EP0787258B1 - Device for injecting a fuel gas mixture into a combustion engine - Google Patents

Abstract

PCT No. PCT/FR95/01372 Sec. 371 Date Jun. 23, 1997 Sec. 102(e) Date Jun. 23, 1997 PCT Filed Oct. 18, 1995 PCT Pub. No. WO96/12886 PCT Pub. Date May 2, 1996A device for transforming internal combustion engines using liquid fuel into over-pressurized engines using gas. Liquid fuel is fed into an annular chamber surrounding a needle. The fuel and primary air is injected at a controlled flow and pressure into a choke chamber to form an air-fuel premixture made of very fine microdrops. During the downstroke of the piston, the premixture is aspirated, causing the projection of the premixture against the blades of a rotor which rotates at high speed. The gasification chamber is then over pressurized during the closing of the intake valve and the introduction of the mixture.

Description

The invention relates to a device for transforming internal combustion engines, using liquid fuels, in boosted gas engines.

Currently only two types of supply devices are known. engine cylinder fuel: carburetors, usually float type and injectors sequential projection.

The closest state of the art is an air-fuel mixture injection device for internal combustion engines according to document US-A-4,982,716. It comprises a micro-mixing chamber into which fuel is injected by an injector and pressurized air.

The main disadvantages resulting from the projection into the cylinders of fuel liquid sprayed in more or less fine droplets cooperating with a volume of air, are essentially incomplete internal combustion of the air / fuel mixture in the cylinders, this causes fouling of the cylinders more or less rapid, bad efficiency and increased pollution of the atmosphere by unburnt parts of the mixture air-fuel. The fouling of the cylinders quickly destroys the characteristics of engine oil lubrication due to particles and soot produced by unburnt fuel. he this results in premature wear of the engine segments and liners as well as the bearings of crankshaft and crankpins in the case of diesel engines with high supply pressure. Very high pressure supply requires the use of very precise pumps and very expensive as well as a supply circuit able to withstand these pressures. The system injection is also very precise and expensive and is easily adjusted.

To overcome these drawbacks, engine manufacturers have sought mechanical means, electric and / or thermal cooperating with, among other things, a pre-chamber preceding the classic collective distributor. However, the improvements made to the engines, more generally gasoline, can not concern the engines commonly called diesel, which are fitted with high pressure injection devices at 150 bar. The current trend is to make this feed even more precise so as to provide each cylinder exactly the same amount of fuel. This with increasingly sophisticated means of control and expensive which will increase the risk of breakdowns. They have the disadvantage of being out of order frequently. In general, current devices require ongoing maintenance, expensive, which is rarely provided by users, but by professionals equipped with result.

• supprimer la pollution des moteurs à combustion interne, à essence et diésel et plus particulièrement celle engendrée par les moteurs diésel des véhicules dits "poids lourds, mais également les moteurs marins, le moteur des groupes électrogènes etc. en supprimant les imbrûlés;
• réduire la consommation en carburant d'environ 20%;
• améliorer notablement le rendement de ces moteurs;
• accroitre leur longévité;
• réduire les coûts d'exploitation, d'entretien et de réglages.

The problems which the invention proposes to remedy are as follows:

• eliminate pollution from internal combustion, gasoline and diesel engines and more particularly that generated by diesel engines of so-called "heavy goods vehicles, but also marine engines, the engine of generator sets etc. by removing unburnt fuel;
• reduce fuel consumption by around 20%;
• significantly improve the performance of these engines;
• increase their longevity;
• reduce operating, maintenance and adjustment costs.

The device according to the invention achieves these objectives by proposing an original and simple means of gasification, at the molecular level, of the air / fuel mixture in a pre-mixing chamber and in a gasification chamber adapted to the intake of each cylinder of the internal combustion engines.
It is intended to replace the carburetors or injectors of petrol engines of all types and, in particular, to suppress the pressurized supply of diesel power engines which are the most polluting, and among these, those which equip vehicles of the heavyweight category, public works machinery, marine engines etc. The proposed gasification means transforms traditional internal combustion engines with liquid fuel into gas engines.
The auto-ignition pressure in diesel engines, from around 23 to 24 bar, is reduced so as to eliminate the auto-ignition effect which requires a high pressure fuel supply. The ignition is obtained by a high voltage electronic ignition center and the engine is suppressed by means of a compressor which allows to recover its full power by making it run faster when necessary. At low speed it operates at reduced power which further reduces its fuel consumption.

