U.S. patent application number 12/887803 was filed with the patent office on 2011-03-24 for air conditioning device for heating, ventilation and/or air conditioning installation.
Invention is credited to Imed GUITARI, Regine HALLER, Mohamed YAHIA.
Application Number | 20110067427 12/887803 |
Document ID | / |
Family ID | 42145184 |
Filed Date | 2011-03-24 |
United States Patent
Application |
20110067427 |
Kind Code |
A1 |
HALLER; Regine ; et
al. |
March 24, 2011 |
Air Conditioning Device For Heating, Ventilation and/or Air
Conditioning Installation
Abstract
The invention is related to an AC loop (12) for ventilation,
heating and/or air conditioning installation comprising, according
to the circulation of an refrigerant in the AC loop, at least a
compressor (14), a first heat exchanger (16) for heating an air
flow distributed into the passenger compartment, a first expansion
device (18), an exterior heat exchanger (20) and a second heat
exchanger (24). The AC loop (12) comprises a storage device (28)
connected to the outlet of the first heat exchanger (16) and to the
outlet of the exterior heat exchanger (20).
Inventors: |
HALLER; Regine; (Boissy Sans
Avoir, FR) ; YAHIA; Mohamed; (Paris, FR) ;
GUITARI; Imed; (Elancourt, FR) |
Family ID: |
42145184 |
Appl. No.: |
12/887803 |
Filed: |
September 22, 2010 |
Current U.S.
Class: |
62/324.6 ;
62/434; 62/498 |
Current CPC
Class: |
F25B 6/04 20130101; B60H
1/00785 20130101; F25B 2400/0411 20130101; F25B 5/04 20130101; B60H
2001/00961 20190501; F25B 41/20 20210101; F25B 47/006 20130101;
F25B 47/02 20130101; F25B 2400/24 20130101; F25B 2400/0409
20130101; B60H 1/005 20130101; B60H 1/00885 20130101; F25B 41/31
20210101 |
Class at
Publication: |
62/324.6 ;
62/498; 62/434 |
International
Class: |
F25B 13/00 20060101
F25B013/00; F25B 1/00 20060101 F25B001/00; F25D 17/02 20060101
F25D017/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 22, 2009 |
FR |
FR 09/04514 |
Claims
1. An air conditioning circuit (12) for a heating, ventilation
and/or air conditioning installation, the air conditioning circuit
(12) comprising at least, according to the direction of closed
circuit coolant circulation, a compressor (14), a first heat
exchanger (16), a first expansion member (18), an external heat
exchanger (20) and a second heat exchanger (24), characterized in
that the air conditioning circuit (12) comprises a storage device
(28) connected to the outlet of the first heat exchanger (16) and
to the outlet of the heat exchanger (20).
2. An air conditioning circuit (12) according to claim 1,
characterized in that the air conditioning circuit (12) comprises a
first bypass arm (36) arranged in parallel with the first expansion
member (18).
3. An air conditioning circuit (12) according to claim 1,
characterized in that the air conditioning circuit (12) comprises a
first switching means (32) at the outlet of the first heat
exchanger (16) to control the circulation of the coolant through
the storage device (28).
4. An air conditioning circuit (12) according to claim 3,
characterized in that the first switching means (32) is arranged
upstream, according to the direction of closed circuit circulation
of a coolant, from the first expansion member (18).
5. An air conditioning circuit (12) according to claim 3,
characterized in that the first switching means (32) is a first
"three-way" valve (32).
6. An air conditioning circuit (12) according to claim 3,
characterized in that the first switching means (32) is a first
intermediate heat transfer fluid/coolant heat exchanger (44).
7. An air conditioning circuit (12) according to claim 1,
characterized in that the air conditioning circuit (12) comprises a
second switching means (34) arranged at the outlet of the external
heat exchanger (20) to control the circulation of the coolant
through the storage device (28).
8. An air conditioning circuit (12) according to claim 7,
characterized in that the second switching means (34) is a second
"three-way" valve (34).
9. An air conditioning circuit (12) according to claim 8,
characterized in that the air conditioning circuit (12) comprises a
second bypass arm (38) of the storage device 28) connected to the
second "three-way" valve (34).
10. An air conditioning circuit (12) according to claim 7,
characterized in that the second switching means (34) is a second
intermediate heat transfer fluid/coolant heat exchanger (46).
11. An air conditioning circuit (12) according to claim 1,
characterized in that the air conditioning circuit (12) comprises a
second expansion member (22).
12. An air conditioning circuit (12) according to claim 11,
characterized in that the air conditioning circuit (12) comprises a
third bypass arm (42) arranged in parallel with the second
expansion member (22) and/or the second heat exchanger (24).
13. An air conditioning circuit (12) according to claim 11,
characterized in that the second expansion member (22) is
controlled such that the pressure of the coolant at the outlet of
the second expansion member (22) is greater than the saturation
pressure of the air flow to be distributed in the vehicle interior
entering the second heat exchanger (24).
14. An air conditioning circuit (12) according to claim 13,
characterized in that the first switching means (32) and the second
switching means (34) are designed such that the coolant from the
compressor (14) passes successively through the first heat
exchanger (16), the first bypass pipe (70), the thermal storage
device (28), the first return pipe (72), the first expansion member
(18), the external heat exchanger (20), the second bypass arm (38)
and the third bypass arm (42).
