U.S. patent application number 13/316261 was filed with the patent office on 2013-03-28 for urea heating system and heating method thereof.
This patent application is currently assigned to KIA MOTORS CORPORATION. The applicant listed for this patent is Dea Gil Hwang, Dong Myoung RYOO, Buyeol Ryu. Invention is credited to Dea Gil Hwang, Dong Myoung RYOO, Buyeol Ryu.
Application Number | 20130074479 13/316261 |
Document ID | / |
Family ID | 47827622 |
Filed Date | 2013-03-28 |
United States Patent
Application |
20130074479 |
Kind Code |
A1 |
RYOO; Dong Myoung ; et
al. |
March 28, 2013 |
UREA HEATING SYSTEM AND HEATING METHOD THEREOF
Abstract
A urea solution heating device prevents freezing of a urea
solution by using exhaust gas of an engine. More particularly, a
urea solution heating device may use a pressure difference between
an exhaust gas pipe and a muffler to bypass the exhaust gas to
exchange heat between the exhaust gas and the urea solution. The
urea solution heating device may include an exhaust gas pipe, a
muffler, a first bypass pipe diverged from the exhaust gas pipe, a
urea solution tank to which the bypassed exhaust gas is supplied, a
second bypass pipe connected to the muffler, and a heat exchanger,
wherein the exhaust gas sequentially flows through the first bypass
line, the heat exchanger, and the second bypass line by a pressure
difference between the exhaust gas pipe and the muffler. An urea
solution heating method is also described.
Inventors: |
RYOO; Dong Myoung;
(Yongin-si, KR) ; Ryu; Buyeol; (Hwaseong-si,
KR) ; Hwang; Dea Gil; (Suwon-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RYOO; Dong Myoung
Ryu; Buyeol
Hwang; Dea Gil |
Yongin-si
Hwaseong-si
Suwon-si |
|
KR
KR
KR |
|
|
Assignee: |
KIA MOTORS CORPORATION
Seoul
KR
HYUNDAI MOTOR COMPANY
Seoul
KR
|
Family ID: |
47827622 |
Appl. No.: |
13/316261 |
Filed: |
December 9, 2011 |
Current U.S.
Class: |
60/287 |
Current CPC
Class: |
F01N 3/2066 20130101;
F01N 2230/00 20130101; F01N 2610/10 20130101; F01N 2610/1406
20130101; Y02T 10/24 20130101; Y02T 10/12 20130101 |
Class at
Publication: |
60/287 |
International
Class: |
F01N 9/00 20060101
F01N009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2011 |
KR |
10-2011-0097125 |
Claims
1. A urea solution heating device, comprising: an exhaust gas pipe
through which exhaust gas of an engine is exhausted; a muffler
connected to one end of the exhaust gas pipe to exhaust the exhaust
gas outside; a first bypass pipe diverging from the exhaust gas
pipe to bypass the exhaust gas; a urea solution tank filled with
urea solution to which the bypassed exhaust gas is supplied; a
second bypass pipe connected to the muffler and that supplies the
exhaust gas passing the urea solution tank to the muffler; and a
heat exchanger disposed in the urea solution tank to connect the
first bypass pipe with the second bypass and through which the
exhaust gas flows such that the exhaust gas heats the urea
solution, wherein the exhaust gas sequentially flows through the
first bypass line, the heat exchanger, and the second bypass line
by a pressure difference between the exhaust gas pipe and the
muffler.
2. The urea solution heating device of claim 1, wherein a solenoid
valve is disposed on the first bypass pipe to selectively bypass
the exhaust gas.
3. The urea solution heating device of claim 2, wherein a
temperature sensor is disposed on the urea solution tank to detect
the temperature of the urea solution.
4. The urea solution heating device of claim 3, further comprising
a dosing control unit (DCU) connected to the solenoid valve and the
temperature sensor, and receives a temperature signal of the urea
solution from the temperature sensor to operate the solenoid
valve.
5. The urea solution heating device of claim 1, wherein an
insulating member is disposed in the urea solution tank, both ends
of the insulating member are opened and urea solution housing holes
are formed in a side surface thereof, and one of the ends is
engaged with a urea solution tank cap to be closed.
6. The urea solution heating device of claim 5, wherein the heat
exchanger is disposed inside the insulating member.
