Integrated refueling system for vehicles

• US 5,505,232 A
• Filed: 10/20/1993
• Issued: 04/09/1996
• Est. Priority Date: 10/20/1993
• Status: Expired due to Term

• Current Assignee: Prometheus Technologies LCC
• Original Assignee: CryoFuel Systems, Inc. (Westport Fuel Systems, Inc.)
• Inventors: Barclay, John A.
• Primary Examiner(s): Recla, Henry J.
• Assistant Examiner(s): Douglas, Steven O.
• Application Number:
  US08/140,732
• Time in Patent Office: 902 Days
• Field of Search: 141/11, 141/82, 141/285, 123/525, 123/527, 62/7, 62/9, 62/48.2, 62/50.2, 62/50.4, 62/53.2
• US Class Current: 141/11
• CPC Class Codes: F17C 2205/0338 Pressure regulators
• CPC Class Codes: F17C 2221/033 Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
• CPC Class Codes: F17C 2223/0123 gaseous, e.g. CNG, GNC
• CPC Class Codes: F17C 2225/0123 gaseous, e.g. CNG, GNC
• CPC Class Codes: F17C 2225/0161 cryogenic, e.g. LNG, GNL, PLNG
• CPC Class Codes: F17C 2225/033 Small pressure, e.g. for liquefied gas
• CPC Class Codes: F17C 2225/036 Very high pressure, i.e. above 80 bars
• CPC Class Codes: F17C 2227/0393 using a vaporiser
• CPC Class Codes: F17C 2250/032 using computers
• CPC Class Codes: F17C 2265/01 Purifying the fluid
• CPC Class Codes: F17C 2265/034 with condensing the gas phase
• CPC Class Codes: F17C 2265/065 for refueling vehicle fuel tanks
• CPC Class Codes: F17C 2270/0168 by vehicles
• CPC Class Codes: F17C 7/02 Discharging liquefied gases
• CPC Class Codes: F25J 1/0022 Hydrocarbons, e.g. natural gas
• CPC Class Codes: F25J 1/0035 by gas expansion with extraction of work
• CPC Class Codes: F25J 1/0045 by vaporising a liquid return stream
• CPC Class Codes: F25J 1/005 by expansion of a gaseous refrigerant stream with extraction of work
• CPC Class Codes: F25J 1/0052 by vaporising a liquid refrigerant stream
• CPC Class Codes: F25J 1/0204 as a single flow SCR cycle
• CPC Class Codes: F25J 1/0221 : using the cold stored in an external cryogenic component in an open refrigeration loop
• CPC Class Codes: F25J 1/0245 : Different modes, i.e. 'runs', of operation; Process control
• CPC Class Codes: F25J 2205/60 : using adsorption on solid adsorbents, e.g. by temperature-swing adsorption [TSA] at the hot or cold end
• CPC Class Codes: F25J 2210/06 : Splitting of the feed stream, e.g. for treating or cooling in different ways
• CPC Class Codes: F25J 2210/42 : Nitrogen
• CPC Class Codes: F25J 2220/66 : Separating acid gases, e.g. CO2, SO2, H2S or RSH
• CPC Class Codes: F25J 2235/60 : the fluid being (a mixture of) hydrocarbons
• CPC Class Codes: F25J 2245/90 : the recycled stream being boil-off gas from storage
• CPC Class Codes: F25J 2270/908 : by regenerative chillers, i.e. oscillating or dynamic systems, e.g. Stirling refrigerator, thermoelectric ("Peltier") or magnetic refrigeration
• CPC Class Codes: F25J 2270/91 : using pulse tube refrigeration
• CPC Class Codes: F25J 2290/62 : Details of storing a fluid in a tank

Abstract

An integrated refueling system comprises a fluid circuit including multiple flow paths for directing natural gas to a natural gas liquefier. A portion of the resulting liquefied natural gas is provided to a liquefied natural gas delivery location. Another portion of the liquefied natural gas may be provided to a compressor and subsequently a heat exchanger/vaporizer to produce compressed natural gas. The heat exchanger/vaporizer may utilize the lower temperature of liquefied natural gas to precool incoming gaseous natural gas while simultaneously vaporizing the pressurized, liquefied natural gas to form the compressed natural gas. Compressed natural gas may be provided at a compressed natural gas delivery location.

