U.S. patent application number 09/883908 was filed with the patent office on 2001-10-11 for modular low-pressure delivery vehicle air conditioning system having an in-cab cool box.
This patent application is currently assigned to Bergstrom, Inc.. Invention is credited to Evans, Phillip Carew, Gavin, William David, Zeigler, Terry A..
Application Number | 20010027663 09/883908 |
Document ID | / |
Family ID | 25383572 |
Filed Date | 2001-10-11 |
United States Patent
Application |
20010027663 |
Kind Code |
A1 |
Zeigler, Terry A. ; et
al. |
October 11, 2001 |
Modular low-pressure delivery vehicle air conditioning system
having an in-cab cool box
Abstract
A modular air conditioning system comprises a self-contained
refrigeration power cell and a remotely located heat exchanger
coupled by a low-pressure refrigerant circuit. The refrigeration
power cell comprises a compressor, a condenser, an expansion
device, and an evaporator, which are serially coupled to form a
high-pressure closed refrigeration circuit. The low-pressure
circuit thermally interfaces with the condenser to remove heat from
the high-pressure circuit. This heat exchanger is adapted to mount
in proximity to or be integrated with the radiator. Alternatively,
this circuit thermally interfaces with the evaporator to remove
heat from the low-pressure refrigerant. This heat exchanger is
adapted to mount in the cabin of the vehicle. When the low-pressure
circuit thermally interfaces with the evaporator, the low-pressure
circuit may further include a cool box for storing items to be
refrigerated. Preferably, the cool box and heat exchanger may each
be operated either alone, or in combination.
Inventors: |
Zeigler, Terry A.; (Byron,
IL) ; Gavin, William David; (Rockford, IL) ;
Evans, Phillip Carew; (Loves Park, IL) |
Correspondence
Address: |
LEYDIG VOIT & MAYER, LTD
6815 WEAVER ROAD
ROCKFORD
IL
61114-8018
US
|
Assignee: |
Bergstrom, Inc.
Rockford
IL
|
Family ID: |
25383572 |
Appl. No.: |
09/883908 |
Filed: |
June 18, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09883908 |
Jun 18, 2001 |
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09467330 |
Dec 20, 1999 |
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6276161 |
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09467330 |
Dec 20, 1999 |
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09083303 |
May 22, 1998 |
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6038877 |
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Current U.S.
Class: |
62/406 |
Current CPC
Class: |
B60H 1/323 20130101;
F25D 16/00 20130101; F25D 17/02 20130101; B60H 1/00007 20130101;
B60H 1/32281 20190501; B60H 1/3204 20130101 |
Class at
Publication: |
62/406 |
International
Class: |
F25D 017/04 |
Claims
What is claimed is:
1. An air conditioning and refrigeration system for a vehicle
having an occupant cabin and an engine located in an engine
compartment, the system comprising: a refrigeration power cell; a
first heat exchanger; a communication circuit having low-pressure
refrigerant, the circuit thermally coupling the first heat
exchanger to the refrigeration power cell; and a cool box thermally
coupled to the low-pressure refrigerant communication circuit.
2. The system of claim 1, wherein the cool box is remotely located
from the refrigeration power cell.
3. The system of claim 1, wherein the cool box is adapted to be
mounted in the occupant cabin.
4. The system of claim 1, wherein the cool box is thermally coupled
to the low-pressure refrigerant communication circuit in parallel
with the first heat exchanger.
5. The system of claim 1, wherein a valve regulates a flow of
low-pressure refrigerant through the cool box.
6. The system of claim 1, wherein a valve regulates a flow of
low-pressure refrigerant through the first heat exchanger.
7. The system of claim 1, wherein a two-way valve regulates a flow
of low-pressure refrigerant through the cool box and the first heat
exchanger.
8. The system of claim 1, wherein the refrigeration power cell
comprises a high-pressure condenser-based refrigeration circuit
having a compressor, condenser, expansion device, and
evaporator.
9. The system of claim 8, wherein the refrigeration power cell
further comprises first circulation means for supplying first
low-pressure refrigerant to said low-pressure communication
circuit.
10. The system of claim 1, further comprising: a second heat
exchanger; and a second communication circuit having low-pressure
refrigerant for operably coupling the second heat exchanger to the
refrigeration power cell.
11. The system of claim 10, wherein the second heat exchanger is
mounted in proximity to an engine radiator.
12. The system of claim 10, wherein the second heat exchanger forms
an integrated assembly with an engine radiator.
13. The system of claim 12, wherein the integrated assembly
comprises an engine cooling section and a secondary loop liquid
condenser heat exchanger section.
14. The system of claim 13, wherein the engine cooling section and
the secondary loop liquid condenser heat exchanger section are
separated by a thermal insulation barrier.
15. A modular air conditioning and refrigeration system comprising:
a high-pressure closed refrigeration circuit; and a low-pressure
refrigerant communication circuit having a cool box and a heat
exchanger, the low-pressure refrigerant communication circuit
operably coupled to the high-pressure closed refrigeration circuit,
the heat exchanger and cool box remotely located from said
high-pressure circuit.
16. The system of claim 15, wherein the low-pressure circuit
thermally interfaces with the high-pressure circuit to remove heat
from the low-pressure refrigerant.
17. The system of claim 15, wherein the heat exchanger and cool box
are coupled to the low-pressure refrigerant communication circuit
in parallel.
