RU19877U1 - GAS ENGINE - Google Patents

Description

Gas engine.

The utility model relates to the field of engine building and can be used on trucks and buses.

Currently, one of the chances of improving the environmental performance of vehicle engines is their conversion to gaseous fuels. In Russia, so-called bit-fuel engines that can run on both gasoline and compressed natural gas are used in small quantities on motor vehicles. These engines usually do not automatically maintain the optimal composition of the mixture when changing atmospheric conditions and gas pressure in the cylinders. In addition, due to the low degree of compression, the high octane number of natural gas is not used enough, which is the reason for the low efficiency of bit-fuel engines.

Gas engines with lower fuel consumption and better environmental performance can be obtained by modernizing the domestic industry, in particular KAMAZ, diesel engines with gas turbine supercharging and intermediate cooling of the charge air (KamAZ 740.11-240 engine. Operation manual. Edited by N. Gataulina N. A., Naberezhnye Chelny, 1997, p. 120.).

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F 02 V 43/00 F 02 M 21/02 F 02 D 43/00

The problem is solved by the fact that the eight-cylinder V-shaped engine with turbocharging and cooling the charge air, according to the utility model, is equipped with a power system with a central gas supply to the intake manifold, a device for maintaining stable idle speed with a bypass channel for supplying the gas-air mixture to the intake manifold bypassing the throttle, bypass valves of a part of the exhaust gases bypassing the turbocharger turbines, multi-channel spark ignition system without high-voltage distributor angle microprocessor control system ignition timing, the gas supply and the gas-air mixture and exhaust gas recirculation.

The power supply system with a central gas supply contains gas cylinders, pipelines and pipe fittings, a gas reducer, a solenoid valve filter, a receiver, a device for dispensing the amount of gas supplied to the engine, made in the form of a spool valve, and a nozzle.

In the first embodiment, at a nominal voltage of 12 V, the ignition system is made eight-channel, with eight ignition coils individual for each cylinder for a voltage of 12V, in the second embodiment, at a nominal voltage of 24 V, the ignition system can be made four-channel, with eight individual for each cylinder ignition coils for voltage 12V, while the primary windings of each pair of coils, in which high voltage is generated simultaneously, are connected in series.

The proposed gas engine is designed to run on lean mixtures and borrows by land; all the main components and parts of a basic diesel engine, except for the fuel supply system, are used by land. The fuel supply system is made with external mixture formation. Central gas supply is based on

simplicity, and therefore, the reliability of the design. In addition, it provides better mixing of gas with air in the intake duct. The main advantage of the distributed supply of liquid fuel is the absence of a film that is not equally divided between the cylinders and is the main reason for the uneven composition of the mixture across the cylinders, in the case of gaseous fuels, it does not appear, and engines with a distributed gas supply have a high cost.

The use of bypass valves for some of the exhaust gases bypassing the turbocompressor turbines allows you to maintain a constant composition of the gas-air mixture in the entire operating range of the engine.

The use of a microprocessor control system allows optimizing the operation of the engine in all modes, taking into account its condition and atmospheric conditions. As a result of conversion, the engine consumes only compressed natural gas based on methane in the form of fuel (the cost of natural gas is much lower than the cost of diesel fuel). The engine, made in accordance with the utility model, differs from the base diesel engine in lower manufacturing costs, lower engine oil consumption and noise emission, and in terms of the content of nitrogen oxides in the exhaust gases, it is possible to fulfill the EURO-3 standards without the use of a neutralizer.

The sequential inclusion of the primary windings of the ignition coils allows you to halve the number of channels in the switch and use standard coils with a nominal voltage of 12 V. in the electrical system with a voltage of 24 V. Ignition coils are installed either directly on the spark plugs, which completely excludes high-voltage wires, or near candles, which allows to reduce the length of high-voltage wires, the number and total length of switching wires.

The sequential inclusion of coils with a central gas supply and a microprocessor ignition system allows you to work without a phase sensor.

In FIG. 1 shows a general view of a gas engine.

In FIG. 2 - gas engine power system.

In FIG. 3- spool valve of gas supply with electric drive.

Figure 4 is a block diagram of a microprocessor control system for a gas engine (option 1)

In FIG. 5 is a block diagram of a microprocessor control system for a gas engine (option 2).

The engine contains two turbochargers 1 (a variant with one turbocharger is possible), a charge air cooler 2, an intake manifold 3.

The engine has two exhaust gas bypass valves 4 (or one, for the version with one turbocharger) with an electromechanical actuator 5, an ignition coil 6, and a spark plug 7.

The power system with a central gas supply includes gas cylinders (not shown), a gas reducer 8, a solenoid valve filter 9, a receiver 10, a spool valve 11 for dispensing a gas supply, a gas idle valve 12 with a stepping motor 13, a mixer 14, gas nozzle 15, throttle valve 16, diffuser 17, idle gas-air valve 18 with a stepper motor 19, bypass channel 20, solenoid valve 21, start-up nozzle 22.