Claims

1. An integrated refueling system for vehicles, comprising:

an inlet for supplying natural gas to a fluid circuit;

a liquefier fluidly coupled to and forming part of the fluid circuit;

a first flow path for incoming natural gas, the first flow path including a first heat exchanger having a forward flow passageway and a counterflow passageway, wherein incoming natural gas flows through the forward flow passageway for precooling thereof, the first flow path terminating at the liquefier;

a storage reservoir fluidly coupled to the fluid circuit for containing liquefied natural gas flowing from the liquefier;

a liquefied natural gas delivery line extending from the storage reservoir to a liquefied natural gas dispensing location for dispensing liquefied natural gas to a vehicle;

a liquefied natural gas feed line fluidly coupled to the storage reservoir;

a compressor fluidly coupled to the liquefied natural gas feed line for converting relatively low pressure liquefied natural gas to relatively high pressure liquefied natural gas;

a first compressed natural gas line fluidly coupled between the compressor and the counterflow passageway of the first heat exchanger, the compressed liquefied natural gas passing through the counterflow passageway being vaporized to form compressed natural gas;

a compressed natural gas dispensing location;

a compressed natural gas dispenser line coupled between the counterflow passageway and the compressed natural gas dispensing location.

2. An integrated refueling system according to claim 1 wherein the first heat exchanger enables precooling of natural gas within the forward flow passageway by directing the liquefied natural gas through the counterflow passageway.

3. An integrated refueling system according to claim 1, further comprising a regenerative purifier system fluidly coupled to the inlet to remove impurities from the natural gas prior to liquefying natural gas.

4. An integrated refueling system according to claim 1, further comprising an expander fluidly coupled to the first heat exchanger to expand and cool the natural gas coming from the first heat exchanger.

5. An integrated refueling system according to claim 1, further comprising:

a second flow path for incoming natural gas, the second flow path including a second heat exchanger to cool incoming natural gas, the second flow path terminating at the liquefier.

6. An integrated refueling system according to claim 5 wherein the second heat exchanger enables precooling of natural gas within the forward flow passageway by the liquefied natural gas flowing in the counterflow passageway.

7. An integrated refueling system according to claim 5, further comprising:

a third flow path for passing the natural gas directly to the liquefier.

8. An integrated refueling system according to claim 1, further comprising an insulating enclosure surrounding the liquefier.

9. An integrated refueling system according to claim 1 further comprising a means for injecting an odorant into the compressed natural gas or the liquefied natural gas being dispensed.

10. An integrated refueling system according to claim 1 wherein the flow paths and natural gas lines are insulated.

11. An integrated refueling system for vehicles according to claim 1, further comprising a vapor recovery system for use in connection with the liquefied natural gas delivery station, the vapor recovery system comprising:

an insulated dispensing line to minimize heat loss as liquefied natural gas is dispensed to a vehicle;

a boil-off line to capture vapors resulting from warming of liquefied natural gas being dispensed to a vehicle;

a vapor return line coupled between the boil-off line and the liquefied natural gas storage reservoir.

12. An integrated refueling system for vehicles according to claim 1, further comprising a vapor recovery system for use in connection with the liquefied natural gas delivery station, the vapor recovery system comprising:

an insulated dispensing line to minimize heat loss as liquefied natural gas is dispensed to a vehicle;

a boil-off line to capture vapors resulting from warming of liquefied natural gas being dispensed to a vehicle;

a vapor return line coupled between the boil-off line and the inlet.

