U.S. patent application number 11/074743 was filed with the patent office on 2005-09-15 for refrigerating machine.
This patent application is currently assigned to SANYO ELECTRIC CO., LTD.. Invention is credited to Imai, Satoshi, Itsuki, Hiroyuki, Kamimura, Ichiro, Mizukami, Kazuaki, Mukaiyama, Hiroshi, Nagae, Etsushi, Sugawara, Akira.
Application Number | 20050198978 11/074743 |
Document ID | / |
Family ID | 34836492 |
Filed Date | 2005-09-15 |
United States Patent
Application |
20050198978 |
Kind Code |
A1 |
Itsuki, Hiroyuki ; et
al. |
September 15, 2005 |
Refrigerating machine
Abstract
A refrigerating machine having a compressor, a radiator, a
pressure-reducing device, a gas-liquid separator, a unit for
selectively introducing gas refrigerant separated in the gas-liquid
separator into an intermediate pressure portion of the compressor,
and a low pressure side circuit in which liquid refrigerant
separated in the gas-liquid separator is circulated. The low
pressure side circuit is provided with a heat absorbing unit
functioning selectively in one of different temperature zones, and
refrigerant passing through the selected heat absorbing unit is
returned to a suction portion of the compressor.
Inventors: |
Itsuki, Hiroyuki; (Gunma,
JP) ; Sugawara, Akira; (Saitama, JP) ;
Mukaiyama, Hiroshi; (Gunma, JP) ; Nagae, Etsushi;
(Gunma, JP) ; Imai, Satoshi; (Gunma, JP) ;
Mizukami, Kazuaki; (Gunma, JP) ; Kamimura,
Ichiro; (Gunma, JP) |
Correspondence
Address: |
MCDERMOTT WILL & EMERY LLP
600 13TH STREET, N.W.
WASHINGTON
DC
20005-3096
US
|
Assignee: |
SANYO ELECTRIC CO., LTD.
|
Family ID: |
34836492 |
Appl. No.: |
11/074743 |
Filed: |
March 9, 2005 |
Current U.S.
Class: |
62/197 ;
62/510 |
Current CPC
Class: |
F25B 2309/061 20130101;
F25B 2400/052 20130101; F25D 2700/123 20130101; F25B 9/008
20130101; F25B 2309/06 20130101; F25B 1/10 20130101; F25B 2400/13
20130101; F25B 2400/23 20130101 |
Class at
Publication: |
062/197 ;
062/510 |
International
Class: |
F25B 041/00; F25B
049/00; F25B 043/04; F25B 001/10 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 2004 |
JP |
P2004-72853 |
Claims
What is claimed is:
1. A refrigerating machine comprising a compressor, a radiator, a
pressure-reducing device, a gas-liquid separator, a unit for
selectively introducing gas refrigerant separated in the gas-liquid
separator into an intermediate pressure portion of the compressor,
and a low pressure side circuit in which liquid refrigerant
separated in the gas-liquid separator is circulated, wherein the
low pressure side circuit is provided with a heat absorbing unit
functioning selectively in one of different temperature zones, and
refrigerant passing through the selected heat absorbing unit is
returned to a suction portion of the compressor.
2. The refrigerating machine according to claim 1, wherein the heat
absorbing unit has plural heat absorbers functioning in different
temperature zones, the heat absorbers selectively function, and the
refrigerating machine further comprises a unit for guiding cold air
passing through the heat absorbers to chambers controlled to the
corresponding temperature zones.
3. The refrigerating machine according to claim 2, wherein the
respective heat absorbers are disposed in the chambers controlled
to the corresponding temperature zones.
4. The refrigerating machine according to claim 1, wherein the heat
absorbing unit is provided with one heat absorber which functions
selectively in different temperature zones, and the refrigerating
machine further comprises a unit for selectively guiding cold air
passing through the heat absorber through a change-over dumper to
plural chambers controlled to different temperature zones.
5. The refrigerating machine according to claim 4, wherein the heat
absorber is disposed in a chamber controlled to a low temperature
zone.
6. The refrigerating machine according to claim 1, wherein the
refrigerant is formed of refrigerant with which the high pressure
side is set to supercritical pressure under operation.
7. The refrigerating machine according to claim 6, wherein the
refrigerant is formed of carbon dioxide.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a refrigerating machine
having a unit for selectively introducing gas refrigerant separated
in a gas-liquid separator into an intermediate pressure portion of
a compressor.
