RU2516043C2 - Fuel system for internal-combustion engine - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to automotive industry and can be used in engines with petrol injection system but most widely in diesel engines. Novelty consists in the fact that the fuel system is made as two interconnected circuits: - a diesel fuel circulation circuit consisting of a fuel tank, a fuel pump connected to a pressure line with a solenoid valve to an engine pump manifold, a return line to return diesel fuel from the manifold to the fuel tank, with a pressure-relief valve and a solenoid valve installed on the return line, a bypass line with the pressure-relief valve, and a line for diesel fuel delivery to a water-fuel emulsion production unit; - a circuit for obtaining water-fuel emulsion circulation consisting of: an inertial separator, a plunger-type fuel pump, an ejector with a suction chamber and a mixing chamber which is directly connected to the manifold of the engine pump, a return line to return fuel-water emulsion to the separator with the pressure-relief valve and the pressure switch, herewith, the separator accommodates a water level regulator connected to the water tank, a fuel level regulator connected to the fuel delivery line, and a water-fuel emulsion inlet manifold, aside from that the separator is connected to lines for water delivery to the ejector suction chamber using a calibrated dose and the solenoid valve.

EFFECT: system feature consists in the fact that it automatically changes the engine operation mode from diesel fuel to alternative fuel (water-fuel emulsion) and back to diesel fuel without stopping the engine, and the fuel system also provides preparation of highly dispersed water-fuel emulsion of guaranteed composition with low power consumption.

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Description

The invention relates to the automotive industry and can be implemented in engines with a gasoline injection system, but especially widely in diesel engines.

Known fuel system of an internal combustion engine containing a fuel tank, a fuel boost pump, a high pressure fuel pump and a nozzle [V.M. Arkhangelsky et al. “Automotive engines”, “Engineering”, 1977, pp. 277-279, Fig. 173].

The main disadvantages of this system are: inefficient fuel consumption in certain engine operating modes, the use of expensive fuels to reduce the emission of harmful products with exhaust gases or expensive filters to neutralize harmful impurities.

Known gas-liquid fuel system of an internal combustion engine containing a fuel tank, two high pressure fuel pumps of different capacities, a working nozzle, as well as equipment for storing, supplying gas and entering it into the engine cylinder [A.S. Orlin et al. “Design and operation of piston and combined engines”, “Mechanical Engineering”, 1970, pp. 343-336, Fig. 173].

Despite the fact that the use of gas-liquid fuels significantly improves sanitary conditions, this system has several disadvantages:

- the need to use two types of fuel;

- the use of diverse and complex equipment;

- increased risk of fire and explosion hazard.

Known fuel system of an internal combustion engine in the form of an installation for preparing a water-fuel emulsion as a part of a tank for fuel and water, valves, a fuel priming pump, a dispersant with a laser device, a water emulsion column and an automatic device for measuring emulsion density (see RF patent 2173210). The main disadvantages of this system are:

- the use of complex and expensive equipment to obtain an emulsion and control its density;

- a long period of the system reaching the calculated mode after each engine stop or failure of the equipment of the emulsion production unit;

- the need to remove water from the system during prolonged shutdowns of the engine.

A known installation for producing a water-fuel emulsion, consisting of a water tank, a dispersant in the form of a mechanical pump with an increased radial clearance between the housing and the impeller, the discharge pipe of which is connected to the main fuel system of the engine, and the suction line is connected to the fuel tank and water tank at the same time, a circulation pump, a water flow meter and an electric water heater are installed on the water supply line, as well as a unit equipped with a bypass valve and a shutoff isolator fittings (Lebedev O.N., Somov V.N. Water-fuel emulsions in marine diesel engines, L., Shipbuilding, 1988, 68 pp.).

The disadvantages of this installation are:

- high energy costs associated with the need to heat water to obtain a highly dispersed emulsion;

- low reliability of the mechanical dispersant;

- the complexity of the entire installation and the need for continuous measurement of the amount of water supplied to the dispersant and regulation to maintain the emulsion of a given composition.

The closest in technical essence and the achieved effect is the fuel system of an internal combustion engine containing a fuel pump, an ejector with a receiving chamber and a mixing chamber, a separator connected by a pipeline to the inlet of the fuel pump, a water tank, a fuel tank connected to the ejector, and a pipeline return of fuel oil emulsion (see RF patent No.2002092).

This fuel system has the following disadvantages:

- the preparation of a water-fuel emulsion requires large energy expenditures, since water from the tank, water from the separator and fuel from the fuel tank are simultaneously supplied to the ejector, for high-quality mixing of which in the ejector high fuel consumption is required under high pressure created by the gear pump, which significantly reduces the possibility the use of these fuel systems in transport;

- the need for constant monitoring of the composition of the emulsion and the complexity of regulation to maintain the required concentration of water-fuel emulsion;

- the termination of the engine in the event of a failure of any main element of the system.

