BACKGROUND
[0001] The present disclosure relates to an environmental control system of a vehicle, and
more particularly, to an environmental control system (ECS) for a vehicle travelling
in a low pressure or zero pressure environment.
[0002] In general, a high-speed public transportation concept called the hyperloop has been
proposed that can include a vehicle similar to a train car that travels inside of
a tube. The air in the tube can be evacuated to a very deep vacuum, allowing the train
to reach very high speeds without incurring the high-power demand that would otherwise
be needed to overcome the high aerodynamic drag at normal atmospheric pressure. An
air lock can permit passenger boarding and disembarking from the train station to
the train without discharging the atmospheric air in the station into the vacuum in
the tube.
[0003] As with similar transportation vehicles, environmental control of the occupied cabin
is generally required to maintain adequate comfort and to provide heating, cooling
and/or a continual supply of fresh air. Some typical methods used to provide air conditioning
may not be conducive to this application. For example, many air conditioning systems
exist which provide cool air to the cabin and on-board electronics may draw air from
or ultimately exhaust the heat to the ambient atmosphere via convection heat transfer.
When the ambient atmosphere is non-existent, as in space applications, heat can be
rejected to deep space via radiation heat transfer. In the case of the hyperloop,
there is little to no atmosphere in the tube, so rejecting heat into the tube via
convection may not be practical while maintaining a reasonably sized heat exchanger
to reject the heat. Moreover, heat rejection via radiation may also not be practical,
since unlike radiating to space, which is near absolute zero degrees in temperature,
the walls of the tube can be warmer than inside the cabin when the outside ambient
temperature is warm. Moreover, while the train is moving at high speed, the amount
of available electrical power consumption is limited since power is generally supplied
solely by on-board batteries that have a limited quantity of electrical energy.
BRIEF DESCRIPTION
[0004] According to an embodiment, an environmental control system for conditioning a cabin
of a vehicle positioned in an enclosed air-evacuated environment includes a first
inlet for receiving a first medium, a second inlet for receiving a second medium,
and a thermodynamic device including a compressor and at least one turbine operably
coupled by a shaft. The at least one turbine is fluidly coupled to and arranged downstream
from the first inlet and the second inlet. A flow of the first medium and a first
flow of the second medium are mixed to form a third medium at a first mixing point
arranged downstream from the thermodynamic device relative to the flow of the first
medium. A dehumidification system is fluidly coupled to the compressor and to the
at least one turbine. The dehumidification system is arranged upstream from the at
least one turbine. A regeneration heat exchanger is fluidly coupled to and is located
downstream from an outlet of the compressor. Heat is removed from the first medium
at the regeneration heat exchanger.
[0005] In addition to one or more of the features described above, or as an alternative,
in further embodiments the compressor and the at least one turbine are arranged in
series relative to the flow of the first medium.
[0006] In addition to one or more of the features described above, or as an alternative,
in further embodiments the dehumidification system is arranged upstream from an inlet
of the at least one turbine.
[0007] In addition to one or more of the features described above, or as an alternative,
in further embodiments the dehumidification system includes a reheater, a condenser,
and a water extractor arranged in series.
[0008] In addition to one or more of the features described above, or as an alternative,
in further embodiments a bypass conduit is fluidly connected to the first inlet and
is arranged in parallel with an inlet of the compressor. A valve is associated with
the bypass conduit and is operable to control the flow of the first medium within
the bypass conduit.
[0009] In addition to one or more of the features described above, or as an alternative,
in further embodiments including a second mixing point fluidly coupled to the first
mixing point and to the bypass conduit. A conditioned medium is output from the second
mixing point.
[0010] In addition to one or more of the features described above, or as an alternative,
in further embodiments a portion of the dehumidification system is positioned between
and fluidly coupled the first mixing point and the second mixing point relative to
a flow of the third medium.
[0011] In addition to one or more of the features described above, or as an alternative,
in further embodiments a portion of the conditioned medium is provided to the regeneration
heat exchanger of a cooling system.
[0012] In addition to one or more of the features described above, or as an alternative,
in further embodiments the portion of the conditioned medium and a second flow of
the second medium is mixed to form a mixed medium. The mixed medium being used to
cool the first medium at the regeneration heat exchanger.
[0013] In addition to one or more of the features described above, or as an alternative,
in further embodiments the mixed medium is provided to the at least one turbine of
the thermodynamic device. The at least one turbine is fluidly coupled to and is arranged
upstream from the regeneration heat exchanger.
