U.S. patent application number 12/007214 was filed with the patent office on 2008-06-05 for air-treatment system with secondary circuit.
This patent application is currently assigned to Caterpillar Inc.. Invention is credited to Mark Thomas Grimm, Ryan Patrick McEnaney, Sean Ronald Motszko, Dan Alan Spurgeon, Norval P. Thomson.
Application Number | 20080127663 12/007214 |
Document ID | / |
Family ID | 33518260 |
Filed Date | 2008-06-05 |
United States Patent
Application |
20080127663 |
Kind Code |
A1 |
Grimm; Mark Thomas ; et
al. |
June 5, 2008 |
Air-treatment system with secondary circuit
Abstract
An air-treatment system includes a cooling circuit, a first heat
exchanger in thermal communication with the cooling circuit, and a
secondary circuit in thermal communication with the first heat
exchanger. The air-treatment system also includes a controller in
communication with at least one of the cooling circuit, the first
heat exchanger, and the secondary circuit. The controller is
operable to receive at least one input indicative of a desired
ambient condition, operable to receive at least one input
indicative of current ambient conditions, operable to receive at
least one input indicative of at least one of the cooling circuit
operation and secondary circuit operation, and operable to change
the operation of at least one of the cooling circuit and the
secondary circuit when the current ambient condition is outside of
a desired operation condition range.
Inventors: |
Grimm; Mark Thomas; (Dunlap,
IL) ; Spurgeon; Dan Alan; (Washington, IL) ;
Motszko; Sean Ronald; (Edelstein, IL) ; Thomson;
Norval P.; (Dunlap, IL) ; McEnaney; Ryan Patrick;
(Peoria, IL) |
Correspondence
Address: |
CATERPILLAR/FINNEGAN, HENDERSON, L.L.P.
901 New York Avenue, NW
WASHINGTON
DC
20001-4413
US
|
Assignee: |
Caterpillar Inc.
|
Family ID: |
33518260 |
Appl. No.: |
12/007214 |
Filed: |
January 8, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10743812 |
Dec 24, 2003 |
|
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|
12007214 |
|
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Current U.S.
Class: |
62/180 |
Current CPC
Class: |
B60H 1/00885 20130101;
B60H 1/032 20130101; B60H 2001/00928 20130101; B60H 1/32281
20190501 |
Class at
Publication: |
62/180 |
International
Class: |
F25D 17/00 20060101
F25D017/00 |
Claims
1.-34. (canceled)
35. An air-treatment system, comprising: a cooling circuit; a first
heat exchanger in thermal communication with the cooling circuit; a
secondary circuit in thermal communication with the first heat
exchanger, a first area, and a second area, the secondary circuit
operable to selectively transfer heat between the first heat
exchanger and the first area or the second area; and a controller
in communication with at least one of the cooling circuit, the
first heat exchanger, and the secondary circuit, the controller
having a storage medium storing a desired ambient condition range,
the controller operable to: receive a first set of values
indicative of a first current ambient condition and a first desired
ambient condition of the first area and a second set of values
indicative of a second current ambient condition and a second
desired ambient condition of the second area, based on the received
first and second sets of values, determine that the first current
ambient condition or the second current ambient condition is
outside of the desired ambient condition range, and initiate a
transfer of heat between the first heat exchanger and the first
area or between the first heat exchanger and the second area based
on the determination and the first or second desired ambient
conditions.
36. The air-treatment system of claim 35, wherein the value
indicative of the first current ambient condition includes a solar
load.
37. The air-treatment system of claim 36, wherein the solar load is
the intensity of solar light.
38. The air-treatment system of claim 35, wherein the cooling
circuit includes: a compressor; a condenser in fluid communication
with the compressor; and an expansion valve in fluid communication
with the condenser.
39. The air-treatment system of claim 35, further including: a
second expansion valve in fluid communication with the condenser;
and a second heat exchanger in fluid communication with the second
expansion valve and the compressor.
