U.S. patent application number 10/543123 was filed with the patent office on 2006-08-17 for transportable hydrogen refueling station.
Invention is credited to Andy Abele, Alan Niedzwiechi.
Application Number | 20060180240 10/543123 |
Document ID | / |
Family ID | 32507521 |
Filed Date | 2006-08-17 |
United States Patent
Application |
20060180240 |
Kind Code |
A1 |
Niedzwiechi; Alan ; et
al. |
August 17, 2006 |
Transportable hydrogen refueling station
Abstract
A portable hydrogen refueling stations which can dispense
gaseous hydrogen from one or more internal high pressure tanks. The
refueling station can be refilled with a lower pressure hydrogen
gas feed and then compressed for storage within a refueling
station.
Inventors: |
Niedzwiechi; Alan; (Newport
Beach, CA) ; Abele; Andy; (San Clemente, CA) |
Correspondence
Address: |
GREENBERG TRAURIG LLP
2450 COLORADO AVENUE, SUITE 400E
SANTA MONICA
CA
90404
US
|
Family ID: |
32507521 |
Appl. No.: |
10/543123 |
Filed: |
January 21, 2004 |
PCT Filed: |
January 21, 2004 |
PCT NO: |
PCT/US04/01634 |
371 Date: |
February 6, 2006 |
Current U.S.
Class: |
141/231 ;
141/82 |
Current CPC
Class: |
B60P 3/24 20130101; F17C
2201/035 20130101; Y02E 60/32 20130101; F17C 2221/012 20130101;
F17C 2265/066 20130101; F17C 2205/0107 20130101; F17C 2205/0332
20130101; B60S 5/02 20130101; F17C 2260/042 20130101; F17C
2205/0329 20130101; F17C 2223/0153 20130101; F17C 2227/0157
20130101; F17C 2221/016 20130101; F17C 2223/036 20130101; F17C
2227/04 20130101; F17C 2250/0636 20130101; F17C 7/02 20130101; F17C
2250/0439 20130101; F17C 2205/0134 20130101; F17C 2205/0157
20130101; F17C 2205/0111 20130101; F17C 2201/056 20130101; F17C
2227/0337 20130101; B60P 3/14 20130101; F17C 2205/0335 20130101;
F17C 2223/0123 20130101; F17C 2270/0168 20130101; F17C 5/007
20130101; B60P 3/2245 20130101; Y02E 60/321 20130101; F17C 2227/044
20130101; Y02P 90/45 20151101; F17C 2201/0109 20130101; F17C
2250/043 20130101; F17C 2205/0176 20130101 |
Class at
Publication: |
141/231 ;
141/082 |
International
Class: |
B65B 1/04 20060101
B65B001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 24, 2003 |
US |
10/350583 |
Claims
1. A hydrogen refueling station comprising: a portable enclosure;
at least one feed line whereinto hydrogen can flow; at least one
compressor means, within the enclosure, connected to the at least
one feed line; one or more hydrogen storage tanks, within the
enclosure, connected to the at least one feed line downstream from
the at least one compressor means; at least one control valve
connected to the at least one feed line; at least one reversible
connector, whereby hydrogen from the at least one hydrogen storage
tank can be dispensed; at least one cooling means, wherethrough
hydrogen can flow; and, at least one system controller to control
at least one of the at least one control valve or the at least one
compressor means, whereby the flow of hydrogen within the refueling
station is affected.
2. he transportable hydrogen refueling station of claim I wherein
each of at least one compressor means is selected from the group
consisting of a compressor and an intensifier.
3. The transportable hydrogen refueling station of claim I wherein
each compressor means comprises an oil cooled intensifier.
4. The transportable hydrogen refueling station of claim I wherein
at least one or more hydrogen storage tanks have a burst pressure
rating of at least 12,000 psi.
5. The transportable hydrogen refueling station of claim 2 wherein
one or more hydrogen storage tanks can store at least 3,500 grams
of hydrogen.
6. The transportable hydrogen refueling station of claim 1 wherein
the gross loaded weight of the refueling station is less than about
4,000 pounds.
7. The transportable hydrogen refueling station of claim 2 wherein
one or more hydrogen storage tanks can store at least 7,500 grams
of hydrogen.
8. The transportable hydrogen refueling station of claim 1 wherein
the gross loaded weight of the refueling station is less than about
5,500 pounds.
9. The transportable hydrogen refueling station of claim I wherein
each of at least one cooling means is selected from the group
consisting of heat exchangers, coolers and radiators.
10. The hydrogen refueling station of claim I wherein the portable
enclosure is a trailer.
