U.S. patent application number 11/059767 was filed with the patent office on 2006-08-17 for system and method for dispensing compressed gas.
Invention is credited to Joseph Perry Cohen, Bryan Clair JR. Hoke.
Application Number | 20060180237 11/059767 |
Document ID | / |
Family ID | 36273432 |
Filed Date | 2006-08-17 |
United States Patent
Application |
20060180237 |
Kind Code |
A1 |
Hoke; Bryan Clair JR. ; et
al. |
August 17, 2006 |
System and method for dispensing compressed gas
Abstract
An apparatus and corresponding method for dispensing compressed
gas to a receiving tank is provided which includes a compressed gas
source, a valve for controlling the flow of the compressed gas
between the compressed gas source and the receiving tank, an
electronic controller, a conduit between the valve and the
receiving tank, and a density sensor for sensing the density of the
compressed gas inside the receiving tank. The density sensor may be
a capacitive sensor, a vibrating element sensor, or a nucleonic
sensor. The electronic controller stores a predetermined set point
density and the density sensor measures the density of the
compressed gas in the receiving tank. The electronic controller
periodically compares the density of the compressed gas with the
predetermined set point density and controls the flow of compressed
gas through the valve.
Inventors: |
Hoke; Bryan Clair JR.;
(Bethlehem, PA) ; Cohen; Joseph Perry; (Bethlehem,
PA) |
Correspondence
Address: |
AIR PRODUCTS AND CHEMICALS, INC.;PATENT DEPARTMENT
7201 HAMILTON BOULEVARD
ALLENTOWN
PA
181951501
US
|
Family ID: |
36273432 |
Appl. No.: |
11/059767 |
Filed: |
February 17, 2005 |
Current U.S.
Class: |
141/94 |
Current CPC
Class: |
F17C 2221/012 20130101;
F17C 2260/022 20130101; F17C 2250/0421 20130101; F17C 2225/036
20130101; F17C 2225/0123 20130101; F17C 2270/0168 20130101; Y02E
60/32 20130101; F17C 5/06 20130101; F17C 7/00 20130101; F17C
2223/036 20130101; Y02E 60/321 20130101; F17C 2250/0443 20130101;
F17C 2270/0139 20130101; F17C 2250/04 20130101; F17C 2260/021
20130101; F17C 2223/0123 20130101; F17C 2250/043 20130101; F17C
5/007 20130101; F17C 2250/0439 20130101; F17C 2250/032
20130101 |
Class at
Publication: |
141/094 |
International
Class: |
B65B 31/00 20060101
B65B031/00 |
Claims
1. An apparatus for dispensing a compressed gas to a receiving tank
comprising: a compressed gas source; a valve in fluid communication
with the compressed gas source, said valve operable by a valve
signal; an electronic controller for generating the valve signal; a
fluid tight conduit having a first end and a second end wherein the
first end is in fluid communication with said valve and wherein the
second end is in fluid communication with a dispensing connector
for connecting to the receiving tank; and a sensor for measuring
the density of a fluid in the receiving tank, said sensor selected
from the group consisting of a capacitive sensor, vibrating element
sensor, and nucleonic sensor, said sensor including a signal
generator for generating a sensor signal corresponding to the
density of the fluid inside the receiving tank, said signal
generator in communication with said electronic controller.
2. The apparatus of claim 1 wherein the sensor is integrated with
the dispensing connector.
3. The apparatus of claim 1 wherein the sensor is integrated with
the receiving tank.
4. The apparatus of claim 1 wherein the electronic controller has
an electronic memory location for storing a predetermined set point
density and is programmed to compare the sensor signal with the
predetermined set point density.
5. A method for dispensing a compressed gas from a compressed gas
source to a receiving tank comprising: storing a predetermined set
point density in an electronic controller; connecting a dispensing
connector to the receiving tank; obtaining a direct density
measurement of the compressed gas in the receiving tank using a
density sensor selected from the group consisting of capacitive
sensor, vibrating element sensor, and nucleonic sensor;
transmitting the direct density measurement to the electronic
controller; comparing the direct density measurement with the
predetermined set point density; and providing a signal to a valve
to control the flow of the compressed gas from the compressed gas
source to the receiving tank.
Description
[0001] This patent application is related to U.S. patent
application Ser. No. ______, entitled "Method and Apparatus for
Dispensing Compressed Gas," contemporaneously filed on Feb. 17,
2005.
