U.S. patent application number 13/141741 was filed with the patent office on 2011-10-20 for air conditioning apparatus and method of controlling the air conditioning apparatus.
This patent application is currently assigned to DAIKIN INDUSTRIES, LTD.. Invention is credited to Hidehiko Kinoshita, Tsuyoshi Yamada.
Application Number | 20110252818 13/141741 |
Document ID | / |
Family ID | 42309900 |
Filed Date | 2011-10-20 |
United States Patent
Application |
20110252818 |
Kind Code |
A1 |
Kinoshita; Hidehiko ; et
al. |
October 20, 2011 |
AIR CONDITIONING APPARATUS AND METHOD OF CONTROLLING THE AIR
CONDITIONING APPARATUS
Abstract
An air conditioning apparatus includes a refrigerant circuit, a
refrigerant heating unit and a stop signal controller. The
refrigerant circuit includes a compressor, an indoor heat
exchanger, a pressure reducing mechanism, and an outdoor heat
exchanger. The refrigerant heating unit heats refrigerant flowing
through the refrigerant circuit. The stop signal controller, in a
case of causing the compressor to stop at a time when the
compressor and the refrigerant heating unit are both operating,
executes first stop control in which a stop signal is issued in
order to stop the refrigerant heating unit, and then a stop signal
is issued in order to stop the compressor after elapse of a first
amount of time. A method of controlling an air conditioning
apparatus having the refrigerant circuit and the refrigerant
heating unit includes executing the first stop control.
Inventors: |
Kinoshita; Hidehiko; (Osaka,
JP) ; Yamada; Tsuyoshi; (Osaka, JP) |
Assignee: |
DAIKIN INDUSTRIES, LTD.
Osaka-shi, Osaka
JP
|
Family ID: |
42309900 |
Appl. No.: |
13/141741 |
Filed: |
December 22, 2009 |
PCT Filed: |
December 22, 2009 |
PCT NO: |
PCT/JP2009/007101 |
371 Date: |
June 23, 2011 |
Current U.S.
Class: |
62/115 ; 62/180;
62/228.1 |
Current CPC
Class: |
Y02B 30/741 20130101;
F25B 2600/021 20130101; F25B 2400/01 20130101; Y02B 30/70 20130101;
F25B 13/00 20130101; F25B 2313/02741 20130101; F25B 49/025
20130101 |
Class at
Publication: |
62/115 ;
62/228.1; 62/180 |
International
Class: |
F25B 1/00 20060101
F25B001/00; F25D 17/06 20060101 F25D017/06; F25B 49/02 20060101
F25B049/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 29, 2008 |
JP |
2008-335746 |
Claims
1. An air conditioning apparatus comprising: a refrigerant circuit
including a compressor, an indoor heat exchanger, a pressure
reducing mechanism, and an outdoor heat exchanger; a refrigerant
heating unit arranged to heat refrigerant flowing through the
refrigerant circuit; and a stop signal controller, in a case of
causing the compressor to stop at a time when the compressor and
the refrigerant heating unit are both operating, configured to
execute a first stop control in which a stop signal is issued in
order to stop the refrigerant heating unit, and then a stop signal
is issued in order to stop the compressor after elapse of a first
amount of time.
2. The air conditioning apparatus according to claim 1, further
comprising a heating unit controller configured to control the
refrigerant heating unit, the stop signal in order to stop the
refrigerant heating unit being issued to the heating unit
controller.
3. The air conditioning apparatus according to claim 1, further
comprising an indoor blower arranged to blow air to the indoor heat
exchanger, when the first stop control is executed the stop signal
controller being further configured to issue a stop signal in order
to stop the indoor blower after elapse of a second amount of time
from when the stop signal is issued in order to stop the
refrigerant heating unit.
4. The air conditioning apparatus according to claim 3, wherein
when the first stop control is executed the stop signal controller
being further configured to, before issuing the stop signal in
order to stop the indoor blower, issue an operation signal that
causes the indoor blower to rotate at a low speed.
5. The air conditioning apparatus according to claim 1, further
comprising an indoor controller housed in an indoor unit together
with the indoor heat exchanger, the refrigerant heating unit and
the indoor controller being connected in parallel to the stop
signal controller.
6. The air conditioning apparatus according to claim 1, wherein the
stop signal controller is further configured to not execute the
first stop control and to execute a second stop control when it is
judged that the compressor is in an abnormal state, when the second
stop signal control is executed the stop signal order to stop the
refrigerant heating unit is issued and then, before the elapse of
the first amount of time, the stop signal for stopping the
compressor is issued.
7. The air conditioning apparatus according to claim 1, wherein the
refrigerant circuit includes a plurality of the indoor heat
exchangers that are connected in parallel to the compressor and are
individually housed in multiple indoor units, and the stop signal
controller lengthens the first amount of time the greater the
number of the indoor units there are.
8. The air conditioning apparatus according to claim 1, wherein the
stop signal controller being further configured to, when the first
stop control is executed at a time of a defrosting operation, wait
for the end of the defrosting operation before issuing the stop
signal in order to stop the refrigerant heating unit.
9. A method of controlling an air conditioning apparatus having a
refrigerant circuit including a compressor, an indoor heat
exchanger, a pressure reducing mechanism, and an outdoor heat
exchanger, and a refrigerant heating unit arranged to heat
refrigerant flowing through the refrigerant circuit, the method
comprising: in a case of causing the compressor to stop at a time
when the compressor and the refrigerant heating unit are both
operating, executing a first stop control in which a stop signal in
order to stop the refrigerant heating unit is issued and then a
stop signal is issued in order to stop the compressor after elapse
of a first amount of time.
10. The air conditioning apparatus according to claim 2, further
comprising an indoor blower arranged to blow air to the indoor heat
exchanger, when the first stop control is executed the stop signal
controller being further configured to issue a stop signal in order
to stop the indoor blower after elapse of a second amount of time
from when the stop signal is issued in order to stop the
refrigerant heating unit.