[0003] 2. Description of the Related Art
[0004] In general, there is known a refrigerating machine having a
compressor, a radiator, a pressure-reducing device, a gas-liquid
separator and a unit which can introduce gas refrigerant separated
in the gas-liquid separator into an intermediate pressure portion
of the compressor as disclosed in JP-A-2003-106693 (hereinafter
referred to as "Patent Document 1"). In this type of refrigerant
machine, gas refrigerant separated in the gas-liquid separator is
introduced into the intermediate pressure portion of the compressor
while kept to a gas state, so that there is achieved an effect that
the efficiency of the compressor can be enhanced.
[0005] In some cases, this type of refrigerating machine is
equipped with a heat absorbing unit containing heat absorbers which
selectively function in different temperature zone in a
refrigerating cycle. For example, when this refrigerating machine
is applied to a refrigerator (fridge) having a refrigerating
chamber and a freezing chamber, heat absorbers functioning as a
refrigerator and a freezer are disposed in the refrigerating cycle,
and a refrigerating or freezing operation is carried out by using
any one of the heat absorbers. In this case, it is important to
carry out the refrigerating or freezing operation without reducing
the efficiency under any operation.
SUMMARY OF THE INVENTION
[0006] Therefore, an object of the present invention is to provide
a refrigerating machine in which when heat absorbing units
selectively functioning in different temperature zones are provided
in the refrigerating cycle, the high efficiency operation can be
performed in any temperature zone without reducing the
efficiency.
[0007] In order to attain the above object, according to the
present invention, there is provided a refrigerating machine having
a compressor, a radiator, a pressure-reducing device, a gas-liquid
separator, a unit for selectively introducing gas refrigerant
separated in the gas-liquid separator into an intermediate pressure
portion of the compressor, and a low pressure side circuit in which
liquid refrigerant separated in the gas-liquid separator is
circulated, wherein the low pressure side circuit is provided with
a heat absorbing unit functioning selectively in one of different
temperature zones, and refrigerant passing through the selected
heat absorbing unit is returned to a suction portion of the
compressor.
[0008] In this case, it is preferable that the heat absorbing unit
has plural heat absorbers which function in different temperature
zones, the heat absorbers function selectively, and there is
provided a unit for guiding cold air passing through the heat
absorbers to chambers controlled to the corresponding temperature
zones. Furthermore, the respective heat absorbers may be disposed
in chambers which are respectively controlled to the corresponding
temperature zones. Furthermore, the heat absorbing unit may be
provided with one heat absorber which functions selectively in
different temperature zones, and there is provided a unit for
selectively guiding cold air passing through the heat absorber
through a change-over dumper to plural chambers controlled to
different temperature zones. In this case, the heat absorber may be
disposed in a chamber controlled to a low temperature zone.
[0009] Furthermore, in all the cases described above, refrigerant
such as carbon dioxide refrigerant or the like with which the high
pressure side is set to supercritical pressure under operation may
be filled.
[0010] According to the present invention, the low pressure side
circuit for circulating liquid refrigerant separated in the
gas-liquid separator is provided, and the low pressure side circuit
is provided with the absorbing unit which selectively functions in
different temperature zones. Therefore, high-efficiency operation
can be performed in the respective temperature zones.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a refrigerant circuit diagram showing an
embodiment of a refrigerating machine according to the present
invention;
[0012] FIG. 2 is an enthalpy-pressure diagram of a refrigerating
cycle;
[0013] FIG. 3 is an enthalpy-pressure diagram of a supercritical
cycle;
[0014] FIG. 4 is a diagram showing an applied example to a
refrigerator;
[0015] FIG. 5 is a diagram showing a cooling example;
[0016] FIG. 6 is a diagram showing a cooling example;
[0017] FIG. 7 is a diagram showing an applied example to a
refrigerator;
[0018] FIG. 8 is a diagram showing an applied example to a
refrigerator;
[0019] FIG. 9 is a refrigerant circuit diagram showing another
embodiment;
[0020] FIG. 10 is a diagram showing an applied example to a
refrigerator; and
[0021] FIG. 11 is a diagram showing an applied example to a
refrigerator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Preferred embodiments according to the present invention
will be described hereunder with reference to the accompanying
drawings.
[0023] FIG. 1 is a refrigerant circuit diagram showing an
embodiment of the present invention.
