阅读说明：本技术 一种带蓄热的双布雷顿联合循环太阳能发电系统及方法 (double-Brayton combined cycle solar power generation system and method with heat storage function ) 是由 高炜 杨玉 李红智 姚明宇 顾正萌 韩万龙 张旭伟 张一帆 张磊 吴帅帅 乔永强 于 2020-09-02 设计创作，主要内容包括：一种带蓄热的双布雷顿联合循环太阳能发电系统及方法,包括压气机,压气机的入口与外界空气相连通,压气机的出口与空气回热器的低温侧入口连通,空气回热器的低温侧出口与空气涡轮入口连通,空气涡轮的出口分为两路,一路与太阳能集热器的入口相连通,另一路与高温蓄热器的入口连接,太阳能集热器出口分为两路,一路连接高温蓄热器的入口,另一路连接空气-二氧化碳换热器的空气侧入口,高温蓄热器的出口分为两路,一路连接空气-二氧化碳换热器的空气侧入口,另一路与空气-二氧化碳换热器的空气侧出口汇合后连接空气换热器的高温侧入口,空气换热器的高温侧出口与外界空气相连通。本发明能够有效地减少材料费用和材料消耗,发电效率更高。(The double-Brayton combined cycle solar power generation system comprises a gas compressor, wherein an inlet of the gas compressor is communicated with outside air, an outlet of the gas compressor is communicated with a low-temperature side inlet of an air heat regenerator, a low-temperature side outlet of the air heat regenerator is communicated with an inlet of an air turbine, an outlet of the air turbine is divided into two paths, one path is communicated with an inlet of a solar heat collector, the other path is connected with an inlet of a high-temperature heat accumulator, an outlet of the solar heat accumulator is divided into two paths, one path is connected with an inlet of the high-temperature heat accumulator, the other path is connected with an air side inlet of an air-carbon dioxide heat exchanger, an outlet of the high-temperature heat accumulator is divided into two paths, one path is connected with an air side inlet of the air-carbon dioxide heat exchanger, the other path is converged with an air side outlet of. The invention can effectively reduce material cost and material consumption, and has higher generating efficiency.)

1. The double-Brayton combined cycle solar power generation system with the heat storage function is characterized by comprising a gas compressor (1), wherein an inlet of the gas compressor (1) is communicated with outside air, an outlet of the gas compressor (1) is communicated with a low-temperature side inlet of an air heat regenerator (2), a low-temperature side outlet of the air heat regenerator (2) is communicated with an inlet of an air turbine (3), an outlet of the air turbine (3) is divided into two paths, one path is communicated with an inlet of a solar heat collector (4), the other path is connected with an inlet of a high-temperature heat accumulator (13), an outlet of the solar heat collector (4) is divided into two paths, one path is connected with an inlet of the high-temperature heat accumulator (13), the other path is connected with an air side inlet of an air-carbon dioxide heat exchanger (5), an outlet of the high-temperature heat accumulator (13) is divided into two paths, and, the other path of the air-carbon dioxide heat exchanger is converged with an air side outlet of the air-carbon dioxide heat exchanger (5) and then is connected with a high-temperature side inlet of the air heat exchanger (2), and a high-temperature side outlet of the air heat exchanger (2) is communicated with the outside air.

2. The system of claim 1, the device is characterized in that a carbon dioxide side outlet of the air-carbon dioxide heat exchanger (5) is communicated with an inlet of a carbon dioxide turbine (6), an outlet of the carbon dioxide turbine (6) is communicated with a high-temperature side inlet of a carbon dioxide regenerator (7), a high-temperature side outlet of the carbon dioxide regenerator (7) is communicated with a carbon dioxide side inlet of a precooler (8), a carbon dioxide side outlet of the precooler (8) is communicated with an inlet of a carbon dioxide compressor (9), an outlet of the carbon dioxide compressor (9) is communicated with a low-temperature side inlet of the carbon dioxide regenerator (7), and a low-temperature side outlet of the carbon dioxide regenerator (7) is communicated with a carbon dioxide side inlet of the air-carbon dioxide heat exchanger (5).

