INTEGRATED LIQUID COOLED INTAKE MANIFOLD

FIELD OF INVENTION

The present invention relates to the intake manifold of an internal combustion engine, and more particularly to an integrated liquid cooled intake manifold having cooling passages incorporated with the intake manifold of engine for temperature reduction of charge air flowing from the turbo charged compressor towards the engine intake through the intake manifold.

BACKGROUND OF INVENTION

Turbochargers are usually provided for charging the intake air into the intake manifold of the IC engine at an increased pressure. Turbo chargers generally comprise of an exhaust gas turbine which rotates an air intake compressor through a connection shaft. The turbine operates by receiving pressurized exhaust gas from an internal combustion engine and passing the exhaust gas over the blades of the turbine wheel, and thereby causing the turbine wheel to rotate. This rotational force is used to rotate the compressor and thereby compressing the intake air to a pressure higher than the surrounding atmospheric pressure. The compressed intake air enables to provide increased amount of air drawn into the internal combustion engine and thereby burning more fuel within the cylinder and increasing the engine power output.

The temperature of charge air compressed from the turbo charger is normally higher than the atmospheric temperature and thus needs temperature reduction to satisfy engine operating conditions and enabling the engine to operate with good mechanical and volumetric efficiency. In order to reduce the charge air temperature from the turbo charged compressor, various cooling methods are employed and the temperature reduced charge air is provided to the engine intake through the engine intake manifold.

In conventional turbocharged engines, an intercooler is generally employed to reduce the charge air temperature from the turbocharger, since higher charge air temperature will increase the cycle temperatures during the combustion process. Also higher cycle temperature results in higher levels of NOx emission which is undesirable. The intercoolers used are of two types respectively, Air-to-Air intercoolers and water to Air intercoolers. The Air-to Air intercoolers are not providing required level of cooling efficiency and water to air cooling is providing better cooling efficiency with respect to the air to air cooling.

Fig. 1 shows a conventional air cooling arrangement for a turbo charged internal combustion engine and the arrangement of intercooler cooling the intake air conveyed from the turbo charger to the intake manifold. The compressed and heated air is forced to flow from the turbocharger 1 to the intake manifold 2 through the intercooler 3. In the intercooler 3, heat exchanging is carried out between the heated air from the turbocharger 1 and the outside air from the air intake, such that the air fed into the engine lowers its temperature. The charge air passed through the intercooler 3 flows smoothly toward the intake manifold 2 and enables heat reduction of charge air in the intake manifold and thus improving the air charging efficiency of the engine.

The engine cylinder head 4 is equipped with the intake manifold 2 and includes curved branch portions which are respectively connected to the intake ports of the cylinder head. The intercooler 3 is arranged near the branch portions of the intake manifold 2, and the inlet part of the intercooler 3 is connected to the turbocharger 1 through an air duct and the outlet part of the intercooler 3 is connected to the intake manifold 2 through another air duct. The compressed and heated air from the turbocharger 1 flows through the passages in the intercooler to carryout heat exchanging action between the heated air from the turbo charger and the outside air from the intercooler intake passage, thus effecting the cooling of heated air from the turbocharger.

However, the above mentioned conventional air cooling arrangement has drawbacks due to its inherency. The usage of intercoolers results in drop in boost pressure of charge air. Even though intercoolers are carefully chosen, it is inevitable to avoid pressure drop of the charged air across the intercooler resulting in expansion of charged air. This undermines the very purpose of compressed air by turbocharger. Hence a suitable compromise is adopted in practice to balance above requirements which are contradictory in nature.

With respect to the conventional cooling arrangement for intake air, it is necessary to provide an improved air cooling system achieving increased air charging efficiency. Therefore, it is desirable to provide an improved system developed for cooling the intake air flowing to engine intake through the intake manifold, which is capable to address and overcome the above disadvantages of conventional air cooling systems.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an improved intake manifold having cooling passages integrally formed to reduce the temperature of heated air flowing through the intake manifold.

Another object of the present invention is to provide an air cooling arrangement to the intake system of the internal combustion engine which boosts the intake pressure.

Further object of the present invention is to provide an improved air cooling system achieving increased air charging efficiency for an internal combustion engine.

Further object of the present invention is to provide an improved system for cooling the intake air flowing through the intake manifold, and capable to address and overcome the disadvantages of conventional air cooling systems.

