Photo-thermal coupling power generation and energy storage system and method

Abstract

The invention discloses a photo-thermal coupling power generation and energy storage system and method, and the system comprises a photo-thermal circulation unit which comprises a heat collector, a photo-thermal circulation pump, a high-temperature heater and a medium-temperature heater; the steam power circulating unit comprises a high-temperature heater, a steam turbine, a condenser and a circulating water pump; the energy storage branch comprises an air compressor, a cooler and an air storage; the power generation branch comprises an air turbine, a medium-temperature heater and a gas storage, and a cooler, a condenser, a steam turbine and an air compressor are sequentially connected to form a closed loop. The system has a photo-thermal coupling power generation mode, a photo-thermal coupling power generation energy storage mode, a photo-thermal coupling power generation-energy storage-adjustment mode, an energy storage adjustment mode, an enhanced photo-thermal coupling power generation mode and a power generation adjustment mode. Meanwhile, the working mode of the system can be adjusted according to power demand changes, and high flexibility is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of energy storage technology, and in particular relates to a solar-thermal coupled power generation energy storage system and method. Background Art

[0002] Under the background of dual carbon goals, the rapid development of wind and solar energy has brought about technical difficulties in the access and consumption of fluctuating power. Since the large-scale access of fluctuating power will bring the risk of voltage and frequency fluctuations to the power grid, it is necessary to use technical means such as energy storage to directly or indirectly smooth the output fluctuations of wind and solar power sources. At the same time, in response to the traditional peak-to-valley difference problem of the power grid, energy storage can also be effectively regulated through controllable electric energy absorption and release. Adiabatic compressed air energy storage, as an effective large-capacity and long-term energy storage technology, plays a supporting role in smoothing the output fluctuations of wind and solar power sources and regulating the peak and valley loads of the power grid. Solar energy is an important component of clean and renewable energy. The main forms of utilization at present are photovoltaic power generation, solar thermal heating and solar thermal power generation. Among them, solar thermal power generation is developed based on solar thermal heating and thermal power generation. It uses solar thermal to heat the flowing working fluid and then drives the power turbine to generate power. Through the storage of heat-carrying medium, solar thermal power generation technology has the ability to continuously supply energy, and the supply of electricity has greater flexibility. Energy storage, as another key technology to support the realization of the dual-carbon vision and the construction of a new power system, has also entered an important period of research and development and application, among which the demand for large-scale long-term energy storage technology is particularly urgent. Advanced adiabatic compressed air energy storage, as a large-scale long-term energy storage technology, has achieved engineering demonstrations of different capacity levels in China. This technology uses electricity to drive an air compressor to compress ambient air to obtain high-temperature and high-pressure compressed air, and then uses a heat carrier to absorb most of the heat energy and store it after heat exchange with it. The air releases heat and cools down before entering the gas storage device, thereby storing electrical energy in two carriers: heat carrier and compressed air. When releasing energy, the stored compressed air exchanges heat with the stored heat carrier again, absorbs heat and heats up before entering the air expander to reduce pressure and do work, and drives the generator to rotate and generate electricity, while storing the cooled heat carrier, thereby realizing the regeneration of electrical energy. Although CSP can achieve continuous power supply through heat storage, all the energy of the system is stored in the form of high-temperature heat storage medium, and the demand for heat storage materials and high-temperature containers is large. At the same time, due to the limitations of CSP heat collection technology, the current maximum heat storage temperature of general CSP power stations is significantly lower than that of conventional thermal power generation (tower type generally does not exceed 540°C, trough type generally does not exceed 375°C), and the power generation efficiency drops significantly when the heat storage temperature is insufficient. The system energy efficiency of adiabatic compressed air energy storage is positively correlated with the exhaust temperature of the air compressor. However, due to the limitations of compressor materials and processes, high-temperature compressor technology is difficult and expensive, which to a certain extent limits the promotion and application of this technology. Summary of the invention

[0003] To solve the above problems, the present invention provides a solar-thermal coupled power generation and energy storage system and method to solve the problems that the existing solar-thermal power generation system is limited by the solar-thermal collection technology, the power generation efficiency drops significantly when the heat storage temperature is insufficient, and the energy storage system is limited by the compressor materials and processes and cannot be flexibly adjusted according to changes in electricity demand.

[0004] Solar thermal power generation systems require large amounts of heat storage materials and high-temperature containers, and the power generation efficiency drops significantly when the heat storage temperature is insufficient. The energy efficiency of adiabatic compressed air energy storage systems is limited by the materials and processes of the compressors.