11. The air conditioning apparatus according to claim 10, wherein
when the first stop control is executed the stop signal controller
being further configured to, before issuing the stop signal in
order to stop the indoor blower, issue an operation signal that
causes the indoor blower to rotate at a low speed.
12. The air conditioning apparatus according to claim 2, further
comprising an indoor controller housed in an indoor unit together
with the indoor heat exchanger, the refrigerant heating unit and
the indoor controller being connected in parallel to the stop
signal controller.
13. The air conditioning apparatus according to claim 2, wherein
the stop signal controller is further configured to not execute the
first stop control and to execute a second stop control when it is
judged that the compressor is in an abnormal state, when the second
stop signal control is executed the stop signal order to stop the
refrigerant heating unit is issued and then, before the elapse of
the first amount of time, the stop signal for stopping the
compressor is issued.
14. The air conditioning apparatus according to claim 2, wherein
the refrigerant circuit includes a plurality of the indoor heat
exchangers that are connected in parallel to the compressor and are
individually housed in multiple indoor units, and the stop signal
controller lengthens the first amount of time the greater the
number of the indoor units there are.
15. The air conditioning apparatus according to claim 2, wherein
the stop signal controller being further configured to, when the
first stop control is executed at a time of a defrosting operation,
wait for the end of the defrosting operation before issuing the
stop signal in order to stop the refrigerant heating unit.
16. The air conditioning apparatus according to claim 3, further
comprising an indoor controller housed in an indoor unit together
with the indoor heat exchanger, the refrigerant heating unit and
the indoor controller being connected in parallel to the stop
signal controller.
17. The air conditioning apparatus according to claim 3, wherein
the stop signal controller is further configured to not execute the
first stop control and to execute a second stop control when it is
judged that the compressor is in an abnormal state, when the second
stop signal control is executed the stop signal order to stop the
refrigerant heating unit is issued and then, before the elapse of
the first amount of time, the stop signal for stopping the
compressor is issued.
18. The air conditioning apparatus according to claim 3, wherein
the refrigerant circuit includes a plurality of the indoor heat
exchangers that are connected in parallel to the compressor and are
individually housed in multiple indoor units, and the stop signal
controller lengthens the first amount of time the greater the
number of the indoor units there are.
19. The air conditioning apparatus according to claim 3, wherein
the stop signal controller being further configured to, when the
first stop control is executed at a time of a defrosting operation,
wait for the end of the defrosting operation before issuing the
stop signal in order to stop the refrigerant heating unit.
Description
TECHNICAL FIELD
[0001] The present invention relates to an air conditioning
apparatus and a method of controlling the air conditioning
apparatus.
BACKGROUND ART
[0002] Among air conditioning apparatus, there are air conditioning
apparatus having a refrigerant heating unit that heats refrigerant
flowing through a refrigerant circuit (e.g., see JP-A No.
2007-255736, which is patent citation 1).
[0003] Usually, in air conditioning apparatus having a refrigerant
heating unit, a stop signal for stopping the refrigerant heating
unit is also issued at the same time as the issuance of a stop
signal for stopping the compressor. This is because when the
compressor is stopped and the refrigerant heating unit is acting
under a circumstance where the refrigerant does not, or virtually
does not, circulate inside the refrigerant circuit, this can lead
to a deterioration of parts such as pipes caused by the heating of
an empty part.
SUMMARY OF THE INVENTION
Technical Problem
[0004] However, even if the stop signals were issued at the same
time, this does not mean that the actions of the compressor and the
refrigerant heating unit will in reality stop at the same time. So
even if it is a short amount of time, a circumstance where the
refrigerant heating unit is acting even though the compressor is
stopped can arise.
[0005] It is an object of the present invention to provide an air
conditioning apparatus that can suppress the heating of an empty
part by a refrigerant heating unit and a method of controlling the
air conditioning apparatus.
Solution to the Problem
[0006] An air conditioning apparatus pertaining to a first aspect
of the present invention is equipped with a refrigerant circuit, a
refrigerant heating unit, and a stop signal controller. The
refrigerant circuit includes a compressor, an indoor heat
exchanger, a pressure reducing mechanism, and an outdoor heat
exchanger. The refrigerant heating unit heats refrigerant flowing
through the refrigerant circuit. The stop signal controller
executes first stop control in a case of causing the compressor to
stop at a time when the compressor and the refrigerant heating unit
are both operating. The first stop control is control that issues a
stop signal for stopping the refrigerant heating unit and then,
after the elapse of a first amount of time, issues a stop signal
for stopping the compressor.
[0007] Here, the timing of the issuance of the stop signal for
stopping the compressor is delayed a predetermined amount of time
from the timing of the issuance of the stop signal for stopping the
refrigerant heating unit, and the compressor residually operates.
Because of this, a circumstance where the refrigerant heating unit
continues operating even after the compressor stops is avoided, and
the heating of an empty part by the refrigerant heating unit is
suppressed.
[0008] An air conditioning apparatus pertaining to a second aspect
of the present invention is the air conditioning apparatus
pertaining to the first aspect of present the invention and is
further equipped with a heating unit controller. The heating unit
controller controls the action of the refrigerant heating unit. The
first stop control is control that issues the stop signal for
stopping the refrigerant heating unit to the heating unit
controller and then, after the elapse of the first amount of time,
issues the stop signal for stopping the compressor.
[0009] Here, the refrigerant heating unit is not directly
controlled by the stop signal controller but is indirectly
controlled via the heating unit controller. Consequently, a delay
in communication can arise between after the signal for stopping
the refrigerant heating unit has been issued from the stop signal
controller and until that stop signal reaches the refrigerant
heating unit and the refrigerant heating unit actually stops.