13. A refueling system for vehicles, comprising:

an inlet for supplying natural gas to a fluid circuit;

a regenerative purifier system fluidly coupled to the inlet to remove impurities from the natural gas;

a liquefier fluidly coupled to the forming part of the fluid circuit;

a first flow path for natural gas, including a first heat exchanger to initially cool the natural gas and an expander serially coupled to the first heat exchanger to expand and cool the natural gas coming from the first heat exchanger, the first flow path terminating at the liquefier;

a second flow path for natural gas, including a second heat exchanger to cool the natural gas, the second flow path terminating at the liquefier;

a third flow path for passing the natural gas directly to the liquefier;

wherein the natural gas is directed through one of the first flow path, the second flow path, or the third flow path depending upon the characteristics of the incoming natural gas or natural gas product to be produced;

a storage reservoir for containing liquefied natural gas from the liquefier;

a liquefied natural gas dispensing location fluidly coupled to the storage reservoir for dispensing liquefied natural gas;

a compressor fluidly coupled to a liquefied natural gas supply line extending from the liquefied natural gas storage reservoir;

a first compressed natural gas line for directing liquefied natural gas to the first heat exchanger for producing compressed natural gas;

a second compressed natural gas line for directing liquefied natural gas to the second heat exchanger for producing compressed natural gas;

a compressed natural gas dispensing location for dispensing the compressed natural gas.

14. An integrated refueling system for vehicles according to claim 13 wherein liquified natural gas is directed through one of the first heat exchanger or the second heat exchanger to precool incoming natural gas flowing through the first heat exchanger or the second heat exchanger prior to liquefaction.

15. An integrated refueling system for vehicles according to claim 13, further comprising an insulating enclosure surrounding the liquefier.

16. An integrated refueling system for vehicles according to claim 13 wherein the flow paths and natural gas lines are insulated.

17. An integrated refueling system for vehicles according to claim 13 wherein the liquefied natural gas dispensing location and the compressed natural gas dispensing location are combined to form a common dispensing location.

18. An integrated refueling system for vehicles according to claim 13, further comprising a vapor recovery system for use in connection with the liquefied natural gas delivery station, the vapor recovery system comprising:

an insulated dispensing line to minimize heat loss as liquefied natural gas is dispensed to a vehicle;

a boil-off line to capture vapors resulting from warming of liquefied natural gas being dispensed to a vehicle; and

a vapor return line coupled between the boil-off line and the liquefied natural gas storage reservoir.

19. An integrated refueling system for vehicles according to claim 13, further comprising a vapor recovery system for use in connection with the liquefied natural gas delivery station, the vapor recovery system comprising:

an insulated dispensing line to minimize heat loss as liquefied natural gas is dispensed to a vehicle;

a boil-off line to capture vapors resulting from warming of liquefied natural gas being dispensed to a vehicle; and

a vapor return line coupled between the boil-off line and the inlet.

20. An integrated refueling system for vehicles, comprising:

a first fluid circuit for liquefying natural gas, the first fluid circuit comprising a plurality of flow paths, incoming natural gas coming from a natural gas source being directed to one of the plurality of flow paths depending upon characteristics of either the incoming natural gas or the desired natural gas product, the plurality of flow paths comprising;

a liquefier;

a first incoming flow path to direct natural gas coming into the fluid circuit through a first heat exchanger/vaporizer to precool the incoming natural gas, through an expander to reduce the natural gas pressure while further cooling the gas, and into the liquefier;

a second incoming flow path to direct natural gas coming into the fluid circuit through a second heat exchanger/vaporizer to precool the incoming natural gas;

a third incoming flow path to direct the natural gas directly into the liquefier.

21. An integrated refueling system for vehicles according to claim 20 wherein liquefied natural gas is directed to one of the first heat exchanger/vaporizer or the second heat exchanger/vaporizer to precool the incoming natural gas passing through one of the first heat exchanger/vaporizer or the second heat exchanger/vaporizer prior to liquefaction.