The present invention, which achieves the objectives, relates to a liquid cooled intake manifold for temperature reduction of charge air from a turbo compressor by incorporating the functions of both manifold and cooling system of charge air. The intake manifold of a turbocharged internal combustion engine is provided to carry the charged air from the turbo charged compressor to the intake ports of the engine cylinder head. The intake manifold ensures the availability of required quantity of air for the desired engine performance at various speeds and load conditions. The cooling arrangement of charged air in the intake manifold reduces the charge air temperature, thereby maintaining the required boost pressure of the charge air, thus improving air charging efficiency.

The integrated liquid cooled intake manifold includes a plenum chamber for collecting and passing the charge air from the turbo charged compressor. Runners are provided to direct the air flow towards the corresponding intake ports of the cylinder head. Liquid coolant inlet and outlet connection flanges are provided for making respective connections at the inlet and outlet of intake manifold and enabling the inlet and outlet of the coolant from the intake manifold.

A radiator is connected with the coolant inlet flange through a piping arrangement for supplying the coolant to carry away the heat in the plenum chamber containing heated charge air. A coolant pump is connected with the coolant outlet flange of the intake manifold to flow the coolant carrying heat from the charge air. The radiator and the coolant pump connected with the intake manifold enables continuous flow of the coolant and take away the heat available in the charge air from the turbo charger flowing through the intake manifold.

The intake manifold consists of two flow circuits respectively, charge air flow circuit and coolant flow circuit. The entry of air from the turbo compressor and flow towards the corresponding intake ports of the engine cylinder head form the air circuit. The entry of liquid coolant from the radiator and cooling the inlet charge air and exiting towards the outlet flange forms the coolant flow circuit.

The filtered air sucked by the compressor of the turbo charger is compressed to a level of required boost pressure. In turbo compression process the charge air pressure is increased to reach the boost pressure, which results in increase in temperature of the charge air. The heated charge air enters the intake manifold plenum through the air duct. As the charge air enters the plenum, it comes into contact with the inner surface of the plenum wall of the intake manifold. The heat transfer takes place in order of convection-conduction-convection process, and provides charge air temperature reduction.

The heat from the charge air is transferred to the inner plenum wall of the intake manifold through convection process, and the inner surface to the outer surface of plenum wall through conduction process, and the outer surface of plenum wall to the coolant through convection process. The outer surface of the plenum wall is in contact with the coolant and hence the outer surface of the plenum is at a temperature below than that of the inner surface. Further the coolant is continuously pumped through the coolant pump and cooled with the radiator, and thus enabling it to continuously carry away the heat from the charged air available in the intake manifold.

The present invention allows for elimination of a separate intercooler on turbocharged diesel engines, thus the pressure loss of charged air from turbocharger is avoided. The elimination of separate intercooler reduces the engine weight thereby improving the engine power to weight ratio and reducing the overall cost.

The charge air is directly fed to the intake manifold, thus improving the purpose of turbo charging by compressing the charge air to a required boost pressure and thus improving the air charging efficiency and improving the performance of the engine. The present invention allows for achieving temperature reduction of the charge air in the intake manifold without using any external intercooler or separate heat exchanger, thus reducing the cooling arrangement complexity and providing an improved intake manifold with cost reduction for cooling arrangements.

BRIEF DESCRIPTION OF DRAWINGS

Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.

Fig. 1 shows a schematic diagram of a conventional system for cooling the charge air in the intake manifold for a turbocharged internal combustion engine, in accordance with a prior art.

Fig. 2 shows a schematic diagram of an improved system for cooling the charge air in the intake manifold for a turbocharged IC engine, in accordance with an exemplary embodiment of the present invention.

Fig. 3 illustrates a schematic arrangement of an integrated liquid cooled intake manifold for cooling charge air in the intake manifold for a turbocharged IC engine, in accordance with an exemplary embodiment of the present invention.

Fig. 4 shows a cross section view of the integrated liquid cooled intake manifold for cooling charge air in the intake manifold for a turbocharged internal combustion engine, in accordance to the present invention.

Fig. 5 shows the plenum wall outer surface of the integrated liquid cooled intake manifold for cooling charge air in the intake manifold for a turbocharged IC engine, in accordance to the present invention.

Fig. 6 shows the air circuit and coolant circuit of an integrated liquid cooled intake manifold for cooling charge air in the intake manifold, in accordance to the present invention.

DETAILED DESCRIPTION OF INVENTION

The present invention relates to an integrated liquid cooled intake manifold having cooling passages incorporated with the intake manifold for temperature reduction of charge air from the turbo charged compressor flowing towards the engine intake through the intake manifold.

The present invention allows for elimination of a separate intercooler on turbocharged internal combustion engines, thus the pressure loss of charged air from turbocharger is avoided and the elimination of separate intercooler.

