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. Such more efficient cooling is achieved through Peltier type cells mounted in the intake manifold of the engine, or on its air filter, or even in the connexion pipes between the 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 it consists, basically, of a piston that moves inside a cylinder associated with a crankshaft. In the upper part of the piston, there is a combustion chamber containing, among others, components such as spark plugs and/or fuel nozzles, and 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 the technicians of this field, therefore no further explanation of them is needed in this descriptive report.

[005] Nowadays, there is a growing concern with the reduction of gas emissions produced by internal combustion engines, that are responsible for a large part of the CO2 emission in 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 the increase of the concentration in the atmosphere of gases, such as carbon dioxide, that generate such 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 increase of the 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 fairly widespread nowadays, and very often compulsory for ail 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 the 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 of the pressure of the air intended for combustion also means an increase in its temperature, according to the well-known relation:

P0 V0 PI VI

To 77 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 prevent 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 above mentioned, 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.

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

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 from an internal combustion engine containing:

- One manifold associated with the intake from an internal combustion engine; this manifold contains one intake duct to receive incoming gases and at least one exhaust to lead these gases to at least one combustion chamber;

- the mentioned manifold also contains at least one heat exchanger that is formed by one Peltier cell; [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:

- This heat exchanger is placed in the intake duct of the mentioned manifold;

- This manifold contains more than one heat exchangers, each exchanger is placed in the exhaust duct of the manifold corresponding to a different cylinder;

- This system also contains a compressor;

- It is a mechanical compressor;

- This compressor may be a turbo compressor driven by the gas combustion of the internal combustion engine.

SHORT DESCRIPTIO QF 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, in such a way that:

Figure 1 is a schematic upper view of an internal combustion engine associated with the air intake system presented by this invention in its first configuration;

Figure 2 is a schematic upper view of an internal combustion engine associated with the air intake system presented by this invention in its second configuration; and

Figure 3 is a diagram like principal depiction of the internal combustion engine equipped with the air intake system.

DESCRIPTIO 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 these characteristics discussed hereunder may be used separately or in any appropriate combination to produce the same technical results. Reference numbers for its parts are the same in both figures.

[017] Figures 1, 2 and 3 are schematic presentations of an internal combustion engine (10) that is associated with an intake manifold (20). The engine (10) here presented may be of the crossed flow type, that is to say, in which the intake and the exhaustion are on opposite sides of the cylinder head along its longitudinal part, but obviously this invention also applies to any engine (10) with intake and its exhaustion on the same side of its cylinder head.

[018] Obviously, the engine (10) is presented in a schematic manner in figures 1 to 3, and several other components have been omitted from it because they are not relevant to understanding this invention.

[019] This invention aims to either naturally aspired engines (10), or to engines (10) that use some means to compress their intake gases, that is to say, the ambient air; either through a mechanically driven compressor (1 10), or through a turbo compressor (120) driven by gases produced by combustion. A compressor (110) which is part of a turbo compressor (120) is depicted in the example of figure 3. It is self-explaining that also in the embodiments if figures 1 and 2 such a compressor (110) can be provided.

[020] In figures 1 to 3 the manifold (20) is presented together with an air intake duct (22) and the ducts (23') for distribution of the air for each intake (12) of the cylinder in its head. There is also a schematic presentation of: its air filter (30), an airflow sensor (40) that is associated with the management electronic unit of the engine (not shown in the figure), and a butterfly valve (60) to control the airflow intake.

[021] The above described intake system (100) is well-known, and, therefore, no further details are necessary in this descriptive report.

[022] This invention proposes that, associated with the intake system (100), a heat exchanger (50) is mounted; more specifically, such heat exchanger (50) is one that uses the Peltier effect.

[023] 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.

[024] According to this invention, there should be a Peltier ceil (70) in contact with the intake air and, as presented in figures 1 and 3; this Peltier cell (70) is placed in the duct (22) leading to the manifold intake (21), just like in the first configuration. According to the invention the heat exchanger (50) comprises at least one of said Peltier cells (70) or is formed of at least one of such Peltier cells (70).

[025] In its second configuration, as presented in figure 2, there are more than one heat exchanger (50), i.e. one exchanger (50) for each cylinder of the internal combustion engine (10), and each exchanger (50) is mounted in each intake duct (23') of the cylinder head.

[026] Obviously, a Peltier cell (70) needs electric current to perform the heat exchange and, for this reason, the Peltier cell (70) may be connected to an electric system of the motor vehicle or linked to the internal combustion engine (10). Furthermore, the Peltier cell (70) used as a second heat exchanger in the way proposed by this invention may also be associated with the electronic command system of the combustion engine (10), to be turned on or off according to the need of respectively increasing or decreasing the cooling of the intake air. [027] In a further configuration depicted in figure 3, there is a mechanical compressor (1 10) or turbo compressor (120) in the intake system (100). In this configuration the compressor (1 10) may be associated with the intake duct (22) of the intake system (100); this configuration of the heat exchanger (50) here described and presented in its features is not different from the one with just one associated compressor (1 10), obviously with the necessary changes for a single compressor usage.

[028] According to figure 3 the intake system (100) can also be provided with an intercooler (130) which is also arranged in the intake duct (22) downstream of the compressor (1 10). Said intercooler (130) is used to cool the compressed or charged gases or air, respectively. In the embodiment of figure 3 the heat exchanger (50) with the Peltier cell (70) is arranged upstream of the intercooler (130) and downstream of the compressor (1 10) in the intake duct (22). To this end the Peltier cell (70) is provided with a relatively high temperature difference in order to improve the energetic effectiveness of the Peltier cell (70) and to improve the recovery of waste energy of the charged air. In other words, the Peltier cell (70) is used to transform heat energy which would be wasted otherwise, into electrical energy that can be stored and/or used in the energy system of the engine (10) or the vehicle equipped with the engine (10).

[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 all and any equivalent claims within the principles of this invention.