However, here, because the compressor residually operates, a
circumstance where the refrigerant heating unit continues operating
even after the compressor stops is avoided, and the heating of an
empty part by the refrigerant heating unit is suppressed.
[0010] An air conditioning apparatus pertaining to a third aspect
of the present invention is the air conditioning apparatus
pertaining to the first or second aspect of present the invention
and is further equipped with an indoor blower. The indoor blower
blows air to the indoor heat exchanger. The first stop control is
control that issues the stop signal for stopping the refrigerant
heating unit and then, after the elapse of a second amount of time,
issues a stop signal for stopping the indoor blower.
[0011] Here, the timing of the issuance of the stop signal for
stopping the indoor blower is also, like in the case of the
compressor, delayed a predetermined amount of time from the timing
of the issuance of the stop signal for stopping the refrigerant
heating unit, and the indoor blower residually operates together
with the compressor. Usually, an excessive rise on the high
pressure side of the refrigerant circuit is feared if the
compressor is acting even though the indoor blower is stopped.
However, here, because the indoor blower also residually operates
together with the compressor, a circumstance where the compressor
continues operating even after the indoor blower stops is avoided,
and an excessive rise on the high pressure side of the refrigerant
circuit is prevented.
[0012] An air conditioning apparatus pertaining to a fourth aspect
of the present invention is the air conditioning apparatus
pertaining to the third aspect of the present invention, wherein
the first stop control is control which, before issuing the stop
signal for stopping the indoor blower, issues an operation signal
that causes the indoor blower to rotate at a low speed.
[0013] Here, the residual operation of the indoor blower is
executed at a relatively low speed. Consequently, the residual
operation of the indoor blower, which serves the purpose of
preventing an excessive rise on the high pressure side of the
refrigerant circuit, can be realized while suppressing useless
rotation of the indoor blower.
[0014] An air conditioning apparatus pertaining to a fifth aspect
of the present invention is the air conditioning apparatus
pertaining to any of the first to fourth aspects of present the
invention and is further equipped with an indoor controller. The
indoor controller is housed in an indoor unit together with the
indoor heat exchanger. The refrigerant heating unit and the indoor
controller are connected in parallel to the stop signal
controller.
[0015] Here, the refrigerant heating unit and the indoor controller
are connected in parallel to the stop signal controller. Under this
circumstance, it is feared that a delay in communication will arise
between the stop signal controller and the refrigerant heating unit
due to communication between the stop signal controller and the
indoor controller. However, here, because the compressor residually
operates, a circumstance where the refrigerant heating unit
continues operating even after the compressor stops is avoided, and
the heating of an empty part by the refrigerant heating unit is
suppressed.
[0016] An air conditioning apparatus pertaining to a sixth aspect
of the present invention is the air conditioning apparatus
pertaining to any of the first to fifth aspects of the present
invention, wherein in a case where it is judged that the compressor
is in an abnormal state, the stop signal controller does not
execute the first stop control and executes second stop control.
The second stop control is control that issues the stop signal for
stopping the refrigerant heating unit and then, before the elapse
of the first amount of time, issues the stop signal for stopping
the compressor.
[0017] Here, the residual operation of the compressor is not
executed at a time when the compressor is abnormal. Consequently,
an abnormality in the compressor can be quickly accommodated.
[0018] An air conditioning apparatus pertaining to a seventh aspect
of the present invention is the air conditioning apparatus
pertaining to any of the first to sixth aspects of the present
invention, wherein the refrigerant circuit includes a plurality of
the indoor heat exchangers. The plural indoor heat exchangers are
connected in parallel to the compressor and are individually housed
in multiple indoor units. The stop signal controller lengthens the
first amount of time the greater the number of the indoor units
there are.
[0019] Usually, it is expected that the greater the number of the
indoor units there are, the longer the delay time in communication
between the stop signal controller and the refrigerant heating unit
will become. However, here, because the residual operating time is
longer the greater the number of the indoor units there are,
residual operations of appropriate lengths are executed.
[0020] An air conditioning apparatus pertaining to an eighth aspect
of the present invention is the air conditioning apparatus
pertaining to any of the first to seventh aspects of the present
invention, wherein the first stop control is control which, at the
time of a defrosting operation, waits for the end of the defrosting
operation, issues the stop signal for stopping the refrigerant
heating unit, and then, after the elapse of the first amount of
time, issues the stop signal for stopping the compressor.
[0021] Here, in a case where it is required that the compressor
stop at the time of the defrosting operation under a predetermined
condition, the first stop control waits for the end of the
defrosting operation and causes the compressor and the refrigerant
heating unit to stop. "Under a predetermined condition" is, for
example, a case where a stop command for stopping an air
conditioning operation has been inputted by a user. Consequently,
the defrosting operation is reliably executed.
[0022] An air conditioning apparatus control method pertaining to a
ninth aspect of the present invention is a method of controlling an
air conditioning apparatus having a refrigerant circuit that
includes a compressor, an indoor heat exchanger, a pressure
reducing mechanism, and an outdoor heat exchanger and a refrigerant
heating unit that heats refrigerant flowing through the refrigerant
circuit, the method including the step of executing first stop
control in a case of causing the compressor to stop at a time when
the compressor and the refrigerant heating unit are both operating.
The first stop control is control that issues a stop signal for
stopping the refrigerant heating unit and then, after the elapse of
a first amount of time, issues a stop signal for stopping the
compressor.
[0023] Here, the timing of the issuance of the stop signal for
stopping the compressor is delayed the predetermined amount of time
from the timing of the issuance of the stop signal for stopping the
refrigerant heating unit, and the compressor residually operates.
Because of this, a circumstance where the refrigerant heating unit
continues operating even after the compressor stops is avoided, and
the heating of an empty part by the refrigerant heating unit is
suppressed.