[0014] In addition to one or more of the features described above, or as an alternative,
in further embodiments the at least one turbine includes a first turbine and a second
turbine. The second turbine is arranged downstream from and is in fluid communication
with the compressor relative to the flow of the first medium. The second turbine is
configured to receive the mixed medium.
[0015] In addition to one or more of the features described above, or as an alternative,
in further embodiments at least one vessel of a pressurized first medium is located
on board the vehicle.
[0016] In addition to one or more of the features described above, or as an alternative,
in further embodiments the vehicle is a train.
[0017] According to an embodiment, a method of operating an environmental control system
to condition a cabin of a vehicle positioned in an enclosed, air-evacuated tube includes
compressing a first medium within a compressor of a thermodynamic device to form a
compressed first medium, extracting energy from the compressed first medium at at
least one turbine of the thermodynamic device to form an expanded first medium, forming
a conditioned flow including the expanded first medium and a first flow of a second
medium; extracting energy from a mixed medium at the at least one turbine of the thermodynamic
device to form an expanded mixed medium; and cooling the compressed first medium using
the expanded mixed medium. The extracted energy is used to drive the compressor.
[0018] In addition to one or more of the features described above, or as an alternative,
in further embodiments drying the expanded first medium prior to extracting energy
from the expanded first medium at the at least one turbine.
[0019] In addition to one or more of the features described above, or as an alternative,
in further embodiments forming the conditioned flow includes mixing the first flow
of the second medium with the expanded first medium to form a third medium and mixing
the third medium with a flow of the first medium provided from a bypass conduit to
form the conditioned medium. The flow of the first medium provided from the bypass
conduit has bypassed the thermodynamic device.
[0020] In addition to one or more of the features described above, or as an alternative,
in further embodiments providing a first portion of a flow of the conditioned medium
to the cabin and providing a second portion of the flow of the conditioned medium
to a cooling system.
[0021] In addition to one or more of the features described above, or as an alternative,
in further embodiments providing the second portion of the flow of the conditioned
medium to the cooling system includes removing heat from the cooling system.
[0022] In addition to one or more of the features described above, or as an alternative,
in further embodiments includes mixing a portion of the conditioned medium with a
second flow of the second medium to form the mixed medium.
[0023] In addition to one or more of the features described above, or as an alternative,
in further embodiments providing the expanded mixed medium to a regeneration heat
exchanger. Cooling the compressed first medium using the expanded mixed medium occurs
at the regeneration heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The following descriptions should not be considered limiting in any way. With reference
to the accompanying drawings, like elements are numbered alike:
[0025] The Figure (Figure 1) is a schematic diagram of an example environmental control
system (ECS) for a vehicle travelling within a hyperloop tube according to an embodiment.
DETAILED DESCRIPTION
[0026] A detailed description of one or more embodiments of the disclosed apparatus and
method are presented herein by way of exemplification and not limitation with reference
to the Figures.
[0027] The example embodiments disclosed herein are illustrative of a hyperloop environmental
control system, and assemblies of the present disclosure and methods/techniques thereof.
It should be understood, however, that the disclosed embodiments are merely examples
of the present disclosure, which may be embodied in various forms. Therefore, details
disclosed herein with reference to example hyperloop environmental control systems
and associated processes/techniques of fabrication/assembly and use are not to be
interpreted as limiting, but merely as the basis for teaching one skilled in the art
how to make and use the systems/assemblies and/or alternative systems/assemblies of
the present disclosure.
[0028] With reference now to the Figure, an example of an environmental control system 20
suitable for use with a vehicle movable within an enclosed air-evacuated environment
is illustrated. The air-evacuated environment has a substantially zero-pressure or
is a vacuum. In an embodiment, the vehicle is a car or train movable through a tube
of a hyperloop system. As shown, the environmental control system 20 includes one
or more vessels 22 located on-board the vehicle and configured to store a pressurized
medium therein, such as high-pressure air for example. In an embodiment, the pressure
of the medium within the at least one vessel 22 is between about 2000psi about 3000psi.
The one or more vessels 22 may be considered a first fluid source and are fluidly
coupled to a first inlet 24 of the environmental control system 20 to deliver a controlled
flow of a first medium A1 to the environmental control system 20. The one or more
vessels 22 may be filled, refilled, or replaced when the vehicle is stopped at a station
or other facility.