[0005] To achieve the above object, the present invention provides a solar-thermal coupled power generation and energy storage system, comprising:

[0006] The photothermal circulation unit includes a heat collector, a photothermal circulation pump, a high-temperature heater and a medium-temperature heater. The heat collector is connected to the photothermal circulation pump, the high-temperature heater and the medium-temperature heater in a counterclockwise closed loop.

[0007] A steam power circulation unit, the steam power circulation unit comprises a high temperature heater, a steam turbine, a condenser and a circulating water pump, the high temperature heater is connected to the steam turbine, the condenser and the circulating water pump in a counterclockwise closed loop, wherein a first generator is provided at the input end of the steam turbine, and the first generator is connected to the steam turbine;

[0008] The energy storage branch includes an air compressor, a cooler and an air storage reservoir connected in sequence, wherein an electric motor is provided at the input end of the air compressor, and the electric motor is connected to the air compressor;

[0009] A power generation branch, the power generation branch comprises an air turbine, a medium temperature heater and an air storage reservoir connected in sequence, wherein a second generator is arranged at the input end of the air turbine, and the second generator is connected to the air turbine;

[0010] The cooler, condenser, steam turbine and air compressor are connected in sequence to form a closed ring loop.

[0011] According to a specific embodiment of the present invention, a coupling C1 is provided between the steam turbine and the first generator, and the first generator is connected to the steam turbine via the coupling C1.

[0012] According to a specific embodiment of the present invention, a coupling C2 is provided between the steam turbine and the air compressor, and the steam turbine is connected to the air compressor through the coupling C2.

[0013] According to a specific embodiment of the present invention, a coupling C3 is provided between the air compressor and the motor, and the air compressor is connected to the motor through the coupling C3.

[0014] According to a specific embodiment of the present invention, a coupling C4 is provided between the air turbine and the second generator, and the air turbine is connected to the second generator through the coupling C4.

[0015] A method for photothermal coupled power generation and energy storage, based on the above-mentioned photothermal coupled power generation and energy storage system, comprises:

[0016] Photothermal coupling power generation mode: In the photothermal coupling power generation mode, coupling C1 is closed, coupling C2, coupling C3 and coupling C4 are disconnected, the photothermal cycle unit and the steam power cycle unit operate jointly, and the energy storage branch and the power generation branch are on standby;

[0017] Photothermal coupled power generation and energy storage mode: In the photothermal coupled power generation and energy storage mode, couplings C1 and C2 are closed, couplings C3 and C4 are disconnected, the photothermal cycle unit, the steam power cycle unit and the energy storage branch operate jointly, and the power generation branch is on standby;

[0018] Photothermal coupling power generation-energy storage regulation mode: In the photothermal coupling power generation-energy storage regulation mode, couplings C1, C2 and C3 are closed, coupling C4 is disconnected, the photothermal cycle unit, steam power cycle unit and energy storage branch operate together, and the energy storage branch absorbs electric energy from the external power system through the motor, and the power generation branch is on standby;

[0019] Energy storage regulation mode: In the energy storage regulation mode, coupling C3 is closed, coupling C1, coupling C2 and coupling C4 are disconnected, the energy storage branch is running, and the photothermal cycle unit, steam power cycle unit and power generation branch are on standby;

[0020] Enhanced solar-thermal coupling power generation mode: In the enhanced solar-thermal coupling power generation mode, couplings C1 and C4 are closed, couplings C2 and C3 are disconnected, the solar-thermal cycle unit, the steam power cycle unit and the power generation branch are operated jointly, and the energy storage branch is on standby;

[0021] Power generation regulation mode: In the power generation regulation mode, coupling C4 is closed, coupling C1, coupling C2 and coupling C3 are disconnected, the photothermal cycle unit and the power generation branch operate simultaneously, and the steam power cycle unit and the energy storage branch are on standby.

[0022] According to a specific embodiment of the present invention, in the solar-thermal coupled power generation mode, the high-temperature heat storage medium in the collector enters the high-temperature heater driven by the solar-thermal circulation pump to heat the circulating water on the opposite side, and after releasing heat, returns to the collector through the medium-temperature heater to absorb heat and store it again. The circulating water absorbs heat and rises in temperature to be converted into high-temperature steam, and then enters the steam turbine to expand and do work, driving the first generator to output electrical energy to the outside.

