U.S. patent application number 12/866566 was filed with the patent office on 2010-12-30 for refrigeration apparatus.
Invention is credited to Syuji Furui, Hideki Hara, Michio Moriwaki.
Application Number | 20100326129 12/866566 |
Document ID | / |
Family ID | 41015771 |
Filed Date | 2010-12-30 |
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United States Patent
Application |
20100326129 |
Kind Code |
A1 |
Moriwaki; Michio ; et
al. |
December 30, 2010 |
REFRIGERATION APPARATUS
Abstract
The whole of a refrigerant circuit in which a refrigeration
cycle is performed is accommodated in a casing. A heat medium
circuit is provided, which is connected to the refrigerant circuit
through a utilization-side heat exchanger, and which supplies a
heat medium exchanging heat with refrigerant in the heat exchanger,
to a predetermined heat utilization target. As the refrigerant of
the refrigerant circuit, refrigerant which is represented by a
molecular formula C.sub.3H.sub.mF.sub.n (note that "m" and "n" are
integers equal to or greater than 1 and equal to or less than 5,
and a relationship represented by an expression m+n=6 is
satisfied), and which has a single double bond in a molecular
structure, or refrigerant mixture containing such refrigerant is
used.
Inventors: |
Moriwaki; Michio; (Osaka,
JP) ; Hara; Hideki; (Osaka, JP) ; Furui;
Syuji; (Osaka, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
41015771 |
Appl. No.: |
12/866566 |
Filed: |
February 24, 2009 |
PCT Filed: |
February 24, 2009 |
PCT NO: |
PCT/JP2009/000800 |
371 Date: |
August 6, 2010 |
Current U.S.
Class: |
62/498 ;
62/513 |
Current CPC
Class: |
C09K 2205/126 20130101;
F25B 9/002 20130101; F25B 25/005 20130101; C09K 2205/22 20130101;
C09K 5/045 20130101 |
Class at
Publication: |
62/498 ;
62/513 |
International
Class: |
F25B 1/00 20060101
F25B001/00; F25B 41/00 20060101 F25B041/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 29, 2008 |
JP |
2008-050855 |
Mar 18, 2008 |
JP |
2008-070240 |
Apr 15, 2008 |
JP |
2008-105821 |
Claims
1. A refrigeration apparatus, comprising: a refrigerant circuit in
which a compressor, a heat-source-side heat exchanger, an expansion
mechanism, and a utilization-side heat exchanger are connected
together, and a refrigeration cycle is performed by circulating
refrigerant; and a casing in which the whole of the refrigerant
circuit is accommodated, wherein refrigerant of the refrigerant
circuit is refrigerant which is represented by a molecular formula
C.sub.3H.sub.mF.sub.n where "m" and "n" are integers equal to or
greater than 1 and equal to or less than 5, and a relationship
represented by an expression m+n=6 is satisfied, and which has a
single double bond in a molecular structure, or refrigerant mixture
containing the refrigerant.
2. The refrigeration apparatus of claim 1, further comprising: a
heat medium circuit which is connected to the refrigerant circuit
through the utilization-side heat exchanger, and which supplies a
heat medium exchanging heat with refrigerant in the
utilization-side heat exchanger, to a predetermined heat
utilization target.
3. The refrigeration apparatus of claim 2, wherein the
utilization-side heat exchanger serves as a heating heat exchanger
for heating the heat medium of the heat medium circuit by the
refrigerant of the refrigerant circuit.
4. The refrigeration apparatus of claim 3, wherein the heat
utilization target is a hot-water generator for generating hot
water.
5. The refrigeration apparatus of claim 3, wherein the heat
utilization target is a floor heater for heating a floor
surface.
6. The refrigeration apparatus of claim 2, wherein the
utilization-side heat exchanger serves as a cooling heat exchanger
for cooling the heat medium of the heat medium circuit by the
refrigerant of the refrigerant circuit.
7. The refrigeration apparatus of claim 6, wherein the heat
utilization target is a cooler for generating cold heat.
8. The refrigeration apparatus of any one of claims 2 to 7, wherein
the heat medium circuit circulates water which is a heat
medium.
9. The refrigeration apparatus of any one of claims 1 to 7, wherein
the refrigerant which is represented by the molecular formula
C.sub.3H.sub.mF.sub.n where "m" and "n" are integers equal to or
greater than 1 and equal to or less than 5, and the relationship
represented by the expression m+n=6 is satisfied, and which has the
single double bond in the molecular structure is
2,3,3,3-tetrafluoro-1-propene.
10. The refrigeration apparatus of claim 9, wherein the refrigerant
of the refrigerant circuit is refrigerant mixture further
containing difluoromethane.
11. The refrigeration apparatus of claim 10, wherein the
refrigerant of the refrigerant circuit is refrigerant mixture
further containing pentafluoroethane.
Description
TECHNICAL FIELD
[0001] The present invention relates to a refrigeration apparatus
including a refrigerant circuit in which a refrigeration cycle is
performed.
BACKGROUND ART
[0002] Conventionally, a refrigeration apparatus including a
refrigerant circuit in which a refrigeration cycle is performed has
been broadly applied to air conditioners, hot-water supply systems,
etc.
[0003] Patent Document 1 discloses the refrigeration apparatus of
this type. The refrigeration apparatus includes a refrigerant
circuit which is a closed circuit filled with refrigerant. A
compressor, a condenser, an expansion valve, and an evaporator are
connected to the refrigerant circuit. When operating the
compressor, refrigerant compressed in the compressor is condensed
by releasing heat to air in the condenser. The pressure of the
refrigerant condensed in the condenser is reduced by the expansion
valve, and then such refrigerant is evaporated in the evaporator.
