Claims:CLAIMS

We Claim

1. A circuit (10) for regulating a temperature of compressed air supplied from a turbocharger (12) to an engine (14) based on an engine exhaust gas temperature, the circuit (10) comprising:
a first heat exchanger (16) comprising an upstream end (18) and a downstream end (20), the upstream end (18) of said first heat exchanger (16) in flow communication with a compressor (22) of said turbocharger (12), the downstream end (20) of said first heat exchanger (16) in flow communication with an inlet manifold (24) of said engine (14) and adapted to deliver heated compressed air to the inlet manifold (24) of said engine (14);
a first engine cooling circuit (25) in flow communication between said engine (14) and an inlet (26) of a high temperature cooler (28), the first engine cooling circuit (25) adapted to supply high temperature coolant from said engine (14) to said high temperature cooler (28); characterized in that
a bypass flow duct (30) comprising an upstream end (32) and a downstream end (34), the upstream end (32) of said bypass flow duct (30) in flow communication with said first engine cooling circuit (25), the downstream end (34) of said bypass flow duct (30) in flow communication with an inlet port (36) of an electric feed pump (38), the bypass flow duct (30) adapted to channel high temperature coolant from the first engine cooling circuit (25) to the first inlet port (36) of said electric feed pump (38);
an outlet port (40) of said electric feed pump (38) in flow communication with an inlet port (42) of said first heat exchanger (16), the outlet port (40) of said electric feed pump (38) adapted to channel high temperature coolant that is delivered to the inlet port (36) of said electric feed pump (38) to the inlet port (42) of said first heat exchanger (16);
an outlet port (44) of said first heat exchanger (16) in flow communication with a second engine cooling circuit (55), said second engine cooling circuit (55) in flow communication between an outlet (58) of said high temperature cooler (28) and an inlet port (60) of a fuel circulation pump (62), the outlet port (44) of said first heat exchanger (16) adapted to channel high temperature coolant to the second engine cooling circuit (55).

2. The circuit (10) for regulating the temperature of compressed air supplied from a turbocharger (12) to an engine (14) based on an engine exhaust gas temperature in accordance with Claim 1, further comprising a three-way valve (90) positioned upstream of said first heat exchanger (16), said three-way valve (90) positioned downstream of said compressor (22) of said turbocharger (12), said three-way valve (90) adapted to receive compressed air from said compressor (22) of said turbocharger (12) and supply the compressed air to the upstream end (18) of said first heat exchanger (16).

3. The circuit (10) for regulating the temperature of compressed air supplied from a turbocharger (12) to an engine (14) based on an engine exhaust gas temperature in accordance with Claim 2, further comprising a second heat exchanger (50) comprising an upstream end (52) and a downstream end (54), the upstream end (52) of said second heat exchanger (50) in flow communication with a downstream end of said three-way valve (90), the downstream end (54) of said second heat exchanger (50) in flow communication with the inlet manifold (24) of said engine (14).

4. The circuit (10) for regulating the temperature of compressed air supplied from a turbocharger (12) to an engine (14) based on an engine exhaust gas temperature in accordance with Claim 3, wherein said second heat exchanger (50) is adapted to cool the compressed air that is supplied from said compressor (22) of said turbocharger (12) to the upstream end (52) of said second heat exchanger (50), the downstream end (54) of said second heat exchanger (50) adapted to channel the cooled compressed air to the inlet manifold (24) of said engine (14).

5. The circuit (10) for regulating the temperature of compressed air supplied from a turbocharger (12) to an engine (14) based on an engine exhaust gas temperature in accordance with Claim 4, further comprising an engine control unit (75) in electronic communication with the three-way valve (90) via a control flow path (80), the engine control unit (75) adapted to control an opening of a first outlet port of said three-way valve (38), thereby channeling compressed air from said compressor (22) of said turbocharger (12) to the upstream end (18) of said first heat exchanger (16) when an exhaust gas temperature of the engine (14) is lower than a threshold temperature value that is defined by a user.

6. The circuit (10) for regulating the temperature of compressed air supplied from a turbocharger (12) to an engine (14) based on an engine exhaust gas temperature in accordance with Claim 5, wherein the engine control unit (75) is adapted to control an opening of a second outlet port of said three-way valve (38), thereby channeling compressed air from said compressor (22) of said turbocharger (12) to the upstream end (52) of said second heat exchanger (50) when an exhaust gas temperature of the engine (14) is higher than a threshold temperature value that is defined by a user.

