Membrane type sealed gravity compressed air energy storage system and energy storage method

Abstract

The invention provides a membrane type sealing gravity compressed air energy storage system and method. The energy storage system comprises a closed air cavity, a communicating pipeline, a multi-stage compressor unit and an air expansion unit, wherein the multi-stage compressor unit and the air expansion unit are connected in series. A flexible sealing film is installed in the middle of the inner wall of the closed air cavity in a sealed mode and divides the closed air cavity into an upper air cavity and a lower air cavity, and the upper portion of the flexible sealing film is filled with gravity liquid. The two ends of the communicating pipeline are connected with the upper air cavity and the lower air cavity respectively, and a valve is arranged on the communicating pipeline; the multi-stage compressor units connected in series are connected with the lower air cavity through energy storage pipelines, and middle-stage air suction ports of the multi-stage compressor units connected in series are connected with the upper air cavity through air suction pipelines. The air expansion unit is connected with the lower air cavity through an energy release pipeline. Constant pressure of the air storage device in the inflation and deflation process can be achieved, stability of the outlet pressure of the air compressor and the air inlet pressure of the air expansion machine is guaranteed, then the operation efficiency of the air compressor and the expansion machine is improved, and the energy storage efficiency of the system is improved.

Description

technical field [0001] The application relates to the technical field of electrical energy storage, and in particular, to a membrane-type sealed gravity compressed air energy storage system and an energy storage method. Background technique [0002] Energy storage, especially the storage of electric energy, is of great significance to the optimization of energy structure and the regulation of power grid operation. The compressed air energy storage system is a new type of large-scale energy storage technology. In the gas storage device; when the electrical load of the power system reaches the peak, the gas storage device releases the stored compressed air, expands in the turboexpander to do work and drives the generator to generate electricity; according to the above principles, the compressed air energy storage system can Complete the conversion of electrical energy-air potential energy-electrical energy. [0003] Conventional compressed air energy storage systems generall...

AI Technical Summary

Problems solved by technology

Specifically, as the inflation process progresses, the gas storage pressure in the gas storage device will gradually increase, so the air compressor is required to continuously increase the discharge pressure to meet the intake pressure requirements, resulting in the air compressor operating outside the design condition , the operating efficiency decreases and the operating power consumption increases, thereby limiting the improvement of the energy storage efficiency of the system; similarly, with the progress of the deflation process, the gas storage pressure in the gas storage device gradually decreases, so the air inlet pressure of the air expander gradually decreases , causing the air expander to deviate from the design operating conditions, resulting in a decrease in operating efficiency and output power, which in turn limits the improvement of the energy storage efficiency of the system

Images