The evaporated refrigerant is sucked into the compressor to be
compressed again.
[0004] In the refrigerant circuit of Patent Document 1, refrigerant
is used, which is represented by a molecular formula
C.sub.3H.sub.mF.sub.n (note that "m" and "n" are integers equal to
or greater than 1 and equal to or less than 5, and a relationship
represented by an expression m+n=6 is satisfied); and which has a
single double bond in a molecular structure. The refrigerant has
excellent properties as refrigerant of the refrigeration cycle, and
a coefficient of performance (COP) of the refrigeration apparatus
has been improved. In addition, it has been known that the
refrigerant does not contain chlorine atoms, bromine atoms, etc.,
and does not contribute to destruction of the ozone layer. Further,
Patent Document 1 discloses refrigerant mixture (zeotropic
refrigerant mixture) of the refrigerant which is represented by the
above-described molecular formula, and which has the single double
bond in the molecular structure, and other refrigerant (R-22, R-32,
etc.).
CITATION LIST
Patent Document
[0005] PATENT DOCUMENT 1: Japanese Patent Application No.
04-110388
SUMMARY OF THE INVENTION
Technical Problem
[0006] As described above, the refrigerant disclosed in Patent
Document 1 has properties including the relatively-high theoretical
COP and low global warming potential (GWP).
[0007] Thus, the refrigerant is used in the refrigeration cycle,
thereby providing an environment-friendly refrigeration apparatus
with high operational efficiency. However, the refrigerant is
so-called "low-pressure refrigerant" with a relatively-high boiling
point, and has properties which tend to increase an influence of a
pressure loss of refrigerant in a refrigerant pipe. Thus, by using
the refrigerant, input etc. of the compressor increase due to the
influence of the pressure loss in the refrigerant pipe, and
therefore there is a possibility that an actual operational
efficiency is rather degraded. In particular, if a refrigerant pipe
between the compressor and other heat exchanger is relatively long,
the influence of the pressure loss is markedly increased, thereby
further degrading the operational efficiency.
[0008] The present invention has been made in view of foregoing,
and it is an object of the present invention to provide a
refrigeration apparatus with high operational efficiency.
Solution to the Problem
[0009] A first aspect of the invention is intended for a
refrigeration apparatus, and the refrigeration apparatus includes a
refrigerant circuit (11) in which a compressor (12), a
heat-source-side heat exchanger (13), an expansion mechanism (15),
and a utilization-side heat exchanger (14) are connected together,
and a refrigeration cycle is performed by circulating refrigerant;
and a casing (10a) in which the whole of the refrigerant circuit
(11) is accommodated. Refrigerant of the refrigerant circuit (11)
is refrigerant which is represented by a molecular formula
C.sub.3H.sub.mF.sub.n (note that "m" and "n" are integers equal to
or greater than 1 and equal to or less than 5, and a relationship
represented by an expression m+n=6 is satisfied), and which has a
single double bond in a molecular structure, or refrigerant mixture
containing the refrigerant.
[0010] In the refrigerant circuit (11) of the first aspect of the
invention, the refrigeration cycle is performed by circulating the
refrigerant. In such a state, as the refrigerant of the refrigerant
circuit (11), the refrigerant (single component refrigerant) which
is represented by the molecular formula C.sub.3H.sub.mF.sub.n (note
that m=1 to 5, n=1 to 5, and m+n=6), and which has the single
double bond in the molecular structure, or the refrigerant mixture
containing such refrigerant is used. The refrigerant has a
relatively-high theoretical COP, and therefore a refrigeration
cycle with a high COP can be performed in the refrigerant circuit
(11) of the present invention. Further, the refrigerant has
properties including relatively-lower global warming potential
(GWP) as compared to that of R410A which is current mainly-used
refrigerant, thereby providing an environment-friendly
refrigeration apparatus. On the other hand, the refrigerant is
so-called "low-pressure refrigerant," and therefore is susceptible
to an influence of a pressure loss in a refrigerant pipe of the
refrigerant circuit (11).
[0011] In the present invention, the whole of the refrigerant
circuit (11) is accommodated in the casing (10a). This shortens the
length of the refrigerant pipe from the compressor (12) to other
heat exchanger (the heat-source-side exchanger (13) or the
utilization-side heat exchanger (14)) in the casing (10a).
Consequently, the influence of the pressure loss in the refrigerant
circuit (11) can be minimized, thereby maximizing an actual
operational efficiency upon the refrigeration cycle.
[0012] A second aspect of the invention is intended for the
refrigeration apparatus of the first aspect of the invention, which
further includes a heat medium circuit (20, 30, 51) which is
connected to the refrigerant circuit (11) through the
utilization-side heat exchanger (14), and which supplies a heat
medium exchanging heat with refrigerant in the utilization-side
heat exchanger (14), to a predetermined heat utilization target (3,
4, 5, 6).
[0013] In the second aspect of the invention, the refrigerant
circuit (11) is connected to the heat medium circuit (20, 30, 51)
through the utilization-side heat exchanger (14). In the
refrigerant circuit (11), the refrigeration cycle is performed by
circulating the refrigerant.
[0014] Consequently, in the utilization-side heat exchanger (14),
the refrigerant releases heat to the heat medium of the heat medium
circuit (20, 30, 51), or absorbs heat from the heat medium of the
heat medium circuit (20, 30, 51). That is, in the utilization-side
heat exchanger (14), heat is exchanged between the refrigerant of
the refrigerant circuit (11) and the heat medium of the heat medium
circuit (20, 30, 51). The heat medium cooled or heated in the
utilization-side heat exchanger (14) is supplied to the
predetermined heat utilization target (3, 4, 5, 6).
