Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02529867 2005-12-12
HEAT EXCHANGER AND AIR CONDITIONER USING THE SAME
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to an air
conditioner, and, more particularly, to a heat exchanger
which contains a path switching member for switching the
flow path of a refrigerant, thereby achieving easy
control of cooling or heating capacity based on an
external load, and an air conditioner using the same.
Description of the Related Art
Generally, an air conditioner is an apparatus for
cooling or heating a room, in order to create a more
pleasant room environment. The air conditioner sucks
indoor air to heat or cool the air, and discharges the
heated or cooled air into a room.
FIG. 1 is a configuration diagram schematically
illustrating a conventional air conditioner. FIG. 2 is a
configuration diagram schematically illustrating the
interior of a conventional heat exchanger.
As shown in FIG. 1, the conventional air
conditioner comprises: a compressor 2 to compress low
temperature and low-pressure gaseous refrigerant into a
high-temperature and high-pressure state; a condenser to
1
CA 02529867 2005-12-12
condense the refrigerant, discharged from the compressor
2, into liquid refrigerant by emitting heat to the
surroundings (i.e. an outdoor heat exchanger 4 upon
cooling, or indoor heat exchanger 8 upon heating); an
expansion member 6 to expand the liquid refrigerant,
condensed by the condenser, into a low-temperature and
low-pressure 2-phase gas/liquid refrigerant; and an
evaporator to change the 2-phase refrigerant into the
gaseous refrigerant by absorbing heat from the
surroundings (i.e. the indoor heat exchanger 8 upon
cooling, or outdoor heat exchanger 4 upon heating).
The compressor 2 is a constant-speed compressor
having a constant capacity. In this type of compressor,
a bypass member 10 is installed between suction and
discharge portions of the compressor 2, in order to
control the capacity of the compressor 2 when a desired
cooling load is low as compared to the capacity of the
compressor 2.
The bypass member 10 includes : a bypass path 12 to
connect the suction and discharge portions of the
compressor 2; and an opening/closing valve 14 provided at
the bypass path 12 to open or close the bypass path 12.
The indoor heat exchanger 4 includes: a panel
shaped heat exchanger body 16 to perform a heat exchange
operation between a refrigerant and outdoor air; a
suction header 18 provided at a side of the heat
2
CA 02529867 2005-12-12
exchanger body 16 to suck the refrigerant discharged from
the compressor 2; one or more tubes 20 branched from the
suction header 18; and a discharge header 22 to discharge
the heat exchanged refrigerant, the tubes 20 being merged
at the discharge header 22.
The interior configuration of the indoor heat
exchanger is applicable to the outdoor heat exchanger in
the same manner.
V~hen the conventional air conditioner having the
above-described configuration performs a cooling
operation, first, the high-temperature and high-pressure
refrigerant, discharged from the compressor 2, is
introduced into the outdoor heat exchanger 4 that serves
as a condenser. Thereby, the refrigerant emits heat to
the surroundings.
Subsequently, the refrigerant, having passed
through the outdoor heat exchanger 4, expands into a low-
temperature and low-pressure state while passing through
the expansion member 6. After that, the low-temperature
and low-pressure refrigerant is introduced into the
indoor heat exchanger 8.
Once being introduced into the indoor heat
exchanger 8, the refrigerant absorbs heat from indoor
air, thereby achieving the cooling of a room.
Meanwhile, when it is necessary to reduce the
capacity of the compressor 2, the opening/closing valve
3
CA 02529867 2005-12-12
14 is opened, so that a part of the refrigerant,
discharged from the compressor 2, is again introduced
into the suction portion of the compressor 2 via the
bypass path 12.
Disadvantages of the conventional air conditioner
includes the fact that, as a method for controlling the
cooling capacity of the air conditioner based on a
cooling load, it attempts to bypass the refrigerant
discharged from the compressor 2 to regulate the flow
rate of the refrigerant. However, there is a limitation
to vary the flow rate of the refrigerant being bypassed,
based on an external load. Further, seeing that the
consumption of electricity, required to drive the
compressor 2, is constant, the conventional air
conditioner exhibits excessive electricity consumption,
suffering from low energy efficiency.
SUN~IARY OF THE INVENTION
Therefore, the present invention has been made in
view of the above problems, and it is an object of the
present invention to provide a heat exchanger in which a
refrigerant path switching unit is provided, thereby
achieving an appropriate control of cooling or heating
capacity based on a varying external load, and an air
conditioner using the same.
4
CA 02529867 2005-12-12
In accordance with the present invention, the
above and other objects can be accomplished by the
provision of a heat exchanger comprising: a refrigerant
path defined inside a heat exchanger body for the passage
of a refrigerant; and at least one path switching unit
provided at the refrigerant path to switch the flow path
of the refrigerant, in order to regulate the flow rate of
the refrigerant passing through the refrigerant path.
Preferably, the path switching unit may include: a
bypass path to bypass the refrigerant passing through
the refrigerant path; and an opening/closing valve to
open or close the bypass path.