15. An air conditioning circuit (12) according to claim 13,
characterized in that the first switching means (32) and the second
switching means (34) are designed such that the coolant from the
compressor (14) passes successively through the first heat
exchanger (16), the first expansion member (18), the external heat
exchanger (20), the storage device (28) and the third bypass arm
(42).
16. An air conditioning circuit (12) according to claim 13,
characterized in that the first switching means (32) and the second
switching means (34) are designed such that the coolant from the
compressor (14) passes successively through the first heat
exchanger (16), the first bypass arm (36), the external heat
exchanger (20), the storage device (28), the second expansion
member (22) and the second heat exchanger (24).
17. An air conditioning circuit (12) according to claim 13,
characterized in that the first switching means (32) and the second
switching means (34) are designed such that the coolant from the
compressor (14) passes successively through the first heat
exchanger (16), the first bypass pipe (70), the thermal storage
device (28), the first return pipe (72), the first expansion member
(18), the external heat exchanger (20), the second bypass arm (38),
the second expansion member (22) and the second heat exchanger
(24).
18. An air conditioning circuit (12) according to claim 1,
characterized in that the storage device (28) contains a phase
change material having a phase change temperature between 5.degree.
C. and 20.degree. C.
Description
[0001] The invention relates to an air conditioning circuit for a
heating, ventilation and/or air conditioning installation.
[0002] Motor vehicles are routinely equipped with a heating,
ventilation and/or air conditioning installation to modify the
aerothermal parameters of an air flow diffused inside the vehicle
interior.
[0003] The heating, ventilation and/or air conditioning
installation also comprises an air conditioning circuit with a
coolant circulating therein. The coolant is, for example, a
hydrofluorocarbon, particularly the coolant known under the
reference R134a, or a hydrofluoro-olefin-based compound,
particularly the coolant known under the reference HFO1234yf. The
present invention is also applicable with any coolants equivalent
to those mentioned above. The present invention is also applicable
with supercritical fluids, particularly carbon dioxide.
[0004] The air conditioning circuit particularly comprises an
external heat exchanger, particularly positioned at the front of
the vehicle, for exchanging heat with an air flow external to the
vehicle. The external heat exchanger is traversed by the external
air flow but is not in contact with the air flow to be diffused in
the vehicle interior.
[0005] The external heat exchanger is a heat exchange device
extracting heat from the external air flow passing therethrough.
However, the efficiency of the external heat exchanger is
particularly degraded due to the formation of frost on the inserts
arranged in the air flow passage on passing through the external
heat exchanger. Frosting may appear when water vapor, present in
the surrounding ambient air flow and passing through the external
heat exchanger, condenses on the external surfaces of the external
heat exchanger and freezes. While slight frost formation is not
detrimental to heat exchanges on the external heat exchanger, an
accumulation of frost is, on the other hand, particularly harmful
and may result in the complete blockage of the external air flow
passage via the external heat exchanger. Such frosting induces
impaired air conditioning circuit performance.
[0006] As a result, air conditioning circuits must be fitted,
almost systematically, with an effective external heat exchanger
defrosting system. To solve the defrosting problem, a number of
solutions have been proposed.
[0007] A first well-known method is that operating on the basis of
"thermodynamic cycle inversion". If defrosting is required, the
role of the external heat exchanger is reversed and, as it operates
as a gas condenser or cooler, the heat released during the
defrosting phase on the external heat exchanger melts the
frost.
[0008] A second method is that operating on the basis of "hot gas
bypassing". When the need for defrosting is detected, opening a
bypass valve enables the compressor to discharge the coolant
directly, particularly in the form of "hot" gases, into the
external heat exchanger, bypassing part of the air conditioning
circuit. The advantages of this method lie in the simplicity of the
embodiment of the air conditioning circuit, the lack of heat
extraction at the heat source and, in sum, a relatively low energy
cost.
[0009] However, such a method only provides a low air conditioning
circuit defrosting power and, in some designs, inefficiency.
Document US 2007/0137228 discloses such a system and envisages an
air conditioning circuit suitable for defrosting at a low ambient
temperature. However, the drawback of the device described in this
document is a loss of heating capacity during defrosting.
[0010] One aim of the invention is thus that of remedying the
abovementioned drawbacks. It thus relates to an air conditioning
circuit for a heating, ventilation and/or air conditioning
installation. More specifically, the invention relates to an air
conditioning circuit for a heating, ventilation and/or air
conditioning installation, particularly a motor vehicle interior,
comprising at least, according to the direction of closed circuit
coolant circulation, a compressor, a first heat exchanger, suitable
for heating an air flow to be distributed in the vehicle interior,
a first expansion member, an external heat exchanger and a second
heat exchanger, suitable for dehumidifying and/or cooling the air
flow to be distributed in the vehicle interior. The air
conditioning circuit comprises a storage device connected to the
outlet of the first heat exchanger, to be able to store the
calories from the first heat exchanger in the storage device with a
maximum capacity, and connected to the outlet of the heat
exchanger, to redistribute the calories via the coolant in the
second heat exchanger to defrost same and/or restore the stored
energy.
[0011] It is thus possible to defrost or limit the frosting of the
external heat exchanger and/or the second heat exchanger by means
of the storage device. Indeed, the temperature of the storage
device is maintained by the air conditioning circuit while ensuring
maximum energy performance. Subsequently, the calories stored are
used to defrost the external heat exchanger and/or second heat
exchanger by limiting the drop in the air conditioning circuit
performance.
