Coal-based supercritical carbon dioxide Brayton cycle double-split-flow efficient power generation system

Abstract

The invention discloses a coal-based supercritical carbon dioxide Brayton cycle double-split-flow efficient power generation system which comprises a low-temperature regenerator, a precooler, a main compressor, a re-compressor, a high-temperature regenerator, a boiler, a high-pressure turbine, a low-pressure turbine and an electric generator. The boiler is composed of a combustion channel, a main heat exchange channel and a tail flue in the smoke flowing direction, wherein the combustion channel, the main heat exchange channel and the tail flue are communicated in sequence; a water-cooled wall and a reheating water-cooled wall are sequentially arranged in the combustion channel in the smoke flowing direction; a high-temperature superheater and a high-temperature reheater are sequentially arranged in the main heat exchange channel in the smoke flowing direction; a baffle, a coal economizer and a low-temperature coal economizer are sequentially arranged in the tail flue in the smoke flowing direction, and a low-temperature reheater and a lower-temperature superheater are arranged on the two sides of the baffle. According to the coal-based supercritical carbon dioxide Brayton cycle double-split-flow efficient power generation system, optimal combining of the coal-fired boiler and the supercritical carbon dioxide Brayton cycle can be achieved, and the heat exchange efficiency of the high-temperature regenerator, the thermal efficiency of the boiler and the efficiency of the power generation system are high.

Description

technical field [0001] The invention belongs to the field of advanced high-efficiency power generation equipment, and relates to a coal-based supercritical carbon dioxide Brayton cycle double-split high-efficiency power generation system. Background technique [0002] The level of efficiency of generating units has an important impact on the development of the national economy and environmental protection, especially in China, where thermal power generation is the mainstay, it is particularly important to improve the efficiency of coal-fired units. However, for the traditional generator set with the steam Rankine cycle as the energy conversion system, if the power generation efficiency is increased to about 50%, the main steam parameters need to be raised to 700°C, which means high economic cost and time cost to develop new nickel-based superalloys. In order to avoid technical bottlenecks in materials, scholars from various countries have turned their attention to new power...

AI Technical Summary

Problems solved by technology

In the system with multi-stage split mentioned in the patent "Coal-based new supercritical working fluid multi-stage split flow reheating high-efficiency power generation system" (201520152457.4), the split working fluid is drawn from the hot side channel of the regenerator, and the hot The average specific heat capacity of carbon dioxide on the carbon dioxide side is smaller than the average specific heat capacity of the working fluid on the cold side, which will increase the heat transfer temperature difference between the hot and cold sides of the high temperature regenerator and the low temperature regenerator, reducing the heat transfer efficiency of the regenerator; and from The cooling effect of the flue gas from the hot side of the regenerator is not as good as that of the working fluid drawn from the cold side of the regenerator into the tail flue of the boiler

Images