Locomotive engine cooling system and method

Claim 2

An internal combustion engine having coolant passages therethrough, a compressor for increasing the density of inlet air thereto, an aftercooler for cooling the inlet air from the compressor and cooling apparatus comprising: a main coolant loop including a main pump, a main radiator and a main coolant conduit connecting the main pump, the engine coolant passages and the main radiator for unidirectional circulation of a liquid coolant; an aftercooler coolant loop including an aftercooler pump, an aftercooler radiator and an aftercooler conduit connecting the aftercooler pump, the aftercooler and the aftercooler radiator for unidirectional circulation of a liquid coolant, the components of the aftercooler coolant loop providing a lower coolant temperature therein than the coolant temperature provided by the components of the main coolant loop therein when coolant flows of the main and aftercooler coolant loops are maintained separate; a first linking conduit connecting a higher pressure portion of the main coolant loop with a lower pressure portion of the aftercooler coolant loop ahead of the aftercooler radiator; a second linking conduit connecting the aftercooler coolant loop with the main coolant loop after the respective radiators; a valve in one of the linking conduits and operable between closed and open positions to respectively prevent or permit-coolant flow from the main pump in the main loop through the aftercooler radiators in the aftercooler loop and back to the main loop into the main pump inlet; and a control responsive to engine and control related parameters to activate the valve to primarily maintain engine temperature below a maximum limit and to secondarily maintain a desired maximum coolant temperature differential across the aftercooler radiator.

Claim 3

An engine as in claim 1 wherein said first linking conduit extends from the main coolant loop between the main pump and the main radiator.

Claim 4

An engine as in claim 1 wherein said second linking conduit connects a coolant tank with both coolant loops.

Claim 5

An engine as in claim 1 wherein said aftercooler pump is driven by an electric motor.

Claim 6

An engine as in claim 1 wherein said control includes means for controlling at least one of an actuator for a flow control valve in the aftercooler loop and a variable speed drive motor for the aftercooler pump.

Claim 7

An internal combustion engine having coolant passages therethrough, a compressor for increasing the density of inlet air thereto, an aftercooler for cooling the inlet air from the compressor and cooling apparatus comprising: a main coolant loop including a main pump, a main radiator and a main coolant conduit connecting the main pump, the engine coolant passages and the main radiator for unidirectional circulation of a liquid coolant; an aftercooler coolant loop including an aftercooler pump, an aftercooler radiator connected for four coolant passes in series, and an aftercooler conduit connecting the aftercooler pump, the aftercooler and the aftercooler radiator for unidirectional circulation of a liquid coolant, the components of the aftercooler coolant loop providing a lower coolant temperature therein than the coolant temperature provided by the components of the main coolant loop therein when coolant flows of the main and aftercooler coolant loops are maintained separate; a first linking conduit extending from the main coolant loop between the engine and the main radiator and connecting a higher pressure portion of the main coolant loop with a lower pressure portion of the aftercooler coolant loop ahead of the aftercooler radiator; a second linking conduit connecting the aftercooler coolant loop with the main coolant loop after the respective radiators; a valve in one of the linking conduits and operable between closed and open positions to respectively prevent or permit coolant flow from the main pump in the main loop through the aftercooler radiators in the aftercooler loop and back to the main loop into the main pump inlet; and a control responsive to engine and control related parameters to activate the valve to primarily maintain engine temperature below a maximum limit and to secondarily maintain a desired maximum coolant temperature differential across the aftercooler radiator.

Claim 8

An internal combustion engine having coolant passages therethrough, a compressor for increasing the density of inlet air thereto, an aftercooler for cooling the inlet air from the compressor and cooling apparatus comprising: a main coolant loop including a main pump, a main radiator and a main coolant conduit connecting the main pump, the engine coolant passages and the main radiator for unidirectional circulation of a liquid coolant; an aftercooler coolant loop including an aftercooler pump, an aftercooler radiator connected for four coolant passes in series, and an aftercooler conduit connecting the aftercooler pump, the aftercooler and the aftercooler radiator for unidirectional circulation of a liquid coolant, the components of the aftercooler coolant loop providing a lower coolant temperature therein than the coolant temperature provided by the components of the main coolant loop therein when coolant flows of the main and aftercooler coolant loops are maintained separate; a first linking conduit extending from the main coolant loop between the engine and the main radiator and connecting a higher pressure portion of the main coolant loop with a lower pressure portion of the aftercooler coolant loop ahead of the aftercooler radiator; a second linking conduit connecting the aftercooler coolant loop with the main coolant loop after the respective radiators; a valve in one of the linking conduits and operable between closed and open positions to respectively prevent or permit coolant flow from the main pump in the main loop through the aftercooler radiators in the aftercooler loop and back to the main loop into the main pump inlet; and a control responsive to engine and control related parameters to activate the valve to primarily maintain engine temperature below a maximum limit and to secondarily maintain a desired maximum coolant temperature differential across the aftercooler radiator.