18. The system of claim 15, wherein the low-pressure refrigerant
communication circuit is selectively coupled to the heat exchanger
and cool box.
19. The system of claim 15, wherein the low-pressure circuit
further includes a valve selectively regulating the flow of
low-pressure refrigerant through the cool box.
20. A refrigeration system for a vehicle, comprising: a
high-pressure closed refrigeration circuit having a compressor, a
condenser, an expansion device and an evaporator coupled by fixed
tubing having permanent connections; a low-pressure refrigerant
communication circuit in thermal communication with said
high-pressure circuit, said low-pressure refrigeration circuit
including a heat exchanger and a cool box.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application
Ser. No. 09/467,330, filed Dec. 20, 1999, which is a divisional of
application Ser. No. 09/083,303, filed May 22, 1998, now U.S. Pat.
No. 6,038,877, issued Mar. 21, 2000, the disclosure and teachings
of each are hereby incorporated in their entireties by reference
thereto.
FIELD OF THE INVENTION
[0002] This invention relates to vehicle air conditioning systems,
and more particularly to over-the-road or off-road or off-road
vehicle air conditioning systems and refrigeration systems.
BACKGROUND OF THE INVENTION
[0003] Over-the-road or off-road vehicles, such as semi-tractor
trailers and construction vehicles, are increasingly utilized to
satisfy the transportation and construction needs of our economy.
These increased needs result in increased utilization of these
vehicles to the point where many are operated seven days a week and
upwards of eighteen (18) to twenty (20) hours a day with a two
person crew or multiple shift operations. This increased
utilization is not simply a vehicle statement, but also includes a
human factor as these vehicles are operated by at least a driver
and often times by a driving team consisting of two individuals who
share the duty of operating the vehicle. Since these vehicles are
operated so extensively, increased driver and passenger comfort is
essential, both in terms of environment temperature and physical
space within the vehicle cab.
[0004] The need for environmental comfort during warm weather is
satisfied through the use of an over-the-road or off-road vehicle
air conditioning system, while the physical layout has been
accommodated through new ergonomic interior designs, including
reduced dash size, to maximize the available room within the
vehicle cab for passenger occupation. Increased driver and
passenger comfort may be further aided by the inclusion of a
refrigerator or ice chest (cooler). Such devices are ideal for
storing cold beverages and foods, or any other personal items which
are desirably kept at low temperatures. This often allows a driver
to remain on the road for longer periods of time between required
stops for food and a cold drink.
[0005] Typical over-the-road or off-road vehicle air conditioning
systems are of the compressor type. These air conditioning systems
utilize a compressor, which is driven by a belt coupled to the
engine to compress a refrigerant vapor under high pressure which is
then circulated through a condenser to remove heat from the
compressed high-pressure vapor and change it to a liquid state. The
liquid refrigerant is then passed through an expansion valve which
reduces the pressure on the refrigerant somewhat. This lower
pressure refrigerant is then passed through an evaporator, which
permits the return of the refrigerant to the vapor state, thereby
removing heat from the air blown thereacross by an in-dash fan.
[0006] In a modem over-the-road or off-road vehicle, the main
components of the refrigeration system, including the compressor
and the condenser, are located remotely from the evaporator which
is typically installed behind the dashboard air vents to provide
cooling of the cabin air as described above, and from the condenser
which is typically mounted with the vehicle radiator in the front
of the engine compartment. Since the typical compressor vehicle air
conditioning system is a closed loop system, the circulating
high-pressure refrigerant must be passed from the remotely located
components within the engine compartment to the vehicle cab-located
evaporator and to the forward engine compartment, radiator located
condenser via expensive high-pressure refrigeration hoses.
[0007] A typical installation includes the compressor and condenser
in the engine compartment of the over-the-road or off-road vehicle,
and utilizes multiple high-pressure refrigeration lines to couple
these components through the firewall and into the cab behind the
dash to the location of the evaporator, and to the radiator area of
the engine compartment. Each of these high-pressure refrigeration
lines require high-pressure couplings at each connection for the
delivery and return of the high-pressure refrigerant in the air
conditioning system.
[0008] As can well be imagined, both from the above-description as
well as from personal experiences with vehicular air conditioning
systems, this typical installation arrangement for an over-the-road
or off-road vehicle air conditioning system is severely prone to
leaks of the high-pressure refrigerant. These leaks occur at
various locations, but are most frequent at the various couplings
of the high-pressure hose which routes the high-pressure
refrigerant from the condenser to the interior of the cab, under
the dash, and to the location of the evaporator. Another frequent
area for leaks occurs at the various couplings of the high-pressure
hose which routes the high-pressure refrigerant from the compressor
to the radiator area located condenser.
[0009] These leaks result in a reduced efficiency of the air
conditioning system, expensive recharging of the system with new
refrigerant, as well as a hazard to the environment through the
escape of the refrigerant. An increased consciousness of the
environmental impact that escaped refrigerant has on the planet, as
well as increased government regulation regarding the inadvertent
release of refrigeration refrigerant, has placed an increased
emphasis on overcoming these problems.
[0010] In addition to the problem of leaks within the air
conditioning system, the use of this type of system requires that
expensive high-pressure refrigeration lines be utilized within the
engine compartment, and between the engine compartment and the
interior of the cab. In addition, expensive high-pressure couplings
must also be utilized in an attempt to reduce the potential for
leaks and catastrophic failure of the air conditioning system due
to a failed connection of the high-pressure refrigeration lines.
