Power plant peak regulation system based on carbon dioxide phase change energy storage
By using a power plant peak-shaving system based on carbon dioxide phase energy storage, electrical energy is converted into pressure energy for storage through two-stage compression using low-pressure axial flow and high-pressure centrifugal compressors. Temperature changes are managed through a tiered thermal storage medium, which solves the peak-shaving problem of the power grid, improves the flexibility and energy storage efficiency of the power plant, and ensures the safety and stability of the power grid.
Patent Information
- Application Number
- CN202511726308.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-24
- Publication Date
- 2026-01-13
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The existing power grid peak-shaving means are insufficient. In particular, when the output time of new energy sources does not match the peak load, the power grid is difficult to regulate peaks, resulting in an imbalance between power supply and demand and affecting the safe and stable operation of the power grid.
A power plant peak-shaving system based on carbon dioxide phase energy storage is adopted, including a gaseous carbon dioxide management unit, an energy storage power unit, a heat exchange unit, a matrix self-balancing pressure storage system, and an energy release power generation unit. The electrical energy is converted into pressure energy for storage through two-stage compression using a low-pressure axial flow compressor and a high-pressure centrifugal compressor. Temperature changes are managed using a graded heat storage medium tank to achieve coordinated peak shaving of thermal power and energy storage.
It improves energy storage efficiency and power plant flexibility, reduces energy storage costs, enhances the peak-shaving capacity of power plants, adapts to changes in grid load, and ensures the safe and stable operation of the grid.
Smart Images
Figure CN121322129A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of power plant energy storage, in particular to a power plant peak shaving system based on carbon dioxide phase change energy storage. BACKGROUND
[0002] Power plant energy storage refers to deploying an energy storage system on the power plant side, storing electrical energy when there is excess power, and releasing electrical energy when there is a power shortage, thereby enhancing the flexibility and regulation capacity of the power plant, dynamically adjusting its output power according to the peak and valley changes of the power grid load, and maintaining the balance between power supply and demand to ensure the safe and stable operation of the power grid.
[0003] The current power grid power peak shaving structure is single, and the power grid mainly relies on thermal power units for peak shaving. With the increasing maximum peak-valley difference of the power grid and the increasing scale of new energy installations year by year, the contradiction between insufficient power grid peak shaving methods is becoming increasingly prominent. For example, during the winter heating period, the duration of new energy output does not match the peak load, and it is often the most difficult period for the power grid to peak shave, which is inconvenient to use. SUMMARY
[0004] The purpose of the present application is to provide a power plant peak shaving system based on carbon dioxide phase change energy storage to solve the problems raised in the background.
[0005] In view of the above problems, the technical solution proposed by the present application is:
[0006] A power plant peak shaving system based on carbon dioxide phase change energy storage, comprising a gaseous carbon dioxide management unit, an energy storage power unit, a heat exchange unit, a matrix self-balancing pressure storage system, and an energy release and power generation unit. The energy storage power unit comprises a low-pressure axial compressor and a high-pressure centrifugal compressor. The heat exchange unit comprises a low-temperature heat storage medium storage tank, a medium-temperature heat storage medium storage tank, a high-temperature heat storage medium storage tank, an energy storage heat exchange module, and an energy release heat exchange module. The energy storage heat exchange module comprises a primary energy storage heat exchange module and a secondary energy storage heat exchange module. The heat storage medium input interface of the energy release heat exchange module is in communication with the high-temperature heat storage medium storage tank, and the heat storage medium output interface of the energy release heat exchange module is in communication with the low-temperature heat storage medium storage tank. The low-temperature heat storage medium storage tank output end and the high-temperature heat storage medium input end are also in communication with a thermal power system cooling module.
[0007] As a preferred technical solution of the present application, the gaseous carbon dioxide management unit comprises a plurality of gas film warehouses made of high-molecular flexible material. The gas film warehouse output end is in communication with the low-pressure axial compressor input end.
[0008] As a preferred technical solution of the present application, the low-pressure axial compressor output interface is in communication with the heat exchange input interface of the primary energy storage heat exchange module, and the heat exchange output interface of the primary energy storage heat exchange module is in communication with the high-pressure centrifugal compressor input interface.
[0009] As a preferred technical solution of the present application, the output interface of the high-pressure centrifugal compressor is in communication with the heat exchange input interface of the secondary energy storage heat exchange module, and the heat exchange output interface of the secondary energy storage heat exchange module is in communication with the input end of the matrix self-balancing pressure storage system.
