Adaptive EGR cooling system
First Claim
1. An internal combustion engine comprising:
- engine structure comprising engine cylinders within which fuel is combusted to operate the engine and coolant passageways;
an intake system for conveying air to the engine cylinders to support fuel combustion and comprising a charge air cooler for cooling the air;
an exhaust system for conveying combustion-created exhaust gas from the cylinders;
an EGR system for recirculating some exhaust gas from the exhaust system successively through a first heat exchanger and a second heat exchanger to the intake system for entrainment with air being conveyed to the cylinders;
a cooling system for circulating liquid coolant in multiple loops and comprising first and second radiators;
a first of the loops comprising the coolant passageways where heat from the engine structure is transferred to coolant and the first radiator where heat in coolant that has passed through the coolant passageways is rejected;
a second of the loops comprising one of the first and second heat exchangers; and
a third of the loops comprising the other of the first and second heat exchangers, the second radiator, a charge air cooler, a first valve that is selectively operable to first and second conditions, and a second valve that is operable to selectively apportion coolant flow entering an inlet of the second valve to parallel flow paths, one of which includes the second radiator and another of which bypasses the second radiator, and which merge into confluent flow downstream of the second radiator to both an inlet of the charge air cooler and a first inlet of the first valve, the first valve having an outlet communicated an inlet of the other of the first and second heat exchangers;
the first condition of the first valve closing a second inlet of the first valve to coolant flowing toward both the second inlet of the first valve and the first inlet of the second valve while opening the first inlet of the first valve to the outlet of the first valve, and the second condition of the first valve opening the second inlet of the first valve to coolant flowing toward the second inlet of the first valve and the first inlet of the second valve while closing the first inlet of the first valve to the outlet of the first valve.
11 Assignments
0 Petitions
Accused Products
Abstract
A first loop contains engine coolant passageways (28, 30) and a first radiator (34). A second loop contains a first EGR cooler (48). A third loop contains a second EGR cooler (50), a second radiator (36), a charge air cooler (26LP), a first valve (66), and a second valve (64). Valve (64) apportions coolant flow entering an inlet (64A) to parallel flow paths, one including second radiator (36) and the other being a bypass around radiator (36). The apportioned flows merge into confluent flow to both an inlet of charge air cooler (26LP) and a first inlet (66B) of valve (66). Valve (66) has an outlet (66C) communicated to an inlet of second EGR cooler (50). The first condition of valve (66) closes a second inlet (66A) to coolant flowing toward both the second inlet (66A) and inlet (64A) while opening inlet (66B) to outlet (66C). The second condition of valve (66) opens second inlet (66A) to coolant flowing toward second inlet (66A) and inlet (64A) of the valve (64) while closing first inlet (66B) of valve (66) to outlet (66C) of valve (66).
66 Citations
24 Claims
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1. An internal combustion engine comprising:
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engine structure comprising engine cylinders within which fuel is combusted to operate the engine and coolant passageways; an intake system for conveying air to the engine cylinders to support fuel combustion and comprising a charge air cooler for cooling the air; an exhaust system for conveying combustion-created exhaust gas from the cylinders; an EGR system for recirculating some exhaust gas from the exhaust system successively through a first heat exchanger and a second heat exchanger to the intake system for entrainment with air being conveyed to the cylinders; a cooling system for circulating liquid coolant in multiple loops and comprising first and second radiators; a first of the loops comprising the coolant passageways where heat from the engine structure is transferred to coolant and the first radiator where heat in coolant that has passed through the coolant passageways is rejected; a second of the loops comprising one of the first and second heat exchangers; and a third of the loops comprising the other of the first and second heat exchangers, the second radiator, a charge air cooler, a first valve that is selectively operable to first and second conditions, and a second valve that is operable to selectively apportion coolant flow entering an inlet of the second valve to parallel flow paths, one of which includes the second radiator and another of which bypasses the second radiator, and which merge into confluent flow downstream of the second radiator to both an inlet of the charge air cooler and a first inlet of the first valve, the first valve having an outlet communicated an inlet of the other of the first and second heat exchangers; the first condition of the first valve closing a second inlet of the first valve to coolant flowing toward both the second inlet of the first valve and the first inlet of the second valve while opening the first inlet of the first valve to the outlet of the first valve, and the second condition of the first valve opening the second inlet of the first valve to coolant flowing toward the second inlet of the first valve and the first inlet of the second valve while closing the first inlet of the first valve to the outlet of the first valve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A circuit for cooling both exhaust gas being recirculated through an EGR system of an internal combustion engine and charge air for supporting combustion in engine combustion chambers, the circuit comprising:
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a first loop comprising coolant passageways in engine structure where heat from the engine structure is transferred to coolant and a first radiator where heat in coolant that has passed through the coolant passageways is rejected; a second loop comprising a first EGR cooler; and a third loop comprising a second EGR cooler, a second radiator, a charge air cooler for cooling charge air entering the engine, a first valve that is selectively operable to first and second conditions, and a second valve that is operable to selectively apportion coolant flow entering an inlet of the second valve to parallel flow paths, one of which includes the second radiator and another of which bypasses the second radiator, and which merge into confluent flow downstream of the second radiator to convey coolant to both an inlet of the charge air cooler and a first inlet of the first valve, the first valve having an outlet communicated an inlet of the second EGR cooler; the first condition of the first valve closing a second inlet of the first valve to coolant flowing toward both the second inlet of the first valve and the first inlet of the second valve while opening the first inlet of the first valve to the outlet of the first valve, and the second condition of the first valve opening the second inlet of the first valve to coolant flowing toward the second inlet of the first valve and the first inlet of the second valve while closing the first inlet of the first valve to the outlet of the first valve. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method for cooling both exhaust gas being recirculated through an EGR system of an internal combustion engine and charge air for supporting combustion in engine combustion chambers, the method comprising:
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circulating liquid coolant in a first loop comprising coolant passageways in engine structure where heat from the engine structure is transferred to coolant and a first radiator where heat in coolant that has passed through the coolant passageways is rejected; circulating liquid coolant in a second loop comprising a first EGR cooler; and circulating liquid coolant in a third loop comprising a second EGR cooler, a second radiator, a charge air cooler for cooling charge air entering the engine, a selectively operable first valve, and a second valve for selectively apportioning coolant flow entering an inlet of the second valve to parallel flow paths, one of which includes the second radiator and another of which bypasses the second radiator, and which merge into confluent flow downstream of the second radiator to convey coolant to both an inlet of the charge air cooler and a first inlet of the first valve, the first valve having an outlet communicated an inlet of the second EGR cooler; selectively operating the first valve to a first condition closing a second inlet of the first valve to coolant flowing toward both the second inlet of the first valve and the first inlet of the second valve while opening the first inlet of the first valve to the outlet of the first valve, and to the second condition opening the second inlet of the first valve to coolant flowing toward the second inlet of the first valve and the first inlet of the second valve while closing the first inlet of the first valve to the outlet of the first valve; and operating the second valve to selectively apportion coolant flow entering the inlet of the second valve to the parallel flow paths.
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Specification