Title of Invention:
Air-conditioning1Hot-water S,upply System
5
Technical Field
[OOO 11
The present'invention relates to an air-conditioninglhot-water supply system
which performs air conditioning and supplies hot water.
10
Background Art
[0002]
For example, Patent Literature 1 discloses a technique of an
air-conditioning/hot-water supply system which performs air conditioning and supplies
15 hot water. ~ ~ e c i f i c a l lP'a~te, nt Literature 1 discloses a complex system for air
conditioning and hot-water supply, in which an indoor unit and a circuit for a hot-water
heat source are connected in parallel, and the indoor unit and the heat source are
connected through a branch unit and at least two connection pipes.
According to the technique disclosed in Patent Literature 1, the primary side
20 (the side of the heat exchanger for air conditioning) of a refrigerant-refrigerant heat
exchanger (intermediate heat exchanger) is used as a condenser, and the secondary side
(the hot-water heat exchanger side) is used as an evaporator in such a manner that
exhaust heat in a heat source for air conditioning and a hot-water heat source is
mutually utilized.
25
Citation List . .
Patent Literature
[0003]
Patent Literature 1 : Japanese Patent Laid-open No. 201 0-2368 17
30
Summary of Invention
Technical Problem
[0004]
However, according to the technique disclosed in Patent Literature 1, the
35 indoor unit and the refrigerant-refrigerant heat exchanger (the intermediate heat
exchanger) are connected in parallel. Therefore, even when the hot-water supply cycle
- ~- p- --- Q. - -- - ~- - - ~- -&. g- ~- -- -~ - - -- ~ - ~- - -- -F ~ : Q - ~ r ~ ~ ~ - ~ ~
DECLARATION
I, Kaoru NEMOTO , who undersigned below, have proven expertise
in translating Japanese patent documents into English, and I am the translator
of the document in Japanese for PCT Patent Application No. JP2012/051843
(PCT Patent Application Publication No. WO 2013/111329 Al), filed on January
27, 2012.
I declare that the attached English document is a true, accurate and
complete translation for the said PCT Patent Application document to the best of
my knowledge and belief.
Signature of Translator: a<& Kaoru NEMOTO
Date: 6 +"c2"/j4
Address :
c/o ISONO INTERNATIONAL PATENT OFFICE P.C.
SABO-KAIKAN ANNEX
7-4, HIRAKAWA-CHO 2-CHOME,
CHNODA-KU, TOKYO, 102-0093, JAPAN
is not in operation, the refrigerant flowing through the refrigerant-refrigerant heat
exchanger comes into'thermal contact with external air. Consequently, in some cases, a
load .in excess of the air-conditioning load (the thermal load accompanied by air
conditioning operation) is imposed on the complex system for air conditioning and
5 hot-water supply.
[0005]
For example, in the case where a heating operation is performed in the
air-conditioning cycle and the hot-water supply cycle is not in operation (i.e., no
hot-water supply load exists), the temperature of the refrigerant flowing through the
10 refrigerant-refrigerant heat exchanger becomes as high as the temperature of the indoor
unit. This is because the refrigerant-refrigerant heat exchanger is connected in parallel
with the indoor unit.
On the other hand, the hot-water supply unit is normally placed in a non-air
. conditioned indoor or outdoor space. Therefore, the temperature of the
15 refi-igerant-refrigerant heat exchanger as a constituent element of the hot-water supply
cycle is near the outdoor temperature, which is the ambient temperature of the
hot-water supply unit.
As a result, when a heating operation is performed, heat is dissipated, in the
above refrigerant-refrigerant heat exchanger, from the high-temperature refrigerant to
20 the low-temperature outdoor air.
[0006]
Consequently, according to the technique disclosed in Patent Literature 1, heat
dissipation from the .refrigerant to the outdoor air occurs in the refrigerant-refrigerant
. heat exchanger, in addition to the occurrence of the load necessary for the air
25 conditioning operation. Since the dissipated heat is utilized for neither of comfort
improvement in the indoor space and hot-water supply, the total system efficiency
deteriorates.
[0007]
In view of above, the object of the present invention is to provide an
30 air-conditioninglhot-water supply system realizing high energetic efficiency.
Solution to Problem
[OOOS]
In order to solve the above problems, according to the present invention, an
35 inside heat exchanger includes a primary-side heat transfer pipe constituting a portion
of a loop circuit provided in a refrigerant circuit for air conditioning, and a
-~p_ -_ Q_ _ -Q_ _--g_&_ &_ -- ~- --- Q--~-- ~- -- F- -~-- %---~.~. ~- -%-- -~g
iecondary-side heat transfer pipe connected to a pipe arrangement whichbranches off
from the loop circuit through a decompression device; and the decompression device
cools a first refrigerant flowing through the primary-side heat transfer pipe, according
to an operation mode, by causing pressure reduction of the first refrigerant flowing in
5 from the pipe arrangement and delivering the first refrigerant having reduced pressure
toward the secondary-side heat transfer pipe.
Effect of Invention
[0009]
10 According to the .present invention, it is possible to provide an
air-conditioninghot-water supply system realizing high energetic efficiency.
Brief Description of Drawings
[OO 1 01
15 FIG. 1 is a system diagram of an air-conditioninglhot-water supply system
according to a first embodiment of the present embodiment.
FIG. 2 is a system diagram indicating flows of refrigerants and a heated fluid
in a hot-water-supply operation mode.
FIG. 3 is a system diagram indicating flows of a refrigerant in a cooling
20 . operation (normal) mode.
FIG. 4 is a system diagram indicating flows of the refrigerants and the heated
fluid in a cooling operation (exhaust heat) mode.
FIG. 5 is a graph of a pressure-specific enthalpy relationship, which indicates
the condition of the refrigerant during a cooling operation.
25 FIG. 6 is a system diagram indicating flows of the refrigerant in a heating
. operation (normal) mode. !
FIG. 7 is a graph of a pressure-specific enthalpy relationship, which indicates
the condition of the refrigerant in the heating operation (normal) mode.
FIG. 8 is a system diagram indicating flows of the refrigerants and the heated
30 fluid in a heating operation (exhaust heat) mode.
FIG. 9 is a graph of a pressure-specific enthalpy relationship, which indicates
the condition of the refrigerant in the heating operation (exhaust heat) mode.
FIG. 10 is a system diagram indicating flows of refrigerants and a heated fluid
in a hot-water-supply operation mode in an air-coriditioninghot-water supply system
35 according to a second embodiment of the present invention.
FIG. 11 is a graph of a pressure-specific enthalpy relationship, which indicates
- ~- p- --- ~--- -~ : g - ~ - ~. ~- -- -. - ~- -- ~- ~- - -- r. ~. - ; @ ~ T ~ ~ ~ - - K . g
the condition of a refrigerant during a heating operation in an
air-conditioninglhot-water supply system according to a conventional technique.
Description of Embodiments
5 [OOll]
Hereinbelow, embodiments of the present invention are explained with
reference to drawings when necessary. In the drawings, identical or equivalent
elements bear identical reference numbers, and the same explanations are not repeated.
[OO 1 21
10 <>
FIG. 1 is a system diagram of an air-conditioninglhot-water supply system
according to the first embodiment of the present embodiment. As illustrated in FIG. 1,
.the air-c~nditionin~fhot-watesur pply system S includes an outdoor unit 1, indoor units
2a and 2b, a hot-water supply unit 3, a hot-water storage tank 4, and a control device
15 50.
The indoor units 2a and 2b are placed indoors (in an air-conditioned space),
and the outdoor unit 1, the hot-water supply unit 3, and the hot-water storage tank 4 are
placed outdoors (outside the air-conditioned space). In the example of FIG. 1, the
air-conditioninglhot-water supply system S is provided with the two indoor units.
20 [0013]
In addition, the indoor units 2a and 2b and the outdoor unit 1 each have a
control unit (not shown), and are arranged to be able to communicate with each other
through communication lines (ndt shown). In FIG. 1, each control unit is schematically
illustrated as the control device 50.