7. The urea solution heating device of claim 6, wherein the heat
exchanger is made by bending a pipe having a predetermine length
several times such that the urea solution exchanges heat with the
exhaust gas flowing in the heat exchanger.
8. The urea solution heating device of claim 6, wherein the heat
exchanger includes two ends, and an exhaust gas suction hole is
formed in one end and an exhaust gas outlet is formed in the other
end.
9. The urea solution heating device of claim 8, wherein the exhaust
gas suction hole is connected to the first bypass pipe through the
urea solution tank cap, and the exhaust gas outlet is connected to
the second bypass line through the urea solution tank cap.
10. The urea solution heating device of claim 5, wherein a urea
solution outlet is formed on the urea solution tank cap such that
the urea solution of the urea solution tank is exhausted
outside.
11. The urea solution heating device of claim 10, wherein a urea
solution pump is disposed at a surface of an interior direction of
the insulating member of the area solution tank cap to exhaust the
urea solution in the urea solution tank to the outside through the
urea solution outlet.
12. The urea solution heating device of claim 5, wherein a sealing
member is disposed between an interior circumference of the urea
solution tank cap and an exterior circumference of the insulating
member to prevent leakage of the urea solution.
13. The urea solution heating device of claim 4, wherein a pressure
sensor is disposed at one end of the first bypass pipe diverged
from the exhaust gas pipe and at one end of the second bypass pipe
connected to the muffler to detect exhaust gas pressure of the
exhaust gas pipe and the muffler.
14. The urea solution heating device of claim 13, wherein the DCU
is connected to the pressure sensors to open the solenoid valve
when the pressure difference between the exhaust gas pipe and the
muffler is larger than a predetermined value.
15. A urea solution heating method, in a urea solution heating
device that includes an exhaust gas pipe exhausting exhaust gas of
an engine, a muffler connected to the exhaust gas pipe, a urea
solution tank filled with a urea solution, a bypass pipe diverging
from the exhaust gas pipe to be connected to the muffler through
the urea solution tank, and a solenoid valve that selectively
open/closes the bypass pipe, comprising the steps of: determining
whether a rotation speed of the engine is faster than an idle
rotation speed of the engine (S100); determining whether a urea
solution temperature is less than a predetermined value through a
temperature sensor disposed in the urea solution tank (S110);
determining whether a rotation speed of the engine is slower than a
maximum rotation speed of the engine (S120); determining whether a
load of the engine is less than a permissible value (S130); opening
the solenoid valve if steps S100, S110, S120, and S130 are
satisfied (S150); closing the solenoid valve if one of steps S100,
S110, S120, and S130 is not satisfied (S160); and performing the
procedures from step S100 again if step S150 or step S160 is
performed.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 10-2011-0097125 filed Sep. 26, 2011,
the entire contents of which application is incorporated herein for
all purposes by this reference.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a urea solution heating
device. More particularly, the present invention relates to a urea
solution heating device that prevents freezing of a urea solution
by using exhaust gas of an engine, and a method thereof.
[0004] 2. Description of Related Art
[0005] Generally, a post-treatment art for exhaust gas is applied
to reduce NOx emissions of a diesel engine. Recently, a new type of
post-treatment art has been introduced to satisfy exhaust gas
regulations such as EURO4 and EURO5. The post-treatment art is a
method for reducing harmful material of exhaust gas that domestic
and foreign countries closely pay attention to, and representative
thereof are an EGR system and a urea-SCR system. Particularly, the
urea-SCR system is an art that has been most widely used among the
introduced post-treatment arts, in which a urea solution is
injected to reduce NOx of exhaust gas, and fuel consumption
efficiency, activation temperature, and purification rate thereof
are relatively excellent.
[0006] More specifically, the urea-SCR (selective catalytic
reduction) system reduces NOx of exhaust gas pollutants (HC, CO,
PM, and NOx) of a diesel engine, wherein a urea solution is
injected into the exhaust gas and the injected urea solution is
transformed into NH3 and HNCO by the heat of the exhaust gas.
Further, the HNCO is resolved by water of the exhaust gas to NH3
and CO2, and the NH3 reacts with NOx through a catalyst to become
N2 and H2O.
[0007] However, the urea solution is frozen at lower than minus 11
degrees Celsius, and the frozen urea solution can cause a fatal
defect in the urea-SCR system. Accordingly, two types of method for
melting the urea solution have been introduced.
