CN-121984055-A - Coupling peak regulation and frequency modulation system and method based on fused salt heat storage and compressed air energy storage

CN121984055ACN 121984055 ACN121984055 ACN 121984055ACN-121984055-A

Abstract

The invention provides a coupling peak regulation and frequency modulation system and method based on molten salt heat storage and compressed air energy storage, and belongs to the technical field of power grid regulation; the system comprises a coal motor unit, a fused salt heat storage subsystem and a compressed air energy storage subsystem, wherein the fused salt heat storage subsystem comprises a high-temperature fused salt tank, a low-temperature fused salt tank and two first heat exchangers and second heat exchangers which adopt the same three-channel structure, and the peak regulation and frequency modulation system is used for realizing peak regulation and frequency modulation of a power grid by coupling fused salt heat storage and compressed air energy storage through the two heat exchangers of the fused salt heat storage subsystem. The invention can realize stable power grid peak regulation and frequency modulation on the basis of considering energy storage efficiency.

Inventors

GONG ZHIQIANG
HAN YUE
SHANG PANFENG
GUO JUNSHAN
Zhong ziwei
LIANG KAI
ZHU LINGKAI
ZHENG WEI

Assignees

国网山东省电力公司电力科学研究院

Dates

Publication Date: 20260505
Application Date: 20260206

Claims (10)

1. The coupling peak regulation and frequency modulation system based on molten salt heat storage and compressed air energy storage is characterized by comprising a coal motor unit, a molten salt heat storage subsystem and a compressed air energy storage subsystem; The fused salt heat storage subsystem comprises a high-temperature fused salt tank, a low-temperature fused salt tank, and two first heat exchangers and two second heat exchangers which adopt the same three-channel structure, wherein the peak regulation and frequency modulation system realizes peak regulation and frequency modulation of a power grid by coupling fused salt heat storage and compressed air energy storage through the two heat exchangers, and is specific: The compressed air energy storage subsystem comprises a compressor, an expander and a gas storage device, wherein the output end of the compressor is connected to the input end of the gas storage device through a pipeline through a second heat exchanger, the output end of the gas storage device is connected to the input end of a low-temperature molten salt tank through a pipeline through a first heat exchanger, the output end of the low-temperature molten salt tank is connected to the input end of a high-temperature molten salt tank through a pipeline through a second heat exchanger, the output end of the high-temperature molten salt tank is connected to the first heat exchanger through a pipeline, and meanwhile, a water supply pipeline and an air exhaust pipeline of a coal motor unit are connected to the first heat exchanger and the second heat exchanger respectively.
2. The coupling peak regulation and frequency modulation system based on molten salt heat storage and compressed air energy storage as set forth in claim 1, wherein the three-channel structure is three independent corrugated plates which are alternately laminated, and the three independent corrugated plates form three parallel flow channels which are not in series leakage.
3. The coupling peak shaving and frequency modulation system based on molten salt heat storage and compressed air energy storage as set forth in claim 2, wherein three parallel flow channels which are not in series leak are flow channel a, flow channel B and flow channel C, respectively, wherein flow channel a is used for circulating steam extraction and water supply from a coal motor group, flow channel B is used for circulating molten salt from a molten salt heat storage subsystem, and flow channel C is used for circulating compressed air from a compressed air energy storage subsystem.
4. The system of claim 1, further comprising an intelligent control subsystem for monitoring grid frequency and electricity price signals and optimizing control of charge and discharge strategies of the molten salt heat storage subsystem and the compressed air energy storage subsystem based on a PID control algorithm and a dynamic programming algorithm.
5. The coupling peak regulation and frequency modulation method based on molten salt heat storage and compressed air energy storage is characterized by comprising the following steps: monitoring the frequency of a power grid and the electricity price signal in real time; judging the stage of peak regulation and frequency modulation of the power grid according to the obtained power grid frequency and power price signals; And the power grid peak shaving and frequency modulation is realized by coupling the fused salt heat storage and the compressed air energy storage based on the power grid peak shaving and frequency modulation belonging stage, wherein the power grid peak shaving and frequency modulation belonging stage comprises an energy storage stage, an energy release stage, a frequency modulation stage and an operation optimization stage.
6. The method for coupling peak shaving and frequency modulation based on molten salt heat storage and compressed air energy storage according to claim 5, wherein the implementation of the power grid peak shaving and frequency modulation comprises the following steps: In the energy storage stage, controlling the heat storage of high-temperature steam and a fused salt heat storage subsystem generated by a coal motor group, starting a compressor of a compressed air energy storage subsystem, storing compressed air to a gas storage device, and storing heat generated in the compression process in the fused salt heat storage subsystem through a three-way heat exchanger; in the energy release stage, the fused salt heat storage subsystem is controlled to release heat, and the water supply of the coal motor unit and the compressed air of the compressed air energy storage subsystem are heated through the three-channel heat exchanger, so that the heated compressed air drives the expansion machine to do work and generate power, and the total output power of the system is increased.
7. The method for peak shaving and frequency modulation based on the coupling of molten salt heat storage and compressed air energy storage according to claim 5, wherein the implementation of the peak shaving and frequency modulation of the power grid further comprises: When the frequency deviates from a set value, the output power of the generator set is controlled, and the quick response capacity of the fused salt heat storage subsystem is utilized for carrying out frequency adjustment; And in the operation optimization stage, according to the price signal, the load prediction and the equipment state of the electric power market, the charging and discharging strategies of the molten salt heat storage subsystem and the compressed air energy storage subsystem are adjusted.
8. The method for coupling peak regulation and frequency modulation based on molten salt heat storage and compressed air energy storage as set forth in claim 7, wherein the frequency regulation comprises the steps of reducing the power of a coal motor group by starting a molten salt heat storage subsystem and a compressor when downward regulation is needed, and starting an expander of the compressed air energy storage subsystem to apply work to generate power and improving the power of the system when upward regulation is needed.
9. A computer readable storage medium having a program stored thereon, which when executed by a processor performs the steps in the method of molten salt heat storage and compressed air energy storage based coupled peak shaving and frequency modulation as claimed in any one of claims 5 to 8.
10. An electronic device comprising a memory, a processor and a program stored on the memory and executable on the processor, wherein the processor performs the steps in the method of coupled peak shaving and frequency modulation based on molten salt heat storage and compressed air energy storage as claimed in any one of claims 5 to 8 when the program is executed.