Also, because the refrigeration system is not closed until assembly
of the vehicle takes place within the manufacturing assembly
facility, the use of this type of system further burdens the
assembly manufacturer by requiring that the initial purging and
charging of the refrigeration system take place within the assembly
plant of the vehicle itself. As mentioned above, since the use of
refrigerant is a highly regulated process, requiring the
manufacturing assembler to charge the refrigeration system greatly
increases the cost associated with the manufacture of the
vehicle.
[0011] In addition to the problems associated with the typical air
conditioning system just described, the inclusion of refrigerators
or ice boxes (coolers) in the cab introduces additional problems.
When coolers are used, the driver or passenger must purchase and
partially fill the cooler with ice to keep the contents (food,
drink, medicine, etc.) cool. Unfortunately, ice can only keep the
contents cool for a relatively short period of time, as the ice
will eventually melt. This melting is accelerated as the cover of
the cooler is opened to gain access to the contents, as warm items
are placed in the cooler, etc. As a result, the cooler tends to
become filled with ice water, which causes many problems. Many
coolers are prone to leaking the melted ice water. Further,
emergency maneuvers may cause the cooler to shift and tip over,
spilling the ice water and other content in the cab. These are
obviously unwanted situations inside a vehicle. Further, the water
from the melting ice often soaks the contents of the cooler. As a
result certain products cannot be stored in the cooler without
risking ruining them.
[0012] To overcome these drawbacks, vehicle refrigerators or cool
boxes have been proposed. A common vehicle cool box is of the
compressor type much like the aforementioned air conditioning
systems. These cool boxes utilize a dedicated refrigeration circuit
(separate from the air conditioning circuit discussed above)
comprising a compressor, condenser, expansion valve and evaporator
for the refrigerator. Therefore, when viewed from the overall
vehicle level these systems require an additional compressor, an
additional condenser, and additional expansion device, and an
additional evaporator. Furthermore, since the compressor is driven
by the engine and since the evaporator must be located within the
cabin of the vehicle, these systems suffer the same drawbacks noted
above with regard to air conditioning systems. Specifically, such
systems require the same high-pressure couplings to route the
refrigerant through the firewall, and therefore are prone to the
same coolant leaks that pose such a problem. The use of a separate
refrigerant circuit also reduces the overall efficiency of the
vehicle, thus increasing the cost of ownership. Aftermarket
installation of such systems is also quite expensive.
[0013] Portable electric powered refrigerators are one solution to
the drawbacks of the current installed systems. However, these
portable units are prone to tipping over in much the same way as
the ice chests discussed above, and present much the same problem
of where to put it in the cabin and still have room for the driver
and co-driver or passenger. Also, the electric plug must typically
be inserted in one of the available power points, such as the
cigarette lighter, thus reducing the number of these that are
available for required items. Further, the electric draw of such
units can be substantial, especially when the vehicle is not
running.
SUMMARY OF THE INVENTION
[0014] It is therefore an object of the invention to overcome many
of these and other problems existing in the art. More specifically,
it is an object of the instant invention to provide an
over-the-road or off-road vehicle air conditioning system that has
increased reliability and decreased impact to the environment. It
is an additional object of the instant invention to provide an
over-the-road or off-road vehicle air conditioning system that
eliminates the necessity for evacuating and charging of the air
conditioning system at the manufacturing assembly plant. Further,
it is an object of the instant invention to provide an
over-the-road or off-road vehicle air conditioning system which
utilizes an in-vehicle heat exchanger with the cab air while
eliminating the necessity for high-pressure refrigeration lines and
high-pressure couplings running to and from the cab compartment. In
one embodiment, the in-vehicle heat exchanger is located
in-dash.
[0015] It is an additional object of the instant invention to
provide an over-the-road or off-road vehicle air conditioning
system that is modular in design, allowing for remote location of
the main refrigeration circuit. It is an additional object of the
instant invention to provide an over-the-road or off-road vehicle
air conditioning system that allows for location of the main air
conditioning circuit outside of the engine compartment in other
more convenient locations.
[0016] It is a further object of the instant invention to eliminate
the need for a separate refrigeration system for an on-board
refrigerator or cool box and improve total system reliability. It
is a related object to provide an on-board refrigerator or cool box
that also eliminates the necessity for long high-pressure
refrigeration lines running to and from the cabin area.
[0017] In view of these and other objects of the invention, it is a
feature of the instant invention to provide an air conditioning
system that utilizes a self-contained refrigeration system that is
remotely located from the in-vehicle heat exchanger for the cabin
air. It is a further feature of the instant invention that the
remotely located self-contained portion of the air conditioning
system contains all of the high-pressure system components in a
closed system having permanent connections therebetween. It is an
additional feature of the instant invention that the in-vehicle
heat exchanger located within the cabin of the over-the-road or
off-road vehicle contain a low-pressure refrigerant circuit which
is utilized to cool the cabin air. It is a further feature of the
instant invention that the low-pressure refrigerant circuit
interfaces with the high-pressure, remotely located refrigerant
system via a heat exchanger. Further, it is a feature of the
instant invention that the air conditioning system also utilizes a
low-pressure refrigerant circuit to remove heat from the compressed
refrigerant in the high-pressure, remotely located self-contained
modular circuit.
