APPARATUS FOR CONTROLLING THE QUANTITY OF GAS IN HYDRO-PNEUMATIC TANKS OF ENERGY STORING SYSTEM

A method and apparatus to monitor a compressible gas volume of one or more hydropneumatic storage tanks of an energy-storing system includes at least one pump to fill the individual storage tanks with hydraulic fluid. The fluid is isolated from the gas volume in each storage tank or unit by a movable partition. The gas volumes of the storage tanks are monitored continuously and free of error for the early detection and signaling of gas volume losses by the use of a minimum of maintenance-free devices. The monitoring is accomplished by determining the state of flow of the hydraulic fluid entering the several hydropneumatic storage tanks while the pump is running. In the event of a coincidence of a running pump and an interruption of the flow to a tank, a loss of gas volume is indicated. A flow monitor having a control contact within each pipeline supplying the hydraulic fluid as well as a signal device for indicating the pump operation is provided. In each storage unit, a stop limits the movement of a free piston which separates the fluid and gas. Furthermore, an additional gas storage tank may be connected with the hydropneumatic storage unit.