25. [0014]
The air-~onditionin~lhot-watesru pply system S has the functions of
performing a "cooling operation", a "heating operation", a "hot-water supply
operation", a "cooling and hot-water supply operation", and a "heating and hot-water
supply operation". The "cooling operation'! cools the indoor space in which thk indoor
30 units 2a and 2b are placed. The "heating operation" warms the indoor space in which
the indoor units 2a and 2b are placed. The hot-water supply operation" heats a fluid
(e.g., water) to be heated, and supplies the heated fluid having high temperature to a
tank 42. The "cooling and hot-water supply operation" includes the cooling operation
and the hot-water supply operation. The "heating and hot-water supply operation"
35 includes the heating operation and the hot-water supply operation.
[OO 1 51
- ~ -p - -- -@ -- - g- -: -~ - ~- ~- -~ - : -_ @_ -_ ~ ~ r - F_ _~_ Q _ - r r ~ ~ r r Q -:--
In addition, the air-conditioninglhot-water supply system S is provided with
an air-conditioning refrigerant circuit 10, a hot-water-supply refrigerant circuit 30, and
a hot-water supply circuit 40. A first refrigerant circulates through the air-conditioning
refrigerant circuit 10, ' a second refrigerant circulates through the hot-water-supply
5 refrigerant circuit 30, and the heated fluid flows through the hot-water supply circuit
40.
[00 1 61

r
Hereinafter, the indoor units 2a and 2b, which are connected in parallel with
10 the outdoor unit 1, may be collectively referred to as "the indoor units 2".
The air-conditioning refrigerant circuit 10 includes a loop circuit in which a
compressor 11 for air conditioning, a four-way valve 12, an outdoor heat exchanger 13,
an outdoor expansion valve 14, a primary-side heat transfer pipe 21a in an intermediate
heat exchanger 2 1, a primary-side heat transfer pipe 15a in an inside heat exchanger 15,
15 and the indoor units 2 are connected in order. In addition, an accumulator 19, which
performs vapor-liquid separation of the first refrigerant for prevention of liquid
compression in the compressor 11 for air conditioning, is arranged on the intake side of
the compressor 11 for air conditioning. Further, an expansion valve 16 for the inside
heat exchanger is arranged to reduce the pressure, of the first refrigerant before'the first
20 refrigerant flows into the secondary side of the inside heat exchanger 15.
[0017]
The compressor 11 for air conditioning is a compressor which coinpresses the ,
first refrigerant so as to make the temperature and the pressure pf the first refrigerant
high. For example, the rotary type, scroll type, or reciprocating type compressor may
25 be used as the compressor 11 for air conditioning.
The four-way valve 12 switches the directions of the first refrigerant flowing
through indoor heat exchangers 18a and 18b according to whether to perform cooling
operation or heating operation. ~ ~ e c i f i c a lthl ~e ,f our-way valve 12 is switched such
that the first refrigerant which is expanded by air-conditioning expansion valves 17a
30 and 17b and has low temperature and low pressure flows into the indoor heat
exchangers 18a and 18b during cooling operation, and the first refrigerant which is
compressed by the compressor 11 for air conditioning and has high temperature and
high pressure flows into the indoor heat exchangers' 18a and 18b during heating
operation.
35 [0018]
The outdoor heat exchanger 13 (i.e., the air-conditioning heat-source side heat
-~- p- -- - ~- -~ - -: - ~- - g~- - -g ~--- ~ --- -F ~:K~/cg%---zq~
exchanger) is a heat exchanger which is connected to the discharge side of the
compressor 11 for air conditioning through the four-way valve 12, and exchanges heat
between the first refrigerant and the air (the outdoor air) sent from an outdoor fan 13f.
The outdoor expansion valve 14 (corresponding to the first expansion valve)
5. is interposed between the outdoor heat exchanger 13 and the intermediate heat
exchanger 2'1, and functions as a decompression device which reduces the pressure of
the first refrigerant in the hot-water-supply operation mode and the heating operation
mode.
The intermediate heat exchanger 21 is a heat exchanger which exchanges heat
10 between the first refrigerant flowing through the primary-side heat transfer pipe 21a
and the second refrigerant flowing through a secondary-side heat transfer pipe 21 b.
[00 191
The inside heat exchanger 15 is a heat exchanger which . exchanges heat between the first refrigerant flowing through the primary side (the side connected to
15 the indoor expansion valves 17a and 17b) and the first refrigerant flowing through the
secondary side (the side connected to the expansion valve 16 for the inside heat
exchanger).
v Specifically, the inside heat exchanger 15 includes the primary-side heat
transfer pipe 15a and a secondary-side heat transfer pipe 15b. The primary-side heat
20 transfer pipe 15a constitutes a portion of the aforementioned loop circuit, and the
secondary-side heat transfer pipe 15b is connected, through the expansion valve 16 for
the inside heat exchanger, to a pipe arrangement P which branches off from the loop
circuit.
Further, one end of the secondary-side heat transfer pipe 15b in the inside heat
25 exchanger 15 is connected to the expansion valve 16 for the inside heat exchanger, and
the other end of the secondary-side heat transfer pipe 15b is connected to a pipe
arrangement connecting the four-way valve 12 and the accumulator 19.
[0020]
The expansion valve 16 (corresponding to the decompression device) for the
30 inside heat exchanger reduces the pressure of the first refrigerant flowing in from the
pipe arrangement P according to the operation mode, and delivers the first refrigerant
having the reduced pressure to the secondary-side heat transfer pipe 15b in the inside
heat exchanger 15. Thus, the first refrigerant flowing through the primary-side heat
transfer pipe 15a in the inside heat exchanger 15 is cooled.
35 [0021]
The indoor expansion valves 17a and 17b (corresponding to the second
- ~- - ~- - g. --- - ~- - *- -~- - ~ ~ ~- -k - - ~-- ~- - -- - F- -~ Q - ~ 7 & - ~ ~ - - ~ ~ '
expansion valve) function as decompression devices which are interposed between the
inside heat exchanger 15 and the indoor heat exchangers 18a and 18b, and reduce the
pressure of the first refrigerant in the cooling operation mode and the heating operation
mode.
5 The indoor heat exchangers 18a and 18b (corresponding to the air-conditioned
side heat exchanger) are heat exchangers which are connected through the four-way
valve 12 to the discharge side of the compressor 11 for air conditioning, and exchange
heat between the first refrigerant and the air (the indoor air) sent from indoor fans 1 Sf.
[0022]
10 As illustrated in FIG. 1, the indoor expansion valve 17a and the indoor heat
exchanger 18a constituting the indoor unit 2a are connected in series, and the indoor
expansion valve 17b and the indoor heat exchanger 18b constituting the indoor unit 2b
are connected in series. In addition, the indoor units 2a and 2b are connected in parallel.
Hereinafter, the indoor expansion valves 17a and 17b may be collectively referred to as
15 the indoor' expansion valves 17, and the indoor heat exchangers 18a and 18b may be
collectively referred to as the indoor heat exchangers 18.
[0023]
For example, HFC, HFO- 1234yf, HFO- 1234ze, a natural refrigerant (e.g.,
COz refrigerant), and other refrigerants can be used as the first refrigerant.
20 [0024]

In the hot-water-supply refrigerant circuit 30 arranged in the hot-water supply
unit 3, a compressor 31 for hot-water supply, a primary-side heat transfer pipe 32a in a
heat exchanger 32 for hot-water supply, an expansion valve 33 for hot-water supply,
25 and the secondary-side heat transfer pipe 21b in the intermediate heat exchanger 21 are
connected with a pipe arrangement to form a loop.
[0025]
The compressor 31 for hot-water supply is a compressor which compresses
the second refrigerant to make the temperature and the pressure of the second
30 refrigerant high.
The heat exchanger 32 for hot-water supply is a heat exchanger which
exchanges heat between the second refrigerant flowing through the primary-side heat
transfer pipe 32a and the heated fluid flowing through the secondary-side heat transfer
pipe 32b.
3 5 The expansion valie 33 for hot-water supply functions as decompression
device which reduces the pressure of the second refrigerant.
- ~- . -~ - ~- - - -- - .~ - ~. - ~-. -.. ~ .~ ._ -_ _-~- - C._ _=F _ 2 T ~ - T ~ T 2 - T ~ Q y :-
For example, HFC, HFO- 1234yf, HFO- 1234ze, a natural refrigerant (e.g.,
C02 refrigerant), and other refrigerants can be used as the second refrigerant. In
addition, it is preferable to use as the second refrigerant a refrigerant having a critical
point (in the temperature-pressure relationship) higher than the critical point of the first
5 refrigerant.
