WO2022198290A1

WO2022198290A1 - Fuel heating device

Info

Publication number: WO2022198290A1
Application number: PCT/BR2022/050052
Authority: WO
Inventors: Fernando Lepsch; Tulio Italico Moreira Coletto; Renato DE BRITO DUENHAS; Erika KAJINO LOSANO; Raul PIMENTEL MAIA; Rohit LENGADE; Victor CERQUEIRA FERNANDES
Original assignee: Robert Bosch Limitada
Priority date: 2021-03-26
Filing date: 2022-02-22
Publication date: 2022-09-29
Also published as: BR102021005990A2

Abstract

The present international application describes a fuel heating device for supplying heated fuel for use in a fuel injection system used preferably in motors in vehicles, in which said heating device is provided with at least one heating element (41) with at least one structural element (42) formed by at least one main body (421) and one positioning element (423).

Description

Descriptive Report of the Patent of Invention for "FUEL HEATING DEVICE"

[0001] The present invention relates to a fuel heater device for providing heated fuel applicable to a fuel injection system preferably used in engines used in vehicles.

STATUS OF THE TECHNIQUE

[0001] In recent years, problems with the amount of pollutants emitted (HC, CO, CO2 and particulates, among others) mainly by car engines, has been a major problem for large cities. Thus, new technologies have been developed to help reduce pollutants emitted by internal combustion engines.

[0002] In order to mitigate the emission of greenhouse gases from automobiles and reduce dependence on fossil fuels, several alternatives for the replacement of the internal combustion engine are available. However, the best solution to this dilemma must take into account the geographic and socioeconomic characteristics of the country, its energy matrix, its emissions legislation and the environmental impact of the fuel's carbon emissions throughout its life cycle.

[0003] Brazil has a strong reputation for its fleet of flex-fuel vehicles, long experience in the use of ethanol fuel and its distribution network. This sets it apart from other global markets and justifies a unique approach to reducing aldehyde emissions, for example.

[0004] However, there are some limitations in the use of bi-fuel engines (popularly known as “flex” engines). To meet the demand for using two fuels in one single tank, the sizing of a flex engine tends to be intermediate, since the sizing of mono-fuel engines is different, depending on the fuel ethanol or gasoline. This is because the vast majority of flex-fuel engines usually have a single geometric compression ratio, which represents the proportion between the aspirated volume plus the combustion chamber volume in relation to the combustion chamber volume).

[0005] In its stroke, the piston reaches a higher and a lower point in its displacement, respectively called top dead center (TDC) and bottom dead center (PMI).

[0006] Usually, the operation of the engine of a passenger vehicle has four strokes:

• Admission

• Compression

• Combustion

• Escape

[0007] The effect of the compression ratio is evident in the second stage - the intake valves close after the injection of the air/fuel mixture and this is compressed so that the combustion process begins. In this way, the geometric compression ratio of the engine is obtained: the ratio between the volume of the piston's combustion chamber at its bottom dead center PMI (largest volume) and its top dead center PMS (smallest volume).

[0008] Gasoline engines often use lower compression ratios (typically between 8:1 and 12:1), while ethanol engines work better with higher ratios (12:1 or even 14:1). [0009] However, before the fuel reaches the combustion chamber, it travels through a path from the vehicle's tank. This fuel is moved by a fuel pump and flows through ducts that transport the fuel - first, a hose and, later, a more rigid and branched duct called gallery. The branches take the fuel to be injected into the respective cylinders and it is at the exit of these branches where the fuel injectors are positioned.

[0010] In addition, the impingement of fuel on the surface of the piston or on the walls of the intake ducts can contribute to the increase of particles emitted. In addition, fuel condensation in cold areas of the engine can result in incomplete combustion generating hydrocarbons and carbon monoxide (HC and CO). [0011 ] When talking about engines that use the Otto cycle (engines traditionally used in automobiles), both those that use Port Fuel Injection (PFI) and those that work with direct injection (Dl - from the English, Direct Injection) emit particulates above the permitted limits. Thus, the use of a particulate filter for gasoline engines (whose acronym is GPF, as it comes from the English Gasoline Particulate Filter ) has been recommended to comply with the new legislation on particulate emissions that came into force.

[0012] However, even with the use of GPF, engines can still generate particulates above the limits determined by official health agencies, since pollutant emissions also depend on the behavior of drivers in terms of the way they drive. and proper maintenance of vehicles.

[0013] That said, one of the most effective techniques to obtain a more correct burning of the fuel is to deliver it to the preheated combustion chamber.

[0014] However, the constructive form of heaters that use a heating chamber where the fuel enters the internal region of the heating chamber through the fuel inlet opening positioned in its lower region, passing entirely through the heating element - effecting the heat exchange - and comes out warm due to the fuel outlet opening positioned in a higher region, despite providing a homogeneous heating of the fuel, it generates a zone of higher fuel temperature, where the fuel present there is at its maximum temperature.

