Hydraulic compressed natural gas filling equipment and gas filling control method

Abstract

The invention relates to a hydraulic CNG (Compressed Natural Gas) filling equipment and a gas filling control method. The CNG filling equipment comprises at least one CNG supply unit, a hydraulic power unit and a control unit. The hydraulic power unit comprises: a tank for storing hydraulic medium of normal pressure; a closed circuits pump for supplying pressurized hydraulic medium to the CNG supply unit, having a first medium port, a second medium port and an inclined plate for Controlling the working states of the first and the second medium ports; a reversible valve for changing the position of the inclined plate; a supply pipe, through which the first and second medium ports of the closed circuits pump are connected to the tank; a first hydraulic pipe connected between the first medium port and the first medium filling and returning pipe; and a second hydraulic pipe connected between the second medium port and the second medium filling and returning pipe. The CNG filling equipment of the invention takes full advantage of the pressure energy in the returning hydraulic medium, so that the power consumption of the hydraulic pump can be significantly reduced when the CNG filling equipment is in operation.