U.S. patent application number 14/822161 was filed with the patent office on 2016-05-05 for system and method for controlling water pump of vehicle having water-cooled intercooler.
This patent application is currently assigned to Hyundai Motor Company. The applicant listed for this patent is Hyundai Motor Company. Invention is credited to Hyungmin Kim.
Application Number | 20160123214 14/822161 |
Document ID | / |
Family ID | 55753362 |
Filed Date | 2016-05-05 |
United States Patent
Application |
20160123214 |
Kind Code |
A1 |
Kim; Hyungmin |
May 5, 2016 |
SYSTEM AND METHOD FOR CONTROLLING WATER PUMP OF VEHICLE HAVING
WATER-COOLED INTERCOOLER
Abstract
A water pump control system of a vehicle having a water-cooled
intercooler includes: the water-cooled intercooler cooling intake
air that is injected from the outside through heat exchange with
coolant; an electric water pump that selectively supplies coolant
to the water-cooled intercooler using an electric motor; and a
controller that controls the electric water pump using a heat
releasing amount of intake air passing through the water-cooled
intercooler.
Inventors: |
Kim; Hyungmin; (Ansan-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company |
Seoul |
|
KR |
|
|
Assignee: |
Hyundai Motor Company
Seoul
KR
|
Family ID: |
55753362 |
Appl. No.: |
14/822161 |
Filed: |
August 10, 2015 |
Current U.S.
Class: |
60/605.1 ;
123/41.02 |
Current CPC
Class: |
F01P 2060/02 20130101;
F01P 7/164 20130101; F01P 2005/125 20130101; F01P 5/12 20130101;
F01P 3/20 20130101 |
International
Class: |
F01P 5/12 20060101
F01P005/12; F01P 7/16 20060101 F01P007/16; F01P 3/18 20060101
F01P003/18 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2014 |
KR |
10-2014-0150106 |
Claims
1. A water pump control system of a vehicle having a water-cooled
intercooler, the water pump control system comprising: the
water-cooled intercooler that cools an intake air that is injected
from an outside through heat exchange with a coolant; an electric
water pump (EWP) that selectively supplies the coolant to the
water-cooled intercooler using an electric motor; and a controller
that controls the EWP using a heat releasing amount of the intake
air passing through the water-cooled intercooler.
2. The water pump control system of claim 1, further comprising: a
first temperature sensor that is provided at a front end of the
water-cooled intercooler to measure a temperature of the inflow air
that is injected into the water-cooled intercooler; and a second
temperature sensor that is provided at a rear end of the
water-cooled intercooler to measure a temperature of the inflow air
that is discharged from the water-cooled intercooler.
3. The water pump control system of claim 2, wherein the controller
determines a heat releasing amount of intake air from a difference
between intake temperatures that are detected by the first
temperature sensor and the second temperature sensor and an intake
air amount that passes through the water-cooled intercooler.
4. The water pump control system of claim 3, wherein the heat
releasing amount of intake air is determined by an equation Q=cmdT
where Q is a heat releasing amount of intake air, c is a specific
heat of intake air, m is an intake amount passing through the
water-cooled intercooler, and dT is a temperature difference
between the front end and the rear end of the water-cooled
intercooler.
5. The water pump control system of claim 1, further comprising: a
second temperature sensor that is provided at a rear end of the
water-cooled intercooler to measure a temperature of the inflow air
that is discharged from the water-cooled intercooler; a
turbocharger comprising a turbine that rotates by exhaust gas that
is discharged from a combustion chamber of an engine and a
compressor that rotates by interlocking with a rotation of the
turbine and that compresses the intake air; and a hot-film mass air
flow (HFM) sensor that is provided at a front end of the
compressor, wherein the controller determines a heat releasing
amount of intake air from a temperature of intake air that is
detected by the HFM sensor, a temperature of intake air that is
detected by the second temperature sensor, and an air amount
passing through the water-cooled intercooler.
6. The water pump control system of claim 5, wherein the controller
estimates a temperature of a front end of the water-cooled
intercooler using a temperature that is detected by the HFM
sensor.
7. The water pump control system of claim 1, wherein the controller
turns on operation of the EWP when a heat releasing amount of
intake air is smaller than a predetermined value and turns off
operation of the EWP when a heat releasing amount of intake air is
a predetermined value or more.
