U.S. patent application number 15/567020 was filed with the patent office on 2018-05-10 for compressor unit, heat source unit, and air conditioner.
This patent application is currently assigned to DAIKIN INDUSTRIES, LTD.. The applicant listed for this patent is DAIKIN EUROPE N.V., DAIKIN INDUSTRIES, LTD.. Invention is credited to Frans BAETENS, Pieter PIRMEZ, Jan VANOOTEGHEM.
Application Number | 20180128505 15/567020 |
Document ID | / |
Family ID | 52991530 |
Filed Date | 2018-05-10 |
United States Patent
Application |
20180128505 |
Kind Code |
A1 |
BAETENS; Frans ; et
al. |
May 10, 2018 |
COMPRESSOR UNIT, HEAT SOURCE UNIT, AND AIR CONDITIONER
Abstract
A compressor unit for an air conditioner includes a compressor
disposed in a first casing, and first and second heat source heat
exchanger unit ports configured to connect the compressor unit to a
heat source heat exchanger of a heat source heat exchanger unit of
the air conditioner, the heat source heat exchanger being disposed
in a second casing separate from the first casing and being
configured to exchange heat with a heat source, first and second
indoor unit ports configured to connect the compressor unit to an
indoor heat exchanger of at least one indoor unit of the air
conditioner, a first refrigerant piping fluidly connecting the
first heat source heat exchanger unit port and the first indoor
unit port, and a sub-cooling heat exchanger disposed inside the
first casing and fluidly connected to the first refrigerant piping
for heat transfer with the refrigerant to be flown through the
first refrigerant piping.
Inventors: |
BAETENS; Frans; (Oostende,
BE) ; PIRMEZ; Pieter; (Oostende, BE) ;
VANOOTEGHEM; Jan; (Oostende, BE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAIKIN INDUSTRIES, LTD.
DAIKIN EUROPE N.V. |
Osaka-shi, Osaka
Oostende |
|
JP
BE |
|
|
Assignee: |
DAIKIN INDUSTRIES, LTD.
Osaka-shi, Osaka
JP
DAIKIN EUROPE N.V.
Oostende
BE
|
Family ID: |
52991530 |
Appl. No.: |
15/567020 |
Filed: |
April 15, 2016 |
PCT Filed: |
April 15, 2016 |
PCT NO: |
PCT/JP2016/002045 |
371 Date: |
October 16, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 2500/12 20130101;
F25B 2400/13 20130101; F24F 1/14 20130101; F25B 2313/0253 20130101;
F24F 1/26 20130101; F25B 13/00 20130101; F25B 30/02 20130101; F25B
2313/0233 20130101; F24F 1/08 20130101 |
International
Class: |
F24F 1/08 20060101
F24F001/08; F24F 1/14 20060101 F24F001/14; F24F 1/26 20060101
F24F001/26; F25B 13/00 20060101 F25B013/00; F25B 30/02 20060101
F25B030/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 17, 2015 |
EP |
15164040.6 |
Claims
1. A compressor unit for an air conditioner comprising: a
compressor disposed in a first casing; and first and second heat
source heat exchanger unit ports configured to connect the
compressor unit to a heat source heat exchanger of at least one
heat source heat exchanger unit of the air conditioner, the heat
source heat exchanger being disposed in a second casing separate
from the first casing and being configured to exchange heat with a
heat source; first and second indoor unit ports configured to
connect the compressor unit to an indoor heat exchanger of at least
one indoor unit of the air conditioner; a first refrigerant piping
fluidly connecting the first heat source heat exchanger unit port
and the first indoor unit port; and a sub-cooling heat exchanger
disposed inside the first casing and fluidly connected to the first
refrigerant piping for heat transfer with the refrigerant to be
flown through the first refrigerant piping.
2. The compressor unit according to claim 1, further comprising: a
second refrigerant piping fluidly connecting the second heat source
heat exchanger unit port and the second indoor unit port, the
compressor and a 4-way valve being interposed between the second
heat source heat exchanger unit port and the second indoor unit
port in the second refrigerant piping; and a bypass passage
connected to the second refrigerant piping at a suction side of the
compressor between the compressor and the 4-way valve, the
sub-cooling heat exchanger being fluidly connected to the bypass
passage for heat transfer between refrigerant flowing in the bypass
passage and refrigerant flowing in the first refrigerant
piping.
3. The compressor unit according to claim 1, wherein the compressor
unit does not comprise a main expansion valve of the air
conditioner.
4. The compressor unit according to claim 1, further comprising an
oil separator located at a discharge side of the compressor between
the compressor and a 4-way valve.
5. A heat source unit for an air conditioner, comprising: a
compressor unit according to claim 1; and a heat source heat
exchanger unit having a heat source heat exchanger, the heat source
heat exchanger being disposed in a second casing separate from the
first casing and being configured to exchange heat with a heat
source, wherein the heat source heat exchanger unit is fluidly
connected to the compressor unit via the first and second heat
source heat exchanger unit ports.
6. The heat source unit according to claim 5, wherein a main
expansion valve of the air conditioner is disposed in the second
casing.
7. An air conditioner having a heat source unit according to claim
5, wherein at least one indoor unit is fluidly connected to the
compressor unit via the first and second indoor unit ports.
8. The compressor unit according to claim 2, wherein the compressor
unit does not comprise a main expansion valve of the air
conditioner.
