U.S. patent application number 12/725874 was filed with the patent office on 2011-09-22 for gas temperature moderation within compressed gas vessel through heat exchanger.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS, INC.. Invention is credited to Bernhard Mueller, Holger Winkelmann.
Application Number | 20110226782 12/725874 |
Document ID | / |
Family ID | 44602735 |
Filed Date | 2011-09-22 |
United States Patent
Application |
20110226782 |
Kind Code |
A1 |
Mueller; Bernhard ; et
al. |
September 22, 2011 |
GAS TEMPERATURE MODERATION WITHIN COMPRESSED GAS VESSEL THROUGH
HEAT EXCHANGER
Abstract
A pressure vessel for storing fuel cell reactants is disclosed.
The pressure vessel includes an inner shell formed from a moldable
material and forming a cavity therein, and an outer shell formed
about the inner shell. A heat transfer member is disposed within
the vessel cavity. The heat transfer member is thermally coupled a
suitable external thermal mass external the pressure vessel to
minimize the effect of thermal energy on the vessel. The heat
transfer member may be a metallic structure within the cavity, or
may be integrated within the inner shell on an inner shell surface.
The external thermal mass may further be thermally coupled to
either an active or a passive external thermal handling system for
controlling the temperature of the fluid within the vessel.
Inventors: |
Mueller; Bernhard;
(Budenheim, DE) ; Winkelmann; Holger; (Wiesbaden,
DE) |
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS,
INC.
Detroit
MI
|
Family ID: |
44602735 |
Appl. No.: |
12/725874 |
Filed: |
March 17, 2010 |
Current U.S.
Class: |
220/592.01 |
Current CPC
Class: |
F17C 2203/0619 20130101;
F17C 2203/0604 20130101; F17C 2260/025 20130101; H01M 8/04208
20130101; F17C 2201/0119 20130101; Y02E 60/32 20130101; F17C
2203/0663 20130101; F17C 2201/056 20130101; F17C 2201/058 20130101;
F17C 2260/023 20130101; F17C 2203/066 20130101; F17C 2205/0397
20130101; F17C 2205/0305 20130101; F17C 2223/036 20130101; F17C
2260/02 20130101; Y02E 60/50 20130101; F17C 2270/0184 20130101;
F17C 2223/0123 20130101; F17C 1/00 20130101; F17C 2221/011
20130101; F17C 2221/012 20130101 |
Class at
Publication: |
220/592.01 |
International
Class: |
B65D 88/74 20060101
B65D088/74 |
Claims
1. A vessel comprising: an inner shell forming a cavity therein; an
outer shell formed over the inner shell; and a heat transfer member
disposed within the cavity to provide thermal communication between
the cavity and outside of the cavity, the heat transfer member
adapted to minimize an effect of thermal energy on the vessel.
2. The vessel of claim 1, wherein the heat transfer member is
thermally coupled to a heat exchange structure external the outer
shell for controlling a temperature in the cavity.
3. The vessel of claim 1, wherein the heat transfer member is a
metallic sheet structure disposed within the cavity.
4. The vessel of claim 3, wherein the heat transfer member further
comprises: a center support; and at least one fin thermally coupled
to and extending substantially outwardly from the center
support.
5. The vessel of claim 4, wherein the at least one fin contacts at
least a portion of an inner surface of the inner shell.
6. The vessel of claim 5, further comprising: a first adapter
having a first thermal mass at a vessel first end, the first
adapter sealingly engaging at least one of the inner shell and the
outer shell and extending therethrough; and a second adapter having
a second thermal mass at a vessel second end, the second adapter
sealingly engaging at least one of the inner shell and the outer
shell and extending therethrough; wherein the center support is
thermally coupled to the first adapter and the second adapter.
7. The vessel of claim 6, wherein at least one of the first and
second thermal masses is thermally coupled to an external heat
exchange structure for controlling the temperature in the
cavity.
8. The vessel of claim 1, further comprising: a first adapter
having a first thermal mass disposed at a vessel first end, the
first adapter sealingly engaging at least one of the inner shell
and the outer shell and extending therethrough; and a second
adapter having a second thermal mass disposed at a vessel second
end, the second adapter sealingly engaging at least one of the
inner shell and the outer shell and extending therethrough; wherein
the center support is thermally coupled to the first adapter and
the second adapter.