[0012] According to one example of an embodiment, the air
conditioning circuit comprises a first bypass arm arranged in
parallel with the first expansion member.
[0013] Advantageously, the air conditioning circuit comprises a
first switching means arranged at the outlet of the first heat
exchanger, to control the circulation of the coolant through the
storage device. Preferentially, the first switching means is a
first "three-way" valve or a first intermediate heat transfer
fluid/coolant heat exchanger.
[0014] Alternatively or additionally, the air conditioning circuit
comprises a second switching means arranged at the outlet of the
external heat exchanger, to control the circulation of the coolant
through the storage device or in a bypass arm of the storage
device, referred to as the second bypass arm, particularly when the
use of the storage device is not intended to favor energy
restoration or further cooling of the coolant at the outlet of the
external heat exchanger operating as a condenser.
[0015] Preferentially, the second switching means is a second
"three-way" valve or a second intermediate heat transfer
fluid/coolant heat exchanger. Particularly advantageously, the
second bypass arm of the storage device is connected to the second
"three-way" valve.
[0016] Moreover, the second intermediate heat transfer
fluid/coolant heat exchanger is arranged at the outlet of the
external heat exchanger, to enable storage management and/or energy
restoration and the high pressure end and/or further cooling at the
low pressure end.
[0017] According to further embodiments, the air conditioning
circuit comprises a second expansion member. In particular, the
second expansion member is controlled such that the coolant
pressure at the outlet of the second expansion member is greater
than the saturation pressure of the air flow to be distributed in
the vehicle interior passing through the second heat exchanger to
prevent frosting of the air flow to be distributed in the vehicle
interior.
[0018] Preferentially, the air conditioning circuit comprises a
third bypass arm arranged in parallel with the second expansion
member and/or the second heat exchanger.
[0019] According to various designs, the first switching means and
the second switching means are designed such that the coolant from
the compressor passes successively through, [0020] the first heat
exchanger, the first bypass pipe, the thermal storage device, the
first return pipe, the first expansion member, the external heat
exchanger, the second bypass arm and the third bypass arm, or
[0021] the first heat exchanger, the first expansion member, the
external heat exchanger, the storage device and the third bypass
arm, or [0022] the first heat exchanger, the first bypass arm, the
external heat exchanger, the storage device, the second expansion
member and the second heat exchanger, or [0023] the first heat
exchanger, the first bypass pipe, the thermal storage device, the
first return pipe, the first expansion member, the external heat
exchanger, the second bypass arm, the second expansion member and
the second heat exchanger.
[0024] Preferentially, the storage device contains a phase change
material having a phase change temperature between 5.degree. C. and
20.degree. C., particularly between 10.degree. C. and 15.degree.
C.
[0025] Further features and advantages of the present invention
will emerge on reading the following detailed description including
examples of embodiments given as a non-limitative illustration with
reference to the appended figures, which may serve to complete the
comprehension of the present invention and the description of the
embodiment thereof, and, if applicable, contribute to the
definition thereof, wherein:
[0026] FIG. 1 represents a schematic view of the air conditioning
circuit according to a first operating mode, referred to as the
"heating--storage mode", wherein the vehicle interior is heated and
the energy stored in the storage device is maintained,
[0027] FIG. 2 represents a schematic view of the air conditioning
circuit according to a second operating mode, referred to as the
"first heating--defrosting mode", wherein the vehicle interior is
heated and the external heat exchanger is defrosted using the
storage device at the low pressure end of the thermodynamic
circuit,
[0028] FIG. 3 represents a schematic view of the air conditioning
circuit according to a third operating mode, referred to as the
"second heating--defrosting mode", wherein the vehicle interior is
heated and the external heat exchanger is defrosted using the
storage device at the high pressure end of the thermodynamic
circuit,
[0029] FIG. 4 represents a schematic view of the air conditioning
circuit according to a fourth operating mode, referred to as the
"demisting--defrosting mode", wherein the vehicle interior is
demisted and/or frost formation on the external heat exchanger is
limited using the storage device,
[0030] FIG. 5 represents a schematic view of the air conditioning
circuit according to a fifth mode, referred to as the "cooling
mode", wherein the interior is cooled using the storage device,
and
[0031] FIG. 6 represents a schematic view of the air conditioning
circuit according to an alternative embodiment of the invention
comprising a circuit on water.
[0032] FIG. 1 represents schematically an air conditioning circuit
12 according to the invention for a heating, ventilation and/or air
conditioning installation.
[0033] The air conditioning circuit 12 enables the circulation of a
coolant, particularly a subcritical fluid, such as R134A or
equivalent, or a supercritical fluid, such as R744 or carbon
dioxide.
[0034] The air conditioning circuit 12 comprises, in particular, in
the direction of closed circuit circulation of the coolant, a
compressor 14, suitable for circulating the coolant inside the air
conditioning circuit 12, a first heat exchanger 16, operating as a
condenser 16 and suitable for heating an air flow to be distributed
in the vehicle interior, a first expansion member 18, such as, for
example, an electronic expansion valve or a thermostatic expansion
valve, an external heat exchanger 20, a second expansion member 22,
a second heat exchanger 24, operating as an evaporator 24 and
suitable for dehumidifying and/or cooling the air flow to be
distributed in the vehicle interior, and an accumulator 26. At the
outlet, the accumulator 26 is connected to the inlet of the
compressor 14.