[0026]
,
The hot-water supply circuit 40 is constituted by connecting, with a pipe
arrangement, a pump 41 for hot-water supply, a secondary-side heat transfer pipe 32b
10 in the heat exchanger 32 for hot-water supply, and the tank 42 so as to form a loop.
The pump 41 for hot-water supply pumps up the heated fluid from the tank 42,
and transfers the heated fluid to the secondary-side heat transfer pipe 32b in the heat
exchanger 32 for hot-water supply.
The tank 42 reserves the heated fluid, and is covered with a heat insulating
15 material (not shown). As mentioned before the heated fluid may be, for example, water.
[0027]
The hot-water storage tank 4 is provided with a splicing fitting 43 for water
feed, a splicing fitting 45 for hot-water supply, and three-way valves 44 and 46.
One end of the splicing fitting 43 for water feed is connected to the three-way
20 valve 44, and the other end of the splicing fitting 43 for water feed is connected to a
water-supply terminal (not shown). The splicing fitting 43 for water feed is arranged
such that the pressure from the water supply source causes the fluid (water) to be
heated to flow into a lower portion of the tank 42 through the splicing fitting 43 for
water feed when a user manipulates a hot-water supply terminal to be opened.
25 [0028]
The three-way valves 44 and 46 are configured to allow adjustment of the
proportions of the flow rate of the heated fluid through the three-way valves'44 and 46,
and connected to each other through the pipe arrangement 47a. The three-way valves
44 and 46 are configured such that the high-temperature heated fluid supplied from the
30 tank 42 is adjusted at an appropriate temperature by causing the fluid to be heated
(water) to flow in through the pipe arrangement 47a at a flow rate corresponding to the
apertures of the three-way valves 44 and 46.
One end of the splicing fitting 45 for hot-water supply is connected to the
three-way valve 46, and the other end of the splicing fitting 45 for hot-water supply is
35 connected to the hot-water supply terminal (not shown). The splicing fitting 45 for
hot-water supply is configured such that the heated fluid (hot water) is supplied to the
- m ~ - - - - ~ g . ,- - ..- - - -- - -- -- - - - - - - _ _ . . _ . - '
hot-water supply terminal through the splicing fitting 45 for hot-water supply when the
user manipulates the hot-water supply terminal to be opened.
[0029]

5 The air-conditioninghot-water supply system S is provided with the control
. device 50. The control device 50 has the functions of determining the operation mode
of the air-conditioninglhot-water supply. system, and controlling various types of
operations of the air-conditioninghot-water supply system S by controlling, on the
basis of the determined operation mode, the states (apertures) of the respective valves
10 (the four-way valve 12, the outdoor expansion valve 14, the expansion valve 16 for the
inside heat exchanger, the indoor expansion valves 17, and the expansion valve 33 for
hot-water supply), the rotational speeds of the compressors (the compressor 11 for air
conditioning and the compress'or 3 1 for hot-water supply), the rotational speeds of the
fans in the respective heat exchangers (the outdoor fan 13f and the indoor fans 18f);
15 and the rotational speed of the pump 41 for hot-water supply.
[0030]
(Control in Each Operational Mode)
The respective operation modes of the air-conditioninglhot-water supply
system S are explained below.
20 In the respective system diagrams which are thereinafter referred to, the pipe
arrangement through which each of the first refrigerant, the second refrigerant, and the
heated fluid flows is illustrated by bold lines, and the directions of the flows are
indicated by arrows. In addition, each of the valves (the outdoor expansion valve 14, I
the expansion valve 16 for the inside heat exchanger, the indoor expansion valves 17,
25 and the expansion valve 33 for hot-water supply) which is closed is illustrated by a
filled symbol.
[003 1 ]
(1. Hot-~ater~suppOlyp eration Mode)
FIG. 2 is a system diagram indicating flows of refrigerants and the heated
30 fluid in the hot-water-supply operation mode. In this mode, the indoor fans 18f are
stopped. I
The control device 50 controls a switch means (not shown) in the four-way
valve 12 so as to position the switch means for the hot-water supply operation.. In
addition, the control device 50 controls the switch means (not shown) in the four-way
35 valve 12 such that the discharge side of the compressor 11 for air conditioning and the
indoor heat exchangers 18 are connected and the accumulator 19 and the outdoor heat .
- ~-~ -. -@- - ~ - G : g a - r ~ ~ & ~ ~ ~ - - ~ ~ y - x Q - .-,i.- - - - - - - - - - - - - - 7.--
exchanger 13 are connected: In addition, the control device 50 completely closes the
expansion valve 16 for the inside heat exchanger, fully opens the indoor expansion
valves 17, and controls the aperture of the outdoor expansion valve 14. Further, the
control device 50 controls the rotational speeds of the compressor '11 for air
5 conditioning, the compressor 3 1 for hot-water supply, and the outdoor fan 13f.
[0032]
The air-conditioning refrigerant circuit 10 ' in the hot-water-supply operation
mode is explained below.
The first refrigerant which is delivered from the compressor 11 for air
10 conditioning and has high temperature and high pressure passes through the four-way
valve 12, the indoor heat exchangers 1 8, the, indoor expansion valves 17, and the
primary-side heat transfer pipe 15a in the inside heat exchanger 15, and flows into the
primary-side heat transfer pipe 21a in the intermediate heat exchanger 21, which
functions as a condenser. In the hot-water-supply operation mode, the indoor fans 18f
15 are stopped. Therefore, almost no heat exchange occurs between the indoor air and the
first refrigerant flowing through the indoor heat exchangers 18.
Heat in the first refrigerant which flows through the primary-side heat transfer
pipe 21a in the intermediate heat exchanger 21 and has high temperature and high
pressure is dissipated by heat exchange with the second refrigerant which flows
20 through the secondary-side heat transfer pipe 21b in the intermediate heat exchanger
21, so that the above first refrigerant comes to have medium temperature and high
pressure. .
[0033]
The first refrigerant which flows out of the primary-side heat transfer pipe 21 a
25 in the intermediate heat exchanger 21 and has medium temperature and high pressure
comes to have low temperature and low pressure by pressure reduction in the outdoor
expansion valve 14, and flows into the outdoor heat exchanger 13, which functions as
an evaporator. The first refrigerant flowing through the outdoor heat exchanger 13
exchanges heat with the air (outdoor air) sent by the outdoor fan 13f, so that the first
30 refrigerant flowing through the outdoor heat exchanger 13 takes (absorbs) heat from
the outdoor air. Then, the first refrigerant having the absorbed heat flows from the
outdoor heat exchanger 13 through the four-way valve 12 and the accumulator 19 back
to the compressor 11 for air conditioning.
[0034]
3 5 Next, the hot-water-supply refrigerant circuit 30 is explained below.
The second refrigerant which is delivered from the compressor 31 for
-r--p - i- - F-%- -g - -- -~- --~- -a ;- -- ~ -~- -~ -~~'li-~w-~$-~-~.rx9
hot-water supply and has high temperature and high pressure flows into the
primary-side heat transfer pipe 32a in the heat' exchanger 32 for hot-water supply,
which functions as a condenser. Heat in the second refrigerant flowing through the
primary-side $eat transfer pipe 32a in the heat exchanger 32 for hot-water supply is
5 dissipated by heat exchange with the heated fluid flowing through the secondary-side
heat transfer pipe 32b, so that the above second refrigerant comes to have medium
temperature and high pressure.
Then, the second refrigerant which flows out of the primary-side heat transfer
pipe 32a in the heat exchanger 32 for hot-water supply and has medium temperature
10' and high pressure comes to have low temperature and low pressure by pressure
reduction in the expansion valve 33 for hot-water- supply.
[0035]
Subsequently, the second refrigerant having low temperature and low pressure
flows into the secondary-side heat transfer pipe 2 1 b in the intermediate heat exchanger
15 21, which functions as an evaporator. The second refrigerant flowing through the
secondary-side heat transfer pipe 21b in the intermediate heat exchanger 21 takes
(absorbs) heat from the first refrigerant having high temperature and high pressure and
flowing through the primary-side heat transfer pipe 2 la, by heat exchange with the first
refrigerant. Further, the second refrigerant having the absorbed heat returns from the
20 intermediate heat exchanger 2 1 to the compressor 3 1 for hot-water supply.