40. The air-treatment system of claim 35, wherein the secondary
circuit includes: at least one pump; at least one heat exchanger in
fluid communication with the pump; and at least one fan proximally
disposed relative to the at least one heat exchanger, the fan
operable to cause a flow of air across the at least one heat
exchanger.
41. The air-treatment system of claim 35, further including a
heating device proximally disposed relative to the at least one
heat exchanger and fan, wherein the airflow from the fan is first
directed across the at least one heat exchanger and subsequently
the heating device.
42. The air-treatment system of claim 35, wherein the values
indicative of the first or second current ambient conditions
includes at least one of an air temperature or a fan speed.
43. The air-treatment system of claim 35, wherein the values
indicative of the first or second desired ambient conditions
includes at least one of a temperature, a treatment mode, or a fan
speed.
44. The air-treatment system of claim 43, wherein the treatment
mode includes at least one of a cooling mode, a defrost mode, or a
ventilation mode.
45. An air-treatment method, comprising: receiving, by a
controller, a first set of values indicative of a first current
ambient condition and a first desired ambient condition of a first
area and a second set of values indicative of a second current
ambient condition and a second desired ambient condition of a
second area, wherein the controller is in communication with a
first heat exchanger, the controller having a storage medium
storing a desired ambient condition range; determining, by the
controller, that the first current ambient condition or the second
current ambient condition is outside of the desired ambient
condition range based on the received first and second sets of
values; and initiating a transfer of heat between the first heat
exchanger and the first area or between the first heat exchanger
and the second area based on the determination and the first or
second desired ambient conditions.
46. The air-treatment system of claim 45, wherein the value
indicative of the first current ambient condition includes a solar
load.
47. The air-treatment system of claim 46, wherein the solar load is
the intensity of solar light.
48. The air-treatment system of claim 45, wherein the values
indicative of the first or second current ambient conditions
includes at least one of an air temperature or a fan speed.
49. The air-treatment system of claim 45, wherein the values
indicative of the first or second desired ambient conditions
includes at least one of a temperature, a treatment mode, or a fan
speed.
50. The air-treatment system of claim 49, wherein the treatment
mode includes at least one of a cooling mode, a defrost mode, or a
ventilation mode.
Description
[0001] This is a division of U.S. patent application Ser. No.
10/743,812, filed Dec. 24, 2003, pending, which is incorporated
herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates generally to an air-treatment
system, and more particularly to an air-treatment system with a
secondary circuit.
BACKGROUND
[0003] Work machines typically include an operator cabin, which
houses one or more machine controls and an operator interface. The
operator cabin may be sealed from the environment and may include
an air-treatment system providing for the comfort of the operator
when the work machine operates in harsh environments.
[0004] The air-treatment system for a work machine may include a
high-pressure refrigeration system driven by the engine and a
low-pressure fluid circulation system. For example, U.S. Pat. No.
6,038,877 (the '877 patent) issued to Peiffer et al. on Mar. 21,
2000, describes an air-conditioning system having a power cell, a
remote heat exchanger, and a low-pressure fluid circuit in
communication with the heat exchanger. The power cell of the '877
patent includes a compressor, a condenser, an expansion device, and
an evaporator in a closed high-pressure cooling circuit. The
low-pressure circuit thermally interfaces with the condenser to
remove heat from the high-pressure cooling circuit. The heat
exchanger mounts in the cabin of a vehicle to allow for air to be
cooled by the heat exchanger as it flows into the cabin.
[0005] The air-conditioning system of the '877 patent, however,
does not include a control system and may operate inefficiently
under a variety of environmental conditions. In addition, the
system of the '877 patent does not include a heating circuit and
can only cool the air entering the cabin. The system of '877 patent
may lack functionality for simultaneous multi-space use, such as in
a work machine having an operator cabin and a sleeping cabin.
[0006] The present invention overcomes one or more of the problems
set forth above.
SUMMARY OF THE INVENTION
[0007] In one aspect, the present disclosure pertains to an
air-treatment system that includes a cooling circuit, a first heat
exchanger in thermal communication with the cooling circuit, and a
secondary circuit in thermal communication with the heat exchanger.