[0035] The first heat exchanger 16 and the second heat exchanger 24
are placed in an air flow circulation pipe, not shown, opening into
various areas of the vehicle interior. The first heat exchanger 16
and the second heat exchanger 24 are suitable for heating and/or
cooling the air flow opening into the vehicle interior,
particularly in an area arranged for demisting the windshield, a
central aeration area and an area for feet.
[0036] The air flow suitable for distribution in the vehicle
interior thus passes, in alternation or succession, through the
first heat exchanger 16 and/or the second heat exchanger 24. In
particular, according to a particular example of an embodiment, a
mixing flap is arranged in the circulation pipe to enable
distribution of the air flow between the first heat exchanger 16
and the second heat exchanger 24. Advantageously, the second heat
exchanger 24 is arranged upstream from the first heat exchanger 16,
along the direction of circulation of the air flow in the
circulation pipe. Preferentially, the entire air flow passes
through the second heat exchanger 24 before passing through and/or
bypassing the first heat exchanger 16.
[0037] Advantageously, according to the invention, a thermal
storage device 28 is incorporated in the air conditioning circuit
12 according to the present invention to store the calories carried
by the coolant for subsequent use thereof according to the device
operating modes.
[0038] According to one preferential arrangement, the thermal
storage device 28 is arranged between the external heat exchanger
20 and the second expansion member 22.
[0039] The air conditioning circuit 12 also comprises a first
switching means 32, particularly consisting of a first "three-way"
valve 32, particularly a first electrovalve 32, arranged at the
outlet of the first heat exchanger 16. The first "three-way" valve
32 is connected, via a first bypass pipe 70, to a first inlet of
the thermal storage device 28. A first outlet of the thermal
storage device 28 is connected, via a first return pipe 72, to the
air conditioning circuit, downstream from the first "three-way"
valve 32, at a first connection point 50. Such an arrangement makes
it possible to control the storage of calories from the heat
exchanger 16 to the storage device 28.
[0040] The air conditioning circuit 12 comprises a first bypass arm
36, arranged parallel with the first expansion member 18. The first
bypass arm 36 is arranged between a second connection point 52,
advantageously arranged downstream from the first connection point
50, and a third connection point 54, arranged downstream from the
first expansion member 18.
[0041] Preferentially, the first bypass channel 36 comprises a
first control valve 30, suitable for adopting an open position or a
closed position to enable or block coolant circulation in the first
bypass channel 36, respectively.
[0042] The air conditioning circuit 12 also comprises a second
switching means 34, particularly a second "three-way" valve 34,
particularly a first electrovalve 34, arranged at the outlet of the
external heat exchanger 20. The second "three-way" valve 34 is
connected to a second bypass arm 38 and to a second inlet of the
thermal storage device 28, respectively.
[0043] The second bypass arm 38 is arranged between the second
"three-way" valve 34 and a fourth connection point 56, arranged
downstream from the thermal storage device 28.
[0044] The circulation of the coolant in the second bypass arm 38,
bypassing the storage device 28, or in the storage device 28 is
controlled by the second "three-way" valve 34 arranged at the
outlet of the external heat exchanger 20.
[0045] Thus, according to the present invention, the thermal
storage device 28 is mounted both: [0046] at the outlet of the
first heat exchanger 16, to store the calories produced by and/or
remaining in the first heat exchanger 16 in the first storage
device 28, with a maximum yield, and [0047] at the outlet of the
external heat exchanger 20, to redistribute the calories via the
coolant.
[0048] According to the invention, the storage device 28 may
consist of a storage fluid tank storing the calories by working
with sensible heat, or using a phase change material storage
material storing the calories by working with latent heat.
[0049] Advantageously, the thermal storage device 28 is a
dual-fluid heat exchanger enabling heat exchange between the
coolant and the storage fluid/material.
[0050] Such a device 28 makes it possible to reduce the mass
required and limit storage temperature variations. The phase change
material has, according to the requirements of the invention, a
phase change temperature between 5.degree. C. and 25.degree. C.,
particularly between 5.degree. C. and 20.degree. C., preferentially
between 10.degree. C. and 20.degree. C. and notably between
10.degree. C. and 15.degree. C.
[0051] Thus, according to the various possible designs of the air
conditioning circuit 12 specific to the various operating modes
according to the figures in the present invention, the storage
device 28 is suitable for storing the calories carried by the
coolant from the first heat exchanger 16 and/or from the external
heat exchanger 20. Therefore, the storage device 28 is thus a heat
and/or cold storage device.
[0052] In the present description, the term "calorie" covers all
types of heat liable to be carried, in particular, by a coolant, a
heat transfer fluid, an air flow, etc. The storage device 28 can
thus store cold or heat according to the energy stored by the
coolant, heat transfer fluid or air flow and according to the
storage status of the storage device 28.
[0053] Finally, the air conditioning circuit 12 comprises a third
bypass arm 42, arranged in parallel with the second expansion
member 22 and the second heat exchanger 24. The third bypass arm 42
is arranged between a fifth connection point 58, arranged
downstream from the second expansion member 22, and a sixth
connection point 60, arranged downstream from the second heat
exchanger 24. Advantageously, the sixth connection point 60 is
arranged upstream from the accumulator 26.
[0054] Preferentially, the third bypass channel 42 comprises a
second control valve 40, suitable for adopting an open position or
a closed position to enable or block coolant circulation in the
third bypass channel 42, respectively.