• une chambre de gazéification par cylindre, située en communication directe avec l'admission de chacune des chambres d'explosion dudit moteur,
• un moyen d'injection de carburant liquide sous pression de 5 à 7 bars;
• un moyen d'injection d'air primaire à une pression de 2 à 4 bars,
• un moyen d'injection d'air secondaire à une pression de quelques centaines de millibars,
• une micro-chambre de diffusion et de constitution d'un prémélange air-carburant;
• un moyen de surpression, de brassage et de fractionnement moléculaire du mélange air/carburant, le transformant en un gaz homogène dans chacune des dites chambres, à une pression de l'ordre de 100 à 400 millibars,
• des moyens de pilotage électronique de manoeuvre synchrone des pointeaux, des admissions d'air et d'optimisation du rapport massique air/carburant, et d'asservissement de la pompe de distribution du carburant liquide sous pression;
• une centrale électronique d'allumage à haut voltage

According to a preferred embodiment, the device according to the invention comprises:

• a gasification chamber per cylinder, located in direct communication with the intake of each of the explosion chambers of said engine,
• means for injecting liquid fuel under pressure from 5 to 7 bars;
• a means for injecting primary air at a pressure of 2 to 4 bars,
• a means of injecting secondary air at a pressure of a few hundred millibars,
• a micro-chamber for diffusing and constituting an air-fuel premix;
• a means of overpressure, stirring and molecular fractionation of the air / fuel mixture, transforming it into a homogeneous gas in each of said chambers, at a pressure of the order of 100 to 400 millibars,
• electronic control means for synchronous maneuvering of the needles, air intake and optimization of the air / fuel mass ratio, and servo-control of the pump for distributing the pressurized liquid fuel;
• a high voltage electronic ignition center

When closing the intake valve of each engine cylinder, the gasification chamber is put under permanent overpressure by means of a propeller multi-blades driven in rotation at high speed by the outlet pressure of the air-fuel premix. When opening the intake valve of each cylinder, the pressure of the gas in the gasification chamber collapses as it passes through the explosion chamber, then in a high vacuum by the cyclic descent of the piston-engine. This arrangement transforms the air / fuel pre-mixture into a gas allowing its total combustion in the explosion chamber, no unburnt residue being detectable exhaust gas outlet. The variation in the flow of fuel admitted into the gasification chamber is obtained inter alia by means of speed variation of fuel pump rotation.

• fractionnement total au niveau moléculaire, et transformation du mélange air/carburant en gaz homogène dans la chambre de gazéification précédant l'admission dans la chambre d'explosion, ayant pour résultat l'absence totale de gaz imbrûlés à la sortie du tuyau d'échappement des moteurs, donc la réduction très importante de la pollution de l'air par ces gaz, se limitant pratiquement au CO2;
• une très grande simplification de l'alimentation des cylindres des moteurs à combustion interne et une réduction notable du coût de cette fonction;
• la suppression des carburateurs aux inconvénients multiples et la suppression de l'injection directe qui remplace de plus en plus les carburateurs en accroissant la consommation de carburant et le volume de gaz imbrulés;
• l'amélioration significative du rendement et de la durée de vie des moteurs à combustion interne du fait que les gaz sont complètement brulés;
• l'économie de carburant de l'ordre de 20% et l'économie d'huile moteur du fait des vidanges moitié moins fréquentes;
• l'amélioration de la lubrification et une longévité accrue des moteurs avec une maintenance plus économique.
• l'amortissement en un temps très court du surcoût du dispositif en raison de l'économie de carburant, d'huile, d'entretien et de longévité du moteur
• la facilité d'adaptation sur les moteurs à combustion interne existants de tous types et particulièrement pour les moteurs diesel.

The advantages presented by the pressurized gasification device according to the invention are the following:

• total fractionation at the molecular level, and transformation of the air / fuel mixture into homogeneous gas in the gasification chamber preceding admission into the explosion chamber, resulting in the total absence of unburnt gases at the outlet of the exhaust pipe engines, therefore the very significant reduction in air pollution by these gases, practically limited to CO2;
• a very great simplification of the supply of the cylinders of internal combustion engines and a significant reduction in the cost of this function;
• the elimination of carburetors with multiple disadvantages and the elimination of direct injection which increasingly replaces carburetors by increasing fuel consumption and the volume of unburned gases;
• significant improvement in the efficiency and service life of internal combustion engines due to the fact that the gases are completely burned;
• fuel savings of around 20% and engine oil savings due to half-less oil changes;
• improved lubrication and longer engine life with more economical maintenance.
• the amortization in a very short time of the additional cost of the device due to the economy of fuel, oil, maintenance and longevity of the engine
• ease of adaptation on existing internal combustion engines of all types and particularly for diesel engines.

