U.S. patent application number 14/372256 was filed with the patent office on 2014-11-06 for ammonia gas pressure booster.
This patent application is currently assigned to International Engine Intellectual Property Company LLC. The applicant listed for this patent is Gregory A. Griffin, Ryan Andrew Wacker. Invention is credited to Gregory A. Griffin, Ryan Andrew Wacker.
Application Number | 20140325964 14/372256 |
Document ID | / |
Family ID | 48799535 |
Filed Date | 2014-11-06 |
United States Patent
Application |
20140325964 |
Kind Code |
A1 |
Wacker; Ryan Andrew ; et
al. |
November 6, 2014 |
AMMONIA GAS PRESSURE BOOSTER
Abstract
A system and method for delivering a reductant into an engine
exhaust stream for use in the reduction of NO.sub.x is disclosed.
The system includes a cartridge having an interior space for
storing the reductant containing material, a fluid supply line
fluidly connected to the cartridge for receiving the reductant, a
pressure boosting device for boosting the flow of reductant, a flow
management device, and, an injector for injecting the reductant
into an after-treatment system for combining with the exhaust
stream. The reductant may include ammonia. Use of the pressure
boosting device increases the reductant pressure into the
aftertreatment system, providing for a reduction in the time to
inject the reductant into the exhaust stream, while improving the
distribution of reductant into the exhaust stream.
Inventors: |
Wacker; Ryan Andrew;
(Marengo, IL) ; Griffin; Gregory A.; (Glendale
Heights, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wacker; Ryan Andrew
Griffin; Gregory A. |
Marengo
Glendale Heights |
IL
IL |
US
US |
|
|
Assignee: |
International Engine Intellectual
Property Company LLC
Lisle
IL
|
Family ID: |
48799535 |
Appl. No.: |
14/372256 |
Filed: |
January 18, 2012 |
PCT Filed: |
January 18, 2012 |
PCT NO: |
PCT/US12/21644 |
371 Date: |
July 15, 2014 |
Current U.S.
Class: |
60/274 ;
60/295 |
Current CPC
Class: |
F01N 3/208 20130101;
Y02T 10/12 20130101; Y02A 50/2325 20180101; F01N 3/2066 20130101;
F01N 2610/02 20130101; F01N 2610/06 20130101; F01N 2610/1433
20130101; Y02T 10/24 20130101 |
Class at
Publication: |
60/274 ;
60/295 |
International
Class: |
F01N 3/20 20060101
F01N003/20 |
Claims
1. A system for delivering a reductant into an engine exhaust
stream, the system comprising: a canister having an interior space
for storing a reductant containing material; a fluid supply line
fluidly connected to the canister for receiving the reductant; a
pressure boosting device for boosting the flow of reductant; a flow
management device; and, an injector for injecting the reductant
into an after-treatment system for combining with the exhaust
stream.
2. The system of claim 1, wherein the reductant containing material
is an adsorbing/desorbing material.
3. The system of claim 1, wherein the reductant is ammonia.
4. The system of claim 1, wherein the pressure boosting device is a
pump integrated into the fluid supply line.
5. The system of claim 4, wherein the pump is positioned between
the canister and the flow management device.
6. The system of claim 4, wherein the pump increases a pressure of
the reductant at the injector.
7. The system of claim 4, wherein the pump decreases injection time
of the reductant into the exhaust stream.
8. A method for reducing NO.sub.x in an exhaust gas stream of a
diesel-engine vehicle, the method comprising the steps of: fluidly
coupling components of an exhaust gas NO.sub.x reduction system
package to an engine exhaust gas system, the components comprising:
a cartridge having an interior space for storing a reductant
containing material; a conduit fluidly connected to the cartridge
for receiving the reductant upon release from the material; a
pressure boosting device for boosting the pressure of the
reductant; a flow management device; and, an injector for injecting
the reductant into the exhaust stream increasing the flow of
reductant through the pump and the flow management device;
injecting gaseous ammonia into the engine exhaust gas system
through the injector; and, reacting the reductant with the engine
exhaust gas stream reducing the level of NO.sub.x in the exhaust
gas stream.