[0055] In the various designs of the air conditioning circuit 12,
preferentially, the first expansion member 18 and the second
expansion member 22 are suitable for adopting closed positions when
the first control valve 30 and the second control value 40 are in
the open position, respectively.
[0056] Such an air conditioning circuit 12 thus makes it possible
to provide various operating methods according to user requirements
and thus improve the comfort thereof.
[0057] FIG. 1 represents a schematic view of the device according
to the present invention in a first operating mode, referred to as
the "heating--storage mode", wherein the vehicle interior is heated
and the energy stored in the storage device 28 is maintained.
[0058] With reference to the diagram in FIG. 1 illustrating the
first operating mode, the first "three-way" valve 32 is controlled
so as to enable the circulation of the coolant in the storage
device 28 and the second "three-way" valve 34 is controlled so as
to enable the circulation of the coolant in the second bypass arm
38, bypassing the storage device 28.
[0059] The first control valve 30 is in the closed position to
block the circulation of the coolant in the first bypass arm 36,
the coolant circulating in the first expansion member 18.
[0060] The second control valve 40 is in the open position to
enable the circulation of the coolant in the third bypass arm 42,
bypassing the second expansion member 22 and the second heat
exchanger 24.
[0061] In this way, in the first operating mode, referred to as the
"heating--storage mode", the coolant from the compressor 14 passes,
in succession, through the first heat exchanger 16, the first
"three-way" valve 32, the first bypass pipe 70, the thermal storage
device 28, the first return pipe 72, the first expansion member 18,
the external heat exchanger 20, the second "three-way" valve 34,
the second bypass arm 38, the third bypass arm 42 and the
accumulator 26 before returning to the compressor 14.
[0062] In the first operating mode design according to FIG. 1, the
external heat exchanger 20 operates as an evaporator 20.
[0063] The coolant condenses in the first heat exchanger 16 by
exchanging heat with the air flow passing therethrough. The air
flow channeled by the circulation pipe is thus heated on passing
through the first heat exchanger 16 before being distributed in the
vehicle interior.
[0064] The coolant is then expanded in the first expansion member
18 before being evaporated in the external heat exchanger 20,
operating in this design as an evaporator 20. For this purpose, the
external heat exchanger 20 is traversed by an external air flow
exchanging calories with the coolant, which is cooled in the
arrangement in FIG. 1. The external air flow is not intended to be
distributed in the vehicle interior.
[0065] In the design in FIG. 1, the second heat exchanger 24 is not
operational. Therefore, the air flow liable to be distributed in
the vehicle interior and channeled by the circulation pipe is only
heated by the first heat exchanger 16.
[0066] Before the first operating mode is started, the temperature
of the coolant contained in the storage device 28 is close to the
external temperature. In this operating mode, the coolant passes
through the second bypass arm 38 by controlling the second
"three-way" valve 34. Indeed, in the first operating mode, it is
not intended for the storage device 28 to be used to restore stored
calories. The first operating mode merely makes it possible to
maintain the storage of calories contained therein.
[0067] According to the arrangement of the air conditioning circuit
in FIG. 1, at the outlet of the first heat exchanger 16, the
coolant circulates in the storage device 28 where it is cooled. As
specified above, the temperature of the coolant initially contained
in the storage device 28 is close to the external temperature,
below the temperature of the coolant at the outlet of the first
heat exchanger 16.
[0068] In this way, in the design of the first operating mode
according to FIG. 1, the storage device 28 collects the calories
carried by the coolant from the first heat exchanger 16. Therefore,
the storage device 28 is thus a heat storage device.
[0069] Advantageously according to the invention, during the first
operating mode, referred to as the "heating--storage mode", the
storage device 28 accumulates energy in the form of calories.
[0070] Furthermore, the storage device 28 helps improve the cycle
performance coefficient by reducing the temperature at the outlet
of the first heat exchanger 16. Increasing the performance
coefficient thus makes it possible to store energy at least cost in
respect to the power consumed by the compressor 14.
[0071] In the design according to the first operating mode, energy
is thus stored in the storage device 28 with an improved
performance coefficient of the air conditioning circuit 12
cycle.
[0072] Also according to the invention, the calories stored in the
storage device 28 are preferably at a mean temperature between
5.degree. C. and 20.degree. C., preferentially between 10.degree.
C. and 15.degree. C.
[0073] FIG. 2 represents a schematic view of the device according
to the present invention in a second operating mode, referred to as
the "first heating--defrosting mode", wherein the vehicle interior
is heated and the external heat exchanger 20 is defrosted using the
storage device 28 at the low pressure end of the air conditioning
circuit 12 and restoration of the energy stored.
[0074] With reference to the diagram in FIG. 2 illustrating the
second operating mode, the first "three-way" valve 32 is controlled
so to enable the direct connection of the outlet of the first heat
exchanger 16 with the inlet of the first expansion member 18, the
circulation of the coolant not being authorized in the storage
device 28, and the second "three-way" valve 34 is controlled so as
to enable the direct circulation of the coolant via the storage
device 28.
[0075] The first control valve 30 is in the closed position to
block the circulation of the coolant in the first bypass arm 36,
the coolant circulating in the first expansion member 18.
[0076] The second control valve 40 is in the open position to
enable the circulation of the coolant in the third bypass arm 42,
bypassing the second expansion member 22 and the second heat
exchanger 24.
