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CN-122014548-A - Solar power generation device and method

CN122014548ACN 122014548 ACN122014548 ACN 122014548ACN-122014548-A

Abstract

The invention relates to the technical field of new energy, in particular to a solar power generation device and a method, wherein the solar power generation device comprises a tower type photo-thermal unit and a supercritical CO2 recompression circulation unit which are connected, two compression storage tanks are added in the supercritical CO2 recompression circulation to respectively store CO2 at a high pressure side and a low pressure side, when solar radiation is excessive, electric power output by a turbine compresses low-pressure fluid in the low-pressure storage tank, the compressed fluid enters the high-pressure storage tank to be stored, when the solar radiation is insufficient, the high-pressure CO2 in the high-pressure storage tank is released to a system, and a fused salt heat storage system is used as a heat source to enable the system to continuously generate power, so that the deep utilization of solar energy is realized.

Inventors

  • WANG YAN
  • LI HONGWEI
  • Akbar Tuheti
  • SHENG WEI
  • AN XIAOYAN

Assignees

  • 哈密职业技术学院

Dates

Publication Date
20260512
Application Date
20260325

Claims (8)

  1. 1. The solar power generation device is characterized by comprising a tower type photo-thermal unit, a supercritical CO 2 recompression circulating unit and a CO 2 energy storage unit, wherein the tower type photo-thermal unit is used for absorbing solar energy to heat a heat storage medium, the supercritical CO 2 recompression circulating unit is used for absorbing heat of the heat storage medium from the tower type photo-thermal unit and generating power, the CO 2 energy storage unit is arranged in the supercritical CO 2 recompression circulating unit, the CO 2 energy storage unit comprises a high-pressure CO 2 storage tank and a low-pressure CO 2 storage tank, the low-pressure CO 2 storage tank is used for storing CO 2 at the low pressure side of the supercritical CO 2 recompression circulating unit, and the high-pressure CO 2 storage tank is used for storing CO 2 at the high pressure side of the supercritical CO 2 recompression circulating unit.
  2. 2. The solar power generation device according to claim 1, wherein the tower type photo-thermal unit comprises a heliostat, a heat absorption tower, a high-temperature heat storage tank, a low-temperature heat storage tank, a main heater and a reheater, wherein the heliostat is used for collecting sunlight to the heat absorption tower, the heat absorption tower is used for heating heat storage media by solar energy, the heat absorber is arranged at the top of the heat absorption tower and is used for absorbing heat of sunlight to heat the heat storage media, the high-temperature heat storage tank is used for storing the heat storage media heated by the heat absorption tower, the low-temperature heat storage tank is used for storing and recovering the heat storage media after heat exchange, the low-temperature heat storage tank is connected with the heat absorption tower and supplies the heat storage media to the heat absorption tower, the main heater is used for heating CO 2 working media in the supercritical CO 2 recompression circulation unit, and the reheater is used for secondarily heating CO 2 working media in the supercritical CO 2 recompression circulation unit.
  3. 3. The solar power generation device of claim 2, wherein the supercritical CO 2 recompression circulation unit comprises a first turbine, a second turbine, a high temperature regenerator, a low temperature regenerator, a cooler, a main compressor and a recompression unit, wherein the working medium outlet of the main heater is connected with the working medium inlet of the first turbine, the working medium outlet of the first turbine is connected with the working medium inlet of the reheater, the working medium outlet of the reheater is connected with the working medium inlet of the second turbine, the dead steam outlet of the first turbine is connected with the hot side inlet of the high temperature regenerator, the hot side outlet of the high temperature regenerator is connected with the hot side inlet of the low temperature regenerator, the hot side first outlet of the low temperature regenerator is connected with the working medium inlet of the cooler, the working medium outlet of the cooler is connected with the working medium inlet of the main compressor, the working medium outlet of the main compressor is connected with the cold side inlet of the low temperature regenerator, the side second outlet of the low temperature regenerator is connected with the cold side inlet of the low temperature regenerator, and the cold side outlet of the high temperature regenerator is connected with the cold side inlet of the low temperature regenerator.
  4. 4. A solar power plant according to claim 3, characterized in that the working medium inlet of the low pressure CO 2 storage tank is connected to the hot side outlet of the low temperature regenerator, the working medium outlet of the low pressure CO 2 storage tank is connected to the working medium inlet of the cooler, the working medium inlet of the high pressure CO 2 storage tank is connected to the working medium outlet of the main compressor, and the working medium outlet of the high pressure CO 2 storage tank is connected to the cold side inlet of the low temperature regenerator.
  5. 5. A solar power plant according to claim 3, characterized in that the first turbine is drivingly connected to the main compressor and the recompressor, respectively, the first turbine being adapted to provide driving power for the main compressor and the recompressor.
  6. 6. A solar power generation device according to claim 1, wherein the heat storage medium used by the tower type photo-thermal unit is molten salt, and the molten salt comprises 60wt% of NaNO 3 and 40wt% of KNO 3 in percentage by mass.
  7. 7. A solar power generation device according to claim 3, wherein the temperature of the heat storage medium conveyed from the tower type photo-thermal unit to the supercritical CO 2 recompression circulation unit is 500 ℃ to 600 ℃.
  8. 8. A solar power generation method applied to a solar power generation device according to any one of claims 1 to 7, comprising the steps of: S1, in the stage of photo-thermal heat collection and heat storage, sunlight is collected to a heat absorption tower through heliostats of a tower type photo-thermal unit, solar energy is absorbed by a heat absorber to heat a heat storage medium, the heated high-temperature heat storage medium is sent to a high-temperature heat storage tank for storage, and the low-temperature heat storage medium after heat exchange is sent to a low-temperature heat storage tank for recovery and is circularly conveyed to the heat absorption tower for heating; S2, in a conventional power generation circulation stage, conveying a high-temperature heat storage medium in a high-temperature heat storage tank to a main heater and a reheating device, heating a CO 2 working medium in a supercritical CO 2 recompression circulation unit by taking the high-temperature heat storage medium as a driving heat source to form supercritical CO 2 , driving a first turbine and a second turbine to do work and generate power, and completing the supercritical CO 2 recompression Brayton cycle; S3, in a surplus energy storage stage, when solar radiation is excessive, compressing low-pressure CO 2 fluid in a low-pressure CO 2 storage tank by surplus power output by a first turbine, and sending compressed high-pressure CO 2 fluid into a high-pressure CO 2 storage tank for storage, so that conversion and storage of electric energy to pressure energy are completed; And S4, in the energy storage, energy release and energy supplement power generation stage, when solar radiation is insufficient, the high-pressure CO 2 fluid in the high-pressure CO 2 storage tank is released to the supercritical CO 2 recompression circulating unit, and meanwhile, the high-temperature heat storage medium stored in the high-temperature heat storage tank is used as a heat source to continuously heat the CO 2 working medium so as to drive the supercritical CO 2 recompression circulating unit to continuously and stably generate power.