8. The water pump control system of claim 7, wherein the
predetermined value is stored as map data according to engine
revolutions per minute (RPM) and an engine load.
9. The water pump control system of claim 8, wherein the
predetermined value increases as engine RPM increases and increases
as an engine load increases.
10. A method of controlling a water pump of a vehicle having a
water-cooled intercooler, the method comprising: determining a heat
releasing amount of an intake air passing through a water-cooled
intercooler that cools the intake air that is injected from an
outside to supply the intake air to a combustion chamber of an
engine; and controlling an electric water pump (EWP) that supplies
coolant to the water-cooled intercooler according to a heat
releasing amount of the intake air.
11. The method of claim 10, wherein the determining of the heat
releasing amount comprises: detecting a temperature of a front end
and a rear end of the water-cooled intercooler; measuring a
temperature difference of the intake air passing through the
water-cooled intercooler from a temperature of the front end and
the rear end of the water-cooled intercooler; and determining a
heat releasing amount of intake air passing through the
water-cooled intercooler using a specific heat of air passing
through the water-cooled intercooler, an air amount passing through
the water-cooled intercooler, and the temperature difference.
12. The method of claim 10, wherein the determining of the heat
releasing amount comprises: estimating a temperature of the front
end of the water-cooled intercooler from a temperature that is
detected at a hot-film mass air flow (HFM) sensor that is provided
at a front end of a turbocharger that compresses air that is
injected into the combustion chamber of the engine; detecting a
temperature of the rear end of the water-cooled intercooler;
measuring a temperature difference of intake air passing through
the water-cooled intercooler from the estimated temperature of the
front end of the water-cooled intercooler and the temperature of
the rear end of the water-cooled intercooler; and determining a
heat releasing amount of intake air passing through the
water-cooled intercooler using a specific heat of air passing
through the water-cooled intercooler, an air amount passing through
the water-cooled intercooler, and the temperature difference.
13. The method of claim 10, wherein the controlling of the EWP
comprises: determining whether the heat releasing amount of the
intake air is smaller than a predetermined value; and turning on
operation of the EWP when a heat releasing amount of the intake air
is smaller than a predetermined value, and turning off the
operation of the EWP when the heat releasing amount of the intake
air is a predetermined value or more.
14. The method of claim 13, wherein the predetermined value is
stored as map data according to engine RPM and an engine load.
15. The method of claim 14, wherein the predetermined value
increases as engine RPM increases and increases as an engine load
increases.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to and the benefit
of Korean Patent Application No. 10-2014-0150106 filed on Oct. 31,
2014, the entire contents of which is incorporated herein for all
purposes by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a system and method for
controlling a water pump of a vehicle having a water-cooled
intercooler. More particularly, the present invention relates to a
system and method for controlling a water pump of a vehicle having
a water-cooled intercooler that can effectively cool compressed air
that is supplied to an engine through a water-cooled
intercooler.
[0004] 2. Description of Related Art
[0005] In general, a turbocharger is a device that rotates a
turbine using pressure of an exhaust gas that is discharged from an
engine and that enhances output of the engine by supplying air of a
high pressure to a combustion chamber of the engine using torque
thereof.
[0006] However, density of air that is quickly compressed through
the turbocharger is lowered by absorbing heat occurring in a
compression process, and supply efficiency of air that is supplied
to the combustion chamber of the engine is resultantly lowered.
[0007] In order to solve such a problem, compressed air having
passed through the turbocharger is cooled through an intercooler
that is disposed on an intake line to be supplied to the combustion
chamber of the engine through a throttle valve. That is, by cooling
air that is compressed through the turbocharger through the
intercooler, air of a high density may be supplied to the
combustion chamber of the engine and output of the engine can be
improved.
[0008] As a conventionally intercooler, an air-cooled intercooler
that cools air that is mostly turbocharged by air is mostly
used.
[0009] However, currently, a water-cooled intercooler that is
integrally formed with an intake manifold and that cools
turbocharged air using a coolant has been developed. Coolant
flowing inside of such a water-cooled intercooler is adjusted by
operation of an electric water pump (EWP).
[0010] However, because operation of a conventional EWP is simply
controlled according to an outlet temperature of the water-cooled
intercooler without considering an environment condition of a
region while a vehicle drives, there is a problem that turbocharged
air that is injected into a combustion chamber of an engine is
actively controlled.