9. The compressor unit according to claim 2, further comprising an
oil separator located at a discharge side of the compressor between
the compressor and a 4-way valve.
10. The compressor unit according to claim 3, further comprising an
oil separator located at a discharge side of the compressor between
the compressor and a 4-way valve.
11. A heat source unit for an air conditioner, comprising: a
compressor unit according to claim 2; and a heat source heat
exchanger unit having a heat source heat exchanger, the heat source
heat exchanger being disposed in a second casing separate from the
first casing and being configured to exchange heat with a heat
source, wherein the heat source heat exchanger unit is fluidly
connected to the compressor unit via the first and second heat
source heat exchanger unit ports.
12. A heat source unit for an air conditioner, comprising: a
compressor unit according to claim 3; and a heat source heat
exchanger unit having a heat source heat exchanger, the heat source
heat exchanger being disposed in a second casing separate from the
first casing and being configured to exchange heat with a heat
source, wherein the heat source heat exchanger unit is fluidly
connected to the compressor unit via the first and second heat
source heat exchanger unit ports.
13. A heat source unit for an air conditioner, comprising: a
compressor unit according to claim 4; and a heat source heat
exchanger unit having a heat source heat exchanger, the heat source
heat exchanger being disposed in a second casing separate from the
first casing and being configured to exchange heat with a heat
source, wherein the heat source heat exchanger unit is fluidly
connected to the compressor unit via the first and second heat
source heat exchanger unit ports.
14. The heat source unit according to claim 11, wherein a main
expansion valve of the air conditioner is disposed in the second
casing.
15. The heat source unit according to claim 12, wherein a main
expansion valve of the air conditioner is disposed in the second
casing.
16. The heat source unit according to claim 13, wherein a main
expansion valve of the air conditioner is disposed in the second
casing.
17. An air conditioner having a heat source unit according to claim
11, wherein at least one indoor unit is fluidly connected to the
compressor unit via the first and second indoor unit ports.
18. An air conditioner having a heat source unit according to claim
12, wherein at least one indoor unit is fluidly connected to the
compressor unit via the first and second indoor unit ports.
19. An air conditioner having a heat source unit according to claim
13, wherein at least one indoor unit is fluidly connected to the
compressor unit via the first and second indoor unit ports.
20. An air conditioner having a heat source unit according to claim
6, wherein at least one indoor unit is fluidly connected to the
compressor unit via the first and second indoor unit ports.
Description
TECHNICAL FIELD
[0001] The present invention relates to air conditioners and
particularly air conditioners using outside air or circulating
water as heat source. Such air-conditioners may as well be called
heat pumps. Further, the air-conditioners may be used for cooling
and/or heating of a space to be conditioned. More particularly, the
present invention relates to a compressor unit for such an air
conditioner and a heat source unit of such an air conditioner.
BACKGROUND ART
[0002] Generally speaking, air-conditioners consist of one or more
outdoor units and one or more indoor units connected via a
refrigerant piping. The outdoor and indoor units each comprise a
heat exchanger for, on the one hand, exchanging heat with the heat
source and, on the other hand, exchanging heat with the space to be
conditioned. Outdoor units of air-conditioners are in most cases
installed outside a building for example on the roof or at the
facade. This, however, has under certain circumstances being
perceived disadvantageous from an aesthetical point of view.
Therefore, EP 2 108 897 A1 suggested to integrate the outdoor unit
into a ceiling of the building so as to be hidden therein and not
to be noticeable from the outside of the building.
[0003] Yet, the outdoor unit suggested in this document has certain
disadvantages. One negative aspect is that the outdoor unit
produces noises which may be perceived disturbing by individuals
inside the building. A second negative aspect is installation and
maintenance, because the outdoor unit is relatively heavy and
because of its construction requires a relatively large
installation space with respect to its height.
CITATION LIST
Patent Literature
[0004] PTL 1: EP 2 108 897 A1
SUMMARY OF INVENTION
Technical Problem
[0005] To overcome these drawbacks, the applicant of the present
application has considered splitting the heat source unit into a
compressor unit and a heat source heat exchanger unit. Further,
some appliances require the integration of a sub-cooling section
into the refrigerant circuit to increase efficiency. Yet, the
integration of a sub-cooling section into a splitted heat source
unit may require more piping between the heat source heat exchanger
unit and the compressor unit as well as the indoor unit leading to
a more complicated installation and higher installation costs. In
addition, more piping through which gaseous refrigerant flows is
required. Such piping is more expensive due to a larger required
diameter and hence more material. Moreover, more time is necessary
for installation. Finally, a loss of effect may be recognized if
the piping for gaseous refrigerant between the compressor unit and
the heat source heat exchanger unit becomes too long. The above
disadvantages have been recognized when disposing the sub-cooling
heat exchanger close to the heat source heat exchanger, i.e. in the
heat source heat exchanger unit.
Solution to Problem
[0006] Accordingly, one object the present invention intends to
solve is to provide a compressor unit, preferably as part of the
above-described heat source unit, as well as a heat source unit
having such a compressor unit, which are capable of reducing the
piping and particularly the piping for gaseous refrigerant for
connecting the several units to a minimum even if a sub-cooling
section is integrated, thereby ensuring ease of installation and
lower installation costs.
