IT201800009869A1 - WATER SUPPLY SYSTEM TO AT LEAST ONE COMBUSTION CHAMBER IN AN INTERNAL COMBUSTION ENGINE AND CORRESPONDING HEATER DEVICE - Google Patents

Description

of the patent for industrial invention entitled:

"WATER SUPPLY SYSTEM WITH AT LEAST ONE COMBUSTION CHAMBER IN AN INTERNAL COMBUSTION ENGINE AND CORRESPONDING HEATER DEVICE"

TECHNIQUE SECTOR

The present invention relates to a water supply system to at least one combustion chamber in an internal combustion engine and to a corresponding heater device.

ANTERIOR ART

As is known, in an internal combustion heat engine it has been proposed to feed water in addition to the fuel in the combustion chambers defined inside the cylinders.

In an internal combustion engine, the water injection system consists of introducing water into the engine through the intake duct, in the form of a spray, or mixed with the fuel, or directly into the combustion chamber, in order to cool the air / fuel mixture increasing the resistance to knocking phenomena. Water has a high latent heat of vaporization, in other words it requires a lot of energy to pass from the liquid to the gaseous state. When water at room temperature is injected into the intake duct, this absorbs heat from the incoming air and from the metal walls, evaporating, and thus cooling the incoming charge. The engine therefore draws in cooler air, in other words denser, the volumetric efficiency is improved and the possibility of detonation is reduced, moreover it is possible to inject more fuel. During compression, the water present in tiny drops evaporates and absorbs heat from the compressed air, cooling it and lowering its pressure. Combustion takes place after compression, and here there is a further beneficial effect: during combustion a lot of heat is developed, which is absorbed by the water, reducing the peak temperature of the cycle and consequently reducing the formation of NOx and the heat that must absorb the walls of the motor. This evaporation also converts part of the heat of the engine (which would otherwise have been wasted) into pressure, given precisely by the vapor formed, increasing the thrust on the piston and also increasing the flow of energy entering a possible turbine at the exhaust (the turbine, moreover, , would benefit from the reduction of the temperature of the exhaust gases due to the absorption of heat by the additional water).

The water supply system includes a tank which is filled with demineralized water (to avoid the formation of scale); the tank can be refueled from outside the vehicle or it could also be refueled using the condensate from the air conditioner, using the condensate from the drain, or even conveying rainwater. In addition, the tank is generally equipped with an electric heating device (ie equipped with a resistance that generates heat due to the Joule effect when it is crossed by an electric current) which is used to melt any ice when the external temperature is particularly cold.

DESCRIPTION OF THE INVENTION

The purpose of the present invention is to provide a water supply system to at least one combustion chamber in an internal combustion engine and a corresponding heater device that allow effective and efficient heating of the water contained in the tank.

According to the present invention, a water supply system is provided to at least one combustion chamber in an internal combustion engine and a corresponding heater device, according to what is established in the attached claims.

The claims describe embodiments of the present invention forming an integral part of the present description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the attached drawings, which illustrate a non-limiting example of embodiment in which:

Figure 1 is a schematic view of a water supply system to at least one combustion chamber in an internal combustion engine;

Figure 2 schematically illustrates a tank of the water supply system of figure 1;

Figure 3 is a perspective view of a heater device of the tank of figure 2;

Figure 4 is a front view of the heater device of figure 3;

Figure 5 is a cross-sectional view of a conducting element of the heater device of Figure 3; And

• Figures 6-10 are cross-sectional views of some construction variants of the conductor element of Figure 5.

PREFERRED FORMS OF IMPLEMENTATION OF THE INVENTION

In Figure 1, the number 1 indicates as a whole a water supply system in an internal combustion thermal engine 2; the water is destined to the combustion chambers obtained in the cylinders of the internal combustion thermal engine 2 to increase combustion efficiency and / or to increase the power generated.

The feeding system 1 comprises a tank 3 which contains a mass of demineralized water and a pump 4 that draws the water inside the tank 3 and sends the pressurized water to a supply duct 5. A plurality of injectors 6 are connected to an end portion of the supply duct 5 and inject the water at low pressure into corresponding intake ducts through which fresh air is conveyed to the cylinders. According to another embodiment, the injectors 6 could inject water at high pressure directly into the cylinders (in this case an additional high pressure pump is generally provided). According to a further embodiment, the water fed by the feeding system 1 is mixed with the fuel which is injected inside the cylinders.

