Fuel supply system for an internal combustion engine

<td rowspan="2">REPUBLIC POLAND</td><td rowspan="2">(12) PATENT DESCRIPTION (19) PL (21) Application number: 370578</td><td colspan="2"> (11) 201498</td>

<td> (13)</td><td>B1</td>

<td>Patent Office of the Republic of Poland</td><td>(22) Date of notification: 03/01/2003 (86) Date and number of the international application: 03/01/2003, PCT / AU03 / 00005 (87) Date and publication number of the international application: 2003-07-10, WO03 / 056165 PCT Gazette No. 28/03</td><td colspan="2">(51) Int.Cl. F02M 31/04 (2006.01)</td>

<td colspan="2">(54) Method and system for conditioning of liquid fuel in an internal combustion engine</td>

<td>(30) Priority: 04/01/2002, AU, PR9832</td><td>(76) Authorized and inventor: Glew Wayne Kenneth, Glenfield via Geraldton, AU</td>

<td>(43) Application was announced:</td><td></td>

<td>May 30, 2005 BUP 11/05</td><td>(74) Representative:</td>

<td>(45) The grant of the patent was announced: April 30, 2009 WUP 04/09</td><td>Słomińska-Dziubek Anna, POLSERVICE, Kancelaria Rzeczników Patentowych Sp. z o. o</td>

⁽⁵⁷⁾ The method of conditioning liquid fuel in an internal combustion engine is by injecting a mist of liquid fuel into the chamber, introducing heated air at a temperature between 110 ° C and 260 ° C into the chamber, mixing the fuel with heated air, causing thermal liquid cracking. of fuel and forming a mixture of thermally cracked fuel and heated air, and then discharging the mixture from the combustion chamber of the internal combustion engine. At the same time, the temperature of the air flowing into the chamber is read and the volume of fuel in the fuel mist changes inversely to the changes in this read air temperature. The system (10) for conditioning of liquid fuel in an internal combustion engine comprises a housing (12) with a thermal cracking chamber (14), a fuel injector (20) for injecting fuel mist into the chamber, a heater (22) for entering the chamber (14), and a regulator. (24) connected to a fuel injector for regulating the injection of fuel mist into the chamber. It also includes an air temperature sensor (26) arranged to produce a first signal to a regulator (24) indicative of the temperature of the air flowing into the chamber (14) through the inlet port (16) and connected to the regulator (24), the regulator (24) being programmed to be changing the volume of fuel in the fuel mist inversely to changes in air temperature.

PL 201 498 B1

Description of the invention

The present invention relates to a method and a system for conditioning a liquid fuel in an internal combustion engine.

The fuel supply system described in the international application No. PCT / AU95 / 00239 is known. The system includes a vaporization chamber in which a foam insert is placed to suspend the fuel in the flow of air from the constricted inlet to vaporize the fuel. The vaporized fuel is mixed with the air in the mixing chamber and then transferred to the intake manifold of the internal combustion engine. Fuel is supplied to the bottom of this liner by a fuel pump and excess fuel is returned through a drainage system to the fuel source. Embodiments of this known fuel supply system provide a significant increase in fuel efficiency in which the fuel consumption of the six cylinder engine of the vehicle has been reduced from about 13 liters per 100 km to about 2.6 liters per km.

An object of the invention is to provide a modified fuel supply system that is mechanically simplified and potentially greater fuel efficiency.

In this specification and claims, the term "thermal cracking" in reference to fuel is used to denote the evaporation, volatilization, or decomposition of high molecular weight hydrocarbons to lower molecular weight hydrocarbons, or any combination thereof.

According to the present invention, a method of conditioning liquid fuel in an internal combustion engine wherein injection of a mist of liquid fuel into a chamber having an inlet at one end and an outlet at the opposite end, introduces heated air at a temperature between 110 ° C and 260 ° C into the chamber via inlet opening, mixing the fuel with the heated air, leading to thermal cracking of the liquid fuel and the formation of a mixture of thermally cracked fuel and heated air, and then discharging the mixture from the combustion exhaust port of the internal combustion engine, characterized in that the temperature of the air entering the chamber is read, and the volume of fuel in the fuel mist is changed inversely to changes in this read air temperature.