Fig. 2 shows a schematic diagram of an improved system for cooling the charge air in the intake manifold for a turbocharged internal combustion engine, in accordance with an exemplary embodiment of the present invention. According to the present invention, the internal combustion engine 12 employs a turbocharger unit to provide compression of charge air to the intake circuit of the engine. The turbine 2 drives the compressor 3 for compressing the fresh air from the air inlet 4 and produce charged air to said intake manifold 6. A shaft connecting the turbine and the compressor transmits the mechanical energy received in the turbine 2 to the compressor 3 to direct the charged air by compressing fresh air received from the air inlet unit 4. The turbine 2 and the compressor 3 are interconnected to form the turbocharger arrangement.

The intake air flows from the compressor 3 to the intake manifold 6 of the engine 12, and the exhaust gas flows from the exhaust manifold 5 to the turbine 2. A radiator 10 is connected with the coolant inlet flange through a piping arrangement for supplying the coolant to carry away the heat in the plenum chamber containing heated charge air 7. In the process of turbo charging, the pressurized exhaust gas acts on the turbine 2 that in turn drives the compressor 3. The compressor pressurizes the intake air from the air inlet 4 and compresses the intake air to a required level and passes through the intake manifold 6 to the engine inlet 9 for combustion process. This charged intake air enables for better combustion process resulting in increased engine performance and better efficiency.

A coolant pump 11 is connected with the coolant outlet flange of the intake manifold 6 to flow the coolant 8 carrying heat from the charge air 7. The radiator 10 and the coolant pump 11 connected with the intake manifold 6 enables continuous flow of the coolant 8 to take away the heat available in the charge air 7 from the turbo charger and flowing through the intake manifold 6. The intake manifold 6 is provided to carry the charged air from the turbo charged compressor 3 to the intake ports 9 of the engine cylinder head. The intake manifold 6 ensures the availability of required quantity of air for the desired engine performance at various speeds and load conditions. The cooling arrangement of charged air 7 in the intake manifold 6 reduces the charge air temperature and thereby allowing improving air charging efficiency.

Fig. 3 illustrates a schematic arrangement of an integrated liquid cooled intake manifold for cooling the charge air in the intake manifold, in accordance with an exemplary embodiment of the present invention. The integrated liquid cooled intake manifold 1 incorporates cooling passages 2 for temperature reduction of charge air from the turbo charged compressor. The intake manifold 1 includes a plenum chamber 3 for collecting and passing the charged air from the turbo charged compressor to the engine intake through charged air inlet 5 and charged air outlet 6. Runners 4 are provided to direct the charged air to flow towards intake ports of engine cylinder head.

The intake manifold 1 incorporates cooling passages 2 integrally formed around the intake manifold for temperature reduction of charged air from the compressor to engine intake through the intake manifold. The plenum wall formed in between the charge air passage 7 and the cooling passage 2 enables heat transfer from the charged air to the coolant in the intake manifold 1. The heat transfer takes place such that, when the charged air enters the intake manifold plenum 3, the heat from the charged air is transferred to the coolant through the plenum wall and the coolant passages 2. The intake manifold ensures the availability of required quantity of air for the desired engine performance at various speeds and load conditions. Fig. 4 shows a cross section view of the integrated liquid cooled intake manifold for the cooling the charge air in the intake manifold, in accordance to the present invention.

The intake manifold includes charged air flow passages having charged air inlet 2 for receiving charged air from the turbocharger and charged air outlet 3 for directing cooled charge air to engine intake ports. Coolant passages are incorporated with the intake manifold such that the coolant inlet 4 enables coolant in from the radiator and coolant outlet 5 enables for coolant out to the coolant pump. A plenum wall formed between the charged air passage and the coolant passage serves a medium for heat transfer from the charged air to the coolant in the intake manifold. The inner wall surface 6 of the plenum wall is having contact with the charged air and the outer wall surface 7 of the plenum is having contact with the coolant for effecting heat transfer process between the charged air and the coolant in the intake manifold.

Fig. 5 shows the plenum wall outer surface of the integrated liquid cooled intake manifold for cooling the charge air in the intake manifold, in accordance to the present invention. The heated charge air enters the intake manifold plenum 2 through the air duct. As the charged air enters the plenum, it comes into contact with the inner surface of the plenum wall 3 of the intake manifold 1. The heat transfer takes place in the order of convection-conduction-convection process, and provides temperature reduction for the charged air.

