EXHAUST THROTTLING FOR CABIN HEATING

• US 20160339764A1
• Filed: 08/02/2016
• Published: 11/24/2016
• Est. Priority Date: 11/05/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Pursifull, Ross Dykstra
• Granted Patent: US 9,636,973 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60H 1/20 using an intermediate heat-transferring medium
• CPC Class Codes: F01N 11/002 the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
• CPC Class Codes: F01N 2550/02 Catalytic activity of catalytic converters
• CPC Class Codes: F01N 5/02 the devices using heat
• CPC Class Codes: F01P 2060/08 Cabin heater
• 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: F02D 21/08 the other gas being the exhaust gas of engine
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2700/04 Controlling by throttling the exhaust conduit
• CPC Class Codes: F02D 41/0065 Specific aspects of external EGR control constructional details of EGR system F02M26/00
• CPC Class Codes: F02D 41/0077 Control of the EGR valve or actuator, e.g. duty cycle, closed loop control of position EGR valve position sensor F02M26/48
• CPC Class Codes: F02D 9/04 concerning exhaust conduits throttle valves, or arrangements thereof in conduits F02D9/08
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/06 Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor
• CPC Class Codes: F02M 26/07 Mixed pressure loops, i.e. wherein recirculated exhaust gas is either taken out upstream of the turbine and reintroduced upstream of the compressor, or is taken out downstream of the turbine and reintroduced downstream of the compressor
• CPC Class Codes: F02M 26/10 having means to increase the pressure difference between the exhaust and intake system, e.g. venturis, variable geometry turbines, check valves using pressure pulsations or throttles in the air intake or exhaust system
• CPC Class Codes: F02M 26/24 with two or more coolers
• CPC Class Codes: F02M 26/27 with air-cooled heat exchangers
• CPC Class Codes: F02M 26/30 Connections of coolers to other devices, e.g. to valves, heaters, compressors or filters; Coolers characterised by their location on the engine
• CPC Class Codes: F02M 26/44 in which a main EGR passage is branched into multiple passages
• CPC Class Codes: F02M 26/47 : the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: F02N 2200/0804 : Temperature inside the vehicle cabin
• CPC Class Codes: F02P 5/15 : Digital data processing
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 : Engine management systems

Abstract

Embodiments for heating a vehicle cabin are disclosed. In one example, a method for heating a vehicle cabin comprises closing an exhaust throttle while diverting at least a portion of throttled exhaust gas through an exhaust gas recirculation (EGR) cooler coupled upstream of the throttle, and transferring heat from the EGR cooler to a heater core configured to provide heat to the vehicle cabin. In this way, exhaust heat may be directly routed to the cabin heating system.

Claims

1. A method for heating a vehicle cabin comprising:

closing an exhaust throttle while diverting at least a portion of throttled exhaust gas through an exhaust gas recirculation (EGR) cooler coupled upstream of the throttle, the throttle coupled downstream of an exhaust catalyst;

transferring heat from the EGR cooler to a heater core to provide heat to the vehicle cabin;

while a temperature of the exhaust catalyst is below a threshold temperature and while the exhaust throttle is closed, retarding spark ignition timing; and

while diverting exhaust gas through the EGR cooler, generating vacuum by flowing gas through an ejector.

2. The method of claim 1, wherein an amount of spark retard adjusted based on the temperature of the exhaust catalyst while the temperature of the exhaust catalyst is below the threshold temperature.

3. The method of claim 1, wherein the flow through the ejector is exhaust gas flow.

4. The method of claim 1, wherein transferring heat from the EGR cooler to the heater core comprises operating a heater core circulation pump to pump coolant from the EGR cooler through the heater core, and adjusting a flow rate of the heater core circulation pump based on an inlet temperature of the heater core.

5. The method of claim 2, further comprising routing the coolant from the heater core to an engine before returning the coolant to the EGR cooler.

6. The method of claim 1, wherein the ejector is coupled between from an EGR passage downstream of the EGR cooler to the exhaust downstream of the exhaust throttle.

