U.S. patent application number 13/256466 was filed with the patent office on 2012-01-05 for air conditioner.
This patent application is currently assigned to DAIKIN INDUSTRIES, LTD.. Invention is credited to Hidehiko Kinoshita, Tsuyoshi Yamada.
Application Number | 20120000225 13/256466 |
Document ID | / |
Family ID | 42739472 |
Filed Date | 2012-01-05 |
United States Patent
Application |
20120000225 |
Kind Code |
A1 |
Kinoshita; Hidehiko ; et
al. |
January 5, 2012 |
AIR CONDITIONER
Abstract
An air conditioner includes a compressing element, a refrigerant
cooler, an expansion element, a refrigerant heater, a magnetic
field generating part, a circulation volume rate ascertaining part
and a control unit. The magnetic field generating part generates a
magnetic field in order to perform inductive heating. The
circulation volume rate ascertaining part ascertains a circulating
refrigerant volume rate. The control unit performs magnetic field
output control when the circulating refrigerant volume rate
ascertained by the circulation volume rate ascertaining part has
increased. When this control is performed the magnetic field
generating part is caused to generate a magnetic field, the
magnetic field generated by the magnetic field generating part is
increased, or the upper limit of the strength of the magnetic field
generated by the magnetic field generating part is increased.
Inventors: |
Kinoshita; Hidehiko; (Osaka,
JP) ; Yamada; Tsuyoshi; (Osaka, JP) |
Assignee: |
DAIKIN INDUSTRIES, LTD.
Osaka-shi, Osaka
JP
|
Family ID: |
42739472 |
Appl. No.: |
13/256466 |
Filed: |
March 18, 2010 |
PCT Filed: |
March 18, 2010 |
PCT NO: |
PCT/JP2010/001941 |
371 Date: |
September 14, 2011 |
Current U.S.
Class: |
62/132 ;
62/498 |
Current CPC
Class: |
F25B 2400/01 20130101;
F25B 13/00 20130101; F25B 2313/02741 20130101 |
Class at
Publication: |
62/132 ;
62/498 |
International
Class: |
F25B 49/02 20060101
F25B049/02; F25B 1/00 20060101 F25B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 19, 2009 |
JP |
2009-069118 |
Claims
1. An air conditioner comprising: a compressing element; a
refrigerant cooler; an expansion element; a refrigerant heater; a
magnetic field generating part arranged to generate a magnetic
field in order to inductively heat at least one element selected
from the group consisting of a refrigerant piping arranged to
circulate a refrigerant to the compressing element. the refrigerant
cooler, the expansion element, and the refrigerant heater, and a
member that thermally contacts the refrigerant flowing through the
refrigerant piping; a circulation volume rate ascertaining part
arranged and configured to ascertain a circulating refrigerant
volume rate of a refrigeration cycle that includes at least the
compressing element, the refrigerant cooler, the expansion element,
and the refrigerant heater; and a control unit configured to
perform a magnetic field output control in which at least one
process selected from the group consisting of causing the magnetic
field generating part to generate a magnetic field, increasing the
magnetic field generated by the magnetic field generating part, and
raising the upper limit of the strength of the magnetic field
generated by the magnetic field generating part is performed when
the circulating refrigerant volume rate ascertained by the
circulation volume rate ascertaining part has increased.
2. An air conditioner according to claim 1, wherein the magnetic
field generating part is further arranged to generate a magnetic
field in order to inductively heat at least one element selected
from the group consisting of suction refrigerant piping disposed on
a suction side of the compressing element, and the member that
thermally contacts the refrigerant flowing through the refrigerant
piping, the refrigerant flowing through the suction refrigerant
piping.
3. An air conditioner according to claim 1, wherein the circulation
volume rate ascertaining part is arranged and configured to
ascertain the circulating refrigerant volume rate based on at least
a prescribed piston displacement volume of the compressing element,
a drive frequency of the compressing element, and density of
refrigerant suctioned by the compressing element.
4. An air conditioner according to claim 3, further comprising: a
low pressure ascertaining part arranged and configured to ascertain
pressure of the refrigerant flowing through a low pressure portion
of the refrigeration cycle; and a suctioned refrigerant temperature
ascertaining part is arranged and configured to ascertain
temperature of the refrigerant suctioned by the compressing
element, the circulation volume rate ascertaining part being is
arranged and configured to derive the density of the refrigerant
suctioned by the compressing element based on the pressure
ascertained by the low pressure ascertaining part and the
temperature ascertained by the suctioned refrigerant temperature
ascertaining part.
5. An air conditioner according to claim 4, wherein the suctioned
refrigerant temperature ascertaining part is disposed on a suction
side of the compressing element in the refrigeration cycle and is
further arranged and configured to detect a state quantity of the
refrigerant that passes on a downstream side of a portion
inductively heated by the magnetic field generating part.
6. An air conditioner according to claim 4, wherein the control
unit is further configured to perform the magnetic field output
control in any one case selected from the group consisting of a
case when the suctioned refrigerant of the compressing element is
in a moist state and a case when the suctioned refrigerant of the
compressing element is in a superheated state wherein the degree of
superheating is less than a prescribed degree of superheating.
7. An air conditioner according to claim 1, wherein the control
unit is further configured to perform the magnetic field output
control if the circulating refrigerant volume rate ascertained by
the circulation volume rate ascertaining part exceeds a prescribed
value.
8. An air conditioner according to claim 5, wherein the control
unit is further configured to perform the magnetic field output
control in any one case selected from the group consisting of a
case when the suctioned refrigerant of the compressing element is
in a moist state and a case when the suctioned refrigerant of the
compressing element is in a superheated state wherein the degree of
superheating is less than a prescribed degree of superheating.
9. An air conditioner according to claim 6, wherein the control
unit is further configured to perform the magnetic field output
control if the circulating refrigerant volume rate ascertained by
the circulation volume rate ascertaining part exceeds a prescribed
value.
10. An air conditioner according to claim 2, wherein the
circulation volume rate ascertaining part is arranged and
configured to ascertain the circulating refrigerant volume rate
based on at least a prescribed piston displacement volume of the
compressing element, a drive frequency of the compressing element,
and density of refrigerant suctioned by the compressing
element.
11. An air conditioner according to claim 10, further comprising: a
low pressure ascertaining part arranged and configured to ascertain
pressure of the refrigerant flowing through a low pressure portion
of the refrigeration cycle; and a suctioned refrigerant temperature
ascertaining part is arranged and configured to ascertain
temperature of the refrigerant suctioned by the compressing
element, the circulation volume rate ascertaining part being is
arranged and configured to derive the density of the refrigerant
suctioned by the compressing element based on the pressure
ascertained by the low pressure ascertaining part and the
temperature ascertained by the suctioned refrigerant temperature
ascertaining part.
12. An air conditioner according to claim 11, wherein the suctioned
refrigerant temperature ascertaining part is disposed on the
suction side of the compressing element in the refrigeration cycle
and is further arranged and configured to detect a state quantity
of the refrigerant that passes on a downstream side of a portion
inductively heated by the magnetic field generating part.