9. The vessel of claim 8, wherein at least one of the first adapter
and the second adapter is thermally coupled to a heat exchange
structure.
10. The vessel of claim 9, wherein the heat exchange structure is
one of a radiator and a heating and air conditioning system.
11. The vessel of claim 8, wherein one of the first adapter and the
second adapter further includes an internal passage formed therein
for receiving a heat exchange fluid, the fluid in thermal
communication with a heat exchange structure.
12. The vessel of claim 11, wherein the heat exchange structure is
an active cooling system.
13. The vessel of claim 11, wherein the heat exchange structure is
one of a radiator and a heating and air conditioning system,
14. A vessel comprising: an inner shell formed from a moldable
material and forming a cavity therein; an outer shell formed over
the inner shell; and a metallic structure disposed within the
cavity adapted to minimize an effect of thermal energy on the
vessel, wherein the metallic structure is thermally coupled to a
heat exchange structure external the outer shell for controlling a
temperature in the cavity.
15. The vessel of claim 15, wherein the metallic structure is in
thermal communication with at least a portion of an inner surface
of the cavity.
16. The vessel of claim 16, further comprising: an adapter
sealingly engaging at least one of the inner shell and the outer
shell and extending therethrough; wherein the metallic structure is
thermally coupled to the adapter.
17. The vessel of claim 17, wherein the adapter is further
thermally coupled to an external heat exchanger.
18. A vessel, comprising: a hollow inner shell formed from a
moldable material and forming a cavity therein; an outer shell
formed over the inner shell; an adapter sealingly engaging at least
one of the inner shell and the outer shell and extending
therethrough; a heat transfer member disposed within the cavity and
thermally coupled to the adapter to minimize an effect of thermal
energy on the vessel.
19. The pressure vessel of claim 19, wherein the heat transfer
member is a metallic structure, comprising: a center support; and
at least one fin thermally coupled to and extending substantially
outwardly from the center support.
Description
FIELD OF THE INVENTION
[0001] The invention relates generally to a compressed gas
container and, more particularly, to a compressed gas container for
storing hydrogen gas on a vehicle for a fuel cell, wherein the
container includes an inner heat exchange structure to militate
against temperature fluctuations while the container is being
filled with compressed gas, and while compressed gas is being
extracted from the container.
BACKGROUND OF THE INVENTION
[0002] Hydrogen is a very attractive source of fuel because it is
clean and can be used to efficiently produce electricity in a fuel
cell. The automotive industry expends significant resources in the
development of hydrogen fuel cells as a source of power for
vehicles. Such vehicles would be more efficient and generate fewer
emissions than vehicles employing internal combustion engines.
[0003] A hydrogen fuel cell is an electro-chemical device that
includes an anode and a cathode with an electrolyte therebetween.
The anode receives hydrogen gas and the cathode receives oxygen.
The hydrogen gas is ionized in the anode to generate free hydrogen
ions and electrons. The hydrogen ions pass through the electrolyte
to the cathode, and react with the oxygen and electrons in the
cathode to generate water as a bi-product. The electrons from the
anode cannot pass through the electrolyte, and are directed through
a load to perform work before being sent to the cathode. The work
acts to operate the vehicle or systems on the vehicle. Many fuel
cells are combined in a stack to generate sufficient power to drive
a motor vehicle.
[0004] A fuel cell can include a processor that converts a liquid
fuel such as alcohols (methanol or ethanol), hydrocarbons
(gasoline), and/or mixtures thereof such as blends of
ethanol/methanol and gasoline, to hydrogen gas for the fuel cell.
Such liquid fuels are easy to store on the vehicle. Further, there
is a nationwide infrastructure for supplying liquid fuels. Gaseous
hydrocarbons, such as methane, propane, natural gas, LPG and, etc.,
are also suitable fuels for both vehicle and non-vehicle fuel cell
applications. Various processors are known in the art for
converting the liquid fuel to gaseous hydrogen suitable for the
fuel cell.
