Claims:We Claim

1. An internal combustion engine, said internal combustion engine comprising:
an inlet manifold;
an engine in flow communication with the inlet manifold, said engine adapted to combust air and fuel;
an exhaust manifold in flow communication with the engine, said exhaust manifold adapted to receive combusted air and fuel from the engine;
an exhaust gas recirculation cooler in flow communication with the exhaust manifold and adapted to receive combusted air and fuel from the exhaust manifold;
an oil heat exchanger in flow communication with the exhaust manifold and adapted to receive combusted air and fuel from the exhaust manifold, wherein a switch control valve is in flow communication with the exhaust gas recirculation cooler and the oil heat exchanger and is adapted to control the flow of combusted air and fuel to one of the exhaust gas recirculation cooler and the oil heat exchanger;
an exhaust gas recirculation valve, an inlet of said exhaust gas recirculation valve in flow communication with an outlet of the exhaust gas recirculation cooler and the oil heat exchanger, and adapted to receive the flow of combusted air and fuel from the exhaust gas recirculation cooler and the oil heat exchanger, an outlet of said exhaust gas recirculation valve in flow communication with the inlet manifold of said internal combustion engine.

2. The internal combustion engine in accordance with Claim 1 wherein the switch control valve is operated to channel exhaust gas into said oil heat exchanger to elevate the temperate of the lubrication oil entering the engine when a temperature of lubrication oil that is required to lubricate the engine decreases below a threshold temperature.

3. The internal combustion engine in accordance with Claim 1 wherein the switch control valve is operated to shut off the flow of exhaust gas to the oil heat exchanger and channel the exhaust gas to the exhaust gas recirculation cooler when a temperature of lubrication oil that is required to lubricate the engine increases above a threshold temperature.
, Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to an internal combustion engine, and more specifically to an oil heat exchanger for the internal combustion engine.

Background of the invention
[0002] GB 2472228 A describes reducing the fuel consumption of an I. C. Engine by using heat from an EGR cooler to heat engine oil after cold starting. The method for reducing the fuel consumption of the I.C. Engine particularly when the engine is below a normal working temperature comprises supplying waste heat from an exhaust gas recirculation cooler via a heat transfer fluid directly to an oil heat exchanger, supplying the oil from the oil heat exchanger directly to a main gallery of an engine, and controlling the flow of EGR gas, heat transfer fluid and oil to maximize oil heating after a cold start. A controller may control an EGR valve, a variable flow rate coolant pump and coolant flow valve, and a variable flow rate oil pump. On cold starting, the EGR gas flow rate may be low while the flow rates of the heat transfer fluid and the oil are very low.

Brief description of the accompanying drawings
[0003] Figure 1 illustrates a schematic diagram of an internal combustion engine illustrating the oil heat exchanger for the internal combustion engine.
[0004] Figure 2 illustrates a schematic diagram of an oil flow circuit of the internal combustion engine.

Detailed description of the embodiments
[0005] Figure 1 illustrates a schematic diagram of an internal combustion engine 10 illustrating the oil heat exchanger 20 in one embodiment of the invention. The internal combustion engine 10 comprises an inlet manifold 12, and an engine 14 in flow communication with the inlet manifold 12, the engine 14 adapted to combust air and fuel. An exhaust manifold 16 is in flow communication with the engine 14, the exhaust manifold 16 adapted to receive combusted air and fuel from the engine 14. An exhaust gas recirculation cooler 18 is in flow communication with the exhaust manifold 16 and adapted to receive combusted air and fuel from the exhaust manifold 16. An oil heat exchanger 20 is in flow communication with the exhaust manifold 16 and is adapted to receive combusted air and fuel from the exhaust manifold 16, wherein a switch control valve 22 is in flow communication with the exhaust gas recirculation cooler 18 and the oil heat exchanger 20, and is adapted to control the flow of combusted air and fuel to one of the exhaust gas recirculation cooler 18 and the oil heat exchanger 20. An exhaust gas recirculation valve 24, an inlet of the exhaust gas recirculation valve 24 in flow communication with an outlet of the exhaust gas recirculation cooler 18 and the oil heat exchanger 20, and adapted to receive the flow of combusted air and fuel from the exhaust gas recirculation cooler 18 and the oil heat exchanger 20, an outlet of the exhaust gas recirculation valve 24 in flow communication with the inlet manifold 12 of the internal combustion engine 10.

