U.S. patent application number 10/597293 was filed with the patent office on 2008-07-24 for air conditioning system for a motor vehicle.
This patent application is currently assigned to Webasto AG. Invention is credited to Oliver Horn, Noureddine Khelifa, Wolfgang Kraemer.
Application Number | 20080173029 10/597293 |
Document ID | / |
Family ID | 34778089 |
Filed Date | 2008-07-24 |
United States Patent
Application |
20080173029 |
Kind Code |
A1 |
Kraemer; Wolfgang ; et
al. |
July 24, 2008 |
Air Conditioning System For a Motor Vehicle
Abstract
An air conditioning system for a motor vehicle having a coolant
circuit (1) that contains an electrically driven compressor (2), a
condenser (4), an expansion valve (10) and a latent cold
accumulator (12). Heat is removed from the latent cold accumulator
(12) by the cooling circuit (1); this is referred to as the
charging of the latent cold accumulator (12). The system is also
equipped with an arrangement for cooling air, which are configured
in such a way that heat is removed from the air and supplied to the
latent cold accumulator (12). Thus, a cost-effective, efficient air
conditioning system can be used, in particular, when the vehicle is
stationary.
Inventors: |
Kraemer; Wolfgang;
(Muenchen, DE) ; Khelifa; Noureddine; (Muenchen,
DE) ; Horn; Oliver; (Muenchen, DE) |
Correspondence
Address: |
ROBERTS MLOTKOWSKI SAFRAN & COLE, P.C.
P. O. BOX 10064
MCLEAN
VA
22102-8064
US
|
Assignee: |
Webasto AG
Stockdorf
DE
|
Family ID: |
34778089 |
Appl. No.: |
10/597293 |
Filed: |
January 14, 2005 |
PCT Filed: |
January 14, 2005 |
PCT NO: |
PCT/DE2005/000043 |
371 Date: |
August 24, 2007 |
Current U.S.
Class: |
62/89 |
Current CPC
Class: |
F28D 20/02 20130101;
B60H 1/323 20130101; B60H 1/005 20130101 |
Class at
Publication: |
62/89 |
International
Class: |
F25D 17/06 20060101
F25D017/06 |
Claims
1. An air conditioning system for a vehicle having a refrigerant
circuit (l) which comprises an electrically driven compressor (2),
a condenser (4), an expansion valve (10) and a latent cold storage
(12) from which heat is drawn by means of the refrigerant circuit
(1), and having means for cooling air which is formed such that
heat is drawn from the air and the heat is supplied to the latent
cold storage (12).
2. The air conditioning system according to claim 1, wherein the
means for cooling air comprises a refrigerant circuit (30) which
comprises a pump (34), the latent cold storage (12) and a heat
exchanger (32) by means of which heat is drawn from the air which
is then supplied to the latent cold storage (12).
3. The air conditioning system according to claim 2, wherein a
blower (32) is assigned to the heat exchanger (32) which influences
an air flow through the heat exchanger (32) and simultaneously
influences the air flow through a heating element.
4. The air conditioning system according to claim 3, wherein the
heating element is a heating heat exchanger (44), wherein a fluid
flows through the latter which can be heated by means of a fuel
heating device (46).
5. The air conditioning system according to claim 1, wherein the
latent cold storage (12) is disposed such that the air to be cooled
flows through the latent cold storage (12) and, in this way, is
cooled.
6. The air conditioning system according to claim 5, wherein the
refrigerant circuit (1) comprises a plurality of latent cold
storages (12).