[0024] A refrigerating machine 30 has a compressor 1, a radiator 2,
a pressure-reducing device 3 and a gas-liquid separator 4. A
refrigerant circuit extending from the compressor 1 through the
radiator 2 to the inlet port of the pressure-reducing device 3
constitutes a high pressure side circuit. The pressure-reducing
device 3 is designed so that the opening degree of the diaphragm
thereof is variable. By varying the opening degree, the pressure of
refrigerant is reduced until the refrigerant reaches the gas-liquid
separator 4, and a lot of gas refrigerant occurs. Under this state,
the refrigerant is input to the gas-liquid separator 4, whereby the
separation efficiency in the gas-liquid separator 4 can be varied.
The compressor 1 is a two-stage compressor, and it contains a
first-stage compressing portion 1A, a second-stage compressing
portion 1B and an intermediate cooler 1C between the first-stage
compressing portion 1A and the second-stage compressing portion 1B.
Reference numeral 8 represents a check valve.
[0025] The refrigerating machine 30 has an introducing unit which
can introduce gas refrigerant separated in the gas-liquid separator
4 to the intermediate portion of the compressor 1, that is, between
the intermediate cooler 1C and the second-stage compressing portion
1B. The compressor is not limited to the two-stage compressor. For
example, when the compressor is a one-stage compressor, the
introducing unit 5 may return the refrigerant to the intermediate
pressure portion of the one-stage compressor. The introducing unit
5 comprises a gas pipe 6 and an opening/closing valve 7 provided to
the gas pipe 6. When the opening/closing valve 7 is opened, the gas
refrigerant separated in the gas-liquid separator 4 is passed
through the gas pipe 6, and introduced to the intermediate pressure
portion of the compressor 1 as indicated by an arrow of a broken
line due to the pressure difference in the gas pipe 6.
[0026] Furthermore, the refrigerating machine 30 is provided with a
low pressure side circuit 9 for circulating liquid refrigerant
separated in the gas-liquid separator 4, and the low pressure side
circuit 9 is provided with a heat absorbing unit 10 which functions
selectively in different temperature zones. The heat absorbing unit
10 comprises a three-way valve 11, a first capillary tube 12, a
second capillary tube 13 provided in parallel to the first
capillary tube 12, and one heat absorber 14.
[0027] The resistance value of the first capillary tube 12 is set
to be larger than the resistance value of the second capillary tube
13. Therefore, when the refrigerant is made to flow to the first
capillary tube 12 by switching the three-way valve 11 and also the
driving frequency of the compressor 1 is reduced, the flow amount
of the refrigerant flowing into the heat absorber 14 is reduced,
the evaporation temperature is increased and thus refrigerating
operation is carried out. When the driving frequency is fixed and
only the resistance value of the capillary tube is increased, the
evaporation temperature is lowered. Furthermore, when the
refrigerant is made to flow to the second capillary tube 13 and the
driving frequency of the compressor 1 is increased, the flow amount
of the refrigerant flowing into the heat absorber 14 is increased,
the evaporation temperature is lowered and the freezing operation
is carried out. The refrigerant passed through the heat absorber 14
is passed through a heat exchanger 15 disposed near to the
pressure-reducing device 3, heat-exchanged by the heat exchanger 15
to be heated. The refrigerant thus heated is passed through a check
valve 8, and then returned to the suction portion of the compressor
1.
[0028] The above construction is equipped with a unit 23 for
selectively guiding cold air passed through the heat absorber 14 to
plural chambers (refrigerating chamber 21, freezing chamber 22)
controlled to different temperature zones. The unit 23 contains an
air blowing duct 24 and a change-over dumper 25. A controller 26 is
connected to the change-over dumper 25. The controller 26 is
connected to the three-way valve 11. For example when the load of
the freezing chamber 22 is increased, by switching the three valve
11, the refrigerant is made to successively flow through the second
capillary tube 13 having the small resistance value and the heat
absorbing unit in this order. The evaporation temperature in the
heat absorber 14 is reduced, and the change-over dumper 25 is
tilted to the position shown in FIG. 1 to guide cold air to the
freezing chamber 22. When the load of the refrigerating chamber 21
is increased, by switching the three-way valve 11, the refrigerant
is made to successively flow through the first capillary tube 12
having a large resistance value and the heat absorber 14 in this
order, and the evaporator temperature in the heat absorber 14 is
increased. Then, the change-over dumper 25 is titled to the
opposite side to the position shown in FIG. 1 to guide cold air to
the refrigerating chamber 21.