[0008] One of the methods is a heating method for heating the urea
solution through a coil. This method measures the temperature of
the urea solution of the urea tank through a temperature sensor,
and the ECU supplies power through a relay such that the heat of
the coil heats the urea solution. However, there is a problem that
the coil needs to be disposed and there is a problem that the power
is supplied through a relay in this method.
[0009] The information disclosed in this Background section is only
for enhancement of understanding of the general background of the
invention and should not be taken as an acknowledgement or any form
of suggestion that this information forms the prior art already
known to a person skilled in the art.
SUMMARY OF INVENTION
[0010] Various aspects of the present invention provide for a urea
solution heating device and a control method thereof having
advantages of heating a urea solution by exhaust gas that is
exhausted from an engine.
[0011] Various aspects of the present invention provide for urea
solution heating device that may include an exhaust gas pipe
through which exhaust gas of an engine is exhausted, a muffler that
is connected to one end of the exhaust gas pipe to exhaust the
exhaust gas outside, a first bypass pipe that is diverged from the
exhaust gas pipe to bypass the exhaust gas, a urea solution tank to
which the bypassed exhaust gas is supplied and in which a urea
solution is filled, a second bypass pipe that is connected to the
muffler and that supplies the exhaust gas passing the urea solution
tank to the muffler, and a heat exchanger that is disposed in the
urea solution tank to connect the first bypass pipe with the second
bypass and through which the exhaust gas flows such that the
exhaust gas heats the urea solution, wherein the exhaust gas
sequentially flows through the first bypass line, the heat
exchanger, and the second bypass line by a pressure difference
between the exhaust gas pipe and the muffler.
[0012] A solenoid valve may be disposed on the first bypass pipe to
selectively bypass the exhaust gas.
[0013] A temperature sensor may bedisposed on the urea solution
tank to detect the temperature of the urea solution.
[0014] The urea solution heating device may further include a
dosing control unit (DCU) that is connected to the solenoid valve
and the temperature sensor, and receives a temperature signal of
the urea solution from the temperature sensor to operate the
solenoid valve.
[0015] An insulating member may bedisposed in the urea solution
tank, both ends of the insulating member are opened and urea
solution housing holes are formed in a side surface thereof, and
one of the ends may beengaged with a urea solution tank cap to be
closed.
[0016] The heat exchanger may bedisposed inside the insulating
member.
[0017] The heat exchanger may bemade by bending a pipe having a
predetermine length several times such that the urea solution
exchanges heat with the exhaust gas flowing in the heat
exchanger.
[0018] The heat exchanger may include two ends, and an exhaust gas
suction hole is formed in one end and an exhaust gas outlet is
formed in the other end.
[0019] The exhaust gas suction hole may beconnected to the first
bypass pipe through the urea solution tank cap, and the exhaust gas
outlet is connected to the second bypass line through the urea
solution tank cap.
[0020] A urea solution outlet may beformed on the urea solution
tank cap such that the urea solution of the urea solution tank is
exhausted outside.
[0021] A urea solution pump may bedisposed at a surface of an
interior direction of the insulating member of the urea solution
tank cap to exhaust the urea solution in the urea solution tank to
the outside through the urea solution outlet.
[0022] A sealing member may bedisposed between an interior
circumference of the urea solution tank cap and an exterior
circumference of the insulating member to prevent leakage of the
urea solution.
[0023] A pressure sensor may bedisposed at one end of the first
bypass pipe diverged from the exhaust gas pipe and at one end of
the second bypass pipe connected to the muffler to detect exhaust
gas pressure of the exhaust gas pipe and the muffler.
[0024] The DCU may beconnected to the pressure sensors to open the
solenoid valve when the pressure difference between the exhaust gas
pipe and the muffler is larger than a predetermined value.