13. An air conditioner according to claim 11, wherein the control
unit is further configured to perform the magnetic field output
control in any one case selected from the group consisting of a
case when the suctioned refrigerant of the compressing element is
in a moist state and a case when the suctioned refrigerant of the
compressing element is in a superheated state wherein the degree of
superheating is less than a prescribed degree of superheating.
14. An air conditioner according to claim 2, wherein the control
unit is further configured to perform the magnetic field output
control if the circulating refrigerant volume rate ascertained by
the circulation volume rate ascertaining part exceeds a prescribed
value.
Description
TECHNICAL FIELD
[0001] The present invention relates to an air conditioner.
BACKGROUND ART
[0002] In the conventional art, an air conditioner that comprises a
refrigerant heating apparatus that employs electromagnetic
induction heating has been proposed.
[0003] For example, Patent Document 1 (i.e., Japanese Unexamined
Patent Application Publication No. 2007-255736) below proposes an
air conditioner that, in order to efficiently heat a refrigerant by
induction heating, controls the start of induction heating in a
state wherein the volume rate of circulation of the refrigerant has
been secured to some degree.
SUMMARY OF THE INVENTION
Technical Problem
[0004] In the art disclosed in Patent Document 1 (i.e., Japanese
Unexamined Patent Application Publication No. 2007-255736)
discussed above, the volume rate of circulation secured is
determined with a view toward efficient heating of the refrigerant;
however, the refrigerant is not directly induction heated but
rather is heated by the transmission of heat from a heat generating
member, such as a magnetic body, that is itself heated by induction
heating. Consequently, even if a certain volume rate of circulation
can be secured to some degree, the volume rate of circulation
needed to perform induction heating sometimes cannot be
secured.
[0005] The present invention was conceived in consideration of the
point discussed above, and an object of the present invention is to
provide an air conditioner that is capable of hindering a member,
which generates heat by induction heating, from generating heat
excessively.
Solution to Problem
[0006] An air conditioner according to a first aspect of the
present invention, which comprises at least a compressing
mechanism, a refrigerant cooler, an expansion mechanism, and a
refrigerant heater, further comprises a magnetic field generating
part, a circulation volume rate ascertaining part, and a control
unit. The magnetic field generating part generates a magnetic field
in order to inductively heat at least one element selected from the
group consisting of a refrigerant piping, which is for circulating
a refrigerant to the compressing mechanism, the refrigerant cooler,
the expansion mechanism, and the refrigerant heater; and a member
that thermally contacts the refrigerant flowing through the
refrigerant piping. The circulation volume rate ascertaining part
ascertains a circulating refrigerant volume rate of a refrigeration
cycle that comprises at least the compressing mechanism, the
refrigerant cooler, the expansion mechanism, and the refrigerant
heater. The control unit performs magnetic field output control
that, when the circulating refrigerant volume rate ascertained by
the circulation volume rate ascertaining part has increased,
performs at least one process selected from the group consisting of
causing the magnetic field generating part to generate a magnetic
field, increasing the magnetic field generated by the magnetic
field generating part, and raising the upper limit of the strength
of the magnetic field generated by the magnetic field generating
part.
[0007] In this air conditioner, when the volume rate at which the
refrigerant is suctioned by the compressing mechanism is low, there
is a risk that, should the magnitude of the magnetic field
generated by the magnetic field generating part increase and
thereby increase the degree of the induction heating, the portion
to be inductively heated will generate heat excessively.
[0008] On the other hand, in this air conditioner, it is possible
to inhibit the induction heated portion from being heated
excessively because the magnetic field is regulated by, for
example, generating the magnetic field if the volume rate at which
the refrigerant is circulating has increased, increasing the
strength of the generated magnetic field, and the like.
[0009] An air conditioner according to a second aspect of the
present invention is the air conditioner according to the first
aspect of the present invention, wherein the magnetic field
generating part generates a magnetic field in order to inductively
heat at least one element selected from the group consisting of the
suction refrigerant piping, which is the refrigerant piping on a
suction side of the compressing mechanism, and the member that
thermally contacts the refrigerant flowing through the suction
refrigerant piping.
[0010] In this air conditioner, the refrigerant that is about to be
suctioned by the compressing mechanism is rapidly heated and the
refrigerant flowing through the refrigerant piping that is
significantly spaced apart from the compressing mechanism is not
rapidly heated. Furthermore, refrigerant flowing on the suction
side of the compressing mechanism either has a high degree of
dryness or is in a superheated state and therefore tends to rise in
temperature because its sensible heat tends to change more than
would be the case wherein the latent heat of the refrigerant in the
vapor-liquid two-phase state and the like and flowing more on the
upstream side changes.
[0011] On the other hand, in this air conditioner, because magnetic
field output control is performed after the volume rate at which
the refrigerant is circulating has increased, it is possible to
prevent excessive induction heating in the state wherein the volume
rate at which the refrigerant is circulating is low. Thereby, even
if the refrigerant that passes on the suction side of the
compressing mechanism and that tends to rise in temperature is
thereby heated, it is possible to inhibit the excessive heating of
the induction heated portion.
[0012] An air conditioner according to a third aspect of the
present invention is the air conditioner according to the first
aspect or the second aspect of the present invention, wherein the
circulation volume rate ascertaining part makes its determination
based on at least a prescribed piston displacement volume of the
compressing mechanism, a drive frequency of the compressing
mechanism, and the density of the refrigerant suctioned by the
compressing mechanism.
[0013] In this air conditioner, it is possible to perform magnetic
field output control in accordance with the state of the
refrigerant that passes on the suction side of the compressing
mechanism.
[0014] An air conditioner according to a fourth aspect of the
present invention is the air conditioner according to the third
aspect of the present invention, further comprising a low pressure
ascertaining part and a suctioned refrigerant temperature
ascertaining part. The low pressure ascertaining part ascertains
the pressure of the refrigerant flowing through a low pressure
portion of the refrigeration cycle. The suctioned refrigerant
temperature ascertaining part ascertains the temperature of the
refrigerant suctioned by the compressing mechanism. The circulation
volume rate ascertaining part derives the density of the
refrigerant suctioned by the compressing mechanism based on the
pressure ascertained by the low pressure ascertaining part and the
temperature ascertained by the suctioned refrigerant temperature
ascertaining part.
[0015] In this air conditioner, the volume rate at which the
refrigerant is circulating can be ascertained more accurately.
[0016] An air conditioner according to a fifth aspect of the
present invention is the air conditioner according to the fourth
aspect of the present invention, wherein the suctioned refrigerant
temperature ascertaining part is on the suction side of the
compressing mechanism in the refrigeration cycle and detects a
state quantity of the refrigerant that passes on the downstream
side of a portion inductively heated by the magnetic field
generating part.
[0017] In this air conditioner, it is possible to ascertain a value
that is not affected by induction heating by ascertaining a state
quantity of the refrigerant that flows on the upstream side of the
portion that generates heat by induction heating.
