System and methods for optimizing efficiency of a hydraulically actuated system

摘要

Systems and methods for efficiently operating a hydraulically actuated device/system are described herein. For example, systems and methods for efficiently operating a gas compression and expansion energy storage system are disclosed herein. Systems and methods are provided for controlling and operating the hydraulic actuators used within a hydraulically actuated device/system, such as, for example, a gas compression and/or expansion energy system, within a desired efficiency range of the hydraulic pump(s)/motor(s) used to supply or receive pressurized hydraulic fluid to or from the hydraulic actuators. In such a system, a variety of different operating regimes can be used depending on the desired output gas pressure and the desired stored pressure of the compressed gas. Hydraulic cylinders used to drive working pistons within the system can be selectively actuated to achieve varying force outputs to incrementally increase the gas pressure within the system for a given cycle.

主权项

1. An apparatus suitable for use in a 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 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; 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; and a hydraulic controller fluidically coupleable to the first hydraulic actuator and the second hydraulic actuator, the hydraulic controller operable to cause the first hydraulic actuator to displace the working piston in a first direction to compress gas contained in the first pneumatic chamber and in a second direction to compress gas contained in the second pneumatic chamber, the hydraulic controller operable to selectively provide or not provide pressurized hydraulic fluid to one or more of the first, second, third, and fourth hydraulic chambers in at least four combinations, each combination producing a different net actuator force on the working piston acting in the first direction, each combination having a different net hydraulic piston area,
wherein, in a first one of the combinations, pressurized hydraulic fluid is provided to the first hydraulic chamber and not provided to the second hydraulic chamber and, wherein, in a second one of the combinations, pressurized hydraulic fluid is provided to the second hydraulic chamber and not provided to the first hydraulic chamber.