U.S. patent application number 12/148988 was filed with the patent office on 2008-10-30 for reversible mode vehicle heating and cooling system for vehicles and method therefor.
Invention is credited to ARTHUR E. HIRSCH, MARION J. HOARD.
Application Number | 20080264088 12/148988 |
Document ID | / |
Family ID | 39885400 |
Filed Date | 2008-10-30 |
United States Patent
Application |
20080264088 |
Kind Code |
A1 |
HIRSCH; ARTHUR E. ; et
al. |
October 30, 2008 |
Reversible mode vehicle heating and cooling system for vehicles and
method therefor
Abstract
A reversible mode heating and cooling system for an interior
space of a vehicle having an Auxiliary Power Unit (APU) employs a
heat pump arrangement, wherein a refrigerant compressor is driven
by APU's diesel engine through pulley and belt arrangement. An air
duct is provided to communicate engine exhaust air to an external
heat exchanger during a heating mode. Openings and dampers are
provided in the air duct to direct engine exhaust air flow to
atmosphere and introduce ambient air into the external heat
exchanger during cooling mode. Exhausted air from the external heat
exchanger may be re-circulated back to the air inlet side of the
engine. Provisions are also provided for operating the refrigerant
compressor from the electrical power grid.
Inventors: |
HIRSCH; ARTHUR E.; (Paris,
IL) ; HOARD; MARION J.; (Cory, IN) |
Correspondence
Address: |
JAMES RAY & ASSOCIATES
2640 PITCAIRN ROAD
MONROEVILLE
PA
15146
US
|
Family ID: |
39885400 |
Appl. No.: |
12/148988 |
Filed: |
April 24, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60926153 |
Apr 24, 2007 |
|
|
|
Current U.S.
Class: |
62/236 ;
62/323.1; 62/324.1 |
Current CPC
Class: |
B60H 2001/00949
20130101; F25B 2313/02741 20130101; Y02A 30/274 20180101; F25B
13/00 20130101; B60H 1/00907 20130101; F25B 27/02 20130101 |
Class at
Publication: |
62/236 ;
62/324.1; 62/323.1 |
International
Class: |
F25B 27/02 20060101
F25B027/02; F25B 30/02 20060101 F25B030/02; F25B 29/00 20060101
F25B029/00 |
Claims
1. In combination with a vehicle including an auxiliary power
system having an air cooled diesel engine and an engine fan
connected to a shaft thereof and further including a heat exchange
unit mounted within an interior space of said vehicle and arranged
in heat exchange relationship with air in said interior space for
condensing a refrigerant and heating said air during the heating
mode and evaporating said refrigerant and cooling said air during
the cooling mode, a reversible mode heating and cooling system for
heating and cooling an interior space comprising: (a) a compressor
for compressing vaporous refrigerant, said compressor arranged in
refrigerant communication with said interior heat exchange unit;
(b) a power transmission means for connecting said compressor to a
rotating shaft of the diesel engine and for operating said
compressor thereby; (c) a heat exchanger mounted externally in heat
exchange relationship with each of the ambient air and exhaust air
from the engine, said heat exchanger further arranged in
refrigerant communication with said compressor for evaporating
refrigerant during the heating mode and condensing said refrigerant
during the cooling mode; (d) a blower unit in air communication
relationship with said heat exchanger; (e) a refrigerant expansion
valve operatively disposed intermediate said heat exchanger and
said heat exchange unit; and (f) a refrigerant flow reversing valve
operable for providing heating and cooling modes from said system
by a refrigerant flow direction selection.
2. The heating and cooling system, according to claim 1, wherein
said power transmission means includes a belt member and a pair of
pulleys, one of said pair of pulleys is secured to the engine shaft
for rotation therewith and another one of said pair of pulleys is
rotatably secured to said compressor.
3. The heating and cooling system, according to claim 1, wherein
said system includes an air duct means arranged in air
communication with each of said engine fan and said heat exchanger
for supplying engine's exhaust air thereto.