7. The method of claim 1, wherein the engine includes a boosting device.

8. The method of claim 1, further comprising, after the temperature of the exhaust catalyst is above the threshold temperature, maintaining the exhaust throttle closed while advancing spark ignition timing.

9. The method of claim 1, further comprising, after the temperature of the exhaust catalyst is above the threshold temperature, adjusting the exhaust throttle based on an inlet temperature of the heater core.

10. The method of claim 9, wherein the adjusting includes, as the inlet temperature of the heater core increases, shifting the exhaust throttle from a more closed position to a more open position.

12. The system of claim 1, wherein the controller further including instructions to, during a cabin heating mode, adjust a flow rate of coolant into a heater core based on a determined relationship between a temperature drop across the heater core and the flow rate of coolant into the heater core, the adjustments including coordination of exhaust throttling and heater core circulation pump adjustments.

13. The vehicle system of claim 12, wherein the controller further includes instructions to, during the cabin heating mode, close the exhaust throttle and the EGR valve to push throttled exhaust through the EGR cooler and back to the exhaust via the EGR bypass to heat the EGR cooler.

14. The vehicle system of claim 13, wherein the controller includes further instructions to adjust a flow rate of the coolant based on a heater core inlet temperature.

15. The vehicle system of claim 14, wherein the controller includes further instructions to deactivate the circulation pump when the heater core inlet temperature is below a threshold temperature and activate the circulation pump when the heater core inlet temperature is above the threshold temperature.

11. A vehicle system, comprising:

an engine including an intake and an exhaust;

an exhaust gas recirculation (EGR) passage coupling the exhaust to the intake, the EGR passage including an EGR cooler and an EGR valve;

an EGR bypass coupled across the EGR cooler;

a cabin heating system including a heater core and a circulation pump configured to pump coolant from the EGR cooler to the heater core;

an exhaust throttle positioned in the exhaust downstream of an inlet of the EGR passage and upstream of an outlet of the EGR bypass,

an ejector coupled from the EGR passage downstream of the EGR cooler to the exhaust downstream of the exhaust throttle; and

a controller including instructions to, while a temperature of an exhaust catalyst is below a threshold temperature and while the exhaust throttle is closed, retard spark ignition timing, an amount of spark retard adjusted based on the temperature of the exhaust catalyst,

wherein the exhaust throttle is coupled downstream of the exhaust catalyst.

16. A method, comprising:

adjusting a flow rate of coolant pumped from an exhaust gas recirculation (EGR) cooler to a cabin heating system heater core based on an inlet temperature of the heater core;

during select conditions, throttling exhaust gas to increase exhaust pressure and to route the exhaust gas through the EGR cooler, heat from the exhaust gas transferred to the heater core via the EGR cooler, wherein the flow rate is further adjusted based on a determined change in temperature across the cooler after unthrottling the exhaust gas responsive to a temperature of the heater core reaching a threshold; and

flowing throttled exhaust gas through an ejector.

17. The method of claim 16, wherein the select conditions comprise one or more of only when an exhaust catalyst temperature is below a first threshold temperature and the inlet temperature of the heater core is below a second threshold temperature, the method further comprising boosting intake air to the engine.

18. The method of claim 16, wherein throttling the exhaust gas comprises closing an exhaust throttle positioned in the engine exhaust, the method further comprising responsive to an EGR valve downstream of the EGR cooler being closed, routing the throttled exhaust from the EGR cooler back to the engine exhaust, downstream of the exhaust throttle, via an EGR bypass.

19. The method of claim 18, further comprising responsive to the EGR valve being at least partially open, routing exhaust from the EGR cooler to an engine intake.

20. The method of claim 16, wherein adjusting a flow rate of coolant based on the inlet temperature of the heater core further comprises operating a heater core circulation pump to route coolant to the heater core only when a temperature of the coolant at an outlet of the EGR cooler is above a threshold temperature.