[0015] However, as the constructive form of the current fuel injectors has an internal cavity capable of storing a volume of fuel (called “dead volume”), from the moment the engine is turned off. When the engine is started, this volume is injected into the combustion chamber.

[0016] However, when the engine is started, until this dead volume is heated, it takes a while, as it is necessary for the heated fuel that leaves the maximum heat zone to leave the heater at a certain speed and push cold fuel from dead volume to be injected. As a consequence, the number of pollutants is considered high in the time between starting the engine and reaching the heating temperature.

[0017] In this sense, the heating time of the fuel present in the dead volume must be reduced, shortening as much as possible the distance between the maximum heating zone and the injector inlet and making the fuel fully heated and reach faster the region where the dead volume is.

[0018] In this way, the present invention proposes to solve the problem of the state of the art in a much more efficient way, aiming at a faster, uniform heating and, consequently, a better atomization of the fuel.

OBJECTIVES OF THE INVENTION

[0019] The present invention aims to provide a fuel heater device applicable to internal combustion engines that operates by delivering heated fuel to an associated fuel injector, so as to ensure that the heated fuel flowing heater is delivered at the correct temperature to the inside of the injector as quickly as possible.

BRIEF DESCRIPTION OF THE INVENTION

[0020] In order to solve the technical problem presented and overcome the drawbacks of the state of the art, the present invention aims to provide a fuel heater device provided with at least one heating element in order to comprise at least one structural element provided with

• at least one main body provided with an external wall comprising a first distance between a geometric center of the heating device;

• at least one positioning element provided with an external positioner wall, comprising a second distance between a geometric center of the heating device greater than the first distance

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 - Perspective of an embodiment of a set for fuel injection.

Figure 2 - Detailing of the fuel heater device object of the present invention.

Figure 3 - Scheme of an embodiment of use of the heater device object of the present invention in an embodiment of an assembly for fuel injection.

Figure 4 - Scheme of the flow of fuel passing through the heater device object of the present invention in an embodiment of a set for fuel injection. DETAILED DESCRIPTION OF THE FIGURES

[0021] The fuel heating and heating management system is responsible for heating the fuel that will be injected into the engine to a predetermined temperature. The heating of fuel aims to improve the atomization of the injected fuel spray, reducing its droplet size, which means better preparation of the air-fuel mixture, leading to a more homogeneous mixture, which will lead to a decrease in the amount of fuel injected and , thus, the amount of gases and particulates emitted.

[0022] The heating system works from the start of the engine. System management aims to keep the injected fuel temperature always at the target temperature. For this, the system determines the amount of energy that must be supplied to the fuel, based on the fuel inlet temperature in the gallery, the fuel flow and the type of fuel. [0023] When the fuel temperature management system can accurately deliver the fuel with the highest temperature, in fact, the measured or calculated temperature value of the fuel leaving the heating zone (region equivalent to a heating) is the one for which the amount of energy was made available and supplied, avoiding energy waste. In addition, the atomization of the fuel becomes greater, improving the burn during combustion.

[0024] In this way, as the constructive form of the current fuel injectors has an internal cavity capable of storing a volume of fuel (called "dead volume"), from the moment the engine is turned off. When the engine is started, this volume is injected into the combustion chamber.

[0025] However, when the engine is started, until the cold fuel from this dead volume is merely pushed out of the injector, it would take too long as the heated fuel leaving the maximum heat zone of the heater moves at a certain speed considered low, causing the amount of displaced movement is considered low as well. As a consequence, the number of pollutants is considered high in the time between starting the engine and reaching the heating temperature. [0026] In this sense, to increase the fuel transport speed between the heater and the dead volume, so that the heated fuel reaches the dead volume in a shorter time, causing the heated fuel that leaves the maximum heat zone moves from the heater at a certain speed and rapidly pushes the cold fuel from the dead volume to be injected, displacing the cold fuel stored therein out of the injector so as to expel it, the present invention discloses a heater device of fuel provided with at least one heating element 41 so that it comprises at least one structural element 42 in the form of

• at least one main body 421 provided with an external wall 422 comprising a first distance D1 between a geometric center of the heating device C;

• at least one positioning element 423 provided with a positioner outer wall 424, which comprises a second distance D2 between a geometric center of the heater device greater than the first distance D1.