The heat transfer takes place such that, when the charged air enters the intake manifold plenum, the heat from the charged air is transferred to the inner wall surface 3 of the plenum through convection process and to the outer surface 4 of the plenum wall through conduction process. The heat carried in the plenum wall outer surface 4 is transferred to the coolant flowing in the cooling passages 5 of the intake manifold through convection process. The plenum wall allows for transferring the heat from the charged air flowing in the intake manifold to the coolant passing in the coolant passages formed in the intake manifold.

Fig. 6 shows the air circuit and coolant circuit of an integrated liquid cooled intake manifold for cooling charge air in the intake manifold, in accordance to the present invention. The intake manifold 1 consists of two flow circuits respectively, charge air flow circuit and coolant flow circuit. The entry of air from the turbo compressor and flow towards the corresponding intake ports of the engine cylinder head form the air circuit. The entry of liquid coolant 2 from the radiator and cooling the inlet charge air and exiting towards the outlet flange 3 forms the coolant flow circuit.

In operation, the filtered air sucked by the compressor of the turbo charger is compressed to a level of required boost pressure. In turbo compression process the charge air pressure is increased to reach the boost pressure, which results in increase in temperature of the charge air. The charged air is directed through the intake manifold to the engine intake for combustion process. The coolant running through the coolant passages of the intake manifold effects heat reduction for the charged air passing through the intake manifold. The heat transfer takes place such that, when the charged air enters the intake manifold plenum, the heat from the charged air is transferred to the coolant through the plenum wall and the coolant passages. Further the coolant is continuously pumped through the coolant pump and cooled with the radiator, and thus enabling to continuously carry away the heat from the charged air available in the intake manifold.

The intake manifold according to the present invention allows for elimination of a separate intercooler on turbocharged internal combustion engines, thus the pressure loss of charged air from the turbocharger is avoided. The elimination of separate intercooler reduces the engine weight thereby improving the engine power to weight ratio and reducing the overall cost.

The internal combustion engine according to the present invention achieves maximum efficiency and minimum Nox emission with the improved intake manifold having integrated liquid cooling arrangement.

The charge air is directly fed to the intake manifold, thus improving the purpose of turbo charging by compressing the charge air to a required boost pressure and thus improving the air charging efficiency and improving the performance of the engine.

The present invention allows for achieving temperature reduction of the charge air in the intake manifold without using any external intercooler or separate heat exchanger, thus reducing the cooling arrangement complexity and providing an improved intake manifold with cost reduction for cooling arrangements.

The air cooling arrangement according to the present invention works with simple components and does not employ any complex elements, thus providing a air cooling system with simple construction and making the system cost effective.

The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

We Claim:

1. An internal combustion engine, comprising,

a turbocharger having a turbine and a compressor for compressing the fresh air from an air inlet to produce charged air, wherein the engine exhaust gas acts on said turbine to drive said compressor;

an intake manifold having a plenum chamber to collect and pass said charged air from said compressor to engine intake, wherein runners are provided to direct said charged air to flow towards the intake ports of the engine cylinder head;

characterized in that said intake manifold incorporates cooling passages integrally formed around said intake manifold for temperature reduction of the charged air flowing through said intake manifold;

wherein heat transfer in intake manifold takes place such that, when said charged air enters said intake manifold plenum, the heat from the charged air is transferred to the coolant through the plenum wall and said cooling passages.

2. The internal combustion engine as claimed in claim 1, wherein said intake manifold directs the charged air from the turbo charged compressor to the intake ports of the engine cylinder head.

3. The internal combustion engine as claimed in claim 1, wherein coolant inlet and outlet connection flanges are provided for making respective connections at the inlet and outlet of the coolant from the intake manifold.

4. The internal combustion engine as claimed in claim 1, wherein a radiator is connected with the coolant inlet flange through a piping arrangement for supplying the coolant to carry away the heat obtained from the charged air.

5. The internal combustion engine as claimed in claim 1, wherein a coolant pump is connected with the coolant outlet flange of said intake manifold to pump the coolant and make the coolant to flow in a circuit.

6. The internal combustion engine as claimed in claim 1,

wherein the radiator and the coolant pump connected with the intake manifold enables continuous flow of the coolamt and takes away the heat available in the charged air flowing through the intake manifold.

7. The internal combustion engine as claimed in claim 1, wherein the coolant pumped out from the coolant pump is cooled with the radiator.

8. The internal combustion engine as claimed in claim 1, wherein the filtered air sucked by the compressor of the turbo charger is compressed to a level of required boost pressure.

9. The internal combustion engine as claimed in claim 1, wherein turbines drive said compressors for compressing the fresh air from the air inlet and produce charged air to said intake manifold.