Method and apparatus for dispensing natural gas

Temperature compensated fluid dispensing apparatus for dispensing fluid from a fluid source to a fluid receiver at an ambient temperature, wherein the fluid in the fluid source has a stagnation temperature and wherein the fluid receiver has a receiver pressure rating at a predetermined pressure and temperature, comprising:

• means for sensing the ambient temperature and for generating an ambient temperature signal related thereto;
• means for determining an initial stagnation pressure of the fluid in the fluid receiver and for generating an initial receiver stagnation pressure signal related thereto;
• means for dispensing an initial mass of fluid into said fluid receiver;
• means for determining an intermediate stagnation pressure of the fluid in the fluid receiver and for generating an intermediate receiver stagnation pressure signal related thereto;
• valve means interconnecting the fluid source and the fluid receiver for selectively closing off the interconnection between the source and the receiver;
• and
• valve control means connected to said valve means, said means for sensing the ambient temperature, said means for determining an initial stagnation pressure, and said means for determining an intermediate stagnation pressure, and responsive to said ambient temperature signal, said initial receiver stagnation pressure signal, and said intermediate receiver stagnation pressure signal for actuating said valve means to close off the interconnection between the fluid source and the fluid receiver when the fluid receiver has been filled to a pressure equivalent to the receiver pressure rating corrected for the ambient temperature;
• calculation means connected to said valve control means and responsive to said ambient temperature signal for determining a cut-off receiver stagnation pressure based on said ambient temperature and based on the receiver pressure rating, for determining a fluid receiver volume based on said initial receiver stagnation pressure and said intermediate receiver stagnation pressure, and for determining an additional mass of fluid to increase said receiver stagnation pressure to about the cut-off receiver stagnation pressure;
• and
• valve actuation means connected to said valve means and to said calculation means for causing said valve means to close off the interconnection between the fluid source and the fluid receiver when said additional mass has been dispensed into said fluid receiver.

Temperature compensated fluid dispensing apparatus for independently dispensing fluid from a fluid source into first and second fluid receivers at an ambient temperature, wherein the fluid in the fluid source has a stagnation temperature and wherein each fluid receiver has a receiver pressure rating at a predetermined stagnation pressure and temperature, comprising:

• means for sensing the ambient temperature and for generating an ambient temperature signal related thereto;
• means for determining a first receiver initial stagnation pressure of the fluid in the first fluid receiver and for generating a first receiver initial stagnation pressure signal related thereto;
• means for determining a second receiver initial stagnation pressure of the fluid in the second fluid receiver and for generating a second receiver initial stagnation pressure signal related thereto;
• means for selectively dispensing a first receiver initial mass of fluid into said first fluid receiver;
• means for selectively dispensing a second receiver initial mass of fluid into said second fluid receiver;
• means for determining a first receiver intermediate stagnation pressure of the fluid in the first receiver after the first receiver initial mass of fluid has been added to said first fluid receiver and for generating a first intermediate receiver stagnation pressure signal related thereto;
• means for determining a second receiver intermediate stagnation pressure of the fluid in the second receiver after the second receiver initial mass of fluid has been added to said second fluid receiver and for generating a second intermediate receiver stagnation pressure signal related thereto;
• a supply plenum connected to the fluid source;
• first valve means interconnecting the fluid source and the first fluid receiver for selectively closing off the interconnection between the source and the first fluid receiver;
• second valve means interconnecting the fluid source and the second fluid receiver for selectively closing off the interconnection between the source and the second fluid receiver;
• and
• two channel valve control means connected to said first valve means, said second valve means, said means for sensing the ambient temperature, said means for determining a first receiver initial stagnation pressure, said means for determining a second receiver initial stagnation pressure, said means for determining a first receiver intermediate stagnation pressure, said means for determining a second receiver intermediate stagnation pressure and responsive to said temperature signal, to said first and second receiver initial stagnation pressure signals, and to said first and second receiver intermediate stagnation pressure signals, for independently actuating said first and second valve means to close off the interconnection between the fluid source and the corresponding fluid receiver when the corresponding fluid receiver has been filled to a pressure equivalent to the receiver pressure rating corrected for the ambient temperature;
• and
• fluid measuring means connected between the fluid source and said first and second valve means for determining the amount of fluid dispensed into each respective fluid receiver.

A fluid dispensing system for controlling an amount of fluid flowing from a fluid source to a fluid receiver, wherein the fluid in the fluid source has a stagnation temperature and wherein the fluid in the fluid receiver has a stagnation pressure, comprising:

• valve means interconnecting the source and the receiver for selectively closing off the interconnection between the source and the receiver;
• means for sensing the ambient temperature and for generating an ambient temperature signal related thereto;
• means responsive to said ambient temperature signal for determining a cut-off receiver stagnation pressure based on said ambient temperature and in accordance with predetermined receiver pressure parameters;
• means for determining an additional mass of fluid to be added to said fluid receiver to increase the pressure in said receiver to about said cut-off receiver stagnation pressure;
• and
• fluid mass measuring means connected between the fluid source and said valve means for determining the amount of fluid mass being dispensed into the fluid receiver
• valve control means connected to said valve means and responsive to said fluid mass measuring means for actuating said valve means to close off the interconnection between the source and the receiver.

A fluid metering and control system for measuring and controlling an amount of fluid flowing from a fluid source to a fluid receiver, wherein the fluid in the fluid source has a stagnation temperature and a stagnation pressure and wherein the fluid in the fluid receiver has a stagnation pressure, comprising:

• a sonic nozzle interconnecting the source and the receiver;
• valve means positioned between said sonic nozzle and the receiver for selectively closing off the interconnection between the source and the receiver;
• means for sensing the ambient temperature and for generating an ambient temperature signal related thereto;
• means for sensing the stagnation pressure of the fluid in the source and for generating a source stagnation pressure signal related thereto;
• means for sensing the stagnation temperature of the fluid in the source and for generating a source stagnation temperature signal related thereto;
• means responsive to said ambient pressure signal and responsive to said source stagnation temperature signal for determining a mass flow rate of fluid flowing through said sonic nozzle when the fluid flow through said sonic nozzle is choked;
• means responsive to said ambient temperature signal for determining a cut-off receiver stagnation pressure based on said ambient temperature and in accordance with predetermined receiver pressure parameters;
• means for determining an additional mass of fluid to be add to said fluid receiver to increase the pressure in said receiver to about said cut-off receiver stagnation pressure;
• and
• valve control means connected to said valve means and responsive to said means for determining an additional mass of fluid to be added to said fluid receiver for actuating said valve means to close off the interconnection between the source and the receiver when said additional mass has been added to said fluid receiver.

A method of dispensing compressed gas from a pressurized storage tank to a receiver under less pressure than the storage tank, comprising the steps of:

• connecting said storage tank and said receiver with a pressure tight dispensing hose;
• sensing an ambient temperature before initiating the dispensing cycle;
• calculating a cut-off pressure for the receiver based on the sensed ambient temperature and based on a predetermined rated pressure for the receiver;
• sensing an initial pressure of said receiver;
• adding a predetermined mass of gas to the receiver;
• sensing an intermediate pressure of said receiver;
• determining a volume of the receiver and an additional mass of fluid to increase said receiver stagnation pressure to about the cut-off pressure;
• initiating a flow of gas through said dispensing hose from said supply tank to said receiver;
• and
• terminating the flow of gas when the additional mass has been added to said receiver.