ADVANTAGEOUS EFFECTS OF THE INVENTION
[0024] In the air conditioning apparatus and the method of
controlling the air conditioning apparatus pertaining to the
present invention, the timing of the issuance of the stop signal
for stopping the compressor is delayed the predetermined amount of
time from the timing of the issuance of the stop signal for
stopping the refrigerant heating unit, and the compressor
residually operates. Because of this, a circumstance where the
refrigerant heating unit continues operating even after the
compressor stops is avoided, and the heating of an empty part by
the refrigerant heating unit is suppressed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a refrigerant circuit diagram of an air
conditioning apparatus pertaining to an embodiment of the present
invention.
[0026] FIG. 2 is a perspective view of the exterior of an outdoor
unit as seen from its front right side.
[0027] FIG. 3 is a perspective view of the outdoor unit with its
front panel, its right side panel, and its back panel having been
removed therefrom.
[0028] FIG. 4 is a perspective view of the outdoor unit with
members other than a bottom plate, an outdoor heat exchanger, and
outdoor fans having been removed therefrom.
[0029] FIG. 5 is a cross-sectional view of an electromagnetic
induction heating unit.
[0030] FIG. 6 is a flowchart showing stop control of a compressor,
an indoor fan, and the electromagnetic induction heating unit.
[0031] FIG. 7 is a timing chart of the stopping of the compressor,
the indoor fan, and the electromagnetic induction heating unit at
the time of execution of a first stop control routine.
[0032] FIG. 8 is a refrigerant circuit diagram of an air
conditioning apparatus pertaining to another embodiment of the
present invention.
DESCRIPTION OF THE EMBODIMENTS
[0033] An air conditioning apparatus 1 and a method of controlling
the air conditioning apparatus 1 pertaining to an embodiment of the
present invention will be described below with reference to the
drawings.
<Configuration of Air Conditioning Apparatus>
(Overall Configuration)
[0034] FIG. 1 is a configuration diagram of the air conditioning
apparatus 1. As shown in FIG. 1, in the air conditioning apparatus
1, an outdoor unit 2 serving as a heat source-side unit and an
indoor unit 4 serving as a utilization-side unit are interconnected
by refrigerant pipes, whereby a refrigerant circuit 10 that
performs a vapor-compression refrigeration cycle is formed.
[0035] The outdoor unit 2 houses a compressor 21, a four-way
switching valve 22, an outdoor heat exchanger 23, an expansion
valve 24, an accumulator 25, outdoor fans 26, a hot gas bypass
valve 27, a capillary tube 28, and an electromagnetic induction
heating unit 6. The indoor unit 4 houses an indoor heat exchanger
41 and an indoor fan 42.
[0036] The refrigerant circuit 10 has a discharge pipe 10a, a gas
pipe 10b, a liquid pipe 10c, an outdoor-side liquid pipe 10d, an
outdoor-side gas pipe 10e, an accumulator pipe 10f, a suction pipe
10g, and a hot gas bypass 10h.
[0037] The discharge pipe 10a interconnects the compressor 21 and
the four-way switching valve 22. The gas pipe 10b interconnects the
four-way switching valve 22 and the indoor heat exchanger 41. The
liquid pipe 10c interconnects the indoor heat exchanger 41 and the
expansion valve 24. The outdoor-side liquid pipe 10d interconnects
the expansion valve 24 and the outdoor heat exchanger 23. The
outdoor-side gas pipe 10e interconnects the outdoor heat exchanger
23 and the four-way switching valve 22.
[0038] The accumulator pipe 10f interconnects the four-way
switching valve 22 and the accumulator 25. The electromagnetic
induction heating unit 6 is attached to a part of the accumulator
pipe 10f. At least the heated portion of the accumulator pipe 10f
covered by the electromagnetic induction heating unit 6 is
configured such that a stainless steel pipe covers the periphery of
a copper pipe. Of the pipes configuring the refrigerant circuit 10,
the portions other than that stainless steel pipe are copper
pipes.
[0039] The suction pipe 10g interconnects the accumulator 25 and
the suction side of the compressor 21. The hot gas bypass 10h
interconnects a branch point A1 disposed midway in the discharge
pipe 10a and a branch point D1 disposed midway in the outdoor-side
liquid pipe 10d.
[0040] The hot gas bypass valve 27 is disposed midway in the hot
gas bypass 10h. A controller 11 opens and closes the hot gas bypass
valve 27 to switch the hot gas bypass 10h between a state where it
allows circulation of refrigerant and a state where it does not
allow circulation of refrigerant. Further, the capillary tube 28,
which reduces the cross-sectional area of the refrigerant
circulation passage, is disposed on the downstream side of the hot
gas bypass valve 27, and the ratio between the refrigerant
circulating through the outdoor heat exchanger 23 and the
refrigerant circulating through the hot gas bypass 10h is
maintained at a constant at the time of a defrosting operation.
[0041] The four-way switching valve 22 can switch between a cooling
operation cycle and a heating operation cycle. In FIG. 1, the solid
lines represent a state of connection for performing the heating
operation and the dashed lines represent a state of connection for
performing the cooling operation. At the time of the heating
operation, the indoor heat exchanger 41 functions as a condenser
and the outdoor heat exchanger 23 functions as an evaporator. At
the time of the cooling operation, the outdoor heat exchanger 23
functions as a condenser and the indoor heat exchanger 41 functions
as an evaporator.
[0042] The outdoor fans 26, which deliver outdoor air to the
outdoor heat exchanger 23, are disposed in the neighborhood of the
outdoor heat exchanger 23. The indoor fan 42, which delivers room
air to the indoor heat exchanger 41, is disposed in the
neighborhood of the indoor heat exchanger 41.
[0043] The controller 11 has an outdoor controller 11a, which
controls the devices placed inside the outdoor unit 2, and an
indoor controller 11b, which controls the devices placed inside the
indoor unit 4. The outdoor controller 11a and the indoor controller
11b are interconnected by a communication line 11c.