4. The heating and cooling system, according to claim 3, wherein
said system includes a pair of openings formed in said air duct
means, wherein one of said pair of openings is employed for
directing a flow of said exhaust air from said engine to atmosphere
and wherein another one of said pair of openings is employed for
enabling flow of ambient air into said first heat exchanger.
5. The heating and cooling system, according to claim 1, wherein
said system includes: (a) an air duct means arranged in air
communication with each of said engine fan and said heat exchanger
for supplying engine's exhaust air thereto; (b) a first opening
formed in said air duct means for directing a flow of said exhaust
air from said engine to atmosphere; (c) a first damper operatively
connected to said air duct means and movable for covering said
first opening during heating mode and uncovering said first opening
during said cooling mode; (d) a second openings formed in said air
duct means for enabling flow of ambient air into said first heat
exchanger; (e) a second damper operatively connected to said air
duct means and movable for selectively covering said second opening
during heating mode and uncovering said second opening during
cooling mode; and (f) means operatively connected to each of said
first and second dampers and operable for moving said each of said
first and second dampers to cover and uncover said first and second
openings respectively.
6. The heating and cooling system, according to claim 5, said
moving means includes a manually operable linkage.
7. The heating and cooling system, according to claim 5, said
moving means includes a pair of electrically operable motors each
of said pair of motors connected to one of said first and second
dampers.
8. The heating and cooling system, according to claim 7, wherein
said system includes one of a generator and alternator for
supplying power to said each motor and said refrigerant flow
reversing valve.
9. The heating and cooling system, according to claim 1, wherein
said system includes a second air duct means for re-circulating air
exhausted by said blower unit to the diesel engine during said
heating mode.
10. The heating and cooling system, according to claim 9, wherein
said system further includes a damper rotatably mounted within said
second duct means and an electric motor coupled to a shaft of said
damper for preventing recirculation of said air exhausted by said
blower unit to the diesel engine during said cooling mode.
11. The heating and cooling system, according to claim 1, wherein
said system includes means for operating at least said refrigerant
compressor from electrical power grid.
12. The heating and cooling system, according to claim 11, wherein
said means includes: (a) a first clutch secured to the shaft of the
engine for rotation therewith; (b) an electric motor connectable to
said electrical power grid; (c) a second clutch secured to an
output shaft of said electric motor for rotation therewith; (d) a
pulley rotatably mounted on said refrigerant compressor; and (e) a
belt member seated on each of said first and second clutches and
said pulley, whereby said refrigerant compressor is operable by way
of said first clutch during operation of the engine and is operable
by way of said second clutch during operation of said electric
motor from the electric power grid.
13. In combination with a vehicle including an auxiliary power
system having an air cooled diesel engine and an engine fan
connected to a shaft thereof and further including a heat exchange
unit mounted within an interior space of said vehicle and arranged
in heat exchange relationship with air in said interior space for
condensing a refrigerant and heating said air during the heating
mode and evaporating said refrigerant and cooling said air during
the cooling mode, a reversible mode heating and cooling system for
heating and cooling an interior space comprising: (a) a compressor
for compressing vaporous refrigerant, said compressor arranged in
refrigerant communication with said interior heat exchange unit;
(b) a heat exchanger mounted externally in heat exchange
relationship with each of the ambient air and exhaust air from the
engine, said heat exchanger further arranged in refrigerant
communication with said compressor for evaporating refrigerant
during the heating mode and condensing said refrigerant during the
cooling mode; (c) an air duct means in air communication with each
of said engine fan and said heat exchanger for supplying air
thereto; (d) a blower unit in air communication relationship with
said heat exchanger; (e) a refrigerant expansion valve operatively
disposed intermediate said heat exchanger and said heat exchange
unit; and (f) a refrigerant flow reversing valve operable for
providing heating and cooling modes from said system by a
refrigerant flow direction selection.