3. The double-Brayton combined cycle solar power generation system with heat storage function according to claim 1, wherein a valve (10) No. 1 is arranged between the outlet of the air turbine (3) and the inlet of the high-temperature heat accumulator (13), the outlet of the solar heat collector (4) is divided into two paths, one path is connected with the inlet of the valve (11) No. 2, the outlet of the valve (11) No. 2 is connected with the air-side inlet of the air-carbon dioxide heat exchanger (5), the other path is connected with the inlet of the valve (12) No. 3, and the outlet of the valve (10) No. 1 and the outlet of the valve (12) No. 3 are merged and then connected with the inlet of the high-temperature heat accumulator (13).

4. The double-Brayton combined cycle solar power generation system with heat storage function according to claim 1, wherein the outlet of the high-temperature heat accumulator (13) is divided into two paths, one path is connected with the inlet of a valve (14) No. 4, the other path is not connected with the inlet of a valve (15) No. 5, the outlet of the valve (14) No. 4 is communicated with the air-side inlet of the air-carbon dioxide heat exchanger (5) after being merged with the outlet of the valve (11) No. 2, and the air-side outlet of the air-carbon dioxide heat exchanger (5) is communicated with the high-temperature-side inlet of the air heat exchanger (2) after being merged with the outlet of the valve (15) No. 5.

5. The method of operating a thermal storage dual brayton combined cycle solar power system in accordance with claim 1, comprising the steps of;

when sunlight is sufficient and heat in a high-temperature heat accumulator (13) is insufficient, a valve (10) No. 1 and a valve (14) No. 4 are closed, a valve (11) No. 2, a valve (12) No. 3 and a valve (15) No. 5 are opened, firstly, an air compressor (1) absorbs air from the outside atmosphere to be compressed, then the air is sent to the cold side of an air heat regenerator (2) to absorb heat, the heated compressed air enters an air turbine (3) to be expanded to do work, the expanded low-pressure air enters a solar heat collector (4) to absorb heat, the air heated to high temperature is divided into two paths, one part of the air directly enters an air-carbon dioxide heat exchanger (5) through the valve (11) No. 2 to be subjected to heat accumulation, the other part of the air enters the high-temperature heat accumulator (13) through the valve (12) to release heat, the air after heat accumulation in the high-temperature heat accumulator (13) is merged with the air after the air- 2) The hot side continuously releases heat and finally discharges the heat to the outside atmosphere, and at the moment, the supercritical carbon dioxide is circulated and normally operates;

when sunlight is insufficient, but certain heat can still be provided, and enough heat can be provided in the high-temperature heat accumulator 13, the valve 1 (10), the valve 2 (11) and the valve 5 (15) are closed, the valve 3 (12) and the valve 4 (14) are opened, firstly, the air compressor (1) absorbs air from the outside atmosphere for compression, then the air is sent into the air heat regenerator (2) for absorbing cold side heat, the heated compressed air enters the air turbine (3) for expansion and work, the expanded low-pressure air enters the solar heat collector (4) for absorbing heat, the air absorbing certain heat enters the high-temperature heat accumulator (13) through the valve 3 (12) for continuously absorbing heat, then releases heat in the air-carbon dioxide heat exchanger (5) through the valve 4 (14), and then enters the air heat regenerator (2) for continuously releasing heat, finally, discharging the carbon dioxide into the external atmosphere, and normally operating the supercritical carbon dioxide circulation;

when sunlight cannot provide heat and enough heat can be provided in a high-temperature heat accumulator (13), a valve (11) No. 2, a valve (12) No. 3 and a valve (15) No. 5 are closed, a valve (10) No. 1 and a valve (14) No. 4 are opened, firstly, an air compressor (1) absorbs air from the external atmosphere to be compressed, then the air is sent to the cold side of an air heat regenerator (2) to absorb heat, the heated compressed air enters an air turbine (3) to be expanded to do work, the expanded low-pressure air directly enters the high-temperature heat accumulator (13) through the valve (10) No. 1 to absorb heat, then the air passes through the valve (14) No. 4 to release heat in an air-carbon dioxide heat exchanger (5), then enters the continuous heat release side of the air heat regenerator (2), and finally the air is discharged into the external atmosphere, and the;