Installing new gasification equipment on diesel engines requires remove the air manifold, remove the injectors and the current supply system under pressure (high pressure pump and hydraulic part) to install a spark plug to the location of the current injector for each cylinder, to set up a spacer gasket to increase the volume of the explosion chambers, mount a gasification block on an adapter base by type of engine, installing a compressor, a central ignition electronics of at least 40,000 volts and a central unit for coordinating physical, fluidic and mechanical parameters of engine operation with the new equipment.

• fig. 1, une coupe en élévation de l'ensemble du dispositif selon l'invention;
• fig.2 et 3, le brise jet placé dans la chambre de pré-mélange;
• fig.4 et 5, une vue de face et une vue en coupe de l'hélice de brassage et de surpression du mélange gazeux;
• fig.6, une vue schématique d'ensemble des blocs de gazéification sur un moteur à quatre cylindres.

The device according to the invention is described in detail in the text which follows with reference to the appended drawings given by way of nonlimiting examples, in which are shown:

• fig. 1, a section in elevation of the entire device according to the invention;
• fig.2 and 3, the jet breaker placed in the premix chamber;
• fig.4 and 5, a front view and a sectional view of the mixing and overpressure propeller of the gas mixture;
• fig.6, a schematic overview of the gasification blocks on a four-cylinder engine.

As shown in Fig.1 , the device is in the form of a gasification block 1 comprising a gasification chamber 2, fixed directly or via an adapter base, by a set of screws to the right of the orifice 3 for admitting the gas into each engine cylinder with which it is in communication. Chamber 2 is closed by a body 3 fitted at its longitudinal central axis XX ′, with a sliding needle injection device 4, acting as a tap in an open position and a closed position. It is controlled for example by an electromagnetic coil 5 attracting its core 6 maintained in the normally closed position by means of a compression spring 7
The fuel is injected under a pressure of approximately 5 to 7 bars on a jet breaker 8 whose function is to reduce the pressure in a micro-chamber 10 of premix by creating an air-fuel premix which is then projected against the blades of a multi-blade propeller 11, freely rotating in a bearing 12 concentrically with the axis XX 'of the gasification block. This propeller generates overpressure and homogenization by stirring, of the air-fuel pre-mixture already produced at the jetbreaker 8.
The bearing 12 of the propeller is for example housed in a bearing holder 13 comprising arms 14 for fixing screws by means of the body 1 of the chamber 2. The propeller 11 rotates freely on its bearing. Its number of blades is a function of the high speed of rotation to be obtained for fractionating the gas mixture at the molecular level, from 3,000 to 20,000 revolutions / minute depending on the engine speed. The liquid fuel is brought by a pipe 16 and a connector 17, to an annular chamber 18 around the needle 4 having fuel passage grooves; the parts delimiting these grooves also serving as a guide in the bore of the needle support. The primary compressed air, generated by an auxiliary compressor, is supplied by a pipe 20 and a connector 21, to an annular chamber 22 opening into the premix chamber 10. The fuel and the premixed air are directed, through a conical orifice 23, towards the blades of the propeller 11; simultaneously, additional secondary air, coming from a lateral orifice 24, also goes towards the blades of the propeller 11. The optimization of the volumes of primary air and secondary air is adjusted according to the flow rate of the fuel supplied by a controlled flow pump cooperating with a variable opening solenoid valve. The air-fuel pre-mixture in micro-droplets, injected on the propeller 11 is fractionated, in cooperation with the temperature of the gasification chamber 2, on an almost molecular scale, transforming it into a pressurized gas before it passes through each engine cylinder.

1) alimentation de carburant liquide sous pression de 5 à 7 bars dans la chambre annulaire 18 du pointeau 4;

2) injection du carburant et d'air primaire, à un débit et à une pression contrôlés, dans la chambre 10 sur le brise-jet 8 pour constituer un pré-mélange air-carburant se présentant déjà en très fines micro-gouttelettes;

3) Aspiration en 3 à la descente du piston créant une dépression dans l'orifice conique 23 d'accès à la chambre de gazéification 2 et projection du pré-mélange en fines micro-gouttelettes sur les pales de l'hélice 11 mise en rotation à grande vitesse alternativement par ladite dépression de la chambre 2 dûe à la descente du piston conjuguée avec la pression d'injection air-carburant;

4) surpression dans la chambre 2 pendant la fermeture de la soupape d'admission et l'introduction du mélange sous pression,

5) dépression dans la chambre 2 à l'ouverture de la soupape pour un nouveau cycle.