[0011] Therefore, development of a control strategy for effectively
controlling the water-cooled intercooler and the EWP is urgently
requested.
[0012] The information disclosed in this Background of the
Invention 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.
BRIEF SUMMARY
[0013] Various aspects of the present invention are directed to
providing a system and method for controlling a water pump of a
vehicle having a water-cooled intercooler having advantages of
being capable of controlling operation of an EWP by estimating a
heat releasing amount of the water-cooled intercooler.
[0014] The present invention further provides a system and method
for controlling a water pump of a vehicle having a water-cooled
intercooler having advantages of being capable of reducing fuel
consumption of the vehicle by minimizing operation of an EWP.
[0015] An aspect of the present invention provides a water pump
control system of a vehicle having a water-cooled intercooler,
including the water-cooled intercooler that cools intake air that
is injected from the outside through heat exchange with a coolant,
an EWP that selectively supplies the coolant to the water-cooled
intercooler using an electric motor, and a control unit that
controls the EWP using a heat releasing amount of intake air
passing through the water-cooled intercooler.
[0016] The water pump control system may further include a first
temperature sensor that is provided at the front end of the
water-cooled intercooler to measure a temperature of inflow air
that is injected into the water-cooled intercooler, and a second
temperature sensor that is provided at the rear end of the
water-cooled intercooler to measure a temperature of inflow air
that is discharged from the water-cooled intercooler.
[0017] The control unit may calculate a heat releasing amount of
intake air from a difference between intake temperatures that are
detected by the first temperature sensor and the second temperature
sensor and an intake air amount that passes through the
water-cooled intercooler.
[0018] The heat releasing amount of intake air may be calculated by
the equation
Q=cmdT,
where Q may be a heat releasing amount of intake air, c may be a
specific heat of intake air, m may be an intake amount passing
through the water-cooled intercooler, and dT may be a temperature
difference between the front end and the rear end of the
water-cooled intercooler.
[0019] The water pump control system may further include a second
temperature sensor that is provided at the rear end of the
water-cooled intercooler to measure a temperature of inflow air
that is discharged from the water-cooled intercooler, a
turbocharger including a turbine that rotates by exhaust gas that
is discharged from a combustion chamber of the engine and a
compressor that rotates by interlocking with rotation of the
turbine and that compresses the intake air, and a hot-film mass air
flow (HFM) sensor that is provided at the front end of the
compressor, wherein the control unit may calculate a heat releasing
amount of intake air from a temperature of intake air that is
detected by the HFM sensor, a temperature of intake air that is
detected by the second temperature sensor, and an air amount
passing through the water-cooled intercooler.
[0020] The control unit may estimate a temperature of the front end
of the water-cooled intercooler using a temperature that is
detected by the HFM sensor.
[0021] The control unit may turn on operation of the EWP if a heat
releasing amount of intake air is smaller than a predetermined
value, and may turn off operation of the EWP if a heat releasing
amount of intake air is a predetermined value or more.
[0022] The predetermined value may be stored as map data according
to engine revolutions per minute (RPM) and an engine load.
[0023] The predetermined value may increase as engine RPM increases
and increase as an engine load increases.
[0024] Another embodiment of the present invention provides a
method of controlling a water pump of a vehicle having a
water-cooled intercooler, including calculating a heat releasing
amount of intake air passing through a water-cooled intercooler
that cools intake air that is injected from the outside to supply
the intake air to a combustion chamber of an engine, and
controlling an EWP that supplies coolant to the water-cooled
intercooler according to a heat releasing amount of the intake
air.
[0025] The calculating of a heat releasing amount may include
detecting a temperature of the front end and the rear end of the
water-cooled intercooler, measuring a temperature difference of
intake air passing through the water-cooled intercooler from a
temperature of the front end and the rear end of the water-cooled
intercooler, and calculating a heat releasing amount of intake air
passing through the water-cooled intercooler using a specific heat
of air passing through the water-cooled intercooler, an air amount
passing through the water-cooled intercooler, and the temperature
difference.