11. A hydrogen re-fueling system comprising: a portable enclosure;
one or more hydrogen storage tanks, within the enclosure; at least
one reversible connector, whereby hydrogen from at least one
hydrogen storage tank can be dispensed; at least one control valve;
at least one cooling means, wherethrough hydrogen can flow; and, at
least one system controller to control at least one control valve,
whereby the flow of hydrogen to the reversible connector is
affected.
12. The hydrogen refueling station of claim 11 wherein the portable
enclosure is a trailer.
13. The transportable hydrogen refueling station of claim II
wherein at least one or more hydrogen storage tanks have a burst
pressure rating of at least 22,500 psi.
14. The transportable hydrogen refueling station of claim 11
wherein one or more hydrogen storage tanks can store at least 35
grams of hydrogen.
15. The transportable hydrogen refueling station of claim 11
wherein each of at least one cooling means is selected from the
group consisting of heat exchangers, coolers and radiators.
16. A hydrogen refueling station comprising: a portable enclosure;
at least one feed line whereinto hydrogen can flow; a hydrogen
producing subsystem, which has at least a hydrogen producing unit
and a hydrogen cooling unit, connected at one end to the feed line;
at least one compressor means, within the enclosure, connected to
at least one feed line downstream from the hydrogen producing
subsystem; one or more hydrogen storage tanks, within the
enclosure, connected to at least one feed line downstream from at
least one compressor means; at least one control valve connected to
at least one feed line; at least one reversible connector, whereby
hydrogen from at least one hydrogen storage tank can be dispensed;
at least one cooling means, wherethrough hydrogen can flow; and, at
least one system controller to control at least one control valve,
at least one compressor means, and the hydrogen producing subsystem
whereby the flow of hydrogen within the refueling station is
affected.
17. The hydrogen refueling station of claim 16 wherein the portable
enclosure is a trailer.
18. The hydrogen refueling station of claim 16 wherein the hydrogen
producing unit is a KOH electrolyzer.
19. The hydrogen refueling station of claim 1 wherein the hydrogen
cooling unit is a closed loop cooler.
20. The hydrogen refueling station of claim 1 further comprising a
tank of pressurized inert gas connected to at least one feed line;
whereby introduction of the inert gas into the feed line will purge
at least a portion of the feed line and/or the reversible
connector.
21. The hydrogen refueling station of claim 9 further comprising a
tank of pressurized inert gas connected to at least one feed line;
whereby introduction of the inert gas into the feed line will purge
at least a portion of the feed line and/or the reversible
connector.
22. The hydrogen refueling station of claim 14 further comprising a
tank of pressurized inert gas connected to at least one feed line;
whereby introduction of the inert gas into the feed line will purge
at least a portion of the feed line and/or the reversible
connector.
23. The hydrogen refueling station of claim 16 further comprising a
tank of pressurized inert gas connected to at least one feed line;
whereby introduction of the inert gas into the feed line will purge
at least a portion of the feed line and/or the reversible
connector.
24. A hydrogen refueling station comprising: a portable enclosure;
at least one feed line whereinto hydrogen can flow; a hydrogen
producing subsystem, which has at least a hydrogen producing unit
and a cooling unit, connected at one end to the feed line; at least
one compressor means, within the enclosure, connected to at least
one feed line; one or more hydrogen storage tanks, within the
enclosure, connected to at least one feed line downstream from at
least one compressor means; at least one control valve connected to
at least one feed line; at least one reversible connector, whereby
hydrogen from at least one hydrogen storage tank can be dispensed;
at least one cooling means, wherethrough hydrogen can flow, at
least one system controller to control at least one control valve
or at least one compressor means, whereby the flow of hydrogen
within the refueling station is affected; and a second system
controller to control the hydrogen producing subsystem.
25. The hydrogen refueling station of claim 1 further comprising
inert gas to purge at least a portion of the feed line.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a rechargeable device for storing
and, when desired, releasing hydrogen. Among other applications,
the device can be used in the energy generation or transportation
industries.
BACKGROUND OF THE INVENTION
[0002] A hydrogen economy has become a National vision. "Hydrogen
has the potential to solve two major energy challenges that
confront America today: reducing dependence on petroleum imports
and reducing pollution and greenhouse gas emissions. There is
general agreement that hydrogen could play an increasingly
important role in America's energy future. Hydrogen is an energy
carrier that provides a future solution for America." A National
Vision of America's Transition to a Hydrogen Economy to 2030 and
Beyond, based on results of the National Hydrogen Vision Meeting,
Washington, D.C., Nov. 15-16, 2001 United States Department of
Energy February 2002.
[0003] For mobile hydrogen powered systems, i.e., fuel cell powered
electric vehicles, hydrogen must be obtainable.
