A molten salt tower type photo-thermal photovoltaic combined power generation system
By arranging concentrated photovoltaic cells and crystalline silicon cells around the receiver, the energy overflow problem in the molten salt tower solar thermal power generation system was solved, achieving efficient photovoltaic-solar thermal power generation, reducing the heliostat tracking accuracy requirements, and improving the overall power generation efficiency and flexibility of the system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INST OF ELECTRICAL ENG CHINESE ACAD OF SCI
- Filing Date
- 2023-10-17
- Publication Date
- 2026-07-10
AI Technical Summary
In existing molten salt tower solar thermal power generation systems, the energy utilization in the area of the heliostat field's concentrated light spot overflow is insufficient, the high tracking accuracy of the heliostat leads to increased costs, and existing photovoltaic-solar thermal power generation systems have low efficiency or pose safety risks.
Concentrated photovoltaic cells and crystalline silicon cells are arranged around the receiver to utilize the overflow energy and reduce the tracking accuracy requirements of the heliostat. The DC-AC conversion and voltage boosting are achieved through the photovoltaic power generation conversion unit, maximizing the combined benefits of solar thermal and photovoltaic power generation.
It improves the overall utilization rate of solar energy, reduces the operating cost of heliostats, increases the energy absorption area, and improves power generation efficiency and system flexibility.
Smart Images
Figure CN117287360B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of solar energy utilization, and specifically relates to a molten salt tower-type solar thermal photovoltaic composite power generation system. Background Technology
[0002] Solar energy is an inexhaustible and renewable energy source. With fossil fuel reserves dwindling and the international energy situation becoming increasingly severe, developing and utilizing solar energy is a crucial way to diversify energy supply and ensure energy security. Solar energy is an important renewable energy utilization method, and solar power generation typically involves two methods: photovoltaic (PV) power generation and concentrated solar power (CSP). PV power generation systems utilize the photovoltaic effect of semiconductor materials to generate electricity, offering advantages such as high efficiency and system simplicity and flexibility. Solar PV power generation has become the primary renewable energy utilization method. Solar thermal power generation systems use concentrators and absorbers to convert solar radiation energy into heat energy, generating electricity through a thermodynamic cycle. Due to the ability to integrate relatively low-cost, large-capacity thermal storage systems, CSP power generation features stable power generation and is suitable for centralized and large-scale operations. Molten salt tower CSP technology has already achieved commercial operation in my country. Photovoltaic and CSP power generation methods have different characteristics, and their respective technical features can be combined and utilized in combination during application. Because the receiver area of a molten salt tower solar thermal power generation system is fixed, the light spot formed by the heliostat field changes over time. In actual operation, a large number of concentrated light spots exceed the receiver area, causing energy overflow. These overflow areas are typically covered with expensive high-temperature resistant insulation materials to prevent damage to the receiver tower structure from prolonged exposure. How to fully utilize this overflow energy is a pressing technical problem. Simultaneously, to prevent energy overflow, thousands of heliostats are required to have high tracking accuracy, increasing their cost. The combination of photovoltaic power generation with solar thermal systems has seen significant development in recent years. Chinese patent CN101608606 discloses a solar low-temperature thermal power generation and photovoltaic power generation composite system, which uses waste heat from photovoltaic power generation to generate electricity through organic Rankine cycle low-temperature power generation technology. However, this technology has relatively low efficiency. Chinese patent CN 103607166 A discloses a photovoltaic-thermal hybrid power generation system comprising a tracking concentrator system, a photovoltaic-thermal module, and a thermodynamic circulation section. The absorber module is arranged around the dense array battery module, projecting the portion of the concentrated light spot with higher energy flux density onto the surface of the dense array battery module, while the remaining portion is projected onto the surface of the absorber module. The coolant after cooling the dense array battery module is pumped into the absorber module as the heat-absorbing working fluid to continue absorbing energy, generating steam at a certain temperature, which is then used to generate electricity through a thermodynamic cycle. This