The complete cycle takes place according to the following phases:

1) supply of pressurized liquid fuel from 5 to 7 bars in the annular chamber 18 of the needle 4;

2) injection of fuel and primary air, at a controlled rate and pressure, into the chamber 10 on the jet breaker 8 to form an air-fuel pre-mixture already present in very fine micro-droplets;

3) Suction in 3 at the descent of the piston creating a depression in the conical orifice 23 of access to the gasification chamber 2 and projection of the premix in fine micro-droplets on the blades of the propeller 11 put into rotation at high speed alternately by said depression of the chamber 2 due to the descent of the piston combined with the air-fuel injection pressure;

4) overpressure in chamber 2 during the closing of the inlet valve and the introduction of the mixture under pressure,

5) vacuum in chamber 2 when the valve opens for a new cycle.

The speed of rotation of the propeller 11 is mainly a function of the vacuum, it is driven at a speed of rotation of the order of 3,000 to 20,000 revolutions / minute, sufficient speed to ensure molecular fractionation of the premix.
This result is obtained with great economy of means. An open or closed needle 4 has been used to regulate a continuous flow rather than a pulse flow as is the case in most conventional motors. It is the speed variation of the fuel pump associated with a variable opening solenoid valve that provides the flow required for engine speed. This variation could also be obtained by any other known means. At start-up and at low engine speed, the rotation of the propeller is assisted by an unrepresented electric motor and at higher speeds, by pressurized air projected at 26, tangentially on the blades of the propeller 11.
The quantities of fuel, primary air and secondary air are metered by an electronic central control and coordination of physical, fluid and mechanical parameters, in particular the speed of rotation of the heat engine, temperature and pressure. The mass ratio of the air-fuel mixture results from these various parameters.

In the case of adaptation of gasification equipment on diesel engines the high pressure pump and its hydraulic equipment as well as the injectors, a thick spacer gasket is introduced to increase the volume of the chambers explosion and reduce the compression ratio below the self-ignition threshold, a spark plug is mounted in place of the injector of each cylinder and cooperates with a central high voltage ignition electronics, at least 40,000 volts to generate the spark ignition of the gas mixture; the gasification blocks are mounted on a base adapted to the type of engine and fixed to the holes of the air collector also removed; The pump high pressure injection system is replaced by a variable pressure low pressure pump, from around 5 to 7 bars.

Figs. 2 and 3 , show in elevation and in end view, an example of a jetbreaker 8 placed in the pre-mixing chamber 10. This jetbreaker is in the form of a threaded and shouldered cross piece, screwed in stop concentrically with the axis XX 'and having its small face in line with the outlet of the injector 15.

Figs. 4 and 5 show a front view and a sectional elevation view of an example of an overpressure propeller 11 with 6 blades 27, the hub of which is integral with the shaft 28 on which it is wedged in carrier overhang, freely rotating in its bearing.

Fig. 6 schematically shows an overview of the gasification blocks 30, 31, 32, 33, each comprising their gasification chamber 2 in line with the engine cylinders. The gasification chambers 2 are under permanent overpressure at a pressure of the order of several bars, by their propeller 11, by the admission of additional air coming from a possible turbocharger and mainly from an auxiliary booster not shown.
The adjustment of the flow rate of the pressurized fuel, admitted into the premix chambers 10, is obtained, in normal rotation of the internal combustion engine, by known electronic means for varying the rotation speed of a pump 35 delivering the fuel at a pressure of 5 to 7 bars in a common piping 36 distributing it to each of the four gasification blocks by the pipes 37, 38, 39, 40.
This variation in the fuel flow of the pump cooperates with a variable opening solenoid valve to refine the adjustment of this flow.
The primary air is generated by the service compressor, not shown, with which heavy vehicles are generally fitted, or by an auxiliary compressor.

To further improve the gasification, an electrical means is added, for example a heating resistance, to heat the fuel oil before injecting it into the pre-mixing chamber. The primary air from the compressor is also hot and facilitates the gasification at the level of said chamber 10.