[0004] In U.S. Pat. No. 6,305,442, issued to Ovshinsky, a hydrogen
infrastructure system is proposed. It teaches hydrogen bound to a
metal alloy hydride. Release and storage of hydrogen bound to the
hydride is a process which requires energy. Ovshinsky states that a
major drawback of hydrogen as a fuel in mobile uses, such as
powering of vehicles, is the lack of an acceptable lightweight
hydrogen storage medium. Ovshinsky identifies hydrogen vessels as
heavy, and having a "very great" explosion/fire hazard. Further,
Ovshinsky identifies pressurized tankers as an unacceptable medium
for transporting all but smaller quantities of hydrogen due to
susceptibility to rupturing and explosion.
[0005] Accordingly, a hydrogen storage medium without necessitating
the use of hydrides that is relatively lightweight and safe would
be desirous.
[0006] A hydrogen replenishment system is taught in U.S. Pat. No.
6,432,283 issued to Fairlie et al. Fairlie teaches an electrolytic
cell which produces oxygen gas during gaseous hydrogen production.
The Fairlie system vents gaseous oxygen during the dispensing of
hydrogen creating the explosive risk of hydrogen-oxygen mixtures.
Accordingly, it would be desirous to have a refueling system
wherein gaseous oxygen is not produced when the system is
dispensing hydrogen thereby avoiding possible mixing of gaseous
hydrogen and gaseous oxygen.
[0007] Additionally, hydrogen gas produced from the electrolytic
cell described by Fairlie et. al is produced at an elevated
temperature. Fairlie et al teaches away from the use of hydrogen
storage tanks identifying them as a "potential safety risk" and
teaches the simultaneous generation and dispensing of hydrogen. it
is a well established principal of physics that the density of
hydrogen gas is inverse to the temperature. In-fact, Fairlie notes
that there is a problem of obtaining a false value of a high
pressure fill (full tank) if the filling is too rapid due to
temperature increase within the tank. At a constant pressure, the
greater the temperature of the gaseous hydrogen, the lower the
density of the gaseous hydrogen thus creating a false value.
Fairlie's temperature management solution is to wait for the
external vessel to cool down by modulating the rate of fill.
[0008] Achieving a full fill, as noted by Fairlie, is particularly
applicable to hydrogen fueled, fuel cell powered vehicles. The
operating range (distance) a fuel cell powered vehicle can
potentially travel is related to the quantity of hydrogen on board.
A second variable equally applicable to promoting the operation of
fuel cell powered vehicles is that sufficient quantity of hydrogen
to support a preselected operating range is dispensed in a time
frame which is within the "convenience expectations" of an end
user. It is therefore desirous to have a hydrogen refueling station
which manages the temperature of the gaseous hydrogen to minimize
reductions in rate of fill.
[0009] Trailers transporting pressurized cylinders of gas are known
in the art. Large semi-tanker/trailers for transporting gaseous
fuels are also known in the art. Semi-tankers are not a convenient
method for providing transportable hydrogen for refueling.
Specifically, the use of a semi-tanker requires a specialized
driver's license and due to weight and size restrictions, a
semi-tanker may be limited to use on some roadways and may have
limited access to some locations. A small trailer suitable for
towing by a passenger vehicle which can transport upwards of 35 kg
of hydrogen would solve many of the limitations of a
semi-tanker.
SUMMARY OF INVENTION
[0010] A refillable hydrogen refueling station within an enclosure
that can dispense upwards of 35 kg of hydrogen is taught. Gaseous
hydrogen is stored at high pressure without the use of heavy tanks,
hydrides or metal alloys. The refueling station within the enclosed
one can be trailer supported. The trailer supported enclosure or
the refueling station within an enclosed trailer can be towed by a
passenger vehicle.
[0011] The energy density of a system for transporting hydrogen
could be measured as grams/liter of stored gas as done by Ovshinsky
in the U.S. Pat. No. 6,305,442 patent, however, such a measurement
can be misleading when transportability of the hydrogen is a
factor. For transportable hydrogen, a useful measure of energy
density is grams of hydrogen per pound (gms/lb) of the gross weight
of the transportable system.
[0012] The hydrogen refueling station accepts a hydrogen feed
stock, increases the pressure of the hydrogen up to a desired
pressure, and stores the hydrogen in one or more tanks for later
dispensing. Distribution of the hydrogen is through a reversible
connector that can dispense the hydrogen from the tanks to a
receiving tank or apparatus.
[0013] In one embodiment, the hydrogen refueling station is
self-refilling. It has a hydrogen producing subsystem which can
also refill the tanks within the refueling station's hydrogen
storage subsystem. The self-refilling function is provided by a
hydrogen generating device such as an electrolyzer or electrolytic
cell.