[0018] An air conditioner according to a sixth aspect of the
present invention is the air conditioner according to the fourth
aspect or the fifth aspect of the present invention, wherein the
control unit performs the magnetic field output control in any one
case selected from the group consisting of the case wherein the
suctioned refrigerant of the compressing mechanism is in a moist
state and the case wherein the suctioned refrigerant of the
compressing mechanism is in a superheated state wherein the degree
of superheating is less than a prescribed degree of
superheating.
[0019] In this air conditioner, if the degree of superheating of
the refrigerant suctioned by the compressing mechanism is high,
then there is a risk that the rise in the temperature of the
portion that generates heat by induction heating will become
significant.
[0020] On the other hand, in this air conditioner, induction
heating is performed if and only if the superheated state wherein
the degree of superheating is less than the prescribed degree of
superheating obtains or if the moist state obtains. Consequently,
even if the drive frequency of the compressing mechanism has been
high and the speed at which the refrigerant is flowing has been
quick, magnetic field output control is not performed unless either
the superheated state wherein the degree of superheating is less
than the prescribed degree of superheating obtains or the moist
state obtains, which makes it possible to better inhibit excessive
superheating.
[0021] An air conditioner according to a seventh aspect of the
present invention is the air conditioner according to any one
aspect of the first through sixth aspects of the present invention,
wherein the control unit performs the magnetic field output control
if the circulating refrigerant volume rate ascertained by the
circulation volume rate ascertaining part exceeds a prescribed
value.
[0022] In this air conditioner, even if magnetic field output
control is performed and the induction heated portion is caused to
generate heat in the state wherein the volume rate at which the
refrigerant is circulating exceeds the prescribed value, the large
amount of the refrigerant that passes through the surrounding
portion inhibits heat generation. Thereby, it is possible to
reliably inhibit the excessive generation of heat of the induction
heated portion.
Advantageous Effects of Invention
[0023] In the air conditioner of the first aspect of the invention,
it is possible to inhibit the excessive heating of the induction
heated portion.
[0024] In the air conditioner of the second aspect of the
invention, it is possible to inhibit the excessive heating of the
induction heated portion even if the refrigerant that passes on the
suction side of the compressing mechanism and that tends to rise in
temperature is heated.
[0025] In the air conditioner of the third aspect of the invention,
it is possible to perform magnetic field output control in
accordance with the state of the refrigerant that passes on the
suction side of the compressing mechanism.
[0026] In the air conditioner of the fourth aspect of the
invention, it is possible to more accurately ascertain the
refrigerant circulation volume rate.
[0027] In the air conditioner of the fifth aspect of the invention,
it is possible to ascertain a value that is not affected by
induction heating.
[0028] In the air conditioner of the sixth aspect of the invention,
it is possible to better inhibit excessive superheating.
[0029] In the air conditioner of the seventh aspect of the
invention, it is possible to reliably inhibit the excessive
generation of heat of the induction heated portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a refrigerant circuit diagram of an air
conditioner according to one embodiment of the present
invention.
[0031] FIG. 2 is an external oblique view of an electromagnetic
induction heating unit.
[0032] FIG. 3 is an external oblique view that shows the state
wherein a shielding cover has been removed from the electromagnetic
induction heating unit.
[0033] FIG. 4 is an external oblique view of an electromagnetic
induction thermistor.
[0034] FIG. 5 is an external oblique view of a fuse.
[0035] FIG. 6 is a schematic cross sectional view that shows the
state wherein the electromagnetic induction thermistor and the fuse
are mounted.
[0036] FIG. 7 is a cross sectional view of the electromagnetic
induction heating unit.
[0037] FIG. 8 is a flow chart of moisture protection induction
heating control.
[0038] FIG. 9 is a flow chart of abnormal superheating inhibition
control.
[0039] FIG. 10 is an explanatory diagram of the refrigerant piping
according to another embodiment (H).
[0040] FIG. 11 is an explanatory diagram of the refrigerant piping
according to another embodiment (I).
[0041] FIG. 12 is a view that shows an example of the layout of
ferrite cases according to another embodiment (J).
DESCRIPTION OF EMBODIMENTS
[0042] An exemplary case of an air conditioner 1, which comprises
an electromagnetic induction heating unit 6 according to one
embodiment of the present invention, will now be explained,
referencing the drawings.
First Embodiment
<1-1> Air Conditioner 1
[0043] FIG. 1 is a refrigerant circuit diagram that shows a
refrigerant circuit 10 of the air conditioner 1.
[0044] The air conditioner 1 is an apparatus wherein an outdoor
unit 2, which serves as a heat source side apparatus, and an indoor
unit 4, which serves as a utilization side apparatus, are connected
by a refrigerant piping, and the space wherein the utilization side
apparatus is disposed is air conditioned; furthermore, the air
conditioner 1 comprises a compressor 21, a four-way switching valve
22, an outdoor heat exchanger 23, a motor operated expansion valve
24, an accumulator 25, outdoor fans 26, an indoor heat exchanger
41, an indoor fan 42, a hot gas bypass valve 27, a capillary tube
28, the electromagnetic induction heating unit 6, and the like.
[0045] The compressor 21, the four-way switching valve 22, the
outdoor heat exchanger 23, the motor operated expansion valve 24,
the accumulator 25, the outdoor fans 26, the hot gas bypass valve
27, the capillary tube 28, and the electromagnetic induction
heating unit 6 are housed inside the outdoor unit 2. The indoor
heat exchanger 41 and the indoor fan 42 are housed inside the
indoor unit 4.
[0046] The refrigerant circuit 10 comprises a discharge pipe A, an
indoor side gas pipe B, an indoor side liquid pipe C, an outdoor
side liquid pipe D, an outdoor side gas pipe E, an accumulator pipe
F, a suction pipe G, and a hot gas bypass circuit H. A large amount
of the refrigerant in the gas state passes through the indoor side
gas pipe B and the outdoor side gas pipe E, but the refrigerant
passing through these pipes is not limited to the gas state. A
large amount of the refrigerant in the liquid state passes through
the indoor side liquid pipe C and the outdoor side liquid pipe D,
but the refrigerant passing through these pipes is not limited to
the liquid state.
[0047] The discharge pipe A connects the compressor 21 and the
four-way switching valve 22. A discharge temperature sensor 29d,
which detects the temperature of the refrigerant passing through
the discharge pipe A, is provided to the discharge pipe A.
Furthermore, an electric current supply part 21e supplies an
electric current to the compressor 21. The amount of electric power
supplied by the electric current supply part 21e is detected by a
compressor electric power detection unit 29f. Furthermore, a
rotational speed ascertaining part 29r detects the drive rotational
speed of a piston of the compressor 21. The indoor side gas pipe B
connects the four-way switching valve 22 and the indoor heat
exchanger 41. A first pressure sensor 29a, which detects the
pressure of the refrigerant passing through the indoor side gas
pipe B, is provided along the indoor side gas pipe B. The indoor
side liquid pipe C connects the indoor heat exchanger 41 and the
motor operated expansion valve 24. The outdoor side liquid pipe D
connects the motor operated expansion valve 24 and the outdoor heat
exchanger 23. The outdoor side gas pipe E connects the outdoor heat
exchanger 23 and the four-way switching valve 22. A second pressure
sensor 29g, which detects the pressure of the refrigerant passing
through the outdoor side gas pipe E, is provided along the outdoor
side gas pipe E.