[0010] As a preferred technical solution of the present application, the matrix self-balancing pressure storage system comprises a plurality of liquid carbon dioxide pressure storage tanks, and a self-balancing pressure valve group is in communication between the liquid carbon dioxide pressure storage tank and the adjacent liquid carbon dioxide pressure storage tank.
[0011] As a preferred technical solution of the present application, the output end of the matrix self-balancing pressure storage system is in communication with the heat exchange input interface of the energy release heat exchange module, and the heat exchange output interface of the energy release heat exchange module is in communication with the energy release power generation unit.
[0012] As a preferred technical solution of the present application, the energy release power generation unit is a turbine generator, and the output end of the energy release power generation unit is in communication with the air film warehouse input end.
[0013] As a preferred technical solution of the present application, the heat storage medium input interfaces of the primary energy storage heat exchange module and the secondary energy storage heat exchange module are in communication with the low-temperature heat storage medium storage tank, and the heat storage medium output interface of the primary energy storage heat exchange module is in communication with the medium-temperature heat storage medium storage tank.
[0014] As a preferred technical solution of the present application, the heat storage medium output interface of the secondary energy storage heat exchange module is in communication with the high-temperature heat storage medium storage tank, and a temperature self-balancing valve group is in communication between the medium-temperature heat storage medium storage tank and the high-temperature heat storage medium storage tank.
[0015] As a preferred technical solution of the present application, the primary energy storage heat exchange module, the secondary energy storage heat exchange module, and the energy release heat exchange module are all plate heat exchangers, and a heat storage medium pump is fixedly installed on the heat storage medium input interface of the plate heat exchanger.
[0016] Compared with the prior art, the beneficial effects of the application are that: the power plant peak shaving system based on carbon dioxide phase change energy storage has the following advantages: the energy storage power unit includes a low-pressure axial compressor and a high-pressure centrifugal compressor, which facilitates two-stage compression of carbon dioxide gas, the low-pressure axial compressor performs first-stage compression on the normal-pressure carbon dioxide stored in the gaseous carbon dioxide management unit, the high-pressure centrifugal compressor performs second-stage compression on the medium-pressure carbon dioxide after first-stage compression, and the carbon dioxide is compressed to a critical pressure to be liquefied, so that the electrical energy is converted into pressure energy for storage, the low-temperature heat storage medium tank, the medium-temperature heat storage medium tank and the high-temperature heat storage medium tank are arranged, which facilitates the hierarchical storage of the heat storage medium and is conducive to improving the heat storage efficiency, facilitating the management of the temperature change caused by the phase change of carbon dioxide, the first-stage energy storage heat exchange module and the second-stage energy storage heat exchange module facilitate the recovery of the compression heat generated by the low-pressure axial compressor and the high-pressure centrifugal compressor during the compression of carbon dioxide, and the low-temperature heat storage medium tank output end and the high-temperature heat storage medium input end are also connected with the thermal power system cooling module, which facilitates the introduction of the waste heat of the thermal power plant into the heat exchange unit, realizes thermal energy storage and peak shaving, and enhances the flexibility of the power plant; the application can convert electrical energy into pressure energy of liquid carbon dioxide for storage, has high storage efficiency, low cost, high safety, low geographical environment requirement and flexible operation mode, and has high practical value. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 A carbon dioxide flow process diagram of the power plant peak shaving system based on carbon dioxide phase change energy storage is disclosed for the embodiments of the application.
[0018] Figure 2 A system block diagram of the heat exchange unit is disclosed for the embodiments of the application.
[0019] Figure 3 A system block diagram of the energy storage power unit is disclosed for the embodiments of the application.
[0020] Figure 4 A heat flow process diagram of the energy storage heat exchange module is disclosed for the embodiments of the application.
[0021] Figure 5 A heat flow process diagram of the energy storage heat exchange module is disclosed for the embodiments of the application. DETAILED DESCRIPTION
[0022] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.