[0006] Figure 1 illustrates a schematic diagram of an internal combustion engine 10 illustrating the oil heat exchanger 20 in one embodiment of the invention. The internal combustion engine 10 comprises an inlet manifold 12 that is adapted to receive air and fuel mixture for combustion. An engine 14 is in flow communication with the inlet manifold 12, wherein the engine 14 is adapted to combust air and fuel to release the products of combustion. In addition, lubrication oil from the inlet manifold 12 is channeled into the engine 14 for lubricating and cooling the engine components of the engine 14. An exhaust manifold 16 is in flow communication with the engine 14. The exhaust manifold 16 is adapted to receive the combusted air-fuel mixture from the engine 14 before channeling it further downstream for waste heat recovery.

[0007] An exhaust gas recirculation cooler 18 is in flow communication with the exhaust manifold 16 and adapted to receive combusted air-fuel mixture from the exhaust manifold 16. More specifically, the exhaust gas recirculation cooler 18 facilitates cooling the combusted air-fuel mixture by means of exchanging heat between a coolant that is supplied to the exhaust gas recirculation cooler 18 and the combusted air-fuel mixture that is supplied to the exhaust gas recirculation cooler 18 from the exhaust manifold 16 of the engine 14. From the exhaust gas recirculation cooler 18, a portion of the exhaust gas is channeled to the intake manifold 12 of the engine 14 where it is mixed with the fresh air and fuel that is to be supplied to the engine 14. An oil heat exchanger 20 is in flow communication with the exhaust manifold 16 and adapted to receive combusted air and fuel from the exhaust manifold 16 in order to heat the lubrication oil that is supplied to the oil heat exchanger 20. In the exemplary embodiment, a switch control valve 22 is in flow communication with the exhaust gas recirculation cooler 18 and the oil heat exchanger 20, and is adapted to control the flow of combusted air and fuel to one of the exhaust gas recirculation cooler 18 and the oil heat exchanger 20. More specifically, an inlet of the exhaust gas recirculation cooler 18 is in flow communication with the switch control valve 22, while an inlet of the oil heat exchanger 20 is in flow communication with the switch control valve 22.

[0008] In the exemplary embodiment, the switch control valve 22 receives exhaust gases from the exhaust manifold 16 of the engine 14 and may be controlled to deliver exhaust gases to either the exhaust gas recirculation cooler 18 or to the oil heat exchanger 20, depending on the requirement. More specifically, the switch control valve 22 is operated to channel exhaust gas into the oil heat exchanger 18 to elevate the temperate of the lubrication oil entering the engine 14 when a temperature of lubrication oil that is required to lubricate the engine 14 decreases below a threshold temperature. When a temperature of the lubrication oil that enters the engine 14 decreases below a threshold temperature, it is required to increase the temperature of the lubrication oil to maintain an operating efficiency of the engine 14. In such circumstances, the switch control valve 22 is operated to channel a flow of exhaust gases from the exhaust manifold 16 of the engine 14 to the oil heat exchanger 20. From the oil heat exchanger 20, the exhaust gas is channeled to an inlet manifold 12 of the engine 14 via the exhaust gas recirculation valve 24. When the temperature of the lubrication oil that enters the engine 14 increases above the threshold temperature, it is required to maintain / decrease the temperature of lubrication oil to maintain an operating efficiency of the engine. In such circumstances, the switch control valve 22 is operated to channel a flow of exhaust gas from the exhaust manifold 16 of the engine 14 to the exhaust gas recirculation cooler 18, thereby bypassing the oil heat exchanger 20. The cooled exhaust gas from the exhaust gas recirculation cooler 18 is channeled to the inlet manifold 12 of the engine 14 via the exhaust gas recirculation valve 24.