[0023] According to a specific embodiment of the present invention, in the solar-thermal coupled power generation and energy storage mode, the high-temperature heat storage medium in the collector enters the high-temperature heater driven by the solar-thermal circulation pump to heat the circulating water on the opposite side, and after releasing heat, returns to the collector through the medium-temperature heater to absorb heat again for storage. The circulating water absorbs heat and rises in temperature to be converted into high-temperature steam, and then enters the steam turbine to expand and do work, driving the first generator to output electrical energy to the outside, and at the same time drives the air compressor to compress and increase the pressure of the ambient air. The compressed air is cooled by the cooler and then enters the gas storage reservoir for storage.

[0024] According to a specific embodiment of the present invention, in the solar-thermal coupled power generation-energy storage regulation mode, the high-temperature heat storage medium in the collector enters the high-temperature heater driven by the solar-thermal circulation pump to heat the circulating water on the opposite side, and after releasing heat, returns to the collector through the medium-temperature heater to absorb heat and store again. The circulating water absorbs heat and rises in temperature to be converted into high-temperature steam, and then enters the steam turbine to expand and do work, driving the first generator to output electrical energy to the outside, and at the same time, together with the electric motor, drives the air compressor to compress and increase the pressure of the ambient air. The compressed air is cooled by the cooler and then enters the gas storage reservoir for storage.

[0025] According to a specific embodiment of the present invention, in the energy storage regulation mode, the electric motor drives the air compressor to compress and increase the pressure of the ambient air, and the compressed air is cooled by the cooler and then enters the air storage reservoir for storage.

[0026] According to a specific embodiment of the present invention, in the enhanced solar-thermal coupling power generation mode, the high-temperature heat storage medium in the collector enters the high-temperature heater driven by the solar-thermal circulation pump to heat the circulating water on the opposite side, and after releasing heat, it heats the compressed air on the opposite side through the medium-temperature heater, and returns to the collector to absorb heat and store it again. The circulating water absorbs heat and rises in temperature to be converted into high-temperature steam, and then enters the steam turbine to expand and do work. The compressed air absorbs heat and rises in temperature and then enters the air turbine to expand and do work, and together they drive the second generator to output electrical energy to the outside.

[0027] According to a specific embodiment of the present invention, in the power generation regulation mode, the high-temperature heat storage medium in the collector is driven by the solar thermal circulation pump to enter the medium-temperature heater through the high-temperature heater to heat the compressed air on the opposite side, and then returns to the collector to absorb heat and store it again. After the compressed air absorbs heat and rises in temperature, it enters the air turbine to expand and do work, driving the second generator to output electrical energy to the outside.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] The present invention provides a solar-thermal coupled power generation and energy storage system and method, which can achieve maximum utilization of solar energy based on energy storage by organically coupling adiabatic compressed air energy storage with the solar-thermal power generation system, and can adjust the system working mode according to changes in power demand, with high flexibility. The present invention adopts a combination of photothermal conversion technology and steam power technology to organically combine direct utilization of solar energy and efficient power generation of steam turbines, which can not only effectively reduce carbon emissions while fully utilizing renewable clean energy, but also significantly improve the overall economic benefits and social value of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 It is a block diagram of a solar-thermal coupled power generation and energy storage system provided according to an embodiment of the present invention.

[0032] Reference numerals:

[0033] 1-Collector; 2-Photothermal circulation pump; 3-High temperature heater; 4-Medium temperature heater; 5-Steam turbine; 6-Condenser; 7-Circulating water pump; 8-Air compressor; 9-Cooler; 10-Air storage; 11-Air turbine; 12-First generator; 13-Second generator; 14-Electric motor. DETAILED DESCRIPTION

[0034] In order to make those skilled in the art understand the concept and thought of the present invention more clearly, the present invention is described in detail below in conjunction with specific embodiment.It should be understood that the embodiment provided herein is only a part of all embodiments that the present invention may have.Those skilled in the art, after reading the specification of the application, have the ability to make improvements, transformations, or replacements to part or the whole of the following embodiments, and these improvements, transformations, or replacements are also included in the scope of the present invention.

[0035] In this article, the terms "first", "second" and other similar words are not intended to imply any order, quantity and importance, but are only used to distinguish different elements. In this article, the terms "one", "an" and other similar words are not intended to indicate that there is only one thing, but to indicate that the relevant description is only for one of the things, and the thing may have one or more. In this article, the terms "comprise", "include" and other similar words are intended to indicate logical mutual relations, and cannot be regarded as indicating spatial structural relations. For example, "A includes B" is intended to indicate that B belongs to A logically, but does not mean that B is located inside A in space. In addition, the meanings of the terms "comprise", "include" and other similar words should be regarded as open, rather than closed. For example, "A includes B" is intended to indicate that B belongs to A, but B does not necessarily constitute the whole of A, and A may also include other elements such as C, D, and E.