[0023] Please refer to Figure 1 - Figure 5 The application provides a technical scheme: a power plant peak shaving system based on carbon dioxide phase change energy storage, comprising a gaseous carbon dioxide management unit, an energy storage power unit, a heat exchange unit, a matrix self-balancing pressure storage system and an energy release power generation unit, the energy storage power unit comprises a low-pressure axial flow compressor and a high-pressure centrifugal compressor, the low-pressure axial flow compressor and the high-pressure centrifugal compressor are used for two-stage compression of gaseous carbon dioxide, the low-pressure axial flow compressor is used for first-stage compression of normal-pressure carbon dioxide stored in the gaseous carbon dioxide management unit, and the high-pressure centrifugal compressor is used for second-stage compression of medium-pressure carbon dioxide after the first-stage compression, so that the carbon dioxide is compressed to a critical pressure to be liquefied, thereby converting electric energy into pressure energy for storage, the heat exchange unit comprises a low-temperature heat storage medium storage tank, a medium-temperature heat storage medium storage tank, a high-temperature heat storage medium storage tank, an energy storage heat exchange module and an energy release heat exchange module, the low-temperature heat storage medium storage tank, the medium-temperature heat storage medium storage tank and the high-temperature heat storage medium storage tank are used for hierarchical storage of heat storage medium, which is beneficial to improving heat storage efficiency and facilitating management of temperature change caused by carbon dioxide phase change, the energy storage heat exchange module comprises a first-stage energy storage heat exchange module and a second-stage energy storage heat exchange module, the first-stage energy storage heat exchange module and the second-stage energy storage heat exchange module are used for recycling compression heat generated by the low-pressure axial flow compressor and the high-pressure centrifugal compressor, respectively, a heat storage medium input interface of the energy release heat exchange module is communicated with the high-temperature heat storage medium storage tank, a heat storage medium output interface of the energy release heat exchange module is communicated with the low-temperature heat storage medium storage tank, and a thermal power system cooling module is further communicated with an output end of the low-temperature heat storage medium storage tank and an input end of the high-temperature heat storage medium, so that waste heat of a thermal power plant can be introduced into the heat exchange unit, thermal energy storage and peak shaving are coordinated, and flexibility of the power plant is enhanced.
[0024] As an embodiment of the application, further, the gaseous carbon dioxide management unit comprises a plurality of gas film bins made of high-molecular flexible material, an output end of the gas film bin is communicated with an input end of the low-pressure axial flow compressor, and the gas film bin is used for storing a large amount of normal-pressure gaseous carbon dioxide, and the flexible structure can automatically expand and contract with volume change of the carbon dioxide and adapt to volume fluctuation in the phase change process.
[0025] As an embodiment of the application, further, an output interface of the low-pressure axial flow compressor is communicated with a heat exchange input interface of the first-stage energy storage heat exchange module, a heat exchange output interface of the first-stage energy storage heat exchange module is communicated with an input interface of the high-pressure centrifugal compressor, and the first-stage energy storage heat exchange module is used for first-stage heat recovery and reducing temperature of the carbon dioxide entering the high-pressure centrifugal compressor.
[0026] As an embodiment of the present application, further, the high-pressure centrifugal compressor output interface is in communication with the heat exchange input interface of the secondary energy storage heat exchange module, the heat exchange output interface of the secondary energy storage heat exchange module is in communication with the input end of the matrix self-balancing pressure storage system, and through the secondary energy storage heat exchange module, second-stage heat recovery is facilitated, and the temperature of the high-pressure liquefied carbon dioxide entering the liquid carbon dioxide pressure storage tank is reduced.
[0027] As an embodiment of the present application, further, the matrix self-balancing pressure storage system comprises a plurality of liquid carbon dioxide pressure storage tanks, and a self-balancing pressure valve group is in communication between the liquid carbon dioxide pressure storage tank and the adjacent liquid carbon dioxide pressure storage tank, through the arrangement of the self-balancing pressure valve group, the liquid carbon dioxide pressure storage tank is facilitated to store high-pressure liquid carbon dioxide, the self-balancing valve group connects adjacent liquid carbon dioxide pressure storage tanks, pressure balance is achieved, and local overpressure is prevented.
[0028] As an embodiment of the present application, further, the matrix self-balancing pressure storage system output end is in communication with the heat exchange input interface of the energy release heat exchange module, the heat exchange output interface of the energy release heat exchange module is in communication with the energy release power generation unit, and through the arrangement of the energy release heat exchange module, the high-temperature heat storage medium is facilitated to heat the liquid carbon dioxide, so that the liquid carbon dioxide becomes high-temperature high-pressure gas to drive the energy release power generation unit to generate power.
[0029] As an embodiment of the present application, further, the energy release power generation unit is a turbine generator, and the energy release power generation unit output end is in communication with the gas film warehouse input end, through the arrangement of the turbine generator, the high-temperature high-pressure carbon dioxide is facilitated to expand and do work, drive the turbine generator to generate power, and convert pressure energy and heat energy into electric energy for discharge.
