Secondary reheat type solar energy and coal-fired power plant complementary power generation system and operation method

Abstract

The invention discloses a secondary reheat type solar energy and coal-fired power plant complementary power generation system. The secondary reheat type solar energy and coal-fired power plant complementary power generation system comprises a solar heat collection field, a steam heating subsystem and a coal-fired power generation subsystem, wherein a steam conveying pipeline of the coal-fired power generation subsystem is in cooperation connection with the steam heating subsystem, and the steam heating subsystem is in cooperation connection with a high temperature heat exchange fluid conveyingpipeline of the solar heat collection field. The solar heat collection field can conduct secondary reheating on a part of the steam used for the coal-fired power generation subsystem through the steam heating subsystem. The secondary reheat type solar energy and coal-fired power plant complementary power generation system carries out secondary reheating on the coal-fired power generation subsystem through the solar heat collection field and the steam heating subsystem, the average heat absorption temperature of circulating working media in the Rankine cycle of the coal-fired power generationsubsystem is increased, and thus the power generation efficiency of a coal-fired power plant is improved. Meanwhile, the coal-fired power generation subsystem can improve the energy grade and work capacity of solar energy heat introduced into the coal-fired power generation subsystem, and the light-heat conversion efficiency of solar energy and the light-electricity conversion efficiency of the power plant are indirectly improved.

Description

technical field [0001] The invention belongs to the technical field of solar thermal utilization and coal-fired power generation, and in particular relates to a complementary power generation system and operation method of a double-reheat type solar energy and coal-fired power station. Background technique [0002] In recent years, the excessive development and utilization of fossil energy has caused serious climate problems. In order to deal with these problems, the world's main energy use has gradually shifted from fossil fuels to renewable energy such as solar energy and wind energy. [0003] my country's resource endowment can be summarized as "rich in coal, poor in oil, and low in gas". Therefore, so far, my country is still dominated by coal-fired power generation, and gradually increases the proportion of renewable energy such as solar energy and wind energy in power generation. With the increase in the proportion of renewable energy generation access, its impact on t...

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Problems solved by technology

For example, the Chinese patent application with the application number CN201010520248.2 proposes a system that utilizes the trough-type solar collector field to heat the drain of the coal-fired power station into steam, and enters the medium-pressure cylinder to do work. The system has two parts of the trough-type solar collector The heat gain ratio of the field changes from time to time, and the evaporation section of the water supply is not fixed, so it is difficult to achieve stable operation in engineering; the Chinese patent application with the application number CN201420107563.6 proposes a biomass gasification device and a solar heat collection field. A system that is heated by hydrophobic heating and mixed with steam exhaust or extraction at a certain stage of the steam turbine. This system also has a complex phase transition process that is difficult to operate in engineering, and does not increase the average endothermic temperature of the Rankine cycle, so it cannot substantially improve the coal-fired system. The power generation efficiency; the Chinese patent application with the application number CN201510499754.0 proposes a system that uses solar collectors to simultaneously heat the inlet steam of the deaerator and the outlet water supply and drainage. However, this system also has complex engineering problems that are difficult to operate. phase change process

[0006] In the existing public information on the complementary power generation of solar energy in coal-fired power stations, there is no report on solar heat as a secondary reheat heat source, and the existing patent application system has a complex structure, many heat transfer processes, and a complex phase change process. , and the heat distribution and heat balance of each heat exchange process cannot be dynamically optimized

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