[0036] In this document, the terms "embodiment", "this embodiment", "one embodiment", and "an embodiment" do not mean that the relevant description is only applicable to a specific embodiment, but rather that the description may also be applicable to one or more other embodiments. Those skilled in the art should understand that in this document, any description of a certain embodiment can be replaced, combined, or combined in other ways with the relevant descriptions in one or more other embodiments, and the new embodiments generated by the replacement, combination, or combination in other ways are easily conceivable by those skilled in the art and fall within the scope of protection of the present invention.

[0037] Example 1

[0038] Additional aspects and advantages of embodiments of the present invention will be given in part in the following description and in part will be obvious from the following description or learned through practice of embodiments of the present invention.

[0039] Combination Figure 1 The embodiment of the present invention provides a solar-thermal coupled power generation and energy storage system, comprising:

[0040] The photothermal circulation unit includes a collector 1, a photothermal circulation pump 2, a high-temperature heater 3 and a medium-temperature heater 4. The collector 1, the photothermal circulation pump 2, the high-temperature heater 3 and the medium-temperature heater 4 are connected in a counterclockwise closed loop.

[0041] The steam power circulation unit includes a high-temperature heater 3, a steam turbine 5, a condenser 6 and a circulating water pump 7. The high-temperature heater 3, the steam turbine 5, the condenser 6 and the circulating water pump 7 are connected in a counterclockwise closed loop, wherein a first generator 12 is provided at the input end of the steam turbine 5, and the first generator 12 is connected to the steam turbine 5.

[0042] The energy storage branch includes an air compressor 8, a cooler 9 and an air storage reservoir 10 which are connected in sequence, wherein an electric motor 14 is provided at the input end of the air compressor 8 and the electric motor 14 is connected to the air compressor 8.

[0043] The power generation branch includes an air turbine 11, a medium temperature heater 4 and a gas storage reservoir 10 connected in sequence. A second generator 13 is provided at the input end of the air turbine 11, and the second generator 13 is connected to the air turbine 11.

[0044] The cooler 9, the condenser 6, the steam turbine 5 and the air compressor 8 are connected in sequence to form a closed ring loop.

[0045] In the embodiment of the present invention, the collector 1 has the ability to store heat storage medium, and absorbs solar energy and converts it into thermal energy of the heat storage medium when there is sunshine or the heat storage medium has not reached the maximum heat storage capacity. The photothermal circulation pump 2 is a key device used in a solar thermal power generation system, which is responsible for circulating and transmitting thermal energy media in the system to store thermal energy or directly drive a turbine generator to generate electricity. In the embodiment of the present invention, the photothermal circulation pump 2 is used to drive the collector 1 to transport the high-temperature heat storage medium inside it to the high-temperature heater 3 so as to heat the circulating water on the opposite side of the high-temperature heater 3. The high-temperature heater 3 is a device for heating in a high-temperature environment, which can quickly reach the required high temperature in a short time and improve production efficiency. In the embodiment of the present invention, the high-temperature heat storage medium in the collector 1 enters the high-temperature heater 3 under the drive of the photothermal circulation pump 2 to heat the circulating water on the opposite side, and then transfers the heat energy of the photothermal circulation unit to the steam power circulation unit. The medium-temperature heater 4 is a device for heating in a medium temperature range. The temperature range of the medium-temperature heater 4 is generally lower than that of the high-temperature heater, which is suitable for application scenarios that do not require extremely high temperatures but still require high heat input. The medium-temperature heater 4 in the embodiment of the present invention is used to recover the circulating water after the high-temperature heater 3 releases heat. The steam turbine 5 is a device that directly converts the thermal energy of steam into mechanical energy. In the embodiment of the present invention, the circulating water absorbs heat and heats up to convert the heat into mechanical energy. After being converted into high-temperature steam, it enters the steam turbine 5 to expand and do work, thereby driving the first generator 12 to output electric energy to the outside. The condenser 6 is a heat exchange device. In the embodiment of the present invention, the condenser 6 is used to condense the high-temperature steam into water and return it to the system for circulation. The circulating water pump 7 is used to circulate the liquid in the closed system to ensure that the liquid continues to circulate in the system. In the embodiment of the present invention, the circulating water pump 7 is used to transport the condensed water passing through the condenser 6 to the high-temperature heater 3 to prepare for the next cycle. The air compressor 8 is a mechanical device that compresses air to a higher pressure. In the embodiment of the present invention, the air compressor 8 is used to compress and increase the pressure of ambient air. The cooler 9 is a heat exchange device, which usually uses water or air as a coolant to remove heat. In the embodiment of the present invention, the cooler 9 is used to cool the air compressed by the air compressor 8. The air storage 10 is used to store the air cooled by the cooler 9. The air turbine 11 is a device that converts the kinetic energy of air or other gases into mechanical energy. In the embodiment of the present invention, the compressed air absorbs heat and heats up before entering the air turbine 11 to expand and do work, thereby driving the second generator 13 to output electric energy to the outside.