14. In combination with a vehicle including an auxiliary power
system having an air cooled diesel engine and an engine fan
connected to a shaft thereof and further including a heat exchange
unit mounted within an interior space of said vehicle and arranged
in heat exchange relationship with air in said interior space for
condensing a refrigerant and heating said air during the heating
mode and evaporating said refrigerant and cooling said air during
the cooling mode, a reversible mode heating and cooling system for
heating and cooling an interior space comprising: (a) a compressor
for compressing vaporous refrigerant; (b) a power transmission
means for connecting said compressor to a rotating shaft of the
diesel engine and for operating said compressor thereby; (c) a
first heat exchanger mounted externally in heat exchange
relationship with exhaust air from the engine, said first heat
exchanger further arranged in refrigerant communication with said
compressor for evaporating refrigerant during the heating mode; (d)
a second heat exchanger mounted externally in heat exchange
relationship with the ambient air, said second heat exchanger
further arranged in refrigerant communication with said compressor
for condensing said refrigerant during the cooling mode; (e) a
blower unit in air communication relationship with said second heat
exchanger; (f) a first refrigerant expansion valve operatively
disposed intermediate said first heat exchanger and said internal
heat exchange unit; (g) a second refrigerant expansion valve
operatively disposed intermediate said second heat exchanger and
said internal heat exchange unit; (h) a refrigerant flow reversing
valve operable for providing heating and cooling modes from said
system by a refrigerant flow direction selection; (i) a first check
valve operatively disposed intermediate said refrigerant flow
reversing valve and said first heat exchanger for preventing
refrigerant flow thereto during the cooling mode; and (j) a second
check valve operatively disposed intermediate said second heat
exchanger and said internal heat exchange unit for preventing
refrigerant flow to said second heat exchanger during the heating
mode.
15. The heating and cooling system, according to claim 14, wherein
said system includes said internal heat exchange unit.
16. A method for at least one of heating and cooling an interior
space of a vehicle including an auxiliary power unit having an
engine and an engine fan connected to a shaft thereof, said method
comprising the steps of: (a) providing a heat pump apparatus having
a refrigerant compressor; (b) connecting, with a power transmission
means, said refrigerant compressor to said shaft of said engine;
and (c) selectively cooling and heating, with said heat pump
apparatus, said interior space.
17. The method, according to claim 16, wherein said heating and
cooling step includes the step of connecting an external heat
exchanger of said heat pump apparatus in air communication means
with an air exhausted from said engine.
18. The method, according to claim 17, wherein said method includes
the additional step of controlling flow of each of the ambient air
and engine exhaust air to an external heat exchanger of said heat
pump apparatus.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to and claims priority from
Provisional Patent Application Ser. No. 60/926,153 filed on Apr.
24, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates, in general, to heating and
cooling systems and, more particularly, this invention relates to a
reversible mode heating and cooling system for an interior space
that employs a heat pump arrangement directly driven by a diesel
engine of the Auxiliary Power Unit (APU).
BACKGROUND OF THE INVENTION
[0003] As is generally well known, the anti-idling laws that
prohibit over-the-road truck drivers from running their truck
engines while stationary have combined with higher fuel prices to
create a high level of interest in Auxiliary Power Units (APU's)
for over-the-road long-haul trucks. These APU's are small power
plants that are attached to the truck frame and utilize one, two or
three cylinder diesel engines often in the nine to fourteen
horsepower range. The APU's provide heat, air conditioning and
electrical power to the trucks when they are parked without the
necessity of running the main truck diesel engine. An in-bunk unit
in the cab uses air conditioning technology to provide cooling and
electrical resistance heating elements to provide heat when needed.
Unused electrical capacity is available to power standard one
hundred ten volt residential type appliances such as refrigerator,
lighting, microwave, etc.
[0004] Prior to the conception and development of the present
invention, an engine-turned electrical generator has been employed
with the APU to provide four to six kilowatts (KW) of one hundred
ten volt alternating current (AC) electrical power.