9. The method of claim 8, wherein the pressure boosting device is a
pump integrated within the conduit and positioned between the
cartridge and the flow management device.
10. The method of claim 9, wherein the pump increases the pressure
of the reductant at the injector.
Description
TECHNICAL FIELD
[0001] The present system and method relates to the delivery of a
reducing agent or reductant into the exhaust stream of a vehicle
for reduction of NO.sub.x in the exhaust stream. Particularly, the
system and method relates to the addition of a pressure boosting
device within the reductant supply line to increase the pressure of
reductant and improve reductant distribution within the exhaust
stream.
BACKGROUND
[0002] Compression ignition engines provide advantages in fuel
economy, but produce both NO and particulates during normal
operation. New and existing regulations continually challenge
manufacturers to achieve good fuel economy and reduce the
particulates and NO.sub.x emissions. Lean-burn engines achieve the
fuel economy objective, but the high concentrations of oxygen in
the exhaust of these engines yields significantly high
concentrations of NO.sub.x as well. Accordingly, the use of NO
reducing exhaust treatment schemes is being employed in a growing
number of systems.
[0003] One such system is the direct addition of a reductant or
reducing agent, such as ammonia gas, to the exhaust stream. It is
an advantage to deliver ammonia directly into the exhaust stream in
the form of a gas, both for simplicity of the flow control system
and for efficient mixing of the reducing agent, ammonia, with the
exhaust gases. The direct use of ammonia also eliminates potential
difficulties related to blocking of the dosing system, which may be
caused by precipitation or impurities, e.g., in a liquid-based urea
solution. In addition, an aqueous urea solution cannot be dosed at
a low engine load since the temperature of the exhaust line would
be too low for complete conversion of urea to ammonia (and
CO.sub.2).
[0004] A couple specific challenges with the direct injection of a
gaseous reductant, such as ammonia, relate to dispersion and mixing
of the reductant or reducing agent with the hot exhaust gases.
Generally, the cartridge storing the reductant-containing material
needs to be heated to a sufficient temperature level so that the
released reductant has enough pressure to overcome the pressure of
the exhaust stream upon injection. Thus, the dispersion issue
considers how to deliver or spread ammonia to the greatest volume
of flowing exhaust, while the mixing issue concerns how to create
the most homogenous mixture of exhaust and ammonia to facilitate
NO.sub.x reduction.
[0005] Thus, the present system and method provide for a reduction
in the time required to inject the reductant into the exhaust
stream, as well as, improving the distribution of the reductant
into the exhaust stream. Additionally, the present system and
method result in a reduction in energy requirements for heating the
cartridges and reductant-containing material to the necessary
level. These and other problems are addressed and resolved by the
disclosed system and method.
SUMMARY
[0006] There is disclosed herein a system and method which avoids
the disadvantages of prior devices and methods while affording
additional structural and operating advantages.
[0007] Generally, a system for delivering a reductant into an
engine exhaust stream, is disclosed. The system comprises a
canister having an interior space for storing the reductant
containing material, a fluid supply line fluidly connected to the
canister for receiving the reductant, a pressure boosting device
for boosting the flow of reductant a flow management device, and,
an injector for injecting the reductant into an after-treatment
system for combining with the exhaust stream.
[0008] In an embodiment of the system, the pressure boosting device
is a pump integrated within the fluid supply line.
[0009] In another embodiment of the system, the pump is integrated
within the fluid supply line between the cartridge and the
injector.