[0029] The refrigerant with which the high pressure side is set to
supercritical pressure during operation, for example, carbon
dioxide refrigerant is filled in the refrigerant circuit described
above.
[0030] FIG. 2 is an enthalpy-pressure (ph) diagram of the
refrigerating cycle containing the two-stage compressor of this
embodiment. In this embodiment, under such a condition that the
outside air temperature is increased to 30.degree. or more in
summer or the load is increased, the high pressure side circuit is
driven at supercritical pressure during operation as indicated by
the enthalpy-pressure (ph) diagram of FIG. 3. The refrigerant with
which the high-pressure circuit is driven at supercritical pressure
may contain ethylene, diborane, ethane, nitride oxide or the
like.
[0031] Next, the refrigerating cycle of the two-stage compressor 1
will be described with reference to FIGS. 2 and 3.
[0032] In FIGS. 2 and 3, "a" represents a ph value at the suction
port of the first-stage compressing portion 1A, "b" represents a ph
value at the discharge port of the first-stage compressing portion
1A, "c" represents a ph value at the outlet port of the
intermediate cooler 1C, "d" represents a ph value at the suction
port of the second-stage compressing portion 1B, and "e" represents
the discharge port of the second-stage compressing portion 1A. The
refrigerant discharge from the compressor 1 is passed through the
radiator 2 and circulated and cooled. "f" represents a ph value at
the outlet port of the radiator 2, "g" represents a ph value at the
inlet port of the pressure-reducing device 3, and "h" represents a
ph value at the outlet port of the pressure-reducing device 3.
Under this state, the refrigerant becomes a two-phase mixture of
gas/liquid. The ratio of gas and liquid corresponds to the ratio of
the length of a line segment (gas) h-i and the length of a line
segment (liquid) h-n. The refrigerant enters the gas-liquid
separator 4 under the two-phase mixture. The gas refrigerant
separated in the gas-liquid separator 4 is introduced to the
intermediate pressure portion of the compressor 1, that is,
introduced between the intermediate cooler 1C and the second-stage
compressing portion 1B. "n" represents a ph value at the outlet
port of the gas-liquid separator 4. The refrigerant passed through
the outlet port of the gas-liquid separator 4 reaches the suction
port of the second-stage compressing portion 1B of "d", and is
compressed in the second-stage compressing portion 1A. On the other
hand, the liquid refrigerant separated in the gas-liquid separator
4 is circulated in the low pressure side circuit 9. "i" represents
a ph value at the outlet port of the gas-liquid separator 4, "i"
represents a ph value at the inlet port of one of the first
capillary tube 12 and the second capillary tube 13, "k" represents
a ph value at the outlet port of one of the first and second
capillary tubes 12 and 13, and "1" represents a ph value at the
outlet port of the heat absorber 14. The refrigerant of gas phase
is passed through the check valve 8 and returned to the suction
port of the first-stage compressing portion 1A of "a".
[0033] In the above construction, the gas refrigerant separated in
the gas-liquid separator 4 is not usable for cooling even when it
is circulated to the low pressure side circuit 9, and returning of
this gas refrigerant to the suction port of the first-stage
compressing portion 1A reduces the compression efficiency of the
compressor 1.
[0034] In this construction, the gas refrigerant separated in the
gas-liquid separator 4 is introduced to the intermediate pressure
portion of the compressor 1, that is, between the intermediate
cooler 1C and the second-stage compressing portion 1B, and thus the
compression efficiency of the compressor 1 can be enhanced. In this
embodiment, particularly carbon dioxide refrigerant is filled in
the refrigerant circuit, and thus with respect to the ratio of gas
and liquid which are separated from each other in the gas-liquid
separator 4, the gas amount (the line segment h-i) is larger as
compared with chlorofluorocarbon refrigerant, and the large amount
of gas refrigerant is introduced to the intermediate pressure
portion of the compressor 1 to thereby enhance the efficiency.
[0035] In this embodiment, all the constituent elements of the heat
absorbing unit 10 functioning selectively in different temperature
zones, that is, the three-way valve 11, the first and second
capillary tubes 12 and 13 and the heat absorber 14 are provided in
the low pressure side circuit 9 in which the liquid refrigerant
separated in the gas-liquid separator 4 is circulated. Therefore,
for example in both the cases where refrigerating operation is
carried out and where freezing operation is carried out, the
high-efficiency operation can be performed without reducing the
efficiency.
[0036] FIG. 4 shows an example in which the above embodiment is
applied to a refrigerator.
