抄録
Gas-charged accumulators are widely used as energy-storage devices in hydraulic systems. In a previous paper, a simple model for predicting thermal-time constants based on the structure of bladder-type accumulators has been proposed, and the validity of the model has been experimentally verified at a constant gas volume. In this paper, a dimensionless heat-transfer model, which simulates the charged-gas pressure, temperature and volume in accumulators during the gas compression and expansion process, is developed. Gas-pressure and temperature changes using the dimensionless model are calculated and compared with the experimental results during continuous processes. Thermodynamic losses during these processes are experimentally confirmed and the validity of the proposed dimensionless model is verified. Efficiency of bladder-type accumulators for energy-storage devices is estimated using the dimensionless model at some operating conditions.