Claim 9

An internal combustion engine having coolant passages therethrough, a compressor for increasing the density of inlet air thereto, an aftercooler for cooling the inlet air from the compressor and cooling apparatus comprising: a main coolant loop including a main pump, a main radiator and a main coolant conduit connecting the main pump, the engine coolant passages and the main radiator for unidirectional circulation of a liquid coolant; an aftercooler coolant loop including an aftercooler pump, an aftercooler radiator connected for eight coolant passes in series, and an aftercooler conduit connecting the aftercooler pump, the aftercooler and the aftercooler radiator for unidirectional circulation of a liquid coolant, the components of the aftercooler coolant loop providing a lower coolant temperature therein than the coolant temperature provided by the components of the main coolant loop therein when coolant flows of the main and aftercooler coolant loops are maintained separate; a first linking conduit extending from the main coolant loop between the main pump and the engine and connecting a higher pressure portion of the main coolant loop with a lower pressure portion of the aftercooler coolant loop ahead of the aftercooler radiator; a second linking conduit connecting the aftercooler coolant loop with the main coolant loop after the respective radiators; a valve in one of the linking conduits and operable between closed and open positions to respectively prevent or permit coolant flow from the main pump in the main loop through the aftercooler radiators in the aftercooler loop and back to the main loop into the main pump inlet; and a control responsive to engine and control related parameters to activate the valve to primarily maintain engine temperature below a maximum limit and to secondarily maintain a desired maximum coolant temperature differential across the aftercooler radiator.

Claim 10

An internal combustion engine having coolant passages therethrough, a compressor for increasing the density of inlet air thereto, an aftercooler for cooling the inlet air from the compressor and cooling apparatus comprising: a main coolant loop including a main pump, a main radiator and a main coolant conduit connecting the main pump, the engine coolant passages and the main radiator for unidirectional circulation of a liquid coolant; an aftercooler coolant loop including an aftercooler pump, an aftercooler radiator connected for eight coolant passes in series, and an aftercooler conduit connecting the aftercooler pump, the aftercooler and the aftercooler radiator for unidirectional circulation of a liquid coolant, the components of the aftercooler coolant loop providing a lower coolant temperature therein than the coolant temperature provided by the components of the main coolant loop therein when coolant flows of the main and aftercooler coolant loops are maintained separate; a first linking conduit extending from the main coolant loop between the main pump and the engine and connecting a higher pressure portion of the main coolant loop with a lower pressure portion of the aftercooler coolant loop ahead of the aftercooler radiator; a second linking conduit connecting the aftercooler coolant loop with the main coolant loop after the respective radiators; a valve in one of the linking conduits and operable between closed and open positions to respectively prevent or permit coolant flow from the main pump in the main loop through the aftercooler radiators in the aftercooler loop and back to the main loop into the main pump inlet; and a control responsive to engine and control related parameters to activate the valve to primarily maintain engine temperature below a maximum limit and to secondarily maintain a desired maximum coolant temperature differential across the aftercooler radiator.

Claim 11

An internal combustion engine having coolant passages therethrough, a compressor for increasing the density of inlet air thereto, an aftercooler for cooling the inlet air from the compressor and cooling apparatus comprising: a main coolant loop including a main pump, a main radiator and a main coolant conduit connecting the main pump, the engine coolant passages and the main radiator for unidirectional circulation of a liquid coolant; an aftercooler coolant loop including an aftercooler pump, an aftercooler radiator and an aftercooler conduit connecting the aftercooler pump, the aftercooler and the aftercooler radiator for unidirectional circulation of a liquid coolant, the components of the aftercooler coolant loop providing a lower coolant temperature therein than the coolant temperature provided by the components of the main coolant loop therein when coolant flows of the main and aftercooler coolant loops are maintained separate; a first linking conduit connecting a higher pressure portion of the main coolant loop with a lower pressure portion of the aftercooler coolant loop ahead of the aftercooler radiator; a second linking conduit connecting the aftercooler coolant loop with the main coolant loop after the respective radiators; a valve in one of the linking conduits and operable between closed and open positions to respectively prevent or permit coolant flow from the main pump in the main loop through the aftercooler radiators in the aftercooler loop and back to the main loop into the main pump inlet; a control responsive to engine and control related parameters to activate the valve to primarily maintain engine temperature below a maximum limit and to secondarily maintain a desired maximum coolant temperature differential across the aftercooler radiator; and a flow control valve in said aftercooler loop between the second and first linking conduits in the direction of coolant flow.

Claim 12

An internal combustion engine having coolant passages therethrough, a compressor for increasing the density of inlet air thereto, an aftercooler for cooling the inlet air from the compressor and cooling apparatus comprising: a main coolant loop including a main pump, a main radiator and a main coolant conduit connecting the main pump, the engine coolant passages and the main radiator for unidirectional circulation of a liquid coolant; an aftercooler coolant loop including an aftercooler pump, an aftercooler radiator and an aftercooler conduit connecting the aftercooler pump, the aftercooler and the aftercooler radiator for unidirectional circulation of a liquid coolant, the components of the aftercooler coolant loop providing a lower coolant temperature therein than the coolant temperature provided by the components of the main coolant loop therein when coolant flows of the main and aftercooler coolant loops are maintained separate; a first linking conduit connecting a higher pressure portion of the main coolant loop with a lower pressure portion of the aftercooler coolant loop ahead of the aftercooler radiator; a second linking conduit connecting the aftercooler coolant loop with the main coolant loop after the respective radiators; a valve in one of the linking conduits and operable between closed and open positions to respectively prevent or permit coolant flow from the main pump in the main loop through the aftercooler radiators in the aftercooler loop and back to the main loop into the main pump inlet; a control responsive to engine and control related parameters to activate the valve to primarily maintain engine temperature below a maximum limit and to secondarily maintain a desired maximum coolant temperature differential across the aftercooler radiator; and a flow control valve in said aftercooler loop between the second and first linking conduits in the direction of coolant flow.