7. The air conditioning system according to any of the preceding
claims, wherein a generator (24) is assigned thereto which is
driven by a driving shaft (26) of a drive (28) of the vehicle and,
thus, provides the electrical energy for driving the electrical
driven compressor (2).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an air conditioning system for a
vehicle having a refrigerant circuit which comprises a compressor,
a condenser, an expansion valve and a latent cold storage the heat
of which can be drawn by means of the refrigerant circuit. This
drawing of heat is referred to as charging. Furthermore, the air
conditioning system comprises means for cooling air, which is
formed such that heat is drawn from the air and the heat is
supplied to the latent cold storage. This supply of heat is
referred to as discharging. In particular, such an air conditioning
system is used for motor trucks, and is used there as a stationary
air conditioning system.
[0003] 2. Description of Related Art
[0004] A stationary air conditioning system for a vehicle is known
from German Patent DE 198 52 641 C1, having a refrigerant circuit
with a compressor, a liquefier, an accnmulator and at least one ice
storage unit. The ice accumulator unit is comprised of a vaporizer
with an expansion organ and an ice accumulator surrounding the
latter. Furthermore, a further vaporizer with an expansion organ is
connected in parallel to the at least one ice accumulator unit,
wherein it can be controlled by means of respective switching
valves, if the refrigerant flows through the further vaporizer or
the vaporizer of the ice accumulator unit. The compressor is
mechanically driven by a driving motor of the vehicle and can be
coupled with the latter by means of a magnetic clutch via a fan
belt.
SUMMARY OF THE INVENTION
[0005] It is the object of the invention to provide a compact air
conditioning system which is adapted to cool a vehicle in a
stationary operation of the vehicle.
[0006] The invention is characterized by an air conditioning system
for a vehicle having a first refrigerant circuit which comprises an
electrically driven compressor, a condenser, an expansion valve and
a latent cold storage the heat of which is drawn by means of the
refrigerant circuit, and having means for cooling air which is
formed such that heat is drawn from the air and the heat is
supplied to the latent cold storage. By means of the electrically
driven compressor, the power of the compressor can be adjusted
independently of the rotational speed of a driving shaft of the
vehicle and, if necessary, the compressor can also be provided with
electrical energy independently of the drive of the vehicle.
Thereby, a predetermined amount of heat can be drawn from the
latent cold storage in a simple manner also during extreme
hotness.
[0007] If a further primary air conditioning system is disposed in
the vehicle, the compressor of which is driven by the driving shaft
of the vehicle, for example, by the crank shaft, the charging of
the latent cold storage of the air conditioning system can also be
affected quickly when the compressor of the primary air
conditioning system is operated at its maximal capacity.
[0008] The latent cold storage is characterized by a very high
specific cold capacity. This has the advantage that the air
conditioning system can be formed very compact. In particular, it
can draw a high amount of heat from the air in the stationary
operation of the vehicle when the driving shaft does not
rotate.
[0009] In an advantageous formation of the invention, the air
conditioning system hast a refrigerant circuit which comprises a
pump, the latent cold storage and a heat exchanger by means of
which heat is drawn from the air and the heat is then supplied to
the latent cold storage. This has the advantage that the heat
exchanger can be disposed at any position in the vehicle.
[0010] In a further advantageous formation of the invention, a
blower is assigned to the heat exchanger which influences the air
flow through the heat exchanger and simultaneously influences the
air flow through a heating element. This has the advantage that
only one blower is necessary for cooling the air, on the one hand,
and for heating the air, on the other hand.
[0011] In particular, it is advantageous when the heating element
is a heating heat exchanger through which a fluid flows which can
be heated by means of a fuel heating device. With a heating element
formed in such a manner a notably high heating power is
possible.
[0012] In a further advantageous formation of the invention, the
latent cold storage is disposed such that the air to be cooled
flows through the latent cold storage and, at the same time, is
cooled by the latter. Thus, the air conditioning system can be
formed notably compact. In this context, it is notably advantageous
when the refrigerant circuit comprises a plurality of latent cold
storages. Accordingly, cooling at many positions of the vehicle can
be affected. In particular, this is advantageous in motor trucks
which have, besides a driver compartment, a sleeping/living
compartment formed separately of the latter.