[0005] Alternatively, hydrogen gas can be processed separate from
the vehicle and stored at filling stations and the like. The
hydrogen gas is transferred from the filling station to pressurized
tanks or containers on the vehicle to supply the desired hydrogen
gas to the fuel cell as needed. Typical pressures within compressed
hydrogen gas containers for fuel cell applications are in the range
of 200 bar-700 bar (2900-10,150 psi).
[0006] Because of the high pressures involved, it is desirable for
storage containers for compressed gases to have mechanical
stability and integrity. It is also desirable to make hydrogen gas
containers on vehicles lightweight so as not to significantly
affect the weight requirements of the vehicle, or to improve
performance, or both. The current trend in the industry is to
employ type 4 compressed gas tanks for storing compressed hydrogen
gas on the vehicle. A type 4 tank includes an outer structural
layer made of synthetic material, such as a glass fiber or a carbon
fiber wrap, and an inner plastic liner. The outer layer provides
the structural integrity of the tank for the pressure contained
therein, while the plastic liner provides a gas impermeable vessel
for sealing the gas therein. Typically, the plastic liner is first
formed by a molding process, after which the fiber wrap is formed
around the liner and adhered thereto.
[0007] FIG. 1 shows a compressed gas vessel 10 currently
contemplated in the industry to store compressed hydrogen gas on a
vehicle for fuel cells. The vessel 10 is cylindrical in shape to
provide the desired structural integrity, and includes an outer
structural wall 12 and an inner liner 14 defining a container
chamber 16 therein. The outer wall 12 is typically made of a
suitable fibrous interconnected synthetic wrap such as filament
wound glass or carbon fiber wrap, and has a sufficient thickness to
provide the desired mechanical rigidity for pressure containment.
The liner 14 is typically made of a suitable high-density polymeric
material such as polyethylene, PET, ethylene vinyl alcohol, or an
ethylene vinyl acetate terpolymer, to provide a substantially
hydrogen impermeable containment vessel within the vessel 10. The
thickness of the liner 14 is generally about 5 mm. Thus, the
combination of the outer wall 12 and the liner 14 provides the
desired structural integrity, pressure containment and gas
tightness in a light-weight and cost effective manner.
[0008] The vessel 10 includes an adapter or boss 18 that provides
the inlet and outlet openings for the hydrogen gas contained
therein. The adapter 18 is typically a steel structure that houses
the various valves, pressure regulators, piping connectors, excess
flow limiters, and the like, that allow the vessel 10 to be filled
with the compressed hydrogen gas, and allow the compressed gas to
be discharged from the vessel 10 at or near ambient pressure, or at
a desired pressure, to be sent to the fuel cell. The adapter 18 is
typically made of steel to provide the structure desired for
storing compressed hydrogen gas. The adapter 18 may be formed of
any metal or metal alloy compatible with hydrogen that is suitable
for the pressure levels within the vessel 10. A suitable adhesive,
sealing ring, or the like (not shown) is employed to seal the liner
14 to the adapter 18 in a gas tight manner, and secure the adapter
18 to the outer wall 12.
[0009] During a vessel filling process, a fill gas 20 flows into
the vessel 10 from one end 22 of the vessel 10 to an opposite end
24 of the vessel 10 and becomes contained gas 26. As the filling
process proceeds, the pressure in the vessel 10 increases. It is
desirable that the temperature of the fill gas 20 is near ambient
temperature (300 K., 27.degree. C.) and be at a suitable pressure
to fill the vessel 10 within a few minutes (less than three
minutes). However, as a result of the thermodynamic properties of
the fill gas 20 and the contained gas 26, compression causes the
contained gas 26 to be heated in response to the fill gas 20 being
introduced therein under pressure. As a result, the temperature of
the contained gas 26 within the vessel 10 rises, because there is
no significant heat transfer from the gas into the vessel and
further into the environment during the fill process. The
relationship between increased pressure and increased temperature
during a filling (i.e. refueling) process is illustrated in FIG. 2
to the left of dashed line 30.
[0010] The heating of the contained gas 26 within the vessel 10
causes an undesirable temperature rise within the plastic liner 14,
which may affect the gas sealing ability of the liner 14.