when the sunlight is insufficient, and the heat in the high-temperature heat accumulator (13) is insufficient to provide the high-temperature heat of the supercritical carbon dioxide circulation, but when the temperature of the Brayton cycle of the air can be met, the No. 2 valve (11), the No. 3 valve (12) and the No. 4 valve (14) are closed, the No. 1 valve (10) and the No. 5 valve (15) are opened, firstly, the air compressor (1) absorbs the air from the external atmosphere for compression, then the air is sent to the cold side of the air heat regenerator (2) to absorb heat, the heated compressed air enters the air turbine (3) to do work by expansion, the expanded low-pressure air directly enters the high-temperature heat accumulator (13) through the No. 1 valve (10) to absorb heat, then directly enters the hot side of the air regenerator (2) through a No. 5 valve (15) to release heat, and finally is discharged into the external atmosphere, and at the moment, the supercritical carbon dioxide cycle stops running.

6. The operation method of the double-Brayton combined cycle solar power generation system with the heat storage function according to claim 5, wherein the supercritical carbon dioxide cycle is a closed cycle, the high-pressure supercritical carbon dioxide after absorbing the heat released by the high-temperature air in the air-carbon dioxide heat exchanger (5) enters the carbon dioxide turbine (6) to do work, the high-pressure supercritical carbon dioxide after expansion work becomes low-pressure supercritical carbon dioxide, the low-pressure supercritical carbon dioxide firstly enters the hot side of the carbon dioxide heat regenerator (7) to release waste heat, then enters the precooler (8) to be continuously cooled, the cooled low-pressure low-temperature supercritical carbon dioxide enters the carbon dioxide compressor (9) to be pressurized, the pressurized supercritical carbon dioxide enters the cold side of the carbon dioxide heat regenerator (7) to absorb the heat, and then enters the air-carbon dioxide heat exchanger (5) to continuously absorb the heat, finally reaching the highest temperature and finally entering a carbon dioxide turbine (6) to finish the final circulation.

Technical Field

The invention relates to the technical field of solar power generation, in particular to a double-Brayton combined cycle solar power generation system with heat storage and a method thereof.

Background

Solar energy is an inexhaustible clean energy, and since solar photo-thermal power generation can reach the same high temperature as the solar temperature theoretically, as is well known, the higher the temperature is, the higher the thermal efficiency is, the more the solar photo-thermal power generation is emphasized.

The photothermal power generation needs to convert light energy into heat energy, and then the thermoelectric conversion is realized through the thermodynamic cycle, and at present, among numerous thermodynamic cycles, the supercritical brayton cycle is the most advantageous cycle form. The novel supercritical working media such as carbon dioxide, helium and nitrous oxide have the inherent advantages of high energy density, high heat transfer efficiency, simple system and the like, can greatly improve the heat-power conversion efficiency, reduce the equipment volume and have very high economical efficiency. Especially, after the temperature of the hot end reaches more than 500 ℃, the advantages of the supercritical carbon dioxide Brayton cycle become more and more obvious along with the temperature, and the thermal efficiency of the Brayton cycle gradually increases to the distance from the traditional steam cycle or other working medium cycles.

However, the heat collection temperature of the tower solar energy is not high at present, wherein the material problem accounts for a large part of the reasons, the high-temperature material actually applied to the power generation of the steam turbine set is within 620 ℃ and is far lower than the heat source temperature which can be reached by the solar heat collector, in addition, the solar photo-thermal power generation generally needs to consider heat storage, and the large-scale heat storage device is generally arranged on the ground, so the distances between the heat collector at the tower top and the heat storage device as well as the power generation set are far, and the main steam pressure of the power generation set with high efficiency is also far, so the pipe wall is very thick, if the pipe is made of high-temperature resistant alloy materials and is conveyed for a long distance, the cost is very huge.

Disclosure of Invention

In order to overcome the technical problems, the invention aims to provide a double-Brayton combined cycle solar power generation system with heat storage and a method thereof, which can effectively reduce material cost and material consumption and have higher power generation efficiency.