[0048] The accumulator pipe F connects the four-way switching valve
22 and the accumulator 25 and, in the state wherein the accumulator
25 is installed in the outdoor unit 2, extends in the vertical
directions. The electromagnetic induction heating unit 6 is mounted
to part of the accumulator pipe F. At least a heat generating
portion of the accumulator pipe F, which is enveloped by a coil 68
(discussed below), comprises a magnetic pipe F2 provided such that
it envelops a copper pipe F1 wherein the refrigerant flows. The
magnetic pipe F2 is made of steel use stainless (SUS) 430. SUS 430
is a ferromagnetic material; when placed in a magnetic field, eddy
currents are induced, which generate heat by the action of Joule
heat induced by the material's own electrical resistance. The
portion of the piping that constitutes the refrigerant circuit 10
and that is outside of the magnetic pipe F2 comprises copper pipes.
By performing electromagnetic induction heating in this manner, the
accumulator pipe F can generate heat by electromagnetic induction,
and thereby the refrigerant that is suctioned into the compressor
21 via the accumulator 25 can be heated. Thereby, the heating
capacity of the air conditioner 1 can be improved. In addition, for
example, even if the compressor 21 is not sufficiently heated when
heating operation is started up, the electromagnetic induction
heating unit 6 can perform rapid heating, thereby supplementing the
capacity shortfall during startup. Furthermore, if the four-way
switching valve 22 switches to the cooling operation state and the
defrosting operation, which eliminates frost that adheres to the
outdoor heat exchanger 23 and the like, is performed, then the
compressor 21 can compress the rapidly heated refrigerant by virtue
of the electromagnetic induction heating unit 6 rapidly heating the
accumulator pipe F. Consequently, the temperature of the hot gas
discharged from the compressor 21 can be rapidly raised. Thereby,
the time needed by the defrosting operation to thaw the frost can
be shortened. Thereby, even if it is necessary to perform the
defrosting operation when appropriate during heating operation, it
is possible to return to the heating operation as quickly as
possible and thereby to improve user comfort.
[0049] Furthermore, a suction temperature sensor 19 that detects
the temperature of the refrigerant that flows between the
electromagnetic induction heating unit 6 and the four-way switching
valve 22 is provided to the accumulator pipe F. In the state
wherein a refrigeration cycle performs heating operation, the
suction temperature sensor 19 detects the temperature of the
refrigerant flowing on the downstream side of the electromagnetic
induction heating unit 6 before the refrigerant is heated by
induction heating by the electromagnetic induction heating unit
6.
[0050] The suction pipe G connects the accumulator 25 and the
suction side of the compressor 21.
[0051] The hot gas bypass circuit H connects a branching point A1,
which is provided along the discharge pipe A, and a branching point
D1, which is provided along the outdoor side liquid pipe D. The hot
gas bypass valve 27, which is capable of switching between the
state in which the refrigerant is permitted to pass through the hot
gas bypass circuit H and the state in which it isn't, is disposed
along the hot gas bypass circuit H. Furthermore, the capillary tube
28, which lowers the pressure of the refrigerant passing through
the hot gas bypass circuit H, is provided along the hot gas bypass
circuit H between the hot gas bypass valve 27 and the branching
point D1. Because the pressure of the refrigerant can approach that
of the refrigerant after the pressure has been decreased by the
motor operated expansion valve 24 during heating operation, the
capillary tube 28 can hinder a rise in the pressure of the
refrigerant in the outdoor side liquid pipe D by supplying hot gas,
which has passed through the hot gas bypass circuit H, to the
outdoor side liquid pipe D.
[0052] The four-way switching valve 22 is capable of switching
between a cooling operation cycle and a heating operation cycle. In
FIG. 1, solid lines indicate the connection state wherein heating
operation is performed, and dotted lines indicate the connection
state wherein cooling operation is performed. During heating
operation, the indoor heat exchanger 41 functions as a cooler of
the refrigerant, and the outdoor heat exchanger 23 functions as a
heater of the refrigerant. During cooling operation, the outdoor
heat exchanger 23 functions as a cooler of the refrigerant, and the
indoor heat exchanger 41 functions as a heater of the
refrigerant.
[0053] One end of the outdoor heat exchanger 23 is connected to the
end part of the outdoor side gas pipe E on the outdoor heat
exchanger 23 side, and the other end of the outdoor heat exchanger
23 is connected to the end part of the outdoor side liquid pipe D
on the outdoor heat exchanger 23 side. In addition, an outdoor heat
exchanger temperature sensor 29c, which detects the temperature of
the refrigerant flowing through the air conditioner 1, is provided
to the outdoor heat exchanger 23. Furthermore, an outdoor
temperature sensor 29b, which detects the outdoor air temperature,
is provided to the outdoor heat exchanger 23 on the downstream side
in the direction of the airflow.
[0054] An indoor temperature sensor 43, which detects the indoor
temperature, is provided inside the indoor unit 4. In addition, an
indoor heat exchanger temperature sensor 44, which detects the
temperature of the refrigerant on the indoor side liquid pipe C,
along which the motor operated expansion valve 24 is connected, is
provided in the indoor heat exchanger 41.
[0055] A control unit 11 is constituted by the connection of an
outdoor control unit 12, which controls equipment disposed inside
the outdoor unit 2, and an indoor control unit 13, which controls
equipment disposed inside the indoor unit 4, via a communications
wire 11a. The control unit 11 performs various control functions
with respect to the air conditioner 1.
[0056] In addition, a timer 95, which counts in order to measure
the time elapsed when various control functions are performed, is
provided to the outdoor control unit 12.
[0057] Furthermore, a controller 90, which accepts the input of
settings from the user, is connected to the control unit 11.
<1-2> Electromagnetic Induction Heating Unit 6
[0058] FIG. 2 is a schematic oblique view of the electromagnetic
induction heating unit 6 mounted to the accumulator pipe F. FIG. 3
is an external oblique view that shows the state wherein a
shielding cover 75 has been removed from the electromagnetic
induction heating unit 6. FIG. 4 is an external oblique view of an
electromagnetic induction thermistor 14. FIG. 5 is an external
oblique view of a fuse 15. FIG. 6 is a cross sectional view for the
state wherein the electromagnetic induction thermistor 14 and the
fuse 15 are mounted to the accumulator pipe F. FIG. 7 is a cross
sectional view of the electromagnetic induction heating unit 6
mounted to the accumulator pipe F.
[0059] The electromagnetic induction heating unit 6 is disposed
such that it covers the magnetic pipe F2, which is the heat
generating portion of the accumulator pipe F, from the outer side
in the radial directions and causes the magnetic pipe F2 to
generate heat by electromagnetic induction heating. The heat
generating portion of the accumulator pipe F has a double pipe
structure that comprises the copper pipe F1 on the inner side and
the magnetic pipe F2 on the outer side.