7. A circuit (10) for regulating a temperature of compressed air supplied from a heat exchanger (16) to an engine (14) based on an engine exhaust gas temperature, the circuit (10) comprising:
the heat exchanger (16) comprising an upstream end (18) and a downstream end (20), the upstream end (18) of said heat exchanger (16) in flow communication with a compressor (22) of a turbocharger (12), the downstream end (20) of said heat exchanger (12) in flow communication with an inlet manifold (24) of an engine (14);
a first engine cooling circuit (25) in flow communication between said engine (14) and an inlet (26) of a high temperature cooler (28), the first engine cooling circuit (25) adapted to deliver high temperature coolant from said engine (14) to said high temperature cooler (28); characterized in that
a bypass flow duct (30) in flow communication with said first engine cooling circuit (25), and adapted to channel high temperature coolant from said first engine cooling circuit (25) to an inlet port (42) of said heat exchanger (16); and
an outlet port (44) of said heat exchanger (16) in flow communication with a second engine cooling circuit (55) and adapted to channel high temperature coolant from the outlet port (44) of said heat exchanger (16) to the second engine cooling circuit (55).
, 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 engine coolant circuit and an air coolant circuit for exchanging heat with compressed air from a turbocharger, and more specifically for regulating a temperature of compressed air supplied from the turbocharger to an engine based on an engine exhaust gas temperature.

Background of the invention
[0002] IN Patent Application Number XXX describes a circuit for regulating a temperature of charge air supplied from a charge air cooler to an engine based on an engine exhaust gas temperature. The circuit comprises the charge air cooler comprising an upstream end and a downstream end. The upstream end of the charge air cooler is in flow communication with a compressor of a turbocharger. The downstream end of the charge air cooler is in flow communication with an inlet manifold of an engine. A first engine cooling circuit is in flow communication between the engine and an inlet of a high temperature cooler. The first engine cooling circuit is adapted to supply high temperature coolant from the engine to the high temperature cooler. A bypass flow duct comprises an upstream end and a downstream end. The upstream end of the bypass flow duct is in flow communication with the first engine cooling circuit. The downstream end of the bypass flow duct is in flow communication with a first inlet port of a first three-way valve. The bypass flow duct is adapted to channel high temperature coolant from the first engine cooling circuit to the first inlet port of the first three-way valve. An outlet port of the first three-way valve is in flow communication with an inlet port of an electric feed pump. The outlet port of the first three-way valve is adapted to channel high temperature coolant that is delivered to the first inlet port of the first three-way valve from the bypass flow duct to the inlet port of the electric feed pump. An outlet port of the electric feed pump is in flow communication with an inlet port of the charge air cooler. The outlet port of the electric feed pump is adapted to channel high temperature coolant that is delivered to the inlet port of the electric feed pump to the inlet port of the charge air cooler. An outlet port of the charge air cooler is in flow communication with an inlet port of a second three-way valve. The outlet port of the charge air cooler is adapted to channel high temperature coolant from the charge air cooler to the inlet port of the second three-way valve. A first outlet port of the second three-way valve is in flow communication with a second engine cooling circuit. The second engine cooling circuit is in flow communication between an outlet of the high temperature cooler and an inlet of a fuel circulation pump. The first outlet port of the second three-way valve is adapted to channel high temperature coolant that is delivered to the first inlet port of the second three-way valve from the outlet port of the charge air cooler to the second engine cooling circuit.

Brief description of the accompanying drawing
[0003] Figure 1 depicts a schematic drawing of an engine coolant circuit and an air coolant circuit for exchanging heat with compressed air from a turbocharger in one embodiment of the invention.