[0044] The indoor controller 11b is a control circuit having a CPU
and a memory and mainly controls the various electrical
devices--such as the indoor fan 42--housed in the indoor unit 4 by
reading and executing on the CPU programs stored in the memory. A
remote controller 44 is connected to the indoor controller 11b. The
remote controller 44 is for a user to input various operation
commands (start commands for starting air conditioning operations,
stop commands for stopping air conditioning operations, change
commands for changing a set temperature Ts, setting commands for
setting operation modes such as a heating operation mode and a
cooling operation mode, etc.) to the indoor unit 4.
[0045] Likewise, the outdoor controller 11a is also a control
circuit having a CPU and a memory and mainly controls the various
electrical devices--such as the compressor 21, the four-way
switching valve 22, the outdoor expansion valve 24, the outdoor
fans 26, and the electromagnetic induction heating unit 6--housed
in the outdoor unit 2 by reading and executing on the CPU programs
stored in the memory.
[0046] The outdoor controller 11a references information acquired
by the indoor controller 11b while communicating with the indoor
controller 11b and unifies the actions of the air conditioning
apparatus 1 overall such that the air conditioning apparatus 1 acts
in accordance with the various operation commands that have been
inputted via the remote controller 44.
[0047] The outdoor controller 11a controls the compressor 21 via an
inverter board 21a and controls the electromagnetic induction
heating unit 6 via a heating unit controller 7. Further, the
outdoor controller 11a is connected to the inverter board 21a via a
communication line 11d exiting from a dedicated communication port
and is connected to the heating unit controller 7 via the same
communication line 11c exiting from the same communication port as
the indoor controller 11b.
(Exterior of Outdoor Unit)
[0048] FIG. 2 is a perspective view of the exterior of the outdoor
unit 2 as seen from its front right side. As shown in FIG. 2, the
outer casing of the outdoor unit 2 is formed in a substantially
cuboidal shape by a top plate 2a, a bottom plate 2b (see FIG. 4)
that opposes the top plate 2a, a front panel 2c, fan guards 2k, a
right side panel 2f, a left side panel (invisible) that opposes the
right side panel 2f, and a back panel (invisible) that opposes the
front panel 2c and the fan guards 2k.
(Structure of Interior of Outdoor Unit)
[0049] FIG. 3 is a perspective view of the outdoor unit 2 as seen
from its front right side with its front panel 2c, its right side
panel 2f, and its back panel having been removed therefrom, and
FIG. 4 is a perspective view of the outdoor unit 2 as seen from its
front right side with members other than bottom plate 2b, the
outdoor heat exchanger 23 and the outdoor fans 26 having been
removed therefrom. As shown in FIG. 3, the outdoor unit 2 is
sectioned by a partition plate 2h into a blower chamber and a
machine chamber. The outdoor heat exchanger 23 and the outdoor fans
26 (see FIG. 4) are placed in the blower chamber, and the
electromagnetic induction heating unit 6, the compressor 21, and
the accumulator 25 are placed in the machine chamber.
[0050] As shown in FIG. 4, the outdoor heat exchanger 23 is a
fin-and-tube heat exchanger formed in an L shape. Additionally, the
two outdoor fans 26 are placed between the fan guards 2k (see FIG.
3) and the outdoor heat exchanger 23 so as to be adjacent to each
other in the vertical direction via a support. When the outdoor
fans 26 rotate, the outdoor air is sucked in from ventilation
openings in the left side panel and in the back panel, passes
between the fins of the outdoor heat exchanger 23, and is blown out
from the fan guards 2k.
[0051] The hot gas bypass 10h is placed on the bottom plate 2b,
extends from the machine chamber side where the compressor 21 is
positioned to the blower chamber side, makes one round around the
blower chamber side bottom portion, and returns to the machine
chamber side. About half of the entire length of the hot gas bypass
10h is positioned below the outdoor heat exchanger 23.
(Structure of Electromagnetic Induction Heating Unit)
[0052] FIG. 5 is a cross-sectional view of the electromagnetic
induction heating unit 6. As shown in FIG. 5, the electromagnetic
induction heating unit 6 is placed so as to cover the heated
portion of the accumulator pipe 10f from its radial direction outer
side and heats the heated portion by electromagnetic induction
heating. The heated portion of the accumulator pipe 10f has a
double pipe structure due to the inside copper pipe and an outside
stainless steel pipe 100f. The stainless steel material used for
the stainless steel pipe 100f is selected from ferrite stainless
steel including 16 to 18% chromium or precipitation-hardening
stainless steel including 3 to 5% nickel, 15 to 17.5% chromium, and
3 to 5% copper.
[0053] The electromagnetic induction heating unit 6 is first
positioned on the accumulator pipe 10f, next its upper end
neighborhood is fixed by a first hexagonal nut 61, and finally its
lower end neighborhood is fixed by a second hexagonal nut 66.
[0054] A coil 68 is spirally coiled around the outer side of a
bobbin body 65, with the axial direction of the coil 68 coinciding
with the direction in which the accumulator pipe 10f extends. The
coil 68 is housed on the inner side of a ferrite case 71. The
ferrite case 71 also houses first ferrite portions 69 and a second
ferrite portion 70.
[0055] The first ferrite portions 69 are formed by ferrite with
high magnetic permeability, gather the magnetic flux that arises
also in the portion other than the stainless steel pipe 100f when
an electric current is passed through the coil 68, and form a path
for the magnetic flux. The first ferrite portions 69 are positioned
on both end sides of the ferrite case 71.
[0056] The second ferrite portion 70 differs in position and shape
from the first ferrite portions 69 but functions in the same way as
the first ferrite portions 69 and is placed in the neighborhood on
the outer side of the bobbin body 65 in the housing portion of the
ferrite case 71.