achieves hybrid photovoltaic and solar thermal power generation. However, this technical solution places the dense array battery module in the region with higher energy flux density at the center of the concentrated light spot, posing a risk of high-temperature burnout. Chinese patent CN111765652 A discloses a tower-type photovoltaic-thermal hybrid power generation device. An infrared reflective layer and thin-film solar cells are sequentially arranged on the surface of a heliostat from the sun-facing side. The heliostat reflects infrared rays from sunlight towards the collector, generating steam to power a turbine that drives a generator. The thin-film solar cells utilize solar energy in other wavelengths to generate electricity.This technology utilizes sunlight in a frequency-division manner to achieve combined photovoltaic and solar thermal power generation. However, frequency division is difficult, resulting in low overall efficiency. Chinese patent CN202758244U discloses an independent tracking unit for a heliostat in a tower-type solar thermal power generation system. A solar panel array is installed at the front end of the heliostat support center. The electrical energy converted from the solar panel array drives the movement of the heliostat support, achieving photovoltaic power generation during the concentration process. In this technology, the solar panel array occupies the installation position of the reflector, reducing the reflective area. International patent WO2012038566A1 discloses a tower-type solar thermal and photovoltaic power generation composite system that replaces some of the sub-mirrors in the heliostat with photovoltaic cells, rationally distributing sunlight to achieve high solar energy utilization efficiency. This technology reduces the reflective area of the heliostat. Summary of the Invention
[0003] The present invention aims to provide a molten salt tower solar thermal and photovoltaic combined power generation system that maximizes the utilization of solar energy and improves the overall efficiency of existing molten salt tower solar thermal power plants.
[0004] This invention is achieved through the following technical means:
[0005] A molten salt tower-type solar thermal and photovoltaic combined power generation system includes heliostats, a heat absorber tower, a heat absorber, a low-temperature molten salt pump, a low-temperature molten salt tank, a high-temperature molten salt pump, a high-temperature molten salt tank, a molten salt steam generator, a water pump, a water supply unit, a steam turbine, a generator, a concentrating photovoltaic cell, a crystalline silicon cell, a photovoltaic power generation conversion unit, and other equipment.
[0006] The heliostats mentioned are concentrating devices in tower-type solar thermal power plants. They track the sun's trajectory in real time and accurately reflect sunlight to a predetermined location. Several heliostats form a heliostat field. The heliostats are arranged on the ground with the absorber tower as a reference. The heliostats can be arranged in a fan shape, a rectangle, or a circle to efficiently concentrate solar energy onto the absorber surface.
[0007] The aforementioned heat-absorbing tower is used to support the heat absorber and its piping system, and is usually made of steel or reinforced concrete. For a heliostat field with a fan-shaped arrangement, the heat-absorbing tower is placed at the center of one side of the fan-shaped heliostat field; for a heliostat field with a circular arrangement, the heat-absorbing tower is placed at the center of the heliostat field. The principle of this arrangement is to achieve the highest light-gathering efficiency of the heliostat field throughout the year.
[0008] The absorber is a photothermal conversion device that absorbs sunlight reflected by the heliostat and converts solar energy into heat energy, which is then transferred to the molten salt flowing inside the absorber.
[0009] The high-temperature molten salt tank is located on the ground near the heat absorption tower and is used to hold high-temperature molten salt heated by the heat absorber.
[0010] The aforementioned low-temperature molten salt tank is located on the ground near the heat absorption tower and is used to hold molten salt at a lower temperature.
[0011] The aforementioned cryogenic molten salt pump is located at the top of the cryogenic molten salt tank and is used to pump molten salt from the cryogenic molten salt tank to the heat absorber;
[0012] The molten salt steam generator is located on the ground near the high-temperature molten salt tank and the low-temperature molten salt tank. It is a device that uses high-temperature molten salt to heat the feedwater to obtain high-temperature and high-pressure steam.
[0013] The high-temperature molten salt pump is located at the top of the high-temperature molten salt tank and is used to pump molten salt from the high-temperature molten salt tank to the molten salt steam generator.
[0014] The turbine and generator are located on the ground near the molten salt steam generator, and generate electricity using high-temperature and high-pressure steam.
