U.S. patent application number 11/435483 was filed with the patent office on 2007-11-22 for engine heater and method.
Invention is credited to Matthew J. Clarke.
Application Number | 20070266999 11/435483 |
Document ID | / |
Family ID | 38710868 |
Filed Date | 2007-11-22 |
United States Patent
Application |
20070266999 |
Kind Code |
A1 |
Clarke; Matthew J. |
November 22, 2007 |
Engine heater and method
Abstract
An apparatus includes an exhaust gas recirculation (EGR) cooler
(111) fluidly communicating with an intake system (117) and an
exhaust system (109) of an engine (100). An EGR valve (113) is in
fluid communication with the EGR cooler (111). A turbocharger
turbine (103) has an inlet in fluid communication with the exhaust
system (109) and an outlet in fluid communication with a vehicle
exhaust system (177). A bypass valve (115) is in fluid
communication with the EGR cooler (111) and the outlet of the
turbine (103). A cooling system (200) includes a heater supply
passage (222) and a heater return passage (224). A vehicle heater
(220) is in fluid communication with the cooling system (200),
wherein a flow path of coolant is defined between the EGR cooler
(111), the heater supply passage (222), the heater (220), the
heater return passage (224), and the engine (100).
Inventors: |
Clarke; Matthew J.;
(Grayslake, IL) |
Correspondence
Address: |
INTERNATIONAL ENGINE INTELLECTUAL PROPERTY COMPANY
4201 WINFIELD ROAD
P.O. BOX 1488
WARRENVILLE
IL
60555
US
|
Family ID: |
38710868 |
Appl. No.: |
11/435483 |
Filed: |
May 17, 2006 |
Current U.S.
Class: |
123/568.12 ;
123/568.2; 165/103; 60/605.2 |
Current CPC
Class: |
F02M 26/25 20160201;
Y02T 10/12 20130101; F02M 26/05 20160201; Y02T 10/144 20130101;
F02M 26/28 20160201; F02B 37/18 20130101; F28F 27/02 20130101; F02B
29/0406 20130101; F28F 2250/06 20130101; F02B 3/06 20130101; F02B
47/08 20130101; F02M 26/44 20160201; B60H 1/025 20130101 |
Class at
Publication: |
123/568.12 ;
123/568.2; 060/605.2; 165/103 |
International
Class: |
F02M 25/07 20060101
F02M025/07; F02B 47/08 20060101 F02B047/08; F02B 33/44 20060101
F02B033/44; F28F 27/02 20060101 F28F027/02 |
Claims
1. An apparatus for warming an internal combustion engine
comprising: an exhaust gas recirculation (EGR) cooler fluidly
communicating with an intake system and an exhaust system; an EGR
valve in fluid communication with the EGR cooler; a turbocharger
turbine having an inlet disposed in fluid communication with the
exhaust system and an outlet in fluid communication with a vehicle
exhaust system; a bypass valve in fluid communication with the EGR
cooler and the outlet of the turbine; a cooling system integrally
disposed with the internal combustion engine and having a heater
supply passage and a heater return passage; a heater in fluid
communication with the cooling system, wherein a flow path of
coolant is defined between the EGR cooler, the heater supply
passage, the heater, the heater return passage, and the engine.
2. The apparatus of claim 1, wherein the cooling system further
includes an EGR cooler supply passage and an EGR cooler return
passage, wherein the EGR cooler supply passage and the EGR cooler
return passage fluidly connect a coolant side of the EGR cooler
with the cooling system of the engine.
3. The apparatus of claim 2, wherein the flow path of coolant
further includes the EGR cooler supply passage and the EGR cooler
return passage.
4. The apparatus of claim 2, further comprising a connecting
passage that is part of the flow path of coolant, wherein the
connecting passage fluidly connects the EGR cooler return passage
directly to the heater supply passage.