<Actions of the Air Conditioning Apparatus>
[0057] The air conditioning apparatus 1 is capable of being
switched to either one of the cooling operation or the heating
operation by the four-way switching valve 22.
(Cooling Operation)
[0058] At the time of the cooling operation, the four-way switching
valve 22 is set in the state indicated by the dashed lines in FIG.
1. When the compressor 21 is driven in this state, a
vapor-compression refrigeration cycle where the outdoor heat
exchanger 23 becomes a condenser and the indoor heat exchanger 41
becomes an evaporator is performed in the refrigerant circuit
10.
[0059] The high-pressure refrigerant that has been discharged from
the compressor 21 exchanges heat with the outdoor air and condenses
in the outdoor heat exchanger 23. The refrigerant that has passed
through the outdoor heat exchanger 23 has its pressure reduced when
it passes through the expansion valve 24 and thereafter exchanges
heat with the room air and evaporates in the indoor heat exchanger
41. Then, the air whose temperature has fallen as a result of
exchanging heat with the refrigerant is blown out into an air
conditioning target space. The refrigerant that has passed through
the indoor heat exchanger 41 is sucked into the compressor 21 and
is compressed.
(Heating Operation)
[0060] At the time of the heating operation, the four-way switching
valve 22 is set in the state indicated by the solid lines in FIG.
1. When the compressor 21 is driven in this state, a
vapor-compression refrigeration cycle where the outdoor heat
exchanger 23 becomes an evaporator and the indoor heat exchanger 41
becomes a condenser is performed in the refrigerant circuit 10.
[0061] The high-pressure refrigerant that has been discharged from
the compressor 21 exchanges heat with the room air and condenses in
the indoor heat exchanger 41. Then, the air whose temperature has
risen as a result of exchanging heat with the refrigerant is blown
out into the air conditioning target space. The condensed
refrigerant has its pressure reduced when it passes through the
expansion valve 24 and thereafter exchanges heat with the outdoor
air and evaporates in the outdoor heat exchanger 23. The
refrigerant that has passed through the outdoor heat exchanger 23
is sucked into the compressor 21 and is compressed.
[0062] When the compressor 21 at the time of the heating operation
and particularly at the time of startup is not sufficiently warm,
the electromagnetic induction heating unit 6 heats the accumulator
pipe 10f, whereby the compressor 21 can compress the refrigerant
that has been warmed. As a result, the temperature of the gas
refrigerant discharged from the compressor 21 rises, and heating
capacity insufficiency at the time of startup is compensated.
(Defrosting Operation)
[0063] When the heating operation has been performed, moisture
included in the air condenses as dew condensation on the surface of
the outdoor heat exchanger 23, turns into frost or freezes, and
covers the surface of the outdoor heat exchanger 23, whereby the
heat exchange performance drops. For this reason, the defrosting
operation is performed in order to melt the frost or ice adhering
to the outdoor heat exchanger 23. The defrosting operation is
performed in the same cycle as the cooling operation.
[0064] The high-pressure refrigerant that has been discharged from
the compressor 21 exchanges heat with the outdoor air and condenses
in the outdoor heat exchanger 23. Because of the radiation of heat
from that refrigerant, the frost or ice covering the outdoor heat
exchanger 23 is melted. The condensed refrigerant has its pressure
reduced when it passes through the expansion valve 24 and
thereafter exchanges heat with the room air and evaporates in the
indoor heat exchanger 41. At this time, the indoor fan 42 is
stopped. The reason is because if the indoor fan 42 runs, the air
that has been cooled will be blown out into the air conditioning
target space and will detract from comfort. Then, the refrigerant
that has passed through the indoor heat exchanger 41 is sucked into
the compressor 21 and is compressed.
[0065] Further, at the time of the defrosting operation, the
electromagnetic induction heating unit 6 heats the accumulator pipe
10f, whereby the compressor 21 can compress the refrigerant that
has been warmed. As a result, the temperature of the gas
refrigerant discharged from the compressor 21 rises and the
defrosting capability improves.
[0066] Further, at the time of the defrosting operation, the
high-pressure refrigerant that has been discharged from the
compressor 21 also flows in the hot gas bypass 10h. Even in a case
where ice is growing on the bottom plate 2b of the outdoor unit 2,
that ice is melted by the radiation of heat from the refrigerant
traveling through the hot gas bypass 10h. (Stop Control of
Compressor, Indoor Fan, and Electromagnetic Induction Heating
Unit)
[0067] The timings of the stopping the compressor 21, the indoor
fan 42, and the electromagnetic induction heating unit 6 at the
time of the heating operation or at the time of the defrosting
operation in which the electromagnetic induction heating unit 6 is
driven will be described below with reference to FIG. 6.
[0068] The processing pertaining to FIG. 6 is started by the
outdoor controller 11a at the time the compressor 21 is driven.
[0069] First, in step S1, the outdoor controller 11a determines
whether or not there is an abnormality in the compressor 21.
Whether or not there is an abnormality in the compressor 21 is
determined at any time by the outdoor controller 11a in parallel
with the processing pertaining to FIG. 6 in accordance with a
preset logic. In a case where it is determined that there is an
abnormality in the compressor 21, a second stop control routine is
executed, and in a case where it is determined that there is no
abnormality in the compressor 21, the processing advances to step
S2.
[0070] In step S2, the outdoor controller 11a determines whether or
not a stop command for stopping the air conditioning operation has
been inputted to the remote controller 44. In a case where it is
determined that a stop command for stopping the air conditioning
operation has been inputted to the remote controller 44, a first
stop control routine is executed, and in a case where it is
determined that a stop command for stopping the air conditioning
operation has not been inputted to the remote controller 44, the
processing advances to step S3.