[0029] The environmental control system 20 may additionally receive a flow of second medium
A2 at a second inlet 26. In one embodiment, the second inlet 26 is operably coupled
to a volume 28, such as the cabin or chamber of the vehicle in which the people are
typically located. In such embodiments, the second medium A2 is cabin recirculation
air. The environmental control system 20 is operable to provide a conditioned flow
of one or both of the first medium A1 and the second medium A2 to the cabin 28 at
standard atmospheric pressure of about 14.7 psi.
[0030] The environmental control system 20 may include at least one thermodynamic device
30, and in some embodiments, may include a plurality of thermodynamic devices. A thermodynamic
device 30, as described herein, is a mechanical device that includes one or more components
for performing thermodynamic work on a medium (e.g., extracts work from or applies
work to the first medium A1 or the second medium A2 by raising and/or lowering pressure
and by raising and/or lowering temperature). Examples of a thermodynamic device 30
include an air cycle machine, a two-wheel air cycle machine, a three-wheel air cycle
machine, a four-wheel air cycle machine etc.
[0031] The single thermodynamic device 30 shown in the FIG. includes a compressor 32 and
at least one turbine operably coupled by a shaft 34. In the illustrated, non-limiting
embodiment, the thermodynamic device includes 30 a first turbine 36 and a second turbine
38. However, embodiments where the thermodynamic device 30 includes a single turbine,
or alternatively, more than two turbines are also within the scope of the disclosure.
[0032] A compressor, such as compressor 32 for example, is a mechanical device configured
to raise a pressure of a medium and can be driven by another mechanical device (e.g.,
a motor or a medium via a turbine). Examples of compressor types include centrifugal,
diagonal or mixed-flow, axial-flow, reciprocating, ionic liquid piston, rotary screw,
rotary vane, scroll, diaphragm, air bubble, etc. A turbine, such as first turbine
36 or second turbine 38 for example, is a mechanical device that expands a medium
and extracts work therefrom (also referred to as extracting energy) to drive the compressor
32 via the shaft 34. The turbines 36, 38 may include a nozzle (not shown) configured
to accelerate the medium supplied thereto for entry into an impeller of the turbine.
[0033] The environmental control system 20 may additionally include at least one dehumidification
system 40. The dehumidification system 40 may be arranged in fluid communication with
the first medium A1. In the illustrated, non-limiting embodiment, the dehumidification
system includes a reheater 42, a condenser 44, and a water extractor or collector
46. The water extractor 46 is a mechanical device that performs a process of removing
water from a medium.
[0034] In addition to providing a conditioned medium to the cabin 28, the environmental
control system 20 may be used to transfer or redistribute heat between various systems
onboard the vehicle. In an embodiment, the environmental control system 20 is operably
coupled to a cooling system 50 used to cool high-powered electronics 52 located onboard
the vehicle. As shown, a coolant, such as propylene glycol or ethylene glycol for
example, is configured to circulate through the electronics 52 via a coolant pump
54, then is then provided to an electronics heat exchanger 56. In the illustrated,
non-limiting embodiment, the environmental control system 20 is operably coupled to
the cooling system 50 via the electronics heat exchanger 56. Accordingly, at the electronics
heat exchanger 56, during operation of the environmental control system 20 in a "cooling
mode" where the air provided to the cabin 28 is intended to reduce the temperature
therein, heat is transferred from the coolant to the relatively cool medium of the
environmental control system 20. Heat may also be transferred from the coolant to
the relatively cool medium of the environmental control system 20 during operation
in a "heating mode" where the air provided to the cabin is intended to increase the
temperature therein.
[0035] The elements of the environmental control system 20 are connected via valves, tubes,
pipes, conduits and the like. Valves (e.g., flow regulation device or mass flow valve)
are devices that regulate, direct, and/or control a flow of a medium by opening, closing,
or partially obstructing various passageways within the tubes, pipes, etc. of the
system. Valves can be operated by actuators, such that flow rates of the medium in
any portion of the environmental control system 20 can be regulated to a desired value.
For instance, a first valve V1, such as an airflow regulator for example, is configured
to control the flow of the first medium A1 provided to the environmental control system
20 via the first inlet 24. A second valve V2 may be operable to selectively divert
the flow of the first medium A1 to bypass the substantially entire environmental control
system 20, including the thermodynamic device 30 and the dehumidification system 40.