The air-treatment system also includes a controller in
communication with at least one of the cooling circuit, the first
heat exchanger, and the secondary circuit. The controller is
operable to receive at least one input indicative of a desired
ambient condition, of current ambient conditions, and of at least
one of the cooling circuit operation and secondary circuit
operation, and is further operable to change the operation of at
least one of the cooling circuit and the secondary circuit when the
current ambient condition is outside of a desired ambient condition
range.
[0008] In another aspect, the present disclosure pertains to a
method of treating ambient air in a work machine. The method
includes operating a cooling circuit to cool a refrigerant and
operating a secondary circuit to selectively transfer heat from at
least one of an operator cabin and a sleeping cabin of the work
machine to the cooled refrigerant. The method further includes
receiving at least one input indicative of a desired ambient
condition, a current ambient condition, and of at least one of a
cooling circuit operation and a secondary circuit operation, and
changing at least one of the cooling circuit operation and the
secondary circuit operation when the desired ambient condition is
outside of a desired ambient condition range.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a pictorial illustration of a work machine having
an air-treatment system according to an exemplary embodiment of the
present invention;
[0010] FIG. 2 is a diagrammatic illustration of an air-treatment
system according to an exemplary embodiment of the present
invention;
[0011] FIG. 3 is a diagrammatic illustration of the air-treatment
system according to an exemplary embodiment of the present
invention;
[0012] FIG. 4 is a diagrammatic illustration of the air-treatment
system according to an exemplary embodiment of the present
invention;
[0013] FIG. 5 is a diagrammatic illustration of the air-treatment
system according to an exemplary embodiment of the present
invention; and
[0014] FIG. 6 is a diagrammatic illustration of a control system of
the air-treatment system according to an exemplary embodiment of
the present invention.
DETAILED DESCRIPTION
[0015] FIG. 1 illustrates an exemplary embodiment of an
air-treatment system 10 for a work machine 5. Air-treatment system
10 may include a cooling circuit 12 working in cooperation with a
secondary circuit 14. Cooling circuit 12, having high-pressure
fluid lines, may be conveniently located anywhere on work machine
5, such as in an engine compartment or outside of an operator cabin
16 or a sleeping cabin 18. Secondary circuit 14, having
low-pressure fluid lines, may be thermally connected to cooling
circuit 12 via a fluid-to-fluid heat exchanging device (HX) 20.
Secondary circuit 14 may be in fluid communication with both
operator cabin 16 and sleeping cabin 18.
[0016] Cooling circuit 12 may be modular and compact with
hard-brazed tubing that reduces the risk of leaks or rupture.
Cooling circuit 12 may include a high-pressure refrigerant such as,
for example, CO.sub.2, R-134a, R-410, R-22, or any other
refrigerant known in the art. As illustrated in FIG. 2, cooling
circuit 12 may include a compressor 22, a condenser 24, a condenser
fan 28, a first thermal expansion valve (TXV) 32, a vapor-injection
heat exchanger (VIHX) 36, and a second TXV 44. Cooling circuit 12
may be hermetically sealed.
[0017] Compressor 22 may be any type of refrigerant compressing
device such as, for example, a scroll-type compressor, or any other
device known in the art. Compressor 22 may be driven in a variety
of ways. For example, compressor 22 may include a direct drive
coupled to a power source, a belt drive, a hydraulic drive, an
electric drive, or any other appropriate driving arrangement.
Compressor 22 may also include an integral pressure lubrication
sump (not shown) for holding a supply of lubricant.
[0018] Compressor 22 may be in fluid communication with condenser
24 via a fluid passageway 26. Condenser 24 may be a two-phase
heat-exchanging device for converting a high-temperature and
high-pressure refrigerant from a vapor phase to a liquid phase
through heat rejection. Condenser fan 28 may be disposed relative
to condenser 24 such that condenser fan 28 can blow ambient air
across condenser 24.
[0019] Condenser 24 may be in fluid communication with VIHX 36 via
a fluid passageway 30 and a fluid passageway 34. VIHX 36 may also
be fluidly connected to compressor 22 via a fluid passageway 40.
