关键词: 高能量密度, 气液溶解, 液压蓄能器, 液压储能

Abstract: To address the issues of low energy density in traditional hydraulic accumulators, a high-energy-density hydraulic energy storage method was proposed based on the combined principle of gas-liquid dissolution and gas compression. This method involved adding a quantitative amount of liquid solvent to the gas section of the hydraulic accumulator, enabling the energy storage processes to encompass both of gas compression and gas-liquid dissolution. Through gas-liquid dissolution, a portion of the energy was stored in the form of internal energy within the liquid phase, thereby reducing the increase in internal energy of the gas. The energy density expression for the composite energy storage method was derived and comparatively analyzed. Numerical relationship between the gas polytropic index and factors such as gas compression rate was established. Finally, a combination of carbon dioxide and water was selected as the energy storage medium for simulation and experimental validation. Both of simulation and experimental results indicate that, under conditions of a pre-charged gas pressure of 5 MPa, an energy storage duration of 5 s, and a water injection volume of 1 L, the energy density improvement rate reaches 9%.

Key words: high energy density, gas liquid dissolution, hydraulic accumulator, hydraulic energy storage