[0036]
Next, the hot-water supply circuit 40 is explained below. The control device
50 controls the rotational speed of the pump 41 for hot-water supply. When the pump
41 is driven, the heated fluid which flows out of the lower portion of the tank 42 flows
25 into the secondary-side heat transfer pipe 32b in the heat exchanger 32 for hot-water
supply. The heated fluid flowing through the secondary-side heat transfer pipe 32b
absorbs heat by heat exchange with the second refrigerant flowing through the
primary-side heat transfer pipe 32a, so that the above heated fluid comes to have high
temperature. Then, the heated fluid having the high temperature which flows out of the
30 secondary-side heat transfer pipe 32b in the heat exchanger 32 is transferred by the
pump 41 for hot-water supply to an upper portion of the tank 42, and reserved in the
tank 42.
[0037]
(2. Cooling Operation (Normal) Mode)
35 FIG. 3 is a system diagram indicating flows of a refrigerant in the cooling
operation (normal) mode. In the cooling operation (normal) mode, the
- ~.p--- -n .. -- m. .-. -~-~ ---~-- ~ f- -i :- F - ~ - y ~ - & ~ - ~ ~ - ~ ; - r g
hot-water-supply refrigerant circuit 30 and the hot-water supply circuit 40 are stopped..
The control device 50 controls the switch means (not shown) in the four-way
valve 12 so as to position the switch means for the cooling operation. In addition, the
control device 50 controls the switch means (not shown) in the four-way valve 12 such
5 that the discharge side of the compressor 11 for air conditioning and the outdoor heat
exchanger 13 are connected and the accumulator 19 and the. indoor heat exchangers 18
are connected.
[003 81
In addition, the control device 50 fully opens the outdoor expansion valve 14,
10 and controls the aperture of the expansion valve 16 for the inside heat excha,n ger such
that the first refrigerant flows through the secondary-side heat transfer pipe 15b in the
inside heat.exchanger 15 at an appropriate flow rate. Further, the control device 50
controls the apertures of the indoor expansion valves 17 such that the first refrigerant
flows through the indoor heat exchangers 18 at a flow rate corresponding to the
15 air-conditioning load occurring in the indoor space (the air-conditioned space).
Furthermore, the control device 50 controls the rotational speeds of the
compressor 11 for air conditioning, the indoor fans 1 Sf, and the outdoor fan 13f.
[0039]
Hereinbelow, the' condition of the first refrigerant flowing through the
20 air-conditioning refrigerant circuit 10 is explained with reference to the graph of the
pressure-specific enthalpy relationship indicated in FIG. 5.
In the graph of FIG. 5, the ordinate corresponds to the absolute pressure (kPa),
. and the abscissa corresponds to the specific enthalpy (kJ/kg). In addition, the first
refrigerant is in a gas-liquid two-phase state in the region surrounded by the saturation
25 liquid line and the saturation gas line, in a liquid state on the left side of the saturation
liquid line, and in a gas state on the right side of the saturation gas line. This is similar
in the other pressure-specific enthalpy relationships.
In the following explanations, the references A to F of the states indicated in
FIG. 5 are indicated in parentheses. In addition, the enthalpy given by the compressor
30 11 for air conditioning is indicated by the reference W. '
[0040]
The first refrigerant being delivered from the. outdoor heat exchanger 13 and
having high temperature and high pressure (as indicated by A) flows through the
four-way valve 12 into the outdoor heat exchanger 13, which functions as a condenser
35 (as indicated by B). Then, the first refrigerant having high temperature and high
pressure flows through the outdoor heat exchanger 13, and exchanges heat with the air
- x-p- 7 ---m -- -m- -- - --.G - :-. K w r- n T- ~- ~ - F ~ : g 7 ~ - ~ ~ ~ - ~ . ~ - * - - - - -
(outdoor air) sent by the outdoor fan 13f, so that heat in the first refrigerant is
dissipated (exhausted) to the air, and the above first refrigerant comes to have medium
temperature and high pressure (as indicated by Cl).
[004 11
5 The first refrigerant which flows out of the outdoor heat exchanger 1? and has
medium temperature and high pressure passes through the outdoor expansion valve 14,
and flows into the primary-side heat transfer pipe 21a in the intermediate heat
exchanger 2 1. Since the ambient temperature of the intermediate heat exchanger 2 1 is
near the outdoor temperature, the first refrigerant flowing through the primary-side
10 heat transfer pipe 21a in the intermediate heat exchanger 2 1 exchanges heat with the
outdoor air, so that heat in the first refrigerant is dissipated, i.e., the first refrigerant is
cooled (as indicated by C2).
Then, the first refrigerant which flows out of the intermediate heat exchanger
2 1 is branched at the branch point Q into the pipe arrangements P1 and P2. At this time,
15 the aperture of the expansion valve 16 for the inside heat exchanger is controlled such
that the flow rate of the first refrigerant branched into the pipe arrangement P2 is 3 to
5% of the flow rate of the first refrigerant flowing into the branch point Q.
[0042]
Then, the first refrigerant which flows from the pipe arrangement P2 into the
20 expansion valve 16 for the inside heat exchanger comes to have low temperature and
low pressure by pressure reduction in the expansion valve 16, and flows into the
secondary-side heat transfer pipe 15b in the inside heat exchanger 15.. The first
refrigerant flowing through the secondary-side heat transfer pipe 15b in the inside heat
exchanger 15 absorbs heat (as indicated by E) by heat exchange'with the first
25 refrigerant flowing through the primary-side heat transfer pipe 15a and having medium
temperature and high pressure, and then flows .into,a pipe arrangement L. The first
refrigerant which flows into the pipe arrangement L merges with the first refrigerant
flowing in from the indoor heat exchangers 18, and returns to the compressor 11 for air
conditioning through the accumulator 19.
30 [0043]
On the other hand; the first refrigerant having medium temperature and high
pressure and flowing through the primary-side heat transfer pipe 15a in the inside heat
exchanger 15 is further cooled (as indicated by C3) by heat exchange with the first
refrigerant flowing through the secondary-side heat transfer pipe 15b and having low
35 temperature and low pressure. Therefore, the enthalpy of the first refrigerant which
flows out of the primary-side heat transfer pipe 15a can be reduced, so that the heat
- ~ -Y - ~ - -- ~- -r. - - -Q- - T & ~ ~ ~ - Q - ~ ~ ~ - F ~ ~ - ~ - ~ ~ ~ - ~ ~ . * - - m - - - . - - - . -
usable for cooling can be increased. Since the flow rate of the refrigerant through
evaporators can be reduced and the pressure loss in the indoor heat exchangers 18,
which function as the evaporators, can be reduced, the first refrigerant can be
efficiently circulated in the air-conditioning refrigerant circuit 10. '
5 [0044]
Further, the first refrigerant which flows out of the primary-side heat transfer
pipe 15a in the inside heat exchanger 15 comes to have low temperature and low
pressure (as indicated by D) by pressure reduction in the indoor expansion valves 17,
and flows into the indoor heat exchangers 18.
10 .The first refrigerant flowing through the indoor heat exchangers 18 absorbs
heat (as indicated by F) by heat exchange with the air (indoor air) sent from the indoor
fans 18f, and then returns to the compressor 11 foi- air conditioning through the
four-way valve 12 and the accumulator 19 (as indicated by G).
[0045]
15 (3. Cooling Operation (Exhaust heat) Mode)
FIG. 4 is a system diagram indicating flows of the refrigerants and the heated
fluid in the cooling operation (exhaust heat) ,mode.