TXV 32 may be disposed in fluid passageways 30 and 40 between
condenser 24 and compressor 22, and VIHX 36. VIHX 36 may be a
refrigerant-to-refrigerant heat exchanger.
[0020] VIHX 36 may be fluidly connected to HX 20 via a fluid
passageway 42. HX 20 may be type of two-phase heat exchanger for
exchanging heat between two circuits of fluid, such as a flat plate
heat exchanger. HX 20 may be fluidly connected to compressor 22 via
a fluid passageway 46. TXV 44 may be disposed in fluid lines 42 and
46 between VIHX 36 and compressor 22, and HX 20. TXV 44 may be a
block-style TXV.
[0021] Secondary circuit 14 may be a low-pressure circuit in
thermal communication with operator cabin 16, sleeping cabin 18,
and HX 20. Secondary circuit 14 may include a low-pressure fluid
such as, for example, water, glycol, a water-glycol mixture, a
blended air mixture, or any other low-pressure fluid known in the
art for transferring heat. Secondary circuit 14 may include two
pumps 48, two heat exchangers 54, and two fans 60. Pumps 48 may be
connected to HX 20 by fluid passageways 50 and 52 and may also be
in fluid communication with heat exchangers 54 located in operator
cabin 16 and in sleeping cabin 18 via fluid passageways 56 and 58.
Heat exchangers 54 may also be in fluid communication with HX 20
via fluid passageways 62 and 64.
[0022] A heating device 59 may also be included in operator cabin
16 next to heat exchanger 54. In one embodiment, heating device 59
may be electrically powered. Moreover, heating device 59 may be any
device for heating the air such as a heat exchanger with heated
coolant. Heat exchanger 54 and heating device 59 in operator cabin
16 and heat exchanger 54 in sleeping cabin 18 may be located in
airflow paths of fans 60.
[0023] One or more heating circuits may also be in communication
with secondary circuit 14, as illustrated in FIG. 3. One exemplary
embodiment of the present disclosure may include a first heating
circuit 66 fluidly connected to heat exchangers 54 associated with
operator cabin 16 and sleeping cabin 18. First heating circuit 66
may contain a device for heating the fluid within first heating
circuit 66. First heating circuit 66 may also include valves 70 and
72 connecting first heating circuit 66 to secondary circuit 14. In
one embodiment, the heating device may be a fuel-fired coolant
heater 68. However, the heating device may be any device to heat
the fluid such as, for example, an electric coolant heater.
[0024] First heating circuit 66 may include valves 70 located in
each of fluid passageways 50 and 52, and valves 72 located in each
of fluid passageways 62 and 64. Fuel-fired coolant heater 68 may be
connected to valves 70 via a fluid passageway 71, and to valves 72
via fluid passageways 73 and 75. It is also contemplated that the
device for heating may also be configured to heat the fluid within
secondary circuit 14 without the additional fluid passageways 71,
73, and 75. For example, the fuel-fired coolant heater 68 may
directly heat the fluid in secondary loop 14. In the case of an
electric coolant heater, the heating device may include electric
heat coils wrapped around portions of fluid passageways 50 and 52
to directly heat the fluid within these passageways.
[0025] As illustrated in FIG. 4, another exemplary embodiment of
the present disclosure may include a second heating circuit 74
integrated with a cooling system of an engine 76. Second heating
circuit 74 may connect engine 76 to secondary circuit 14 via valves
70 and 72 and fluid passageways 78, 80, and 82.
[0026] Another exemplary embodiment, as illustrated in FIG. 5, may
include both first heating circuit 66 and second heating circuit
74. Both first heating circuit 66 and second heating circuit 74 may
be connected to secondary circuit 14 via valves 70 and 72.
[0027] As illustrated in FIG. 6, air-treatment system 10 may
include a control system 84 in communication with cooling circuit
12, secondary circuit 14 and first and second heating circuits 66,
74. Control system 84 may include a controller 86 and an operator
interface 88 configured to receive input from the operator
indicative of a desired ambient condition. Controller 86 may also
be configured to receive, from the various circuits, sensory input
indicative of current ambient conditions and current air-treatment
system operation. Controller 86 may be further configured to change
the operation of air-treatment system 10 when the desired ambient
conditions are outside of a predetermined condition range.