[0046] Specifically, a coupling C1 is provided between the first generator 12 and the steam turbine 5, and the first generator 12 is connected to the steam turbine 5 through the coupling C1. The coupling C1 is used to control the on-off of the first generator 12 and the steam turbine 5. When the coupling C1 is closed, the first generator 12 is connected to the steam turbine 5, and the first generator 12 outputs electrical energy to the outside under the drive of the steam turbine 5. When the coupling C1 is disconnected, the connection between the first generator 12 and the steam turbine 5 is blocked.

[0047] Specifically, a coupling C2 is provided between the steam turbine 5 and the air compressor 8, and the steam turbine 5 is connected to the air compressor 8 through the coupling C2. The coupling C2 is used to control the on-off of the steam turbine 5 and the air compressor 8. When the coupling C2 is closed, the steam turbine 5 is connected to the air compressor 8, and the steam turbine 5 can drive the air compressor 8 to compress and increase the pressure of the ambient air. When the coupling C2 is disconnected, the connection between the steam turbine 5 and the air compressor 8 is blocked.

[0048] Specifically, a coupling C3 is provided between the motor 14 and the air compressor 8, and the motor 14 is connected to the air compressor 8 through the coupling C3. The coupling C3 is used to control the on-off of the motor 14 and the air compressor 8. When the coupling C3 is closed, the motor 14 is connected to the air compressor 8, and the motor 14 can drive the air compressor 8 to compress and increase the pressure of the ambient air. When the coupling C3 is disconnected, the connection between the motor 14 and the air compressor 8 is blocked.

[0049] Specifically, a coupling C4 is provided between the second generator 13 and the air turbine 11, and the second generator 13 is connected to the air turbine 11 through the coupling C4. The coupling C4 is used to control the on and off of the second generator 13 and the air turbine 11. When the coupling C4 is closed, the second generator 13 is connected to the air turbine 11, and the air turbine 11 can drive the second generator 13 to output electrical energy. When the coupling C4 is disconnected, the connection between the second generator 13 and the air turbine 11 is blocked.

[0050] Example 2

[0051] Based on the above system, an embodiment of the present invention further provides a method for solar-thermal coupled power generation and energy storage, including:

[0052] Photothermal coupling power generation mode. In the photothermal coupling power generation mode, coupling C1 is closed, coupling C2, coupling C3 and coupling C4 are disconnected, the photothermal circulation unit and the steam power circulation unit operate jointly, and the energy storage branch and the power generation branch are on standby. In the photothermal coupling power generation mode, the high-temperature heat storage medium in the collector 1 enters the high-temperature heater 3 to heat the circulating water on the opposite side under the drive of the photothermal circulation pump 2. After releasing heat, it returns to the collector 1 through the medium-temperature heater 4 to absorb heat again and store it in preparation for the next cycle. The circulating water absorbs heat and heats up to be converted into high-temperature steam, and then enters the steam turbine 5 to expand and do work, driving the first generator 12 to output electrical energy to the outside. In the photothermal coupling power generation mode of the embodiment of the present invention, the photothermal circulation unit drives the steam power circulation unit to operate independently at full load for power generation, and its function is basically the same as that of the traditional photothermal power generation system.

[0053] Photothermal coupled power generation and energy storage mode. In the photothermal coupled power generation and energy storage mode, couplings C1 and C2 are closed, couplings C3 and C4 are disconnected, the photothermal cycle unit, the steam power cycle unit and the energy storage branch are operated together, and the power generation branch is on standby. In the photothermal coupled power generation and energy storage mode, the high-temperature heat storage medium in the collector 1 enters the high-temperature heater 3 under the drive of the photothermal circulation pump 2 to heat the circulating water on the opposite side. After releasing heat, it returns to the collector 1 through the medium-temperature heater 4 to absorb heat again for storage and prepare to enter the next cycle. The circulating water absorbs heat and heats up to be converted into high-temperature steam, and then enters the steam turbine 5 to expand and do work, driving the first generator 12 to output electrical energy to the outside, and at the same time drives the air compressor 8 to compress and increase the pressure of the ambient air. The compressed air is cooled by the cooler 9 and then enters the gas storage reservoir 10 for storage. In the photovoltaic coupled power generation and energy storage mode of the embodiment of the present invention, the photovoltaic cycle unit drives the steam power cycle unit to generate electricity at full load, and while the steam power cycle unit outputs electric energy to the outside, it reduces the user's electric energy demand to drive the energy storage branch to operate, thereby avoiding the negative impact on the equipment efficiency and service life caused by the steam turbine 5 deviating too much from the design operating conditions. The energy storage branch stores the energy absorbed by the steam power cycle unit, avoiding energy waste.