According to the invention, a fuel system for conditioning of liquid fuel in an internal combustion engine having an exhaust manifold including a housing with a thermal cracking chamber provided with a fuel inlet in front of the chamber and a fuel outlet in the rear therein, a fuel injector for injecting a fuel mist into the chamber, an air heater for heating the air flowing through the inlet opening to the chamber to a temperature in the range of 110 ° -260 ° C, a regulator connected to the fuel injector for regulating the injection of fuel mist into the chamber, characterized by an air temperature sensor arranged to generate a first signal to a regulator indicating the temperature of the air flowing into the chamber through the intake port and connected to the regulator, the regulator being programmed to changing the volume of fuel in the fuel mist inversely to changes in air temperature, as a result of which, during use, fuel is thermally cracked in this chamber by colliding with this heated air molecules to form a mixture of thermally cracked fuel and heated air that is supplied to the fuel intake manifold of an internal combustion engine through the chamber exhaust port.

Preferably, an oxygen sensor is positioned in the exhaust manifold of the internal combustion engine to generate a second signal to a regulator indicating the oxygen content of the exhaust gas produced by burning cracked fuel in the engine connected to the regulator, the regulator being programmed to vary the volume of fuel in the fuel mist vice versa. to changes in oxygen content.

Preferably, a choke valve connected to the accelerator of a vehicle in which the internal combustion engine is mounted is provided in the chamber outlet, the choke valve being in a minimum open position to minimize cracked fuel flow into the fuel inlet manifold and a maximum open position to provide minimum restriction of cracked fuel flow to the fuel inlet manifold. and a throttle valve position sensor is positioned at the outlet of the chamber to produce a third signal to the regulator indicating the degree of opening of the throttle valve, the regulator being programmed to vary the volume of fuel in the fuel mist in proportion to the degree of opening of the valve.

PL 201 498 B1

It is preferably connected to the exhaust port in an exhaust conduit which houses a cold start fuel injector for injecting fuel mist in the initial operation of an internal combustion engine.

The controller is further operatively connected to the cold start fuel injector for adjusting the volume of fuel in the fuel mist injected by the cold start injector based on air temperature, the controller being programmed to disconnect the cold start fuel injector when the air temperature is above a threshold temperature.

The inlet port has a diameter smaller than that of the chamber for reducing the pressure of the heated air as it flows through the inlet port into the chamber.

The outlet opening preferably has a diameter smaller than the inlet opening.

The chamber has a diameter at least two and a half times the diameter of the outlet opening.

The inlet opening and the outlet opening may be at least 20 cm apart. The inlet opening may be approximately 60 mm in diameter and the outlet opening may be approximately 42 mm in diameter.

The fuel injector may include at least one nozzle positioned at the inlet port.

The inlet opening may have a rear portion with a gradually increasing diameter.

The housing preferably has first and second opposing end walls and a side wall extending between the first and second opposite end walls, the inlet opening is formed in the first end wall and the outlet opening is formed in the second end wall.

The invention provides a method for increasing fuel efficiency and a system that is mechanically simpler.

An embodiment of the present invention is described in detail with reference to the accompanying drawings in which: Fig. 1 is a schematic illustration of a first embodiment of a fuel supply system according to the present invention; and Fig. 2 is a schematic illustration of an embodiment of a fuel supply system.

Referring to Fig. 1, a fuel supply system 10 for an internal combustion engine (not shown) comprises a housing 12 defining a chamber 14 and having an air inlet 16 in the front of the chamber 14 and an outlet 18 in the rear of the chamber 14. The system uses a device. a fuel injector comprising a fuel injector 20 for injecting fuel mist into the cavity 14. System 10 further includes a heater 22 for heating air flowing through intake conduit 17 into chamber 14 and through intake port 16 to produce heated air having a temperature in the range 110 to 260 ° C. Fuel injected into chamber 14 through fuel injector 20 is thermally cracked by collision with heated air particles, which creates a mixture of thermally cracked fuel and heated air that is supplied to the engine's fuel intake manifold (not shown) through exhaust port 18 for combustion in the engine exhaust manifold. combustion chambers of the engine (not shown).