[0060] The electromagnetic induction heating unit 6 comprises a
first hex nut 61, a second hex nut 66, a first bobbin cover 63, a
second bobbin cover 64, a bobbin main body 65, a first ferrite case
71, a second ferrite case 72, a third ferrite case 73, a fourth
ferrite case 74, first ferrite parts 98, second ferrite parts 99,
the coil 68, the shielding cover 75, the electromagnetic induction
thermistor 14, the fuse 15, and the like.
[0061] The first hex nut 61 and the second hex nut 66 are made of
resin, and the electromagnetic induction heating unit 6 and the
accumulator pipe F are stably fixed using a C ring (not shown). The
first bobbin cover 63 and the second bobbin cover 64 are made of
resin and cover the accumulator pipe F from the outer side in the
radial directions at the upper end position and the lower end
position, respectively. The first bobbin cover 63 and the second
bobbin cover 64 each have four screw holes, which are for screwing
the first through fourth ferrite cases 71-74 (discussed below) to
the first bobbin cover 63 and the second bobbin cover 64 using
screws 69. Furthermore, the second bobbin cover 64 has an
electromagnetic induction thermistor insertion opening 64f, which
is for inserting the electromagnetic induction thermistor 14 into
the second bobbin cover 64 in order to mount the electromagnetic
induction thermistor 14 to the outer surface of the magnetic pipe
F2. In addition, the second bobbin cover 64 has a fuse insertion
opening 64e, which is for inserting the fuse 15 into the second
bobbin cover 64 in order to mount the fuse 15 to the outer surface
of the magnetic pipe F2. As shown in FIG. 4, the electromagnetic
induction thermistor 14 comprises an electromagnetic induction
thermistor detecting part 14a, an outer side projection 14b, a side
surface projection 14c, and an electromagnetic induction thermistor
wiring 14d, which converts the detection result of the
electromagnetic induction thermistor detecting part 14a to a signal
and transmits such to the control unit 11. The electromagnetic
induction thermistor detecting part 14a has a shape that conforms
to the curved shape of the outer surface of the accumulator pipe F
and has a substantial contact surface area. As shown in FIG. 5, the
fuse 15 comprises a fuse detection part 15a, an asymmetrically
shaped member 15b, and a fuse wiring 15d, which converts the
detection result of the fuse detection part 15a to a signal and
transmits such to the control unit 11. If the control unit 11
receives a notification from the fuse 15 that the temperature
detected exceeds a prescribed limit, then the control unit 11
performs control such that the supply of electric power to the coil
68 is stopped, thereby avoiding thermal damage to the equipment.
The bobbin main body 65 is made of resin, and the coil 68 is wound
around the bobbin main body 65. The coil 68 is wound helically
around the outer side of the bobbin main body 65, the directions in
which the accumulator pipe F extends being the axial directions.
The coil 68 is connected to a control printed circuit board (not
shown), and receives the supply of a high frequency electric
current. The output of the control printed circuit board is
controlled by the control unit 11. As shown in FIG. 6, the
electromagnetic induction thermistor 14 and the fuse 15 are mounted
in the state wherein the bobbin main body 65 and the second bobbin
cover 64 are mated. Here, in the state wherein the electromagnetic
induction thermistor 14 is mounted, satisfactory pressure contact
between the electromagnetic induction thermistor 14 and the outer
surface of the magnetic pipe F2 is maintained by a leaf spring 16,
which presses the electromagnetic induction thermistor 14 inward in
the radial directions of the magnetic pipe F2. In addition, in the
state wherein the fuse 15 is mounted, too, satisfactory contact
pressure between the fuse 15 and the outer surface of the magnetic
pipe F2 is likewise maintained by a leaf spring 17, which presses
the fuse 15 inward in the radial directions of the magnetic pipe
F2. Thus, because tight contact is satisfactorily maintained
between the electromagnetic induction thermistor 14 and the outer
surface of the accumulator pipe F as well as between the fuse 15
and the outer surface of the accumulator pipe F, responsiveness is
improved and sudden changes in temperature owing to electromagnetic
induction heating can be detected rapidly. The first ferrite case
71 is inserted into the first bobbin cover 63 and the second bobbin
cover 64 from the directions in which the accumulator pipe F
extends and is fixed by the screws 69. The first ferrite case 71
through the fourth ferrite case 74 each house the first ferrite
parts 98 and the second ferrite parts 99, which are made of
ferrite--a raw material that has high magnetic permeability. As
shown in the cross sectional view of the accumulator pipe F and the
electromagnetic induction heating unit 6 of FIG. 7, by capturing
the magnetic field generated by the coil 68 and thereby forming a
path for the magnetic flux, the first ferrite parts 98 and the
second ferrite parts 99 tend not to externally leak the magnetic
field. The shielding cover 75 is disposed at the outermost
circumferential portion of the electromagnetic induction heating
unit 6 and collects the magnetic flux that cannot be completely
gathered by the first ferrite parts 98 and the second ferrite parts
99 alone. Thereby, virtually none of the magnetic flux leaks to the
outer side of the shielding cover 75; furthermore, the location at
which the magnetic flux is generated can be determined
independently.
<1-3> Electromagnetic Induction Heating Control
[0062] Control is performed wherein the electromagnetic induction
heating unit 6 discussed above causes the magnetic pipe F2 of the
accumulator pipe F to generate heat at startup, namely, to start
heating operation when the refrigeration cycle is caused to perform
heating operation, when heating performance is supplemented, and
when defrosting operation is performed.
[0063] Here, as an example of the various types of control
performed by the electromagnetic induction heating unit 6 when
supplementing heating performance, control for inhibiting an
abnormal rise in the temperature of the magnetic pipe F2 of the
accumulator pipe F will be explained.
(Abnormal Superheating Inhibition Control)
[0064] Abnormal superheating inhibition control is control
performed after control at startup of the compressor 21 and the
like has ended in order to verify--in the regular control state
wherein the state of the distribution of the refrigerant in the
refrigerant circuit 10 of the air conditioner 1 has
stabilized--that the volume rate at which the refrigerant is
circulating through the accumulator pipe F is sufficiently secured
when the electromagnetic induction heating unit 6 starts induction
heating for the purpose of, for example, supplementing heating
operation capacity.
[0065] Here, the control unit 11 calculates the volume rate at
which the refrigerant is circulating in the refrigeration cycle
(i.e., the volume rate at which the refrigerant passes through the
magnetic pipe F2 portion of the accumulator pipe F) by multiplying
the piston displacement volume of the compressor 21, which is
stored in memory (not shown) as a predetermined quantity, the drive
rotational speed of the compressor 21, which is ascertained by the
rotational speed ascertaining part 29r, and the density of the
refrigerant suctioned into the compressor 21. The suctioned
refrigerant density is calculated by the control unit 11 based on
the refrigerant pressure detected by the second pressure sensor 29g
and the refrigerant temperature detected by the suction temperature
sensor 19.