[0014] To reduce the risk of the gaseous oxygen, produced as a
by-product of hydrogen generation, from mixing with gaseous
hydrogen the hydrogen refueling station can be operated to produce
and store hydrogen in the storage tanks at a time remote and
distinct from the dispensing of the hydrogen. Connections from the
hydrogen producing subsystem to the hydrogen storage tanks are
fixed and easily monitored for leaks as opposed to the temporary
connections made by the reversible connector.
[0015] Common to the embodiments described herein is temperature
management of the hydrogen. Hydrogen produced by an electrolyzer or
electrolytic cell is produced at temperature elevated above ambient
This elevated temperature decrease the density of the hydrogen gas.
To provide a higher density of the hydrogen gas the elevated
temperature of the hydrogen produced can be reduced by cooling the
hydrogen as it flows and not simply reducing the rate of fill.
[0016] Temperature management can result in higher density of the
hydrogen gas, which equates to more grams of hydrogen. The quantity
of hydrogen dispensed to the end user, and the rate at which it is
dispensed, should meet the reasonable convenience expectations of
the end user.
[0017] Most preferably the time it should take to refill a fuel
cell powered vehicle will be similar in duration to the time it
takes to refuel an automobile with gasoline. Further, the quantity
of hydrogen dispensed should have the potential to power a fuel
cell powered vehicle a range of travel also within the reasonable
convenience expectations of an end user.
[0018] In some instance the hydrogen storage tanks may be by-passed
and the hydrogen from the hydrogen producing subsystem cooled and
dispensed directly to an end user.
[0019] The electrolyzer may be powered by renewable source
including to not limited to wind, hydroelectric and solar.
Electricity from turbines and/or Photovoltaic panels can be
connected to the electrolyzer or electrolytic cell to support
hydrogen generation.
[0020] Other features and advantages of the present invention will
be set forth, in part, in the descriptions which follow and the
accompanying drawings, wherein the preferred embodiments of the
present invention are described and shown, and in part, will become
apparent to those skilled in the art upon examination of the
following detailed description taken in conjunction with the
accompanying drawings or may be learned by practice of the present
invention. The advantages of the present invention may be realized
and attained by means of the instrumentalities and combinations
particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1A is an overview of the transportable hydrogen
refueling station.
[0022] FIG. 1B is an overview of the transportable hydrogen
refueling station in use.
[0023] FIG. 2A is a partially cutaway view of a transportable
hydrogen refueling station.
[0024] FIG. 2B is a table comparing the capacity of different
configurations of the transportable hydrogen refueling station of
FIG. 2A.
[0025] FIG. 3A is a semi-tanker.
[0026] FIG. 3B is a table of the specifications for the semi-tanker
of FIG. 3.
[0027] FIG. 4 is a schematic of a transportable hydrogen refueling
station.
[0028] FIG. 5A is a partial cutaway view of a self fueling
transportable hydrogen refueling station.
[0029] FIG. 5B is a table comparing the capacity of different
configurations of the hydrogen refueling station of FIG. 5A.
[0030] FIG. 6 is a schematic of a self fueling transportable
hydrogen refueling station.
THE PREFERRED EMBODIMENTS OF THE INVENTION
[0031] A hydrogen refueling station 10 shown in FIGS. 1A, 1B and 2A
is transportable. The hydrogen refueling station 10 or "hydrogen
hauler" is useful to provide pressurized hydrogen gas to external
hydrogen storage vessels. Those vessels may be part of a hydrogen
powered motor vehicle 12.
[0032] The refueling station 10 is constructed on a substantially
flat base 14, which supports a lightweight shell 16 into which the
hydrogen storage, pressurization and distribution systems, are
placed. An enclosure with its own base that can be detached or
removed from the base 14 can be substituted for the lightweight
shell 16. The base 14 is supported by axle mounted wheels 18. Vents
19 placed along the upper regions of the lightweight shell 16 allow
any build up of gases to escape the shell 16.
[0033] The table provided in FIG. 2B indicates that the hydrogen
refueling station 10 has a curb weight of under 5,500 pounds. The
low curb weight is, in part, achieved by fitting the refueling
station 10 with lightweight internal hydrogen storage tanks 100.
Thus the refueling station 10 can be towed by a passenger
vehicle.
[0034] Lightweight internal hydrogen storage tanks 100 should have
a pressure rating of up to about 10,000 psi or more and a failure
rating, or burst rating, of at least 2.25 times the pressure
rating. One such hydrogen storage vessel is the Dynecell available
from Dynetek Industries, Ltd. in Alberta, Canada. Another
lightweight hydrogen storage vessel is the Tri-Shield available
from Quantum Technologies. Inc. in Irvine, Calif.
