FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
OUTDOOR UNIT, INDOOR UNIT, AND AIR CONDITIONER;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED
AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
DESCRIPTION
5 Field
[0001] The present invention relates to an outdoor unit
including two air blowers, an indoor unit including two air
blowers, and an air conditioner.
10 Background
[0002] Outdoor units of air conditioners (with heater)
include air blowers that are used to pass air through heat
exchangers. Moreover, airflow generated by an air blower
is also used to lower the temperature of a cooling fin. A
15 cooling fin cools power devices that are power
semiconductor devices on a compressor drive substrate. An
outdoor unit in some cases includes a plurality of air
blowers. Patent literature 1 discloses an outdoor unit
that includes upper and lower air blowers and in which the
20 upper air blower cools a cooling fin with higher efficiency
than the lower air blower. Moreover, the outdoor unit
described in Patent Literature 1 cools the cooling fin
efficiently by individually controlling the ratio of the
number of rotations between the air blowers in accordance
25 with the temperature of the cooling fin.
Citation List
Patent Literature
[0003] Patent Literature 1: Japanese Patent Application
30 Laid-open No. 2013-24537
Summary
Technical Problem
3
[0004] However, if the upper and lower air blowers of
the outdoor unit described in Patent Literature 1 are
disposed the other way round or if the leads connecting the
air blowers to the control substrate are connected the
other way round, the ratio of the number 5 of rotations
between the air blowers is controlled in a vertically
reverse manner. This results in insufficient cooling of
the power devices on the compressor drive substrate. Thus,
there is a problem in that heat generation in the power
10 devices cannot be reduced and the air-conditioning capacity
of the air conditioner decreases.
[0005] The present invention has been achieved in view
of the above and an object of the present invention is to
provide an outdoor unit capable of inhibiting reduction in
15 air-conditioning capacity of an air conditioner.
Solution to Problem
[0006] In order to solve the above problems and achieve
the object, an outdoor unit according to aspect of the
20 present invention includes: a heat exchanger to exchange
heat between refrigerant and air; a first air blower and a
second air blower to blow air on the heat exchanger; a
compressor drive unit to drive a compressor compressing the
refrigerant, the compressor drive unit including a power
25 device; a cooling fin to cool the power device; a coolingfin-
temperature detection unit to detect temperature of the
cooling fin; and a position determination unit to determine
a position of the first air blower and a position of the
second air blower by using the temperature of the cooling
30 fin.
Advantageous Effects of Invention
[0007] An outdoor unit according to the present
4
invention provides an effect of inhibiting reduction in
air-conditioning capacity of an air conditioner.
Brief Description of Drawings
[0008] FIG. 1 is a diagram illustrating 5 a configuration
of an air conditioner according to a first embodiment.
FIG. 2 is a diagram illustrating an internal
configuration of an outdoor unit according to the first
embodiment.
10 FIG. 3 is a diagram illustrating a control circuit
according to the first embodiment.
FIG. 4 is a flowchart illustrating an operation of an
air-blower-position determination unit according to the
first embodiment.
15 FIG. 5 is a graph illustrating the relationship
between determination temperature and outside temperature
according to the first embodiment.
FIG. 6 is a graph illustrating another example of the
relationship between determination temperature and outside
20 temperature according to the first embodiment.
FIG. 7 is a diagram illustrating an internal
configuration of an indoor unit according to a second
embodiment.
25 Description of Embodiments
[0009] An outdoor unit, an indoor unit, and an air
conditioner according to embodiments of the present
invention will be explained below in detail with reference
to the drawings. This invention is not limited to the
30 embodiments.
[0010] First Embodiment.
FIG. 1 is a diagram illustrating a configuration of an
air conditioner (with heater) according to a first
5
embodiment. An air conditioner 100 includes an outdoor
unit 50 and an indoor unit 51. The outdoor unit 50 and the
indoor unit 51 are connected via a gas connection pipe 52
and a liquid connection pipe 53. The gas connection pipe
52 and the liquid connection pipe 53 may 5 be collectively
referred to as a refrigerant pipe. The refrigerant pipe is
filled with refrigerant, and the refrigerant circulates
between the outdoor unit 50 and the indoor unit 51 via the
refrigerant pipe, whereby the air conditioner 100 exchanges
10 heat between the indoors and the outdoors.