A third valve can control the flow of a conditioned medium to both the cabin 28 and
to the cooling system 50. In an embodiment, a fourth valve is operable to control
the flow of the second medium mixed with the first medium and the control of the second
medium used to power the compressor and/or as a heat sink. The environmental control
system 20 may additionally include a V5 operable to exhaust a flow of medium from
the cabin 28 or the environmental control system 20 overboard from the vehicle, such
as into the atmosphere surrounding the exterior of the vehicle.
[0036] One or more of the valves V1-V5 may be configured to receive commands from an ECS
controller (not shown), such as in response to feedback provided from one or more
sensors S located in specific/desired locations in the environmental control system
20. Although various pressure and temperature sensors are illustrated, it should be
appreciated that other sensors operable to monitor any suitable parameter of the environmental
control system 20 and/or the cooling system 50 are within the scope of the disclosure.
[0037] Furthermore, a heater 60, such as an electrical heater for example, may also be provided
for instances where the conditioned medium to be delivered to the cabin 28 needs to
be heated. In such embodiments, the heater 60 may be arranged directly upstream from
the cabin 28 relative to a flow of the conditioned medium. Alternatively, or in addition,
a heater 62, such as an electrical heater, may be provided in the cooling system 50
for instances where the conditioned medium to be delivered to the cabin 28 needs additional
heat beyond the load exhausted by the electronics 52.
[0038] In operation, a flow of first medium A1 at the first inlet 24, controlled by valve
V1, is provided to the environmental control system 20. When the downstream valve
V2 is in a first position, all or at least a portion of the flow of the first medium
A1 is provided to the thermodynamic device 30, such as to the compressor 32 for example.
However, when the valve V2 is in a second position, some or all of the flow of the
first medium A1 is directed to a bypass conduit 64 in which the flow of the first
medium A1 is configured to bypass the entire thermodynamic device 30.
[0039] The act of compressing the first medium A1 heats the first medium A1 and increases
the pressure thereof. In an embodiment, a first inlet of a regeneration heat exchanger
66 is arranged directly downstream from the outlet of the compressor 32 and upstream
from an inlet of a turbine of the thermodynamic device 30, such as the first turbine
36 for example. In such embodiments, the first medium A1 output from the thermodynamic
device 30 is cooled within the regeneration heat exchanger 66.
[0040] The cool first medium A1 output from the regeneration heat exchanger 66 may then
be provided to the dehumidification system 40, and more specifically to the reheater
42 and the condenser 44 in series. Within both the reheater 42 and the condenser 44,
the flow of the first medium A1 is further cooled, causing moisture within the first
medium A1 to condenser into a liquid. Upon exiting the condenser 44, the first medium
A1 is provided to a water extractor 46, wherein the condenser water is removed from
the first medium A1. From the outlet of the water extractor 46, the dry first medium
A1 makes a second pass through the reheater 42. Accordingly, at the reheater 42, heat
from the first medium A1 output from the regeneration heat exchanger 66 transfers
to the first medium A1 output from the water extractor.
[0041] From the reheater 45, the warm dry first medium A1 is provided to an inlet of the
second turbine 38, such as through a nozzle. The first medium A1 is expanded across
the turbine and work is extracted therefrom. The extracted energy drives the compressor
32 via the shaft 34. Accordingly, the first medium A1 provided at the outlet of second
turbine 38 is cooler and/or has a lower pressure than the first medium A1 provided
to the inlet of the second turbine 38.
[0042] Simultaneously, a flow of second medium A2 is provided to the second inlet 26 of
the environmental control system 20, such as from the cabin 28. Operation of a circulation
fan 68 associated with the cabin 28 is configured not only to move the air within
the cabin 28, but also to pump the second medium A2 toward the fourth valve V4. When
the fourth valve V4 is in a first position, all, or at least a portion of the second
medium A2 is directed to a first mixing point M1 where the second medium A2 is mixed
with the first medium A1 to form a third medium A3. The portion of the flow of the
second medium A2 directed towards the first mixing point M1 is also referred to herein
as "a first flow A2(1) of the second medium." As shown, the first flow A2(1) of the
second medium A2 may be configured to mix with the flow of the expanded first medium
A1 from the outlet of the second turbine 38 of the thermodynamic device 30 at the
first mixing point M1. The resulting third medium A3 may be configured to make at
least one pass through the condenser 44, where the third medium A3 absorbs heat from
the first medium A1 therein. The outlet of the condenser 44 may be fluidly coupled
to a second mixing point M2. The second mixing point M2 is also fluidly coupled to
the bypass conduit 64, such that in embodiments where a portion of the first medium
A1 provided at the first inlet 24 is directed to the bypass conduit 64, this flow
of first medium A1 mixes with the third medium A3 at the second mixing point M2 to
form a conditioned medium A4. It should be appreciated that in embodiments where none
of the first medium A1 is directed into the bypass conduit 64, the conditioned medium
A4 output from the second mixing point M2 is simply the third medium A3.