The technical task is to reduce the energy consumption of the process of obtaining water-fuel emulsion and increase the reliability of the fuel system.

This goal is achieved in that the fuel system of an internal combustion engine comprising a fuel pump, an ejector with a receiving chamber and a mixing chamber, a separator connected by a pipe to the inlet of the fuel pump, a water tank, a fuel tank connected to the ejector, and a return pipe for water-fuel emulsion equipped with a low pressure pump connected to the fuel tank and to the engine pump manifold by a pressure pipe with an electromagnetic valve, water and fuel level controllers are installed in the separator and a collector for receiving a fuel-oil emulsion connected to the engine pump manifold by a return pipe of a fuel-oil emulsion, wherein a pressure signaling device and a pressure regulator are installed on the return line of the fuel-oil emulsion, and a water level regulator is connected by a pipeline to the water tank, a separator is connected by a pipeline on which an electromagnetic valve is installed and nozzle to the receiving chamber of the ejector, and the mixing chamber of the ejector is directly connected to the engine pump manifold, which is piped through return of fuel from the pressure regulator and a solenoid valve associated with the fuel tank, and besides low-pressure pump connected to the fuel tank bypass line with a pressure regulator and a fuel conduit a level regulator.

The analysis of the prior art made it possible to establish that the applicant has not found an analogue characterized by cumulative features identical to all the essential features of the claimed invention, therefore, it meets the criterion of "novelty."

The technical essence of the invention is illustrated in the figure, which shows a diagram of the proposed fuel system of an internal combustion engine.

The fuel system of an internal combustion engine contains a water tank 1, a fuel tank 2, a fuel pump 3, an ejector 4 with a receiving chamber and a mixing chamber, a manifold 5 of the engine pump, a separator 6 with a fuel level regulator 7, a water level regulator 8 and a collector 9 for receiving a fuel-oil emulsion, wherein the water level regulator 8 is connected by a pipeline 10 to the water tank 1, and the collector 9 for receiving a fuel-oil emulsion to the engine pump manifold 5 by a water-fuel emulsion return pipe 11 on which the signaling device is installed pressure p 12 and pressure regulator 13. In addition, the separator 6 is connected by a pipe 14 to the inlet of the fuel pump 3, and by a pipe 15, on which the solenoid valve 16 and nozzle 17 are mounted, to the receiving chamber of the ejector 4, and the mixing chamber of the ejector 4 is directly connected to the collector 5 engine pumps. The fuel system is additionally equipped with a low pressure pump 18, connected by a pipe 19 to the fuel tank 2 and a pressure pipe 20 with an electromagnetic valve 21 to the manifold 5 of the engine pump, which is connected through a fuel return pipe 22 with a pressure regulator 23 and an electromagnetic valve 24 to the fuel tank 2, and in addition, the low-pressure pump 18 bypass line 25 with a pressure regulator 26 is connected to the fuel tank 2, and the pipe 27 to the fuel level regulator 7.

The proposed fuel system of an internal combustion engine operates as follows.

Start-up and initial operation of the engine is done with fuel. In this case, the fuel from the fuel tank 2 through the pipeline 19 enters the inlet of the low-pressure pump 18, after which under the pressure of 0.15 ÷ 0.2 MPa through the open solenoid valve 21 through the pressure pipe 20 to the manifold 5 of the engine pump, of which fuel is taken to the engine pump and then distributed to the nozzles (the engine pump and nozzles are not shown in the drawing), and the rest of the fuel through the fuel regulator 23 and the open solenoid valve 24 through the fuel return pipe 22 is returned to the tank for Liwa 2.

Transition of the engine to a water-fuel emulsion is performed at the command of the driver automatically in three stages. At the first stage, fuel from the separator 6 through the pipe 14 enters the inlet of the fuel pump 3, after which it is sent under pressure 7.0 ÷ 10.0 MPa to the ejector 4, the mixing chamber of which is directly connected to the manifold 5 of the engine pump. In the manifold 5 of the engine pump, the fuel flows after the low pressure pump 18 and the ejector 4 are connected. Further, the total fuel flow, minus the fuel taken for engine operation, is returned to the fuel tank 2, while the fuel flow to the inlet of the fuel pump 3 from the separator 6 is compensated by the selection of fuel after the low pressure pump 18, coming through the pipeline 27 through fuel level regulator 7 to the separator 6.

