U.S. patent application number 10/292857 was filed with the patent office on 2004-05-13 for clutching mechanism for positive displacement air cycle system.
This patent application is currently assigned to Visteon Global Technologies, Inc.. Invention is credited to Christen, Brian John, Gielda, Thomas Paul, Harte, Shane A., Schnaidt, Wayne Charles.
Application Number | 20040089000 10/292857 |
Document ID | / |
Family ID | 32229540 |
Filed Date | 2004-05-13 |
United States Patent
Application |
20040089000 |
Kind Code |
A1 |
Christen, Brian John ; et
al. |
May 13, 2004 |
Clutching mechanism for positive displacement air cycle system
Abstract
An air cycle air conditioning system for treating air contained
within a passenger compartment of a vehicle. The system includes a
compressor for receiving air from the passenger compartment and
compressing the air, thereby producing charged air. Further, an
expander is provided selectively coupled to the compressor for
expanding the air and cooling the air communicated to the passenger
compartment. The system further includes an air-to-air heat
exchanger that cools the air received by the compressor-and
supplies cooled charged air to the vehicle's engine.
Inventors: |
Christen, Brian John;
(Canton, MI) ; Schnaidt, Wayne Charles; (Novi,
MI) ; Gielda, Thomas Paul; (Brighton, MI) ;
Harte, Shane A.; (Farmington Hills, MI) |
Correspondence
Address: |
VISTEON 29074
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60611
US
|
Assignee: |
Visteon Global Technologies,
Inc.
|
Family ID: |
32229540 |
Appl. No.: |
10/292857 |
Filed: |
November 12, 2002 |
Current U.S.
Class: |
62/86 ;
62/402 |
Current CPC
Class: |
F25B 9/06 20130101; B60H
1/3204 20130101; B60H 1/32 20130101 |
Class at
Publication: |
062/086 ;
062/402 |
International
Class: |
F25B 009/00; F25D
009/00 |
Claims
1. An air cycle air conditioning system for treating air contained
within a passenger compartment of a vehicle, the system comprising:
a compressor for receiving air from the passenger compartment and
compressing the air, thereby producing charged air; an expander
selectively coupled to the compressor for expanding the air,
thereby cooling the air communicated to the passenger compartment;
and an air-to-air heat exchanger, wherein the heat exchanger cools
the air received by the compressor and supplies the cooled charged
air to the vehicle's engine.
2. The system of claim 1 wherein the air-to-air heat exchanger
further comprises a water separator for removing a portion of water
from the air passing through the heat exchanger.
3. The system of claim 1 further comprising a clutch for
selectively coupling and decoupling the compressor from the
expander.
4. The system of claim 1 further comprising a valve located between
the heat exchanger and the expander for reducing air flow to the
expander.
5. The system of claim 1 further comprising a bleed tube that
connects an inlet of the expander to an outlet of the expander.
6. The system of claim 1 wherein the expander is a positive
displacement expander.
7. The system of claim 1 wherein the expander is a variable
displacement expander.
8. The system of claim 7 wherein the variable displacement expander
is a reciprocating type of expander wherein a stroke of the
expander may be adjusted to vary a displacement of the
expander.
9. The system of claim 7 wherein the variable displacement expander
is a screw type expander wherein an inlet point is varied to change
a displacement of the expander.
10. A method for treating air contained within a passenger
compartment of a vehicle using an air cycle air conditioning
system, the method comprising: receiving air from the passenger
compartment and compressing the air, thereby producing charged air
using a compressor; expanding the air using an expander selectively
coupled to the compressor for, thereby cooling the air communicated
to the passenger compartment; cooling the air received by the
compressor; and supplying the cooled charged air to the vehicle's
engine using an air-to-air heat exchanger.
11. The method of claim 10 further comprising deactivating the
expansion process carried out by the expander by decoupling the
expander from the compressor when the expander starts to heat the
air.
12. The method of claim 10 further comprising deactivating an
expansion process carried out by the expander by regulating a valve
located upstream of the expander when the expander starts to heat
the air.
13. The method of claim 10 further comprising removing a portion of
water from the air passing through the heat exchanger.
14. The method of claim 10 further comprising selectively coupling
and decoupling the compressor from the expander using a clutch to
regulate an expansion process carried out by the expander.
15. The method of claim 10 further comprising redirecting air from
an inlet of the expander to an outlet of the expander to regulate
an expansion process carried out by the expander.
16. The method of claim 10 further comprising adjusting a variable
displacement expander to regulate an expansion process carried out
by the expander wherein the variable displacement expander is a
reciprocating type of expander and wherein a stroke of the expander
is varied to change a displacement of the expander.
17. The method of claim 10 further comprising adjusting a variable
displacement expander to regulate an expansion process carried out
by the expander, wherein the variable displacement expander is a
screw type expander wherein an inlet point is varied to change a
displacement of the expander.
Description
TECHNICAL FIELD
[0001] The present invention relates to air cycle air conditioning
systems and to systems that also deliver charged air to an
automobile engine.
