U.S. patent application number 12/087100 was filed with the patent office on 2009-01-29 for air conditioner.
Invention is credited to Makoto Kojima, Takayuki Setoguchi.
Application Number | 20090025420 12/087100 |
Document ID | / |
Family ID | 38256422 |
Filed Date | 2009-01-29 |
United States Patent
Application |
20090025420 |
Kind Code |
A1 |
Kojima; Makoto ; et
al. |
January 29, 2009 |
Air Conditioner
Abstract
An air conditioner that reverses and appropriately controls the
stream of refrigerant between paths of a flow divider corresponding
to an air conditioner heat exchanger having a plurality of paths to
increase the heat exchange capacity is provided. The air
conditioner includes a compressor, a four-way valve, an outdoor
heat exchanger, a restriction device, and an indoor heat exchanger
including a plurality of paths. These members are sequentially
connected by a refrigerant pipe to form a refrigerant circuit. A
flow divider including a plurality of paths is arranged between the
indoor heat exchanger, which includes the plurality of paths, and
the restriction device. A refrigerant flow amount regulation valve
is provided for each of the plurality of paths in the flow divider.
In a predetermined operation state, more refrigerant is distributed
to a predetermined passage in which the processing capacity is
large and the refrigerant temperature at an outlet of the indoor
heat exchanger is high in comparison with other paths.
Inventors: |
Kojima; Makoto; (Sakai-shi,
JP) ; Setoguchi; Takayuki; (Sakai-shi, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
38256422 |
Appl. No.: |
12/087100 |
Filed: |
January 16, 2007 |
PCT Filed: |
January 16, 2007 |
PCT NO: |
PCT/JP2007/050476 |
371 Date: |
June 26, 2008 |
Current U.S.
Class: |
62/527 |
Current CPC
Class: |
F25B 2600/2507 20130101;
F25B 41/39 20210101; F24F 1/0059 20130101; F25B 41/385 20210101;
F25B 41/20 20210101; F25B 5/02 20130101; F25B 13/00 20130101 |
Class at
Publication: |
62/527 |
International
Class: |
F25B 41/04 20060101
F25B041/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 16, 2006 |
JP |
2006-007578 |
Claims
1. An air conditioner including a compressor, a four-way valve, an
outdoor heat exchanger, a restriction device, and an indoor heat
exchanger provided with a plurality of paths, wherein the four-way
valve, outdoor heat exchanger, restriction device, and indoor heat
exchanger are sequentially connected by a refrigerant pipe to form
a refrigerant circuit, with a flow divider including a plurality of
paths being arranged between the indoor heat exchanger, which
includes the plurality of paths, and the restriction device, the
air conditioner being characterized by: a refrigerant flow amount
regulation valve provided for each of the plurality of paths in the
flow divider, wherein in a predetermined operation state, more
refrigerant is distributed to a predetermined path in which the
processing capacity is large and the refrigerant temperature at an
outlet of the indoor heat exchanger is high in comparison with
other paths.
2. The air conditioner according to claim 1, being characterized in
that the predetermined operation state is an operation state in
which the load is low, and in the low load state, an opening is
decreased in the refrigerant flow amount regulation valve for the
path at which the processing capacity is small and the refrigerant
temperature at the outlet of the indoor heat exchanger is low so
that a large amount of refrigerant flows to the predetermined path
in which the processing capacity is large and the refrigerant
temperature at the outlet of the indoor heat exchanger is high.
3. The air conditioner according to claim 1, being characterized in
that the predetermined path is a path in which the flow velocity is
high, and in a low load state, an opening is decreased in the
refrigerant flow amount regulation valve for a path in which the
flow velocity is low so that more refrigerant flows to the path
that has a margin in heat exchange capacity and a high flow
velocity.
4. The air conditioner according to claim 1, being characterized in
that the predetermined operation state is an operation state during
a rated load, and in the rated load state, the refrigerant flow
amount regulation valve for each path is completely open, and the
capacity of the heat exchanger is fully used.
Description
TECHNICAL FIELD
[0001] The present invention relates to an air conditioner, and
more particularly, to an air conditioner including a flow divider
for appropriately dividing the flow of refrigerant to a plurality
of paths in an indoor heat exchanger of the air conditioner.
