exhaust gases. The most modern mixture formation systems in gasoline engines consist of two injectors delivering fuel to the cylinder: one injector delivers fuel under the intake valve, the other directly into the combustion chamber.In this case, it is possible to ignite a lean mixture, saving fuel at partial idle. This is achieved by organizing stratified mixture formation using an injector that delivers fuel into the combustion chamber. The air is accelerated through additional techniques, creating a vortex in the longitudinal plane. At the moment the spark jumps, a rich mixture is supplied to the spark plug, which ignites. The burning mixture ignites the lean mixture in the cylinder.

[0002] Diesel engines use high-quality control, and efficiency increases at partial loads. However, significant soot formation occurs during combustion. This is due to the fact that the outer droplets of injected fuel, when they begin to burn, sharply raise the temperature in the cylinder, and the internal fuel particles, which have not been exposed to oxygen, turn into soot. Combustion temperatures in diesel engines exceed 2000 degrees Celsius, which leads to increased nitrogen oxides in the exhaust gases. In winter operation, diesel engines are known to use wide-phase fuels (WPF), consisting of gasoline, kerosene, and diesel fuel. This improves starting performance. Disclosure of the invention.

[0003] Technical result: the invention is aimed at reducing carbon monoxide emissions and achieving high-quality control of gasoline engines. When igniting diesel fuel at a temperature below the autoignition temperature, it must be pre-atomized for more uniform mixing with air, which reduces soot formation. The diesel-air mixture is compressed in the cylinder to a value below the autoignition temperature, which leads to a decrease in the maximum combustion temperature and, consequently, a reduction in nitrogen oxides. By igniting a stoichiometric or lean gasoline-air, gas-air, or diesel-air mixture with hot gas, it is possible to achieve high-quality control of the injected fuel volume in partial modes, reducing carbon monoxide emissions, soot formation, and combustion temperatures below 2000 degrees. To solve these problems, an additional chamber (hot gas injection chamber) was developed.It is recommended that when injecting gasoline into a cylinder or under the intake valves, the temperature in the working cylinder at the end of the compression stroke should not exceed the detonation threshold. When injecting diesel fuel into a cylinder at the end of the compression stroke, the temperature in the working cylinder should be below the autoignition temperature.

[0004] Hot gases are extracted from the previous power stroke during the "power stroke" and enter the injection chamber. The device works as follows: when the piston in the working cylinder moves toward the head on the compression stroke, the injection chamber opens 15-20 degrees before top dead center (TDC). The hot gas pressure is more than twice the pressure in the combustion chamber. The hot gases rush into the combustion chamber and ignite the air-fuel mixture. The hot gas injection valve remains open until the piston drops 30-40 degrees past TDC, after which the injection chamber valve closes. Hot gases remain in the injection chamber at a temperature and pressure close to the cylinder pressure at 30-40 degrees after TDC. The cycle then repeats. At partial loads, the hot gas injection chamber closes earlier; at idle speed, it can close when lowered by 5 degrees from TDC.When running on gasoline, the injectors are installed before the intake valves. When running on other fuels, additional injectors must be installed in the intake manifold before the valves or directly in the cylinder (Fig. 1). To maintain a high temperature until the next compression stroke, the chamber consists of a heat-resistant steel cylinder lined with thermal insulation both inside and outside. A high-resistance wire is inserted into the internal thermal insulation, which is constantly heated by current from the battery during starting and during operation. The injection chamber volume is 5-10% of the combustion chamber volume of the working cylinder. A valve is installed in the center of the injection chamber into the combustion chamber of the working cylinder. The valve is a heat-resistant steel needle covered with thermal insulation and terminated in a conical end at the inlet of the combustion chamber.The valve is opened and held by an opening solenoid when energized, and the closing solenoid is de-energized. To close and hold the valve, the opening solenoid is de-energized and the closing solenoid is energized. The valve opening and closing timing is determined by the piston engine's electronic control unit.

[0005] Hot gas ignition of gasoline mixtures increases the initial combustion volume of the fuel-air mixture, reducing the risk of detonation and allowing for an increased compression ratio, thereby improving the thermal efficiency of the combustion cycle. It is recommended to inject diesel fuel at compression ratios at which the temperature at TDC does not reach the autoignition temperature. Hot gas ignition of diesel mixtures allows for a lower compression ratio, allowing fuel injection throughout virtually the entire compression stroke, improving fuel-air mixing. As the piston approaches TDC, the hot gas injection chamber valve opens, igniting the diesel mixture. Diesel fuel is better mixed with air, reducing soot production. The combustion cycle temperature drops below 2000°C, reducing nitrogen oxide emissions. A decrease in combustion cycle temperature reduces thermal efficiency.When diesel mixtures are ignited with hot gases, the initial combustion volume of the fuel-air mixture increases, ignition delay is reduced, and diesel fuel burns to a greater extent at a constant volume, which improves cycle efficiency. Better mixing of fuel and air reduces excess air, which increases specific power. Increasing the volume of the hot gas injection chamber is desirable for improving detonation resistance in gasoline engines; in diesel engines, it will increase the combustion rate, which will occur at a constant volume. A larger injection chamber volume will allow leaner mixtures to be ignited, thereby increasing efficiency at partial throttle. Increasing the volume of the injection chamber can only be limited by the design constraints of the injection chamber's location upstream of the combustion chamber. The hot gas injection chamber valve is actuated by two solenoids. One solenoid opens the valve, and the second solenoid closes it.Each solenoid consists of a housing, an armature, and a winding. The opening solenoid has a "Stop" switch, while the closing solenoid's "Stop" switch is the hot gas chamber valve needle, which closes the passage into the combustion chamber. The solenoid armature is connected to the injection chamber valve via a thermally insulating coupling. The cores of each solenoid have an operating air gap; when voltage is applied to the solenoid coil, they become a source of electromagnetic driving force. When voltage is applied to the far solenoid, the armature is pulled outward and opens the injection chamber valve. The near solenoid is de-energized. When the far solenoid is de-energized and voltage is applied to the near solenoid, the armature closes the injection chamber valve. Information for the solenoid valve control unit comes from a sensor located on the crankshaft, which records its angular position. For each valve, the electronic solenoid control unit determines the start of their opening and closing.The use of electronic control allows for more precise regulation of engine operation and achieves better efficiency and greater power in different engine operating modes (Fig. 2).