[0071] In step S3, the outdoor controller 11a determines whether or
not there has been a thermostat off determination. "Thermostat off
determination" means that a room temperature Tr has reached the set
temperature Ts of the indoor unit 4 and it is determined that there
is no need for a thermostat on operation. Whether or not there has
been a thermostat off determination is determined at any time by
the outdoor controller 11a in parallel with the processing
pertaining to FIG. 6 in accordance with a preset logic. In a case
where it is determined that there has been a thermostat off
determination, the first stop control routine is executed, and in a
case where it is determined that there has not been a thermostat
off determination, the processing returns to step S1.
<First Stop Control Routine>
[0072] The first stop control routine is executed as follows by the
outdoor controller 11a.
[0073] The outdoor controller 11a first determines the current
operation mode; if the current operation mode is the defrosting
operation mode, the outdoor controller 11a executes the following
processing immediately after standing by until the defrosting
operation ends, and if the current operation mode is a mode other
than the defrosting operation mode, that is, the heating operation
mode, the outdoor controller 11a executes the following processing
immediately without standing by until the defrosting operation
ends.
[0074] FIG. 7 is a timing chart of the stopping of the compressor
21, the indoor fan 42, and the electromagnetic induction heating
unit 6 at the time of execution of the first stop control routine.
0 seconds in FIG. 7 is based on the later of the point in time when
the first stop control routine starts and the point in time when
the defrosting operation ends. The outdoor controller 11a issues a
stop signal for stopping the electromagnetic induction heating unit
6 to the heating unit controller 7 at the timing of 0 seconds in
FIG. 7. Further, at the same timing of 0 seconds in FIG. 7, the
outdoor controller 11a issues a signal ordering that the indoor fan
42 be rotated at a predetermined low speed (it is desirable for
this speed to be the next smallest speed after stop or a low speed
conforming thereto) to the indoor controller 11b. Thereafter, the
outdoor controller 11a stands by for 5 seconds and issues a stop
signal for stopping the compressor 21 to the inverter board 21a at
the timing of 5 seconds in FIG. 7, and at the same timing of 5
seconds in FIG. 7, the outdoor controller 11a issues a stop command
ordering that the indoor fan 42 be immediately stopped to the
indoor controller 11b.
[0075] Because of the above, the first stop control routine ends
and, together therewith, the processing shown in FIG. 6 also
ends.
[0076] The reason the first stop control routine is executed in
this embodiment is as follows.
[0077] The heating unit controller 7 is designed to cause the
electromagnetic induction heating unit 6 to immediately stop when
the heating unit controller 7 receives the stop signal for stopping
the electromagnetic induction heating unit 6 from the outdoor
controller 11a. However, from the time when the outdoor controller
11a issues that stop signal to until the heating unit controller 7
actually receives that stop signal and stops the electromagnetic
induction heating unit 6a, a delay in communication of 0 seconds to
5 seconds is predicted. This is because the heating unit controller
7 and the indoor controller 11b are connected in parallel to the
outdoor controller 11a--that is, because the heating unit
controller 7 and the indoor controller 11b share the same
communication port on the outdoor controller 11a. On the other
hand, because the inverter board 21a and the outdoor controller 11a
are interconnected via a dedicated communication port, it is
conceivable for the compressor 21 to stop at substantially the same
time as when the outdoor controller 11a issues the stop signal for
stopping the compressor 21 to the inverter board 21a. So if the
stop signal for stopping the electromagnetic induction heating unit
6 and the stop signal for stopping the compressor 21 have been
issued at the same time from the outdoor controller 11a, it is
expected that the stopping of the electromagnetic induction heating
unit 6 will be 0 seconds to 5 seconds later than the stopping of
the compressor 21.
[0078] However, in the first stop control routine, the timing when
the outdoor controller 11a issues the stop signal for stopping the
compressor 21 to the inverter board 21a is set to 5 seconds after
the outdoor controller 11a issues the stop signal for stopping the
electromagnetic induction heating unit 6 to the heating unit
controller 7. Consequently, even if a delay in communication of 0
seconds to 5 seconds arises between the outdoor controller 11a and
the heating unit controller 7, a circumstance in which the
electromagnetic induction heating unit 6 continues acting after the
compressor 21 stops becomes avoided. In other words, even though
the circumstance is one where the compressor 21 stops and the
refrigerant does not circulate, or virtually does not circulate,
inside the refrigerant circuit 10, "the heating of an empty part"
in which the electromagnetic induction heating unit 6 acts is
suppressed.
[0079] Further, in the first stop control routine, the timing of
the issuance of the stop signal for stopping the indoor fan 42 is
also, like the timing of the issuance of the stop signal for
stopping the compressor 21, a timing of 5 seconds in FIG. 7. This
is because the high pressure side of the refrigerant circuit 10 can
excessively rise if the compressor 21 is acting even though the
indoor fan 42 is stopped. In other words, as the purpose of
operating the indoor fan 42 during the 0 seconds to 5 seconds in
FIG. 7 is to prevent an excessive rise on the high pressure side of
the refrigerant circuit 10, the indoor fan 42 in that period is
designed to rotate at the predetermined low speed.
<Second Stop Control Routine>
[0080] The second stop control routine is executed as follows by
the outdoor controller 11a.
[0081] Immediately when the second stop control routine starts, the
outdoor controller 11a simultaneously issues a stop signal for
stopping the compressor 21 to the inverter board 21a, a stop signal
for stopping the electromagnetic induction heating unit 6 to the
heating unit controller 7, and a stop signal ordering that the
indoor fan 42 be immediately stopped to the indoor unit controller
11b. That is, in the second stop control routine, which is
processing in a case where an abnormality has been detected in the
compressor 21, the outdoor controller 11a issues a stop signal for
stopping the compressor 21 to the outdoor controller 11a without
waiting for the reliable stopping of the electromagnetic induction
heating unit 6 like in the first stop control routine (that is,
before the elapse of 5 seconds after the issuance of the stop
signal for stopping the electromagnetic induction heating unit
6).