The control device 50 controls a switch means (not shown) in the four-way
valve 12 so as to position the switch means for the cooling operation. In addition, the
20 control device 50 fully opens the outdoor expansion valve 14, andcontrols the aperture
of the expansion valve 16 for the inside heat exchanger such that the first refrigerant
flows through the secondary-side heat transfer pipe 15b in the inside heat exchanger 15
at an appropriate flow rate. In addition, the control device 50 controls the aperture of
the indoor expansion valve such that the first refrigerant flows through the indoor heat
25 exchangers 18 at a flow rate corresponding to the air-conditioning load occurring in the
indoor space (the air-conditioned space). Further, the control device 50 controls the
rotational speeds of the compressor 11 for air conditioning, the indoor fans 1 8f, and the
outdoor fan 1 3 f.
Furthermore, the control device 50 controls the aperture of the rotational
30 speed of the compressor 31 for hot-water supply and the aperture of the expansion
valve 33 for hot-water supply such that the refrigerant flows at a flow rate appropriate
for the hot-water supply load. In addition, the control device 50 controls the rotational
speed of the pump 41 for hot-water supply such that the heated fluid (water) flows
through the hot-water supply circuit 40 at an appropriate circulation rate.
35 [0046]
Hereinbelow, the operations of the air-conditioning refrigerant circuit -- 8 : > . D m - m T E ~ Q T ~ ~ - F ~ ~ r ~ - ~ 7ci~rcui~t 1 0 are
- - -, . - - - - -- -- - - - - _ _ _ _ _ _ -- - - - - -
explained with reference to FIGS. 4 and 5. Since the operations of the hot-water-supply
refrigerant circuit 30 and the hot-water supply circuit 40 in the cooling operation
(exhaust heat) mode are similar to the aforementioned operations \in the hot-water
supply operation mode explained before, explanations. on the operations of the
5 hot-water-supply refrigerant circuit 30 and the hot-water supply circuit 40 in the
cooling operation (exhaust. heat) mode are not presented.
[0047]
The first refrigerant which is delivered from the compressor 11 for air
conditioning and has high temperature and high pressure (as indicated by A) flows
10 through the four-way valve 12 into the outdoor heat exchanger 13 (as indicated by B),
where the outdoor heat exchanger 13 functions as a condenser. The first refrigerant
having high temperature and high pressure and flowing through the outdoor heat
exchanger 13 exchanges heat with the air (outdoor air) sent by the outdoor fan 13f, so
that heat in the first refrigerant flowing through the outdoor heat exchanger 13 is
15 dissipated (exhausted) to the air, and the above first refrigerant comes to have medium
temperature and high pressure (as indicated by Cl). d
[0048]
The first refrigerant which flows out of the outdoor heat exchanger 13 and has
medium temperature and high pressure flows through the outdoor expansion valve 14
20 into the primary-side heat transfer pipe 21a in the intermediate heat exchanger 21.
Since the secondary-side heat'transfer pipe 21 b in the intermediate heat exchanger 21
functions as an evaporator, heat in the first refrigerant flowing through the
primary-side heat transfer pipe 21a is dissipated to the second refrigerant flowing
through the secondary-side heat transfer pipe 21b, i.e., the first refrigerant flowing
25 through the primary-side heat transfer pipe 21a is cooled '(as indicated by C2).
Therefore, the temperature of the first refrigerant which flows out of the primary-side
heat transfer pipe 2 1 a can be lowered to a sufficiently low temperature.
Then, the first refrigerant which flows out of the intermediate heat exchanger
21 is branched at the branch point Q into the pipe arrangements P1 and P2.
30 [0049]
Then, the first.refrigerant which flows from the pipe arrangement P2 into the
expansion valve 16 for the inside heat exchanger comes to have low temperature and
low pressure by pressure reduction in the expansion valve 16, and then flows into the
secondary-side heat transfer pipe 15b in the inside heat exchanger 15. The first
35 refrigerant flowing through the secondary-side heat transfer pipe 15b in the inside heat ,
exchanger 15 absorbs heat (as indicated by E) by heat exchange with the first - ~ ~ - Q - ~ ~ ~ - ~,A>3 L: - .kA.u ~ ,k& e : & -2 ,.5 . I
- - - - - - - - - - - - - - - - -
refrigerant flowing through the primary-side heat transfer pipe 15a and having medium ~ temperature and high pressure, and then flows into the pipe arrangement L. The first ~ refrigerant which flows into. the pipe arrangement L merges with the first refrigerant
flowing in from the indoor heat exchangers 18, and then returns through the
5 accumulator 19 to the compressor 11 for air conditioning.
[0050]
On the other hand, the first refrigerant flowing through the primary-side heat
transfer pipe 15a in the inside heat exchanger 15 is further cooled (as indicated by C3)
by heat exchange with the first refrigerant flowing through the secondary-side heat
10 ' transfer pipe 15b and having low temperature and low pressure. Then, the first
refrigerant which flows out of the primary-side heat transfer pipe 15a in the inside heat
exchanger 15 comes to have low temperature and low pressure (as indicated by D) by
pressure reduction in the indoor expansion valves 17, and then flows into the indobr
heat exchangers 1 8.
15 The first refrigerant flowing through the indoor heat exchangers 18 absorbs
heat (indicated by F) from the air (indoor air) sent from the indoor fans 18f, by heat
exchange with the air, and the first refrigerant having the absorbed heat returns through
the four-way valve 12 and the accumulator 19 to the compressor 1 1 for air conditioning
(as indicated by G).
20 [0051]
As described above, the first refrigerant circulating in the air-conditioning
refrigerant circuit 10 is cooled by the outdoor heat exchanger 13, and is further cooled
by the intermediate heat exchanger 21 and the inside heat exchanger 15. Therefore, the
enthalpy difference which can be utilized in the indoor heat exchangers 18, which
25 function as evaporators, increases, so that the flow rate of the first refrigerant flowing
through the indoor heat exchangers 18 can, be reduced; Thus, the pressure loss
occurring in the indoor heat exchangers 18 (functioning as the evaporators) is reduced, l
and therefore the efficiency in the air-conditioning refrigerant circuit 10 can be
improved.
1
30 Since, in the cooling operation (exhaust 'heat) mode, the low-temperature I I
exhaust heat in the hot-water-supply refrigerant circuit 30 can be utilized by the
intermediate heat exchanger 21, the cooling rate in the intermediate heat exchanger 21
can be increased, compared with the cooling operation (normal) mode, which is
explained before. Therefore, the efficiency in the air-conditioning refrigerant circuit 10
35, can be further improved.
[0052]
-rpm.- - --!@ -- . - - -& ; -k *-e; -.~- @- -~- ~ ---F ~- - Q - - ~ - ~ ~ - ~ - - $ T ~ . I
(4. Heating Operation (Normal) Mode)
FIG. 6 is a system diagram indicating flows of the refrigerant in the heating
operation (normal) mode. In the heating operation (normal) mode, the
hot-water-supply refrigerant circuit 30 and the hot-water supply circuit 40 are stopped.
5 The control device 50 controls a switch means (not shown) in the four-way
valve 12 so as to position.the switch means for the heating operation. In addition, the
control device 50 controls the switch means (not shown) in the four-way valve 12 such
that the discharge side of the compressor 11 for air conditioning and the indoor heat
exchangers 18 are connected and the intake side of the accumulator 19 and the
10 outdoor heat exchanger 13 are connected.
[0053]
In addition, the control device 50 controls the apertures of the indoor
expansion valves 17 and the outdoor expansion valve 14 such that the first refrigerant
circulates in the air-conditioning refrigerant circuit 10 at a flow rate corresponding to
15 the air-conditioning load occurring in the indoor space (the air-conditioned space). In
addition, the control device 50 controls the aperture of the expansion valve 16 for the
inside heat exchanger such that the first refrigerant flows through the secondary-side
heat transfer pipe 15b in the inside heat exchanger 15 at an appropriate flow rate.
Further, the control device 50 controls the rotational speeds of the compressor
20 ' 11 for air conditioning, the indoor fans 18f, and the outdoor fan 13f.
[0054]
Hereinbelow, the operation of the air-conditioning refrigerant circuit 10 are
explained with reference to FIGS. 6 and 7.
The first refrigerant which is delivered from the compressor 11 for air
25 conditioning and has high temperature and high pressure (as indicated by A) flows
through the four-way valve 12 into the indoor heat exchangers 18 (as indicated by B),
where the indoor heat exchangers 18 function as condensers. The first refrigerant
flowing through the indoor heat exchangers 18 and having high temperature and high
pressure exchanges heat with the air (indoor air) sent by the indoor .fans 18f, so that
30 heat in the first refrigerant flowing through the indoor heht exchangers 18 is dissipated
(exhausted) to the air and the above first .refrigerant comes .to have medium
temperature and high pressure (as indicated by Cl).