[0015] The water supply unit is a set of devices that connects the steam turbine and the molten salt steam generator, including a condenser, a steam heater, and a deaerator.
[0016] The concentrated photovoltaic cell is a high-performance photovoltaic cell, such as a multi-junction gallium arsenide cell, which can withstand high heat flux density and high temperature, and is arranged in the area around the absorber.
[0017] The crystalline silicon solar cell can withstand low-concentration sunlight and is arranged on the outer surface of the heat absorption tower to receive natural light or sunlight reflected onto its surface by a small number of heliostats to generate electricity.
[0018] The photovoltaic power generation conversion unit can be arranged on the ground or placed in a heat absorption tower to convert the DC power of concentrated photovoltaic cells and crystalline silicon cells into AC power and boost the voltage to meet grid connection requirements.
[0019] The molten salt mentioned is the solar salt currently used in tower solar thermal power plants, which is composed of 60% sodium nitrate and 40% potassium nitrate by mass ratio, and has a liquid operating temperature range of 240℃-570℃.
[0020] The arrangement of the concentrated photovoltaic cells and crystalline silicon cells in this invention is determined based on the heat flux density distribution provided by the heliostat's concentrating process. The area of the concentrated photovoltaic cells arranged near the receiver and the heat absorption area of the receiver are determined comprehensively based on the concentrating effect of the heliostat field, provided that the concentrated photovoltaic cells are operating safely and are not burned out.
[0021] Crystalline silicon cells cover the entire outer surface of the receiver tower, increasing the flexibility of heliostat operation. During receiver startup and shutdown, the heliostats can focus sunlight onto the surface of the crystalline silicon cells to generate electricity, extending the heliostats' operating time. While heliostats located near the receiver may have lower efficiency at certain times due to reflecting sunlight into the receiver, during operation, they can reflect sunlight onto the surface of the crystalline silicon cells to generate electricity, thus improving the overall solar power generation efficiency.
[0022] Because concentrated photovoltaic cells and crystalline silicon cells are arranged around the receiver and on the outer surface of the receiver tower, the area of sunlight reflected by the heliostat field is greatly increased, the tracking accuracy requirements of the heliostat are reduced, and solar energy that was not originally absorbed by the receiver can be utilized, which greatly improves the overall power generation efficiency of the power station.
[0023] The working process of this invention is as follows: Concentrated solar radiation energy flow, focused by a heliostat, is projected onto the surface of the receiver. A cryogenic molten salt pump pumps molten salt from a cryogenic molten salt storage tank into the receiver. The molten salt in the receiver is heated and then transported to a high-temperature molten salt storage tank for storage. A high-temperature molten salt pump pumps molten salt from the high-temperature molten salt storage tank into a molten salt steam generator. A water pump simultaneously pumps feedwater from the feedwater unit into the molten salt steam generator. The feedwater and molten salt exchange heat in the molten salt steam generator and are heated into superheated steam. The superheated steam is transported to a steam turbine to drive a generator to produce electricity. The generated electricity is connected to the power grid. The exhaust steam from the steam turbine flows back to the feedwater unit, and the heat-exchanged molten salt flows back to the cryogenic molten salt storage tank, completing the power generation process. Concentrated solar radiation energy flow, focused by a heliostat, is projected onto the surfaces of concentrated photovoltaic cells and crystalline silicon cells. The generated direct current is converted to alternating current and boosted in voltage by a photovoltaic power generation conversion unit before being connected to the power grid. Concentrated photovoltaic (CPV) cells receive concentrated solar radiation with a higher energy flux density, while crystalline silicon cells receive a relatively lower concentration of solar radiation. Both CPV and crystalline silicon cells can simultaneously receive natural sunlight to generate electricity. The concentrated solar radiation, focused by the heliostat, can be allocated according to the energy input required by the receiver, CPV cells, and crystalline silicon cells to maximize the benefits of solar thermal and photovoltaic power generation. By arranging CPV cells around the receiver, the area for receiving the concentrated solar radiation is expanded, reducing the requirements for heliostat tracking accuracy. The CPV cells also recover energy overflowing from the receiver, improving the utilization rate of solar energy. Arranging crystalline silicon cells on the outer surface of the receiver tower fully utilizes the outer surface space, improving the overall utilization effect of the receiver tower.