[0009] The exhaust gas recirculation valve is in flow communication with the exhaust gas recirculation cooler and the oil heat exchanger. More specifically, an inlet of the exhaust gas recirculation valve is in flow communication with an outlet of the exhaust gas recirculation cooler and the oil heat exchanger. The exhaust gas recirculation valve is adapted to receive the flow of combusted air and fuel from the exhaust gas recirculation cooler or the oil heat exchanger depending on whether the exhaust gas recirculation cooler is operational or the oil heat exchanger is operational. The exhaust gas recirculation valve is in flow communication with the inlet manifold of the internal combustion engine and is adapted to channel the flow of exhaust gas from either the exhaust gas recirculation cooler or the oil heat exchanger to the intake manifold of the engine.

[0010] Figure 2 illustrates a schematic diagram of an oil flow circuit of the internal combustion engine. The engine comprises an oil inlet conduit that is adapted to supply lubrication oil for cooling the various components of the engine. An oil outlet conduit is in flow communication with an outlet of the engine and is adapted to supply heated lubrication oil from the engine to be cooled by the components of the oil flow circuit. An oil pump is in flow communication with the outlet of the engine, and is adapted to pressurize and supply lubrication oil from the oil sump of the engine to be cooled by the components of the oil flow circuit. An oil cooler is in flow communication downstream from the oil pump and is adapted to receive pressurized lubrication oil from the oil pump. Coolant is supplied and withdrawn from the oil pump and is adapted to withdraw waste heat from the heated lubrication oil that is excessively heated up. From the cooler, the lubrication oil is channeled to the oil heat exchanger for heating the lubrication oil before supplying it back to the inlet manifold of the engine for cooling the various components of the engine.

[0011] When a temperature of the lubrication oil that enters the engine decreases below a threshold temperature, it is required to increase the temperature of the lubrication oil to maintain an operating efficiency of the engine. In such circumstances, the switch control valve is operated to channel a flow of exhaust gases from the exhaust manifold of the engine to the oil heat exchanger in order to heat the lubrication oil that is supplied from the cooler. When the temperature of the lubrication oil that enters the engine increases above the threshold temperature, it is required to maintain / decrease the temperature of lubrication oil to maintain an operating efficiency of the engine. In such circumstances, the switch control valve is operated to channel a flow of exhaust gas from the exhaust manifold of the engine to the exhaust gas recirculation cooler, thereby bypassing the oil heat exchanger. Therefore, the lubrication oil that is channeled into the oil heat exchanger does not get heated up and is therefore supplied directly to the engine at the same temperature at which it entered the oil heat exchanger.

[0012] The lubrication oil that is supplied to the engine is channeled around the outer circumference of the engine cylinders in order to cool the pistons, cylinders, and other movable components of the engine. Due to the contact between the lubrication oil with the pistons, cylinders, and other movable components of the engine, the lubrication oil gets heated up before it is deposited into the oil sump. From the oil sump, the heated lubrication oil is supplied to the oil pump where it is pressurized and circulated to the cooler for withdrawing the heat from the lubrication oil. If the lubrication oil is not sufficiently heated, the cooler is bypassed and the lubrication oil is supplied directly to the oil heat exchanger for heating the lubrication oil before the lubrication oil is supplied to the engine.

[0013] A working of the oil heat exchanger for an internal combustion engine is described as an example. Heated lubrication oil from the oil sump is supplied to the oil pump. The oil pump pressurizes the heated lubrication oil and supplies it to a cooler that partially cools the lubrication oil. If the temperature of the lubrication oil is too low, the cooler is bypassed and the lubrication oil is supplied to the oil heat exchanger for heating it for delivery to the engine. The lubrication oil entering the oil heat exchanger gets heated up due to the exhaust gases that are supplied from the exhaust manifold of the engine. The heated lubrication oil from the oil heat exchanger is supplied to the engine for lubricating the engine components and withdrawing the waste heat from the engine before it is recirculated to the oil pump once again.

[0014] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.