[0005] U.S. Pat. No. 7,152,421 issued to Parks et al. discloses one
type of such system that also incorporates a heat pump operating
conventionally with air drawn from outside the system through its
condenser coils and removing heat to the exterior for cooling. In
the heating cycle, the condenser motor blower stops and reverses
rotation. Outside air is drawn in by the condenser fan, is
circulated across the diesel engine and generator, and is blown
through the condenser coils outside of the unit. This system can be
installed within a truck, bus, boat, cabin, camper, and the like.
While this system adequately cools and heats cab compartment, use
of the electrical generator increases installation and maintenance
costs as well as decreases overall efficiency of the system by
first converting the mechanical energy of the diesel engine into
the electric energy at the generator and then converting the
generated electrical energy into mechanical energy driving the
refrigerant compressor for enabling heating or cooling modes.
[0006] Therefore, there is a need for a cost effective and energy
efficient system employing a heat pump technology and operable in
combination with APU for heating and cooling an interior space.
SUMMARY OF THE INVENTION
[0007] The invention provides a novel reversible mode heating and
cooling system for heating and cooling an interior space of a
vehicle including an air cooled diesel engine and an engine fan
connected to a shaft thereof and further including a heat exchange
unit mounted within an interior space of the vehicle and arranged
in heat exchange relationship with air in the interior space for
condensing a refrigerant and heating the air during the heating
mode and evaporating the refrigerant and cooling the air during the
cooling mode.
[0008] In accordance with aspect, the invention provides a
compressor for compressing vaporous refrigerant. The compressor is
arranged in refrigerant communication with the interior heat
exchange unit. A power transmission means is provided for
connecting the compressor to a rotating shaft of the diesel engine
and for operating the compressor thereby. A heat exchanger is
mounted externally in heat exchange relationship with each of the
ambient air and exhaust air from the engine. The heat exchanger is
further arranged in refrigerant communication with the compressor
for evaporating refrigerant during the heating mode and condensing
the refrigerant during the cooling mode. A blower unit is provided
in air communication relationship with the heat exchanger. A
refrigerant expansion valve is operatively disposed intermediate
the heat exchanger and the heat exchange unit. Finally, a
refrigerant flow reversing valve is operable for providing heating
and cooling modes from the system by a refrigerant flow direction
selection.
[0009] In accordance with another aspect, the invention provides a
compressor for compressing vaporous refrigerant. The compressor is
arranged in refrigerant communication with the interior heat
exchange unit. A heat exchanger is mounted externally in heat
exchange relationship with each of the ambient air and exhaust air
from the engine. The heat exchanger is further arranged in
refrigerant communication with the compressor for evaporating
refrigerant during the heating mode and condensing the refrigerant
during the cooling mode. An air duct means is provided in air
communication with each of the engine fan and the heat exchanger
for supplying air thereto. A blower unit is disposed in air
communication relationship with the heat exchanger. A refrigerant
expansion valve is operatively disposed intermediate the heat
exchanger and the heat exchange unit. A refrigerant flow reversing
valve is operable for providing heating and cooling modes from the
system by a refrigerant flow direction selection.
[0010] According with a further aspect of the invention, there is
provided a compressor for compressing vaporous refrigerant. A power
transmission means connects the compressor to a rotating shaft of
the diesel engine for operating the compressor thereby. A first
heat exchanger is mounted externally in heat exchange relationship
with exhaust air from the engine, the first heat exchanger further
arranged in refrigerant communication with the compressor for
evaporating refrigerant during the heating mode. A second heat
exchanger is also mounted externally in heat exchange relationship
with the ambient air, the second heat exchanger further arranged in
refrigerant communication with the compressor for condensing the
refrigerant during the cooling mode. A blower unit is disposed in
air communication relationship with the second heat exchanger. A
pair of refrigerant expansion valve are provided. The first
refrigerant expansion valve is operatively disposed intermediate
the first heat exchanger and the internal heat exchange unit. The
second refrigerant expansion valve is operatively disposed
intermediate the second heat exchanger and the internal heat
exchange unit. A refrigerant flow reversing valve is operable for
providing heating and cooling modes from the system by a
refrigerant flow direction selection. A first check valve is
operatively disposed intermediate the refrigerant flow reversing
valve and the first heat exchanger for preventing refrigerant flow
thereto during the cooling mode. A second check valve operatively
disposed intermediate the second heat exchanger and the internal
heat exchange unit for preventing refrigerant flow to the second
heat exchanger during the heating mode.