[0015] As described above, in the present invention, the
refrigerant circuit (11) is provided separately from the heat
medium circuit (20, 30, 51), and the heat medium of the heat medium
circuit (20, 30, 51) is sent to the predetermined heat utilization
target (3, 4, 5, 6). Thus, the length of the pipe of the
refrigerant circuit (11) can be shortened while controlling the
temperature of the predetermined heat utilization target (3, 4, 5,
6). Consequently, the influence of the pressure loss in the
refrigerant circuit (11) can be minimized, thereby further
improving the actual operational efficiency upon the refrigeration
cycle.
[0016] A third aspect of the invention is intended for the
refrigeration apparatus of the second aspect of the invention, in
which the heat exchanger (14) serves as a heating heat exchanger
(14) for heating the heat medium of the heat medium circuit (20,
30, 51) by the refrigerant of the refrigerant circuit (11).
[0017] In the heat exchanger (14) of the third aspect of the
invention, the heat medium of the heat medium circuit (20, 30, 51)
is heated by the refrigerant of the refrigerant circuit (11). The
heated heat medium is supplied to the predetermined heat
utilization target (3, 4, 5, 6), and then is used for heating the
heat utilization target (3, 4, 5, 6).
[0018] A fourth aspect of the invention is intended for the
refrigeration apparatus of the third aspect of the invention, in
which the heat utilization target is a hot-water generator (3, 4)
for generating hot water.
[0019] In the fourth aspect of the invention, the heat medium
heated in the heating heat exchanger (14) is supplied to the
hot-water generator (3, 4), and then is used for generating hot
water.
[0020] A fifth aspect of the invention is intended for the
refrigeration apparatus of the third aspect of the invention, in
which the heat utilization target is a floor heater (5) for heating
a floor surface.
[0021] In the fifth aspect of the invention, the heat medium heated
in the heating heat exchanger (14) is supplied to the floor heater
(5), and then is used for heating the floor surface.
[0022] A sixth aspect of the invention is intended for the
refrigeration apparatus of the second aspect of the invention, in
which the utilization-side heat exchanger serves as a cooling heat
exchanger (14) for cooling the heat medium of the heat medium
circuit (20, 30, 51) by the refrigerant of the refrigerant circuit
(11).
[0023] In the sixth aspect of the invention, the heat medium of the
heat medium circuit (20, 30, 51) is cooled by the refrigerant of
the refrigerant circuit (11). The cooled heat medium is supplied to
the predetermined heat utilization target (3, 4, 5, 6), and then is
used for cooling the heat utilization target (6).
[0024] A seventh aspect of the invention is intended for the
refrigeration apparatus of the sixth aspect of the invention, in
which the heat utilization target is a cooler (6) for generating
cold heat.
[0025] In the seventh aspect of the invention, the heat medium
cooled in the cooling heat exchanger (14) is supplied to the cooler
(6), and then is used for, e.g., cooling a room or
refrigerating/cooling an inside of a container.
[0026] An eighth aspect of the invention is intended for the
refrigeration apparatus of any one of the second to seventh aspects
of the invention, in which the heat medium circuit (20, 30, 51)
circulates water which is a heat medium.
[0027] In the utilization-side heat exchanger (14) of the eighth
aspect of the invention, the water of the heat medium circuit (20,
30, 51) is heated or cooled by the refrigerant of the refrigerant
circuit (11). The water heated or cooled in the heat exchanger (14)
is supplied to the predetermined heat utilization target (3, 4, 5,
6).
[0028] A ninth aspect of the invention is intended for the
refrigeration apparatus of any one of the first to eighth aspects
of the invention, in which the refrigerant which is represented by
the molecular formula C.sub.3H.sub.mF.sub.n (note that "m" and "n"
are integers equal to or greater than 1 and equal to or less than
5, and the relationship represented by the expression m+n=6 is
satisfied), and which has the single double bond in the molecular
structure is 2,3,3,3-tetrafluoro-1-propene.
[0029] In the ninth aspect of the invention, the refrigerant
(single component refrigerant) containing
2,3,3,3-tetrafluoro-1-propene or the refrigerant mixture containing
such refrigerant is used as the refrigerant of the refrigerant
circuit (11). The refrigerant has the relatively-high theoretical
COP, thereby improving the theoretical COP in the refrigerant
circuit (11). Further, the refrigerant has the properties including
the relatively-lower global warming potential (GWP) as compared to
that of R410A which is current mainly-used refrigerant, thereby
providing the environment-friendly refrigeration apparatus. On the
other hand, 2,3,3,3-tetrafluoro-1-propene is low-pressure
refrigerant, and is susceptible to the influence of the pressure
loss. However, in the present invention, the whole of the
refrigerant circuit (11) is accommodated in the casing (10a),
thereby shortening the length of the refrigerant pipe.
Consequently, as in the first aspect of the invention, the actual
operational efficiency upon the refrigeration cycle can be
maximized.
[0030] A tenth aspect of the invention is intended for the
refrigeration apparatus of any one of the first to ninth aspects of
the invention, in which the refrigerant of the refrigerant circuit
(11) is refrigerant mixture further containing difluoromethane.