[0035] The table provided in FIG. 2B indicates that a refueling
station 10 with a curb weight of about 4,000 lbs (option A) should
have a capacity of up to about 40 kg of hydrogen. The energy
density measured as curb weight/quantity hydrogen for the 4,000 lb
trailer is about 10 gm/lb (40,000 grams/4,000 lbs). A transportable
hydrogen refueling station with a curb weight of about 5,500 lbs
(option B) and a capacity of about 80 kg of hydrogen has an energy
density of about 14.5 gm/lb (80,000 gm/5,500 lbs).
[0036] Conversely, a traditional tanker 20 for transporting
hydrogen shown in FIG. 3A, the hydrogen filled tanker 20, according
to its specifications provided in the table of FIG. 3B only has an
energy density of about 5.3 gm/lb (320,000 gms/60,000 lbs). The
refueling station 10 therefore has an energy density about twice
the energy density of the semi-tanker.
[0037] FIG. 4 is a schematic of the refueling station 10. The
refueling station 10 can be used to refuel a variety of external
hydrogen storage vessels and is not limited to supplying hydrogen
to fuel cell powered vehicles, although such vehicles are one focus
of the invention.
Filling the Refueling Station
[0038] Before the refueling station 10 can be used to supply
hydrogen to an external hydrogen storage vessel 25, the internal
hydrogen storage tanks 100 in the refueling station 10 must be
filled. A hydrogen storage subsystem 30 is provided within the
transportable hydrogen refueling station 10 to refill or charge the
lightweight composite hydrogen storage tanks 100, a quick connect
32, which can be any standard hydrogen connector, is used to
connect an external hydrogen source to hydrogen storage subsystem
30.
[0039] Downstream from the quick connect 32 is a pressure release
valve 34. The pressure release valve 34 is a safety element to
prevent hydrogen, at a pressure exceeding a pre-determined maximum,
from entering the hydrogen storage subsystem 30. If the pressure of
hydrogen being introduced through the quick connect 32 exceeds a
safe limit a restricted orifice 33 working in combination with a
pressure relief valve 34 causes the excess hydrogen to be vented
through a vent stack 36. In general, the valves are used to affect
the flow of hydrogen within the refueling station. A check valve
38, between the vent stack 36 and pressure relief valve 34,
maintains a one way flow of the flow of pressurized hydrogen being
relived from the storage subsystem 30. The restrictive orifice 33
also prevents the hydrogen from entering the pressure rated feed
line 40 at a rate which causes extreme rapid filling of the
lightweight hydrogen storage tanks 100. Prior to connecting the
quick connect 32 nitrogen gas, or other inert gas can be introduced
into the feed line 40 to purge any air from the feed line.
Pressurized nitrogen dispensed from a nitrogen tank 200 can be
introduced through a nitrogen filling valve 202.
[0040] The feed line 40 should be constructed of stainless steel
and typically has a safety margin of 4. Safety margins for a
pressurized hydrogen gas line are a measure of burst pressure to
operating pressure. It is important to control the rate of fill of
the hydrogen storage tanks 100 and in general the temperature of
the gaseous hydrogen. Although a rapid fill is desired, physics
dictates that as you increase the fill rate, all things being
equal, an elevation in temperature will occur. With an elevation in
temperature there is a corresponding decrease in the mass of
hydrogen that can be stored at a predetermined input pressure.
Accordingly, if the hydrogen entering the hydrogen storage tanks
100 is at an elevated temperature the density of the gaseous
hydrogen will also be reduced. Cooling the gaseous hydrogen, by
directing it through a cooling unit 300, is used to reduce
temperature elevations.
[0041] The cooling unit 300 in this embodiment is a finned tube
type heat exchanger, however, other heat exchangers, coolers, or
radiators which can manage the temperature of the gaseous hydrogen
may be used. Temperature is measured at various places on the feed
line 40 by temperature sensors 42 which are monitored by a system
controller 400 which is typically based on a 8-32 bit
microprocessor.
[0042] Connections between the feed line 40 sensors, valves,
transducers, inlet or outlets, should be constructed to minimize
any potential for leakage of hydrogen. Common construction
techniques include welds, face seals, metal to metal seals and
tapered threads. One or more hydrogen leak sensors 43 are also
distributed and connected to the system controller 400. The
pressure of the gaseous hydrogen is measured by one or more
pressure sensors 44 placed in the feed line 40. No specific sensors
is called out for but generally the sensor may be a transducer, or
MEMS that incorporate polysilicon strain gauge sensing elements
bonded to stainless steel diaphragms. The temperature and pressure
of the hydrogen, entering the pressure rated feed line 40 can be
checked as it passes into the first compressor subsystem 50.