[0007] This object is solved by a compressor unit according to
claim 1 or a heat source unit according to claim 5. Embodiments of
the invention are named in the dependent claims, the following
description and the accompanying drawings.
[0008] According to one aspect, a compressor unit for an air
conditioner is suggested. The air-conditioner is configured to
condition a space such as a room inside the building, be it heating
or cooling. The compressor unit comprises a compressor disposed in
a first casing. Accordingly, the first casing is accommodating the
compressor and preferably encapsulating the compressor.
Additionally, a sound insulation may be provided at the inside or
outside of the casing to avoid noises produced by the compressor
from being transferred to the environment in which the compressor
unit is installed. Further, a first and second heat source ports
are provided and preferably accessible from the outside of the
casing for ease of connection. The first and second heat source
ports are configured to connect the compressor to a heat source
heat exchanger of a heat source unit of the air conditioner by
means of a refrigerant piping. The first and second heat source
ports may be of any kind capable of connecting a refrigerant piping
to the compressor such as a pipe open at one end and having an
outer thread at the end. Yet, also so-called self-sealing
connectors or quick fasteners may be used. In most cases it will
however due to regulations be required to use flairs or braised
connections. The heat source heat exchanger is disposed in a second
casing separate from the first casing and configured to exchange
heat with a heat source. "Separate" in this context means that the
casings represent separate assemblies or units and should not
encompass that one casing is disposed within the other casing. In a
particular embodiment, the heat source heat exchanger unit uses
outside air (i.e. air outside the building) as heat source. For
this purpose, it is preferred that the second casing has a first
connection at one side of the heat exchanger and a second
connection at an opposite side of the heat exchanger. The first and
second connections are preferably connected to ducting fluidly
communicated with the outside of the building so that outside air
may pass the first heat exchanger. Moreover, the compressor unit
comprises a first and second indoor unit ports configured to
connect the compressor to an indoor heat exchanger of at least one
indoor unit of the air conditioner by refrigerant piping. The first
and second indoor unit ports may be of the same or different kind
as the first and second heat source ports. Further, the compressor
unit comprises a first refrigerant piping preferably disposed
within the first casing. The first refrigerant piping fluidly
connects the first heat source port and the first indoor unit port.
Accordingly, the first heat source port and the first indoor unit
port are used to fluidly connect the heat source heat exchanger
unit to one or more indoor units using refrigerant piping. Even
though the connection between the heat source heat exchanger unit
and the indoor unit/-s could be made to direct, one aspect suggests
to connect these units via the compressor unit so that part of the
refrigerant piping connecting these units passes through the first
casing of the compressor unit. Furthermore, a sub-cooling heat
exchanger is disposed inside the first casing and fluidly connected
to the first refrigerant piping for sub-cooling refrigerant to be
flown through the first refrigerant piping. Because the first
refrigerant piping is passing through the first casing, the
sub-cooling heat exchanger may be integrated into the air
conditioner without an additional gaseous refrigerant piping being
necessary to connect the compressor unit and the heat source heat
exchanger unit and particularly the heat source heat exchanger and
the suction side of the compressor passing the sub-cooling heat
exchanger. This additional long gaseous refrigerant piping is
integrated into the compressor unit and therefore much shorter so
that less material is required and less installation time
necessary. Therefore, ease of installation is obtained and the
installation costs are reduced.
[0009] According to an embodiment the compressor unit further
comprises a second refrigerant piping. The second refrigerant
piping fluidly communicates or connects the second heat source port
and the second indoor unit port. The compressor and preferably a
4-way valve are interposed between the second heat source port and
the second indoor unit port or more particular in the second
refrigerant piping connecting these ports. An accumulator may be
included on the suction side of the compressor. Moreover, a bypass
passage is connected to the second refrigerant piping at the
suction side of the compressor between the compressor and the 4-way
valve and the sub-cooling heat exchanger is fluidly connected to
the bypass passage for heat transfer between the refrigerant
flowing in the bypass line and refrigerant flowing through the
first refrigerant piping. Hence, all piping relating to the
sub-cooling unit is a contained in the first casing so that in one
embodiment only four ports are required in the compressor unit. To
connect the compressor unit, the heat source heat exchanger unit
and one indoor unit. In particular, an additional route between the
heat source heat exchanger unit and the indoor unit can be avoided
by placing the sub-cooling heat exchanger in the compressor unit
and looping the refrigerant piping connecting the heat source heat
exchanger module to the indoor unit through the compressor unit. An
additional advantage of disposing the sub-cooling heat exchanger in
the compressor module is that a large diameter pipe usually
required to flow the gaseous refrigerant can be avoided.
[0010] According to an aspect, the compressor unit does not
comprise a main expansion valve of the air conditioner. The "main
expansion valve" of an air conditioner is defined as that expansion
valve through which the entire amount of refrigerant in the
refrigerant circuit passes during cooling.
[0011] In heating the main expansion valve defines the superheat
after the heat source heat exchanger. In cooling the main expansion
valve is always fully opened to avoid a high pressure drop. In
cooling the entire amount of refrigerant passes the main expansion
valve. In heating, the amount of refrigerant is separated between
the flow through the sub-cooling heat exchanger and the heat source
heat exchanger.
[0012] In heating operation, a relatively large pressure drop
exists because of a relatively long refrigerant piping connecting
the sub-cooling heat exchanger to the heat source heat exchanger.