BACKGROUND ART
[0002] FIG. 5 shows the structure of a typical wall-mount air
conditioner (indoor equipment) 21 employing a cross flow fan 29. As
shown in FIG. 5, the air conditioner 21 includes a main body casing
20 having an upper surface in which a first air intake grille 23 is
formed and a front surface upper portion in which a second air
intake grille 24 is formed. The main body casing 20 also has an air
discharge port 25 arranged in a lower corner of the front
surface.
[0003] An air passage 27 extends from the air intake grilles 23 and
24 to the air discharge port 25 in the main body casing 20. An
indoor heat exchanger 26, which has a V-shaped cross-section so as
to face toward the first and second air intake grilles 23 and 24,
is arranged in an upstream region of the air passage 27. The indoor
heat exchanger 26 is a lambda-type heat exchanger. A cross flow fan
29, a tongue 22, and a scroll 30 are arranged in the downstream
region of the air passage 27. The cross flow fan 29 has an impeller
(fan rotor) 29a, which is rotated in the direction of the arrow
shown in FIG. 5 and which is arranged in an opening 22a of the
tongue 22 and opening 30a of the scroll 30.
[0004] The tongue 22 is located at a position facing toward the
second air intake grill 24 and has a predetermined length along the
outer circumference of the impeller (fan rotor) 29a in the cross
flow fan 29.
[0005] The tongue 22 has a lower portion that is continuous with an
air flow guide 22b, which also serves as a drain pan and which is
arranged below the indoor heat exchanger 26. The air flow guide 22b
has a downstream portion, which extends toward the air discharge
port 25 together with a downstream portion 30b of the scroll 30 and
which forms an air discharge passage 28 having a diffuser structure
as shown in the drawing. As a result, the flow of air generated by
the impeller (fan rotor) 29a of the cross flow fan 29 is
efficiently discharged from the air discharge port 25.
[0006] A stream deflection plate 31 is arranged in the air
discharge passage 28 between the scroll 30 and the air flow guide
22b, which is located at the lower portion of the tongue 22.
[0007] The tongue 22 is shaped as shown in FIG. 5. The flow of air
from the indoor heat exchanger 26 to the air discharge port 25 via
the impeller (fan rotor) 29a of the cross flow fan 29 is curved in
its entirety along the rotation direction of the impeller (fan
rotor) 29a and discharged in a direction perpendicular to the
rotation axis of the impeller (fan rotor) 29a. Then, the flow of
air is curved along the air discharge passage 28 toward the air
discharge port 25 and discharged out of the front surface of the
air conditioner 21.
[0008] In the indoor heat exchanger 26 having such a structure, the
heat exchanger 26 was divided into portions A, B, C, and D to
analyze the flow velocity distribution. As a result, the flow
velocity in portion D, which directly faces toward the second air
intake grille 24, was the highest. The flow velocity was lower than
portion D in portion C, which diagonally faces toward the first air
intake grille 23. Further, the flow velocity was lower than portion
C in portion B, which is covered by the upper portion of the front
surface of the main body casing 20 and thus does not directly
receive the flow of air. The flow velocity was lower than portion B
in portion A, which is blocked by the tongue 22 from the flow of
air.
[0009] An indoor heat exchanger 26 having a plurality of paths in
an air conditioner as described above usually includes a flow
divider 6 including branch flow paths 7a and 7b, as shown in. FIG.
6, to distribute the refrigerant that flows into the main body of
the heat exchanger 26 into each path in the main body of the heat
exchanger 26. The flow divider 6 determines the distribution ratio
of the refrigerant for the branch flow paths 7a and 7b in
accordance with rated operation. An expansion valve V and a
refrigerant inlet 6a are arranged at the entrance of the flow
divider 6. When the load is low, in the indoor heat exchanger 26,
the branch flow path 7a extends through a portion 26a in which the
flow velocity is high, and the branch flow path 7b extends through
a portion 26b in which the flow velocity is low.
[0010] Accordingly, as expressed by the width of the arrows in FIG.
