FIELD OF THIS INVENTION

[001] This invention proposes in a general manner an intake system for internal combustion engines and, more specifically, an intake system that improves the cooling efficiency of the intake air. Thus, more efficient cooling is achieved because of the inclusion of Peltier cells in the air coolers commonly found in air intake systems.

BACKGROUND OF THIS INVENTION

[002] Internal combustion engines, such as engines that use the well known Otto or Diesel cycles, are largely and commonly used in motor vehicles for transporting people as well as goods, such as private and public passenger and cargo motor vehicles, including trucks and railway engines. In brief, such engines use fuels with a high content of hydrocarbons, such as fossil fuels and/or fuels from renewable resources, to transform the thermal energy from the fuel combustion into kinetic energy.

[003] The construction of internal combustion engines is well known and consists, basically, of a piston that moves inside a cylinder associated with a crankshaft. In the upper part of the piston is a combustion chamber containing, among others, components such as spark plugs and/or fuel nozzles, at least one intake valve and one exhaust valve.

[004] The components and the operation of internal combustion engines with either an Otto cycle or a Diesel cycle are well known to technicians in this field, therefore no further explanation of them is needed in this descriptive report. [005] Nowadays, there is growing concern regarding the reduction of gas emissions produced by internal combustion engines, that are responsible for a large part of CO: emission into the atmosphere. Climate change is one of the more relevant environmental challenges nowadays, and it has serious consequences. This problem is becoming increasingly serious because of intensification of the greenhouse effect, that is related to increased concentration in the atmosphere of gases, such as carbon dioxide, that generate such a greenhouse effect (GEE).

[006] In recent years, in order to minimize the emission of harmful gases into the environment, such as carbon monoxide (CO), hydrocarbon gases (HC), nitrogen oxides (NOx), as well as particulate matters and/or other GEEs, a number of technological improvements have been added to internal combustion engines. The reduction of gas emissions relates, among other factors, to the increased thermal yield of the engine and, consequently, to a reduction of the specific fuel consumption.

[007] Thus, technologies such as electronic injection, catalysers, and filters for particulate matters are quite widespread nowadays, and very often compulsory for all internal combustion engines. Other more recent technologies, such as direct fuel injection, common-rail for engines using a Diesel cycle, and larger scale utilization of technologies already known for quite some time, such as mechanical compressors or turbo compressors, have also being further implemented to increase energy efficiency and comply with emission standards that are constantly becoming more strict.

[008] When mechanical compressors or turbo compressors are used, this leads to the intrinsic problem of temperature increase of the intake air, because this increase in the pressure of the air intended for combustion also means an increase in its temperature, according to the well-known relation: Pa Vo PI VI

To Tl in which Po is the initial pressure of the fluid before its compression, PI is the pressure of the fluid after its compression, Vo is the initial volume of the fluid before its compression, VI is the final volume of the fluid after its compression, To is the temperature of the fluid before its compression and Tl is the temperature of the fluid after its compression.

[009] In order to avoid this inconvenience related to the increase in air temperature after compression, radiators are widely used to cool the air before it enters the combustion chamber; this is usually referred to as the Intercooler system.

[010] However, as mentioned above, internal combustion engines have been reaching higher and higher specific powers, and mechanical compressors and turbo compressors have therefore been operating with higher and higher pressures. A more efficient cooling device is also needed for the air used for the combustion, in order to improve the thermal yield of the combustion engine.

[Oi l] One of the aims of this invention is to prevent these inconveniences, still unsolved by currently used techniques.

DESCRIPTION OF THIS INVENTION

[012] Therefore, the first objective of this invention is to provide an intake system for internal combustion engines that decreases the temperature of the intake air to a larger degree than the well-known systems that use a mechanical compressor or a turbo compressor associated with an intercooler.

[013] In order to achieve the above objective, and others, this invention proposes an intake system for an internal combustion engine containing: - One manifold associated to the intake from an internal combustion engine; this manifold contains:

One opening to receive the intake of compressed gases coming from a compressor; and

At least one intake and one exhaust for the circulation of a cooling fluid in the above-mentioned manifold; and

- One cooling line associated with the above-mentioned manifold. Each cooling line contains at least a first heat exchanger fluidly associated with the above-mentioned intake and exhaust;

- The above-mentioned cooling line also contains a second heat exchanger.

[014] Depending on the additional and/or alternative configurations of this invention, it may also include the following features, either alone or in any possible technical combination:

- Its compressor may also be mechanical;

- This compressor may be a turbo compressor driven by the combustion of gas from an internal combustion engine;

- The above-mentioned first heat exchanger may also be a radiator;

- The above-mentioned second heat exchanger may be a Peltier heat exchanger.

SHORT DESCRIPTION OF THE DRAWINGS

[015] This invention will now be described with its specific features; reference is made to the attached figure. This is a schematic figure, and its dimensions and/or proportions may not correspond to the real ones, because its purpose is only to illustrate this invention configuration in a clear manner. Certain very well known components have been omitted to make this figure easier to understand:

Figure 1 is a schematic upper view of an internal combustion engine associated with the air intake system presented by this invention.

DESCRIPTION OF FEATURES OF THIS INVENTION

[016] This invention will now be described with its specific features. Its specific features are described in detail; it is understood that they should be considered only one example of its principles, and are not intended to be any limitation to this invention to only those that are described in this report. It must be noted that the different statements concerning the characteristics discussed hereunder may be used separately or in any appropriate combination to produce the same technical results.