Along the supply duct 5 and immediately downstream of the pump 4 there is a maximum pressure valve 7, that is a valve which opens by re-introducing the excess water into the tank 3 when the pressure inside the supply duct 5 exceeds a predetermined threshold value; in essence, the maximum pressure valve 7 operates as a pressure regulator to prevent the pressure inside the supply duct 5 from exceeding the predetermined threshold value.

According to an alternative and perfectly equivalent embodiment, a pressure sensor is provided arranged downstream of the pump 4 (for example in a common channel to which the injectors 6 are connected) and the flow rate of the pump 4 is adjusted in feedback to maintain the pressure downstream of the pump 4 around a desired value (which can also be variable according to the motor point); in this embodiment, the maximum pressure valve 7 is absent or is present only for safety reasons (ie it intervenes only in the event of errors in the control or in the event of malfunctions).

According to what is illustrated in Figure 2, the feeding system 1 comprises a heater device 8, which is coupled to the tank 3, is suitable for heating the water contained in the tank 3 itself and comprises an electrical resistance (i.e. an organ which transforms for Joule effect of electrical energy into heat). The heater device 8 has an internally hollow cylindrical shape and is arranged between an upper wall 9 of the tank 3 and a lower wall 10 of the tank 3.

As illustrated in Figure 2, the feeding system 1 comprises an integrated sensor 11 which is preferably arranged on the bottom of the tank 3 (i.e. through the lower wall 10 of the tank 3) and is adapted to measure the temperature, the level and the quality. of the water contained in the tank 3. In other words, the sensor 11 integrates in a single body three different sensitive elements which are adapted to determine respectively the temperature, the level and the quality of the water contained in the tank 3; that is, the sensor 11 is actually composed of several sensing elements that are functionally independent of each other which are arranged (integrated) in a single common support. As an example, the sensor 11 could determine the level of water contained in the tank 3 (i.e. the degree of filling of the tank 3) by ultrasound (alternatively a float could be provided). According to a different embodiment not shown, the sensor 11 could not be integrated (or not completely integrated), ie the various sensitive elements of the sensor could be physically separate and independent from each other.

As an example, the sensor 11 could determine the density and electrical conductivity of the water contained in the tank 3, since the density and the electrical conductivity are indicators of the quality of the water contained in the tank 3. If the density of the water contained in the tank 3 is significantly lower than a first predetermined threshold value (around 997 kg / m³ corresponding to the density of pure water) then it is an indication that in the water there are polluting liquids less dense than water (typically motor oil , petrol or diesel). On the other hand, if the electrical conductivity contained in the tank 3 is significantly higher than a second threshold value then it indicates that in the water there are mineral salts ions in the solution (i.e. the water is not adequately demineralized and therefore in the long run it can give rise to to the formation of encrustations). According to a further embodiment, the sensor 11 could also determine the PH (i.e. the degree of acidity or basicity) of the water contained in the tank 3; if the PH of the water contained in the tank 3 is significantly different from the value 7 (typical of distilled water at 25 ° C) then it is an indication that foreign substances are present in the water.

The feeding system 1 comprises a control unit 12 which supervises the operation of the feeding system 1 itself and, among other things, receives the readings made by the sensor 11 and drives the heater device 8.

When the sensor 11 detects an unsatisfactory quality of the water contained in the tank 3, the control unit 12 generates a signal for the driver of the vehicle in which the internal combustion engine 2 is installed and, if the quality of the water contained in the tank 3 it is very unsatisfactory, it cuts off the water supply to the internal combustion engine 2 (consequently causing the internal combustion engine 2 to operate in a reduced performance mode of operation, not being able to enjoy the benefits given by the injection of water ) and requires emptying and washing the tank 3.