In order to achieve the purpose, the invention adopts the technical scheme that:

a double-Brayton combined cycle solar power generation system with heat storage comprises a gas compressor 1, wherein the inlet of the gas compressor 1 is communicated with outside air, the outlet of the gas compressor 1 is communicated with the low-temperature side inlet of an air heat regenerator 2, the low-temperature side outlet of the air heat regenerator 2 is communicated with the inlet of an air turbine 3, the outlet of the air turbine 3 is divided into two paths, one path is communicated with the inlet of a solar heat collector 4, the other path is connected with the inlet of a high-temperature heat accumulator 13, the outlet of the solar heat collector 4 is divided into two paths, one path is connected with the inlet of the high-temperature heat accumulator 13, the other path is connected with the air side inlet of an air-carbon dioxide heat exchanger 5, the outlet of the high-temperature heat accumulator 13 is divided into two paths, one path is connected with the air side inlet of the air-carbon dioxide heat exchanger, the high-temperature side outlet of the air heat exchanger 2 is communicated with the outside air.

The carbon dioxide side outlet of the air-carbon dioxide heat exchanger 5 is communicated with the inlet of the carbon dioxide turbine 6, the outlet of the carbon dioxide turbine 6 is communicated with the high-temperature side inlet of the carbon dioxide regenerator 7, the high-temperature side outlet of the carbon dioxide regenerator 7 is communicated with the carbon dioxide side inlet of the precooler 8, the carbon dioxide side outlet of the precooler 8 is communicated with the inlet of the carbon dioxide compressor 9, the outlet of the carbon dioxide compressor 9 is communicated with the low-temperature side inlet of the carbon dioxide regenerator 7, and the low-temperature side outlet of the carbon dioxide regenerator 7 is communicated with the carbon dioxide side inlet of the air-carbon dioxide heat exchanger 5.

A valve 10 No. 1 is arranged between an outlet of the air turbine 3 and an inlet of the high-temperature heat accumulator 13, an outlet of the solar heat collector 4 is divided into two paths, one path is connected with an inlet of the valve 11 No. 2, an outlet of the valve 11 No. 2 is connected with an air side inlet of the air-carbon dioxide heat exchanger 5, the other path is connected with an inlet of the valve 12 No. 3, and an outlet of the valve 10 No. 1 and an outlet of the valve 12 No. 3 are converged and then connected with an inlet of the high-temperature heat accumulator 13.

The outlet of the high-temperature heat accumulator 13 is divided into two paths, one path is connected with the inlet of the No. 4 valve 14, the other path is not connected with the inlet of the No. 5 valve 15, the outlet of the No. 4 valve 14 is communicated with the air side inlet of the air-carbon dioxide heat exchanger 5 after being converged with the outlet of the No. 2 valve 11, and the air side outlet of the air-carbon dioxide heat exchanger 5 is communicated with the high-temperature side inlet of the air heat exchanger 2 after being converged with the outlet of the No. 5 valve 15.

An operation method of a double-Brayton combined cycle solar power generation system with heat storage comprises the following steps;

when sunlight is sufficient and heat in the high-temperature heat accumulator 13 is insufficient, the valve 10, the valve 14 No. 1 is closed, the valve 11 No. 2, the valve 12 No. 3 and the valve 15 No. 5 are opened, firstly, the air compressor 1 absorbs air from the outside atmosphere for compression, then, the air is sent to the cold side of the air heat accumulator 2 for absorbing heat, the heated compressed air enters the air turbine 3 for expansion and work doing, the expanded low-pressure air enters the solar heat collector 4 for absorbing heat, the air heated to high temperature is divided into two paths, one part of the air directly enters the air-carbon dioxide heat exchanger 5 for heat release through the valve 11 No. 2, the other part of the air enters the high-temperature heat accumulator 13 for heat release through the valve 12 No. 3, the air after heat release in the high-temperature heat accumulator 13 is merged with the air after heat release of the air-carbon dioxide heat exchanger 5, finally, discharging the carbon dioxide into the external atmosphere, wherein the supercritical carbon dioxide circulates and normally operates;