[0025] Other aspects of the present invention provide for an urea
solution heating method, in a urea solution heating device that
includes an exhaust gas pipe exhausting exhaust gas of an engine, a
muffler that is connected to the exhaust gas pipe, a urea solution
tank in which a urea solution is filled, a bypass pipe that is
diverged from the exhaust gas pipe to be connected to the muffler
through the urea solution tank, and a solenoid valve that
selectively open/closes the bypass pipe, may include the steps of
determining whether a rotation speed of the engine is faster than
an idle rotation speed of the engine (S100), determining whether a
urea solution temperature is less than a predetermined value
through a temperature sensor disposed in the urea solution tank
(S110), determining whether a rotation speed of the engine is
slower than a maximum rotation speed of the engine (S120),
determining whether a load of the engine is less than a permissible
value (S130), opening the solenoid valve if the steps S100, S110,
S120, and S130 are satisfied (S150), closing the solenoid valve if
one of the steps S100, S110, S120, and S130 is not satisfied
(S160), and performing the procedures from step S100 again if step
S150 or step S160 is performed.
[0026] As described, the urea solution may be heated by high
temperature and pressure exhaust gas exhausted from the engine, and
separate constituent elements such as a heating device or a power
supply device are not necessary according to various aspects of the
present invention.
[0027] Also, flow of exhaust gas may be controlled by a pressure
difference between an exhaust pipe and a muffler, and therefore
separate constituent elements for supplying exhaust gas to a urea
solution tank are not necessary.
[0028] Accordingly, the device for heating the urea solution and
the method are simplified and production cost can be saved.
[0029] The methods and apparatuses of the present invention have o
her features and other advantages which will be apparent from or
are set forth in more detail in the accompanying drawings, which
are incorporated herein, and the following Detailed Description,
which together serve to explain certain principles of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a schematic diagram of an exemplary urea solution
heating device according to the present invention.
[0031] FIG. 2 is an enlarged view showing an "A" part of FIG.
1.
[0032] FIG. 3 is a schematic diagram of an exemplary urea solution
heating device according to the present invention.
[0033] FIG. 4 is a perspective view of an exemplary heat exchanger
according to the present invention.
[0034] FIG. 5 is a flowchart for an exemplary urea solution heating
method according to the present invention.
DETAILED DESCRIPTION
[0035] Reference will now be made in detail to various embodiments
of the present invention(s), examples of which are illustrated in
the accompanying drawings and described below. While the
invention(s) will be described in conjunction with exemplary
embodiments, it will be understood that present description is not
intended to limit the invention(s) to those exemplary embodiments.
On the contrary, the invention(s) is/are intended to cover not only
the exemplary embodiments, but also various alternatives,
modifications, equivalents and other embodiments, which may be
included within the spirit and scope of the invention as defined by
the appended claims.
[0036] FIG. 1 is a schematic diagram of a urea solution heating
device according to various embodiments of the present
invention.
[0037] As shown in FIG. 1, a urea solution heating device according
to various embodiments of the present invention includes an exhaust
gas pipe 10, a muffler 20, a urea solution tank 50, a heat
exchanger 60, first and second bypass pipes 80 and 82, a solenoid
valve 30, a temperature sensor 70, and a DCU 40.
[0038] The exhaust gas pipe 10 is connected to a combustion chamber
of an engine to exhaust high temperature and high pressure exhaust
gas of the engine.
[0039] The muffler 20 is a device that reduces pressure and
temperature of exhaust gas to exhaust the exhaust gas to the
outside. Also, the muffler 20 is connected to one end of the
exhaust gas pipe 10. That is, one end of the exhaust gas pipe 10 is
connected to the muffler 20, and the other end thereof is connected
to the engine to supply the muffler 20 with the exhaust gas that is
exhausted from the combustion chamber of the engine.
[0040] The urea solution tank 50 holds a urea solution that is used
to treat the exhaust gas. Also, the urea solution tank 50 is
separately disposed from the exhaust gas pipe 10 and the muffler
20.
[0041] The heat exchanger 60 is disposed in the urea solution tank
50 such that heat is exchanged between the exhaust gas and the urea
solution.
[0042] The first and second bypass pipes 80 and 82 bypass a part of
exhaust gas flowing in the exhaust gas pipe 10 such that the
exhaust gas flows through the urea solution tank 50 to be
transferred to the muffler 20. The first bypass pipe 80 is diverged
from one side of the exhaust pipe 10 to be connected to the heat
exchanger 60 that is disposed in the urea solution tank 50. Also,
one end of the second bypass pipe 82 is connected to the heat
exchanger 60 and the other end thereof is connected to the muffler
20. That is, a part of the exhaust gas flowing in the exhaust gas
pipe 10 passes the first bypass pipe 80 to be supplied to the heat
exchanger 60, heat is exchanged between urea solution and the
exhaust gas in the heat exchanger 60, and the heat-exchanged
exhaust gas is transferred to the muffler 20 through the second
bypass pipe 82.