At the second stage, 20 ÷ 30 s after turning on the fuel pump 3, an automatic command is issued to close the solenoid valves 21 and 24, as a result of which the pressure regulators 13 and 26 are set, which are set to a slightly higher response pressure than the pressure regulator 23. Thus, at this stage, the engine is still running on fuel circulating along the circuit: separator 6, fuel pump 3, ejector 4, manifold 5 of the engine pump, pressure regulator 13, emulsion return pipe 11, collector for receiving water 9 fuel emulsion.

At the third stage of operation, 20 ÷ 40 s after closing the solenoid valves 21 and 24 and reaching the required pressure in the manifold 5 of the engine pump, fixed using the pressure switch 12, a command is issued to open the solenoid valve 16, as a result of which water from the bottom of the separator 6 through the pipeline 15 it enters the working chamber of the ejector 4 with the flow rate necessary for obtaining the concentration of the water-fuel emulsion, which is determined by the nozzle opening 17 and the pressure drop between the separator 6 and the receiving chamber ctor 4. The finely dispersed water-fuel emulsion formed in the mixing chamber of the ejector 4 enters the manifold 5 of the engine pump, where, depending on the operating mode, the necessary part is taken by the engine pump and fed to the nozzles, and the excess through the pressure regulator 13 through the emulsion return pipe 11 enters the collector for receiving the fuel-oil emulsion 9 of the separator 6, where the emulsion is decomposed into water and fuel, while the flow of water spent on the formation of the emulsion from the volume of the separator is replenished from the water tank 1, th through the pipeline 10 enters the inlet of the separator 6 to the water level regulator 8, which maintains a predetermined level, and the fuel consumption from the separator 6 is replenished using the fuel level regulator 7 due to the part of the fuel taken after the fuel pump 18 through the pipeline 27, and excess fuel are returned via the bypass pipe 25 through the pressure regulator 26 to the fuel tank 2. The operation of the water-fuel emulsion production unit is constantly monitored by the pressure in the manifold 5 of the engine pump using the pressure switch 12. If the pressure drops below a predetermined value, the pressure switch 12 receives a command to turn off the fuel pump 3, open the solenoid valves 21 and 24, close the solenoid valve 16. Thus, the engine automatically switches to fuel from the circulation circuit: fuel tank 2, fuel low pressure pump 18, solenoid valve 21, engine pump manifold 5, pressure regulator 23, solenoid valve 24 and fuel return pipe 22 to the fuel tank 2.

The same transition at any time can be performed at the command of the driver.

Thus, in the proposed technical solution, by reducing the active fuel consumption through the ejector, it is possible to reduce the energy consumption for preparing a water-fuel emulsion, in addition, there is no need to regulate the water in the ejector and control the moisture content of the emulsion obtained, and the high quality of the emulsion can be maintained by connecting the mixing chamber ejector directly to the engine pump manifold, while the required composition of the water-fuel emulsion, regardless of the engine operating mode, is guaranteed due to basic design parameters of the ejector (active nozzle diameter and mixing section and the water nozzle chamber) and the stability of process parameters: fuel pressure at the inlet of the ejector, vacuum in the receiving chamber, fuel and water levels in the separator.

The proposed fuel system was tested at a special stand. Tests have shown the stable operation of a 3.0 kW diesel engine under the regimes performed by both load and speed characteristics when the water concentration in the composition of the fuel emulsion changes from 5 to 30%, as well as engine stability in transient modes of changing diesel fuel to water fuel emulsion and reverse transition.

A comparison of the essential features of the proposed and known solutions gives reason to believe that the proposed solution meets the criteria of "inventive step" and "industrial applicability".

Claims (1)

A fuel system of an internal combustion engine comprising a fuel pump, an ejector with a receiving chamber, a separator connected by a pipe to the inlet of the fuel pump, a water tank, a fuel tank connected to the ejector, and a return pipe of the water-fuel emulsion, characterized in that it is equipped with a low pressure pump connected to the fuel tank and to the engine pump manifold by a pressure pipe with an electromagnetic valve, water and fuel regulators and a collector for receiving water-fuel emulsions are installed in the separator This is connected to the engine pump manifold by a water-fuel emulsion return pipe, the water level regulator being connected to a water tank, a pressure signaling device and a pressure regulator installed on the water-oil return pipe, a separator connected by a pipe on which an electromagnetic valve and a nozzle are installed to the receiving chamber of the ejector , the low-pressure pump is connected to the fuel tank bypass with a pressure regulator, and the pipe is connected to the fuel level regulator, the collector the engine pump through the fuel return pipe with a pressure regulator and an electromagnetic valve is connected to the fuel tank, the mixing chamber of the ejector is directly connected to the engine pump manifold.

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