when sunlight is insufficient, but still a certain amount of heat can be supplied, and sufficient heat can be supplied in the high-temperature heat accumulator 13, the No. 1 valve 10, the No. 2 valve 11 and the No. 5 valve 15 are closed, the No. 3 valve 12 and the No. 4 valve 14 are opened, firstly, the compressor 1 absorbs air from the outside atmosphere to compress, then the air is sent to the cold side of the air heat regenerator 2 to absorb heat, the heated compressed air enters the air turbine 3 to do work by expansion, the expanded low-pressure air enters the solar heat collector 4 to absorb heat, the air absorbing certain heat enters the high-temperature heat accumulator 13 through the No. 3 valve 12 to continuously absorb heat, then the heat is released in the air-carbon dioxide heat exchanger 5 through a No. 4 valve 14, then the heat enters the hot side of the air heat regenerator 2 to continue releasing the heat, and finally the heat is discharged into the external atmosphere, and the supercritical carbon dioxide cycle normally operates;

when sunlight cannot provide heat and enough heat can be provided in the high-temperature heat accumulator 13, the valve 11, the valve 12 and the valve 15 of No. 2, the valve 10 and the valve 14 of No. 4 are closed, firstly, the air compressor 1 absorbs air from the external atmosphere to compress, then, the air is sent to the cold side of the air heat regenerator 2 to absorb heat, the heated compressed air enters the air turbine 3 to expand to do work, the expanded low-pressure air directly enters the high-temperature heat accumulator 13 through the valve 10 of No. 1 to absorb heat, then, the air passes through the valve 14 of No. 4 to release heat in the air-carbon dioxide heat exchanger 5, then, the air enters the hot side of the air heat regenerator 2 to continuously release heat, finally, the air is discharged into the external atmosphere, and the supercritical carbon dioxide cycle;

when sunlight is insufficient, meanwhile, the heat in the high-temperature heat accumulator 13 is insufficient to provide high-temperature heat of supercritical carbon dioxide circulation, but the temperature of the air Brayton circulation can be met, the valve 11 No. 2, the valve 12 No. 3 and the valve 14 No. 4 are closed, the valve 10 No. 1 and the valve 15 No. 5 are opened, firstly, the air compressor 1 absorbs air from the external atmosphere to be compressed, then the air is sent to the cold side of the air regenerator 2 to absorb heat, the heated compressed air enters the air turbine 3 to be expanded to do work, the expanded low-pressure air directly enters the high-temperature heat accumulator 13 through the valve 10 No. 1 to absorb heat, then directly enters the hot side of the air regenerator 2 through the valve 15 No. 5 to release heat, and finally is discharged into the external atmosphere, and at the moment, the supercritical.

The supercritical carbon dioxide cycle is a closed cycle, high-pressure supercritical carbon dioxide after absorbing heat released by high-temperature air in the air-carbon dioxide heat exchanger 5 enters the carbon dioxide turbine 6 to do work and becomes low-pressure supercritical carbon dioxide after expansion work, the low-pressure supercritical carbon dioxide firstly enters the hot side of the carbon dioxide heat regenerator 7 to release waste heat and then enters the precooler 8 to be continuously cooled, the cooled low-pressure low-temperature supercritical carbon dioxide enters the carbon dioxide compressor 9 to be pressurized, the pressurized supercritical carbon dioxide enters the cold side of the carbon dioxide heat regenerator 7 to absorb heat and then enters the air-carbon dioxide heat exchanger 5 to continuously absorb heat, finally the temperature reaches the highest temperature, and finally the cooled low-pressure low-temperature supercritical carbon dioxide enters the carbon dioxide turbine 6 to complete.

The invention has the beneficial effects that:

according to the double-Brayton combined cycle solar power generation system with the heat storage function, firstly, the exhaust of an air Brayton cycle turbine is used as a heat absorption working medium of a solar heat collector, and the pressure is close to normal pressure, so that the heat collector and a channel material for conveying fluid can be selected and commonly used, and the problem of strength at high temperature is not considered. When the high-temperature hot fluid is conveyed to the energy storage system and the vicinity of the unit, the high-temperature alloy material is selected, so that the material cost can be greatly reduced.