[0037] A refrigerator 40 has a refrigerating chamber 41 at the
upper stage, and a freezing chamber 42 at a lower stage. A
refrigerator partition wall 43 is provided at an inner back side of
the freezing chamber 42, and the heat absorber 14 is disposed in an
air flow path 44 partitioned by the refrigerator partition wall 43.
A first change-over dumper 45 is disposed at the inlet port of the
air flow path 44, and the first change-over duper 45 is switched
between a closing position (broken-line position) at which the
inlet port A of the air flow path 44 is closed and an opening
position (solid-line position) at which the inlet port A of the air
flow path 44 is opened. Furthermore, a back-side air flow path 46
is formed in the back wall 47 of the refrigerator 40, and when the
first change-over dumper 45 is switched to the broken-line
position, the inlet port A of the air flow path 44 and the
refrigerating chamber 41 intercommunicate with each other through
the back-side air flow path 46. A fan 48 and a second change-over
dumper 49 are disposed at the outlet port B of the air flow path
44, and the second change-over dumper 49 is switched between a
closing position (broken-line position) at which the outlet port B
of the air blow path 44 is closed and an opening position
(solid-line position) at which the outlet port B of the air blow
path 44 is opened. At the solid-line position, the second
change-over dumper 49 closes an opening 51 of an intermediate
partition wall 50.
[0038] FIG. 5 shows an cooling example 1.
[0039] The area from the initial point to the point a corresponds
to the freezing operation. Referring to FIG. 4 (the dumpers 45 and
49 are located at the solid-line positions), cold air cooled by the
heat absorber 14 is circulated in the air flow path 44, and fed to
the freezing chamber 42, whereby the temperature of the freezing
chamber 42 is gradually reduced. On the other hand, the temperature
of the refrigerating chamber 41 to which no cold air is fed is
gradually increased. During this period, the compressor 1 is turned
on, the fan 48 is turned on, and each of the dumpers 45 and 49 is
switched to the solid-line position. By switching the three-way
valve 11, refrigerant is made to flow into the second capillary
tube 13, and the opening/closing valve 7 is opened. From a point to
b point, the operation is stopped. During this period, no cold air
is fed to both the refrigerating chamber 41 and the freezing
chamber 42, and the temperature of each of the chambers 41 and 42
is gradually increased. That is, the compressor 1 is turned off and
the fan 48 is turned off. In addition, each of the dumpers 45 and
49 is kept to the solid-line position and the three-way valve 11 is
fully closed while the opening/closing valve 7 is closed. From b
point to c point, the refrigerating operation is carried out.
Referring to FIG. 4 (the dumpers 45 and 49 are set to the
broken-line positions), air in the refrigerating chamber 41 is
circulated through the back-side air flow path 46, and cold air
cooled by the heat absorber 14 is fed through the opening 51 of the
intermediate partition wall 50 to the refrigerating chamber 41.
Accordingly, the temperature of the refrigerating chamber 41 turns
into reduction, however, the temperature of the freezing chamber 42
to which no cold air is fed keeps increase. During this period, the
compressor 1 is turned on, the fan 48 is turned on, each of the
dumpers 45 and 49 is switched to the broken-line position, and the
three-way valve 11 is switched, so that the refrigerant flows into
the first capillary tube 12. When the refrigerating operation is
started, the opening/closing valve 7 is opened with a predetermined
time delay in order to prevent short-cut of the refrigerant passing
through the opening/closing valve 7 at the start time of the
operation of the compressor 1. Subsequently, this control is
repeated from d point to i point.
[0040] FIG. 6 shows a cooling example 2.