BACKGROUND OF THE INVENTION
[0002] The present invention is related to a compressed gas
dispensing system. More particularly, the present invention is
directed to a method and apparatus useful for transferring a
compressed gas from a refueling station into one or more storage
tanks.
[0003] Because of the interrelationship between the temperature,
pressure, and density of gases, the amount of hydrogen, H.sub.2,
(or compressed natural gas (CNG)) that can safely be introduced
into a storage tank, such as a vehicle storage tank, during
refueling necessarily depends upon factors such as the volume,
design pressure, and temperature of the tank, and the temperature
and pressure of the compressed gas inside the tank. Industry
convention sets the pressure rating for H.sub.2 fuel tanks at the
standard temperature of 15 degrees Celsius, so nominal pressure
ratings such as 250 bar (25 MPa), 350 bar (35 MPa), 500 bar (50
MPa) and 700 bar (70 MPa), correspond to an internal gas
temperature of 15 degrees Celsius. During rapid refueling of
hydrogen, the internal tank temperature will typically rise about
50 degrees Celsius due to adiabatic compression of the gas and the
reverse Joule-Thompson effect. After the tank is filled, the
temperature and pressure inside the tank will decrease as the gas
cools. Wide variations in ambient temperature above or below the
standard condition of 15 degrees Celsius can also have a
significant effect on the indicated pressure inside the tank during
and after refueling.
[0004] As referred to herein, a compressed gas includes pressurized
gas and supercritical fluids. A pressurized gas is a fluid below
its critical pressure and below its critical temperature. A
supercritical fluid is a fluid above either its critical pressure
or its critical temperature.
[0005] It is desirable to have a compressed gas dispensing station
capable of transferring a compressed gas to a receiving vessel
until the density in the receiving vessel reaches a preselected
density without the problem or risk of overfilling.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention relates to an apparatus for dispensing
a compressed gas to a receiving tank comprising a compressed gas
source, a valve in fluid communication with the compressed gas
source wherein the valve is operable by a valve signal, an
electronic controller for generating the valve signal, a conduit
having a first end and a second end wherein the first end is in
fluid communication with the valve and wherein the second end is in
fluid communication with a dispensing connector for connecting to
the receiving tank, and a sensor for measuring the density of a
fluid in the receiving tank. The sensor is selected from the group
consisting of a capacitive sensor, vibrating element sensor, and
nucleonic sensor. The sensor includes a signal generator for
generating a sensor signal corresponding to the density of the
fluid inside the receiving tank. The signal generator is in
communication with the electronic controller.
[0007] The sensor may be integrated with the dispensing connector.
Alternatively, the sensor may be integrated with the receiving
tank.
[0008] The electronic controller may have an electronic memory
location for storing a predetermined set point density and may be
programmed to compare the sensor signal with the predetermined set
point density.
[0009] The present invention also relates to a method for
dispensing a compressed gas from a compressed gas source to a
receiving tank, the step comprising storing a predetermined set
point density in an electronic controller, connecting a dispensing
connector to the receiving tank, obtaining a direct density
measurement of the compressed gas in the receiving tank using a
density sensor selected from the group consisting of capacitive
sensor, vibrating element sensor, and nucleonic sensor,
transmitting the direct density measurement to the electronic
controller, comparing the direct density measurement with the
predetermined set point density, and providing a signal to a valve
to control the flow of the compressed gas from the compressed gas
source to the receiving tank.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0010] FIG. 1 is a schematic view of an embodiment of the apparatus
of the present invention for dispensing compressed gas.
[0011] FIG. 2 is a schematic view of another embodiment of the
apparatus of the present invention for dispensing compressed gas
where the density sensor is integrated with the dispensing
connector.
[0012] FIG. 3 is a schematic view of another embodiment of the
apparatus of the present invention for dispensing compressed gas
where the connection between the density sensor and electronic
controller is integrated with the dispensing connector.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring to the drawings, wherein like reference numbers
refer to like elements throughout the several views, there is shown
in FIG. 1, an apparatus 10 for dispensing compressed gas to a
receiving tank 14 in accordance with an embodiment of the present
invention. The apparatus 10 for dispensing compressed gas comprises
a compressed gas source 12, a valve 20, a conduit 18 linking the
valve 20 to a dispensing connector 30, a density sensor 40, and an
electronic controller 28. The apparatus may optionally comprise a
temperatures sensor 41.
[0014] The compressed gas may be hydrogen gas and it may be
compressed natural gas.