5. A method for reducing a time required to warm-up an engine,
comprising the steps of: determining whether cold conditions exist
when the engine is first started; when the engine is first started
under cold conditions, determining an operational state of the
engine; when the engine is in an idling mode, opening a bypass
valve; passing exhaust gas through an exhaust gas recirculation
(EGR) cooler to heat a flow of coolant passing through the EGR
cooler, wherein the exhaust gas passing through the EGR cooler does
not enter an intake system of the engine; routing the flow of
coolant from the EGR cooler to a cabin heater of a vehicle.
6. The method of claim 5, wherein the step of determining whether
cold conditions exist includes determining at least one engine
operating parameter selected from: coolant temperature, oil
temperature, intake air temperature, exhaust temperature, and
ambient temperature; and comparing the at least one engine
operating parameter to a predetermined value.
7. The method of claim 5, further comprising the step of closing
the bypass valve when it is determined that the engine has reached
a sufficiently warm operating temperature.
8. The method of claim 5, further comprising the step of closing
the bypass valve when it is determined that the engine is no longer
in the idling mode.
9. The method of claim 5, further comprising the step of resuming
normal engine operation when the engine has reached a sufficiently
warm operating temperature.
10. The method of claim 5, further comprising the step of resuming
normal engine operation when the engine is no longer in the idling
mode.
11. (canceled)
12. A method of operating a turbocharged internal combustion
engine, comprising the steps of: determining that the engine
requires warming by comparing an engine operating parameter to a
predetermined value; actuating a valve to divert a flow of exhaust
gas through a first heat exchanger without passing through a
turbine of an engine turbocharger; using the first heat exchanger
to warm a flow of coolant passing therethrough; routing the flow of
coolant from the first heat exchanger into a second heat exchanger
disposed in a cabin of a vehicle, wherein the first heat exchanger
is an EGR cooler having a coolant outlet that is directly connected
to a coolant inlet of the second heat exchanger.
13. A method of operating a turbocharged internal combustion
engine, comprising the steps of: determining that the engine
requires warming by comparing an engine operating parameter to a
predetermined value; actuating a valve to divert a flow of exhaust
gas through a first heat exchanger without passing through a
turbine of an engine turbocharger; using the first heat exchanger
to warm a flow of coolant passing therethrough; routing the flow of
coolant from the first heat exchanger into a second heat exchanger
disposed in a cabin of a vehicle, wherein the step of rerouting is
accomplished by opening a bypass valve.
14. The method of claim 13, further comprising the step of closing
the bypass valve when the engine is warm.
15. The method of claim 12, wherein the step of determining is
accomplished in an electronic engine controller, wherein the
electronic engine controlled is arranged and constructed to receive
at least one input from a sensor disposed on the engine.
16. The method of claim 15, wherein the at least one input is at
least one of a coolant temperature, an oil temperature, an intake
air temperature, and exhaust temperature, and an ambient
temperature.
Description
FIELD OF THE INVENTION
[0001] This invention relates to internal combustion engines,
including but not limited to engines having engine warm-up
devices.
BACKGROUND OF THE INVENTION
[0002] Many engines may exhibit poor performance when first started
at cold ambient conditions until a desired operating temperature is
reached. A typical measure to improve a performance of an engine,
especially a diesel engine, during cold start conditions may be to
advance ignition timing thus raising firing pressures of the
engine. However, these high firing pressures may strain various
engine components, including head gaskets and power generation
components, such as pistons, connecting rods, crankshafts, intake,
and/or exhaust valves. Moreover, a typical vehicle operator must
sometimes wait for the engine to warm up before heat is available
in the vehicle cab.
[0003] Other measures that have been taken in the past to improve
quality of operation for engines that are starting in cold
conditions have included raising the exhaust back pressure to make
the engine work harder during warm-up and the addition of engine
components, for example, fuel-fired or electrical heaters or
secondary heater units for a vehicle cab. Such measures may be
partly effective in accomplishing a faster warm-up for an engine or
cab, but are usually very costly and complicated in their
implementation.
[0004] Accordingly, there is a need for an engine heating system
that accomplishes a short engine warm-up period and that is simple
and cost effective in its implementation.