[0010] A method for reducing NO.sub.x in an exhaust gas stream of a
diesel-engine vehicle, is disclosed. The method comprises the steps
of fluidly coupling components of an exhaust gas treatment system
package to an engine exhaust gas system, wherein the components
comprise a cartridge having an interior space for storing a
reductant containing material, a conduit fluidly connected to the
cartridge for receiving the reductant upon release from the
material, a pressure boosting device for boosting the pressure of
the reductant, a flow management device; and, an injector for
injecting the reductant into the exhaust stream. The method further
comprises the steps of increasing the flow of reductant through the
pump and the flow management device, injecting gaseous ammonia into
the engine exhaust gas system through the injector, and, reacting
the reductant with the engine exhaust gas stream reducing the level
of NO.sub.x in the exhaust gas stream.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic of an exhaust gas NO.sub.x reduction
(EGNR) system;
[0012] FIG. 2 is a schematic of the ASDS portion of the EGNR
incorporating the pressure boosting device of the present
system.
DETAILED DESCRIPTION
[0013] Referring to FIG. 1, there is illustrated the general
components of a reductant storage and dosing system, specifically
an exhaust gas NO.sub.x reduction (EGNR) system 10, which includes
an ammonia storage and delivery system (ASDS) 50. The ASDS 50
involves delivery of gaseous ammonia to an after-treatment assembly
60, which is used in the reduction of NO.sub.x in an engine exhaust
gas stream as part of the EGNR system 10 found on combustion engine
vehicles. The ASDS 50 is comprised of several components, including
at least one ammonia-containing main canister or cartridge 20,
which may be contained within a housing or storage compartment (not
shown), an ammonia-containing start-up canister or cartridge 24
located on the outside of the housing, an ammonia flow module (AFM)
26, a peripheral interface module (PIM) 30, and possibly other
components depending on vehicle specifications.
[0014] In addition to the ASDS 50, the EGNR 10 includes vehicle
engine components, including an electronic control module 32. The
specific components of the ASDS 50 and EGNR will not be discussed
in further detail with the exception of discussing, as necessary,
how a component or system may relate to the present system and
method. Further, as the vehicle ignition system and the vehicle
exhaust system, including those used on a diesel engine vehicle,
are well-known, these systems also will not be described in
detail.
[0015] In the ASDS system, the components for storing a reductant
or reducing agent, including an ammonia adsorbing/desorbing
material (not shown), stored within a main canister or cartridge
20. The present system may include a start-up canister 24,
generally useful for the initial release of reductant into the
exhaust stream before the main canister 20 or canisters reach the
required temperature level to release its reductant. As heat is
necessary to release the reductant or reducing agent from the
adsorbing/desorbing material within the cartridge, it is useful to
have a heating source, such as through an electrical source or an
engine coolant sourced heater. Alternatively, the cartridge 20 may
be placed within a heating unit or jacket or other type of housing
for storage, heating and transport (not shown).
[0016] The ammonia adsorbing/desorbing material loaded into the
main and start-up cartridges 20 and 24, respectively, is generally
in a solid form, such as a compressed powder or granules, and may
include any suitable shape for packing into the cartridges,
including balls, granules, or a tightly-packed powder formed as a
disk. Suitable adsorbing/desorbing material for use with the
present system include metal-ammine salts, which offer a solid
storage medium for ammonia, and represent a safe, practical and
compact option for storage and transportation of ammonia. Ammonia
may be released from the metal ammine salt by heating the salt to
temperatures in the range from 10.degree. C. to the melting point
to the metal ammine salt complex, for example, to a temperature
from 30.degree. to 150.degree. C. Generally speaking, metal ammine
salts useful in the present device include the general formula
M(NH.sub.3).sub.nX.sub.z, where M is one or more metal ions capable
of binding ammonia, such as Li, Mg, Ca, Sr, V, Cr, Mn, Fe, Co, Ni,
Cu, Zn, etc., n is the coordination number usually 2-12, and X is
one or more anions, depending on the valence of M, where
representative examples of X are F, Cl, Br, I, SO.sub.4, MoO.sub.4,
PO.sub.4, etc. Preferably, ammonia saturated strontium chloride,
Sr(NH.sub.3)Cl.sub.2, is used. While embodiments using ammonia as
the preferred reductant are disclosed, the disclosure is not
limited to such embodiments, and other reductants may be utilized
instead of, or in addition to, ammonia for carrying out the system
and method disclosed and claimed herein. Examples of such other, or
additional reductants include, but are not limited to, urea, and
ammonium carbamate.
