Thermal power generating unit peak load and frequency regulation system and method based on liquid compressed air energy storage

Abstract

The invention discloses a thermal power generating unit peak load and frequency regulation system and method based on liquid compressed air energy storage. The system comprises a coal-fired power generating unit, a liquid compressed air energy storage system and a liquid compressed air energy release system. The liquid compressed air energy storage system and thermal power generating unit steam-water thermodynamic cycle are subjected to multiple coupling, a compressor is driven by a straight condensing turbine with admission steam and exhaust steam of a thermal power generating unit medium-pressure cylinder as heat sources, heat in the energy storage compression process is used for heating condensed water so as to squeeze low-pressure cylinder regenerative extraction steam, and heat absorption in the energy release expansion process is provided by high-temperature water supply. According to the system operation mode for improving the peak load and frequency regulation capacity, space-time transfer of part of energy of thermal power generating unit steam-water thermodynamic cycle can be achieved, and the peak load and frequency regulation capacity of the thermal power generating unit participating in a power grid can be improved. The thermal power generating unit peak load and frequency regulation system is suitable for all thermal power generating units and has the universalitycondition of large-scale popularization.

Description

【Technical field】 [0001] The invention belongs to the technical field of power transmission in terms of energy storage, and relates to a peak-shaving and frequency-regulating system and method for thermal power units based on liquid compressed air energy storage. 【Background technique】 [0002] By the end of 2019, the cumulative installed capacity of photovoltaic and wind power reached 205 million kilowatts and 210 million kilowatts, accounting for 10.2% and 10.4% of the total installed capacity (2.01 billion kilowatts); 3% and 5.5% of power generation (7,325.3 billion kilowatts). New energy power will develop substantially and rapidly in the future, requiring thermal power units to further tap the peak-shaving potential on the current basis. The large-scale grid integration of renewable energy with the characteristics of volatility and intermittency puts forward higher requirements for the power grid to shave peaks and fill valleys, and to operate safely and stably. Build...

AI Technical Summary

Problems solved by technology

However, there is still a strong coupling relationship between the heat release of the compressor and the heat absorption of the expander, which limits the improvement of the overall power-to-electricity conversion efficiency of the system and the manufacturing process and cost of key equipment such as compressors and expansion generators: for air expansion power generation As far as the air compressor is concerned, its internal efficiency is directly proportional to the inlet air temperature, which requires the air compression process to provide high-temperature heat; for the air compressor unit, the most efficient should be isothermal compression

Generally speaking, it is difficult to balance the efficient operation of the compressor and expander of the compressed air energy storage power generation system

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