[0018] It is yet another feature of the instant invention to
provide a low-pressure refrigerant circuit in communication with
the evaporator having an on-board cool box that can be used alone
or in conjunction with the in-vehicle heat exchanger.
[0019] In view of the above, an embodiment of the air conditioning
system for an over-the-road or off-road vehicle having an engine
located in an engine compartment and an occupant cabin, the
occupant cabin having a dashboard including air flow vents and a
vent fan included, the system of the present invention comprises a
refrigeration power cell, a first heat exchanger adapted to be
mounted in the dashboard of the occupant cabin, and a first
low-pressure refrigerant communication circuit operably coupling
the first heat exchanger to the refrigeration power cell.
[0020] In this system the refrigeration power cell comprises a
high-pressure condenser-based refrigeration circuit. This circuit
has a compressor, a condenser, an expansion device, and an
evaporator. Also included is a circulation circuit which supplies
low-pressure refrigerant to the low-pressure refrigerant
communication circuit. The evaporator and the circulation circuit
are in thermal communications whereby heat is removed from the
low-pressure refrigerant. Preferably, the circulation circuit
comprises a low-pressure refrigerant pump and an input and output
low-pressure refrigerant coupling. This pump circulates the
low-pressure refrigerant through this heat exchanger across which
the vent fan blows air to be cooled. This produces cooled air which
flows through the vents and into the occupant cabin to cool
same.
[0021] Preferably, the system of the present invention further
comprises a second heat exchanger adapted to be mounted in the
engine compartment, and a second low-pressure refrigerant
communication circuit operably coupling this second heat exchanger
to the refrigeration power cell. Additionally, the refrigeration
power cell further comprises a second circulation circuit supplying
a second low-pressure refrigerant to this second low-pressure
refrigerant communication circuit. The condenser and this second
circulation means are preferably in thermal communications whereby
heat is removed from the refrigeration power cell by the second
low-pressure refrigerant. In a system wherein the engine includes a
radiator and an engine fan within the engine compartment, this
second low-pressure refrigerant circulates through the second heat
exchanger across which the engine fan draws air to remove heat from
this second heat exchanger thereby cooling the second low-pressure
refrigerant.
[0022] In an embodiment of the instant invention, the refrigeration
power cell further comprises a sub-cooler thermally coupling the
low temperature input of the compressor to the high temperature
output of the compressor. This heat exchange increases the
efficiency of the compressor. Additionally, the refrigeration power
cell further comprises a drier interposed between the condenser and
the expansion device. This drier removes water from the
refrigeration circuit.
[0023] In an alternate embodiment of the instant invention, a
modular air conditioning system comprises a self-contained
refrigeration power cell, a heat exchanger remotely located from
the refrigeration power cell, and a low-pressure refrigerant
communication circuit. This low-pressure refrigerant communication
circuit operably couples the refrigeration power cell to the heat
exchanger, conveying low-pressure refrigerant therebetween. The
refrigeration power cell comprises a compressor, a condenser, an
expansion device, and an evaporator. The compressor, condenser,
expansion device, and evaporator are serially coupled to form a
high-pressure closed refrigeration circuit.
[0024] The refrigeration power cell further comprises a drive
mechanism coupled to the compressor. This drive mechanism may be a
hydraulic motor, an electric motor, or other appropriate device to
allow remote operation from the engine compartment. Alternatively,
the compressor may be belt driven in a conventional manner.
[0025] In an embodiment of the instant invention, the low-pressure
refrigerant communication circuit thermally interfaces with the
condenser to remove heat from the high-pressure closed
refrigeration circuit. In this embodiment this heat exchanger is
adapted to mount in proximity to a radiator in an engine
compartment of an over-the-road or off-road vehicle.
[0026] Alternatively, the low-pressure refrigerant communication
circuit thermally interfaces with the evaporator to remove heat
from the low-pressure refrigerant. In this alternative embodiment
the heat exchanger is adapted to mount under a dashboard of an
over-the-road or off-road vehicle. Preferably, this embodiment of
the instant invention further comprises a second heat exchanger
remotely located from the refrigeration power cell, and a second
low-pressure refrigerant communication circuit which is operably
coupled to the refrigeration power cell and to the second heat
exchanger for conveying second low-pressure refrigerant
therebetween. In this embodiment the second low-pressure
refrigerant communication circuit thermally interfaces with the
condenser to remove heat from the high-pressure closed
refrigeration circuit. Ideally, this second heat exchanger is
adapted to mount in proximity to a radiator in an engine
compartment of an over-the-road or off-road vehicle.
[0027] In yet another embodiment of the instant invention, a
modular air conditioning and refrigeration system comprises a
refrigeration power cell having a high-pressure condenser-based
refrigeration circuit. This circuit has a compressor, a condenser,
an expansion device and an evaporator. Also included is a
low-pressure communication circuit having a low-pressure
refrigerant. The evaporator and the low-pressure communication
circuit are in thermal communication whereby heat is removed from
the low-pressure refrigerant. The communication circuit includes a
first heat exchanger and an onboard cool box. Preferably, a vent
fan blows air to be cooled across the first heat exchanger that
flows into the occupant cabin to cool the same. The heat exchanger
and cool box are preferably coupled in parallel with appropriate
valving such that low-pressure refrigerant can be supplied to the
heat exchanger and cool box either individually or in
combination.
