Tower solar thermal power generation method and system using closed Brayton cycle

Abstract

The invention relates to a tower solar thermal power generation method and system using a closed Brayton cycle. The method and the system reserve the advantages of liquid pressurization and closed Brayton cycle of a supercritical carbon dioxide tower solar thermal power generation system, eliminate the disadvantages of excessively high system pressure and excessively low critical temperature, use extracted steam in an open Brayton cycle as the heat source of the closed Brayton cycle and water vapor as the heat absorbing working medium of the tower solar thermal power generation system, greatly reduce power consumption in working medium pressurization in a solar Brayton cycle by using the uncompressible fluid property and very good heat transfer performance of liquid water, and use a bottom Rankine cycle for absorbing heat released in the closed Brayton cycle, thereby forming an open Brayton-closed Brayton-Rankine combined cycle solar thermal power generation system which has the advantages of higher efficiency and better economic performance.

Description

technical field [0001] The invention relates to a method and system for tower-type solar energy focused thermal power generation, in particular to a method and system for tower-type solar thermal power generation using a closed Breton cycle. Background technique [0002] With the vigorous development of renewable energy utilization in the world, concentrated solar power (CSP) and photovoltaic solar power (PV) have developed rapidly. The use of solar photovoltaic power generation can only make use of light with a shorter wavelength, and the light with a longer wavelength is completely wasted, and the temperature of the battery increases, resulting in a decrease in the efficiency of the battery, while the use of solar thermal power generation can make full use of the entire wavelength Therefore, concentrating solar power (CSP) is gradually recognized, researched and valued by people. Compared with photovoltaic solar power (PV), concentrating solar power (CSP) has outstanding...

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Problems solved by technology

But it also has certain disadvantages: due to the low critical temperature and high critical pressure of carbon dioxide, which are 31.05°C and 7.53MPa respectively, it is necessary to ensure that the circulating working medium is pressurized by liquid, and the outlet pressure of the Britton cycle should be controlled at 1146psi (ie 7.9MPa), so the supercritical carbon dioxide concentrating solar power generation system device must adopt higher operating pressure and lower condensation temperature, and the system can withstand high pressure

[0030] Therefore, how to solve the problems existing in the above-mentioned prior art, give full play to the advantages of high concentrating ratio and high temperature of tower solar energy, select a suitable tower solar heat absorbing working medium, expand the advantages of Cheng's cycle and HAT cycle, and overcome the problems of arrangement The disadvantage of high power consumption in gas compression of the Burton cycle, the establishment of a more efficient closed-circuit Breton cycle power generation mode has become a difficulty in research in this field

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