[0011] FIG. 2 is a diagram illustrating an internal
configuration of the outdoor unit 50 according to the first
embodiment. The outdoor unit 50 includes a first air
blower 2, a second air blower 3, a cooling fin 4, a
15 cooling-fin-temperature detection unit 5, a compressor 6, a
control substrate 7, a compressor drive substrate 8, a heat
exchanger 9, a pipe temperature detection unit 10, an air
temperature detection unit 11, and an air-blower-position
determination unit 12. The first air blower 2 blows air on
20 the heat exchanger 9. The second air blower 3 is installed
below the first air blower 2 and blows air on the heat
exchanger 9. Moreover, the first air blower 2 and the
second air blower 3 blow air on the cooling fin 4. The
first air blower 2 is installed at a position closer to the
25 cooling fin 4 than the second air blower 3. The cooling
fin 4 cools power devices of a compressor drive unit. The
cooling-fin-temperature detection unit 5 detects the
temperature of the cooling fin 4. The compressor 6
compresses refrigerant. The control substrate 7 includes
30 the air-blower-position determination unit 12. The
compressor drive substrate 8 includes the compressor drive
unit. The compressor drive unit drives the compressor 6
and includes the power devices. The heat exchanger 9
6
exchanges heat between refrigerant and air. The pipe
temperature detection unit 10 detects the temperature of
the refrigerant pipe connected to the heat exchanger 9.
The air temperature detection unit 11 includes an outside
temperature thermistor and detects the outside 5 temperature.
The air temperature detection unit 11 is installed at the
inlet of the heat exchanger 9. The air-blower-position
determination unit 12 determines the positions of the first
air blower 2 and the second air blower 3. The air-blower10
position determination unit 12 is referred to also as a
position determination unit.
[0012] The outdoor unit 50 includes an air blower
chamber 60 and a machine chamber 61. The first air blower
2 and the second air blower 3 are disposed in the air
15 blower chamber 60. The air temperature detection unit 11
is disposed outside the air blower chamber 60. The
cooling-fin-temperature detection unit 5, the compressor 6,
the control substrate 7, the compressor drive substrate 8,
the pipe temperature detection unit 10, and the air-blower20
position determination unit 12 are disposed in the machine
chamber 61. As illustrated in FIG. 2, the cooling fin 4 is
disposed such that it projects from the machine chamber 61
into the air blower chamber 60. The first air blower 2 and
the second air blower 3 are each connected to the control
25 substrate 7 with a lead. Moreover, the first air blower 2
and the second air blower 3 are each supplied with power
and a drive signal for driving from the control substrate 7.
[0013] The cooling-fin-temperature detection unit 5, the
pipe temperature detection unit 10, the air temperature
30 detection unit 11, and the air-blower-position
determination unit 12 are implemented by processing
circuitry that is electronic circuitry that performs each
processing.
7
[0014] The processing circuitry may be dedicated
hardware or may be a control circuit that includes a memory
and a central processing unit (CPU) that executes programs
stored in the memory. Here, the memory corresponds to, for
example, a non-volatile or volatile semiconductor 5 memory
such as a random access memory (RAM), a read-only memory
(ROM), and a flash memory, a magnetic disk, an optical disk,
or the like. In the case where the processing circuitry is
a control circuit that includes a CPU, the control circuit
10 is, for example, a control circuit 200 having a
configuration illustrated in FIG. 3.
[0015] As illustrated in FIG. 3, the control circuit 200
includes a processor 200a, which is a CPU, and a memory
200b. In the case where the above-described units are
15 implemented by the control circuit 200 illustrated in FIG.
3, these units are implemented by the processor 200a
reading and executing the programs corresponding to the
respective processing, stored in the memory 200b. The
memory 200b is also used as a temporary memory in each
20 processing executed by the processor 200a.
[0016] The operation of the outdoor unit 50 will be
described. The outdoor unit 50 controls the temperature of
the refrigerant and the pressure of the refrigerant by
changing the number of rotations of the air blowers. Here,
25 the number of rotations indicates the number of rotations
per unit time, i.e., the rotation speed. A greater number
of rotations indicates a higher rotation speed, and a
smaller number of rotations indicates a lower rotation
speed. The refrigerant is compressed by the compressor 6.