[0026] The calculating of a heat releasing amount may include
estimating a temperature of the front end of the water-cooled
intercooler from a temperature that is detected at an HFM sensor
that is provided at the front end of a turbocharger that compresses
air that is injected into the combustion chamber of the engine,
detecting a temperature of the rear end of the water-cooled
intercooler, measuring a temperature difference of intake air
passing through the water-cooled intercooler from the estimated
temperature of the front end of the water-cooled intercooler and
the temperature of the rear end of the water-cooled intercooler,
and calculating a heat releasing amount of intake air passing
through the water-cooled intercooler using a specific heat of air
passing through the water-cooled intercooler, an air amount passing
through the water-cooled intercooler, and the temperature
difference.
[0027] The controlling of an EWP may include determining whether
the heat releasing amount of intake air is smaller than a
predetermined value, and turning on operation of the EWP if a heat
releasing amount of the intake air is smaller than a predetermined
value and turning off operation of the EWP if a heat releasing
amount of the intake air is a predetermined value or more.
[0028] The predetermined value may be stored as map data according
to engine RPM and an engine load.
[0029] The predetermined value may increase as engine RPM increases
and may increase as an engine load increases.
[0030] According to a system and method for controlling a water
pump of a vehicle having a water-cooled intercooler by an aspect of
the present invention, by controlling an EWP through a heat
releasing amount of intake air passing through the water-cooled
intercooler in consideration of an environment condition
(atmosphere temperature, pressure), compared with an existing
control method of monitoring and controlling only a target
temperature of the rear end of an intercooler, operation of the EWP
can be more accurately controlled.
[0031] Further, by optimizing an operation time of an EWP in
consideration of an environment condition, fuel consumption of a
vehicle is improved.
[0032] In addition, because an intake temperature of the front end
of a water-cooled intercooler may be estimated through an HFM
sensor that is provided at the front end of a compressor,
production cost of a vehicle can be reduced.
[0033] The methods and apparatuses of the present invention have
other features and 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
[0034] FIG. 1 is a schematic view illustrating a configuration of a
water pump control system of a vehicle having a water-cooled
intercooler according to an exemplary embodiment of the present
invention.
[0035] FIG. 2 is a flowchart illustrating a method of controlling a
water pump of a vehicle having a water-cooled intercooler.
[0036] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various features illustrative of the basic
principles of the invention. The specific design features of the
present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
[0037] In the figures, reference numbers refer to the same or
equivalent parts of the present invention throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0038] 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 the 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.
[0039] The drawings and description are to be regarded as
illustrative in nature and not restrictive. Like reference numerals
designate like elements throughout the specification.
[0040] Further, in the drawings, size and thickness of each element
are randomly represented for better understanding and ease of
description, but the present invention is not limited thereto, and
the thickness of several portions and areas are exaggerated for
clarity.
[0041] Hereinafter, a water pump control system of a vehicle having
a water-cooled intercooler according to an exemplary embodiment of
the present invention will be described in detail with reference to
the accompanying drawings.
[0042] FIG. 1 is a schematic view illustrating a configuration of a
water pump control system of a vehicle having a water-cooled
intercooler according to an exemplary embodiment of the present
invention. As shown in FIG. 1, a water pump control system of a
vehicle having a water-cooled intercooler according to an exemplary
embodiment of the present invention includes an intake line 150, a
turbocharger 130, an intercooler 120, an electric water pump (EWP)
128, an engine 110, and a controller 170.
[0043] The turbocharger 130 rotates a turbine 132 by exhaust gas
that is discharged to an exhaust line 160, and the turbine 132
compresses intake air that is injected from external air flowing
through the intake line 150 while rotating by interlocking with
rotation thereof and supplies the compressed intake air to a
combustion chamber 112 of the engine 110.
[0044] A hot-film mass air flow (HFM) sensor 140 is provided at the
front end of the compressor 134 of the turbocharger 130. The HFM
sensor 140 may measure an amount and temperature of intake air that
is injected from the outside therethrough. The temperature of the
intake air that is detected by the HFM sensor 140 is provided to
the controller 170.
[0045] The water-cooled intercooler 120 cools the intake air
flowing through the intake line 150. In this case, the water-cooled
intercooler 120 cools intake air that is injected from the outside
through heat exchange with a coolant. In this case, the coolant
that is heated by cooling intake air in the water-cooled
intercooler 120 is cooled through a radiator 126.