Because the main expansion valve is not disposed in the compressor
unit, a refrigerant pressure drop between the compressor unit and
the heat source heat exchanger unit can be can be compensated and
two phase flow noise is reduced.
[0013] According to an embodiment, the compressor unit may comprise
an oil separator located at the discharge side of the compressor
between the compressor and a (the) 4-way valve.
[0014] According to another aspect a heat source unit for an air
conditioner is suggested which comprises the above-described
compressor unit and a heat source heat exchanger unit. The heat
source heat exchanger unit has a heat source heat exchanger
disposed in the second casing separate from the first casing as
described above. The heat source heat exchanger is configured to
exchange heat with a heat source particularly outside air and is
fluidly connected or communicated to the compressor unit via the
first and second heat source port. In this context, and because of
the connection of the first heat source port and the first indoor
unit port by the first refrigerant piping the connection of the
heat source heat exchanger unit and the indoor unit is looped
through the compressor unit (first casing). Thereby, it is possible
to integrate the sub-cooling unit into the compressor unit without
an additional piping required to connect the compressor unit with
the heat source heat exchanger unit.
[0015] As described previously, the main expansion valve of the air
conditioner is disposed in the second casing, i.e. in the heat
source heat exchanger unit. Accordingly, the pressure drop between
the compressor unit and the heat source heat exchanger unit is kept
as low as possible and two phase flow noises can be avoided.
[0016] As previously indicated, one or more indoor units can be
fluidly connected or communicated to the compressor unit via the
first and second indoor unit port. This context, the first indoor
unit port serves for the connection of the indoor unit and
particularly an indoor heat exchanger to the heat source heat
exchanger unit and particularly the heat source heat exchanger. The
second indoor unit port serves to connect the indoor unit and
particularly the indoor heat exchanger to the second refrigerant
piping and, hence, the compressor. If more than one indoor unit is
provided, the indoor units can be connected in parallel.
[0017] Further features and effects of the heat source unit may be
obtained from the following description of embodiments. In the
description of these embodiments reference is made to the
accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1 shows a schematic circuit diagram of an air
conditioner,
[0019] FIG. 2 a schematic sketch of the air conditioner shown in
FIG. 1 installed in a building,
[0020] FIG. 3 shows a perspective view of a heat source heat
exchanger unit,
[0021] FIG. 4 shows a perspective view of a compressor unit,
[0022] FIG. 5 shows a longitudinal section of the heat source heat
exchanger unit of FIG. 3, and
[0023] FIG. 6 shows a schematic circuit diagram of an air
conditioner according to a variation of the configuration shown in
FIG. 1.
DESCRIPTION OF EMBODIMENTS
[0024] FIG. 1 shows the circuit diagram of an air conditioner. The
air-conditioner has a heat source unit 30 comprising a heat source
heat exchanger unit 31 and a compressor unit 32.
[0025] The heat source heat exchanger unit 31 comprises a heat
exchanger 5 which consists of an upper heat exchanger element 6 and
a lower heat exchanger element 7 which are positioned relative to
each other to form the shape of a "V" in a side view or cross
sectional view (see FIG. 5). The heat source heat exchanger unit 31
further comprises the main expansion valve 33 of the refrigerant
circuit. As becomes apparent from FIG. 1, the entire amount of
refrigerant contained in the circuit also passes the main expansion
valve 33 during cooling. In other words, the entire amount of
refrigerant delivered or supplied from the compressor 37 flows
through the main expansion valve 33 during cooling.
[0026] The heat source heat exchanger unit is also shown in more
detail in FIGS. 3 and 5.
[0027] FIGS. 3 and 5 show a heat source heat exchanger unit 31
which may be part of the heat source unit 30.
[0028] The heat source heat exchanger unit 31 comprises a casing 2
(second casing) being configured for connection to an outside air
duct of an air conditioner. In particular, the heat source heat
exchanger unit is configured as an "outdoor" unit of an air
conditioner which is, however, disposed inside particularly within
the ceiling of a building. Hence, a first connection 3 is provided
at the casing 2 for connection to an air duct communicating the
heat source heat exchanger unit 31 with the outside of the building
and so as to enable taking of outdoor air into the casing 2. A
connection 4 (See FIG. 5), provided for the connection of the heat
source heat exchanger unit 31 to the air duct again leading to the
outside of the building and to enable exhausting of air having
passed the heat exchanger 5 to the outside, is disposed at the
opposite end of the casing 2.
[0029] The casing 2 is substantially rectangular and flat, meaning
that the height H is a smaller than the width W and the length L.
In one embodiment the height H is not more than 50 cm, preferably
not more than 45 cm, more preferred not more than 40 cm and most
preferred not more than 35 cm.
[0030] The heat source heat exchanger unit 31 further comprises a
heat exchanger 5 (heat source heat exchanger) which is also visible
in FIG. 3. However, the configuration of the heat exchanger 5 can
be best seen from FIG. 5. FIG. 5 also represents a side view of the
heat exchanger 5 in the sense of the present application.
[0031] The heat exchanger 5 comprises an upper heat exchanger
element 6 and a lower heat exchanger element 7. Both, the upper and
lower heat exchanger elements 6, 7 are flat or planar shaped and
are positioned with an angle .alpha. enclosed between them. As best
visible from FIG. 1, the upper and lower heat exchanger elements 6,
7 are fluidly connected in parallel to the refrigerant piping.