[0028] Controller 86 may include a memory, a secondary storage
device, a processor, and any other components for running an
application. Various other circuits may be associated with
controller 86 such as power supply circuitry, signal conditioning
circuitry, solenoid driver circuitry, and other types of
circuitry.
[0029] Operator interface 88 may be used to provide inputs
indicative of desired ambient conditions to controller 86. These
inputs may include: a desired temperature 94, a desired mode 96,
and a desired fan speed 98. Desired mode input 96 may include a
signal indicating a cooling mode, a heating mode, a defrost mode,
and/or a ventilation mode. The operator may also input a desired
operator cabin fan speed and/or a desired sleeping cabin fan speed.
The desired fan speed input 98 may be a signal provided to
controller 86, which may also provide the main on/off indication
for air-treatment system 10.
[0030] Control system 84 may also be operable to receive input from
sensors located in cooling circuit 12, secondary circuit 14, first
heating circuit 66, second heating circuit 74, operator cabin 16,
and/or sleeping cabin 18 to determine current ambient conditions
and current air-treatment system operation. These sensory inputs
may include: a compressor discharge temperature sensor 106, a
condenser outlet temperature sensor 108, a HX temperature sensor
110, an operator cabin air temperature sensor 112, an operator
cabin water valve actuator 114 configured to provide actuator
position information, a sleeping cabin air temperature sensor 116,
a sleeping cabin water valve actuator 118 also configured to
provide actuator position information, and a solar load sensor
120.
[0031] Each of these sensors may be different types of sensors
and/or provide different types of information. For example,
compressor discharge temperature sensor 106 may be a
surface-temperature-type sensor that measures refrigerant
temperature at the point where the refrigerant exits compressor 22.
Condenser outlet temperature sensor 108 may also be a
surface-temperature-type sensor that measures refrigerant
temperature at the point the refrigerant exits condenser 24. HX
temperature sensor 110 may also be a surface-temperature-type
sensor. This sensor measures the temperature of cooling fins
located on HX 20. Operator and sleeping cabin air temperature
sensors 112, 116 may be air-temperature-type sensors that measure
the temperature of the air exiting air-treatment system 10 and
entering the operator and/or sleeping cabin environments. Operator
and sleeping cabin water valve actuators 114, 118 provide position
feedback to controller 86 for diagnostic operation. The actuator
position feedback includes an active sensor input to controller 86.
Solar load sensor 120 may be an illumination-type sensor that
measures the intensity of solar light entering the operator cabin
environment through the windshield. Solar load sensor 120 may be
part of an automatic temperature control function of controller
86.
[0032] A greater or lesser number of sensors may be used, and the
sensors may be positioned differently and/or provide different
types of information. The information from the sensors may be used
to automatically adjust air-treatment system operation, diagnose
operation of air-treatment system 10, and/or prevent damaging
operation of air-treatment system 10.
INDUSTRIAL APPLICABILITY
[0033] The disclosed system may be used in any work machine
application requiring the treatment of air in response to an
indication of a desired ambient condition. For example, in a work
machine 5, having operator cabin 16 and sleeping cabin 18, as
illustrated in FIG. 1, an operator may indicate a desired ambient
condition through operator interface 88 (FIG. 6). The operator may
input a desired air temperature 94, a desired mode 96, and a
desired fan speed 98. The desired mode input 96 may include a
cooling mode, a heating mode, a defrosting mode, and/or a
ventilation mode. The desired ambient condition may be indicated
for operator cabin 16 and/or sleeping cabin 18. In addition, the
desired ambient condition of operator cabin 16 may be indicated
simultaneously and as a different desired ambient condition
relative to sleeping cabin 18.
[0034] As depicted in FIG. 6, the desired ambient condition may be
input via operator interface 88. Controller 86 of air-treatment
system 10 may receive the input indicative of the desired ambient
condition, input indicative of current ambient condition, and input
indicative of current air-treatment system operation. Controller 86
may automatically change the performance of air-treatment system 10
when the current ambient condition is outside of a predetermined
condition range.
