RU2338920C1 - Gas-diesel engine liquid and gaseous fuel feed system - Google Patents

Abstract

FIELD: engines and pumps, chemistry.

SUBSTANCE: gas-diesel engine liquid and gaseous fuel feed system incorporates diesel and liquid-phase gaseous fuel proportioner arranged in the lines between the two-channel nozzle, high-pressure fuel pump and liquefied gas source, the aforesaid proportioner being made up of the main plunger with a stop and the auxiliary plunger forming three spaces. Note here that the channel communicating the aforesaid high-pressure fuel pump with the proportioner upper space is furnished with a dual-action pressure valve, while the channels communicating the proportioner medium and lower spaces with the two-channel nozzle are provided with check displacement valves. Note also that the medium and lower spaces of the said proportioner communicate with the liquefied gas and diesel fuel lines, respectively.

EFFECT: higher efficiency of fuel feed system.

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Description

The invention relates to engine building, and specifically to systems for supplying fuel to internal combustion engines operating on liquefied gaseous fuel with a pilot dose of liquid (diesel) fuel.

Known systems for supplying liquid and gaseous fuel to a gas diesel engine, containing a single-section fuel pump introducing 5 ... 10% of diesel fuel or engine oil into a mixer of a low pressure line of a liquefied gas fuel supply system, a gas cooler with a control valve installed on the low pressure pipeline immediately before high pressure fuel pump (TNVD) [V.A. Makarov, S.I. Kozlov. "Fuel and fuel supply of multi-fuel and gas-diesel engines." - M.: Publishing House of MSTU. N.E. Bauman, 2000. - S. 268-269].

The disadvantage of these fuel and gas supply systems is the presence of an additional single-section pump with a nozzle, as well as its increased fire hazard due to leakage of liquefied gas through the gaps of the plunger couples and their evaporation in the low pressure line ..

Also known is a gas-diesel fuel supply system with internal mixture formation, comprising a high-pressure fuel pump with a pressure valve, a high-pressure pipe, a closed nozzle with needle-and-needle cavities, diesel fuel and liquefied petroleum gas sources, diesel fuel supply and shut-off lines, oil supply pipeline liquefied gas and a non-return valve, and the high pressure fuel pump and the oil supply pipeline are connected to the nozzle cavity of the nozzle gas through a non-return valve - a source of petroleum liquefied gas, the system is equipped with a device for regulating pressure, the source of petroleum liquefied gas is connected by a gas supply pipe to the nozzle cavity of the nozzle through its nozzle cavity made hermetically closed and containing the input of the petroleum liquefied gas supply pipe check valve [US Pat. 2126908 RF, IPC F02M 43/00. Publ. 02/27/1999, prototype].

The disadvantage of the system is the lack of regulation of the composition of the mixture and the sequence of input of different fuels into the combustion chamber of a gas diesel engine.

The technical result of the invention is to increase the efficiency of the gas-diesel supply system by ensuring a strict sequence for introducing liquid and gaseous fuels using a standard injection pump with a speed controller.

The specified technical result is achieved in that, unlike the prototype, the system for supplying liquid and gaseous fuel to a gas diesel engine contains a high-pressure fuel pump, a two-channel nozzle, sources of diesel fuel and liquefied gas with supply lines, moreover, on the lines between the two-channel nozzle, a high pressure fuel pump and a diesel and gaseous fuel dispenser in a liquid phase is installed as a source of liquefied gas, including a main plunger with an emphasis and an additional one forming three cavities, moreover the channel connecting the high-pressure fuel pump with the upper cavity of the dispenser is equipped with a double-acting discharge valve, while the channels connecting the middle and lower cavities of the dispenser with a two-channel nozzle are equipped with volumetric check valves, and the middle and lower cavities are connected respectively to the liquefied gas supply lines and diesel fuel.

Figure 1 presents a system for supplying liquid and gaseous fuel to a gas diesel engine. Figure 2 shows the position of the metering plungers during operation of a gas diesel engine with a power of less than 30 ... 35% of the nominal. Figure 3 shows the position of the metering plungers during operation of a gas diesel engine with a power of more than 30 ... 35% of the nominal.