Claims (10)

1. A gas-fuel mixture injection device for internal combustion engines using a liquid fuel, comprising a micro-chamber wherein a liquid fuel is injected by means of an injector and air under pressure is also injected, so as to generate a mixture to be admitted into each of the cylinders of said engine, characterized in that it comprises, for each of the engine explosion chambers, a gasification block (25) having said micro-chamber (10) performing an air-fuel pre-mixture, fed with fuel by a means (4) for the injection of primary air (20) under pressure; in that it comprises a propeller (11) which rotates freely inside a gasification chamber (2) of said block (25), driven by means of the depression generated upon connection with the corresponding explosion chamber and by means of the said pre-mixture under pressure, towards their blades, for the over-pressurizing, mixing and high speed molecular breaking-up of the air-fuel pre-mixture in collaboration with additional secondary air (24), thereby transforming it into homogeneous gas inside the said gasification chamber (2) of each cylinder; and in that the said block (25) is secured on the engine block, directly connected to the gas mixture intake port (A) towards the corresponding explosion chamber of said engine.
2. A device according to claim 1, characterized in that the pre-mixing micro-chamber (10) comprises a choke (8) to facilitate forming the pre-mixture.
3. A device according to claims 1 and 2, characterized in that the propeller (11) for the over-pressurizing, mixing and high speed molecular breaking-up of said air-fuel pre-mixture, is a multiblade propeller, concentrically arranged with the axis XX' of the gasification block at the exit of the premixing chamber (10) and which freely rotates within a bearing integrally formed with the body (1) of the chamber (2); and in that the propeller (11) is rotated by means of the pressure of the air-fuel pre-mixture and by means of the depression generated on aspiration of the broken-up gas mixture from the chamber (2) to the explosion chamber upon the opening of the intake valve.
4. A device according to claims 1 and 3, characterized in that the propeller (11) is rotated at the starting and at other speeds by projecting air under pressure through a pipe (26) against the periphery of the blades thereof.
5. A device according to one of the preceding claims, characterized in that the primary air feeding the pre-mixing micro-chamber (10) is compressed at a pressure ranging from 2 to 4 bars by means of an air compressor; and in that the secondary air is fed into the chamber (2) at a pressure of some hundreds millibars.
6. A device according to one of claims 1 to 5, characterized in that an electronic facility regulates the physical, fluid and mechanical operating parameters of the engine, by actuation on a liquid fuel flow variation means, a primary air pressure adjusting means, a secondary air inlet adjusting means, in function of the fuel and primary air flows, in order to optimise the mass ratio air/fuel, and a high voltage spark plug ignition facility.
7. A device according to one of claims 1 to 6, characterized each operating cycle of the thermal engine is carried out according to the following steps:

   1) feeding of the liquid fuel under pressure;

   2) injection of the fuel and the primary air, at a controlled flow and pressure, into the pre-mixing micro-chamber (10) for forming an air-fuel pre-mixture;

   3) projection of the pre-mixture under pressure in the form of very fine micro-drops against the blades of the mixing propeller (10), causing the rotation thereof;

   4) aspiration through (A) upon the down stroke of the piston, generating a depression inside the chamber (2) which contributes to the high speed rotation of the propeller, alternatively by means of the depression in the chamber (2) caused by the downward motion of the piston and bay the air-fuel injection pressure;

   5) over-pressurizing the inside of the chamber (2) during the closing of the intake valve after the introduction of the mixture under pressure into the explosion chamber; and

   6) putting the chamber (2) under depression upon the opening of the valve at the beginning of a new cycle.
8. A device according to claims 1 and 7, characterized in that the flow variation of the liquid fuel under pressure injected through a common pipe (36), which distributes it into each of the gasification blocks (25) through tubes (37, 38, 39, 40), is achieved by means of a variable opening electrovalve which collaborates with a means for the variation of the rotation speed of the fuel pump (35), so as to adjust such flow.
9. A device according to one of claims 1 to 8, adapted on the existing diesel engines, characterized in that a bed joint is fitted between the engine and the cylinders head to reduce the compression ratio below the auto-ignition threshold; in that a gasification block (25) is fixed, instead of the trap, at the right side of the port (A) to each explosion chamber of the engine, through an adaptation part according to the diesel engine type; in that an ignition spark plug is mounted instead of the injector in each cylinder; in that a low pressure fuel pump (35) is mounted instead of the high pressure pump; in that an auxiliary compressor for the feeding of primary air is mounted adjacent to the internal combustion engine; and in that a high-voltage ignition facility is provided for the sequential feeding of the spark plugs.
10. A device according to one of claims 1 to 9, characterized in that an electric means overheats the fuel prior to the injection of the latter into the pre-mixing micro-chamber (10).

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