SUMMARY OF THE INVENTION
[0005] An apparatus and method are disclosed to aid in engine
warm-up following engine startup at cold conditions. An apparatus
is disclosed that includes an exhaust gas recirculation (EGR)
cooler fluidly communicating with an intake system and an exhaust
system of an engine. An EGR valve is in fluid communication with
the exhaust side of the EGR cooler. A turbocharger turbine has an
inlet disposed in fluid communication with the exhaust system and
an outlet in fluid communication with a vehicle exhaust system. A
bypass valve is in fluid communication with the exhaust side of the
EGR cooler and the outlet of the turbine. A cooling system may be
partially integrated with the internal combustion engine, and
include a heater supply passage and a heater return passage. A
cabin heater is in fluid communication with the cooling system,
wherein a flow path of coolant is defined between the coolant side
of the EGR cooler, the heater supply passage, the heater, the
heater return passage, and the engine.
[0006] A method is disclosed for reducing a time required to
warm-up an engine includes the step of determining whether cold
conditions exist when the engine is first started. At times when
the engine is first started under cold conditions, an operational
state of the engine is determined. When the engine is in an idling
mode, a bypass valve is opened that allows exhaust gas to pass
through an exhaust gas recirculation (EGR) cooler but not the
intake system of the engine so as to heat a flow of coolant passing
through the EGR cooler. The flow of coolant from the EGR cooler is
routed to a cabin heater of a vehicle.
[0007] A method of operating a turbocharged internal combustion
engine is disclosed that includes the step of determining that the
engine requires warming by comparing an engine operating parameter
to a predetermined value. A flow of exhaust gas may be rerouted
around a turbocharger turbine and through a first heat exchanger.
The first heat exchanger may be used to warm a flow of coolant
passing therethrough. The flow of coolant from the first heat
exchanger may then be routed into a second heat exchanger disposed
in a cabin of a vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram of an internal combustion engine
having a high-pressure EGR system with a bypass valve in accordance
with the invention.
[0009] FIG. 2 is a block diagram of a cooling system for an
internal combustion engine in accordance with the invention.
[0010] FIG. 3 is a flowchart for a method of operating an internal
combustion engine in accordance with the invention.
DESCRIPTION OF A PREFERRED EMBODIMENT
[0011] The following describes an apparatus for and method of
providing a heater system in an internal combustion engine. A
turbocharged engine 100 having a system to bypass exhaust gas
around the turbocharger and through a heat exchanger is shown in
FIG. 1. The engine 100 includes an engine block 101 having a
plurality of cylinders. A compressor 102 is connected to an air
cleaner (not shown) and a turbine 103 of turbocharger 104. An
outlet of the compressor 102 is connected to a charge air cooler
105, which in turn is connected to an intake system 117. A turbine
103 is connected to an exhaust system 109. The exhaust system 109
is connected to the engine block 101, and may be connected to an
EGR cooler 111. The EGR cooler 111 may be connected to an EGR valve
113 and to a dump or bypass valve 115. The EGR valve 113 and the
bypass valve 115 may be actuated by electrical, pneumatic,
mechanical, hydraulic, or any other type of actuation mode known in
the art. The bypass valve 115 is in fluid communication with an
outlet of the EGR cooler 111 on one end, and an outlet of the
turbine 103 on another end. The outlet of the turbine 103 and the
bypass valve 115 may both fluidly communicate with a tailpipe or
vehicle exhaust passage 117.
[0012] Even though one EGR cooler 111 is shown connected with the
bypass valve 115, additional EGR coolers may be utilized in a
serial or parallel arrangement that may use additional bypass
valves. The bypass valve 115 is shown in fluid communication with
the EGR valve 113, but may not be directly connected to the EGR
valve 113 if the EGR valve 113 is not in fluid communication with
the outlet of a single EGR cooler 111, but is instead disposed at
another location, for example, at the outlet of a first EGR cooler
in the presence of at least a second EGR cooler (not shown). In
such a case, the bypass valve 115 could be disposed at the outlet
of the second EGR cooler.