[0043] The solenoid valve 30 is used to selectively open the first
bypass pipe 80. Also, the solenoid valve 30 is disposed on the
first bypass pipe 80 between the exhaust gas pipe 10 and the urea
solution tank 50.
[0044] The temperature sensor 70 measures the temperature of the
urea solution that is filled in the urea solution tank 50. Also,
the temperature sensor 70 can be disposed inside the heat exchanger
that is disposed in the urea solution tank 50. Meanwhile, the
position of the temperature sensor 70 in the urea solution tank 50
can be varied by a person of ordinary skill in the art.
[0045] The DCU 40 is a dosing control unit. The DCU 40 is
separately disposed outside the urea solution tank 50 to be
electrically connected to the temperature sensor 70 and the
solenoid valve 30. Further, the DCU 40 receives the temperature
signal of the urea solution filled in the urea solution tank 50
from the temperature sensor 70 and selectively opens or closes the
solenoid valve 30. That is, if the temperature of the urea solution
becomes less than a predetermined value, the solenoid valve 30 is
opened so that the high temperature and high pressure exhaust gas
is supplied to the urea solution tank 50. Meanwhile, the
predetermined temperature can be varied by a person of ordinary
skill in the art.
[0046] FIG. 2 is an enlarged view showing an "A" part of FIG. 1.
That is, FIG. 2 is an enlarged view of a part where the first
bypass pipe 80 is diverged from the exhaust gas pipe 10.
[0047] As shown in FIG. 2, the urea solution heating device
according to various embodiments of the present invention further
includes a nipple 12, a nipple penetration hole 14, a nipple cap
16, a nipple cap penetration hole 18, and a wrinkle pipe 84 around
a part where the first bypass pipe 80 is diverged from the exhaust
gas pipe 10.
[0048] The nipple 12 is integrally formed with a side surface of
the exhaust gas pipe 10 such that the exhaust gas pipe 10 is
engaged with the first bypass pipe 80. Also, the nipple 12
protrudes on a side surface of the exhaust gas pipe 10.
[0049] The nipple penetration hole 14 is formed such that a part of
the exhaust gas flowing in the exhaust gas pipe 10 is supplied to
the first bypass pipe 80. That is, the nipple penetration hole 14
is formed to penetrate the side surface of the nipple 12 and the
exhaust gas pipe 10.
[0050] The nipple cap 16 is disposed at one end of the first bypass
pipe 80 such that the exhaust gas pipe 10 is engaged with the first
bypass pipe 80. Also, the nipple cap 16 covers the outside of the
nipple 12 that is protruded to be engaged therewith. Further, a
screw thread is formed on an outside surface of the nipple 12 and
on an inside surface of the nipple cap 16. The nipple cap 16 can be
integrally formed with one end of the first bypass pipe 80 or can
be engaged with one end thereof.
[0051] The nipple cap 16 penetrates the exhaust gas pipe 10 in a
vertical direction thereof such that the nipple cap penetration
hole 18 forms one penetration passage together with the nipple
penetration hole 14. As described above, one end of the first
bypass pipe 80 is integrally formed with the nipple cap penetration
hole 18 or is engaged therewith to be able to form one passage.
[0052] A method that is equal to the engagement method of the
nipple 12 and the nipple cap 16 can be applied in an engagement
structure of the muffler 20 and the second bypass pipe 82. The
passage in the nipple penetration hole 14 and the nipple cap
penetration hole 18 can be formed to be the same. A combination
using the nipple 12 and the nipple cap 16 is shown in FIG. 2, but
the combination can be varied by a person of ordinary skill in the
art.
[0053] The wrinkle pipe 84 can be formed in a part of the first
bypass pipe 80 so as to reduce an impact that can be generated in
the first bypass pipe 80. The wrinkle pipe 84 is prepared as a
damping device in FIG. 2, but various methods can be applied
thereto by a person of ordinary skill in the art so as to reduce
the impact or vibration.
[0054] FIG. 3 is a schematic diagram of a urea solution heating
device according to various embodiments of the present
invention.
[0055] Detailed description for constituent elements that are equat
to that of the FIG. 1 will be omitted in FIG. 3.