BACKGROUND
[0002] Conventional air conditioning systems for conditioning air
within a passenger compartment of a vehicle include a cooling and a
heating system. The cooling system is typically a refrigerant based
vapor compression system. The system includes a compressor, a
condenser, an expansion device, an evaporator and a refrigerant
supply. In operation, air in the vehicle passenger compartment is
cooled by blowing the air over the evaporator and thereby
transferring heat from the air to the refrigerant. The refrigerant
is then cycled back to the compressor and compressed, cooled in the
condenser, expanded by the expansion device and then routed back to
the evaporator to complete the cycle.
[0003] The air heating system is also a closed system, however, it
is not pressurized. Typically, liquid coolant from the engine
cooling system is pumped to a heat exchanger called a heater core.
The vehicle passenger compartment air to be heated is blown over
the heater core transferring the heat from the liquid coolant in
the heater core to the passenger compartment air.
[0004] Air cycle air conditioning systems are also well known,
especially in airplanes. Air cycle air conditioning systems operate
based off the compression and expansion of air. For example, an
airplane has a ready supply of compressed air from the airplane's
jet engine compressor. The compressed air may be expanded in a
cooling turbine to provide chilled air for cooling and
pressurization of the airplane's passenger compartment.
[0005] Therefore, it would be desirable to provide an air cycle air
conditioning system for an automobile.
SUMMARY
[0006] In an aspect of the present invention, an air cycle air
conditioning system for treating air contained within a passenger
compartment of a vehicle is provided. The system includes a
compressor for receiving air from the passenger compartment and
compressing the air, thereby producing charged air. An expander
selectively coupled to the compressor for expanding the air,
thereby cooling the air communicated to the passenger compartment.
The system includes an air-to-air heat exchanger that cools the air
received by the compressor and supplies the cooled charged air to
the vehicle's engine as well as to the expander.
[0007] In another aspect of the present invention, the system
includes an air-to-air heat exchanger having a water separator for
removing a portion of water from the air passing through the heat
exchanger.
[0008] In another aspect of the present invention, the system
includes a clutch for selectively coupling and decoupling the
compressor from the expander.
[0009] In yet another aspect of the present invention, the system
includes a valve located between the heat exchanger and the
expander for reducing air flow to the expander.
[0010] In still another aspect of the present invention, the system
includes a bleed tube that connects an inlet of the expander to an
outlet of the expander.
[0011] In still another aspect of the present invention, the
expander is a positive displacement expander and a variable
displacement expander.
[0012] In yet another aspect of the present invention, the variable
displacement expander is a reciprocating type of expander in which
a stroke of the expander may be adjusted to vary a displacement of
the expander.
[0013] In yet another aspect of the present invention, the variable
displacement expander is a screw type expander wherein an inlet
point is varied to change a displacement of the expander.
[0014] In still another aspect of the present invention, a method
for treating air contained within a passenger compartment of a
vehicle using an air cycle air conditioning system is provided. The
method includes receiving air from the passenger compartment and
compressing the air, thereby producing charged air using a
compressor, expanding the air using an expander selectively coupled
to the compressor, thereby cooling the air communicated to the
passenger compartment, cooling the air received by the compressor,
and supplying the cooled charged air to the vehicle's engine using
an air-to-air heat exchanger.
[0015] These and other aspects and advantages of the present
invention will become apparent upon reading the following detailed
description of the invention in combination with the accompanying
drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0016] FIG. 1 is a schematic diagram of an air cycle air
conditioning system for a vehicle, in accordance with the present
invention; and
[0017] FIG. 2 is a schematic diagram of an air cycle air
conditioning system for a vehicle having a bleed line connecting an
inlet of expander to an outlet of expander, in accordance with the
present invention.
DETAILED DESCRIPTION
[0018] Referring now to FIG. 1, an air cycle air conditioning
system 10 for selectively cooling or heating a passenger
compartment of a vehicle is provided, in accordance with the
present invention. System 10 includes a compressor 12 coupled to a
vehicle engine 14 through a pulley and belt drive arrangement 16.
Compressor 12 is an air cycle compressor and would replace a
conventional automotive air conditioning compressor. Further,
system 10 includes an expander 18, an intercooler 20, a water
separator 22, a fan 24 and a heater core 26.
[0019] Expander 18 expands the air in system 10 which lowers the
temperature of the air, lowers the pressure of the air to
sub-atmospheric pressure, and condenses a portion of water vapor
contained in the air. Expander 18 is connected to compressor 12
through shafts 28 and 30 which are in turn coupled to a clutch
mechanism 32. Clutch mechanism 32 is an electromagnetic clutch used
in prior art A/C systems for engaging and disengaging the A/C
compressor. However, the present invention contemplates using any
other suitable clutch mechanism for engaging and disengaging
expander 18 from compressor 12. Further, the present invention
contemplates other means and arrangements for selectively coupling
compressor 12 to expander 18. For example, a pulley and belt
arrangement may be employed where a first pulley is fixedly and
rotatably coupled to the compressor 12 and a second pulley is
fixedly and rotatably coupled to expander 18 and a belt engages the
pulleys to transmit a driving torque therebetween. Additionally, in
this pulley and belt arrangement, clutch mechanism 32 could be
located within one of the pulleys. In operation, the clutch would
be engaged to transmit driving torque from the pulley to an input
shaft of the expander and disengaged to remove the driving torque
form the expander.