Therefore, it is necessary to control the temperature of the
contained gas 26 within the vessel 10 while the vessel 10 is being
filled and thereafter. In fact, for composite vessels with plastic
liners, the gas temperature within the vessel is a limiting factor
for the refueling time. It is not uncommon that the refueling has
to be slowed down or interrupted because of the gas temperature in
the vessel. This can even be the case if the fill gas 20 is
pre-cooled at the filling station.
[0011] Removal of gas from the vessel 10 results in the opposite
problem, as illustrated in FIG. 2 to the right of the dashed line
30. For example, during operation of the fuel cell as gas is
withdrawn from the pressure vessel, the temperature within the
vessel drops significantly. If left alone, the temperature could
fall below a minimum desired operation temperature of the vessel
material or neighboring components. Known techniques to prevent too
low of a temperature within the vessel include heaters applied to
the vessel 10 or to the adapter 18, or flow reductions of the
extracted gas. Heaters consume energy produced by the fuel cell
that otherwise would be used to operate the vehicle. Flow
reductions of the extracted gas operate to limit the power output
by the fuel cell, thereby affecting operation of the vehicle.
[0012] It would be desirable to develop a hollow pressure vessel
adapted to minimize the effect of thermal energy on the vessel, by
providing a heat transfer between the fill gas and the outside
environment while also minimizing the assembly and material costs
thereof.
SUMMARY OF THE INVENTION
[0013] Concordant and congruous with the present invention, a
hollow pressure vessel adapted to minimize the effect of thermal
energy on the vessel, while also minimizing the assembly and
material costs thereof, has surprisingly been discovered.
[0014] In one embodiment, a vessel comprises an inner shell formed
from a moldable material and forming a cavity therein; an outer
shell formed over the inner shell; and a heat transfer member
integrated within the vessel, the heat transfer member thermally
coupled to the environment to minimize the effect of thermal energy
on the vessel. The heat transfer member may be a metallic sheet
structure within the cavity, or may be integrated within the inner
shell on an inner shell surface. The heat transfer member may be
thermally coupled to a suitable external thermal mass for
controlling the temperature of a fill gas.
[0015] In another embodiment, a vessel comprises an inner shell
formed from a moldable material and forming a cavity therein; an
outer shell formed over the inner shell; and a heat transfer member
integrated within the vessel, the heat transfer member thermally
coupled to the environment to minimize the effect of thermal energy
on the vessel. The heat transfer member may be a metallic sheet
structure within the cavity, or may be integrated within the inner
shell on an inner shell surface. The heat transfer structure is
thermally coupled to an active external thermal system for
controlling the temperature of fill gas.
DESCRIPTION OF THE DRAWINGS
[0016] The above, as well as other advantages of the present
invention, will become readily apparent to those skilled in the art
from the following detailed description of a preferred embodiment
when considered in the light of the accompanying drawings in
which:
[0017] FIG. 1 is a schematic cross-sectional elevational view of a
pressure vessel as known in the art;
[0018] FIG. 2 is a graphical representation of the relationship of
pressure and temperature of a fill gas to time during a typical
refueling/filling process and a typical extraction/driving
process;
[0019] FIG. 3 is schematic cross-sectional elevational view of a
vessel according to an embodiment of the invention; and
[0020] FIG. 4 is a schematic cross-sectional elevational view of a
vessel according to another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] The following detailed description and appended drawings
describe and illustrate various exemplary embodiments of the
invention. The description and drawings serve to enable one skilled
in the art to make and use the invention, and are not intended to
limit the scope of the invention in any manner. In respect of the
methods disclosed, the steps presented are exemplary and nature,
and thus, the order of the steps is not necessary or critical.
[0022] FIG. 3 illustrates a hollow pressure vessel 110 having an
outer structural wall 112 and an inner liner 114 defining a vessel
chamber 116 therein. Like the vessel 10 of FIG. 1, the vessel 110
has a substantially cylindrical shape and is adapted to hold a
pressurized fluid 126. It is understood that the vessel 110 may
have any shape as desired, and the vessel 110 may include
additional layers such as a barrier layer, a foil layer, a porous
permeation layer, and the like, as desired, similar to those
disclosed in commonly-owned U.S. patent application Ser. No.