[0006] Hot gases are taken from the previous power stroke, therefore, for all types of fuel used, gasoline is used during a cold start, and a traditional spark ignition is installed in the combustion chamber, which also operates with the hot gas injection chamber operating for all types of fuel. After starting and warming up the engine on gasoline, the gasoline supply is disconnected and another type of fuel is connected. Other types of fuel (gas, diesel fuel, SFS, and other liquid fuels) are injected under the intake valves or directly into the combustion chamber. The exhaust gas recirculation (EGR) valve (EGR - Exhaust Gas Recirculation) leaves carbon deposits on the intake valve during exhaust gas injection, thereby impairing its operation. To flush deposits from the intake valve, engines operating on all types of fuel periodically switch to injection under the gasoline valves. The frequency of switching to gasoline is stored in the ECU memory (Fig. 3). Brief description of the drawings.

[0007] Figure 1. Internal combustion engine with injection chamber.

[0008] 1. Engine cylinder. 2. Engine cylinder head. 3. Hot gas injection chamber.

[0009] Figure 2. Hot gas injection chamber with a needle valve driven by solenoids, the opening and closing periods of which are generated in the engine electronic control unit. The battery provides operation of the solenoids, the electronic valve control unit, and heating of the injection chamber. 3. Injection chamber. 4. Battery. 5. Electronic control unit. 6. Opening solenoid. 7. Closing solenoid. 8. Valve into the engine combustion chamber. 9. Valve thermal insulation. 10. External thermal insulation. 11. Internal thermal insulation. 12. Injection chamber heating coil.

[0010] Figure 3. Cold start of a gasoline engine. The electronic control unit ensures constant spark formation at the spark plug.

[0011] 1. Engine cylinder. 2. Engine cylinder head. 3. Hot gas injection chamber. 4. Injection chamber heating battery. 5. Electronic control unit for solenoids and ignition. 13. Spark plug. 14. Combustion chamber. 15. Gasoline injection nozzle under the valves. 16. Injector for injection directly into the cylinder.

Claims

1. An internal combustion engine with combined systems of fuel injection directly into the cylinder and pulse injection under the intake valves, in which the ignition of the combustible mixture in the combustion chamber of the cylinder is carried out with the help of an additional chamber for the injection of hot gases, which are taken from the previous working cycle in this cylinder, characterized in that the hot gas injection chamber consists of the following main parts: a cylinder made of heat-resistant steel, covered with thermal insulation inside and outside, while a wire with high electrical resistance is laid in the internal thermal insulation, which, when starting and during the operation of the engine, is constantly heated by current from the battery, a valve for supplying hot gases to the combustion chamber of the working cylinder is installed in the center of the injection chamber, which is a steel needle made of heat-resistant steel, covered with thermal insulation and ending in a conical end at the entrance to the combustion chamber,The hot gas injection valve is driven by two solenoids, each solenoid consists of a housing, a stop, an anchor, a winding, the cores of each solenoid have an air working gap, the valve is opened and held by the opening solenoid when it is energized, and the closing solenoid is de-energized, to close and hold the valve, the voltage of the opening solenoid is disconnected and voltage is applied to the closing solenoid, the moments of opening and closing the valve are generated in the electronic control unit, the anchor of the solenoids is connected to the injection chamber valve through a heat-insulating coupling.

2. An internal combustion engine according to paragraph 1, characterized in that a spark plug is installed in the combustion chamber, wherein the cold engine is started on gasoline, the spark plug supplies a spark synchronized with the opening of the hot gas injection chamber, the spark supply continues while the injection chamber is operating, after the engine has warmed up, the gasoline supply can be turned off to connect another type of fuel.

3. An internal combustion engine according to paragraph 1, characterized in that for engines operating on several types of fuel, a cold start is carried out on gasoline using a spark plug installed in the combustion chamber of the engine, which supplies a spark synchronized with the opening of the hot gas injection chamber, the supply of a spark continues with the injection chamber operating, after warming up the supply of gasoline is turned off and another type of fuel is connected, for example, gas or diesel fuel, the injection of which is carried out under the intake valves or directly into the combustion chamber.

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