In addition, the invention adopts a supercritical carbon dioxide generator set, has the characteristic of small volume and can also reduce the material consumption. In addition, the system adopts the combination of air Brayton cycle and a supercritical carbon dioxide generator set, so that the generating efficiency is higher.

Meanwhile, the system is provided with a high-temperature heat storage device and a related pipeline valve, so that the system has the functions of energy storage and regulation, and the impact of solar radiation on a power grid along with the change of time can be greatly reduced. And the heat storage system can give consideration to both supercritical carbon dioxide cycle heat storage and air Brayton cycle heat storage, and can realize that the air Brayton cycle utilizes medium-high temperature heat to continue to operate for a period of time after the high-temperature supercritical carbon dioxide Brayton cycle stops operating, thereby utilizing the solar heat to the maximum extent.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

The system comprises an air compressor 1, an air heat regenerator 2, an air turbine 3, a solar heat collector 4, an air-carbon dioxide heat exchanger 5, a carbon dioxide turbine 6, a carbon dioxide heat regenerator 7, a precooler 8, a carbon dioxide compressor 9, a valve 10 No. 1, a valve 11 No. 2, a valve 12 No. 3, a high-temperature heat accumulator 13, a valve 14 No. 4 and a valve 15 No. 5.

Detailed Description

The present invention will be described in further detail with reference to examples.

Referring to fig. 1, the double brayton combined cycle solar power generation system with heat storage of the invention is characterized by comprising a compressor 1, an air heat regenerator 2, an air turbine 3, a solar heat collector 4, an air-carbon dioxide heat exchanger 5, a carbon dioxide turbine 6, a carbon dioxide heat regenerator 7, a precooler 8, a carbon dioxide compressor 9, a valve 10 No. 1, a valve 11 No. 2, a valve 12 No. 3, a high-temperature heat accumulator 13, and a valve 14 No. 4, wherein an inlet of the compressor 1 is communicated with outside air, an outlet of the compressor 1 is communicated with a low-temperature side inlet of the air heat regenerator 2, a low-temperature side outlet of the air heat regenerator 2 is communicated with an inlet of the air turbine, an outlet of the air turbine 3 is divided into two paths, one path is communicated with an inlet of the solar heat collector 4, the other path is connected with an inlet of the valve 10 No., one path is connected with an inlet of a No. 2 valve 11, the other path is connected with an inlet of a No. 3 valve 12, a No. 1 valve 10 is connected with an outlet of the No. 3 valve 12 after being converged with an inlet of a high-temperature heat accumulator 13, an outlet of the high-temperature heat accumulator 13 is divided into two paths, one path is connected with an inlet of a No. 4 valve 14, the other path is not connected with an inlet of a No. 5 valve, an outlet of the No. 4 valve 14 is communicated with an air side inlet of an air-carbon dioxide heat exchanger 5 after being converged with an outlet of the No. 2 valve 11, an air side outlet of the air-carbon dioxide heat exchanger 5 is communicated with a high-temperature side inlet of the air heat exchanger 2 after being converged with an outlet of the No. 5 valve 15, a high-temperature side outlet of the air heat exchanger 2 is communicated with outside air, an outlet of a carbon dioxide turbine 6 is communicated with a, the carbon dioxide side outlet of the precooler 8 is communicated with the inlet of a carbon dioxide compressor 9, the outlet of the carbon dioxide compressor 9 is communicated with the low-temperature side inlet of a carbon dioxide heat regenerator 7, the low-temperature side outlet of the carbon dioxide heat regenerator 7 is communicated with the carbon dioxide side inlet of an air-carbon dioxide heat exchanger 5, and the carbon dioxide side outlet of the air-carbon dioxide heat exchanger 5 is communicated with the inlet of a carbon dioxide turbine 6.