6, during rated operation, the refrigerant temperatures become
substantially the same at the outlet of the paths 8A and 8B, which
are located at the outlet of the heat exchanger 26. However, in a
low load (partial load) state in which the amount of refrigerant
decreases, the flow velocity distribution that differs in
correspondence with the position of the air flow passage in the
heat exchanger 26 has affects that result in problems that will now
be described. For example, as shown in the graph of FIG. 7, the
refrigerant temperature increases at the outlet of the paths 7a and
8A in which the flow velocity is high since there is a margin in
heat exchange capacity. However, in comparison with the refrigerant
temperature at the outlet of the paths 7a and 8A, the refrigerant
temperature becomes lower (refer to .DELTA.T in FIG. 7) at the
outlet of the paths 7b and 8B in which the flow velocity is low
since there is no margin in heat exchange capacity. In the graph of
FIG. 7, the outlet of paths 7a and 8A in which the flow velocity is
high is shown by the blank backgrounds, and the outlet of paths 7b
and 8B in which the flow velocity is low is shown by the shadowed
backgrounds.
[0011] As one solution for solving this problem, a refrigerant flow
amount regulation valve V.sub.1 is arranged in the outlet of the
paths 7b and 8B at which the temperature becomes low at least when
the load is low. As a result, for example, as shown by the graph of
FIG. 9, the temperature (dryness) at the outlet of the paths 7a and
8A is matched with the temperature (dryness) at the outlet of the
paths 7b and 8B (for example, refer to patent publication 1). In
the graph of FIG. 9, the paths of high flow velocity are shown by
the blank backgrounds, and the paths of low flow velocity are shown
by the shadowed backgrounds.
Patent Publication 1: Japanese Laid-Open Patent Publication No.
5-118682
DISCLOSURE OF THE INVENTION
[0012] However, with such a structure, particularly when the
proportions of the shadowed portions in FIGS. 6 and 8 are increased
to increase the dryness, the capacity in a low load state does not
increase that much.
[0013] It is an object of the present invention to provide an air
conditioner that increases the heat exchanging capacity by
appropriately controlling the refrigerant drift between the paths
of a flow divider that corresponds to the heat exchanger of an air
conditioner.
[0014] To achieve the above object, one aspect of the present
invention is an air conditioner including a compressor, a four-way
valve, an outdoor heat exchanger, a restriction device, and an
indoor heat exchanger provided with a plurality of paths. These
members are sequentially connected by a refrigerant pipe to form a
refrigerant circuit. A flow divider including a plurality of paths
is arranged between the indoor heat exchanger, which includes the
plurality of paths, and the restriction device. A refrigerant flow
amount regulation valve is provided for each of the plurality of
paths in the flow divider. In a predetermined operation state, more
refrigerant is distributed to a predetermined path in which the
processing capacity is large and the refrigerant temperature at an
outlet of the indoor heat exchanger is high in comparison with
other paths.
[0015] With this structure, in a predetermined operation state,
more refrigerant is positively distributed to paths having margins
in processing capacities to increase the in-pipe flow velocity in
such paths. Further, the difference between the temperature at the
outlet of the indoor heat exchanger and the intake temperature
increases. This increases the capacity of the indoor heat exchanger
and increases the refrigerant capacity.
[0016] Preferably, the predetermined operation state is an
operation state in which the load is low, and in the low load
state, an opening is decreased in the refrigerant flow amount
regulation valve of the path at which the processing capacity is
small and the refrigerant temperature at the outlet of the indoor
heat exchanger is low so that a large amount of refrigerant flows
to the predetermined path in which the processing capacity is large
and the refrigerant temperature at the outlet of the indoor heat
exchanger is high.
[0017] In this structure, when the load is low and the entire
refrigerant flow amount decreases, the opening of the refrigerant
flow amount regulation valve is decreased for the path at which the
processing capacity is small and the refrigerant temperature at the
outlet of the indoor heat exchanger is low. Further, by
distributing more refrigerant to the predetermined path at which
there is a margin in the processing capacity and the flow velocity
is high, the in-pipe flow velocity of the path increases.
Additionally, the difference between the temperature at the outlet
of the indoor heat exchanger and the intake temperature increases.
As a result, the capacity of the heat exchanger is effectively
increased, and the refrigerant capacity is increased.
[0018] Preferably, the predetermined path is a path in which the
flow velocity is high, and in a low load state, an opening of the
refrigerant flow amount regulation valve is decreased for a path in
which the flow velocity is low so that more refrigerant flows to
the path that has a margin in heat exchange capacity and a high
flow velocity. With this structure, the refrigerant flow amount
regulation valve is closed for a path having a low flow velocity
and no margin in the processing capacity so that more refrigerant
is distributed to a path that has a margin in the processing
capacity and has a high flow velocity. This increases the in-pipe
flow velocity of the path. Additionally, the difference between the
temperature at the outlet of the indoor heat exchanger and the
intake temperature increases. As a result, the capacity of the heat
exchanger is effectively increased, and the refrigerant capacity is
increased.