Detailed description of the embodiments
[0004] A circuit 10 for regulating a temperature of compressed air supplied from a turbocharger 12 to an engine 14 based on an engine exhaust gas temperature is described. The circuit 10 comprises a first heat exchanger 16 comprising an upstream end 18 and a downstream end 20. The upstream end 18 of the first heat exchanger 16 is in flow communication with a compressor 22 of the turbocharger 12. The downstream end 20 of the first heat exchanger 16 is in flow communication with an inlet manifold 24 of the engine 14 and is adapted to deliver heated compressed air to the inlet manifold 24 of the engine 14. A first engine cooling circuit 25 is in flow communication between the engine 14 and an inlet 26 of a high temperature cooler 28. The first engine cooling circuit 25 is adapted to supply high temperature coolant from the engine 14 to the high temperature cooler 28. A bypass flow duct 30 comprises an upstream end 32 and a downstream end 34. The upstream end 32 of the bypass flow duct 30 is in flow communication with the first engine cooling circuit 25. The downstream end 34 of the bypass flow duct 30 is in flow communication with an inlet port 36 of an electric feed pump 38. The bypass flow duct 30 is adapted to channel high temperature coolant from the first engine cooling circuit 25 to the first inlet port 36 of the electric feed pump 38. An outlet port 40 of the electric feed pump 38 is in flow communication with an inlet port 42 of the first heat exchanger 16. The outlet port 40 of the electric feed pump 38 is adapted to channel high temperature coolant that is delivered to the inlet port 36 of the electric feed pump 38 to the inlet port 42 of the first heat exchanger 16. An outlet port 44 of the first heat exchanger 16 is in flow communication with a second engine cooling circuit 55. The second engine cooling circuit 55 is in flow communication between an outlet 58 of the high temperature cooler 28 and an inlet 60 of a fuel circulation pump 62. The outlet port 44 of the first heat exchanger 16 is adapted to channel high temperature coolant to the second engine cooling circuit 55.

[0005] Figure 1 depicts a schematic drawing of an engine coolant circuit and an air coolant circuit for exchanging heat with compressed air from a turbocharger 12 in one embodiment of the invention. In an exemplary embodiment, a circuit 10 for regulating a temperature of compressed air supplied from the turbocharger 12 to the engine 14 based on an engine exhaust gas temperature is described. The circuit 10 comprises a first heat exchanger 16 that comprises an upstream end 18 and a downstream end 20. The upstream end 18 of the first heat exchanger 16 is in flow communication with a compressor 22 of a turbocharger 12 and received compressed air from the compressor 22 of the turbocharger 12. The downstream end 20 of the first heat exchanger 16 is in flow communication with an inlet manifold 24 of an engine 14 and delivers the compressed air that is received from the compressor 22 of the turbocharger 12 to the inlet manifold 24 of the engine 14. A first engine cooling circuit 25 is in flow communication between an outlet of cooling jackets of the engine 14 and an inlet 26 of a high temperature cooler 28. The first engine cooling circuit 25 is adapted to supply high temperature coolant from the outlet of the cooling jackets of the engine 14 to the high temperature cooler 28 via a thermostat 19 and via the inlet 26 of the high temperature cooler 28.

[0006] A bypass flow duct 30 comprises an upstream end 32 and a downstream end 34. The upstream end 32 of the bypass flow duct 30 is in flow communication with the first engine cooling circuit 25 that is in flow communication between the outlet of the cooling jackets of the engine 14 and the inlet 26 of the high temperature cooler 28. The downstream end 34 of the bypass flow duct 30 is in flow communication with an inlet port 36 of an electric feed pump 38. The downstream end 34 of the bypass flow duct 30 is adapted to channel high temperature coolant from the first engine cooling circuit 25 to the inlet port 36 of the electric feed pump 38. Correspondingly, an outlet port 40 of the electric feed pump 44 is in flow communication with an inlet port 42 of the first heat exchanger 16, and is adapted to deliver high temperature coolant that is delivered to the inlet port 36 of the electric feed pump 38 to the inlet port 42 of the first heat exchanger 16. An outlet port 44 of the first heat exchanger 16 is in flow communication with a second engine cooling circuit 55, and is adapted to deliver the high temperature coolant from the outlet port 44 of the first heat exchanger 16 to the second cooling circuit 55. More specifically, the second engine cooling circuit 55 is in flow communication between an outlet 58 of the high temperature cooler 28 and an inlet port 60 of a fuel circulation pump 62, and delivers high temperature coolant to the inlet port 60 of the fuel circulation pump 62, that is further channeled into the cooling jackets of the engine 14. Therefore, the first outlet port 44 of the first heat exchanger 16 is adapted to channel high temperature coolant to the second engine cooling circuit 55.
[0007] In an exemplary embodiment, the circuit 10 for regulating the temperature of compressed air supplied from the turbocharger 12 to the engine 14 based on the engine exhaust gas temperature further comprises a three-way valve 90 positioned upstream of the first heat exchanger 16. The three-way valve 90 is positioned downstream from the compressor 22 of the turbocharger 12. The three-way valve 90 is adapted to receive compressed air from the compressor 22 of the turbocharger 12, and supply the compressed air to the upstream end 18 of the first heat exchanger 16. The compressed air that is delivered from the compressor 22 of the turbocharger 12 to the first heat exchanger 16 via the upstream end 18 of the first heat exchanger 16 is warmed up by the high temperature coolant that is channeled from the downstream end 40 of the electric feed pump 38 to the inlet port 42 of the first heat exchanger 16. The compressed air that is delivered from the compressor 22 of the turbocharger 12 to the first heat exchanger 16 that is warmed up by the high temperature coolant that is channeled from the downstream end 40 of the electric feed pump 38 to the inlet port 42 of the first heat exchanger 16 is channeled via the downstream end 20 of the first heat exchanger 16 to the inlet manifold 24 of the engine 14.