Preferably, the at least one path switching unit
may include a plurality of path switching units.
Preferably, the refrigerant path may include: a
suction header to suck the refrigerant; a discharge
header to discharge the heat exchanged refrigerant; and
at least one tube to connect the suction header to the
discharge header for the passage of the refrigerant.
Preferably, the bypass path may be formed between
the tube and the discharge header.
Preferably, the opening/closing valve may be
installed at a connection location between the
refrigerant path and the bypass path.
Preferably, the opening/closing valve may be a 3-
way valve.
5
CA 02529867 2005-12-12
Preferably, the at least one tube may include a
plurality of tubes branched from the suction header.
Preferably, the at least one path switching unit
may include a plurality of path switching units, and the
bypass path of each of the path switching units is
connected to an associated one of the tubes.
Preferably, the tube may have a multiple-bend
shape, and the bypass path may connect a bent portion of
the tube to the discharge header.
In the heat exchanger for use in an air
conditioner according to the present invention, as a
result of installing the path switching units at the
tubes that form refrigerant paths, it is possible to
regulate the flow rate of the refrigerant by switching
the flow path of a refrigerant passing through the tubes
in accordance with a cooling or heating load. This has
the effect of achieving an effective control of cooling
or heating capacity thereof based on an external load.
Further, when the heat exchanger provided with the
path switching unit is used along with a variable
capacity compressor, a variation of capacity is possible
even under a low load condition with reduced electricity
consumption.
6
CA 02529867 2005-12-12
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and other
advantages of the present invention will be more clearly
understood from the following detailed description taken
in conjunction with the accompanying drawings, in which:
FIG. 1 is a configuration diagram schematically
illustrating a conventional air conditioner;
FIG. 2 is a configuration diagram schematically
illustrating the interior of a conventional heat
exchanger;
FIG. 3 is a configuration diagram schematically
illustrating an air conditioner according to an
embodiment of the present invention; and
FIG. 4 is a configuration diagram schematically
illustrating the interior of a heat exchanger according
to the embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, an embodiment of the present invention will be
described with reference to the accompanying drawings.
FIG. 3 is a configuration diagram schematically
illustrating an air conditioner according to an
embodiment of the present invention. FIG. 4 is a
configuration diagram schematically illustrating the
7
CA 02529867 2005-12-12
interior of a heat exchanger provided in the air
conditioner according to the embodiment of the present
invention.
As shown in FIG. 3, the air conditioner according
to the present invention comprises: a compressor 50 to
compress low-temperature and low-pressure gaseous
refrigerant into a high-temperature and high-pressure
state; a condenser to condense the refrigerant,
discharged from the compressor 50, into liquid
refrigerant by emitting heat to the surroundings (i.e. an
outdoor heat exchanger 52 upon cooling, or indoor heat
exchanger 54 upon heating); an expansion member 56 to
expand the liquid refrigerant, condensed by the
condenser, into a low-temperature and low-pressure 2-
phase gas/liquid refrigerant; and an evaporator to change
the 2-phase refrigerant into gaseous refrigerant by
absorbing heat of the surroundings (i.e. the indoor heat
exchanger 54 upon cooling, or outdoor heat exchanger 52
upon heating).
The compressor 50 may be a constant-speed
compressor having a constant capacity, or may be a
variable capacity compressor. The following description
is limited to the use of the constant-speed compressor.
The indoor heat exchanger 54 includes: a
refrigerant path defined inside a heat exchanger body 64
for the passage of the refrigerant; and a path switching
8
CA 02529867 2005-12-12
unit 70 to switch the flow path of the refrigerant, in
order to regulate the flow rate of the refrigerant
passing through the refrigerant path.
The refrigerant path includes: a suction header 60
to suck the refrigerant; a discharge header 62 to
discharge the heat exchanged refrigerant; and a plurality
of tubes to connect the suction header 60 to the
discharge header 62 for allowing for the passage of the
refrigerant from the suction header 60 to the discharge
header 62.
The plurality of tubes are branched from the
suction header 60, and each has a multiple-bend shape.
The discharge header 62 is configured so that the
plurality of tubes are merged thereat.
The heat exchanger body 64 has a panel shape. The
plurality of tubes are enclosed by the heat exchanger
body 64. Both the suction header 60 and the discharge
header 62 may be arranged at a side of the heat
exchanger body 64 together, or may be arranged at both
sides of the heat exchanger body 64, respectively.
In association with the plurality of tubes, the
following description is limited to only two tubes, i.e.
a first tube 66 and a second tube 68.
One end of each of the first and second tubes 66
and 68 is connected to the suction header 60, and the
9
CA 02529867 2005-12-12
other ends of the first and second tubes 66 and 68 are
connected to the discharge header 62.