[0055]
The first refrigerant which flows out of the outdoor heat exchanger 13 and has
35 medium temperature and high pressure passes through the indoor expansion valves 17
(as indicated by C2), and flows into the primary-side heat transfer pipe 21a in the
- r.- F> n --Tm K:K: 7 a r Q T ~ ~ - F , ~ ~ r ~ ~ & - r ~ g - - - - - - - - - -- - - - - - . - . '
. intermediate heat exchanger 21. At this time, the apertures of the indoor expansion
valves 17 are almost fully open, so that almost no pressure reduction occurs in the
indoor expansion valves 17. (See the transition from the state C1 to C2 indicated in
FIG. 7.) Thus, it is possible to prevent transition of the first refrigerant flowing out of
5 the indoor expansion valves 17 to a liquid-gas two-phase state, reduce the pressure loss
occurring in the inside heat exchanger 15 and the intermediate heat exchanger 2 1, and
suppress the temperature fall caused by the pressure loss.
[0056]
After the first refrigerant passes through the indoor expansion valves 17, the
10 first refrigerant flows into the primary-side heat transfer pipe 15a in the inside heat
exchanger 15. The first refrigerant flowing through the primary-side heat transfer pipe
15a is cooled (as indicated by C3) by heat exchange with the first refrigerant flowing
through the secondary-side heat transfer pipe 15b and having low temperature and low
pressure. Resultantly, the temperature of the first refrigerant flowing through the
15 primary-side heat transfer pipe 15a can be lowered to approximately the ambient
temperature (outdoor temperature), so that heat exchange with the outdoor air in the
intermediate heat exchanger 21 can be suppressed. Thus, it is possible to prevent
imposition, on the air-conditioning refrigerant circuit 10, of a load exceeding the
air-conditioning load, and efficiently operate the air-conditioning refrigerant circuit 10.
20 [0057]
The first refrigerant which flows out of the inside heat exchanger 15, is
branched at the branch point Q into the pipe arrangement P2 and the pipe arrangement
P3. At this time, the aperture of the expansion valve 16 for the inside heat exchanger is
controlled such that the flow rate of the first refrigerant branched into 'the pipe
25 arrangement P2 is 3 to 5% of the flow rate of the first refrigerant flowing through the
pipe arrangement P 1.
The first refrigerant which. flows into the expansion valve 16 for the inside
- heat exchanger comes to have low temperature and low pressure by pressure reduction
in the expansion valve 16, and then flows into the secondary-side heat transfer pipe
30 15b in the inside heat exchanger 15. The first refrigerant flowing through the
secondary-side heat transfer pipe 15b absorbs heat to be heated (as indicated by E) by
heat exchange with the first refrigerant flowing through the primary-side heat transfer
pipe 15a and having medium temperature and high pressure, and then flows into the
pipe arrangement L.
35 [0058]
As explained above, the heat dissipated from the first refrigerant flowing
- ~ p- -- ~ - n : K r ~ ~ - ~ ~ - c ~ ~ - r r - ~ - - ~ q . _7?_ 2.T _ _ _ _ _ ____i
through the primary-side heat transfer pipe 15a in the inside heat exchanger 15 is
absorbed by the first refrigerant flowing through the secondary-side heat transfer pipe
15b, so that the above heat can be retrieved within the air-conditioning refrigerant
circuit,lO.
5 In addition, the first refrigerant which flows into the pipe arrangement L
merges with the first refrigerant which flows in from theloutdoor heat exchanger 13,
and then returns through the accumulator 19 to the compressor 11 for air conditioning.
[0059]
On the other hand, the first refrigerant which flows out of the primary-side
10 heat transfer pipe 15a in the inside heat exchanger 15 flows into the primary-side heat
transfer pipe 21 a in the intermediate heat exchanger 21. As mentioned before, the
temperature of the first refrigerant flowing through the primary-side heat transfer pipe
21a can be lowered to approximately the ambient temperature (outdoor temperature),
so that almost no heat exchange occurs in the intermediate heat exchanger 2 1.
15 Then, the first refrigerant which flows out of the intermediate heat exchanger
21 comes to have low temperature and low pressure (as indicated by.D) by pressure
reduction in ,the outdoor expansion valve 14; and then flows into the outdoor heat
exchanger 13, which functions as an evaporator. The first refrigerant flowing through
the outdoor heat.exchanger 13 absorbs heat (as indicated by F) from the air (outdoor
20 air) sent by the outdoor fan 13f, by heat exchange with the air, and then returns through
the four-way valve 12 and the accumulator 19 to the compressor 1 1 for air conditioning
(as indicated by G).
[0060]
In the above operations, it is possible to reduce heat dissipation, occurring in
25 the intermediate heat exchanger 21, to the outdoor air from the first refrigerant
circulating in the air-conditioning refrigerant circuit 10, and prevent imposition of a
load exceeding the air-conditioning load on the air-conditioning refrigerant circuit 10.
Therefore, when heat is retrieved by the inside heat exchanger 15, the amount of heat
absorption required in the evaporator (the outdoor heat exchanger 13) can be reduced.
30 Thus, the evaporation pressure Pe2 in the evaporator can be increased compared with
- the evaporation pressure Pel in the case where no heat is retrieved, so that the
efficiency in the air-conditioning refrigerant circuit 10 can be improved.
[0061]
(5. Heating Operation (Exhaust heat) Mode)
35 FIG. 8 is a system diagram indicating flows of the refrigerants and the heated
I fluid in the heating operation (exhaust heat) mode.
- ~ p- - --Q- - - ~ - ~ , -- --- ~ --~.~ Q- - ~ - ~ - ~ 7 ~ ~ ~ - J - / r ~ 7 - ~ ; - ~ 7 ~
The control device 50 controls a switch means (not shown) in the four-way
valve 12 so as to position the switch means for the heating operation. In addition, the
control device 50 controls the apertures of the indoor expansion valves 17 and the
outdoor expansion valve 14 such that the first refrigerant circulates in the
5 air-conditioning refrigerant circuit 10 at a flow rate corresponding to the
air-conditioning load occurring in the indoor space (the air-conditioned space). In
addition, the control device 50 fully opens the expansion valve 16 for the inside heat
exchanger. Thus, hot heat can be fed from the first refrigerant flowing through
primary-side heat transfer pipe 2 1 a in the intermediate heat exchanger 21 to the second
10 refrigerant flowing through the secondary-side heat transfer pipe 21b, so that the hot
heat can be used as a heat source in the hot-water-supply refrigerant circuit 30.
Further, the control device 50 controls the rotational speeds of the compressor
11 for air conditioning, the indoor fans 18f, and the outdoor fan 13f.
[0062]
15 The control device 50 controls the rotational speed of the compressor 31 for
hot-water supply and the apertures of the expansion valve 33 for hot-water supply such
that the refrigerant flows at a flow rate'appropriate for the hot-water supply load. In
addition, the control device 50 controls the rotational speed of the pump 41 for
hot-water supply such that the heated fluid (water) circulates in the hot-water supply
20 circuit 40 at an appropriate flow rate.
[0063]
Hereinbelow, the operations of the air-conditioning refrigerant circuit 10 are
explained with reference to FIGS. 8 and 9. Since the operations of the hot-water-supply
refrigerant circuit 30 and the hot-water supply circuit 40 in the heating operation
25 (exhaust heat) mode are similar to the operations in the hot-water-supply operation
mode explained before, explanations on the operations of the hot-water-supply
refrigerant circuit 30 and the hot-water supply circuit 40 in the heating operation
(exhaust heat) mode are not presented.