[0035] For the purposes of this disclosure a predetermined
condition range may include a range of acceptable margin around a
desired operator input, in which controller 86 keeps constant the
performance of air-treatment system 10. The desired operator input
may include, for example, a desired temperature. The predetermined
condition range may be determined through lab and/or field testing.
Alternately, the predetermined condition range may be determined
through other methods such as, for example, operator input.
[0036] When a cooling mode is indicated, control system 84 may
activate cooling circuit 12, causing compressor 22 to engage and
compress the refrigerant. As the refrigerant is pressurized, the
temperature of the refrigerant increases. The heated, pressurized
refrigerant may then be passed to condenser 24.
[0037] Condenser 24 may convert the heated, pressurized refrigerant
from a vapor phase to a liquid phase through heat rejection. Heat
is removed from the refrigerant as it passes through condenser 24
as condenser fan 28 blows ambient air across condenser 24, thereby
cooling the refrigerant. A portion of the cooled refrigerant may
then be sent through first TXV 32 and then to VIHX 36, while the
remaining portion is sent directly to VIHX 36.
[0038] The portion of the refrigerant that flows through TXV 32
expands and drops to a lower temperature as compared to the
refrigerant that flows directly to VIHX 36. The two flows of
refrigerant may exchange heat in VIHX 36. TXV 32 may meter liquid
refrigerant flow in response to a load on VIHX 36 and maintain a
desired superheat at a VIHX outlet. TXV 32 provides the necessary
pressure drop to deliver a chilled mixture of liquid and vapor
refrigerant to VIHX 36. The portion of refrigerant that is expanded
through TXV 32 may be returned to compressor 22 after exiting VIHX
36. Before entering HX 20, the sub-cooled refrigerant from VIHX 36
may flow through TXV 44 where the refrigerant is expanded to cause
an additional drop in temperature.
[0039] TXV 44 may meter liquid refrigerant flow in response to load
on HX 20 to maintain a desired superheat at a HX outlet. TXV 44 may
provide the necessary pressure drop to deliver a mixture of chilled
liquid and vapor refrigerant to HX 20. After expansion in TXV 44,
the chilled fluid may flow to HX 20, absorb heat, and then flow
back to compressor 22 to begin the cycle anew.
[0040] Secondary circuit 14 may be configured to exchange heat with
cooling circuit 12 and/or with one or more heating circuits. Low
pressure secondary circuit 14 allows the delivery of airflow at an
operator-requested temperature and rate without the risk associated
with a high-pressure circuit. HX 20 may chill the fluid used to
cool the air forced into the operator cabin 16 and sleeping cabin
18.
[0041] HX 20 may impart heat from secondary circuit 14 to the
chilled fluid of cooling circuit 12 as the fluid, moved by pumps
48, flows through HX 20. After the cooled fluid exits HX 20, it may
be directed to heat exchangers 54 of operator cabin 16 and sleeping
cabin 18. As the fluid flows through heat exchangers 54, fans 60
may blow intake and/or recirculated ambient air at the desired fan
speed across heat exchangers 54, thereby cooling the air to the
desired temperature. After receiving heat from the air blown across
heat exchangers 54, the then-warmed fluid of the secondary circuit
is directed back to HX 20 where it is again chilled.
[0042] When a heating mode is indicated, control system 84 may
activate first and/or second heating circuits 66, 74. Heating
device 68 of first heating circuit 66 and/or engine 76 of second
heating circuit 74 may engage to heat the fluid within first and/or
second heating circuits 66, 74.
[0043] Valves 70 and 72 may be used to control the flow rate of the
fluid heated by heating device 68 through secondary circuit 14.
Depending on the operator's temperature input and mode input,
valves 70 and 72 may be moved between an open position and a closed
position to allow flow, restrict flow, and block flow of heated
fluid through secondary circuit 14.