[0019] Preferably, the predetermined operation state is an
operation state during a rated load, and in the rated load state,
the refrigerant flow amount regulation valve for each path is
completely open, and the capacity of the heat exchanger is fully
used. With this structure, in an operation state during a rated
load, the refrigerant flow amount regulation valve for each path is
completely open, and the capacity of the heat exchanger can be
fully used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a diagram showing a refrigerant circuit of an air
conditioner according to a first embodiment of the present
invention;
[0021] FIG. 2 is a diagram showing the operation and structure of a
heat exchanger including a plurality of paths and a flow divider
corresponding to the paths of the heat exchanger in the indoor
equipment of the air conditioner;
[0022] FIG. 3 is a graph showing the comparison of temperatures at
the outlet of the indoor equipment heat exchanger resulting from
the flow divider shown in FIG. 2 in a rated state and a low load
state;
[0023] FIG. 4 is a diagram showing the operation and structure of a
heat exchanger including a plurality of paths and a flow divider
corresponding to the paths of the heat exchanger in the indoor
equipment of an air conditioner according to a second embodiment of
the present invention;
[0024] FIG. 5 is a diagram showing the structure of the indoor
equipment for an air conditioner of the prior art;
[0025] FIG. 6 is a diagram showing the operation and structure of a
heat exchanger including a plurality of paths and a flow divider
corresponding to the paths of the heat exchanger in the indoor
equipment of an air conditioner:
[0026] FIG. 7 is a graph showing the comparison of temperatures at
the outlet of the indoor equipment heat exchanger resulting from
the flow divider shown in FIG. 6 in a rated state and a low load
state;
[0027] FIG. 8 is a diagram showing the operation and structure of a
heat exchanger including a plurality of paths and a flow divider
corresponding to the paths of the heat exchanger in the indoor
equipment of a prior art air conditioner which has been modified to
cope with the outlet temperature problems; and
[0028] FIG. 9 is a graph showing the comparison of temperatures at
the outlet of the indoor equipment heat exchanger resulting from
the flow divider shown in FIG. 8 in a rated state and a low load
state.
BEST MODE FOR CARRYING OUT THE INVENTION
First Embodiment
[0029] FIGS. 1 and 2 show the structures of a refrigerant circuit
and its flow divider in an air conditioner according to a first
embodiment of the present invention, and FIG. 3 shows the operation
and effect of such a structure. To facilitate description, in the
structure of this embodiment, the heat exchanger 26 is broadly
divided into two flow velocity regions, low flow velocity portions
A and B and high flow velocity portions C and D. Further, the flow
divider 6 has two paths.
[0030] As shown in FIG. 1, the air conditioner includes outdoor
equipment 1 and indoor equipment 10. The outdoor equipment 1
includes a compressor 2, a four-way valve 3, an outdoor heat
exchanger 4, and a restriction device 5. The indoor equipment 10
includes a flow divider 6, an inlet 6a for the flow of refrigerant
into the flow divider 6, a first branch flow path 7a in the flow
divider 6, a second branch flow path 7b in the flow divider 6, an
indoor heat exchanger 26, a first path 8A located at the outlet of
indoor heat exchanger 26, a second path 8B located at the outlet of
the heat exchanger 26, and an expansion valve V. These members are
connected to a first refrigerant pipe 9A and a second refrigerant
pipe 9B to form an irreversible refrigerant circulation circuit as
shown in FIG. 1.
[0031] The expansion valve V and the flow divider 6 are arranged
between the indoor heat exchanger 26 and the restriction device 5.
First and second refrigerant flow amount regulation valves V.sub.1
and V.sub.2 that are electromagnetic valves of which the opening
degrees of each are electrically adjustable. The valves V.sub.1 and
V.sub.2 are respectively arranged in first and second branch flow
paths 7a and 7b of the flow divider 6. Under a predetermined
operation state, more refrigerant is distributed to the one of the
predetermined paths 7a and 7b at which the processing capacity is
larger and the temperature at the outlet of the heat exchanger 26
is higher. This refrigerant distribution amount control is
performed by separately controlling the opening degrees of the
first and second refrigerant flow amount regulation valves V.sub.1
and V.sub.2 with, for example, a predetermined control unit
including a microcomputer.