[0031] In the tenth aspect of the invention, the refrigerant
mixture containing the refrigerant represented by the
above-described molecular formula and having the single double bond
in the molecular structure, and difluoromethane is used as the
refrigerant of the refrigerant circuit (11). In such a state,
difluoromethane is so-called "high-pressure refrigerant." Thus,
difluoromethane is added to the refrigerant represented by the
above-described molecular formula, thereby reducing the influence
of the pressure loss of the refrigerant on the operational
efficiency of the refrigeration apparatus. Consequently, the actual
operational efficiency upon the refrigeration cycle can be
enhanced.
[0032] An eleventh aspect of the invention is intended for the
refrigeration apparatus of any one of the first to tenth aspects of
the invention, in which the refrigerant of the refrigerant circuit
(11) is refrigerant mixture further containing
pentafluoroethane.
[0033] In the eleventh aspect of the invention, the refrigerant
mixture containing the refrigerant represented by the
above-described molecular formula and having the single double bond
in the molecular structure, and pentafluoroethane is used as the
refrigerant of the refrigerant circuit (11). The refrigerant
represented by the above-described molecular formula and having the
single double bond in the molecular structure is low flammable
refrigerant, but there is no possibility that such refrigerant does
not catch fire. Thus, in the present invention, pentafluoroethane
which is non-flammable refrigerant is added to the refrigerant
represented by the above-described molecular formula and having the
single double bond in the molecular structure.
ADVANTAGES OF THE INVENTION
[0034] In the present invention, the refrigerant which is
represented by the molecular formula C.sub.3H.sub.mF.sub.n (note
that m=1 to 5, n=1 to 5, and m+n=6), and which has the single
double bond in the molecular structure, or the refrigerant mixture
containing such refrigerant is used as the refrigerant of the
refrigerant circuit (11). The refrigerant has the relatively-high
theoretical COP, and therefore the theoretical COP of the
refrigerant circuit (11) increases. Thus, energy conservation of
the refrigeration apparatus can be improved. Further, the
refrigerant has the properties including the relatively-lower
global warming potential (GWP) as compared to that of R410A which
is current mainly-used refrigerant, thereby providing the
environment-friendly refrigeration apparatus.
[0035] In addition, in the present invention, the whole of the
refrigerant circuit (11) is accommodated in the casing (10a). This
shortens the length of the refrigerant pipe of the refrigerant
circuit (11), thereby minimizing the influence of the pressure
loss. Consequently, in the refrigeration apparatus of the present
invention, the actual operational efficiency can be enhanced,
thereby further improving the energy conservation of the
refrigeration apparatus.
[0036] In the second aspect of the invention, the refrigerant
circuit (11) is provided separately from the heat medium circuit
(20, 30, 51), thereby further shortening the length of the pipe of
the refrigerant circuit (11). Consequently, the influence of the
pressure loss can be further minimized, thereby further enhancing
the actual operational efficiency. In addition, the length of the
pipe of the refrigerant circuit (11) is shortened, thereby reducing
the size of the casing (10a) in which the refrigerant circuit (11)
is accommodated.
[0037] According to the third to fifth aspects of the invention,
the refrigeration apparatus with the high COP can heat the
predetermined heat utilization target (the hot-water generators (3,
4) or the floor heater (5)). In addition, according to the sixth or
seventh aspect of the invention, the refrigeration apparatus with
the high COP can cool the predetermined heat utilization target
(the cooler (6)). Further, according to the eighth aspect of the
invention, the water which is the heat medium circulates in the
heat medium circuit (20, 30, 51), thereby providing the heat medium
circuit (20, 30, 51) at relatively low cost.
[0038] In the ninth aspect of the invention, the refrigerant
containing 2,3,3,3-tetrafluoro-1-propene or the refrigerant mixture
containing such refrigerant is used as the refrigerant of the
refrigerant circuit (11), thereby providing the refrigeration
apparatus with the high COP. Further, the refrigerant has the
properties including the relatively-lower global warming potential
(GWP) as compared to that of R410A which is current mainly-used
refrigerant, thereby providing the environment-friendly
refrigeration apparatus.
[0039] In the tenth aspect of the invention, difluoromethane which
is the so-called "high-pressure refrigerant" is added to the
refrigerant represented by the above-described molecular formula
and having the single double bond in the molecular structure. This
reduces the influence of the pressure loss of the refrigerant on
the operational efficiency of the refrigeration apparatus, thereby
improving the actual operational efficiency of the refrigeration
apparatus.
[0040] In the eleventh aspect of the invention, pentafluoroethane
which is the non-flammable refrigerant is added to the refrigerant
represented by the above-described molecular formula and having the
single double bond in the molecular structure. Thus, the
refrigerant of the refrigerant circuit (11) becomes
flame-resistant, thereby improving safety of the refrigeration
apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 is a schematic configuration diagram of a
refrigeration apparatus of a first embodiment.
[0042] FIG. 2 is a schematic configuration diagram of a
refrigeration apparatus of a second embodiment.
[0043] FIG. 3 is a schematic configuration diagram of a
refrigeration apparatus of a third embodiment.
DESCRIPTION OF REFERENCE CHARACTERS
[0044] 3 Faucet (Heat Utilization Target, Hot-Water Generator)
[0045] 4 Bathtub (Heat Utilization Target, Hot-Water Generator)
[0046] 5 Floor Heater (Heat Utilization Target) [0047] 6 Air
Conditioning Unit (Heat Utilization Target, Cooler) [0048] 10
Hot-Water Supply System (Refrigeration Apparatus) [0049] 10a Casing
[0050] 11 Refrigerant Circuit [0051] 12 Compressor [0052] 13
Air-Heat Exchanger (Heat-Source-Side Heat Exchanger) [0053] 14
Water-Heat Exchanger (Utilization-Side Heat Exchanger, Water-Heat
Exchanger) [0054] 15 Expansion Valve (Expansion Mechanism) [0055]
20 Circulation Circuit (Heat Medium Circuit) [0056] 30 Hot-Water
Utilization Circuit (Heat Medium Circuit) [0057] 51
Air-Conditioning-Side Circuit (Heat Medium Circuit)
DESCRIPTION OF EMBODIMENTS
[0058] Embodiments of the present invention will be described in
detail hereinafter with reference to the drawings.