[0054] Photothermal coupling power generation-energy storage regulation mode. In the photothermal coupling power generation-energy storage regulation mode, couplings C1, C2 and C3 are closed, coupling C4 is disconnected, the photothermal cycle unit, steam power cycle unit and energy storage branch operate together, and the energy storage branch absorbs electric energy from the external power system through the motor, and the power generation branch is on standby. In the photothermal coupling power generation-energy storage regulation mode, the high-temperature heat storage medium in the collector 1 enters the high-temperature heater 3 to heat the circulating water on the opposite side under the drive of the photothermal circulation pump 2, and returns to the collector 1 through the medium-temperature heater 4 after releasing heat to absorb heat again for storage and prepare to enter the next cycle. The circulating water absorbs heat and heats up to be converted into high-temperature steam, and then enters the steam turbine 5 to expand and do work, driving the first generator 12 to output electric energy to the outside, and at the same time, it drives the air compressor 8 together with the motor 14 to compress and increase the pressure of the ambient air. The compressed air is cooled by the cooler 9 and then enters the gas storage reservoir 10 for storage. In the solar-thermal coupled power generation energy storage regulation mode of the embodiment of the present invention, the solar-thermal cycle unit drives the steam power cycle unit to generate electricity at full load, and while the steam power cycle unit outputs electric energy to the outside, it reduces the user's electric energy demand to drive the energy storage branch to operate, thereby avoiding the negative impact of the steam turbine 5 deviating too much from the design operating conditions on the equipment efficiency and service life. The energy storage branch stores the energy absorbed by the steam power cycle to avoid energy waste. In addition, the energy storage branch absorbs additional electric energy from the outside through the motor 14, thereby realizing energy storage regulation of the external power system.

[0055] Energy storage regulation mode. In the energy storage regulation mode, coupling C3 is closed, coupling C1, coupling C2 and coupling C4 are disconnected, the energy storage branch is running, and the photothermal circulation unit, steam power circulation unit and power generation branch are on standby. In the energy storage regulation mode, the motor 14 drives the air compressor 8 to compress and increase the pressure of the ambient air, and the compressed air is cooled by the cooler 9 and then enters the gas storage reservoir 10 for storage. In the energy storage regulation mode of the embodiment of the present invention, the energy storage branch absorbs additional electrical energy from the outside through the motor 14 alone, thereby realizing energy storage regulation of the external power system.

[0056] Enhanced solar-thermal coupling power generation mode. In the enhanced solar-thermal coupling power generation mode, couplings C1 and C4 are closed, couplings C2 and C3 are disconnected, the solar-thermal cycle unit, the steam power cycle unit and the power generation branch are jointly operated, and the energy storage branch is on standby. In the enhanced solar-thermal coupling power generation mode, the high-temperature heat storage medium in the collector 1 enters the high-temperature heater 3 to heat the circulating water on the opposite side under the drive of the solar-thermal circulation pump 2, and heats the compressed air on the opposite side through the medium-temperature heater 4 after releasing heat, and returns to the collector 1 to absorb heat again for storage and prepare to enter the next cycle. The circulating water absorbs heat and heats up to be converted into high-temperature steam, and then enters the steam turbine 5 to expand and do work. The compressed air absorbs heat and heats up and then enters the air turbine 11 to expand and do work, and jointly drives the second generator 13 to output electric energy to the outside. In the embodiment of the present invention, in the enhanced solar-thermal coupling power generation mode, the solar-thermal cycle unit simultaneously drives the steam power cycle unit and the power generation branch to operate, and the two further simultaneously drive the second generator 13 to output electric energy to the outside, thereby jointly meeting the power supply demand when the external power demand is large. At the same time, since steam has a higher working temperature range than compressed air, the high-temperature heat storage medium in the collector 1 heats the steam power cycle unit and the power generation branch working medium in turn, which can realize the cascade rational utilization of stored thermal energy, thereby improving the utilization of solar thermal energy. efficiency.

