Water-gas composite energy-storage power generation system and method

Abstract

The invention provides a water-gas composite energy-storage power generation system and method, and belongs to the field of peak shaving of power grids. The system comprises a pressure water tank (1),a water pool (2), a water turbine (3), a high-pressure nitrogen storage tank (4), a first-stage compressor (5), a second-stage compressor (6), a first-stage expansion machine (7), a second-stage expansion machine (8), a low-temperature heat accumulator (9), a high-temperature heat accumulator (10), a normal-pressure nitrogen storage tank (12), multiple communicating pipelines (13) and multiple valves (14). The air is replaced by nitrogen which is not dissolved in water easily, so that the cavitation damage to blades of a hydro-generator is avoided, and the durability of the energy-storage power generation system is improved; and gradient utilization is performed on the energy of compressed nitrogen during energy storage, one part of low-pressure nitrogen is stored in the pressure water tank (1), and the other part of high-pressure nitrogen is stored in the high-pressure nitrogen storage tank (4), so that the nitrogen under different pressure intensity can be utilized sufficiently, andthe energy storage efficiency of the energy-storage power generation system can be improved.

Description

technical field [0001] The invention belongs to the technical field of power grid peak regulation, and in particular relates to a water-gas composite energy storage power generation system and method. Background technique [0002] With the rapid development of renewable energy and the deepening of the contradiction between power resources and power loads in various regions of our country, it is often necessary to adjust the peak of the power grid and store energy during the low power consumption period so as to discharge during the peak power consumption period. Therefore, energy storage systems are getting more and more attention in engineering applications. At this stage, the only energy storage system that is really used on a large scale in my country is pumped storage. However, pumped storage has very strict requirements on natural geographical conditions and water resources. [0003] Considering that compressed gas energy storage has little dependence on natural geogra...

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Problems solved by technology

[0005] In the existing water-gas composite energy storage power generation system, the gas is only compressed to a single pressure value during energy storage, and the gas energy cannot be utilized in steps, and the energy storage efficiency is low; and the existing water-gas composite energy storage power generation system The gas generally used in the hydroelectric generator is air, and air is easily dissolved in water. When the water dissolved in a large amount of air flows through the hydro-generator, it will cause cavitation damage to the blades of the hydro-generator, reducing the overall energy storage power generation system. efficiency and durability

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