First Embodiment
[0059] A first embodiment of the present invention will be
described. In the first embodiment, a refrigeration apparatus of
the present invention serves as a hot-water supply system (10) in
which hot-water generators such as a faucet (3) and a bathtub (4)
are heat utilization targets. As illustrated in FIG. 1, the
hot-water supply system (10) includes a refrigerant circuit (11); a
circulation circuit (20); and a hot-water utilization circuit (30).
The refrigerant circuit (11) is connected to the circulation
circuit (20) through a water-heat exchanger (14). The circulation
circuit (20) is connected to the hot-water utilization circuit (30)
through a hot-water storage tank (25). The circulation circuit (20)
and the hot-water utilization circuit (30) serve as a heat medium
circuit for supplying hot-water to the heat utilization targets (3,
4) as a heat medium.
[0060] The refrigerant circuit (11) is a closed circuit in which a
refrigeration cycle is performed by circulating refrigerant. The
refrigerant circuit (11) includes a compressor (12); an air-heat
exchanger (13); the water-heat exchanger (14); and an expansion
valve (15). The air-heat exchanger (13) is connected to a suction
side of the compressor (12), and the water-heat exchanger (14) is
connected to a discharge side of the compressor (12). The expansion
valve (15) is connected between the air-heat exchanger (13) and the
water-heat exchanger (14).
[0061] The compressor (12) is an inverter compressor with variable
operational capacity. The air-heat exchanger (13) is a cross-fin
type fin-and-tube heat exchanger, and serves as a heat-source-side
heat exchanger. An outdoor fan (16) is provided near the air-heat
exchanger (13). The expansion valve (15) is an electric expansion
valve with variable opening, and serves as an expansion
mechanism.
[0062] The water-heat exchanger (14) is a plate-fin type heat
exchanger, and serves as a utilization-side heat exchanger. The
water-heat exchanger (14) includes a first flow path (14a) and a
second flow path (14b). The first flow path (14a) is connected to
the refrigerant circuit (11), and the second flow path (14b) is
connected to the circulation circuit (20). That is, the circulation
circuit (20) is connected to the refrigerant circuit (11) through
the water-heat exchanger (14). In the water-heat exchanger (14),
heat is exchanged between refrigerant flowing in the first flow
path (14a) and water (heat medium) flowing in the second flow path
(14b). That is, the water-heat exchanger (14) serves as a heating
heat exchanger for heating water of the circulation circuit (20) by
refrigerant of the refrigerant circuit (11).
[0063] A circulation pump (21) is provided in the circulation
circuit (20). The circulation pump (21) serves as a pump mechanism
for transferring and circulating water in the circulation circuit
(20). In addition, the hot-water storage tank (25) is connected to
the circulation circuit (20). The hot-water storage tank (25) is an
elongated cylindrical hermetic container. A water supply port (26),
a hot-water outlet port (27), a water discharge port (28), and a
hot-water inlet port (29) are formed in the hot-water storage tank
(25). The water supply port (26) and the water discharge port (28)
are formed in a bottom section of the hot-water storage tank (25).
The hot-water outlet port (27) is formed in a top section of the
hot-water storage tank (25). The hot-water inlet port (29) is
formed in a section closer to an upper portion of a side wall of
the hot-water storage tank (25). One end of the circulation circuit
(20) is connected to the hot-water inlet port (29) of the hot-water
storage tank (25), and the other end is connected to the water
discharge port (28) of the hot-water storage tank (25). That is, in
the circulation circuit (20), water (hot water) heated in the
water-heat exchanger (14) flows into the hot-water storage tank
(25) through the hot-water inlet port (29), and water in the bottom
section of the hot-water storage tank (25) is sucked into the
circulation pump (21) through the water discharge port (28).
[0064] A water supply path (31) and a hot-water supply path (32)
are formed in the hot-water utilization circuit (30). An upstream
side of the water supply path (31) is connected to supply sources
of water such as tap water. An outflow end of the water supply path
(31) is connected to the water supply port (26) of the hot-water
storage tank (25). An inflow end of the hot-water supply path (32)
is connected to the hot-water outlet port (27) of the hot-water
storage tank (25). An outflow side of the hot-water supply path
(32) branches into two paths, and such branched paths are connected
to a faucet-side flow path (33) and a bathtub-side flow path (34).
An outflow end of the faucet-side flow path (33) is connected to
the faucet (3), and an outflow end of the bathtub-side flow path
(34) opens to an inside of the bathtub (4).
[0065] A first bypass path (35) and a second bypass path (36) are
formed in the hot-water utilization circuit (30). Inflow ends of
the first bypass path (35) and the second bypass path (36) are
connected to the water supply path (31). An outflow end of the
first bypass path (35) is connected to the faucet-side flow path
(33) through a first mixing valve (37), and an outflow end of the
second bypass path (36) is connected to the bathtub-side flow path
(34) through a second mixing valve (38).