An internal combustion engine running on gaseous fuel with ignition from the injection of an ignition dose of liquid fuel is a gas diesel engine. The gas-diesel supply system contains (Fig. 1) a low-pressure line, a fuel tank 1 of liquid (diesel) fuel, a booster pump 2, a filter 3, a valve 23 and a section of a high-pressure fuel pump (TNVD) 5 with a plunger 4. At the outlet of the injection pump section 5, a double-acting discharge valve 6 is installed with valves 8 and 10 pressed against each other by springs 7 and 9. The liquefied gas cylinder 24 is connected by a pipeline to the high-pressure air cylinder 25 through valve 26, or a booster pump 21 can be used instead of cylinder 25, providing present pressure exceeding the saturation vapor pressure liquefied gas, which eliminates the possibility of the formation of vapor tubes violating normal operation power supply system. The cylinder 24 is connected by a gas line through a valve 22, a pump 21 and a filter 20 with a dispenser 12. On the lines between the two-channel nozzle 27 with a cavity 28, a high-pressure fuel pump section 5 and a source of liquefied gas, a dispenser 12 of diesel and gaseous fuel in a liquid phase is installed. The dispenser 12 includes a main plunger with an emphasis 14 and an additional 13. The plungers 13 and 14 are held in the upper position by a spring 15. The dispenser housing with the plungers form three cavities A, B and C, a channel 11 connecting the high pressure fuel pump with the upper cavity A of the dispenser, equipped with a double-acting discharge valve 6, channels connecting the middle B and lower C of the cavity of the dispenser 12 with the two-channel nozzle 27 are equipped with non-return valves of volume action 17 and 18, the middle B and lower C of the cavity are connected respectively to the supply lines gas 19 and diesel fuel 16.

The system operates as follows.

When working on gaseous fuel in the diesel mode, close the valve 23 and open the gas valve 20. Gas under pressure fills the cavity In the dispenser.

When the diesel engine is idling and with a capacity of less than 30 ... 35% of the nominal, the charge pump 2 pumps fuel into the injection pump section 5 and into the cavity C of the metering unit 12. Plunger 4 supplies a portion of diesel fuel through a double-acting pressure valve 6, both of which valves 8 and 10, pressed against each other by springs 7 and 9, rise and pass fuel into the cavity A of the dispenser. Under pressure, the plungers 13 and 14 of the dispenser 12 move downward (FIG. 2), compressing the spring 15, gaseous fuel from the cavity B is transferred to the channel 19, and diesel fuel from the cavity C under pressure enters the cavity 28 of the two-channel nozzle 27, tears the needle from the seat atomizer and injected into the combustion chamber.

After the valves 17 and 10 are cut off and seated on the seats, the check valve 8 opens under pressure of the fuel in cavity A and transfers part of the fuel into the supraplunger cavity D. This ensures the elimination of possible injections and a predetermined residual pressure in the cavity A and the high pressure line. In this case, the plungers 13 and 14 under the action of the spring 15 rise up.

When a gas diesel engine operates with a power exceeding 30 ... 35% of the nominal one, the ignition dose of diesel fuel is injected first, and then a portion of gaseous fuel. This is achieved by the fact that the pressure developed by the injection pump section 5 acts on the plungers 13 and 14, moving them down (Fig. 3), while when the plunger 14 drops to the stop, the plunger 13 will block the channel 19 and the gaseous fuel from the cavity B under pressure enters the cavity 28 of the two-channel nozzle 27 and is injected into the combustion chamber. The magnitude and duration of the injection depends on the portion of fuel supplied by the injection pump section to cavity A.

When working only on liquid (diesel) fuel, close the gas valve 22 and open the valve 23. Fuel fills the cavity In the mixer, and the engine runs only on liquid fuel.

Thus, the described version of the power system allows for operation on liquid and gaseous fuels, provides a favorable sequence for introducing different fuels into the combustion chamber when operating in the diesel mode, automatically adjusts the amount of fuel supplied to the operating mode of the diesel due to a standard speed controller, and increases the uniformity of distribution gaseous fuel in cylinders. As a result, the efficiency of the gas-diesel power system increases.

The system for supplying liquid and gaseous fuels to a gas diesel engine serves to reduce operating costs and can be easily implemented in engine building.

Claims (1)

A system for supplying liquid and gaseous fuel to a gas diesel engine containing a high pressure fuel pump, a two-channel nozzle, sources of diesel fuel and liquefied gas with supply lines, characterized in that a diesel dispenser is installed on the lines between the two-channel nozzle, a high pressure fuel pump and a liquefied gas source gaseous fuel in the liquid phase, including the main plunger with emphasis and an additional, forming three cavities, moreover, the channel connecting the high-pressure fuel pump with It cavity of the dispenser, provided with a double-acting discharge valve, and channels connecting the middle and lower cavity dispenser with a two-channel nozzle, provided with volumetric check valves, the middle and lower cavities are respectively connected to the lines for supplying the liquefied gas and diesel fuel.

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