[0028] These and other objects and advantages of the invention will
become more apparent from the following detailed description when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The accompanying drawings incorporated in and forming a part
of the specification illustrate several aspects of the present
invention, and together with the description serve to explain the
principles of the invention. In the drawings:
[0030] FIG. 1 is a system block diagram illustrating an embodiment
of the instant invention;
[0031] FIG. 2 is a system block diagram illustrating in greater
detail an aspect of an embodiment of the instant invention;
[0032] FIG. 3 is an expanded system block diagram of the embodiment
of the instant invention illustrated in FIG. 1;
[0033] FIG. 4 is a system block diagram illustrating an alternate
embodiment of the instant invention;
[0034] FIG. 5 is an expanded system block diagram of the alternate
embodiment of the instant invention illustrated in FIG. 4;
[0035] FIG. 6 is a system block diagram illustrating a further
alternate embodiment of the instant invention; and
[0036] FIG. 7 is an expanded system block diagram of the further
alternate embodiment of the instant invention illustrated in FIG.
6.
[0037] FIG. 8 is an expanded system block diagram illustrating an
alternate embodiment of the instant invention illustrated in FIG.
4.
[0038] While the invention is susceptible of various modifications
and alternative constructions, certain illustrative embodiments
thereof have been shown in the drawings and will be described below
in detail. It should be understood, however, that there is no
intention to limit the invention to the specific forms disclosed,
but on the contrary, the intention is to cover all modifications,
alternative constructions and equivalents falling within the spirit
and scope of the invention as defined by the appended claims.
[0039] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] In a preferred embodiment of the instant invention as
illustrated in FIG. 1, a modular low-pressure delivery vehicle air
conditioning system comprises a refrigeration power cell 10 which
may be located anywhere room allows within or without the
over-the-road or off-road vehicle. This refrigeration power cell 10
is a modular self-contained unit and comprises a high-pressure
refrigeration circuit having permanent connections between
components as will be described more fully hereinbelow. In a
preferred embodiment of the instant invention, the level of
modularization of the system is total and includes an in-vehicle
heat exchange unit 12 and a radiator mounted heat exchanger 14. In
one embodiment, the in-vehicle heat exchange unit 12 is located
in-dash, although those skilled in the art will recognize that
other in-vehicle installations are within the scope of the
invention. The heat exchanger 14 may also be integral with the
radiator as will be discussed in greater detail below. Each of
these heat exchangers 12, 14 are in thermal communication with the
refrigeration power cell by low-pressure refrigerant communication
means 16, 18.
[0041] As described above, an over-the-road or off-road vehicle
includes an occupant cabin for the driver and passenger to sit, and
possibly an occupant sleeper cabin which provides a bunk area for
the driver or occupant to sleep while not driving the vehicle. As
is conventional, the occupant cabin includes a dashboard having,
among other things, air vents located therein. Typically, a vent
fan is included behind the dashboard to force air through the dash
mounted vents into the occupant cabin. In a preferred embodiment of
the instant invention, the in-dash heat exchanger 12 is configured
or adapted to mount behind the dashboard within the occupant cabin.
The operation of this in-dash mounted heat exchanger will be
described more fully below with reference to FIG. 3.
[0042] Also as described briefly above, an over-the-road or
off-road vehicle includes an engine compartment that typically
houses the vehicle's main drive engine as well as other accessory
components. One such accessory component is the vehicle's radiator
through which engine refrigerant typically circulates to remove
heat from the vehicle's engine. Typically, an engine fan is also
included behind the radiator to draw air thereacross to aid in the
heat removal process, especially when the vehicle is not moving. In
a preferred embodiment of the instant invention, the
radiator-mounted heat exchanger 14 is configured or adapted to
allow mounting on or in proximity to the radiator. In this way, air
that enters the engine compartment or that is drawn therein by the
engine fan will flow across this heat exchanger 14 to also remove
heat therefrom.
[0043] In an alternate embodiment of the present invention, the
heat exchanger 14 may be integrated into the radiator as
illustrated in FIG. 2. With the sealed system of the present
invention having a secondary loop for the condenser (heat exchanger
14), it becomes possible to eliminate the use of a separate
condenser hot gas refrigerant cooler and integrate this function as
part of the current radiator cooling package. This may be realized
because currently the radiator must be sized to provide adequate
engine cooling and overcome the additional condenser load
introduced by the radiator mounted configuration. Since radiators
must be sized to handle the load of the condenser anyway, it is
possible to integrate the secondary low-pressure cooling loop
(described more fully below) liquid condenser heat exchanger into
the current sized radiators without increasing the size of these
radiators. This is illustrated schematically in FIG. 2.
[0044] As may be seen from this FIG. 2, the secondary loop liquid
condenser heat exchanger section 14' is integrated as part of the
radiator 14" to form the integral assembly 14. In addition to the
radiator, the secondary low-pressure coolant loop heat exchanger
14' may alternatively be integrated with the oil cooler, the charge
air cooler, the transmission cooler, power steering cooler, or the
fuel cooler to form the integrated assembly 14. An optional thermal
insulation barrier 15 may be utilized between sections 14' and 14"
to reduce the heat transfer therebetween. As will be appreciated by
those skilled in the art, the elimination of a separately mounted
hot gas heat exchanger will eliminate the assembly costs at the
vehicle/machine manufacturer, increase the reliability of the
system, and improve the efficiency both from a performance and cost
perspective. Further, this integration is only made possible by the
present invention through the use of the secondary low-pressure
coolant loop 18, allowing a construction similar or identical to
current radiator constructions.