[0013] In a further advantageous formation of the invention, a
generator is assigned to the air conditioning system which is
driven by a driving shaft of a drive of the combustion engine and
thus, provides the electrical energy of the electrically driven
compressor. In such a manner, the electrical driven compressor can
be operated with high power during the driving operation.
[0014] Embodiments of the invention are described in greater detail
below in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a first embodiment of the air conditioning
system,
[0016] FIG. 2 shows a second embodiment of the air conditioning
system,
[0017] FIG. 3 shows a third embodiment of the air conditioning
system,
[0018] FIG. 4 shows a fourth embodiment of the air conditioning
system,
[0019] FIG. 5 shows a fifth embodiment of the air conditioning
system, and
[0020] FIG. 6 shows a sixth embodiment of the air conditioning
system.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Elements of the same construction and function are
identified with the same reference numerals in all figures of the
drawings.
[0022] An air conditioning system (FIG. 1) is disposed in a
vehicle, in particular, in a motor truck. The air conditioning
system has a refrigerant circuit 1 which comprises an electrically
driven compressor 2, a condenser 4 which has assigned a condenser
blower 6 thereto, an accumulator 8, an expansion valve 10 and a
latent cold storage 12.
[0023] The expansion valve 10 can be controlled or can merely be
formed as a flow restrictor. The output of the compressor 2 is
connected to the condenser 4 via a first line 14 and the output of
the condenser 4, in turn, is connected to the accumulator 8 via a
second line 16 which, preferably, also comprises a drier. The
accumulator 8 is connected with the expansion valve 10 via a third
line 18, and the output of the expansion valve 10 is connected to
the latent cold storage via a fourth line 20. The output of the
latent cold storage 12 is connected to the intake of the compressor
2 via a fifth line 22. The electrically driven compressor 2 is,
preferably, supplied with electrical energy from a generator 24
which is driven by a driving shaft 26 of a drive 28 of the vehicle.
For example, the drive 28 can be a combustion engine. However, the
electrically driven compressor 2 can also be supplied with
electrical energy in another way, for example, by means of a fuel
cell or any elements outputting electrical energy, for example, a
battery. Also, the electrically driven compressor 2 can be supplied
with electrical energy by any combination of the elements mentioned
above. By a respective dimensioning of these elements, the
electrically driven compressor 2 can be operated with a power which
is sufficient also under extreme operating conditions in order to
draw the desired amount of heat from the latent cold storage
12.
[0024] During the operation of the electrically driven compressor
2, the refrigerant which can be, for example, R134a or also
CO.sub.2, is compressed, whereby its temperature increases. The
condenser 4 is formed in cooperation with the condenser blower 6
such that heat is drawn from the refrigerant by the air flowing
through the condenser 4.
[0025] The thus cooled and liquefied refrigerant flows further to
the accumulator 8 via the second line 16, and then, to the
expansion valve 10 via the third line 18 by means of which it is
expanded to a lower pressure, wherein the temperature of the
refrigerant decreases significantly. Subsequently, the refrigerant
flows to the latent cold storage 12, and there, draws heat from the
cold storage medium by vaporizing it. The refrigerant which is then
gaseous again flows further to the electrically driven compressor 2
via the fifth line 22 and, there, is compressed again.
[0026] The high specific cold capacity of the latent cold storage
12 results from the fact that the cold storage medium in the latent
cold storage draws energy by means of the refrigerant such that a
phase transition from a liquid state to a solid state occurs. Thus,
the latent cold storage can be compact. Furthermore, it can be
produced inexpensively.
[0027] When the refrigerant is CO.sub.2, it is preferred that the
condenser 4 is a gas cooler and the lines 18, 22 contact each other
in a internal heat exchanger and the accumulator is disposed in the
line 22.