[0082] Because of the above, the second stop control routine ends
and, together therewith, the processing shown in FIG. 6 also
ends.
<Characteristics>
[0083] (1)
[0084] In the above-described embodiment, the heating unit
controller 7 and the indoor controller 11b are connected in
parallel to the outdoor controller 11a, and it becomes easy for a
delay in communication to arise between the outdoor controller 11a
and the heating unit controller 7.
[0085] However, in the above-described embodiment, the timing of
the issuance of the stop signal for stopping the compressor 21 is
delayed 5 seconds from the timing of the issuance of the stop
signal for stopping the electromagnetic induction heating unit 6,
and the compressor 21 is designed to residually operate.
Consequently, even if a delay in communication has arisen between
the outdoor controller 11a and the heating unit controller 7, a
circumstance where the electromagnetic induction heating unit 6
continues operating even after the compressor 21 stops is avoided,
and the heating of an empty part by the electromagnetic induction
heating unit 6 is suppressed.
(2)
[0086] Further, in the above-described embodiment, the timing of
the issuance of the stop signal for stopping the indoor fan 42 is
also, like in the case of the compressor 21, delayed 5 seconds from
the timing of the issuance of the stop signal for stopping the
electromagnetic induction heating unit 6, and the indoor fan 42 is
also designed to residually operate together with the compressor
21. Consequently, a circumstance where the compressor 21 continues
operating even after the indoor fan 42 stops is avoided, and an
excessive rise on the high pressure side of the refrigerant circuit
10 is prevented.
[0087] Further, the residual operation of the indoor fan 42 is
executed at a relatively low speed. This is because, as the purpose
of the residual operation of the indoor fan 42 is to prevent an
excessive rise on the high pressure side of the refrigerant circuit
10, it suffices for the speed to be a speed sufficient enough to
serve that purpose.
Other Embodiments
[0088] (1)
[0089] The processing pertaining to FIG. 6 of the above-described
embodiment can also be applied to air conditioning apparatus of a
different type than the air conditioning apparatus 1. For example,
the processing can also be applied to a multi-type air conditioning
apparatus.
[0090] In the case of introducing the processing pertaining to FIG.
6 to a multi-type air conditioning apparatus where multiple indoor
units are connected in parallel to an outdoor unit (a compressor),
it is desirable to design the air conditioning apparatus as
follows.
[0091] In the above-described embodiment pertaining to the air
conditioning apparatus 1 having one each of the indoor unit 4 and
the outdoor unit 2, the time difference between the timing of the
issuance of the stop signal for stopping the electromagnetic
induction heating unit 6 and the timing of the issuance of the stop
signals for stopping the compressor 21 and the indoor fan 42 in the
first stop control routine is equally 5 seconds. However, as shown
in FIG. 8, in a case where the air conditioning apparatus 1 is a
multi-type air conditioning apparatus having multiple indoor units
4, the outdoor controller 11a may be designed to use the number of
the indoor units 4 there are as a parameter and lengthen the time
difference the greater the number of the indoor units 4 there
are.
[0092] In order to realize this embodiment, it is conceivable, for
example, for the outdoor controller 11a to call out for responses
to all of the indoor controllers 11b included in the same
refrigerant circuit 10 at an appropriate timing so that the outdoor
controller 11a can thereby grasp the number of the indoor
controllers 11b--that is, the number of the indoor units
4--connected to the outdoor controller 11a. Further, it is
conceivable for the appropriate timing here to be at the time of a
test operation when installing the air conditioning apparatus 1 on
site or at the time of startup of the compressor 21.
[0093] Usually, it is expected that the greater the number of the
indoor units 4 there are, the longer the delay time in
communication between the outdoor controller 11a and the
electromagnetic induction heating unit 6 will become. However,
here, because the residual operating time of the compressor 21 and
the indoor fan 42 is longer the greater the number of the indoor
units 4 there are, residual operations of appropriate lengths are
executed.
[0094] In a multi-type air conditioning apparatus, ordinarily the
refrigerant circuit includes multiple indoor heat exchangers, and
the multiple indoor heat exchangers are connected in parallel to
the compressor and are individually housed in multiple indoor
units.
(2)
[0095] In the first stop control routine of the above-described
embodiment, the signal for stopping the electromagnetic induction
heating unit 6 and the signal ordering that the indoor fan 42 be
rotated at the predetermined low speed are issued at the same
timings. However, these timings may also be different.
(3)
[0096] In the first stop control routine of the above-described
embodiment, the signal for stopping the compressor 21 and the stop
signal ordering that the indoor fan 42 be immediately stopped are
issued at the same timings. However, these timings may also be
different. Because a delay in communication can arise between the
outdoor controller 11a and the indoor controller 11b, for example,
the stop signal ordering that the indoor fan 42 be immediately
stopped may also be issued before the signal for stopping the
compressor 21.
INDUSTRIAL APPLICABILITY
[0097] The present invention is useful as an air conditioning
apparatus that can suppress the heating of an empty part by a
refrigerant heating unit and as a method of controlling the air
conditioning apparatus.
REFERENCE SIGNS LIST
[0098] 1 Air Conditioning Apparatus [0099] 2 Outdoor Unit [0100] 4
Indoor Unit [0101] 6 Electromagnetic Induction Heating Unit
(Refrigerant Heating Unit) [0102] 7 Heating Unit Controller [0103]
10 Refrigerant Circuit [0104] 11 Controller [0105] 11a Outdoor
Controller (Stop Signal Controller) [0106] 11b Indoor Controller
[0107] 21 Compressor [0108] 23 Outdoor Heat Exchanger [0109] 24
Expansion Valve (Pressure Reducing Mechanism) [0110] 41 Indoor Heat
Exchanger [0111] 42 Indoor Fan (Indoor Blower)
CITATION LIST
Patent Literature
[0111] [0112] Patent Citation 1: JP-A No. 2007-255736
* * * * *