[0011] In accordance with another aspect of the invention, there is
provided a method for at least one of heating and cooling an
interior space of a vehicle including an auxiliary power unit
having an engine and an engine fan connected to a shaft thereof.
The method includes the step of providing a heat pump apparatus
having a refrigerant compressor. Connecting the refrigerant
compressor to the shaft of the engine with a power transmission
means. Then, selectively cooling and heating the interior space
with the heat pump apparatus.
OBJECTS OF THE INVENTION
[0012] It is, therefore, one of the primary objects of the present
invention to provide a reversible mode heating and cooling system
for an interior space that employs a heat pump technology.
[0013] Another object of the present invention is to provide a heat
pump based heating and cooling system wherein the refrigerant
compressor is powered directly by the diesel engine of the APU.
[0014] Yet another object of the present invention is to provide a
heat pump based heating and cooling system that employs a pair of
movable flaps for controlling air flow during heating and cooling
modes.
[0015] A further object of the present invention is to provide a
heat pump based heating and cooling system that meets present
cooling and heating requirements even though such system is less
expensive to manufacture.
[0016] An additional object of the present invention is to provide
a heat pump based heating and cooling system that can operate from
electrical power grid.
[0017] In addition to the several objects and advantages of the
present invention which have been described with some degree of
specificity above, various other objects and advantages of the
invention will become more readily apparent to those persons who
are skilled in the relevant art, particularly, when such
description is taken in conjunction with the attached drawing
Figures and with the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a side schematic view of a long-hole truck with a
reversible mode cooling and heating system of the present
invention;
[0019] FIG. 2 is an air flow schematic diagram illustrating a
cooling mode operation of a reversible mode cooling and heating
system of the present invention constructed in accordance with a
presently preferred embodiment of the invention;
[0020] FIG. 3 is a refrigerant flow schematic diagram illustrating
cooling mode operation of the reversible mode cooling and heating
system of FIG. 2;
[0021] FIG. 4 is an air flow diagram illustrating heating mode
operation of the reversible mode cooling and heating system of FIG.
2;
[0022] FIG. 5 is a refrigerant flow diagram illustrating heating
mode operation of the reversible mode cooling and heating system of
FIG. 2;
[0023] FIG. 6 is an air flow diagram illustrating operation of the
reversible mode cooling and heating system constructed in
accordance with an alternative embodiment of the present
invention;
[0024] FIG. 7 is a refrigerant flow diagram illustrating operation
of the reversible mode cooling and heating system of FIG. 6;
and
[0025] FIG. 8 is a schematic block diagram of the reversible mode
cooling and heating system of the present invention, particularly
illustrating an optional apparatus for operating the refrigerant
compressor from an electrical power grid.
BRIEF DESCRIPTION OF THE VARIOUS EMBODIMENTS OF THE INVENTION
[0026] Prior to proceeding to the more detailed description of the
present invention, it should be noted that, for the sake of clarity
and understanding, identical components which have identical
functions have been identified with identical reference numerals
throughout the several views illustrated in the drawing
figures.
[0027] It is to be understood that the definition of an interior
space applies nut is not limited to an interior compartment for
truck, bus, boat, cabin, camper, and the like vehicles and
structures.
[0028] The best mode for carrying out the invention is presented in
terms of its presently preferred and alternative embodiment, herein
depicted within FIGS. 1 through 8. However, the invention is not
limited to the described embodiments, and a person skilled in the
art will appreciate that many other embodiments of the invention
are possible without deviating from the basic concept of the
invention and that any such work around will also fall under scope
of this invention. It is envisioned that other styles and
configurations of the present invention can be easily incorporated
into the teachings of the present invention, and only several
particular configurations shall be shown and described for purposes
of clarity and disclosure and not by way of limitation of
scope.