[0028] The air conditioning system comprises a refrigerant circuit
30 which has a heat exchanger 32, a pump 34 and a latent cold
storage 12. The latent cold storage 12 is connected to the heat
exchanger 32 via a sixth line 36, the output of which is connected
with the intake of the pump 34 via a seventh line 38. The output of
the pump 34 is connected with to the latent cold storage 12 via an
eighth line 40.
[0029] Preferably, the pump 34 is electrically driven and, for
example, can obtain the electrical energy necessary for it from a
battery not shown. The pump 34 pumps the refrigerant of the
refrigerant circuit through the latent cold storage 12, wherein the
latent cold storage 12 is supplied with heat and is cooled in this
manner. The cooled refrigerant then pours or flows to the heat
exchanger 32 through the sixth line 36 which is supplied with air
by a blower 42 in a controlled manner which then delivers the heat
to the heat exchanger 32, and thus, is cooled and contributes to
the desired cooling of the internal space of the vehicle. The heat
exchanger 32 can be disposed in the region of the passenger
compartment or can also be disposed in a sleeping or living room of
the vehicle. The heat delivered from the flowing air heats the
refrigerant in the heat exchanger 32, and thus, the heated
refrigerant flows to the pump 34 via the seventh line 38 where it
is pumped again to the latent cold storage 12.
[0030] It is preferred that the electrically driven compressor 2 is
operated during the driving operation of the vehicle, and thus,
heat is drawn from the latent cold storage 12. Dining the
stationary operation of the vehicle, it is preferred that the
compressor 22 is not operated, or at the most, is operated with a
low electrical power. In the stationary operation, the pump 34 is
driven dependent on the required cooling power, and accordingly,
air is cooled in the vehicle by means of the refrigerant circuit
30.
[0031] In a second embodiment of the invention (FIG. 2), in
addition a heating element is provided which is a heating heat
exchanger 44, wherein fluid, preferably a water glycol mixture, is
flowing through the latter which can be heated by means of a fuel
heating device 46 and is supplied to the heating heat exchanger 44
via a ninth line 48. The heating heat exchanger 44 is disposed such
that the blower 44 also controls the air flowing through the
heating heat exchanger 44. Thus, simply with one blower 44, the air
flowing through both the heating heat exchanger 44 and the air
flowing through the heat exchanger 32 can be controlled.
[0032] In a third embodiment of the air conditioning system (FIG.
3), an air heating element 50 is provided which, for example, can
be formed as a PTC-resistance element, and thus, transforms
electrical energy to heat and which is disposed such that the
amount of air which flows next to the air heating element 50 is
controlled by means of the blower 42. For example, the air heating
element 50 can be formed as fuel air heating device.
[0033] In a fourth embodiment of the air conditioning system (FIG.
4), the blower 42 is assigned to the latent cold storage 12 and the
air to be cooled flows through the latent cold storage or flows
next to cooling fins which are assigned to the latter and, thus,
delivers heat to the latent cold storage 12 and is thus cooled. In
this way, the air conditioning system can be formed notably
compact, since the refrigerant circuit 30 can be omitted, in
particular when at the plurality of positions of the vehicle, a
cooling of the air has to be affected, it is advantageous in this
context when the air conditioning system comprises a plurality of
latent cold storages 12. This plurality of latent cold storages 12
can then be disposed at respective positions of the vehicle, for
example the latent cold storage 12 in a motor truck can be disposed
in the passenger compartment and the further latent cold storage 12
can be disposed in a sleeping and/or living room which is
separately formed from the latter.
[0034] In the fourth embodiment of the air conditioning system, the
fuel heating device 46 and the heating heat exchanger 44 or the air
heating element 50 according to the embodiments of FIGS. 2 & 3
can also exist.
[0035] In a fifth embodiment of the air conditioning system (FIG.
5), the fuel heating device 46 is disposed in a bypass 48 of the
refrigerant circuit 30. In a sixth embodiment of the air
conditioning system, the fuel heating device 46 is coupled to the
sixth line 36.
* * * * *