[0017] As noted above, in order to use ammonia gas in the treatment
of NO.sub.x in an exhaust system, it is necessary to apply a
sufficient amount of heat to the cartridges and the contained
ammonia adsorbing/desorbing material, in order to release the
ammonia into its useful gaseous form. Once released, the ammonia
gas is delivered to the exhaust stream by way of a fluid tubing or
conduit 34 connected at one end to the ammonia source (main or
start-up canister) 20, 24 and at the other end to an injector 62
positioned within the after-treatment assembly 60 (FIGS. 1 and 2).
Prior to reaching the injector, the reductant flows through a flow
management device (ammonia flow modulator-AFM) 26. The AFM 26
generally comprises a housing 28 having an inlet 28a, 28b for each
of the start-up unit 24 and main unit 20, respectively, and an
outlet 28c leading to the injector 62 and the after-treatment
assembly 60. The AFM may also include a plurality of check valves,
control valves and pressure release valves, as well as, a plurality
of circuits and sensors, all of which are designed to facilitate
the flow of a sufficient amount of ammonia gas to the exhaust
after-treatment assembly 60.
[0018] In the present system, in order to increase the pressure and
reduce the time for injecting the reductant into the exhaust
stream, a pressure boosting device 100 is added to the system.
Specifically, a pressure boosting device 100 is integrated to the
fluid supply line 34. As shown in FIG. 2, the pressure boosting
device 100 is a pump, which is integrated into the fluid supply
line between the reductant source (main and start-up cartridges 20,
24) and the AFM 26. The addition of the pressure boosting device
100 results in an increase in the pressure of the reductant at the
injector 62. Prior to use of the present pressure boosting device,
the cartridges in the system needed to be heated to a level
sufficient to create enough ammonia gas pressure to overcome the
pressure of the exhaust stream. Addition of the pressure boosting
device 100 increases pressure of the reductant for injection into
the exhaust stream when the cartridge 20, 24 pressure is still
below the pressure of the exhaust stream. Use of the pressure
boosting device 100 allows for shorter periods of time before
reductant can be injected and a reduction in energy required to
heat the cartridge. The increase in reductant gas pressure at the
injector 62 will also result in improved reductant distribution
within the after-treatment system 60. Operation of the pressure
boosting device 100 will be controlled by the electronic control
module (ECM) 32 and powered by the vehicle's electrical system (not
shown). Overall, use of the pressure boosting device results in
shorter warm-up periods before reductant can be injected into
exhaust streams, better distribution of reductant into the exhaust
stream, and a reduction in the energy requirement to electrically
heat the cartridge of the ASDS.
[0019] The present pressure boosting device 100 is useful in a
method that reduces the amount of time need for the ASDS to be able
to inject a reductant, such as ammonia, into the exhaust stream,
while also improving the distribution of reductant in the exhaust
stream. The present method includes the steps of fluidly coupling
components of an exhaust gas NO.sub.x reduction (EGNR) system
package to an engine exhaust gas system, wherein the components
comprise a cartridge 20 having an interior space for storing a
reductant containing material, a conduit 34 fluidly connected to
the cartridge for receiving the reductant upon release from the
material, a pressure boosting device 100 for boosting the flow of
reductant, a flow management device 26, and, an injector 62 for
injecting the reductant into the exhaust stream flowing through an
after-treatment assembly 60. The method further includes increasing
the pressure of reductant through the pressure boosting device and
the flow management device, injecting gaseous ammonia into the
engine exhaust gas system through the injector, and, reacting the
reductant with the engine exhaust gas stream thereby reducing the
level of NO.sub.x in the exhaust gas stream. In the present method,
the pressure boosting device is a pump, which is integrated into
the reductant supply line or conduit between the cartridge and the
flow management device.
* * * * *