[0024] The present invention has the following advantages:
[0025] (1) It can utilize solar energy to simultaneously produce electricity and heat, and can store heat for power generation;
[0026] (2) The comprehensive utilization rate of energy has been improved, and the energy overflowing from the heliostat field has been recovered;
[0027] (3) Solar cell modules are directly installed on the heat absorption tower, saving land;
[0028] (4) Concentrating photovoltaic cells are arranged around the absorber to effectively utilize the radiation energy overflowing from the absorber, increase the absorption area, reduce the requirements for the heliostat's focusing accuracy, reduce the frequency of correction during the operation of the heliostat, and reduce costs. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the tower-type solar thermal power generation and photovoltaic power generation system with an external cylindrical heat absorber according to the present invention;
[0030] Figure 2 This is a schematic diagram of the tower solar thermal power generation and photovoltaic power generation system with cavity-type heat absorber of the present invention;
[0031] Figure 3 This is a schematic diagram of the cross-section of a cavity-type heat absorber receiving sunlight.
[0032] In the diagram: 1-Heliostat, 2-Heat absorber tower, 3-Heat absorber, 4-Low-temperature molten salt pump, 5-Low-temperature molten salt storage tank, 6-High-temperature molten salt storage tank, 7-High-temperature molten salt pump, 8-Molten salt steam generator, 9-Feed water pump, 10-Feed water unit, 11-Steam turbine, 12-Generator, 13-Concentrating photovoltaic cell, 14-Crystalized silicon cell, 15-Photovoltaic power generation conversion unit, 16-Power grid, 17-Concentrating radiation energy flow, 18-Cavity absorber opening. Detailed Implementation
[0033] Embodiment 1 of the present invention is a molten salt tower-type solar thermal and photovoltaic composite power generation system with an external cylindrical heat absorber, such as... Figure 1 As shown, the power generation system consists of a solar thermal power generation system and a photovoltaic power generation system. The molten salt tower solar thermal power generation system includes heliostats 1, an absorber tower 2, an absorber 3, a cryogenic molten salt pump 4, a cryogenic molten salt storage tank 5, a high-temperature molten salt storage tank 6, a high-temperature molten salt pump 7, a molten salt steam generator 8, a feedwater pump 9, a feedwater unit 10, a steam turbine 11, a generator 12, and other main equipment and auxiliary equipment. The solar photovoltaic power generation system includes concentrating photovoltaic cells 13, crystalline silicon cells 14, and photovoltaic power conversion units 15. The electricity generated by the molten salt tower solar thermal and photovoltaic combined power generation is transmitted to the power grid 16.
[0034] The heat exchanger tower 2 serves as the reference point for the power generation system, with heliostats 1 arranged in a circular pattern around it. The receiver 3, an external cylindrical receiver, is located at the top of the heat exchanger tower 2. Following the flow direction of the molten salt, the cryogenic molten salt pump 4 is connected to the cryogenic molten salt storage tank 5, the receiver 3, and the high-temperature molten salt storage tank 6. The high-temperature molten salt pump 7 is connected to the high-temperature molten salt storage tank 6, the molten salt steam generator 8, and the cryogenic molten salt storage tank 5, collectively forming the thermal storage system. Following the flow direction of the water, the feedwater pump 9 is sequentially connected to the feedwater unit 10 and the molten salt steam generator 8 via pipelines. Following the flow direction of the steam, the molten salt steam generator 8 is connected to the steam turbine 11 via pipelines. The steam turbine 11 and the generator 12 are fixedly connected by a coupling.
[0035] Concentrated photovoltaic cells 13 are arranged on the heat absorber tower 2, close to the perimeter of the heat absorber 3. Crystalline silicon cells 14 are arranged on the outer surface of the heat absorber tower 2, excluding the heat absorber 3 and the concentrated photovoltaic cells 13, with the crystalline silicon cells 14 located at the top of the heat absorber tower 2. The direct current generated by the concentrated photovoltaic cells 13 and the crystalline silicon cells 14 is converted to alternating current and stepped up in voltage by the photovoltaic power generation conversion unit 15 before being connected to the power grid 16.