[0066] In the refrigeration apparatus (10), the whole of the
refrigerant circuit (11) is accommodated in a casing (10a) of a
heat source unit. In addition, in the refrigeration apparatus (10),
the whole of the hot-water utilization circuit (30), the hot-water
storage tank (25), the circulation pump (21), etc. is accommodated
in a casing (10b) of a hot-water supply unit.
[0067] The refrigerant circuit (11) of the present embodiment is
filled with single component refrigerant containing HFO-1234yf
(2,3,3,3-tetrafluoro-1-propene) as refrigerant. A chemical formula
of the HFO-1234yf is represented by an expression
CF.sub.3--CF.dbd.CH.sub.2.
[0068] Operation
[0069] An operation of the hot-water supply system (10) will be
described. When operating the hot-water supply system (10), the
compressor (12) and the circulation pump (21) are in operation.
Consequently, in the refrigerant circuit (11), a vapor compression
refrigeration cycle is performed by circulating refrigerant.
[0070] In the refrigerant circuit (11), refrigerant compressed in
the compressor (12) flows in the first flow path (14a) of the
water-heat exchanger (14). In the water-heat exchanger (14), the
refrigerant is cooled and condensed by water of the circulation
circuit (20). The pressure of the refrigerant condensed in the
water-heat exchanger (14) is reduced by the expansion valve (15),
and then such refrigerant flows into the air-heat exchanger (13).
In the air-heat exchanger (13), the refrigerant is evaporated by
absorbing heat from outdoor air. The refrigerant evaporated in the
air-heat exchanger (13) is sucked into the compressor (12) to be
compressed again. As described above, in the refrigerant circuit
(11), a refrigeration cycle is performed, in which the water-heat
exchanger (14) serves as a condenser (radiator), and the air-heat
exchanger (13) serves as an evaporator.
[0071] On the other hand, in the circulation circuit (20), water
transferred by the circulation pump (21) flows in the second flow
path (14b) of the water-heat exchanger (14). In the water-heat
exchanger (14), the water flowing in the second flow path (14b) is
heated by refrigerant flowing in the first flow path (14a). The
hot-water storage tank (25) is refilled with the water (hot water)
heated in the water-heat exchanger (14). This generates hot water
in the hot-water storage tank (25). The hot water in the hot-water
storage tank (25) is supplied to the faucet (3) and the bathtub (4)
through the hot-water utilization circuit (30).
Advantages of First Embodiment
[0072] In the present embodiment, as the refrigerant of the
refrigerant circuit (11), the single component refrigerant
containing the HFO-1234yf (2,3,3,3-tetrafluoro-1-propene) is used.
The HFO-1234yf has properties including a relatively-high
theoretical COP. Thus, such refrigerant is used as the single
component refrigerant, thereby performing a refrigeration cycle
with excellent operational efficiency. Consequently, an operational
efficiency of the hot-water supply system (10) can be improved.
Further, the HFO-1234yf has properties including relatively-lower
global warming potential (GWP) as compared to that of R410A which
is current mainly-used refrigerant, thereby providing an
environment-friendly refrigeration apparatus.
[0073] On the other hand, the HFO-1234yf has a relatively-high
boiling point, and serves as so-called "low-pressure refrigerant."
Thus, such refrigerant is used as the single component refrigerant,
resulting in an increase in input etc. of the compressor (12) due
to an influence of a pressure loss of refrigerant. Consequently,
there is a possibility that an actual operational efficiency is
rather degraded. However, in the first embodiment, the whole of the
refrigerant circuit (11) is accommodated in the casing (10a). This
shortens the length of the pipe of the refrigerant circuit (11).
Further, in the first embodiment, the circulation circuit (20) and
the hot-water utilization circuit (30) are provided separately from
the refrigerant circuit (11) to supply water heated in the
water-heat exchanger (14) to the heat utilization targets (the
faucet (3) and the bathtub (4)). Thus, the length of the
refrigerant pipe of the refrigerant circuit (11) can be requisite
minimum. Consequently, in the first embodiment, the influence of
the pressure loss of refrigerant in the refrigerant circuit (11)
can be minimized, thereby preventing the degradation of the actual
operational efficiency due to the influence of the pressure loss in
the refrigerant circuit (11).
Second Embodiment
[0074] A second embodiment will be described. In the second
embodiment, the refrigeration apparatus of the present invention
serves as a floor heating system (40) in which a floor heater (5)
is a heat utilization target. As illustrated in FIG. 2, the floor
heating system (40) includes a refrigerant circuit (11) and a
circulation circuit (20) which are similar to those in the first
embodiment. In addition, the floor heating system (40) includes a
hot-water utilization circuit (30) which is a closed circuit in
which hot-water circulates, and the circulation circuit (20) and
the hot-water utilization circuit (30) serve as a heat medium
circuit.
[0075] In the second embodiment, the hot-water utilization circuit
(30) includes the floor heater (5) and a circulation pump (41). The
circulation pump (41) is provided on an upstream side of the floor
heater (5). In addition, the floor heater (5) is installed below a
floor of a room, and heats the floor by hot water. Further, the
whole of the refrigerant circuit (11) is accommodated in a casing
(10a) of a heat source unit.
[0076] In the refrigerant circuit (11) of the second embodiment,
single component refrigerant containing HFO-1234yf
(2,3,3,3-tetrafluoro-1-propene) is used as in the first embodiment.
In addition, in the circulation circuit (20) and the hot-water
utilization circuit (30), water is used as a heat medium.