[0030] As an embodiment of the present application, further, the heat storage medium input interfaces of the primary energy storage heat exchange module and the secondary energy storage heat exchange module are in communication with the low-temperature heat storage medium storage tank, the heat storage medium output interface of the primary energy storage heat exchange module is in communication with the medium-temperature heat storage medium storage tank, and through the arrangement of the medium-temperature heat storage medium storage tank, the medium-temperature heat storage medium recovering the first-stage compression heat is facilitated to be stored.
[0031] As an embodiment of the present application, further, the heat storage medium output interface of the secondary energy storage heat exchange module is in communication with the high-temperature heat storage medium storage tank, and a temperature self-balancing valve group is in communication between the medium-temperature heat storage medium storage tank and the high-temperature heat storage medium storage tank, through the setting of the high-temperature heat storage medium storage tank, the high-temperature heat storage medium recovered from the second stage compression heat is conveniently stored, the temperature self-balancing valve group connects the medium-temperature heat storage medium storage tank and the high-temperature heat storage medium storage tank, is used for monitoring the temperature of the heat storage medium inside the high-temperature heat storage medium storage tank, when the temperature is close to a threshold value, controls the medium-temperature heat storage medium stored inside the medium-temperature heat storage medium storage tank to flow into the high-temperature heat storage medium storage tank, avoids the temperature of the heat storage medium inside the high-temperature heat storage medium storage tank being higher than the threshold value, and is favorable for improving safety.
[0032] As an embodiment of the present application, further, the first energy storage heat exchange module, the second energy storage heat exchange module and the energy release heat exchange module are all plate heat exchangers, and the heat storage medium input interface of the plate heat exchanger is fixedly installed with a heat storage medium pump, through the setting of the heat storage medium pump, the heat storage medium is conveniently driven to circulate between the heat exchanger and the storage tank.
[0033] Specifically, the working principle of the power plant peak shaving system based on carbon dioxide phase change energy storage is that, through the gas film bin, it is convenient to store a large amount of normal pressure gaseous carbon dioxide, the flexible structure can automatically expand and contract with the volume change of carbon dioxide, and the volume fluctuation in the phase change process is adapted. Through the energy storage power unit including a low-pressure axial flow compressor and a high-pressure centrifugal compressor, it is convenient to perform two-stage compression on the carbon dioxide. The low-pressure axial flow compressor performs first-stage compression on the normal pressure carbon dioxide stored in the gaseous carbon dioxide management unit, and the high-pressure centrifugal compressor performs second-stage compression on the medium pressure carbon dioxide after the first-stage compression, so that the carbon dioxide is compressed to the critical pressure to be liquefied, thereby converting the electric energy into pressure energy for storage. Through the first-stage energy storage heat exchange module and the second-stage energy storage heat exchange module, it is convenient to recover the compression heat generated by the low-pressure axial flow compressor and the high-pressure centrifugal compressor in compressing the carbon dioxide, respectively. The low-temperature heat storage medium storage tank output end and the high-temperature heat storage medium input end are also communicated with the thermal power system cooling module, so that the waste heat of the thermal power plant is introduced into the heat exchange unit, the thermal energy storage and peak shaving of the thermal power plant are realized, the flexibility of the power plant is enhanced, the first-stage heat recovery is realized through the first-stage energy storage heat exchange module, the temperature of the carbon dioxide entering the high-pressure centrifugal compressor is reduced, the second-stage heat recovery is realized through the second-stage energy storage heat exchange module, the temperature of the high-pressure liquefied carbon dioxide entering the liquid carbon dioxide pressure storage tank is reduced, the liquid carbon dioxide pressure storage tank is convenient for storing the high-pressure liquid carbon dioxide through the setting of the self-balancing pressure valve group, the self-balancing valve group connects adjacent liquid carbon dioxide pressure storage tanks to realize pressure balance and prevent local overpressure, the release heat exchange module is set to heat the liquid carbon dioxide by using the high-temperature heat storage medium, so that the liquid carbon dioxide becomes high-temperature and high-pressure gas to drive the release power generation unit to generate power, the turbine generator is set to expand the high-temperature and high-pressure carbon dioxide to do work and drive the turbine generator to generate power, so that the pressure energy and the heat energy are converted into electric energy for discharge, the medium-temperature heat storage medium is stored in the medium-temperature heat storage medium storage tank through the setting of the medium-temperature heat storage medium storage tank, the high-temperature heat storage medium is stored in the high-temperature heat storage medium storage tank through the setting of the high-temperature heat storage medium storage tank, the temperature self-balancing valve group connects the medium-temperature heat storage medium storage tank and the high-temperature heat storage medium storage tank, and is used for monitoring the temperature of the heat storage medium in the high-temperature heat storage medium storage tank. When the temperature approaches the threshold value, the medium-temperature heat storage medium stored in the medium-temperature heat storage medium storage tank is controlled to flow into the high-temperature heat storage medium storage tank, so that the temperature of the heat storage medium in the high-temperature heat storage medium storage tank is prevented from being higher than the threshold value, and the safety is improved. Through the setting of the heat storage medium pump, the heat storage medium is driven to circulate between the heat exchanger and the storage tank.