[0036] The working process is as follows: The concentrated radiation energy flow 17, focused by the heliostat 1, is projected onto the surface of the receiver 3. The cryogenic molten salt pump 4 pumps molten salt from the cryogenic molten salt storage tank 5 into the receiver 3. The molten salt in the receiver 3 is heated and then transported to the high-temperature molten salt storage tank 6 for storage. The high-temperature molten salt pump 7 pumps molten salt from the high-temperature molten salt storage tank 6 into the molten salt steam generator 8. The feedwater pump 9 pumps feedwater from the feedwater unit 10 into the molten salt steam generator 8 at the same time. After heat exchange between the feedwater and molten salt in the molten salt steam generator 8, they are heated into superheated steam. The superheated steam is transported to the steam turbine 11 to do work and drive the generator 12 to generate electricity. The generated electricity is connected to the power grid 16. The exhaust steam from the steam turbine 11 flows back to the feedwater unit 10, and the heat-exchanged molten salt flows back to the cryogenic molten salt storage tank 5, completing the power generation process. The concentrated solar radiation energy flow 17, focused by the heliostat 1, is projected onto the surfaces of the concentrated photovoltaic cell 13 and the crystalline silicon cell 14. The generated direct current (DC) is converted to alternating current (AC) and boosted in voltage by the photovoltaic power generation conversion unit 15 before being connected to the power grid 16. The concentrated photovoltaic cell 13 receives the concentrated solar radiation energy flow 17 with a higher energy density, while the crystalline silicon cell 14 receives a relatively lower concentration of concentrated solar radiation energy flow 17. Both the concentrated photovoltaic cell 13 and the crystalline silicon cell 14 can simultaneously receive natural sunlight to generate DC. The concentrated solar radiation energy flow 17 focused by the heliostat 1 can be adjusted according to the energy input required by the receiver 3, the concentrated photovoltaic cell 13, and the crystalline silicon cell 14 to maximize the benefits of solar thermal and photovoltaic power generation. Because the concentrated photovoltaic cell 13 is arranged around the receiver 3, the area receiving the concentrated solar radiation energy flow 17 focused by the heliostat 1 is expanded, reducing the tracking accuracy requirements of the heliostat 1. The concentrated photovoltaic cell 13 recovers the energy that overflows outside the receiver 3, improving the utilization rate of solar energy. Crystalline silicon cells 14 are arranged on the outer surface of the heat absorption tower 2, which makes full use of the outer surface space of the heat absorption tower 2 and improves the overall utilization effect of the heat absorption tower 2.
[0037] Embodiment 2 of the present invention is a molten salt tower-type solar thermal and photovoltaic combined power generation system with a cavity-type heat absorber, such as... Figure 2 As shown, the power generation system consists of a solar thermal power generation system and a photovoltaic power generation system. The molten salt tower solar thermal power generation system includes heliostats 1, an absorber tower 2, an absorber 3, a cryogenic molten salt pump 4, a cryogenic molten salt storage tank 5, a high-temperature molten salt storage tank 6, a high-temperature molten salt pump 7, a molten salt steam generator 8, a feedwater pump 9, a feedwater unit 10, a steam turbine 11, a generator 12, and other main equipment and auxiliary equipment. The solar photovoltaic power generation system includes concentrating photovoltaic cells 13, crystalline silicon cells 14, and photovoltaic power conversion units 15. The electricity generated by the molten salt tower solar thermal and photovoltaic combined power generation is transmitted to the power grid 16.
[0038] The heat-absorbing tower 2 serves as the reference for this power generation system. The heat absorber 3, located at the top of the heat-absorbing tower 1, is a cavity-type heat absorber, and its cross-section for receiving sunlight is as follows: Figure 3As shown, it includes a cavity receiver opening 18 and concentrating photovoltaic cells 13 arranged around it. Heliostats 1 are arranged around the receiver tower 2, with the heliostats 1 facing the cavity receiver opening 18 arranged in a fan shape and the heliostats 1 facing away from the cavity receiver opening 18 arranged in a semi-circular shape.