[0015] The compressed gas source 12 of the various embodiments of
the present invention may be a large volume storage tank, hydril
tubes, a compressed gas supply line, a compressor discharge line,
or any combination of these elements suitable for use in supplying
gas to the receiving tank in an amount and at a pressure great
enough to achieve a desired fill rate, density, and pressure in the
receiving tank. The compressed gas source may also originate from a
liquid source that has been pressurized and heated in a heat
exchanger. In the case of hydrogen, the compressed gas source may
also originate from metal hydrides or chemical hydrides.
[0016] The valve 20 is in fluid communication with the compressed
gas source 12 and regulates the flow from the compressed gas source
12 to the receiving tank 14. The valve is operable, i.e. opened and
closed, via a valve signal. The valve 20 may be pneumatically
actuated or electrically actuated. Such valves are conventional in
the art. Valve 20 may be constructed of any material known in the
art compatible with the compressed gas. In case of a pneumatically
operated valve, an electric signal must be converted to a pneumatic
signal.
[0017] The conduit 18 links the valve 20 to a dispensing connector
30. The conduit 18 may be constructed of any material known in the
art compatible with the compressed gas. The conduit 18 may be rigid
or flexible.
[0018] The dispensing connector 30 may be any suitable connector
for mating to the receiving tank 14. Dispensing connectors are
conventional in the art. Dispensing connector 30 may be constructed
of any material in the art compatible with the compressed gas.
[0019] The density sensor 40 may be disposed inside the receiving
tank 14 and senses the density of the fluid inside the receiving
tank 14. The density sensor 40 may be incorporated in the receiving
tank 14 or it may be a separate device that is connected to the
receiving tank 14 at the dispensing location. More than one density
sensor may be used. The density sensor 40 may be a capacitive
sensor, vibrating element sensor, or nucleonic sensor. For the case
where the density sensor 40 is a capacitive sensor, a temperature
sensor 41 may also be desired for improved accuracy of the density
measurement. The temperature sensor 41 may be integrated with the
density sensor 40. The density sensor 40 includes a signal
generator for generating a sensor signal corresponding to the
density of the fluid inside the receiving tank 14. The signal
generator is in communication with the electronic controller 28.
The communication between the signal generator of the density
sensor 40 and the electronic controller 28 may be hardwired or
wireless. The signal may be relayed to the electronic controller 28
by, for example, any conventional, commercially available devices
or systems as desired.
[0020] The density may be the mass density (mass per volume), molar
density (moles per volume), or equivalent, for example, any density
directly related to these quantities.
[0021] A capacitive sensor is defined as any sensor that senses a
fluid's dielectric properties. Examples of capacitive sensors are
illustrated in U.S. Pat. Nos. 3,421,077, 3,903,478, 4,835,456, and
5,027,076.
[0022] A vibrating element sensor is defined as any sensor that has
a vibrating structure. It is known that, in a vibration
densitometer, if a structure is vibrated at its resonant frequency
while being immersed in a fluid, the density of the said fluid can
be determined by measuring the resonant frequency. The vibrating
element may be a vane as described in U.S. Pat. No. 3,677,067, a
tuning fork as described in U.S. Pat No. 4,526,480, a cylinder as
described in U.S. Pat. No. 6,029,501, a double-bar double-ended
resonator or double-bar single-ended as described in U.S. Pat. No.
4,535,638, or any other vibrating element known in the art. The
vibrating element, for example a tuning fork and vane, may be
surrounded by the fluid to be measured or the fluid may flow inside
of the vibrating element, for example a tube. Examples of vibrating
element sensors are also illustrated in U.S. Pat. Nos. 3,426,593,
3,715,912, 4,574,639, 4,644,796, 4,644,803,
[0023] A nucleonic sensor is defined as any sensor that uses a
radiation source and detector. The radiation may be x-ray as in
U.S. Pat. No. 4,277,681, gamma-ray (y-ray) as in U.S. Pat. Nos.
5,166,964 and 2,898,466, neutrons as in U.S. Pat. No. 4,582,991,
beta-ray as in U.S. Pat. No. 2,757,290 or other radiation source
known in the art. Nucleonic, also called radiation type, sensors
are also discussed in U.S. Pat. Nos. 2,763,790, 2,968,729,
2,922,888, 3,196,271, and 6,548,814.
[0024] Direct measurement of density inside receiving tank 14 using
at least one of the sensors above offers several advantages over
systems in the prior art. With the system 10 disclosed herein, the
actual density of gas inside receiving tank 14 is compared
periodically to a tank rated density (based on a tank rated
temperature at a tank rated pressure) of the full receiving tank 14
by the electronic controller 28. The tank rated density may be
calculated based on the receiving tank specifications, for example,
a manufacturer's specification, for a full tank. Tank rated
pressure and temperature may be converted to a tank rated density.