[0057] Power generation regulation mode. In the power generation regulation mode, coupling C4 is closed, coupling C1, coupling C2 and coupling C3 are disconnected, the photothermal circulation unit and the power generation branch operate simultaneously, and the steam power circulation unit and the energy storage branch are on standby. In the power generation regulation mode, the high-temperature heat storage medium in the collector 1 enters the medium-temperature heater 4 through the high-temperature heater 3 under the drive of the photothermal circulation pump 2 to heat the compressed air on the opposite side, and then returns to the collector 1 to absorb heat again for storage and prepare to enter the next cycle. After the compressed air absorbs heat and heats up, it enters the air turbine 11 to expand and do work, driving the second generator 13 to output electrical energy to the outside. In the power generation regulation mode of the embodiment of the present invention, the photothermal circulation unit drives the power generation branch to operate independently to generate electricity. Since the operating temperature of the air turbine is relatively low, it is more suitable for variable operating condition regulation. This embodiment can cope with application scenarios with low or large fluctuations in external power demand.

[0058] In summary, the solar-thermal coupled power generation and energy storage system and method described in the present invention have the following advantages:

[0059] The present invention provides a solar-thermal coupled power generation and energy storage system and method, which can achieve maximum utilization of solar energy based on energy storage by organically coupling adiabatic compressed air energy storage with the solar-thermal power generation system, and can adjust the system working mode according to changes in power demand, with high flexibility. The present invention adopts a combination of photothermal conversion technology and steam power technology to organically combine direct utilization of solar energy and efficient power generation of steam turbines, which can not only effectively reduce carbon emissions while fully utilizing renewable clean energy, but also significantly improve the overall economic benefits and social value of the power plant.

[0060] The above describes in detail the concepts, principles and ideas of the present invention in conjunction with specific implementation methods (including embodiments and examples). Those skilled in the art should understand that the implementation methods of the present invention are not limited to the forms given above. After reading this application document, those skilled in the art can make any possible improvements, substitutions and equivalent forms to the steps, methods, systems and components in the above implementation methods. These improvements, substitutions and equivalent forms should be deemed to fall within the scope of the present invention, and the protection scope of the present invention is subject only to the claims.

Claims

1. A solar-thermal coupled power generation and energy storage system, characterized in that: include: A photothermal circulation unit, the photothermal circulation unit comprising a heat collector, a photothermal circulation pump, a high-temperature heater and a medium-temperature heater, the heat collector being connected to the photothermal circulation pump, the high-temperature heater and the medium-temperature heater in a counterclockwise closed loop; A steam power circulation unit, the steam power circulation unit comprising a high temperature heater, a steam turbine, a condenser and a circulating water pump, the high temperature heater being connected to the steam turbine, the condenser and the circulating water pump in a counterclockwise closed loop, wherein a first generator is provided at an input end of the steam turbine, and the first generator is connected to the steam turbine; An energy storage branch, the energy storage branch comprising an air compressor, a cooler and an air storage reservoir connected in sequence, wherein an input end of the air compressor is provided with an electric motor, and the electric motor is connected to the air compressor; A power generation branch, the power generation branch comprising an air turbine, a medium-temperature heater and an air storage reservoir connected in sequence, wherein a second generator is provided at the input end of the air turbine, and the second generator is connected to the air turbine; The cooler, the condenser, the steam turbine and the air compressor are connected in sequence to form a closed ring loop.

2. The solar-thermal coupled power generation and energy storage system according to claim 1, characterized in that: A coupling C1 is provided between the steam turbine and the first generator, and the first generator is connected to the steam turbine via the coupling C1.

3. The solar-thermal coupled power generation and energy storage system according to claim 2, characterized in that: A coupling C2 is provided between the steam turbine and the air compressor, and the steam turbine is connected to the air compressor via the coupling C2.

4. The solar-thermal coupled power generation and energy storage system according to claim 3, characterized in that: A coupling C3 is provided between the air compressor and the motor, and the air compressor is connected to the motor via the coupling C3.

5. The solar-thermal coupled power generation and energy storage system according to claim 4, characterized in that: A coupling C4 is provided between the air turbine and the second generator, and the air turbine is connected to the second generator via the coupling C4.