[0046] A second temperature sensor 124 that measures the
temperature of intake air that is discharged from the water-cooled
intercooler 120 is provided at the rear end of the water-cooled
intercooler 120. A first temperature sensor 122 that measures the
temperature of intake air that is injected into the water-cooled
intercooler 120 is provided at the front end of the water-cooled
intercooler 120. The temperatures of intake air that are detected
by the first temperature sensor 122 and the second temperature
sensor 124 are provided to the controller 170.
[0047] That is, the first temperature sensor 122 measures the
temperature of intake air that is injected into the water-cooled
intercooler 120, and when estimating a temperature of the front end
of the water-cooled intercooler 120 by measuring the temperature of
the front end of a compressor 134 through the HFM sensor 140, it is
unnecessary to have the first temperature sensor 122.
[0048] The EWP 128 selectively supplies the coolant that cools the
intake air using an electric motor to the water-cooled intercooler
120. That is, when the temperature of the intake air passing
through the intercooler 120 increases, by supplying the coolant
from the EWP 128 to the intercooler 120, the temperature of the
intake air is lowered. In contrast, when the temperature of the
intake air passing through the intercooler 120 is lowered, the
coolant is blocked from being supplied from the EWP 128.
[0049] The controller 170 may be provided as at least one processor
operating by a predetermined program, and the predetermined program
performs each step of a method of controlling a water pump of a
vehicle having the water-cooled intercooler 120 according to an
exemplary embodiment of the present invention.
[0050] The controller 170 controls operation of the turbocharger
130, the EWP 128, and the engine 110. Particularly, the controller
170 controls the EWP 128 using a heat releasing amount of intake
air passing through the water-cooled intercooler 120.
[0051] According to an exemplary embodiment of the present
invention, a heat releasing amount of the intake air may be
calculated from a difference between intake temperatures that are
detected by the first temperature sensor 122 and the second
temperature sensor 124 and an intake air amount passing through the
water-cooled intercooler 120.
[0052] That is, a heat releasing amount of the intake air may be
calculated by Equation 1.
Q=cmdT (Equation 1)
[0053] Here, Q is a heat releasing amount of intake air, c is a
specific heat of intake air, m is an intake air amount passing
through the water-cooled intercooler 120, and dT is a temperature
difference between the front end and the rear end of the
water-cooled intercooler 120.
[0054] According to another exemplary embodiment of the present
invention, a heat releasing amount of the intake air may be
calculated from a temperature of intake air that is detected by the
HFM sensor 140, a temperature of intake air that is detected by the
second temperature sensor 124, and an air amount passing through
the water-cooled intercooler 120.
[0055] That is, the controller 170 may estimate a temperature of
intake air at the front end of the water-cooled intercooler 120
from the temperature of intake air that is detected by the HFM
sensor 140.
[0056] Specifically, the intake line 150 including the turbocharger
130 is one isolated system, and an intake process before and after
being compressed through the compressor 134 may be assumed to be an
isentropic compression process.
[0057] First, a temperature of intake air is measured at the front
end of the compressor 134 by the HFM sensor 140. In this case, the
temperature of intake air before being compressed through the
compressor 134 is the temperature of intake air that is measured
through the HFM sensor 140.
[0058] Because an intake process before and after being compressed
through the compressor 134 is an isentropic compression process,
the temperature of intake air before and after being compressed
through the compressor 134 has a relationship of Equation 2.
.DELTA. T ( T 2 - T 1 ) = P c 1 c p 1 m . ( Equation 2 )
##EQU00001##
[0059] Here, T1 is a temperature of intake air before being
compressed through the compressor 134, T2 is a temperature of
intake air after being compressed through the compressor 134, Pc is
work of air that is compressed through the compressor 134, Cp is a
constant pressure specific heat, and {dot over (m)} is a mass flow
rate of air that is compressed through the compressor 134.
[0060] A pressure of intake air before and after being compressed
through the compressor 134 has a relationship of Equation 3.
T 2 T 1 = P 1 P 2 ( Equation 3 ) ##EQU00002##
[0061] Here, T1 is a temperature of intake air before being
compressed through the compressor 134, T2 is a temperature of
intake air after being compressed through the compressor 134, P1 is
a pressure of intake air before being compressed through the
compressor 134, and P2 is a pressure of intake air after being
compressed through the compressor 134.