Generally, the control unit 12 uses the heater device 8 when the temperature of the water contained in the tank 3 (and detected by the sensor 11) is lower or close to zero to avoid the formation of ice inside the tank 3 or to melt the ice formed previously (in the case of a cold start of the internal combustion engine 2 after a relatively long stop). In this case, the control unit 12 drives the heater device 8 to heat the water contained in the tank 3 to a temperature slightly above zero (for example 5 ° C - 10 ° C), since the sole purpose of the heating means avoiding the formation of ice or melting any ice present.

The water contained in the tank 3 may contain microorganisms (for example bacteria, spores ...), or living organisms having dimensions (less than 0.1 mm) that cannot be seen with the naked eye. These microorganisms can proliferate over time inside the tank 3, generating colonies which can, for example, obstruct (partially or completely) the water intake of the pump 4 or they can be sucked by the pump 4 and then sent towards the injectors 6 with the risk of clogging the pump 4, any filters arranged downstream of the pump 4, the injectors 6 or, if they reach the combustion chambers obtained in the cylinders of the internal combustion engine 2, disturb the combustion with a potential degradation of performance and / or a potential increase in the generation of pollutants. In other words, the microorganisms that are present in the water contained in the tank 3 can over time proliferate and increase in number, leading, for example, to the formation of algae or biofilm on the walls of the tank 3; such algae or biofilm detaching from the walls can obstruct the intake of the pump 4 or can also be sucked in by the pump 4 and thus reach the injectors 6 and / or the combustion chambers formed in the cylinders.

The control unit 12 drives (occasionally) the heater device 8 also to heat the water contained in the tank 3 to a temperature above 60 ° C (preferably 70 ° C) for a time exceeding 20 seconds (preferably above 40 -60 seconds) in order to obtain a heat treatment (i.e. a sort of sterilization / pasteurization) of the water contained in the tank 3 (or in order to obtain, due to the effect of heat, a reduction in the concentration of microorganisms present in the water 3 contained in the tank 3). It is important to underline that the heat treatment that is carried out using the device 8 heater is a sort of sterilization (i.e. a partial, incomplete sterilization) since, not being able to reach very high temperatures (above 100 ° C) in order not to damage the tank 3 or the components housed in the tank 3 itself, at the end of the heat treatment the water contained in the tank 3 is not “sterile” in the medical sense, but in any case it has significantly reduced the presence of microorganisms.

In other words, the control unit 12 uses (occasionally) the heater device 8 (initially provided only as an anti-ice function) to subject the water contained in the tank 3 to a heat treatment aimed at reducing (as far as possible) microorganisms in vegetative form, of germs and, with a prolonged action, also of some bacterial spores. Experimental tests have shown that by heating the water contained in tank 3 to 70 ° C - 75 ° C for at least 2-5 minutes, a reduction of 90-98% of the total bacterial concentration can be achieved.

Generally, the control unit 12 determines when new water has been added inside the tank 3 and then drives the heater device 8 to heat (in order to carry out a heat treatment aimed at reducing the concentration of microorganisms) the water contained in tank 3 immediately after adding new water to tank 3.

That is, as soon as new potentially non-sterile water is added, the control unit 12 performs (at least) a heat treatment aimed at reducing the concentration of microorganisms of all the water contained in the tank 3. The addition of new water into the tank 3 is determined on the basis of the level signal provided by the sensor 11, i.e. the control unit 12 determines that new water has been added inside the tank 3 when there is an increase in the level of the water contained in the tank 3.

According to a possible embodiment, the control unit 12 performs (at least) a heat treatment aimed at reducing the concentration of microorganisms of all the water contained in the tank 3 with a predetermined frequency (for example monthly, bi-monthly, quarterly ... or every month since the last heat treatment) regardless of adding new water to the tank 3.

Generally, the heater device 8 can be used to perform a heat treatment aimed at reducing the concentration of microorganisms only when the internal combustion engine 2 is on, or when the internal combustion engine 2 can generate (through its alternator) a sufficient amount of electricity for the electrical resistance of the device 8 heater. Consequently, when it is necessary to heat the water contained in the tank 3 to carry out a heat treatment aimed at reducing the concentration of microorganisms, the control unit 12 must in any case wait for the first useful opportunity, i.e. the first (sufficiently prolonged) ignition of the internal combustion engine 2.