11/847,007 and U.S. patent application Ser. No. 11/956,863, both
hereby incorporated herein by reference in their entireties. The
pressurized fluid 126 may be any fluid such as hydrogen gas and
oxygen gas, a liquid, and both a liquid and gas, for example.
[0023] The inner liner 114 of the vessel 110 is a hollow container
adapted to store the pressurized fluid 126. As shown, the inner
liner 114 is formed from a layer of polymer material, but the inner
liner 114 may be formed from multiple layers, as desired. The inner
liner 114 may be formed by blow molding, extrusion blow molding,
rotational molding, or any other suitable process. In the
embodiment shown, the inner liner 114 has a substantially
cylindrical shape. However, the inner liner 114 may have any shape,
as desired. The inner liner 114 may be formed from a plastic such
as polyethylene, PET, ethylene vinyl alcohol, or an ethylene vinyl
acetate terpolymer. The inner liner 114 may also be formed from
other moldable materials such as a metal, a glass, and the like,
chosen to minimize escape or diffusion of the pressurized fluid
126.
[0024] The outer structural wall 112 of the vessel 110 is disposed
on the inner liner 114. The outer structural wall 112 has a
substantially cylindrical shape, and substantially abuts the inner
liner 114 to provide structural support for the vessel 110,
allowing the vessel 110 to withstand high pressures. The outer
structural wall 112 may be formed from any moldable material such
as a metal and plastic, for example, or the outer structural wall
112 may be formed with a filament winding process or other process.
If the outer structural wall 112 is formed by a filament winding
process, the outer structural wall 112 may be formed from a carbon
fiber, glass fiber, a composite fiber, a fiber having a resin
coating, and the like, for example. It is understood that the
material used to form the outer structural wall 112 may be selected
based on the process used to affix the outer structural wall 112 to
the inner liner 114, the use of the vessel 110, and the properties
of the fluid to be stored in the vessel 110.
[0025] Like the vessel 10 of FIG. 1, the vessel 110 includes an
adapter 118 attached at a vessel first end 122 that provides the
inlet and outlet opening for the pressurized fluid 126 contained
therein. As noted previously, the adapter 118 is typically a steel
structure that houses the various valves, pressure regulators,
piping connectors, access flow limiter's, etc., that allow the
vessel 110 to be filled with the fill gas 120 that becomes the
pressurized fluid 126, and allow the pressurized fluid 126 to be
discharged from the vessel 110 at or near ambient pressure, or any
desired pressure, to be sent to the fuel cell. A suitable adhesive,
sealing ring, or the like (not shown) is employed to seal the inner
liner 114 to the adapter 118 in a gas tight manner as is known in
the art. Similarly, conventional means are used to secure the
adapter 118 to the outer structural wall 112 of the hollow vessel
110.
[0026] A heat transfer member 130 is located within the hollow
vessel 110, and more specifically, within the inner liner 114 and
within the vessel chamber 116. The heat transfer member 130 shown
in FIG. 3 is shown as a metallic structure within the vessel cavity
or chamber 116. The heat transfer member 130 may include a center
support 132 and a plurality of fins or arms 134 integrally
connected or thermally connected to the center support 132. The
center support 132 is thermally connected to the adapter 118 at a
center support first end 136. In one embodiment, a center support
second end 138 is thermally connected to a second adapter or boss
140 embedded within a vessel second end 124. The fins 134 project
outwardly from the center support 132 within the vessel chamber
116. The fins 134 are sized and designed to extend sufficiently
within the vessel cavity 116 to provide a desired thermal
interaction with the pressurized fluid 126. The fins 134 may also
contact the inner surface 128 of the inner liner 114. In one
embodiment, at least a portion 158 of the fins 134 are formed on
the inner surface 128 of the inner line 114.