[0077] In this way, in the second operating mode, referred to as
the "first heating--defrosting mode", the coolant from the
compressor 14 passes, in succession, through the first heat
exchanger 16, the first "three-way" valve 32, the first expansion
member 18, the external heat exchanger 20, the second "three-way"
valve 34, the second bypass arm 38, the third bypass arm 42 and the
accumulator 26 before returning to the compressor 14.
[0078] In the second operating mode design according to FIG. 2, the
external heat exchanger 20 operates as an evaporator 20.
[0079] According to the second operating mode illustrated in FIG.
2, defrosting of the external surfaces of the external heat
exchanger 20 may be performed at low pressures.
[0080] The coolant condenses in the first heat exchanger 16 by
exchanging heat with the air flow passing therethrough. The air
flow channeled by the circulation pipe is thus heated on passing
through the first heat exchanger 16 before being distributed in the
vehicle interior.
[0081] So as to heat the vehicle interior and simultaneously
defrost the external heat exchanger 20, the coolant evaporates
partially in the external heat exchanger 20, at a pressure
determined by the storage device 28, thus making it possible to
defrost or limit the frosting of the external heat exchanger 20.
The storage device 28 thus acts, in this design, as a thermal load,
performing a "thermal leverage" function at the low pressure end.
The heat conveyed by the storage device 28 compensates for the
cooling of the coolant such that the defrosting capacity is
essentially provided by the storage device 28.
[0082] The energy stored in the form of calories in the storage
device 28 can thus be used at the low pressure end of the air
conditioning circuit 12 to complete the evaporation of the coolant
leaving the external heat exchanger 20, which is defrosted.
[0083] The storage device 28 thus helps defrost the external heat
exchanger 20 without impairing the efficiency of the air
conditioning circuit 12, which is the aim of the present
invention.
[0084] Furthermore, according to the storage status of the storage
device 28, in the second operating mode design according to FIG. 2,
the storage device 28 may also collect calories carried by the
coolant from the external heat exchanger 20. Therefore,
alternatively, the storage device 28 is thus a cold storage
device.
[0085] FIG. 3 represents a schematic view of the device according
to the present invention in a third operating mode, referred to as
the "second heating--defrosting mode", wherein the vehicle interior
is heated and the external heat exchanger is defrosted using the
storage device 28 at the high pressure end of the air conditioning
circuit 12 and restoration of the stored energy.
[0086] With reference to the diagram in FIG. 3 illustrating the
third operating mode, the first "three-way" valve 32 is controlled
so to enable the direct connection of the outlet of the first heat
exchanger 16 with the inlet of the first expansion member 18, the
circulation of the coolant not being authorized in the storage
device 28, and the second "three-way" valve 34 is controlled so as
to enable the direct circulation of the coolant via the storage
device 28.
[0087] The first control valve 30 is in the open position to enable
the circulation of the coolant in the first bypass arm 36, the
coolant bypassing the first expansion member 18.
[0088] The second control valve 40 is in the closed position to
block the circulation of the coolant in the third bypass arm 42,
the coolant circulating in succession in the second expansion
member 22 and the second heat exchanger 24.
[0089] In this way, in the third operating mode, referred to as the
"second heating--defrosting mode", the coolant from the compressor
14 passes, in succession, through the first heat exchanger 16, the
first "three-way" valve 32, the first bypass arm 36, the external
heat exchanger 20, the second "three-way" valve 34, the storage
device 28, the second expansion member 22, the second heat
exchanger 24 and the accumulator 26 before returning to the
compressor 14.
[0090] The coolant condenses in the first heat exchanger 16 by
exchanging heat with the air flow passing therethrough. The air
flow channeled by the circulation pipe is thus heated on passing
through the first heat exchanger 16 before being distributed in the
vehicle interior.
[0091] In the third operating mode design according to FIG. 3, the
external heat exchanger 20 operates as a condenser 20.
[0092] According to the third operating mode of the air
conditioning circuit 12 illustrated in FIG. 3, defrosting of the
external surfaces of the external heat exchanger 20 may also be
performed at high pressures.
[0093] The coolant condenses in the first heat exchanger 16 by
exchanging heat with the air flow passing therethrough. The air
flow channeled by the circulation pipe is thus heated on passing
through the first heat exchanger 16 before being distributed in the
vehicle interior.
[0094] The coolant then passes through the external heat exchanger
20 exchanging calories with the air flow passing through the
external heat exchanger 20.
[0095] In the event of the coolant not being completely condensed
in the first heat exchanger 16, the coolant continues to condense
in the external heat exchanger 20 thus enabling the defrosting of
the external heat exchanger 20.
[0096] Furthermore, according to the design in FIG. 3, the coolant
at the outlet of the first heat exchanger 16 is at a high
temperature and high pressure. By bypassing the first expansion
member 18, the state of the coolant is substantially unchanged.
Therefore, the external heat exchanger 20 is traversed by the
coolant at a high temperature and at a high pressure thus helping,
additionally and alternatively, defrost the external heat exchanger
20.
[0097] At the outlet of the external heat exchanger 20, the second
"three-way" vale 34 is arranged to enable the direct circulation of
the coolant via the storage device 28. The coolant thus recovers
energy on passing through the storage device 28 prior to expansion
by the second expansion member 22.
[0098] According to the previous storage statuses in question, the
storage device 28 may alternatively store heat or cold. Therefore,
the coolant is cooled or heated on passing through the storage
device 28 prior to expansion by the second expansion member 22.
