Natural gas compressing and refueling system and method

Abstract

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.

Description

CROSS REFERENCE[0001]This application claims the benefit of priority from U.S. Provisional Application No. 61 / 783,781, filed Mar. 14, 2013, titled “Natural Gas Home Refueling System,” the entire contents of which are hereby incorporated by reference herein.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present disclosure relates to a home refueling gas compression system and method for use with natural gas vehicles (NGV).[0004]2. Description of Related Art[0005]Currently, NGV infrastructure is lacking due to the high capital costs associated with construction of public NGV filling stations. Typical gas compression systems are physically too large and / or expensive to operate in a normal home.SUMMARY OF EMBODIMENTS OF THE INVENTION[0006]One or more aspects of the present disclosure provides an economic home refueling system (HRS) that allows consumers to realize the economic and convenience benefits of NGV vehicles and at-home refueling. One or more aspects of the...

AI Technical Summary

Benefits of technology

The present patent provides an economic and convenient home refueling system for natural gas vehicles. The system includes a first stage rotary compressor, a pump, and a second stage liquid piston compressor. The system uses a cascade fill system with pressure vessels and valves to hold and utilize compressed gas during peak demand. The second stage compressor is a liquid piston compressor that can compress the gas to a high pressure level. The compression is responsive to coupling with a natural gas vehicle and is near-isothermal to mitigate temperature rise. The system also includes a shaft and seal to prevent gas leakage and a cold-line cooler to transfer heat out of the compressed gas. The hydraulic pump is placed above the first stage rotary compressor and the second stage compressor is within a sealed shell. The technical effects of the patent include an efficient and economical home refueling system that reduces expansion losses and improves efficiency.

Problems solved by technology

Currently, NGV infrastructure is lacking due to the high capital costs associated with construction of public NGV filling stations.

Typical gas compression systems are physically too large and / or expensive to operate in a normal home.

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