[0027] In this sense, the inventive and innovative technical effect of the set, object of the present invention, is achieved in its constructive form, as it allows it to be mounted on any devices: from covers that delimit and form a “heating chamber” , such as mounting on adapters or the like that enable the use of any fuel injector devices 2 (popularly known as “injectors”) that are common and already established in the current market, or even direct mounting on injectors that have physical space to receive the heater device object of the present invention, provided that the assembly between the fuel heater device 4 and such elements (caps, adapters and injectors) favors the increase in speed by reducing the fuel passage area and consequent increase in the speed of fuel flow by the association between the outer wall 422 of the main body 421 and the inner wall of these elements. By this assembly, the fuel is forced to flow only and mostly through the space between the inner wall of the caps, adapters or injectors, increasing its speed. Furthermore, the fact that the heating element 41 is mounted so that it is positioned in the passage region adjacent to said external walls ensures that all the fuel flowing therethrough is heated evenly. Thus, this construction allows the heated fuel that flows through the heater to be delivered to the inside of the injector at the correct temperature and as quickly as possible.

[0028] Another feature that is extremely relevant is that, as the main body 421 is associated with the internal wall of elements such as covers, adapters and injectors by the positioning element 423 (such association can be by simple mechanical contact, interference assembly or any other way that makes contact between the parts) prevents the heating device from vibrating and being affected by the vibration of the engine or the movement of the vehicle.

[0029] In a first preferred, but not mandatory, embodiment, the present invention describes a fuel heater device such that the positioning element 423 comprises a first positioning element portion associated with the outer wall 422 and a second positioning element portion associated with outer wall 422, such that the first positioner portion and the second positioner portion are dissociated from each other. [0030] In a preferred embodiment, the device for heating fuel comprises a heating element 41 associated with the main body 421 of the structural element 42.

[0031] Preferably, heating element 41 comprises at least element provided with electrical resistance, more preferably, an electrical filament. However, the use of a spiral electrical resistance type heating element or any other type or format of heating element that projects inside the previous reservoir and produces the effect of heating the fuel stored there is perfectly acceptable.

[0032] In this sense, the inventive and innovative technical effect of the device, object of the present invention, is achieved in the integration and association between the fuel heater device 4 and the internal wall of adapter elements 3 such as covers, adapters, ducts, tubes, hoses and the like, and injectors and adapters 3 the fuel injector device 2. The assembly between the fuel heater device 4 and the adapter element 3 (for example) favors the increase in speed, as it causes the reduction of the fuel passage area and consequent increase in passage speed. With this constructive form of heating device, the fuel is forced to flow solely and mainly through the space between the inner wall of the caps, adapters or injectors, increasing its speed. Furthermore, the fact that the heating element 41 is mounted so that it is positioned in the passage region adjacent to said external walls ensures that all the fuel flowing therethrough is heated evenly. Thus, this construction allows the heated fuel that flows through the heater to be delivered to the inside of the injector at the correct temperature and as quickly as possible.

[0033] As the main body 421 is associated with the inner wall 34 of the adapter element 3 by its outer wall 422, the fuel is obliged to flow solely and mostly through the interior of groove 423, which can be either helical (preferred) or straight (alternative embodiment), also being admitted any other forms of grooves or spaces that allow the fuel to flow there. Furthermore, the fact that the heating element 41 is mounted so that it is positioned in the passage region and in a position inside the groove 423 ensures that all the fuel flowing therethrough is heated evenly. With this, this constructivity allows the heated fuel flowing through the heater to be delivered to the inside of the injector at the correct temperature and as quickly as possible, allowing the use of any common and already 2 fuel injector devices (popularly known as “injectors”). established in the current market.

[0034] Another feature that is extremely relevant is that, as the main body 421 is associated with the inner wall 34 of the adapter element 3 by its outer wall 422 (such association can be by simple mechanical contact, interference assembly or what or otherwise that provides contact between the parts) prevents the heater device from vibrating and being affected by engine vibration or vehicle movement.

[0035] Thus, it should be noted that, as described above, the present invention achieves the objective of providing a fuel heater device for supplying heated fuel to injectors in internal combustion engines that ensures that the heated fuel flowing the output of the heating chamber reaches the dead volume of the injector in a reduced time, leading to an accuracy in the preheating temperature of the fuel and, consequently, a great precision in the reduction of polluting gases.

Claims

1. FUEL HEATER DEVICE provided with at least one heating element (41) characterized in that it comprises at least one structural element (42) provided with

• at least one main body (421) provided with an external wall (422) comprising a first distance (D1) between a geometric center of the heating device (C);

• at least one positioning element (423) provided with an external positioner wall (424), comprising a second distance (D2) between a geometric center of the heater device greater than the first distance (D1).

2. FUEL HEATER DEVICE, according to claim 1, characterized in that the positioning element (423) comprises a first portion of positioning element associated with the external wall (422) and a second portion of positioning element associated with the wall outer (422) so that the first positioner portion and the second positioner portion are dissociated from each other.

3. FUEL HEATER DEVICE, according to claim 1, characterized in that the heating element (41) is associated with the main body (421) of the structural element (42).

4. FUEL HEATER DEVICE, according to claim 1, characterized in that the heating element (41) comprises at least an element equipped with electrical resistance.

5. FUEL HEATER DEVICE, according to claim 1, characterized in that the heating element (41) comprises at least one filament.