[0066] In the regular control state, which is the state that
obtains after the various types of control performed at the startup
of the air conditioner 1 have ended, the control unit 11--in the
state wherein the drive frequency of the compressor 21 is
maintained at the rated maximum frequency--performs control that
responds to changes such as a change in the outdoor air temperature
and a change in the user setting temperature by a variation in the
circulating refrigerant volume rate owing to regulation of the
degree of opening of the motor operated expansion valve 24. Here,
the control unit 11 controls the degree of opening of the motor
operated expansion valve 24 such that the degree of supercooling of
the refrigerant that passes between the indoor heat exchanger 41
and the motor operated expansion valve 24 in the heating operation
state, is maintained at 5.degree. C. This degree of supercooling is
obtained by virtue of the control unit 11 calculating the
difference between the saturation temperature corresponding to the
pressure detected by the second pressure sensor 29g and the
temperature detected by the indoor heat exchanger temperature
sensor 44.
[0067] The explanation below references the flow chart of moisture
abnormal superheating inhibition control shown in FIG. 8.
[0068] In a step S11, the control unit 11 determines whether the
regular control state obtains. Here, if it is determined that the
regular control state does obtain, then the method transitions to a
step S12. Furthermore, in the regular control state, the output of
the electromagnetic induction heating unit 6 is zero.
[0069] In the step S12, the control unit 11 determines whether the
volume rate at which the refrigerant is circulating in the
refrigeration cycle is greater than or equal to a prescribed
abnormal superheating inhibition volume rate. If it is less than
the abnormal superheating inhibition volume rate, then the method
repeats the step S12. If it is greater than or equal to the
abnormal superheating inhibition volume rate, then the method
transitions to a step S13.
[0070] In the step S13, the control unit 11 causes the
electromagnetic induction heating unit 6 to start induction heating
the accumulator pipe F.
[0071] In a step S14, the control unit 11 waits for the elapse of a
prescribed time while maintaining the control state as is.
[0072] In a step S15, the control unit 11 once again determines
whether the volume rate at which the refrigerant is circulating in
the refrigeration cycle is greater than or equal to the prescribed
abnormal superheating inhibition volume rate. If it is greater than
or equal to the abnormal superheating inhibition volume rate, then
the method returns to the step S14. If it is less than the abnormal
superheating inhibition volume rate, then the method transitions to
a step S16.
[0073] In the step S16, the control unit 11 causes the
electromagnetic induction heating unit 6 to stop induction heating
the accumulator pipe F.
[0074] In so doing, it is possible to prevent an abnormal rise in
the temperature of the accumulator pipe F by ensuring the fluidity
of the refrigerant in the accumulator pipe F when the
electromagnetic induction heating unit 6 performs induction
heating.
<Characteristics of the Air Conditioner 1 of the First
Embodiment>
[0075] In the air conditioner 1, abnormal superheating inhibition
control is performed, before the accumulator pipe F is induction
heated by the electromagnetic induction heating unit 6, in order to
first verify whether the state that obtains is the state wherein
the volume rate at which refrigerant is circulating in the
refrigeration cycle is greater than or equal to the abnormal
superheating inhibition volume rate. Consequently, the
electromagnetic induction heating unit 6 induction heats only in
the state wherein the refrigerant is flowing in the refrigeration
cycle at a volume rate that is greater than or equal to the
abnormal superheating inhibition volume rate and not in the state
wherein that volume rate is less than the abnormal superheating
inhibition volume rate.
[0076] Consequently, the heat supplied to the accumulator pipe F by
virtue of the induction heating by the electromagnetic induction
heating unit 6 is robbed by the circulating refrigerant, and
therefore an abnormal rise in the temperature of the accumulator
pipe F can be prevented because a sufficient refrigerant
circulation volume rate has been secured.
Second Embodiment
[0077] The configuration of an air conditioner of a second
embodiment is the same as that of the air conditioner 1 of the
first embodiment discussed above, and consequently an explanation
thereof is omitted.
[0078] In the air conditioner of the second embodiment, abnormal
superheating inhibition moisture protection control is performed
instead of the abnormal superheating inhibition control of the
first embodiment.
[0079] Abnormal superheating inhibition moisture protection control
is control that is performed after control at the startup of the
compressor 21 and the like has ended in order to verify--when the
electromagnetic induction heating unit 6 induction heats to
supplement heating capacity--that a sufficient volume rate of
refrigerant circulating through the accumulator pipe F is secured
when the electromagnetic induction heating unit 6 starts induction
heating such that liquid compression does not occur in the
compressor 21. Here, when the electromagnetic induction heating
unit 6 induction heats to supplement heating capacity, the electric
power supplied to the coil 68 is set to 50% of the maximum
output.
[0080] In the state wherein the electromagnetic induction heating
unit 6 induction heats to supplement heating capacity, which is the
state that obtains after the various types of control performed at
the startup of the air conditioner 1 have ended, the control unit
11--in the state wherein the drive frequency of the compressor 21
is maintained at the rated maximum frequency--responds to state
changes such as a change in the outdoor air temperature, a change
in the set temperature made by the user, and the like by a
variation in the circulating refrigerant volume rate owing to
regulation of the degree of opening of the motor operated expansion
valve 24. Here, the control unit 11 controls the degree of opening
of the motor operated expansion valve 24 such that the degree of
supercooling of the refrigerant that passes between the indoor heat
exchanger 41 and motor operated expansion valve 24 in the heating
operation state, is maintained at 5.degree. C. This degree of
supercooling is obtained by virtue of the control unit 11
calculating the difference between the saturation temperature that
corresponds to the pressure detected by the second pressure sensor
29g and the temperature detected by the indoor heat exchanger
temperature sensor 44.
[0081] The control unit 11 calculates the degree of dryness or the
degree of superheating of the refrigerant suctioned by the
compressor 21 based on the difference between the saturation
temperature that corresponds to the pressure detected by the second
pressure sensor 29g and the temperature detected by the
electromagnetic induction thermistor 14.
[0082] The control unit 11 calculates the degree of dryness or the
degree of superheating of the refrigerant discharged by the
compressor 21 based on the difference between the saturation
temperature that corresponds to the pressure detected by the first
pressure sensor 29a and the temperature detected by the discharge
temperature sensor 29d.
[0083] The explanation below references the flow chart of abnormal
superheating inhibition moisture protection control shown in FIG.
9.
[0084] In a step S21, the control unit 11 determines whether the
electromagnetic induction heating unit 6 is induction heating.
Here, if it is determined that induction heating is in progress,
then the method transitions to a step S22. If induction heating is
not in progress, then the method repeats the step S21.
[0085] In the step S22, the control unit 11 determines whether an
induction heating start condition, wherein the degree of
superheating of the suctioned refrigerant is less than 4.degree. C.
and the degree of superheating of the discharged refrigerant is
less than 10.degree. C., is satisfied. If the induction heating
start condition is not satisfied, then the method repeats the step
S22. If the induction heating start condition is satisfied, then
the method transitions to a step S23.