Hence the heat exchanger 5 has a V-shape wherein the "V" is
oriented horizontally. A line CL passing the apex 8 of the "V" is
oriented horizontally, that is along the length L extension of the
heat source heat exchanger unit 31. The line CL is also the
centerline of the heat exchanger 5 or to put it differently a line
of symmetry as regards the heat exchanger elements 6, 7.
[0032] The heat exchanger 5 is arranged within the air duct formed
by the casing 2 so that all air sucked in through the opening at
the connection 3 has a to flow through the heat exchanger 5 without
any air bypassing the heat exchanger 5 at the top or the bottom or
the sides of the heat exchanger 5 in the width direction W.
[0033] The upper and lower heat exchanger elements 6, 7 are
connected to each other at the apex 8 by a connecting element 9.
The connecting element is impermeable to air and also used to
mechanically or physically connect the upper and lower heat
exchanger elements 6, 7. Each of the heat exchanger elements 6, 7
comprises heat exchanger coils 10 (loops of tubing) and fins 11
disposed there between. The heat exchanger of the present
embodiment is applied for outdoor applications, i.e. as part of the
heat source unit of an air conditioner. In this case, the fins of
the upper and lower heat exchanger element 6, 7 are preferably
waffled fins. Even though louvered fins are preferably used for a
good air flow through the heat exchanger as several holes are
provided to allow the air to flow through the fins, condensation
water may accumulate in these holes and may lead to problems
regarding the formation of frost during heating operation, when the
ambient temperature is lower than about 7 degrees Celsius. To
prevent these problems it is in these cases preferred to use
waffled fins.
[0034] Two backward curved centrifugal fans 20 are provided inside
the casing. These backward curved centrifugal fans 20 each have a
suction opening 21. In the side view (FIG. 5), the center axis of
the suction opening 21 and hence the fans 20 is substantially
congruent or aligned with the center line CL of the heat exchanger
5. In some appliances, it may however be sufficient as in the
depicted embodiment that the center axis of the suction opening 21
and the centerline CL of the heat exchanger 5 are parallel but
displaced relative to each other in a horizontal direction.
[0035] In use, the fans 20 create a suction force at the suction
opening 21 so as to induce a fluid flow (airflow) in the direction
F. Thus air, particularly outside air is drawn in through the
connection 3 toward the open end 12 of the heat exchanger 5, passes
through the upper and lower heat exchanger elements 6, 7 and is
sucked through the suction opening 21 to be flown out through the
connection 4. As such the casing 2 defines a duct from the
connection 3 via the heat exchanger 5 and the fan 20 to the
connection 4. In this context, the connection 3 and the connection
4 define an inlet opening 13 and an outlet opening 14.
[0036] Furthermore, a drain pan 15 is provided within the casing.
The drain pan 15 is separated into two halves 16, 17 along the
length L of the casing 2 in the side view. In FIG. 5, the two
halves 16, 17 are identified by the dotted line with one half being
located on the left side and one half being located on the right
side of the dotted line. The drain pan 15 has a lowest position 18
at which a drain opening 19 is provided. The bottom of the drain
pan 15 slants toward the drain opening 19 and hence the lowest
position 18. Thus water dropping from any component into the drain
pan is directly guided to the drain opening 19 and the lowest
position 18 which is furthest away from the fan 20. Thereby it is
prevented that water accumulated within the drain pan may be sucked
into the fan 20 and hence through the opening 14 into the duct. The
drain opening 19 is directly connected to drainage so that water is
directly drained.
[0037] Moreover, a sound and/or thermal insulation 22 are provided
within the casing 2 at the side opposite to the drain pan 15 with
respect to the line CL. In the cross section and hence a side view
(FIG. 5), the inner surfaces of the drain pan 15 and the insulation
22 respectively directed to the heat exchanger 15 should be
approximated so that the duct created within the casing 2 is as
symmetric as possible.
[0038] Further, the distance between the apex 8 and the entry of
the suction opening 21 should be as short as possible to reduce the
length. In particular, the high velocity zone of the fans should in
the side view not overlap with the heat exchanger 5 and/or the
drain pan 15.
[0039] At a side of the casing 2, one can see a first and second
refrigerant piping connection 34 and 35 for connecting the heat
source heat exchanger unit 31 to the refrigerant piping of the
refrigerant circuit. In addition a connection port 36 for
connecting the drain opening 19 to drainage (not shown) extends
from the same side surface of the casing 2 as the refrigerant
piping connections 34 and 35.
[0040] The casing 2 is completely closed relative to the
environment except for the connections 3 and 4 as well as the
refrigerant piping connections 34 and 35 and the connection 36 to
the drainage. Accordingly and as can be seen from FIG. 5 the casing
may be sound insulated and thereby encapsuled to prevent any noises
for example from the fans from being transferred to the space to be
conditioned. In addition and because the compressor 37 is not
disposed in the casing 2 but the compressor unit 32 as described
below, no noise of the compressor is induced and transferred via
the air flowing through the heat source heat exchanger unit 31 and
in the air duct connected to the outside of the building.
