Exhaust aftertreatment system with heated flash-boiling doser

Patent metadata

Field	Value
Publication number	US-11022014-B1
Application number	US-202016860721-A
Country	US
Kind code	B1
Filing date	Apr 28, 2020
Priority date	Apr 28, 2020
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

An exhaust aftertreatment system for use with an over-the-road vehicle is disclosed. The exhaust aftertreatment system includes a flash-boil doser mounted to an exhaust conduit and a catalyst coupled to the exhaust conduit. The flash-boil doser configured to inject heated and pressurized reducing agent into an exhaust passageway defined by the exhaust conduit for distribution throughout exhaust gases passed through the exhaust conduit. The catalyst configured to react the reducing agent with the nitrous oxide in the flow of exhaust gases to provide treated exhaust gases with a reduced nitrous oxide amount.

First claim

The invention claimed is:

1. An automotive exhaust aftertreatment system for dosing heated reducing agent into a flow of exhaust gases to reduce nitrous oxides in the flow of exhaust gases, the system comprising
an exhaust conduit defining an exhaust passageway for receiving the flow of exhaust gases therein,
a flash-boil doser mounted to the exhaust conduit and configured to heat a reducing agent to drive the reducing agent to a predetermined pressure and to inject the reducing agent into the flow of exhaust gases in the exhaust conduit upon reaching the predetermined pressure, the flash-boil doser including a doser body that defines a flash-boil chamber, an active heating element configured to produce heat from electrical energy to heat the reducing agent in the flash-boil chamber, and a passive heat exchanger configured to withdraw heat from exhaust gases to heat the reducing agent in the flash-boil doser,
a catalyst coupled to the exhaust conduit and configured to react the reducing agent with the nitrous oxides in the flow of exhaust gases to provide treated exhaust gases with a reduced nitrous oxide amount, and
a waste heat recovery system fluidly coupled to the exhaust conduit downstream of the catalyst and configured to selectively transfer heat from the treated exhaust gases directly to the flash-boil doser, wherein the waste heat recovery system is fluidly coupled to the passive heat exchanger to provide the heat from the treated exhaust gases to the passive heat exchanger to heat the reducing agent in the flash-boil chamber and at least reduce an amount of electrical power used by the active heating element to heat the reducing agent in the flash-boil chamber.

2. The system of claim 1 , wherein the waste heat recovery system includes a heat exchanger inlet valve fluidly connected between the exhaust passageway and the passive heat exchanger of the flash-boil doser to selectively provide a flow of treated exhaust gases to the passive heat exchanger and a heating system controller coupled to the heat exchanger inlet valve and configured to selectively open and close the heat exchanger inlet valve to control the flow of treated exhaust gases to the passive heat exchanger to manage the heat provided by the passive heat exchanger to the reducing agent in the flash-boil chamber.

3. The system of claim 2 , wherein the waste heat recovery system further includes a temperature sensor coupled to the exhaust passageway to measure a temperature of the treated exhaust gases in the exhaust passageway and the heating system controller is configured to direct the heat exchanger inlet valve to open in response to the temperature measured by the temperature sensor being above a predetermined value.

4. The system of claim 2 , wherein the waste heat recovery system is coupled to the active heating element of the flash-boil doser and further configured to optionally generate electrical power from the heat of the treated exhaust gases in the exhaust passageway and provide the electrical power generated to the active heating element to heat the reducing agent in the flash-boil chamber.

5. The system of claim 4 , wherein the waste heat recovery system further includes a thermoelectric-generator coupled to the exhaust passageway to receive the treated exhaust gases and generate electrical power from the heat of the treated exhaust gases for the active heating element of the flash-boil doser.

6. The system of claim 5 , wherein the heating system controller is coupled to the thermoelectric-generator and configured to selectively direct the thermoelectric-generator to provide the electrical power generated by the thermoelectric-generator to the active heating element of the flash-boil doser to heat the reducing agent in the flash-boil doser.

7. An automotive exhaust aftertreatment system for dosing reducing agent into a flow of exhaust gases, the system comprising
an exhaust conduit defining an exhaust passageway for receiving the flow of exhaust gases therein,
a flash-boil doser mounted to the exhaust conduit and configured to heat a reducing agent to drive the reducing agent to a predetermined pressure and to inject the reducing agent into the flow of exhaust gases in the exhaust conduit upon reaching the predetermined pressure, the flash-boil doser including a doser body that defines a flash-boil chamber, an active heating element configured to produce heat from electrical energy to heat the reducing agent in the flash-boil chamber, and a passive heat exchanger configured to withdraw heat from exhaust gases to heat the reducing agent in the flash-boil doser,
a catalyst coupled to the exhaust conduit and configured to react the reducing agent with the nitrous oxides in the flow of exhaust gases to provide treated exhaust gases with a reduced nitrous oxide amount, and
a waste heat recovery system fluidly coupled to the exhaust conduit downstream of the catalyst and configured to selectively generate electrical power from the heat of the treated exhaust gases in the exhaust passageway, wherein the waste heat recovery system is coupled to the active heating element of the flash-boil doser to provide the electrical power generated from the heat of the treated exhaust gases to the active heating element to heat the reducing agent in the flash-boil chamber.

8. The system of claim 7 , wherein the waste heat recovery system includes a thermoelectric-generator coupled to the exhaust passageway to receive the treated exhaust gases and generate electrical power from the heat of the treated exhaust gases for the active heating element of the flash-boil doser and a heating system controller coupled to the thermoelectric-generator to selectively provide electrical power from the thermoelectric-generator to the active heating element of the flash-boil doser to heat the reducing agent in the flash-boil doser.

9. The system of claim 8 , wherein the waste heat recovery system is coupled to the passive heat exchanger and configure to selectively provide heat of the treated exhaust gases directly to the passive heat exchanger to heat the reducing agent in the flash-boil chamber and at least reduce an amount of electrical power used by the active heating element to heat the reducing agent in the flash-boil chamber.

10. The system of claim 9 , wherein the waste heat recovery system further includes a heat exchanger inlet valve fluidly connected between the exhaust passageway and the passive heat exchanger of the flash-boil doser to selectively provide a flow of treated exhaust gases to the passive heat exchanger, and wherein the heating system controller is coupled to the heat exchanger inlet valve and configured to selectively open and close the heat exchanger inlet valve to control the flow of treated exhaust gases to the passive heat exchanger to manage the heat provided by the passive heat exchanger to the reducing agent in the flash-boil doser.

11. An over-the-road vehicle comprising
an internal combustion engine configured to produce a flow of exhaust gases that are conducted through an exhaust passageway,
an electrical network coupled to the internal combustion engine and configured to generate electrical power from work produced by the internal combustion engine to power electrical components of the over-the-road vehicle, and
an automotive exhaust aftertreatment system configured to treat the flow of exhaust gases, the system comprising
a flash-boil doser mounted to the exhaust passageway and configured to heat the reducing agent to drive the reducing agent to a predetermined pressure and inject the reducing agent into the flow of exhaust gases upon reaching the predetermined pressure, the flash-boil doser including a doser body that d

Assignees

• Faurecia Emissions Control Technologies Usa Llc

Inventors

• Parrish Tony
• Rohde John

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• Y02A50/20

  Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters · CPC title

• F01N2900/1811

  Temperature · CPC title

• F01N5/025

  the device being thermoelectric generators · CPC title

• F01N5/02

  the devices using heat · CPC title