[0013] During engine operation, exhaust gas from the exhaust system
109 enters the EGR cooler 111 where it is cooled, and then enters
the EGR valve 113. When the EGR valve 113 is open, the bypass valve
115 is advantageously closed so as to prevent leakage of exhaust
gas around the turbine 103. In the case where the engine 100 also
has emission after-treatment components, such as a particulate
filter or a catalyst (not shown) in fluid communication with the
outlet of the turbine 103, the bypass valve 115 may be at least
partially opened to facilitate an increase of temperature, flow
rate, pressure, or change transient conditions in the exhaust gas
at the outlet of the turbine 103.
[0014] On certain occasions or events during engine operation,
especially at times when the engine 100 first begins to operate
under cold ambient conditions, the bypass valve 115 may open while
the EGR valve 113 is advantageously closed, to bypass exhaust gas
from the exhaust system 109 into the outlet of the turbine 103.
Exhaust gas being bypassed may advantageously be cooled by passing
through the EGR cooler 111. Heat removed from the exhaust gas
passing through the bypass valve 105 and the EGR cooler 111 may
advantageously be passed to a coolant flow passing through the EGR
cooler 111.
[0015] The EGR cooler 111 may be connected to a cooling system of
the engine 100. A block diagram of a heating system 200 associated
with the engine 100 is shown in FIG. 2. The heating or cooling
system 200 may include a coolant pump (not shown) along with
various coolant passages integrated with the engine 100, or
external to the engine 100. The EGR cooler 111 may have an exhaust
gas supply passage 202 and an exhaust gas return passage 204 as
described above. A coolant supply passage 206 may supply the EGR
cooler 111 with a flow of coolant from the engine 100, while a
coolant return passage 208 may return the flow of coolant from the
EGR cooler 111 back into the engine 100. The passages 206 and 208
may or may not be integrated in whole or in part with other engine
components on the engine 100, and may be part of the heating or
cooling system 200. A radiator 210 may be located on a vehicle (not
shown) and be in fluid communication with the cooling system 200
through a radiator supply passage 212 and a radiator return passage
214. A thermostat 216 may be arranged to interrupt a coolant flow
between the engine 100 and the radiator 210 through the supply
passage 212. A bypass passage 218 may be connected between the
supply passage 212 and the return passage 214 at the thermostat
216.
[0016] The engine 100 may be installed into a vehicle (not shown)
and be arranged to provide power for operation of the vehicle. An
ancillary function of the engine may be to provide heat to a cabin
of the vehicle as is known. A vehicle cabin heater 220 may be
disposed in the cabin of the vehicle. The heater 220 may be an
air-to-water heat exchanger that may transfer thermal energy from
coolant coming from the engine 100 to the air inside the cabin of
the vehicle.
[0017] The heater 220 may receive a flow of coolant from the engine
100 through a heater supply passage 222. The flow of coolant may
return to the engine 100 through a heater return passage 224.
During operation of the engine 100, a vehicle operator may take
appropriate action to enable use of the heater 220. While the
heater 220 is operating, a flow of warm coolant from the engine 100
may enter the heater 220 through the passage 222 where heat may be
extracted therefrom and released into the cabin of the vehicle for
warming the passengers during cold conditions. After heat has been
extracted from the flow of coolant passing through the heater 220,
the coolant may be returned to the engine 100 through the passage
224.
[0018] It may be advantageous to the operation of the heater 220 to
have warm coolant being supplied thereto through the passage 222.
Warm coolant supplied to the heater 220 may increase an
effectiveness of the heater 220. The effectiveness and the total
heat the heater 220 is capable of transferring into the cabin of
the vehicle may become especially important under conditions of
initial startup during cold ambient conditions. A typical engine,
especially a compression ignition engine, may take 15 minutes or
more after initial startup to reach a satisfactorily high operating
temperature that is capable of providing adequate heat to the
heater 200 for heating the cabin of the vehicle. For this and other
reasons, the EGR cooler return passage 208 may advantageously be in
direct fluid communication with the heater supply passage 222
through an optional connecting passage 226.