30 When it is necessary to exchange more heat between air and
the refrigerant, the outdoor unit 50 increases the number
of rotations of each of the first air blower 2 and the
second air blower 3. In contrast, when it is not necessary
8
to exchange a large amount of heat between air and the
refrigerant, the outdoor unit 50 reduces the number of
rotations of each of the first air blower 2 and the second
air blower 3. Moreover, the outdoor unit 50 can further
reduce the heat exchange by stopping the 5 second air blower
3 and operating only the first air blower 2. The first air
blower 2 blows air on the cooling fin 4 attached to the
power devices of the compressor drive unit to cool the
power devices. When the temperature of the power devices
10 of the compressor drive unit is high, the number of
rotations of the first air blower 2 is increased to blow
air on the cooling fin 4, thereby cooling the power devices
and increasing the reliability of the power devices. This
means that the first air blower 2 has two roles, i.e.,
15 controlling the temperature and pressure of the refrigerant
and cooling the power devices of the compressor drive unit.
[0017] At the time of product shipment, the first air
blower 2 and the second air blower 3 are installed at the
defined positions and thus no problem occurs. However, if
20 the first air blower 2 or the second air blower 3 fails or
if the control substrate 7 fails, the position of the first
air blower 2 and the position of the second air blower 3
may be reversed after component replacement or the like.
When heat exchange is performed by using only the first air
25 blower 2 in a state where the position of the first air
blower 2 and the position of the second air blower 3 are
reversed, air cannot be blown on the cooling fin 4. This
results in insufficient cooling of the power devices and
may thus lead to thermal destruction of the power devices.
30 For this reason, it is important to install the first air
blower 2 and the second air blower 3 at the correct
positions. The outdoor unit 50 according to the first
embodiment enables determination of the position of the
9
first air blower 2 used for cooling the power devices in a
case where the outdoor unit 50 includes a plurality of air
blowers.
[0018] FIG. 4 is a flowchart illustrating the operation
of the air-blower-position determination 5 unit 12 according
to the first embodiment. The air-blower-position
determination unit 12 detects whether the compressor 6 in
operation has stopped (Step S1). When the air-blowerposition
determination unit 12 detects that the compressor
10 6 in operation has stopped (Yes in Step S1), the airblower-
position determination unit 12 determines whether
the duration of operation of the compressor 6 is longer
than or equal to t1 (Step S2). The period of time t1
indicates the period of time necessary for the temperature
15 of the power devices of the compressor drive unit to
increase sufficiently as a result of continuous operation
of the compressor 6 and necessary for the difference
between the temperature of the power devices and the
outside temperature to become large. When the duration of
20 operation of the compressor 6 is shorter than t1 (No in
Step S2), the process returns to Step S1. When the
duration of operation of the compressor 6 is longer than or
equal to t1 (Yes in Step S2), the air-blower-position
determination unit 12 detects outside temperature Ta by
25 using the outside temperature thermistor of the air
temperature detection unit 11 (Step S3). The air-blowerposition
determination unit 12 determines determination
temperature A indicating the temperature for determining
the positions of the air blowers (Step S4). The
30 determination temperature A is a value obtained by
subtracting the temperature of the cooling fin 4 before the
compressor 6 operates from the temperature of the cooling
fin 4 after the compressor 6 has operated for t1 or longer.
10
In other words, the determination temperature A is the
amount of change in the temperature of the cooling fin 4.
Moreover, the determination temperature A is the threshold
used for determining whether air is blown on the cooling
fin 4. The determination temperature 5 A is compared with
cooling fin temperature Th indicating the temperature of
the cooling fin 4.
[0019] The outside temperature Ta and the determination
temperature A will be described. FIG. 5 is a graph
10 illustrating the relationship between the determination
temperature and the outside temperature according to the
first embodiment. In FIG. 5, the vertical axis indicates
the determination temperature A and the horizontal axis
indicates the outside temperature Ta. As illustrated in
15 FIG. 3, the first air blower 2 brings in the outside air to
cool the cooling fin 4; therefore, as the outside
temperature Ta increases, the cooling performance of the
cooling fin 4 decreases. Thus, as the outside temperature
Ta increases, the amount of change in the temperature of
20 the cooling fin 4 decreases. That is, the determination
temperature A in the case when the outside temperature Ta
is high is lower than the determination temperature A in
the case when the outside temperature Ta is low.
[0020] The air-blower-position determination unit 12
25 operates the first air blower 2 and detects the cooling fin
temperature Th (Step S5). The air-blower-position
determination unit 12 determines whether the cooling fin
temperature Th is lower than the determination temperature
A (Step S6). When the cooling fin temperature Th is lower
30 than the determination temperature A (Yes in Step S6), the
air-blower-position determination unit 12 determines that
the first air blower 2 is the air blower installed above
the second air blower 3, that is, the air blower placed
11
closer to the cooling fin 4 than the second air blower 3,
and determines that the second air blower 3 is the air
blower placed below the first air blower 2 (Step S7). When
the cooling fin temperature Th is higher than or equal to
the determination temperature A (No in 5 Step S6), the airblower-
position determination unit 12 determines that the
second air blower 3 is the air blower installed above the
first air blower 2, that is, the air blower placed closer
to the cooling fin 4 than the first air blower 2, and
10 determines that the first air blower 2 is the air blower
installed below the second air blower 3 (Step S8).