[0027] Both the adapter 118 and the boss 140 may act as heat sinks
due to the thermal mass of each of the adapter 118 and the boss
140. Additionally, one or both of the adapter 118 and the boss 140
may be thermally coupled to heat exchange structures 142, 144,
respectively. The heat exchange structures 142, 144 may comprise
additional thermal masses 146, 148, respectively, such as valve
blocks used to control the extraction of gases from the vessel 110,
or the like. The thermal masses 146, 148 may be actively or
passively cooled, and any heat removed by the thermal masses 146,
148 may be stored or may be utilized to control the temperature of
other areas of the gas extraction system, thereby enhancing the
efficiency of the design. As a non-limiting example, heat extracted
and stored within the thermal masses 146, 148 during a refueling
event, when the temperature of the pressurized fluid 126 rises, may
be used to heat the gas 120 as it is extracted from the vessel 110
during operation of the fuel cell, or may be used to elevate the
temperature of the pressurized fluid itself during extraction of
the gas 120 from the vessel 110.
[0028] During refueling operations (i.e. within the regime shown to
the left of dashed line 30 in FIG. 2), as the fluid 120 is added to
the hollow vessel 110, both the pressure 32 and the temperature 34
of the pressurized fluid 126 within the vessel rise. The heat
produced during the fill process flows through the heat transfer
member 130, and is conducted from the fins 134 to the center
support 132, and from there into both the adapter 118 and the boss
140. As a result, heat is extracted from the pressurized fluid 126
and conducted out of the vessel 110, thereby controlling the
temperature within the vessel 110. If the thermal mass of the
adapter 118 and the boss 140 is sufficiently large, the temperature
within the vessel 110 may be maintained below the desired point
without a further heat sink. Alternatively, a suitable heat
dissipating structure such as the thermal masses 146, 148 could
store the heat or transfer the heat to the environment, such as
through external fins 160, or through a radiator (not shown), or
the like.
[0029] During periods of fluid extraction from the vessel 110 (i.e.
within the regime shown to the right of the dashed line 30 in FIG.
2), as the fluid 120 is extracted from the hollow vessel 110, the
pressure 32' and the temperature 34' of the pressurized contained
fluid 126 within the vessel drop. In this operating regime,
external heat is conducted from the thermal masses 146, 148 through
the adapter 118 and the boss 140, respectively, and is further
conducted into the respective first and second ends 136, 138 of the
center support 132, where it may be further conducted into the fins
134 to support heating of the pressurized fluid 126 within the
vessel 110. Heat from outside of the vessel 110 is therefore made
available to the vessel chamber 116 to maintain the operating
temperature of the pressurized fluid 126 above any minimum desired
operating temperature of the vessel 110. As noted previously, the
thermal masses 146, 148 may be passively or actively heated and
cooled. Passive thermal masses 146, 148 may take the form of a
large metallic mass, and may include fins 160 or other desired
passive heat radiating structure.
[0030] With reference to FIG. 4, a further embodiment of the
invention including an active thermal handling system is described.
For the purpose of clarity, like structures from FIG. 3 have the
same reference numerals and are denoted with a prime (640)
symbol.
[0031] In the embodiment shown in FIG. 4, the adapter 118' and the
boss 140' may include passages 150, 152, respectively, to allow a
heat exchange fluid 154 to flow through the adapter 118' and the
boss 140. The passages 150, 152, and hence the adapter 118' and the
boss 140', are thermally coupled to thermal masses 146', 148' to
allow heat from the vessel chamber 116' to be stored or transferred
to the environment. Favorable results have been obtained when the
passages 150, 152 are coupled to the climate control system of a
motor vehicle powered by the fuel cell. Thus, the heat transfer
member 130' may be heated or cooled by the heating and
air-conditioning system of the motor vehicle. Alternatively, the
heat exchange fluid 154 may be a fluid that undergoes a phase
change as it is either heated or cooled. Such a phase changing
fluid may further conduct heat from the adapter 118' and the boss
140' to thermal masses 146', 148', and from there to an exterior
heat exchange structure 142', 144', such as fins 160', a radiator
(not shown) or the like. In this way, the heat transfer member 130'
within the vessel 110' may be thermally coupled to any exterior
heat exchanger, as desired.
[0032] While certain representative embodiments and details have
been shown for purposes of illustrating the invention, it will be
apparent to those skilled in the art that various changes may be
made without departing from the scope of the disclosure, which is
further described in the following appended claims.
* * * * *