[0045] As described above with regard to the background of the
invention, one of the problems existing in the art pertains to the
physical space requirements of an air conditioning system if placed
within the engine compartment of an over-the-road or off-road
vehicle. These engine compartments are typically quite crowded with
the engine and accessory components which are required to be
located in this same area. However, with the embodiment of the
instant invention as illustrated in FIG. 1, the refrigeration power
cell 10 is a self-contained, closed, modular unit which may be
located remotely from the engine compartment, mounted within the
vehicle or externally thereto.
[0046] However, as described above, one of the problems associated
with distributing the components of the air conditioning system
from the in-dash delivery of cooled air is that the high-pressure
refrigerant typically leaks from the system at the various
high-pressure couplings required to route this high-pressure
refrigerant to the various required areas within the vehicle. The
instant invention obviates this problem by utilizing low-pressure
refrigerant which is circulated to the heat exchangers 12, 14 by a
low-pressure refrigerant communication circuits 16, 18
respectively. These low-pressure refrigerant communication circuits
16, 18 are in thermal communication with the high-pressure
refrigeration power cell 10 but do not suffer from the same
high-pressure refrigerant leak problem as a typical system. In this
way, the refrigeration power cell 10 is able to be located in any
convenient remote location on or in the vehicle without concern for
the number of couplings required to place the heat exchangers 12,
14 in their preferred locations.
[0047] FIG. 3 illustrates in greater detail the embodiment of the
instant invention illustrated in simplified block diagrammatic form
in FIG. 1. As may be seen from FIG. 3, the refrigeration power cell
10 comprises a high-pressure condenser based refrigeration circuit
having a compressor 20, a condenser 22, an expansion device 24, and
an evaporator 26. These components operate to form a high-pressure
closed refrigeration circuit, the specific operation of which is
well known in the art.
[0048] However, unlike prior high-pressure refrigeration systems,
the components of the refrigeration power cell 10 are coupled by
fixed tubing having permanent connections, such as soldered,
braised, etc., connections, as opposed to releasable connectors
which are typical in prior systems. This fixed tubing and permanent
connections allow for the refrigeration power cell 10 to be a
highly reliable essentially leak proof system which does not suffer
from the problems of prior vehicle air conditioning systems of
allowing high-pressure refrigerant to leak through the various
removable connections between components. Preferably, this
refrigeration power cell will be a prepackaged and pre-charged unit
which may be installed in the vehicle without concern for
evacuating and charging of the air conditioning system at the
manufacturing assembly facility of the vehicle as is common with
prior systems.
[0049] The refrigeration power cell 10 may also include, in the
high-pressure refrigeration circuit, a sub-cooler 28 which
thermally associates the low temperature input to the compressor
containing vaporized refrigerant with the high temperature
condenser output containing high temperature compressed
refrigerant. In this way, the efficiency of the compressor is
greatly increased as the high temperature liquid refrigerant in the
compressor output is used to heat the refrigerant vapor flowing
into the compressor, while at the same time the low temperature
vapor in the compressor input is used to cool the compressed
refrigerant flowing to the condenser. Additionally, a conventional
dryer 30 may be included in the high-pressure refrigeration circuit
of the refrigeration power cell 10 to remove water from the
circuit. While the use of such a dryer 30 is typically not needed
in a totally closed high-pressure refrigeration circuit, if the
compressor 20 utilized in the circuit includes a seal, the use of
the dryer 30 is preferred.
[0050] Unlike a conventional high-pressure refrigeration circuit
which places the condenser 22 in proximity to the radiator of the
vehicle to remove heat from the high-pressure refrigeration
circuit, the condenser 22 of the instant invention is not
positioned remotely from the other components of the refrigeration
power cell 10. Instead, the condenser 22 of this embodiment of the
instant invention serves as a heat exchanger between the
high-pressure refrigeration circuit 32 and the low-pressure
refrigerant circuit 18 which circulates low-pressure refrigerant to
a radiator mounted heat exchanger 14. In this way, heat generated
by the high-pressure refrigeration circuit 32 is removed to the
low-pressure refrigerant circuit 18 and circulated to the radiator
mounted heat exchanger 14. As the engine fan 34 operates, air is
drawn across the heat exchanger 14 thereby removing heat from the
low-pressure refrigerant circulating therethrough. As is
conventional, the fan need not operate while the vehicle is
traveling, as normal air flow through the engine compartment may
serve to remove sufficient heat from the heat exchanger 14 to
obviate the necessity of running the engine fan 34.
[0051] The means 18 for this low-pressure refrigerant communication
may utilize simple, inexpensive, insulated tubing such as that
utilized for a low-pressure heating system. To coordinate with the
low-pressure refrigerant communication means 18, the refrigeration
power cell 10 includes a low-pressure refrigerant circulation means
which includes the low-pressure couplings to interface with the
low-pressure tubing, as well as a low-pressure refrigerant pump 36.
This pump 36 is utilized to circulate the low-pressure refrigerant
through the low-pressure circuit which includes the heat exchanger
14 and the condenser heat exchanger 22. As will be recognized by
one skilled in the art, while the heat exchanger 14 has been
described in a radiator mount configuration, the heat exchanger 14
may actually be mounted in any convenient location having
sufficient air flow to remove heat from the heat exchanger 14.