[0021] When the compressor 6 stops after continuous
operation for a predetermined period of time, the power
devices of the compressor drive unit generate heat due to
15 the loss generated during operation and thus the
temperature of the power devices becomes higher than the
outside temperature. In such a case, by operating the air
blower that is installed on the opposite side of the
cooling fin 4 to the power devices, air is blown on the
20 cooling fin 4 and the power devices are cooled. As the
outside temperature Ta gets lower, the cooling fin
temperature Th decreases more sharply. In contrast, as the
outside temperature gets higher, the cooling fin
temperature Th decreases more gradually. Meanwhile, when
25 the air blower installed in a place around which the
cooling fin 4 for the power devices is not installed is
operated, air is not blown on the cooling fin 4 and thus
the temperature of the cooling fin 4 does not substantially
decrease. The air-blower-position determination unit 12
30 uses the difference in this temperature change to determine
the positions of the first air blower 2 and the second air
blower 3.
[0022] In Step S3, the air-blower-position determination
12
unit 12 may make the determination by using the temperature
of the liquid connection pipe 53 instead of the temperature
of the cooling fin 4. When the first air blower 2 is
operated, the temperature of the liquid connection pipe 53
approaches the outside temperature. The 5 temperature of the
liquid connection pipe 53 is detected by the pipe
temperature detection unit 10. In this case, the
determination temperature A is a value obtained by
subtracting the temperature of the liquid connection pipe
10 53 before the compressor 6 operates from the temperature of
the liquid connection pipe 53 after the compressor 6 has
operated for t1 or longer. In other words, the
determination temperature A is the amount of change in the
temperature of the liquid connection pipe 53. When the
15 air-blower-position determination unit 12 makes the
determination by using the temperature of the liquid
connection pipe 53, the relationship between the outside
temperature Ta and the determination temperature A is
different depending on the air conditioning settings of the
20 air conditioner 100. When the air conditioner 100 is set
to heating mode, the temperature of the liquid connection
pipe 53 is lower than the outside temperature. Thus, the
outside temperature Ta and the determination temperature A
have an inverse relationship as illustrated in FIG. 5.
25 [0023] FIG. 6 is a graph illustrating another example of
the relationship between the determination temperature and
the outside temperature according to the first embodiment.
When the air conditioner 100 is set to cooling mode, the
temperature of the liquid connection pipe 53 is higher than
30 the outside temperature. Thus, the outside temperature Ta
and the determination temperature A have a direct
relationship as illustrated in FIG. 6. When the
temperature of the liquid connection pipe 53 is used to
13
make the determination, t1 is the period of time necessary
for the temperature of the liquid connection pipe 53 to
change sufficiently as a result of continuous operation of
the compressor 6 and necessary for the difference between
the temperature of the liquid connection 5 pipe 53 and the
outside temperature to become large.
[0024] The cooling fin 4 may be disposed not to project
into the air blower chamber 60, and the configuration may
be such that the cooling fin 4 is cooled by the air drawn
10 from the machine chamber 61 side through a duct by any of
the air blowers installed in the air blower chamber 60.
When the output frequency of the compressor 6 is low, the
characteristics in the graphs between the outside
temperature and the determination temperature A illustrated
15 in FIGS. 5 and 6 cannot be satisfied in some cases. For
this reason, the determination may be made only when the
compressor 6 operates with frequency f or higher. The
frequency f is, for example, the lower limit of the
frequency of the compressor 6 within the range within which
20 the characteristics in the graphs illustrated in FIGS. 5
and 6 are satisfied. It is satisfactory if the frequency f
is determined based on the frequency of the compressor 6
that satisfies the characteristics in the graphs
illustrated in FIGS. 5 and 6, and is not limited to the
25 lower limit described above. The frequency f may be, for
example, a value higher than the lower limit described
above.