[0019] During operation of the engine 100 shortly following initial
startup, exhaust gas may be used to heat a flow of coolant passing
through the EGR cooler 111. This flow of coolant may then pass
through the vehicle cabin heater 220 either directly through the
optional passage 226, or through a normal flow path through the
engine 100 defined by the passage 222.
[0020] A method of operating an internal combustion engine for
accelerated warm-up during cold start conditions, as compared to
warm-up for a typical engine, is shown in FIG. 3. When the engine
begins operation, a determination is made on whether cold
conditions are present at step 302. This determination may be made
based on input(s) from various sensors disposed on or around the
engine that may be relayed to an electronic engine controller
(EEC). The EEC may calculate a thermal condition of the engine by
comparing one or more engine parameters to predetermined threshold
values. These engine parameters may advantageously include coolant
temperature, oil temperature, exhaust temperature, intake air
temperature, ambient temperature, and so forth. At times when it is
determined that the engine is operating in cold conditions, a
determination may be made as to the operational status of the
engine.
[0021] A determination of whether the engine is idling may be made
at step 304. This determination may again be made in the engine's
EEC and be based on engine operating parameters including engine
speed, fueling commanded, engine timing, and so forth. In a typical
application, a fuel or ignition timing for the engine may be
adjusted to increase a cylinder combustion pressure. This increase
typically increases an internal work of the engine, which may
result in a faster warm-up of the engine, but also may create
issues with various engine components as a result of increased
combustion pressures. For example, high combustion pressures during
engine warm-up have been known to cause failures in head gaskets,
piston rings, and other components. Use of a bypass valve for
routing exhaust gas during engine warm-up through an EGR cooler
before releasing them to a tailpipe, especially at times when EGR
for recirculation is not required, may be used to avoid many of the
known disadvantages associated with engine warm-up.
[0022] Hence, at times when it has been determined that the engine
is cold (at step 302) and idling (at step 304), a bypass valve may
open at step 306 to allow exhaust gas that previously would have
been released to the tailpipe of a vehicle, to pass through the EGR
cooler, at step 308, and warm a coolant flow passing therethrough
before passing back to the tailpipe. On engines having a
turbocharger that are idling, the quantity of exhaust gas required
by the turbine is low. Consequently, most of the exhaust gas being
passed through the EGR cooler at step 308 can advantageously bypass
the turbocharger to ensure that the exhaust gas being re-routed to
the EGR cooler has a higher enthalpy, and thus more thermal energy
to transfer to the flow of coolant passing through the EGR cooler,
thereby providing a faster warm-up.
[0023] The flow of coolant passing through the EGR cooler that has
been warmed by the exhaust gas being re-routed may be routed to the
vehicle cabin heater at step 310. While passing through the cabin
heater, the flow of coolant may release some of its thermal energy
to heat the cabin of the vehicle before returning to the engine.
This process may be repeated as long as the engine still requires
warming or, while the engine is still idling and there is no power
output required. Should the engine becomes sufficiently warm, or
should the driver demand power from the engine to move the vehicle,
then the output at determination steps 302 and 304 will become
negative and the bypass valve will close at step 312, for normal
operation of the engine to resume at step 314.
[0024] This method of reducing the time required for an engine to
reach normal operating temperature during a cold start condition is
advantageous over the prior art because it does not require the
engine to operate with higher cylinder compression pressures.
Moreover, use of existing engine components, for example the EGR
cooler, enables a cost effective implementation. The bypass valve
added to the system that fluidly connects a gas outlet of the EGR
cooler with an outlet of a turbine, of one is used, may
advantageously also be used during normal operation of the engine
to purge the EGR cooler.
[0025] The present invention may be embodied in other specific
forms without departing from its spirit or essential
characteristics. The described embodiments are to be considered in
all respects only as illustrative and not restrictive. The scope of
the invention is, therefore, indicated by the appended claims
rather than by the foregoing description. All changes that come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
* * * * *