[0029] The heating and cooling system of the present invention is
shown and described in combination with an Auxiliary Power Unit
(APU) employed on over-the-road long-haul truck, although it will
be apparent to those skilled in the art that the heating and
cooling system of the present invention may be employed for heating
other interior spaces.
[0030] Reference is now made to FIG. 1 that depicts an environment
wherein a reversible mode heating and cooling system, generally
designated as 20, of the present invention is employed.
Particularly shown is a long-haul truck 2. The truck 2 includes a
cab 4 to which a sleeper cabin 6 may be connected. The cab 4 and
the sleeper cabin 6 (when provided) define the interior space to be
cooled or heated by the system 20 of the present invention. The
auxiliary power unit (APU) system 10 is also provided and is
generally mounted on the side of a frame 8 of the truck 2.
[0031] The APU 10 can be any conventional APU presently in use and,
thus, the detail description of such APU 10 will be omitted for the
sake of brevity. The elements of the APU 10 that have importance to
the operation of the system 20 are an engine 12 and an engine fan
16 mounted within the housing 18 and provided for cooling the
engine 12 with air.
[0032] Preferably, the engine 12 is of one cylinder an air-cooled
diesel type, such as a Yanmar LV 100 or equivalent which is
advantageous for its low power consumption and employment of a
small, about one hundred seventy five watt electrical
generator.
[0033] Now in reference to FIGS. 2-5, there is shown the reversible
mode heating and cooling system 20 which is constructed in
accordance with a presently preferred embodiment of the
invention.
[0034] The system 20 includes a compressor 22 for compressing
vaporous refrigerant, such as a Freon. There is also a power
transmission means that is provided for connecting the compressor
22 to a rotating shaft 14 of the diesel engine 12 so that the
compressor 22 can be operated directly by the engine 12.
[0035] A first heat exchanger 30 is externally mounted and is
arranged in a heat exchange relationship with outdoor ambient air
and in refrigerant communication with the compressor 22 for
evaporating refrigerant during the heating mode and condensing the
refrigerant during the cooling mode. As is conventional, the first
heat exchanger includes a coil 32. A blower unit 34 is provided in
air communication relationship with the first heat exchanger 30.
The blower unit 34 has a fan 36 which is preferably electrically
operable.
[0036] An air duct 40 is provided in air communication with the
engine fan 14 and the first heat exchanger 30 for supplying air
thereto.
[0037] There is also a conventional heat exchange unit 50 which is
arranged in heat exchange relationship with air in the interior
space for condensing refrigerant and heating the air and in
refrigerant communication with the compressor 30 during the heating
mode and evaporating refrigerant and cooling the air during the
cooling mode. The second heat exchanger 50 is generally referred to
as "in-bunk" unit and is mounted internal to the interior space to
be cooled or heated. As is conventional, a bi-directional
refrigerant expansion valve 60 is operatively disposed intermediate
the first and second heat exchangers 30, 50 to maintain the
pressure drop in the refrigerant and control the refrigerant flow.
Any existing residential or automotive expansion valves may be
employed in the present invention.
[0038] A refrigerant flow reversing valve 62 is also provided and
is operable for providing heating and cooling modes from the system
20 by a refrigerant flow direction selection.
[0039] The presently preferred power transmission means, best
illustrated in FIG. 4, includes a belt member 24 and a pair of
pulleys 26, 28. One of the pair of pulleys, referenced with numeral
26, is secured to the rotating shaft 14 of the engine 12 for
rotation therewith. The other pulley, referenced with numeral 28 is
rotatably secured to the shaft 23 of the compressor 22.