[0064]
30 The first refrigerant which is delivered from the. compressor 11 for air
conditioning and has high temperature and high pressure (as indicated by A) flows
through the four-way valve 12 into the indoor heat exchangers 18 (as indicated by B),
where the indoor heat exchangers 18 function as condensers. The first refrigerant
flowing through the indoor heat exchangers 18 and having high temperature and high
35 pressure exchanges heat with the air (indoor air) sent by the indoor fans 18f, so that
heat in the first refrigerant flowing through the indoor heat exchangers 18 is dissipated
- ~ - W - Q L ~ E ~ - ~ -X - 7 ~- -~ - -- -- F ~. @- - - - - r 5 - ~ - - ~ 9
(exhausted) to the air, and the above first refrigerant comes to have medium
temperature and high pressure (as indicated by Cl).
[0065]
The first refrigerant which flows out of the outdoor heat exchanger 13 and has
5 medium temperature and high pressure passes through the indoor expansion valves 17
and the primary-side heat transfer pipe 15a in the inside heat exchanger 15, and flows
into the primary-side heat transfer pipe 21a in the intermediate heat exchanger 21. At
this time, the indoor expansion valves 17 is almost fully open, so that almost no
pressure reduction occurs in the indoor expansion valves.
10 In addition, the expansion valve 16 for the inside heat exchanger is fully open,
so that no heat exchange occurs with the first refrigerant in the inside heat exchanger
15.
[0066]
The first refrigerant flowing through the primary-side heat transfer pipe 2 1 a in
15 the intermediate heat exchanger 21 and having medium temperature and high pressure
exchanges heat with the second refrigerant flowing through the secondary-side heat
transfer pipe 21b in the intermediate heat exchanger 21, so that heat in the first
refrigerant flowing through the primary-side heat transfer pipe 21a is dissipated' (as
indicated by C2). Subsequently, the first refrigerant whith flows out of the
20 intermediate heat exchanger 21 comes to have low temperature and low pressure by
pressure reduction in the outdoor expansion valve 14 (as indicated by D), and then
flows into the outdoor heat exchanger 13.
The first refrigerant flowing through the outdoor heat exchanger 13 absorbs
heat (as indicated by E) from the air (outdoor air) sent by the outdoor fan 13f, by heat
25 exchange with the air, and returns through the four-way valve 12 and the accumulator
19 to the compressor 1 1 for air conditioning (as indicated by F).
[0067]

In the air-conditioninglhot-water supply system S according to the present
30 embodiment, during the cooling operation, the first refrigerant flowing through the
primary-side heat transfer pipe 15a in the inside heat exchanger 15 is cooled by the
first refrigerant flowing through the secondary-side heat transfer pipe 15b and having
low temperature and low pressure. Therefore, the pressure loss in the indoor heat
exchangers 18, which function as evaporators, can be reduced, and thus the total
35 operational efficiency in the air-conditioninglhot-water supply system S can be
improved.
- T-P=- - m - n - K r K r m : ~ ~ - F ~ g 7 - r ~ ~ ~ - - 7 ~ ~ -- ---.---..? . - - - -
[0068]
In addition, in the heating operation (normal) mode, the first refrigerant is
cooled in the inside heat exchanger 15 before the first refrigerant flows into the
intermediate heat exchanger 2 1. Therefore, the heat dissipation to the outdoor air in the
5 intermediate heat exchanger 21 can be reduced, and imposition, on the air-conditioning
refrigerant circuit 10, of'a load exceeding the air-conditioning load can be prevented.
In addition, since the heat dissipated from the first refrigerant flowing through the
.primary-side heat transfer pipe 15a in the inside heat exchanger 15 is absorbed by the
first refrigerant flowing through the secondary-side heat transfer pipe 15b, the heat
10 dissipated from the first refrigerant flowing through the primary-side heat transfer pipe
15a can be retrieved within the air-conditioning refrigerant circuit 10.
As explained above, it is possible to suppress the surplus load occurring in the
intermediate heat exchanger 21 even when the refrigeration cycle on the hot-water
supply side is not in operation, and improve the total efficiency in the
15 air-conditioninglhot-water supply system S during each of cooling operation and
heating operation. .
[0069]
Further, in the heating operation (exhaust heat) mode, heat exchange in the
inside heat exchanger 15 is prevented by completely closing the expansion valve 16 for
20 the inside heat exchanger, so that the first refrigerant having high temperature is caused
to flow through the intermediate heat exchanger 21 and exchange heat with the second
refrigerant. Therefore, the total efficiency in the air-conditioninglhot-water supply
system S can be improved.
[0070]
2 5 FIG. 11 is a graph of a pressure-specific enthalpy relationship, which indicates
the condition of a refrigerant during a heating operation in . a n
air-conditioninglhot-water supply system according to a conventional technique (for
example, the technique disclosed in Patent Literature 1).
As indicated in FIG. 11, a first refrigerant delivered from a compressor for air
30 conditioning (in the state indicated by A) flows into an indoor heat exchanger (as
indicated by B). Subsequently, the first refrigerant exchanges heat with indoor air in
the indoor heat exchanger (as indicated by Cl), and then flows into an intermediate
heat exchanger. As mentioned before, since the intermediate heat exchanger is
normally arranged in an outdoor unit, the intermediate heat exchanger is in thermal
35 contact with the outdoor air. Therefore, heat in the first refrigerant in the intermediate
heat exchanger is dissipated to the outdoors (as indicated by C2). Thus, the amount of -~- - ~- - ~- -- - - Q - -- ~. - ~. - - ~- ~- -- - -~ - ~ -- ~ - ~ ~ - F ~ F ~ - ~ 7 ~ o~f + - - ~ ~
heating which is required in the outdoor heat exchanger, which functions as an
evaporator, increases by the amount of the heat dissipation in the transition .from the
state C1 to the state C2 indicated in FIG. 11. Resultantly, the evaporation pressure of
the first refrigerant is lowered from Pel to Pe2, and the work load in the compressor
5 for air conditioning is lowered from W1 to W2. Consequently, the total efficiency in
the air-conditioninghot-water supply system is lowered.
[0071]
In contrast, according to the present embodiment, as explained before, the
total efficiency in the air-conditioninghot-water supply system S can be improved in
10 each of the cooling operation and the heating operation.
[0072]
<>
The'second embodiment is different from the first embodiment in that a
bypass pipe arrangement U and two-way valves 61, 62, and 63 (the open-close means)
15 are arranged, and is similar to the first embodiment in the other configuration.
Therefore, only the differences are explained b'elow, and explanations on the identical
portions are not repeated.
[0073]
FIG. 10 is a system diagram indicating flows of refrigerants and a heated fluid
20 in a hot-water-supply operation mode in an air-~onditionin~hot-watesur pply system
S 1 according to the second embodiment of the present invention.
The bypass pipe arrangement U illustrated in FIG. 10 is a pipe arrangement
which connects the pipe arrangement connecting the primary-side heat transfer pipe
' 15a in the inside heat exchanger 15 and the indoor expansion valves 17 and a pipe
25 arrangement arranged on the discharge side of the compressor 11 for air conditioning.
One end of the bypass pipe arrangement U is connected (at the point T) to a pipe
arrangement connecting the discharge side of the compressor 11 for air conditioning
and the two-way valve 61, and the other end of the bypass pipe arrangement U is
connected (at the point V) to a pipe arrangement connecting the primary-side heat
30 transfer pipe 15a in the inside heat exchanger 15 and the two-way valve 63.
[0074]
In the air-conditioning refrigerant circuit 10, the two-way valve 61 is arranged
between the discharge side of the compressor 11 for air conditioning and the four-way
valve 12, and the two-way valve 62 is arranged at a halfway position in the.bypass pipe
35 arrangement U. In addition, the two-way valve 63 is arranged between the
primary-side heat transfer pipe 15a in the inside heat exchanger 15 and the indoor - - .r -- -F- -Q _-_ _ @ ~ E ~ ~ @ ~ ~ - c 2 - Q : r ~ ~ 7 ~ ~ g g ? _ _ _ _ _ _ _ _ . 2 - - _ _ 7 _ _ _ _ _ , .
expansion valves 17.
That is, the two-way valves 61, 62, and 63 realize the "open-close means"
' which causes the first refrigerant flowing out of the compressor 11 for air conditioning
to flow into the primary-side heat transfer pipe 15a in the inside heat exchanger 15
5 through the bypass pipe arrangement U in the hot-water-supply operation mode.