[0041] The compressor unit 32 has a casing 44 (First casing)
wherein in FIG. 4 a front wall of the casing 44 and a corresponding
sound insulation have been removed to partly show the interior of
the casing 44. A compressor 37 (see FIG. 1) is disposed in the
casing 44. Furthermore, all other components of the compressor unit
described below and if present will be disposed in the casing 44 as
well. In addition, the compressor unit may comprise an optional
accumulator 38 and a 4-way valve 39.
[0042] In addition, the compressor unit 32 comprises a sub-cooling
heat exchanger 40 and a sub-cooling expansion valve 41. The
sub-cooling heat exchanger is a tube heat exchanger.
[0043] The compressor unit 32 further comprises first and second
refrigerant piping connections 42 and 43 (first and second heat
source heat exchanger unit ports) as shown in FIG. 4.
[0044] A stop the valve 45 (two stop valves, one for each
connection 42, 43) may be provided close to the first and second
refrigerant piping connections 42 and 43, respectively.
[0045] Further a third and fourth refrigerant piping connection 46
and 47 (first and second indoor unit ports) are provided for
connection of one or more indoor units 50 (one in the present
embodiment) disposed in fluid communication with the space to be
conditioned. A stop valve 48 (two stop valves, one for each
connection 46, 47) is also provided close to the refrigerant piping
connections 46 and 47, respectively.
[0046] Ports 42, 43 and 46, 47 are all disposed close to the front
of the compressor unit to improve serviceability. In particular, if
the front wall of the casing 44 and the corresponding insulation is
removed as in FIG. 4, the ports are easily accessible.
[0047] Moreover, a refrigerant piping 80 (second refrigerant
piping) connects the refrigerant piping connection 42 and the
refrigerant piping connection 47 with the 4 way valve 39, the
compressor 37, the accumulator 38, the connection 81 to the
refrigerant piping 57, the connection 82 to the refrigerant piping
52 and the 4-way valve 39 being interposed in this order.
[0048] The aforesaid components are disposed in the following order
from the refrigerant piping connection 47 to the refrigerant piping
connection 42 considering cooling operation (solid arrows in FIG.
1): the 4-way valve 39, the accumulator 38, the compressor 37, the
4-way valve 39 and the refrigerant piping connection 42. The
aforesaid components are disposed in the following order from the
refrigerant piping connection 42 to the refrigerant piping
connection 47 considering heating operation (broken arrows in FIG.
1): the 4-way valve 39, the accumulator 38, the compressor 37, the
4-way valve 39 and the refrigerant piping connection 47.
[0049] Furthermore, a refrigerant piping 49 connects the first
refrigerant piping connection 43 and the third refrigerant piping
connection 46. The sub-cooling heat exchanger 40 is configured to
exchange heat between the refrigerant flowing in the refrigerant
piping 49 and the refrigerant flowing in the refrigerant piping 52.
A sub-cooling expansion valve 41 is disposed in the refrigerant
piping 52 between the sub-cooling heat exchanger and the
refrigerant piping connection 43. To put it differently, the
sub-cooling expansion valve 41 is disposed between the connection
of the refrigerant piping 52 with the refrigerant piping 49 and the
sub-cooling heat exchanger 40. In any case and during heating and
cooling operation, the sub-cooling expansion valve 41 is disposed
upstream of the sub-cooling heat exchanger 40 in the refrigerant
piping 52.
[0050] A refrigerant piping 51 connects the accumulator 38 and the
4-way valve 39. Even further, a refrigerant piping 52 (gaseous
refrigerant piping) connects at one end to the refrigerant piping
49 and at the other end to the refrigerant piping 51. Further, a
refrigerant piping 57 connects the refrigerant piping 49 and the
refrigerant piping 51 with a pressure regulating valve 58 being
integrated into the refrigerant piping 57 at an intermediate
position.
[0051] The casing 44 of the compressor unit 32 may be sound
insulated so that noise produced by the compressor 37 can be
prevented from exiting the casing and disturbing individuals inside
the building. Further, the casing 44 can because of its compact
size be disposed on the floor for easy installation and maintenance
and even below a cupboard of a kitchen or other technical equipment
rooms. The casing 44 may additionally comprise feet 59 as shown in
FIG. 4 for placing and fixing the casing 44 on a horizontal
supporting surface. The size of the casing 44 particularly relating
to its height, widths and depth complies with DIN EN 1116 for
kitchen furniture and kitchen appliances.
[0052] An example of an indoor unit 50 comprises an indoor heat
exchanger 53 (second heat exchanger) connected respectively via
third and fourth refrigerant piping connections 54 and 55 and a
refrigerant piping to the third and fourth refrigerant connections
46 and 47 of the compressor unit 32. Optionally, the indoor unit 50
may comprise an indoor expansion valve 56 disposed between the
indoor heat exchanger 53 and the third refrigerant piping
connection 54. The indoor unit 50 may in principle be configured as
a common indoor units used in such air-conditioners.
[0053] As can be best seen from FIG. 2, the air conditioner may be
installed in a building 70. In one possible embodiment, the heat
source heat exchanger unit 31 can be disposed in the ceiling 71 of
a space 72 to be conditioned and being hidden within the ceiling
71. The connections 3 and 4 are preferably connected to an air duct
73 so that the casing 2 of the heat source heat exchanger unit 31
forms part of the air duct 73. The end of the air duct 73 opens at
both ends 74 and 75 to the outside of the building so that outside
air may be sucked in through the end 74 passes the heat exchanger 5
of the heat source heat exchanger unit 31 and is exhausted through
the end 75.