[0040] In operation, during the cooling mode of FIGS. 2 and 3, the
compressor 22 pumps the refrigerant to the reversing valve 62. The
reversing valve 62 directs the flow to the first heat exchanger 30
which functions as a condenser where the fan 34 cools and condenses
the refrigerant to liquid. The air flowing across the first heat
exchanger coil 32 from the engine 12 through the air duct member 40
removes heat from the refrigerant. The liquid refrigerant then
flows to the second heat exchanger 50 which functions as an
evaporator. There it picks up heat energy from the air blowing
across the coil of the second heat exchanger 50 and the air comes
out cooler for cooling the interior space. The resulting
refrigerant vapor then travels back to the reversing valve 62 to be
directed to the compressor 22 to start the cycle all over
again.
[0041] During the heating mode of FIGS. 4 and 5, the reversing
valve 62 directs the compressed refrigerant to the second heat
exchanger 50 first. This makes the second heat exchanger 50
function as the condenser and releases the heat energy. This heated
air is then communicated into the interior space. The first heat
exchanger 30 then functions as evaporator and collects the heat
energy. As has been described above, the first heat exchanger 30 is
in direct communication with the waste heat released during cooling
of the engine 12. This arrangement facilitates the use of the
engine cooling air (waste heat) to heat the first heat exchanger 30
during the heating mode. This provides two advantages. First, the
system 20 consumes less energy and second, the system 20 operates
efficiently even when the ambient temperature drops below 23
degrees Fahrenheit due to the higher temperature of the air
entering the first heat exchanger 30. This is a significant
improvement over the prior art cooling and heating systems, for
example where the colder ambient air may be drawn into the heat
exchanger.
[0042] Furthermore, during the heating mode, operation of the fan
36 is not necessary. Thus, the system may be adapted with ON/OFF
controls, such as switch 38, for selectively operating the fan 36
which, in this arrangement, is not required during the heating
mode.
[0043] While the above described system 20 is capable of cooling
and heating the interior space, it has been found that adapting the
duct means 40 with a pair of openings and a pair of dampers or
flaps, which are operable to selectively cover and uncover the
openings, improve the efficiency of the system 20 particularly in
the heating mode when the ambient air is below about twenty three
degrees on the Fahrenheit scale.
[0044] Accordingly, a first opening 70 is provided for exhausting
air from the engine fan 14 to atmosphere and is equipped with a
first damper or flap 74 which is movable for covering the first
opening 70 during heating mode and opening the first opening 70
during the cooling mode. The first damper or flap 74 may be of a
conventional type, for example rotatably mounted within the air
duct 40 with a shaft 73. A second opening 72, which may be a pair
of openings 72, is provided for enabling flow of ambient air into
the first heat exchanger 30 and is equipped with a second damper or
flap 76 for covering the second opening(s) 72 during heating mode
and uncovering the second opening(s) 72 during cooling mode. Each
damper or flap may be manually operated however it is presently
preferred to provide a powered actuator, for example such as an
electric motor 78 for operating such each damper or flap.
[0045] During the heating mode, the openings 72 and 74 are covered
facilitating flow of the heated air from the engine 12 to the first
heat exchanger 30.
[0046] During the cooling mode, the openings 72 and 74 are
uncovered. Subsequently, the heated air from the engine 12 is
exhausted to outside through the first damper 74 by the engine fan
18 while cooler ambient air is drawn into the first heat exchanger
30 by the fan 36. Thus, during the cooling cycle, the system 20 of
the present invention uses less energy to compress refrigerant
vapors. It would be understood from the above discussion, that the
fan 36 is rotatable in only one direction, thus reducing the
complexity of the control system (not shown).
