REAR AXLE LUBRICATION OIL TEMPERATURE CONTROL USING EXHAUST HEAT RECOVERY AND A THERMAL BATTERY

• US 20190331209A1
• Filed: 07/11/2019
• Published: 10/31/2019
• Est. Priority Date: 12/09/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Cole, Cary, Katragadda, Sunil, Bonkoski, Phillip, Bidner, David Karl, Levin, Michael, Buckman, Colby Jason, Demitroff, Danrich Henry, Karnik, Amey Y., Shaikh, Furqan
• Granted Patent: US 11,578,795 B2
• Time in Patent Office: Days
• CPC Class Codes: F16H 57/0417 Heat exchangers adapted or integrated in the gearing
• CPC Class Codes: F28D 20/0034 using liquid heat storage material
• CPC Class Codes: F28D 20/02 using latent heat
• CPC Class Codes: F28D 2021/0089 Oil coolers
• CPC Class Codes: F28D 21/0003 the heat being recuperated from exhaust gases F28D21/0014 takes precedence
• CPC Class Codes: F28F 27/02 for controlling the distribution of heat-exchange media between different channels static flow control means in header boxes F28F9/026; arrangements of guide plates or guide vanes F28F9/22, F28F25/12
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

Methods and systems are provided for regulating the temperature of rear axle lubrication oil. In one example, a rear axle coolant system may include a coolant loop with a plurality of valves and sensors, regulating the coolant flow in heat exchange relationship with an exhaust gas heat recovery and storage system to deliver warm coolant to a rear axle heat exchanger to warm the rear axle lubrication oil. The method may regulate the components of the rear axle coolant system through a controller, receiving sensor input from the components of the coolant system.

Claims

1. A rear axle coolant system, comprising:

an exhaust heat recovery system to transfer heat from an engine exhaust system to a cooling fluid;

a rear-axle heat exchanger to transfer heat between the cooling fluid and rear axle lubrication oil; and

a thermal battery system positioned intermediate the exhaust heat recovery system and the rear-axle heat exchanger, the thermal battery system configured to store excess heat from the exhaust heat recovery system.

2. The rear axle coolant system of claim 1, further comprising a controller storing instructions executable to:

responsive to a first condition, bypass exhaust gas around the exhaust heat recovery system and flow cooling fluid from the thermal battery system to the rear-axle heat exchanger; and

responsive to a second condition, bypass exhaust gas around the exhaust heat recovery system and flow cooling fluid from the exhaust heat recovery system to the rear-axle heat exchanger.

3. The rear axle coolant system of claim 2, wherein the first condition comprises rear axle lubrication oil temperature above a threshold temperature and thermal battery system temperature lower than the rear axle lubrication temperature, and wherein the second condition comprises rear axle lubrication oil temperature above the threshold temperature and thermal battery system temperature equal to or greater than the rear axle lubrication oil temperature.

4. The rear axle coolant system of claim 3, wherein the threshold temperature is a first threshold temperature, and wherein the controller includes further instructions executable to, responsive to a rear axle lubrication oil temperature below a second threshold temperature, lower than the first threshold temperature, direct exhaust gas to the exhaust heat recovery system and flow heated cooling fluid from the exhaust heat recovery system to the rear-axle heat exchanger.

5. The rear axle coolant system of claim 4, further comprising a first valve positioned upstream of the rear-axle heat exchanger, wherein responsive to rear axle lubrication oil temperature being in a range of temperatures between the first threshold temperature and the second threshold temperature, the controller is configured to adjust the first valve to a first position to direct cooling fluid to bypass the rear-axle heat exchanger, and responsive to the first condition and the second condition, the controller is configured to adjust the first valve to a second position to direct cooling fluid to the rear-axle heat exchanger.

6. The rear axle coolant system of claim 5, further comprising a second valve upstream of the thermal battery system, the second valve configured to bypass cooling fluid around the thermal battery system responsive to the second condition, and direct cooling fluid to the thermal battery system responsive to the first condition.

7. The rear axle coolant system of claim 2, wherein the exhaust heat recovery system includes an exhaust gas heat exchanger configured to receive exhaust gas and the cooling fluid and an exhaust gas bypass valve controlling flow of exhaust gas to the exhaust gas heat exchanger, and wherein the controller is configured to actuate the exhaust gas bypass valve to a first position to direct exhaust gas to the exhaust gas heat exchanger, and actuate the exhaust gas bypass valve to a second position to bypass the exhaust gas around the exhaust gas heat exchanger.

8. The rear axle coolant system of claim 7, wherein the controller is configured to adjust the exhaust gas bypass valve responsive to an exhaust gas pressure drop across the exhaust gas heat exchanger.

9. The rear axle coolant system of claim 2, further comprising a first temperature sensor downstream of the thermal battery system and a second temperature sensor downstream of the rear-axle heat exchanger.

10. The rear axle coolant system of claim 9, wherein the controller is configured to determine rear axle lubrication oil temperature based on cooling fluid flow rate and temperature measured by the second temperature sensor and determine thermal battery system temperature based on cooling fluid flow rate and temperature measured by the first temperature sensor.

11. The rear axle coolant system of claim 1, further comprising a pump to circulate cooling fluid.

12-20. -20. (canceled)