[0020] During selective operation, work done by the expanding air
within expander 18 may be directed back to compressor 12 to
increase the overall efficiency of system 10. Alternatively,
expander 18 may be decoupled from compressor 12 to prevent the
expander from acting like a vacuum pump.
[0021] An air to air heat exchanger or intercooler 20 is provided
in communication with compressor 12 for lowering the temperature of
hot compressed air exiting compressor 12. Typically, intercooler 20
includes a water separator for removing water condensing in the
intercooler. At an exit of intercooler 20 a portion of the cold and
charged air is thereafter provided to engine 14. Thus, system 10 of
the present invention provides supercharging of engine 14.
Intercooler 20 exchanges heat contained in the pressurized air with
the ambient air. Thus, cold air is received by expander 18 and the
air is expanded to a point or the temperature may drop below
freezing.
[0022] Water separator 22 is provided in communication with
expander 18 therefore further eliminating water from the system.
Cold air from expander 18 may then be mixed with outside air by an
air mixer 34 before reaching the vehicle's passenger compartment
36. Air is then re-circulated and may be mixed with outside air by
another air mixer 38 before being received by compressor 12 of
system 10.
[0023] Clutch 32 operates to decouple compressor 12 from expander
18 during selected operating conditions. This is a critical feature
in a positive displacement system such as the present invention.
The flow rate of the compressor 12 is defined largely by the speed
of the compressor. The flow rate of the engine is a function of the
intake air boost pressure (supplied by intercooler 20) and the
engine speed. To balance the mass flow rate, the inlet pressure to
the expander must be reduced. Disadvantageously, the flow through
the expander is actually heated. Unchecked the temperature of the
air exiting the expander rises to an unacceptable condition for the
vehicle occupants.
[0024] In an embodiment of the present invention a method for
balancing the mass flow rate in system 10 is provided. The method
of the instant embodiment contemplates deactivating the expansion
process by decoupling expander 18 from compressor 12. Expander 18
may be decoupled from compressor 12, for example, by controlling
clutch 32. That is, by causing clutch 32 to disengage.
[0025] In another embodiment of the invention, a method for
balancing the mass flow rate is provided. The inlet pressure to the
expander is reduced by controlling valve 40. More specifically, the
method of the present invention specifies closing valve 40 to
balance the mass flow rate in system 10. Thus, the work of
expansion is eliminated.
[0026] In yet another embodiment of the present invention, an
alternate method for balancing the mass flow rate in system 10 and
avoiding the potential heat build up in the expander 18 is to close
valve 40 and deactivate the expansion process. The in-built
positive displacement process can only occur if the working volume
is completely contained. Thus, as shown in FIG. 2, the expansion
process may be deactivated by allowing atmospheric air to bleed
back to the expander inlet and the to the expansion chamber itself.
In the present embodiment, the atmospheric air is bleed back to the
expander inlet 52 and the to the expansion chamber by a bleed line
50. Although, the air in system 10 is likely to heat up, due to the
inefficiencies of the compressor, the air will be sufficiently
lower so that high heat will not be generated during average engine
boosting periods. Advantageously, a relatively smooth transition
for the air flow into the cabin is provided by the method of the
present invention, as compared with the instantaneous effect of
activating clutch 32.
[0027] In still another embodiment of the present invention, an
alternate embodiment of a method for balancing the mass flow rate
in system 10 and avoiding the potential heat build up in the
expander 18 is provided. The method of the instant embodiment
includes varying the capacity of the expander. In a reciprocating
type expander, varying the capacity is most effectively achieved by
varying the stroke. In a screw type of expander, varying the
capacity is most effectively achieved by changing the inlet point
of the variable pitch expander. However, care must be taken to keep
the in-built expansion ratio at the appropriate level. In the case
of a screw type expander the inlet point as well as the outlet
point would need to be controlled.
[0028] The present invention has many advantages and benefits over
the prior art. For example, the present invention provides an air
cycle air conditioning system that also serves as an engine
boosting mechanism and further provides a mechanism whereby the
flow capacity of the expander may be reduced. Moreover the present
invention provides a simple to control and simple to implement
clutch mechanism to control the flow capacity of the expander. In
other embodiments of the present invention flow valves are
activated to balance the mass air flow in system 10 and avoid the
potential heat build up in the expander.
[0029] As any person skilled in the art of air cycle air
conditioning systems and to systems that also delivery charged air
to an automobile engine will recognize from the previous detailed
description and from the figures and claims, modifications and
changes can be made to the preferred embodiments of the invention
without departing from the scope of this invention defined in the
following claims.
* * * * *