[0099] Preferentially, on passing through the second expansion
member 22, the pressure and temperature of the coolant fall before
passing through the second heat exchanger 24 wherein the coolant
vaporizes by absorbing heat from the air flow passing therethrough
to thus produce the cooled air flow.
[0100] The energy stored in the form of calories in the storage
device 28 can thus be used at the high pressure end of the air
conditioning circuit 12. The storage device 28 thus enables heat
exchange between the coolant and the storage fluid/material. The
coolant is then situated at the outlet of the storage device 28 in
a specific pressure and temperature state before passing through
the second expansion member 22 wherein the expansion of the coolant
is controlled such that, at the outlet of the second expansion
member 22, the low pressure of the coolant is greater than the
saturation pressure of the air flow entering the second heat
exchanger 24. It is thus possible to defrost or prevent frosting of
the second heat exchanger 24 without impairing the efficiency of
the air conditioning circuit 12.
[0101] According to this arrangement, the high pressure end of the
air conditioning circuit 12 advantageously supplies a minimal
amount of heat so as to heat the air flow suitable for being
distributed in the vehicle interior. An additional, particularly
electric, heating member may be arranged upstream from the first
heat exchanger 16, according to the direction of circulation of the
air flow in the circulation pipe, so as to heat the air flow
completely or partially to the desired temperature.
[0102] FIG. 4 represents a schematic view of the device according
to the present invention in a fourth operating mode, referred to as
the "demisting--defrosting mode", wherein the vehicle interior is
demisted and/or frost formation on the external heat exchanger 20
is limited using the storage device 28.
[0103] With reference to the diagram in FIG. 4 illustrating the
fourth operating mode, the first "three-way" valve 32 is controlled
so as to enable the circulation of the coolant in the storage
device 28 and the second "three-way" valve 34 is controlled so as
to enable the circulation of the coolant in the second bypass arm
38, bypassing the storage device 28.
[0104] The first control valve 30 is in the closed position to
block the circulation of the coolant in the first bypass arm 36,
the coolant circulating in the first expansion member 18.
[0105] The second control valve 40 is in the open position to
enable the circulation of the coolant in the third bypass arm 42,
bypassing the second expansion member 22 and the second heat
exchanger 24.
[0106] In this way, in the fourth operating mode, referred to as
the "demisting--defrosting mode", the coolant from the compressor
14 passes, in succession, through the first heat exchanger 16, the
first "three-way" valve 32, the first bypass pipe 70, the thermal
storage device 28, the first return pipe 72, the first expansion
member 18, the external heat exchanger 20, the second "three-way"
valve 34, the second bypass arm 38, the third bypass arm 42 and the
accumulator 26 before returning to the compressor 14.
[0107] In the fourth operating mode design according to FIG. 4, the
external heat exchanger 20 operates as an evaporator 20.
[0108] In order to demist the vehicle interior windows and/or limit
frost formation in the external heat exchanger 20 according to FIG.
4, the coolant evaporates in the external heat exchanger 20 by
absorbing the heat from the air flow passing through the external
heat exchanger 20.
[0109] The fluid then passes through the bypass channel 38 by
controlling the second "three-way" valve 34, since, in this
operating mode, it is not intended for the storage device 28 to be
used, but merely for the stored heat contained therein to be
maintained.
[0110] The fluid then circulates in the expansion member 22 and the
main evaporator 24 in succession. For this, the second control
valve 40 is closed, the second expansion member 22 being open such
that the coolant passes through the second heat exchanger 24. On
passing through the second expansion member 22, the pressure and
temperature of the coolant fall before passing through the second
heat exchanger 24 wherein the coolant vaporizes by absorbing heat
from the air flow passing therethrough to thus produce the cooled
air flow.
[0111] According to the previous storage statuses in question, the
coolant may pass through or bypass the storage device 28. The
storage device 28 is thus, according to requirements and the type
of storage carried out, an energy accumulator or a thermal load,
carrying out a "thermal leverage" function at the low pressure end,
as defined above with reference to FIG. 1.
[0112] When the storage device 28 is used as a thermal load,
carrying out a "thermal leverage" function at the low pressure end,
a positive evaporation temperature can be defined in the external
heat exchanger 20 to limit the risks of frosting of the external
heat exchanger 20.
[0113] In this operating mode, the storage device 28 is
advantageously situated in a temperature range between 10.degree.
C. and 15.degree. C.
[0114] Moreover, according to the energy storage temperature, the
storage device 28 may be used as an additional cooling element,
improving the performance coefficient of the air conditioning
circuit 12.
[0115] Therefore, the temperature of the storage device 28 makes it
possible to define the design of the second "three-way" valve 34 in
order to define whether, during the cycle, the storage device 28 is
used to optimize the performance coefficient of the air
conditioning circuit 12 by storing calories. In this way, for
example, if the storage temperature, in the storage device 28, is
below a reference temperature, for example 15.degree. C., the
coolant from the air conditioning circuit 12 will supply the
storage device 28 with calories until the reference temperature is
reached. Once the reference temperature has been reached, the air
conditioning circuit 12 will use the stored energy from the storage
device 28 to optimize the performance coefficient of the air
conditioning circuit 12 by deciding to restore the stored energy at
the low pressure end as for the energy restoration for the
defrosting function.