Spool valve 11 for metering gas supply includes a housing 23, spool 24, front cover 25, channel 26 for supplying gas from the idle gas valve 19, gear reducer 27, position sensor 28, stepper motor 29, rear cover 30, sleeve 31.

The microprocessor engine control system with an eight-channel ignition system contains an electronic microprocessor unit 32, to the inputs of which are connected the position sensor 28 of the spool 24 of the spool valve 11, revolutions 33, oxygen 34, intake air temperature 35, coolant temperature 36, gas temperature 37, absolute pressure in the inlet pipe 38, gas pressure 39, position 40 of the throttle valve 16, phase 41. An electromechanical actuator 5 of the bypass valve 4 is connected to the outputs of the electronic unit 32 there are ignition coils 6, a stepping motor 13 of a gas idle valve 12, a stepping motor 19 of a gas-air idle valve 18, a stepping motor 29 of a spool valve 11 of a gas supply, an electromagnet of a gas valve 21. The signals in the speed sensor 33 are generated by means of a rotating disk 42, in the phase sensor 41 by means of a rotating synchronization disk 43 and are fed to the input of the microprocessor unit 32.

The microprocessor gas engine control system with a four-channel ignition system includes all the elements of a microprocessor gas engine control system with an eight-channel ignition system, it is distinguished by the absence of a phase sensor 41 and a synchronization disk 43, four pairs of ignition coils 6 are connected to the output of the electronic unit 32 with the primary connected in series windings.

The engine operates as follows.

Natural gas stored in high-pressure cylinders is reduced in a gas reducer 8 and, under constant pressure (0.4 ... 0.5 MPa), is supplied to the engine through a main pipeline. When the engine is started, the solenoid valve-filter 9 opens and the gas through the receiver 10 enters the spool valve 11, through the idle gas valve 12 to the mixer 14, through the solenoid valve 21 and the start-up nozzle 22 directly to the engine intake manifold 3. The spool valve 11 when starting and running the engine at idle is in the closed state. After the engine reaches idle speed, the solenoid valve 21 of the starting system is turned off. When a load occurs at idle (the inclusion of a hydromechanical gearbox, air conditioner, etc.), stable idle speed is maintained by supplying an additional amount of gas-air mixture bypassing the throttle valve 16 via the bypass channel 20 to the inlet pipe 3. The specified gas the air mixture supports the idle gas valve 12 with a stepper motor 13 and is controlled by an oxygen sensor 34. The gas-air valve doses an additional amount of the mixture an idle 18 driven by a stepper motor 19. The gas supply is regulated at all engine operating modes by turning the spool 24 of the spool valve 11 by the stepper motor 29 through the gearbox 27. The degree of opening of the spool valve 11 registers the position sensor 28. The shape of the working window in the spool 24 provides fine adjustment of gas supply to the engine in all modes of its operation.

Air) to the mixer 17 is supplied by turbochargers 1 through an air-air cooler 2. The gas-air mixture formed in the mixer 17 enters the intake manifolds 3, and then into the engine cylinders. The amount of gas-exaggerated mixture is regulated by turning the throttle valve 16, driven by the driver’s pedal. To optimize the change in air flow depending on the engine operation mode, 4 exhaust gas bypass valves 4 bypassing turbocharger turbines 1 are installed at the exhaust. These valves have an electromechanical actuator 5.

The signals from the sensors 28, 33-41 enter the electronic unit 32 and are processed. Based on the program laid down in the block, command signals are generated that are sent to the electromechanical actuator 5 of the bypass valve 4, to the ignition coil 6, which generates high voltage pulses coming to the spark plugs 7, to the stepping motor 13 of the idle gas valve 12, the stepping motor 19 of the gas-air valve idle 18, a stepper motor 29 of the spool valve 11 of the gas supply, the electromagnet of the gas valve 21 of the starting system.

Claims (3)

1. An eight-cylinder V-shaped engine with turbocharging and cooling the charge air, characterized in that it is equipped with a central gas supply system to the intake manifold, a device for maintaining stable idle speed with a bypass channel for supplying the gas-air mixture into the intake manifold bypassing the throttle valve bypassing part of the exhaust gases bypassing the turbines of the turbochargers, a multi-channel spark ignition system without a high-voltage distributor, a microprocessor control system I ignition timing, gas and gas-air mixture, as well as exhaust gas bypass.  2. The engine according to claim 1, characterized in that the central gas supply system contains gas cylinders, pipelines and pipe fittings, a gas reducer, a solenoid valve filter, a receiver, a device for dispensing the amount of gas supplied to the engine, made in the form of a spool valve , and nozzle. 3. The engine according to claim 1 or 2, characterized in that at a nominal voltage of 24 V, the ignition system is made with eight ignition coils for a voltage of 12 V, while the primary windings of each pair of coils in which high voltage is generated simultaneously are connected in series.