[0025] Examples of a method of determining the position
of the first air blower 2 and the position of the second
30 air blower 3 include a method of differentiating between
the shapes of the connectors connecting the respective air
blowers to the control substrate 7 and a method of
differentiating between the attachment structures of the
14
air blowers. However, the above methods cause the air
blowers to have different specifications and thus the air
blowers cannot share specifications in common, which leads
to an increase in costs and complexity of parts management
due to the differentiation. However, with 5 the air-blowerposition
determination unit 12 of the outdoor unit 50
according to the first embodiment, the first air blower 2
and the second air blower 3 can have common specifications;
therefore, the cost can be reduced and the parts management
10 can be simplified.
[0026] As described above, with the outdoor unit 50
according to the present embodiment, the air-blowerposition
determination unit 12 can regularly determine the
position of the first air blower 2 that blows air on the
15 cooling fin 4. Thus, even when the air blowers are
replaced and, as a result, the position of the first air
blower 2 and the position of the second air blower 3 are
reversed, the air-blower-position determination unit 12 can
determine the positions of the air blowers and can switch
20 control between the first air blower 2 and the second air
blower 3. Moreover, even when the first air blower 2 and
the second air blower 3 are individually controlled, the
power devices can be cooled by allowing the air-blowerposition
determination unit 12 to switch control.
25 Consequently, the reliability of the power devices of the
compressor drive unit can be prevented from degrading.
Therefore, reduction in air-conditioning capacity of the
air conditioner 100 can be inhibited.
[0027] Second Embodiment.
30 A description will be given of an operation of
determining the positions of the air blowers in the indoor
unit of the air conditioner according to a second
embodiment. Components having the same functions as those
15
in the first embodiment are denoted by the same reference
symbols as those in the first embodiment and duplicate
descriptions will be omitted.
[0028] FIG. 7 is a diagram illustrating an internal
configuration of an indoor unit according 5 to the second
embodiment. The configuration of an indoor unit 51a is
different from that of the outdoor unit 50 in that the
indoor unit 51a includes a third air blower 21 instead of
the first air blower 2 and includes a fourth air blower 22
10 instead of the second air blower 3. Further, the indoor
unit 51a includes an air blower drive substrate 23 instead
of the compressor drive substrate 8. The air blower drive
substrate 23 includes an air blower drive unit. The air
blower drive unit drives the third air blower 21 and the
15 fourth air blower 22, and includes power devices. The
indoor unit 51a does not include the compressor 6. The
functional units other than the first air blower 2, the
second air blower 3, the compressor drive substrate 8, and
the compressor 6 are provided in the indoor unit 51a in a
20 similar manner to the indoor unit 51a. The third air
blower 21 blows air on the heat exchanger 9. The cooling
fin 4 cools the power devices of the air blower drive unit.
The fourth air blower 22 is installed on the left side of
the third air blower 21 and blows air on the heat exchanger
25 9. Moreover, the third air blower 21 and the fourth air
blower 22 blow air on the cooling fin 4. The air
temperature detection unit 11 detects the temperature drawn
in by the indoor unit 51a.
[0029] In the first embodiment, the outside temperature
30 is used to determine the positions of the air blowers;
however, in the position determination operation for the
air blowers in the second embodiment, the suction
temperature drawn in by the indoor unit 51a is used instead
16
of the outside temperature. The relationship between the
determination temperature A and the temperature of the air
drawn in by the indoor unit 51a is the same as the
relationship between the determination temperature A and
the outside temperature Ta in the first 5 embodiment. The
position determination operation other than the operation
of comparing the determination temperature A with the
temperature of the air drawn in by the indoor unit 51a is
similar to that in the first embodiment.
10 [0030] The determination may be made by using, instead
of using the suction temperature of the indoor unit 51a,
the refrigerant pipe temperature with which a similar
effect can be obtained. Functions as a condenser and an
evaporator in the indoor unit 51a are opposite to those in
15 the outdoor unit. Thus, when the air conditioner 100 is
set to cooling mode, the temperature of the liquid
connection pipe 53 is lower than the outside temperature.
Thus, the outside temperature Ta and the determination
temperature A have an inverse relationship as illustrated
20 in FIG. 5. When the air conditioner 100 is set to heating
mode, the temperature of the liquid connection pipe 53 is
higher than the outside temperature. Thus, the outside
temperature Ta and the determination temperature A have a
direct relationship as illustrated in FIG. 6. The cooling
25 fin 4 may be disposed not to project into the air blower
chamber, and the configuration may be such that the cooling
fin 4 is cooled by the air drawn from the machine chamber
side through a duct by any of the air blowers installed in
the air blower chamber. Alternatively, the configuration
30 may be such that an electrical item is surrounded by metal
plates and is cooled by directly applying the air blown
from the air blower to the metal plates.