[0054] The heat source heat exchanger unit 31 is connected by
refrigerant piping 76 to the compressor unit 32 using the
refrigerant piping connections 34 and 35 as well as 43 and 42,
respectively. The compressor unit 32 again is connected to the
indoor unit/-s 50 via refrigerant piping 77 using the third to
fourth refrigerant piping connections 46, 47 and 54, 55
respectively.
[0055] The operation of the air conditioner described above is as
follows. During cooling operation (solid arrows in FIG. 1),
refrigerant flows into the compressor unit 32 at the refrigerant
piping connection 47 passes the 4-way valve 39 and is introduced
into the accumulator 38. When passing the accumulator associate
liquid refrigerant is separated from the gaseous refrigerant and
liquid refrigerant is temporarily stored in the accumulator 38.
[0056] Subsequently, the gaseous refrigerant is introduced into the
compressor 37 and compressed. The compressed refrigerant is
introduced into the heat source heat exchanger unit 31 via the
first refrigerant piping connections 42, 35 and a refrigerant
piping 71. The refrigerant passes the heat exchanger 5 with its
plates 6, 7 of the heat source heat exchanger unit 31, whereby the
refrigerant is condensed (the heat exchanger 5 functions as a
condenser). Hence, heat is transferred to the outside air parallely
passing through the heat exchanger elements 6, 7 of the heat
exchanger 5. The expansion valve 33 is entirely opened to avoid
high pressure drops during cooling. Then, the refrigerant flows
into the compressor unit 32 via the third refrigerant piping
connections 34, 43 and refrigerant piping. In the compressor unit
32, the refrigerant flows in part through the refrigerant piping 52
and, hence, the sub-cooling expansion valve 41 and the sub-cooling
heat exchanger 40 and in part through the refrigerant piping 49
being introduced via the third refrigerant piping connection 46, a
refrigerant piping and the third refrigerant connection 54 into the
indoor unit 50. The refrigerant is then further expanded by the
indoor expansion valve 56 and evaporated in the heat exchanger 53
(the heat exchanger 53 functions as evaporator) cooling the space
72 to be conditioned. Accordingly, the heat is transferred from air
in the space to be conditioned to the refrigerant flowing through
the heat exchanger 53. In cooling the main purpose of the
sub-cooling heat exchanger 40 is to sub-cool the liquid refrigerant
flowing through the refrigerant piping 49 to the indoor unit 50.
Finally, the refrigerant is again introduced via the fourth
refrigerant piping connections 55, 47 and refrigerant piping into
the compressor unit 32.
[0057] As is generally known, the capacity of an air conditioner at
the indoor side is the multiplication of enthalpy and mass flow.
Hence a reduced mass flow may be used when the enthalpy is
increased. The sub-cooling heat exchanger serves to increase
enthalpy at the indoor side. As a consequence, the mass flow can be
reduced without impairing capacity. As a result the pressure drop
in the liquid pipe can be reduced so that the compressor 37 needs
to deliver less work improving the entire system efficiency.
[0058] During heating, this circuit is reversed wherein heating is
shown by the broken arrows in FIG. 1. The process is in principle
the same. Yet, the first heat exchanger 5 functions as evaporator
whereas the second heat exchanger 53 functions as condenser during
heating. In particular, refrigerant is introduced into the
compressor unit 32 via the first refrigerant piping connection 42,
flows via the 4-way valve 39 into the accumulator 38 and is then
compressed in the compressor 37 before flowing into the 4-way valve
39 and through the fourth refrigerant piping connections 47, 55 and
refrigerant piping into the indoor unit 50 and particularly the
indoor heat exchanger 53 where the refrigerant is condensed (the
indoor heat exchanger 53 functions as a condenser). Subsequently,
the refrigerant is expanded by the expansion valve 56 and then
reintroduced via the third refrigerant piping interconnections 54,
46 into the compressor unit 32 where the refrigerant flows into the
piping 49 and passes the sub-cooling heat exchanger 40.
[0059] By refrigerant injection after the evaporator, the suction
superheat before the compressor can be optimized. As a result, the
discharge temperature can be reduced with the beneficial effect of
better efficiency of the system and prolonged lifetime. In heating,
the sub-cooling heat exchanger 40 serves to improve the refrigerant
quality at the compressor inlet via the refrigerant piping 52
connected to the refrigerant piping 51 upstream of the compressor
37, that is on the suction side of thereof. Further, the
sub-cooling heat exchanger 40 serves to evaporate the two phase
refrigerant in the refrigerant piping 49 as desired.
[0060] Subsequently, part of the refrigerant flows into the
refrigerant piping 52, is expanded in the sub-cooling expansion
valve 41 and flows through the sub-cooling heat exchanger 40 before
being reintroduced into the refrigerant piping 51 upstream of the
accumulator 38 thereby pre-cooling the refrigerant flowing through
the refrigerant piping 49 passing the sub-cooling heat exchanger
40. The remaining part flows into the heat source heat exchanger
unit 31 via the second refrigerant piping connections 43 and 34 and
refrigerant piping. The refrigerant is further expanded by the main
expansion valve 33 in the heat source heat exchanger unit 31 and
then evaporated in the heat exchanger 5 (the heat exchanger 5
functions as evaporator) before being reintroduced into the
compressor unit 32 via the first refrigerant piping connections 35
and 42 and refrigerant piping.