[0077] Operation
[0078] When operating the floor heating system (40) of the second
embodiment, a compressor (12), and two circulation pumps (21, 41)
are in operation. In the refrigerant circuit (11), a refrigeration
cycle similar to that of the first embodiment is performed. In the
circulation circuit (20), a hot-water storage tank (25) is refilled
with water heated in a water-heat exchanger (14) as necessary. The
hot water drawn from the hot-water storage tank (25) into the
hot-water utilization circuit (30) flows in a heat exchange section
(5a) of the floor heater (5). In the heat exchange section (5a),
heat of the hot water is released to a floor surface. Consequently,
the floor surface is heated to heat the room.
Advantages of Second Embodiment
[0079] In the second embodiment, the single component refrigerant
containing the HFO-1234yf (2,3,3,3-tetrafluoro-1-propene) is also
used as the refrigerant of the refrigerant circuit (11), thereby
providing the floor heating system (40) with a high COP. In
addition, the whole of the refrigerant circuit (11) is accommodated
in the casing (10a), and the refrigerant circuit (11) is separated
from the heat medium circuits (20, 30), thereby allowing the
requisite minimum length of the pipe of the refrigerant circuit
(11). Thus, in the second embodiment, the influence of the pressure
loss in the refrigerant pipe can be also minimized, thereby
improving an actual operational efficiency of the floor heating
system (40).
Third Embodiment
[0080] A third embodiment will be described. In the third
embodiment, the refrigeration apparatus of the present invention
serves as a so-called "heat-pump/chiller type" air conditioning
system (50) in which a plurality of air conditioning units (6) are
heat utilization targets.
[0081] As illustrated in FIG. 3, a refrigerant circuit (11) of the
third embodiment includes a four-way switching valve (17). The
four-way switching valve (17) has first to fourth ports. The first
port is connected to a discharge side of a compressor (12); the
second port is connected to a suction side of the compressor (12);
the third port is connected to one end of an air-heat exchanger
(13); and the fourth port is connected to one end of a water-heat
exchanger (14). The four-way switching valve (17) is switchable
between a state in which the first port communicates with the
fourth port with the second port communicating with the third port
(state indicated by a solid line in FIG. 3), and a state in which
the first port communicates with the third port with the second
port communicating with the fourth port (state indicated by a
dashed line in FIG. 3).
[0082] The air conditioning system (50) includes an
air-conditioning-side circuit (51). The air-conditioning-side
circuit (51) is connected to a second flow path (14b) of the
water-heat exchanger (14), and serves as a heat medium circuit. In
the air-conditioning-side circuit (51), the plurality of air
conditioning units (6) are connected in parallel. The air
conditioning units (6) are installed in a ceiling etc. of a room of
a building etc. The air conditioning unit (6) serves as a fan coil
unit including an indoor heat exchanger and an indoor fan. Further,
the whole of the refrigerant circuit (11) is accommodated in a
casing (10a) of a heat source unit.
[0083] In the refrigerant circuit (11) of the third embodiment,
single component refrigerant containing HFO-1234yf
(2,3,3,3-tetrafluoro-1-propene) is used as in the foregoing
embodiments. In addition, in the air-conditioning-side circuit
(51), water is used as a heat medium.
[0084] Operation
[0085] In the air conditioning system (50), each of the air
conditioning units (6) switches between a cooling operation and a
heating operation.
[0086] In the cooling operation, the four-way switching valve (17)
of the refrigerant circuit (11) is in the state indicated by the
dashed line in FIG. 3. Consequently, in the refrigerant circuit
(11), a refrigeration cycle is performed, in which the air-heat
exchanger (13) serves as a condenser (radiator), and the water-heat
exchanger (14) serves as an evaporator. That is, in the
air-conditioning-side circuit (51), water flowing in the second
flow path (14b) of the water-heat exchanger (14) is cooled by
refrigerant flowing in a first flow path (14a). The water cooled in
the water-heat exchanger (14) is sent to each of the air
conditioning units (6). In the air conditioning unit (6), room air
is cooled by the water. As described above, in the cooling
operation, the water-heat exchanger (14) serves as a cooling heat
exchanger for cooling water of the air-conditioning-side circuit
(51). In addition, the air conditioning unit (6) serves as a cooler
for cooling room air.
[0087] In the heating operation, the four-way switching valve (17)
of the refrigerant circuit (11) is in the state indicated by the
solid line in FIG. 3. Consequently, in the refrigerant circuit
(11), a refrigeration cycle is performed, in which the water-heat
exchanger (14) serves as the condenser (radiator), and the air-heat
exchanger (13) serves as the evaporator. That is, in the
air-conditioning-side circuit (51), water flowing in the second
flow path (14b) of the water-heat exchanger (14) is heated by
refrigerant flowing in the first flow path (14a). The water heated
in the air-heat exchanger (13) is sent to each of the air
conditioning units (6). In the air conditioning unit (6), room air
is heated by the water. As described above, in the heating
operation, the water-heat exchanger (14) serves as a heating heat
exchanger for heating water of the air-conditioning-side circuit
(51). In addition, the air conditioning unit (6) serves as a heater
for heating room air.
Advantages of Third Embodiment
[0088] In the third embodiment, the single component refrigerant
containing the HFO-1234yf (2,3,3,3-tetrafluoro-1-propene) is also
used as the refrigerant of the refrigerant circuit (11), thereby
providing the air conditioning system (50) with a high COP. In
addition, the whole of the refrigerant circuit (11) is accommodated
in the casing (10a), and the refrigerant circuit (11) is separated
from the heat medium circuits (20, 30, 51), thereby minimizing an
influence of a pressure loss in the refrigerant circuit (11).
Consequently, an actual operational efficiency of the floor heating
system (40) can be improved.