[0056] As shown in FIG. 3, the urea solution heating device
according various embodiments of the present invention further
includes first and second pressure sensors 90 and 92.
[0057] The first pressure sensor 90 is disposed on the first bypass
pipe 80. Also, the first pressure sensor 90 can be disposed at a
part where the first bypass pipe 80 is diverged from the exhaust
gas pipe 10 so as to measure the pressure of the inside of the
exhaust gas pipe 10.
[0058] The second pressure sensor 92 is disposed on the second
bypass pipe 82. Also, the second pressure sensor 92 can be disposed
at a part where the second bypass pipe 80 is engaged with the
muffler 20 so as to measure the pressure of the inside of the
muffler 20.
[0059] The first and second pressure sensors 90 and 92 are
connected to the DCU 40. The DCU 40 receives the pressure signal of
the inside of the exhaust gas pipe 10 and the muffler 20 from the
first and second pressure sensors 90 and 92 to selectively open or
close the solenoid valve 30. That is, if the pressure difference
between the exhaust gas pipe 10 and the muffler 20 becomes larger
than a predetermined value, the solenoid valve 30 is opened so that
the high temperature and high pressure exhaust gas is supplied to
the urea solution tank 50. The predetermined value of the pressure
difference can be varied by a person of ordinary skill in the
art.
[0060] Accordingly, various embodiments of the present invention,
such as that shown in FIG. 3 gathers data on the urea solution
temperature and exhaust gas pressure and opens the solenoid valve
30 if the predetermined temperature or the predetermined pressure
is satisfied. Also, a condition in which the pressure of the
exhaust gas pipe 10 is higher than that of the muffler 20 is used
in various embodiments shown in FIG. 1 and FIG. 3. That is, when
the solenoid valve 30 is opened, a part of the exhaust gas flowing
in the exhaust gas pipe 10 is naturally supplied to the muffler 20
through the first bypass pipe 80, the heat exchanger 60, and the
second bypass pipe 82.
[0061] FIG. 4 is a perspective view of a heat exchanger according
to various embodiments of the present invention.
[0062] As shown in FIG. 4, the heat exchanger 60 includes an
insulating member 62, a urea solution tank cap 102, a heat exchange
pipe 110, an exhaust gas suction hole 112, an exhaust gas outlet
114, a urea solution outlet 104, and a urea solution pump 100.
[0063] The insulating member 62 prevents the heat from being wasted
to improve heat exchange efficiency between the exhaust gas and the
urea solution. The insulating member 62 has a pipe shape of which
both ends are opened. A plurality of urea solution housing holes 64
are formed to penetrate the insulating member 62such that the urea
solution is supplied to the heat exchanger 60.
[0064] The urea solution tank cap 102 can be a cover of the urea
solution tank 50. The urea solution tank cap 102 covers one of the
opened ends of the insulating member 62 to be engaged with the
insulating member 62. That is, one of the opened both ends of the
insulating member 62 is closed by the urea solution tank cap 102.
The insulating member 62 has a cylindrical shape of which both ends
thereof are opened, and the urea solution tank cap 102 has a
cylindrical shape of which one of the ends is closed. A sealing
member 106 is disposed between an interior circumference of the
urea solution tank cap 102 and an exterior circumference of the
insulating member 62.
[0065] The heat exchange pipe 110 is disposed in an interior space
of the insulating member 62 that is encircled by the insulating
member 62 and the urea solution tank cap 102. The heat exchange
pipe 110 has a predetermined length such that the heat exchange is
sufficiently performed between the urea solution and the exhaust
gas. The heat exchange pipe 110 having the predetermined length is
formed by being bent several times such that it may be disposed in
a limited space of the insulating member 62.
[0066] The heat exchange pipe 110 has two ends. One end is
connected to the first bypass pipe 80 and the other end is
connected to the second bypass pipe 82 such that the first bypass
pipe 80, the heat exchange pipe 110, and the second bypass pipe 82
form one passage line.
[0067] The exhaust gas suction hole 112 is integrally formed with
one end of the heat exchange pipe 110. One will apprecaite that the
exhaust gas suction hole and the heat exchange pipe may be
monolithically formed. One end penetrates the urea solution tank
cap 102 to be protruded outside the urea solution tank 50. The
exhaust gas suction hole 112 that protrudes outside the urea
solution tank 50 is connected to the first bypass pipe 80.
