ENGINE-WASTE-HEAT UTILIZATION DEVICE

• US 20140165562A1
• Filed: 08/06/2012
• Published: 06/19/2014
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Ishikawa, Takayuki, Nagai, Hiroyuki, Mizoguchi, Shinichiro
• Granted Patent: US 9,562,444 B2
• Time in Patent Office: Days
• US Class Current: 60/615
• CPC Class Codes: F01K 23/065 the combustion taking place in an internal combustion piston engine, e.g. a diesel engine
• CPC Class Codes: F01K 23/10 with exhaust fluid of one cycle heating the fluid in another cycle F01K17/025 takes precedence
• CPC Class Codes: F01K 23/101 Regulating means specially adapted therefor F01K23/105, F01K23/108 take precedence
• CPC Class Codes: F01K 23/14 including at least one combustion engine
• CPC Class Codes: F01N 5/02 the devices using heat
• CPC Class Codes: F01P 2060/16 Outlet manifold
• CPC Class Codes: F01P 2060/18 Heater
• CPC Class Codes: F01P 7/165 characterised by systems with two or more loops
• CPC Class Codes: F02G 5/04 in combination with other waste heat from combustion engines
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An engine-waste-heat utilization device includes a Rankine cycle which includes a heat exchanger through which cooling water coming out from an engine flows to recover waste-heat of the engine to refrigerant, an expander which generates power using the refrigerant coming out from the heat exchanger, a condenser which condenses the refrigerant coming out from the expander and a refrigerant pump which supplies the refrigerant coming out from the condenser to the heat exchanger, and a cooling water passage in which the cooling water having a higher temperature flows when the Rankine cycle is operated than when the Rankine cycle is not operated.

Claims

1-6. -6. (canceled)

7. An engine-waste-heat utilization device, comprising:

a Rankine cycle which includes a heat exchanger through which cooling water coming out from an engine flows to recover waste-heat of the engine to refrigerant, an expander which generates power using the refrigerant coming out from the heat exchanger, a condenser which condenses the refrigerant coming out from the expander and a refrigerant pump which supplies the refrigerant coming out from the condenser to the heat exchanger;

wherein a temperature of the engine cooling water is set to be higher when the Rankine cycle is operated after the warm-up of the engine is completed than when the Rankine cycle is not operated.

8. An engine-waste-heat utilization device, comprising:

a Rankine cycle which includes a heat exchanger through which cooling water coming out from an engine flows to recover waste-heat of the engine to refrigerant, an expander which generates power using the refrigerant coming out from the heat exchanger, a condenser which condenses the refrigerant coming out from the expander and a refrigerant pump which supplies the refrigerant coming out from the condenser to the heat exchanger; and

a cooling water passage which includes a first cooling water passage which supplies the cooling water coming out from the engine to a radiator, a second cooling water passage which returns the cooling water coming out from the radiator to the engine, a bypass cooling water passage which is branched off from the first cooling water passage, bypasses the radiator and joins the second cooling water passage, and

a valve whose valve opening temperature is set higher when the Rankine cycle is operated than when the Rankine cycle is not operated and which causes the cooling water to flow into the bypass cooling water passage without causing the cooling water to flow into the radiator in a valve closing state and causes the cooling water to flow into the radiator in a valve opening state.

9. The engine-waste-heat utilization device according to claim 8, wherein:

the valve opening temperature of the valve when the engine has a high load is set at the same value as when the Rankine cycle is not operated.

11. The engine-waste-heat utilization device according to claim 8, wherein:

the heat exchanger is provided in the bypass cooling water passage and performs heat exchange between the cooling water flowing in the bypass cooling water passage and the refrigerant.

10. An engine-waste-heat utilization device, comprising:

a Rankine cycle which includes a heat exchanger through which cooling water coming out from an engine flows to recover waste-heat of the engine to refrigerant, an expander which generates power using the refrigerant coming out from the heat exchanger, a condenser which condenses the refrigerant coming out from the expander and a refrigerant pump which supplies the refrigerant coming out from the condenser to the heat exchanger; and

a cooling water passage which includes a first cooling water passage which supplies the cooling water coming out from the engine to a radiator, a second cooling water passage which returns the cooling water coming out from the radiator to the engine, a bypass cooling water passage which is branched off from the first cooling water passage, bypasses the radiator and joins the second cooling water passage, and

a valve whose valve opening temperature is set smaller when the Rankine cycle is operated than when the Rankine cycle is not operated and which causes the cooling water to flow into the bypass cooling water passage without causing the cooling water to flow into the radiator in a valve closing state and causes the cooling water to flow into the radiator in a valve opening state.

12. An engine-waste-heat utilization device, comprising:

a cooling water passage in which cooling water having a higher temperature flows when a rotation speed of an engine is not higher than a predetermined rotation speed than when the rotation speed of the engine is higher than the predetermined rotation speed; and

a Rankine cycle which includes a heat exchanger through which the cooling water coming out from the engine flows to recover waste-heat of the engine to refrigerant, an expander which generates power using the refrigerant coming out from the heat exchanger, a condenser which condenses the refrigerant coming out from the expander and a refrigerant pump which supplies the refrigerant coming out from the condenser to the heat exchanger, and is operated when the rotation speed of the engine is not higher than the predetermined rotation speed while being not operated when the rotation speed of the engine is higher than the predetermined rotation speed.