Other Embodiments
[0089] The foregoing embodiments may have the following
configurations.
[0090] In the foregoing embodiments, as the refrigerant of the
refrigerant circuit (11), single component refrigerant may be used,
which is refrigerant represented by the above-described molecular
formula and having a single double bond in a molecular structure
other than the HFO-1234yf. Specifically, refrigerant includes,
e.g., 1,2,3,3,3-pentafluoro-1-propene (referred to as "HFO-1225ye,"
and a chemical formula thereof is represented by an expression
CF.sub.3--CF.dbd.CHF); 1,3,3,3-tetrafluoro-1-propene (referred to
as "HFO-1234ze," and a chemical formula thereof is represented by
an expression CF.sub.3--CH.dbd.CHF); 1,2,3,3-tetrafluoro-1-propene
(referred to as "HFO-1234ye," and a chemical formula thereof is
represented by an expression CHF.sub.2--CF.dbd.CHF);
3,3,3-trifluoro-1-propene (referred to as "HFO-1243zf," and a
chemical formula thereof is represented by an expression
CF.sub.3--CH.dbd.CH.sub.2); 1,2,2-trifluoro-1-propene (a chemical
formula thereof is represented by an expression
CH.sub.3--CF.dbd.CF.sub.2); and 2-fluoro-1-propene (a chemical
formula thereof is represented by an expression
CH.sub.3--CF.dbd.CH.sub.2).
[0091] In the foregoing embodiments, refrigerants other than HFC-32
may be used as refrigerant to be mixed with the refrigerant
represented by the above-described molecular formula and having the
single double bond in the molecular structure. Specifically, the
mixed refrigerant is made by using at least one of HFC-32
(difluoromethane); HFC-125 (pentafluoroethane); HFC-134
(1,1,2,2-tetrafluoroethane); HFC-134a (1,1,1,2-tetrafluoroethane);
HFC-143a (1,1,1-trifluoroethane); HFC-152a (1,1-difluoroethane);
HFC-161 (fluoroethane); HFC-227ea
(1,1,1,2,3,3,3-heptafluoropropane); HFC-236ea
(1,1,1,2,3,3-hexafluoropropane); HFC-236fa
(1,1,1,3,3,3-hexafluoropropane); HFC-365mfc
(1,1,1,3,3-pentafluorobutane); methane; ethane; propane; propene;
butane; isobutane; pentane; 2-methylbutane; cyclopentane; dimethyl
ether; bis-trifluoromethyl-sulfide; carbon dioxide; and helium.
[0092] When using refrigerant mixture of, e.g., the HFO-1234yf and
the HFC-32, a mixing ratio may be as follows. That is, for the
refrigerant mixture of the HFO-1234yf and the HFC-32, the
proportion of the HFO-1234yf may be equal to or greater than 70% by
mass and equal to or less than 94% by mass, and the proportion of
the HFC-32 may be equal to or greater than 6% by mass and equal to
or less than 30% by mass. The proportion of the HFO-1234yf may be
preferably equal to or greater than 77% by mass and equal to or
less than 87% by mass, and the proportion of the HFC-32 may be
preferably equal to or greater than 13% by mass and equal to or
less than 23% by mass. More preferably, the proportion of the
HFO-1234yf may be equal to or greater than 77% by mass and equal to
or less than 79% by mass, and the proportion of the HFC-32 may be
equal to or greater than 21% by mass and equal to or less than 23%
by mass. More preferably, the proportion of the HFO-1234yf may be
78.2% by mass, and the proportion of the HFC-32 may be 21.8% by
mass.
[0093] Refrigerant mixture of the HFO-1234yf and the HFC-125 may be
used. In such a case, the proportion of the HFC-125 may be equal to
or greater than 10% by mass, and more preferably equal to or
greater than 10% by mass and equal to or less than 20% by mass.
[0094] Refrigerant mixture of the HFO-1234yf, the HFC-32, and the
HFC-125 may be used. In such a case, the refrigerant mixture
containing the HFO-1234yf of 52% by mass, the HFC-32 of 23% by
mass, and the HFC-125 of 25% by mass.
[0095] The refrigeration apparatus of the present invention may be
applied to other systems other than the hot-water supply system
(10), the floor heating system (40), and the air conditioning
system (50). Specifically, the present invention may be applied to,
e.g., a window-type air conditioner in which the whole of a
refrigerant circuit (11) is accommodated in a casing; and a
roof-trap-type or central air conditioner in which cold/warm air is
transferred through a duct. In addition, the present invention may
be applied to a freezing/refrigeration apparatus (in particular, a
refrigeration apparatus for cooling a refrigerator or an inside of
a container for marine transportation etc.) in which the whole of a
refrigerant circuit (11) is accommodated in a casing. Further, the
present invention may be applied to a snow melting system for
melting snow by a heat medium, a chiller unit only for cooling, a
turbo refrigerator, etc. Air may be used as a heat medium instead
of water. In particular, for low-temperature applications such as
low-temperature chillers, water mixed with brine or antifreeze
solution to lower a freezing point may be used as a heat medium. In
addition, the heat source of the refrigerant circuit is air in the
embodiments, but such a heat source may be a water heat source or
an underground heat source.
[0096] The foregoing embodiments have been set forth merely for
purposes of preferred examples in nature, and are not intended to
limit the scope, applications, and use of the invention.
INDUSTRIAL APPLICABILITY
[0097] As described above, the present invention is useful for the
refrigeration apparatus which includes the refrigerant circuit in
which the refrigeration cycle is performed, and which supplies
warm/cold heat to predetermined heat utilization target(s).
* * * * *