[0052] The high-pressure refrigeration refrigerant circuit 32 of
the refrigeration power cell 10 also deviates from a typical
high-pressure refrigeration circuit by utilizing its evaporator 26
to cool the low-pressure refrigerant circuit 16 as opposed to
directly cooling the air in the cabin. Instead, the high-pressure
refrigeration circuit 32 of the instant invention is utilized as a
heat exchanger which extracts heat from the low-pressure
refrigerant circulating in the circuit 16. As with the
configuration described above, the refrigeration power cell 10
includes a low-pressure refrigerant circulation means including
low-pressure fittings and a low-pressure refrigerant pump 36 which
circulates the low-pressure refrigerant through the low-pressure
communication circuit 16, the heat exchanger 12, and the evaporator
heat exchanger 26.
[0053] Unlike a conventional system which utilizes a dashboard
mounted evaporator, the system of the instant invention utilizes
the evaporator 26 to serve as a heat exchanger cooling the
low-pressure refrigerant circulating therethrough. As this
low-pressure refrigerant is circulated through the low-pressure
tubing to the in-dash mounted heat exchanger 12, the vent fan 40
blows air thereacross, through the air vents located in the
dashboard, and into the occupant cabin to cool the air therein.
Since this system is circulating low-pressure refrigerant, the
distance and number of couplings from the refrigeration power cell
10 to the dashboard of the vehicle is not a concern, unlike systems
which attempt to circulate high-pressure refrigerant as is
typical.
[0054] The operation of the compressor 20 in the refrigeration
power cell 10 may be driven by a suitable drive means 42 which is
included as part of the refrigeration power cell 10. In this way,
the refrigeration power cell 10 may be a totally self-contained
modular unit capable of being located anywhere within or outside of
the vehicle. Devices which may be utilized to drive the compressor
20 include electric or hydraulic motors, or other appropriate drive
mechanisms. If the refrigeration power cell is to be located within
the engine compartment, or in proximity to other rotating elements,
a shaft drive, belt drive, or magnetic coupling may be utilized as
appropriate and desired.
[0055] As will be recognized by one skilled in the art, the use of
the self-contained refrigeration power cell 10 eliminates the need
for separate refrigeration hoses or tubing, thereby reducing the
cost of the manufacture of this system. The absence of hoses and
their required connections also greatly reduces the possibility of
refrigeration leaks in the high-pressure refrigeration circuit 32,
thereby reducing the cost of ownership and providing enhanced
benefits to the environment. Since the components are located in
close proximity to one another within the refrigeration power cell
10, the system is inherently more efficient and utilizes a reduced
volume of refrigerant, once again reducing the cost of the system.
Since this unit is modular, it is easy to install within the
vehicle which reduces the cost of manufacturing the vehicle.
Additionally, since the refrigeration power cell 10 is a
self-contained unit, it may be delivered to the vehicle assembly
plant fully charged with refrigerant, thereby obviating the need
for evacuation or charging during the installation of the unit
within the vehicle. This not only greatly reduces the cost of
manufacturing of the vehicle, but also relieves the assembly plant
from various government regulations that govern the handling and
installation of refrigerant.
[0056] An alternate embodiment of the instant invention is
illustrated in FIG. 4. As may be seen with reference to this FIG.
4, the refrigeration power cell 10 interfaces solely with an
in-dash heat exchanger 12 via a low-pressure refrigerant
communication circuit 16. In this embodiment of the instant
invention, the need for a separate low-pressure circuit and heat
exchanger 14 (see FIG. 1) is obviated by the location of the
refrigeration power cell 10 within the vehicle. Particularly, if
the refrigeration power cell is located in an area which receives
sufficient airflow to cool the high-pressure refrigeration circuit
32 (see FIG. 5) then a separate low-pressure refrigerant circuit to
perform this function is not required.
[0057] With specific reference to FIG. 5, this embodiment of the
instant invention utilizes the condenser 22 in a more conventional
fashion as a direct heat exchange element for the high-pressure
refrigeration circuit 32. This configuration may be appropriate
where, for example, the refrigeration power cell 10 is located
within the engine compartment and may utilize the airflow generated
by the movement of the vehicle and/or the engine fan 34.
Alternatively, this configuration may be appropriate when the
refrigeration power cell 10 is located externally to the vehicle in
a location which receives sufficient airflow across the condenser
22 to provide adequate heat removal from the high-pressure
refrigeration circuit 32. The inclusion of a fan to aid air flow
may be appropriate to enhance performance.
[0058] Alternatively, as illustrated in FIG. 6, the location and
configuration of the refrigeration power cell 10 may obviate the
need for a separate in-dash heat exchanger 12 (see FIGS. 1 and 3),
and may only need to utilize a separate remotely located heat
exchanger 14 to cool the high-pressure refrigeration circuit 32
(see FIG. 7). This particular configuration, as illustrated in
greater detail in FIG. 7, utilizes the evaporator 26 of the
high-pressure refrigeration circuit 32 in a more conventional
manner by providing direct heat exchange to the cabin air as
delivered by the vent fan 40. Such a configuration is appropriate
when the refrigeration power cell is configured to mount within the
vehicle's occupant cabin so that direct heat exchange to the cabin
air is appropriate across the evaporator 26. In such a
configuration, the heat generated by the high-pressure
refrigeration circuit must still be removed through the condenser
by the low-pressure refrigerant circuit 18 to the remotely located
heat exchanger 14 described above. As will be recognized by one
skilled in the art, while the heat exchanger 14 has been described
with regard to a proximity mounting with the engine radiator, one
skilled in the art will recognize that any remote location of this
heat exchanger 14 in an area having sufficient air flow to
accomplish the requisite heat removal from the system is
appropriate. Likewise, one skilled in the art will also recognize
that the reference to in-dash mounted heat exchangers, while a
conventional configuration for an air conditioning system within an
over-the-road or off-road vehicle, is not limiting as alternate
configurations such as floor or ceiling mounted vents are also
appropriate and included within the scope of the instant
invention.