[0062] An intake temperature of the front end of the water-cooled
intercooler 120 may be estimated through the HFM sensor 140 that is
provided at the front end of the compressor 134 with a method.
Therefore, because it is unnecessary to have a separate temperature
sensor at the front end of the water-cooled intercooler 120, a
production cost of a product can be reduced.
[0063] The controller 170 controls the EWP 128 using a heat
releasing amount of the intake air.
[0064] Specifically, if a heat releasing amount of intake air is
smaller than a predetermined value, the controller 170 turns on
operation of the EWP 128, and if a heat releasing amount of intake
air is a predetermined value or more, the controller 170 turns off
operation of the EWP 128.
[0065] A heat releasing amount of the intake air being smaller than
a predetermined value device that a temperature change of intake
air that passes through the water-cooled intercooler 120 is small.
That is, it device a case in which intake air is not cooled through
the water-cooled intercooler 120. Therefore, by turning on
operation of the EWP 128, intake air passing through the
water-cooled intercooler 120 is cooled.
[0066] In contrast, a heat releasing amount of the intake air being
a predetermined value or more device that a temperature change of
intake air that passes through the water-cooled intercooler 120 is
large. That is, it device a case in which intake air is fully
cooled through the water-cooled intercooler 120. Therefore, by
turning off operation of the EWP 128, cooling of intake air passing
through the water-cooled intercooler 120 is stopped.
[0067] Here, the predetermined value may be changed according to
engine RPM and an engine load. That is, the predetermined value is
previously stored at the controller 170 in a map data form
according to engine RPM and an engine load. In this case, as engine
RPM increases, the predetermined value increases, and as an engine
load increases, the predetermined value increases.
[0068] Therefore, when a vehicle drives in a high speed and high
load condition, the EWP 128 operates much more compared with when a
vehicle drives in a low speed and low load condition.
[0069] Hereinafter, a method of controlling a water pump of a
vehicle having a water-cooled intercooler according to an exemplary
embodiment of the present invention will be described in
detail.
[0070] FIG. 2 is a flowchart illustrating a method of controlling a
water pump of a vehicle having a water-cooled intercooler.
[0071] As shown in FIG. 2, an intake temperature of the rear end of
the water-cooled intercooler 120 and an intake temperature of the
front end of the water-cooled intercooler 120 are measured through
the second temperature sensor 124 and the first temperature sensor
122, respectively (S10). The controller 170 calculates an intake
temperature difference dT between the front end and the rear end of
the water-cooled intercooler 120 from the intake temperature that
is measured through the first temperature sensor 122 and the second
temperature sensor 124 (S20).
[0072] Alternatively, an intake temperature of the rear end of the
water-cooled intercooler 120 is measured through the second
temperature sensor 124, and an intake temperature of the front end
of the water-cooled intercooler 120 is estimated using a
temperature that is measured through the HFM sensor 140 (S10). In
this case, an intake temperature of the front end of the
water-cooled intercooler 120 may be estimated through Equations 2
and 3. The controller 170 calculates an intake temperature
difference dT of the front end and the rear end of the water-cooled
intercooler 120 from an intake temperature of the front end of the
water-cooled intercooler 120 that is estimated through the HFM
sensor 140 and an intake temperature that is measured through the
second temperature sensor (S20).
[0073] The controller 170 calculates a heat releasing amount Q of
intake air using a temperature difference dT of intake air passing
through the water-cooled intercooler 120 that is calculated at step
S20, an intake air amount m passing through the water-cooled
intercooler 120, and a specific heat of intake air (S30). In this
case, the heat releasing amount Q of intake air may be calculated
by Equation 1.
[0074] The controller 170 determines whether a heat releasing
amount Q of intake air is smaller than a predetermined value
(S40).
[0075] If a heat releasing amount Q of intake air is smaller than a
predetermined value, the controller 170 turns on operation of the
EWP 128 to cool intake air passing through the water-cooled
intercooler 120 (S60).
[0076] If a heat releasing amount Q of intake air is a
predetermined value or more, the controller 170 turns off operation
of the EWP 128 to stop cooling intake air passing through the
water-cooled intercooler 120 (S50).
[0077] As described above, the predetermined value is previously
stored at the controller 170 in a map data form according to engine
RPM and an engine load, and as engine RPM increases, the
predetermined value increases, and as an engine load increases, the
predetermined value increases.
[0078] 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.
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