[0043] The first compressor subsystem 50 contains an oil cooled
first intensifier 52. An intensifier switch 53, connected to the
system controller 400, controls the start/stop function of the
first intensifier 52. An oil to air heat exchanger 54 for cooling
hydraulic oil which is supplied to a first intensifier heat
exchanger 56 to cool the first intensifier 52. A hydraulic pump 58,
powered by a brushless motor 60, supplies cooling oil from an oil
reservoir 62 to the first intensifier heat exchanger 56. A speed
control 64 for the brushless motor 60 is provided. A brushless
motor 60 is preferred to eliminate the risk of sparks. The system
controller 400 receives data from the oil temperature sensor 65.
the gaseous hydrogen temperature sensors 42, the gaseous hydrogen
pressure sensors 44, and the hydrogen leak sensors 43. The system
controller 400 in turn is used to, among other things, effect the
speed control 64.
[0044] The intensifier is a device, which unlike a simple
compressor, can receive gas at varying pressures and provide an
output stream at a near constant pressure. However, it may be
suitable in some cases to use a compressor in place of an
intensifier. The first intensifier 52 increases the pressure of the
incoming gaseous hydrogen about four fold. Within the first
compressor subsystem 50, hydrogen gas from the feed line 40 enters
the first intensifier 52 through an inlet valve 68. The gaseous
hydrogen exits the first intensifier through an outlet check valve
70. At this point, the gaseous hydrogen is directed through a
cooling unit 300 to manage any temperature increases in the gaseous
hydrogen. The gaseous hydrogen passing through the cooling unit 300
may be directed to enter a second compressor subsystem 80 or into a
by-pass feed line 90.
[0045] If entering the second compressor subsystem 80 the gaseous
hydrogen passes through an inlet check valve 82 which directs it to
the second intensifier 84. An intensifier switch 85, connects to
the system controller 400, and controls the start/stop function of
the second intensifier 84. The gaseous hydrogen exits the second
intensifier 84 through an outlet check valve 86 and is directed
down the inlet/outlet line 88 to a line control valve 92 which
directs the gaseous hydrogen through a cooling unit 300 and into
the inlet/outlet control valves 94 and 94' for the lightweight
composite hydrogen storage tanks 100 and 100'. The dual compressor
sub-systems 50 & 80 are not a limitation. If the storage
pressure for the hydrogen gas can be achieved with a single
compressor sub-system, the second compressor subsystem can be
bypassed or eliminated. By closing the inlet check valve 82 to the
second intensifier 84, the gaseous hydrogen exiting the first
intensifier 52 is directed through the by-pass feed line 90 and to
a by-pass inlet/outlet control valve 96 which directs the flow of
gaseous hydrogen to the lightweight composite hydrogen storage
tanks 100 and 100'. Conversely, in those instances where storage
pressure exceeding that which can be efficiently achieved with dual
intensifiers is desired, additional intensifiers can be added.
EXAMPLES
[0046] The following examples are given to enable those skilled in
the art to more clearly understand and to practice the present
invention. They should not be considered as limiting the scope of
the invention, but merely as being illustrative and representative
thereof.
Example 1
[0047] If the external hydrogen feed gas is supplied to the
hydrogen storage subsystem 30 at approximately 1,000 psi then the
first compressor subsystem 50 can increase the pressure of the
hydrogen gas by up to about four times which would be as high as
approximately 4,000 psi. However, if the desired storage is about
10,000 psi then the gaseous hydrogen is directed by the actions of
the system controller 400 (i.e. opening and closing valves) from
the first compressor subsystem 50 to the second intensifier
subsystem 80.
[0048] The pressure of gaseous hydrogen which enters the second
compressor subsystem 80 at about 4,000 psi can be increased to
achieve the desired 10,000 psi. As an additional fail safe, manual
control valves 98 and 98' may be affixed to each of the lightweight
composite hydrogen storage tanks 100 and 100' to physically prevent
the flow of hydrogen gas in or out of the lightweight composite
hydrogen storage tanks 100 and 100'.
[0049] The system controller 400 can be used to maintain balance
during the refilling of the lightweight composite hydrogen storage
tanks 100 and 100' by monitoring the pressure of each of the
lightweight composite hydrogen storage tanks 100 and 100' via
adjacent pressure sensors 99 and 99'. The system controller 400, in
turn can switch between storage tanks and select which tank to fill
at a given time interval during the filling.
