Isothermal compressed air energy storage system with primary frequency modulation capability and operation method thereof

Abstract

The invention discloses an isothermal compressed air energy storage system with primary frequency modulation capability and an operation method thereof. The system comprises a high-pressure air storage cavity, an impulse turbine, a synchronous power generator and at least two working units, wherein the working units are connected in parallel, the top ends of the working units communicate with the high-pressure air storage cavity and the tail water pipeline of the impulse turbine, the bottom ends of the working units arecommunicated with the water inlet of the impulse turbine through a pipeline, the working unit comprises two compression tanks, a top outlet formed by connecting the two compression tanks in parallel serves as the top end of the working unit, two pipelines are arranged at the bottom ends of the two compression tanks, the first pipeline is used for connecting the two compression tanks in parallel and serves as the bottom end of the working unit, the second pipeline is communicated with the two compression tanks, a water pump system is arranged on the second pipeline, and a nozzle with an adjustable opening degree is adopted in the impulse turbine. According to the invention, long-time constant-power output can be achieved, the purpose of stable overall output power is achieved through phase-shifting superposition of the multiple independent working units, the opening degree adjusting time of the nozzle is short, and throttling loss is small.

Description

technical field [0001] The invention relates to the field of physical energy storage, in particular to an isothermal compressed air energy storage system capable of primary frequency regulation and an operating method thereof. Background technique [0002] In recent years, the scale of wind power and photovoltaics has developed rapidly, but wind power resources and light resources fluctuate greatly in a short period of time. Coupled with the demand for frequency regulation and load regulation of the power grid, the grid connection of new energy makes the power grid face higher requirements for variable load and primary frequency regulation. , thus giving rise to the demand for energy storage. At present, mature large-scale energy storage technologies include compressed air energy storage, pumped hydro storage and electrochemical energy storage. Pumped storage has high requirements on geological conditions; electrochemical energy storage has serious pollution throughout its ...

AI Technical Summary

Problems solved by technology

With the expansion of the scale of new energy power stations, the proportion of new energy power generation in the power grid is gradually increasing. However, at this stage, wind turbines mostly use double-fed asynchronous generator sets, which have high energy utilization rate but small system moment of inertia and primary frequency modulation capability. Weak; the solar power station uses an AC inverter to convert DC power into AC power and merge it into the grid. The system has almost no moment of inertia and cannot participate in a frequency modulation

However, each new energy power station must have a certain percentage of primary frequency regulation capability when connected to the grid. At present, the more commonly used primary frequency regulation method is flywheel energy storage, but the system maintenance is complicated, the energy storage density is low, and the cost is high.

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