Therefore, the tank may be filled such that at no time during the
dispensing cycle or afterward does the actual pressure inside the
receiving tank exceed the manufacturer's maximum allowable pressure
for that tank.
[0025] The quantity transferred, which may be required for the
billing process, may be calculated from the final and initial
density in the receiving vessel.
[0026] The electronic controller 28 is a comparative device that
receives an input signal from the signal generator of the density
sensor 40, compares this value with that of a predetermined control
point value (set point), and determines the appropriate amount of
output signal required by the valve 20 to control the flow of the
compressed gas. The electronic controller uses electrical signals
and digital algorithms to perform its receptive, comparative, and
control functions.
[0027] The density sensor 40, installed at the measurement location
may continuously send an input signal to the controller 28. At set
intervals the controller compares this signal to a predefined set
point. If the input signal reaches the set point indicating that
the fill is complete, the controller sends an output signal to the
valve 20 to close. This electric signal must be converted to a
pneumatic signal when used with an pneumatically operated
valve.
[0028] An apparatus 10 for dispensing compressed gas to a receiving
tank 14 in accordance with another embodiment of the present
invention is illustrated in FIG. 2. The apparatus 10 for dispensing
compressed gas comprises a compressed gas source 12, a valve 20, a
conduit 18 linking the valve 20 to a dispensing connector with
integrated a density sensor 50, and an electronic controller 28.
Having the dispensing connector integrated with the density sensor
means that the density sensor is in communication with the
receiving tank only when the dispensing connector is connected to
the receiving tank. The dispensing connector with integrated
density sensor 50 may also comprise a temperature sensor.
[0029] An apparatus 10 for dispensing compressed gas to a receiving
tank 14 in accordance with yet another embodiment of the present
invention is illustrated in FIG. 3. The apparatus 10 for dispensing
compressed gas comprises a compressed gas source 12, a valve 20, a
conduit 18 linking the valve 20 to a dispensing connector 30, a
density sensor 40, and an electronic controller 28. In this
embodiment, the dispensing connector 30 also incorporates a
hardwire connection to the density sensor 40 for communication with
the electronic controller. The apparatus 10 may also optionally
comprise a temperature sensor 41, which may improve the accuracy of
the density measurement. The temperature sensor 41 may be
integrated with the density sensor 40.
[0030] To use the apparatus of the invention, the dispensing
connector 30 is connected to the receiving tank 14. As applicable,
the electronic controller 28 may be put in hardwired or wireless
communication with the density sensor 40. The electronic controller
28 may authorize the use of the station for an authorized user by
any number of commonly used methods such as a credit card, debit
card, or other magnetic or electronically encoded card, with our
without an identifying Personal Identification Number or "PIN." The
electronic controller 28 may read a tank rated density for the
receiving tank 14 or the user may input the tank rated density. The
user may input a predetermined set point density corresponding to
the desired fill amount. The density sensor 40 communicates the
density of the fluid in the receiving tank 14 to the electronic
controller 28. Provided the density of the fluid in the tank is
less than the predetermined set point density, the electronic
controller 28 causes control valve 20 to open, via a valve signal,
and allows compressed gas to flow from the compressed gas source 12
through conduit 18 to the receiving tank 14.
[0031] During the refilling of receiving tank 14, density sensor 40
continues to forward real time density data to the electronic
controller 28, which repeatedly compares the measured density
inside receiving tank 14 to the predetermined set point
density.
[0032] When the measured density inside the receiving tank 14
reaches the predetermined set point temperature, within a given
tolerance, the electronic controller 28 then signals valve 20 to
halt the flow of gas, via the valve signal. The electronic
controller 28 may wait, for example, 1 to 60 seconds, or for
example five seconds, while the tank and the instrumentation
equilibrate. If the density is within a specified tolerance to the
predetermined set point density, then filling is complete. If the
density is less than the rated density, filling may resume if
desired, as above.
[0033] After filling is complete the dispensing connector 30 is
detached from the receiving tank 14 and communication between the
density sensor 40 and electronic controller 28 stopped.
[0034] Although illustrated and described herein with reference to
specific embodiments, the present invention nevertheless is not
intended to be limited to the details shown. Rather, various
modifications may be made in the details within the scope and range
of equivalents of the claims without departing from the spirit of
the invention.
* * * * *