Multi-tower binary-working-medium solar high-temperature heat power generation system

Abstract

The invention relates to a multi-tower binary-working-medium solar high-temperature heat power generation system which comprises a water working-medium heat absorber, a steam dome, a molten salt heat absorber, a water feeding pump, a saturated heat accumulator, a molten salt pump, a molten salt tank, a steam overheater, an auxiliary heater, a deaerator, a steam turbine, a condenser and a condensate pump; water in the steam dome enters the water medium heat absorber in a natural circulation way to finish the preheating and evaporating process of water; after steam-water separation, saturated steam is introduced to the saturated heat accumulator; molten salt is heated in the molten salt heat absorber and is subjected to heat release in the steam overheater so that the saturated steam is heated to reach required overheat parameter parameters, and finally, the heated saturated steam is introduced to the steam turbine to work; and the steam subjected to expansion working is condensed into condensed water in the condenser, the condensed water is conveyed to the steam-type deaerator through the condensate pump, and the deaerated water is conveyed to the steam dome on the heat absorber through the water feeding pump, thereby a circulation process is finished. The multi-tower binary-working-medium solar high-temperature heat power generation system has the characteristics of high safety, saved investment, simpleness in operation and maintenance, and the like at the same time of improving the efficiency of the solar heat power generation system.

Description

technical field [0001] The invention relates to a multi-tower type binary working medium solar high-temperature thermal power generation system, which belongs to the technical field of solar energy utilization. Background technique [0002] Solar high-temperature thermal power generation technology is an important direction for large-scale utilization of solar energy, and it has far-reaching significance for human beings to solve problems such as fossil energy crisis and air pollution. There are many technical directions for solar high-temperature thermal power generation: according to different focusing methods, it can be divided into three types: dish type, trough type, and tower type; the working fluids used include water (water vapor), molten salt, air, heat transfer oil, Liquid metals, other organic matter, etc. The tower-type focusing method has attracted the attention of many countries in the world due to its advantages of large capacity and high parameters, and the ...

AI Technical Summary

Problems solved by technology

Although the solar thermal power generation system using water (steam) as the heat-carrying medium has many advantages such as common media, low cost, and simple control, there are also some insurmountable problems in this system: due to the low heat transfer coefficient of superheated steam , The heat transfer effect is poor, so it is difficult to achieve higher steam parameters on a limited heat absorption area; if the superheat degree is increased by increasing the area of ​​superheated steam on the heat absorber, this will not only increase the manufacturing cost of the heat absorber, It will also increase the radiation and convective heat loss of the heat absorber. These factors will limit the energy conversion efficiency of the system; at the same time, the small heat capacity and poor heat transfer performance of steam will also affect the safety of the system. Tower-type concentrated solar energy For thermal power generation systems, the focusing factor can usually reach 500-1000 times, and the local heat load can reach 1000kW / m 2 , such a high heat flux is a serious test for the superheated area on the heat sink; especially in the meteorological conditions with local clouds, when the evaporation rate changes rapidly due to the influence of cloud cover, it is more likely to cause overheating in the overheated area , Burst, thus threatening the safe operation of the system

However, the piping of the molten salt system is complicated, and the freezing point of the molten salt is very high. The system has strict requirements on pipeline preheating, equipment insulation, operation and maintenance, etc., which reduces the safety of the system and increases the investment and operation of the system. cost

These factors restrict the development of solar thermal power generation technology

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