System and methods for optimizing efficiency of a hydraulically actuated system

An apparatus suitable for use in compressed gas-based energy storage and recovery system, the apparatus comprising:

• a pneumatic cylinder having a working piston disposed therein for reciprocating movement in the pneumatic cylinder, the working piston dividing the pneumatic cylinder into, and defining therewith, a first pneumatic chamber and a second pneumatic chamber, movement of the working piston in a first direction operable to compress gas contained in the first pneumatic chamber and movement of the working piston in a second direction, opposite to the first direction, operable to compress gas contained in the second pneumatic chamber;
• a first hydraulic actuator coupled to the working piston to drive, or be driven by, the working piston, the first hydraulic actuator including a first hydraulic cylinder and a first hydraulic piston disposed for reciprocating movement in the first hydraulic cylinder, the first hydraulic piston dividing the first hydraulic cylinder into, and defining therewith;
• a first hydraulic chamber and a second hydraulic chamber;
• and
• a second hydraulic actuator coupled to the working piston to drive, or be driven by, the working piston, the second hydraulic actuator including a second hydraulic cylinder and a second hydraulic piston disposed for reciprocating movement in the second hydraulic cylinder, the second hydraulic piston dividing the second hydraulic cylinder into, and defining therewith, a third hydraulic chamber and a fourth hydraulic chamber.

An apparatus suitable for use in compressed gas-based energy storage and recovery system, the apparatus comprising:

• a pneumatic cylinder having a working piston disposed therein for reciprocating movement in the pneumatic cylinder, the working piston dividing the pneumatic cylinder into, and defining therewith, a first pneumatic chamber and a second pneumatic chamber;
• a first hydraulic actuator coupled to the working piston;
• a second hydraulic actuator coupled to the working piston;
• and
• a hydraulic controller fluidically coupleable to the first hydraulic actuator and the second hydraulic actuator, the hydraulic controller operable with a pressurized hydraulic fluid to cause at least the first hydraulic actuator to produce a selected hydraulic actuator force to displace the working piston in a first direction such that gas contained in the first pneumatic chamber is compressed from a first pressure to a second pressure,
• the hydraulic controller further operable with the pressurized hydraulic fluid to cause at least the second hydraulic actuator to produce a selected hydraulic actuator force to displace the working piston in a second direction such that gas contained in the second pneumatic chamber is compressed from a third pressure to a fourth pressure.

An apparatus suitable for use in compressed gas-based energy storage and recovery system, the apparatus comprising:

• a pneumatic cylinder having a working piston disposed therein for reciprocating movement in the pneumatic cylinder, the working piston dividing the pneumatic cylinder into, and defining therewith, a first pneumatic chamber and a second pneumatic chamber, movement of the working piston in a first direction operable to compress gas contained in the first pneumatic chamber and movement of the working piston in a second direction, opposite to the first direction, operable to compress gas contained in the second pneumatic chamber;
• a first hydraulic actuator coupled to the working piston to drive, or be driven by, the working piston, the first hydraulic actuator including a first hydraulic cylinder and a first hydraulic piston disposed for reciprocating movement in the first hydraulic cylinder, the first hydraulic piston having a first diameter and dividing the first hydraulic cylinder into, and defining therewith, a first hydraulic chamber and a second hydraulic chamber;
• and
• a second hydraulic actuator coupled to the working piston to drive, or be driven by, the working piston, the second hydraulic actuator including a second hydraulic cylinder and a second hydraulic piston disposed for reciprocating movement in the second hydraulic cylinder, the second hydraulic piston having a second diameter, different than the first diameter, the second hydraulic piston dividing the second hydraulic cylinder into, and defining therewith, a third hydraulic chamber and a fourth hydraulic chamber.