[0043] Depending on the operating conditions of the environmental control system 20, in
some embodiments, the conditioned medium A4 may be separated into a first portion
of conditioned medium A4a used to condition the cabin 28 and a second portion of conditioned
medium A4b for use by the cooling system 50. The amount of conditioned medium A4 provided
to the cabin 28 and the cooling system 50, respectively, is controlled by the position
of the valve V3. In an embodiment, the volume, or the rate at which the first portion
of conditioned medium A4a is provided to the cabin 28 is equal to the volume or rate
at which air is exhausted from the cabin 28 overboard, such as via operation of the
cabin pressure regulator V5. As a result, the pressure within the cabin 28 remains
generally constant.
[0044] When the fourth valve V4 is in a second position, some or all of the second medium
A2 from the second inlet 26 is directed towards an inlet of the turbine, such as the
first turbine 36. The flow of the second medium A2 directed towards the first turbine
36 is referred to herein as a "second flow A2(2) of the second medium." In an embodiment,
the second flow of conditioned medium A4b, after being heated within the cooling system
50, is mixed with this second flow A2(2) of second medium to form a fifth or mixed
medium A5 at a location upstream from the turbine inlet. It should be appreciated
that embodiments where the mixed medium A5 includes only the second flow A2(2) of
the second medium and embodiments where the mixed medium A5 includes only the second
flow of conditioned medium A4b are within the scope of the disclosure based on the
operating conditions of the environmental control system 20.
[0045] As shown, the warm mixed medium A5 is provided to a nozzle of the first turbine 36.
Within the first turbine 36, the mixed medium A5 is expanded and work is extracted
therefrom to form an expanded mixed medium A5. The work extracted from the mixed medium
A5 in the first turbine 36 is used alone or in combination with the work extracted
at the second turbine 38 to drive the compressor 32 to compress the first medium A1.
Accordingly, the expanded mixed medium A5 provided at the outlet of the first turbine
36 is cooler and/or has a lower pressure than the mixed medium A5 provided to the
inlet of the first turbine 36.
[0046] The outlet of the first turbine 36 may be fluidly connected to an inlet of the regeneration
heat exchanger 66. Accordingly, the expanded mixed medium A5 may be used as a heat
sink at the regeneration heat exchanger 66. Within the regeneration heat exchanger
66, heat transfers from the hot flow of compressed first medium A1 to the warm mixed
medium A5. The resulting heated mixed medium A5 may then be exhausted overboard, into
the air-evacuated atmosphere at the exterior of the vehicle.
[0047] An environmental control system 20 as illustrated and described here provides an
efficient system for conditioning a cabin 28 of a vehicle travelling within low pressure
environment or a vacuum.
[0048] The term "about" is intended to include the degree of error associated with measurement
of the particular quantity based upon the equipment available at the time of filing
the application.
[0049] The terminology used herein is for the purpose of describing particular embodiments
only and is not intended to be limiting of the present disclosure. As used herein,
the singular forms "a," "an" and "the" are intended to include the plural forms as
well, unless the context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this specification, specify
the presence of stated features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other features, integers,
steps, operations, element components, and/or groups thereof.
[0050] While the present disclosure has been described with reference to an exemplary embodiment
or embodiments, it will be understood by those skilled in the art that various changes
may be made, and equivalents may be substituted for elements thereof without departing
from the scope of the present disclosure. In addition, many modifications may be made
to adapt a particular situation or material to the teachings of the present disclosure
without departing from the essential scope thereof. Therefore, it is intended that
the present disclosure not be limited to the particular embodiment disclosed as the
best mode contemplated for carrying out this present disclosure, but that the present
disclosure will include all embodiments falling within the scope of the claims.