[0041] The time period from 1 point to m point corresponds to the
freezing operation. Referring to FIG. 4 (the dumpers 45 and 49 are
set to the solid-line position), and cold air cooled by the heat
absorber 14 is circulated in the air flow path 44 and fed to the
freezing chamber 42. Accordingly, the temperature of the freezing
chamber 42 is gradually reduced. On the other hand, the temperature
of the refrigerating chamber 41 to which no cold air is fed is
gradually increased. During this time period, the compressor 1 is
turned on, the fan 48 is turned on, each of the dumpers 45 and 49
is switched to the solid-line position and the three-way valve 11
is switched, so that the refrigerant is made to flow in the second
capillary tube 13 and the opening/closing valve 7 is opened. From
the time period from m point to n point, the refrigerating
operation is carried out. Referring to FIG. 4 (the dumpers 45 and
49 are set to the broken-line positions), air in the refrigerating
chamber 41 is circulated through the back-side air blow path 46,
and cold air cooled by the heat absorber 14 is passed through the
opening 51 of the intermediate partition wall 50 to the
refrigerating chamber 41. Accordingly, the temperature of the
refrigerating chamber 41 turns into reduction, however, the
temperature of the freezing chamber 42 to which no cold air is fed
turns into increase. During this period, the compressor 1 and the
fan 48 are kept to ON-state, each of the dumpers 45 and 49 is
switched to the broken-line position, and the three-way valve 11 is
switched, so that the refrigerant is made to flow into the first
capillary tube 12. From the time period from n point too point, the
operation is stopped. During this period, no cold air is fed to
both the refrigerating chamber 41 and the freezing chamber 42, and
the temperature of each of the chambers 41 and 42 is gradually
increased. That is, the compressor 1 is turned off and the fan 48
is turned off. Both the dumpers 45 and 49 are not switched, and
kept to the broken-line positions. The three-way valve 11 is fully
closed, and the opening valve 7 is closed. Subsequently, this
control is repeated during the time period from p point to s
point.
[0042] FIG. 7 shows another embodiment. This embodiment is
different from the embodiment shown in FIG. 4 in the dumper
construction at the outlet and inlet ports of the air flow path 44.
The dumper at the inlet port A is constructed by two dumpers 145A
and 145B, and the dumper at the outlet port B is constructed by two
dumpers 149A and 149B.
[0043] FIG. 8 shows another embodiment. This embodiment is
different from the embodiment of FIG. 4 in the construction of the
heat absorbing unit 10. That is, the heat absorbing unit 10
comprises a fourth capillary tube 55 and an electric motor operated
valve 56 connected t the fourth capillary tube 55 in series.
Reference numeral 54 represents an electric motor operated valve.
The fourth capillary tube 55 has a fixed resistance value, and the
overall resistance value can be varied by adjusting the resistance
value of the fourth capillary tube 55 and the valve opening degree
of the electric motor operated valve 56, so that the refrigeration
or freezing operation can be performed. Substantially the same
effect as the above embodiment can be achieved.
[0044] FIG. 9 shows the construction of another refrigerant
circuit.
[0045] This construction is different from the construction shown
in FIG. 1 in the construction of the heat absorbing unit 10. The
heating unit of this embodiment comprises a three-way valve 11, a
first capillary tube 12, a heat absorber for refrigeration which is
connected to the first capillary tube 12 in series, a second
capillary tube 13 which is provided in parallel to the above
elements, and a heat absorber 58 for freezing which is connected to
the second capillary tube 13. Reference numeral 59 represents a
check valve.
[0046] FIG. 10 shows an applied example to a refrigerator. The
refrigerator 40 has a refrigerating chamber 41 at the upper stage
and a freezing chamber 42 at the lower stage. Inner partition walls
61 and 62 are provided at the inner back sides of the respective
chambers 41 and 42, and the heat absorbers 57 and 58 and fans 63
and 64 are provided in the air flow paths 44 partitioned by the
inner partition walls 61 and 62, respectively. In this
construction, the three-way valve 11 is switched in accordance with
the thermo-on, thermo-off of the refrigerating operation and the
freezing operation so that refrigerant is made to flow into any one
of the heat absorbers 57 and 58, and the corresponding fan 62 or 63
is operated.
[0047] FIG. 11 shows another construction.
[0048] This construction is different from the construction of FIG.
10 in the construction of the heat absorbing unit 10. The three-way
valve is eliminated from the heat absorbing unit 10, however,
electric motor operated valves 65 and 66 are connected to the
capillary tubes 12 and 13, respectively. Reference numeral 67
represents an electric motor operated valve. In this construction,
the electric motor operated valves 65 and 66 are turned on or off
in accordance with the thermo-on or thermo-off of the refrigerating
operation and the freezing operation so that refrigerant is made to
selectively flow into any one of the heat absorbers 57 and d58, and
also the corresponding fan 62 or 63 is driven. In these
embodiments, the same effect as the embodiment described above can
be achieved.
[0049] The present invention is not limited to the above
embodiments, and various modifications may be made without
departing from the subject matter of the present invention. In the
above embodiments, carbon dioxide refrigerant is filled in the
refrigerant circuit, however, the refrigerant used in the present
invention is not limited to carbon dioxide. For example,
chlorofluorocarbon (Freon) type refrigerant or the like may be
used.
* * * * *