[0031] As described above, in the present embodiment, in
17
the indoor unit 51a of the air conditioner including a
plurality of air blowers, the position of the air blower
for blowing air on the cooling fin 4 can be regularly
determined. Thus, even when the air blowers of the indoor
unit 51a are replaced and, as a result, 5 the positions of
the third air blower 21 and the fourth air blower 22 are
reversed, the positions of the air blowers can be
determined and it is possible to switch control between the
air blowers. Moreover, even when a plurality of air
10 blowers are individually controlled, the power devices can
be cooled. Consequently, the reliability of the power
devices of the compressor drive unit can be prevented from
degrading. Therefore, reduction in air-conditioning
capacity of the air conditioner can be inhibited.
15 [0032] The configurations illustrated in the above
embodiments merely illustrate examples of the content of
the present invention, and can thus be combined with
another known technique or partially omitted and/or
modified without departing from the scope of the present
20 invention.
Reference Signs List
[0033] 2 first air blower; 3 second air blower; 4
cooling fin; 5 cooling-fin-temperature detection unit; 6
25 compressor; 7 control substrate; 8 compressor drive
substrate; 9 heat exchanger; 10 pipe temperature
detection unit; 11 air temperature detection unit; 12
air-blower-position determination unit; 21 third air
blower; 22 fourth air blower; 23 air blower drive
30 substrate; 50 outdoor unit; 51, 51a indoor unit; 52 gas
connection pipe; 53 liquid connection pipe; 60 air blower
chamber; 61 machine chamber; 100 air conditioner; 200
control circuit; 200a processor; 200b memory.
18
We Claim :
1. An outdoor unit comprising:
a heat exchanger to exchange heat between refrigerant
and air;
a first air blower and a second air 5 blower to blow air
on the heat exchanger;
a compressor drive unit to drive a compressor
compressing the refrigerant, the compressor drive unit
including a power device;
10 a cooling fin to cool the power device;
a cooling-fin-temperature detection unit to detect
temperature of the cooling fin; and
a position determination unit to determine a position
of the first air blower and a position of the second air
15 blower by using the temperature of the cooling fin.
2. The outdoor unit according to claim 1, wherein
when the temperature of the cooling fin after the
first air blower is operated is lower than a determination
20 temperature, the position determination unit determines
that the first air blower is located at a position closer
to the cooling fin than the second air blower.
3. The outdoor unit according to claim 2, comprising an
25 air temperature detection unit to detect outside air
temperature, wherein
the determination temperature is calculated by using
the outside air temperature.
30 4. The outdoor unit according to claim 1, comprising a
pipe temperature detection unit to detect temperature of a
refrigerant pipe connected to the heat exchanger, wherein
the position determination unit determines a position
19
of the first air blower and a position of the second air
blower by using the temperature of the refrigerant pipe.
5. An indoor unit comprising:
a heat exchanger to exchange heat between 5 refrigerant
and air;
a third air blower and a fourth air blower to blow air
on the heat exchanger;
an air blower drive unit to drive the third air blower
10 and the fourth air blower, the air blower drive unit
including a power device;
a cooling fin to cool the power device;
a cooling-fin-temperature detection unit to detect
temperature of the cooling fin; and
15 a position determination unit to determine a position
of the third air blower and a position of the fourth air
blower by using the temperature of the cooling fin.
6. The indoor unit according to claim 5, wherein
20 when the temperature of the cooling fin after the
third air blower is operated is lower than a determination
temperature, the position determination unit determines
that the third air blower is located at a position closer
to the cooling fin than the fourth air blower.
25
7. The indoor unit according to claim 6, comprising an
air temperature detection unit to detect suction
temperature, wherein
the determination temperature is calculated by using
30 the suction temperature.
8. The indoor unit according to claim 5, comprising a
pipe temperature detection unit to detect temperature of a
20
refrigerant pipe connected to the heat exchanger, wherein
the position determination unit determines a position
of the third air blower and a position of the fourth air
blower by using the temperature of the refrigerant pipe.
5
9. An air conditioner comprising:
the outdoor unit according to any one of claims 1 to
4; and
an indoor unit connected to the outdoor unit via a
10 refrigerant pipe.
10. An air conditioner comprising:
the indoor unit according to any one of claims 5 to 8;
and
15 an outdoor unit connected to the indoor unit via a
refrigerant pipe.