[017] Figure 1 is a schematic presentation of an internal combustion engine (10) that is associated on one side with an intake manifold (20) and on the other with an exhaust manifold (30). The engine presented here is of the crossed flow type, i.e. the intake and exhaust are on opposite sides of the cylinder head along its longitudinal part, but obviously, this invention also applies to any engine with the intake and exhaust on the same side of the cylinder head.

[018] Obviously, the engine is presented in a schematic manner in Figure 1 , and several other components have been omitted from it because they are not relevant to understanding this invention.

[019] This invention is particularly aimed at internal combustion engines that use some means to compress their intake gases i.e. the ambient air, either through a mechanically driven compressor, or through a turbo compressor driven by gases produced by combustion. [020] In Figure 1 , we have a turbo compressor (40) driven by engine combustion gases that are collected by the exhaust manifold (30), sent to the turbine (41) and then to the exhaust system (not shown in the Ffigure) of the motor vehicle, as indicated by arrow (A). On the other side, the compressor (42) intakes the ambient air, compressing the gases that are then taken to the intake manifold (20) and led to the combustion chambers, as indicated by arrow (B). Obviously, the intake air is mixed with a fuel to produce the combustion; furthermore, the intake system of the motor vehicle generally contains a butterfly valve (28) to regulate the amount of air that enters.

[021] The system presented by this invention also contains a means for cooling the gases from the intake that were previously compressed, in order to lower the air temperature and, therefore, allow for a larger volume of air to be introduced into the combustion chamber.

[22] Specifically, the cooling is performed by an air/water intercooler, in which the heat exchange of the intake air is performed in the intake manifold

(20) itself and, in this way, in the manifold there is provided one intake or inlet

(21) and one exhaust or outlet (22) of a fluid intended to perform the heat exchange; generally, this fluid is water. Inside the intake manifold (20) itself is a heat exchanger (29) for the cooling of the intake air. In other words, the intake manifold (20) comprises a housing (12) in which the internal heat exchanger (29) of the intake manifold (20) is arranged in such a way that the inlet (21) and outlet (22) of the internal heat exchanger (29) are arranged at this housing (12) or on an outside of this housing (12) respectively. Additionally, this housing (12) is provided with an intake opening (27) of the intake manifold (20), said intake opening (27) is adapted to receive the intake of compressed gases coming from the compressor (42). According to this integration of such an internal heat exchanger (29) inot the intake manifold (20), said intake manifold (20) itself represents an intercooler (20) for cooling charged air.

[023] A first heat exchanger (25) is mounted for cooling the intercooler fluid and, in this way; the intake or inlet (21) and the exhaust or outlet (22) of water are flu idly associated with the first heat exchanger (25) through suitable ducts or lines (23, 24). This first heat exchanger (25) is arranged outside of the intake manifold (20) and therefore represents a first external heat exchanger (25). The aforementioned first line (23) leads the cooled cooling fluid from the first heat exchanger (25) to the inlet (21) and therefore represents a feed line (23). The aforementioned second line (24) leads the heated cooling fluid from the outlet (22) to the first heat exchanger (25) and therefore represents a return line (24). Feed line (23) and return line (24) therefore represent a cooling circuit (16), in which the intercooler (20) or the internal heat exchanger (29), respectively, and the first external heat exchanger (25) are arranged. During operation, the water that has being cooled by the first external heat exchanger

(25) is taken to the intake/inlet (21) of the intake manifold (20), where the heat exchange with the intake air takes place, thus cooling the charged air. The resulting warm water flows out through the exhaust/outlet (22) in the direction of the first external heat exchanger (25), where the heat exchange with the environment takes place to cool the water. The water circulation may be performed either by convection, or by being forced, for instance, by a pump

(26) . Said pump (26) is arranged in the feed line (23).

[024] Intake systems using a water/air intercooler as described above are well-known; therefore, no further details are necessary in this descriptive report.

[025] This invention proposes the introduction of a second heat exchanger (50) for further cooling the intercooler fluid, in order to increase the heat exchange that takes place in the manifold (20) and, consequently, further reduce the temperature of the intake air, making the combustion more efficient. This second heat exchanger (50) is also arranged outside of the intake manifold (20) and therefore represents a second external heat exchanger (50). Specifically, according to this invention configuration, the second external heat exchanger (50) is a Peltier heat exchanger (50). The second heat exchanger (50) is arranged in the feed line (23), preferably between the pump (26) and the inlet (21).

[026] The Peltier effect is the production of a temperature gradient in the junction of two different conductor or semi-conductor materials under electric tension in a closed circuit, creating a warm side and a cold side because of heat transfer. The Peltier effect, or thermoelectric effect, is also well known and has very many applications.

[027] According to this invention, there should be a Peltier cell (14) in contact with the water (or other fluid) used as cooling fluid in the intercooler and, as presented in Figure 1 , the Peltier cell (14) is placed in the fluid duct (23) before the entry (21) of the intake manifold. The Peltier ceil (14) is an internal part of the second external heat exchanger (50) or represents the second external heat exchanger (50), respectively.

[028] Obviously, a Peltier cell (14) needs an electric current to perform the heat exchange and, for this reason, the Peltier cell (14) may be connected to the electric system of the motor vehicle or linked to the internal combustion engine (10). Furthermore, the Peltier cell (14) used as or in the second external heat exchanger (50) in the way proposed by this invention may also be associated with the electronic control system of the combustion engine (10), to be turned on or off according to the need to respectively increase or decrease the cooling of the fluid used in the heat exchange of the intercooler (20).

[029] Although this invention has been described here with its specific features, experts in the area may implement changes or combinations not described above but not in any way deviating from the statements described here, as well as expand them to other applications not presented in this descriptive report. Therefore, the attached claims should be interpreted as covering any and all equivalent claims within the principles of this invention.