NATURAL GAS COMPRESSING AND REFUELING SYSTEM AND METHOD

摘要

A refueling system for natural gas users (e.g., natural gas vehicles) includes a two-stage compression system that compresses low-pressure gas in a natural gas supply line to compressed natural gas (CNG) pressure for use by a user. A single motor drives both a first stage rotary compressor and a rotary hydraulic pump that powers a second-stage liquid piston compressor. The motor, first stage compressor, and pump may be co-axially aligned. Booster vessels store compressed gas to augment the system's compressed gas delivery flow rate when desired. The booster vessels may be recharged with compressed gas when the system is not delivering gas to a user. Hydraulic liquid may be pumped into and out of the booster vessels during booster vessel discharge and recharge, respectively, to maintain a desired pressure within the vessels.

主权项

1. A two-stage gas compression system configured to compress gas, the system comprising:
a rotary power source having an output shaft; a positive-displacement first stage rotary compressor having a first stage gas inlet and a first stage gas outlet, the first stage rotary compressor being operatively connected to the rotary power source to be driven by the output shaft; a hydraulic pump operatively connected to the rotary power source to be driven by the output shaft, the pump having a hydraulic liquid inlet and a hydraulic liquid outlet; and a positive-displacement second stage compressor having
a second stage gas inlet fluidly connected to the first stage gas outlet, anda second stage gas outlet configured to provide second stage compressed gas to a user, wherein the second stage compressor operatively connects to the liquid outlet of the pump so as to be driven by pressurized liquid provided by the pump.