The path switching unit 70 includes: first and
second bypass paths 72 and 76; and opening/closing
valves 74 and 78 to open or close the first and second
bypass paths 72 and 76, respectively. The first and
second bypass paths 72 and 76 connect bent portions of
the first and second tubes 66 and 68 to the discharge
header 62, respectively, to bypass the refrigerant,
passing through the first and second tubes 66 and 68, to
the discharge header 62.
Although the embodiment of the present invention
is limited to the design wherein both the first and
second bypass paths 72 and 76 are provided at selected
bent portions of the first and second tubes 66 and 68,
respectively, it should be understood that the present
invention is not limited to the embodiment, and a
plurality of bypass paths may be provided at a plurality
of locations of the first and second tubes 66 and 68.
The opening/closing valves 74 and 78 are 3-way
valves installed between the selected bent portions of
the f first and second tubes 66 and 68 and the f first and
second bypass paths 72 and 76. In accordance with the
operation of the opening/closing valves 74 and 78, the
first and second bypass paths 72 and 76 are opened when
it is necessary to reduce the flow rate of the
CA 02529867 2005-12-12
refrigerant in accordance with a low cooling load,
whereas are closed when the flow rate of the refrigerant
is appropriate for a desired cooling load.
In an alternative embodiment of the present
invention, solenoid valves may be installed at the first
and second bypass paths 72 and 76, respectively, to open
or close the bypass paths 72 and 76.
Hereinafter, the operation of the air conditioner
having the indoor heat exchanger according to the
present invention as stated above will be explained.
When the air conditioner of the present invention
operates in cooling mode, first, the high-temperature
and high-pressure refrigerant, compressed in the
compressor 50, is introduced into the outdoor heat
exchanger 52 that serves as a condenser. Thereby, the
refrigerant emits heat to the surroundings.
Subsequently, the refrigerant, having passed
through the outdoor heat exchanger 52, expands into a
low-temperature and low-pressure state while passing
through the expansion member 56. After that, the low-
temperature and low-pressure refrigerant is introduced
into the indoor heat exchanger 54.
Once being introduced into the indoor heat
exchanger 54, the refrigerant is divided by way of the
suction header 60, to be introduced into the first and
second tubes 66 and 68. Thereby, the refrigerant is
11
CA 02529867 2005-12-12
heat exchanged with indoor air while passing through the
first and second tubes 66 and 68. Then, after being
discharged from the discharge header 62, the refrigerant
is again circulated into the compressor 50.
As stated above, the refrigerant absorbs heat from
indoor air while passing through the indoor heat
exchanger 54, thereby cooling a room.
In this case, when a cooling load is low, the
first and second 3-way valves 74 and 78 operate to open
the first and second bypass paths 72 and 76.
If the first and second bypass paths 72 and 76 are
opened, the refrigerant, passing through the first and
second tubes 66 and 68 of the indoor heat exchanger 54,
is bypassed into the first and second bypass paths 72
and 76 through the first and second 3-way valves 74 and
78.
ln~hen a cooling load is low, bypassing the
refrigerant, passing through the first and second tubes
66 and 68, into the first and second bypass paths 72 and
76, effectively reduces a heat exchange between the
refrigerant and the indoor air, so that the refrigerant
takes less heat from the indoor air. This ensures the
cooling degree of a room can be lowered in proportional
to the low cooling load.
Accordingly, the cooling temperature of a room can
be regulated with a high cooling load sensitivity.
12
CA 02529867 2005-12-12
Meanwhile, although the above description is
limited to install the path switching unit 70 in the
indoor heat exchanger 54, the path switching unit 70 may
be provided at the outdoor heat exchanger 52 to switch
the flow path of the refrigerant passing through the
outdoor heat exchanger 52 based on a heating load, for
enabling a control of heating capacity.
Also, in an alternative embodiment of the present
invention, the compressor 50 may be a variable capacity
compressor. Using the variable capacity compressor has
several advantages. For example, the size of the
refrigerant path inside the heat exchanger as well as
the consumption of electricity required to drive the
compressor can be reduced. Also, more sensitive
response to a cooling load is possible, and therefore,
an enhancement in cooling efficiency can be achieved.
As apparent from the above description, a heat
exchanger for use in an air conditioner according to the
present invention has the following advantageous
effects.
Firstly, according to the present invention, a
path switching unit is provided in the heat exchanger at
a tube that forms a refrigerant path. The path
switching unit is used to switch the flow path of a
refrigerant passing through the tube in accordance with
a cooling or heating load, thereby regulating the flow
13
CA 02529867 2005-12-12
rate of the refrigerant. The use of the path switching
unit has the effect of achieving an effective control of
cooling or heating capacity thereof based on an external
load.
Secondly, when the heat exchanger provided with
the path switching unit is used along with a variable
capacity compressor, a variation of capacity is possible
even under a low load condition with reduced electricity
consumption.
Although the preferred embodiments of the present
invention have been disclosed for illustrative purposes,
those skilled in the art will appreciate that various
modifications, additions and substitutions are possible,
without departing from the scope and spirit of the
invention as disclosed in the accompanying claims.
14