Example 2
[0050] If the external hydrogen feed gas is supplied to the
hydrogen storage subsystem 30 at approximately 3,300 psi then the
first compressor subsystem 50 can increase the pressure of the
hydrogen gas by up to about four times which would be as high as
approximately 9,900 psi. Accordingly, if the desired storage
pressure of the hydrogen gas in the lightweight hydrogen storage
vessels is about 10,000 psi the second compressor subsystem can be
by-passed by keeping the inlet check valve 82 closed and directing
the hydrogen gas to the by-pass inlet/outlet control valve 96.
Self-Filling Refueling Station
[0051] In another embodiment shown in FIGS. 5A and 5B a hydrogen
producing subsystem 500 is part of the hydrogen storage subsystem
30. The hydrogen producing subsystem 500, in this embodiment, is
comprised of a KOH electrolyzer module 502 and a cooling module
504. One suitable KOH electrolyzer is a IMET electrolyzer
manufactured by Vandenborre Hydrogen Systems. The cooling module
504 should be sufficient to reduce the temperature to at or below
ambient for maximum volume in the pressure rated hydrogen storage
tanks 100. The cooling module 504 may be a closed loop cooler,
receive a water input, or use heat exchangers and or radiators.
[0052] The hydrogen producing subsystem 500 is affixed to the
pressure rated feed line 40 upstream from the pressure release
valve 34. A hydrogen production controller (HPC) 550 can receive
data from the oil temperature sensor 65, the gaseous hydrogen
temperature sensors 42, the gaseous hydrogen pressure sensors 44
and the hydrogen leak sensors 43. The HPC 550 in turn is used to,
among other things, switch on and off the electrolyzer module 502
and can also effect the speed control 64.
[0053] A polymer electrolyte membrane (PEM) cell may be substituted
for the IMET electrolyzer. A PEM electrolyzer splits hydrogen from
a water source and generates a hydrogen gas stream. Both the
electrolyzer and the polymer electrolyte membrane are known in the
art and therefore a detailed description of their construction is
not necessary. Gaseous hydrogen produced by a PEM electrolyzer is
also generated at a temperature which is elevated above
ambient.
Refueling from the High Pressure Tanks
[0054] The refueling station 10 can be towed to a desired location.
It can also be disconnected from the tow vehicle (FIG. 1A), or it
can be transported from place to place.
[0055] The hydrogen fueling subsystem 110 is used to refuel an
external hydrogen storage vessel 25 with pressurized hydrogen from
the refueling station 10. As the refueling begins after the system
controller 400 will check pre-identified parameters, such as,
temperature and pressure of the external hydrogen storage vessel,
confirmation of ground connection and in some cases, confirmation
from vehicles of readiness to fill, in order to determine whether
hydrogen should be dispensed to the external hydrogen vessel
25.
[0056] The actual hydrogen refueling process can be preceded by
safety measures. Pressurized nitrogen, or other inert gas, may be
introduced through a purge line 112 into the hydrogen dispensing
feed lines 114 and 114' to purge any air from the hydrogen
dispensing feed lines 114 and 114'. The purge is to manage the risk
of dangerous hydrogen-air (oxygen) mixtures being formed and or
being supplied to the external hydrogen vessel 25. Purge pressure
relief valves 120 and 120' are appropriately located to vent gas
from the hydrogen dispensing feed lines 114 and 114'. In this
embodiment, the system controller 400 also controls the nitrogen
valve 202.
[0057] The fill couplers 116 and 116' can be any industrial or any
standard hydrogen connector. A suitable fill connector is WEH TK 15
hydrogen fill nozzle by WEH of Germany in combination with a
WEH-TN1 receptacle. Each fill coupler 116 and 116' is connected to
the refueling station 10 via break away couplers 118 and 118'. A
break away coupler 118 is another safety element not uncommon to
refueling systems. A purge pressure relief valve can vent hydrogen
to a vent 121 and 121' from the hydrogen dispensing line if a break
away coupler is decoupled.
[0058] One proposed industry standard for a fuel cell vehicle fill
coupler is described in the proposed "Fueling Interface
Specification" prepared by the California Fuel Cell Partnership
that description which is hereby incorporated by reference. The
fill coupler, indicated in the proposed "Fueling Interface
Specification", has a "smart" connect which, among other
parameters, checks the pressure, temperature and volume of hydrogen
within the tanks of a vehicle 12 (the external hydrogen storage
vessel 25) being refueled. It will also check that the vehicle is
grounded.
[0059] The "smart" fill coupler can communicate with the refueling
station 10 through the system controller 400 or other data
processor, controller and or computer (not shown). A user interface
panel 600 may also be provided whereby the user may confirm
conditions, enter data or otherwise communicate with the refueling
station 10.
[0060] After the external hydrogen vessel 25 and the fill coupler
116 are connected, recharging or filling of the hydrogen receptacle
can occur. The fill coupler should meet or exceed the appropriate
governmental or industry mechanical specifications to fill the
hydrogen storage vessel at a pressure not to exceed any
predetermined pressure rating thereof.