[0008] In an exemplary embodiment, the circuit 10 for regulating the temperature of compressed air supplied from the turbocharger 12 to the engine 14 based on the engine exhaust gas temperature further comprises a second heat exchanger 50 comprising an upstream end 52 and a downstream end 54. The upstream end 52 of the second heat exchanger 50 is in flow communication with a downstream end of the three-way valve 90. The downstream end 54 of the second heat exchanger 50 is in flow communication with the inlet manifold 24 of the engine 14. More specifically, the second heat exchanger 50 is adapted to cool the compressed air that is supplied from the compressor 22 of the turbocharger 12 to the upstream end 52 of the second heat exchanger 50. Once the compressed air that is supplied from the compressor 22 of the turbocharger 12 to the upstream end 52 of the second heat exchanger 50, the compressed air is cooled in the second heat exchanger 50 by ambient air that is permitted to flow through the second heat exchanger 50, and thereby absorb the heat from the compressed air that is supplied from the compressor 22 of the turbocharger 12 to the second heat exchanger 50. Once the compressed air is cooled in the second heat exchanger 50 by the ambient air that is permitted to flow through the second heat exchanger 50, the downstream end 54 of the second heat exchanger 50 is adapted to channel the cooled compressed air to the inlet manifold 24 of the engine 14 and delivered therein.

[0009] In an exemplary embodiment, an engine control unit 75 is in electronic communication with the three-way valve 90 via a control flow path 80. The engine control unit 75 is adapted to control an opening of a first outlet port of the three-way valve 38, thereby channeling compressed air from the compressor 22 of the turbocharger 12 to the upstream end 18 of the first heat exchanger 16 when an exhaust gas temperature of the engine 14 is lower than the threshold temperature value that is defined by the user. Therefore, when the exhaust gas temperature of the engine 14 is lower than the threshold temperature value that is defined by the user, the exhaust gas is required to be warmed up for optimum engine operating efficiency. Therefore, compressed air from the compressor 22 of the turbocharger 12 is channeled to the first heat exchanger 16, where the high temperature coolant from the first cooling circuit 25 is permitted to flow through the first heat exchanger 16, thereby warming the compressed air from the turbocharger 12, and ultimately delivering the compressed air to the inlet manifold 24 of the engine 14.

[0010] In an alternate exemplary embodiment, the engine control unit 75 is adapted to control an opening of a second outlet port of the three-way valve 38, thereby channeling compressed air from the compressor 22 of the turbocharger 12 to the upstream end 52 of the second heat exchanger 50 when an exhaust gas temperature of the engine 14 is higher than a threshold temperature value that is defined by a user. Therefore, when the exhaust gas temperature of the engine 14 is higher than a threshold temperature value that is defined by the user, the exhaust gas is required to be cooled down within the second heat exchanger 50 to ensure optimum engine operating efficiency. Therefore, compressed air from the compressor 22 of the turbocharger 12 is channeled to the second heat exchanger 50, where the ambient air from the surrounding atmosphere is permitted to flow through the second heat exchanger 50, thereby cooling the compressed air from the turbocharger 12 and ultimately delivering the cooled compressed air to the inlet manifold 24 of the engine 14.