[0059] An alternate embodiment of the instant invention is
illustrated in FIG. 8. As in the previous embodiments, the
refrigeration power cell 10 includes a high-pressure refrigeration
circuit 32 having a compressor 20, a condenser 22, an expansion
device 24 and an evaporator 26. As shown in the figure, the
condenser 22 acts as a direct heat exchange element for the
high-pressure refrigeration circuit 32, although it will be readily
understood that the condenser 22 may be operatively coupled to a
low-pressure refrigerant communication circuit 18 as in the
embodiment shown in FIG. 3. A low-pressure refrigerant
communication circuit 56 is operatively coupled to the
high-pressure refrigeration circuit 32 via the evaporator 26. The
circuits 32, 56 are thermally coupled to remove heat from the
low-pressure refrigerant of communication circuit 56.
[0060] As in previous embodiments, the compressor 20 may be driven
by the engine or an alternate drive means 42 as the power cell 10
may be located in the engine compartment, the operator cabin or
externally from either of these locations i.e., anywhere inside or
outside of the vehicle. A pump 38 circulates low-pressure
refrigerant through the communication circuit 56 to be cooled by
the high-pressure refrigeration circuit 32. The pump 38 and
corresponding low-pressure couplings may be provided as part of the
power cell 10, assisting the mobility and versatility of the
air-conditioning and refrigeration system.
[0061] The low-pressure circuit 56 includes a heat exchanger 12. By
exchanging heat between the low-pressure refrigerant communications
circuit 56 and the high-pressure refrigeration circuit 32, the heat
exchanger 12 can be located remotely from the high-pressure circuit
32 and power cell 10, yet remain environmentally friendly by
eliminating the need for elongated high-pressure couplings.
Preferably, the heat exchanger 12 is provided as an in-dash mount
whereby a vent fan 40 can blow air thereacross, through air vents
located in the dashboard. The air exiting the vents enters the
occupant cabin to cool the air therein.
[0062] It can be seen in FIG. 8 that the low-pressure refrigerant
communication circuit 56 also includes a cool box or refrigerator
50. The cool box 50 integrally transfers heat to the low-pressure
refrigerant to cool a storage area provided in the cool box 50. The
cool box 50 is preferably mounted within the occupant cabin or even
within the dash, thereby remaining accessible to occupants located
in the cabin. Similarly, the cool box 50 may be located in the
sleeper of an off-road or over-the-road vehicle. Since the cool box
50 is coupled with the low-pressure circuit 56, the location of the
cool box 50 is not limited by concerns for high-pressure coupling.
The cool box 50 may be used to store perishable foods, beverages,
medicine, or anything an occupant may desire to be kept at a
relatively low temperature.
[0063] As shown in FIG. 8, the low-pressure refrigerant circuit 56
includes a valve 52 to selectively regulate the flow of refrigerant
through the cool box 50. For some applications, valve 52 alone may
be sufficient as it allows the occupant determine whether cool box
50 shall be operative or not, while the heat exchanger 12 may at
all times be utilized. This is permitted by the heat exchanger 12
and cool box 50 being placed in parallel in the low-pressure
refrigerant communication circuit 56, which allows the refrigerant
to flow through either the heat exchanger 12 or cool box 50 to
complete the circuit. Alternately, a second valve 54 may be
supplied to selectively regulate the flow of low-pressure
refrigerant through the heat exchanger 12.
[0064] It will now be recognized that by use of valve 52 and valve
54, heat exchanger 12 (used preferably for air conditioning) and
cool box 50 may each be operated either alone or in conjunction
with each other, providing a robust and versatile system. It will
also now be understood by those having skill in the art from the
foregoing description that valves 52 and 54 may be replaced by a
single two-way valve, or that the cool box 50 be provided with a
bypass valve to allow the cool box 50 to pass refrigerant
therethrough with minimal heat transfer. It is also easily
recognized in view of the preceding description of the invention
that operation of valve 52, valve 54, bypass valve or any
combination thereof may be thermostatically controlled for superior
efficiency and control of the system. Further, it will be
recognized by those in the art that the heat exchanger 12 and cool
box 50 may be placed in series in the low-pressure refrigerant
communication circuit 56, although the preferred system has been
illustrated in FIG. 8.
[0065] Numerous modifications and alternative embodiments of the
invention will be apparent to those skilled in the art in view of
the foregoing description. Accordingly, this description is to be
construed as illustrative only and is for the purpose of teaching
those skilled in the art the best mode for carrying out the
invention. The details of the structure and architecture may be
varied substantially without departing from the spirit of the
invention, and the exclusive use of all modifications which come
within the scope of the appended claims is reserved.
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