[0068] The exhaust gas outlet 114 is integrally formed with the
other end of the heat exchange pipe 110. One will apprecaite that
the exhaust gas outlet and the heat exchange pipe may be
monolithically formed. The other end penetrates the urea solution
tank cap 102 to be protruded outside the urea solution tank 50. The
exhaust gas outlet 114 that protrudes outside the urea solution
tank 50 is connected to the second bypass pipe 82. That is, a part
of the exhaust gas flowing in the exhaust gas pipe 10 is
sequentially supplied to the muffler through the first bypass pipe
80, the heat exchange pipe 110, and the second bypass pipe 82.
[0069] The urea solution outlet 104 protrudes on an exterior
surface of the urea solution tank cap 102 to exhaust the urea
solution of the urea solution tank 50 to the outside. The exhausted
urea solution can be used to treat the exhaust gas. The usage of
the urea solution for treating the exhaust gas can be performed by
a person of ordinary skill in the art, and therefore a detailed
description thereof will be omitted.
[0070] The urea solution pump 100 pumps the urea solution to the
outside of the urea solution tank 50. The urea solution pump 100 is
disposed on an interior surface of the urea solution tank cap 102
to exhaust the urea solution through the urea solution outlet
104.
[0071] Hereinafter, a urea solution heating method will be
described according to various embodiments of the present invention
with reference to FIG. 5.
[0072] FIG. 5 is a flowchart for a urea solution heating method
according to various embodiments of the present invention.
[0073] As shown in FIG. 5, the engine is started in S100, and the
DCU 40 determines whether a rotation speed of the engine is faster
than an idle rotation speed of the engine in S110.
[0074] If the rotation speed of the engine is faster than the idle
rotation speed in S110, the DCU 40 receives the temperature data of
the urea solution from the temperature sensor 70 that is disposed
in the urea solution tank 50 to determine whether the urea solution
temperature is less than a predetermined value in S120.
[0075] If the rotation speed of the engine is slower than the idle
rotation speed in S110, the DCU 40 closes the solenoid valve 30 in
S160.
[0076] If the urea solution temperature is lower than a
predetermined temperature in S120, the DCU 40 determines whether
the rotation speed of the engine is slower than a maximum rotation
speed in S130.
[0077] If the urea solution temperature is higher than a
predetermined value in S120, the DCU 40 closes the solenoid valve
30 in S160.
[0078] If it is determined that the present rotation speed of the
engine is less than the maximum rotation speed in S130, the DCU 40
determines that the load of the engine is less than a permissible
value in S140.
[0079] If it is determined that the present rotation speed of the
engine is greater than the maximum rotation speed in S130, the DCU
40 closes the solenoid valve 30 in S160.
[0080] If it is determined that the load of the engine is less than
a permissible value in S140, the DCU 40 opens the solenoid valve 30
in S150. That is, the solenoid valve 30 is opened in S150 if S100,
S110, S120, and S130 are all satisfied.
[0081] If it is determined that the load of the engine is larger
than the permissible value in S140, the DCU 40 closes the solenoid
valve 30 in S160. That is, the solenoid valve 30 is closed in S160
if one of S100, S110, S120, and S130 is not satisfied.
[0082] If S150 or S160 is performed, S100 is performed again by the
DCU 40 and sensors.
[0083] Data for the engine is detected by the ECU, the DCU 40
receives the data for the engine from the ECU, and S110, S130, and
S140 can be performed thereby.
[0084] For convenience in explanation and accurate definition in
the appended claims, the terms inside or outside, and etc. are used
to describe features of the exemplary embodiments with reference to
the positions of such features as displayed in the figures.
[0085] The foregoing descriptions of specific exemplary embodiments
of the present invention have been presented for purposes of
illustration and description. They are not intended to be
exhaustive or to limit the invention to the precise forms
disclosed, and obviously many modifications and variations are
possible in light of the above teachings. The exemplary embodiments
were chosen and described in order to explain certain principles of
the invention and their practical application, to thereby enable
others skilled in the art to make and utilize various exemplary
embodiments of the present invention, as well as various
alternatives and modifications thereof. It is intended that the
scope of the invention be defined by the Claims appended hereto and
their equivalents.
* * * * *