[0039] Following the flow direction of the molten salt, molten salt pump 4 is connected to low-temperature molten salt storage tank 5, heat absorber 3, and high-temperature molten salt storage tank 6. High-temperature molten salt pump 7 is connected to high-temperature molten salt storage tank 6, molten salt steam generator 8, and low-temperature molten salt storage tank 5, together forming a thermal storage system. Following the flow direction of the water, feedwater pump 9 is sequentially connected to feedwater unit 10 and molten salt steam generator 8 via pipelines. Following the flow direction of the steam, molten salt steam generator 8 is connected to steam turbine 11 via pipelines. Steam turbine 11 and generator 12 are fixedly connected by a coupling.
[0040] Concentrated photovoltaic (PV) cells 13 are arranged on the heat-absorbing tower 2, covering all areas where the heliostat can concentrate sunlight. Crystalline silicon cells 14 are arranged on the outer surface of the heat-absorbing tower 2, excluding the heat absorber 3 and the PV cells 13, including the top plane of the heat absorber 3. The direct current (DC) generated by the PV cells 13 and the crystalline silicon cells 14 is converted to alternating current (AC) and boosted in voltage by the photovoltaic power generation conversion unit 15 before being connected to the power grid 16.
[0041] The working process is as follows: The concentrated radiation energy flow 17, focused by the heliostat 1, is projected through the cavity absorber opening 18 onto the surface of the absorber 3. The cryogenic molten salt pump 4 pumps molten salt from the cryogenic molten salt storage tank 5 into the absorber 3. The molten salt in the absorber 3 is heated and then transported to the high-temperature molten salt storage tank 6 for storage. The high-temperature molten salt pump 7 pumps molten salt from the high-temperature molten salt storage tank 6 into the molten salt steam generator 8. The feedwater pump 9 pumps feedwater from the feedwater unit 10 into the molten salt steam generator 8 at the same time. After heat exchange between the feedwater and molten salt in the molten salt steam generator 8, they are heated into superheated steam. The superheated steam is transported to the turbine 11 to do work and drive the generator 12 to generate electricity. The generated electricity is connected to the power grid 16. The turbine exhaust steam flows back to the feedwater unit 10, and the heat-exchanged molten salt flows back to the cryogenic molten salt storage tank 5, completing the power generation process. The concentrated solar radiation energy flow 17, focused by the heliostat 1, is projected onto the surfaces of the concentrated photovoltaic cell 13 and the crystalline silicon cell 14. The generated direct current (DC) is converted to alternating current (AC) and boosted in voltage by the photovoltaic power generation conversion unit 15 before being connected to the power grid 16. The concentrated photovoltaic cell 13 receives the concentrated solar radiation energy flow 17 with a higher energy density, while the crystalline silicon cell 14 receives a relatively lower concentration of concentrated solar radiation energy flow 17. Both the concentrated photovoltaic cell 13 and the crystalline silicon cell 14 can simultaneously receive natural sunlight to generate DC. The concentrated solar radiation energy flow 17 focused by the heliostat 1 can be adjusted according to the energy input required by the receiver 3, the concentrated photovoltaic cell 13, and the crystalline silicon cell 14 to maximize the benefits of solar thermal and photovoltaic power generation. Because the concentrated photovoltaic cell 13 is arranged around the receiver 3, the area receiving the concentrated solar radiation energy flow 17 focused by the heliostat 1 is expanded, reducing the tracking accuracy requirements of the heliostat 1. The concentrated photovoltaic cell 13 recovers the energy that overflows outside the receiver 3, improving the utilization rate of solar energy. Concentrated photovoltaic cells 13 and crystalline silicon cells 14 are arranged on the outer surface of the heat absorption tower 2, which makes full use of the outer surface space of the heat absorption tower 2 and improves the overall utilization effect of the heat absorption tower 2.