There is a natural temperature gradient between the inlet 16 and outlet 18 ports, with the air temperature being lower in outlet 18 due to fuel mixing (which is initially at a lower temperature) with air and due to heat absorption in the thermal cracking of the fuel. Substantially all of the fuel injected into the chamber 14 is thermally cracked as it exits through the exit port 18.

Connected to the fuel injector 20 is a regulator 24 for regulating the injection of fuel mist into the chamber 14. For this purpose, the regulator 24 receives inputs from an air temperature sensor 26 located in the intake conduit 17, a position sensor 28 of a throttle valve 34 arranged in the exhaust conduit 19 connected to the opening exhaust 18 and an oxygen sensor 30 disposed in the exhaust manifold 32 of the engine.

Temperature sensor 26 provides regulator 24 with a first signal indicative of the temperature of the hot air passing through inlet 16 into chamber 14. The regulator 24 is programmed to vary the volume of fuel in the fuel mist injected through the injector 20 inversely of a sensed air temperature. In this way, as the temperature increases, the regulator 24 acts to reduce the volume of fuel injected into the chamber 14.

Similarly, regulator 24 receives a second signal from oxygen sensor 30 indicative of the amount of oxygen in exhaust gas of the engine fuel system 10 is supplying fuel to. The regulator 24 changes the volume of fuel injected by the injector 20 into the chamber 14 inverse to the changes in the detected oxygen content or level in the exhaust gas.

PL 201 498 B1

A mixture of thermally cracked fuel and heated air passes from the exhaust port 18 through the exhaust 19 as vapor to the fuel intake manifold. A throttle (butterfly) valve 34 is provided in the exhaust line 19. The throttle valve 34 is connected to a vehicle acceleration controller such as an accelerator pedal via a cable 36. The throttle valve 34 has a minimum open position (as shown in Fig. 1), which provides a maximum restriction of the cracked fuel flow through the outlet port 18 to the fuel inlet manifold. This position may be equivalent to the idle state of the engine. The valve 34 also has a maximum open position that is arranged in a substantially horizontal plane that provides minimum resistance to flow of technically cracked fuel through the outlet 18 into the fuel inlet manifold. The valve position sensor 28 reads the position of the throttle 34 providing a third signal to the regulator indicating the degree of opening of the valve 34. The regulator 24 is programmed to vary the volume of fuel in the fuel mist injected by the injector 20 in proportion to the read degree of opening of the throttle valve 34. Thus, when valve 24 is in its minimum open position, regulator 24 controls injector 24 to spray a smaller volume of fuel into chamber 14 than when throttle valve 34 is in its maximum open position.

The heater 22 is typically in the form of a heat source in thermal contact with the exhaust manifold 32. The air inlet 16 is adapted to absorb heat from the heater 22.

It should be noted that during the initial start-up, there is a delay in heating the air supplied to the chamber 14 through the inlet port 14 causing thermal cracking of the fuel. To assist in the smooth operation of the engine during this period, a cold start injector 38 is provided which is connected to the exhaust line 19 to spray fuel mist directly into the air passing through the exhaust port 18 on its path to the inlet fuel manifold. The cold start injector 38 is also under the control of the regulator 24 and is connected by the regulator 24 when the temperature of the air passing through the air inlet port 16 as read by the temperature sensor 26 is at a limit of 110 ° C, for example.

Furthermore, when the engine to which system 10 is connected has been started for a certain period of time and then shut down and started shortly thereafter, so that the engine is kept warm, the temperature of the air in the intake port 16 may already be at a threshold level at start-up, or at least may be reach the threshold earlier than during a cold start. Accordingly, the cold start injector 38 will operate in less time.

The thermal cracking of the fuel in chamber 14 is believed to involve at least one of the following processes: non-catalytic cracking, breaking down the fuel into lower molecular weight particles, evaporation, and volatilization. It has been found in a series of tests that the use of embodiments of the invention results in an improvement in the fuel consumption of a six-cylinder engine up to 5 liters per 100 km relative to a standard fuel consumption of 16 liters per 100 km.

In operation of the system 10, chamber 14 is under negative pressure relative to the pressure in the outlet line 19. This is due to the larger diameter of the chamber 14 relative to the diameter of the inlet port 16. It is believed that creating a negative pressure in the chamber 14 helps with cracking in the chamber.