Description

Solar power generation device and method Technical Field The invention relates to the technical field of new energy, in particular to a solar power generation device and a method. Background Global climate change is a major challenge facing humans, and reducing greenhouse gas emissions and developing clean energy have become a global consensus; In order to cope with global energy crisis and climate change, the development of renewable energy sources to replace traditional fossil energy power generation has become a key path; The solar energy resources in China are rich, the number of sunshine hours in the region with the total area of more than 2/3 of the whole country is more than 2000 hours, the average annual radiation quantity is more than 0.6GJ cm < -2 >, and the solar energy power generation technology is rapidly developed in China by virtue of the advantages of huge reserves and clean utilization; However, solar power generation systems are susceptible to weather, diurnal, seasonal fluctuations, and energy supply has strong intermittence and volatility, and cannot directly match the stable power supply requirements of the grid; The existing tower type photo-thermal power generation technology mostly adopts a single fused salt heat storage system, although the cross-period storage of heat energy can be realized, the instantaneous power fluctuation in the power generation process cannot be stabilized, the surplus electric energy cannot be recovered efficiently, the supercritical CO 2 power generation cycle has the advantages of high heat efficiency and small system volume, the prior art does not deeply couple the supercritical CO 2 power generation cycle with compressed CO 2 energy storage, the full-period deep utilization of solar energy cannot be realized, and the whole solar energy utilization rate still has a large improvement space. Disclosure of Invention The present invention is directed to a solar power generation device and a method thereof, which solve the above-mentioned problems in the prior art. In order to achieve the above purpose, the present invention adopts the following technical scheme: A solar power generation device comprises a tower type photo-thermal unit, a supercritical CO 2 recompression circulation unit and a CO 2 energy storage unit. The tower type photo-thermal unit is used for absorbing solar energy to heat a heat storage medium to convert and store solar energy into heat energy, the supercritical CO 2 recompression circulating unit is used for absorbing heat energy from the heat storage medium of the tower type photo-thermal unit to convert the heat energy into electric energy, the CO 2 energy storage unit is arranged in the supercritical CO 2 recompression circulating unit and comprises a high-pressure CO 2 storage tank and a low-pressure CO 2 storage tank, the low-pressure CO 2 storage tank is used for storing CO 2 on the low-pressure side of the supercritical CO 2 recompression circulating unit, and the high-pressure CO 2 storage tank is used for storing CO 2 on the high-pressure side of the supercritical CO 2 recompression circulating unit. Further, the tower type photo-thermal unit comprises a heliostat, a heat absorption tower, a high-temperature heat storage tank, a low-temperature heat storage tank, a main heater and a reheater. The heliostat is used for gathering sunlight to a heat absorption tower, a heat absorber is arranged at the top of the heat absorption tower and used for absorbing the gathered sunlight heat to heat a heat storage medium flowing through, an inlet of the high-temperature heat storage tank is connected with a medium outlet of the heat absorber and used for storing the heated high-temperature heat storage medium, an outlet of the low-temperature heat storage tank is connected with a medium inlet of the heat absorber and used for storing and recovering the low-temperature heat storage medium subjected to heat exchange and supplying a circulating heat storage medium to the heat absorption tower, hot side inlets of the main heater and the reheating heater are connected with an outlet of the high-temperature heat storage tank, hot side outlets of the main heater and the reheating heater are connected with an inlet of the low-temperature heat storage tank, the main heater is used for heating CO 2 working medium in the supercritical CO 2 recompression circulation unit, and the reheating heater is used for secondarily heating CO 2 working medium in the supercritical CO 2 recompression circulation unit. Further, the supercritical CO 2 recompression circulation unit includes a first turbine, a second turbine, a high temperature regenerator, a low temperature regenerator, a cooler, a main compressor, and a recompression. The cold side working medium outlet of the main heater is connected with the working medium inlet of the first turbine, the working medium outlet of the first turbine is connected with the cold side working medium inlet of the reheate