The specific working process of the invention is as follows:

when sunlight is sufficient and heat in the high-temperature heat accumulator 13 is insufficient, the valve 10, the valve 14 No. 1 is closed, the valve 11 No. 2, the valve 12 No. 3 and the valve 15 No. 5 are opened, firstly, the air compressor 1 absorbs air from the outside atmosphere for compression, then, the air is sent to the cold side of the air heat accumulator 2 for absorbing heat, the heated compressed air enters the air turbine 3 for expansion and work doing, the expanded low-pressure air enters the solar heat collector 4 for absorbing heat, the air heated to high temperature is divided into two paths, one part of the air directly enters the air-carbon dioxide heat exchanger 5 for heat release through the valve 11 No. 2, the other part of the air enters the high-temperature heat accumulator 13 for heat release through the valve 12 No. 3, the air after heat release in the high-temperature heat accumulator 13 is merged with the air after heat release of the air-carbon dioxide heat exchanger 5, and finally discharged to the outside atmosphere. At the moment, the supercritical carbon dioxide cycle normally runs, the supercritical carbon dioxide cycle is closed cycle, high-pressure supercritical carbon dioxide after absorbing heat released by high-temperature air in the air-carbon dioxide heat exchanger 5 enters the carbon dioxide turbine 6 to do work, the high-pressure supercritical carbon dioxide is changed into low-pressure supercritical carbon dioxide after expansion work, the low-pressure supercritical carbon dioxide firstly enters the hot side of the carbon dioxide heat regenerator 7 to release waste heat, then enters the precooler 8 to be continuously cooled, the cooled low-pressure low-temperature supercritical carbon dioxide enters the carbon dioxide compressor 9 to be pressurized, the pressurized supercritical carbon dioxide enters the cold side of the carbon dioxide heat regenerator 7 to absorb heat, then enters the air-carbon dioxide heat exchanger 5 to continuously absorb heat, finally reaches the highest temperature, and finally enters the carbon dioxide turbine 6 to finish.

When sunlight is insufficient, a certain amount of heat can still be provided, and enough heat can be provided in the high-temperature heat accumulator 13, the valve 10 of the No. 1, the valve 11 of the No. 2 and the valve 15 of the No. 5 are closed, the valve 12 of the No. 3 and the valve 14 of the No. 4 are opened, firstly, the air compressor 1 absorbs air from the external atmosphere to be compressed, then, the air is sent to the cold side of the air heat regenerator 2 to absorb heat, the heated compressed air enters the air turbine 3 to be expanded to do work, the expanded low-pressure air enters the solar heat collector 4 to absorb heat, the air absorbing a certain amount of heat enters the high-temperature heat accumulator 13 through the valve 12 of the No. 3 to continuously absorb heat, then, the air passes through the valve 14 of the No. 4 to release heat in the air-carbon. The supercritical carbon dioxide cycle itself operates normally.

When sunlight cannot provide heat and enough heat can be provided in the high-temperature heat accumulator 13, the valve 11, the valve 12 and the valve 15 of the No. 2, the valve 10 and the valve 14 of the No. 1 are opened, firstly, the air compressor 1 absorbs air from the external atmosphere to compress the air, then the air is sent to the cold side of the air heat regenerator 2 to absorb the heat, the heated compressed air enters the air turbine 3 to expand to do work, the expanded low-pressure air directly enters the high-temperature heat accumulator 13 through the valve 10 of the No. 1 to absorb the heat, then the air passes through the valve 14 of the No. 4 to release heat in the air-carbon dioxide heat exchanger 5, then enters the hot side of the air heat regenerator 2 to continuously release heat, and finally the air is discharged. The supercritical carbon dioxide cycle itself operates normally.

When sunlight is insufficient, meanwhile, the heat in the high-temperature heat accumulator 13 is insufficient to provide high-temperature heat of supercritical carbon dioxide circulation, but the temperature of air Brayton circulation can be met, the valve 11 No. 2, the valve 12 No. 3 and the valve 14 No. 4 are closed, the valve 10 No. 1 and the valve 15 No. 5 are opened, firstly, the air compressor 1 absorbs air from the external atmosphere to be compressed, then the air is sent to the cold side of the air heat regenerator 2 to absorb heat, the heated compressed air enters the air turbine 3 to be expanded to do work, the expanded low-pressure air directly enters the high-temperature heat accumulator 13 through the valve 10 No. 1 to absorb heat, then directly enters the hot side of the air heat regenerator 2 through the valve 15 No. 5 to release heat, and finally the heat is. At which point the supercritical carbon dioxide cycle itself ceases to operate. The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.