[0047] A small auxiliary type generator or alternator 79 may be
provided for powering each electric motor 78 as well as the
reversing valve 62. It is contemplated that about one thousand
(1,000) watts of electric power will be sufficient to power the
components of the system 20, power various appliances in use by the
operator of such motor vehicle (not shown) and charging the main
batteries. Accordingly, an auxiliary generator 80 capable of
generating between about five hundred (500) watts and about eight
hundred (800) watts should be sufficient in providing required
electric energy. Advantageously, the diesel engine manufactured
under Yanmar LV 100 brand employs a small alternator capable of
providing about one hundred seventy (170) watts of power. It must
be important to note that prior art electrically driven compressors
and other devices require about five thousand (5,000) watt of
energy. Thus, by eliminating the conversion from mechanical power
at the crankshaft of the small diesel engine to electrical power in
a generator and then back again from electrical power from to
mechanical power in an electric powered air conditioning
compressor, the costs associated with the generator and electric
motor of the prior art systems are eliminated and the heating and
cooling system 20 of the present invention requires significantly
less electric energy than comparable prior art systems.
[0048] It will be apparent to those skilled in the relevant arm
form that the ability of the system 20 of the present invention to
utilize waste heat from the engine 12 during heating mode and
control air flow to and from the first heat exchanger 30 by way of
openings and dampers increase efficiency of the system to cool or
heat the interior space of the cab 4. Furthermore, a mechanically
driven compressor 22 eliminates the need for a large electrical
generator thus facilitating the reduction in manufacturing costs of
the system 20.
[0049] It is also within the scope of the present invention to
re-circulate air passed through the first heat exchanger 30 and
exhausted by the fan 34 back to the engine 12. This replaces cold
ambient air with warmer air from the first heat exchanger 30.
Accordingly, a second air duct 42 is installed to connect the
outlet end of the blower 34 with the air inlet end of the engine
12. A damper or flap 44 controlled by an actuator 46 and a
temperature sensor 48 may be provided to disable recirculation
during warmer ambient temperatures.
[0050] While the system 20 has been described above as using one
first heat exchanger 30 in combination with the air duct
arrangement 40, it is contemplated that a pair of heat exchangers
referenced as 30a and 30b and a pair of check valves 38 may be
alternatively provided, as best shown in FIGS. 6-7.
[0051] It is also within the scope of the present invention to
provide means, generally designated as 80, for operating the system
20 from a one hundred ten volt power outlet. Such arrangement is
commonly referred to in the art as "shore power" and is employed
when state emission mandates prohibit or significantly limit the
use of APUs. Now in reference to FIG. 8, such means 80 may include
a first one way clutch 82 which is secured to the engine shaft 12,
an electric motor 84 capable of being connected to the source of
one hundred ten volt power outlet 86, for example with a cord 88, a
second one-way clutch 90 which is secured to the output shaft 92 of
the electric motor 84 for rotation therewith. A belt 94 is then
provided to operatively engage the pair of clutches 82, 90 and the
compressor pulley 28. Thus, when the compressor 22 is operable by
the engine 12, the second clutch 90 prevents rotation of the motor
output shaft 92. Likewise, when the motor 84 is operable from the
electrical power grid, the first clutch 82 prevents rotation of the
engine shaft 14.
[0052] Although the present invention has been described in terms
of the cooling and heating system 20 in use for heating an interior
space of a cab 4 and/or sleeper cabin 6 of the over-the-road truck
2, it will be apparent to those skilled in the art, that the
present invention may be applied to other vehicles such as bus,
boat, and camper often requiring the use of APU.
[0053] Furthermore, the novel air duct and damper arrangement will
be advantageous for improving efficiency of a conventional
eclectically driven heating and cooling system.
[0054] Additionally, as a single cylinder air-cooled engine is
advantageous in reducing the cost of operating the system 20, other
engine types are also contemplated for use within the present
invention.
[0055] It will be also understood that the configuration of the air
ducts 40, 42 and physical location and mounting of various
components of the system 20 will depend on the construction of the
vehicle 2 as well as on the construction and location of the APU
10.
[0056] Thus, the present invention has been described in such full,
clear, concise and exact terms as to enable any person skilled in
the art to which it pertains to make and use the same. It will be
understood that variations, modifications, equivalents and
substitutions for components of the specifically described
embodiments of the invention may be made by those skilled in the
art without departing from the spirit and scope of the invention as
set forth in the appended claims.
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