According to a preferred embodiment, at least one body containing silver is provided which is arranged in the tank 3 in contact with water and has an antibacterial capacity. In other words, silver has natural bacteriostatic properties that allow the bacterial concentration of the water contained in the tank 3 to be kept under control, thus avoiding the proliferation of algae and biofilm over time.

In the embodiment illustrated in the attached figures, both the heating of the water and the presence of the body containing silver are used to limit the proliferation of microorganisms in the water contained in the tank 3; according to other embodiments not illustrated, to limit the proliferation of microorganisms in the water contained in the tank 3, only water heating could be used.

As illustrated in Figures 3 and 4, the heater device 8 comprises a conductive element 13 which has two opposite ends 14 and is capable of being crossed by an indifferently alternating or direct electric current (which generates heat due to the Joule effect) by applying a difference of potential between the two ends 14. The conducting element 13 is serpentine-shaped, that is, although they have a relatively long length, it is made compact by being wound around itself; according to a preferred embodiment, the serpentine conformation of the conducting element 13 is also made to arrange the two ends of the conducting element 13 close to each other.

According to the preferred embodiment illustrated in the attached figures, the coil-shaped conducting element 13 has an internally empty cylindrical shape (i.e. the conducting element 13 surrounds and delimits an internally empty cylindrical volume). According to the preferred embodiment illustrated in the attached figures, the conductor element 13 is shaped like a "fret", ie it has an uninterrupted series of segments alternately arranged in perpendicular and parallel lines; in other words, the conducting element 13 consists of an alternation of main straight sections 15 arranged axially (i.e. parallel to a longitudinal axis of symmetry of the cylindrical volume) and connecting sections 16 which are arranged perpendicularly to the main sections 15, connecting between them the main sections 15 themselves, and are shaped as circular sectors.

According to a different embodiment not shown, the coil-shaped conducting element 13 has a cylindrical spiral shape that wraps around a longitudinal axis of symmetry of the cylindrical volume.

As shown in Figure 2, the sensor 11 is arranged inside the conducting element 13, or inside (normally in the center) of the cylindrical volume delimited externally by the conducting element 13 shaped like a serpentine.

According to a preferred embodiment illustrated in Figure 5, the conductive element 13 is composed of an internal layer 17 (i.e. not in contact with the water contained in the tank 3) made of copper (or other electrically conductive metallic material such as, for example for example, the constantan)) and an outer layer 18 (i.e. in direct contact with the water contained in the tank 3) in silver. In this way, the conducting element 13 performs a dual function: to generate heat by the Joule effect (when necessary, or when crossed by an electric current) and to form a body containing silver in direct contact with the water contained in the tank 3. Second a preferred embodiment illustrated in Figure 5, the conducting element 13 comprises a support body 19 which is arranged inside the conducting element 13 (i.e. constitutes an internal core of the conducting element 13), is made of molded plastic material injection, and gives mechanical strength to the conducting element 13. In fact, in order not to have too small an electrical resistance (which would require to generate at the same time a very low voltage difference and a very high electric current intensity to obtain a heating power of the order of hundreds of Watts) the thickness of the layers 17 and 18 must be contained (of the order of fractions of a millimeter) and therefore the layers 17 and 18 alone would not be able to present an adequate mechanical strength.

The realization of the conductive element 13 foresees to form the support body 19 in plastic material by means of a common injection molding, to apply the internal copper layer 17 on the plastic material, and then to apply (typically by means of a galvanic bath) on the layer 17 inner copper layer 18 outer silver.

It is important to underline that the internal copper layer 17 has both the function of achieving better adhesion to the underlying plastic support body 19 (copper adheres better than silver to plastic compared to silver, commercially available systems for covering a plastic body with a copper layer, and it is trivial to cover the copper with a layer of silver by galvanic deposition), and the function of reducing the amount of silver used (silver is much more expensive than copper and therefore is used only a thin outer layer 18 of silver in direct contact with the water contained in the tank 3). In other words, the inner copper layer 17 constitutes an "adhesion" of the outer silver layer 18 to the plastic support body 19.