[0061] Because of the splitting of the compressor unit 32 and the
heat source heat exchanger unit 31, the compressor unit 32 may be
installed in areas that are not noise sensitive so that there is no
noise disturbance caused by the compressor even though disposed
indoors. In addition the casing 44 of the compressor unit 32 may be
well insulated with sound insulation. Even further, there is no
compressor noise in the air flowing through the heat source heat
exchanger unit 31 due to the split concept between the heat source
heat exchanger unit 31 and the compressor unit 32 which could be
transferred into the space to be conditioned.
[0062] Because of the lower weight per unit of the heat source heat
exchanger unit 31 and the compressor unit 32, the installation is
improved. In addition, the compressor unit 32 may be installed on
the floor so that there is no need to lift the heavy compressor
unit. Because of a relatively small footprint (width and depth) of
the compressor unit 32 and a lower height of the compressor unit 32
and particularly its casing 44, the compressor unit 32 may even be
hidden when disposed inside the room to be conditioned such as
below a cupboard or counter-board.
[0063] The heat source heat exchanger unit 31 has also the
advantage that there is no noise disturbance. Because the
compressor is not contained in the heat source heat exchanger unit
31 the only sound that can be entrained in the airstream is the
noise of the fan whereby the noise in the airstream is drastically
reduced. Further, the casing 2 can be entirely closed to the space
72 to be conditioned so that no sounds are transferred into the
space. Also this casing may be well insulated with sound
insulation. Because of the lower height of the heat source heat
exchanger unit 31, it is easy to hide the unit for example in the
ceiling. Therefore, the unit 31 is not visible from the outside.
The installation is also improved because of the lower weight as
compared to units having the compressor in the same casing and
because of the lower height of the heat source heat exchanger unit
31. The lower height is particularly assisted by using the "V"
shape of the heat exchanger 5, which enables high-efficiency with a
relatively low height.
[0064] Because of the integration of the sub-cooling unit
particularly the sub-cooling heat exchanger into the compressor
unit rather than the heat source heat exchanger unit, one long
gaseous refrigerant piping connecting the heat source heat
exchanger with the suction side of the compressor can be
substituted by a shorter line 52 contained in the compressor unit.
Hence, a large diameter pipe usually required to flow the gaseous
refrigerant can be shortened. In other words, an additional route
between the heat source heat exchanger unit and the indoor unit can
be avoided by placing the sub-cooling heat exchanger in the
compressor unit and looping the refrigerant piping connecting the
heat source heat exchanger module to the indoor unit through the
compressor unit.
[0065] If the sub-cooling heat exchanger was disposed in the heat
source heat exchanger module and the fluid connection between the
units 31 and 50 would not be looped through the casing 44 of the
compressor unit 32, but directly connected, a third heat source
heat exchanger port was necessary at the compressor unit 32 with an
additional line connecting the compressor unit 32 and the heat
source heat exchanger unit 31 to implement the line 52. The present
embodiment is hence improved as compared to this case with a
consequence of easier installation and lower installation
costs.
[0066] Moreover, because the main expansion valve 33 is disposed in
the heat source heat exchanger unit 31, the refrigerant pressure
drop caused by a relatively long refrigerant piping between the
compressor unit 32 and the heat source heat exchanger unit 31 can
be compensated and two phase flow noise can be reduced to at least
some extent.
[0067] FIG. 6 shows the circuit diagram of an air conditioner
according to a variation of the configuration shown in FIG. 1. The
difference between the configurations in FIG. 1 and FIG. 6 is the
use of a heat source heat exchanger module 31' that is configured
to utilize water heat source.
[0068] The air-conditioner according to this variation has a heat
source unit 30 comprising a heat source heat exchanger unit 31', a
cooling tower 90, and a compressor unit 32. The heat source heat
exchanger unit 31' operates in cooperation with the cooling tower
90 in order to serve as a water heat source.
[0069] During cooling operation (solid arrows in FIG. 8), the
gaseous refrigerant is introduced into the compressor 37 and
compressed. The compressed refrigerant is introduced into the heat
source heat exchanger unit 31' via the first refrigerant piping
connections 42, 35 and a refrigerant piping 76. The refrigerant
passes the refrigerant circuit portion of the water-refrigerant
heat exchanger 5' of the heat source heat exchanger unit 31',
whereby the refrigerant is condensed (the water-refrigerant heat
exchanger 5' functions as a condenser). Hence, heat is transferred
to the water passing through the water circuit portion of the
water-refrigerant heat exchanger 5'. The expansion valve 33 is
entirely opened to avoid high pressure drops during cooling. Then,
the refrigerant flows into the compressor unit 32 via the third
refrigerant piping connections 34, 43 and refrigerant piping.
[0070] The water circulates through the water circuit, which
includes the cooling tower 90 and the water circuit portion of the
water-refrigerant heat exchanger 5'. At the cooling tower 90, the
circulating water releases heat to be cooled.
[0071] Regarding installation, the heat source heat exchanger unit
31' can be disposed in the ceiling of a space to be conditioned
whereas the cooling tower 90 may be arranged on the roof of the
building, for example.
[0072] For heating operation, a boiler equipment (not shown) to
heat the circulating water may be employed instead of or in
addition to the cooling tower 90.
* * * * *