Cracking of the fuel can also be increased by adding a suitable catalyst. The housing 12 is a cylindrical vessel 40 having first 42 and second 44 opposing end walls and a cylindrical side wall 46 extending therebetween. The end wall 42 forms the base of the reservoir 40 and is provided with an inlet 14, which may be considered an orifice, for directing heated air into chamber 14. The end wall 42 is also formed with a channel 48 and a plurality of vertical ducts terminated in nozzles 50 that form part of the fuel injector 23 for spraying the fuel mist into the chamber 14. Each of the vertical ducts is open as a nozzle 50 on the surface of the wall 42 inside the chamber 14 and they are disposed around the inlet 16. The diameter of the nozzles 50 of the vertical conduits is selected sufficient to cause a fluid to exit as a mist. Alternatively, spray nozzles (not shown) can be placed or connected at the ends of the risers to provide a fine mist of fluid.

The outlet 18 may be formed with a diameter smaller than the diameter of the inlet 16. Also, the diameter of the chamber 14 is preferably at least 2.5 times the diameter of the opening 16.

18. For example, inlet 16 may have a diameter of approximately 60mm against the inner surface of wall 42, and outlet 18 has a diameter in the order of 42mm. The distance between the walls 42 and 44, i.e. the axial length of the chamber 40, should be at least 20 cm. The inlet opening 16 is formed with a rear portion 47 of gradually increasing diameter. In tests carried out on an embodiment of the present invention, the pressure drop provided in the chamber 14 was about 3 Pa at an engine speed of 1000 rpm.

Fig. 2 shows a variant of the fuel supply system 10. The fuel system 10 differs from that shown in Fig. 1 in the use of a foam insert 52 of the bell valve 54 and the screen 56, each of which is similar in design and operation to that described in earlier international application No. PCT / AU95 / 00239, the contents of which are incorporated in the following by reference.

In particular, the foam liner 52 is ring-shaped and is seated on the end wall 42 of the reservoir 40 and extends to about half the axial length of the reservoir 40. A portion of the fuel mist injected into the cavity 14 may be retained in the liner 52. The bell valve 54 is slidably mounted on the post 58 extending axially through reservoir 40. A bell valve 54 is adapted to adjust the volume of air supplied to the chamber 14 through the inlet port 16 in accordance with the air pressure in the chamber 14, which in turn is influenced by the vacuum exerted by the engine through the fuel inlet manifold and the outlet 18. A spring 60 forces the valve 54 to position. wherein it minimizes the size of the inlet 16 and thus the amount of heated air entering chamber 14. By creating a vacuum or at least a relative vacuum in chamber 14, valve 54 is moved up along post 58 against the biasing force of spring 60. An outwardly widening inlet 16 provides a seat for the valve that also directs air towards liner 52. This aids fuel cracking. suspended in the carpet 42.

The screen 56, which extends radially above liner 52, provides support against which the spring 60 acts and also functions to break up large drops of fuel in chamber 14. Screen 56 may be coated with or made of a catalytic material that assists cracking of the fuel.

While embodiments of the present invention have been described in detail, it is apparent to those skilled in the art that many modifications and variations can be made without departing from the principle of the invention. For example, the heater 22 is shown as a heat reservoir in thermal communication with the exhaust manifold 32 of the engine connected to the system 10. However, in an alternative embodiment, heater 22 may be a separate electric heater positioned within or wrapped around inlet 16. Further, referring in particular to the embodiment in Fig. 1, system 10 may be provided with an axially extending conduit in fluid communication with the fuel injector 20 for injecting fuel mist at one or more points along its length into chamber 14. Additionally, an auxiliary air inlet valve 62 may be provided in line 19 to provide additional air to the mixture exiting the exhaust 18. This may be advantageous for large volume engines such as large V-6 or V-8 engines, especially at high engine speeds. The valve 62 may be actuated on the basis of the engine vacuum or alternatively by the regulator 24 to provide varying amounts of additional air depending on the engine speed or load.

All such modifications and variations along with others which may be apparent to one skilled in the art are considered to fall within the scope of the present invention, the essence of which is defined in the foregoing description and appended claims.