[0075]
The control device 50 controls the switch means (not shown) in the four-way
valve 12 so as to position the switch means for the hot-water supply operation. In
addition, the control device 50 completely closes the expansion valve 16 for the inside
10 heat exchanger, fully opens the indoor expansion valves 17, and controls the aperture
of the outdoor expansion valve 14.
Further, the control device 50 closes the two-way valves 61 and 63, and opens
the two-way valve 62. Thus, it is possible to prevent the first refrigerant being
delivered from the compressor 11 for air conditioning and having high temperature and
15 high pressure from flowing into the indoor heat exchangers 18.
Furthermore, the .control'device 50 controls the rotational speeds of the
compressor 11 for air conditioning, the compressor 31 for hot-water supply, and the
outdoor fan 13f. The indoor fans 18f are stopped by the control device 50 in the
hot-water-supply operation mode.
20 [0076]
The air-conditioning refrigerant circuit 10 in the hot-water-supply operation
mode is explained below. Since the operations of the hot-water-supply refrigerant
circuit 30 and the hot-water supply circuit 40 in the hot-water-supply operation mode
are similar to the operations in the hot-water-supply operation mode which are
25 explained before, explanations on the operations of the hot-water-supply refrigerant
circuit 30 and the hot-water supply circuit 40 in the hot-water-supply operation mode
according to the second embodiment are not presented.
The first refrigerant being delivered from the compressor 11 for air
conditioning and having high temperature and high pressure passes through the
30 two-way valve and the primary-side heat transfer pipe 15a in the inside heat exchanger
15, and flows into the primary-side heat transfer pipe 21a in the intermediate heat
exchanger 2 1, which funcFions as a condenser.
The first refrigerant flowing through the primary-side heat transfer pipe 21a
and having high temperature and high pressure exchanges heat with the heated fluid
35 flowing through the secondary-side heat transfer pipe 21b in the intermediate heat
exchanger 21, so that heat in the first refrigerant flowing through the primary-side heat
- r.P - --- n- - m:-- - K- E- - ~ ~- k- - ~ :-~ .~ -- F1-~ 7m - l 7 & T ~ g - - ~ . ~ , -- . .-. . -
transfer pipe 21a is d'issipated, and the above first refrigerant comes to have medium
temperature and high pressure.
[0077]
The first refrigerant which flows out of the primary-side heat transfer pipe 2 la
5 in the intermediate heat exchanger 21 and has medium temperature and high pressure
comes to have low temperature and low pressure by pressure reduction in the outdoor
expansion valve 14.
Subsequently, the first refrigerant having low temperature and low pressure
flows into the outdoor .heat exchanger 13, which functions as an evaporator. The first
10 ' refrigerant flowing through the outdoor heat exchanger 13 takes (absorbs) heat from
the air (outdoor air) sent by the outdoor fan 13f, by heat exchange with the air.
Thereafter, the first refrigerant having the absorbed heat returns from the outdoor heat
exchanger 13 through the four-way valve 12 and the accumulator 19 to the compressor
11 for air conditioning.
15 [0078]
Further, when the air-conditioninglhot-water supply system S1 is operated in
the other operation modes (including the cooling operation (normal) mode, the cooling
operation (exhaust heat) mode, the heating operation (normal) mode, and the heating
operation (exhaust heat) mode), the control device 50 fully opens the two-way valves
20 61 and 63, and completely closes the two-way valve 62.
Since the control operations in the above modes in the second embodiment are
similar to the operations in the first embodiment, explanations on the above cases.are
not presented.
[0079]
25
When the bypass pipe arrangement U and the two-way valves 61, 62, and 63
are arranged as illustrated in FIG. 10, the first refrigerant does not flow into the indoor
heat exchangers 18 during hot-water supply operation. Therefore, unnecessary heat
exchange does not occur in the indoor heat exchangers 18, so that the heat exchange
30 between the second refrigerant and the high-temperature first refrigerant can be further
efficiently performed in the intermediate heat exchanger 2 1.
[0080]
<>
Although the air-conditioninglhot-water supply system according to the
35 present invention is explained by the respective embodiments, the present invention is
not limited to the disclosed embodiments, and various modifications and the like can
- ~- -- -p - -- -Q - -- - g- - ~- -: - K- ~ ~ Q ~ r ~ c ~ 7 Q - r r ~ ~ - - ~ ~ 7 _ _ _ -z--- . _ _ -
be made.
For example, although the outdoor unit 1, the hot-water supply unit 3, and the
hot-water storage tank 4 in each of the embodiments are described as separate units,
the present invention is not limited to such arrangements. For example, the above units
5 may be integrated into a single heat pump unit.
[008 11
In addition, although the case in which the pressure of the first refrigerant is
reduced by the expansion valve 16 for the inside heat exchanger (the decompression
' device) is explained in each of the embodiments, for example, a capillary tube or the
10 like, instead of the expansion valve 16 for the inside heat exchanger, may be used.
Further, although the case in which the two .indoor units are arranged is
explained in each of the embodiments, the number of indoor units may be one, or three
or more. In the case where multiple indoor units are arranged, the multiple indoor units
are connected in parallel.
15 Furthermore, although, in the second embodiment, the two-way valves 61, 62,
and 63 are used as the "open-close means" for causing the first refrigerant flowing out
of the compressor 11 for air conditioning to flow into the primary-side heat transfer
pipe.15a in the inside heat exchanger 15 through the bypass pipe arrangement U, the
present invention. is not limited to such an arrangement: For example, one or more
20 three-way valves,. instead of the two-way valves, may be arranged for realizing the
"open-close means".
List of References
[0082]
25 S, S 1 : Air-conditioning1Hot-water Supply System
1 : Outdoor Unit
10: Air-conditioning Refrigerant Circuit
1 1 : Compressor for Air Conditioning
12: Four-way Valve
30 13: Outdoor Heat Exchanger (Air-conditioning Heat-source Side Heat Exchanger)
14: Outdoor Expansion Valve (First Expansion Valve)
15: Inside Heat Exchanger
16: Expansion Valve for Inside Heat Exchanger (Decompression device)
17a, 17b: Indoor Expansion Valves (Second Expansion Valve)
35 18a, 18b: Indoor Heat Exchangers (Air-conditioned Side Heat Exchanger)
19: Accumulator
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Claims
1. An air-conditioninglhot-water supply system comprising,
a refrigerant circuit for air conditioning in which a first
5 refrigerant circulates, and
a refrigerant circuit for hot-water supply in which a second
refrigerant circulates;
. . characterized in that
the refrigerant circuit for air conditioning includes a loop
10 circuit in which a compressor for air conditioning, a four-way valve, an
air-conditioning heat-source side heat exchanger, a first expansion valve, an
intermediate heat exchanger capable of exchanging heat between the first refrigerant
and the second refrigerant, an inside heat exchanger capable'of cooling the first
refrigerant, a second expansion valve, and an air-conditioned side heat exchanger are
15 connected in order;
' the inside heat exchanger includes,
a primary-side heat transfer pipe constituting a
portion of the loop circuit, and
a secondary-side heat transfer pipe connected to a
20 branch pipe arrangement which branches off from the loop circuit through a
decompression device; and
the decompression device cools the first refrigerant flowing
,through the primary-side heat transfer pipe, according to an operation mode, by
. causing pressure reduction of the first refrigerant flowing in from the branch pipe
25 arrangement and delivering the first refrigerant having reduced pressure toward the
secondary-side heat transfer pipe.
2. The air-conditioninglhot-water supply system according to claim 1,
further comprising a plurality of indoor units each including the second expansion
valve and the air-conditioned side heat exchanger, which is connected in series to the
30 second expansion valve, where the plurality of indoor units are connected in parallel.
3. The air-conditioninglhot-water supply system according to either of
claims 1 and 2, wherein the decompression device is an expansion valve or a capillary
tube.
4. The air-conditioninglhot-water supply system according to claim 3,
35 further comprising,
a bypass pipe arrangement which connects a pipe arrangement connecting the primary-side heat transfer pipe in the inside heat exchanger and the second expansion valve and a pipe arrangement arranged on a discharge side of the compressor for air conditioning, and an open-close means for causing the first refrigerant flowing out of the compressor for air conditioning to flow into the primary-side heat transfer pipe in the inside heat exchanger through the bypass pipe arrangement in a hot-water-supply operation mode.