In the embodiment illustrated in Figure 5, the plastic support body 19 is solid, while in the variant illustrated in Figure 6 the plastic support body 19 is internally hollow (to reduce production cost and weight).

In the alternative embodiment illustrated in Figure 7, the support body 19 made of plastic material is not present; this solution generally requires a greater thickness at least of the internal copper layer 17 for mechanical strength requirements. In this embodiment, in order not to excessively reduce the overall electrical resistance of the conducting body 13, the internal layer 17 of copper could be replaced by an internal layer 17 of another metal (for example constantan or stainless steel) which has an electrical resistivity decidedly higher than copper and also a higher mechanical strength than copper.

In the alternative embodiment illustrated in Figure 8, only the outer layer 18 of silver is present (ie the inner layer 17 of copper is not present).

In the alternative embodiment illustrated in Figure 9, only the copper layer 17 is present, which therefore becomes the external layer (ie the external silver layer 18 is not present).

In the further embodiment illustrated in Figure 10, between the inner layer 17 of copper (but, as previously mentioned, it could also be of another electrically conductive metallic material such as, for example, constantan) and the outer layer 18 of silver a separation layer 20 of electrically insulating material (and, as far as possible, thermally conductive) is interposed; in this embodiment, the electric current circulates only through the inner layer 17 and not through the outer layer 18 (which is electrically isolated from the inner layer 17 by the separation layer 20). In other words, in this embodiment the function of generating heat by the Joule effect (i.e. through the circulation of an electric current) is reserved for the inner layer 17 (in copper or other conducting metal) while the outer layer 18 in silver has only a bacteriostatic function (i.e. an antimicrobial agent to inhibit or limit bacterial replication). Avoiding the circulation of electric current through the outer silver layer 18 allows to better preserve the integrity of the outer silver layer 18 and also allows to avoid short circuits on the outer silver layer 18 due to deposited particles or due to the use of incorrect fluids.

In the embodiment illustrated in the attached figures, the conductor element 13 has a rounded rectangular shape in cross section (in order not to have sharp edges in which the deposition of layers 17 and 18 is more problematic); according to a different embodiment not shown, the conductor element 13 has a circular shape, an elliptical shape, or a square shape in cross section.

In the embodiment illustrated in the attached figures, the conductor element 13 has an internally empty cylindrical shape; according to a different embodiment not shown, the conductor element 13 has a parallelepiped shape with a square, rectangular, triangular or polygonal cross section.

The embodiments described here can be combined with each other without departing from the scope of protection of the present invention.

The feeding system 1 described above has numerous advantages.

In the first place, the feeding system 1 described above allows the water contained in the tank 3 to be heated effectively and efficiently, particularly in the presence of ice (i.e. the melting of the ice is extremely rapid), and this result is obtained thanks to the particular conformation of the heater device 8. In fact, the heater device 8 is particularly large and affects a significant part of the internal volume of the tank 3 and therefore allows the heat produced to be distributed over all the water (more or less frozen) contained in the tank 3.

Furthermore, the power supply system 1 described above is of particularly easy and economical construction thanks to the conformation of the heater device 8 which allows the conductor element 13 to be produced quickly and easily.

Finally, the power supply system 1 described above is particularly easy and economical to implement also because it allows to integrate in the heater device 8 both the heating function of the water contained in the tank 3, and the anti-bacterial function performed by the silver.

LIST OF REFERENCE NUMBERS OF THE FIGURES

1 power system

2 internal combustion engine

3 tank

4 pump

5 supply duct

6 injectors

7 pressure relief valve 8 heater device

9 upper wall

10 lower wall

11 sensor

12 control units

13 conductor element

14 ends

15 main features

16 connecting sections

17 inner layer

18 outer layer

19 support body

20 separation layer

Claims (15)