[0011] A working of the circuit 10 for regulating a temperature of compressed air supplied from the turbocharger 12 to the engine 14 based on the engine exhaust gas temperature is described as an example. When the temperature of the exhaust gas that exits from the engine 14 is below a threshold temperature that is defined by a user, the exhaust gas sensor transmits a signal to the engine control unit 75. The engine control unit 75 therein facilitates the opening of the first outlet port and closing the second outlet port of the three-way valve 90, thereby channeling high temperature coolant that flows from the outlet of the engine 14 to the inlet 26 of the high temperature cooler 28 through the bypass flow path 30 to the inlet port 36 of the electric feed pump 38. The high temperature coolant is therein circulated by the electric feed pump 44 to the inlet port 42 of the first heat exchanger 16. The temperature of the compressed air that is delivered from the compressor 20 of the turbocharger 22 to the first heat exchanger 16 is increased by the high temperature coolant that is circulated by the electric feed pump 38 to the inlet port 42 of the first heat exchanger 16. Once the temperature of the compressed air that is delivered from the compressor 22 of the turbocharger 22 to the first heat exchanger 16 is increased by the high temperature coolant, the high temperature compressed air from the turbocharger 12 is delivered to the inlet manifold 24 of the engine 14 for combustion in the engine cylinder. Due to the increase in the temperature of the compressed air that is delivered to the inlet manifold 24 of the engine 14, the temperature of the exhaust gas that exits from the outlet manifold of the engine 14 may be effectively increased. The high temperature coolant from the first heat exchanger 16 is delivered to the second engine cooling circuit 55 that is in flow communication between the outlet 58 of the high temperature cooler 28 and the inlet 60 of the fuel circulation pump 62.

[0012] When the temperature of the exhaust gas that exits from the engine 14 is above the threshold temperature that is defined by the user, the exhaust gas sensor transmits a signal to the engine control unit 75. The engine control unit 75 therein facilitates the opening of the second inlet port and closing the first inlet port of the three-way valve 90, thereby channeling high temperature compressed air from the three-way valve to the second heat exchanger 50, where the high temperature compressed air is cooled by the ambient air in the second heat exchanger 50. Therein, the high temperature compressed air that is cooled by the ambient air in the second heat exchanger 50 is channeled to the downstream end 54 of the second heat exchanger 50, and is finally delivered to the inlet manifold 24 of the engine 14. When the engine control unit 75 therein facilitates the opening of the second outlet port and closing the first outlet port of the three-way valve 90, compressed air is delivered from the compressor 22 of the turbocharger 12 to the second heat exchanger 50. The temperature of the compressed air that is delivered from the compressor 22 of the turbocharger 12 to the second heat exchanger 50 is decreased by the ambient air that circulates within the second heat exchanger 50. Once the temperature of the compressed air that is delivered from the compressor 22 of the turbocharger 22 to the second heat exchanger 50 is decreased by the ambient air that circulates within the second heat exchanger 50, the low temperature compressed air from the downstream end 54 of the second heat exchanger 50 is delivered to the inlet manifold 24 of the engine 14 for combustion in the engine cylinder. Due to the reduction in the temperature of the compressed air that is delivered to the inlet manifold 24 of the engine 14, the temperature of the exhaust gas that exits from the outlet manifold of the engine 14 can be effectively decreased. Therefore, when the temperature of the exhaust gas that is channeled from the outlet manifold of the engine 14 is lower than a threshold temperature and is required to be heated up, high temperature coolant is permitted to circulate from the first engine cooling circuit 25 to the first heat exchanger 16 via the electric feed pump 38, and back from the first heat exchanger 16 to the second engine cooling circuit 55. Similarly, when the temperature of the exhaust gas that is channeled from the outlet manifold of the engine 14 is higher than a threshold temperature and is required to be cooled down, the compressed air from the compressor 22 of the turbocharger 12 is permitted to flow through the second heat exchanger 50 to the inlet manifold 24 of the engine 14 via the second outlet port of the three-way valve 90, while the first outlet port of the three-way valve 90 is completely closed by means of a signal that is transmitted by the engine control unit 75 to the three-way valve 90 via the control flow path 80. In addition, when the compressed air from the compressor 22 of the turbocharger 12 is permitted to flow through the second heat exchanger 50 to the inlet manifold 24 of the engine 14 via the second outlet port of the three-way valve 90, the electric feed pump 38 is disconnected by a signal being transmitted from the engine control unit 75 to the electric feed pump 38 via the control flow path 81 to prevent high temperature coolant from being channeled from the first engine cooling circuit 25 to the inlet port 42 of the first heat exchanger 16.

[0013] 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.