[0116] FIG. 5 represents a schematic view of the device according
to the present invention in a fifth mode, referred to as the
"cooling mode", wherein the interior is cooled using the storage
device 28.
[0117] With reference to the diagram in FIG. 5 illustrating the
fifth operating mode, the first "three-way" valve 32 is controlled
so as to enable the direct connection of the outlet of the first
heat exchanger 16 with the inlet of the first expansion member 18,
the circulation of the coolant not being authorized in the storage
device 28, and the second "three-way" valve 34 is controlled so as
to enable the direct circulation of the coolant via the storage
device 28.
[0118] The first control valve 30 is in the open position to enable
the circulation of the coolant in the first bypass arm 36, the
coolant bypassing the first expansion member 18.
[0119] The second control valve 40 is in the closed position to
block the circulation of the coolant in the third bypass arm 42,
the coolant circulating in succession in the second expansion
member 22 and the second heat exchanger 24.
[0120] In this way, in the fifth operating mode, referred to as the
"cooling mode", the coolant from the compressor 14 passes, in
succession, through the first heat exchanger 16, the first
"three-way" valve 32, the first bypass arm 36, the external heat
exchanger 20, the second "three-way" valve 34, the storage device
28, the second expansion member 22, the second heat exchanger 24
and the accumulator 26 before returning to the compressor 14.
[0121] In the fifth operating mode design according to FIG. 5, the
external heat exchanger 20 operates as a condenser 20.
[0122] The energy stored in the form of calories in the storage
device 28 can thus be used at the "high pressure" end of the air
conditioning circuit 12. The energy stored in the storage device 28
is thus heated by the "high temperature" of the coolant before
passing through the second expansion member 22. The coolant is thus
in a subcooled state at the outlet of the storage device 28.
[0123] Therefore, the temperature of the storage device 28 makes it
possible to define the design of the second "three-way" valve 34 in
order to define whether, during the cycle, the storage device 28 is
used to optimize the performance coefficient of the air
conditioning circuit 12 by storing calories. In this way, for
example, if the storage temperature, in the storage device 28, is
below a reference temperature, for example 15.degree. C. as may
occur when starting the vehicle, the coolant from the air
conditioning circuit 12 is cooled in the storage device 28,
releasing heat. The storage device 28 thus becomes an additional
cooler until the reference temperature is reached. The performance
coefficient of the air conditioning circuit 12 during this
operating mode is thus improved.
[0124] According to the invention, a second embodiment of the
invention can be envisaged and is illustrated in FIG. 6
representing a schematic view of the device according to a second
embodiment of the invention comprising a circuit on water in a
design equivalent to that in FIG. 3.
[0125] The other operating modes of this second embodiment may be
deduced from the various designs represented in FIGS. 1 to 5 with
reference to the first embodiment.
[0126] The first and second switching means 32 and 34 are replaced
by a first intermediate heat transfer fluid/coolant heat exchanger
44 and a second intermediate heat transfer fluid/coolant heat
exchanger 46, respectively, to store energy in the thermal storage
device 28.
[0127] The first and second intermediate heat transfer
fluid/coolant heat exchangers 44 and 46 form, with the thermal
storage device 28, wherein a heat transfer fluid, particularly
water, circulates, linking the thermal storage device 28 and the
low pressure end and/or the high pressure end of the air
conditioning circuit 12 according to the operating modes of the air
conditioning circuit 12.
[0128] The first and second intermediate heat transfer
fluid/coolant heat exchangers 44 and 46 are thus dual-fluid heat
exchangers enabling heat exchange between the coolant and the heat
transfer fluid.
[0129] As represented in FIG. 6, the thermal storage device 28 is
connected to the first intermediate heat transfer fluid/coolant
heat exchanger 44 respectively via a first bypass pipe 70 and a
first return pipe 72. Moreover, the thermal storage device 28 is
connected to the second intermediate heat transfer fluid/coolant
heat exchanger 46 respectively via a second bypass pipe 80 and a
second return pipe 82.
[0130] The arrangement according to FIG. 6 is such that the thermal
storage device 28 is not traversed by the coolant. However,
according to one alternative embodiment not shown, the thermal
storage device 28 may be embodied in the form of a three-fluid heat
exchanger between the coolant, heat transfer fluid and storage
fluid/material. In such a case, the three-fluid thermal storage
device 28 may be traversed by the heat transfer fluid and be
arranged as defined in FIGS. 1 to 5.
[0131] For all the embodiments described above, a particular
arrangement, not shown, of the second expansion member 22 may also
be envisaged. Indeed, the second expansion member 22 may be formed
in an equivalent manner to the first expansion member 18 and
comprise a bypass arm comprising a dedicated control valve.
[0132] In addition to this alternative embodiment, it is also
possible for the first connection point 58 to be arranged
downstream from the second expansion member 22 and the bypass arm
connection point of the second expansion member 22.
[0133] It should be understood, however, that these examples of
operation are given as illustrations of the subject matter of the
invention. Obviously, the invention is not limited to these
embodiments described above and merely given as examples. It covers
various modifications, alternative forms and other alternative
embodiments liable to be envisaged by those skilled in the art
within the scope of the present invention, in particular any
combinations of the various embodiments described above.
[0134] Furthermore, the various operating modes described above may
be taken separately or combined to embody alternative embodiments
and various designs of the same air conditioning circuit according
to an air conditioning circuit thermal management method as defined
according to the present invention.
* * * * *