Rapid warm-up schemes of engine and engine coolant for higher fuel efficiency

Patent metadata

Field	Value
Publication number	US-10082047-B2
Application number	US-201514979461-A
Country	US
Kind code	B2
Filing date	Dec 27, 2015
Priority date	Dec 27, 2015
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

A system for rapidly heating a vehicle engine when the engine is below a pre-determined temperature allows for improved fuel efficiency after a vehicle cold-start. The system includes an organic Rankine cycle (ORC) loop having a two-phase ORC fluid traveling circuitously through a conduit. The ORC fluid is vaporized by a power electronics cooling device and by an evaporator in thermal communication with exhaust waste heat. The vaporized ORC fluid is passed through an expander to generate electrical power. When the vehicle engine is below the pre-determined temperature, heat from the vaporized ORC fluid is transferred directly or indirectly to the engine. When the vehicle engine is at or above the pre-determined temperature, heat from the vaporized ORC fluid is instead transferred to an alternate heat sink.

First claim

What is claimed is:

1. A system for rapidly heating a vehicle engine, the system comprising:
an engine block;
an evaporator;
an expander;
a condenser;
a heat sink in fluid communication with the condenser;
an organic Rankine cycle (ORC) loop comprising:
an ORC fluid conduit in direct thermal communication with the evaporator, the expander, the condenser, and the engine block, the ORC fluid conduit being configured to direct an ORC fluid through a circuit, the ORC loop being configured to selectively:
direct ORC fluid from the evaporator and through the expander to create a vaporized ORC fluid, the vaporized ORC fluid being directed through the engine block when the engine is operating below a pre-determined temperature; and
direct ORC fluid from the evaporator and through the expander to create a vaporized ORC fluid, the vaporized ORC fluid being directed through the condenser and the heat sink, configured to remove heat from low pressure vaporized ORC fluid to create a condensed ORC fluid, the condensed ORC fluid being directed through the engine block when the engine is operating at or above the pre-determined temperature; and

a power electronics cooler in thermal communication with the ORC fluid circuit to at least partially vaporize the ORC fluid.

2. The system as recited in claim 1 , wherein the expander is in mechanical communication with an electric generator configured to produce electrical power.

3. The system as recited in claim 1 , wherein the ORC loop further comprises a plurality of valves configured to selectively direct low pressure vaporized ORC fluid to:
a first valve in fluid communication with the engine when the engine is below the pre-determined temperature; and
a second valve in fluid communication with a heat sink, prior to the engine, when the engine is at or above the pre-determined temperature.

4. The system as recited in claim 1 , wherein the engine block comprises a dual layered jacket defining a first chamber in thermal communication with engine cylinders and in fluid communication with an engine coolant loop, the first chamber configured to absorb heat from the engine cylinders.

5. The system as recited in claim 4 , wherein the dual layered jacket further defines a second chamber in thermal contact with the first chamber and in fluid communication with the ORC fluid conduit, the second chamber selectively forming an insulative layer when filled with vaporized ORC fluid and forming a conductive layer when filled with liquid ORC fluid.

6. A system for rapidly heating a vehicle engine, the system comprising:
an engine block;
an organic Rankine cycle (ORC) loop having an ORC fluid conduit to direct an ORC fluid through a circuit in direct thermal communication with the engine block;
an evaporator to vaporize the ORC fluid;
an expander configured to decrease a pressure of vaporized ORC fluid;
a heat exchanger;
a condenser in fluid communication with the ORC fluid circuit;
an engine coolant loop in thermal communication with the heat exchanger to transfer heat from ORC fluid in the ORC loop to coolant circulating in the engine coolant loop;
a power electronics cooler in thermal communication with the ORC fluid circuit to at least partially vaporize the ORC fluid; and
a heat sink in selective thermal communication with the engine coolant loop;
wherein the engine coolant loop is configured to direct an engine coolant through the circuit that includes the engine block, the engine coolant loop further comprising a first valve configured to direct heated engine coolant through the engine only when the engine is operating below a pre-determined temperature, and a second valve configured to selectively direct heated coolant to the heat sink when the engine is operating at or above the pre-determined temperature.

7. The system as recited in claim 6 , wherein the expander is in mechanical communication with an electric generator.

8. The system as recited in claim 6 , wherein the heat exchanger is positioned within the ORC loop downstream of the expander.

9. The system as recited in claim 6 , wherein the heat exchanger is positioned within the ORC loop upstream of the expander.

10. The system as recited in claim 9 , wherein the ORC loop further comprises a plurality of valves configured to selectively direct ORC fluid through:
the expander when the engine is at or above the pre-determined temperature; and
an expander bypass loop when the engine is below the pre-determined temperature.

11. A system for rapidly heating a vehicle engine, the system comprising:
an engine block;
an organic Rankine cycle (ORC) loop comprising:
an ORC fluid conduit to direct an ORC fluid through a circuit that is in direct thermal communication with the engine block;
a power electronics cooler in thermal communication with the circuit to at least partially vaporize the ORC fluid;
an expander configured to decrease a pressure of the vaporized ORC fluid, the expander being in mechanical communication with an electric generator;
a first plurality of valves configured to direct ORC fluid through the expander when the engine is at or above a pre-determined temperature, and to direct the ORC fluid through an expander bypass loop when the engine is below the pre-determined temperature;

a heat exchanger configured to transfer heat from the vaporized ORC fluid in the ORC loop to coolant circulating in an engine coolant loop, the engine coolant loop in fluid communication with:
the engine block;
a heat sink; and
a second plurality of valves configured to selectively direct heated coolant to the engine when the engine is below a pre-determined temperature, and to the heat sink when the engine is at or above the pre-determined temperature;

wherein the engine block comprises a dual layered jacket defining:
a first chamber in thermal communication with engine cylinders and in fluid communication with the engine coolant loop, the first chamber configured to absorb heat from engine cylinders; and
a second chamber in thermal communication the first chamber and in fluid communication with the ORC fluid conduit, the second chamber forming an insulative layer when filled with vaporized ORC fluid, and forming a conductive layer when filled with liquid ORC fluid.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Joshi Shailesh N
• Dede Ercan Mehmet

Classifications

• F01P2003/021

  Cooling cylinders · CPC title

• F01P3/02

  Arrangements for cooling cylinders or cylinder heads · CPC title

• F02N19/10

  by heating of engine coolants · CPC title

• F02N19/02

  Aiding engine start by thermal means, e.g. using lighted wicks · CPC title

• F01P2060/18

  Heater · CPC title