Dead-volume management in compressed-gas energy storage and recovery systems
AssigneeSustainX, Inc.
InventorsTroy O. McBride, Benjamin R. Bollinger, Joel Berg
Life of this patent
Estimating the term…
Abstract
In various embodiments, coupling losses between a cylinder assembly and other components of a gas compression and/or expansion system are reduced or eliminated via valve-timing control.
Claims18
A method of increasing efficiency of an energy-recovery process performed in a cylinder assembly in which gas is expanded, the cylinder assembly being selectively fluidly connected to a high-side component by a high-side valve and selectively fluidly connected to a low-side component by a low-side valve, the method comprising:
- performing a first valve transition by opening the high-side valve to allow compressed gas to enter the cylinder assembly from the high-side component, the cylinder assembly containing gas at a first pressure prior to the first valve transition;
- performing a second valve transition by closing the high-side valve, the gas within the cylinder assembly expanding thereafter;
- performing a third valve transition by opening the low-side valve to allow a portion of the expanded gas to enter the low-side component from the cylinder assembly, wherein (i) a remnant portion of the gas remains in the cylinder assembly after the third valve transition and (ii) the expanded gas is at a second pressure prior to the third valve transition;
- performing a fourth valve transition by closing the low-side valve, the remnant portion of the gas within the cylinder assembly being compressed thereafter to approximately the first pressure;
- and
- enforcing a transition restriction comprising at least one of (i) performing the first valve transition only when the first pressure is approximately equal to a pressure of the high-side component or (ii) performing the third valve transition only when the second pressure is approximately equal to a pressure of the low-side component.
A method of increasing efficiency of an energy-recovery process performed in a cylinder assembly in which gas is expanded, the cylinder assembly being selectively fluidly connected to a high-side component by a high-side valve and selectively fluidly connected to a low-side component by a low-side valve, the method comprising:
- performing, within the cylinder assembly, a plurality of expansion cycles each comprising:
- performing a first valve transition by opening the high-side valve to allow compressed gas to enter the cylinder assembly from the high-side component,
- performing a second valve transition by closing the high-side valve, the gas within the cylinder assembly expanding thereafter,
- performing a third valve transition by opening the low-side valve to allow a portion of the expanded gas to enter the low-side component from the cylinder assembly, a remnant portion of the gas remaining in the cylinder assembly after the third valve transition, and
- performing a fourth valve transition by closing the low-side valve, the remnant portion of the gas within the cylinder assembly being compressed thereafter;
- and
- during each expansion cycle, altering a timing of at least one of the first, second, third, or fourth valve transitions to maximize efficiency of the expansion cycle.
Dependencies are inferred from the claim text.