1. An environmental control system for conditioning a cabin of a vehicle positioned in
an enclosed air-evacuated environment, the environmental control system comprising:
a first inlet (24) for receiving a first medium (A1);
a second inlet (26) for receiving a second medium (A2);
a thermodynamic device including a compressor and at least one turbine operably coupled
by a shaft, the at least one turbine being fluidly coupled to and arranged downstream
from the first inlet (24) and the second inlet (26);
a first mixing point (M1) at which a flow of the first medium (A1) and a first flow
of the second medium (A2) are mixed to form a third medium, the first mixing point
(M1) being arranged downstream from the thermodynamic device relative to the flow
of the first medium (A1);
a dehumidification system (40) fluidly coupled to the compressor and to the at least
one turbine, the dehumidification system (40) being arranged upstream from the at
least one turbine; and
a regeneration heat exchanger (60) fluidly coupled to and located downstream from
an outlet of the compressor, wherein heat is removed from the first medium (A1) at
the regeneration heat exchanger (60).
2. The environmental control system of claim 1, wherein the compressor and the at least
one turbine are arranged in series relative to the flow of the first medium (A1).
3. The environmental control system of claim 1 or 2, wherein the dehumidification system
(40) is arranged upstream from an inlet of the at least one turbine, and preferably
wherein the dehumidification system (40) further comprises a reheater, a condenser,
and a water extractor arranged in series.
4. The environmental control system of any preceding claim, further comprising:
a bypass conduit fluidly connected to the first inlet (24), the bypass conduit being
arranged in parallel with an inlet of the compressor; and
a valve associated with the bypass conduit, the valve being operable to control the
flow of the first medium (A1) within the bypass conduit.
5. The environmental control system of claim 4, further comprising a second mixing point
fluidly coupled to the first mixing point (M1) and to the bypass conduit, wherein
a conditioned medium is output from the second mixing point.
6. The environmental control system of claim 5, wherein a portion of the dehumidification
system (40) is positioned between and fluidly coupled the first mixing point (M1)
and the second mixing point relative to a flow of the third medium.
7. The environmental control system of claim 5, wherein a portion of the conditioned
medium is provided to the regeneration heat exchanger (60) of a cooling system, and
preferably wherein the portion of the conditioned medium and a second flow of the
second medium (A2) is mixed to form a mixed medium, the mixed medium being used to
cool the first medium (A1) at the regeneration heat exchanger (60), and preferably
wherein the mixed medium is provided to the at least one turbine of the thermodynamic
device, the at least one turbine being fluidly coupled to and arranged upstream from
the regeneration heat exchanger (60), and more preferably wherein the at least one
turbine further comprises a first turbine and a second turbine, the second turbine
being arranged downstream from and in fluid communication with the compressor relative
to the flow of the first medium (A1), the second turbine being configured to receive
the mixed medium.
8. The environmental control system of any preceding claim, further comprising at least
one vessel of a pressurized first medium located on board the vehicle.
9. The environmental control system of any preceding claim, wherein the vehicle is a
train.
10. A method of operating an environmental control system to condition a cabin of a vehicle
positioned in an enclosed, air-evacuated tube, the method comprising:
compressing a first medium (A1) within a compressor of a thermodynamic device to form
a compressed first medium (A1);
extracting energy from the compressed first medium (A1) at at least one turbine of
the thermodynamic device to form an expanded first medium (A1), the extracted energy
being used to drive the compressor;
forming a conditioned flow including the expanded first medium (A1) and a first flow
of a second medium (A2);
extracting energy from a mixed medium at the at least one turbine of the thermodynamic
device to form an expanded mixed medium; and
cooling the compressed first medium (A1) using the expanded mixed medium.
11. The method of claim 10, further comprising drying the expanded first medium (A1) prior
to extracting energy from the expanded first medium (A1) at the at least one turbine.
12. The method of claim 10 or 11, wherein forming the conditioned flow further comprises:
mixing the first flow of the second medium (A2) with the expanded first medium (A1)
to form a third medium; and
mixing the third medium with a flow of the first medium (A1) provided from a bypass
conduit to form the conditioned medium, the flow of the first medium (A1) provided
from the bypass conduit having bypassed the thermodynamic device.
13. The method of claim 12, further comprising:
providing a first portion of a flow of the conditioned medium to the cabin; and
providing a second portion of the flow of the conditioned medium to a cooling system,
and preferably wherein providing the second portion of the flow of the conditioned
medium to the cooling system further comprises removing heat from the cooling system.
14. The method of claim 12, further comprising mixing a portion of the conditioned medium
with a second flow of the second medium (A2) to form the mixed medium.
15. The method of any of claims 10-14, further comprising providing the expanded mixed
medium to a regeneration heat exchanger (60), wherein cooling the compressed first
medium (A1) using the expanded mixed medium occurs at the regeneration heat exchanger
(60).