[0044] When in heating mode, heated fluid may pass from first
and/or second heating circuits 66, 74 to secondary circuit 14 where
the fluid circulates through heat exchangers 54 of operator cabin
16 and/or sleeping cabin 18. Fans 60 may blow intake and/or
recirculated ambient air at the desired fan speed across heat
exchangers 54, thereby heating the air to the desired temperature.
The flow rate of the heated fluid through heat exchangers 48 may
directly affect the temperature of the airflow into operator cabin
16 and sleeping cabin 18.
[0045] During the heating operation, first or second heating
circuits 66, 74 may be active. During times of cold starting and/or
during cold operation, both first and second heating circuits 66,
74 may operate simultaneously. In addition to heating the operator
and/or sleeping cabins 16, 18, first heating circuit 66 may be used
to heat second heating circuit 74 and engine 76. In this way,
engine 76 may be warmed more quickly than under normal operating
conditions. Reducing the warm-up time of engine 76 may reduce
emissions, improve efficiency and reduce wear of engine 76.
[0046] When a defrost mode is input, controller 86 may activate
cooling circuit 12 and heating device 59. The cooled liquid of the
secondary circuit 14 may be directed to heat exchanger 54 located
in operator cabin 16 to remove humidity from the air before the air
is heated by heating device 59 and forced into operator cabin
16.
[0047] When a ventilation mode is input, control system 84 may
activate fans 60 located in operator and/or sleeping cabins 16, 18.
Fans 60 may blow intake and/or recirculated ambient air at the
desired fan speed. When in a ventilation mode, the coolant in the
air-treatment system 10 remains stationary, thereby allowing air
that is neither heated nor cooled to enter the operator and/or
sleeping cabins. Valves 70 and 72 may be closed during ventilation
mode, thereby isolating HX 20 from heat exchangers 54.
[0048] In response to a desired fan speed input, controller 86 may
adjust the fan speed and deliver the requested airflow.
Air-treatment system 10 may be turned on and off based on the
desired fan speed input.
[0049] Information from the sensors located in cooling circuit 12,
secondary circuit 14, first heating circuit 66, second heating
circuit 74, operator cabin 16, and sleeping cabin 18 may be used to
determine current ambient conditions and current air-treatment
system operation. This information may then be used to ensure
proper function of air-treatment system 10.
[0050] For example, information from the compressor discharge
sensor described above, may be used by controller 86 to prevent
compressor 22 from operating in a condition that may damage
compressor 22. Such conditions may include overheating of the
compressor, which may cause over-current of an electric compressor
drive. In the case of a mechanically-driven compressor, compressor
discharge temperature sensor 106 may be replaced with a pressure
sensor that sends a signal indicating the mechanically-driven
compressor should be switched off when pressures exceed a
predetermined limit. Additionally, the condenser outlet temperature
sensor information may also be used for compressor protection to
prevent compressor 22 from operating in a condition that may
damage. Similar to the condenser and compressor sensors, the HX
temperature sensor may be used to ensure proper function of HX 20.
The information from the HX temperature sensor may be used to
prevent HX 20 from freezing, thereby causing diminished cooling
performance.
[0051] The information from the various sensors may also be used in
conjunction with desired ambient condition inputs to automatically
adjust the temperature and/or flow rate of the air blown into
operator and/or sleeping cabins 16, 18. For example, the operator
and sleeping cabin air temperature sensor information may be used
as part of a closed circuit temperature control. The sensors may
provide air temperature information to controller 86, which may
automatically adjust the air-treatment system 10 to deliver the
operator requested temperature. In addition, the operator and
sleeping cabin water valve actuators 114, 118 may provide position
feedback to controller 86 for diagnostic operation. Further, the
solar load sensor information may be used to automatically adjust
air-treatment system 10 to deliver more or less airflow to the
operator to offset the effects of solar warming.
[0052] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed
air-treatment system without departing from the scope of the
invention. Other embodiments of the invention will be apparent to
those skilled in the art from consideration of the specification,
and practice of the invention disclosed herein. It is intended that
the specification and examples be considered as exemplary only,
with a true scope of the invention being indicated by the following
claims and their equivalents.
* * * * *