1) System (1) for feeding water to at least one combustion chamber in an internal combustion engine (2); the power supply system (1) includes: a tank (3) adapted to contain a quantity of water; a supply conduit (5); a pump (4) which is suitable for drawing water from the tank (3) and for pumping pressurized water into the supply duct (5); and a heater device (8) which is coupled to the tank (3), is adapted to heat the water contained in the tank (3) itself, and comprises at least one conducting element (13) which has two opposite ends (14) and is suitable to be crossed by an electric current; the power supply system (1) is characterized by the fact that the conductor element (13) includes an external layer (18) which is in direct contact with the water contained in the tank (3) and is made of silver. 2) Power supply system (1) according to claim 1, wherein the conductive element (13) comprises an inner layer (17) which is made of a metal other than silver, in particular copper, and supports the layer ( 18) silver exterior. 3) Power supply system (1) according to claim 1 or 2, wherein the conducting element (13) comprises a support body (19) which is arranged inside the conducting element (13), constitutes an internal core of the conductor element (13), and is made of plastic material. 4) Power system (1) according to claim 1, 2 or 3, in which the conductor element (13) comprises: an inner layer (17) which is made of a metal other than silver, in particular copper, and supports the outer layer (18) in silver; and a support body (19) which constitutes an internal core of the conductor element (13), supports the internal layer (17), and is made of plastic material. 5) Feeding system (1) according to claim 4, wherein: the conductor element (13) comprises a separation layer (20) in electrically insulating material which is interposed between the inner layer (17) and the outer silver layer (18); And the electric current is adapted to circulate only through the inner layer (17) and not through the outer silver layer (18). 6) Power supply system (1) according to one of claims 1 to 5, in which the conductor element (13) is shaped like a serpentine. 7) Power system (1) according to claim 6, in which the conductor element (13) shaped like a serpentine has an internally hollow cylindrical shape. 8) Power system (1) according to claim 7, in which the conductor element (13) has an uninterrupted series of segments alternately arranged in perpendicular and parallel lines. 9) Feeding system (1) according to claim 6, 7 or 8, in which the conducting element (13) consists of an alternation of main straight sections (15) arranged axially and connecting sections (16) which are arranged perpendicular to the main sections (15), they connect the main sections (15) themselves, and are shaped as circular sectors. 10) Feeding system (1) according to one of claims 1 to 9, wherein: the conductor element (13) has an internally empty cylindrical shape; and a sensor (11) is provided which is arranged inside the conductor element (13) and is able to detect the temperature, level and / or quality of the water contained in the tank (3). 11) Feeding system (1) according to one of claims 1 to 10 and comprising a control unit (12) which is adapted to drive the heater device (8) to heat the water contained in the tank (3) to a temperature higher than 70 ° C for more than 20 seconds to carry out a heat treatment aimed at reducing the concentration of microorganisms present in the water contained in the tank (3). 12) System (1) for feeding water to at least one combustion chamber in an internal combustion engine (2); the power supply system (1) includes: a tank (3) adapted to contain a quantity of water; a supply conduit (5); a pump (4) which is suitable for drawing water from the tank (3) and for pumping pressurized water into the supply duct (5); and a heater device (8) which is coupled to the tank (3), is adapted to heat the water contained in the tank (3) itself, and comprises at least one conducting element (13) which has two opposite ends (14) and is suitable to be crossed by an electric current; the power supply system (1) is characterized by the fact that the conductor element (13) is shaped like a serpentine and has an internally hollow cylindrical shape. 13) Internal combustion engine (2) comprising: at least one cylinder in which a combustion chamber is defined; and a system (1) for supplying water to the combustion chamber according to one of claims 1 to 12. 14) Heater device (8) for a water supply system (1) to at least one combustion chamber in an internal combustion engine (2); the heater device (8) is adapted to be coupled to a tank (3) containing water and comprises at least one conducting element (13) which has two opposite ends (14) and is capable of being crossed by an electric current; the device (8) heater is characterized by the fact that the conductor element (13) includes an external layer (18) which is in direct contact with the water contained in the tank (3) and is made of silver. 15) Heater device (8) for a water supply system (1) to at least one combustion chamber in an internal combustion engine (2); the heater device (8) is adapted to be coupled to a tank (3) containing water and comprises at least one conducting element (13) which has two opposite ends (14) and is capable of being crossed by an electric current; the device (8) heater is characterized by the fact that the conductor element (13) is shaped like a serpentine and has an internally hollow cylindrical shape.