[0061] When refueling or recharging an external hydrogen storage
vessel 25 preferably a map of the external hydrogen vessel 25
should be obtained. A map should check the temperature, volume and
pressure of the hydrogen gas in the external hydrogen vessel 25 and
the volume pressure and temperature of the hydrogen in each
lightweight composite hydrogen storage tanks 100 and 100'. It is
also envisioned that the map may include information about the
pressure rating and capacity of the external hydrogen vessel 25.
The pressure rating and capacity information could alternatively be
input on the interface panel 600 and or transmitted via a smart
connect. External hydrogen vessel 25 identification information
could be received by the system controller 400 which can use a look
up table (LUT) to set the refueling parameters.
[0062] One pathway of the hydrogen gas being dispensed is from the
pressure rated tanks 100 and 100', via the inlet/outlet control
valves 94 and 94', through the cooling unit 300, then via the line
control valve 92 into the inlet/outlet feed line 88.
[0063] The cooling unit 300 can reduce the temperature of the
hydrogen gas by about at least 20.degree. C., more preferable by
about at least 40.degree. C. and most preferably by about at least
80.degree. C.
[0064] By controlling the temperature of the hydrogen gas during
refueling a faster refueling can take place. If the temperature of
the hydrogen in the external hydrogen vessel 25 increase past
ambient the volume of hydrogen which the external hydrogen vessel
25 can store is decreased. If the temperature increase is as little
as about 20.degree. C. from 20 to 40 volume may be decreased by
about 6%. If that temperature increase is about 40 degrees volume
may be decreased by about 12%. If the temperature increase is about
80 degrees volume may be decreased by about 22%.
[0065] Temperature management supports faster dispensing of dense
gaseous hydrogen. An end user or consumer may have convenience
expectations such as a reference on the time interval it took to
refuel a gasoline powered combustion automobile, and how the
combustion automobile could travel on the quantity of gasoline
received during the time interval. To meet convenience
expectations, a hydrogen refueling station should dispense enough
hydrogen (grams), in a similar time interval, to potentially travel
a similar distance.
[0066] The hydrogen gas, in the inlet/outlet feed line 88, is
directed to one or both of the hydrogen dispensing feed lines 114
and 114' via a dispensing line check valve 97.
[0067] When dispensing the gaseous hydrogen, the system controller
400 can be used to select between the lightweight composite
hydrogen storage tanks 100 and 100' by comparing pressure in the
lightweight composite hydrogen storage tanks 100 and 100' and the
external hydrogen storage vessel 25 to balance the pressure.
Pressure balancing between sources is a known mechanism used to
more efficiently dispense gaseous fuels from multiple pressurized
sources. The system controller 400 controls the control valves and
check valves during the dispensement of hydrogen (refueling) to an
external hydrogen vessel 25. Refueling can normally continue until
an external hydrogen storage vessel 25 reaches a selected or
predetermined fill pressure.
[0068] At the completion of refueling, in conjunction with
decoupling a fill coupler 116 or 166' from an external hydrogen
vessel 25 or 25', a decoupling control valve 122 or 122' directs
the hydrogen, in that portion of a hydrogen dispensing feed lines
114 or 114' via break away couplers 118 or 118' and fill coupler
116 or 166', to a vent 121 or 121'. Venting the hydrogen will
depressurize the portion of the hydrogen dispensing feed lines 114
or 114' connected to the fill coupler 116 or 166'.
Refueling Direct
[0069] The embodiment shown in FIG. 6 can also be used to dispense
gaseous hydrogen directly to an external hydrogen storage vessel
25. The system controller 400 can shut off the inlet/outlet control
valves 94 and 94' and direct the gaseous hydrogen from the first or
second compressor subsystems 50 or 80 through the inlet/outlet feed
line 88.
[0070] During a direct refill the gaseous hydrogen from the
electrolyzer module 502 passes through the cooling module 504 to
reduce the elevated temperature of the gaseous hydrogen produced by
the electrolyzer module 502. At this point, without any further
cooling the dispensed hydrogen will have a greater density than
hydrogen dispensed directly from the electrolyzer module 502.
[0071] To further reduce the temperature of the hydrogen exiting
the cooling module, the gaseous hydrogen output from either the
first or second compressor subsystems 50 or 80 passes through a
cooling unit 300 before being dispensed to an end user.
[0072] Since certain changes may be made in the above apparatus
without departing from the scope of the invention herein involved,
it is intended that all matter contained in the above description,
as shown in the accompanying drawing, shall be interpreted in an
illustrative, and not a limiting sense.
* * * * *