6. A method for photovoltaic-thermal coupling power generation and energy storage, the method being based on the photovoltaic-thermal coupling power generation and energy storage system according to claim 5, characterized in that: The method comprises: Photothermal coupling power generation mode, in which coupling C1 is closed, coupling C2, coupling C3 and coupling C4 are disconnected, the photothermal cycle unit and the steam power cycle unit operate jointly, and the energy storage branch and the power generation branch are on standby; Photothermal coupled power generation and energy storage mode, in which couplings C1 and C2 are closed, couplings C3 and C4 are disconnected, the photothermal cycle unit, the steam power cycle unit and the energy storage branch are operated jointly, and the power generation branch is on standby; Photothermal coupling power generation-energy storage regulation mode, in which couplings C1, C2 and C3 are closed, coupling C4 is disconnected, the photothermal cycle unit, the steam power cycle unit and the energy storage branch operate jointly, and the energy storage branch absorbs electric energy from the external power system through the motor, and the power generation branch is on standby; Energy storage regulation mode, in which coupling C3 is closed, coupling C1, coupling C2 and coupling C4 are disconnected, the energy storage branch is running, and the photothermal cycle unit, steam power cycle unit and power generation branch are on standby; Enhanced solar-thermal coupling power generation mode, in which couplings C1 and C4 are closed, couplings C2 and C3 are disconnected, the solar-thermal cycle unit, the steam power cycle unit and the power generation branch are operated jointly, and the energy storage branch is on standby; Power generation regulation mode, in which coupling C4 is closed, coupling C1, coupling C2 and coupling C3 are disconnected, the photothermal cycle unit and the power generation branch operate simultaneously, and the steam power cycle unit and the energy storage branch are on standby.

7. The method for storing solar-thermal coupled power generation according to claim 6, characterized in that: In the solar-thermal coupled power generation mode, the high-temperature heat storage medium in the collector enters the high-temperature heater driven by the solar-thermal circulation pump to heat the circulating water on the opposite side. After releasing heat, it returns to the collector through the medium-temperature heater to absorb heat and store it again. The circulating water absorbs heat and rises in temperature to be converted into high-temperature steam, which then enters the steam turbine to expand and do work, driving the first generator to output electrical energy to the outside.

8. The method for storing solar-thermal coupled power generation according to claim 6, characterized in that: In the solar-thermal coupled power generation and energy storage mode, the high-temperature heat storage medium in the collector enters the high-temperature heater driven by the solar-thermal circulation pump to heat the circulating water on the opposite side. After releasing heat, it returns to the collector through the medium-temperature heater to absorb heat and store it again. The circulating water absorbs heat and rises in temperature to be converted into high-temperature steam, and then enters the steam turbine to expand and do work, driving the first generator to output electrical energy to the outside, and at the same time drives the air compressor to compress and increase the pressure of the ambient air. The compressed air is cooled by the cooler and then enters the gas storage reservoir for storage.

9. The method for storing solar-thermal coupled power generation according to claim 6, characterized in that: In the solar-thermal coupled power generation-energy storage regulation mode, the high-temperature heat storage medium in the collector enters the high-temperature heater driven by the solar-thermal circulation pump to heat the circulating water on the opposite side, and after releasing heat, returns to the collector through the medium-temperature heater to absorb heat and store it again. The circulating water absorbs heat and rises in temperature to be converted into high-temperature steam, and then enters the steam turbine to expand and do work, driving the first generator to output electrical energy to the outside, and at the same time, together with the electric motor, drives the air compressor to compress and increase the pressure of the ambient air. The compressed air is cooled by the cooler and then enters the gas storage reservoir for storage.

10. The method for storing solar-thermal coupled power generation according to claim 6, characterized in that: In the energy storage regulation mode, the electric motor drives the air compressor to compress and increase the pressure of the ambient air, and the compressed air is cooled by the cooler and then enters the air storage reservoir for storage.

11. The method for storing solar-thermal coupled power generation according to claim 6, characterized in that: In the enhanced solar-thermal coupling power generation mode, the high-temperature heat storage medium in the collector enters the high-temperature heater driven by the solar-thermal circulation pump to heat the circulating water on the opposite side. After releasing heat, it is heated by the medium-temperature heater for the compressed air on the opposite side, and returns to the collector to absorb heat and store it again. The circulating water absorbs heat and rises in temperature to be converted into high-temperature steam, and then enters the steam turbine to expand and do work. The compressed air absorbs heat and rises in temperature and then enters the air turbine to expand and do work, and together they drive the second generator to output electrical energy to the outside.

12. The method for solar-thermal coupled power generation and energy storage according to claim 6, characterized in that: In the power generation regulation mode, the high-temperature heat storage medium in the collector is driven by the solar thermal circulation pump to enter the medium-temperature heater through the high-temperature heater to heat the compressed air on the opposite side, and then returns to the collector to absorb heat and store it again. After the compressed air absorbs heat and rises in temperature, it enters the air turbine to expand and do work, driving the second generator to output electrical energy to the outside.

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