Natural gas home fast fill refueling station

A self-contained home-based fast-fill compressed natural gas refueling station, located adjacent to a driveway at a home, for providing compressed natural gas fuel to one or more a vehicle compressed natural gas tanks, comprising:

• A) a natural gas fill line connected to a natural gas supply source providing natural gas for heating the home or natural gas appliances or heating the home and natural gas appliances,
• B) a multi-stage gas compressor able to pump gas at a range of at least 0.5 gallons per hour and having at least three stages of compression, connected to said natural gas fill line and adapted to compress natural gas from an initial pressure of about 15 psia to a final pressure of about 4500 psia,
• C) a natural gas storage tank array, said storage tank array comprising a plurality of natural gas storage tanks providing a total storage volume approximately three times the volume of a typical compressed natural gas vehicle storage tank, said plurality of natural gas storage tanks being commonly connected so as to simultaneously receive compressed natural gas from the multi-stage compressor,
• D) a check valve positioned between the multi-stage compressor and the natural gas storage tank array adapted to prevent backflow of compressed natural gas from the natural gas storage tank array through the multi-stage compressor into the home,
• E) a pressurized natural gas storage tank exit line connected to said storage tank array so as to convey compressed natural gas, from all of the storage tanks in the storage tank array, to the vehicle compressed natural gas tank to compress the vehicle tank to about 3,000 psi or about 3,600 psi,
• F) a compressed natural gas fill nozzle connected to said exit line and adapted to provide a sealed connection to the vehicle compressed natural gas tank,
• G) a control system for opening and closing solenoid valves,
• H) a first seal testing solenoid valve, a second seal testing solenoid valve and a pressure transducer configured to measure compressed gas pressure at the natural gas fill nozzle for testing seals between the fill nozzle and the vehicle compressed natural gas tanks, wherein the control system is programmed so that during the start of each process of dispensing gas to a vehicle, the control system will open the first seal testing solenoid valve, to let a small amount of compressed gas to fill the space between the first and second seal testing solenoid valves, then the control system will open the second seal testing solenoid valve to permit compressed gas filling the space between the first and second seal testing solenoid valves to expand fill space in the exit line and the nozzle between the first seal testing solenoid valve and the vehicle storage tanks, wherein the seal testing pressure transducer will send signals to the control system to check, for each vehicle at each refueling, the seal between the compress gas fill nozzle and the vehicle storage tanks,
• I) a water trap having a T section and a vertical drain pipe below the T section positioned at a low spot in compressed gas piping upstream of the storage tank array for keeping excessive moisture from the storage tank array, said water trap comprising an upper solenoid valve and a lower solenoid valve next to each other in series wherein the control system is programmed so that, during the start of each process of dispensing gas to a car, the control system will open the upper solenoid valve then close it, then open the lower solenoid valve then close it, to permit a small amount of high pressure gas along with any water trapped between the upper and lower solenoid valves to be automatically ejected from the drain pipe, and
• J) a sound-proofed, weather-proofed, lockable shed large enough to house, and housing, the array of storage tanks and the compressor with the shed being firmly fastened to ground close enough to the driveway so that a car on the driveway can be filled with compressed natural gas through the compressed natural gas fill nozzle.