COOLING CIRCUIT FOR INTERNAL COMBUSTION ENGINES

• US 20170184008A1
• Filed: 05/23/2014
• Published: 06/29/2017
• Est. Priority Date: 05/23/2014
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: NAGAI, Hiroyuki
• Granted Patent: US 10,450,938 B2
• Time in Patent Office: Days
• CPC Class Codes: F01N 5/02 the devices using heat
• CPC Class Codes: F01P 11/20 concerning atmospheric freezing conditions, e.g. automatically draining or heating during frosty weather
• CPC Class Codes: F01P 2060/16 Outlet manifold
• CPC Class Codes: F01P 2060/18 Heater
• CPC Class Codes: F01P 3/02 Arrangements for cooling cylinders or cylinder heads
• CPC Class Codes: F01P 3/20 Cooling circuits not specific to a single part of engine or machine F01P3/22 takes precedence
• CPC Class Codes: F01P 7/167 by adjusting the pre-set temperature according to engine parameters, e.g. engine load, engine speed
• CPC Class Codes: F02B 29/0412 Multiple heat exchangers arranged in parallel or in series
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A cooling circuit for internal combustion engines includes an internal combustion engine, a pressure-feeding unit for feeding coolant, which cools the internal combustion engine under pressure, a valve unit having a plurality of heat exchangers connected in parallel thereto, an exhaust heat recovery system for recovering heat from exhaust air of the internal combustion engine by the coolant, a first circulation circuit including the pressure-feeding unit, the valve unit and the exhaust heat recovery system, and a second circulation circuit including the pressure-feeding unit and the exhaust heat recovery system.

Claims

1-12. -12. (canceled)

13. A cooling circuit for internal combustion engines, comprising:

an internal combustion engine;

a pressure-feeding unit for feeding coolant under pressure, the coolant cooling the internal combustion engine;

a valve unit having a plurality of heat exchangers connected in parallel thereto;

an exhaust heat recovery system for recovering heat from exhaust air of the internal combustion engine by the coolant;

a first circulation circuit including the pressure-feeding unit, the valve unit and the exhaust heat recovery system; and

a second circulation circuit including the pressure-feeding unit and the exhaust heat recovery system;

a flow rate of the coolant flowing through the exhaust heat recovery system via the second circulation circuit being smaller than that of the coolant flowing through the exhaust heat recovery system via the first circulation circuit.

14. The cooling circuit for internal combustion engines according to claim 13, wherein:

the valve unit is arranged upstream of the exhaust heat recovery system in the first circulation circuit; and

the second circulation circuit is branched off from the first circulation circuit at a position upstream of the valve unit and joins the first circulation circuit at a position upstream of the exhaust heat recovery system.

15. The cooling circuit for internal combustion engines according to claim 13, wherein:

the valve unit is arranged downstream of the exhaust heat recovery system in the first circulation circuit; and

the second circulation circuit is branched off from the first circulation circuit at a position downstream of the exhaust heat recovery system and joins the first circulation circuit at a position downstream of the valve unit.

16. The cooling circuit for internal combustion engines according to claim 13, wherein:

the plurality of heat exchangers includes a heater for heating air utilized to heat an inside of a cabin of a vehicle mounted with the internal combustion engine through heat radiation from the coolant;

the first circulation circuit further includes the heater.

17. The cooling circuit for internal combustion engines according to claim 13, wherein:

the plurality of heat exchangers includes a cooler for cooling lubricating oil of a transmission for changing a speed of output rotation of the internal combustion engine through heat radiation to the coolant; and

the first and second circulation circuits further include the cooler and the exhaust heat recovery system is arranged upstream of the cooler.

18. The cooling circuit for internal combustion engines according to claim 14, wherein:

the valve unit has a valve opening pattern for shutting off all circulation circuits passing through the valve unit including the first circulation circuit.

19. The cooling circuit for internal combustion engines according to claim 18, wherein:

the plurality of heat exchangers includes;

a heater for heating air utilized to heat an inside of a cabin of a vehicle mounted with the internal combustion engine through heat radiation from the coolant;

a cooler for cooling lubricating oil of a transmission for changing a speed of output rotation of the internal combustion engine through heat radiation to the coolant; and

a radiator for radiating heat of the coolant; and

the valve unit further has;

a valve opening pattern for causing the coolant to flow through the heater out of the plurality of heat exchangers;

a valve opening pattern for causing the coolant to flow through the heater and the cooler out of the plurality of heat exchangers; and

a valve opening pattern for causing the coolant to flow through the heater, the cooler and the radiator out of the plurality of heat exchangers.

20. The cooling circuit for internal combustion engines according to claim 19, wherein:

the valve unit further has a valve opening pattern for causing the coolant to flow only through the radiator out of the plurality of heat exchangers.

21. The cooling circuit for internal combustion engines according to claim 13, wherein:

the second circulation circuit further includes the valve unit and causes the coolant to flow via an opening of the valve unit, the coolant flowing through the radiator via the opening.

22. The cooling circuit for internal combustion engines according to claim 13, wherein:

the exhaust heat recovery system includes a heat exchange unit for performing a heat exchange between the exhaust air and the coolant;

the exhaust heat recovery system is configured as a bypass-less exhaust heat recovery system for causing flowing-in exhaust air to flow via the heat exchange unit.

23. The cooling circuit for internal combustion engines according to claim 13, wherein:

the second circulation circuit circulates the coolant in a state where the pressure-feeding unit is feeding the coolant under pressure.

24. The cooling circuit for internal combustion engines according to claim 15, wherein:

the valve unit has a valve opening pattern for shutting off all circulation circuits passing through the valve unit including the first circulation circuit.