Description

Coupling peak regulation and frequency modulation system and method based on fused salt heat storage and compressed air energy storage Technical Field The invention belongs to the technical field of power grid regulation, and particularly relates to a coupling peak shaving and frequency modulation system and method based on molten salt heat storage and compressed air energy storage. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. With the rapid increase of the installed capacity of renewable energy sources such as wind power, photovoltaic and the like, the peak regulation and frequency modulation pressures facing the power grid are increasingly increased, and the demand for flexible resource regulation is also more urgent. The energy storage technology is used as a key means for improving the flexibility of the power system, the fluctuation and the randomness of the new energy output can be effectively relieved through energy space-time allocation, and the running safety and the running economy of the power grid are improved. In various energy storage technologies, the compressed air energy storage has the characteristics of high response speed, large energy storage scale, long service life and the like, and is particularly suitable for frequency modulation application of short-time high frequency. However, such existing systems for peak shaving and frequency modulation have mainly the following drawbacks: (1) The existing coal motor group peak shaving system generally depends on a single energy storage form, is difficult to meet the requirements of quick frequency modulation and long-time peak shaving, has insufficient system flexibility, and generally depends on natural gas afterburning or electric heating and other modes to raise the air inlet temperature in the energy release process of the existing compressed air energy storage, so that the problems of efficiency loss and high operation cost exist. (2) The existing peak shaving system also has the function of fused salt heat storage, but the fused salt heat storage system can realize thermal decoupling, but has slower response speed, and is difficult to meet second-level frequency modulation requirements, and meanwhile, due to the lack of efficient coupling and cooperative control mechanisms among various energy storage devices, the overall operation efficiency is lower, and the economical efficiency is poor. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides a coupling peak regulation and frequency modulation system and method based on molten salt heat storage and compressed air energy storage, which are compared with the prior coal electric machine group peak regulation system which generally depends on a single energy storage form or has a systematic design with a simple molten salt heat storage function, and can realize stable power grid peak regulation and frequency modulation on the basis of considering energy storage efficiency. To achieve the above object, one or more embodiments of the present invention provide the following technical solutions: The first aspect of the invention provides a coupling peak shaving and frequency modulation system based on molten salt heat storage and compressed air energy storage. The coupling peak regulation and frequency modulation system based on molten salt heat storage and compressed air energy storage comprises a coal motor unit, a molten salt heat storage subsystem and a compressed air energy storage subsystem; the molten salt heat storage subsystem comprises a high-temperature molten salt tank, a low-temperature molten salt tank and two first and second heat exchangers which adopt the same three-channel structure; the peak regulation and frequency modulation system realizes the peak regulation and frequency modulation of a power grid by coupling molten salt heat storage and compressed air energy storage through two heat exchangers, and is specific: The compressed air energy storage subsystem comprises a compressor, an expander and a gas storage device; the output end of the compressor is connected to the input end of the gas storage device through a pipeline through a second heat exchanger, the output end of the gas storage device is connected to the input end of the low-temperature molten salt tank through a pipeline through a first heat exchanger, the output end of the low-temperature molten salt tank is connected to the input end of the high-temperature molten salt tank through a pipeline through a second heat exchanger, the output end of the high-temperature molten salt tank is connected to the first heat exchanger through a pipeline, and meanwhile, a water supply pipeline and an air exhaust pipeline of the coal motor unit are connected to the first heat exchanger and the second heat exchanger respectively. Further, the three-channel structure is