Claims
1. A molten salt tower-type solar thermal and photovoltaic combined power generation system, characterized in that, The solar thermal and photovoltaic power generation system utilizes heliostats to concentrate light, including a heliostat (1), a heat absorber tower (2), a heat absorber (3), a low-temperature molten salt pump (4), a low-temperature molten salt storage tank (5), a high-temperature molten salt storage tank (6), a high-temperature molten salt pump (7), a molten salt steam generator (8), a water pump (9), a water supply unit (10), a steam turbine (11), a generator (12), a concentrated photovoltaic cell (13), a crystalline silicon cell (14), and a photovoltaic power generation conversion unit (15). The electricity generated by the molten salt tower solar thermal and photovoltaic composite power generation system is transmitted to the power grid (16). Concentrated photovoltaic cells (13) are arranged around the heat absorber (3), and crystalline silicon cells (14) are arranged on the outer surface and top of the heat absorber tower (2). When the heat absorber (3) is an external cylindrical heat absorber, the heat absorption tower (2) is the reference of the power generation system, the heliostat (1) is arranged around the heat absorption tower (2) in a circular arrangement; the heat absorber (3) is located at the top of the heat absorption tower (2); the concentrating photovoltaic cell (13) Arranged on the heat absorber (2) around the heat absorber (3); crystalline silicon cells (14) are arranged on the outer surface of the heat absorber (2) in other areas except for the heat absorber (3) and the concentrated photovoltaic cells (13), and crystalline silicon cells (14) are arranged in the top area of the heat absorber (2); when the heat absorber (3) is a cavity heat absorber, the heliostat (1) facing the cavity heat absorber opening (18) is arranged in a fan shape, and the heliostat facing away from the cavity heat absorber opening (18) is arranged in a semi-circular shape; the concentrated photovoltaic cells (13) are arranged on the heat absorber (2), and the concentrated photovoltaic cells (13) are arranged in the area irradiated by the heliostat (1); The concentrated radiation energy flow (17) converged by the heliostat (1) is projected onto the surface of the receiver (3). The low-temperature molten salt pump (4) pumps molten salt from the low-temperature molten salt storage tank (5) into the receiver (3). The molten salt in the receiver (3) is heated and then transported to the high-temperature molten salt storage tank (6) for storage. The high-temperature molten salt pump (7) pumps molten salt from the high-temperature molten salt storage tank (6) into the molten salt steam generator (8). The feed water pump (9) pumps feed water from the feed water unit (10) into the molten salt steam generator (8) at the same time. The feed water and molten salt are heated into superheated steam after heat exchange in the molten salt steam generator (8). The superheated steam is transported to the turbine (11) to do work and drive the generator (12) to generate electricity. The generated electricity is connected to the power grid (16). The exhaust steam from the turbine (11) flows back to the feed water unit (10). The molten salt after heat exchange flows back to the low-temperature molten salt storage tank. 5) The power generation process is completed. The concentrated radiation energy flow (17) converged by the heliostat (1) is projected onto the surface of the concentrated photovoltaic cell (13) and the crystalline silicon cell (14). The generated DC power is converted to AC power and stepped up by the photovoltaic power generation conversion unit (15) and connected to the power grid (16). The concentrated photovoltaic cell (13) receives the concentrated radiation energy flow (17) with a higher energy flow density, while the crystalline silicon cell (14) receives the relatively lower concentrated radiation energy flow (17). Both the concentrated photovoltaic cell (13) and the crystalline silicon cell (14) can simultaneously receive natural sunlight to generate DC power. The concentrated radiation energy flow (17) converged by the heliostat (1) can be allocated according to the input energy required by the absorber (3), the concentrated photovoltaic cell (13) and the crystalline silicon cell (14) to maximize the benefits of solar thermal and photovoltaic power generation.
2. The molten salt tower-type solar thermal and photovoltaic power generation system according to claim 1, characterized in that, Crystalline silicon cells (14) are arranged on the outer surface of the heat absorber (2) in areas other than the heat absorber (3) and the concentrating photovoltaic cell (13), including the top plane of the heat absorber (3).