[0086] In the step S23, the control unit 11 determines whether the
volume rate at which the refrigerant is circulating in the
refrigeration cycle is greater than or equal to a prescribed
abnormal superheating inhibition volume rate at maximum output. If
less than the abnormal superheating inhibition volume rate at
maximum output, then the method repeats the step S23. If greater
than or equal to the abnormal superheating inhibition volume rate
at maximum output, then the method transitions to a step S24.
[0087] In the step S24, the control unit 11 increases the degree to
which the electromagnetic induction heating unit 6 induction heats
the accumulator pipe F. Namely, the amount of electric power
supplied to the coil 68 of the electromagnetic induction heating
unit 6 is increased. Here, the electric power supplied to the coil
68 is increased from the state wherein it is at 50% of the maximum
output to the state wherein it is at the maximum output.
[0088] In the step S25, the control unit 11 waits for the
prescribed time to elapse while maintaining the control state as
is.
[0089] In a step S26, the control unit 11 once again determines
whether the volume rate at which the refrigerant is circulating in
the refrigeration cycle is greater than or equal to the prescribed
abnormal superheating inhibition volume rate at maximum output. If
greater than or equal to the abnormal superheating inhibition
volume rate at maximum output, then the method transitions to a
step S27. If less than the abnormal superheating inhibition volume
rate at maximum output, then the method transitions to a step
S28.
[0090] In the step S27, the control unit 11 determines whether an
induction heating end condition, wherein the degree of superheating
of the suctioned refrigerant is greater than or equal to 5.degree.
C. or the degree of superheating of the discharged refrigerant is
greater than or equal to 12.degree. C., is satisfied. If the
induction heating end condition is not satisfied, then the method
returns to the step S25. If the induction heating end condition is
satisfied, then the method transitions to the step S28.
[0091] In the step S28, the control unit 11 decreases the output of
the electromagnetic induction heating unit 6 in its induction
heating of the accumulator pipe F to 50% of the maximum output,
which is the state wherein heating performance is supplemented.
[0092] In so doing, even if the output of induction heating by the
electromagnetic induction heating unit 6 increases, then it is
possible to prevent an abnormal rise in the temperature of the
accumulator pipe F while preventing liquid compression in the
compressor 21 by ensuring the fluidity of the refrigerant of the
accumulator pipe F.
<Characteristics of the Air Conditioner 1 of the Second
Embodiment>
[0093] In the abnormal superheating inhibition moisture protection
control of the second embodiment, it is possible to achieve not
only the characteristics of the abovementioned first embodiment but
also to prevent both liquid compression in the compressor 21 and an
abnormal rise in the temperature of the accumulator pipe F.
[0094] Furthermore, if, in the second embodiment, the output of the
electromagnetic induction heating unit 6 is further increased while
the electromagnetic induction heating unit 6 is induction heating
at an output of 50% in order to supplement heating performance,
then it is difficult to determine whether the volume rate at which
the refrigerant is circulating through the portion to be induction
heated by the electromagnetic induction heating unit 6 has been
secured because the temperature detected by the electromagnetic
induction thermistor 14 has already risen. In contrast, in the air
conditioner 1 of the second embodiment, the suction temperature
sensor 19 is installed at a position on the downstream side of the
portion to be induction heated by the electromagnetic induction
heating unit 6. Consequently, with regard to the volume rate at
which the refrigerant is circulating in the refrigeration cycle, it
is possible to ascertain the volume rate at which the refrigerant
is flowing on the downstream side of the portion to be induction
heated by the electromagnetic induction heating unit 6 by deriving
the density of that refrigerant, not the volume rate at which the
refrigerant is flowing between the induction heating target portion
and the compressor 21 in the state after the refrigerant has been
heated. Furthermore, if this circulation volume rate is the
abnormal superheating inhibition volume rate at maximum output,
then the control unit 11 permits the output of the electromagnetic
induction heating unit 6 to be set at the maximum. Thereby, even if
the electromagnetic induction heating unit 6 performs induction
heating at maximum output, it is possible to inhibit an abnormal
rise in the temperature of the portion to be induction heated.
Other Embodiments
[0095] The above text explained an embodiment of the present
invention based on the drawings, but the specific constitution is
not limited to these embodiments, and it is understood that
variations and modifications may be effected without departing from
the spirit and scope of the invention.
(A)
[0096] The abovementioned embodiment explained an exemplary case
wherein SUS 430 is used as the material of the magnetic pipe
F2.
[0097] However, the present invention is not limited thereto. For
example, it can be a conductor such as iron, copper, aluminum,
chrome, nickel, and the like, or an alloy containing at least two
metals selected from that group.
[0098] In addition, the magnetic material may be, for example, one
of two types, namely, ferritic or martensitic, or a combination
thereof, but is preferably a material that is ferromagnetic and
that has a comparatively high electrical resistance and a Curie
temperature higher than that of the working temperature range.
[0099] Furthermore, the accumulator pipe F herein requires a larger
amount of electric power; however, instead of a magnetic body and a
material that contains a magnetic body, it may contain a material
that can be induction heated.
[0100] Furthermore, for example, the magnetic material may
constitute all of the accumulator pipe F, only an inner side
surface of the accumulator pipe F, or be simply included in the
material that constitutes the piping of the accumulator pipe F.
(B)
[0101] The abovementioned second embodiment explained an exemplary
case wherein the degree of dryness or the degree of superheating of
the refrigerant suctioned by the compressor 21 is ascertained based
on the temperature detected by the electromagnetic induction
thermistor 14.
[0102] However, the present invention is not limited thereto.
[0103] For example, in the electromagnetic induction thermistor 14,
it is difficult to detect the temperature of the refrigerant
flowing through the portion to be induction heated while the
electromagnetic induction heating unit 6 is induction heating, and
therefore a higher temperature is sometimes inadvertently detected
owing to the heat generated at the magnetic pipe F2.
[0104] In such a case, instead of the electromagnetic induction
thermistor 14, a sensor that detects the temperature of the
accumulator pipe F at a location spaced apart from the portion to
be induction heated to the extent that any error in the
transmission of heat by induction heating can be ignored may be
further provided between the suction side of the compressor 21 and
the portion to be induction heated. Thereby, even while induction
heating is in progress, the degree of dryness or the degree of
superheating of the refrigerant suctioned by the compressor 21 can
be ascertained more accurately.
(C)
[0105] The induction heating start condition and the induction
heating end condition of the first embodiment and the induction
heating start condition and the induction heating end condition of
the second embodiment were explained according to exemplary cases
wherein the same conditions were set.
[0106] However, the present invention is not limited thereto. For
example, abnormal superheating inhibition moisture protection
control in the second embodiment is control wherein the output of
the electromagnetic induction heating unit 6 in performing
induction heating is already at 50% and is then further increased
to the maximum output. Consequently, the induction heating start
condition for increasing the output to the maximum output (i.e.,
the induction heating start condition in the second embodiment) may
be set to a condition wherein the refrigerant suctioned by the
compressor 21 is in a moister state than it is in the induction
heating start condition of the first embodiment.