Claims
1. A power plant peak-shaving system based on carbon dioxide phase-storage, characterized in that, The system includes a gaseous carbon dioxide management unit, an energy storage power unit, a heat exchange unit, a matrix-type self-balancing pressure storage system, and an energy release power generation unit. The energy storage power unit includes a low-pressure axial flow compressor and a high-pressure centrifugal compressor. The heat exchange unit includes a low-temperature thermal storage medium tank, a medium-temperature thermal storage medium tank, a high-temperature thermal storage medium tank, an energy storage heat exchange module, and an energy release heat exchange module. The energy storage heat exchange module includes a primary energy storage heat exchange module and a secondary energy storage heat exchange module. The thermal storage medium input interface of the energy release heat exchange module is connected to the high-temperature thermal storage medium tank, and the thermal storage medium output interface of the energy release heat exchange module is connected to the low-temperature thermal storage medium tank. The output end of the low-temperature thermal storage medium tank and the input end of the high-temperature thermal storage medium tank are also connected to a thermal power system cooling module.
2. The power plant peak-shaving system based on carbon dioxide phase-storage according to claim 1, characterized in that, The gaseous carbon dioxide management unit includes several air film chambers made of flexible polymer material, and the output end of the air film chamber is connected to the input end of the low-pressure axial flow compressor.
3. A power plant peak-shaving system based on carbon dioxide phase-storage energy storage according to claim 2, characterized in that, The output interface of the low-pressure axial flow compressor is connected to the heat exchange input interface of the primary energy storage heat exchange module, and the heat exchange output interface of the primary energy storage heat exchange module is connected to the input interface of the high-pressure centrifugal compressor.
4. A power plant peak-shaving system based on carbon dioxide phase-storage energy storage according to claim 3, characterized in that, The output interface of the high-pressure centrifugal compressor is connected to the heat exchange input interface of the secondary energy storage heat exchange module, and the heat exchange output interface of the secondary energy storage heat exchange module is connected to the input end of the matrix self-balancing pressure storage system.
5. A power plant peak-shaving system based on carbon dioxide phase-storage according to claim 4, characterized in that, The matrix-type self-balancing pressure storage system includes several liquid carbon dioxide pressure storage tanks, and the liquid carbon dioxide pressure storage tanks are connected to adjacent liquid carbon dioxide pressure storage tanks by a self-balancing pressure valve group.
6. A power plant peak-shaving system based on carbon dioxide phase-storage energy storage according to claim 5, characterized in that, The output end of the matrix self-balancing pressure storage system is connected to the heat exchange input interface of the energy release heat exchange module, and the heat exchange output interface of the energy release heat exchange module is connected to the energy release generator unit.
7. A power plant peak-shaving system based on carbon dioxide phase-storage energy storage according to claim 6, characterized in that, The energy release power generation unit is a turbine generator, and the output end of the energy release power generation unit is connected to the input end of the air-supported membrane chamber.
8. A power plant peak-shaving system based on carbon dioxide phase-storage energy storage according to claim 4, characterized in that, The thermal storage medium input interfaces of both the primary and secondary energy storage heat exchange modules are connected to the low-temperature thermal storage medium tank, and the thermal storage medium output interface of the primary energy storage heat exchange module is connected to the medium-temperature thermal storage medium tank.
9. A power plant peak-shaving system based on carbon dioxide phase-storage energy storage according to claim 8, characterized in that, The heat storage medium output interface of the secondary energy storage heat exchange module is connected to the high-temperature heat storage medium tank, and a temperature self-balancing valve group is connected between the medium-temperature heat storage medium tank and the high-temperature heat storage medium tank.
10. A power plant peak-shaving system based on carbon dioxide phase-storage according to claim 9, characterized in that, The primary energy storage heat exchange module, the secondary energy storage heat exchange module, and the energy release heat exchange module are all plate heat exchangers, and the heat storage medium input interface of each plate heat exchanger is fixedly installed with a heat storage medium pump.