[0032] In this case, the predetermined operation state is, for
example, a low load operation state in which the amount of
refrigerant flowing to the refrigerant inlet 6a of the flow divider
6 becomes low. For example, as shown in FIG. 2, in a low load
state, when the second branch flow path 7b extends through a
portion 26b in which the flow velocity is low and the first branch
flow path 7a extends through a portion 26a in which the flow
velocity is high, that is, when the flow velocity is low in the
second branch flow path 7b and the flow velocity is high in the
first branch flow path 7a, there is, for example, no margin in heat
exchange capacity. Thus, the opening degree is decreased for the
refrigerant flow amount regulation valve V.sub.2 that corresponds
to the second branch flow path 7b in which the flow velocity is
low. Therefore, in comparison with the second branch flow path 7b,
more refrigerant flows to the first branch flow path 7a, in which
the flow velocity is high and a margin in heat exchange capacity is
provided.
[0033] In this manner, in a low load state in which the entire
refrigerant flow amount decreases, the in-pipe flow velocity
becomes high in the first branch flow path 7a in which the flow
velocity is high by decreasing the opening degree for the
refrigerant flow amount regulation valve V.sub.2 of the second
branch flow path 7b in which the flow velocity is low to distribute
more refrigerant to the first branch flow path 7a in which the flow
velocity is high than the second branch flow path 7b. Further, as
shown by the graph in FIG. 3, the difference .DELTA.T is increased
between the temperature at the outlet of the heat exchanger 26 and
the intake temperature. As a result, the capacity of the indoor
heat exchanger 26 is increased, and the refrigerant capacity is
increased. In the graph of FIG. 3, the first branch flow path 7a is
shown by the blank backgrounds, and the second branch flow path 7b
is shown by the shadowed backgrounds.
[0034] In a rated load state, the first and second refrigerant flow
amount regulation valves V.sub.1 and V.sub.2 are completely open so
that the heat exchange capacity of the heat exchanger 26 is fully
used. As a result, in the present embodiment, in comparison with
the prior art structure that merely equalizes the temperatures at
the outlets of the paths 8A and 8B of the indoor heat exchanger 26,
the heat exchange capacity of the indoor heat exchanger 26 for an
air conditioner is effectively increased.
Second Embodiment
[0035] FIG. 4 shows the structure of a flow divider and a heat
exchanger for an air conditioner according to a second embodiment
of the present invention. In the structure of the first embodiment,
to facilitate description, for example, the indoor heat exchanger
26 of FIG. 6 is divided into two flow velocity regions, low flow
velocity portions A and B and high flow velocity portions C and D,
and refrigerant is distributed to the two paths, the first and
second branch flow paths 7a and 7b. The features of the second
embodiment are in the structure that will now be described. The
flow velocity region of the heat exchanger 26 shown in FIG. 6 is
finely divided into, for example, four flow velocity regions, low
flow velocity portions A, B, and C and high flow velocity portion
D. First, second, third, and fourth branch flow paths 7a to 7d are
respectively arranged in correspondence with the velocity regions.
In the same manner as the first embodiment, first to fourth
refrigerant flow amount regulation valves V.sub.21 to V.sub.24 are
respectively arranged in the branch flow paths 7a to 7d.
[0036] In this manner, in a low load state in which at least the
entire refrigerant flow amount is low, even when using the first to
fourth branch flow paths 7a to 7d, the opening degrees are
decreased for the first to third refrigerant flow amount regulation
valves V.sub.21 to V.sub.23 of the first to third branch flow paths
7a to 7c in which the flow velocity is low and no margin is
provided for the processing capacity. Further, more refrigerant is
distributed to the fourth branch flow path 7d in which the flow
velocity is high and a margin is provided for the processing
capacity. This increases the in-pipe flow velocity of the fourth
branch flow path 7d and increases the difference between the
temperature at the outlet of the indoor heat exchanger 26 and the
intake temperature. As a result, the capacity of the indoor heat
exchanger 26 is increased, and the refrigerant capacity is
increased. In a rated load state, the refrigerant flow amount
regulation valves V.sub.21 to V.sub.24 are completely open so that
the capacity of the heat exchanger 26 is fully used.
* * * * *