(D)
[0107] The second embodiment explained an exemplary case wherein,
when the circulating refrigerant volume rate is greater than or
equal to the abnormal superheating inhibition volume rate at
maximum output, the output of the electromagnetic induction heating
unit 6 is increased from 50% to the maximum output.
[0108] However, the present invention is not limited thereto. For
example, the output of the electromagnetic induction heating unit 6
may be adjusted in accordance with the derived circulating
refrigerant volume rate.
(E)
[0109] The first and second embodiments explained exemplary cases
that determine whether the abnormal superheating inhibition volume
rate has been reached or whether the abnormal superheating
inhibition volume rate at maximum output has been reached.
[0110] However, the present invention is not limited thereto. For
example, if the output of the electromagnetic induction heating
unit 6 cannot be increased because the abnormal superheating
inhibition volume rate, the abnormal superheating inhibition volume
rate at maximum output, or the like could not be achieved, then
control that raises the rotational frequency of the compressor 21
may be performed and a state may be created wherein the capacity of
induction heating by the electromagnetic induction heating unit 6
can be actively increased without an attendant abnormal rise in the
temperature of the portion to be induction heated.
(F)
[0111] In the abovementioned first embodiment, an exemplary case
was explained wherein the state of the refrigerant in the
refrigeration cycle is stabilized by supercooling degree constant
control.
[0112] However, the present invention is not limited thereto.
[0113] For example, control may be performed wherein the degree of
change in the distribution state of the refrigerant in the
refrigeration cycle is maintained in a prescribed distribution
state or within a prescribed distribution range during a prescribed
time. With regard to detecting the distribution state of the
refrigerant, for example, a sight glass and the like may be
provided in advance to a condenser of the refrigeration cycle and
the distribution state of the refrigerant may be ascertained by
using the sight glass to ascertain the liquid level of the
refrigerant; furthermore, control may be performed to stabilize the
distribution state such that it is in the prescribed distribution
state or within the prescribed distribution range.
(G)
[0114] The abovementioned embodiments explained a case wherein the
electromagnetic induction heating unit 6 is mounted to the
accumulator pipe F of the refrigerant circuit 10.
[0115] However, the present invention is not limited thereto.
[0116] For example, the electromagnetic induction heating may be
mounted to a refrigerant piping other than the accumulator pipe F.
In such a case, a magnetic body, for example, the magnetic pipe F2
is provided to a portion of the refrigerant piping whereto the
electromagnetic induction heating unit 6 is provided.
(H)
[0117] The abovementioned embodiments explained an exemplary case
wherein the accumulator pipe F is configured as a double pipe,
namely, as the copper pipe F1 and the magnetic pipe F2.
[0118] However, the present invention is not limited thereto.
[0119] As shown in FIG. 10, for example, a magnetic body member F2a
and two stoppers F1a, F1b may be disposed inside the accumulator
pipe F, the refrigerant piping to be heated, or the like. Here, the
magnetic body member F2a contains a magnetic material and generates
heat by the electromagnetic induction heating of the abovementioned
embodiment. At two locations on the inner side of the copper pipe
F1, the stoppers F1a, F1b continuously permit the passage of the
refrigerant but do not permit the passage of the magnetic body
member F2a. Thereby, the magnetic body member F2a does not move
even when the refrigerant flows. Consequently, the target heating
position of the accumulator pipe F and the like can be heated.
Furthermore, the heat transfer efficiency can be improved because
the magnetic body member F2a, which generates heat, and the
refrigerant directly contact one another.
(I)
[0120] Instead of using the stoppers F1a, F1b the position of the
magnetic body member F2a explained in the abovementioned other
embodiment (H) may be prescribed with respect to the piping.
[0121] As shown in FIG. 11, for example, bent portions FW may be
provided to the copper pipe F1 at two locations, and the magnetic
body member F2a may be disposed on the inner side of the copper
pipe F1 between the two bent portions FW. In so doing, too, the
movement of the magnetic body member F2a can be hindered while the
refrigerant is made to pass through.
(J)
[0122] The abovementioned embodiment explained a case wherein the
coil 68 is helically wound around the accumulator pipe F.
[0123] However, the present invention is not limited thereto.
[0124] For example, as shown in FIG. 12, coils 168, which are wound
around bobbin main bodies 165, are disposed at the circumference
of--without being wound around--the accumulator pipe F. Here, each
of the bobbin main bodies 165 is disposed such that its axial
directions are substantially perpendicular to the axial directions
of the accumulator pipe F. In addition, the two pairs, each pair
comprising one of the bobbin main bodies 165 and one of the coils
168, are disposed such that they sandwich the accumulator pipe F.
In this case, as shown in FIG. 12, a first bobbin cover 163 and a
second bobbin cover 164, wherethrough the accumulator pipe F is
inserted, are preferably disposed in a state wherein they are mated
to the bobbin main bodies 165. In addition, as shown in FIG. 12,
the first bobbin cover 163 and the second bobbin cover 164 are
preferably interposed by a first ferrite case 171 and a second
ferrite case 172, and thereby fixed.
[0125] FIG. 12 shows an exemplary case wherein the two ferrite
cases 171, 172 are provided such that they sandwich the accumulator
pipe F; however, as in the above-mentioned embodiments, ferrite
cases may be disposed in four directions around the accumulator
pipe F. In addition, as in the abovementioned embodiments, the
ferrite parts may be housed therein.
<Miscellaneous>
[0126] The above text explained embodiments of the present
invention with some examples, but the present invention is not
limited to these embodiments. For example, the present invention
also includes other combination embodiments obtained by
appropriately combining parts of the abovementioned embodiments
within a range that a person skilled in the art could effect based
on the scope of the invention described above.
INDUSTRIAL APPLICABILITY
[0127] The present invention is capable of hindering a member,
which generates heat by induction heating, from generating heat
excessively, and consequently is particularly useful in an air
conditioner that is capable of heating a refrigerant by
electromagnetic induction heating.
REFERENCE SIGNS LIST
[0128] 1 Air conditioner [0129] 11 Control unit [0130] 19 Suction
temperature sensor (suctioned refrigerant temperature ascertaining
part) [0131] 21 Compressor (compressing mechanism) [0132] 23
Outdoor heat exchanger (refrigerant heater) [0133] 24 Motor
operated expansion valve (expansion mechanism) [0134] 29a First
pressure sensor [0135] 29g Second pressure sensor (low pressure
ascertaining part) [0136] 29r Rotational speed ascertaining part
(circulation volume rate ascertaining part) [0137] 41 Indoor heat
exchanger (refrigerant cooler) [0138] 44 Indoor heat exchanger
temperature sensor (supercooling degree ascertaining part) [0139]
68 Coil (magnetic field generating part) [0140] F Accumulator pipe
(suction refrigerant piping)
CITATION LIST
Patent Literature
Patent Document 1
[0140] [0141] Japanese Unexamined Patent Application Publication
No. 2007-255736
* * * * *