22. An integrated refueling system for vehicles according to claim 20, further comprising:

a storage reservoir for storing liquefied natural gas;

a second fluid circuit for producing compressed natural gas for vehicle consumption, comprising;

a compressor for compressing a portion of liquefied natural gas from the storage reservoir;

a first compressed natural gas line directing liquefied natural gas from the compressor through the first heat exchanger/vaporizer to produce compressed natural gas;

a second compressed natural gas line directing liquefied natural gas from the compressor through the second heat exchanger/vaporizer to produce compressed natural gas.

23. An integrated refueling system for vehicles according to claim 22, further comprising:

a compressed natural gas supply line for directing compressed natural gas to compressed natural gas dispenser;

a buffer tank fluidly coupled to the compressed natural gas supply line for storing a supply of compressed natural gas to be directed to the compressed natural gas dispenser.

24. A method for providing a supply of compressed natural gas and liquefied natural gas to a delivery location, comprising the steps of:

providing a natural gas supply to a fluid circuit;

directing the natural gas through a first flow path, including a heat exchanger to precool the natural gas;

directing the precooled natural gas to a liquefier for liquefaction thereof;

directing the liquefied natural gas to a storage tank for storage thereof;

directing a first portion of the liquefied natural gas within the storage tank through a liquefied natural gas delivery line to a liquefied natural gas delivery location for dispensing to a vehicle;

directing a second portion of the liquefied natural gas within the storage tank through a compressor to pressurize the liquefied natural gas;

directing the natural gas from the compressor through the first heat exchanger to vaporize the pressurized, liquefied natural gas and produce compressed natural gas;

directing the compressed natural gas from the first heat exchanger through a compressed natural gas delivery line to a compressed natural gas delivery location for dispensing to a vehicle.

25. The method of claim 24, further comprising the step of directing the precooled natural gas from the heat exchanger through an expander located upstream of the liquefier to further precool the natural gas.

26. The method of claim 24, further comprising the step of directing the compressed natural gas into a compressed natural gas storage tank for supplying compressed natural gas to the compressed natural gas delivery line.

27. The method of claim 24, further comprising the steps of:

providing a boil-off line at the liquefied natural gas delivery location;

capturing vaporized natural gas caused by cooling of the liquefied natural gas dispensing line in the dispenser or a warm fuel tank;

reliquefying the captured vaporized natural gas.

28. The method of claim 24, further comprising the step of reliquefying natural gas vaporized as a result of heat leaks into the storage tank.

29. The method of claim 24, further comprising the steps of:

providing cooled, compressed natural gas at below room temperature to the compressed natural gas delivery location;

quick filling the compressed natural gas into a vehicle fuel tank so that the tank remains full after the compressed natural gas has cooled to room temperature.

30. A method for providing a supply of liquefied natural gas and compressed natural gas, comprising the steps of:

providing an incoming flow of natural gas into a fluid circuit;

directing the incoming flow of natural gas to one of a group of flow paths consisting of;

a first flow path directing the flow of natural gas through a first heat exchanger to lower the temperature of the natural gas, through an expander to further lower the temperature of the natural gas, and to a liquefier;

a second flow path directing the flow of natural gas through a second heat exchanger and then the liquefier; and

a third flow path directly fluidly coupled to the liquefier;

supplying liquefied natural gas to an LNG reservoir.

31. The method of 30 wherein the incoming flow of natural gas through one of the first flow path or the second flow path is precooled by liquefied natural gas.

33. The method of claim 31 or 32, further comprising the steps of providing compressed natural gas and liquefied natural gas at an integrated delivery station for supplying both compressed natural gas and liquefied natural gas to vehicles.

34. The method of claim 33, further comprising the step of providing a vapor recovery system for vapors that are created when supplying liquefied natural gas to vehicles.

32. The method of 30, further comprising the steps of:

directing at least part of the liquefied natural gas to a compressor for compressing the liquefied natural gas;

directing the compressed liquefied natural gas to a heat exchanger/vaporizer to produce compressed natural gas.